/src/wolfssl-openssl-api/src/tls13.c

Source
/* tls13.c
 *
 * Copyright (C) 2006-2026 wolfSSL Inc.
 *
 * This file is part of wolfSSL.
 *
 * wolfSSL is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * wolfSSL is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
 */

#include <wolfssl/wolfcrypt/libwolfssl_sources.h>

/*
 * TLS 1.3-Specific Build Options:
 * (See tls.c for generic TLS options: extensions, curves, callbacks, etc.)
 *
 * Protocol:
 * WOLFSSL_TLS13:            Enable TLS 1.3 protocol               default: on
 * WOLFSSL_TLS13_DRAFT:      Enable TLS 1.3 draft version support  default: off
 * WOLFSSL_QUIC:             Enable QUIC protocol support (TLS 1.3) default: off
 * WOLFSSL_DTLS13_NO_HRR_ON_RESUME: Skip HRR on DTLS 1.3 resume   default: off
 * WOLFSSL_DTLS_CH_FRAG:     Enable DTLS 1.3 ClientHello frag     default: off
 *
 * Handshake:
 * WOLFSSL_TLS13_MIDDLEBOX_COMPAT: Client-side middlebox compatibility
 *                            default: off
 *                            Makes the client send a fake session id and its
 *                            own ChangeCipherSpec. The server always answers
 *                            a non-empty client session id with a
 *                            ChangeCipherSpec, as RFC 8446 Appendix D.4
 *                            requires, whether or not this is defined.
 * WOLFSSL_SEND_HRR_COOKIE:  Send cookie in HelloRetryRequest     default: off
 *                            for stateless ClientHello tracking. A client
 *                            always echoes back a cookie it is sent.
 * WOLFSSL_MAX_TLS13_COOKIE_SZ: Largest cookie a client accepts  default: 4096
 *                            in a HelloRetryRequest.
 * WOLFSSL_EARLY_DATA:       Allow 0-RTT early data                default: off
 * WOLFSSL_EARLY_DATA_GROUP: Group early data with ClientHello     default: off
 * WOLFSSL_POST_HANDSHAKE_AUTH: Post-handshake client auth         default: off
 * WOLFSSL_TLS13_TICKET_BEFORE_FINISHED: Send NewSessionTicket     default: off
 *                            before client Finished message. Violates the
 *                            RFC 8446 Section 4.6.1 ordering requirement; for
 *                            interop with peers that expect the early ticket.
 * WOLFSSL_DTLS13_ECHO_LEGACY_SESSION_ID: Echo legacy_session_id   default: off
 *                            in DTLS 1.3. Violates RFC 9147 Section 5 ("DTLS
 *                            servers MUST NOT echo the legacy_session_id
 *                            value from the client"). A server built with this
 *                            option echoes the session ID, which a compliant
 *                            client rejects, so enable it only where the peer
 *                            is wolfSSL <= 5.9.0 or shares this option.
 * WOLFSSL_NO_CLIENT_AUTH:   Disable TLS 1.3 client authentication default: off
 * WOLFSSL_NO_CLIENT_CERT_ERROR: Require client certificate        default: off
 * WOLFSSL_CERT_SETUP_CB:    Certificate setup callback            default: off
 * WOLFSSL_ALLOW_BAD_TLS_LEGACY_VERSION: Allow bad legacy version  default: off
 *
 * Security:
 * WOLFSSL_BLIND_PRIVATE_KEY: Blind private key during signing     default: off
 * WOLFSSL_CHECK_SIG_FAULTS: Verify signature after ECC signing    default: off
 *                            to detect fault injection attacks
 * WOLFSSL_CIPHER_TEXT_CHECK: Verify ciphertext integrity          default: off
 * WOLFSSL_TLS13_NULL_CIPHER_IN_DEFAULT: Include RFC 9150 suites   default: off
 *                            in the default cipher suite list (requires
 *                            HAVE_NULL_CIPHER). Without it the integrity-only
 *                            suites must be requested explicitly in the
 *                            cipher list, by name or with "eNULL".
 *
 * TLS 1.3 PSK:
 * WOLFSSL_PSK_ONE_ID:       Single PSK identity per connect       default: off
 * WOLFSSL_PSK_MULTI_ID_PER_CS: Multiple PSK IDs per cipher suite default: off
 * WOLFSSL_PRIORITIZE_PSK:   Prioritize PSK over ciphersuite order default: off
 *
 * TLS 1.3 Session Tickets:
 * WOLFSSL_TICKET_HAVE_ID:   Session tickets include ID            default: off
 *                            Forced on when WOLFSSL_EARLY_DATA is set.
 * WOLFSSL_TICKET_NONCE_MALLOC: Dynamically allocate ticket nonce  default: off
 * WOLFSSL_TLS13_TICKET_CHECK_PSK_MODES: Withhold NewSessionTicket default: off
 *                            when the ClientHello advertised no usable
 *                            psk_key_exchange_modes, as RFC 9846 Sections
 *                            4.3.9 and 4.7.1 require. Off by default: a peer
 *                            that omits the extension but expects a ticket
 *                            stops getting one.
 *
 * TLS 1.3 Key Exchange:
 * HAVE_KEYING_MATERIAL:     Export keying material (RFC 8446 7.5) default: off
 * WOLFSSL_HAVE_TLS_UNIQUE:  Enable tls-unique channel binding     default: off
 *
 * TLS 1.3 Hash/Signature:
 * WOLFSSL_TLS13_SHA512:     Allow SHA-512 in TLS 1.3 handshake   default: off
 *                            (no ciphersuite requires it currently)
 * WOLFSSL_ERROR_CODE_OPENSSL: Use OpenSSL-compatible error codes  default: off
 * WOLFSSL_SSLKEYLOGFILE_OUTPUT: Set key log output file path      default: off
 * WOLFSSL_SSLKEYLOGFILE_USE_ENV: Use SSLKEYLOGFILE env var path   default: off
 * WOLFSSL_RW_THREADED:      Enable read/write threading support   default: off
 * WOLFSSL_ASYNC_IO:         Enable async I/O operations           default: off
 * WOLFSSL_NONBLOCK_OCSP:    Non-blocking OCSP processing          default: off
 * WOLFSSL_TLS_OCSP_MULTI:   Multiple OCSP responses               default: off
 * WOLFSSL_WOLFSENTRY_HOOKS: wolfSentry integration hooks          default: off
 */

#if !defined(NO_TLS) && defined(WOLFSSL_TLS13)

/* 0-RTT anti-replay eviction needs the session cache. */
#if defined(WOLFSSL_EARLY_DATA) && defined(HAVE_SESSION_TICKET) && \
    defined(NO_SESSION_CACHE) && !defined(NO_WOLFSSL_SERVER) && \
    !defined(WOLFSSL_EARLY_DATA_NO_ANTI_REPLAY)
#error "WOLFSSL_EARLY_DATA with tickets requires !NO_SESSION_CACHE, or " \
       "define WOLFSSL_EARLY_DATA_NO_ANTI_REPLAY to opt out."
#endif

#ifndef WOLFCRYPT_ONLY

#ifdef HAVE_ERRNO_H
    #include <errno.h>
#endif

#if defined(__MACH__) || defined(__FreeBSD__) || \
    defined(__INCLUDE_NUTTX_CONFIG_H) || defined(WOLFSSL_RIOT_OS)
#include <sys/time.h>
#endif /* __MACH__ || __FreeBSD__ ||
          __INCLUDE_NUTTX_CONFIG_H || WOLFSSL_RIOT_OS */


#include <wolfssl/internal.h>
#include <wolfssl/error-ssl.h>
#include <wolfssl/wolfcrypt/asn.h>
#include <wolfssl/wolfcrypt/dh.h>
#include <wolfssl/wolfcrypt/kdf.h>
#include <wolfssl/wolfcrypt/signature.h>
#ifdef NO_INLINE
    #include <wolfssl/wolfcrypt/misc.h>
#else
    #define WOLFSSL_MISC_INCLUDED
    #include <wolfcrypt/src/misc.c>
#endif

#ifdef __sun
    #include <sys/filio.h>
#endif

#ifndef TRUE
    #define TRUE  1
#endif
#ifndef FALSE
    #define FALSE 0
#endif

#ifndef HAVE_AEAD
    #if !defined(_MSC_VER) && !defined(__TASKING__)
        #error "The build option HAVE_AEAD is required for TLS 1.3"
    #else
        #pragma \
        message("error: The build option HAVE_AEAD is required for TLS 1.3")
    #endif
#endif

#ifndef HAVE_HKDF
    #if !defined(_MSC_VER) && !defined(__TASKING__)
        #error "The build option HAVE_HKDF is required for TLS 1.3"
    #else
        #pragma message("error: The build option HAVE_HKDF is required for TLS 1.3")
    #endif
#endif

#ifndef HAVE_TLS_EXTENSIONS
    #if !defined(_MSC_VER) && !defined(__TASKING__)
        #error "The build option HAVE_TLS_EXTENSIONS is required for TLS 1.3"
    #else
        #pragma message("error: The build option HAVE_TLS_EXTENSIONS is required for TLS 1.3")
    #endif
#endif


/* Set ret to error value and jump to label.
 *
 * err     The error value to set.
 * eLabel  The label to jump to.
 */
#define ERROR_OUT(err, eLabel) { ret = (err); goto eLabel; }

/* Senders suspend/resume a pending record build only on the re-invoke path;
 * poll-completing backends block inside EncryptTls13() as before. */
#if defined(WOLFSSL_ASYNC_REINVOKE) && !defined(WOLF_CRYPTO_CB_ASYNC_POLL)
    #define TLS13_HS_ASYNC_OKAY 1
#else
    #define TLS13_HS_ASYNC_OKAY 0
#endif

#ifdef WOLFSSL_ASYNC_REINVOKE
/* Arm ssl->kdfAsyncDev for a key-schedule op that may pend, retiring this
 * connection's previous KDF event first (re-pushing a queued event would
 * self-link the event list). Returns 0 on success. */
static int Tls13KdfAsyncInit(WOLFSSL* ssl)
{
    int ret;

    if (ssl->asyncDev == &ssl->kdfAsyncDev) {
        ret = wolfSSL_AsyncPop(ssl, NULL);
        if (ret != 0 && ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E) &&
                ret != WC_NO_ERR_TRACE(WC_PENDING_E)) {
            return ret;
        }
    }

#if defined(WOLF_CRYPTO_CB) && defined(WOLF_CRYPTO_CB_ASYNC_POLL)
    /* Never poll-routed: a zeroed cryptocbDevId would look poll-stamped to
     * wolfSSL_AsyncPop() and stop the resume state advancing. */
    ssl->kdfAsyncDev.cryptocbDevId = INVALID_DEVID;
#endif
    return wolfSSL_AsyncInit(ssl, &ssl->kdfAsyncDev, WC_ASYNC_FLAG_CALL_AGAIN);
}

#endif /* WOLFSSL_ASYNC_REINVOKE */

/* Cap on re-invoking a callback for a record the caller cannot resume
 * (alerts, asyncOkay = 0 senders); bounds the otherwise unbounded spin. */
#ifndef WOLFSSL_ASYNC_MAX_REINVOKE
#define WOLFSSL_ASYNC_MAX_REINVOKE 1000
#endif

/* Size of the TLS v1.3 label use when deriving keys. */
#define TLS13_PROTOCOL_LABEL_SZ    6
/* The protocol label for TLS v1.3. */
static const byte tls13ProtocolLabel[TLS13_PROTOCOL_LABEL_SZ + 1] = "tls13 ";

#ifdef WOLFSSL_DTLS13
#define DTLS13_PROTOCOL_LABEL_SZ    6
static const byte dtls13ProtocolLabel[DTLS13_PROTOCOL_LABEL_SZ + 1] = "dtls13";
#endif /* WOLFSSL_DTLS13 */

#if defined(HAVE_ECH)
#define ECH_ACCEPT_CONFIRMATION_LABEL_SZ 23
#define ECH_HRR_ACCEPT_CONFIRMATION_LABEL_SZ 27
static const byte
    echAcceptConfirmationLabel[ECH_ACCEPT_CONFIRMATION_LABEL_SZ + 1] =
    "ech accept confirmation";
static const byte
    echHrrAcceptConfirmationLabel[ECH_HRR_ACCEPT_CONFIRMATION_LABEL_SZ + 1] =
    "hrr ech accept confirmation";
#endif

#ifndef NO_CERTS
#if !defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519) || \
    defined(HAVE_ED448) || defined(HAVE_FALCON) || defined(WOLFSSL_HAVE_MLDSA) || \
    defined(WOLFSSL_HAVE_SLHDSA)

static WC_INLINE int GetMsgHash(WOLFSSL* ssl, byte* hash);

#endif
#endif

/* Expand data using HMAC, salt and label and info.
 * TLS v1.3 defines this function. Use callback if available. */
static int Tls13HKDFExpandLabel(WOLFSSL* ssl, byte* okm, word32 okmLen,
                                const byte* prk, word32 prkLen,
                                const byte* protocol, word32 protocolLen,
                                const byte* label, word32 labelLen,
                                const byte* info, word32 infoLen,
                                int digest)
{
    int ret = WC_NO_ERR_TRACE(NOT_COMPILED_IN);
#ifdef WOLFSSL_ASYNC_REINVOKE
    int aret;

    /* Armed before the provider runs so a pending from the PK callback or
     * wolfCrypt path falls through to the single push below. */
    aret = Tls13KdfAsyncInit(ssl);
    if (aret != 0)
        return aret;
#endif

#if defined(HAVE_PK_CALLBACKS)
    if (ssl->ctx && ssl->ctx->HKDFExpandLabelCb) {
        ret = ssl->ctx->HKDFExpandLabelCb(okm, okmLen, prk, prkLen,
                                          protocol, protocolLen,
                                          label, labelLen,
                                          info, infoLen, digest,
                                          WOLFSSL_CLIENT_END /* ignored */);
    }

    if (ret == WC_NO_ERR_TRACE(NOT_COMPILED_IN))
#endif
    {
    PRIVATE_KEY_UNLOCK();
#if !defined(HAVE_FIPS) || (defined(FIPS_VERSION_GE) && FIPS_VERSION_GE(6,0))
    ret = wc_Tls13_HKDF_Expand_Label_ex(okm, okmLen, prk, prkLen,
                                     protocol, protocolLen,
                                     label, labelLen,
                                     info, infoLen, digest,
                                     ssl->heap, ssl->devId);
#else
    (void)ssl;
    ret = wc_Tls13_HKDF_Expand_Label(okm, okmLen, prk, prkLen,
                                     protocol, protocolLen,
                                     label, labelLen,
                                     info, infoLen, digest);
#endif
    PRIVATE_KEY_LOCK();
    }
#ifdef WOLFSSL_ASYNC_REINVOKE
    /* HKDF has no key object to carry a WC_ASYNC_DEV, so queue the
     * SSL-owned KDF device; without it the pop finds nothing pending and
     * replays the handshake message. CALL_AGAIN keeps the state put. */
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E))
        ret = wolfSSL_AsyncPush(ssl, &ssl->kdfAsyncDev);
#endif
    return ret;
}

/* Same as above, but pass in the side we are expanding for:
 * side: either WOLFSSL_CLIENT_END or WOLFSSL_SERVER_END.
 */
static int Tls13HKDFExpandKeyLabel(WOLFSSL* ssl, byte* okm, word32 okmLen,
                                   const byte* prk, word32 prkLen,
                                   const byte* protocol, word32 protocolLen,
                                   const byte* label, word32 labelLen,
                                   const byte* info, word32 infoLen,
                                   int digest, int side)
{
    int ret;
#ifdef WOLFSSL_ASYNC_REINVOKE
    ret = Tls13KdfAsyncInit(ssl);
    if (ret != 0)
        return ret;
#endif

#if defined(HAVE_PK_CALLBACKS)
    ret = WC_NO_ERR_TRACE(NOT_COMPILED_IN);
    if (ssl->ctx && ssl->ctx->HKDFExpandLabelCb) {
        ret = ssl->ctx->HKDFExpandLabelCb(okm, okmLen, prk, prkLen,
                                         protocol, protocolLen,
                                         label, labelLen,
                                         info, infoLen,
                                         digest, side);
    }
    /* No early return: a pending here must reach the push at the end. */
    if (ret == WC_NO_ERR_TRACE(NOT_COMPILED_IN))
#endif
    {

#if !defined(HAVE_FIPS) || (defined(FIPS_VERSION_GE) && FIPS_VERSION_GE(6,0))
    ret = wc_Tls13_HKDF_Expand_Label_ex(okm, okmLen, prk, prkLen,
                                      protocol, protocolLen,
                                      label, labelLen,
                                      info, infoLen, digest,
                                      ssl->heap, ssl->devId);

#elif defined(HAVE_FIPS) && defined(wc_Tls13_HKDF_Expand_Label)
    ret = wc_Tls13_HKDF_Expand_Label_fips(okm, okmLen, prk, prkLen,
                                      protocol, protocolLen,
                                      label, labelLen,
                                      info, infoLen, digest);
#else
    ret = wc_Tls13_HKDF_Expand_Label(okm, okmLen, prk, prkLen,
                                      protocol, protocolLen,
                                      label, labelLen,
                                      info, infoLen, digest);
#endif
    }
#ifdef WOLFSSL_ASYNC_REINVOKE
    /* HKDF has no key object to carry a WC_ASYNC_DEV, so queue the
     * SSL-owned KDF device; without it the pop finds nothing pending and
     * replays the handshake message. CALL_AGAIN keeps the state put. */
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E))
        ret = wolfSSL_AsyncPush(ssl, &ssl->kdfAsyncDev);
#endif
    (void)ssl;
    (void)side;
    return ret;
}


/* Derive a key from a message.
 *
 * ssl        The SSL/TLS object.
 * output     The buffer to hold the derived key.
 * outputLen  The length of the derived key.
 * secret     The secret used to derive the key (HMAC secret).
 * label      The label used to distinguish the context.
 * labelLen   The length of the label.
 * msg        The message data to derive key from.
 * msgLen     The length of the message data to derive key from.
 * hashAlgo   The hash algorithm to use in the HMAC.
 * returns 0 on success, otherwise failure.
 */
static int DeriveKeyMsg(WOLFSSL* ssl, byte* output, int outputLen,
                        const byte* secret, const byte* label, word32 labelLen,
                        byte* msg, int msgLen, int hashAlgo)
{
    byte        hash[WC_MAX_DIGEST_SIZE];
    Digest      digest;
    word32      hashSz = 0;
    const byte* protocol;
    word32      protocolLen;
    int         digestAlg = -1;
    int         ret = WC_NO_ERR_TRACE(BAD_FUNC_ARG);

    switch (hashAlgo) {
#ifndef NO_SHA256
        case sha256_mac:
            ret = wc_InitSha256_ex(&digest.sha256, ssl->heap, ssl->devId);
            if (ret == 0) {
                    ret = wc_Sha256Update(&digest.sha256, msg, (word32)msgLen);
                if (ret == 0)
                    ret = wc_Sha256Final(&digest.sha256, hash);
                wc_Sha256Free(&digest.sha256);
            }
            hashSz = WC_SHA256_DIGEST_SIZE;
            digestAlg = WC_SHA256;
            break;
#endif
#ifdef WOLFSSL_SHA384
        case sha384_mac:
            ret = wc_InitSha384_ex(&digest.sha384, ssl->heap, ssl->devId);
            if (ret == 0) {
                ret = wc_Sha384Update(&digest.sha384, msg, (word32)msgLen);
                if (ret == 0)
                    ret = wc_Sha384Final(&digest.sha384, hash);
                wc_Sha384Free(&digest.sha384);
            }
            hashSz = WC_SHA384_DIGEST_SIZE;
            digestAlg = WC_SHA384;
            break;
#endif
#ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            ret = wc_InitSha512_ex(&digest.sha512, ssl->heap, ssl->devId);
            if (ret == 0) {
                ret = wc_Sha512Update(&digest.sha512, msg, (word32)msgLen);
                if (ret == 0)
                    ret = wc_Sha512Final(&digest.sha512, hash);
                wc_Sha512Free(&digest.sha512);
            }
            hashSz = WC_SHA512_DIGEST_SIZE;
            digestAlg = WC_SHA512;
            break;
#endif
#ifdef WOLFSSL_SM3
        case sm3_mac:
            ret = wc_InitSm3(&digest.sm3, ssl->heap, ssl->devId);
            if (ret == 0) {
                ret = wc_Sm3Update(&digest.sm3, msg, (word32)msgLen);
                if (ret == 0)
                    ret = wc_Sm3Final(&digest.sm3, hash);
                wc_Sm3Free(&digest.sm3);
            }
            hashSz = WC_SM3_DIGEST_SIZE;
            digestAlg = WC_SM3;
            break;
#endif
        default:
            ret = BAD_FUNC_ARG;
            digestAlg = -1;
            break;
    }

    if (digestAlg < 0)
        return HASH_TYPE_E;

    if (ret != 0)
        return ret;

    switch (ssl->version.minor) {
        case TLSv1_3_MINOR:
            protocol = tls13ProtocolLabel;
            protocolLen = TLS13_PROTOCOL_LABEL_SZ;
            break;
#ifdef WOLFSSL_DTLS13
        case DTLSv1_3_MINOR:
            if (!ssl->options.dtls)
                return VERSION_ERROR;

            protocol = dtls13ProtocolLabel;
            protocolLen = DTLS13_PROTOCOL_LABEL_SZ;
            break;
#endif /* WOLFSSL_DTLS13 */
        default:
            return VERSION_ERROR;
    }
    if (outputLen == -1)
        outputLen = (int)hashSz;

    ret = Tls13HKDFExpandLabel(ssl, output, (word32)outputLen, secret, hashSz,
                               protocol, protocolLen, label, labelLen,
                               hash, hashSz, digestAlg);
    return ret;
}

/* Derive a key.
 *
 * ssl          The SSL/TLS object.
 * output       The buffer to hold the derived key.
 * outputLen    The length of the derived key.
 * secret       The secret used to derive the key (HMAC secret).
 * label        The label used to distinguish the context.
 * labelLen     The length of the label.
 * hashAlgo     The hash algorithm to use in the HMAC.
 * includeMsgs  Whether to include a hash of the handshake messages so far.
 * side         The side that we are deriving the secret for.
 * returns 0 on success, otherwise failure.
 */
int Tls13DeriveKey(WOLFSSL* ssl, byte* output, int outputLen,
                   const byte* secret, const byte* label, word32 labelLen,
                   int hashAlgo, int includeMsgs, int side)
{
    int         ret = 0;
    byte        hash[WC_MAX_DIGEST_SIZE];
    word32      hashSz = 0;
    word32      hashOutSz = 0;
    const byte* protocol;
    word32      protocolLen;
    int         digestAlg = 0;


    switch (hashAlgo) {
    #ifndef NO_SHA256
        case sha256_mac:
            hashSz    = WC_SHA256_DIGEST_SIZE;
            digestAlg = WC_SHA256;
            if (includeMsgs)
                ret = wc_Sha256GetHash(&ssl->hsHashes->hashSha256, hash);
            break;
    #endif

    #ifdef WOLFSSL_SHA384
        case sha384_mac:
            hashSz    = WC_SHA384_DIGEST_SIZE;
            digestAlg = WC_SHA384;
            if (includeMsgs)
                ret = wc_Sha384GetHash(&ssl->hsHashes->hashSha384, hash);
            break;
    #endif

    #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            hashSz    = WC_SHA512_DIGEST_SIZE;
            digestAlg = WC_SHA512;
            if (includeMsgs)
                ret = wc_Sha512GetHash(&ssl->hsHashes->hashSha512, hash);
            break;
    #endif

    #ifdef WOLFSSL_SM3
        case sm3_mac:
            hashSz    = WC_SM3_DIGEST_SIZE;
            digestAlg = WC_SM3;
            if (includeMsgs)
                ret = wc_Sm3GetHash(&ssl->hsHashes->hashSm3, hash);
            break;
    #endif

        default:
            ret = HASH_TYPE_E;
            break;
    }
    if (ret != 0)
        return ret;

    protocol = tls13ProtocolLabel;
    protocolLen = TLS13_PROTOCOL_LABEL_SZ;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
         protocol = dtls13ProtocolLabel;
         protocolLen = DTLS13_PROTOCOL_LABEL_SZ;
    }
#endif /* WOLFSSL_DTLS13 */

    if (outputLen == -1) {
        outputLen = (int)hashSz;
    }
    if (includeMsgs) {
        hashOutSz = hashSz;
    }
    else {
        /* Appease static analyzers by making sure hash is cleared, since it is
         * passed into expand key label where older wc_Tls13_HKDF_Expand_Label
         * will unconditionally try to call a memcpy on it, however length will
         * always be 0. */
        XMEMSET(hash, 0, sizeof(hash));
        hashOutSz = 0;
    }

    PRIVATE_KEY_UNLOCK();
    ret = Tls13HKDFExpandKeyLabel(ssl, output, (word32)outputLen, secret, hashSz,
                                  protocol, protocolLen, label, labelLen,
                                  hash, hashOutSz, digestAlg, side);
    PRIVATE_KEY_LOCK();

#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Add("TLS 1.3 derived key", output, outputLen);
#endif
    return ret;
}

/* Convert TLS mac ID to a hash algorithm ID
 *
 * mac Mac ID to convert
 * returns hash ID on success, or the NONE type.
 */
static WC_INLINE int mac2hash(int mac)
{
    int hash;
    switch (mac) {
        #ifndef NO_SHA256
        case sha256_mac:
            hash = WC_SHA256;
            break;
        #endif

        #ifdef WOLFSSL_SHA384
        case sha384_mac:
            hash = WC_SHA384;
            break;
        #endif

        #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            hash = WC_SHA512;
            break;
        #endif

        #ifdef WOLFSSL_SM3
        case sm3_mac:
            hash = WC_SM3;
            break;
        #endif

    default:
        hash = WC_HASH_TYPE_NONE;
    }
    return hash;
}

#ifndef NO_PSK
/* The length of the binder key label. */
#define BINDER_KEY_LABEL_SZ         10
/* The binder key label. */
static const byte binderKeyLabel[BINDER_KEY_LABEL_SZ + 1] =
    "ext binder";

/* Derive the binder key.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
static int DeriveBinderKey(WOLFSSL* ssl, byte* key)
{
    WOLFSSL_MSG("Derive Binder Key");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }
    return DeriveKeyMsg(ssl, key, -1, ssl->arrays->secret,
                        binderKeyLabel, BINDER_KEY_LABEL_SZ,
                        NULL, 0, ssl->specs.mac_algorithm);
}
#endif /* !NO_PSK */

#if defined(HAVE_SESSION_TICKET) && \
    (!defined(NO_WOLFSSL_CLIENT) || !defined(NO_WOLFSSL_SERVER))
/* The length of the binder key resume label. */
#define BINDER_KEY_RESUME_LABEL_SZ  10
/* The binder key resume label. */
static const byte binderKeyResumeLabel[BINDER_KEY_RESUME_LABEL_SZ + 1] =
    "res binder";

/* Derive the binder resumption key.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
static int DeriveBinderKeyResume(WOLFSSL* ssl, byte* key)
{
    WOLFSSL_MSG("Derive Binder Key - Resumption");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }
    return DeriveKeyMsg(ssl, key, -1, ssl->arrays->secret,
                        binderKeyResumeLabel, BINDER_KEY_RESUME_LABEL_SZ,
                        NULL, 0, ssl->specs.mac_algorithm);
}
#endif /* HAVE_SESSION_TICKET && (!NO_WOLFSSL_CLIENT || !NO_WOLFSSL_SERVER) */

#ifdef WOLFSSL_EARLY_DATA

/* The length of the early traffic label. */
#define EARLY_TRAFFIC_LABEL_SZ      11
/* The early traffic label. */
static const byte earlyTrafficLabel[EARLY_TRAFFIC_LABEL_SZ + 1] =
    "c e traffic";

/* Derive the early traffic key.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * side The side that we are deriving the secret for.
 * returns 0 on success, otherwise failure.
 */
static int DeriveEarlyTrafficSecret(WOLFSSL* ssl, byte* key, int side)
{
    int ret;
    WOLFSSL_MSG("Derive Early Traffic Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }

#if defined(WOLFSSL_SNIFFER) && defined(WOLFSSL_SNIFFER_KEYLOGFILE)
    /* If this is called from a sniffer session with keylog file support,
     * obtain the appropriate secret from the callback */
    if (ssl->snifferSecretCb != NULL) {
        return ssl->snifferSecretCb(ssl->arrays->clientRandom,
                                    SNIFFER_SECRET_CLIENT_EARLY_TRAFFIC_SECRET,
                                    key);
    }
#endif /* WOLFSSL_SNIFFER && WOLFSSL_SNIFFER_KEYLOGFILE */

    ret = Tls13DeriveKey(ssl, key, -1, ssl->arrays->secret,
                    earlyTrafficLabel, EARLY_TRAFFIC_LABEL_SZ,
                    ssl->specs.mac_algorithm, 1, side);
#ifdef HAVE_SECRET_CALLBACK
    if (ret == 0 && ssl->tls13SecretCb != NULL) {
        ret = ssl->tls13SecretCb(ssl, CLIENT_EARLY_TRAFFIC_SECRET, key,
                                 ssl->specs.hash_size, ssl->tls13SecretCtx);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#ifdef OPENSSL_EXTRA
    if (ret == 0 && ssl->tls13KeyLogCb != NULL) {
        ret = ssl->tls13KeyLogCb(ssl, CLIENT_EARLY_TRAFFIC_SECRET, key,
                                ssl->specs.hash_size, NULL);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#endif /* OPENSSL_EXTRA */
#endif /* HAVE_SECRET_CALLBACK */
    return ret;
}

#endif

/* The length of the client handshake label. */
#define CLIENT_HANDSHAKE_LABEL_SZ   12
/* The client handshake label. */
static const byte clientHandshakeLabel[CLIENT_HANDSHAKE_LABEL_SZ + 1] =
    "c hs traffic";

/* Derive the client handshake key.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
static int DeriveClientHandshakeSecret(WOLFSSL* ssl, byte* key)
{
    int ret;
    WOLFSSL_MSG("Derive Client Handshake Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }

#if defined(WOLFSSL_SNIFFER) && defined(WOLFSSL_SNIFFER_KEYLOGFILE)
    /* If this is called from a sniffer session with keylog file support,
     * obtain the appropriate secret from the callback */
    if (ssl->snifferSecretCb != NULL) {
        return ssl->snifferSecretCb(ssl->arrays->clientRandom,
                               SNIFFER_SECRET_CLIENT_HANDSHAKE_TRAFFIC_SECRET,
                               key);
    }
#endif /* WOLFSSL_SNIFFER && WOLFSSL_SNIFFER_KEYLOGFILE */

    ret = Tls13DeriveKey(ssl, key, -1, ssl->arrays->preMasterSecret,
                    clientHandshakeLabel, CLIENT_HANDSHAKE_LABEL_SZ,
                    ssl->specs.mac_algorithm, 1, WOLFSSL_CLIENT_END);
#ifdef HAVE_SECRET_CALLBACK
    if (ret == 0 && ssl->tls13SecretCb != NULL) {
        ret = ssl->tls13SecretCb(ssl, CLIENT_HANDSHAKE_TRAFFIC_SECRET, key,
                                 ssl->specs.hash_size, ssl->tls13SecretCtx);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#ifdef OPENSSL_EXTRA
    if (ret == 0 && ssl->tls13KeyLogCb != NULL) {
        ret = ssl->tls13KeyLogCb(ssl, CLIENT_HANDSHAKE_TRAFFIC_SECRET, key,
                                ssl->specs.hash_size, NULL);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#endif /* OPENSSL_EXTRA */
#endif /* HAVE_SECRET_CALLBACK */
    return ret;
}

/* The length of the server handshake label. */
#define SERVER_HANDSHAKE_LABEL_SZ   12
/* The server handshake label. */
static const byte serverHandshakeLabel[SERVER_HANDSHAKE_LABEL_SZ + 1] =
    "s hs traffic";

/* Derive the server handshake key.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
static int DeriveServerHandshakeSecret(WOLFSSL* ssl, byte* key)
{
    int ret;
    WOLFSSL_MSG("Derive Server Handshake Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }

#if defined(WOLFSSL_SNIFFER) && defined(WOLFSSL_SNIFFER_KEYLOGFILE)
    /* If this is called from a sniffer session with keylog file support,
     * obtain the appropriate secret from the callback */
    if (ssl->snifferSecretCb != NULL) {
        return ssl->snifferSecretCb(ssl->arrays->clientRandom,
                                SNIFFER_SECRET_SERVER_HANDSHAKE_TRAFFIC_SECRET,
                                key);
    }
#endif /* WOLFSSL_SNIFFER && WOLFSSL_SNIFFER_KEYLOGFILE */

    ret = Tls13DeriveKey(ssl, key, -1, ssl->arrays->preMasterSecret,
                    serverHandshakeLabel, SERVER_HANDSHAKE_LABEL_SZ,
                    ssl->specs.mac_algorithm, 1, WOLFSSL_SERVER_END);

#ifdef HAVE_SECRET_CALLBACK
    if (ret == 0 && ssl->tls13SecretCb != NULL) {
        ret = ssl->tls13SecretCb(ssl, SERVER_HANDSHAKE_TRAFFIC_SECRET, key,
                                 ssl->specs.hash_size, ssl->tls13SecretCtx);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#ifdef OPENSSL_EXTRA
    if (ret == 0 && ssl->tls13KeyLogCb != NULL) {
        ret = ssl->tls13KeyLogCb(ssl, SERVER_HANDSHAKE_TRAFFIC_SECRET, key,
                                ssl->specs.hash_size, NULL);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#endif /* OPENSSL_EXTRA */
#endif /* HAVE_SECRET_CALLBACK */
    return ret;
}

/* The length of the client application traffic label. */
#define CLIENT_APP_LABEL_SZ         12
/* The client application traffic label. */
static const byte clientAppLabel[CLIENT_APP_LABEL_SZ + 1] =
    "c ap traffic";

/* Derive the client application traffic key.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
static int DeriveClientTrafficSecret(WOLFSSL* ssl, byte* key)
{
    int ret;
    WOLFSSL_MSG("Derive Client Traffic Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }

#if defined(WOLFSSL_SNIFFER) && defined(WOLFSSL_SNIFFER_KEYLOGFILE)
    /* If this is called from a sniffer session with keylog file support,
     * obtain the appropriate secret from the callback */
    if (ssl->snifferSecretCb != NULL) {
        return ssl->snifferSecretCb(ssl->arrays->clientRandom,
                                    SNIFFER_SECRET_CLIENT_TRAFFIC_SECRET,
                                    key);
    }
#endif /* WOLFSSL_SNIFFER && WOLFSSL_SNIFFER_KEYLOGFILE */

    ret = Tls13DeriveKey(ssl, key, -1, ssl->arrays->masterSecret,
                    clientAppLabel, CLIENT_APP_LABEL_SZ,
                    ssl->specs.mac_algorithm, 1, WOLFSSL_CLIENT_END);

#ifdef HAVE_SECRET_CALLBACK
    if (ret == 0 && ssl->tls13SecretCb != NULL) {
        ret = ssl->tls13SecretCb(ssl, CLIENT_TRAFFIC_SECRET, key,
                                 ssl->specs.hash_size, ssl->tls13SecretCtx);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#ifdef OPENSSL_EXTRA
    if (ret == 0 && ssl->tls13KeyLogCb != NULL) {
        ret = ssl->tls13KeyLogCb(ssl, CLIENT_TRAFFIC_SECRET, key,
                                ssl->specs.hash_size, NULL);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#endif /* OPENSSL_EXTRA */
#endif /* HAVE_SECRET_CALLBACK */
    return ret;
}

/* The length of the server application traffic label. */
#define SERVER_APP_LABEL_SZ         12
/* The  server application traffic label. */
static const byte serverAppLabel[SERVER_APP_LABEL_SZ + 1] =
    "s ap traffic";

/* Derive the server application traffic key.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
static int DeriveServerTrafficSecret(WOLFSSL* ssl, byte* key)
{
    int ret;
    WOLFSSL_MSG("Derive Server Traffic Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }

#if defined(WOLFSSL_SNIFFER) && defined(WOLFSSL_SNIFFER_KEYLOGFILE)
    /* If this is called from a sniffer session with keylog file support,
     * obtain the appropriate secret from the callback */
    if (ssl->snifferSecretCb != NULL) {
        return ssl->snifferSecretCb(ssl->arrays->clientRandom,
                                    SNIFFER_SECRET_SERVER_TRAFFIC_SECRET,
                                    key);
    }
#endif /* WOLFSSL_SNIFFER && WOLFSSL_SNIFFER_KEYLOGFILE */

    ret = Tls13DeriveKey(ssl, key, -1, ssl->arrays->masterSecret,
                    serverAppLabel, SERVER_APP_LABEL_SZ,
                    ssl->specs.mac_algorithm, 1, WOLFSSL_SERVER_END);

#ifdef HAVE_SECRET_CALLBACK
    if (ret == 0 && ssl->tls13SecretCb != NULL) {
        ret = ssl->tls13SecretCb(ssl, SERVER_TRAFFIC_SECRET, key,
                                 ssl->specs.hash_size, ssl->tls13SecretCtx);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#ifdef OPENSSL_EXTRA
    if (ret == 0 && ssl->tls13KeyLogCb != NULL) {
        ret = ssl->tls13KeyLogCb(ssl, SERVER_TRAFFIC_SECRET, key,
                                ssl->specs.hash_size, NULL);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#endif /* OPENSSL_EXTRA */
#endif /* HAVE_SECRET_CALLBACK */
    return ret;
}

#ifdef HAVE_KEYING_MATERIAL
/* The length of the exporter master secret label. */
#define EXPORTER_MASTER_LABEL_SZ    10
/* The exporter master secret label. */
static const byte exporterMasterLabel[EXPORTER_MASTER_LABEL_SZ + 1] =
    "exp master";

/* Derive the exporter secret.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
static int DeriveExporterSecret(WOLFSSL* ssl, byte* key)
{
    int ret;
    WOLFSSL_ENTER("Derive Exporter Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }
    ret = Tls13DeriveKey(ssl, key, -1, ssl->arrays->masterSecret,
                        exporterMasterLabel, EXPORTER_MASTER_LABEL_SZ,
                        ssl->specs.mac_algorithm, 1, 0 /* Unused */);
#ifdef HAVE_SECRET_CALLBACK
    if (ret == 0 && ssl->tls13SecretCb != NULL) {
        ret = ssl->tls13SecretCb(ssl, EXPORTER_SECRET, key,
                                 ssl->specs.hash_size, ssl->tls13SecretCtx);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#ifdef OPENSSL_EXTRA
    if (ret == 0 && ssl->tls13KeyLogCb != NULL) {
        ret = ssl->tls13KeyLogCb(ssl, EXPORTER_SECRET, key,
                                ssl->specs.hash_size, NULL);
        if (ret != 0) {
            WOLFSSL_ERROR_VERBOSE(TLS13_SECRET_CB_E);
            return TLS13_SECRET_CB_E;
        }
    }
#endif /* OPENSSL_EXTRA */
#endif /* HAVE_SECRET_CALLBACK */
    return ret;
}

/* The length of the exporter label. */
#define EXPORTER_LABEL_SZ    8
/* The exporter label. */
static const byte exporterLabel[EXPORTER_LABEL_SZ + 1] =
    "exporter";
/* Hash("") */
#ifndef NO_SHA256
static const byte emptySHA256Hash[] = {
    0xE3, 0xB0, 0xC4, 0x42, 0x98, 0xFC, 0x1C, 0x14, 0x9A, 0xFB, 0xF4, 0xC8,
    0x99, 0x6F, 0xB9, 0x24, 0x27, 0xAE, 0x41, 0xE4, 0x64, 0x9B, 0x93, 0x4C,
    0xA4, 0x95, 0x99, 0x1B, 0x78, 0x52, 0xB8, 0x55
};
#endif
#ifdef WOLFSSL_SHA384
static const byte emptySHA384Hash[] = {
    0x38, 0xB0, 0x60, 0xA7, 0x51, 0xAC, 0x96, 0x38, 0x4C, 0xD9, 0x32, 0x7E,
    0xB1, 0xB1, 0xE3, 0x6A, 0x21, 0xFD, 0xB7, 0x11, 0x14, 0xBE, 0x07, 0x43,
    0x4C, 0x0C, 0xC7, 0xBF, 0x63, 0xF6, 0xE1, 0xDA, 0x27, 0x4E, 0xDE, 0xBF,
    0xE7, 0x6F, 0x65, 0xFB, 0xD5, 0x1A, 0xD2, 0xF1, 0x48, 0x98, 0xB9, 0x5B
};
#endif
#ifdef WOLFSSL_TLS13_SHA512
static const byte emptySHA512Hash[] = {
    0xCF, 0x83, 0xE1, 0x35, 0x7E, 0xEF, 0xB8, 0xBD, 0xF1, 0x54, 0x28, 0x50,
    0xD6, 0x6D, 0x80, 0x07, 0xD6, 0x20, 0xE4, 0x05, 0x0B, 0x57, 0x15, 0xDC,
    0x83, 0xF4, 0xA9, 0x21, 0xD3, 0x6C, 0xE9, 0xCE, 0x47, 0xD0, 0xD1, 0x3C,
    0x5D, 0x85, 0xF2, 0xB0, 0xFF, 0x83, 0x18, 0xD2, 0x87, 0x7E, 0xEC, 0x2F,
    0x63, 0xB9, 0x31, 0xBD, 0x47, 0x41, 0x7A, 0x81, 0xA5, 0x38, 0x32, 0x7A,
    0xF9, 0x27, 0xDA, 0x3E
};
#endif
#ifdef WOLFSSL_SM3
static const byte emptySM3Hash[] = {
    0x1A, 0xB2, 0x1D, 0x83, 0x55, 0xCF, 0xA1, 0x7F, 0x8E, 0x61, 0x19, 0x48,
    0x31, 0xE8, 0x1A, 0x8F, 0x22, 0xBE, 0xC8, 0xC7, 0x28, 0xFE, 0xFB, 0x74,
    0x7E, 0xD0, 0x35, 0xEB, 0x50, 0x82, 0xAA, 0x2B
};
#endif
/**
 * Implement section 7.5 of RFC 8446
 * @return  0 on success
 *         <0 on failure
 */
int Tls13_Exporter(WOLFSSL* ssl, unsigned char *out, size_t outLen,
        const char *label, size_t labelLen,
        const unsigned char *context, size_t contextLen)
{
    int                 ret;
    enum wc_HashType    hashType = WC_HASH_TYPE_NONE;
    word32              hashLen = 0;
    byte                hashOut[WC_MAX_DIGEST_SIZE];
    const byte*         emptyHash = NULL;
    byte                firstExpand[WC_MAX_DIGEST_SIZE];
    const byte*         protocol = tls13ProtocolLabel;
    word32              protocolLen = TLS13_PROTOCOL_LABEL_SZ;

    if (ssl->options.dtls && ssl->version.minor != DTLSv1_3_MINOR)
        return VERSION_ERROR;

    if (!ssl->options.dtls && ssl->version.minor != TLSv1_3_MINOR)
        return VERSION_ERROR;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        protocol = dtls13ProtocolLabel;
        protocolLen = DTLS13_PROTOCOL_LABEL_SZ;
    }
#endif /* WOLFSSL_DTLS13 */

    /* Sanity check contextLen to prevent truncation when cast to word32. */
    if (contextLen > WOLFSSL_MAX_32BIT)
        return BAD_FUNC_ARG;
    /* RFC 8446 HkdfLabel encodes the output length as a uint16, so requested
     * lengths > 65535 cannot be represented and must be rejected. */
    if (outLen > WOLFSSL_MAX_16BIT)
        return BAD_FUNC_ARG;
    /* RFC 8446 HkdfLabel encodes the label length in a single byte, so
     * anything > 255 cannot be represented and must be rejected.
     * The protocol length is included in the label. */
    if ((labelLen +  protocolLen) > WOLFSSL_MAX_8BIT)
        return BAD_FUNC_ARG;

    switch (ssl->specs.mac_algorithm) {
        #ifndef NO_SHA256
        case sha256_mac:
            hashType  = WC_HASH_TYPE_SHA256;
            hashLen   = WC_SHA256_DIGEST_SIZE;
            emptyHash = emptySHA256Hash;
            break;
        #endif

        #ifdef WOLFSSL_SHA384
        case sha384_mac:
            hashType  = WC_HASH_TYPE_SHA384;
            hashLen   = WC_SHA384_DIGEST_SIZE;
            emptyHash = emptySHA384Hash;
            break;
        #endif

        #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            hashType  = WC_HASH_TYPE_SHA512;
            hashLen   = WC_SHA512_DIGEST_SIZE;
            emptyHash = emptySHA512Hash;
            break;
        #endif

        #ifdef WOLFSSL_SM3
        case sm3_mac:
            hashType  = WC_HASH_TYPE_SM3;
            hashLen   = WC_SM3_DIGEST_SIZE;
            emptyHash = emptySM3Hash;
            break;
        #endif

        default:
            return BAD_FUNC_ARG;
    }

#ifdef WOLFSSL_CHECK_MEM_ZERO
    /* Poison and register firstExpand before it is written so that any path
     * below (all of which funnel through cleanup) is covered. */
    XMEMSET(firstExpand, 0xff, sizeof(firstExpand));
    wc_MemZero_Add("Tls13_Exporter firstExpand", firstExpand,
                   sizeof(firstExpand));
#endif

    /* Derive-Secret(Secret, label, "") */
    ret = Tls13HKDFExpandLabel(ssl, firstExpand, hashLen,
            ssl->arrays->exporterSecret, hashLen,
            protocol, protocolLen, (byte*)label, (word32)labelLen,
            emptyHash, hashLen, (int)hashType);
    if (ret != 0)
        goto cleanup;

    /* Hash(context_value) */
    ret = wc_Hash(hashType, context, (word32)contextLen, hashOut, WC_MAX_DIGEST_SIZE);
    if (ret != 0)
        goto cleanup;

    ret = Tls13HKDFExpandLabel(ssl, out, (word32)outLen, firstExpand, hashLen,
            protocol, protocolLen, exporterLabel, EXPORTER_LABEL_SZ,
            hashOut, hashLen, (int)hashType);

cleanup:
    /* firstExpand is the per-label Derive-Secret PRK and hashOut holds
     * Hash(context_value); wipe both before the stack frame is reclaimed. */
    ForceZero(firstExpand, sizeof(firstExpand));
    ForceZero(hashOut, sizeof(hashOut));
#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Check(firstExpand, sizeof(firstExpand));
#endif
    return ret;
}
#endif

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
/* The length of the resumption master secret label. */
#define RESUME_MASTER_LABEL_SZ      10
/* The resumption master secret label. */
static const byte resumeMasterLabel[RESUME_MASTER_LABEL_SZ + 1] =
    "res master";

/* Derive the resumption secret.
 *
 * ssl  The SSL/TLS object.
 * key  The derived key.
 * returns 0 on success, otherwise failure.
 */
int DeriveResumptionSecret(WOLFSSL* ssl, byte* key)
{
    byte* masterSecret;

    WOLFSSL_MSG("Derive Resumption Secret");
    if (ssl == NULL) {
        return BAD_FUNC_ARG;
    }
    if (ssl->arrays != NULL) {
        masterSecret = ssl->arrays->masterSecret;
    }
    else {
        masterSecret = ssl->session->masterSecret;
    }
    return Tls13DeriveKey(ssl, key, -1, masterSecret, resumeMasterLabel,
                     RESUME_MASTER_LABEL_SZ, ssl->specs.mac_algorithm, 1,
                     0 /* Unused */);
}
#endif

/* Length of the finished label. */
#define FINISHED_LABEL_SZ           8
/* Finished label for generating finished key. */
static const byte finishedLabel[FINISHED_LABEL_SZ+1] = "finished";
/* Derive the finished secret.
 *
 * ssl     The SSL/TLS object.
 * key     The key to use with the HMAC.
 * secret  The derived secret.
 * side    The side that we are deriving the secret for.
 * returns 0 on success, otherwise failure.
 */
static int DeriveFinishedSecret(WOLFSSL* ssl, byte* key, byte* secret,
                                int side)
{
    WOLFSSL_MSG("Derive Finished Secret");
    return Tls13DeriveKey(ssl, secret, -1, key, finishedLabel,
                          FINISHED_LABEL_SZ,  ssl->specs.mac_algorithm, 0,
                          side);
}

/* The length of the application traffic label. */
#define APP_TRAFFIC_LABEL_SZ        11
/* The application traffic label. */
static const byte appTrafficLabel[APP_TRAFFIC_LABEL_SZ + 1] =
    "traffic upd";

/* Update the traffic secret.
 *
 * ssl     The SSL/TLS object.
 * secret  The previous secret and derived secret.
 * side    The side that we are deriving the secret for.
 * returns 0 on success, otherwise failure.
 */
static int DeriveTrafficSecret(WOLFSSL* ssl, byte* secret, int side)
{
    WOLFSSL_MSG("Derive New Application Traffic Secret");
    return Tls13DeriveKey(ssl, secret, -1, secret,
                     appTrafficLabel, APP_TRAFFIC_LABEL_SZ,
                     ssl->specs.mac_algorithm, 0, side);
}


static int Tls13_HKDF_Extract(WOLFSSL *ssl, byte* prk, const byte* salt,
                              int saltLen, byte* ikm, int ikmLen, int digest)
{
    int ret;
#ifdef HAVE_PK_CALLBACKS
    void *cb_ctx;
    CallbackHKDFExtract cb;
#endif

#ifdef WOLFSSL_ASYNC_REINVOKE
    ret = Tls13KdfAsyncInit(ssl);
    if (ret != 0)
        return ret;
#endif

#ifdef HAVE_PK_CALLBACKS
    cb_ctx = ssl->HkdfExtractCtx;
    cb = ssl->ctx->HkdfExtractCb;
    if (cb != NULL) {
        ret = cb(prk, salt, (word32)saltLen, ikm, (word32)ikmLen, digest, cb_ctx);
    }
    else
#endif
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    if ((int)ssl->arrays->psk_keySz < 0) {
        ret = PSK_KEY_ERROR;
    }
    else
#endif
    {
    #if !defined(HAVE_FIPS) || \
        (defined(FIPS_VERSION_GE) && FIPS_VERSION_GE(6,0))
        ret = wc_Tls13_HKDF_Extract_ex(prk, salt, (word32)saltLen, ikm, (word32)ikmLen, digest,
            ssl->heap, ssl->devId);
    #else
        ret = wc_Tls13_HKDF_Extract(prk, salt, saltLen, ikm, ikmLen, digest);
        (void)ssl;
    #endif
    }
#ifdef WOLFSSL_ASYNC_REINVOKE
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E))
        ret = wolfSSL_AsyncPush(ssl, &ssl->kdfAsyncDev);
#endif
    return ret;
}

/* Derive the early secret using HKDF Extract.
 *
 * ssl  The SSL/TLS object.
 */
int DeriveEarlySecret(WOLFSSL* ssl)
{
    int ret;

    WOLFSSL_MSG("Derive Early Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }
#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13DeriveEarlySecret(ssl);
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE))
        return ret;
#endif
    PRIVATE_KEY_UNLOCK();
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ret = Tls13_HKDF_Extract(ssl, ssl->arrays->secret, NULL, 0,
            ssl->arrays->psk_key, (int)ssl->arrays->psk_keySz,
            mac2hash(ssl->specs.mac_algorithm));
#else
    ret = Tls13_HKDF_Extract(ssl, ssl->arrays->secret, NULL, 0,
            ssl->arrays->masterSecret, 0, mac2hash(ssl->specs.mac_algorithm));
#endif
    PRIVATE_KEY_LOCK();
    return ret;
}

/* The length of the derived label. */
#define DERIVED_LABEL_SZ        7
/* The derived label. */
static const byte derivedLabel[DERIVED_LABEL_SZ + 1] =
    "derived";

/* Derive the handshake secret using HKDF Extract.
 *
 * ssl  The SSL/TLS object.
 */
int DeriveHandshakeSecret(WOLFSSL* ssl)
{
    byte key[WC_MAX_DIGEST_SIZE];
    int ret;
    WOLFSSL_MSG("Derive Handshake Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }
#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13DeriveHandshakeSecret(ssl);
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE))
        return ret;
#endif

    /* Derive-Secret(., "derived", "") per RFC 8446 Section 7.1.
     * Empty hash (NULL, 0) is required by the TLS 1.3 key schedule. */
    ret = DeriveKeyMsg(ssl, key, -1, ssl->arrays->secret,
                        derivedLabel, DERIVED_LABEL_SZ,
                        NULL, 0, ssl->specs.mac_algorithm);
    if (ret == 0) {
        PRIVATE_KEY_UNLOCK();
        ret = Tls13_HKDF_Extract(ssl, ssl->arrays->preMasterSecret,
                key, ssl->specs.hash_size,
                ssl->arrays->preMasterSecret, (int)ssl->arrays->preMasterSz,
                mac2hash(ssl->specs.mac_algorithm));
        PRIVATE_KEY_LOCK();
    }

#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Add("DeriveHandshakeSecret key", key, WC_MAX_DIGEST_SIZE);
#endif
    ForceZero(key, sizeof(key));
#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Check(key, sizeof(key));
#endif
    return ret;
}

/* Derive the master secret using HKDF Extract.
 *
 * ssl  The SSL/TLS object.
 */
int DeriveMasterSecret(WOLFSSL* ssl)
{
    byte key[WC_MAX_DIGEST_SIZE];
    int ret;
    WOLFSSL_MSG("Derive Master Secret");
    if (ssl == NULL || ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }

#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13DeriveMasterSecret(ssl);
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE))
        return ret;
#endif

    /* Derive-Secret(., "derived", "") per RFC 8446 Section 7.1.
     * Empty hash (NULL, 0) is required by the TLS 1.3 key schedule. */
    ret = DeriveKeyMsg(ssl, key, -1, ssl->arrays->preMasterSecret,
                        derivedLabel, DERIVED_LABEL_SZ,
                        NULL, 0, ssl->specs.mac_algorithm);
    if (ret == 0) {
        PRIVATE_KEY_UNLOCK();
        ret = Tls13_HKDF_Extract(ssl, ssl->arrays->masterSecret,
                                 key, ssl->specs.hash_size,
                                 ssl->arrays->masterSecret, 0,
                                 mac2hash(ssl->specs.mac_algorithm));
        PRIVATE_KEY_LOCK();
    }

#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Add("DeriveMasterSecret key", key, WC_MAX_DIGEST_SIZE);
#endif
    ForceZero(key, sizeof(key));
#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Check(key, sizeof(key));
#endif

#ifdef HAVE_KEYING_MATERIAL
    if (ret != 0)
        return ret;
    /* Calculate exporter secret only when saving arrays */
    if (ssl->options.saveArrays)
        ret = DeriveExporterSecret(ssl, ssl->arrays->exporterSecret);
#endif

    return ret;
}

#if defined(HAVE_SESSION_TICKET)
/* Length of the resumption label. */
#define RESUMPTION_LABEL_SZ         10
/* Resumption label for generating PSK associated with the ticket. */
static const byte resumptionLabel[RESUMPTION_LABEL_SZ+1] = "resumption";

/* Derive the PSK associated with the ticket.
 *
 * ssl       The SSL/TLS object.
 * nonce     The nonce to derive with.
 * nonceLen  The length of the nonce to derive with.
 * secret    The derived secret.
 * returns 0 on success, otherwise failure.
 */
int DeriveResumptionPSK(WOLFSSL* ssl, byte* nonce, byte nonceLen, byte* secret)
{
    int         digestAlg;
    /* Only one protocol version defined at this time. */
    const byte* protocol    = tls13ProtocolLabel;
    word32      protocolLen = TLS13_PROTOCOL_LABEL_SZ;
    int         ret;

    WOLFSSL_MSG("Derive Resumption PSK");

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        protocol = dtls13ProtocolLabel;
        protocolLen = DTLS13_PROTOCOL_LABEL_SZ;
    }
#endif /* WOLFSSL_DTLS13 */

    switch (ssl->specs.mac_algorithm) {
        #ifndef NO_SHA256
        case sha256_mac:
            digestAlg = WC_SHA256;
            break;
        #endif

        #ifdef WOLFSSL_SHA384
        case sha384_mac:
            digestAlg = WC_SHA384;
            break;
        #endif

        #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            digestAlg = WC_SHA512;
            break;
        #endif

        #ifdef WOLFSSL_SM3
        case sm3_mac:
            digestAlg = WC_SM3;
            break;
        #endif

        default:
            return BAD_FUNC_ARG;
    }

#if defined(WOLFSSL_TICKET_NONCE_MALLOC) &&                                    \
    (!defined(HAVE_FIPS) || (defined(FIPS_VERSION_GE) && FIPS_VERSION_GE(5,3)))
    PRIVATE_KEY_UNLOCK();
    ret = wc_Tls13_HKDF_Expand_Label_Alloc(secret, ssl->specs.hash_size,
        ssl->session->masterSecret, ssl->specs.hash_size, protocol, protocolLen,
        resumptionLabel, RESUMPTION_LABEL_SZ, nonce, nonceLen, digestAlg,
        ssl->heap);
    PRIVATE_KEY_LOCK();
#else
    ret = Tls13HKDFExpandLabel(ssl, secret, ssl->specs.hash_size,
                               ssl->session->masterSecret, ssl->specs.hash_size,
                               protocol, protocolLen, resumptionLabel,
                               RESUMPTION_LABEL_SZ, nonce, nonceLen, digestAlg);
#endif /* !defined(HAVE_FIPS) || FIPS_VERSION_GE(5,3) */
    return ret;
}
#endif /* HAVE_SESSION_TICKET */


/* Calculate the HMAC of message data to this point.
 *
 * ssl   The SSL/TLS object.
 * key   The HMAC key.
 * hash  The hash result - verify data.
 * returns length of verify data generated.
 */
#if defined(WOLFSSL_ASYNC_REINVOKE) && !defined(NO_HMAC)
/* Release the held transcript Hmac and its resume state. */
void Tls13FreeHsHmac(WOLFSSL* ssl)
{
    if (ssl->hsHmac != NULL) {
        wc_HmacFree(ssl->hsHmac);
        XFREE(ssl->hsHmac, ssl->heap, DYNAMIC_TYPE_HMAC);
        ssl->hsHmac = NULL;
    }
    ssl->hsHmacStep = 0;
    ssl->hsHmacOut = NULL;
}
#endif /* WOLFSSL_ASYNC_REINVOKE && !NO_HMAC */

static int BuildTls13HandshakeHmac(WOLFSSL* ssl, byte* key, byte* hash,
    word32* pHashSz)
{
#ifndef WOLFSSL_ASYNC_REINVOKE
    WC_DECLARE_VAR(verifyHmac, Hmac, 1, 0);
#endif
    int  hashType = WC_SHA256;
    int  hashSz = WC_SHA256_DIGEST_SIZE;
    int  ret = WC_NO_ERR_TRACE(BAD_FUNC_ARG);

    if (ssl == NULL || key == NULL || hash == NULL) {
        return BAD_FUNC_ARG;
    }

    /* Get the hash of the previous handshake messages. */
    switch (ssl->specs.mac_algorithm) {
    #ifndef NO_SHA256
        case sha256_mac:
            hashType = WC_SHA256;
            hashSz = WC_SHA256_DIGEST_SIZE;
            ret = wc_Sha256GetHash(&ssl->hsHashes->hashSha256, hash);
            break;
    #endif /* !NO_SHA256 */
    #ifdef WOLFSSL_SHA384
        case sha384_mac:
            hashType = WC_SHA384;
            hashSz = WC_SHA384_DIGEST_SIZE;
            ret = wc_Sha384GetHash(&ssl->hsHashes->hashSha384, hash);
            break;
    #endif /* WOLFSSL_SHA384 */
    #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            hashType = WC_SHA512;
            hashSz = WC_SHA512_DIGEST_SIZE;
            ret = wc_Sha512GetHash(&ssl->hsHashes->hashSha512, hash);
            break;
    #endif /* WOLFSSL_TLS13_SHA512 */
    #ifdef WOLFSSL_SM3
        case sm3_mac:
            hashType = WC_SM3;
            hashSz = WC_SM3_DIGEST_SIZE;
            ret = wc_Sm3GetHash(&ssl->hsHashes->hashSm3, hash);
            break;
    #endif /* WOLFSSL_SM3 */
        default:
            ret = BAD_FUNC_ARG;
            break;
    }
    if (ret != 0)
        return ret;

#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("  Key");
    WOLFSSL_BUFFER(key, ssl->specs.hash_size);
    WOLFSSL_MSG("  Msg Hash");
    WOLFSSL_BUFFER(hash, hashSz);
#endif

#ifdef WOLFSSL_ASYNC_REINVOKE
    /* Held on the SSL object so a crypto callback WC_PENDING_E resumes by
     * re-invoking the same Hmac with identical arguments; the transcript
     * hash input is recomputed deterministically by the caller's retry.
     * Bound to the output buffer: a replayed caller that computes several
     * HMACs (the PSK binder list) must not resume one request against
     * another's key, so a different output discards the held state. */
    if (ssl->hsHmac != NULL && ssl->hsHmacOut != hash)
        Tls13FreeHsHmac(ssl);
    if (ssl->hsHmac == NULL) {
        ssl->hsHmac = (Hmac*)XMALLOC(sizeof(Hmac), ssl->heap,
                                     DYNAMIC_TYPE_HMAC);
        if (ssl->hsHmac == NULL)
            return MEMORY_E;
        ret = wc_HmacInit(ssl->hsHmac, ssl->heap, ssl->devId);
        if (ret != 0) {
            Tls13FreeHsHmac(ssl);
            return ret;
        }
        ssl->hsHmacStep = 0;
        ssl->hsHmacOut = hash;
    }
    /* Armed before the operations, matching the HKDF helpers. */
    ret = Tls13KdfAsyncInit(ssl);
    if (ret != 0) {
        Tls13FreeHsHmac(ssl);
        return ret;
    }
    if (ssl->hsHmacStep == 0) {
        ret = wc_HmacSetKey(ssl->hsHmac, hashType, key,
                            ssl->specs.hash_size);
        if (ret == 0)
            ssl->hsHmacStep = 1;
    }
    if (ret == 0 && ssl->hsHmacStep == 1) {
        ret = wc_HmacUpdate(ssl->hsHmac, hash, (word32)hashSz);
        if (ret == 0)
            ssl->hsHmacStep = 2;
    }
    if (ret == 0 && ssl->hsHmacStep == 2)
        ret = wc_HmacFinal(ssl->hsHmac, hash);
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E))
        return wolfSSL_AsyncPush(ssl, &ssl->kdfAsyncDev);
    Tls13FreeHsHmac(ssl);
#else
    WC_ALLOC_VAR_EX(verifyHmac, Hmac, 1, NULL, DYNAMIC_TYPE_HMAC,
        return MEMORY_E);

    /* Calculate the verify data. */
    ret = wc_HmacInit(verifyHmac, ssl->heap, ssl->devId);
    if (ret == 0) {
        ret = wc_HmacSetKey(verifyHmac, hashType, key, ssl->specs.hash_size);
        if (ret == 0)
            ret = wc_HmacUpdate(verifyHmac, hash, (word32)hashSz);
        if (ret == 0)
            ret = wc_HmacFinal(verifyHmac, hash);
        wc_HmacFree(verifyHmac);
    }

    WC_FREE_VAR_EX(verifyHmac, NULL, DYNAMIC_TYPE_HMAC);
#endif /* WOLFSSL_ASYNC_REINVOKE */

#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("  Hash");
    WOLFSSL_BUFFER(hash, hashSz);
#endif

    if (pHashSz)
        *pHashSz = (word32)hashSz;

    return ret;
}

/* The length of the label to use when deriving keys. */
#define WRITE_KEY_LABEL_SZ     3
/* The length of the label to use when deriving IVs. */
#define WRITE_IV_LABEL_SZ      2
/* The label to use when deriving keys. */
static const byte writeKeyLabel[WRITE_KEY_LABEL_SZ+1] = "key";
/* The label to use when deriving IVs. */
static const byte writeIVLabel[WRITE_IV_LABEL_SZ+1]   = "iv";

/* Derive the keys and IVs for TLS v1.3.
 *
 * ssl      The SSL/TLS object.
 * secret   early_data_key when deriving the key and IV for encrypting early
 *          data application data and end_of_early_data messages.
 *          handshake_key when deriving keys and IVs for encrypting handshake
 *          messages.
 *          traffic_key when deriving first keys and IVs for encrypting
 *          traffic messages.
 *          update_traffic_key when deriving next keys and IVs for encrypting
 *          traffic messages.
 *          no_key when deriving keys and IVs from existing secrets without
 *          re-deriving the secrets. Used during early data transitions.
 * side     ENCRYPT_SIDE_ONLY when only encryption secret needs to be derived.
 *          DECRYPT_SIDE_ONLY when only decryption secret needs to be derived.
 *          ENCRYPT_AND_DECRYPT_SIDE when both secret needs to be derived.
 * store    1 indicates to derive the keys and IVs from derived secret and
 *          store ready for provisioning.
 * returns 0 on success, otherwise failure.
 */
int DeriveTls13Keys(WOLFSSL* ssl, int secret, int side, int store)
{
    int   ret = WC_NO_ERR_TRACE(BAD_FUNC_ARG); /* Assume failure */
    int   i = 0;
    WC_DECLARE_VAR(key_dig, byte, MAX_PRF_DIG, 0);
    int   provision;

#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13DeriveKeys(ssl, secret, side);
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE)) {
        return ret;
    }
    ret = WC_NO_ERR_TRACE(BAD_FUNC_ARG); /* Assume failure */
#endif

    WC_ALLOC_VAR_EX(key_dig, byte, MAX_PRF_DIG, ssl->heap,
        DYNAMIC_TYPE_DIGEST, return MEMORY_E);

#ifdef WOLFSSL_CHECK_MEM_ZERO
    XMEMSET(key_dig, 0xff, MAX_PRF_DIG);
    wc_MemZero_Add("DeriveTls13Keys key_dig", key_dig, MAX_PRF_DIG);
#endif

    if (side == ENCRYPT_AND_DECRYPT_SIDE) {
        provision = PROVISION_CLIENT_SERVER;
    }
    else {
        provision = ((ssl->options.side != WOLFSSL_CLIENT_END) ^
                     (side == ENCRYPT_SIDE_ONLY)) ? PROVISION_CLIENT :
                                                    PROVISION_SERVER;
    }

    /* Derive the appropriate secret to use in the HKDF. */
    switch (secret) {
#ifdef WOLFSSL_EARLY_DATA
        case early_data_key:
            ret = DeriveEarlyTrafficSecret(ssl, ssl->clientSecret,
                                           WOLFSSL_CLIENT_END);
            if (ret != 0)
                goto end;
            break;
#endif

        case handshake_key:
            if (provision & PROVISION_CLIENT) {
                ret = DeriveClientHandshakeSecret(ssl,
                                                  ssl->clientSecret);
                if (ret != 0)
                    goto end;
            }
            if (provision & PROVISION_SERVER) {
                ret = DeriveServerHandshakeSecret(ssl,
                                                  ssl->serverSecret);
                if (ret != 0)
                    goto end;
            }
            break;

        case traffic_key:
            if (provision & PROVISION_CLIENT) {
                ret = DeriveClientTrafficSecret(ssl, ssl->clientSecret);
                if (ret != 0)
                    goto end;
            }
            if (provision & PROVISION_SERVER) {
                ret = DeriveServerTrafficSecret(ssl, ssl->serverSecret);
                if (ret != 0)
                    goto end;
            }
            break;

        case update_traffic_key:
            if (provision & PROVISION_CLIENT) {
                ret = DeriveTrafficSecret(ssl, ssl->clientSecret,
                                          WOLFSSL_CLIENT_END);
                if (ret != 0)
                    goto end;
            }
            if (provision & PROVISION_SERVER) {
                ret = DeriveTrafficSecret(ssl, ssl->serverSecret,
                                          WOLFSSL_SERVER_END);
                if (ret != 0)
                    goto end;
            }
            break;

        case no_key:
            /* Called with early data to derive keys from existing secrets
             * without re-deriving the secrets themselves. */
            ret = 0;
            break;

        default:
            ret = BAD_FUNC_ARG;
            break;
    }

#ifdef WOLFSSL_QUIC
    if (WOLFSSL_IS_QUIC(ssl)) {
        ret = wolfSSL_quic_forward_secrets(ssl, secret, side);
        if (ret != 0)
            goto end;
    }
#endif /* WOLFSSL_QUIC */

    if (!store)
        goto end;

    /* Key data = client key | server key | client IV | server IV */

    if (provision & PROVISION_CLIENT) {
        /* Derive the client key.  */
        WOLFSSL_MSG("Derive Client Key");
        ret = Tls13DeriveKey(ssl, &key_dig[i], ssl->specs.key_size,
                        ssl->clientSecret, writeKeyLabel,
                        WRITE_KEY_LABEL_SZ, ssl->specs.mac_algorithm, 0,
                        WOLFSSL_CLIENT_END);
        if (ret != 0)
            goto end;
        i += ssl->specs.key_size;
    }

    if (provision & PROVISION_SERVER) {
        /* Derive the server key.  */
        WOLFSSL_MSG("Derive Server Key");
        ret = Tls13DeriveKey(ssl, &key_dig[i], ssl->specs.key_size,
                        ssl->serverSecret, writeKeyLabel,
                        WRITE_KEY_LABEL_SZ, ssl->specs.mac_algorithm, 0,
                        WOLFSSL_SERVER_END);
        if (ret != 0)
            goto end;
        i += ssl->specs.key_size;
    }

    if (provision & PROVISION_CLIENT) {
        /* Derive the client IV.  */
        WOLFSSL_MSG("Derive Client IV");
        ret = Tls13DeriveKey(ssl, &key_dig[i], ssl->specs.iv_size,
                        ssl->clientSecret, writeIVLabel,
                        WRITE_IV_LABEL_SZ, ssl->specs.mac_algorithm, 0,
                        WOLFSSL_CLIENT_END);
        if (ret != 0)
            goto end;
        i += ssl->specs.iv_size;
    }

    if (provision & PROVISION_SERVER) {
        /* Derive the server IV.  */
        WOLFSSL_MSG("Derive Server IV");
        ret = Tls13DeriveKey(ssl, &key_dig[i], ssl->specs.iv_size,
                        ssl->serverSecret, writeIVLabel,
                        WRITE_IV_LABEL_SZ, ssl->specs.mac_algorithm, 0,
                        WOLFSSL_SERVER_END);
        if (ret != 0)
            goto end;
        /* Server IV is the last key material written to key_dig, so i is not
         * advanced here; the whole buffer is zeroed at end regardless. */
    }

    /* Store keys and IVs but don't activate them. */
    ret = StoreKeys(ssl, key_dig, provision);

#ifdef WOLFSSL_DTLS13
    if (ret != 0)
      goto end;

    if (ssl->options.dtls) {
        w64wrapper epochNumber;
        ret = Dtls13DeriveSnKeys(ssl, provision);
        if (ret != 0)
            goto end;

        switch (secret) {
            case early_data_key:
                epochNumber = w64From32(0, DTLS13_EPOCH_EARLYDATA);
                break;
            case handshake_key:
                epochNumber = w64From32(0, DTLS13_EPOCH_HANDSHAKE);
                break;
            case traffic_key:
            case no_key:
                epochNumber = w64From32(0, DTLS13_EPOCH_TRAFFIC0);
                break;
            case update_traffic_key:
                if (side == ENCRYPT_SIDE_ONLY) {
                    epochNumber = ssl->dtls13Epoch;
                }
                else if (side == DECRYPT_SIDE_ONLY) {
                    epochNumber = ssl->dtls13PeerEpoch;
                }
                else {
                    ret = BAD_STATE_E;
                    goto end;
                }
                w64Increment(&epochNumber);
                break;
            default:
                ret = BAD_STATE_E;
                goto end;
        }
        ret = Dtls13NewEpoch(ssl, epochNumber, side);
        if (ret != 0)
            goto end;
    }

#endif /* WOLFSSL_DTLS13 */

end:
    /* Zero the whole key_dig buffer (not just the i bytes derived) so no
     * key-schedule material can linger in the unused tail. */
    ForceZero(key_dig, MAX_PRF_DIG);
#ifdef WOLFSSL_SMALL_STACK
    XFREE(key_dig, ssl->heap, DYNAMIC_TYPE_DIGEST);
#elif defined(WOLFSSL_CHECK_MEM_ZERO)
    wc_MemZero_Check(key_dig, MAX_PRF_DIG);
#endif

    if (ret != 0) {
        WOLFSSL_ERROR_VERBOSE(ret);
    }

    return ret;
}

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK) || defined(WOLFSSL_DTLS13)
#ifdef WOLFSSL_32BIT_MILLI_TIME
#ifndef NO_ASN_TIME
#if defined(USER_TICKS)
#if 0
    word32 TimeNowInMilliseconds(void)
    {
        /*
        write your own clock tick function if don't want gettimeofday()
        needs millisecond accuracy but doesn't have to correlated to EPOCH
        */
    }
#endif

#elif defined(TIME_OVERRIDES)
#if !defined(NO_ASN) && !defined(NO_ASN_TIME)
    word32 TimeNowInMilliseconds(void)
    {
        return (word32) wc_Time(0) * 1000;
    }
#else
    #ifndef HAVE_TIME_T_TYPE
        typedef long time_t;
    #endif
    extern time_t XTIME(time_t * timer);

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (word32) XTIME(0) * 1000;
    }
#endif

#elif defined(XTIME_MS)
    word32 TimeNowInMilliseconds(void)
    {
        return (word32)XTIME_MS(0);
    }

#elif defined(USE_WINDOWS_API)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        static int           init = 0;
        static LARGE_INTEGER freq;
        LARGE_INTEGER        count;

        if (!init) {
            QueryPerformanceFrequency(&freq);
            init = 1;
        }

        QueryPerformanceCounter(&count);

        return (word32)(count.QuadPart / (freq.QuadPart / 1000));
    }

#elif defined(HAVE_RTP_SYS)
    #include "rtptime.h"

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (word32)rtp_get_system_sec() * 1000;
    }
#elif defined(WOLFSSL_DEOS)
    word32 TimeNowInMilliseconds(void)
    {
        const word32 systemTickTimeInHz = 1000000 / systemTickInMicroseconds();
        word32 *systemTickPtr = systemTickPointer();

        return (word32) (*systemTickPtr/systemTickTimeInHz) * 1000;
    }
#elif defined(MICRIUM)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        OS_TICK ticks = 0;
        OS_ERR  err;

        ticks = OSTimeGet(&err);

        return (word32) (ticks / OSCfg_TickRate_Hz) * 1000;
    }
#elif defined(MICROCHIP_TCPIP_V5)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (word32) (TickGet() / (TICKS_PER_SECOND / 1000));
    }
#elif defined(MICROCHIP_TCPIP)
    #if defined(MICROCHIP_MPLAB_HARMONY)
        #include <system/tmr/sys_tmr.h>

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (word32)(SYS_TMR_TickCountGet() /
                        (SYS_TMR_TickCounterFrequencyGet() / 1000));
    }
    #else
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (word32)(SYS_TICK_Get() / (SYS_TICK_TicksPerSecondGet() / 1000));
    }

    #endif

#elif defined(FREESCALE_MQX) || defined(FREESCALE_KSDK_MQX)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        TIME_STRUCT mqxTime;

        _time_get_elapsed(&mqxTime);

        return (word32) mqxTime.SECONDS * 1000;
    }
#elif defined(FREESCALE_FREE_RTOS) || defined(FREESCALE_KSDK_FREERTOS)
    #include "include/task.h"

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (unsigned int)(((float)xTaskGetTickCount()) /
                              (configTICK_RATE_HZ / 1000));
    }
#elif defined(FREESCALE_KSDK_BM)
    #include "lwip/sys.h" /* lwIP */

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return sys_now();
    }

#elif defined(WOLFSSL_CMSIS_RTOS) || defined(WOLFSSL_CMSIS_RTOSv2)

    word32 TimeNowInMilliseconds(void)
    {
        return (word32)osKernelGetTickCount();
    }

#elif defined(WOLFSSL_TIRTOS)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (word32) Seconds_get() * 1000;
    }
#elif defined(WOLFSSL_UTASKER)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        return (word32)(uTaskerSystemTick / (TICK_RESOLUTION / 1000));
    }
#elif defined(WOLFSSL_LINUXKM)
    word32 TimeNowInMilliseconds(void)
    {
        s64 t;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
        struct timespec ts;
        getnstimeofday(&ts);
        t = ts.tv_sec * (s64)1000;
        t += ts.tv_nsec / (s64)1000000;
#else
        struct timespec64 ts;
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
        ts = current_kernel_time64();
#else
        ktime_get_coarse_real_ts64(&ts);
#endif
        t = ts.tv_sec * 1000L;
        t += ts.tv_nsec / 1000000L;
#endif
        return (word32)t;
    }
#elif defined(WOLFSSL_QNX_CAAM)
    word32 TimeNowInMilliseconds(void)
    {
        struct timespec now;
        clock_gettime(CLOCK_REALTIME, &now);
        return (word32)(now.tv_sec * 1000 + now.tv_nsec / 1000000);
    }
#elif defined(FUSION_RTOS)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        struct timeval now;
        if (FCL_GETTIMEOFDAY(&now, 0) < 0)
            return 0;

        /* Convert to milliseconds number. */
        return (word32)(now.tv_sec * 1000 + now.tv_usec / 1000);
    }
#elif defined(WOLFSSL_ZEPHYR)
    word32 TimeNowInMilliseconds(void)
    {
        int64_t t;
    #if defined(CONFIG_ARCH_POSIX)
        k_cpu_idle();
    #endif
        t = k_uptime_get(); /* returns current uptime in milliseconds */
        return (word32)t;
    }
#elif defined(FREERTOS)
    word32 TimeNowInMilliseconds(void)
    {
        return (word32)((uint64_t)(xTaskGetTickCount() * 1000) /
            configTICK_RATE_HZ);
    }
#else
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    word32 TimeNowInMilliseconds(void)
    {
        struct timeval now;

        if (gettimeofday(&now, 0) < 0)
            return 0;

        /* Convert to milliseconds number. */
        return (word32)(now.tv_sec * 1000 + now.tv_usec / 1000);
    }
#endif
#else
    /* user must supply time in milliseconds function:
     *   word32 TimeNowInMilliseconds(void);
     * The response is milliseconds elapsed
     */
#endif /* !NO_ASN_TIME */
#else
#ifndef NO_ASN_TIME
#if defined(USER_TICKS)
#if 0
    sword64 TimeNowInMilliseconds(void)
    {
        /*
        write your own clock tick function if don't want gettimeofday()
        needs millisecond accuracy but doesn't have to correlated to EPOCH
        */
    }
#endif

#elif defined(TIME_OVERRIDES)
#if !defined(NO_ASN) && !defined(NO_ASN_TIME)
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64) wc_Time(0) * 1000;
    }
#else
    #ifndef HAVE_TIME_T_TYPE
        typedef long time_t;
    #endif
    extern time_t XTIME(time_t * timer);

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 32-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64) XTIME(0) * 1000;
    }
#endif

#elif defined(XTIME_MS)
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)XTIME_MS(0);
    }

#elif defined(USE_WINDOWS_API)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        static int           init = 0;
        static LARGE_INTEGER freq;
        LARGE_INTEGER        count;

        if (!init) {
            QueryPerformanceFrequency(&freq);
            init = 1;
        }

        QueryPerformanceCounter(&count);

        return (sword64)(count.QuadPart / (freq.QuadPart / 1000));
    }

#elif defined(HAVE_RTP_SYS)
    #include "rtptime.h"

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)rtp_get_system_sec() * 1000;
    }
#elif defined(WOLFSSL_DEOS)
    sword64 TimeNowInMilliseconds(void)
    {
        const word32 systemTickTimeInHz = 1000000 / systemTickInMicroseconds();
        word32 *systemTickPtr = systemTickPointer();

        return (sword64) (*systemTickPtr/systemTickTimeInHz) * 1000;
    }
#elif defined(MICRIUM)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        OS_TICK ticks = 0;
        OS_ERR  err;

        ticks = OSTimeGet(&err);

        return (sword64) (ticks / OSCfg_TickRate_Hz) * 1000;
    }
#elif defined(MICROCHIP_TCPIP_V5)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64) (TickGet() / (TICKS_PER_SECOND / 1000));
    }
#elif defined(MICROCHIP_TCPIP)
    #if defined(MICROCHIP_MPLAB_HARMONY)
        #include <system/tmr/sys_tmr.h>

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)SYS_TMR_TickCountGet() /
                        (SYS_TMR_TickCounterFrequencyGet() / 1000);
    }
    #else
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)SYS_TICK_Get() / (SYS_TICK_TicksPerSecondGet() / 1000);
    }

    #endif

#elif defined(FREESCALE_MQX) || defined(FREESCALE_KSDK_MQX)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        TIME_STRUCT mqxTime;

        _time_get_elapsed(&mqxTime);

        return (sword64) mqxTime.SECONDS * 1000;
    }
#elif defined(FREESCALE_FREE_RTOS) || defined(FREESCALE_KSDK_FREERTOS)
    #include "include/task.h"

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)xTaskGetTickCount() / (configTICK_RATE_HZ / 1000);
    }
#elif defined(FREESCALE_KSDK_BM)
    #include "lwip/sys.h" /* lwIP */

    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return sys_now();
    }

#elif defined(WOLFSSL_CMSIS_RTOS) || defined(WOLFSSL_CMSIS_RTOSv2)

    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)osKernelGetTickCount();
    }

#elif defined(WOLFSSL_TIRTOS)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64) Seconds_get() * 1000;
    }
#elif defined(WOLFSSL_UTASKER)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)(uTaskerSystemTick / (TICK_RESOLUTION / 1000));
    }
#elif defined(WOLFSSL_LINUXKM)
    sword64 TimeNowInMilliseconds(void)
    {
        s64 t;
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 0, 0)
        struct timespec ts;
        getnstimeofday(&ts);
        t = ts.tv_sec * (s64)1000;
        t += ts.tv_nsec / (s64)1000000;
#else
        struct timespec64 ts;
#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 0, 0)
        ts = current_kernel_time64();
#else
        ktime_get_coarse_real_ts64(&ts);
#endif
        t = ts.tv_sec * 1000L;
        t += ts.tv_nsec / 1000000L;
#endif
        return (sword64)t;
    }
#elif defined(WOLFSSL_QNX_CAAM)
    sword64 TimeNowInMilliseconds(void)
    {
        struct timespec now;
        clock_gettime(CLOCK_REALTIME, &now);
        return (sword64)(now.tv_sec * 1000 + now.tv_nsec / 1000000);
    }
#elif defined(FUSION_RTOS)
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        struct timeval now;
        if (FCL_GETTIMEOFDAY(&now, 0) < 0)
            return 0;

        /* Convert to milliseconds number. */
        return (sword64)now.tv_sec * 1000 + now.tv_usec / 1000;
    }
#elif defined(WOLFSSL_ZEPHYR)
    sword64 TimeNowInMilliseconds(void)
    {
        int64_t t;
    #if defined(CONFIG_ARCH_POSIX)
        k_cpu_idle();
    #endif
        t = k_uptime_get(); /* returns current uptime in milliseconds */
        return (sword64)t;
    }
#elif defined(FREERTOS)
    sword64 TimeNowInMilliseconds(void)
    {
        return (sword64)((uint64_t)(xTaskGetTickCount() * 1000) /
            configTICK_RATE_HZ);
    }
#else
    /* The time in milliseconds.
     * Used for tickets to represent difference between when first seen and when
     * sending.
     *
     * returns the time in milliseconds as a 64-bit value.
     */
    sword64 TimeNowInMilliseconds(void)
    {
        struct timeval now;

        if (gettimeofday(&now, 0) < 0)
            return 0;

        /* Convert to milliseconds number. */
        return (sword64)now.tv_sec * 1000 + now.tv_usec / 1000;
    }
#endif
#else
    /* user must supply time in milliseconds function:
     *   sword64 TimeNowInMilliseconds(void);
     * The response is milliseconds elapsed
     */
#endif /* !NO_ASN_TIME */
#endif /* WOLFSSL_32BIT_MILLI_TIME */
#endif /* HAVE_SESSION_TICKET || !NO_PSK || WOLFSSL_DTLS13 */

/* Add record layer header to message.
 *
 * output  The buffer to write the record layer header into.
 * length  The length of the record data.
 * type    The type of record message.
 * ssl     The SSL/TLS object.
 */
static void AddTls13RecordHeader(byte* output, word32 length, byte type,
                                 WOLFSSL* ssl)
{
    RecordLayerHeader* rl;

    rl = (RecordLayerHeader*)output;
    rl->type    = type;
    rl->pvMajor = ssl->version.major;
    /* NOTE: May be TLSv1_MINOR when sending first ClientHello. */
    rl->pvMinor = TLSv1_2_MINOR;
    c16toa((word16)length, rl->length);
}

/* Add handshake header to message.
 *
 * output      The buffer to write the handshake header into.
 * length      The length of the handshake data.
 * fragOffset  The offset of the fragment data. (DTLS)
 * fragLength  The length of the fragment data. (DTLS)
 * type        The type of handshake message.
 * ssl         The SSL/TLS object. (DTLS)
 */
static void AddTls13HandShakeHeader(byte* output, word32 length,
                                    word32 fragOffset, word32 fragLength,
                                    byte type, WOLFSSL* ssl)
{
    HandShakeHeader* hs;
    (void)fragOffset;
    (void)fragLength;
    (void)ssl;

#ifdef WOLFSSL_DTLS13
    /* message_hash type is used for a synthetic message that replaces the first
       ClientHello in the hash transcript when using HelloRetryRequest. It will
       never be transmitted and, as the DTLS-only fields must not be considered
       when computing the hash transcript, we can avoid to use the DTLS
       handshake header. */
    if (ssl->options.dtls && type != message_hash) {
        Dtls13HandshakeAddHeader(ssl, output, (enum HandShakeType)type, length);
        return;
    }
#endif /* WOLFSSL_DTLS13 */

    /* handshake header */
    hs = (HandShakeHeader*)output;
    hs->type = type;
    c32to24(length, hs->length);
}


/* Add both record layer and handshake header to message.
 *
 * output      The buffer to write the headers into.
 * length      The length of the handshake data.
 * type        The type of record layer message.
 * ssl         The SSL/TLS object. (DTLS)
 */
static void AddTls13Headers(byte* output, word32 length, byte type,
                            WOLFSSL* ssl)
{
    word32 lengthAdj = HANDSHAKE_HEADER_SZ;
    word32 outputAdj = RECORD_HEADER_SZ;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        Dtls13AddHeaders(output, length, (enum HandShakeType)type, ssl);
        return;
    }
#endif /* WOLFSSL_DTLS13 */

    AddTls13RecordHeader(output, length + lengthAdj, handshake, ssl);
    AddTls13HandShakeHeader(output + outputAdj, length, 0, length, type, ssl);
}

#if (!defined(NO_WOLFSSL_CLIENT) || !defined(NO_WOLFSSL_SERVER)) \
    && !defined(NO_CERTS)
/* Add both record layer and fragment handshake header to message.
 *
 * output      The buffer to write the headers into.
 * fragOffset  The offset of the fragment data. (DTLS)
 * fragLength  The length of the fragment data. (DTLS)
 * length      The length of the handshake data.
 * type        The type of record layer message.
 * ssl         The SSL/TLS object. (DTLS)
 */
static void AddTls13FragHeaders(byte* output, word32 fragSz, word32 fragOffset,
                                word32 length, byte type, WOLFSSL* ssl)
{
    word32 lengthAdj = HANDSHAKE_HEADER_SZ;
    word32 outputAdj = RECORD_HEADER_SZ;
    (void)fragSz;

#ifdef WOLFSSL_DTLS13
    /* we ignore fragmentation fields here because fragmentation logic for
       DTLS1.3 is inside dtls13_handshake_send(). */
    if (ssl->options.dtls) {
        Dtls13AddHeaders(output, length, (enum HandShakeType)type, ssl);
        return;
    }
#endif /* WOLFSSL_DTLS13 */

    AddTls13RecordHeader(output, fragSz + lengthAdj, handshake, ssl);
    AddTls13HandShakeHeader(output + outputAdj, length, fragOffset, fragSz,
                            type, ssl);
}
#endif /* (!NO_WOLFSSL_CLIENT || !NO_WOLFSSL_SERVER) && !NO_CERTS */

/* Write the sequence number into the buffer.
 * No DTLS v1.3 support.
 *
 * ssl          The SSL/TLS object.
 * verifyOrder  Which set of sequence numbers to use.
 * out          The buffer to write into.
 */
static WC_INLINE void WriteSEQTls13(WOLFSSL* ssl, int verifyOrder, byte* out)
{
    word32 seq[2] = {0, 0};

    if (ssl->options.dtls) {
#ifdef WOLFSSL_DTLS13
        Dtls13GetSeq(ssl, verifyOrder, seq, 1);
#endif /* WOLFSSL_DTLS13 */
    }
    else if (verifyOrder == PEER_ORDER) {
        seq[0] = ssl->keys.peer_sequence_number_hi;
        seq[1] = ssl->keys.peer_sequence_number_lo++;
        /* handle rollover */
        if (seq[1] > ssl->keys.peer_sequence_number_lo)
            ssl->keys.peer_sequence_number_hi++;
    }
    else {
        seq[0] = ssl->keys.sequence_number_hi;
        seq[1] = ssl->keys.sequence_number_lo++;
        /* handle rollover */
        if (seq[1] > ssl->keys.sequence_number_lo)
            ssl->keys.sequence_number_hi++;
    }
#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG_EX("TLS 1.3 Write Sequence %d %d", seq[0], seq[1]);
#endif

    c32toa(seq[0], out);
    c32toa(seq[1], out + OPAQUE32_LEN);
}

/* Build the nonce for TLS v1.3 encryption and decryption.
 *
 * ssl    The SSL/TLS object.
 * nonce  The nonce data to use when encrypting or decrypting.
 * iv     The derived IV.
 * order  The side on which the message is to be or was sent.
 */
static WC_INLINE void BuildTls13Nonce(WOLFSSL* ssl, byte* nonce, const byte* iv,
                                   int ivSz, int order)
{
    int seq_offset;
    /* Ensure minimum nonce size for standard AEAD ciphers */
    if (ivSz < AEAD_NONCE_SZ)
        ivSz = AEAD_NONCE_SZ;
    seq_offset = ivSz - SEQ_SZ;
    /* The nonce is the IV with the sequence XORed into the last bytes. */
    WriteSEQTls13(ssl, order, nonce + seq_offset);
    XMEMCPY(nonce, iv, seq_offset);
    xorbuf(nonce + seq_offset, iv + seq_offset, SEQ_SZ);
}

#if defined(HAVE_CHACHA) && defined(HAVE_POLY1305)
/* Encrypt with ChaCha20 and create authentication tag with Poly1305.
 *
 * ssl     The SSL/TLS object.
 * output  The buffer to write encrypted data and authentication tag into.
 *         May be the same pointer as input.
 * input   The data to encrypt.
 * sz      The number of bytes to encrypt.
 * nonce   The nonce to use with ChaCha20.
 * aad     The additional authentication data.
 * aadSz   The size of the addition authentication data.
 * tag     The authentication tag buffer.
 * returns 0 on success, otherwise failure.
 */
static int ChaCha20Poly1305_Encrypt(WOLFSSL* ssl, byte* output,
                                    const byte* input, word16 sz, byte* nonce,
                                    const byte* aad, word16 aadSz, byte* tag)
{
    /* Persistent-key stitched helper: derives the per-record Poly1305 key from
     * the keyed ChaCha, then encrypts and authenticates in one pass (the IFMA
     * stitch for large records, else two-pass).  TLS 1.3 is always RFC 8439. */
    return wc_ChaCha20Poly1305_Encrypt_ex(ssl->encrypt.chacha,
        ssl->auth.poly1305, output, input, sz, nonce, tag, aad, aadSz);
}
#endif

#ifdef HAVE_NULL_CIPHER
/* Create authentication tag and copy data over input.
 *
 * ssl     The SSL/TLS object.
 * output  The buffer to copy data into.
 *         May be the same pointer as input.
 * input   The data.
 * sz      The number of bytes of data.
 * nonce   The nonce to use with authentication.
 * aad     The additional authentication data.
 * aadSz   The size of the addition authentication data.
 * tag     The authentication tag buffer.
 * returns 0 on success, otherwise failure.
 */
static int Tls13IntegrityOnly_Encrypt(WOLFSSL* ssl, byte* output,
                                      const byte* input, word16 sz,
                                      const byte* nonce,
                                      const byte* aad, word16 aadSz, byte* tag)
{
    int ret;

    /* HMAC: nonce | aad | input  */
    ret = wc_HmacUpdate(ssl->encrypt.hmac, nonce, ssl->specs.iv_size);
    if (ret == 0)
        ret = wc_HmacUpdate(ssl->encrypt.hmac, aad, aadSz);
    if (ret == 0)
        ret = wc_HmacUpdate(ssl->encrypt.hmac, input, sz);
    if (ret == 0)
        ret = wc_HmacFinal(ssl->encrypt.hmac, tag);
    /* Copy the input to output if not the same buffer */
    if (ret == 0 && output != input)
        XMEMCPY(output, input, sz);
    return ret;
}
#endif

/* Encrypt data for TLS v1.3.
 *
 * ssl     The SSL/TLS object.
 * output  The buffer to write encrypted data and authentication tag into.
 *         May be the same pointer as input.
 * input   The record header and data to encrypt.
 * sz      The number of bytes to encrypt.
 * aad     The additional authentication data.
 * aadSz   The size of the addition authentication data.
 * asyncOkay If non-zero can return WC_PENDING_E, otherwise blocks on crypto
 * returns 0 on success, otherwise failure.
 */
static int EncryptTls13(WOLFSSL* ssl, byte* output, const byte* input,
                        word16 sz, const byte* aad, word16 aadSz, int asyncOkay)
{
    int    ret    = 0;
    word16 dataSz;
    word16 macSz  = ssl->specs.aead_mac_size;
    word32 nonceSz = 0;
#ifdef WOLFSSL_ASYNC_CRYPT
    /* Only AES-GCM/AES-CCM assign asyncDev, so only they may pend under a
     * poll-completing device; the crypto-callback re-invoke path returns
     * before the push and is not limited this way. */
    WC_ASYNC_DEV* asyncDev = NULL;
    word32 event_flags = WC_ASYNC_FLAG_CALL_AGAIN;
#endif

    WOLFSSL_ENTER("EncryptTls13");
    if (sz < ssl->specs.aead_mac_size)
        return BUFFER_E;
    dataSz = sz - ssl->specs.aead_mac_size;

    (void)output;
    (void)input;
    (void)sz;
    (void)dataSz;
    (void)macSz;
    (void)asyncOkay;
    (void)nonceSz;

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ssl->error == WC_NO_ERR_TRACE(WC_PENDING_E)) {
        ssl->error = 0; /* clear async */
    }
#endif
#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13AesEncrypt(ssl, output, input, dataSz);
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE)) {
        if (ret > 0) {
            ret = 0; /* tsip_Tls13AesEncrypt returns output size */
        }
        return ret;
    }
    ret = 0;
#endif /* WOLFSSL_RENESAS_TSIP_TLS */

    switch (ssl->encrypt.state) {
        case CIPHER_STATE_BEGIN:
        {
        #ifdef WOLFSSL_DEBUG_TLS
            WOLFSSL_MSG("Data to encrypt");
            WOLFSSL_BUFFER(input, dataSz);
            WOLFSSL_MSG("Additional Authentication Data");
            WOLFSSL_BUFFER(aad, aadSz);
        #endif

        #ifdef WOLFSSL_CIPHER_TEXT_CHECK
            if (ssl->specs.bulk_cipher_algorithm != wolfssl_cipher_null &&
                    dataSz >= sizeof(ssl->encrypt.sanityCheck)) {
                XMEMCPY(ssl->encrypt.sanityCheck, input,
                    sizeof(ssl->encrypt.sanityCheck));
            }
        #endif

        #ifdef CIPHER_NONCE
            if (ssl->encrypt.nonce == NULL) {
                ssl->encrypt.nonce = (byte*)XMALLOC(AEAD_MAX_IMP_SZ,
                                                ssl->heap, DYNAMIC_TYPE_CIPHER);
            #ifdef WOLFSSL_CHECK_MEM_ZERO
                if (ssl->encrypt.nonce != NULL) {
                    wc_MemZero_Add("EncryptTls13 nonce", ssl->encrypt.nonce,
                        ssl->specs.iv_size);
                }
            #endif
            }
            if (ssl->encrypt.nonce == NULL)
                return MEMORY_E;

            BuildTls13Nonce(ssl, ssl->encrypt.nonce, ssl->keys.aead_enc_imp_IV,
                            ssl->specs.iv_size, CUR_ORDER);
        #endif

            /* Advance state and proceed */
            ssl->encrypt.state = CIPHER_STATE_DO;
        }
        FALL_THROUGH;

        case CIPHER_STATE_DO:
        {
            switch (ssl->specs.bulk_cipher_algorithm) {
            #ifdef BUILD_AESGCM
                case wolfssl_aes_gcm:
                #ifdef WOLFSSL_ASYNC_CRYPT
                    /* initialize event */
                    asyncDev = &ssl->encrypt.aes->asyncDev;
                    ret = wolfSSL_AsyncInit(ssl, asyncDev, event_flags);
                    if (ret != 0)
                        break;
                #endif

                    nonceSz = AESGCM_NONCE_SZ;

                #if defined(HAVE_PK_CALLBACKS)
                    ret = WC_NO_ERR_TRACE(NOT_COMPILED_IN);
                    if (ssl->ctx && ssl->ctx->PerformTlsRecordProcessingCb) {
                        ret = ssl->ctx->PerformTlsRecordProcessingCb(ssl, 1,
                                  output, input, dataSz,
                                  ssl->encrypt.nonce, nonceSz,
                                  output + dataSz, macSz,
                                  aad, aadSz);
                    }
                    if (ret == WC_NO_ERR_TRACE(NOT_COMPILED_IN))
                #endif
                    {

                #if ((defined(HAVE_FIPS) || defined(HAVE_SELFTEST)) && \
                    (!defined(HAVE_FIPS_VERSION) || (HAVE_FIPS_VERSION < 2)))
                        ret = wc_AesGcmEncrypt(ssl->encrypt.aes, output, input,
                            dataSz, ssl->encrypt.nonce, nonceSz,
                            output + dataSz, macSz, aad, aadSz);
                #else
                        ret = wc_AesGcmSetExtIV(ssl->encrypt.aes,
                                ssl->encrypt.nonce, nonceSz);
                        if (ret == 0) {
                            ret = wc_AesGcmEncrypt_ex(ssl->encrypt.aes, output,
                                    input, dataSz, ssl->encrypt.nonce, nonceSz,
                                    output + dataSz, macSz, aad, aadSz);
                        }
                #endif
                    }
                    break;
            #endif

            #ifdef HAVE_AESCCM
                case wolfssl_aes_ccm:
                #ifdef WOLFSSL_ASYNC_CRYPT
                    /* initialize event */
                    asyncDev = &ssl->encrypt.aes->asyncDev;
                    ret = wolfSSL_AsyncInit(ssl, asyncDev, event_flags);
                    if (ret != 0)
                        break;
                #endif

                    nonceSz = AESCCM_NONCE_SZ;
                #if defined(HAVE_PK_CALLBACKS)
                    ret = WC_NO_ERR_TRACE(NOT_COMPILED_IN);
                    if (ssl->ctx && ssl->ctx->PerformTlsRecordProcessingCb) {
                        ret = ssl->ctx->PerformTlsRecordProcessingCb(ssl, 1,
                                  output, input, dataSz,
                                  ssl->encrypt.nonce, nonceSz,
                                  output + dataSz, macSz,
                                  aad, aadSz);
                    }
                    if (ret == WC_NO_ERR_TRACE(NOT_COMPILED_IN))
                #endif
                    {
                #if ((defined(HAVE_FIPS) || defined(HAVE_SELFTEST)) && \
                    (!defined(HAVE_FIPS_VERSION) || (HAVE_FIPS_VERSION < 2)))
                        ret = wc_AesCcmEncrypt(ssl->encrypt.aes, output, input,
                            dataSz, ssl->encrypt.nonce, nonceSz,
                            output + dataSz, macSz, aad, aadSz);
                #else
                        ret = wc_AesCcmSetNonce(ssl->encrypt.aes,
                                ssl->encrypt.nonce, nonceSz);
                        if (ret == 0) {
                            ret = wc_AesCcmEncrypt_ex(ssl->encrypt.aes, output,
                                    input, dataSz, ssl->encrypt.nonce, nonceSz,
                                    output + dataSz, macSz, aad, aadSz);
                        }
                #endif
                    }
                    break;
            #endif

            #if defined(HAVE_CHACHA) && defined(HAVE_POLY1305)
                case wolfssl_chacha:
                    ret = ChaCha20Poly1305_Encrypt(ssl, output, input, dataSz,
                        ssl->encrypt.nonce, aad, aadSz, output + dataSz);
                    break;
            #endif

            #ifdef WOLFSSL_SM4_GCM
                case wolfssl_sm4_gcm:
                    nonceSz = SM4_GCM_NONCE_SZ;
                    ret = wc_Sm4GcmEncrypt(ssl->encrypt.sm4, output, input,
                        dataSz, ssl->encrypt.nonce, nonceSz, output + dataSz,
                        macSz, aad, aadSz);
                    break;
            #endif

            #ifdef WOLFSSL_SM4_CCM
                case wolfssl_sm4_ccm:
                    nonceSz = SM4_CCM_NONCE_SZ;
                    ret = wc_Sm4CcmEncrypt(ssl->encrypt.sm4, output, input,
                        dataSz, ssl->encrypt.nonce, nonceSz, output + dataSz,
                        macSz, aad, aadSz);
                    break;
            #endif

            #ifdef HAVE_NULL_CIPHER
                case wolfssl_cipher_null:
                    ret = Tls13IntegrityOnly_Encrypt(ssl, output, input, dataSz,
                        ssl->encrypt.nonce, aad, aadSz, output + dataSz);
                    break;
            #endif

                default:
                    WOLFSSL_MSG("wolfSSL Encrypt programming error");
                    return ENCRYPT_ERROR;
            }

        #ifdef WOLFSSL_ASYNC_CRYPT
            if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
                /* if async is not okay, then block */
                if (!asyncOkay) {
                #if defined(WOLFSSL_ASYNC_REINVOKE) && \
                    !defined(WOLF_CRYPTO_CB_ASYNC_POLL)
                    /* wc_AsyncWait() never runs a callback: leave the state
                     * at CIPHER_STATE_DO for the caller to re-invoke. */
                    return ret;
                #else
                    ret = wc_AsyncWait(ret, asyncDev, event_flags);
                #endif
                }
                else {
                #if !defined(WOLFSSL_ASYNC_REINVOKE) || \
                    defined(WOLF_CRYPTO_CB_ASYNC_POLL)
                    /* Poll completes into output; the resume must skip the
                     * in-place AEAD or it would encrypt its own output. */
                    ssl->encrypt.state = CIPHER_STATE_END;
                #endif
                    /* Else stay at CIPHER_STATE_DO: the retry must re-invoke
                     * the callback or the record goes out unencrypted. */
                    return wolfSSL_AsyncPush(ssl, asyncDev);
                }
            }
        #endif

            /* Advance state */
            ssl->encrypt.state = CIPHER_STATE_END;
        }
        FALL_THROUGH;

        case CIPHER_STATE_END:
        {
        #ifdef WOLFSSL_DEBUG_TLS
            #ifdef CIPHER_NONCE
                WOLFSSL_MSG("Nonce");
                WOLFSSL_BUFFER(ssl->encrypt.nonce, ssl->specs.iv_size);
            #endif
                WOLFSSL_MSG("Encrypted data");
                WOLFSSL_BUFFER(output, dataSz);
                WOLFSSL_MSG("Authentication Tag");
                WOLFSSL_BUFFER(output + dataSz, macSz);
        #endif

        #ifdef WOLFSSL_CIPHER_TEXT_CHECK
            if (ssl->specs.bulk_cipher_algorithm != wolfssl_cipher_null &&
                    dataSz >= sizeof(ssl->encrypt.sanityCheck) &&
                XMEMCMP(output, ssl->encrypt.sanityCheck,
                    sizeof(ssl->encrypt.sanityCheck)) == 0) {

                WOLFSSL_MSG("EncryptTls13 sanity check failed! Glitch?");
                return ENCRYPT_ERROR;
            }
            ForceZero(ssl->encrypt.sanityCheck,
                sizeof(ssl->encrypt.sanityCheck));
        #endif
        #ifdef WOLFSSL_CHECK_MEM_ZERO
            if ((ssl->specs.bulk_cipher_algorithm != wolfssl_cipher_null) &&
                    (output != input) && (ret == 0)) {
                wc_MemZero_Add("TLS 1.3 Encrypt plaintext", input, sz);
            }
        #endif

        #ifdef CIPHER_NONCE
            ForceZero(ssl->encrypt.nonce, ssl->specs.iv_size);
        #endif

            break;
        }

        default:
            break;
    }


    /* Reset state */
    ssl->encrypt.state = CIPHER_STATE_BEGIN;

    return ret;
}

#if defined(HAVE_CHACHA) && defined(HAVE_POLY1305)
/* Decrypt with ChaCha20 and check authentication tag with Poly1305.
 *
 * ssl     The SSL/TLS object.
 * output  The buffer to write decrypted data into.
 *         May be the same pointer as input.
 * input   The data to decrypt.
 * sz      The number of bytes to decrypt.
 * nonce   The nonce to use with ChaCha20.
 * aad     The additional authentication data.
 * aadSz   The size of the addition authentication data.
 * tagIn   The authentication tag data from packet.
 * returns 0 on success, otherwise failure.
 */
static int ChaCha20Poly1305_Decrypt(WOLFSSL* ssl, byte* output,
                                    const byte* input, word16 sz, byte* nonce,
                                    const byte* aad, word16 aadSz,
                                    const byte* tagIn)
{
    int ret;

    /* Persistent-key stitched helper: verifies the Poly1305 tag over
     * aad+ciphertext and decrypts in one pass (the IFMA decrypt stitch for
     * large records, else two-pass); it zeroes output on tag mismatch. */
    ret = wc_ChaCha20Poly1305_Decrypt_ex(ssl->decrypt.chacha,
        ssl->auth.poly1305, output, input, sz, nonce, tagIn, aad, aadSz);
    if (ret == WC_NO_ERR_TRACE(MAC_CMP_FAILED_E)) {
        WOLFSSL_MSG("MAC did not match");
        ret = VERIFY_MAC_ERROR;
    }

    return ret;
}
#endif

#ifdef HAVE_NULL_CIPHER
/* Check HMAC tag and copy over input.
 *
 * ssl     The SSL/TLS object.
 * output  The buffer to copy data into.
 *         May be the same pointer as input.
 * input   The data.
 * sz      The number of bytes of data.
 * nonce   The nonce to use with authentication.
 * aad     The additional authentication data.
 * aadSz   The size of the addition authentication data.
 * tagIn   The authentication tag data from packet.
 * returns 0 on success, otherwise failure.
 */
static int Tls13IntegrityOnly_Decrypt(WOLFSSL* ssl, byte* output,
                                      const byte* input, word16 sz,
                                      const byte* nonce,
                                      const byte* aad, word16 aadSz,
                                      const byte* tagIn)
{
    int ret;
    byte hmac[WC_MAX_DIGEST_SIZE];

    /* HMAC: nonce | aad | input  */
    ret = wc_HmacUpdate(ssl->decrypt.hmac, nonce, ssl->specs.iv_size);
    if (ret == 0)
        ret = wc_HmacUpdate(ssl->decrypt.hmac, aad, aadSz);
    if (ret == 0)
        ret = wc_HmacUpdate(ssl->decrypt.hmac, input, sz);
    if (ret == 0)
        ret = wc_HmacFinal(ssl->decrypt.hmac, hmac);
    /* Check authentication tag matches */
    if (ret == 0 && ConstantCompare(tagIn, hmac, ssl->specs.hash_size) != 0)
        ret = DECRYPT_ERROR;
    /* Copy the input to output if not the same buffer */
    if (ret == 0 && output != input)
        XMEMCPY(output, input, sz);
    ForceZero(hmac, sizeof(hmac));
    return ret;
}
#endif

/* Decrypt data for TLS v1.3.
 *
 * ssl     The SSL/TLS object.
 * output  The buffer to write decrypted data into.
 *         May be the same pointer as input.
 * input   The data to decrypt and authentication tag.
 * sz      The length of the encrypted data plus authentication tag.
 * aad     The additional authentication data.
 * aadSz   The size of the addition authentication data.
 * returns 0 on success, otherwise failure.
 */
int DecryptTls13(WOLFSSL* ssl, byte* output, const byte* input, word16 sz,
                 const byte* aad, word16 aadSz)
{
    int    ret    = 0;
    word16 dataSz;
    word16 macSz  = ssl->specs.aead_mac_size;
    word32 nonceSz = 0;

    WOLFSSL_ENTER("DecryptTls13");
    if (sz < ssl->specs.aead_mac_size) {
        return BAD_FUNC_ARG;
    }
    dataSz = sz - ssl->specs.aead_mac_size;

#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13AesDecrypt(ssl, output, input, sz);

    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE)) {
        #ifndef WOLFSSL_EARLY_DATA
        if (ret < 0) {
            ret = VERIFY_MAC_ERROR;
            WOLFSSL_ERROR_VERBOSE(ret);
        }
        #endif
        return ret;
    }
#endif

#ifdef WOLFSSL_ASYNC_CRYPT
    ret = wolfSSL_AsyncPop(ssl, &ssl->decrypt.state);
    if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
        /* check for still pending */
        if (ret == WC_NO_ERR_TRACE(WC_PENDING_E))
            return ret;

        ssl->error = 0; /* clear async */

        /* let failures through so CIPHER_STATE_END logic is run */
    }
    else
#endif
    {
        /* Reset state */
        ret = 0;
        ssl->decrypt.state = CIPHER_STATE_BEGIN;
    }

    (void)output;
    (void)input;
    (void)sz;
    (void)dataSz;
    (void)macSz;
    (void)nonceSz;

    switch (ssl->decrypt.state) {
        case CIPHER_STATE_BEGIN:
        {
        #ifdef WOLFSSL_DEBUG_TLS
            WOLFSSL_MSG("Data to decrypt");
            WOLFSSL_BUFFER(input, dataSz);
            WOLFSSL_MSG("Additional Authentication Data");
            WOLFSSL_BUFFER(aad, aadSz);
            WOLFSSL_MSG("Authentication tag");
            WOLFSSL_BUFFER(input + dataSz, macSz);
        #endif

        #ifdef CIPHER_NONCE
            if (ssl->decrypt.nonce == NULL) {
                ssl->decrypt.nonce = (byte*)XMALLOC(AEAD_MAX_IMP_SZ,
                                                ssl->heap, DYNAMIC_TYPE_CIPHER);
            #ifdef WOLFSSL_CHECK_MEM_ZERO
                if (ssl->decrypt.nonce != NULL) {
                    wc_MemZero_Add("DecryptTls13 nonce", ssl->decrypt.nonce,
                        ssl->specs.iv_size);
                }
            #endif
            }
            if (ssl->decrypt.nonce == NULL)
                return MEMORY_E;

            BuildTls13Nonce(ssl, ssl->decrypt.nonce, ssl->keys.aead_dec_imp_IV,
                            ssl->specs.iv_size, PEER_ORDER);
        #endif

            /* Advance state and proceed */
            ssl->decrypt.state = CIPHER_STATE_DO;
        }
        FALL_THROUGH;

        case CIPHER_STATE_DO:
        {
            switch (ssl->specs.bulk_cipher_algorithm) {
            #ifdef BUILD_AESGCM
                case wolfssl_aes_gcm:
                #ifdef WOLFSSL_ASYNC_CRYPT
                    /* initialize event */
                    ret = wolfSSL_AsyncInit(ssl, &ssl->decrypt.aes->asyncDev,
                        WC_ASYNC_FLAG_NONE);
                    if (ret != 0)
                        break;
                #endif

                    nonceSz = AESGCM_NONCE_SZ;

                #if defined(HAVE_PK_CALLBACKS)
                    ret = WC_NO_ERR_TRACE(NOT_COMPILED_IN);
                    if (ssl->ctx && ssl->ctx->PerformTlsRecordProcessingCb) {
                        ret = ssl->ctx->PerformTlsRecordProcessingCb(ssl, 0,
                                  output, input, dataSz,
                                  ssl->decrypt.nonce, nonceSz,
                                  (byte *)(input + dataSz), macSz,
                                  aad, aadSz);
                    }
                    if (ret == WC_NO_ERR_TRACE(NOT_COMPILED_IN))
                #endif
                    {

                        ret = wc_AesGcmDecrypt(ssl->decrypt.aes, output, input,
                            dataSz, ssl->decrypt.nonce, nonceSz,
                            input + dataSz, macSz, aad, aadSz);

                #ifdef WOLFSSL_ASYNC_CRYPT
                        if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
                            ret = wolfSSL_AsyncPush(ssl,
                                &ssl->decrypt.aes->asyncDev);
                        }
                #endif

                    }
                    break;
            #endif

            #ifdef HAVE_AESCCM
                case wolfssl_aes_ccm:
                #ifdef WOLFSSL_ASYNC_CRYPT
                    /* initialize event */
                    ret = wolfSSL_AsyncInit(ssl, &ssl->decrypt.aes->asyncDev,
                        WC_ASYNC_FLAG_NONE);
                    if (ret != 0)
                        break;
                #endif

                    nonceSz = AESCCM_NONCE_SZ;
                #if defined(HAVE_PK_CALLBACKS)
                    ret = WC_NO_ERR_TRACE(NOT_COMPILED_IN);
                    if (ssl->ctx && ssl->ctx->PerformTlsRecordProcessingCb) {
                        ret = ssl->ctx->PerformTlsRecordProcessingCb(ssl, 0,
                                  output, input, dataSz,
                                  ssl->decrypt.nonce, nonceSz,
                                  (byte *)(input + dataSz), macSz,
                                  aad, aadSz);
                    }
                    if (ret == WC_NO_ERR_TRACE(NOT_COMPILED_IN))
                #endif
                    {
                        ret = wc_AesCcmDecrypt(ssl->decrypt.aes, output, input,
                            dataSz, ssl->decrypt.nonce, nonceSz,
                            input + dataSz, macSz, aad, aadSz);
                #ifdef WOLFSSL_ASYNC_CRYPT
                        if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
                            ret = wolfSSL_AsyncPush(ssl,
                                &ssl->decrypt.aes->asyncDev);
                        }
                #endif
                    }
                    break;
            #endif

            #if defined(HAVE_CHACHA) && defined(HAVE_POLY1305)
                case wolfssl_chacha:
                    ret = ChaCha20Poly1305_Decrypt(ssl, output, input, dataSz,
                        ssl->decrypt.nonce, aad, aadSz, input + dataSz);
                    break;
            #endif

            #ifdef WOLFSSL_SM4_GCM
                case wolfssl_sm4_gcm:
                    nonceSz = SM4_GCM_NONCE_SZ;
                    ret = wc_Sm4GcmDecrypt(ssl->decrypt.sm4, output, input,
                        dataSz, ssl->decrypt.nonce, nonceSz, input + dataSz,
                        macSz, aad, aadSz);
                    break;
            #endif

            #ifdef WOLFSSL_SM4_CCM
                case wolfssl_sm4_ccm:
                    nonceSz = SM4_CCM_NONCE_SZ;
                    ret = wc_Sm4CcmDecrypt(ssl->decrypt.sm4, output, input,
                        dataSz, ssl->decrypt.nonce, nonceSz, input + dataSz,
                        macSz, aad, aadSz);
                    break;
            #endif

            #ifdef HAVE_NULL_CIPHER
                case wolfssl_cipher_null:
                    ret = Tls13IntegrityOnly_Decrypt(ssl, output, input, dataSz,
                        ssl->decrypt.nonce, aad, aadSz, input + dataSz);
                    break;
            #endif
                default:
                    WOLFSSL_MSG("wolfSSL Decrypt programming error");
                    return DECRYPT_ERROR;
            }

        #ifdef WOLFSSL_ASYNC_CRYPT
            if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
            #if !defined(WOLFSSL_ASYNC_REINVOKE) || \
                defined(WOLF_CRYPTO_CB_ASYNC_POLL)
                /* The poll completes the operation into the output buffer,
                 * so the resume must not run the AEAD again: advance past
                 * it now (the pop does not, the event is CALL_AGAIN). */
                ssl->decrypt.state = CIPHER_STATE_END;
            #else
                /* Crypto callback re-invocation: leave the state at
                 * CIPHER_STATE_DO so the retry re-enters the AEAD;
                 * advancing would hand back the undecrypted record. */
            #endif
                return ret;
            }
        #endif

            /* Advance state */
            ssl->decrypt.state = CIPHER_STATE_END;
        }
        FALL_THROUGH;

        case CIPHER_STATE_END:
        {
        #ifdef WOLFSSL_DEBUG_TLS
            #ifdef CIPHER_NONCE
                WOLFSSL_MSG("Nonce");
                WOLFSSL_BUFFER(ssl->decrypt.nonce, ssl->specs.iv_size);
            #endif
                WOLFSSL_MSG("Decrypted data");
                WOLFSSL_BUFFER(output, dataSz);
        #endif
        #ifdef WOLFSSL_CHECK_MEM_ZERO
            if ((ssl->specs.bulk_cipher_algorithm != wolfssl_cipher_null) &&
                    (ret == 0)) {
                wc_MemZero_Add("TLS 1.3 Decrypted data", output, sz);
            }
        #endif

        #ifdef CIPHER_NONCE
            ForceZero(ssl->decrypt.nonce, ssl->specs.iv_size);
        #endif

            break;
        }

       default:
            break;
    }

    if (ret < 0) {
        WOLFSSL_ERROR_VERBOSE(ret);
    }

    return ret;
}

/* Build SSL Message, encrypted.
 * TLS v1.3 encryption is AEAD only.
 *
 * ssl         The SSL/TLS object.
 * output      The buffer to write record message to.
 * outSz       Size of the buffer being written into.
 * input       The record data to encrypt (excluding record header).
 * inSz        The size of the record data.
 * type        The recorder header content type.
 * hashOutput  Whether to hash the unencrypted record data.
 * sizeOnly    Only want the size of the record message.
 * asyncOkay   If non-zero can return WC_PENDING_E, otherwise blocks on crypto
 * returns the size of the encrypted record message or negative value on error.
 */
int BuildTls13Message(WOLFSSL* ssl, byte* output, int outSz, const byte* input,
                int inSz, int type, int hashOutput, int sizeOnly, int asyncOkay)
{
    int ret;
    BuildMsgArgs* args;
    BuildMsgArgs  lcl_args;

    WOLFSSL_ENTER("BuildTls13Message");

    if (ssl == NULL) {
        return BAD_FUNC_ARG;
    }

#ifdef WOLFSSL_ASYNC_CRYPT
    ret = WC_NO_PENDING_E;
    if (asyncOkay) {
        if (ssl->async == NULL) {
            ssl->async = (struct WOLFSSL_ASYNC*)
                    XMALLOC(sizeof(struct WOLFSSL_ASYNC), ssl->heap,
                            DYNAMIC_TYPE_ASYNC);
            if (ssl->async == NULL)
                return MEMORY_E;
            XMEMSET(ssl->async, 0, sizeof(struct WOLFSSL_ASYNC));
        }
        /* Not ssl->async->args: that buffer belongs to the handler that
         * called down into the record builder. */
        args = &ssl->async->buildArgs;

        ret = wolfSSL_AsyncPop(ssl, &ssl->options.buildMsgState);
        if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
            /* Check for error */
            if (ret < 0)
                goto exit_buildmsg;
        }
    }
    else
#endif
    {
        args = &lcl_args;
    }

    /* buildArgs13Set, not the pop result, marks a resume: the handler
     * already popped the pending, and resetting on the pop result would
     * rebuild a half-built record (transcript/sequence advance twice). */
#ifdef WOLFSSL_ASYNC_CRYPT
    if (!asyncOkay || !ssl->options.buildArgs13Set)
#endif
    {
        /* Note: these hit ssl->options even for a sizeOnly probe, where every
         * other result goes to lcl_args, so a probe destroys the resume point
         * of a suspended asynchronous build. wolfssl_local_GetRecordSize() is
         * the only sizeOnly caller and restores them; a new one must too. */
        ret = 0;
        ssl->options.buildMsgState = BUILD_MSG_BEGIN;
        /* A fresh record must not inherit a suspended build's mid-way
         * cipher state. Not for sizeOnly probes: GetRecordSize() does not
         * save this field and rewinding would re-run the AEAD. */
        if (!sizeOnly)
            ssl->encrypt.state = CIPHER_STATE_BEGIN;
        XMEMSET(args, 0, sizeof(BuildMsgArgs));

        args->headerSz = RECORD_HEADER_SZ;
#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls)
            args->headerSz = Dtls13GetRlHeaderLength(ssl, 1);
#endif /* WOLFSSL_DTLS13 */

        args->sz = args->headerSz + (word32)inSz;
        args->idx  = args->headerSz;
    }

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ret == WC_NO_ERR_TRACE(WC_NO_PENDING_E))
        ret = 0;
#endif

    switch (ssl->options.buildMsgState) {
        case BUILD_MSG_BEGIN:
        {
           /* catch mistaken sizeOnly parameter */
            if (sizeOnly) {
                if (output || input) {
                    WOLFSSL_MSG("BuildTls13Message with sizeOnly "
                                "doesn't need input or output");
                    return BAD_FUNC_ARG;
                }
            }
            else if (output == NULL || input == NULL) {
                return BAD_FUNC_ARG;
            }

            /* Record layer content type at the end of record data. */
            args->sz++;
            /* Authentication data at the end. */
            args->sz += ssl->specs.aead_mac_size;
#ifdef WOLFSSL_DTLS13
            /* Pad to minimum length */
            if (ssl->options.dtls &&
                    args->sz < (word32)Dtls13MinimumRecordLength(ssl)) {
                args->pad = Dtls13MinimumRecordLength(ssl) - args->sz;
                args->sz = Dtls13MinimumRecordLength(ssl);
            }
#endif
            if (sizeOnly)
                return (int)args->sz;

            if (args->sz > (word32)outSz) {
                WOLFSSL_MSG("Oops, want to write past output buffer size");
                return BUFFER_E;
            }

            /* Record data length. */
            args->size = (word16)(args->sz - args->headerSz);
            /* Write/update the record header with the new size.
             * Always have the content type as application data for encrypted
             * messages in TLS v1.3.
             */

            if (ssl->options.dtls) {
#ifdef WOLFSSL_DTLS13
                Dtls13RlAddCiphertextHeader(ssl, output, args->size);
#endif /* WOLFSSL_DTLS13 */
            }
            else {
                AddTls13RecordHeader(output, args->size, application_data, ssl);
            }

            /* TLS v1.3 can do in place encryption. */
            if (input != output + args->idx)
                XMEMCPY(output + args->idx, input, (size_t)inSz);
            args->idx += (word32)inSz;

    #ifdef WOLFSSL_ASYNC_CRYPT
            /* Set only after the argument checks above cannot return any
             * more: an early error return must not leave the resume marker
             * set, or the next build would reuse stale args. */
            if (asyncOkay)
                ssl->options.buildArgs13Set = 1;
    #endif
            ssl->options.buildMsgState = BUILD_MSG_HASH;
        }
        FALL_THROUGH;

        case BUILD_MSG_HASH:
        {
            if (hashOutput) {
                ret = HashOutput(ssl, output, (int)args->headerSz + inSz, 0);
                if (ret != 0)
                    goto exit_buildmsg;
            }

            /* The real record content type goes at the end of the data. */
            output[args->idx++] = (byte)type;
            /* Double check that any necessary padding is zero'd out */
            XMEMSET(output + args->idx, 0, args->pad);
            args->idx += args->pad;

            ssl->options.buildMsgState = BUILD_MSG_ENCRYPT;
        }
        FALL_THROUGH;

        case BUILD_MSG_ENCRYPT:
        {
#ifdef WOLFSSL_QUIC
            if (WOLFSSL_IS_QUIC(ssl)) {
                /* QUIC does not use encryption of the TLS Record Layer.
                 * Return the original length + added headers
                 * and restore it in the record header. */
                AddTls13RecordHeader(output, (word32)inSz, (byte)type, ssl);
                ret = (int)args->headerSz + inSz;
                goto exit_buildmsg;
            }
#endif
        #ifdef ATOMIC_USER
            if (ssl->ctx->MacEncryptCb) {
                /* User Record Layer Callback handling */
                byte* mac = output + args->idx;
                output += args->headerSz;

                ret = ssl->ctx->MacEncryptCb(ssl, mac, output, (unsigned int)inSz, (byte)type, 0,
                        output, output, args->size, ssl->MacEncryptCtx);
            }
            else
        #endif
            {
                const byte* aad = output;
                output += args->headerSz;
                ret = EncryptTls13(ssl, output, output, args->size, aad,
                                   (word16)args->headerSz, asyncOkay);
            #ifdef WOLFSSL_ASYNC_REINVOKE
                /* Non-resumable caller (alerts): finish the encryption by
                 * re-invoking; devices were already waited on above. */
                if (!asyncOkay) {
                    int reinvoke = 0;

                    while (ret == WC_NO_ERR_TRACE(WC_PENDING_E) &&
                            reinvoke++ < WOLFSSL_ASYNC_MAX_REINVOKE) {
                        ret = EncryptTls13(ssl, output, output, args->size,
                                           aad, (word16)args->headerSz,
                                           asyncOkay);
                    }
                    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
                        /* A device that never completes would otherwise spin
                         * here forever, which is what wc_AsyncWait() used to
                         * do. Report it instead. */
                        WOLFSSL_MSG("Crypto callback still pending after "
                                    "retry limit on a blocking record");
                        ret = WC_HW_WAIT_E;
                    }
                }
            #endif
                if (ret != 0) {
                #ifdef WOLFSSL_ASYNC_CRYPT
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                #endif
                    {
                        /* Zeroize plaintext. */
                        ForceZero(output, args->size);
                    }
                }
#ifdef WOLFSSL_DTLS13
                if (ret == 0 && ssl->options.dtls) {
                    /* AAD points to the header. Reuse the variable  */
                    ret = Dtls13EncryptRecordNumber(ssl, (byte*)aad,
                                                    (word16)args->sz);
                }
#endif /* WOLFSSL_DTLS13 */
            }
            break;
        }

        default:
            break;
    }

exit_buildmsg:

    WOLFSSL_LEAVE("BuildTls13Message", ret);

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
        return ret;
    }
#endif

    /* make sure build message state is reset */
    ssl->options.buildMsgState = BUILD_MSG_BEGIN;

    /* return sz on success */
    if (ret == 0) {
        ret = (int)args->sz;
    }
    else {
        WOLFSSL_ERROR_VERBOSE(ret);
    }

    /* Final cleanup */
#ifdef WOLFSSL_ASYNC_CRYPT
    if (asyncOkay)
        ssl->options.buildArgs13Set = 0;
#endif

    return ret;
}

#if !defined(NO_WOLFSSL_CLIENT) || (!defined(NO_WOLFSSL_SERVER) && \
    (defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)) && \
    (defined(WOLFSSL_PSK_ONE_ID) || defined(WOLFSSL_PRIORITIZE_PSK)))
/* Find the cipher suite in the suites set in the SSL.
 *
 * ssl    SSL/TLS object.
 * suite  Cipher suite to look for.
 * returns 1 when suite is found in SSL/TLS object's list and 0 otherwise.
 */
int FindSuiteSSL(const WOLFSSL* ssl, byte* suite)
{
    word16 i;
    const Suites* suites = WOLFSSL_SUITES(ssl);

    for (i = 0; i < suites->suiteSz; i += 2) {
        if (suites->suites[i+0] == suite[0] &&
                suites->suites[i+1] == suite[1]) {
            return 1;
        }
    }

    return 0;
}
#endif

#ifndef NO_PSK
/* Get the MAC algorithm for the TLS 1.3 cipher suite.
 *
 * @param [in] suite.
 * @return  A value from wc_MACAlgorithm enumeration.
 */
byte SuiteMac(const byte* suite)
{
    byte mac = no_mac;

    if (suite[0] == TLS13_BYTE) {
        switch (suite[1]) {
        #ifdef BUILD_TLS_AES_128_GCM_SHA256
            case TLS_AES_128_GCM_SHA256:
                mac = sha256_mac;
                break;
        #endif
        #ifdef BUILD_TLS_CHACHA20_POLY1305_SHA256
            case TLS_CHACHA20_POLY1305_SHA256:
                mac = sha256_mac;
                break;
        #endif
        #ifdef BUILD_TLS_AES_128_CCM_SHA256
            case TLS_AES_128_CCM_SHA256:
                mac = sha256_mac;
                break;
        #endif
        #ifdef BUILD_TLS_AES_128_CCM_8_SHA256
            case TLS_AES_128_CCM_8_SHA256:
                mac = sha256_mac;
                break;
        #endif
        #ifdef BUILD_TLS_AES_256_GCM_SHA384
            case TLS_AES_256_GCM_SHA384:
                mac = sha384_mac;
                break;
        #endif
            default:
                break;
        }
    }
#if (defined(WOLFSSL_SM4_GCM) || defined(WOLFSSL_SM4_CCM)) && \
     defined(WOLFSSL_SM3)
    else if (suite[0] == CIPHER_BYTE) {
        switch (suite[1]) {
        #ifdef BUILD_TLS_SM4_GCM_SM3
            case TLS_SM4_GCM_SM3:
                mac = sm3_mac;
                break;
        #endif
        #ifdef BUILD_TLS_SM4_CCM_SM3
            case TLS_SM4_CCM_SM3:
                mac = sm3_mac;
                break;
        #endif
            default:
                break;
        }
    }
#endif
#ifdef HAVE_NULL_CIPHER
    else if (suite[0] == ECC_BYTE) {
        switch (suite[1]) {
        #ifdef BUILD_TLS_SHA256_SHA256
            case TLS_SHA256_SHA256:
                mac = sha256_mac;
                break;
        #endif
        #ifdef BUILD_TLS_SHA384_SHA384
            case TLS_SHA384_SHA384:
                mac = sha384_mac;
                break;
        #endif
            default:
                break;
        }
    }
#endif

    return mac;
}
#endif

#if defined(WOLFSSL_SEND_HRR_COOKIE) && !defined(NO_WOLFSSL_SERVER)
/* Create Cookie extension using the hash of the first ClientHello.
 *
 * ssl     SSL/TLS object.
 * hash    The hash data.
 * hashSz  The size of the hash data in bytes.
 * returns 0 on success, otherwise failure.
 */
int CreateCookieExt(const WOLFSSL* ssl, byte* hash, word16 hashSz,
                    TLSX** exts, byte cipherSuite0, byte cipherSuite)
{
    int  ret;
    byte mac[WC_MAX_DIGEST_SIZE] = {0};
    WC_DECLARE_VAR(cookieHmac, Hmac, 1, ssl->heap);
    byte cookieType = 0;
    byte macSz = 0;
    byte cookie[OPAQUE8_LEN + WC_MAX_DIGEST_SIZE + OPAQUE16_LEN * 2];
    TLSX* ext;
    word16 cookieSz = 0;

    if (hash == NULL || hashSz == 0) {
        return BAD_FUNC_ARG;
    }

    if (ssl->buffers.tls13CookieSecret.buffer == NULL ||
            ssl->buffers.tls13CookieSecret.length == 0) {
        WOLFSSL_MSG("Missing DTLS 1.3 cookie secret");
        return COOKIE_ERROR;
    }

    /* Cookie Data = Hash Len | Hash | CS | KeyShare Group */
    cookie[cookieSz++] = (byte)hashSz;
    XMEMCPY(cookie + cookieSz, hash, hashSz);
    cookieSz += hashSz;
    cookie[cookieSz++] = cipherSuite0;
    cookie[cookieSz++] = cipherSuite;
    if ((ext = TLSX_Find(*exts, TLSX_KEY_SHARE)) != NULL) {
        KeyShareEntry* kse = (KeyShareEntry*)ext->data;
        if (kse == NULL) {
            WOLFSSL_MSG("KeyShareEntry can't be empty when negotiating "
                        "parameters");
            return BAD_STATE_E;
        }
        c16toa(kse->group, cookie + cookieSz);
        cookieSz += OPAQUE16_LEN;
    }

#ifndef NO_SHA256
    cookieType = WC_SHA256;
    macSz = WC_SHA256_DIGEST_SIZE;
#elif defined(WOLFSSL_SHA384)
    cookieType = WC_SHA384;
    macSz = WC_SHA384_DIGEST_SIZE;
#elif defined(WOLFSSL_TLS13_SHA512)
    cookieType = WC_SHA512;
    macSz = WC_SHA512_DIGEST_SIZE;
#elif defined(WOLFSSL_SM3)
    cookieType = WC_SM3;
    macSz = WC_SM3_DIGEST_SIZE;
#else
    #error "No digest to available to use with HMAC for cookies."
#endif /* NO_SHA */

    WC_ALLOC_VAR_EX(cookieHmac, Hmac, 1, ssl->heap, DYNAMIC_TYPE_HMAC,
                    return MEMORY_E);

    ret = wc_HmacInit(cookieHmac, ssl->heap, ssl->devId);
    if (ret == 0) {
        ret = wc_HmacSetKey(cookieHmac, cookieType,
                            ssl->buffers.tls13CookieSecret.buffer,
                            ssl->buffers.tls13CookieSecret.length);
    }
    if (ret == 0)
        ret = wc_HmacUpdate(cookieHmac, cookie, cookieSz);
#ifdef WOLFSSL_DTLS13
    /* Tie cookie to peer address */
    if (ret == 0) {
        /* peerLock not necessary. Still in handshake phase. */
        if (ssl->options.dtls && ssl->buffers.dtlsCtx.peer.sz > 0) {
            ret = wc_HmacUpdate(cookieHmac,
                (byte*)ssl->buffers.dtlsCtx.peer.sa,
                ssl->buffers.dtlsCtx.peer.sz);
        }
    }
#endif
    if (ret == 0)
        ret = wc_HmacFinal(cookieHmac, mac);

    wc_HmacFree(cookieHmac);
    WC_FREE_VAR_EX(cookieHmac, ssl->heap, DYNAMIC_TYPE_HMAC);
    if (ret != 0)
        return ret;

    /* The cookie data is the hash and the integrity check. */
    return TLSX_Cookie_Use(ssl, cookie, cookieSz, mac, macSz, 1, exts);
}
#endif

#ifdef WOLFSSL_DTLS13
#define HRR_MAX_HS_HEADER_SZ DTLS_HANDSHAKE_HEADER_SZ
#else
#define HRR_MAX_HS_HEADER_SZ HANDSHAKE_HEADER_SZ
#endif /* WOLFSSL_DTLS13 */

static int CreateCookie(const WOLFSSL* ssl, byte** hash, byte* hashSz,
                            Hashes* hashes, TLSX** exts)
{
    int    ret = 0;

    (void)exts;

    *hash = NULL;
    switch (ssl->specs.mac_algorithm) {
    #ifndef NO_SHA256
        case sha256_mac:
            *hash = hashes->sha256;
            break;
    #endif
    #ifdef WOLFSSL_SHA384
        case sha384_mac:
            *hash = hashes->sha384;
            break;
    #endif
    #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            *hash = hashes->sha512;
            break;
    #endif
    #ifdef WOLFSSL_SM3
        case sm3_mac:
            *hash = hashes->sm3;
            break;
    #endif
    }
    *hashSz = ssl->specs.hash_size;

    /* check hash */
    if (*hash == NULL && *hashSz > 0)
        return BAD_FUNC_ARG;

#if defined(WOLFSSL_SEND_HRR_COOKIE) && !defined(NO_WOLFSSL_SERVER)
    if (ssl->options.sendCookie && ssl->options.side == WOLFSSL_SERVER_END)
        ret = CreateCookieExt(ssl, *hash, *hashSz, exts,
                ssl->options.cipherSuite0, ssl->options.cipherSuite);
#endif
    return ret;
}

/* Restart the handshake hash with a hash of the previous messages.
 *
 * ssl The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
int RestartHandshakeHash(WOLFSSL* ssl)
{
    int    ret;
    byte   header[HANDSHAKE_HEADER_SZ] = {0};
    Hashes hashes;
    byte*  hash = NULL;
    byte   hashSz = 0;

    ret = BuildCertHashes(ssl, &hashes);
    if (ret != 0)
        return ret;
    ret = CreateCookie(ssl, &hash, &hashSz, &hashes, &ssl->extensions);
    if (ret != 0)
        return ret;
#if defined(WOLFSSL_SEND_HRR_COOKIE) && !defined(NO_WOLFSSL_SERVER)
    if (ssl->options.sendCookie && ssl->options.side == WOLFSSL_SERVER_END)
        return 0;
#endif

    AddTls13HandShakeHeader(header, hashSz, 0, 0, message_hash, ssl);

#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("Restart Hash");
    WOLFSSL_BUFFER(hash, hashSz);
#endif

    ret = InitHandshakeHashes(ssl);
    if (ret != 0)
        return ret;
    ret = HashRaw(ssl, header, sizeof(header));
    if (ret != 0)
        return ret;
    return HashRaw(ssl, hash, hashSz);
}

#if !defined(NO_WOLFSSL_CLIENT) || !defined(NO_WOLFSSL_SERVER)
/* The value in the random field of a ServerHello to indicate
 * HelloRetryRequest.
 */
static byte helloRetryRequestRandom[] = {
    0xCF, 0x21, 0xAD, 0x74, 0xE5, 0x9A, 0x61, 0x11,
    0xBE, 0x1D, 0x8C, 0x02, 0x1E, 0x65, 0xB8, 0x91,
    0xC2, 0xA2, 0x11, 0x16, 0x7A, 0xBB, 0x8C, 0x5E,
    0x07, 0x9E, 0x09, 0xE2, 0xC8, 0xA8, 0x33, 0x9C
};
#endif

#ifdef HAVE_ECH
/* returns the index of the first supported cipher suite, -1 if none */
int EchConfigGetSupportedCipherSuite(WOLFSSL_EchConfig* config)
{
    int i = 0;

    if (!wc_HpkeKemIsSupported(config->kemId)) {
        WOLFSSL_MSG("ECH config: KEM not supported");
        return WOLFSSL_FATAL_ERROR;
    }

    for (i = 0; i < config->numCipherSuites; i++) {
        if (wc_HpkeKdfIsSupported(config->cipherSuites[i].kdfId) &&
                wc_HpkeAeadIsSupported(config->cipherSuites[i].aeadId)) {
            return i;
        }
    }

    WOLFSSL_MSG("ECH config: KDF or AEAD not supported");
    return WOLFSSL_FATAL_ERROR;
}

/* Hash the inner client hello, initializing the hsHashesEch field if needed.
 * This should receive the client hello without outer_extensions 'encoding'
 *
 * ssl      SSL/TLS object.
 * ech      ECH object.
 * returns 0 on success and otherwise failure.
 */
static int EchHashHelloInner(WOLFSSL* ssl, WOLFSSL_ECH* ech)
{
    int ret = 0;
    int headerSz;
    word32 realSz;
    HS_Hashes* tmpHashes;
#ifndef NO_WOLFSSL_CLIENT
    byte falseHeader[HRR_MAX_HS_HEADER_SZ];
#endif

    if (ssl == NULL || ech == NULL) {
        return BAD_FUNC_ARG;
    }

#ifdef WOLFSSL_DTLS13
    headerSz = ssl->options.dtls ? DTLS13_HANDSHAKE_HEADER_SZ :
                                   HANDSHAKE_HEADER_SZ;
#else
    headerSz = HANDSHAKE_HEADER_SZ;
#endif

    realSz = ech->innerClientHelloLen;

    tmpHashes = ssl->hsHashes;

    ssl->hsHashes = ssl->hsHashesEch;
    if (ssl->hsHashes == NULL) {
        ret = InitHandshakeHashes(ssl);
        if (ret == 0) {
            ssl->hsHashesEch = ssl->hsHashes;
        }
    }

    if (ret == 0) {
#ifndef NO_WOLFSSL_CLIENT
        if (ssl->options.side == WOLFSSL_CLIENT_END) {
            /* client-side: innerClientHello contains body only */
            AddTls13HandShakeHeader(falseHeader, realSz, 0, 0, client_hello,
                                    ssl);
            ret = HashRaw(ssl, falseHeader, headerSz);
            if (ret == 0) {
                ret = HashRaw(ssl, ech->innerClientHello, realSz);
            }
        }
#endif
#ifndef NO_WOLFSSL_SERVER
        if (ssl->options.side == WOLFSSL_SERVER_END) {
            /* server-side: innerClientHello contains header + body */
            ret = HashRaw(ssl, ech->innerClientHello, headerSz + realSz);
        }
#endif
    }

    ssl->hsHashes = tmpHashes;
    return ret;
}

/* Calculate the 8 ECH confirmation bytes.
 *
 * ssl            SSL/TLS object.
 * label          Ascii string describing ECH acceptance or rejection.
 * labelSz        Length of label excluding NULL character.
 * input          The buffer to calculate confirmation off of.
 * acceptOffset   Where the 8 ECH confirmation bytes start.
 * helloSz        Size of hello message.
 * isHrr          Whether message is a HelloRetryRequest or not.
 * acceptExpanded An 8 byte array to store calculated confirmation to.
 * returns 0 on success and otherwise failure.
 */
static int EchCalcAcceptance(WOLFSSL* ssl, byte* label, word16 labelSz,
    const byte* input, int acceptOffset, int helloSz, byte isHrr,
    byte* acceptExpanded)
{
    int ret = 0;
    int digestType = 0;
    int digestSize = 0;
    int hashSz = 0;
    int headerSz;
    HS_Hashes* tmpHashes;
    HS_Hashes* acceptHash = NULL;
    byte zeros[WC_MAX_DIGEST_SIZE];
    byte transcriptEchConf[WC_MAX_DIGEST_SIZE];
    byte clientHelloInnerHash[WC_MAX_DIGEST_SIZE];
    byte expandLabelPrk[WC_MAX_DIGEST_SIZE];
    byte messageHashHeader[HRR_MAX_HS_HEADER_SZ];

    XMEMSET(zeros, 0, sizeof(zeros));
    XMEMSET(transcriptEchConf, 0, sizeof(transcriptEchConf));
    XMEMSET(clientHelloInnerHash, 0, sizeof(clientHelloInnerHash));
    XMEMSET(expandLabelPrk, 0, sizeof(expandLabelPrk));

#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Add("ECH PRK", expandLabelPrk, sizeof(expandLabelPrk));
#endif

    tmpHashes = ssl->hsHashes;
    ssl->hsHashes = ssl->hsHashesEch;

#ifdef WOLFSSL_DTLS13
    headerSz = ssl->options.dtls ? DTLS13_HANDSHAKE_HEADER_SZ :
                                   HANDSHAKE_HEADER_SZ;
#else
    headerSz = HANDSHAKE_HEADER_SZ;
#endif

    if (isHrr) {
        /* the transcript hash of ClientHelloInner1 */
        ret = GetMsgHash(ssl, clientHelloInnerHash);
        if (ret > 0) {
            hashSz = ret;
            ret = 0;
        }
        else if (ret == 0) {
            ret = HASH_TYPE_E;
        }

        /* restart ECH transcript hash, similar to RestartHandshakeHash but
         * don't add a cookie */
        if (ret == 0) {
            ret = InitHandshakeHashes(ssl);
            ssl->hsHashesEch = ssl->hsHashes;
        }
        if (ret == 0) {
            AddTls13HandShakeHeader(messageHashHeader, (word32)hashSz, 0, 0,
                message_hash, ssl);
            ret = HashRaw(ssl, messageHashHeader, headerSz);
        }
        if (ret == 0) {
            ret = HashRaw(ssl, clientHelloInnerHash, (word32)hashSz);
        }
    }

    /* hash with zeros for confirmation computation */
    if (ret == 0) {
        ret = InitHandshakeHashesAndCopy(ssl, ssl->hsHashesEch, &acceptHash);
    }
    if (ret == 0) {
        ssl->hsHashes = acceptHash;
        ret = HashRaw(ssl, input, acceptOffset);
    }
    if (ret == 0) {
        ret = HashRaw(ssl, zeros, ECH_ACCEPT_CONFIRMATION_SZ);
    }
    if (ret == 0) {
        ret = HashRaw(ssl, input + acceptOffset + ECH_ACCEPT_CONFIRMATION_SZ,
            helloSz + headerSz - (acceptOffset + ECH_ACCEPT_CONFIRMATION_SZ));
    }

    /* get the modified transcript hash */
    if (ret == 0) {
        ret = GetMsgHash(ssl, transcriptEchConf);
        if (ret > 0) {
            ret = 0;
        }
        else if (ret == 0) {
            ret = HASH_TYPE_E;
        }
    }

    /* pick the right type and size based on mac_algorithm */
    if (ret == 0) {
        switch (ssl->specs.mac_algorithm) {
#ifndef NO_SHA256
            case sha256_mac:
                digestType = WC_SHA256;
                digestSize = WC_SHA256_DIGEST_SIZE;
                break;
#endif /* !NO_SHA256 */
#ifdef WOLFSSL_SHA384
            case sha384_mac:
                digestType = WC_SHA384;
                digestSize = WC_SHA384_DIGEST_SIZE;
                break;
#endif /* WOLFSSL_SHA384 */
#ifdef WOLFSSL_TLS13_SHA512
            case sha512_mac:
                digestType = WC_SHA512;
                digestSize = WC_SHA512_DIGEST_SIZE;
                break;
#endif /* WOLFSSL_TLS13_SHA512 */
#ifdef WOLFSSL_SM3
            case sm3_mac:
                digestType = WC_SM3;
                digestSize = WC_SM3_DIGEST_SIZE;
                break;
#endif /* WOLFSSL_SM3 */
            default:
                ret = WOLFSSL_FATAL_ERROR;
                break;
        }
    }

    /* extract clientRandomInner with a key of all zeros */
    if (ret == 0) {
        PRIVATE_KEY_UNLOCK();
    #if !defined(HAVE_FIPS) || \
        (defined(FIPS_VERSION_GE) && FIPS_VERSION_GE(6,0))
        ret = wc_HKDF_Extract_ex(digestType, zeros, (word32)digestSize,
            ssl->arrays->clientRandomInner, RAN_LEN, expandLabelPrk,
            ssl->heap, ssl->devId);
    #else
        ret = wc_HKDF_Extract(digestType, zeros, digestSize,
            ssl->arrays->clientRandomInner, RAN_LEN, expandLabelPrk);
    #endif
        PRIVATE_KEY_LOCK();
    }

    /* tls expand with the confirmation label */
    if (ret == 0) {
        PRIVATE_KEY_UNLOCK();
#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls) {
            ret = Tls13HKDFExpandKeyLabel(ssl, acceptExpanded,
                ECH_ACCEPT_CONFIRMATION_SZ, expandLabelPrk, (word32)digestSize,
                dtls13ProtocolLabel, DTLS13_PROTOCOL_LABEL_SZ, label, labelSz,
                transcriptEchConf, (word32)digestSize, digestType,
                WOLFSSL_SERVER_END);
        }
        else
#endif
        {
            ret = Tls13HKDFExpandKeyLabel(ssl, acceptExpanded,
                ECH_ACCEPT_CONFIRMATION_SZ, expandLabelPrk, (word32)digestSize,
                tls13ProtocolLabel, TLS13_PROTOCOL_LABEL_SZ, label, labelSz,
                transcriptEchConf, (word32)digestSize, digestType,
                WOLFSSL_SERVER_END);
        }
        PRIVATE_KEY_LOCK();
    }

    if (acceptHash != NULL) {
        ssl->hsHashes = acceptHash;
        FreeHandshakeHashes(ssl);
    }

    ssl->hsHashes = tmpHashes;
    ForceZero(expandLabelPrk, sizeof(expandLabelPrk));
#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Check(expandLabelPrk, sizeof(expandLabelPrk));
#endif
    return ret;
}
#endif

#if !defined(NO_CERTS) && !defined(WOLFSSL_NO_SIGALG) && \
    (!defined(NO_WOLFSSL_CLIENT) || !defined(NO_WOLFSSL_SERVER))
/* Record whether the peer's advertised algorithms permit SHA-1 signed
 * certificates.
 *
 * RFC 8446 Section 4.2.3 has signature_algorithms cover certificate signatures
 * when signature_algorithms_cert is absent.
 *
 * ssl         The SSL/TLS object.
 * peerSuites  The peer's signature_algorithms list.
 */
static void SetPeerSha1CertOk(WOLFSSL* ssl, const Suites* peerSuites)
{
    const byte* list = NULL;
    word16      listSz = 0;
    word16      i;

    ssl->options.peerSha1CertOk = 0;

    if (ssl->certHashSigAlgoSz > 0) {
        list = ssl->certHashSigAlgo;
        listSz = ssl->certHashSigAlgoSz;
    }
    else if (peerSuites != NULL) {
        list = peerSuites->hashSigAlgo;
        listSz = peerSuites->hashSigAlgoSz;
    }
    else {
        return;
    }

    for (i = 0; i + 2 <= listSz; i += 2) {
        /* Only rsa_pkcs1_sha1, dsa_sha1 and ecdsa_sha1 carry sha_mac as the
         * first byte of the signature scheme. */
        if (list[i] == sha_mac) {
            ssl->options.peerSha1CertOk = 1;
            break;
        }
    }
}
#endif /* !NO_CERTS && !WOLFSSL_NO_SIGALG && (client || server) */

#ifndef NO_WOLFSSL_CLIENT
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
#if defined(OPENSSL_EXTRA) && !defined(WOLFSSL_PSK_ONE_ID) && \
    !defined(NO_PSK)
/**
* convert mac algorithm to WOLFSSL_EVP_MD
* @param mac_alg mac algorithm
* @return const WOLFSSL_EVP_MD on successful, otherwise NULL
*/
static const WOLFSSL_EVP_MD* ssl_handshake_md(const byte mac_alg)
{
    switch(mac_alg) {
        case no_mac:
            return NULL;
    #ifndef NO_MD5
        case md5_mac:
            return wolfSSL_EVP_md5();
    #endif
    #ifndef NO_SHA
        case sha_mac:
            return wolfSSL_EVP_sha1();
    #endif
    #ifdef WOLFSSL_SHA224
        case sha224_mac:
            return wolfSSL_EVP_sha224();
    #endif
        case sha256_mac:
            return wolfSSL_EVP_sha256();
    #ifdef WOLFSSL_SHA384
        case sha384_mac:
            return wolfSSL_EVP_sha384();
    #endif
    #ifdef WOLFSSL_SHA512
        case sha512_mac:
            return wolfSSL_EVP_sha512();
    #endif
        case rmd_mac:
        case blake2b_mac:
            WOLFSSL_MSG("no suitable EVP_MD");
            return NULL;
        default:
            WOLFSSL_MSG("Unknown mac algorithm");
            return NULL;
    }
}
#endif
/* Setup pre-shared key based on the details in the extension data.
 *
 * ssl          SSL/TLS object.
 * psk          Pre-shared key extension data.
 * clientHello  Whether called from client_hello construction.
 * returns 0 on success, PSK_KEY_ERROR when the client PSK callback fails and
 * other negative value on failure.
 */
static int SetupPskKey(WOLFSSL* ssl, PreSharedKey* psk, int clientHello)
{
#if defined(HAVE_SESSION_TICKET) || !defined(WOLFSSL_PSK_ONE_ID)
    int ret;
#endif
    byte suite[2];

    if (psk == NULL)
        return BAD_FUNC_ARG;

    if (!HaveUniqueSessionObj(ssl)) {
        WOLFSSL_MSG("Unable to have unique session object");
        WOLFSSL_ERROR_VERBOSE(MEMORY_ERROR);
        return MEMORY_ERROR;
    }

    suite[0] = ssl->options.cipherSuite0;
    suite[1] = ssl->options.cipherSuite;

#ifdef HAVE_SESSION_TICKET
    if (psk->resumption) {
        if (clientHello) {
            suite[0] = psk->cipherSuite0;
            suite[1] = psk->cipherSuite;

            /* Ensure cipher suite is supported or changed suite to one with
             * the same MAC algorithm. */
            if (!FindSuiteSSL(ssl, suite)) {
                WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                return PSK_KEY_ERROR;
            }

            ssl->options.cipherSuite0 = suite[0];
            ssl->options.cipherSuite = suite[1];

            /* Setting mac for binder and keys for deriving EarlyData. */
            ret = SetCipherSpecs(ssl);
            if (ret != 0)
                return ret;
        }

    #ifdef WOLFSSL_EARLY_DATA
        if (ssl->session->maxEarlyDataSz == 0)
            ssl->earlyData = no_early_data;
    #endif
        /* Resumption PSK is master secret. */
        ssl->arrays->psk_keySz = ssl->specs.hash_size;
        if ((ret = DeriveResumptionPSK(ssl, ssl->session->ticketNonce.data,
                   ssl->session->ticketNonce.len, ssl->arrays->psk_key)) != 0) {
            return ret;
        }
        if (!clientHello) {
            /* CLIENT: using secret in ticket for peer authentication. */
            ssl->options.peerAuthGood = 1;
        }
    }
#endif
#ifndef NO_PSK
    if (!psk->resumption) {
        /* Get the pre-shared key. */
#ifndef WOLFSSL_PSK_ONE_ID
        const char* cipherName = NULL;
    #ifdef OPENSSL_EXTRA
        WOLFSSL_SESSION* psksession = NULL;
    #endif

        /* Set the client identity to use. */
        if (psk->identityLen > MAX_PSK_ID_LEN)
            return PSK_KEY_ERROR;
        XMEMSET(ssl->arrays->client_identity, 0,
            sizeof(ssl->arrays->client_identity));
        XMEMCPY(ssl->arrays->client_identity, psk->identity, psk->identityLen);

    #ifdef WOLFSSL_DEBUG_TLS
        WOLFSSL_MSG("PSK cipher suite:");
        WOLFSSL_MSG(GetCipherNameInternal(psk->cipherSuite0, psk->cipherSuite));
    #endif

        /* Get the pre-shared key. */
    #ifdef OPENSSL_EXTRA
        if (ssl->options.session_psk_cb != NULL) {
            const unsigned char* id = NULL;
            size_t idlen = 0;
            const WOLFSSL_EVP_MD* handshake_md = NULL;

            if (ssl->msgsReceived.got_hello_retry_request >= 1) {
                handshake_md = ssl_handshake_md(ssl->specs.mac_algorithm);
            }
            /* OpenSSL compatible callback that gets cached session. */
            if (ssl->options.session_psk_cb(ssl, handshake_md, &id, &idlen,
                                                            &psksession) == 0) {
                wolfSSL_FreeSession(ssl->ctx, psksession);
                WOLFSSL_MSG("psk session callback failed");
                return PSK_KEY_ERROR;
            }
            if (psksession != NULL) {
                if (idlen > MAX_PSK_KEY_LEN) {
                    wolfSSL_FreeSession(ssl->ctx, psksession);
                    WOLFSSL_MSG("psk key length is too long");
                    WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                    return PSK_KEY_ERROR;
                }

                ssl->arrays->psk_keySz = (word32)idlen;
                XMEMCPY(ssl->arrays->psk_key, id, idlen);
                suite[0] = psksession->cipherSuite0;
                suite[1] = psksession->cipherSuite;
                /* Not needed anymore. */
                wolfSSL_FreeSession(ssl->ctx, psksession);
                /* Leave pointer not NULL to indicate success with callback. */
            }
        }
        if (psksession != NULL) {
            /* Don't try other callbacks - we have an answer. */
        }
        else
    #endif /* OPENSSL_EXTRA */
        if (ssl->options.client_psk_cs_cb != NULL) {
        #ifdef WOLFSSL_PSK_MULTI_ID_PER_CS
            ssl->arrays->client_identity[0] = 0;
        #endif
            /* Lookup key again for next identity. */
            ssl->arrays->psk_keySz = ssl->options.client_psk_cs_cb(
                ssl, ssl->arrays->server_hint,
                ssl->arrays->client_identity, MAX_PSK_ID_LEN,
                ssl->arrays->psk_key, MAX_PSK_KEY_LEN,
                GetCipherNameInternal(psk->cipherSuite0, psk->cipherSuite));
            if (clientHello) {
                /* Use PSK cipher suite. */
                ssl->options.cipherSuite0 = psk->cipherSuite0;
                ssl->options.cipherSuite  = psk->cipherSuite;
            }
            else {
                byte pskCS[2];
                pskCS[0] = psk->cipherSuite0;
                pskCS[1] = psk->cipherSuite;

                /* Ensure PSK and negotiated cipher suites have same hash. */
                if (SuiteMac(pskCS) != SuiteMac(suite)) {
                    WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                    return PSK_KEY_ERROR;
                }
                /* Negotiated cipher suite is to be used - update PSK. */
                psk->cipherSuite0 = suite[0];
                psk->cipherSuite  = suite[1];
            }
        }
        else if (ssl->options.client_psk_tls13_cb != NULL) {
            byte cipherSuite0;
            byte cipherSuite;
            int cipherSuiteFlags = WOLFSSL_CIPHER_SUITE_FLAG_NONE;

            ssl->arrays->psk_keySz = ssl->options.client_psk_tls13_cb(ssl,
                    ssl->arrays->server_hint, ssl->arrays->client_identity,
                    MAX_PSK_ID_LEN, ssl->arrays->psk_key, MAX_PSK_KEY_LEN,
                    &cipherName);
            if (GetCipherSuiteFromName(cipherName, &cipherSuite0,
                            &cipherSuite, NULL, NULL, &cipherSuiteFlags) != 0) {
                WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                return PSK_KEY_ERROR;
            }
            ssl->options.cipherSuite0 = cipherSuite0;
            ssl->options.cipherSuite  = cipherSuite;
            (void)cipherSuiteFlags;
        }
        else {
            ssl->arrays->psk_keySz = ssl->options.client_psk_cb(ssl,
                    ssl->arrays->server_hint, ssl->arrays->client_identity,
                    MAX_PSK_ID_LEN, ssl->arrays->psk_key, MAX_PSK_KEY_LEN);
            ssl->options.cipherSuite0 = TLS13_BYTE;
            ssl->options.cipherSuite  = WOLFSSL_DEF_PSK_CIPHER;
        }
        if (ssl->arrays->psk_keySz == 0 ||
                (ssl->arrays->psk_keySz > MAX_PSK_KEY_LEN &&
            (int)ssl->arrays->psk_keySz != WC_NO_ERR_TRACE(USE_HW_PSK))) {
            WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
            return PSK_KEY_ERROR;
        }

        ret = SetCipherSpecs(ssl);
        if (ret != 0)
            return ret;
#else
        /* PSK information loaded during setting of default TLS extensions. */
#endif /* !WOLFSSL_PSK_ONE_ID */

        if (!clientHello && (psk->cipherSuite0 != suite[0] ||
                             psk->cipherSuite  != suite[1])) {
            WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
            return PSK_KEY_ERROR;
        }

        if (!clientHello) {
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
            if (ssl->options.certWithExternPsk) {
                /* Certificate authentication is still required. */
                ssl->options.peerAuthGood = 0;
            }
            else
#endif
            {
                /* CLIENT: using PSK for peer authentication. */
                ssl->options.peerAuthGood = 1;
            }
        }
    }
#endif

#ifdef HAVE_SUPPORTED_CURVES
    if (!clientHello) {
        TLSX* ext;
        word32 modes;
        KeyShareEntry* kse = NULL;

        /* Get the PSK key exchange modes the client wants to negotiate. */
        ext = TLSX_Find(ssl->extensions, TLSX_PSK_KEY_EXCHANGE_MODES);
        if (ext == NULL) {
            WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
            return PSK_KEY_ERROR;
        }
        modes = ext->val;

        ext = TLSX_Find(ssl->extensions, TLSX_KEY_SHARE);
        if (ext != NULL) {
            kse = (KeyShareEntry*)ext->data;
        }
        /* Use (EC)DHE for forward-security if possible. */
        if (((modes & (1 << PSK_DHE_KE)) != 0) && (!ssl->options.noPskDheKe) &&
                                                (kse != NULL) && kse->derived) {
            if ((kse->session != 0) && (kse->session != kse->group)) {
                WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                return PSK_KEY_ERROR;
            }
        }
        else if (ssl->options.onlyPskDheKe ||
                 (ssl->options.failNoPSK && !psk->resumption)) {
            /* A mandatory external PSK (failNoPSK) must be combined with
             * (EC)DHE for forward secrecy, so reject a pure psk_ke
             * negotiation. Session-ticket resumption is exempt. */
            WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
            return PSK_KEY_ERROR;
        }
        else if (ssl->options.noPskDheKe) {
            ssl->arrays->preMasterSz = 0;
        }
    }
    else
#endif
    if (ssl->options.noPskDheKe) {
        ssl->arrays->preMasterSz = 0;
    }

    /* Derive the early secret using the PSK. */
    return DeriveEarlySecret(ssl);
}

/* Derive and write the binders into the ClientHello in space left when
 * writing the Pre-Shared Key extension.
 *
 * ssl     The SSL/TLS object.
 * output  The buffer containing the ClientHello.
 * idx     The index at the end of the completed ClientHello.
 * returns 0 on success and otherwise failure.
 */
static int WritePSKBinders(WOLFSSL* ssl, byte* output, word32 idx)
{
    int           ret;
    TLSX*         ext;
    PreSharedKey* current;
    byte          binderKey[WC_MAX_DIGEST_SIZE];
    word16        len;

    WOLFSSL_ENTER("WritePSKBinders");

    if (idx > WOLFSSL_MAX_16BIT) {
        return INPUT_SIZE_E;
    }

    ext = TLSX_Find(ssl->extensions, TLSX_PRE_SHARED_KEY);
    if (ext == NULL)
        return SANITY_MSG_E;

    /* Get the size of the binders to determine where to write binders. */
    ret = TLSX_PreSharedKey_GetSizeBinders((PreSharedKey*)ext->data,
                                                            client_hello, &len);
    if (ret < 0)
        return ret;
    idx -= len;

    /* Hash truncated ClientHello - up to binders. */
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        ret = Dtls13HashHandshake(ssl, output + Dtls13GetRlHeaderLength(ssl, 0),
                                 (word16)idx - Dtls13GetRlHeaderLength(ssl, 0));
    else
#endif /* WOLFSSL_DTLS13 */
        ret = HashOutput(ssl, output, (int)idx, 0);

    if (ret != 0)
        return ret;

    current = (PreSharedKey*)ext->data;
#ifdef WOLFSSL_CHECK_MEM_ZERO
    if (current != NULL) {
        wc_MemZero_Add("WritePSKBinders binderKey", binderKey,
            sizeof(binderKey));
    }
#endif
    /* Calculate the binder for each identity based on previous handshake data.
     */
    while (current != NULL) {
        if ((ret = SetupPskKey(ssl, current, 1)) != 0)
            break;

    #ifdef HAVE_SESSION_TICKET
        if (current->resumption)
            ret = DeriveBinderKeyResume(ssl, binderKey);
    #endif
    #ifndef NO_PSK
        if (!current->resumption)
            ret = DeriveBinderKey(ssl, binderKey);
    #endif
        if (ret != 0)
            break;

        /* Derive the Finished message secret. */
        ret = DeriveFinishedSecret(ssl, binderKey,
                                   ssl->keys.client_write_MAC_secret,
                                   0 /* neither end */);
        if (ret != 0)
            break;

        /* Build the HMAC of the handshake message data = binder. */
        ret = BuildTls13HandshakeHmac(ssl, ssl->keys.client_write_MAC_secret,
            current->binder, &current->binderLen);
        if (ret != 0)
            break;

        current = current->next;
    }

    ForceZero(binderKey, sizeof(binderKey));
#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Check(binderKey, sizeof(binderKey));
#endif
    if (ret != 0)
        return ret;

    /* Data entered into extension, now write to message. */
    ret = TLSX_PreSharedKey_WriteBinders((PreSharedKey*)ext->data, output + idx,
                                                            client_hello, &len);
    if (ret < 0)
        return ret;

    /* Hash binders to complete the hash of the ClientHello. */
    ret = HashRaw(ssl, output + idx, len);
    if (ret < 0)
        return ret;

    #ifdef WOLFSSL_EARLY_DATA
    if (ssl->earlyData != no_early_data) {
        if ((ret = SetupPskKey(ssl, (PreSharedKey*)ext->data, 1)) != 0)
            return ret;

        /* Derive early data encryption key. */
        ret = DeriveTls13Keys(ssl, early_data_key, ENCRYPT_SIDE_ONLY, 1);
        if (ret != 0)
            return ret;
        if ((ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY)) != 0)
            return ret;

    }
    #endif

    WOLFSSL_LEAVE("WritePSKBinders", ret);

    return ret;
}
#endif

static void GetTls13SessionId(WOLFSSL* ssl, byte* output, word32* idx)
{
    if (ssl->session->sessionIDSz > 0) {
        /* Session resumption for old versions of protocol. */
        if (ssl->session->sessionIDSz <= ID_LEN) {
            if (output != NULL)
                output[*idx] = ssl->session->sessionIDSz;
            (*idx)++;
            if (output != NULL) {
                XMEMCPY(output + *idx, ssl->session->sessionID,
                    ssl->session->sessionIDSz);
            }
            *idx += ssl->session->sessionIDSz;
        }
        else {
            /* Invalid session ID length. Reset it. */
            ssl->session->sessionIDSz = 0;
            if (output != NULL)
                output[*idx] = 0;
            (*idx)++;
        }
    }
    else {
    #ifdef WOLFSSL_TLS13_MIDDLEBOX_COMPAT
        if (ssl->options.tls13MiddleBoxCompat) {
            if (output != NULL)
                output[*idx] = ID_LEN;
            (*idx)++;
            if (output != NULL)
                XMEMCPY(output + *idx, ssl->arrays->clientRandom, ID_LEN);
            *idx += ID_LEN;
        }
        else
    #endif /* WOLFSSL_TLS13_MIDDLEBOX_COMPAT */
        {
            /* TLS v1.3 does not use session id - 0 length. */
            if (output != NULL)
                output[*idx] = 0;
            (*idx)++;
        }
    }
}

/* handle generation of TLS 1.3 client_hello (1) */
/* Send a ClientHello message to the server.
 * Include the information required to start a handshake with servers using
 * protocol versions less than TLS v1.3.
 * Only a client will send this message.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success and otherwise failure.
 */

typedef struct Sch13Args {
    byte*  output;
    word32 idx;
    int    sendSz;
    word32 length;
#if defined(HAVE_ECH)
    int clientRandomOffset;
    word32 preXLength;
    word32 expandedInnerLen;
    WOLFSSL_ECH* ech;
#endif
} Sch13Args;

#ifdef WOLFSSL_EARLY_DATA
/* Check if early data can potentially be sent.
 * Returns 1 if early data is possible, 0 otherwise.
 */
static int EarlyDataPossible(WOLFSSL* ssl)
{
    /* Need session resumption OR PSK callback configured */
    if (ssl->options.resuming) {
        return 1;
    }
#ifndef NO_PSK
    if (ssl->options.client_psk_tls13_cb != NULL ||
        ssl->options.client_psk_cb != NULL) {
        return 1;
    }
#endif
    return 0;
}
#endif /* WOLFSSL_EARLY_DATA */

int SendTls13ClientHello(WOLFSSL* ssl)
{
    int ret;
#ifdef WOLFSSL_ASYNC_CRYPT
    Sch13Args* args = NULL;
    WOLFSSL_ASSERT_SIZEOF_GE(ssl->async->args, *args);
#else
    Sch13Args  args[1];
#endif
    byte major, tls12minor;
    const Suites* suites;

    WOLFSSL_START(WC_FUNC_CLIENT_HELLO_SEND);
    WOLFSSL_ENTER("SendTls13ClientHello");

    if (ssl == NULL) {
        return BAD_FUNC_ARG;
    }

#if defined(HAVE_SECURE_RENEGOTIATION) || defined(HAVE_SERVER_RENEGOTIATION_INFO)
    /* Re-establish renegotiation_info advertising for a reused object
     * (wolfSSL_clear frees it) so a TLS 1.2 downgrade still enforces what the
     * ClientHello advertised. Only when absent, to keep any existing state. */
    if (ssl->secure_renegotiation == NULL) {
        ret = SetupClientSecureRenegotiation(ssl);
        if (ret != WOLFSSL_SUCCESS)
            return ret;
    }
#endif

    ssl->options.buildingMsg = 1;
    major = SSLv3_MAJOR;
    tls12minor = TLSv1_2_MINOR;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        major = DTLS_MAJOR;
        tls12minor = DTLSv1_2_MINOR;
    }
#endif /* WOLFSSL_DTLS */

    if (ssl->options.resuming &&
            ssl->session->version.major != 0 &&
            (ssl->session->version.major != ssl->version.major ||
             ssl->session->version.minor != ssl->version.minor)) {
    #ifndef WOLFSSL_NO_TLS12
        if (ssl->session->version.major == ssl->version.major &&
            ssl->session->version.minor < ssl->version.minor) {
            /* Cannot resume with a different protocol version. */
            ssl->options.resuming = 0;
            ssl->version.major = ssl->session->version.major;
            ssl->version.minor = ssl->session->version.minor;
            return SendClientHello(ssl);
        }
        else
    #endif
        {
            WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
            return VERSION_ERROR;
        }
    }

    suites = WOLFSSL_SUITES(ssl);
    if (suites == NULL) {
        WOLFSSL_MSG("Bad suites pointer in SendTls13ClientHello");
        return SUITES_ERROR;
    }

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ssl->async == NULL) {
        ssl->async = (struct WOLFSSL_ASYNC*)
                XMALLOC(sizeof(struct WOLFSSL_ASYNC), ssl->heap,
                        DYNAMIC_TYPE_ASYNC);
        if (ssl->async == NULL)
            return MEMORY_E;
        ssl->async->freeArgs = NULL;
    }
    args = (Sch13Args*)ssl->async->args;

    ret = wolfSSL_AsyncPop(ssl, &ssl->options.asyncState);
    if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
        /* Check for error */
        if (ret < 0)
            return ret;
    }
    else
#endif
    {
        /* Reset state */
        ssl->options.asyncState = TLS_ASYNC_BEGIN;
        XMEMSET(args, 0, sizeof(Sch13Args));
    }

    switch (ssl->options.asyncState) {
    case TLS_ASYNC_BEGIN:
    {
    word32 sessIdSz = 0;

    args->idx = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        args->idx += DTLS_RECORD_EXTRA + DTLS_HANDSHAKE_EXTRA;
#endif /* WOLFSSL_DTLS13 */

    /* Version | Random | Cipher Suites | Compression */
    args->length = VERSION_SZ + RAN_LEN + suites->suiteSz +
            SUITE_LEN + COMP_LEN + ENUM_LEN;
#ifdef WOLFSSL_QUIC
    if (WOLFSSL_IS_QUIC(ssl)) {
        /* RFC 9001 ch. 8.4 sessionID in ClientHello MUST be 0 length */
        ssl->session->sessionIDSz = 0;
        ssl->options.tls13MiddleBoxCompat = 0;
    }
#endif
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        /* RFC 9147 Section 5: DTLS implementations do not use the
         *                     TLS 1.3 "compatibility mode" */
        ssl->options.tls13MiddleBoxCompat = 0;
    }
#endif
    GetTls13SessionId(ssl, NULL, &sessIdSz);
    args->length += (word16)sessIdSz;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        /* legacy_cookie_id len */
        args->length += ENUM_LEN;

        /* server sent us an HelloVerifyRequest and we allow downgrade  */
        if (ssl->arrays->cookieSz > 0 && ssl->options.downgrade)
            args->length += ssl->arrays->cookieSz;
    }
#endif /* WOLFSSL_DTLS13 */

    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_BUILD;
    } /* case TLS_ASYNC_BEGIN */
    FALL_THROUGH;

    case TLS_ASYNC_BUILD:
    case TLS_ASYNC_DO:
    {
    /* Auto populate extensions supported unless user defined. */
    if ((ret = TLSX_PopulateExtensions(ssl, 0)) != 0)
        return ret;

    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_FINALIZE;
    } /* case TLS_ASYNC_BUILD */
    FALL_THROUGH;

    case TLS_ASYNC_FINALIZE:
    {
#ifdef WOLFSSL_EARLY_DATA
    if (!EarlyDataPossible(ssl))
        ssl->earlyData = no_early_data;
    if (ssl->options.serverState == SERVER_HELLO_RETRY_REQUEST_COMPLETE)
        ssl->earlyData = no_early_data;
    if (ssl->earlyData == no_early_data)
        TLSX_Remove(&ssl->extensions, TLSX_EARLY_DATA, ssl->heap);
    if (ssl->earlyData != no_early_data &&
        (ret = TLSX_EarlyData_Use(ssl, 0, 0)) < 0) {
        return ret;
    }
#endif
#ifdef WOLFSSL_QUIC
    if (WOLFSSL_IS_QUIC(ssl) && IsAtLeastTLSv1_3(ssl->version)) {
        ret = wolfSSL_quic_add_transport_extensions(ssl, client_hello);
        if (ret != 0)
            return ret;
    }
#endif

    /* find length of outer and inner */
#if defined(HAVE_ECH)
    if (!ssl->options.disableECH) {
        TLSX* echX = TLSX_Find(ssl->extensions, TLSX_ECH);
        void* hostName = NULL;
        word16 nameLen;
        if (echX == NULL)
            return WOLFSSL_FATAL_ERROR;

        args->ech = (WOLFSSL_ECH*)echX->data;
        if (args->ech == NULL)
            return WOLFSSL_FATAL_ERROR;

        /* if ECH was rejected by the HRR then the server MUST stop
         * decrypting ECH, so send a GREASE ECH for the follow-up CH */
        if (ssl->echConfigs != NULL && !ssl->options.echAccepted &&
                ssl->options.serverState ==
                    SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
            args->ech->state = ECH_WRITE_GREASE;
        }

        /* only prepare if we have a chance at acceptance (real ECH only) */
        if (ssl->echConfigs != NULL &&
                (ssl->options.echAccepted || args->ech->innerCount == 0)) {
            word32 encodedLen;
            byte downgrade;

            /* ensure that a version less than TLS1.3 is never offered  */
            downgrade = ssl->options.downgrade;
            ssl->options.downgrade = 0;

            /* set the type to inner */
            args->ech->type = ECH_TYPE_INNER;
            args->preXLength = args->length;

            /* get expanded inner size (used for transcript) */
            ret = TLSX_GetRequestSize(ssl, client_hello, &args->length);
            if (ret != 0) {
                args->ech->type = ECH_TYPE_OUTER;
                ssl->options.downgrade = downgrade;
                return ret;
            }

            /* args->expandedInnerLen carries the length for the hash */
            args->expandedInnerLen = args->length;
            if (args->expandedInnerLen > 0xFFFF) {
                args->ech->type = ECH_TYPE_OUTER;
                ssl->options.downgrade = downgrade;
                return BUFFER_E;
            }

            /* get encoded inner size */
            args->ech->writeEncoded = 1;
            encodedLen = args->preXLength;
            ret = TLSX_GetRequestSize(ssl, client_hello, &encodedLen);
            args->ech->writeEncoded = 0;
            /* set the type to outer */
            args->ech->type = ECH_TYPE_OUTER;
            ssl->options.downgrade = downgrade;
            if (ret != 0)
                return ret;

            /* calculate padding (RFC 9849, section 6.1.3) */
            nameLen = TLSX_SNI_GetRequest(ssl->extensions,
                WOLFSSL_SNI_HOST_NAME, &hostName, 1);
            if (nameLen == 0 && ssl->ctx != NULL)
                nameLen = TLSX_SNI_GetRequest(ssl->ctx->extensions,
                    WOLFSSL_SNI_HOST_NAME, &hostName, 1);

            if (nameLen != 0) {
                if (nameLen > args->ech->echConfig->maxNameLen)
                    args->ech->paddingLen = 0;
                else
                    args->ech->paddingLen =
                        (word16)args->ech->echConfig->maxNameLen - nameLen;
            }
            else {
                /* maxNameLen + length of the SNI extension */
                args->ech->paddingLen = args->ech->echConfig->maxNameLen + 9;
            }

            /* innerClientHelloLen and padding are based on the
             * encoded (sealed) inner */
            args->ech->paddingLen +=
                ECH_PADDING_TO_32(encodedLen + args->ech->paddingLen);
            args->ech->innerClientHelloLen = encodedLen +
                args->ech->paddingLen + args->ech->hpke->Nt;

            if (args->ech->innerClientHelloLen > 0xFFFF)
                return BUFFER_E;

            /* restore the length to pre-ClientHelloInner computations */
            args->length = args->preXLength;
        }
    }
#endif

    {
#ifdef WOLFSSL_DTLS_CH_FRAG
        word16 maxFrag = wolfssl_local_GetMaxPlaintextSize(ssl);
        word16 lenWithoutExts = args->length;
#endif

        /* Include length of TLS extensions. */
        ret = TLSX_GetRequestSize(ssl, client_hello, &args->length);
        if (ret != 0)
            return ret;

        /* Total message size. */
        args->sendSz =
                (int)(args->length + HANDSHAKE_HEADER_SZ + RECORD_HEADER_SZ);

#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls)
            args->sendSz += DTLS_RECORD_EXTRA + DTLS_HANDSHAKE_EXTRA;
#endif /* WOLFSSL_DTLS13 */

#ifdef WOLFSSL_DTLS_CH_FRAG
        /* Only empty the key share on the first CH; this avoids first CH
         * fragmentation (wolfSSL refuses them) */
        if (ssl->options.dtls && args->sendSz > maxFrag &&
                ssl->options.serverState !=
                    SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
            /* Try again with an empty key share if we would be fragmenting */
            ret = TLSX_KeyShare_Empty(ssl);
            if (ret != 0)
                return ret;
            args->length = lenWithoutExts;
            ret = TLSX_GetRequestSize(ssl, client_hello, &args->length);
            if (ret != 0)
                return ret;
            args->sendSz = (int)(args->length +
                    DTLS_HANDSHAKE_HEADER_SZ + DTLS_RECORD_HEADER_SZ);
            if (args->sendSz > maxFrag) {
                WOLFSSL_MSG("Can't fit first CH in one fragment.");
                return BUFFER_ERROR;
            }
            WOLFSSL_MSG("Sending empty key share so we don't fragment CH1");
        }
#endif
    }

    /* Check buffers are big enough and grow if needed. */
    if ((ret = CheckAvailableSize(ssl, args->sendSz)) != 0)
        return ret;

    /* Get position in output buffer to write new message to. */
    args->output = GetOutputBuffer(ssl);

    /* Put the record and handshake headers on. */
    AddTls13Headers(args->output, args->length, client_hello, ssl);

    /* Protocol version - negotiation now in extension: supported_versions. */
    args->output[args->idx++] = major;
    args->output[args->idx++] = tls12minor;

    /* Keep for downgrade. */
    ssl->chVersion = ssl->version;

    if (ssl->arrays == NULL) {
        return BAD_FUNC_ARG;
    }
    /* Client Random */
    if (ssl->options.connectState == CONNECT_BEGIN) {
        ret = wc_RNG_GenerateBlock(ssl->rng, args->output + args->idx, RAN_LEN);
        if (ret != 0)
            return ret;

        /* Store random for possible second ClientHello. */
        XMEMCPY(ssl->arrays->clientRandom, args->output + args->idx, RAN_LEN);
    }
    else
        XMEMCPY(args->output + args->idx, ssl->arrays->clientRandom, RAN_LEN);

#if defined(HAVE_ECH)
    args->clientRandomOffset = (int)args->idx;
#endif

    args->idx += RAN_LEN;

    GetTls13SessionId(ssl, args->output, &args->idx);

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        args->output[args->idx++] = ssl->arrays->cookieSz;

        if (ssl->arrays->cookieSz > 0) {
            /* We have a cookie saved, so the server sent us an
             * HelloVerifyRequest, it means it is a v1.2 server */
            if (!ssl->options.downgrade)
                return VERSION_ERROR;
            XMEMCPY(args->output + args->idx, ssl->arrays->cookie,
                ssl->arrays->cookieSz);
            args->idx += ssl->arrays->cookieSz;
        }
    }
#endif /* WOLFSSL_DTLS13 */

    /* Cipher suites */
    c16toa(suites->suiteSz, args->output + args->idx);
    args->idx += OPAQUE16_LEN;
    XMEMCPY(args->output + args->idx, &suites->suites,
        suites->suiteSz);
    args->idx += suites->suiteSz;
#ifdef WOLFSSL_DEBUG_TLS
    {
        int ii;
        WOLFSSL_MSG("Ciphers:");
        for (ii = 0 ; ii < suites->suiteSz; ii += 2) {
            WOLFSSL_MSG(GetCipherNameInternal(suites->suites[ii+0],
                                              suites->suites[ii+1]));
        }
    }
#endif

    /* Compression not supported in TLS v1.3. */
    args->output[args->idx++] = COMP_LEN;
    args->output[args->idx++] = NO_COMPRESSION;

#if defined(HAVE_ECH)
    /* Build the expanded inner ClientHello */
    if (ssl->echConfigs != NULL && !ssl->options.disableECH &&
            (ssl->options.echAccepted || args->ech->innerCount == 0)) {
        byte downgrade;

        /* calculate maximum buffer size needed */
        word32 encodedBodyLen = args->ech->innerClientHelloLen -
            args->ech->hpke->Nt;
        word32 innerBufSize = args->expandedInnerLen;
        if (encodedBodyLen > innerBufSize)
            innerBufSize = encodedBodyLen;

        /* set the type to inner */
        args->ech->type = ECH_TYPE_INNER;
        /* innerClientHello may already exist from hrr, free if it does */
        if (args->ech->innerClientHello != NULL) {
            XFREE(args->ech->innerClientHello, ssl->heap,
                DYNAMIC_TYPE_TMP_BUFFER);
        }
        /* allocate the inner */
        args->ech->innerClientHello =
            (byte*)XMALLOC(innerBufSize, ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
        if (args->ech->innerClientHello == NULL) {
            args->ech->type = ECH_TYPE_OUTER;
            return MEMORY_E;
        }
        /* copy everything before extensions into the innerClientHello
         * ignore record and handshake headers */
        XMEMCPY(args->ech->innerClientHello,
            args->output + RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ,
            args->preXLength);
        /* copy the client random to inner - only for first CH, not after HRR */
        if (!ssl->options.echAccepted) {
            XMEMCPY(ssl->arrays->clientRandomInner, ssl->arrays->clientRandom,
                RAN_LEN);
        }
        else {
            /* After HRR, use the same inner random as CH1 */
            XMEMCPY(args->ech->innerClientHello + VERSION_SZ,
                ssl->arrays->clientRandomInner, RAN_LEN);
        }
        /* change the outer client random */
        ret = wc_RNG_GenerateBlock(ssl->rng, args->output +
            args->clientRandomOffset, RAN_LEN);
        if (ret != 0) {
            args->ech->type = ECH_TYPE_OUTER;
            return ret;
        }
        /* copy the new client random */
        XMEMCPY(ssl->arrays->clientRandom, args->output +
            args->clientRandomOffset, RAN_LEN);

        /* ensure that a version less than TLS1.3 is never offered  */
        downgrade = ssl->options.downgrade;
        ssl->options.downgrade = 0;

        /* write the expanded extensions into the inner buffer */
        args->length = 0;
        ret = TLSX_WriteRequest(ssl,
            args->ech->innerClientHello + args->preXLength, client_hello,
            &args->length);
        if (ret != 0) {
            args->ech->type = ECH_TYPE_OUTER;
            ssl->options.downgrade = downgrade;
            return ret;
        }

        /* hash expanded form */
        args->ech->innerClientHelloLen = args->expandedInnerLen;
        ret = EchHashHelloInner(ssl, args->ech);
        args->ech->innerClientHelloLen = encodedBodyLen + args->ech->hpke->Nt;
        if (ret != 0) {
            args->ech->type = ECH_TYPE_OUTER;
            ssl->options.downgrade = downgrade;
            return ret;
        }

        /* zero padding bytes sealed with the inner hello */
        XMEMSET(args->ech->innerClientHello +
            args->ech->innerClientHelloLen - args->ech->hpke->Nt -
            args->ech->paddingLen, 0, args->ech->paddingLen);
        /* Rewrite inner buffer with the encoded form for sealing */
        args->ech->writeEncoded = 1;
        args->length = 0;
        ret = TLSX_WriteRequest(ssl,
            args->ech->innerClientHello + args->preXLength, client_hello,
            &args->length);
        args->ech->writeEncoded = 0;
        /* set the type to outer */
        args->ech->type = ECH_TYPE_OUTER;
        ssl->options.downgrade = downgrade;
        if (ret != 0)
            return ret;
    }
#endif

    /* Write out extensions for a request. */
    args->length = 0;
    ret = TLSX_WriteRequest(ssl, args->output + args->idx, client_hello,
        &args->length);
    if (ret != 0)
        return ret;

    args->idx += args->length;

#if defined(HAVE_ECH)
    /* HPKE-seal inner hello and place into outer ECH extension's payload */
    if (ssl->echConfigs != NULL && !ssl->options.disableECH &&
            (ssl->options.echAccepted || args->ech->innerCount == 0)) {
#if defined(WOLFSSL_TEST_ECH)
        if (ssl->echInnerHelloCb != NULL) {
            ret = ssl->echInnerHelloCb(args->ech->innerClientHello,
                args->ech->innerClientHelloLen - args->ech->hpke->Nt);
            if (ret != 0)
                return ret;
        }
#endif
        ret = TLSX_FinalizeEch(ssl, args->ech,
            args->output + RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ,
            (word32)(args->sendSz - (RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ)));

        if (ret != 0)
            return ret;
    }
    /* Mark CH1 done for any ECH extension (real or GREASE) */
    if (args->ech != NULL)
        args->ech->innerCount = 1;
#endif

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    /* Resumption has a specific set of extensions and binder is calculated
     * for each identity.
     */
    if (TLSX_Find(ssl->extensions, TLSX_PRE_SHARED_KEY)) {
        ret = WritePSKBinders(ssl, args->output, args->idx);
    }
    else
#endif
    {
#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls)
            ret = Dtls13HashHandshake(ssl,
                args->output + Dtls13GetRlHeaderLength(ssl, 0),
                (word16)args->idx - Dtls13GetRlHeaderLength(ssl, 0));
        else
#endif /* WOLFSSL_DTLS13 */
        {
            /* compute the outer hash */
            ret = HashOutput(ssl, args->output, (int)args->idx, 0);
        }
    }
    if (ret != 0)
        return ret;

    ssl->options.clientState = CLIENT_HELLO_COMPLETE;

#if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
    if (ssl->hsInfoOn) AddPacketName(ssl, "ClientHello");
    if (ssl->toInfoOn) {
        ret = AddPacketInfo(ssl, "ClientHello", handshake, args->output,
                      args->sendSz, WRITE_PROTO, 0, ssl->heap);
        if (ret != 0)
            return ret;
    }
#endif

    ssl->options.buildingMsg = 0;
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        ret = Dtls13HandshakeSend(ssl, args->output, (word16)args->sendSz,
                                  (word16)args->idx, client_hello, 0);
        break;
    }
#endif /* WOLFSSL_DTLS13 */

    ssl->buffers.outputBuffer.length += (word32)args->sendSz;

    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_END;
    }
    /* case TLS_ASYNC_BUILD */
    FALL_THROUGH;

    case TLS_ASYNC_END:
    {
#ifdef WOLFSSL_EARLY_DATA_GROUP
    /* QUIC needs to forward records at their encryption level
     * and is therefore unable to group here */
    if (ssl->earlyData == no_early_data || WOLFSSL_IS_QUIC(ssl))
#endif
        ret = SendBuffered(ssl);

    break;
    }
    default:
        ret = INPUT_CASE_ERROR;
    } /* switch (ssl->options.asyncState) */

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ret == 0)
        FreeAsyncCtx(ssl, 0);
#endif

    WOLFSSL_LEAVE("SendTls13ClientHello", ret);
    WOLFSSL_END(WC_FUNC_CLIENT_HELLO_SEND);

    return ret;
}

#if defined(WOLFSSL_DTLS13) && !defined(NO_WOLFSSL_CLIENT)
static int Dtls13ClientDoDowngrade(WOLFSSL* ssl)
{
    int ret;
    if (ssl->dtls13ClientHello == NULL)
        return BAD_STATE_E;

    /* v1.3 and v1.2 hash messages to compute the transcript hash. When we are
     * using DTLSv1.3 we hash the first clientHello following v1.3 but the
     * server can negotiate a lower version. So we need to re-hash the
     * clientHello to adhere to DTLS <= v1.2 rules. */
    ret = InitHandshakeHashes(ssl);
    if (ret != 0)
        return ret;
    ret = HashRaw(ssl, ssl->dtls13ClientHello, ssl->dtls13ClientHelloSz);
    XFREE(ssl->dtls13ClientHello, ssl->heap, DYNAMIC_TYPE_DTLS_MSG);
    ssl->dtls13ClientHello = NULL;
    ssl->dtls13ClientHelloSz = 0;
    ssl->keys.dtls_sequence_number_hi =
        (word16)w64GetHigh32(ssl->dtls13EncryptEpoch->nextSeqNumber);
    ssl->keys.dtls_sequence_number_lo =
        w64GetLow32(ssl->dtls13EncryptEpoch->nextSeqNumber);
    return ret;
}
#endif /* WOLFSSL_DTLS13 && !NO_WOLFSSL_CLIENT*/

#if defined(HAVE_ECH)
/* Calculate ECH acceptance and verify the server accepted ECH.
 *
 * ssl          SSL/TLS object.
 * label        Ascii string describing ECH acceptance type.
 * labelSz      Length of label excluding NULL character.
 * input        The buffer to calculate confirmation off of.
 * acceptOffset Where the 8 ECH confirmation bytes start.
 * helloSz      Size of hello message.
 * returns 0 on success and otherwise failure.
 */
static int EchCheckAcceptance(WOLFSSL* ssl, byte* label, word16 labelSz,
    const byte* input, int acceptOffset, int helloSz, byte msgType)
{
    int ret = 0;
    int headerSz;
    HS_Hashes* tmpHashes;
    byte acceptConfirmation[ECH_ACCEPT_CONFIRMATION_SZ];

    XMEMSET(acceptConfirmation, 0, sizeof(acceptConfirmation));

#ifdef WOLFSSL_DTLS13
    headerSz = ssl->options.dtls ? DTLS13_HANDSHAKE_HEADER_SZ :
                                   HANDSHAKE_HEADER_SZ;
#else
    headerSz = HANDSHAKE_HEADER_SZ;
#endif

    ret = EchCalcAcceptance(ssl, label, labelSz, input, acceptOffset, helloSz,
            msgType == hello_retry_request, acceptConfirmation);

    if (ret == 0) {
        tmpHashes = ssl->hsHashes;
        ssl->hsHashes = ssl->hsHashesEch;

        /* last 8 bytes must match the expand output */
        ret = ConstantCompare(acceptConfirmation, input + acceptOffset,
            ECH_ACCEPT_CONFIRMATION_SZ);

        if (ret == 0) {
            WOLFSSL_MSG("ECH accepted");
            ssl->options.echAccepted = 1;

            /* after HRR, hsHashesEch must contain:
             * message_hash(ClientHelloInner1) || HRR (actual, not zeros) */
            if (msgType == hello_retry_request) {
                ret = HashRaw(ssl, input, helloSz + headerSz);
            }
            /* normal TLS code will calculate transcript of ServerHello */
            else {
                ssl->hsHashes = tmpHashes;
                FreeHandshakeHashes(ssl);
                tmpHashes = ssl->hsHashesEch;
                ssl->hsHashesEch = NULL;
            }
        }
        else {
            if (msgType != hello_retry_request && ssl->options.echAccepted) {
                /* the SH has rejected ECH after the HRR has accepted it
                 * RFC 9849, section 6.1.5 */
                WOLFSSL_MSG("ECH rejected, but it was previously accepted...");
                ret = INVALID_PARAMETER;
            }
            else {
                WOLFSSL_MSG("ECH rejected");
                ret = 0;
            }
            ssl->options.echAccepted = 0;

            /* ECH rejected, continue with outer transcript */
            FreeHandshakeHashes(ssl);
            ssl->hsHashesEch = NULL;
        }

        ssl->hsHashes = tmpHashes;
    }

    /* Skip only when the HRR signals ECH acceptance
     * -> CH2 still needs ech->extensions for inner/outer extension swap
     *    during write */
    if (ret == 0 &&
            (msgType != hello_retry_request || !ssl->options.echAccepted))
        ret = TLSX_EchReplaceExtensions(ssl, ssl->options.echAccepted);

    return ret;
}
#endif /* HAVE_ECH */

/* handle processing of TLS 1.3 server_hello (2) and hello_retry_request (6) */
/* Handle the ServerHello message from the server.
 * Only a client will receive this message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of ServerHello.
 *           On exit, the index of byte after the ServerHello message.
 * helloSz   The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */

typedef struct Dsh13Args {
    ProtocolVersion pv;
    word32          idx;
    word32          begin;
    const byte*     sessId;
    word16          totalExtSz;
    byte            sessIdSz;
    byte            extMsgType;
#if defined(HAVE_ECH)
    TLSX* echX;
    byte* acceptLabel;
    word32 acceptOffset;
    word16 acceptLabelSz;
#endif
} Dsh13Args;

/* sessIdSz below bounds both the copy into arrays->sessionID and the comparison
 * against arrays->clientRandom, so one check only covers both while these
 * match. */
wc_static_assert(ID_LEN == RAN_LEN);

int DoTls13ServerHello(WOLFSSL* ssl, const byte* input, word32* inOutIdx,
                       word32 helloSz, byte* extMsgType)
{
    int ret;
    byte suite[2];
    byte tls12minor;
#ifdef WOLFSSL_ASYNC_CRYPT
    Dsh13Args* args = NULL;
#else
    Dsh13Args  args[1];
#endif
#ifdef WOLFSSL_ASYNC_CRYPT
    WOLFSSL_ASSERT_SIZEOF_GE(ssl->async->args, *args);
#endif

    WOLFSSL_START(WC_FUNC_SERVER_HELLO_DO);
    WOLFSSL_ENTER("DoTls13ServerHello");

    if (ssl == NULL || ssl->arrays == NULL)
        return BAD_FUNC_ARG;

    tls12minor = TLSv1_2_MINOR;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        tls12minor = DTLSv1_2_MINOR;
#endif /*  WOLFSSL_DTLS13 */

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ssl->async == NULL) {
        ssl->async = (struct WOLFSSL_ASYNC*)
                XMALLOC(sizeof(struct WOLFSSL_ASYNC), ssl->heap,
                        DYNAMIC_TYPE_ASYNC);
        if (ssl->async == NULL)
            return MEMORY_E;
        ssl->async->freeArgs = NULL;
    }
    args = (Dsh13Args*)ssl->async->args;

    ret = wolfSSL_AsyncPop(ssl, &ssl->options.asyncState);
    if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
        /* Check for error */
        if (ret < 0) {
            if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
                /* Mark message as not received so it can process again */
                ssl->msgsReceived.got_server_hello = 0;
            }
            return ret;
        }
    }
    else
#endif
    {
        /* Reset state */
        ssl->options.asyncState = TLS_ASYNC_BEGIN;
        XMEMSET(args, 0, sizeof(Dsh13Args));
    }

    switch (ssl->options.asyncState) {
    case TLS_ASYNC_BEGIN:
    {
    byte b;
#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_DTLS_CID)
    ssl->options.haveSupportedVersions = 0;
#endif
#ifdef WOLFSSL_CALLBACKS
    if (ssl->hsInfoOn) AddPacketName(ssl, "ServerHello");
    if (ssl->toInfoOn) AddLateName("ServerHello", &ssl->timeoutInfo);
#endif

    /* Protocol version length check. */
    if (helloSz < OPAQUE16_LEN)
        return BUFFER_ERROR;

    args->idx = *inOutIdx;
    args->begin = args->idx;

    /* Protocol version */
    XMEMCPY(&args->pv, input + args->idx, OPAQUE16_LEN);
    args->idx += OPAQUE16_LEN;

#ifdef WOLFSSL_DTLS
    if (ssl->options.dtls &&
        (args->pv.major != DTLS_MAJOR || args->pv.minor == DTLS_BOGUS_MINOR))
        return VERSION_ERROR;
#endif /* WOLFSSL_DTLS */

#ifndef WOLFSSL_NO_TLS12
    {
        byte wantDowngrade;

        wantDowngrade = args->pv.major == ssl->version.major &&
            args->pv.minor < TLSv1_2_MINOR;

#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls)
            wantDowngrade = args->pv.major == ssl->version.major &&
                args->pv.minor > DTLSv1_2_MINOR;
#endif /* WOLFSSL_DTLS13 */

        if (wantDowngrade && ssl->options.downgrade) {
            /* Force client hello version 1.2 to work for static RSA. */
            ssl->chVersion.minor = TLSv1_2_MINOR;
            ssl->version.minor = TLSv1_2_MINOR;
            ssl->options.tls1_3 = 0;

#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls) {
                ssl->chVersion.minor = DTLSv1_2_MINOR;
                ssl->version.minor = DTLSv1_2_MINOR;
                ret = Dtls13ClientDoDowngrade(ssl);
                if (ret != 0)
                    return ret;
            }
#endif /* WOLFSSL_DTLS13 */

            return DoServerHello(ssl, input, inOutIdx, helloSz);
        }
    }
#endif

    if (args->pv.major != ssl->version.major ||
        args->pv.minor != tls12minor) {
        WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
        return VERSION_ERROR;
    }

    /* Random and session id length check */
    if ((args->idx - args->begin) + RAN_LEN + ENUM_LEN > helloSz)
        return BUFFER_ERROR;

    /* Check if hello retry request */
    if (XMEMCMP(input + args->idx, helloRetryRequestRandom, RAN_LEN) == 0) {
        WOLFSSL_MSG("HelloRetryRequest format");
        *extMsgType = hello_retry_request;

        if (ssl->msgsReceived.got_hello_verify_request) {
            WOLFSSL_MSG("Received HelloRetryRequest after a "
                        "HelloVerifyRequest");
            WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
            return VERSION_ERROR;
        }

        /* A HelloRetryRequest comes in as an ServerHello for MiddleBox compat.
         * Found message to be a HelloRetryRequest.
         * Don't allow more than one HelloRetryRequest or ServerHello.
         */
        if (ssl->msgsReceived.got_hello_retry_request) {
            WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
            return DUPLICATE_MSG_E;
        }
    }
    args->extMsgType = *extMsgType;

    /* Server random - keep for debugging. */
    XMEMCPY(ssl->arrays->serverRandom, input + args->idx, RAN_LEN);
#if defined(HAVE_ECH)
    /* last 8 bytes of server random */
    args->acceptOffset = args->idx + RAN_LEN - ECH_ACCEPT_CONFIRMATION_SZ;
#endif
    args->idx += RAN_LEN;

    /* Session id */
    args->sessIdSz = input[args->idx++];
    if (args->sessIdSz > ID_LEN ||
        ((args->idx - args->begin) + args->sessIdSz > helloSz))
        return BUFFER_ERROR;
    args->sessId = input + args->idx;
    args->idx += args->sessIdSz;

    ssl->options.haveSessionId = 1;

    /* Ciphersuite and compression check */
    if ((args->idx - args->begin) + OPAQUE16_LEN + OPAQUE8_LEN > helloSz)
        return BUFFER_ERROR;

    /* Set the cipher suite from the message. */
    ssl->options.cipherSuite0 = input[args->idx++];
    ssl->options.cipherSuite  = input[args->idx++];
    if (*extMsgType == hello_retry_request) {
        ssl->options.hrrCipherSuite0 = ssl->options.cipherSuite0;
        ssl->options.hrrCipherSuite  = ssl->options.cipherSuite;
    }
    else if (ssl->msgsReceived.got_hello_retry_request &&
             (ssl->options.hrrCipherSuite0 != ssl->options.cipherSuite0 ||
                     ssl->options.hrrCipherSuite != ssl->options.cipherSuite)) {
        WOLFSSL_MSG("Received ServerHello with different cipher suite than "
                    "HelloRetryRequest");
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }
#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("Chosen cipher suite:");
    WOLFSSL_MSG(GetCipherNameInternal(ssl->options.cipherSuite0,
                                      ssl->options.cipherSuite));
#endif

    /* Compression */
    b = input[args->idx++];
    if (b != 0) {
        WOLFSSL_MSG("Must be no compression types in list");
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }

    if ((args->idx - args->begin) + OPAQUE16_LEN > helloSz) {
        /* Fewer than OPAQUE16_LEN bytes remain after the compression method, so
         * there is no complete extensions length field. */
        if ((args->idx - args->begin) < helloSz) {
            /* A partial extensions length field is genuinely malformed: report
             * it as a decode error regardless of message type. */
            WOLFSSL_MSG("Truncated extensions length in ServerHello");
            return BUFFER_ERROR;
        }

        /* No extensions field at all. */
        if (args->extMsgType == hello_retry_request) {
            /* The sentinel Random (RFC 8446 4.1.3) identifies this as a TLS 1.3
             * HelloRetryRequest, which MUST carry supported_versions
             * (4.2.1/9.2). Its complete absence is a missing mandatory
             * extension, so - consistently with the extensions-present case
             * handled later - report it as missing_extension (via
             * INCOMPLETE_DATA), regardless of whether a downgrade would
             * otherwise be allowed. Reject here before DoServerHello would
             * reinterpret the sentinel as a plain TLS 1.2 ServerHello.Random. */
            WOLFSSL_MSG("HelloRetryRequest with no supported_versions");
            WOLFSSL_ERROR_VERBOSE(INCOMPLETE_DATA);
            return INCOMPLETE_DATA;
        }

        if (!ssl->options.downgrade) {
            /* A plain ServerHello with no extensions is not offering TLS 1.3
             * (no supported_versions extension - see RFC 8446 4.2.1) but TLS
             * 1.2 or below. This is a well-formed message, so a TLS 1.3-only
             * client (downgrade disabled) must reject it as a version mismatch,
             * not as a malformed message. Returning VERSION_ERROR makes the
             * caller send a protocol_version alert (RFC 8446 6.2) rather than
             * decode_error. */
            WOLFSSL_MSG("Server offered TLS 1.2 (no supported_versions ext) "
                        "but downgrade not allowed");
            WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
            return VERSION_ERROR;
        }
#ifndef WOLFSSL_NO_TLS12
        /* Force client hello version 1.2 to work for static RSA. */
        ssl->chVersion.minor = TLSv1_2_MINOR;
        ssl->version.minor = TLSv1_2_MINOR;

#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls) {
            ssl->chVersion.minor = DTLSv1_2_MINOR;
            ssl->version.minor = DTLSv1_2_MINOR;
            ssl->options.tls1_3 = 0;
            ret = Dtls13ClientDoDowngrade(ssl);
            if (ret != 0)
                return ret;
        }
#endif /* WOLFSSL_DTLS13 */

#endif
        ssl->options.haveEMS = 0;
        if (args->pv.minor < ssl->options.minDowngrade) {
            WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
            return VERSION_ERROR;
        }
#ifndef WOLFSSL_NO_TLS12
        ssl->options.tls1_3 = 0;
        return DoServerHello(ssl, input, inOutIdx, helloSz);
#else
        WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
        return VERSION_ERROR;
#endif
    }

    if ((args->idx - args->begin) < helloSz) {
        int foundVersion;

        /* Get extension length and length check. */
        if ((args->idx - args->begin) + OPAQUE16_LEN > helloSz)
            return BUFFER_ERROR;
        ato16(&input[args->idx], &args->totalExtSz);
        args->idx += OPAQUE16_LEN;
        if ((args->idx - args->begin) + args->totalExtSz > helloSz)
            return BUFFER_ERROR;

        /* Need to negotiate version first. */
        if ((ret = TLSX_ParseVersion(ssl, input + args->idx,
            args->totalExtSz, *extMsgType, &foundVersion))) {
            return ret;
        }
        if (!foundVersion) {
            /* RFC 8446 4.1.4: "The server's extensions MUST contain
             * 'supported_versions'." (also 9.2: "supported_versions" is
             * REQUIRED for all ... HelloRetryRequest messages). The HRR random
             * unambiguously identifies a TLS 1.3 server, so its absence is not
             * a downgrade attempt but a missing mandatory extension, which per
             * the "missing_extension" alert definition must be reported as
             * such. Return INCOMPLETE_DATA (which maps to a missing_extension
             * alert) and let the caller emit the alert via
             * TranslateErrorToAlert(). */
            if (*extMsgType == hello_retry_request) {
                WOLFSSL_MSG("HelloRetryRequest missing supported_versions "
                            "extension");
                WOLFSSL_ERROR_VERBOSE(INCOMPLETE_DATA);
                return INCOMPLETE_DATA;
            }
            if (!ssl->options.downgrade) {
                WOLFSSL_MSG("Server trying to downgrade to version less than "
                            "TLS v1.3");
                WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
                return VERSION_ERROR;
            }
#if defined(OPENSSL_EXTRA) || defined(HAVE_WEBSERVER) || \
    defined(WOLFSSL_WPAS_SMALL)
            /* Check if client has disabled TLS 1.2 */
            if (args->pv.minor == TLSv1_2_MINOR &&
                (ssl->options.mask & WOLFSSL_OP_NO_TLSv1_2)
                == WOLFSSL_OP_NO_TLSv1_2)
            {
                WOLFSSL_MSG("\tOption set to not allow TLSv1.2");
                WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
                return VERSION_ERROR;
            }
#endif

            if (!ssl->options.dtls &&
                args->pv.minor < ssl->options.minDowngrade) {
                WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
                return VERSION_ERROR;
            }

            if (ssl->options.dtls &&
                args->pv.minor > ssl->options.minDowngrade) {
                WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
                return VERSION_ERROR;
            }

            ssl->version.minor = args->pv.minor;
            ssl->options.tls1_3 = 0;

#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls) {
                ret = Dtls13ClientDoDowngrade(ssl);
                if (ret != 0)
                    return ret;
            }
#endif /* WOLFSSL_DTLS13 */
        }
    }

#ifdef WOLFSSL_DTLS13
    /* we are sure that version is >= v1.3 now, we can get rid of buffered
     * ClientHello that was buffered to re-compute the hash in case of
     * downgrade */
    if (ssl->options.dtls && ssl->dtls13ClientHello != NULL) {
        XFREE(ssl->dtls13ClientHello, ssl->heap, DYNAMIC_TYPE_DTLS_MSG);
        ssl->dtls13ClientHello = NULL;
        ssl->dtls13ClientHelloSz = 0;
    }
#endif /* WOLFSSL_DTLS13 */

    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_BUILD;
    } /* case TLS_ASYNC_BEGIN */
    FALL_THROUGH;

    case TLS_ASYNC_BUILD:
    case TLS_ASYNC_DO:
    {
    /* restore message type */
    *extMsgType = args->extMsgType;

    /* Parse and handle extensions, unless lower than TLS1.3. In that case,
     * extensions will be parsed in DoServerHello. */
    if (args->totalExtSz > 0 && IsAtLeastTLSv1_3(ssl->version)) {
        ret = TLSX_Parse(ssl, input + args->idx, args->totalExtSz,
            *extMsgType, NULL);
        if (ret != 0) {
        #ifdef WOLFSSL_ASYNC_CRYPT
            /* Handle async operation */
            if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
                /* Mark message as not received so it can process again */
                ssl->msgsReceived.got_server_hello = 0;
            }
        #endif
            return ret;
        }

        if (*extMsgType == hello_retry_request) {
            /* Update counts to reflect change of message type. */
            ssl->msgsReceived.got_hello_retry_request = 1;
            ssl->msgsReceived.got_server_hello = 0;
        }
    }

    if (args->totalExtSz > 0) {
        args->idx += args->totalExtSz;
    }

#ifdef WOLFSSL_DTLS_CID
    if (ssl->options.useDtlsCID && *extMsgType == server_hello)
        DtlsCIDOnExtensionsParsed(ssl);
#endif /* WOLFSSL_DTLS_CID */

    if (IsAtLeastTLSv1_3(ssl->version)) {
        *inOutIdx = args->idx;
    }

    ssl->options.serverState = SERVER_HELLO_COMPLETE;

#ifdef HAVE_SECRET_CALLBACK
    if (ssl->sessionSecretCb != NULL
#ifdef HAVE_SESSION_TICKET
            && ssl->session->ticketLen > 0
#endif
            ) {
        int secretSz = SECRET_LEN;
        ret = ssl->sessionSecretCb(ssl, ssl->session->masterSecret,
                                   &secretSz, ssl->sessionSecretCtx);
        if (ret != 0 || secretSz != SECRET_LEN) {
            WOLFSSL_ERROR_VERBOSE(SESSION_SECRET_CB_E);
            return SESSION_SECRET_CB_E;
        }
    }
#endif /* HAVE_SECRET_CALLBACK */

    /* Version only negotiated in extensions for TLS v1.3.
     * Only now do we know how to deal with session id.
     */
    if (!IsAtLeastTLSv1_3(ssl->version)) {
#ifndef WOLFSSL_NO_TLS12
        ssl->arrays->sessionIDSz = args->sessIdSz;

        if (ssl->arrays->sessionIDSz > ID_LEN) {
            WOLFSSL_MSG("Invalid session ID size");
            ssl->arrays->sessionIDSz = 0;
            return BUFFER_ERROR;
        }
        else if (ssl->arrays->sessionIDSz) {
            XMEMCPY(ssl->arrays->sessionID, args->sessId,
                ssl->arrays->sessionIDSz);
            ssl->options.haveSessionId = 1;
        }

        /* Force client hello version 1.2 to work for static RSA. */
        if (ssl->options.dtls)
            ssl->chVersion.minor = DTLSv1_2_MINOR;
        else
            ssl->chVersion.minor = TLSv1_2_MINOR;
        /* Complete TLS v1.2 processing of ServerHello. */
        ret = DoServerHello(ssl, input, inOutIdx, helloSz);
#else
        WOLFSSL_MSG("Client using higher version, fatal error");
        WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
        ret = VERSION_ERROR;
#endif

        WOLFSSL_LEAVE("DoTls13ServerHello", ret);

        return ret;
    }

    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_FINALIZE;
    } /* case TLS_ASYNC_BUILD || TLS_ASYNC_DO */
    FALL_THROUGH;

    case TLS_ASYNC_FINALIZE:
    {
#ifdef WOLFSSL_TLS13_MIDDLEBOX_COMPAT
    if (ssl->options.tls13MiddleBoxCompat) {
        if (args->sessIdSz == 0) {
            WOLFSSL_MSG("args->sessIdSz == 0");
            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
            return INVALID_PARAMETER;
        }
        if (ssl->session->sessionIDSz != 0) {
            if (ssl->session->sessionIDSz != args->sessIdSz ||
                XMEMCMP(ssl->session->sessionID, args->sessId,
                    args->sessIdSz) != 0) {
                WOLFSSL_MSG("session id doesn't match");
                WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
                return INVALID_PARAMETER;
            }
        }
        else if (XMEMCMP(ssl->arrays->clientRandom, args->sessId,
                args->sessIdSz) != 0) {
            WOLFSSL_MSG("session id doesn't match client random");
            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
            return INVALID_PARAMETER;
        }
    }
    else
#endif /* WOLFSSL_TLS13_MIDDLEBOX_COMPAT */
#if defined(WOLFSSL_QUIC) || defined(WOLFSSL_DTLS13)
    if (0
#ifdef WOLFSSL_QUIC
        || WOLFSSL_IS_QUIC(ssl)
#endif
#ifdef WOLFSSL_DTLS13
        || ssl->options.dtls
#endif
    ) {
        /* RFC 9147 Section 5 / RFC 9001 Section 8.4: DTLS 1.3 and QUIC
         * ServerHello must have empty legacy_session_id_echo. */
        int requireEmptyEcho = 1;
#ifdef WOLFSSL_DTLS13_ECHO_LEGACY_SESSION_ID
        /* Compat: a wolfSSL <= 5.9.0 DTLS 1.3 server echoes the client's
         * legacy_session_id back instead of omitting it. */
        if (ssl->options.dtls)
            requireEmptyEcho = 0;
#endif
        if (requireEmptyEcho && args->sessIdSz != 0) {
            WOLFSSL_MSG("args->sessIdSz != 0");
            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
            return INVALID_PARAMETER;
        }
#ifdef WOLFSSL_DTLS13_ECHO_LEGACY_SESSION_ID
        /* An echoing wolfSSL <= 5.9.0 server must still send back what was
         * sent (RFC 8446 Section 4.1.3), so don't accept an arbitrary value.
         * An empty echo is the compliant server case and stays acceptable. */
        if (!requireEmptyEcho && args->sessIdSz != 0 &&
                (args->sessIdSz != ssl->session->sessionIDSz ||
                 XMEMCMP(ssl->session->sessionID, args->sessId,
                         args->sessIdSz) != 0)) {
            WOLFSSL_MSG("Server sent different session id");
            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
            return INVALID_PARAMETER;
        }
#endif
    }
    else
#endif /* WOLFSSL_QUIC || WOLFSSL_DTLS13 */
    if (args->sessIdSz != ssl->session->sessionIDSz || (args->sessIdSz > 0 &&
        XMEMCMP(ssl->session->sessionID, args->sessId, args->sessIdSz) != 0))
    {
        WOLFSSL_MSG("Server sent different session id");
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }

    ret = SetCipherSpecs(ssl);
    if (ret != 0)
        return ret;

#ifdef HAVE_NULL_CIPHER
    if (ssl->options.cipherSuite0 == ECC_BYTE &&
                              (ssl->options.cipherSuite == TLS_SHA256_SHA256 ||
                               ssl->options.cipherSuite == TLS_SHA384_SHA384)) {
        ;
    }
    else
#endif
#if defined(WOLFSSL_SM4_GCM) && defined(WOLFSSL_SM3)
    if (ssl->options.cipherSuite0 == CIPHER_BYTE &&
            ssl->options.cipherSuite == TLS_SM4_GCM_SM3) {
        ; /* Do nothing. */
    }
    else
#endif
#if defined(WOLFSSL_SM4_CCM) && defined(WOLFSSL_SM3)
    if (ssl->options.cipherSuite0 == CIPHER_BYTE &&
            ssl->options.cipherSuite == TLS_SM4_CCM_SM3) {
        ; /* Do nothing. */
    }
    else
#endif
    /* Check that the negotiated ciphersuite matches protocol version. */
    if (ssl->options.cipherSuite0 != TLS13_BYTE) {
        WOLFSSL_MSG("Server sent non-TLS13 cipher suite in TLS 1.3 packet");
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }

    suite[0] = ssl->options.cipherSuite0;
    suite[1] = ssl->options.cipherSuite;
    if (!FindSuiteSSL(ssl, suite)) {
        WOLFSSL_MSG("Cipher suite not supported on client");
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }

#if defined(HAVE_ECH)
    /* check for acceptConfirmation */
    if (ssl->echConfigs != NULL && !ssl->options.disableECH &&
            ssl->hsHashesEch != NULL) {
        args->echX = TLSX_Find(ssl->extensions, TLSX_ECH);
        if (args->echX == NULL || args->echX->data == NULL)
            return WOLFSSL_FATAL_ERROR;

        if (args->extMsgType == hello_retry_request &&
                ((WOLFSSL_ECH*)args->echX->data)->confBuf == NULL) {
            /* server rejected ECH, fall back to outer */
            Free_HS_Hashes(ssl->hsHashesEch, ssl->heap);
            ssl->hsHashesEch = NULL;
            /* EchCheckAcceptance is bypassed, so replace extensions now */
            ret = TLSX_EchReplaceExtensions(ssl, 0);
            if (ret != 0)
                return ret;
        }
        else {
            /* account for hrr extension instead of server random */
            if (args->extMsgType == hello_retry_request) {
                args->acceptOffset =
                    (word32)(((WOLFSSL_ECH*)args->echX->data)->confBuf - input);
                args->acceptLabel = (byte*)echHrrAcceptConfirmationLabel;
                args->acceptLabelSz = ECH_HRR_ACCEPT_CONFIRMATION_LABEL_SZ;
            }
            else {
                args->acceptLabel = (byte*)echAcceptConfirmationLabel;
                args->acceptLabelSz = ECH_ACCEPT_CONFIRMATION_LABEL_SZ;
            }
            /* check acceptance */
            if (ret == 0) {
                ret = EchCheckAcceptance(ssl, args->acceptLabel,
                    args->acceptLabelSz, input, args->acceptOffset, helloSz,
                    args->extMsgType);
            }
            if (ret != 0)
                return ret;
            /* use the inner random for client random */
            if (args->extMsgType != hello_retry_request &&
                    ssl->options.echAccepted) {
                XMEMCPY(ssl->arrays->clientRandom,
                    ssl->arrays->clientRandomInner, RAN_LEN);
            }
        }
    }
#endif /* HAVE_ECH */

    if (*extMsgType == server_hello) {
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
        PreSharedKey* psk = NULL;
        TLSX* ext = TLSX_Find(ssl->extensions, TLSX_PRE_SHARED_KEY);
        if (ext != NULL)
            psk = (PreSharedKey*)ext->data;
        while (psk != NULL && !psk->chosen)
            psk = psk->next;
        if (psk == NULL) {
            /* A mandatory PSK is satisfied by any PSK the server chose,
             * including a resumption PSK - this matches the server-side
             * failNoPSK semantics, where a negotiated PSK (external or
             * resumption) is accepted. The error only fires when no PSK was
             * chosen at all. havePSK is only set by an external-PSK callback,
             * so a peer relying solely on session-ticket resumption is
             * unaffected. */
            if (ssl->options.havePSK && ssl->options.failNoPSK) {
                WOLFSSL_MSG("Server did not negotiate a mandatory PSK");
                WOLFSSL_ERROR_VERBOSE(PSK_MISSING_ERROR);
                return PSK_MISSING_ERROR;
            }
            ssl->options.resuming = 0;
            ssl->arrays->psk_keySz = 0;
            XMEMSET(ssl->arrays->psk_key, 0, MAX_PSK_KEY_LEN);
        }
        else {
#if defined(HAVE_ECH)
            /* do not resume when outerHandshake will be negotiated */
            if (ssl->echConfigs != NULL && !ssl->options.disableECH &&
                    !ssl->options.echAccepted) {
                WOLFSSL_MSG("ECH rejected but server negotiated PSK");
                return INVALID_PARAMETER;
            }
#endif
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
            if (ssl->options.certWithExternPsk && psk->resumption) {
                /* RFC 9973 mode requires external PSK, not ticket resumption. */
                WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                return PSK_KEY_ERROR;
            }
            if (ssl->options.certWithExternPsk && ssl->options.shSentKeyShare == 0) {
                /* RFC 9973 Sect. 3: cert_with_extern_psk requires psk_dhe_ke;
                 * a ServerHello without a key_share confirms only psk_ke. */
                WOLFSSL_MSG("cert_with_extern_psk: ServerHello missing key_share");
                WOLFSSL_ERROR_VERBOSE(EXT_MISSING);
                return EXT_MISSING;
            }
#endif
            if ((ret = SetupPskKey(ssl, psk, 0)) != 0)
                return ret;
            ssl->options.pskNegotiated = 1;
        }
#else
        /* no resumption possible */
        ssl->options.resuming = 0;
#endif

        /* sanity check on PSK / KSE */
        if (
    #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
            ssl->options.pskNegotiated == 0 &&
    #endif
            (ssl->session->namedGroup == 0 ||
             ssl->options.shSentKeyShare == 0)) {
            return EXT_MISSING;
        }

        ssl->keys.encryptionOn = 1;
        ssl->options.serverState = SERVER_HELLO_COMPLETE;

    }
    else {
        /* https://datatracker.ietf.org/doc/html/rfc8446#section-4.1.4
         * Clients MUST abort the handshake with an
         * "illegal_parameter" alert if the HelloRetryRequest would not result
         * in any change in the ClientHello.
         */
        /* Check if the HRR contained a cookie or a keyshare */
        if (!ssl->options.hrrSentKeyShare
#ifdef WOLFSSL_TLS13_COOKIE
                && !ssl->options.hrrSentCookie
#endif
                ) {
            SendAlert(ssl, alert_fatal, illegal_parameter);
            return EXT_MISSING;
        }

        ssl->options.tls1_3 = 1;
        ssl->options.serverState = SERVER_HELLO_RETRY_REQUEST_COMPLETE;

        ret = RestartHandshakeHash(ssl);
    }

    break;
    } /* case TLS_ASYNC_FINALIZE */
    default:
        ret = INPUT_CASE_ERROR;
    } /* switch (ssl->options.asyncState) */

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ret == 0) {
        FreeAsyncCtx(ssl, 0);
        /* Replays skip the sanity check that re-sets got_server_hello;
         * restore on completion (not for HRR, which re-counts it). */
        if (*extMsgType == server_hello &&
                ssl->msgsReceived.got_server_hello == 0) {
            ssl->msgsReceived.got_server_hello = 1;
        }
    }
#endif

    WOLFSSL_LEAVE("DoTls13ServerHello", ret);
    WOLFSSL_END(WC_FUNC_SERVER_HELLO_DO);

    return ret;
}

/* handle processing TLS 1.3 encrypted_extensions (8) */
/* Parse and handle an EncryptedExtensions message.
 * Only a client will receive this message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of
 *           EncryptedExtensions.
 *           On exit, the index of byte after the EncryptedExtensions
 *           message.
 * totalSz   The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */
static int DoTls13EncryptedExtensions(WOLFSSL* ssl, const byte* input,
                                      word32* inOutIdx, word32 totalSz)
{
    int    ret;
    word32 begin = *inOutIdx;
    word32 i = begin;
    word16 totalExtSz;

    WOLFSSL_START(WC_FUNC_ENCRYPTED_EXTENSIONS_DO);
    WOLFSSL_ENTER("DoTls13EncryptedExtensions");

#ifdef WOLFSSL_CALLBACKS
    if (ssl->hsInfoOn) AddPacketName(ssl, "EncryptedExtensions");
    if (ssl->toInfoOn) AddLateName("EncryptedExtensions", &ssl->timeoutInfo);
#endif

    /* Length field of extension data. */
    if (totalSz < OPAQUE16_LEN)
        return BUFFER_ERROR;
    ato16(&input[i], &totalExtSz);
    i += OPAQUE16_LEN;

    /* Extension data. */
    if (i - begin + totalExtSz != totalSz)
        return BUFFER_ERROR;
    if ((ret = TLSX_Parse(ssl, input + i, totalExtSz, encrypted_extensions,
                                                                       NULL))) {
        return ret;
    }

    /* Move index to byte after message. */
    *inOutIdx = i + totalExtSz;

#ifdef WOLFSSL_EARLY_DATA
    if (ssl->earlyData != no_early_data) {
        TLSX* ext = TLSX_Find(ssl->extensions, TLSX_EARLY_DATA);
        if (ext == NULL || !ext->val) {
            WOLFSSL_MSG("Early data rejected by server (no early_data "
                        "EncryptedExtensions response)");
            ssl->earlyData = no_early_data;
        }
    }

    if (ssl->earlyData == no_early_data) {
        ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY);
        if (ret != 0)
            return ret;
    }
#endif /* WOLFSSL_EARLY_DATA */

    ssl->options.serverState = SERVER_ENCRYPTED_EXTENSIONS_COMPLETE;

    WOLFSSL_LEAVE("DoTls13EncryptedExtensions", ret);
    WOLFSSL_END(WC_FUNC_ENCRYPTED_EXTENSIONS_DO);

    return ret;
}

#ifndef NO_CERTS
/* handle processing TLS v1.3 certificate_request (13) */
/* Handle a TLS v1.3 CertificateRequest message.
 * This message is always encrypted.
 * Only a client will receive this message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of CertificateRequest.
 *           On exit, the index of byte after the CertificateRequest message.
 * size      The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */
static int DoTls13CertificateRequest(WOLFSSL* ssl, const byte* input,
                                     word32* inOutIdx, word32 size)
{
    word16      len;
    word32      begin = *inOutIdx;
    int         ret = 0;
    Suites      peerSuites;
#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    word16      reqCtxLen;
    const byte* reqCtxData;
#endif

    WOLFSSL_START(WC_FUNC_CERTIFICATE_REQUEST_DO);
    WOLFSSL_ENTER("DoTls13CertificateRequest");

    XMEMSET(&peerSuites, 0, sizeof(Suites));
#if !defined(WOLFSSL_NO_SIGALG)
    /* Post-handshake auth can deliver several requests; each one's cert
     * signature algorithms replace the last rather than adding to them. */
    ssl->certHashSigAlgoSz = 0;
#endif

#ifdef WOLFSSL_CALLBACKS
    if (ssl->hsInfoOn) AddPacketName(ssl, "CertificateRequest");
    if (ssl->toInfoOn) AddLateName("CertificateRequest", &ssl->timeoutInfo);
#endif

    if (OPAQUE8_LEN > size)
        return BUFFER_ERROR;

    /* Length of the request context. */
    len = input[(*inOutIdx)++];
    if ((*inOutIdx - begin) + len > size)
        return BUFFER_ERROR;
    /* INVALID_PARAMETER does not map to illegal_parameter in the central
     * alert path, so emit the alert explicitly before returning. */
    if (ssl->options.connectState < FINISHED_DONE) {
        /* RFC 8446 Section 4.3.2: in the handshake the context is zero
         * length. */
        if (len > 0) {
            SendAlert(ssl, alert_fatal, illegal_parameter);
            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
            return INVALID_PARAMETER;
        }
    }
#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
#ifdef WOLFSSL_QUIC
    else if (WOLFSSL_IS_QUIC(ssl)) {
        WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
        return OUT_OF_ORDER_E;
    }
#endif
    else if (len == 0) {
        /* RFC 8446 Section 4.3.2: a post-handshake CertificateRequest context
         * MUST be non-empty and unique for the connection. */
        SendAlert(ssl, alert_fatal, illegal_parameter);
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }
#endif

#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    /* Remember the request context bytes; the CertReqCtx allocation and
     * linking into ssl->certReqCtx is deferred until after the rest of the
     * message has been validated.
     */
    reqCtxLen = len;
    reqCtxData = input + *inOutIdx;
    /* Reject a context that duplicates one still pending on the connection. */
    if (ssl->options.connectState >= FINISHED_DONE) {
        CertReqCtx* dup;
        for (dup = ssl->certReqCtx; dup != NULL; dup = dup->next) {
            if (dup->len == reqCtxLen &&
                    XMEMCMP(&dup->ctx, reqCtxData, reqCtxLen) == 0) {
                SendAlert(ssl, alert_fatal, illegal_parameter);
                WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
                return INVALID_PARAMETER;
            }
        }
    }
#endif
    *inOutIdx += len;

    /* TODO: Add support for more extensions:
     *   signed_certificate_timestamp, certificate_authorities, oid_filters.
     */
    /* Certificate extensions */
    if ((*inOutIdx - begin) + OPAQUE16_LEN > size)
        return BUFFER_ERROR;
    ato16(input + *inOutIdx, &len);
    *inOutIdx += OPAQUE16_LEN;
    if ((*inOutIdx - begin) + len > size)
        return BUFFER_ERROR;
    /* RFC 9846 Section 4.4.2: CertificateRequest.extensions has a lower bound of
     * 0, so an empty extensions block is parsed rather than rejected here. A
     * request missing the mandatory signature_algorithms extension is caught by
     * the check below. */
    if ((ret = TLSX_Parse(ssl, input + *inOutIdx, len, certificate_request,
                                                                &peerSuites))) {
        return ret;
    }
    *inOutIdx += len;

    /* No trailing bytes allowed (RFC 8446 4.3.2). */
    if ((*inOutIdx - begin) != size)
        return BUFFER_ERROR;

    /* RFC 8446 Section 4.3.2: the signature_algorithms extension MUST be
     * present in a CertificateRequest. */
    if (peerSuites.hashSigAlgoSz == 0) {
        SendAlert(ssl, alert_fatal, missing_extension);
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }

#if !defined(NO_CERTS) && !defined(WOLFSSL_NO_SIGALG)
    SetPeerSha1CertOk(ssl, &peerSuites);
#endif

#ifdef WOLFSSL_CERT_SETUP_CB
    if ((ret = CertSetupCbWrapper(ssl)) != 0)
        return ret;
#endif

#if defined(HAVE_ECH)
    /* RFC 9849 s6.1.7: ECH was offered but rejected by the server...
     * the client MUST respond with an empty Certificate message. */
    if (ssl->echConfigs != NULL && !ssl->options.disableECH &&
            !ssl->options.echAccepted) {
        ssl->options.sendVerify = SEND_BLANK_CERT;
    }
    else
#endif
    if ((ssl->buffers.certificate && ssl->buffers.certificate->buffer &&
        ((ssl->buffers.key && ssl->buffers.key->buffer)
        #ifdef HAVE_PK_CALLBACKS
            || wolfSSL_CTX_IsPrivatePkSet(ssl->ctx)
        #endif
    ))
        #ifdef OPENSSL_EXTRA
            || ssl->ctx->certSetupCb != NULL
        #endif
            ) {
        if (PickHashSigAlgo(ssl, peerSuites.hashSigAlgo,
                            peerSuites.hashSigAlgoSz, 0) != 0) {
            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
            return INVALID_PARAMETER;
        }
        ssl->options.sendVerify = SEND_CERT;
    }
    else {
#ifndef WOLFSSL_NO_CLIENT_CERT_ERROR
        ssl->options.sendVerify = SEND_BLANK_CERT;
#else
        WOLFSSL_MSG("Certificate required but none set on client");
        /* RFC 8446 Section 4.4.2.4: send certificate_required when a
         * peer (here, the client) cannot provide a certificate that the
         * other peer required. */
        SendAlert(ssl, alert_fatal, certificate_required);
        WOLFSSL_ERROR_VERBOSE(NO_CERT_ERROR);
        return NO_CERT_ERROR;
#endif
    }

#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    {
        /* CertReqCtx has one byte at end for context value.
        * Increase size to handle other implementations sending more than one byte.
        * That is, allocate extra space, over one byte, to hold the context value.
        */
        CertReqCtx* certReqCtx = (CertReqCtx*)XMALLOC(
            sizeof(CertReqCtx) + (reqCtxLen == 0 ? 0 : reqCtxLen - 1),
            ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
        if (certReqCtx == NULL)
            return MEMORY_E;
        certReqCtx->next = ssl->certReqCtx;
        certReqCtx->len = reqCtxLen;
        XMEMCPY(&certReqCtx->ctx, reqCtxData, reqCtxLen);
        ssl->certReqCtx = certReqCtx;
    }
#endif

    WOLFSSL_LEAVE("DoTls13CertificateRequest", ret);
    WOLFSSL_END(WC_FUNC_CERTIFICATE_REQUEST_DO);

    return ret;
}
#endif /* !NO_CERTS */
#endif /* !NO_WOLFSSL_CLIENT */

#ifndef NO_WOLFSSL_SERVER
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
#ifndef NO_PSK
int FindPskSuite(const WOLFSSL* ssl, PreSharedKey* psk, byte* psk_key,
        word32* psk_keySz, const byte* suite, int* found, byte* foundSuite)
{
    const char* cipherName = NULL;
    byte        cipherSuite0 = TLS13_BYTE;
    byte        cipherSuite  = WOLFSSL_DEF_PSK_CIPHER;
    int         ret = 0;

    *found = 0;
    (void)suite;

    if (ssl->options.server_psk_tls13_cb != NULL) {
         *psk_keySz = ssl->options.server_psk_tls13_cb((WOLFSSL*)ssl,
             (char*)psk->identity, psk_key, MAX_PSK_KEY_LEN, &cipherName);
         if (*psk_keySz != 0) {
             int cipherSuiteFlags = WOLFSSL_CIPHER_SUITE_FLAG_NONE;
             *found = (GetCipherSuiteFromName(cipherName, &cipherSuite0,
                 &cipherSuite, NULL, NULL, &cipherSuiteFlags) == 0);
             (void)cipherSuiteFlags;
         }
    }
    if (*found == 0 && (ssl->options.server_psk_cb != NULL)) {
         *psk_keySz = ssl->options.server_psk_cb((WOLFSSL*)ssl,
                             (char*)psk->identity, psk_key,
                             MAX_PSK_KEY_LEN);
         *found = (*psk_keySz != 0);
    }
    if (*found) {
        if (*psk_keySz > MAX_PSK_KEY_LEN &&
            (int)*psk_keySz != WC_NO_ERR_TRACE(USE_HW_PSK)) {
            WOLFSSL_MSG("Key len too long in FindPsk()");
            ret = PSK_KEY_ERROR;
            WOLFSSL_ERROR_VERBOSE(ret);
            *found = 0;
        }
        if (ret == 0) {
        #if !defined(WOLFSSL_PSK_ONE_ID) && !defined(WOLFSSL_PRIORITIZE_PSK)
            /* Check whether PSK ciphersuite is in SSL. */
            *found = (suite[0] == cipherSuite0) && (suite[1] == cipherSuite);
        #else
            (void)suite;
            /* Check whether PSK ciphersuite is in SSL. */
            {
                byte s[2] = {
                    cipherSuite0,
                    cipherSuite,
                };
                *found = FindSuiteSSL(ssl, s);
            }
        #endif
        }
    }
    if (*found && foundSuite != NULL) {
        foundSuite[0] = cipherSuite0;
        foundSuite[1] = cipherSuite;
    }

    return ret;
}

/* Attempt to find the PSK (not session ticket) that matches.
 *
 * @param [in, out] ssl    The SSL/TLS object.
 * @param [in]      psk    A pre-shared key from the extension.
 * @param [out]     suite  Cipher suite to use with PSK.
 * @param [out]     err    Error code.
 *                         PSK_KEY_ERROR when key is too big,
 *                         UNSUPPORTED_SUITE on invalid suite.
 *                         Other error when attempting to derive early secret.
 * @return  1 when a match found - but check error code.
 * @return  0 when no match found.
 */
static int FindPsk(WOLFSSL* ssl, PreSharedKey* psk, const byte* suite, int* err)
{
    int         ret = 0;
    int         found = 0;
    byte        foundSuite[SUITE_LEN];

    WOLFSSL_ENTER("FindPsk");

    XMEMSET(foundSuite, 0, sizeof(foundSuite));

    ret = FindPskSuite(ssl, psk, ssl->arrays->psk_key, &ssl->arrays->psk_keySz,
                       suite, &found, foundSuite);
    if (ret == 0 && found) {
        /* This identity matched via external PSK callback, not ticket resume. */
        psk->resumption = 0;
        /* Default to ciphersuite if cb doesn't specify. */
        ssl->options.resuming = 0;
        /* Don't send certificate request when using PSK. */
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
        if (!ssl->options.certWithExternPsk)
#endif
            ssl->options.verifyPeer = 0;

        /* obfuscated_ticket_age is not checked: RFC 8446 Section 4.2.11
         * requires servers to ignore it for an external identity. */
        /* Set PSK ciphersuite into SSL. */
        ssl->options.cipherSuite0 = foundSuite[0];
        ssl->options.cipherSuite  = foundSuite[1];
        ret = SetCipherSpecs(ssl);
        if (ret == 0) {
            /* Derive the early secret using the PSK. */
            ret = DeriveEarlySecret(ssl);
        }
        if (ret == 0) {
            /* PSK negotiation has succeeded */
            ssl->options.isPSK = 1;
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
            if (!ssl->options.certWithExternPsk)
#endif
            {
                /* SERVER: using PSK for peer authentication. */
                ssl->options.peerAuthGood = 1;
            }
        }
    }

    *err = ret;
    WOLFSSL_LEAVE("FindPsk", found);
    WOLFSSL_LEAVE("FindPsk", ret);
    return found;
}
#endif /* !NO_PSK */

/* Handle any Pre-Shared Key (PSK) extension.
 * Find a PSK that supports the cipher suite passed in.
 *
 * ssl         SSL/TLS object.
 * suite       Cipher suite to find PSK for.
 * usingPSK    1=Indicates handshake is using Pre-Shared Keys (2=Ephemeral)
 * first       Set to 1 if first in extension
 * returns 0 on success and otherwise failure.
 */
static int DoPreSharedKeys(WOLFSSL* ssl, const byte* input, word32 inputSz,
    const byte* suite, int* usingPSK, int* first)
{
    int           ret = 0;
    TLSX*         ext;
    PreSharedKey* current;
    byte          binderKey[WC_MAX_DIGEST_SIZE];
    byte          binder[WC_MAX_DIGEST_SIZE];
    word32        binderLen;
#if defined(WOLFSSL_CERT_WITH_EXTERN_PSK) && defined(HAVE_SESSION_TICKET)
    int           certWithExternOffered = 0;
#endif

    #ifdef NO_PSK
        (void) suite; /* to avoid unused var warning when not used */
    #endif

    WOLFSSL_ENTER("DoPreSharedKeys");

    (void)suite;

#ifdef WOLFSSL_CHECK_MEM_ZERO
    /* Poison and register binderKey up front; every exit below (including the
     * error paths) funnels through the cleanup label which zeroes it. */
    XMEMSET(binderKey, 0xff, sizeof(binderKey));
    wc_MemZero_Add("DoPreSharedKeys binderKey", binderKey, sizeof(binderKey));
#endif

#if defined(HAVE_SESSION_TICKET) && defined(WOLFSSL_EARLY_DATA)
    ssl->options.ticketPredatesCtx = 0;
#endif

    ext = TLSX_Find(ssl->extensions, TLSX_PRE_SHARED_KEY);
    if (ext == NULL) {
        WOLFSSL_MSG("No pre shared extension keys found");
        ret = BAD_FUNC_ARG;
        goto cleanup;
    }
#if defined(WOLFSSL_CERT_WITH_EXTERN_PSK) && defined(HAVE_SESSION_TICKET)
    certWithExternOffered =
        TLSX_Find(ssl->extensions, TLSX_CERT_WITH_EXTERN_PSK) != NULL;
#endif

    /* Look through all client's pre-shared keys for a match. */
    for (current = (PreSharedKey*)ext->data; current != NULL;
            current = current->next) {
    #ifndef NO_PSK
        if (current->identityLen > MAX_PSK_ID_LEN) {
            ret = BUFFER_ERROR;
            goto cleanup;
        }
        XMEMCPY(ssl->arrays->client_identity, current->identity,
                current->identityLen);
        ssl->arrays->client_identity[current->identityLen] = '\0';
    #endif

    #ifdef HAVE_SESSION_TICKET
        /* Decode the identity. */
        switch (current->decryptRet) {
            case PSK_DECRYPT_NONE:
                ret = DoClientTicket_ex(ssl, current, 1);
                /* psk->sess may be set. Need to clean up later. */
                break;
            case PSK_DECRYPT_OK:
                ret = WOLFSSL_TICKET_RET_OK;
                break;
            case PSK_DECRYPT_CREATE:
                ret = WOLFSSL_TICKET_RET_CREATE;
                break;
            case PSK_DECRYPT_FAIL:
                ret = WOLFSSL_TICKET_RET_REJECT;
                break;
        }

        #ifdef WOLFSSL_ASYNC_CRYPT
        if (ret == WC_NO_ERR_TRACE(WC_PENDING_E))
            goto cleanup;
        #endif

        if (ret != WOLFSSL_TICKET_RET_OK && current->sess_free_cb != NULL) {
            current->sess_free_cb(ssl, current->sess,
                    &current->sess_free_cb_ctx);
            current->sess = NULL;
            current->sess_free_cb = NULL;
            XMEMSET(&current->sess_free_cb_ctx, 0,
                    sizeof(psk_sess_free_cb_ctx));
        }
        if (ret == WOLFSSL_TICKET_RET_OK) {
#if defined(WOLFSSL_CERT_WITH_EXTERN_PSK) && defined(HAVE_SESSION_TICKET)
            /* RFC 9973 Sect. 5.1: all PSKs listed alongside
             * tls_cert_with_extern_psk MUST be external PSKs.  A successfully
             * decrypted session ticket identity is a resumption PSK, so the
             * server MUST abort with illegal_parameter regardless of whether
             * the ticket would otherwise be acceptable.  Check here, before
             * DoClientTicketFinalize, to avoid polluting ssl->session with
             * ticket state that will not be used. */
            if (certWithExternOffered) {
                if (current->sess_free_cb != NULL) {
                    current->sess_free_cb(ssl, current->sess,
                            &current->sess_free_cb_ctx);
                    current->sess = NULL;
                    current->sess_free_cb = NULL;
                    XMEMSET(&current->sess_free_cb_ctx, 0,
                            sizeof(psk_sess_free_cb_ctx));
                }
                ret = PSK_KEY_ERROR;
                WOLFSSL_ERROR_VERBOSE(ret);
                goto cleanup;
            }
#endif
            ret = DoClientTicketCheck(ssl, current, ssl->timeout, suite);
        #if defined(HAVE_SNI) || defined(HAVE_ALPN)
            if (ret == 0) {
                /* Decline this PSK if the SNI/ALPN bound to the ticket
                 * does not match the current connection. RFC 6066 Sect.
                 * 3 mandates this for SNI; wolfSSL applies the same
                 * policy to ALPN as defense in depth. Skipping the PSK
                 * (rather than aborting) lets the server try the next
                 * candidate or fall back to a full handshake naturally
                 * without unwinding committed PSK state. ALPN_Select
                 * has already run earlier in DoTls13ClientHello so the
                 * negotiated ALPN is available to TicketAlpnHash. */
                byte curHash[TICKET_BINDING_HASH_SZ];
            #ifdef HAVE_SNI
                if (TicketSniHash(ssl, curHash) != 0 ||
                        XMEMCMP(curHash, current->it->sniHash,
                                TICKET_BINDING_HASH_SZ) != 0) {
                    WOLFSSL_MSG("Ticket SNI mismatch, skipping PSK");
                    ret = WOLFSSL_FATAL_ERROR;
                }
            #endif
            #ifdef HAVE_ALPN
                if (ret == 0 &&
                        (TicketAlpnHash(ssl, curHash) != 0 ||
                         XMEMCMP(curHash, current->it->alpnHash,
                                 TICKET_BINDING_HASH_SZ) != 0)) {
                    WOLFSSL_MSG("Ticket ALPN mismatch, skipping PSK");
                    ret = WOLFSSL_FATAL_ERROR;
                }
            #endif
            }
        #endif
            if (ret == 0)
                DoClientTicketFinalize(ssl, current->it, current->sess);
            if (current->sess_free_cb != NULL) {
                current->sess_free_cb(ssl, current->sess,
                        &current->sess_free_cb_ctx);
                current->sess = NULL;
                current->sess_free_cb = NULL;
                XMEMSET(&current->sess_free_cb_ctx, 0,
                        sizeof(psk_sess_free_cb_ctx));
            }
            if (ret != 0)
                continue;

            /* SERVER: using secret in session ticket for peer auth. */
            ssl->options.peerAuthGood = 1;

        #ifdef WOLFSSL_EARLY_DATA
            ssl->options.maxEarlyDataSz = ssl->session->maxEarlyDataSz;
            /* RFC 8446 Section 8.2: fresh servers should reject 0-RTT.
             * Flag tickets minted before this ctx was created. */
            if (!ssl->ctx->noFreshStartCheck) {
        #ifdef WOLFSSL_32BIT_MILLI_TIME
                /* A 32 bit ms clock wraps every ~49.7 days, so the ctx age is
                 * only exact while it stays below the max ticket age. Past
                 * that point DoClientTicketCheck has already rejected
                 * anything old enough to predate the ctx, so the check can be
                 * skipped.
                 *
                 * ctxAge is unsigned, so a clock reading before the ctx start
                 * time (a backward step) wraps to just under 2^32. Letting
                 * that count as an old ctx would silently disable the check
                 * and admit 0-RTT for tickets minted before a restart, so the
                 * near-wrap band stays in the checked range.
                 *
                 * The two cases are indistinguishable on a wrapping 32 bit
                 * clock, so a ctx aged between (2^32 - max ticket age) and
                 * 2^32 ms also lands in the band and refuses 0-RTT until it
                 * wraps out. Refusing 0-RTT only costs the early data round
                 * trip, so the ambiguity is resolved that way. */
                word32 maxAge = (word32)TLS13_MAX_TICKET_AGE * 1000;
                word32 now = TimeNowInMilliseconds();
                word32 ctxAge = now - ssl->ctx->ticketStartTime;
                word32 delta = ssl->ctx->ticketStartTime -
                               ssl->session->ticketSeen;
                ssl->options.ticketPredatesCtx =
                    (now != 0 &&
                     (ctxAge <= maxAge || ctxAge >= (word32)0u - maxAge) &&
                     delta != 0 &&
                     delta <= maxAge);
        #else
                ssl->options.ticketPredatesCtx =
                    (ssl->session->ticketSeen < ssl->ctx->ticketStartTime);
        #endif
            }
        #endif
            /* Use the same cipher suite as before and set up for use. */
            ssl->options.cipherSuite0   = ssl->session->cipherSuite0;
            ssl->options.cipherSuite    = ssl->session->cipherSuite;
            ret = SetCipherSpecs(ssl);
            if (ret != 0)
                goto cleanup;

            /* Resumption PSK is resumption master secret. */
            ssl->arrays->psk_keySz = ssl->specs.hash_size;
            if ((ret = DeriveResumptionPSK(ssl, ssl->session->ticketNonce.data,
                ssl->session->ticketNonce.len, ssl->arrays->psk_key)) != 0) {
                goto cleanup;
            }

            /* Derive the early secret using the PSK. */
            ret = DeriveEarlySecret(ssl);
            if (ret != 0)
                goto cleanup;

            /* Hash data up to binders for deriving binders in PSK extension.
             * A pended binder derive below re-enters DoTls13ClientHello at
             * TLS_ASYNC_BEGIN, so the hash is guarded to run only once. */
        #ifdef WOLFSSL_ASYNC_CRYPT
            if (!ssl->options.chHashInput)
        #endif
            {
                ret = HashInput(ssl, input, (int)inputSz);
                if (ret < 0)
                    goto cleanup;
            }
        #ifdef WOLFSSL_ASYNC_CRYPT
            ssl->options.chHashInput = 1;
        #endif

            /* Derive the binder key to use with HMAC. */
            ret = DeriveBinderKeyResume(ssl, binderKey);
            if (ret != 0)
                goto cleanup;
        }
        else
    #endif /* HAVE_SESSION_TICKET */
    #ifndef NO_PSK
        if (FindPsk(ssl, current, suite, &ret)) {
            if (ret != 0)
                goto cleanup;

        #ifdef WOLFSSL_ASYNC_CRYPT
            if (!ssl->options.chHashInput)
        #endif
            {
                ret = HashInput(ssl, input, (int)inputSz);
                if (ret < 0)
                    goto cleanup;
            }
        #ifdef WOLFSSL_ASYNC_CRYPT
            ssl->options.chHashInput = 1;
        #endif

            /* Derive the binder key to use with HMAC. */
            ret = DeriveBinderKey(ssl, binderKey);
            if (ret != 0)
                goto cleanup;
        }
        else
    #endif
        {
            continue;
        }

        ssl->options.sendVerify = 0;

        /* Derive the Finished message secret. */
        ret = DeriveFinishedSecret(ssl, binderKey,
                                   ssl->keys.client_write_MAC_secret,
                                   0 /* neither end */);
        if (ret != 0)
            goto cleanup;

        /* Derive the binder and compare with the one in the extension. */
        ret = BuildTls13HandshakeHmac(ssl,
                         ssl->keys.client_write_MAC_secret, binder, &binderLen);
        if (ret != 0)
            goto cleanup;
        if (binderLen != current->binderLen ||
                             ConstantCompare(binder, current->binder,
                                binderLen) != 0) {
            WOLFSSL_ERROR_VERBOSE(BAD_BINDER);
            ret = BAD_BINDER;
            goto cleanup;
        }

        /* This PSK works, no need to try any more. */
        current->chosen = 1;
        ext->resp = 1;
        break;
    }

    if (current == NULL) {
        ret = 0;
        goto cleanup;
    }

    *first = (current == ext->data);
    *usingPSK = 1;

cleanup:
    ForceZero(binderKey, sizeof(binderKey));
    ForceZero(binder, sizeof(binder));
#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Check(binderKey, sizeof(binderKey));
#endif
    WOLFSSL_LEAVE("DoPreSharedKeys", ret);

    return ret;
}

/* Check whether a PSK may be used given the key exchange modes the client
 * advertised and the modes this server is configured to allow.
 *
 * RFC 9846 Section 4.3.9 forbids selecting a mode the client did not list.
 * Section 4.3.11 says a server that finds no acceptable PSK should perform a
 * non-PSK handshake instead of aborting. Deciding before a PSK is selected
 * leaves nothing to unwind: no ticket is decrypted, no binder is verified, no
 * secret is derived and no early data is accepted.
 *
 * The configured policy is read, not ssl->options.noPskDheKe, which also
 * carries negotiated state and is cleared by every certificate handshake.
 *
 * ssl         SSL/TLS object.
 * clSuites    Client's cipher suite list.
 * returns 1 when PSK selection may proceed and 0 when the PSK must be ignored.
 */
static int PskModesUsable(const WOLFSSL* ssl, const Suites* clSuites)
{
#ifdef HAVE_SUPPORTED_CURVES
    TLSX*  ext;
    word32 modes;

    /* Offering pre_shared_key without psk_key_exchange_modes is a MUST-level
     * abort (Section 4.3.9). Leave it to CheckPreSharedKeys. */
    ext = TLSX_Find(ssl->extensions, TLSX_PSK_KEY_EXCHANGE_MODES);
    if (ext == NULL)
        return 1;
    modes = ext->val;

#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
    /* RFC 9973 requires psk_dhe_ke and overrides the no-(EC)DHE policy, so a
     * mismatch must abort rather than fall back. */
    if (TLSX_Find(ssl->extensions, TLSX_CERT_WITH_EXTERN_PSK) != NULL)
        return 1;
#endif

    /* Only decline when a certificate handshake can actually run instead.
     * These are the same two things DoTls13ClientHello() requires of a
     * ClientHello that negotiates no PSK. */
    if (TLSX_Find(ssl->extensions, TLSX_KEY_SHARE) == NULL)
        return 1;
    if (clSuites == NULL || clSuites->hashSigAlgoSz == 0)
        return 1;

    if ((modes & (1 << PSK_DHE_KE)) != 0 && !ssl->options.noPskDheKePolicy)
        return 1;
    if (ssl->options.onlyPskDheKe)
        return 0;
    return (modes & (1 << PSK_KE)) != 0;
#else
    /* Without (EC)DHE there is no certificate handshake to fall back to. */
    (void)ssl;
    (void)clSuites;
    return 1;
#endif
}

/* Handle any Pre-Shared Key (PSK) extension.
 * Must do this in ClientHello as it requires a hash of the truncated message.
 * Don't know size of binders until Pre-Shared Key extension has been parsed.
 *
 * ssl         SSL/TLS object.
 * input       ClientHello message.
 * helloSz     Size of the ClientHello message (including binders if present).
 * clSuites    Client's cipher suite list.
 * usingPSK    Indicates handshake is using Pre-Shared Keys.
 */
static int CheckPreSharedKeys(WOLFSSL* ssl, const byte* input, word32 helloSz,
                              Suites* clSuites, int* usingPSK)
{
    int    ret;
    TLSX*  ext;
    word16 bindersLen;
    int    first = 0;
    int    usePsk;
#ifndef WOLFSSL_PSK_ONE_ID
    int    i;
    const Suites* suites;
#else
    byte   suite[2];
#endif

    WOLFSSL_ENTER("CheckPreSharedKeys");

    ext = TLSX_Find(ssl->extensions, TLSX_PRE_SHARED_KEY);
    if (ext == NULL) {
#ifdef WOLFSSL_EARLY_DATA
        ssl->earlyData = no_early_data;
#endif
        if (usingPSK)
            *usingPSK = 0;

        /* No PSK extension at all: if a mandatory external PSK is configured,
         * refuse the connection rather than continue without one. havePSK is
         * only set by an external-PSK callback, so a peer relying solely on
         * session-ticket resumption is unaffected. */
        if (ssl->options.havePSK && ssl->options.failNoPSK) {
            WOLFSSL_ERROR_VERBOSE(PSK_MISSING_ERROR);
            return PSK_MISSING_ERROR;
        }

        /* Hash data up to binders for deriving binders in PSK extension. */
        ret = HashInput(ssl, input,  (int)helloSz);
        return ret;
    }

    /* Wire-order check that PSK was the last extension in ClientHello is
     * performed in DoTls13ClientHello immediately after TLSX_Parse, since
     * post-parse code (e.g. ALPN_Select via TLSX_SetALPN) may legitimately
     * prepend new entries to ssl->extensions before this point and would
     * otherwise trip a head-of-list check here. */

    /* Assume we are going to resume with a pre-shared key. */
    ssl->options.resuming = 1;

    /* Find the pre-shared key extension and calculate hash of truncated
     * ClientHello for binders.
     */
    ret = TLSX_PreSharedKey_GetSizeBinders((PreSharedKey*)ext->data,
                                                     client_hello, &bindersLen);
    if (ret < 0)
        return ret;
    if (bindersLen > helloSz)
        return BUFFER_ERROR;

    /* Refine list for PSK processing. */
    sslRefineSuites(ssl, clSuites);

    usePsk = PskModesUsable(ssl, clSuites);
    if (!usePsk) {
        WOLFSSL_MSG("No usable psk_key_exchange_modes, ignoring PSK");
    }

#ifndef WOLFSSL_PSK_ONE_ID
    if (usingPSK == NULL)
        return BAD_FUNC_ARG;

    /* set after refineSuites, to avoid taking a stale ptr to ctx->Suites */
    suites = WOLFSSL_SUITES(ssl);
    /* Server list has only common suites from refining in server or client
     * order. */
    for (i = 0; usePsk && !(*usingPSK) && i < suites->suiteSz; i += 2) {
        ret = DoPreSharedKeys(ssl, input, helloSz - bindersLen,
                suites->suites + i, usingPSK, &first);
        if (ret != 0) {
#ifdef HAVE_SESSION_TICKET
#ifdef WOLFSSL_ASYNC_CRYPT
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
#endif
                CleanupClientTickets((PreSharedKey*)ext->data);
#endif
            WOLFSSL_MSG_EX("DoPreSharedKeys: %d", ret);
            return ret;
        }
    }
#ifdef HAVE_SESSION_TICKET
    CleanupClientTickets((PreSharedKey*)ext->data);
#endif
#else
    if (usePsk) {
        ret = DoPreSharedKeys(ssl, input, helloSz - bindersLen, suite, usingPSK,
            &first);
        if (ret != 0) {
            WOLFSSL_MSG_EX("DoPreSharedKeys: %d", ret);
            return ret;
        }
    }
#endif

    if (!*usingPSK) {
        /* No suitable PSK was negotiated. When a mandatory external PSK is
         * configured, fail with a dedicated error instead of falling back to a
         * certificate handshake. This must run before the no-certificate
         * BAD_BINDER check below so a PSK-only server (no cert) still reports
         * PSK_MISSING_ERROR. havePSK is only set by an external-PSK callback, so
         * a peer relying solely on session-ticket resumption is unaffected. */
        if (ssl->options.havePSK && ssl->options.failNoPSK) {
            WOLFSSL_ERROR_VERBOSE(PSK_MISSING_ERROR);
            return PSK_MISSING_ERROR;
        }
    #ifndef NO_CERTS
        if (ssl->buffers.certificate == NULL
        #ifdef WOLFSSL_CERT_SETUP_CB
                && ssl->ctx->certSetupCb == NULL
        #endif
                )
    #endif
        {
            /* Reused for identity protection: an unknown identity must look
             * like a bad binder, so keep the error code shared. */
            WOLFSSL_ERROR_VERBOSE(BAD_BINDER);
            return BAD_BINDER;
        }
    }

    if (*usingPSK) {
        /* While verifying the selected PSK, we updated the
         * handshake hash up to the binder bytes in the PSK extensions.
         * Continuing, we need the rest of the ClientHello hashed as well.
         */
        ret = HashRaw(ssl, input + helloSz - bindersLen, bindersLen);
    }
    else {
        /* No suitable PSK found, Hash the complete ClientHello,
         * as caller expect it after we return */
        ret = HashInput(ssl, input,  (int)helloSz);
    }
    if (ret != 0)
        return ret;

    if (*usingPSK != 0) {
        word32 modes;
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
        int usingCertWithExternPsk = 0;
        TLSX* certExt = NULL;
        TLSX* pskExt = NULL;
        PreSharedKey* chosenPsk = NULL;
#endif
    #ifdef WOLFSSL_EARLY_DATA
        TLSX*  extEarlyData;
    #ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
        int hasCertWithExternPsk = (TLSX_Find(ssl->extensions,
                                    TLSX_CERT_WITH_EXTERN_PSK) != NULL);
    #endif

        extEarlyData = TLSX_Find(ssl->extensions, TLSX_EARLY_DATA);
        if (extEarlyData != NULL) {
            /* Check if accepting early data and first PSK.
             * RFC 9973: early_data is not compatible with
             * cert_with_extern_psk, so skip key derivation in that case. */
            if (ssl->earlyData != no_early_data && first
                && ssl->options.maxEarlyDataSz > 0
    #ifdef HAVE_SESSION_TICKET
                /* RFC 8446 section 8.2: freshly started servers should
                 * reject 0-RTT. Tickets minted before this ctx was created
                 * belong to a previous instance. */
                && !ssl->options.ticketPredatesCtx
    #endif
    #ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
                && !hasCertWithExternPsk
    #endif
    #if defined(HAVE_SESSION_TICKET) && !defined(NO_SESSION_CACHE)
                /* RFC 8446 section 8: evict the session from the cache.
                 * Accept 0-RTT only when the eviction found the entry
                 * (single-use). */
                && wolfSSL_SSL_CTX_remove_session(ssl->ctx, ssl->session)
                    == 1
    #endif
            ) {
                extEarlyData->resp = 1;

                /* Derive early data decryption key. */
                ret = DeriveTls13Keys(ssl, early_data_key, DECRYPT_SIDE_ONLY,
                                                                             1);
                if (ret != 0)
                    return ret;
                if ((ret = SetKeysSide(ssl, DECRYPT_SIDE_ONLY)) != 0)
                    return ret;

                ssl->keys.encryptionOn = 1;
                ssl->earlyData = process_early_data;
            }
            else
                extEarlyData->resp = 0;
        }
    #endif

        /* Get the PSK key exchange modes the client wants to negotiate. */
        ext = TLSX_Find(ssl->extensions, TLSX_PSK_KEY_EXCHANGE_MODES);
        if (ext == NULL) {
            WOLFSSL_ERROR_VERBOSE(MISSING_HANDSHAKE_DATA);
            return MISSING_HANDSHAKE_DATA;
        }
        modes = ext->val;

    #ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
        certExt = TLSX_Find(ssl->extensions, TLSX_CERT_WITH_EXTERN_PSK);
        if (certExt != NULL) {
            pskExt = TLSX_Find(ssl->extensions, TLSX_PRE_SHARED_KEY);
            if (pskExt != NULL)
                chosenPsk = (PreSharedKey*)pskExt->data;
            while (chosenPsk != NULL && !chosenPsk->chosen)
                chosenPsk = chosenPsk->next;
            if (chosenPsk == NULL || chosenPsk->resumption) {
                WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                return PSK_KEY_ERROR;
            }
            if ((modes & (1 << PSK_DHE_KE)) == 0) {
                WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                return PSK_KEY_ERROR;
            }
            usingCertWithExternPsk = 1;
            ssl->options.certWithExternPsk = 1;
            if (clSuites->hashSigAlgoSz == 0) {
                WOLFSSL_ERROR_VERBOSE(MISSING_HANDSHAKE_DATA);
                return MISSING_HANDSHAKE_DATA;
            }
            ret = PickHashSigAlgo(ssl, clSuites->hashSigAlgo,
                                  clSuites->hashSigAlgoSz, 1);
            if (ret != 0)
                return ret;
            ssl->options.sendVerify = SEND_CERT;
            certExt->resp = 1;
        #ifdef WOLFSSL_EARLY_DATA
            /* RFC 9973: early_data is not compatible with
             * cert_with_extern_psk.  TLSX_Parse already rejects the
             * combination in the ClientHello, but clear the response flag
             * here as a defense-in-depth measure. */
            if (extEarlyData != NULL) {
                WOLFSSL_MSG("Rejecting early data: "
                            "cert_with_extern_psk is not 0-RTT compatible");
                extEarlyData->resp = 0;
                ssl->earlyData = no_early_data;
            }
        #endif
        }
        else {
            ssl->options.certWithExternPsk = 0;
        }
    #endif

#ifndef HAVE_SUPPORTED_CURVES
    #ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
        if (usingCertWithExternPsk) {
            WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
            return PSK_KEY_ERROR;
        }
    #endif
#endif
    #ifdef HAVE_SUPPORTED_CURVES
        ext = TLSX_Find(ssl->extensions, TLSX_KEY_SHARE);
        /* Use (EC)DHE for forward-security if possible. */
        if (((modes & (1 << PSK_DHE_KE)) != 0 &&
             !ssl->options.noPskDheKePolicy && ext != NULL)
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
             || usingCertWithExternPsk
#endif
        ) {
            if (ext == NULL) {
                WOLFSSL_ERROR_VERBOSE(EXT_MISSING);
                return EXT_MISSING;
            }
            /* Resumption path uses previous session group. */
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
            if (!usingCertWithExternPsk)
#endif
                ssl->namedGroup = ssl->session->namedGroup;
            *usingPSK = 2; /* generate new ephemeral key */
        }
        else if (ssl->options.onlyPskDheKe ||
                 (ssl->options.failNoPSK && !ssl->options.resuming)) {
            /* A mandatory external PSK (failNoPSK) must be combined with
             * (EC)DHE for forward secrecy, so reject a pure psk_ke
             * negotiation. Session-ticket resumption is exempt.
             * onlyPskDheKe only reaches here when PskModesUsable() could not
             * decline, i.e. there is no certificate handshake to fall back
             * to. */
            WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
            return PSK_KEY_ERROR;
        }
        else
    #endif
        {
            if ((modes & (1 << PSK_KE)) == 0) {
                WOLFSSL_MSG("psk_ke mode does not allow key share");
                WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
                return PSK_KEY_ERROR;
            }
            ssl->options.noPskDheKe = 1;
            ssl->arrays->preMasterSz = 0;

            *usingPSK = 1;
        }
    }
    else {
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
        /* If no PSK is found, we remove the extension to make sure it
         * is not sent back to the client */
        TLSX_Remove(&ssl->extensions, TLSX_CERT_WITH_EXTERN_PSK, ssl->heap);
        ssl->options.certWithExternPsk = 0;
#endif
        /* No PSK negotiated; the check above already aborted when there is no
         * certificate. Fall through so the trace is emitted here too. */
    }

    WOLFSSL_LEAVE("CheckPreSharedKeys", ret);

    return 0;
}
#endif /* HAVE_SESSION_TICKET || !NO_PSK */

#if defined(WOLFSSL_SEND_HRR_COOKIE)
/* Compute the cookie integrity HMAC over the cookie data (and, for DTLS, the
 * peer address) using the given secret and compare it in constant time against
 * the MAC trailing the cookie.
 *
 * ssl        SSL/TLS object.
 * cookie     The cookie data - hash and MAC.
 * dataSz     Length of the cookie data preceding the trailing MAC.
 * secret     Secret to key the HMAC with.
 * secretSz   Length of the secret in bytes.
 * cookieType Digest type to use for the HMAC.
 * macSz      Length of the MAC in bytes.
 * returns 0 on match, HRR_COOKIE_ERROR on mismatch, otherwise a negative error.
 */
static int TlsCheckCookieMac(const WOLFSSL* ssl, const byte* cookie,
    word16 dataSz, const byte* secret, word32 secretSz, byte cookieType,
    byte macSz)
{
    int  ret;
    byte mac[WC_MAX_DIGEST_SIZE] = {0};
    WC_DECLARE_VAR(cookieHmac, Hmac, 1, ssl->heap);

    WC_ALLOC_VAR_EX(cookieHmac, Hmac, 1, ssl->heap, DYNAMIC_TYPE_HMAC,
                    return MEMORY_E);

    ret = wc_HmacInit(cookieHmac, ssl->heap, ssl->devId);
    if (ret == 0)
        ret = wc_HmacSetKey(cookieHmac, cookieType, secret, secretSz);
    if (ret == 0)
        ret = wc_HmacUpdate(cookieHmac, cookie, dataSz);
#ifdef WOLFSSL_DTLS13
    /* Tie cookie to peer address */
    if (ret == 0) {
        /* peerLock not necessary. Still in handshake phase. */
        if (ssl->options.dtls && ssl->buffers.dtlsCtx.peer.sz > 0) {
            ret = wc_HmacUpdate(cookieHmac,
                (byte*)ssl->buffers.dtlsCtx.peer.sa,
                ssl->buffers.dtlsCtx.peer.sz);
        }
    }
#endif
    if (ret == 0)
        ret = wc_HmacFinal(cookieHmac, mac);

    wc_HmacFree(cookieHmac);
    WC_FREE_VAR_EX(cookieHmac, ssl->heap, DYNAMIC_TYPE_HMAC);
    if (ret != 0)
        return ret;

    if (ConstantCompare(cookie + dataSz, mac, macSz) != 0)
        return HRR_COOKIE_ERROR;

    return 0;
}

/* Check that the Cookie data's integrity.
 *
 * ssl       SSL/TLS object.
 * cookie    The cookie data - hash and MAC.
 * cookieSz  The length of the cookie data in bytes.
 * returns Length of the hash on success, otherwise failure.
 */
int TlsCheckCookie(const WOLFSSL* ssl, const byte* cookie, word16 cookieSz)
{
    int  ret;
    byte cookieType = 0;
    byte macSz = 0;

#ifndef NO_SHA256
    cookieType = WC_SHA256;
    macSz = WC_SHA256_DIGEST_SIZE;
#elif defined(WOLFSSL_SHA384)
    cookieType = WC_SHA384;
    macSz = WC_SHA384_DIGEST_SIZE;
#elif defined(WOLFSSL_TLS13_SHA512)
    cookieType = WC_SHA512;
    macSz = WC_SHA512_DIGEST_SIZE;
#elif defined(WOLFSSL_SM3)
    cookieType = WC_SM3;
    macSz = WC_SM3_DIGEST_SIZE;
#else
    #error "No digest to available to use with HMAC for cookies."
#endif /* NO_SHA */

    if ((ssl->buffers.tls13CookieSecret.buffer == NULL ||
            ssl->buffers.tls13CookieSecret.length == 0)
#ifdef WOLFSSL_DTLS13
        && (ssl->buffers.tls13CookieSecretSecondary.buffer == NULL ||
            ssl->buffers.tls13CookieSecretSecondary.length == 0)
#endif
        ) {
        WOLFSSL_MSG("Missing DTLS 1.3 cookie secret");
        return COOKIE_ERROR;
    }

    if (cookieSz < ssl->specs.hash_size + macSz)
        return HRR_COOKIE_ERROR;
    cookieSz -= macSz;

    /* Verify against the primary secret first.  If that fails and a secondary
     * (verify-only) secret is configured, try that too.  This lets a stateless
     * DTLS 1.3 server keep accepting cookies issued under the secret it held
     * before an application-driven secret rotation.  The secondary secret is
     * DTLS 1.3 only, so its verify path is compiled in only for WOLFSSL_DTLS13. */
    ret = WC_NO_ERR_TRACE(HRR_COOKIE_ERROR);
    if (ssl->buffers.tls13CookieSecret.buffer != NULL &&
            ssl->buffers.tls13CookieSecret.length > 0) {
        ret = TlsCheckCookieMac(ssl, cookie, cookieSz,
            ssl->buffers.tls13CookieSecret.buffer,
            ssl->buffers.tls13CookieSecret.length, cookieType, macSz);
        if (ret != 0 && ret != WC_NO_ERR_TRACE(HRR_COOKIE_ERROR))
            return ret;
    }
#ifdef WOLFSSL_DTLS13
    if (ret == WC_NO_ERR_TRACE(HRR_COOKIE_ERROR) &&
            ssl->buffers.tls13CookieSecretSecondary.buffer != NULL &&
            ssl->buffers.tls13CookieSecretSecondary.length > 0) {
        ret = TlsCheckCookieMac(ssl, cookie, cookieSz,
            ssl->buffers.tls13CookieSecretSecondary.buffer,
            ssl->buffers.tls13CookieSecretSecondary.length, cookieType, macSz);
        if (ret != 0 && ret != WC_NO_ERR_TRACE(HRR_COOKIE_ERROR))
            return ret;
    }
#endif

    if (ret != 0) {
        WOLFSSL_ERROR_VERBOSE(HRR_COOKIE_ERROR);
        return HRR_COOKIE_ERROR;
    }

    return cookieSz;
}

/* Length of the KeyShare Extension */
#define HRR_KEY_SHARE_SZ   (OPAQUE16_LEN + OPAQUE16_LEN + OPAQUE16_LEN)
/* Length of the Supported Versions Extension */
#define HRR_VERSIONS_SZ    (OPAQUE16_LEN + OPAQUE16_LEN + OPAQUE16_LEN)
/* Length of the Cookie Extension excluding cookie data */
#define HRR_COOKIE_HDR_SZ  (OPAQUE16_LEN + OPAQUE16_LEN + OPAQUE16_LEN)
/* PV | Random | Session Id | CipherSuite | Compression | Ext Len */
#define HRR_BODY_SZ        (VERSION_SZ + RAN_LEN + ENUM_LEN + ID_LEN + \
                            SUITE_LEN + COMP_LEN + OPAQUE16_LEN)
/* HH | PV | CipherSuite | Ext Len | Key Share | Supported Version | Cookie */
#define MAX_HRR_SZ   (HRR_MAX_HS_HEADER_SZ   + \
                        HRR_BODY_SZ         + \
                          HRR_KEY_SHARE_SZ  + \
                          HRR_VERSIONS_SZ   + \
                          HRR_COOKIE_HDR_SZ)


/* Restart the handshake hash from the cookie value.
 *
 * ssl     SSL/TLS object.
 * cookie  Cookie data from client.
 * returns 0 on success, otherwise failure.
 */
static int RestartHandshakeHashWithCookie(WOLFSSL* ssl, Cookie* cookie)
{
    byte   header[HANDSHAKE_HEADER_SZ] = {0};
    byte   hrr[MAX_HRR_SZ] = {0};
    int    hrrIdx;
    word32 idx;
    byte   hashSz;
    byte*  cookieData;
    word16 cookieDataSz;
    word16 length;
    int    keyShareExt = 0;
    int    ret;
    byte   sessIdSz;

    ret = TlsCheckCookie(ssl, cookie->data, cookie->len);
    if (ret < 0)
        return ret;
    cookieDataSz = (word16)ret;
    hashSz = cookie->data[0];
    cookieData = cookie->data;
    idx = OPAQUE8_LEN;

    /* Restart handshake hash with synthetic message hash. */
    AddTls13HandShakeHeader(header, hashSz, 0, 0, message_hash, ssl);

    if ((ret = InitHandshakeHashes(ssl)) != 0)
        return ret;
    if ((ret = HashRaw(ssl, header, sizeof(header))) != 0)
        return ret;
#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("Restart Hash from Cookie");
    WOLFSSL_BUFFER(cookieData + idx, hashSz);
#endif
    if ((ret = HashRaw(ssl, cookieData + idx, hashSz)) != 0)
        return ret;

    /* Reconstruct the HelloRetryMessage for handshake hash. */
    sessIdSz = ssl->session->sessionIDSz;
#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_DTLS13_ECHO_LEGACY_SESSION_ID)
    /* RFC 9147 Section 5: a DTLS 1.3 server does not echo the session ID, so
     * the reconstructed transcript must not carry one either. */
    if (ssl->options.dtls)
        sessIdSz = 0;
#endif
    length = HRR_BODY_SZ - ID_LEN + sessIdSz +
             HRR_COOKIE_HDR_SZ + cookie->len;
    length += HRR_VERSIONS_SZ;
    /* HashSz (1 byte) + Hash (HashSz bytes) + CipherSuite (2 bytes) */
    if (cookieDataSz > OPAQUE8_LEN + hashSz + OPAQUE16_LEN) {
        keyShareExt = 1;
        length += HRR_KEY_SHARE_SZ;
    }

    AddTls13HandShakeHeader(hrr, length, 0, 0, server_hello, ssl);

    idx += hashSz;
    hrrIdx = HANDSHAKE_HEADER_SZ;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        hrrIdx += DTLS_HANDSHAKE_EXTRA;
#endif /* WOLFSSL_DTLS13 */

    /* The negotiated protocol version. */
    hrr[hrrIdx++] = ssl->version.major;
    hrr[hrrIdx++] = ssl->options.dtls ? DTLSv1_2_MINOR : TLSv1_2_MINOR;

    /* HelloRetryRequest message has fixed value for random. */
    XMEMCPY(hrr + hrrIdx, helloRetryRequestRandom, RAN_LEN);
    hrrIdx += RAN_LEN;

    hrr[hrrIdx++] = sessIdSz;
    if (sessIdSz > 0) {
        XMEMCPY(hrr + hrrIdx, ssl->session->sessionID, sessIdSz);
        hrrIdx += sessIdSz;
    }

    /* Restore the cipher suite from the cookie. */
    ssl->options.hrrCipherSuite0 = cookieData[idx];
    hrr[hrrIdx++] = cookieData[idx++];
    ssl->options.hrrCipherSuite  = cookieData[idx];
    hrr[hrrIdx++] = cookieData[idx++];

    /* Compression not supported in TLS v1.3. */
    hrr[hrrIdx++] = 0;

    /* Extensions' length */
    length -= HRR_BODY_SZ - ID_LEN + sessIdSz;
    c16toa(length, hrr + hrrIdx);
    hrrIdx += 2;

    /* Optional KeyShare Extension */
    if (keyShareExt) {
        c16toa(TLSX_KEY_SHARE, hrr + hrrIdx);
        hrrIdx += 2;
        c16toa(OPAQUE16_LEN, hrr + hrrIdx);
        hrrIdx += 2;
        /* Restore the HRR key share group from the cookie. */
        ato16(cookieData + idx, &ssl->hrr_keyshare_group);
        hrr[hrrIdx++] = cookieData[idx++];
        hrr[hrrIdx++] = cookieData[idx++];
    }
    c16toa(TLSX_SUPPORTED_VERSIONS, hrr + hrrIdx);
    hrrIdx += 2;
    c16toa(OPAQUE16_LEN, hrr + hrrIdx);
    hrrIdx += 2;
    #ifdef WOLFSSL_TLS13_DRAFT
        hrr[hrrIdx++] = TLS_DRAFT_MAJOR;
        hrr[hrrIdx++] = TLS_DRAFT_MINOR;
    #else
        hrr[hrrIdx++] = ssl->version.major;
        hrr[hrrIdx++] = ssl->version.minor;
    #endif

    /* Mandatory Cookie Extension */
    c16toa(TLSX_COOKIE, hrr + hrrIdx);
    hrrIdx += 2;
    c16toa(cookie->len + OPAQUE16_LEN, hrr + hrrIdx);
    hrrIdx += 2;
    c16toa(cookie->len, hrr + hrrIdx);
    hrrIdx += 2;

#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("Reconstructed HelloRetryRequest");
    WOLFSSL_BUFFER(hrr, hrrIdx);
    WOLFSSL_MSG("Cookie");
    WOLFSSL_BUFFER(cookieData, cookie->len);
#endif

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        ret = Dtls13HashHandshake(ssl, hrr, (word16)hrrIdx);
    }
    else
#endif /* WOLFSSL_DTLS13 */
        {
            ret = HashRaw(ssl, hrr, hrrIdx);
        }

    if (ret != 0)
        return ret;

    return HashRaw(ssl, cookieData, cookie->len);
}
#endif

/* Do SupportedVersion extension for TLS v1.3+ otherwise it is not.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * i         The index into the message buffer of ClientHello.
 * helloSz   The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */
static int DoTls13SupportedVersions(WOLFSSL* ssl, const byte* input, word32 i,
                                    word32 helloSz, int* wantDowngrade)
{
    int    ret;
    byte   b;
    word16 suiteSz;
    word16 totalExtSz;
    int    foundVersion = 0;

    /* Client random */
    i += RAN_LEN;

    if (i > helloSz)
        return BUFFER_ERROR;
    /* Session id - not used in TLS v1.3 */
    if (helloSz - i < OPAQUE8_LEN) {
        return BUFFER_ERROR;
    }
    b = input[i++];
    if (b > helloSz - i) {
        return BUFFER_ERROR;
    }
    i += b;
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        /* legacy_cookie - not used in DTLS v1.3 */
        if (helloSz - i < OPAQUE8_LEN) {
            return BUFFER_ERROR;
        }
        b = input[i++];
        if (b > helloSz - i) {
            return BUFFER_ERROR;
        }
        i += b;
    }
#endif /* WOLFSSL_DTLS13 */
    /* Cipher suites */
    if (helloSz - i < OPAQUE16_LEN)
        return BUFFER_ERROR;
    ato16(input + i, &suiteSz);
    i += OPAQUE16_LEN;
    if ((word32)suiteSz + OPAQUE8_LEN > helloSz - i)
        return BUFFER_ERROR;
    i += suiteSz;
    /* Compression */
    b = input[i++];
    if (b > helloSz - i)
        return BUFFER_ERROR;
    i += b;

    /* TLS 1.3 must have extensions */
    if (i < helloSz) {
        if (helloSz - i < OPAQUE16_LEN)
            return BUFFER_ERROR;
        ato16(&input[i], &totalExtSz);
        i += OPAQUE16_LEN;
        if (totalExtSz != helloSz - i)
            return BUFFER_ERROR;

        /* Need to negotiate version first. */
        if ((ret = TLSX_ParseVersion(ssl, input + i, totalExtSz, client_hello,
                                                              &foundVersion))) {
            return ret;
        }
    }
    *wantDowngrade = !foundVersion || !IsAtLeastTLSv1_3(ssl->version);

    return 0;
}

#ifdef HAVE_ECH
/* Calculate and write the 8 ECH confirmation bytes.
 * Output into confirmation field on HRR and into ServerRandom on ServerHello.
 *
 * ssl          SSL/TLS object.
 * label        Ascii string describing ECH acceptance or rejection.
 * labelSz      Length of label excluding NULL character.
 * output       The buffer to calculate/write confirmation from/to.
 * acceptOffset Where the 8 ECH confirmation bytes should be placed.
 * helloSz      Size of hello message.
 * msgType      Type of message being written.
 * returns 0 on success and otherwise failure.
 */
static int EchWriteAcceptance(WOLFSSL* ssl, byte* label, word16 labelSz,
    byte* output, int acceptOffset, int helloSz, byte msgType)
{
    int ret = 0;
    int headerSz;
    HS_Hashes* tmpHashes;

#ifdef WOLFSSL_DTLS13
    headerSz = ssl->options.dtls ? DTLS13_HANDSHAKE_HEADER_SZ :
                                   HANDSHAKE_HEADER_SZ;
#else
    headerSz = HANDSHAKE_HEADER_SZ;
#endif

    ret = EchCalcAcceptance(ssl, label, labelSz, output, acceptOffset,
            helloSz - headerSz, msgType == hello_retry_request,
            output + acceptOffset);

    if (ret == 0) {
        tmpHashes = ssl->hsHashes;
        ssl->hsHashes = ssl->hsHashesEch;

        /* after HRR, hsHashesEch must contain:
         * message_hash(ClientHelloInner1) || HRR (actual, not zeros) */
        if (msgType == hello_retry_request) {
            ret = HashRaw(ssl, output, helloSz);
        }
        /* normal TLS code will calculate transcript of ServerHello */
        else {
            ssl->hsHashes = tmpHashes;
            FreeHandshakeHashes(ssl);
            tmpHashes = ssl->hsHashesEch;
            ssl->hsHashesEch = NULL;
        }

        ssl->hsHashes = tmpHashes;
    }

    return ret;
}
#endif

/* Handle a ClientHello handshake message.
 * If the protocol version in the message is not TLS v1.3 or higher, use
 * DoClientHello()
 * Only a server will receive this message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of ClientHello.
 *           On exit, the index of byte after the ClientHello message and
 *           padding.
 * helloSz   The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */

typedef struct Dch13Args {
    ProtocolVersion pv;
    word32          idx;
    word32          begin;
    int             usingPSK;
} Dch13Args;

static void FreeDch13Args(WOLFSSL* ssl, void* pArgs)
{
    /* openssl compat builds hang on to the client suites until WOLFSSL object
     * is destroyed */
#ifndef OPENSSL_EXTRA
    if (ssl->clSuites) {
        XFREE(ssl->clSuites, ssl->heap, DYNAMIC_TYPE_SUITES);
        ssl->clSuites = NULL;
    }
#endif
    (void)ssl;
    (void)pArgs;

}

int DoTls13ClientHello(WOLFSSL* ssl, const byte* input, word32* inOutIdx,
                       word32 helloSz)
{
    int ret;
#ifdef WOLFSSL_ASYNC_CRYPT
    Dch13Args* args = NULL;
    WOLFSSL_ASSERT_SIZEOF_GE(ssl->async->args, *args);
#else
    Dch13Args  args[1];
#endif
#if defined(HAVE_ECH)
    TLSX* echX = NULL;
#endif

    WOLFSSL_START(WC_FUNC_CLIENT_HELLO_DO);
    WOLFSSL_ENTER("DoTls13ClientHello");

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ssl->async == NULL) {
        ssl->async = (struct WOLFSSL_ASYNC*)
                XMALLOC(sizeof(struct WOLFSSL_ASYNC), ssl->heap,
                        DYNAMIC_TYPE_ASYNC);
        if (ssl->async == NULL)
            ERROR_OUT(MEMORY_E, exit_dch);
        /* Zeroed so the mid-flight resume test below can never route into
         * uninitialised args. */
        XMEMSET(ssl->async, 0, sizeof(struct WOLFSSL_ASYNC));
    }
    args = (Dch13Args*)ssl->async->args;

    ret = wolfSSL_AsyncPop(ssl, &ssl->options.asyncState);
    if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
        /* Check for error */
        if (ret < 0) {
            goto exit_dch;
        }
    }
    else if (ssl->options.asyncState > TLS_ASYNC_BEGIN &&
             ssl->options.asyncState < TLS_ASYNC_END) {
        /* Mid-flight replay: the event may already be retired but
         * asyncState/args are intact, so resume; resetting would hash the
         * message twice. Fresh ClientHellos arrive at TLS_ASYNC_BEGIN. */
        ret = 0;
    }
    else
#endif
    {
        /* Reset state */
        ret = WC_NO_ERR_TRACE(VERSION_ERROR);
        ssl->options.asyncState = TLS_ASYNC_BEGIN;
        XMEMSET(args, 0, sizeof(Dch13Args));
    #ifdef WOLFSSL_ASYNC_CRYPT
        ssl->async->freeArgs = FreeDch13Args;
    #endif
    }

    switch (ssl->options.asyncState) {
    case TLS_ASYNC_BEGIN:
    {
    byte b;
    byte sessIdSz;
    int wantDowngrade = 0;
    word16 totalExtSz = 0;

#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_DTLS_CID)
    /* Reset for each ClientHello, including retries and legacy fallbacks. */
    ssl->options.haveSupportedVersions = 0;
#endif
#ifdef WOLFSSL_CALLBACKS
    if (ssl->hsInfoOn) AddPacketName(ssl, "ClientHello");
    if (ssl->toInfoOn) AddLateName("ClientHello", &ssl->timeoutInfo);
#endif

    /* do not change state in the SSL object before the next region of code
     * to be able to statelessly compute a DTLS cookie */
#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_SEND_HRR_COOKIE)
    /* Update the ssl->options.dtlsStateful setting `if` statement in
     * wolfSSL_accept_TLSv13 when changing this one. */
    if (IsDtlsNotSctpMode(ssl) && ssl->options.sendCookie &&
            !ssl->options.dtlsStateful) {
        DtlsSetSeqNumForReply(ssl);
        ret = DoClientHelloStateless(ssl, input + *inOutIdx, helloSz, 0, NULL);
        if (ret != 0 || !ssl->options.dtlsStateful) {
            *inOutIdx += helloSz;
            goto exit_dch;
        }
        if (ssl->chGoodCb != NULL) {
            int cbret = ssl->chGoodCb(ssl, ssl->chGoodCtx);
            if (cbret < 0) {
                ssl->error = cbret;
                WOLFSSL_MSG("ClientHello Good Cb don't continue error");
                return WOLFSSL_FATAL_ERROR;
            }
        }
    }
    ssl->options.dtlsStateful = 1;
#endif /* WOLFSSL_DTLS */

    args->idx = *inOutIdx;
    args->begin = args->idx;

    /* protocol version, random and session id length check */
    if (OPAQUE16_LEN + RAN_LEN + OPAQUE8_LEN > helloSz) {
        ERROR_OUT(BUFFER_ERROR, exit_dch);
    }

    /* Protocol version */
    XMEMCPY(&args->pv, input + args->idx, OPAQUE16_LEN);
    ssl->chVersion = args->pv;   /* store */
    args->idx += OPAQUE16_LEN;


    /* this check pass for DTLS Major (0xff) */
    if (args->pv.major < SSLv3_MAJOR) {
        WOLFSSL_MSG("Legacy version field contains unsupported value");
        ERROR_OUT(VERSION_ERROR, exit_dch);
    }

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls &&
        args->pv.major == DTLS_MAJOR && args->pv.minor > DTLSv1_2_MINOR) {
        wantDowngrade = 1;
        ssl->version.minor = args->pv.minor;
    }
#endif /* WOLFSSL_DTLS13 */

    if (!ssl->options.dtls) {
#ifndef WOLFSSL_ALLOW_BAD_TLS_LEGACY_VERSION
        /* Check for TLS 1.3 version (0x0304) in legacy version field. RFC 8446
         * Section 4.2.1 allows this action:
         *
         * "Servers MAY abort the handshake upon receiving a ClientHello with
         * legacy_version 0x0304 or later."
         *
         * Note that if WOLFSSL_ALLOW_BAD_TLS_LEGACY_VERSION is defined then the
         * semantics of RFC 5246 Appendix E will be followed. A ServerHello with
         * version 1.2 will be sent. The same is true if TLS 1.3 is not enabled.
         */
        if (args->pv.major == SSLv3_MAJOR && args->pv.minor >= TLSv1_3_MINOR) {
            WOLFSSL_MSG("Legacy version field is TLS 1.3 or later. Aborting.");
            ERROR_OUT(VERSION_ERROR, exit_dch);
        }
#endif /* WOLFSSL_ALLOW_BAD_TLS_LEGACY_VERSION */

        /* Legacy protocol version cannot negotiate TLS 1.3 or higher. */
        if (args->pv.major > SSLv3_MAJOR || (args->pv.major == SSLv3_MAJOR &&
                                             args->pv.minor >= TLSv1_3_MINOR)) {
            args->pv.major = SSLv3_MAJOR;
            args->pv.minor = TLSv1_2_MINOR;
            wantDowngrade = 1;
            ssl->version.minor = args->pv.minor;
        }
        /* Legacy version must be [ SSLv3_MAJOR, TLSv1_2_MINOR ] for TLS v1.3 */
        else if (args->pv.major == SSLv3_MAJOR &&
                 args->pv.minor < TLSv1_2_MINOR) {
            wantDowngrade = 1;
            ssl->version.minor = args->pv.minor;
        }
    }

    if (!wantDowngrade) {
        ret = DoTls13SupportedVersions(ssl, input + args->begin,
            args->idx - args->begin, helloSz, &wantDowngrade);
        if (ret < 0)
            goto exit_dch;
    }

    if (wantDowngrade) {
#ifndef WOLFSSL_NO_TLS12
        byte realMinor;
#endif
#if defined(HAVE_ECH)
        if (ssl->options.echProcessingInner) {
            WOLFSSL_MSG("ECH: inner client hello does not support version "
                        "less than TLS v1.3");
            ERROR_OUT(INVALID_PARAMETER, exit_dch);
        }
#endif
#ifndef WOLFSSL_NO_TLS12
        if (!ssl->options.downgrade) {
            WOLFSSL_MSG("Client trying to connect with lesser version than "
                        "TLS v1.3");
            ERROR_OUT(VERSION_ERROR, exit_dch);
        }

        if ((!ssl->options.dtls
                 && args->pv.minor < ssl->options.minDowngrade) ||
            (ssl->options.dtls && args->pv.minor > ssl->options.minDowngrade)) {
            WOLFSSL_MSG("\tversion below minimum allowed, fatal error");
            ERROR_OUT(VERSION_ERROR, exit_dch);
        }

        realMinor = ssl->version.minor;
        ssl->version.minor = args->pv.minor;
        ret = HashInput(ssl, input + args->begin, (int)helloSz);
        ssl->version.minor = realMinor;
        if (ret == 0) {
            ret = DoClientHello(ssl, input, inOutIdx, helloSz);
        }
        goto exit_dch;
#else
        WOLFSSL_MSG("Client trying to connect with lesser version than "
                    "TLS v1.3");
        ERROR_OUT(VERSION_ERROR, exit_dch);
#endif
    }

    /* From here on we are a TLS 1.3 ClientHello. */

    /* Client random
     * ECH Accepted -> This will fill with the innerClientRandom */
    XMEMCPY(ssl->arrays->clientRandom, input + args->idx, RAN_LEN);
    args->idx += RAN_LEN;

#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("client random");
    WOLFSSL_BUFFER(ssl->arrays->clientRandom, RAN_LEN);
#endif

    sessIdSz = input[args->idx++];
    if (sessIdSz > ID_LEN)
    {
        ERROR_OUT(INVALID_PARAMETER, exit_dch);
    }

    if (sessIdSz + args->idx > helloSz)
        ERROR_OUT(BUFFER_ERROR, exit_dch);

#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_DTLS13_ECHO_LEGACY_SESSION_ID)
    /* RFC 9147 Section 5: "DTLS servers MUST NOT echo the legacy_session_id
     * value from the client." Don't store it so SendTls13ServerHello can't
     * echo it. */
    if (ssl->options.dtls) {
        ssl->session->sessionIDSz = 0;
    }
    else
#endif
    {
        ssl->session->sessionIDSz = sessIdSz;
        if (sessIdSz > 0)
            XMEMCPY(ssl->session->sessionID, input + args->idx, sessIdSz);
    }
    args->idx += sessIdSz;

    /* RFC 8446 Appendix D.4: server MUST only send CCS if the client's
     * ClientHello contains a non-empty legacy_session_id. An ECH inner hello
     * is rebuilt with the outer session id, so it decides either way. */
    if (sessIdSz == 0) {
        ssl->options.tls13MiddleBoxCompat = 0;
    }
#ifdef WOLFSSL_QUIC
    /* RFC 9001 Section 8.4: QUIC has no compatibility mode to be had. */
    if (WOLFSSL_IS_QUIC(ssl)) {
        ssl->options.tls13MiddleBoxCompat = 0;
    }
#endif

#ifdef WOLFSSL_DTLS13
    /* legacy_cookie */
    if (ssl->options.dtls) {
        word32 rel = args->idx - args->begin;
        byte cookieLen;
        if (rel > helloSz || helloSz - rel < OPAQUE8_LEN)
            ERROR_OUT(BUFFER_ERROR, exit_dch);
        /* https://www.rfc-editor.org/rfc/rfc9147.html#section-5.3 */
        cookieLen = input[args->idx++];
        if (cookieLen != 0) {
            ERROR_OUT(INVALID_PARAMETER, exit_dch);
        }
    }
#endif /* WOLFSSL_DTLS13 */

    XFREE(ssl->clSuites, ssl->heap, DYNAMIC_TYPE_SUITES);
    ssl->clSuites = (Suites*)XMALLOC(sizeof(Suites), ssl->heap,
        DYNAMIC_TYPE_SUITES);
    if (ssl->clSuites == NULL) {
        ERROR_OUT(MEMORY_E, exit_dch);
    }

    /* Cipher suites */
    if ((args->idx - args->begin) + OPAQUE16_LEN > helloSz)
        ERROR_OUT(BUFFER_ERROR, exit_dch);
    ato16(&input[args->idx], &ssl->clSuites->suiteSz);
    args->idx += OPAQUE16_LEN;
    if ((ssl->clSuites->suiteSz % 2) != 0) {
        ERROR_OUT(INVALID_PARAMETER, exit_dch);
    }
    /* suites and compression length check */
    if ((args->idx - args->begin) + ssl->clSuites->suiteSz + OPAQUE8_LEN >
            helloSz) {
        ERROR_OUT(BUFFER_ERROR, exit_dch);
    }
    if (ssl->clSuites->suiteSz > WOLFSSL_MAX_SUITE_SZ)
        ERROR_OUT(BUFFER_ERROR, exit_dch);
    XMEMCPY(ssl->clSuites->suites, input + args->idx, ssl->clSuites->suiteSz);
    args->idx += ssl->clSuites->suiteSz;
    ssl->clSuites->hashSigAlgoSz = 0;
#if !defined(NO_CERTS) && !defined(WOLFSSL_NO_SIGALG)
    /* Discard any list kept from a previous ClientHello on this object; a
     * second hello that drops signature_algorithms_cert must not inherit it. */
    ssl->certHashSigAlgoSz = 0;
#endif

    /* Compression */
    b = input[args->idx++];
    if ((args->idx - args->begin) + b > helloSz)
        ERROR_OUT(BUFFER_ERROR, exit_dch);
    if (b != COMP_LEN) {
        WOLFSSL_MSG("Must be one compression type in list");
        ERROR_OUT(INVALID_PARAMETER, exit_dch);
    }
    b = input[args->idx++];
    if (b != NO_COMPRESSION) {
        WOLFSSL_MSG("Must be no compression type in list");
        ERROR_OUT(INVALID_PARAMETER, exit_dch);
    }

    /* Extensions */
    if ((args->idx - args->begin) == helloSz)
        ERROR_OUT(BUFFER_ERROR, exit_dch);
    if ((args->idx - args->begin) + OPAQUE16_LEN > helloSz)
        ERROR_OUT(BUFFER_ERROR, exit_dch);

    ato16(&input[args->idx], &totalExtSz);
    args->idx += OPAQUE16_LEN;
    if ((args->idx - args->begin) + totalExtSz > helloSz)
        ERROR_OUT(BUFFER_ERROR, exit_dch);

    /* Auto populate extensions supported unless user defined. */
    if ((ret = TLSX_PopulateExtensions(ssl, 1)) != 0)
        goto exit_dch;

#if defined(HAVE_ECH)
    if (ssl->ctx->echConfigs != NULL && !ssl->options.disableECH) {
        /* save the start of the buffer so we can use it when parsing ech */
        echX = TLSX_Find(ssl->extensions, TLSX_ECH);

        if (echX == NULL)
            ERROR_OUT(WOLFSSL_FATAL_ERROR, exit_dch);

        ((WOLFSSL_ECH*)echX->data)->aad = input + args->begin;
        ((WOLFSSL_ECH*)echX->data)->aadLen = helloSz;
    }
#endif

    /* Parse extensions */
    if ((ret = TLSX_Parse(ssl, input + args->idx, totalExtSz, client_hello,
                                                            ssl->clSuites))) {
        goto exit_dch;
    }

#if !defined(NO_CERTS) && !defined(WOLFSSL_NO_SIGALG)
    SetPeerSha1CertOk(ssl, ssl->clSuites);
#endif

#if (defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)) && \
    defined(HAVE_TLS_EXTENSIONS)
    /* RFC 8446 Section 4.2.11: the pre_shared_key extension MUST be the
     * last extension in the ClientHello. wolfSSL stores extensions in
     * reverse wire order (TLSX_Push prepends), so a well-formed
     * ClientHello with PSK leaves PSK at the head of ssl->extensions
     * here, before any post-parse code (e.g. ALPN_Select) modifies the
     * list. */
    {
        TLSX* pskExt = TLSX_Find(ssl->extensions, TLSX_PRE_SHARED_KEY);
        if (pskExt != NULL && ssl->extensions != pskExt) {
            WOLFSSL_MSG("pre_shared_key extension was not last in "
                        "ClientHello");
            WOLFSSL_ERROR_VERBOSE(PSK_KEY_ERROR);
            ERROR_OUT(PSK_KEY_ERROR, exit_dch);
        }
    }
#endif

#if defined(HAVE_ECH)
    /* ECH accept/reject reconciliation is done at the end of TLSX_Parse. On
     * acceptance the inner hello was decrypted, so jump to exit and let the
     * caller re-invoke with the inner hello. */
    if (!ssl->options.echProcessingInner && echX != NULL &&
            ((WOLFSSL_ECH*)echX->data)->state == ECH_WRITE_NONE &&
            ((WOLFSSL_ECH*)echX->data)->innerClientHello != NULL) {
        goto exit_dch;
    }
#endif

#ifdef HAVE_SNI
        if ((ret = SNI_Callback(ssl)) != 0)
            goto exit_dch;
        ssl->options.side = WOLFSSL_SERVER_END;
#endif

    args->idx += totalExtSz;
    ssl->options.haveSessionId = 1;
    ssl->options.sendVerify = SEND_CERT;

#if defined(WOLFSSL_SEND_HRR_COOKIE)
    ssl->options.cookieGood = 0;
    if (ssl->options.sendCookie &&
            (ssl->options.serverState == SERVER_HELLO_RETRY_REQUEST_COMPLETE
#ifdef WOLFSSL_DTLS13
                    /* Always check for a valid cookie since we may have already
                     * sent a HRR but we reset the state. */
                    || ssl->options.dtls
#endif
                    )) {
        TLSX* ext = TLSX_Find(ssl->extensions, TLSX_COOKIE);

        if (ext != NULL) {
            /* Ensure the cookie came from client and isn't the one in the
            * response - HelloRetryRequest.
            */
            if (ext->resp == 0) {
                ret = RestartHandshakeHashWithCookie(ssl, (Cookie*)ext->data);
                if (ret != 0)
                    goto exit_dch;
                /* Don't change state here as we may want to enter
                 * DoTls13ClientHello again. */
                ssl->options.cookieGood = 1;
            }
            else {
                ERROR_OUT(HRR_COOKIE_ERROR, exit_dch);
            }
        }
        else {
#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_DTLS13_NO_HRR_ON_RESUME)
            /* Don't error out as we may be resuming. We confirm this later. */
            if (!ssl->options.dtls)
#endif
                ERROR_OUT(HRR_COOKIE_ERROR, exit_dch);
        }
    }
#endif

#ifdef HAVE_SUPPORTED_CURVES
    if (ssl->hrr_keyshare_group != 0) {
        /*
         * https://datatracker.ietf.org/doc/html/rfc8446#section-4.2.8
         *   when sending the new ClientHello, the client MUST
         *   replace the original "key_share" extension with one containing only
         *   a new KeyShareEntry for the group indicated in the selected_group
         *   field of the triggering HelloRetryRequest.
         */
        TLSX* extension = TLSX_Find(ssl->extensions, TLSX_KEY_SHARE);
        if (extension != NULL) {
            KeyShareEntry* kse = (KeyShareEntry*)extension->data;
            /* Exactly one KeyShareEntry with the HRR group must be present. */
            if (kse == NULL || kse->next != NULL ||
                                        kse->group != ssl->hrr_keyshare_group) {
                ERROR_OUT(BAD_KEY_SHARE_DATA, exit_dch);
            }
        }
        else
            ERROR_OUT(BAD_KEY_SHARE_DATA, exit_dch);
    }
#endif

#if defined(HAVE_ECH)
    /* hash clientHelloInner to hsHashesEch */
    if (echX != NULL && ssl->ctx->echConfigs != NULL &&
            !ssl->options.disableECH &&
            ((WOLFSSL_ECH*)echX->data)->innerClientHello != NULL) {
        ret = EchHashHelloInner(ssl, (WOLFSSL_ECH*)echX->data);
        if (ret != 0)
            goto exit_dch;
        ((WOLFSSL_ECH*)echX->data)->innerCount = 1;
    }
#endif

#ifdef HAVE_ALPN
    /* Select the ALPN protocol before PSK selection so that the
     * selected value is available to the per-PSK SNI/ALPN binding check
     * inside CheckPreSharedKeys/DoPreSharedKeys. ALPN_Select itself
     * only inspects ssl->extensions and the app callback; it does not
     * depend on any state set during PSK validation. */
    if ((ret = ALPN_Select(ssl)) != 0)
        goto exit_dch;
#endif
#if (defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)) && \
                                                    defined(HAVE_TLS_EXTENSIONS)
    ret = CheckPreSharedKeys(ssl, input + args->begin, helloSz, ssl->clSuites,
        &args->usingPSK);
    if (ret != 0)
        goto exit_dch;
#else
    if ((ret = HashInput(ssl, input + args->begin, (int)helloSz)) != 0)
        goto exit_dch;
#endif

#if (defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)) && \
                                                    defined(HAVE_TLS_EXTENSIONS)
    if (!args->usingPSK
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
        || ssl->options.certWithExternPsk
#endif
    )
#endif
    {
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
        /* Not using PSK so don't require no KE. */
        ssl->options.noPskDheKe = 0;
#endif

#ifndef NO_CERTS
        if (TLSX_Find(ssl->extensions, TLSX_KEY_SHARE) == NULL) {
            WOLFSSL_MSG("Client did not send a KeyShare extension");
            ERROR_OUT(INCOMPLETE_DATA, exit_dch);
        }
        /* Can't check ssl->extensions here as SigAlgs are unconditionally
           set by TLSX_PopulateExtensions */
        if (ssl->clSuites->hashSigAlgoSz == 0) {
            WOLFSSL_MSG("Client did not send a SignatureAlgorithms extension");
            ERROR_OUT(INCOMPLETE_DATA, exit_dch);
        }
#else
        ERROR_OUT(INVALID_PARAMETER, exit_dch);
#endif
    }

    } /* case TLS_ASYNC_BEGIN */
    FALL_THROUGH;

    case TLS_ASYNC_BUILD:
    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_DO;
    FALL_THROUGH;

    case TLS_ASYNC_DO:
    {
#ifdef WOLFSSL_CERT_SETUP_CB
    if ((ret = CertSetupCbWrapper(ssl)) != 0)
        goto exit_dch;
#endif
#ifndef NO_CERTS
    if (!args->usingPSK) {
        if ((ret = MatchSuite(ssl, ssl->clSuites)) < 0) {
        #ifdef WOLFSSL_ASYNC_CRYPT
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
        #endif
                WOLFSSL_MSG("Unsupported cipher suite, ClientHello 1.3");
            goto exit_dch;
        }
    }
#endif
#ifdef HAVE_SUPPORTED_CURVES
    if (args->usingPSK == 2) {
        /* Pick key share and Generate a new key if not present. */
        int doHelloRetry = 0;
        ret = TLSX_KeyShare_Establish(ssl, &doHelloRetry);
        if (doHelloRetry) {
            /* Make sure we don't send HRR twice */
            if (ssl->options.serverState == SERVER_HELLO_RETRY_REQUEST_COMPLETE)
                ERROR_OUT(INVALID_PARAMETER, exit_dch);
            ssl->options.serverState = SERVER_HELLO_RETRY_REQUEST_COMPLETE;
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                ret = 0; /* for hello_retry return 0 */
        }
        if (ret != 0)
            goto exit_dch;
    }
#endif

    /* Verify the cipher suite is the same as what was chosen in HRR.
     * got_client_hello == 2 covers the stateful path.
     * cookieGood covers the stateless DTLS path. */
    if ((ssl->msgsReceived.got_client_hello == 2
#ifdef WOLFSSL_SEND_HRR_COOKIE
            || ssl->options.cookieGood
#endif
        ) &&
            (ssl->options.cipherSuite0 != ssl->options.hrrCipherSuite0 ||
             ssl->options.cipherSuite  != ssl->options.hrrCipherSuite)) {
        WOLFSSL_MSG("Cipher suite in second ClientHello does not match "
                    "HelloRetryRequest");
        ERROR_OUT(INVALID_PARAMETER, exit_dch);
    }

    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_VERIFY;
    } /* case TLS_ASYNC_BUILD || TLS_ASYNC_DO */
    FALL_THROUGH;

    case TLS_ASYNC_VERIFY:
    {
#if defined(WOLFSSL_ASYNC_CRYPT) && defined(HAVE_SUPPORTED_CURVES)
    /* Check if the KeyShare calculations from the previous state are complete.
     * wolfSSL_AsyncPop advances ssl->options.asyncState so we may end up here
     * with a pending calculation. */
    TLSX* extension = TLSX_Find(ssl->extensions, TLSX_KEY_SHARE);
    if (extension != NULL && extension->resp == 1) {
        KeyShareEntry* serverKSE = (KeyShareEntry*)extension->data;
        if (serverKSE != NULL &&
            serverKSE->lastRet == WC_NO_ERR_TRACE(WC_PENDING_E)) {
    #if defined(WOLFSSL_HAVE_MLKEM)
            if (WOLFSSL_NAMED_GROUP_IS_PQC_HYBRID(serverKSE->group)) {
                ret = TLSX_KeyShare_HandlePqcHybridKeyServer(ssl, serverKSE,
                        serverKSE->ke, serverKSE->keLen);
            }
            else
    #endif
            {
                ret = TLSX_KeyShare_GenKey(ssl, serverKSE);
            }
            if (ret != 0)
                goto exit_dch;
        }
    }
#endif
    /* Advance state and proceed */
    ssl->options.asyncState = TLS_ASYNC_FINALIZE;
    }
    FALL_THROUGH;

    case TLS_ASYNC_FINALIZE:
    {
    *inOutIdx = args->idx;
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ssl->options.pskNegotiated = (args->usingPSK != 0);
#endif

    if (!args->usingPSK) {
#ifndef NO_CERTS
        /* Check that the negotiated ciphersuite matches protocol version. */
    #ifdef HAVE_NULL_CIPHER
        if (ssl->options.cipherSuite0 == ECC_BYTE &&
                              (ssl->options.cipherSuite == TLS_SHA256_SHA256 ||
                               ssl->options.cipherSuite == TLS_SHA384_SHA384)) {
            ;
        }
        else
    #endif
    #if defined(WOLFSSL_SM4_GCM) && defined(WOLFSSL_SM3)
        if (ssl->options.cipherSuite0 == CIPHER_BYTE &&
                ssl->options.cipherSuite == TLS_SM4_GCM_SM3) {
            ; /* Do nothing. */
        }
        else
    #endif
    #if defined(WOLFSSL_SM4_CCM) && defined(WOLFSSL_SM3)
        if (ssl->options.cipherSuite0 == CIPHER_BYTE &&
                ssl->options.cipherSuite == TLS_SM4_CCM_SM3) {
            ; /* Do nothing. */
        }
        else
    #endif
        if (ssl->options.cipherSuite0 != TLS13_BYTE) {
            WOLFSSL_MSG("Negotiated ciphersuite from lesser version than "
                        "TLS v1.3");
            ERROR_OUT(MATCH_SUITE_ERROR, exit_dch);
        }

    #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
        if (ssl->options.resuming) {
            ssl->options.resuming = 0;
            ssl->arrays->psk_keySz = 0;
            XMEMSET(ssl->arrays->psk_key, 0, ssl->specs.hash_size);
        }
    #endif

        /* Derive early secret for handshake secret. */
        if ((ret = DeriveEarlySecret(ssl)) != 0)
            goto exit_dch;
#endif /* !NO_CERTS */
    }

    /* Advanced only after the derive: earlier would let the accept loop
     * proceed on an unfinished early secret. */
    ssl->options.clientState = CLIENT_HELLO_COMPLETE;
    break;
    } /* case TLS_ASYNC_FINALIZE */
    default:
        ret = INPUT_CASE_ERROR;
    } /* switch (ssl->options.asyncState) */

#ifdef WOLFSSL_SEND_HRR_COOKIE
    if (ret == 0 && ssl->options.sendCookie) {
        if (ssl->options.cookieGood &&
                ssl->options.acceptState == TLS13_ACCEPT_FIRST_REPLY_DONE) {
            /* Processing second ClientHello. Clear HRR state. */
            ssl->options.serverState = NULL_STATE;
        }

        if (ssl->options.cookieGood &&
            ssl->options.serverState == SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
            /* If we already verified the peer with a cookie then we can't
             * do another HRR for cipher negotiation. Send alert and restart
             * the entire handshake. */
            ERROR_OUT(INVALID_PARAMETER, exit_dch);
        }
#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls &&
            ssl->options.serverState == SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
            /* Cookie and key share negotiation should be handled in
             * DoClientHelloStateless. If we enter here then something went
             * wrong in our logic. */
            ERROR_OUT(BAD_HELLO, exit_dch);
        }
#endif
        /* Send a cookie */
        if (!ssl->options.cookieGood &&
            ssl->options.serverState != SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls) {
#ifdef WOLFSSL_DTLS13_NO_HRR_ON_RESUME
                /* We can skip cookie on resumption */
                if (!ssl->options.dtls || !ssl->options.dtls13NoHrrOnResume ||
                        !args->usingPSK)
#endif
                    ERROR_OUT(BAD_HELLO, exit_dch);
            }
            else
#endif
            {
                /* Need to remove the keyshare ext if we found a common group
                 * and are not doing curve negotiation. */
                TLSX_Remove(&ssl->extensions, TLSX_KEY_SHARE, ssl->heap);
                ssl->options.serverState = SERVER_HELLO_RETRY_REQUEST_COMPLETE;
            }

        }
    }
#endif /* WOLFSSL_DTLS13 */

#ifdef WOLFSSL_DTLS_CID
    /* do not modify CID state if we are sending an HRR  */
    if (ret == 0 && ssl->options.dtls && ssl->options.useDtlsCID &&
            ssl->options.serverState != SERVER_HELLO_RETRY_REQUEST_COMPLETE)
        DtlsCIDOnExtensionsParsed(ssl);
#endif /* WOLFSSL_DTLS_CID */



exit_dch:

    WOLFSSL_LEAVE("DoTls13ClientHello", ret);

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
        ssl->msgsReceived.got_client_hello = 0;
        return ret;
    }
#endif

    FreeDch13Args(ssl, args);
#ifdef WOLFSSL_ASYNC_CRYPT
    FreeAsyncCtx(ssl, 0);
    /* Back to BEGIN so a later ClientHello (HRR, duplicate) can never be
     * mistaken for a replay and resume into freed args. */
    ssl->options.asyncState = TLS_ASYNC_BEGIN;
    /* This ClientHello is done; a later one (HRR CH2, duplicate) must hash
     * itself afresh. */
    ssl->options.chHashInput = 0;
    /* Replays skip the sanity check that re-sets got_client_hello; restore
     * on completion (only from 0: an HRR second ClientHello counts to 2). */
    if (ret == 0 && ssl->msgsReceived.got_client_hello == 0) {
        ssl->msgsReceived.got_client_hello = 1;
    }
#endif
    WOLFSSL_END(WC_FUNC_CLIENT_HELLO_DO);

    if (ret != 0) {
        WOLFSSL_ERROR_VERBOSE(ret);
    }

#if defined(HAVE_ECH)
    if (ret == 0 && echX != NULL &&
        ((WOLFSSL_ECH*)echX->data)->state == ECH_WRITE_NONE &&
        ((WOLFSSL_ECH*)echX->data)->innerClientHello != NULL) {

        /* add the header to the inner hello */
        AddTls13HandShakeHeader(((WOLFSSL_ECH*)echX->data)->innerClientHello,
            ((WOLFSSL_ECH*)echX->data)->innerClientHelloLen, 0, 0,
            client_hello, ssl);
    }
#endif

    return ret;
}

/* Send TLS v1.3 ServerHello message to client.
 * Only a server will send this message.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
/* handle generation of TLS 1.3 server_hello (2) */
int SendTls13ServerHello(WOLFSSL* ssl, byte extMsgType)
{
    int    ret;
    byte*  output;
    word16 length;
    word32 idx = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;
    int    sendSz;
#if defined(HAVE_ECH)
    TLSX* echX = NULL;
    byte* acceptLabel = (byte*)echAcceptConfirmationLabel;
    word32 acceptOffset;
    word16 acceptLabelSz = ECH_ACCEPT_CONFIRMATION_LABEL_SZ;
#endif

    WOLFSSL_START(WC_FUNC_SERVER_HELLO_SEND);
    WOLFSSL_ENTER("SendTls13ServerHello");

    /* When ssl->options.dtlsStateful is not set then cookie is calculated in
     * dtls.c */
    if (extMsgType == hello_retry_request
#ifdef WOLFSSL_DTLS13
            && (!ssl->options.dtls || ssl->options.dtlsStateful)
#endif
            ) {
        WOLFSSL_MSG("wolfSSL Sending HelloRetryRequest");
        if ((ret = RestartHandshakeHash(ssl)) < 0)
            return ret;
    }

    ssl->options.buildingMsg = 1;
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        idx = DTLS_RECORD_HEADER_SZ + DTLS_HANDSHAKE_HEADER_SZ;
#endif /* WOLFSSL_DTLS13 */

    /* Protocol version, server random, session id, cipher suite, compression
     * and extensions.
     */
    length = VERSION_SZ + RAN_LEN + ENUM_LEN + ssl->session->sessionIDSz +
             SUITE_LEN + COMP_LEN;
    ret = TLSX_GetResponseSize(ssl, extMsgType, &length);
    if (ret != 0)
        return ret;
    sendSz = (int)(idx + length);

    /* Check buffers are big enough and grow if needed. */
    if ((ret = CheckAvailableSize(ssl, sendSz)) != 0)
        return ret;

    /* Get position in output buffer to write new message to. */
    output = GetOutputBuffer(ssl);

    /* Put the record and handshake headers on. */
    AddTls13Headers(output, length, server_hello, ssl);

    /* The protocol version must be TLS v1.2 for middleboxes. */
    output[idx++] = ssl->version.major;
    output[idx++] = ssl->options.dtls ? DTLSv1_2_MINOR : TLSv1_2_MINOR;

    if (extMsgType == server_hello) {
        /* Generate server random. */
        if ((ret = wc_RNG_GenerateBlock(ssl->rng, output + idx, RAN_LEN)) != 0)
            return ret;
    }
    else {
        /* HelloRetryRequest message has fixed value for random. */
        XMEMCPY(output + idx, helloRetryRequestRandom, RAN_LEN);
    }

#if defined(HAVE_ECH)
    /* last 8 bytes of server random */
    acceptOffset = idx + RAN_LEN - ECH_ACCEPT_CONFIRMATION_SZ;
#endif

    /* Store in SSL for debugging. */
    XMEMCPY(ssl->arrays->serverRandom, output + idx, RAN_LEN);
    idx += RAN_LEN;

#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("Server random");
    WOLFSSL_BUFFER(ssl->arrays->serverRandom, RAN_LEN);
#endif

#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_DTLS13_ECHO_LEGACY_SESSION_ID)
    if (ssl->options.dtls) {
        /* RFC 9147 Section 5: "DTLS servers MUST NOT echo the
         * legacy_session_id value from the client." */
        output[idx++] = 0;
    }
    else
#endif
    {
        output[idx++] = ssl->session->sessionIDSz;
        if (ssl->session->sessionIDSz > 0) {
            XMEMCPY(output + idx, ssl->session->sessionID,
                ssl->session->sessionIDSz);
            idx += ssl->session->sessionIDSz;
        }
    }

    /* Chosen cipher suite */
    output[idx++] = ssl->options.cipherSuite0;
    output[idx++] = ssl->options.cipherSuite;
#ifdef WOLFSSL_DEBUG_TLS
    WOLFSSL_MSG("Chosen cipher suite:");
    WOLFSSL_MSG(GetCipherNameInternal(ssl->options.cipherSuite0,
                                      ssl->options.cipherSuite));
#endif

    /* Compression not supported in TLS v1.3. */
    output[idx++] = 0;

    /* Extensions */
    ret = TLSX_WriteResponse(ssl, output + idx, extMsgType, NULL);
    if (ret != 0)
        return ret;

    /* When we send a HRR, we store the selected key share group to later check
     * that the client uses the same group in the second ClientHello.
     *
     * In case of stateless DTLS, we do not store the group, however, as it is
     * already stored in the cookie that is sent to the client. We later recover
     * the group from the cookie to prevent storing a state in a stateless
     * server.
     *
     * Similar logic holds for the hrrCipherSuite. */
    if (extMsgType == hello_retry_request
#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_SEND_HRR_COOKIE)
        && (!ssl->options.dtls || ssl->options.dtlsStateful)
#endif
    ) {
        TLSX* ksExt = TLSX_Find(ssl->extensions, TLSX_KEY_SHARE);
        if (ksExt != NULL) {
            KeyShareEntry* kse = (KeyShareEntry*)ksExt->data;
            if (kse != NULL)
                ssl->hrr_keyshare_group = kse->group;
        }

        ssl->options.hrrCipherSuite0 = ssl->options.cipherSuite0;
        ssl->options.hrrCipherSuite  = ssl->options.cipherSuite;
    }

#ifdef WOLFSSL_SEND_HRR_COOKIE
    if (ssl->options.sendCookie && extMsgType == hello_retry_request) {
        /* Reset the hashes from here. We will be able to restart the hashes
         * from the cookie in RestartHandshakeHashWithCookie */
#ifdef WOLFSSL_DTLS13
        /* When ssl->options.dtlsStateful is not set then cookie is calculated
         * in dtls.c */
        if (ssl->options.dtls && !ssl->options.dtlsStateful)
            ret = 0;
        else
#endif
            ret = InitHandshakeHashes(ssl);
    }
    else
#endif
    {
#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls) {
            ret = Dtls13HashHandshake(
                ssl,
                output + Dtls13GetRlHeaderLength(ssl, 0) ,
                (word16)sendSz - Dtls13GetRlHeaderLength(ssl, 0));
        }
        else
#endif /* WOLFSSL_DTLS13 */
        {
#if defined(HAVE_ECH)
            if (ssl->ctx->echConfigs != NULL && !ssl->options.disableECH) {
                echX = TLSX_Find(ssl->extensions, TLSX_ECH);
                if (echX == NULL)
                    return WOLFSSL_FATAL_ERROR;
                /* use hrr offset */
                if (extMsgType == hello_retry_request) {
                    acceptOffset =
                        (word32)(((WOLFSSL_ECH*)echX->data)->confBuf - output);
                    acceptLabel = (byte*)echHrrAcceptConfirmationLabel;
                    acceptLabelSz = ECH_HRR_ACCEPT_CONFIRMATION_LABEL_SZ;
                }
                /* replace the last 8 bytes of server random with the accept */
                if (((WOLFSSL_ECH*)echX->data)->state == ECH_PARSED_INTERNAL) {
                    if (ret == 0) {
                        ret = EchWriteAcceptance(ssl, acceptLabel,
                            acceptLabelSz, output + RECORD_HEADER_SZ,
                            acceptOffset - RECORD_HEADER_SZ,
                            sendSz - RECORD_HEADER_SZ, extMsgType);
                    }
                    if (extMsgType == hello_retry_request) {
                        /* reset the ech state for round 2 */
                        ((WOLFSSL_ECH*)echX->data)->state = ECH_WRITE_NONE;
                        /* inner hello no longer needed, free it */
                        XFREE(((WOLFSSL_ECH*)echX->data)->innerClientHello,
                              ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
                        ((WOLFSSL_ECH*)echX->data)->innerClientHello = NULL;
                    }
                    else {
                        if (ret == 0) {
                            /* update serverRandom on success */
                            XMEMCPY(ssl->arrays->serverRandom,
                                output + acceptOffset -
                                (RAN_LEN -ECH_ACCEPT_CONFIRMATION_SZ), RAN_LEN);
                        }
                        /* remove ech so we don't keep sending it in write */
                        TLSX_Remove(&ssl->extensions, TLSX_ECH, ssl->heap);
                    }
                }
            }
#endif
            if (ret == 0)
                ret = HashOutput(ssl, output, sendSz, 0);
        }
    }

    if (ret != 0)
        return ret;

#if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
    if (ssl->hsInfoOn)
        AddPacketName(ssl, "ServerHello");
    if (ssl->toInfoOn) {
        ret = AddPacketInfo(ssl, "ServerHello", handshake, output, sendSz,
                      WRITE_PROTO, 0, ssl->heap);
        if (ret != 0)
            return ret;
    }
    #endif

    if (extMsgType == server_hello)
        ssl->options.serverState = SERVER_HELLO_COMPLETE;

    ssl->options.buildingMsg = 0;
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        ret = Dtls13HandshakeSend(ssl, output, (word16)sendSz, (word16)sendSz,
            (enum HandShakeType)extMsgType, 0);

        WOLFSSL_LEAVE("SendTls13ServerHello", ret);
        WOLFSSL_END(WC_FUNC_SERVER_HELLO_SEND);
        return ret;
    }
#endif /* WOLFSSL_DTLS13 */

    ssl->buffers.outputBuffer.length += (word32)sendSz;

    if (!ssl->options.groupMessages || extMsgType != server_hello)
        ret = SendBuffered(ssl);

    WOLFSSL_LEAVE("SendTls13ServerHello", ret);
    WOLFSSL_END(WC_FUNC_SERVER_HELLO_SEND);

    return ret;
}

/* handle generation of TLS 1.3 encrypted_extensions (8) */
/* Send the rest of the extensions encrypted under the handshake key.
 * This message is always encrypted in TLS v1.3.
 * Only a server will send this message.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
static int SendTls13EncryptedExtensions(WOLFSSL* ssl)
{
    int    ret;
    byte*  output;
    word16 length = 0;
    word32 idx;
    int    sendSz;

    WOLFSSL_START(WC_FUNC_ENCRYPTED_EXTENSIONS_SEND);
    WOLFSSL_ENTER("SendTls13EncryptedExtensions");

    ssl->options.buildingMsg = 1;
    ssl->keys.encryptionOn = 1;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        idx = Dtls13GetHeadersLength(ssl, encrypted_extensions);
    }
    else
#endif /* WOLFSSL_DTLS13 */
    {
        idx = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;
    }

#ifdef WOLFSSL_ASYNC_CRYPT
    /* A suspended build already ran the key schedule below; re-running it
     * would extract in place over preMasterSecret a second time. */
    if (ssl->options.buildArgs13Set)
        goto tls13_send_ee_build;
#endif

#if defined(HAVE_SUPPORTED_CURVES) && !defined(WOLFSSL_NO_SERVER_GROUPS_EXT)
    if ((ret = TLSX_SupportedCurve_CheckPriority(ssl)) != 0)
        return ret;
#endif

    /* Derive the handshake secret now that we are at first message to be
     * encrypted under the keys.
     */
    if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_NONE) {
        ret = DeriveHandshakeSecret(ssl);
        if (ret != 0) {
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
            return ret;
        }
        ssl->kdfDeriveStep = TLS13_SEND_KDF_EE_HS_SECRET;
    }
    if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_EE_HS_SECRET) {
        ret = DeriveTls13Keys(ssl, handshake_key, ENCRYPT_AND_DECRYPT_SIDE, 1);
        if (ret != 0) {
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
            return ret;
        }
        ssl->kdfDeriveStep = TLS13_SEND_KDF_EE_HS_KEYS;
    }

    /* Setup encrypt/decrypt keys for following messages. */
#ifdef WOLFSSL_EARLY_DATA
    if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_EE_HS_KEYS) {
        ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY);
        if (ret != 0) {
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
            return ret;
        }
        ssl->kdfDeriveStep = TLS13_SEND_KDF_EE_ENC_KEYS_SET;
    }
    if (ssl->earlyData != process_early_data) {
        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_EE_ENC_KEYS_SET) {
            ret = SetKeysSide(ssl, DECRYPT_SIDE_ONLY);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_EE_KEYS_SET;
        }
    }
#else
    if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_EE_ENC_KEYS_SET) {
        ret = SetKeysSide(ssl, ENCRYPT_AND_DECRYPT_SIDE);
        if (ret != 0) {
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
            return ret;
        }
        ssl->kdfDeriveStep = TLS13_SEND_KDF_EE_KEYS_SET;
    }
#endif
#ifdef WOLFSSL_QUIC
    if (IsAtLeastTLSv1_3(ssl->version) && WOLFSSL_IS_QUIC(ssl)) {
        ret = wolfSSL_quic_add_transport_extensions(ssl, encrypted_extensions);
        if (ret != 0)
            return ret;
    }
#endif

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        w64wrapper epochHandshake = w64From32(0, DTLS13_EPOCH_HANDSHAKE);
        ssl->dtls13Epoch = epochHandshake;

        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_EE_KEYS_SET) {
            ret = Dtls13SetEpochKeys(ssl, epochHandshake,
                                     ENCRYPT_AND_DECRYPT_SIDE);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_EE_DTLS_EPOCH;
        }
    }
#endif /* WOLFSSL_DTLS13 */
    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;

#ifdef WOLFSSL_ASYNC_CRYPT
tls13_send_ee_build:
#endif

    ret = TLSX_GetResponseSize(ssl, encrypted_extensions, &length);
    if (ret != 0)
        return ret;

    sendSz = (int)(idx + length);
    /* Encryption always on. */
    sendSz += MAX_MSG_EXTRA;

    /* Check buffers are big enough and grow if needed. */
    ret = CheckAvailableSize(ssl, sendSz);
    if (ret != 0)
        return ret;

    /* Get position in output buffer to write new message to. */
    output = GetOutputBuffer(ssl);

#ifdef WOLFSSL_ASYNC_CRYPT
    /* Skip on a resume: BuildTls13Message already replaced the record
     * header; rewriting the plaintext headers would corrupt it. */
    if (!ssl->options.buildArgs13Set)
#endif
    {
        /* Put the record and handshake headers on. */
        AddTls13Headers(output, length, encrypted_extensions, ssl);

        ret = TLSX_WriteResponse(ssl, output + idx, encrypted_extensions, NULL);
        if (ret != 0)
            return ret;
    }
    idx += length;

#if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
    if (ssl->hsInfoOn)
        AddPacketName(ssl, "EncryptedExtensions");
    if (ssl->toInfoOn) {
        ret = AddPacketInfo(ssl, "EncryptedExtensions", handshake, output,
                      sendSz, WRITE_PROTO, 0, ssl->heap);
        if (ret != 0)
            return ret;
    }
#endif

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        ssl->options.buildingMsg = 0;
        ret = Dtls13HandshakeSend(ssl, output, (word16)sendSz, (word16)idx,
                                  encrypted_extensions, 1);

        if (ret == 0)
            ssl->options.serverState = SERVER_ENCRYPTED_EXTENSIONS_COMPLETE;

        WOLFSSL_LEAVE("SendTls13EncryptedExtensions", ret);
        WOLFSSL_END(WC_FUNC_ENCRYPTED_EXTENSIONS_SEND);

        return ret;
    }
#endif /* WOLFSSL_DTLS13 */

    /* This handshake message is always encrypted. */
    sendSz = BuildTls13Message(ssl, output, sendSz, output + RECORD_HEADER_SZ,
                               (int)(idx - RECORD_HEADER_SZ),
                               handshake, 1, 0, TLS13_HS_ASYNC_OKAY);
    if (sendSz < 0)
        return sendSz;

    ssl->buffers.outputBuffer.length += (word32)sendSz;
    ssl->options.buildingMsg = 0;
    ssl->options.serverState = SERVER_ENCRYPTED_EXTENSIONS_COMPLETE;

    if (!ssl->options.groupMessages)
        ret = SendBuffered(ssl);


    WOLFSSL_LEAVE("SendTls13EncryptedExtensions", ret);
    WOLFSSL_END(WC_FUNC_ENCRYPTED_EXTENSIONS_SEND);

    return ret;
}

#ifndef NO_CERTS
/* handle generation TLS v1.3 certificate_request (13) */
/* Send the TLS v1.3 CertificateRequest message.
 * This message is always encrypted in TLS v1.3.
 * Only a server will send this message.
 *
 * ssl        SSL/TLS object.
 * reqCtx     Request context.
 * reqCtxLen  Length of context. 0 when sending as part of handshake.
 * returns 0 on success, otherwise failure.
 */
static int SendTls13CertificateRequest(WOLFSSL* ssl, byte* reqCtx,
                                       word32 reqCtxLen)
{
    byte*   output;
    int    ret;
    int    sendSz;
    word32 i;
    word32 reqSz;
    SignatureAlgorithms* sa;

    WOLFSSL_START(WC_FUNC_CERTIFICATE_REQUEST_SEND);
    WOLFSSL_ENTER("SendTls13CertificateRequest");

    ssl->options.buildingMsg = 1;

    if (ssl->options.side != WOLFSSL_SERVER_END)
        return SIDE_ERROR;

    /* Use ssl->suites->hashSigAlgo so wolfSSL_set1_sigalgs_list() is honored.
     * hashSigAlgoSz=0 makes GetSize/Write fall back to WOLFSSL_SUITES(ssl). */
    sa = TLSX_SignatureAlgorithms_New(ssl, 0, ssl->heap);
    if (sa == NULL)
        return MEMORY_ERROR;
    ret = TLSX_Push(&ssl->extensions, TLSX_SIGNATURE_ALGORITHMS, sa, ssl->heap);
    if (ret != 0) {
        TLSX_SignatureAlgorithms_FreeAll(sa, ssl->heap);
        return ret;
    }

    i = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        i = Dtls13GetRlHeaderLength(ssl, 1) + DTLS_HANDSHAKE_HEADER_SZ;
#endif /* WOLFSSL_DTLS13 */

    reqSz = (word16)(OPAQUE8_LEN + reqCtxLen);
    ret = TLSX_GetRequestSize(ssl, certificate_request, &reqSz);
    if (ret != 0)
        return ret;

    sendSz = (int)(i + reqSz);
    /* Always encrypted and make room for padding. */
    sendSz += MAX_MSG_EXTRA;

    /* Check buffers are big enough and grow if needed. */
    if ((ret = CheckAvailableSize(ssl, sendSz)) != 0)
        return ret;

    /* Get position in output buffer to write new message to. */
    output = GetOutputBuffer(ssl);

    /* Put the record and handshake headers on. */
    AddTls13Headers(output, reqSz, certificate_request, ssl);

    /* Certificate request context. */
    output[i++] = (byte)reqCtxLen;
    if (reqCtxLen != 0) {
        XMEMCPY(output + i, reqCtx, reqCtxLen);
        i += reqCtxLen;
    }

    /* Certificate extensions. */
    reqSz = 0;
    ret = TLSX_WriteRequest(ssl, output + i, certificate_request, &reqSz);
    if (ret != 0)
        return ret;
    i += reqSz;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        ssl->options.buildingMsg = 0;
        ret =
            Dtls13HandshakeSend(ssl, output, (word16)sendSz, (word16)i,
                                certificate_request, 1);

        WOLFSSL_LEAVE("SendTls13CertificateRequest", ret);
        WOLFSSL_END(WC_FUNC_CERTIFICATE_REQUEST_SEND);

        return ret;

    }
#endif /* WOLFSSL_DTLS13 */

    /* Always encrypted. */
    sendSz = BuildTls13Message(ssl, output, sendSz, output + RECORD_HEADER_SZ,
                               (int)(i - RECORD_HEADER_SZ), handshake, 1, 0, 0);
    if (sendSz < 0)
        return sendSz;

    #if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
        if (ssl->hsInfoOn)
            AddPacketName(ssl, "CertificateRequest");
        if (ssl->toInfoOn) {
            ret = AddPacketInfo(ssl, "CertificateRequest", handshake, output,
                          sendSz, WRITE_PROTO, 0, ssl->heap);
            if (ret != 0)
                return ret;
        }
    #endif

    ssl->buffers.outputBuffer.length += (word32)sendSz;
    ssl->options.buildingMsg = 0;
    if (!ssl->options.groupMessages)
        ret = SendBuffered(ssl);

    WOLFSSL_LEAVE("SendTls13CertificateRequest", ret);
    WOLFSSL_END(WC_FUNC_CERTIFICATE_REQUEST_SEND);

    return ret;
}
#endif /* NO_CERTS */
#endif /* NO_WOLFSSL_SERVER */

#ifndef NO_CERTS
#if (!defined(NO_WOLFSSL_SERVER) || !defined(WOLFSSL_NO_CLIENT_AUTH)) && \
    (!defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519) || \
     defined(HAVE_ED448) || defined(HAVE_FALCON) || defined(WOLFSSL_HAVE_MLDSA) || \
     defined(WOLFSSL_HAVE_SLHDSA))
/* Encode the signature algorithm into buffer.
 *
 * hashalgo  The hash algorithm.
 * hsType   The signature type.
 * output    The buffer to encode into.
 */
static WC_INLINE void EncodeSigAlg(const WOLFSSL * ssl, byte hashAlgo,
    byte hsType, byte* output)
{
    (void)ssl;
    (void)hashAlgo;
    switch (hsType) {
#ifdef HAVE_ECC
        case ecc_dsa_sa_algo:
            if (ssl->pkCurveOID == ECC_BRAINPOOLP256R1_OID) {
                output[0] = NEW_SA_MAJOR;
                output[1] = ECDSA_BRAINPOOLP256R1TLS13_SHA256_MINOR;
            }
            else if (ssl->pkCurveOID == ECC_BRAINPOOLP384R1_OID) {
                output[0] = NEW_SA_MAJOR;
                output[1] = ECDSA_BRAINPOOLP384R1TLS13_SHA384_MINOR;
            }
            else if (ssl->pkCurveOID == ECC_BRAINPOOLP512R1_OID) {
                output[0] = NEW_SA_MAJOR;
                output[1] = ECDSA_BRAINPOOLP512R1TLS13_SHA512_MINOR;
            }
            else {
                output[0] = hashAlgo;
                output[1] = ecc_dsa_sa_algo;
            }
            break;
#endif
#if defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
        case sm2_sa_algo:
            output[0] = SM2_SA_MAJOR;
            output[1] = SM2_SA_MINOR;
            break;
#endif
#ifdef HAVE_ED25519
        /* ED25519: 0x0807 */
        case ed25519_sa_algo:
            output[0] = ED25519_SA_MAJOR;
            output[1] = ED25519_SA_MINOR;
            break;
#endif
#ifdef HAVE_ED448
        /* ED448: 0x0808 */
        case ed448_sa_algo:
            output[0] = ED448_SA_MAJOR;
            output[1] = ED448_SA_MINOR;
            break;
#endif
#ifndef NO_RSA
        /* PSS signatures: 0x080[4-6] or 0x080[9-B] */
        case rsa_pss_sa_algo:
            output[0] = rsa_pss_sa_algo;
#ifdef WC_RSA_PSS
            /* If the private key uses the RSA-PSS OID, and the peer supports
             * the rsa_pss_pss_* signature algorithm in use, then report
             * rsa_pss_pss_* rather than rsa_pss_rsae_*. */
            if (ssl->useRsaPss &&
                ((ssl->pssAlgo & (1U << hashAlgo)) != 0U) &&
                (sha256_mac <= hashAlgo) && (hashAlgo <= sha512_mac))
            {
                output[1] = PSS_RSAE_TO_PSS_PSS(hashAlgo);
            }
            else
#endif
            {
                output[1] = hashAlgo;
            }
            break;
#endif
#ifdef HAVE_FALCON
        case falcon_level1_sa_algo:
            output[0] = FALCON_LEVEL1_SA_MAJOR;
            output[1] = FALCON_LEVEL1_SA_MINOR;
            break;
        case falcon_level5_sa_algo:
            output[0] = FALCON_LEVEL5_SA_MAJOR;
            output[1] = FALCON_LEVEL5_SA_MINOR;
            break;
#endif
#ifdef WOLFSSL_HAVE_MLDSA
        case mldsa_44_sa_algo:
            output[0] = MLDSA_44_SA_MAJOR;
            output[1] = MLDSA_44_SA_MINOR;
            break;
        case mldsa_65_sa_algo:
            output[0] = MLDSA_65_SA_MAJOR;
            output[1] = MLDSA_65_SA_MINOR;
            break;
        case mldsa_87_sa_algo:
            output[0] = MLDSA_87_SA_MAJOR;
            output[1] = MLDSA_87_SA_MINOR;
            break;
#endif
#ifdef WOLFSSL_HAVE_SLHDSA
    #if defined(WOLFSSL_SLHDSA_SHA2) && defined(WOLFSSL_SLHDSA_PARAM_SHA2_128S)
        case slhdsa_sha2_128s_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHA2_128S_SA_MINOR;
            break;
    #endif
    #if defined(WOLFSSL_SLHDSA_SHA2) && defined(WOLFSSL_SLHDSA_PARAM_SHA2_128F)
        case slhdsa_sha2_128f_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHA2_128F_SA_MINOR;
            break;
    #endif
    #if defined(WOLFSSL_SLHDSA_SHA2) && defined(WOLFSSL_SLHDSA_PARAM_SHA2_192S)
        case slhdsa_sha2_192s_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHA2_192S_SA_MINOR;
            break;
    #endif
    #if defined(WOLFSSL_SLHDSA_SHA2) && defined(WOLFSSL_SLHDSA_PARAM_SHA2_192F)
        case slhdsa_sha2_192f_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHA2_192F_SA_MINOR;
            break;
    #endif
    #if defined(WOLFSSL_SLHDSA_SHA2) && defined(WOLFSSL_SLHDSA_PARAM_SHA2_256S)
        case slhdsa_sha2_256s_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHA2_256S_SA_MINOR;
            break;
    #endif
    #if defined(WOLFSSL_SLHDSA_SHA2) && defined(WOLFSSL_SLHDSA_PARAM_SHA2_256F)
        case slhdsa_sha2_256f_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHA2_256F_SA_MINOR;
            break;
    #endif
    #ifdef WOLFSSL_SLHDSA_PARAM_128S
        case slhdsa_shake_128s_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHAKE_128S_SA_MINOR;
            break;
    #endif
    #ifdef WOLFSSL_SLHDSA_PARAM_128F
        case slhdsa_shake_128f_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHAKE_128F_SA_MINOR;
            break;
    #endif
    #ifdef WOLFSSL_SLHDSA_PARAM_192S
        case slhdsa_shake_192s_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHAKE_192S_SA_MINOR;
            break;
    #endif
    #ifdef WOLFSSL_SLHDSA_PARAM_192F
        case slhdsa_shake_192f_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHAKE_192F_SA_MINOR;
            break;
    #endif
    #ifdef WOLFSSL_SLHDSA_PARAM_256S
        case slhdsa_shake_256s_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHAKE_256S_SA_MINOR;
            break;
    #endif
    #ifdef WOLFSSL_SLHDSA_PARAM_256F
        case slhdsa_shake_256f_sa_algo:
            output[0] = SLHDSA_SA_MAJOR;
            output[1] = SLHDSA_SHAKE_256F_SA_MINOR;
            break;
    #endif
#endif /* WOLFSSL_HAVE_SLHDSA */
        default:
            break;
    }
}
#endif

#if !defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519) || \
    defined(HAVE_ED448) || defined(HAVE_FALCON) || defined(WOLFSSL_HAVE_MLDSA) || \
    defined(WOLFSSL_HAVE_SLHDSA)
#ifdef WOLFSSL_DUAL_ALG_CERTS
/* These match up with what the OQS team has defined. */
#define HYBRID_SA_MAJOR 0xFE
#define HYBRID_P256_MLDSA_44_SA_MINOR            0xA1
#define HYBRID_RSA3072_MLDSA_44_SA_MINOR         0xA2
#define HYBRID_P384_MLDSA_65_SA_MINOR            0xA4
#define HYBRID_P521_MLDSA_87_SA_MINOR            0xA6
/* Falcon hybrid codepoints aligned with oqs-provider. */
#define HYBRID_P256_FALCON_LEVEL1_SA_MINOR       0xD8
#define HYBRID_RSA3072_FALCON_LEVEL1_SA_MINOR    0xD9
#define HYBRID_P521_FALCON_LEVEL5_SA_MINOR       0xDB

/* Custom defined ones for PQC first */
#define HYBRID_MLDSA_44_P256_SA_MINOR            0xD1
#define HYBRID_MLDSA_44_RSA3072_SA_MINOR         0xD2
#define HYBRID_MLDSA_65_P384_SA_MINOR            0xD3
#define HYBRID_MLDSA_87_P521_SA_MINOR            0xD4
#define HYBRID_FALCON_LEVEL1_P256_SA_MINOR       0xD5
#define HYBRID_FALCON_LEVEL1_RSA3072_SA_MINOR    0xD6
#define HYBRID_FALCON_LEVEL5_P521_SA_MINOR       0xD7


static void EncodeDualSigAlg(byte sigAlg, byte altSigAlg, byte* output)
{
    /* Initialize output to error indicator. */
    output[0] = 0x0;
    output[1] = 0x0;

    if (sigAlg == ecc_dsa_sa_algo && altSigAlg == mldsa_44_sa_algo) {
        output[1] = HYBRID_P256_MLDSA_44_SA_MINOR;
    }
    else if (sigAlg == rsa_pss_sa_algo &&
             altSigAlg == mldsa_44_sa_algo) {
        output[1] = HYBRID_RSA3072_MLDSA_44_SA_MINOR;
    }
    else if (sigAlg == ecc_dsa_sa_algo &&
             altSigAlg == mldsa_65_sa_algo) {
        output[1] = HYBRID_P384_MLDSA_65_SA_MINOR;
    }
    else if (sigAlg == ecc_dsa_sa_algo &&
             altSigAlg == mldsa_87_sa_algo) {
        output[1] = HYBRID_P521_MLDSA_87_SA_MINOR;
    }
    else if (sigAlg == ecc_dsa_sa_algo &&
             altSigAlg == falcon_level1_sa_algo) {
        output[1] = HYBRID_P256_FALCON_LEVEL1_SA_MINOR;
    }
    else if (sigAlg == rsa_pss_sa_algo &&
             altSigAlg == falcon_level1_sa_algo) {
        output[1] = HYBRID_RSA3072_FALCON_LEVEL1_SA_MINOR;
    }
    else if (sigAlg == ecc_dsa_sa_algo &&
             altSigAlg == falcon_level5_sa_algo) {
        output[1] = HYBRID_P521_FALCON_LEVEL5_SA_MINOR;
    }
    else if (sigAlg == mldsa_44_sa_algo &&
             altSigAlg == ecc_dsa_sa_algo) {
        output[1] = HYBRID_MLDSA_44_P256_SA_MINOR;
    }
    else if (sigAlg == mldsa_44_sa_algo &&
             altSigAlg == rsa_pss_sa_algo) {
        output[1] = HYBRID_MLDSA_44_RSA3072_SA_MINOR;
    }
    else if (sigAlg == mldsa_65_sa_algo &&
             altSigAlg == ecc_dsa_sa_algo) {
        output[1] = HYBRID_MLDSA_65_P384_SA_MINOR;
    }
    else if (sigAlg == mldsa_87_sa_algo &&
             altSigAlg == ecc_dsa_sa_algo) {
        output[1] = HYBRID_MLDSA_87_P521_SA_MINOR;
    }
    else if (sigAlg == falcon_level1_sa_algo &&
             altSigAlg == ecc_dsa_sa_algo) {
        output[1] = HYBRID_FALCON_LEVEL1_P256_SA_MINOR;
    }
    else if (sigAlg == falcon_level1_sa_algo &&
             altSigAlg == rsa_pss_sa_algo) {
        output[1] = HYBRID_FALCON_LEVEL1_RSA3072_SA_MINOR;
    }
    else if (sigAlg == falcon_level5_sa_algo &&
             altSigAlg == ecc_dsa_sa_algo) {
        output[1] = HYBRID_FALCON_LEVEL5_P521_SA_MINOR;
    }

    if (output[1] != 0x0) {
        output[0] = HYBRID_SA_MAJOR;
    }
}
#endif /* WOLFSSL_DUAL_ALG_CERTS */

static enum wc_MACAlgorithm GetNewSAHashAlgo(int typeIn)
{
    switch (typeIn) {
        case RSA_PSS_RSAE_SHA256_MINOR:
        case RSA_PSS_PSS_SHA256_MINOR:
        case ECDSA_BRAINPOOLP256R1TLS13_SHA256_MINOR:
            return sha256_mac;

        case RSA_PSS_RSAE_SHA384_MINOR:
        case RSA_PSS_PSS_SHA384_MINOR:
        case ECDSA_BRAINPOOLP384R1TLS13_SHA384_MINOR:
            return sha384_mac;

        case RSA_PSS_RSAE_SHA512_MINOR:
        case RSA_PSS_PSS_SHA512_MINOR:
        case ED25519_SA_MINOR:
        case ED448_SA_MINOR:
        case ECDSA_BRAINPOOLP512R1TLS13_SHA512_MINOR:
            return sha512_mac;
        default:
            return no_mac;
    }
}

/* Decode the signature algorithm.
 *
 * input     The encoded signature algorithm.
 * hashalgo  The hash algorithm.
 * hsType    The signature type.
 * returns INVALID_PARAMETER if not recognized and 0 otherwise.
 */
static WC_INLINE int DecodeTls13SigAlg(byte* input, byte* hashAlgo,
                                       byte* hsType)
{
    int ret = 0;
#if defined(WOLFSSL_HAVE_SLHDSA)
    byte slhType;
#endif

    switch (input[0]) {
    #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
        case SM2_SA_MAJOR:
            if (input[1] == SM2_SA_MINOR) {
                *hsType = sm2_sa_algo;
                *hashAlgo = sm3_mac;
            }
            else
                ret = INVALID_PARAMETER;
            break;
    #endif
        case NEW_SA_MAJOR:
        {
            enum wc_MACAlgorithm mac = GetNewSAHashAlgo(input[1]);
            *hashAlgo = (byte)mac;
        }

            /* PSS encryption: 0x080[4-6] */
            if (input[1] >= RSA_PSS_RSAE_SHA256_MINOR &&
                    input[1] <= RSA_PSS_RSAE_SHA512_MINOR) {
                *hsType   = input[0];
            }
            /* PSS signature: 0x080[9-B] */
            else if (input[1] >= RSA_PSS_PSS_SHA256_MINOR &&
                    input[1] <= RSA_PSS_PSS_SHA512_MINOR) {
                *hsType   = input[0];
            }
    #ifdef HAVE_ED25519
            /* ED25519: 0x0807 */
            else if (input[1] == ED25519_SA_MINOR) {
                *hsType = ed25519_sa_algo;
                /* Hash performed as part of sign/verify operation. */
            }
    #endif
    #ifdef HAVE_ED448
            /* ED448: 0x0808 */
            else if (input[1] == ED448_SA_MINOR) {
                *hsType = ed448_sa_algo;
                /* Hash performed as part of sign/verify operation. */
            }
    #endif
    #ifdef HAVE_ECC_BRAINPOOL
            else if ((input[1] == ECDSA_BRAINPOOLP256R1TLS13_SHA256_MINOR) ||
                     (input[1] == ECDSA_BRAINPOOLP384R1TLS13_SHA384_MINOR) ||
                     (input[1] == ECDSA_BRAINPOOLP512R1TLS13_SHA512_MINOR)) {
                *hsType = ecc_dsa_sa_algo;
            }
    #endif
            else
                ret = INVALID_PARAMETER;
            break;
#if defined(HAVE_FALCON)
        case FALCON_SA_MAJOR:
            if (input[1] == FALCON_LEVEL1_SA_MINOR) {
                *hsType = falcon_level1_sa_algo;
                /* Hash performed as part of sign/verify operation. */
                *hashAlgo = sha512_mac;
            } else if (input[1] == FALCON_LEVEL5_SA_MINOR) {
                *hsType = falcon_level5_sa_algo;
                /* Hash performed as part of sign/verify operation. */
                *hashAlgo = sha512_mac;
            }
            else
                ret = INVALID_PARAMETER;
            break;
#endif /* HAVE_FALCON */
#if defined(WOLFSSL_HAVE_MLDSA) || defined(WOLFSSL_HAVE_SLHDSA)
        /* ML-DSA and SLH-DSA share the same major byte (0x09); their minor
         * bytes are disjoint (ML-DSA 0x04-0x06, SLH-DSA 0x11-0x1C). */
        case MLDSA_SA_MAJOR:
            ret = INVALID_PARAMETER;
    #if defined(WOLFSSL_HAVE_MLDSA)
            if (input[1] == MLDSA_44_SA_MINOR) {
                *hsType = mldsa_44_sa_algo;
                /* Hash performed as part of sign/verify operation. */
                *hashAlgo = sha512_mac;
                ret = 0;
            } else if (input[1] == MLDSA_65_SA_MINOR) {
                *hsType = mldsa_65_sa_algo;
                *hashAlgo = sha512_mac;
                ret = 0;
            } else if (input[1] == MLDSA_87_SA_MINOR) {
                *hsType = mldsa_87_sa_algo;
                *hashAlgo = sha512_mac;
                ret = 0;
            }
    #endif /* WOLFSSL_HAVE_MLDSA */
    #if defined(WOLFSSL_HAVE_SLHDSA)
            if (ret != 0) {
                slhType = SlhDsaSigMinorToType(input[1]);
                if (slhType != (byte)invalid_sa_algo) {
                    *hsType = slhType;
                    /* Hash performed as part of sign/verify operation. */
                    *hashAlgo = sha512_mac;
                    ret = 0;
                }
            }
    #endif /* WOLFSSL_HAVE_SLHDSA */
            break;
#endif /* WOLFSSL_HAVE_MLDSA || WOLFSSL_HAVE_SLHDSA */
        default:
            *hashAlgo = input[0];
            *hsType   = input[1];
            break;
    }

    return ret;
}

#ifdef WOLFSSL_DUAL_ALG_CERTS
/* Decode the hybrid signature algorithm.
 *
 * input     The encoded signature algorithm.
 * hashalgo  The hash algorithm.
 * hsType    The signature type.
 * returns INVALID_PARAMETER if not recognized and 0 otherwise.
 */
static WC_INLINE int DecodeTls13HybridSigAlg(byte* input, byte* hashAlg,
                                             byte *sigAlg, byte *altSigAlg)
{

    if (input[0] != HYBRID_SA_MAJOR) {
        return INVALID_PARAMETER;
    }

    if (input[1] == HYBRID_P256_MLDSA_44_SA_MINOR) {
        *sigAlg = ecc_dsa_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = mldsa_44_sa_algo;
    }
    else if (input[1] == HYBRID_RSA3072_MLDSA_44_SA_MINOR) {
        *sigAlg = rsa_pss_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = mldsa_44_sa_algo;
    }
    else if (input[1] == HYBRID_P384_MLDSA_65_SA_MINOR) {
        *sigAlg = ecc_dsa_sa_algo;
        *hashAlg = sha384_mac;
        *altSigAlg = mldsa_65_sa_algo;
    }
    else if (input[1] == HYBRID_P521_MLDSA_87_SA_MINOR) {
        *sigAlg = ecc_dsa_sa_algo;
        *hashAlg = sha512_mac;
        *altSigAlg = mldsa_87_sa_algo;
    }
    else if (input[1] == HYBRID_P256_FALCON_LEVEL1_SA_MINOR) {
        *sigAlg = ecc_dsa_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = falcon_level1_sa_algo;
    }
    else if (input[1] == HYBRID_RSA3072_FALCON_LEVEL1_SA_MINOR) {
        *sigAlg = rsa_pss_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = falcon_level1_sa_algo;
    }
    else if (input[1] == HYBRID_P521_FALCON_LEVEL5_SA_MINOR) {
        *sigAlg = ecc_dsa_sa_algo;
        *hashAlg = sha512_mac;
        *altSigAlg = falcon_level5_sa_algo;
    }
    else if (input[1] == HYBRID_MLDSA_44_P256_SA_MINOR) {
        *sigAlg = mldsa_44_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = ecc_dsa_sa_algo;
    }
    else if (input[1] == HYBRID_MLDSA_44_RSA3072_SA_MINOR) {
        *sigAlg = mldsa_44_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = rsa_pss_sa_algo;
    }
    else if (input[1] == HYBRID_MLDSA_65_P384_SA_MINOR) {
        *sigAlg = mldsa_65_sa_algo;
        *hashAlg = sha384_mac;
        *altSigAlg = ecc_dsa_sa_algo;
    }
    else if (input[1] == HYBRID_MLDSA_87_P521_SA_MINOR) {
        *sigAlg = mldsa_87_sa_algo;
        *hashAlg = sha512_mac;
        *altSigAlg = ecc_dsa_sa_algo;
    }
    else if (input[1] == HYBRID_FALCON_LEVEL1_P256_SA_MINOR) {
        *sigAlg = falcon_level1_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = ecc_dsa_sa_algo;
    }
    else if (input[1] == HYBRID_FALCON_LEVEL1_RSA3072_SA_MINOR) {
        *sigAlg = falcon_level1_sa_algo;
        *hashAlg = sha256_mac;
        *altSigAlg = rsa_pss_sa_algo;
    }
    else if (input[1] == HYBRID_FALCON_LEVEL5_P521_SA_MINOR) {
        *sigAlg = falcon_level5_sa_algo;
        *hashAlg = sha512_mac;
        *altSigAlg = ecc_dsa_sa_algo;
    }
    else {
        return INVALID_PARAMETER;
    }

    return 0;
}
#endif /* WOLFSSL_DUAL_ALG_CERTS */

/* Get the hash of the messages so far.
 *
 * ssl   The SSL/TLS object.
 * hash  The buffer to write the hash to.
 * returns the length of the hash.
 */
static WC_INLINE int GetMsgHash(WOLFSSL* ssl, byte* hash)
{
    int ret = 0;
    switch (ssl->specs.mac_algorithm) {
    #ifndef NO_SHA256
        case sha256_mac:
            ret = wc_Sha256GetHash(&ssl->hsHashes->hashSha256, hash);
            if (ret == 0)
                ret = WC_SHA256_DIGEST_SIZE;
            break;
    #endif /* !NO_SHA256 */
    #ifdef WOLFSSL_SHA384
        case sha384_mac:
            ret = wc_Sha384GetHash(&ssl->hsHashes->hashSha384, hash);
            if (ret == 0)
                ret = WC_SHA384_DIGEST_SIZE;
            break;
    #endif /* WOLFSSL_SHA384 */
    #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            ret = wc_Sha512GetHash(&ssl->hsHashes->hashSha512, hash);
            if (ret == 0)
                ret = WC_SHA512_DIGEST_SIZE;
            break;
    #endif /* WOLFSSL_TLS13_SHA512 */
    #ifdef WOLFSSL_SM3
        case sm3_mac:
            ret = wc_Sm3GetHash(&ssl->hsHashes->hashSm3, hash);
            if (ret == 0)
                ret = WC_SM3_DIGEST_SIZE;
            break;
    #endif /* WOLFSSL_SM3 */
        default:
            break;
    }
    return ret;
}

/* The server certificate verification label. */
static const byte serverCertVfyLabel[CERT_VFY_LABEL_SZ] =
    "TLS 1.3, server CertificateVerify";
/* The client certificate verification label. */
static const byte clientCertVfyLabel[CERT_VFY_LABEL_SZ] =
    "TLS 1.3, client CertificateVerify";
/* The prefix byte in the signature data. */
#define SIGNING_DATA_PREFIX_BYTE   0x20

/* Create the signature data for TLS v1.3 certificate verification.
 *
 * ssl        The SSL/TLS object.
 * sigData    The signature data.
 * sigDataSz  The length of the signature data.
 * check      Indicates this is a check not create.
 */
int CreateSigData(WOLFSSL* ssl, byte* sigData, word16* sigDataSz,
                  int check)
{
    word16 idx;
    int side = ssl->options.side;
    int ret;

    /* Signature Data = Prefix | Label | Handshake Hash */
    XMEMSET(sigData, SIGNING_DATA_PREFIX_BYTE, SIGNING_DATA_PREFIX_SZ);
    idx = SIGNING_DATA_PREFIX_SZ;

    if ((side == WOLFSSL_SERVER_END && check) ||
        (side == WOLFSSL_CLIENT_END && !check)) {
        XMEMCPY(&sigData[idx], clientCertVfyLabel, CERT_VFY_LABEL_SZ);
    }
    if ((side == WOLFSSL_CLIENT_END && check) ||
        (side == WOLFSSL_SERVER_END && !check)) {
        XMEMCPY(&sigData[idx], serverCertVfyLabel, CERT_VFY_LABEL_SZ);
    }
    idx += CERT_VFY_LABEL_SZ;

    ret = GetMsgHash(ssl, &sigData[idx]);
    if (ret < 0)
        return ret;
    if (ret == 0)
        return HASH_TYPE_E;

    *sigDataSz = (word16)(idx + ret);
    ret = 0;

    return ret;
}

#ifndef NO_RSA
/* Encode the PKCS #1.5 RSA signature.
 *
 * sig        The buffer to place the encoded signature into.
 * sigData    The data to be signed.
 * sigDataSz  The size of the data to be signed.
 * hashAlgo   The hash algorithm to use when signing.
 * returns the length of the encoded signature or negative on error.
 */
int CreateRSAEncodedSig(byte* sig, byte* sigData, int sigDataSz,
                        int sigAlgo, int hashAlgo)
{
    Digest digest;
    int    hashSz = 0;
    int    ret = WC_NO_ERR_TRACE(BAD_FUNC_ARG);
    byte*  hash;

    (void)sigAlgo;

    hash = sig;

    /* Digest the signature data. */
    switch (hashAlgo) {
#ifndef NO_SHA256
        case sha256_mac:
            ret = wc_InitSha256(&digest.sha256);
            if (ret == 0) {
                ret = wc_Sha256Update(&digest.sha256, sigData, (word32)sigDataSz);
                if (ret == 0)
                    ret = wc_Sha256Final(&digest.sha256, hash);
                wc_Sha256Free(&digest.sha256);
            }
            hashSz = WC_SHA256_DIGEST_SIZE;
            break;
#endif
#ifdef WOLFSSL_SHA384
        case sha384_mac:
            ret = wc_InitSha384(&digest.sha384);
            if (ret == 0) {
                ret = wc_Sha384Update(&digest.sha384, sigData, (word32)sigDataSz);
                if (ret == 0)
                    ret = wc_Sha384Final(&digest.sha384, hash);
                wc_Sha384Free(&digest.sha384);
            }
            hashSz = WC_SHA384_DIGEST_SIZE;
            break;
#endif
#ifdef WOLFSSL_SHA512
        case sha512_mac:
            ret = wc_InitSha512(&digest.sha512);
            if (ret == 0) {
                ret = wc_Sha512Update(&digest.sha512, sigData, (word32)sigDataSz);
                if (ret == 0)
                    ret = wc_Sha512Final(&digest.sha512, hash);
                wc_Sha512Free(&digest.sha512);
            }
            hashSz = WC_SHA512_DIGEST_SIZE;
            break;
#endif
       default:
            ret = BAD_FUNC_ARG;
            break;

    }

    if (ret != 0)
        return ret;

    return hashSz;
}
#endif /* !NO_RSA */

#ifdef HAVE_ECC
/* Encode the ECC signature.
 *
 * sigData    The data to be signed.
 * sigDataSz  The size of the data to be signed.
 * hashAlgo   The hash algorithm to use when signing.
 * returns the length of the encoded signature or negative on error.
 */
static int CreateECCEncodedSig(byte* sigData, int sigDataSz, int hashAlgo)
{
    Digest digest;
    int    hashSz = 0;
    int    ret = WC_NO_ERR_TRACE(BAD_FUNC_ARG);

    /* Digest the signature data. */
    switch (hashAlgo) {
#ifndef NO_SHA256
        case sha256_mac:
            ret = wc_InitSha256(&digest.sha256);
            if (ret == 0) {
                ret = wc_Sha256Update(&digest.sha256, sigData, (word32)sigDataSz);
                if (ret == 0)
                    ret = wc_Sha256Final(&digest.sha256, sigData);
                wc_Sha256Free(&digest.sha256);
            }
            hashSz = WC_SHA256_DIGEST_SIZE;
            break;
#endif
#ifdef WOLFSSL_SHA384
        case sha384_mac:
            ret = wc_InitSha384(&digest.sha384);
            if (ret == 0) {
                ret = wc_Sha384Update(&digest.sha384, sigData, (word32)sigDataSz);
                if (ret == 0)
                    ret = wc_Sha384Final(&digest.sha384, sigData);
                wc_Sha384Free(&digest.sha384);
            }
            hashSz = WC_SHA384_DIGEST_SIZE;
            break;
#endif
#ifdef WOLFSSL_SHA512
        case sha512_mac:
            ret = wc_InitSha512(&digest.sha512);
            if (ret == 0) {
                ret = wc_Sha512Update(&digest.sha512, sigData, (word32)sigDataSz);
                if (ret == 0)
                    ret = wc_Sha512Final(&digest.sha512, sigData);
                wc_Sha512Free(&digest.sha512);
            }
            hashSz = WC_SHA512_DIGEST_SIZE;
            break;
#endif
        default:
            ret = BAD_FUNC_ARG;
            break;
    }

    if (ret != 0)
        return ret;

    return hashSz;
}
#endif /* HAVE_ECC */

#if !defined(NO_RSA) && defined(WC_RSA_PSS)
/* Check that the decrypted signature matches the encoded signature
 * based on the digest of the signature data.
 *
 * ssl       The SSL/TLS object.
 * sigAlgo   The signature algorithm used to generate signature.
 * hashAlgo  The hash algorithm used to generate signature.
 * decSig    The decrypted signature.
 * decSigSz  The size of the decrypted signature.
 * returns 0 on success, otherwise failure.
 */
static int CheckRSASignature(WOLFSSL* ssl, int sigAlgo, int hashAlgo,
                             byte* decSig, word32 decSigSz)
{
    int    ret = 0;
    byte   sigData[MAX_SIG_DATA_SZ];
    word16 sigDataSz;

    ret = CreateSigData(ssl, sigData, &sigDataSz, 1);
    if (ret != 0)
        return ret;

    if (sigAlgo == rsa_pss_sa_algo) {
        enum wc_HashType hashType = WC_HASH_TYPE_NONE;
        word32 sigSz;

        ret = ConvertHashPss(hashAlgo, &hashType, NULL);
        if (ret < 0)
            return ret;

        /* PSS signature can be done in-place */
        ret = CreateRSAEncodedSig(sigData, sigData, sigDataSz,
                                  sigAlgo, hashAlgo);
        if (ret < 0)
            return ret;
        sigSz = (word32)ret;

        ret = wc_RsaPSS_CheckPadding(sigData, sigSz, decSig, decSigSz,
                                     hashType);
    }

    return ret;
}
#endif /* !NO_RSA && WC_RSA_PSS */
#endif /* !NO_RSA || HAVE_ECC */

#if !defined(NO_WOLFSSL_CLIENT) || !defined(NO_WOLFSSL_SERVER)
/* Get the next certificate from the list for writing into the TLS v1.3
 * Certificate message.
 *
 * data    The certificate list.
 * length  The length of the certificate data in the list.
 * idx     The index of the next certificate.
 * returns the length of the certificate data. 0 indicates no more certificates
 * in the list.
 */
static word32 NextCert(byte* data, word32 length, word32* idx)
{
    word32 len;

    /* Would index read past end of list? */
    if (*idx + 3 > length)
        return 0;

    /* Length of the current ASN.1 encoded certificate. */
    c24to32(data + *idx, &len);
    /* Include the length field. */
    len += 3;

    /* Ensure len does not overrun certificate list */
    if (*idx + len > length)
        return 0;

    /* Move index to next certificate and return the current certificate's
     * length.
     */
    *idx += len;
    return len;
}

#if defined(HAVE_CERTIFICATE_STATUS_REQUEST) && !defined(NO_WOLFSSL_SERVER)
/* Write certificate status request into certificate to buffer.
 *
 * ssl       SSL/TLS object.
 * certExts  DerBuffer array. buffers written
 * extSz     word32 array.
 *           Length of the certificate status request data for the certificate.
 * extSz_num number of the CSR written
 * extIdx    The index number of certificate status request data
 *           for the certificate.
 * offset    index offset
 * returns   Total number of bytes written on success or negative value on error.
 */
static int WriteCSRToBuffer(WOLFSSL* ssl, DerBuffer** certExts,
                                word16* extSz,  word16 extSz_num)
{
    int    ret = 0;
    TLSX* ext;
    CertificateStatusRequest* csr;
    word32 ex_offset = HELLO_EXT_TYPE_SZ + OPAQUE16_LEN /* extension type */
                    + OPAQUE16_LEN /* extension length */;
    word32 totalSz = 0;
    word32 tmpSz;
    word32 extIdx;
    DerBuffer* der;

    if (extSz_num > MAX_CERT_EXTENSIONS)
        return MAX_CERT_EXTENSIONS_ERR;

    ext = TLSX_Find(ssl->extensions, TLSX_STATUS_REQUEST);
    csr = ext ? (CertificateStatusRequest*)ext->data : NULL;

    if (csr) {
        for (extIdx = 0; extIdx < (word16)(extSz_num); extIdx++) {
            tmpSz = TLSX_CSR_GetSize_ex(csr, 0, (int)extIdx);

            if (ssl->fragOffset != 0 && certExts[extIdx] != NULL) {
                /* A fragmented send is being resumed and this buffer was
                 * written by the earlier call. extSz starts over on every
                 * call, so recover this entry's size from the length written
                 * into the buffer. */
                ato16(certExts[extIdx]->buffer, &extSz[extIdx]);
                extSz[extIdx] += OPAQUE16_LEN;
            }
            else {
                /* Not a resume, so anything still allocated here is left over
                 * from a completed message and must not be reused. */
                FreeDer(&certExts[extIdx]);

                if (tmpSz > (OPAQUE8_LEN + OPAQUE24_LEN)) {
                    /* csr extension is not zero */
                    if (tmpSz > WOLFSSL_MAX_16BIT)
                        return BUFFER_E;
                    extSz[extIdx] = (word16)tmpSz;

                    ret = AllocDer(&certExts[extIdx], extSz[extIdx] + ex_offset,
                                                        CERT_TYPE, ssl->heap);
                    if (ret < 0)
                        return ret;
                    der = certExts[extIdx];

                    /* write extension type */
                    c16toa(ext->type, der->buffer
                                    + OPAQUE16_LEN);
                    /* writes extension data length. */
                    c16toa(extSz[extIdx], der->buffer
                                + HELLO_EXT_TYPE_SZ + OPAQUE16_LEN);
                    /* write extension data */
                    extSz[extIdx] = (word16)TLSX_CSR_Write_ex(csr,
                            der->buffer + ex_offset, 0, extIdx);
                    /* add extension offset */
                    extSz[extIdx] += (word16)ex_offset;
                    /* extension length */
                    c16toa(extSz[extIdx] - OPAQUE16_LEN,
                                der->buffer);
                }
            }
            totalSz += extSz[extIdx];
        }
    }
    else {
        /* chain cert empty extension size */
        totalSz += OPAQUE16_LEN * extSz_num;
    }
    return (int)totalSz;
}
#endif /* HAVE_CERTIFICATE_STATUS_REQUEST */
/* Add certificate data and empty extension to output up to the fragment size.
 *
 * ssl     SSL/TLS object.
 * cert    The certificate data to write out.
 * len     The length of the certificate data.
 * extSz   Length of the extension data with the certificate.
 * idx     The start of the certificate data to write out.
 * fragSz  The maximum size of this fragment.
 * output  The buffer to write to.
 * extIdx  The index number of the extension data with the certificate
 * returns the number of bytes written.
 */
static word32 AddCertExt(WOLFSSL* ssl, byte* cert, word32 len, word16 extSz,
                         word32 idx, word32 fragSz, byte* output, word16 extIdx)
{
    word32 i = 0;
    word32 copySz = min(len - idx, fragSz);

    if (idx < len) {
        XMEMCPY(output, cert + idx, copySz);
        i = copySz;
        if (copySz == fragSz)
            return i;
    }
    copySz = len + extSz - idx - i;

    if (extSz == OPAQUE16_LEN) {
        if (copySz <= fragSz) {
            /* Empty extension */
            output[i++] = 0;
            output[i++] = 0;
        }
    }
    else {
        byte* certExts = ssl->buffers.certExts[extIdx]->buffer + idx + i - len;
        /* Put out as much of the extensions' data as will fit in fragment. */
        if (copySz > fragSz - i)
            copySz = fragSz - i;
        XMEMCPY(output + i, certExts, copySz);
        i += copySz;
    }

    return i;
}

#if defined(HAVE_CERTIFICATE_STATUS_REQUEST) && !defined(NO_WOLFSSL_SERVER)
static int SetupOcspResp(WOLFSSL* ssl)
{
    DecodedCert* cert = NULL;
    CertificateStatusRequest* csr = NULL;
    TLSX* extension = NULL;
    int ret = 0;
    OcspRequest* request = NULL;
    byte ctxOwnsRequest = 0;

    extension = TLSX_Find(ssl->extensions, TLSX_STATUS_REQUEST);
#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    /* During post-handshake client authentication the client must staple
     * its own OCSP response, but the status_request extension it offered in
     * the initial ClientHello is no longer present on ssl->extensions.
     * Recreate it here (the request extension still lives on
     * ctx->extensions). Pass ssl so csr->ssl is set, which the response
     * size/write path requires. */
    if (extension == NULL &&
            ssl->options.side == WOLFSSL_CLIENT_END &&
            ssl->options.handShakeDone &&
            TLSX_Find(ssl->ctx->extensions, TLSX_STATUS_REQUEST) != NULL) {
        ret = TLSX_UseCertificateStatusRequest(&ssl->extensions,
                WOLFSSL_CSR_OCSP, 0, ssl, ssl->heap, ssl->devId);
        if (ret != WOLFSSL_SUCCESS)
            return ret;
        extension = TLSX_Find(ssl->extensions, TLSX_STATUS_REQUEST);
    }
#endif
    if (extension == NULL)
        return 0; /* peer didn't signal ocsp support */
    csr = (CertificateStatusRequest*)extension->data;
    if (csr == NULL)
        return MEMORY_ERROR;

    if (SSL_CM(ssl) != NULL &&
            SSL_CM(ssl)->ocsp_stapling != NULL &&
            SSL_CM(ssl)->ocsp_stapling->statusCb != NULL) {
        return TLSX_CSR_SetResponseWithStatusCB(ssl);
    }

    if (ssl->buffers.certificate == NULL) {
        WOLFSSL_MSG("Certificate buffer not set!");
        return BUFFER_ERROR;
    }
    cert = (DecodedCert*)XMALLOC(sizeof(DecodedCert), ssl->heap,
                                 DYNAMIC_TYPE_DCERT);
    if (cert == NULL) {
        return MEMORY_E;
    }
    InitDecodedCert(cert, ssl->buffers.certificate->buffer,
                    ssl->buffers.certificate->length, ssl->heap);
    ret = ParseCert(cert, CERT_TYPE, NO_VERIFY, SSL_CM(ssl));
    if (ret != 0) {
        FreeDecodedCert(cert);
        XFREE(cert, ssl->heap, DYNAMIC_TYPE_DCERT);
        return ret;
    }
#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    /* On client PHA the same certificate is re-stapled every round; reuse
     * request slot 0 instead of appending, else csr->requests grows until
     * MAX_CERT_EXTENSIONS_ERR. */
    if (ssl->options.side == WOLFSSL_CLIENT_END && ssl->options.handShakeDone) {
        ret = TLSX_CSR_InitRequest_ex(ssl->extensions, cert, ssl->heap, 0);
    }
    else
#endif
    {
        ret = TLSX_CSR_InitRequest(ssl->extensions, cert, ssl->heap);
    }
    FreeDecodedCert(cert);
    XFREE(cert, ssl->heap, DYNAMIC_TYPE_DCERT);
    if (ret != 0 )
        return ret;

    /* Free previous OCSP response buffers to avoid leak on PHA reuse */
    {
        int j;
        for (j = 0; j < MAX_CERT_EXTENSIONS; j++) {
            XFREE(csr->responses[j].buffer, ssl->heap,
                DYNAMIC_TYPE_TMP_BUFFER);
            csr->responses[j].buffer = NULL;
            csr->responses[j].length = 0;
        }
    }
    request = &csr->request.ocsp[0];
    ret = CreateOcspResponse(ssl, &request, &csr->responses[0],
                             &ctxOwnsRequest);
    /* Only a successful call replaces "request", and only a request the CTX did
     * not take ownership of is ours to free. Both are checked, matching the
     * SendCertificateStatus() callers. */
    if (ret == 0 && request != &csr->request.ocsp[0] && !ctxOwnsRequest) {
        /* request was allocated in CreateOcspResponse() */
        FreeOcspRequest(request);
        XFREE(request, ssl->heap, DYNAMIC_TYPE_OCSP_REQUEST);
    }
    if (ret != 0)
        return ret;

    if (csr->responses[0].buffer)
        extension->resp = 1;
#if defined(WOLFSSL_TLS_OCSP_MULTI)
    /* process OCSP request in certificate chain */
    if ((ret = ProcessChainOCSPRequest(ssl)) != 0) {
        WOLFSSL_MSG("Process Cert Chain OCSP request failed");
        WOLFSSL_ERROR_VERBOSE(ret);
        return ret;
    }
#endif
    return ret;
}
#endif

#if !defined(NO_CERTS) && !defined(WOLFSSL_NO_SIGALG)
/* Certificate is signed with the deprecated SHA-1 hash. An unrecognized or
 * unparsable algorithm is not SHA-1; the peer still verifies the chain.
 *
 * der    Buffer holding the DER encoded certificate.
 * derSz  Length of the DER encoded certificate.
 * returns 1 when SHA-1 signed, 0 otherwise.
 */
static int IsSha1SignedCert(const byte* der, word32 derSz)
{
    word32 idx = 0;
    word32 oid = 0;
    word32 algoIdEnd = 0;
    int    len = 0;
    int    isSha1 = 0;
    int    ret;
#if defined(WC_RSA_PSS) && !defined(NO_RSA)
    enum wc_HashType hash = WC_HASH_TYPE_NONE;
    int    mgf = 0;
    int    saltLen = 0;
#endif

    /* Certificate ::= SEQUENCE { tbsCertificate, signatureAlgorithm, ... }.
     * GetSequence() checks each length against the maximum index passed in, so
     * idx and idx + len stay inside the buffer. */
    ret = GetSequence(der, &idx, &len, derSz);
    if (ret >= 0)
        ret = GetSequence(der, &idx, &len, derSz);
    if (ret >= 0) {
        /* signatureAlgorithm immediately follows the tbsCertificate. Decode
         * the AlgorithmIdentifier here rather than with GetAlgoId() so the
         * RSASSA-PSS parameters, which hold the digest, stay reachable. */
        idx += (word32)len;
        ret = GetSequence(der, &idx, &len, derSz);
    }
    if (ret >= 0) {
        algoIdEnd = idx + (word32)len;
        ret = GetObjectId(der, &idx, &oid, oidSigType, algoIdEnd);
    }
    if (ret >= 0) {
        if ((oid == CTC_SHAwRSA) || (oid == CTC_SHAwECDSA) ||
                (oid == CTC_SHAwDSA)) {
            isSha1 = 1;
        }
    #if defined(WC_RSA_PSS) && !defined(NO_RSA)
        /* RSASSA-PSS uses one signature OID for every digest and names the
         * digest in the algorithm parameters instead. Absent parameters are
         * passed through as a zero length buffer rather than skipped: RFC 4055
         * makes them mean all defaults, which is SHA-1, and
         * wc_DecodeRsaPssParams() reports that. */
        else if ((oid == RSAPSSk) && (idx <= algoIdEnd) &&
                (wc_DecodeRsaPssParams(der + idx, algoIdEnd - idx, &hash, &mgf,
                                       &saltLen) == 0)) {
            isSha1 = (hash == WC_HASH_TYPE_SHA);
        }
    #endif
    }

    return isSha1;
}

/* Certificate is self signed. RFC 8446 Section 4.4.2.2: "Certificates that are
 * self-signed or certificates that are expected to be trust anchors are not
 * validated as part of the chain and therefore MAY be signed with any
 * algorithm."
 *
 * DecodedCert.selfSigned is an issuer/subject name hash compare rather than a
 * verified self-signature, which is enough here: the chain is the one this end
 * was configured with, not one an attacker supplies.
 *
 * The certificate is parsed as CA_TYPE rather than CERT_TYPE so a trust anchor
 * carrying serial number 0 still decodes. ParseCertRelative() rejects a zero
 * serial for CERT_TYPE, and legacy roots, the certificates most likely to be
 * SHA-1 signed, are the ones that use it. With NO_VERIFY and no certificate
 * manager the serial exemption is all the type changes, and that exemption
 * still requires a self signed CA, so a leaf carrying serial 0 is reported as
 * not self signed and stays subject to the SHA-1 rule.
 *
 * ssl           The SSL/TLS object.
 * der           Buffer holding the DER encoded certificate.
 * derSz         Length of the DER encoded certificate.
 * isSelfSigned  On success, 1 when self signed, 0 otherwise. A certificate
 *               that will not parse is reported as not self signed so the
 *               SHA-1 rule still applies to it.
 * returns 0 on success, MEMORY_E when the decoder cannot be allocated.
 */
static int IsSelfSignedCert(WOLFSSL* ssl, const byte* der, word32 derSz,
                            int* isSelfSigned)
{
    DecodedCert* cert;

    *isSelfSigned = 0;

    cert = (DecodedCert*)XMALLOC(sizeof(DecodedCert), ssl->heap,
                                 DYNAMIC_TYPE_DCERT);
    if (cert == NULL)
        return MEMORY_E;

    InitDecodedCert(cert, der, derSz, ssl->heap);
    if (ParseCertRelative(cert, CA_TYPE, NO_VERIFY, NULL, NULL) == 0)
        *isSelfSigned = (cert->selfSigned != 0);
    else
        WOLFSSL_MSG("Cannot decode certificate, not treating as self signed");
    FreeDecodedCert(cert);
    XFREE(cert, ssl->heap, DYNAMIC_TYPE_DCERT);

    return 0;
}

/* Check the chain about to be sent against what the peer advertised.
 *
 * RFC 8446 Section 4.4.2.2 permits a fallback chain the peer did not advertise
 * support for, but the chain "MUST NOT" use SHA-1 unless the peer's
 * advertisement permits it. Section 4.4.2.3 requires client certificates to be
 * signed with an acceptable algorithm "as described in Section 4.4.2.2", so the
 * same rule covers both sides. How a failure is resolved differs by side and is
 * left to the caller.
 *
 * ssl  The SSL/TLS object.
 * returns 0 when the chain may be sent, MATCH_SUITE_ERROR when it may not and
 * MEMORY_E when a certificate could not be examined.
 */
static int CheckCertChainSigAlgo(WOLFSSL* ssl)
{
    byte*  chain;
    byte*  cur;
    word32 chainSz;
    word32 len;
    word32 idx = 0;
    int    selfSigned = 0;
    int    ret = 0;

    if (ssl->options.peerSha1CertOk)
        return 0;

    if (ssl->buffers.certificate == NULL ||
            ssl->buffers.certificate->buffer == NULL) {
        return 0;
    }

    if (IsSha1SignedCert(ssl->buffers.certificate->buffer,
                         ssl->buffers.certificate->length)) {
        ret = IsSelfSignedCert(ssl, ssl->buffers.certificate->buffer,
                               ssl->buffers.certificate->length, &selfSigned);
        if (ret != 0)
            return ret;
        if (!selfSigned)
            ret = MATCH_SUITE_ERROR;
    }

    if (ret == 0 && ssl->buffers.certChain != NULL &&
            ssl->buffers.certChain->buffer != NULL &&
            ssl->buffers.certChainCnt > 0) {
        chain = ssl->buffers.certChain->buffer;
        chainSz = ssl->buffers.certChain->length;

        while (ret == 0) {
            cur = chain + idx;
            /* NextCert() length includes the CERT_HEADER_SZ byte prefix and
             * is 0 at the end of the list. Keep this terminator matching the
             * send loop so both walk the same certificates. */
            len = NextCert(chain, chainSz, &idx);
            if (len == 0)
                break;
            if (len <= CERT_HEADER_SZ)
                continue;
            cur += CERT_HEADER_SZ;
            len -= CERT_HEADER_SZ;

            if (IsSha1SignedCert(cur, len)) {
                ret = IsSelfSignedCert(ssl, cur, len, &selfSigned);
                if (ret != 0)
                    return ret;
                if (!selfSigned)
                    ret = MATCH_SUITE_ERROR;
            }
        }
    }

    if (ret == WC_NO_ERR_TRACE(MATCH_SUITE_ERROR))
        WOLFSSL_MSG("Chain is SHA-1 signed but peer did not advertise SHA-1");

    return ret;
}
#endif /* !NO_CERTS && !WOLFSSL_NO_SIGALG */

/* handle generation TLS v1.3 certificate (11) */
/* Send the certificate for this end and any CAs that help with validation.
 * This message is always encrypted in TLS v1.3.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
static int SendTls13Certificate(WOLFSSL* ssl)
{
    int    ret = 0;
    word32 certSz, certChainSz, headerSz, listSz, payloadSz;
    word16 extSz[MAX_CERT_EXTENSIONS];
    word16 extIdx = 0;
    word32 maxFragment;
    word32 totalextSz = 0;
    word32 len = 0;
    word32 idx = 0;
    word32 offset = 0;
    word32 entrySz = 0;
    byte*  p = NULL;
    byte   certReqCtxLen = 0;
    sword32 length;
#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    byte*  certReqCtx = NULL;
#endif
#ifndef WOLFSSL_NO_SIGALG
    int    chainRet;
#endif

#ifdef OPENSSL_EXTRA
    WOLFSSL_X509* x509 = NULL;
    WOLFSSL_EVP_PKEY* pkey = NULL;
#endif

    WOLFSSL_START(WC_FUNC_CERTIFICATE_SEND);
    WOLFSSL_ENTER("SendTls13Certificate");

    XMEMSET(extSz, 0, sizeof(extSz));

    ssl->options.buildingMsg = 1;

#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    if (ssl->options.side == WOLFSSL_CLIENT_END && ssl->certReqCtx != NULL) {
        certReqCtxLen = ssl->certReqCtx->len;
        certReqCtx = &ssl->certReqCtx->ctx;
    }
#endif

#if defined(OPENSSL_EXTRA) && defined(WOLFSSL_CERT_SETUP_CB)
    /* call client cert callback if no cert has been loaded */
    if ((ssl->ctx->CBClientCert != NULL) &&
        (!ssl->buffers.certificate || !ssl->buffers.certificate->buffer)) {
        ret = ssl->ctx->CBClientCert(ssl, &x509, &pkey);
        if (ret == 1) {
            if ((wolfSSL_CTX_use_certificate(ssl->ctx, x509) == WOLFSSL_SUCCESS) &&
                (wolfSSL_CTX_use_PrivateKey(ssl->ctx, pkey) == WOLFSSL_SUCCESS)) {
                ssl->options.sendVerify = SEND_CERT;
            }
            wolfSSL_X509_free(x509);
            x509 = NULL;
            wolfSSL_EVP_PKEY_free(pkey);
        }
    }
#endif

#ifndef WOLFSSL_NO_SIGALG
    /* Run before the blank certificate branch below so a client with nothing
     * acceptable can fall into it. Only on first entry: fragOffset is reset to
     * 0 before this message is built and is non-zero only while resuming a
     * fragmented send, whose chain was checked on the first pass. The result is
     * kept out of ret so a pending value there is left alone. */
    if (ssl->options.sendVerify != SEND_BLANK_CERT && ssl->fragOffset == 0) {
        chainRet = CheckCertChainSigAlgo(ssl);
        if ((chainRet != 0) &&
                (chainRet != WC_NO_ERR_TRACE(MATCH_SUITE_ERROR))) {
            return chainRet;
        }
        if (chainRet == WC_NO_ERR_TRACE(MATCH_SUITE_ERROR)) {
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                SendAlert(ssl, alert_fatal, handshake_failure);
                WOLFSSL_ERROR_VERBOSE(MATCH_SUITE_ERROR);
                return MATCH_SUITE_ERROR;
            }
        #ifndef WOLFSSL_NO_CLIENT_CERT_ERROR
            /* RFC 8446 Section 4.4.2: a client with no acceptable certificate
             * sends an empty certificate_list rather than failing. */
            WOLFSSL_MSG("Client chain not acceptable, sending blank cert");
            ssl->options.sendVerify = SEND_BLANK_CERT;
        #else
            /* RFC 8446 Section 4.4.2.2: an endpoint that cannot produce an
             * acceptable chain aborts with a certificate related alert,
             * unsupported_certificate by default. */
            WOLFSSL_MSG("Client chain not acceptable and blank cert not "
                        "allowed");
            SendAlert(ssl, alert_fatal, unsupported_certificate);
            WOLFSSL_ERROR_VERBOSE(NO_CERT_ERROR);
            return NO_CERT_ERROR;
        #endif
        }
    }
#endif

    if (ssl->options.sendVerify == SEND_BLANK_CERT) {
        certSz = 0;
        certChainSz = 0;
        headerSz = OPAQUE8_LEN + certReqCtxLen + CERT_HEADER_SZ;
        length = (sword32)headerSz;
        listSz = 0;
    }
    else {
        if (!ssl->buffers.certificate || !ssl->buffers.certificate->buffer) {
            WOLFSSL_MSG("Send Cert missing certificate buffer");
            return NO_CERT_ERROR;
        }
        /* Certificate Data */
        certSz = ssl->buffers.certificate->length;
        if (ssl->buffers.certChainCnt > MAX_CHAIN_DEPTH) {
            WOLFSSL_MSG("Certificate chain count exceeds maximum depth");
            return MAX_CHAIN_ERROR;
        }
        /* Cert Req Ctx Len | Cert Req Ctx | Cert List Len | Cert Data Len */
        headerSz = OPAQUE8_LEN + certReqCtxLen + CERT_HEADER_SZ +
                   CERT_HEADER_SZ;
        /* set empty extension as default */
        for (extIdx = 0; extIdx < (word16)XELEM_CNT(extSz); extIdx++)
            extSz[extIdx] = OPAQUE16_LEN;

    #if defined(HAVE_CERTIFICATE_STATUS_REQUEST) && !defined(NO_WOLFSSL_SERVER)
        /* Staple our own OCSP response with the Certificate. Normally only the
         * server staples; the client's CSR holds the server's response, so
         * echoing it back is wrong. The exception is post-handshake auth (PHA),
         * where the client sends its own Certificate and staples for it. */
        if (ssl->options.side == WOLFSSL_SERVER_END
        #ifdef WOLFSSL_POST_HANDSHAKE_AUTH
            || (ssl->options.side == WOLFSSL_CLIENT_END
                && ssl->options.handShakeDone)
        #endif
        ) {
            /* Build the responses once. A resumed send reuses them: looking
             * them up again appends another set of requests to the extension
             * until it overflows with MAX_CERT_EXTENSIONS_ERR. */
            if (ssl->fragOffset == 0) {
                ret = SetupOcspResp(ssl);
                if (ret != 0)
                    return ret;
            }

            if ((1 + ssl->buffers.certChainCnt) > MAX_CERT_EXTENSIONS)
                ret = MAX_CERT_EXTENSIONS_ERR;
            if (ret == 0)
                ret = WriteCSRToBuffer(ssl, &ssl->buffers.certExts[0], &extSz[0],
                        1 /* +1 for leaf */ + (word16)ssl->buffers.certChainCnt);
            if (ret < 0)
                return ret;
            totalextSz += ret;
            ret = 0; /* Clear to signal no error */
        }
        else
    #endif
        {
            /* Leaf cert empty extension size */
            totalextSz += OPAQUE16_LEN;
            /* chain cert empty extension size */
            totalextSz += OPAQUE16_LEN * ssl->buffers.certChainCnt;
        }

        /* Length of message data with one certificate and extensions. */
        length = (sword32)(headerSz + certSz + totalextSz);
        /* Length of list data with one certificate and extensions. */
        listSz = CERT_HEADER_SZ + certSz + totalextSz;

        /* Send rest of chain if sending cert (chain has leading size/s). */
        if (certSz > 0 && ssl->buffers.certChainCnt > 0) {
            p = ssl->buffers.certChain->buffer;
            /* Chain length including extensions. */
            certChainSz = ssl->buffers.certChain->length;

            length += certChainSz;
            listSz += certChainSz;
        }
        else
            certChainSz = 0;
    }

    payloadSz = (word32)length;

    if (ssl->fragOffset != 0)
        length -= (ssl->fragOffset + headerSz);

    maxFragment = (word32)wolfssl_local_GetMaxPlaintextSize(ssl);

    extIdx = 0;

    /* Only ssl->fragOffset survives a WANT_WRITE, so a resume inside the chain
     * has to rebuild the walk cursor from it. */
    if (certChainSz > 0 && ssl->fragOffset >= certSz + extSz[0]) {
        word32 chainPos = ssl->fragOffset - (certSz + extSz[0]);

    #if defined(HAVE_CERTIFICATE_STATUS_REQUEST) && !defined(NO_WOLFSSL_SERVER)
        /* The leaf is behind us and its buffer was rebuilt above. */
        FreeDer(&ssl->buffers.certExts[0]);
    #endif

        while (chainPos > 0) {
            word32 prevIdx = idx;

            len = NextCert(ssl->buffers.certChain->buffer,
                           ssl->buffers.certChain->length, &idx);
            if (len == 0)
                break;
        #if defined(HAVE_CERTIFICATE_STATUS_REQUEST) && \
                !defined(NO_WOLFSSL_SERVER)
            if (extIdx + 1 < MAX_CERT_EXTENSIONS)
                extIdx++;
        #endif
            entrySz = len + extSz[extIdx];

            if (chainPos < entrySz) {
                /* Resume part way through this entry. */
                p = ssl->buffers.certChain->buffer + prevIdx;
                offset = chainPos;
                chainPos = 0;
            }
            else {
                /* Entry already sent in full; stay primed for the next one. */
            #if defined(HAVE_CERTIFICATE_STATUS_REQUEST) && \
                    !defined(NO_WOLFSSL_SERVER)
                /* Its buffer was rebuilt above and nothing writes it again. */
                FreeDer(&ssl->buffers.certExts[extIdx]);
            #endif
                chainPos -= entrySz;
                offset = 0;
                entrySz = 0;
            }
        }
    }

    while (length > 0 && ret == 0) {
        byte*  output = NULL;
        word32 fragSz = 0;
        word32 i = RECORD_HEADER_SZ;
        int    sendSz = RECORD_HEADER_SZ;

#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls) {
            i = Dtls13GetRlHeaderLength(ssl, 1);
            sendSz = (int)i;
        }
#endif /* WOLFSSL_DTLS13 */

        if (ssl->fragOffset == 0) {
            if (headerSz + certSz + totalextSz + certChainSz <=
                                            maxFragment - HANDSHAKE_HEADER_SZ) {
                fragSz = headerSz + certSz + totalextSz + certChainSz;
            }
#ifdef WOLFSSL_DTLS13
            else if (ssl->options.dtls){
                /* short-circuit the fragmentation logic here. DTLS
                   fragmentation will be done in dtls13HandshakeSend() */
                fragSz = headerSz + certSz + totalextSz + certChainSz;
            }
#endif /* WOLFSSL_DTLS13 */
            else {
                fragSz = maxFragment - HANDSHAKE_HEADER_SZ;
            }

            sendSz += fragSz + HANDSHAKE_HEADER_SZ;
            i += HANDSHAKE_HEADER_SZ;
#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls) {
                sendSz += DTLS_HANDSHAKE_EXTRA;
                i += DTLS_HANDSHAKE_EXTRA;
            }
#endif /* WOLFSSL_DTLS13 */
        }
        else {
            fragSz = min((word32)length, maxFragment);
            sendSz += fragSz;
        }

        sendSz += MAX_MSG_EXTRA;

        /* Check buffers are big enough and grow if needed. */
        if ((ret = CheckAvailableSize(ssl, sendSz)) != 0)
            return ret;

        /* Get position in output buffer to write new message to. */
        output = GetOutputBuffer(ssl);

        if (ssl->fragOffset == 0) {
            AddTls13FragHeaders(output, fragSz, 0, payloadSz, certificate, ssl);

            /* Request context. */
            output[i++] = certReqCtxLen;
        #ifdef WOLFSSL_POST_HANDSHAKE_AUTH
            if (certReqCtxLen > 0) {
                XMEMCPY(output + i, certReqCtx, certReqCtxLen);
                i += certReqCtxLen;
            }
        #endif
            length -= OPAQUE8_LEN + certReqCtxLen;
            fragSz -= OPAQUE8_LEN + certReqCtxLen;
            /* Certificate list length. */
            c32to24(listSz, output + i);
            i += CERT_HEADER_SZ;
            length -= CERT_HEADER_SZ;
            fragSz -= CERT_HEADER_SZ;
            /* Leaf certificate data length. */
            if (certSz > 0) {
                c32to24(certSz, output + i);
                i += CERT_HEADER_SZ;
                length -= CERT_HEADER_SZ;
                fragSz -= CERT_HEADER_SZ;
            }
        }
        else
            AddTls13RecordHeader(output, fragSz, handshake, ssl);

        if (extIdx == 0) {
            if (certSz > 0 && ssl->fragOffset < certSz + extSz[0]) {
                /* Put in the leaf certificate with extensions. */
                word32 copySz = AddCertExt(ssl, ssl->buffers.certificate->buffer,
                                certSz, extSz[0], ssl->fragOffset, fragSz,
                                output + i, 0);
                i += copySz;
                ssl->fragOffset += copySz;
                length -= copySz;
                fragSz -= copySz;
                if (ssl->fragOffset == certSz + extSz[0])
                    FreeDer(&ssl->buffers.certExts[0]);
            }
        }
        if (certChainSz > 0 && fragSz > 0) {
             /* Put in the CA certificates with extensions. */
             while (fragSz > 0) {
                word32 l;

                if (offset == entrySz) {
                    /* Find next CA certificate to write out. */
                    offset = 0;
                    /* Point to the start of current cert in chain buffer. */
                    p = ssl->buffers.certChain->buffer + idx;
                    len = NextCert(ssl->buffers.certChain->buffer,
                            ssl->buffers.certChain->length, &idx);
                    if (len == 0)
                        break;
                #if defined(HAVE_CERTIFICATE_STATUS_REQUEST) && \
                        !defined(NO_WOLFSSL_SERVER)
                    if (extIdx + 1 < MAX_CERT_EXTENSIONS)
                        extIdx++;
                #endif
                    /* Certificate and its extensions make up the entry. */
                    entrySz = len + extSz[extIdx];
                }
                /* Write out certificate and extension. */
                l = AddCertExt(ssl, p, len, extSz[extIdx], offset, fragSz,
                                                       output + i, extIdx);
                i += l;
                ssl->fragOffset += l;
                length -= l;
                fragSz -= l;
                offset += l;

                if (extIdx != 0 && extIdx < MAX_CERT_EXTENSIONS &&
                    ssl->buffers.certExts[extIdx] != NULL &&
                                offset == entrySz) {
                    FreeDer(&ssl->buffers.certExts[extIdx]);
                }
            }
        }

        if ((int)i - RECORD_HEADER_SZ < 0) {
            WOLFSSL_MSG("Send Cert bad inputSz");
            return BUFFER_E;
        }

#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls) {
            /* DTLS1.3 uses a separate variable and logic for fragments */
            ssl->options.buildingMsg = 0;
            ssl->fragOffset = 0;
            if ((word32)sendSz > WOLFSSL_MAX_16BIT || i > WOLFSSL_MAX_16BIT) {
                WOLFSSL_MSG("Send Cert DTLS size exceeds word16");
                return BUFFER_E;
            }
            ret = Dtls13HandshakeSend(ssl, output, (word16)sendSz, (word16)i,
                                      certificate, 1);
        }
        else
#endif /* WOLFSSL_DTLS13 */
        {
            /* This message is always encrypted. */
            sendSz = BuildTls13Message(ssl, output, sendSz,
                output + RECORD_HEADER_SZ, (int)(i - RECORD_HEADER_SZ),
                handshake, 1,
                0, 0);
            if (sendSz < 0)
                return sendSz;

#if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
            if (ssl->hsInfoOn)
                AddPacketName(ssl, "Certificate");
            if (ssl->toInfoOn) {
                ret = AddPacketInfo(ssl, "Certificate", handshake, output,
                              sendSz, WRITE_PROTO, 0, ssl->heap);
                if (ret != 0)
                    return ret;
            }
#endif

            ssl->buffers.outputBuffer.length += (word32)sendSz;
            ssl->options.buildingMsg = 0;
            if (!ssl->options.groupMessages)
                ret = SendBuffered(ssl);
        }
    }

    if (ret != WC_NO_ERR_TRACE(WANT_WRITE)) {
        /* Clean up the fragment offset. */
        ssl->options.buildingMsg = 0;
        ssl->fragOffset = 0;
        if (ssl->options.side == WOLFSSL_SERVER_END)
            ssl->options.serverState = SERVER_CERT_COMPLETE;
    }

#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
    if (ssl->options.side == WOLFSSL_CLIENT_END && ssl->certReqCtx != NULL) {
        CertReqCtx* ctx = ssl->certReqCtx;
        ssl->certReqCtx = ssl->certReqCtx->next;
        XFREE(ctx, ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
    }
#endif

    WOLFSSL_LEAVE("SendTls13Certificate", ret);
    WOLFSSL_END(WC_FUNC_CERTIFICATE_SEND);

    return ret;
}

#if (!defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519) || \
     defined(HAVE_ED448) || defined(HAVE_FALCON) || \
     defined(WOLFSSL_HAVE_MLDSA) || defined(WOLFSSL_HAVE_SLHDSA)) && \
    (!defined(NO_WOLFSSL_SERVER) || !defined(WOLFSSL_NO_CLIENT_AUTH))
/* Members are grouped widest first so the struct carries no interior padding.
 * Under WOLFSSL_ASYNC_CRYPT this must fit ssl->async->args (MAX_ASYNC_ARGS
 * word32s), which the static assert in SendTls13CertificateVerify enforces. */
typedef struct Scv13Args {
    byte*  output; /* not allocated */
    byte*  verify; /* not allocated */
    byte*  sigData;
#ifndef NO_RSA
    byte*  toSign; /* not allocated */
#endif
#ifdef WOLFSSL_DUAL_ALG_CERTS
    byte*  altSigData;
#endif
    /* Fragmented CertificateVerify send cursor, used when the signature does
     * not fit in a single TLS record (SLH-DSA and other oversized signatures).
     * Kept in the async args so a WC_PENDING_E from the record AEAD under
     * WOLFSSL_ASYNC_CRYPT resumes on the same fragment instead of re-emitting
     * the records already committed to the output buffer. */
    byte*  frag;         /* body copy, freed by FreeScv13Args; NULL when idle */

    word32 idx;
    word32 sigLen;
    int    sendSz;
    word32 length;
#ifndef NO_RSA
    word32 toSignSz;
#endif
#ifdef WOLFSSL_DUAL_ALG_CERTS
    word32 altSigLen;    /* Only used in the case of both native and alt. */
#endif
    word32 outputSz;     /* reserved capacity of the output record buffer */
    word32 fragOffset;   /* body bytes already committed to records */

    word16 sigDataSz;
#ifdef WOLFSSL_DUAL_ALG_CERTS
    word16 altSigDataSz;
#endif

    byte   sigAlgo;
#ifdef WOLFSSL_DUAL_ALG_CERTS
    byte   altSigAlgo;
#endif
    byte   fragActive;   /* current fragment laid out, record build may pend */
} Scv13Args;

static void FreeScv13Args(WOLFSSL* ssl, void* pArgs)
{
    Scv13Args* args = (Scv13Args*)pArgs;

    (void)ssl;

    if (args && args->sigData) {
        XFREE(args->sigData, ssl->heap, DYNAMIC_TYPE_SIGNATURE);
        args->sigData = NULL;
    }
#ifdef WOLFSSL_DUAL_ALG_CERTS
    if (args && args->altSigData != NULL) {
        XFREE(args->altSigData, ssl->heap, DYNAMIC_TYPE_SIGNATURE);
        args->altSigData = NULL;
    }
#endif
    if (args != NULL && args->frag != NULL) {
        XFREE(args->frag, ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
        args->frag = NULL;
    }
}

/* handle generation TLS v1.3 certificate_verify (15) */
/* Send the TLS v1.3 CertificateVerify message.
 * A hash of all the message so far is used.
 * The signed data is:
 *     0x20 * 64 | context string | 0x00 | hash of messages
 * This message is always encrypted in TLS v1.3.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
static int SendTls13CertificateVerify(WOLFSSL* ssl)
{
    int ret = 0;
#ifndef NO_RSA
    /* Use this as a temporary buffer for RSA signature verification. */
    buffer* rsaSigBuf = &ssl->buffers.sig;
#endif
#ifdef WOLFSSL_ASYNC_CRYPT
    Scv13Args* args = NULL;
    WOLFSSL_ASSERT_SIZEOF_GE(ssl->async->args, *args);
#else
    Scv13Args  args[1];
#endif

#ifdef WOLFSSL_DTLS13
    int recordLayerHdrExtra;
#endif /* WOLFSSL_DTLS13 */

    WOLFSSL_START(WC_FUNC_CERTIFICATE_VERIFY_SEND);
    WOLFSSL_ENTER("SendTls13CertificateVerify");

#ifdef WOLFSSL_BLIND_PRIVATE_KEY
    wolfssl_priv_der_blind_toggle(ssl->buffers.key, ssl->buffers.keyMask);
#endif

    ssl->options.buildingMsg = 1;

#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13SendCertVerify(ssl);
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE)) {
        goto exit_scv;
    }
    ret = 0;
#endif /* WOLFSSL_RENESAS_TSIP_TLS */

#ifdef WOLFSSL_DTLS13
    /* can be negative */
    if (ssl->options.dtls)
        recordLayerHdrExtra = Dtls13GetRlHeaderLength(ssl, 1) - RECORD_HEADER_SZ;
    else
        recordLayerHdrExtra = 0;

#endif /* WOLFSSL_DTLS13 */

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ssl->async == NULL) {
        ssl->async = (struct WOLFSSL_ASYNC*)
                XMALLOC(sizeof(struct WOLFSSL_ASYNC), ssl->heap,
                        DYNAMIC_TYPE_ASYNC);
        if (ssl->async == NULL)
            ERROR_OUT(MEMORY_E, exit_scv);
    }
    args = (Scv13Args*)ssl->async->args;

    ret = wolfSSL_AsyncPop(ssl, &ssl->options.asyncState);
    if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
        /* Check for error */
        if (ret < 0)
            goto exit_scv;
    }
    else
#endif
    {
        /* Reset state */
        ret = 0;
        ssl->options.asyncState = TLS_ASYNC_BEGIN;
        XMEMSET(args, 0, sizeof(Scv13Args));
    #ifdef WOLFSSL_ASYNC_CRYPT
        ssl->async->freeArgs = FreeScv13Args;
    #endif
    }

#ifdef WOLFSSL_TLS13_STREAM_CERT_VERIFY
    /* Resuming a partially-sent streamed CertificateVerify (e.g. after a
     * non-blocking WANT_WRITE): the signature is already assembled in
     * ssl->buffers.certVerifyMsg and ssl->fragOffset marks how much has been
     * committed to records, so skip re-signing and continue sending. */
    if (ssl->buffers.certVerifyMsg.buffer != NULL && ssl->fragOffset != 0) {
        ssl->options.asyncState = TLS_ASYNC_END;
    }
#endif

    switch(ssl->options.asyncState)
    {
        case TLS_ASYNC_BEGIN:
        {
            if (ssl->options.sendVerify == SEND_BLANK_CERT) {
            #ifdef WOLFSSL_BLIND_PRIVATE_KEY
                wolfssl_priv_der_blind_toggle(ssl->buffers.key,
                    ssl->buffers.keyMask);
            #endif
                return 0;  /* sent blank cert, can't verify */
            }

            /* The output buffer is reserved in TLS_ASYNC_BUILD, once the
             * private key has been decoded and the actual signature size is
             * known. This avoids reserving the worst-case WC_MAX_CERT_VERIFY_SZ
             * (very large when SLH-DSA is enabled) for every algorithm. */

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_BUILD;
        } /* case TLS_ASYNC_BEGIN */
        FALL_THROUGH;

        case TLS_ASYNC_BUILD:
        {
            int rem;
#ifdef WOLFSSL_TLS13_STREAM_CERT_VERIFY
            word32 bodySz;
            word32 maxFrag;
#endif
            int doStream = 0;

            /* Decode the private key first so the output buffer can be sized
             * to the actual signature length rather than the worst-case
             * WC_MAX_CERT_VERIFY_SZ (very large when SLH-DSA is enabled). */
            if (ssl->buffers.key == NULL) {
            #ifdef HAVE_PK_CALLBACKS
                if (wolfSSL_CTX_IsPrivatePkSet(ssl->ctx))
                    args->sigLen = (word32)GetPrivateKeySigSize(ssl);
                else
            #endif
                    ERROR_OUT(NO_PRIVATE_KEY, exit_scv);
            }
            else {
#ifdef WOLFSSL_DUAL_ALG_CERTS
                if (ssl->sigSpec != NULL &&
                    *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_ALTERNATIVE) {
                    /* In the case of alternative, we swap in the alt. */
                    if (ssl->buffers.altKey == NULL) {
                        ERROR_OUT(NO_PRIVATE_KEY, exit_scv);
                    }
                    ssl->buffers.keyType = ssl->buffers.altKeyType;
                    ssl->buffers.keySz = ssl->buffers.altKeySz;
                    /* If we own it, free key before overriding it. */
                    if (ssl->buffers.weOwnKey) {
                        FreeDer(&ssl->buffers.key);
                    #ifdef WOLFSSL_BLIND_PRIVATE_KEY
                        FreeDer(&ssl->buffers.keyMask);
                    #endif
                    }

                    /* Swap keys */
                    ssl->buffers.key     = ssl->buffers.altKey;
                    ssl->buffers.weOwnKey = ssl->buffers.weOwnAltKey;
                    /* buffers.key is the only owner of the alt key now. */
                    ssl->buffers.weOwnAltKey = 0;

                #ifdef WOLFSSL_BLIND_PRIVATE_KEY
                    ssl->buffers.keyMask = ssl->buffers.altKeyMask;
                    /* Unblind the alternative key before decoding */
                    wolfssl_priv_der_blind_toggle(ssl->buffers.key, ssl->buffers.keyMask);
                #endif
                }
#endif /* WOLFSSL_DUAL_ALG_CERTS */
                ret = DecodePrivateKey(ssl, &args->sigLen);
                if (ret != 0)
                    goto exit_scv;
            }

            if (args->sigLen == 0) {
                ERROR_OUT(NO_PRIVATE_KEY, exit_scv);
            }

#ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->peerSigSpec == NULL) {
                /* The peer did not respond. We didn't send CKS or they don't
                 * support it. Either way, we do not need to handle dual
                 * key/sig case. */
                ssl->sigSpec = NULL;
                ssl->sigSpecSz = 0;
            }

            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                /* The native was already decoded. Decode the alternative now
                 * too so its signature length is included when the output
                 * buffer is sized below. */
                if (ssl->buffers.altKey == NULL) {
                    ERROR_OUT(NO_PRIVATE_KEY, exit_scv);
                }

                /* After this call, args->altSigLen has the length we need for
                 * the alternative signature. */
                ret = DecodeAltPrivateKey(ssl, &args->altSigLen);
                if (ret != 0)
                    goto exit_scv;

                if (ssl->buffers.altKeyType == ecc_dsa_sa_algo ||
                    ssl->buffers.altKeyType == falcon_level1_sa_algo ||
                    ssl->buffers.altKeyType == falcon_level5_sa_algo ||
                    ssl->buffers.altKeyType == mldsa_44_sa_algo ||
                    ssl->buffers.altKeyType == mldsa_65_sa_algo ||
                    ssl->buffers.altKeyType == mldsa_87_sa_algo) {
                    args->altSigAlgo = ssl->buffers.altKeyType;
                }
                else if (ssl->buffers.altKeyType == rsa_sa_algo &&
                         ssl->hsAltType == DYNAMIC_TYPE_RSA) {
                    args->altSigAlgo = rsa_pss_sa_algo;
                }
                else {
                    ERROR_OUT(ALGO_ID_E, exit_scv);
                }
            }
#endif /* WOLFSSL_DUAL_ALG_CERTS */

            /* Decide how the CertificateVerify body will be emitted. When it
             * exceeds a single record (e.g. a large SLH-DSA/ML-DSA signature,
             * or any signature under a small max_fragment_length) on TLS 1.3,
             * use the streaming path: generate the signature into a
             * connection-level body buffer and send it one record at a time in
             * TLS_ASYNC_END, so the shared output buffer never has to hold the
             * whole signature. Otherwise reserve the output buffer for the
             * whole message and build it in place. */
#ifdef WOLFSSL_TLS13_STREAM_CERT_VERIFY
            bodySz = HASH_SIG_SIZE + VERIFY_HEADER + (word32)args->sigLen;
        #ifdef WOLFSSL_DUAL_ALG_CERTS
            /* A dual (BOTH) body carries a second length-prefixed signature.
             * args->sigLen/altSigLen are upper bounds here for variable-length
             * schemes (ECDSA, Falcon), so this may over-size the body buffer by
             * a few bytes; the body is assembled contiguously with the actual
             * lengths, the exact length is recorded in TLS_ASYNC_FINALIZE, and
             * the trailing slack is never sent. */
            if (ssl->sigSpec != NULL &&
                    *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                bodySz += (word32)args->altSigLen + OPAQUE16_LEN + OPAQUE16_LEN;
            }
        #endif
            maxFrag = (word32)wolfssl_local_GetMaxPlaintextSize(ssl);
            if (!ssl->options.dtls &&
                    (word32)HANDSHAKE_HEADER_SZ + bodySz > maxFrag) {
                doStream = 1;
            }
#endif /* WOLFSSL_TLS13_STREAM_CERT_VERIFY */

            if (doStream) {
#ifdef WOLFSSL_TLS13_STREAM_CERT_VERIFY
                /* Generate the body directly into the connection-level buffer.
                 * bodySz is exact here (a single fixed-or-max-length
                 * signature); the final length is recorded in
                 * TLS_ASYNC_FINALIZE. args->output stays NULL to mark the
                 * streaming path; the send loop reserves one record at a
                 * time. */
                XFREE(ssl->buffers.certVerifyMsg.buffer, ssl->heap,
                      DYNAMIC_TYPE_TMP_BUFFER);
                ssl->buffers.certVerifyMsg.buffer =
                    (byte*)XMALLOC(bodySz, ssl->heap, DYNAMIC_TYPE_TMP_BUFFER);
                if (ssl->buffers.certVerifyMsg.buffer == NULL) {
                    ssl->buffers.certVerifyMsg.length = 0;
                    ERROR_OUT(MEMORY_E, exit_scv);
                }
                ssl->buffers.certVerifyMsg.length = bodySz;
                ssl->fragOffset = 0;
                args->verify = ssl->buffers.certVerifyMsg.buffer;
                args->idx = 0;
                args->sendSz = (int)bodySz;
                args->output = NULL;
                args->outputSz = 0;
#endif /* WOLFSSL_TLS13_STREAM_CERT_VERIFY */
            }
            else {
                /* Reserve the output buffer, sized from the actual signature
                 * length(s) plus record/handshake framing and encryption
                 * slack. */
                args->sendSz = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ +
                               HASH_SIG_SIZE + VERIFY_HEADER + (int)args->sigLen;
            #ifdef WOLFSSL_DUAL_ALG_CERTS
                /* A dual (BOTH) body carries a second signature behind its own
                 * length prefix, plus the combined length prefix. Matches the
                 * streaming bodySz above. */
                if (ssl->sigSpec != NULL &&
                        *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                    args->sendSz += (int)args->altSigLen + OPAQUE16_LEN +
                                    OPAQUE16_LEN;
                }
                else {
                    args->sendSz += (int)args->altSigLen;
                }
            #endif
            #ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls)
                    args->sendSz += recordLayerHdrExtra + DTLS_HANDSHAKE_EXTRA;
            #endif /* WOLFSSL_DTLS13 */
                /* Framing and always-on encryption expansion. */
                args->sendSz += MAX_MSG_EXTRA;

                /* check for available size */
                if ((ret = CheckAvailableSize(ssl, args->sendSz)) != 0) {
                    goto exit_scv;
                }

                /* get output buffer */
                args->output = GetOutputBuffer(ssl);
                /* Remember the reserved capacity for BuildTls13Message /
                 * Dtls13HandshakeSend in TLS_ASYNC_END. */
                args->outputSz = (word32)args->sendSz;

                rem = (int)(ssl->buffers.outputBuffer.bufferSize
                                - ssl->buffers.outputBuffer.length
                                - RECORD_HEADER_SZ - HANDSHAKE_HEADER_SZ);

                /* idx is used to track verify pointer offset to output */
                args->idx = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;
                args->verify =
                          &args->output[RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ];

            #ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls) {
                    rem -= recordLayerHdrExtra + DTLS_HANDSHAKE_EXTRA;
                    args->idx += recordLayerHdrExtra + DTLS_HANDSHAKE_EXTRA;
                    args->verify += recordLayerHdrExtra + DTLS_HANDSHAKE_EXTRA;
                }
            #endif /* WOLFSSL_DTLS13 */

                if (rem < 0 || (int)args->sigLen > rem) {
                    ERROR_OUT(BUFFER_E, exit_scv);
                }
            }

            /* Add signature algorithm. */
            if (ssl->hsType == DYNAMIC_TYPE_RSA)
                args->sigAlgo = rsa_pss_sa_algo;
        #ifdef HAVE_ECC
            else if (ssl->hsType == DYNAMIC_TYPE_ECC) {
        #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
                if (ssl->buffers.keyType == sm2_sa_algo) {
                    args->sigAlgo = sm2_sa_algo;
                }
                else
        #endif
                {
                    args->sigAlgo = ecc_dsa_sa_algo;
                }
            }
        #endif
        #ifdef HAVE_ED25519
            else if (ssl->hsType == DYNAMIC_TYPE_ED25519)
                args->sigAlgo = ed25519_sa_algo;
        #endif
        #ifdef HAVE_ED448
            else if (ssl->hsType == DYNAMIC_TYPE_ED448)
                args->sigAlgo = ed448_sa_algo;
        #endif
        #if defined(HAVE_FALCON)
            else if (ssl->hsType == DYNAMIC_TYPE_FALCON) {
                args->sigAlgo = ssl->buffers.keyType;
            }
        #endif /* HAVE_FALCON */
        #if defined(WOLFSSL_HAVE_MLDSA)
            else if (ssl->hsType == DYNAMIC_TYPE_MLDSA) {
                args->sigAlgo = ssl->buffers.keyType;
            }
        #endif /* WOLFSSL_HAVE_MLDSA */
        #if defined(WOLFSSL_HAVE_SLHDSA)
            else if (ssl->hsType == DYNAMIC_TYPE_SLHDSA) {
                args->sigAlgo = ssl->buffers.keyType;
            }
        #endif /* WOLFSSL_HAVE_SLHDSA */
            else {
                ERROR_OUT(ALGO_ID_E, exit_scv);
            }

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                /* The alternative key was already decoded and its sig-alg
                 * determined above (when sizing the output buffer). Encode the
                 * dual (native + alternative) signature algorithm pair. */
                EncodeDualSigAlg(args->sigAlgo, args->altSigAlgo, args->verify);
                if (args->verify[0] == 0) {
                    ERROR_OUT(ALGO_ID_E, exit_scv);
                }
            }
            else
        #endif /* WOLFSSL_DUAL_ALG_CERTS */
                EncodeSigAlg(ssl, ssl->options.hashAlgo, args->sigAlgo,
                             args->verify);

            if (args->sigData == NULL) {
                word32 sigLen = MAX_SIG_DATA_SZ;
                if ((ssl->hsType == DYNAMIC_TYPE_RSA) &&
                    (args->sigLen > MAX_SIG_DATA_SZ)) {
                    /* We store the RSA signature in the sigData buffer
                     * temporarily, hence its size must be fitting. */
                    sigLen = args->sigLen;
                }
                args->sigData = (byte*)XMALLOC(sigLen, ssl->heap,
                                                    DYNAMIC_TYPE_SIGNATURE);
                if (args->sigData == NULL) {
                    ERROR_OUT(MEMORY_E, exit_scv);
                }
            }

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if ((ssl->sigSpec != NULL) &&
                (*ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) &&
                (args->altSigData == NULL)) {
                word32 sigLen = MAX_SIG_DATA_SZ;
                if (ssl->hsAltType == DYNAMIC_TYPE_RSA &&
                    args->altSigLen > MAX_SIG_DATA_SZ) {
                    /* We store the RSA signature in the sigData buffer
                     * temporarily, hence its size must be fitting. */
                    sigLen = args->altSigLen;
                }
                args->altSigData = (byte*)XMALLOC(sigLen, ssl->heap,
                                                    DYNAMIC_TYPE_SIGNATURE);
                if (args->altSigData == NULL) {
                    ERROR_OUT(MEMORY_E, exit_scv);
                }
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */

            /* Create the data to be signed. */
            ret = CreateSigData(ssl, args->sigData, &args->sigDataSz, 0);
            if (ret != 0)
                goto exit_scv;

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if ((ssl->sigSpec != NULL) &&
                (*ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH)) {
                XMEMCPY(args->altSigData, args->sigData, args->sigDataSz);
                args->altSigDataSz = args->sigDataSz;
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */

        #ifndef NO_RSA
            if (ssl->hsType == DYNAMIC_TYPE_RSA) {
                /* build encoded signature buffer */
                rsaSigBuf->length = WC_MAX_DIGEST_SIZE;
                rsaSigBuf->buffer = (byte*)XMALLOC(rsaSigBuf->length, ssl->heap,
                                                   DYNAMIC_TYPE_SIGNATURE);
                if (rsaSigBuf->buffer == NULL) {
                    ERROR_OUT(MEMORY_E, exit_scv);
                }

                ret = CreateRSAEncodedSig(rsaSigBuf->buffer, args->sigData,
                    args->sigDataSz, args->sigAlgo, ssl->options.hashAlgo);
                if (ret < 0)
                    goto exit_scv;
                rsaSigBuf->length = (unsigned int)ret;
                ret = 0;
            }
        #endif /* !NO_RSA */
        #ifdef HAVE_ECC
            if (ssl->hsType == DYNAMIC_TYPE_ECC) {
                args->sigLen = (word32)args->sendSz - args->idx -
                               HASH_SIG_SIZE -
                               VERIFY_HEADER;
            #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
                if (ssl->buffers.keyType != sm2_sa_algo)
            #endif
                {
                    ret = CreateECCEncodedSig(args->sigData,
                        args->sigDataSz, ssl->options.hashAlgo);
                    if (ret < 0)
                        goto exit_scv;
                    args->sigDataSz = (word16)ret;
                    ret = 0;
                }
            }
        #endif /* HAVE_ECC */
        #ifdef HAVE_ED25519
            if (ssl->hsType == DYNAMIC_TYPE_ED25519) {
                ret = Ed25519CheckPubKey(ssl);
                if (ret < 0) {
                    ERROR_OUT(ret, exit_scv);
                }
                args->sigLen = ED25519_SIG_SIZE;
            }
        #endif /* HAVE_ED25519 */
        #ifdef HAVE_ED448
            if (ssl->hsType == DYNAMIC_TYPE_ED448) {
                ret = Ed448CheckPubKey(ssl);
                if (ret < 0) {
                    ERROR_OUT(ret, exit_scv);
                }
                args->sigLen = ED448_SIG_SIZE;
            }

        #endif /* HAVE_ED448 */
        #if defined(HAVE_FALCON)
            if (ssl->hsType == DYNAMIC_TYPE_FALCON) {
                /* Per-key, not the family maximum: this is handed to the
                 * signer as the output capacity and the buffer above was
                 * reserved from this key's signature length. */
                int fSigSz = wc_falcon_sig_size((falcon_key*)ssl->hsKey);
                if (fSigSz <= 0) {
                    ERROR_OUT(ALGO_ID_E, exit_scv);
                }
                args->sigLen = (word32)fSigSz;
            }
        #endif /* HAVE_FALCON */
        #if defined(WOLFSSL_HAVE_MLDSA) && !defined(WOLFSSL_MLDSA_NO_SIGN)
            if (ssl->hsType == DYNAMIC_TYPE_MLDSA) {
                int mSigSz = wc_MlDsaKey_SigSize((wc_MlDsaKey*)ssl->hsKey);
                if (mSigSz <= 0) {
                    ERROR_OUT(ALGO_ID_E, exit_scv);
                }
                args->sigLen = (word32)mSigSz;
            }
        #endif /* WOLFSSL_HAVE_MLDSA && !WOLFSSL_MLDSA_NO_SIGN */
        #if defined(WOLFSSL_HAVE_SLHDSA)
            if (ssl->hsType == DYNAMIC_TYPE_SLHDSA) {
                int slhSigSz = wc_SlhDsaKey_SigSize((SlhDsaKey*)ssl->hsKey);
                if (slhSigSz <= 0) {
                    ERROR_OUT(ALGO_ID_E, exit_scv);
                }
                args->sigLen = (word32)slhSigSz;
            }
        #endif /* WOLFSSL_HAVE_SLHDSA */

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {

            #ifndef NO_RSA
                if (ssl->hsAltType == DYNAMIC_TYPE_RSA) {
                    /* build encoded signature buffer */
                    XFREE(rsaSigBuf->buffer, ssl->heap, DYNAMIC_TYPE_SIGNATURE);
                    rsaSigBuf->length = WC_MAX_DIGEST_SIZE;
                    rsaSigBuf->buffer = (byte*)XMALLOC(rsaSigBuf->length,
                                                       ssl->heap,
                                                       DYNAMIC_TYPE_SIGNATURE);
                    if (rsaSigBuf->buffer == NULL) {
                        ERROR_OUT(MEMORY_E, exit_scv);
                    }

                    ret = CreateRSAEncodedSig(rsaSigBuf->buffer,
                                    args->altSigData, args->altSigDataSz,
                                    args->altSigAlgo, ssl->options.hashAlgo);
                    if (ret < 0)
                        goto exit_scv;
                    rsaSigBuf->length = ret;
                    ret = 0;
                }
            #endif /* !NO_RSA */
            #ifdef HAVE_ECC
                if (ssl->hsAltType == DYNAMIC_TYPE_ECC) {
                    ret = CreateECCEncodedSig(args->altSigData,
                            args->altSigDataSz, ssl->options.hashAlgo);
                    if (ret < 0)
                        goto exit_scv;
                    args->altSigDataSz = (word16)ret;
                    ret = 0;
                }
            #endif /* HAVE_ECC */
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_DO;
        } /* case TLS_ASYNC_BUILD */
        FALL_THROUGH;

        case TLS_ASYNC_DO:
        {
            byte* sigOut = args->verify + HASH_SIG_SIZE + VERIFY_HEADER;
        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                /* As we have two signatures in the message, we store
                 * the length of each before the actual signature. This
                 * is necessary, as we could have two algorithms with
                 * variable length signatures. */
                sigOut += OPAQUE16_LEN;
            }
        #endif
            /* Only the per-algorithm signing branches below consume this. */
            (void)sigOut;
        #ifdef HAVE_ECC
            if (ssl->hsType == DYNAMIC_TYPE_ECC) {
            #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
                if (ssl->buffers.keyType == sm2_sa_algo) {
                    ret = Sm2wSm3Sign(ssl, TLS13_SM2_SIG_ID,
                        TLS13_SM2_SIG_ID_SZ, args->sigData, args->sigDataSz,
                        sigOut, &args->sigLen, (ecc_key*)ssl->hsKey, NULL);
                }
                else
            #endif
                {
                    ret = EccSign(ssl, args->sigData, args->sigDataSz,
                        sigOut, &args->sigLen, (ecc_key*)ssl->hsKey,
                #ifdef HAVE_PK_CALLBACKS
                        ssl->buffers.key
                #else
                        NULL
                #endif
                    );
                }
                args->length = args->sigLen;
            }
        #endif /* HAVE_ECC */
        #ifdef HAVE_ED25519
            if (ssl->hsType == DYNAMIC_TYPE_ED25519) {
                ret = Ed25519Sign(ssl, args->sigData, args->sigDataSz,
                    sigOut, &args->sigLen, (ed25519_key*)ssl->hsKey,
            #ifdef HAVE_PK_CALLBACKS
                    ssl->buffers.key
            #else
                    NULL
            #endif
                );
                args->length = args->sigLen;
            }
        #endif
        #ifdef HAVE_ED448
            if (ssl->hsType == DYNAMIC_TYPE_ED448) {
                ret = Ed448Sign(ssl, args->sigData, args->sigDataSz,
                    sigOut, &args->sigLen, (ed448_key*)ssl->hsKey,
            #ifdef HAVE_PK_CALLBACKS
                    ssl->buffers.key
            #else
                    NULL
            #endif
                );
                args->length = args->sigLen;
            }
        #endif
        #if defined(HAVE_FALCON)
            if (ssl->hsType == DYNAMIC_TYPE_FALCON) {
                ret = wc_falcon_sign_msg(args->sigData, args->sigDataSz,
                                         sigOut, &args->sigLen,
                                         (falcon_key*)ssl->hsKey, ssl->rng);
                args->length = args->sigLen;
            }
        #endif /* HAVE_FALCON */
        #if defined(WOLFSSL_HAVE_MLDSA) && !defined(WOLFSSL_MLDSA_NO_SIGN)
            if (ssl->hsType == DYNAMIC_TYPE_MLDSA) {
                ret = wc_MlDsaKey_SignCtx((wc_MlDsaKey*)ssl->hsKey, NULL, 0,
                                          sigOut, &args->sigLen,
                                          args->sigData, args->sigDataSz,
                                          ssl->rng);
                args->length = args->sigLen;
            }
        #endif /* WOLFSSL_HAVE_MLDSA */
        #if defined(WOLFSSL_HAVE_SLHDSA) && !defined(WOLFSSL_SLHDSA_VERIFY_ONLY)
            if (ssl->hsType == DYNAMIC_TYPE_SLHDSA) {
                /* The FIPS wrapper for wc_SlhDsaKey_Sign gates on the per-thread
                 * privateKeyReadEnable flag (unlike ML-DSA sign), returning
                 * FIPS_PRIVATE_KEY_LOCKED_E when the key is locked. Bracket the
                 * sign so it can read the SLH-DSA private key. */
                PRIVATE_KEY_UNLOCK();
                ret = wc_SlhDsaKey_Sign((SlhDsaKey*)ssl->hsKey, NULL, 0,
                                        args->sigData, args->sigDataSz,
                                        sigOut, &args->sigLen, ssl->rng);
                PRIVATE_KEY_LOCK();
                args->length = args->sigLen;
            }
        #endif /* WOLFSSL_HAVE_SLHDSA */
        #if !defined(NO_RSA) && !defined(WOLFSSL_RSA_PUBLIC_ONLY) && \
            !defined(WOLFSSL_RSA_VERIFY_ONLY)
            if (ssl->hsType == DYNAMIC_TYPE_RSA) {
                args->toSign = rsaSigBuf->buffer;
                args->toSignSz = (word32)rsaSigBuf->length;
            #if defined(HAVE_PK_CALLBACKS) && \
                defined(TLS13_RSA_PSS_SIGN_CB_NO_PREHASH)
                /* Pass full data to sign (args->sigData), not hash of */
                if (ssl->ctx->RsaPssSignCb) {
                    args->toSign = args->sigData;
                    args->toSignSz = args->sigDataSz;
                }
            #endif
                ret = RsaSign(ssl, (const byte*)args->toSign, args->toSignSz,
                              sigOut, &args->sigLen, args->sigAlgo,
                              ssl->options.hashAlgo, (RsaKey*)ssl->hsKey,
                              ssl->buffers.key);
                if (ret == 0) {
                    args->length = args->sigLen;
                    XMEMCPY(args->sigData, sigOut, args->sigLen);
                }
            }
        #endif /* !NO_RSA && !WOLFSSL_RSA_PUBLIC_ONLY && !WOLFSSL_RSA_VERIFY_ONLY */

            /* Check for error */
            if (ret != 0) {
                goto exit_scv;
            }

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                /* Add signature length for the first signature. */
                c16toa((word16)args->sigLen, sigOut - OPAQUE16_LEN);
                args->length += OPAQUE16_LEN;

                /* Advance our pointer to where we store the alt signature.
                 * We also add additional space for the length field of the
                 * second signature. */
                sigOut += args->sigLen + OPAQUE16_LEN;

                /* Generate the alternative signature */
            #ifdef HAVE_ECC
                if (ssl->hsAltType == DYNAMIC_TYPE_ECC) {
                    ret = EccSign(ssl, args->altSigData, args->altSigDataSz,
                                  sigOut, &args->altSigLen,
                                  (ecc_key*)ssl->hsAltKey,
                    #ifdef HAVE_PK_CALLBACKS
                                  ssl->buffers.altKey
                    #else
                                  NULL
                    #endif
                                  );
                }
            #endif /* HAVE_ECC */
            #if !defined(NO_RSA) && !defined(WOLFSSL_RSA_PUBLIC_ONLY) && \
                !defined(WOLFSSL_RSA_VERIFY_ONLY)
                if (ssl->hsAltType == DYNAMIC_TYPE_RSA) {
                    args->toSign = rsaSigBuf->buffer;
                    args->toSignSz = (word32)rsaSigBuf->length;
                #if defined(HAVE_PK_CALLBACKS) && \
                    defined(TLS13_RSA_PSS_SIGN_CB_NO_PREHASH)
                    /* Pass full data to sign (args->altSigData), not hash of */
                    if (ssl->ctx->RsaPssSignCb) {
                        args->toSign = args->altSigData;
                        args->toSignSz = (word32)args->altSigDataSz;
                    }
                #endif
                    ret = RsaSign(ssl, (const byte*)args->toSign,
                                  args->toSignSz, sigOut, &args->altSigLen,
                                  args->altSigAlgo, ssl->options.hashAlgo,
                                  (RsaKey*)ssl->hsAltKey,
                                  ssl->buffers.altKey);

                    if (ret == 0) {
                        XMEMCPY(args->altSigData, sigOut, args->altSigLen);
                    }
                }
            #endif /* !NO_RSA && !WOLFSSL_RSA_PUBLIC_ONLY && !WOLFSSL_RSA_VERIFY_ONLY */
            #if defined(HAVE_FALCON)
                if (ssl->hsAltType == DYNAMIC_TYPE_FALCON) {
                    ret = wc_falcon_sign_msg(args->altSigData,
                                             args->altSigDataSz, sigOut,
                                             &args->altSigLen,
                                             (falcon_key*)ssl->hsAltKey,
                                             ssl->rng);
                }
            #endif /* HAVE_FALCON */
            #if defined(WOLFSSL_HAVE_MLDSA) && !defined(WOLFSSL_MLDSA_NO_SIGN)
                if (ssl->hsAltType == DYNAMIC_TYPE_MLDSA) {
                    ret = wc_MlDsaKey_SignCtx((wc_MlDsaKey*)ssl->hsAltKey,
                                NULL, 0, sigOut, &args->altSigLen,
                                args->altSigData, args->altSigDataSz, ssl->rng);
                }
            #endif /* WOLFSSL_HAVE_MLDSA */

                /* Check for error */
                if (ret != 0) {
                    goto exit_scv;
                }

                /* Add signature length for the alternative signature. */
                c16toa((word16)args->altSigLen, sigOut - OPAQUE16_LEN);

                /* Add length of the alt sig to the total length */
                args->length += args->altSigLen + OPAQUE16_LEN;
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */

            /* The TLS 1.3 CertificateVerify signature is length-prefixed with a
             * 2-byte field (opaque signature<0..2^16-1>), so the body - a single
             * signature, or the combined native + alternative signature with
             * WOLFSSL_DUAL_ALG_CERTS - cannot exceed 65535 bytes. Reject rather
             * than let c16toa truncate it into a malformed message. args->length
             * is word32 so the dual-alg accumulation above cannot wrap before
             * this check. */
            if (args->length > WOLFSSL_MAX_16BIT) {
                ERROR_OUT(BUFFER_E, exit_scv);
            }

            /* Add signature length. */
            c16toa((word16)args->length, args->verify + HASH_SIG_SIZE);

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_VERIFY;
        } /* case TLS_ASYNC_DO */
        FALL_THROUGH;

        case TLS_ASYNC_VERIFY:
        {
        #ifndef NO_RSA
            if (ssl->hsType == DYNAMIC_TYPE_RSA) {
                /* check for signature faults */
                ret = VerifyRsaSign(ssl, args->sigData, args->sigLen,
                    rsaSigBuf->buffer, (word32)rsaSigBuf->length, args->sigAlgo,
                    ssl->options.hashAlgo, (RsaKey*)ssl->hsKey,
                    ssl->buffers.key);
            }
        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH &&
                ssl->hsAltType == DYNAMIC_TYPE_RSA) {
                /* check for signature faults */
                ret = VerifyRsaSign(ssl, args->altSigData, args->altSigLen,
                        rsaSigBuf->buffer, (word32)rsaSigBuf->length,
                        args->altSigAlgo, ssl->options.hashAlgo,
                        (RsaKey*)ssl->hsAltKey, ssl->buffers.altKey);
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */
        #endif /* !NO_RSA */
        #if defined(HAVE_ECC) && defined(WOLFSSL_CHECK_SIG_FAULTS)
            if (ssl->hsType == DYNAMIC_TYPE_ECC) {
                byte* sigOut = args->verify + HASH_SIG_SIZE + VERIFY_HEADER;
            #ifdef WOLFSSL_DUAL_ALG_CERTS
                if (ssl->sigSpec != NULL &&
                    *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                    /* Add our length offset. */
                    sigOut += OPAQUE16_LEN;
                }
            #endif
            #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
                if (ssl->buffers.keyType == sm2_sa_algo) {
                    ret = Sm2wSm3Verify(ssl, TLS13_SM2_SIG_ID,
                        TLS13_SM2_SIG_ID_SZ,
                        sigOut, args->sigLen, args->sigData, args->sigDataSz,
                        (ecc_key*)ssl->hsKey, NULL);
                }
                else
            #endif
                {
                #ifdef HAVE_PK_CALLBACKS
                    buffer tmp;

                    /* Private key may be held by the PK callback. */
                    tmp.length = ssl->buffers.key ?
                        ssl->buffers.key->length : 0;
                    tmp.buffer = ssl->buffers.key ?
                        ssl->buffers.key->buffer : NULL;
                #endif
                    ret = EccVerify(ssl, sigOut, args->sigLen,
                            args->sigData, args->sigDataSz,
                            (ecc_key*)ssl->hsKey,
                #ifdef HAVE_PK_CALLBACKS
                            &tmp
                #else
                            NULL
                #endif
                            );
                }
            }
        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH &&
                ssl->hsAltType == DYNAMIC_TYPE_ECC) {
                /* check for signature faults */
                byte* sigOut = args->verify + HASH_SIG_SIZE + VERIFY_HEADER +
                                args->sigLen + OPAQUE16_LEN + OPAQUE16_LEN;
            #ifdef HAVE_PK_CALLBACKS
                buffer tmp;

                /* Private key may be held by the PK callback. */
                tmp.length = ssl->buffers.altKey ?
                    ssl->buffers.altKey->length : 0;
                tmp.buffer = ssl->buffers.altKey ?
                    ssl->buffers.altKey->buffer : NULL;
            #endif
                ret = EccVerify(ssl, sigOut, args->altSigLen,
                        args->altSigData, args->altSigDataSz,
                        (ecc_key*)ssl->hsAltKey,
            #ifdef HAVE_PK_CALLBACKS
                        &tmp
            #else
                        NULL
            #endif
                        );
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */
        #endif /* HAVE_ECC && WOLFSSL_CHECK_SIG_FAULTS */

            /* Check for error */
            if (ret != 0) {
                goto exit_scv;
            }

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_FINALIZE;
        } /* case TLS_ASYNC_VERIFY */
        FALL_THROUGH;

        case TLS_ASYNC_FINALIZE:
        {
#ifdef WOLFSSL_TLS13_STREAM_CERT_VERIFY
            if (ssl->buffers.certVerifyMsg.buffer != NULL) {
                /* Streaming path: the assembled body sits in certVerifyMsg;
                 * record its final length (exact even for variable-length
                 * signatures). Per-fragment record/handshake headers are added
                 * in TLS_ASYNC_END. */
                ssl->buffers.certVerifyMsg.length =
                    (word32)args->length + HASH_SIG_SIZE + VERIFY_HEADER;
            }
#endif /* WOLFSSL_TLS13_STREAM_CERT_VERIFY */
            /* In-place path: put the record and handshake headers on now.
             * args->output is NULL only on the streaming path. */
            if (args->output != NULL) {
                AddTls13Headers(args->output, args->length + HASH_SIG_SIZE +
                                VERIFY_HEADER, certificate_verify, ssl);

                args->sendSz = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ +
                                args->length + HASH_SIG_SIZE + VERIFY_HEADER;
            #ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls)
                    args->sendSz += recordLayerHdrExtra + DTLS_HANDSHAKE_EXTRA;
            #endif /* WOLFSSL_DTLS13 */
            }
            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_END;
        } /* case TLS_ASYNC_FINALIZE */
        FALL_THROUGH;

        case TLS_ASYNC_END:
        {
            /* Body of the handshake message: [sigAlg(2) | sigLen(2) | sig]. In
             * the in-place path it sits at args->verify in the output buffer;
             * in the streaming path it sits in ssl->buffers.certVerifyMsg. */
            word32 msgSz;
            word32 maxFrag = (word32)wolfssl_local_GetMaxPlaintextSize(ssl);
            byte*  output;
            word32 fragSz;
            word32 i;
            int    recSz;
            int    thisSendSz;

#ifdef WOLFSSL_TLS13_STREAM_CERT_VERIFY
            if (ssl->buffers.certVerifyMsg.buffer != NULL) {
                /* Streamed send: the assembled body lives in
                 * ssl->buffers.certVerifyMsg and the send cursor in
                 * ssl->fragOffset - both connection-level - so a non-blocking
                 * WANT_WRITE resumes here (via TLS_ASYNC_END) without
                 * recomputing the signature. Emit one encrypted record per
                 * iteration and flush it, so the output buffer never holds more
                 * than a single fragment. Only the first record carries the
                 * handshake header; BuildTls13Message hashes each fragment's
                 * plaintext in order, keeping the transcript hash correct. The
                 * cursor is advanced before the flush because the record is
                 * already committed to the output buffer; the cursor tracks
                 * message-body -> record progress, not bytes on the wire, so a
                 * WANT_WRITE resumes on the next fragment. Advancing after the
                 * flush would rebuild and double-send the fragment on resume.
                 * This is not merely a convention: the accept/connect loop
                 * flushes pending output and returns WANT_WRITE without
                 * re-entering this function until the output buffer drains, so
                 * the committed record is never skipped or overwritten.
                 * certVerifyMsg is released on completion or error at exit_scv;
                 * it is kept across WANT_WRITE for resume. */
                msgSz = ssl->buffers.certVerifyMsg.length;
                if (maxFrag <= HANDSHAKE_HEADER_SZ) {
                    ERROR_OUT(BUFFER_E, exit_scv);
                }
                while (ssl->fragOffset < msgSz && ret == 0) {
                    if (ssl->fragOffset == 0) {
                        fragSz = maxFrag - HANDSHAKE_HEADER_SZ;
                        if (fragSz > msgSz)
                            fragSz = msgSz;
                        i = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;
                        thisSendSz = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ +
                                     (int)fragSz + MAX_MSG_EXTRA;
                    }
                    else {
                        fragSz = msgSz - ssl->fragOffset;
                        if (fragSz > maxFrag)
                            fragSz = maxFrag;
                        i = RECORD_HEADER_SZ;
                        thisSendSz = RECORD_HEADER_SZ + (int)fragSz +
                                     MAX_MSG_EXTRA;
                    }

                    if ((ret = CheckAvailableSize(ssl, thisSendSz)) != 0) {
                        goto exit_scv;
                    }
                    output = GetOutputBuffer(ssl);

                    if (ssl->fragOffset == 0) {
                        AddTls13FragHeaders(output, fragSz, 0, msgSz,
                                            certificate_verify, ssl);
                    }
                    else {
                        AddTls13RecordHeader(output, fragSz, handshake, ssl);
                    }
                    XMEMCPY(output + i,
                            ssl->buffers.certVerifyMsg.buffer + ssl->fragOffset,
                            fragSz);

                    /* This message is always encrypted. */
                    recSz = BuildTls13Message(ssl, output, thisSendSz,
                                output + RECORD_HEADER_SZ,
                                (int)(i - RECORD_HEADER_SZ + fragSz), handshake,
                                1, 0, 0);
                    if (recSz < 0) {
                        ret = recSz;
                        goto exit_scv;
                    }

                #if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
                    /* Trace the logical CertificateVerify once (first fragment),
                     * matching the single-record path. */
                    if (ssl->fragOffset == 0) {
                        if (ssl->hsInfoOn)
                            AddPacketName(ssl, "CertificateVerify");
                        if (ssl->toInfoOn) {
                            ret = AddPacketInfo(ssl, "CertificateVerify",
                                        handshake, output, recSz, WRITE_PROTO, 0,
                                        ssl->heap);
                            if (ret != 0)
                                goto exit_scv;
                        }
                    }
                #endif

                    ssl->buffers.outputBuffer.length += (word32)recSz;
                    ssl->fragOffset += fragSz;
                    /* Flush every fragment unconditionally - unlike the
                     * in-place path this cannot honor ssl->options.groupMessages
                     * (batch with later handshake messages), because streaming
                     * exists precisely to keep the output buffer bounded to a
                     * single fragment. */
                    ret = SendBuffered(ssl);
                }

                ssl->options.buildingMsg = 0;
                break;
            }
#endif /* WOLFSSL_TLS13_STREAM_CERT_VERIFY */

            /* In-place path: the whole message is in args->output. */
            msgSz = (word32)args->length + HASH_SIG_SIZE + VERIFY_HEADER;

#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls) {
                ssl->options.buildingMsg = 0;

                /* Dtls13HandshakeSend takes word16 output/send sizes, so the
                 * whole assembled CertificateVerify (signature plus framing)
                 * must fit in 16 bits. Every current SLH-DSA parameter set
                 * stays well under this (256f, the largest, is ~50KB), but
                 * guard the casts explicitly - mirroring the args->length check
                 * on the TLS path - so a future larger signature fails loudly
                 * instead of being silently truncated into a malformed record.
                 * outputSz is the reserved capacity and is >= sendSz, so it
                 * bounds both casts. */
                if (args->outputSz > WOLFSSL_MAX_16BIT) {
                    ERROR_OUT(BUFFER_E, exit_scv);
                }

                ret = Dtls13HandshakeSend(ssl, args->output,
                    (word16)args->outputSz,
                    (word16)args->sendSz, certificate_verify, 1);
                if (ret != 0)
                    goto exit_scv;

                break;
            }
#endif /* WOLFSSL_DTLS13 */

            if (HANDSHAKE_HEADER_SZ + msgSz <= maxFrag) {
                /* Fits in a single record: the common path used by RSA, ECC,
                 * EdDSA and ML-DSA is left byte-for-byte unchanged. */

                /* Always encrypted. A record AEAD pend propagates through
                 * exit_scv (args kept) and the retry resumes the build. */
                ret = BuildTls13Message(ssl, args->output,
                                        (int)args->outputSz,
                                        args->output + RECORD_HEADER_SZ,
                                        args->sendSz - RECORD_HEADER_SZ,
                                        handshake, 1, 0,
                                        TLS13_HS_ASYNC_OKAY);

                if (ret < 0) {
                    goto exit_scv;
                }
                else {
                    args->sendSz = ret;
                    ret = 0;
                }

            #if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
                if (ssl->hsInfoOn)
                    AddPacketName(ssl, "CertificateVerify");
                if (ssl->toInfoOn) {
                    ret = AddPacketInfo(ssl, "CertificateVerify", handshake,
                                args->output, args->sendSz, WRITE_PROTO, 0,
                                ssl->heap);
                    if (ret != 0)
                        goto exit_scv;
                }
            #endif

                ssl->buffers.outputBuffer.length += (word32)args->sendSz;
            }
            else {
                /* Signature does not fit in a single TLS record (e.g. SLH-DSA,
                 * whose signatures range up to ~50KB). Fragment the handshake
                 * message across multiple encrypted records. Only the first
                 * fragment carries the 4-byte handshake header; the transcript
                 * hash is maintained correctly because BuildTls13Message hashes
                 * each fragment's plaintext in order.
                 *
                 * The fragmentation cursor lives in args (frag/fragOffset/
                 * fragActive) so that a WC_PENDING_E from the record AEAD under
                 * WOLFSSL_ASYNC_CRYPT resumes on the same fragment rather than
                 * restarting at offset 0 and re-emitting committed records. */
                if (maxFrag <= HANDSHAKE_HEADER_SZ) {
                    ERROR_OUT(BUFFER_E, exit_scv);
                }

                /* Copy the assembled body out of the output buffer once, before
                 * we begin overwriting it with per-record data. args->frag is
                 * preserved across async resumes and freed by FreeScv13Args. */
                if (args->frag == NULL) {
                    args->frag = (byte*)XMALLOC(msgSz, ssl->heap,
                                                DYNAMIC_TYPE_TMP_BUFFER);
                    if (args->frag == NULL) {
                        ERROR_OUT(MEMORY_E, exit_scv);
                    }
                    XMEMCPY(args->frag, args->verify, msgSz);
                    args->fragOffset = 0;
                    args->fragActive = 0;
                }

                while (args->fragOffset < msgSz && ret == 0) {
                    if (args->fragOffset == 0) {
                        fragSz = maxFrag - HANDSHAKE_HEADER_SZ;
                        if (fragSz > msgSz)
                            fragSz = msgSz;
                        thisSendSz = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ +
                                     (int)fragSz + MAX_MSG_EXTRA;
                    }
                    else {
                        fragSz = msgSz - args->fragOffset;
                        if (fragSz > maxFrag)
                            fragSz = maxFrag;
                        thisSendSz = RECORD_HEADER_SZ + (int)fragSz +
                                     MAX_MSG_EXTRA;
                    }

                    if ((ret = CheckAvailableSize(ssl, thisSendSz)) != 0) {
                        goto exit_scv;
                    }
                    output = GetOutputBuffer(ssl);

                    i = RECORD_HEADER_SZ;
                    if (args->fragOffset == 0)
                        i += HANDSHAKE_HEADER_SZ;

                    /* Lay out this fragment's record header and plaintext once.
                     * On an async resume of a pending fragment they are already
                     * in place (outputBuffer.length was not advanced), so skip
                     * straight to re-driving BuildTls13Message. */
                    if (!args->fragActive) {
                        if (args->fragOffset == 0) {
                            AddTls13FragHeaders(output, fragSz, 0, msgSz,
                                                certificate_verify, ssl);
                        }
                        else {
                            AddTls13RecordHeader(output, fragSz, handshake, ssl);
                        }
                        XMEMCPY(output + i, args->frag + args->fragOffset,
                                fragSz);
                        args->fragActive = 1;
                    }
                    i += fragSz;

                    /* This message is always encrypted. */
                    recSz = BuildTls13Message(ssl, output, thisSendSz,
                                output + RECORD_HEADER_SZ,
                                (int)(i - RECORD_HEADER_SZ), handshake, 1, 0, 0);
                    if (recSz < 0) {
                        /* WC_PENDING_E leaves frag/fragOffset/fragActive intact
                         * for resume; real errors are cleaned up by
                         * FreeScv13Args at exit_scv. */
                        ret = recSz;
                        goto exit_scv;
                    }

                #if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
                    /* Trace the logical CertificateVerify once (on the first
                     * fragment), matching the single-record path rather than
                     * emitting one entry per record. */
                    if (args->fragOffset == 0) {
                        if (ssl->hsInfoOn)
                            AddPacketName(ssl, "CertificateVerify");
                        if (ssl->toInfoOn) {
                            ret = AddPacketInfo(ssl, "CertificateVerify",
                                        handshake, output, recSz, WRITE_PROTO, 0,
                                        ssl->heap);
                            if (ret != 0)
                                goto exit_scv;
                        }
                    }
                #endif

                    ssl->buffers.outputBuffer.length += (word32)recSz;
                    args->fragOffset += fragSz;
                    args->fragActive = 0;
                }
            }

            ssl->options.buildingMsg = 0;
            if (!ssl->options.groupMessages)
                ret = SendBuffered(ssl);
            break;
        }
        default:
            ret = INPUT_CASE_ERROR;
    } /* switch(ssl->options.asyncState) */

exit_scv:
#ifdef WOLFSSL_TLS13_STREAM_CERT_VERIFY
    /* A streamed CertificateVerify keeps its assembled body across a
     * non-blocking WANT_WRITE so the send resumes without recomputing the
     * signature; release it on completion or on any real error. This path is
     * mutually exclusive with WOLFSSL_ASYNC_CRYPT (see the feature guard in
     * internal.h), so ret is never WC_PENDING_E here and the buffer needs no
     * retention across an async resume. */
    if (ret != WC_NO_ERR_TRACE(WANT_WRITE) &&
            ssl->buffers.certVerifyMsg.buffer != NULL) {
        XFREE(ssl->buffers.certVerifyMsg.buffer, ssl->heap,
              DYNAMIC_TYPE_TMP_BUFFER);
        ssl->buffers.certVerifyMsg.buffer = NULL;
        ssl->buffers.certVerifyMsg.length = 0;
        ssl->fragOffset = 0;
    }
#endif /* WOLFSSL_TLS13_STREAM_CERT_VERIFY */
#ifdef WOLFSSL_BLIND_PRIVATE_KEY
    if (ret == 0) {
        ret = wolfssl_priv_der_blind(ssl->rng, ssl->buffers.key,
            &ssl->buffers.keyMask);
    }
    else {
        wolfssl_priv_der_blind_toggle(ssl->buffers.key, ssl->buffers.keyMask);
    }
#endif

    WOLFSSL_LEAVE("SendTls13CertificateVerify", ret);
    WOLFSSL_END(WC_FUNC_CERTIFICATE_VERIFY_SEND);

#ifdef WOLFSSL_ASYNC_CRYPT
    /* Handle async operation */
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
        return ret;
    }
#endif /* WOLFSSL_ASYNC_CRYPT */

    /* Final cleanup */
    FreeScv13Args(ssl, args);
    FreeKeyExchange(ssl);
#ifdef WOLFSSL_ASYNC_IO
    /* Cleanup async */
    FreeAsyncCtx(ssl, 0);
#endif

    if (ret != 0) {
        WOLFSSL_ERROR_VERBOSE(ret);
    }

    return ret;
}
#endif
#endif /* !NO_WOLFSSL_CLIENT || !NO_WOLFSSL_SERVER */

#if !defined(NO_WOLFSSL_CLIENT) || !defined(WOLFSSL_NO_CLIENT_AUTH)
/* handle processing TLS v1.3 certificate (11) */
/* Parse and handle a TLS v1.3 Certificate message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of Certificate.
 *           On exit, the index of byte after the Certificate message.
 * totalSz   The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */
static int DoTls13Certificate(WOLFSSL* ssl, byte* input, word32* inOutIdx,
                              word32 totalSz)
{
    int ret = 0;

    WOLFSSL_START(WC_FUNC_CERTIFICATE_DO);
    WOLFSSL_ENTER("DoTls13Certificate");

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls && ssl->options.handShakeDone) {
        /* certificate needs some special care after the handshake */
        ret = Dtls13RtxProcessingCertificate(
            ssl, input + *inOutIdx, totalSz);
    }
#endif /* WOLFSSL_DTLS13 */

    if (ret == 0)
        ret = ProcessPeerCerts(ssl, input, inOutIdx, totalSz);
    if (ret == 0) {
#if !defined(NO_WOLFSSL_CLIENT)
        if (ssl->options.side == WOLFSSL_CLIENT_END)
            ssl->options.serverState = SERVER_CERT_COMPLETE;
#endif
#if !defined(NO_WOLFSSL_SERVER) && defined(WOLFSSL_POST_HANDSHAKE_AUTH)
        if (ssl->options.side == WOLFSSL_SERVER_END &&
                                ssl->options.handShakeState == HANDSHAKE_DONE) {
            /* reset handshake states */
            ssl->options.serverState = SERVER_FINISHED_COMPLETE;
            ssl->options.acceptState  = TICKET_SENT;
            ssl->options.handShakeState = SERVER_FINISHED_COMPLETE;
        }
#endif
    }

    WOLFSSL_LEAVE("DoTls13Certificate", ret);
    WOLFSSL_END(WC_FUNC_CERTIFICATE_DO);

    return ret;
}
#endif

#if (!defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519) || \
     defined(HAVE_ED448) || defined(HAVE_FALCON) || \
     defined(WOLFSSL_HAVE_MLDSA) || defined(WOLFSSL_HAVE_SLHDSA)) && \
    !defined(NO_CERTS)

typedef struct Dcv13Args {
    byte*  output; /* not allocated */
    word32 sendSz;
    word16 sz;
    word32 sigSz;
    word32 idx;
    word32 begin;

    byte*  sigData;
    word16 sigDataSz;
#ifdef WOLFSSL_DUAL_ALG_CERTS
    byte   altSigAlgo;
    byte*  altSigData;
    word32 altSigDataSz;
    word32 altSignatureSz;
    byte   altPeerAuthGood;
#endif
} Dcv13Args;

static void FreeDcv13Args(WOLFSSL* ssl, void* pArgs)
{
    Dcv13Args* args = (Dcv13Args*)pArgs;

    if (args && args->sigData != NULL) {
        XFREE(args->sigData, ssl->heap, DYNAMIC_TYPE_SIGNATURE);
        args->sigData = NULL;
    }
#ifdef WOLFSSL_DUAL_ALG_CERTS
    if (args && args->altSigData != NULL) {
        XFREE(args->altSigData, ssl->heap, DYNAMIC_TYPE_SIGNATURE);
        args->altSigData = NULL;
    }
#endif
    (void)ssl;
}

#ifdef WOLFSSL_DUAL_ALG_CERTS
#ifndef NO_RSA
/* ssl->peerCert->sapkiDer is the alternative public key. Hopefully it is a
 * RSA public key. Convert it into a usable public key. */
static int decodeRsaKey(WOLFSSL* ssl)
{
    int keyRet;
    word32 tmpIdx = 0;

    if (ssl->peerRsaKeyPresent)
        return INVALID_PARAMETER;

    keyRet = AllocKey(ssl, DYNAMIC_TYPE_RSA, (void**)&ssl->peerRsaKey);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    ssl->peerRsaKeyPresent = 1;
    keyRet = wc_RsaPublicKeyDecode(ssl->peerCert.sapkiDer, &tmpIdx,
                                   ssl->peerRsaKey,
                                   ssl->peerCert.sapkiLen);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    return 0;
}
#endif /* !NO_RSA */

#ifdef HAVE_ECC
/* ssl->peerCert->sapkiDer is the alternative public key. Hopefully it is a
 * ECC public key. Convert it into a usable public key. */
static int decodeEccKey(WOLFSSL* ssl)
{
    int keyRet;
    word32 tmpIdx = 0;

    if (ssl->peerEccDsaKeyPresent)
        return INVALID_PARAMETER;

    keyRet = AllocKey(ssl, DYNAMIC_TYPE_ECC, (void**)&ssl->peerEccDsaKey);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    ssl->peerEccDsaKeyPresent = 1;
    keyRet = wc_EccPublicKeyDecode(ssl->peerCert.sapkiDer, &tmpIdx,
                                   ssl->peerEccDsaKey,
                                   ssl->peerCert.sapkiLen);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    return 0;
}
#endif /* HAVE_ECC */

#ifdef WOLFSSL_HAVE_MLDSA
/* ssl->peerCert->sapkiDer is the alternative public key. Hopefully it is a
 * ML-DSA public key. Convert it into a usable public key. */
static int decodeMlDsaKey(WOLFSSL* ssl, int level)
{
    int keyRet;
    word32 tmpIdx = 0;

    if (ssl->peerMlDsaKeyPresent)
        return INVALID_PARAMETER;

    keyRet = AllocKey(ssl, DYNAMIC_TYPE_MLDSA,
                      (void**)&ssl->peerMlDsaKey);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    ssl->peerMlDsaKeyPresent = 1;
    keyRet = wc_MlDsaKey_SetParams(ssl->peerMlDsaKey, level);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    keyRet = wc_MlDsaKey_PublicKeyDecode(ssl->peerMlDsaKey,
                                         ssl->peerCert.sapkiDer,
                                         ssl->peerCert.sapkiLen, &tmpIdx);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    return 0;
}
#endif /* WOLFSSL_HAVE_MLDSA */

#ifdef HAVE_FALCON
/* ssl->peerCert->sapkiDer is the alternative public key. Hopefully it is a
 * falcon public key. Convert it into a usable public key. */
static int decodeFalconKey(WOLFSSL* ssl, int level)
{
    int keyRet;
    word32 tmpIdx = 0;

    if (ssl->peerFalconKeyPresent)
        return INVALID_PARAMETER;

    keyRet = AllocKey(ssl, DYNAMIC_TYPE_FALCON, (void**)&ssl->peerFalconKey);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    ssl->peerFalconKeyPresent = 1;
    keyRet = wc_falcon_set_level(ssl->peerFalconKey, level);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    keyRet = wc_Falcon_PublicKeyDecode(ssl->peerCert.sapkiDer, &tmpIdx,
                                       ssl->peerFalconKey,
                                       ssl->peerCert.sapkiLen);
    if (keyRet != 0)
        return PEER_KEY_ERROR;

    return 0;
}
#endif /* HAVE_FALCON */
#endif /* WOLFSSL_DUAL_ALG_CERTS */

/* handle processing TLS v1.3 certificate_verify (15) */
/* Parse and handle a TLS v1.3 CertificateVerify message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of
 *           CertificateVerify.
 *           On exit, the index of byte after the CertificateVerify message.
 * totalSz   The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */
static int DoTls13CertificateVerify(WOLFSSL* ssl, byte* input,
                                    word32* inOutIdx, word32 totalSz)
{
    int         ret = 0;
    byte*       sig = NULL;
#ifndef NO_RSA
    /* Use this as a temporary buffer for RSA signature verification. */
    buffer*     rsaSigBuf = &ssl->buffers.sig;
#endif
#ifdef WOLFSSL_ASYNC_CRYPT
    Dcv13Args* args = NULL;
    WOLFSSL_ASSERT_SIZEOF_GE(ssl->async->args, *args);
#else
    Dcv13Args  args[1];
#endif

    WOLFSSL_START(WC_FUNC_CERTIFICATE_VERIFY_DO);
    WOLFSSL_ENTER("DoTls13CertificateVerify");

#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13CertificateVerify(ssl, input, inOutIdx, totalSz);
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE)) {
        goto exit_dcv;
    }
    ret = 0;
#endif

#ifdef WOLFSSL_ASYNC_CRYPT
    if (ssl->async == NULL) {
        ssl->async = (struct WOLFSSL_ASYNC*)
                XMALLOC(sizeof(struct WOLFSSL_ASYNC), ssl->heap,
                        DYNAMIC_TYPE_ASYNC);
        if (ssl->async == NULL)
            ERROR_OUT(MEMORY_E, exit_dcv);
    }
    args = (Dcv13Args*)ssl->async->args;

    ret = wolfSSL_AsyncPop(ssl, &ssl->options.asyncState);
    if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
        /* Check for error */
        if (ret < 0)
            goto exit_dcv;
    }
    else
#endif
    {
        /* Reset state */
        ret = 0;
        ssl->options.asyncState = TLS_ASYNC_BEGIN;
        XMEMSET(args, 0, sizeof(Dcv13Args));
        ssl->options.peerHashAlgo = sha_mac;
        ssl->options.peerSigAlgo = anonymous_sa_algo;
        args->idx = *inOutIdx;
        args->begin = *inOutIdx;
    #ifdef WOLFSSL_ASYNC_CRYPT
        ssl->async->freeArgs = FreeDcv13Args;
    #endif
    }

    switch(ssl->options.asyncState)
    {
        case TLS_ASYNC_BEGIN:
        {
        #ifdef WOLFSSL_CALLBACKS
            if (ssl->hsInfoOn) AddPacketName(ssl, "CertificateVerify");
            if (ssl->toInfoOn) AddLateName("CertificateVerify",
                                           &ssl->timeoutInfo);
        #endif

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_BUILD;
        } /* case TLS_ASYNC_BEGIN */
        FALL_THROUGH;

        case TLS_ASYNC_BUILD:
        {
            int validSigAlgo;
            const Suites* suites = WOLFSSL_SUITES(ssl);
            word16 i;

            /* Signature algorithm. */
            if ((args->idx - args->begin) + ENUM_LEN + ENUM_LEN > totalSz) {
                ERROR_OUT(BUFFER_ERROR, exit_dcv);
            }

#ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->peerSigSpec == NULL) {
                /* The peer did not respond. We didn't send CKS or they don't
                 * support it. Either way, we do not need to handle dual
                 * key/sig case. */
                ssl->sigSpec = NULL;
                ssl->sigSpecSz = 0;
            }

            /* If no CKS extension or either native or alternative, then just
             * get a normal sigalgo.  But if BOTH, then get the native and alt
             * sig algos. */
            if (ssl->sigSpec == NULL ||
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_NATIVE ||
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_ALTERNATIVE) {
#endif /* WOLFSSL_DUAL_ALG_CERTS */
                validSigAlgo = 0;
                for (i = 0; i < suites->hashSigAlgoSz; i += 2) {
                     if ((suites->hashSigAlgo[i + 0] == input[args->idx + 0]) &&
                             (suites->hashSigAlgo[i + 1] == input[args->idx + 1])) {
                         validSigAlgo = 1;
                         break;
                     }
                }
                if (!validSigAlgo) {
                    ERROR_OUT(INVALID_PARAMETER, exit_dcv);
                }

                ret = DecodeTls13SigAlg(input + args->idx,
                        &ssl->options.peerHashAlgo, &ssl->options.peerSigAlgo);
#ifdef WOLFSSL_DUAL_ALG_CERTS
            }
            else {
                ret = DecodeTls13HybridSigAlg(input + args->idx,
                                              &ssl->options.peerHashAlgo,
                                              &ssl->options.peerSigAlgo,
                                              &args->altSigAlgo);
            }
#endif /* WOLFSSL_DUAL_ALG_CERTS */

            if (ret < 0)
                goto exit_dcv;
            args->idx += OPAQUE16_LEN;

            /* Signature length. */
            if ((args->idx - args->begin) + OPAQUE16_LEN > totalSz) {
                ERROR_OUT(BUFFER_ERROR, exit_dcv);
            }
            ato16(input + args->idx, &args->sz);
            args->idx += OPAQUE16_LEN;

            /* Signature data. */
            if ((args->idx - args->begin) + args->sz > totalSz) {
                ERROR_OUT(BUFFER_ERROR, exit_dcv);
            }

#ifdef WOLFSSL_DUAL_ALG_CERTS
            if ((ssl->sigSpec != NULL) &&
                (*ssl->sigSpec != WOLFSSL_CKS_SIGSPEC_NATIVE)) {

                word16 sa;
                if (args->altSigAlgo == 0)
                    sa = ssl->options.peerSigAlgo;
                else
                    sa = args->altSigAlgo;

                switch(sa) {
            #ifndef NO_RSA
                case rsa_pss_sa_algo:
                    ret = decodeRsaKey(ssl);
                    break;
            #endif
            #ifdef HAVE_ECC
                case ecc_dsa_sa_algo:
                    ret = decodeEccKey(ssl);
                    break;
            #endif
            #ifdef WOLFSSL_HAVE_MLDSA
                case mldsa_44_sa_algo:
                    ret = decodeMlDsaKey(ssl, WC_ML_DSA_44);
                    break;
                case mldsa_65_sa_algo:
                    ret = decodeMlDsaKey(ssl, WC_ML_DSA_65);
                    break;
                case mldsa_87_sa_algo:
                    ret = decodeMlDsaKey(ssl, WC_ML_DSA_87);
                    break;
            #endif
            #ifdef WOLFSSL_HAVE_SLHDSA
                case slhdsa_sha2_128s_sa_algo:
                case slhdsa_sha2_128f_sa_algo:
                case slhdsa_sha2_192s_sa_algo:
                case slhdsa_sha2_192f_sa_algo:
                case slhdsa_sha2_256s_sa_algo:
                case slhdsa_sha2_256f_sa_algo:
                case slhdsa_shake_128s_sa_algo:
                case slhdsa_shake_128f_sa_algo:
                case slhdsa_shake_192s_sa_algo:
                case slhdsa_shake_192f_sa_algo:
                case slhdsa_shake_256s_sa_algo:
                case slhdsa_shake_256f_sa_algo:
                    /* SLH-DSA is not supported as an alternative (dual-algorithm
                     * / CKS) key. The alternative-signature verification block
                     * in this function has no SLH-DSA case, so a decoded key
                     * would never be verified and the handshake would always be
                     * rejected at TLS_ASYNC_FINALIZE. Fail fast here instead of
                     * allocating a key that can never authenticate the peer. */
                    ERROR_OUT(ALGO_ID_E, exit_dcv);
            #endif
            #ifdef HAVE_FALCON
                case falcon_level1_sa_algo:
                    ret = decodeFalconKey(ssl, 1);
                    break;
                case falcon_level5_sa_algo:
                    ret = decodeFalconKey(ssl, 5);
                    break;
            #endif
                default:
                    ERROR_OUT(PEER_KEY_ERROR, exit_dcv);
                }

                if (ret != 0)
                    ERROR_OUT(ret, exit_dcv);

                if (*ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_ALTERNATIVE) {
                    /* Now swap in the alternative by removing the native.
                     * sa contains the alternative signature type. */
                #ifndef NO_RSA
                    if (ssl->peerRsaKeyPresent && sa != rsa_pss_sa_algo) {
                        FreeKey(ssl, DYNAMIC_TYPE_RSA,
                                (void**)&ssl->peerRsaKey);
                        ssl->peerRsaKeyPresent = 0;
                    }
                #endif
                #ifdef HAVE_ECC
                    else if (ssl->peerEccDsaKeyPresent &&
                             sa != ecc_dsa_sa_algo) {
                        FreeKey(ssl, DYNAMIC_TYPE_ECC,
                                (void**)&ssl->peerEccDsaKey);
                        ssl->peerEccDsaKeyPresent = 0;
                    }
                #endif
                #ifdef WOLFSSL_HAVE_MLDSA
                    else if (ssl->peerMlDsaKeyPresent &&
                             sa != mldsa_44_sa_algo &&
                             sa != mldsa_65_sa_algo &&
                             sa != mldsa_87_sa_algo) {
                        FreeKey(ssl, DYNAMIC_TYPE_MLDSA,
                                (void**)&ssl->peerMlDsaKey);
                        ssl->peerMlDsaKeyPresent = 0;
                    }
                #endif
                #ifdef WOLFSSL_HAVE_SLHDSA
                    else if (ssl->peerSlhDsaKeyPresent &&
                             !IsSlhDsaSigAlgo(sa)) {
                        FreeKey(ssl, DYNAMIC_TYPE_SLHDSA,
                                (void**)&ssl->peerSlhDsaKey);
                        ssl->peerSlhDsaKeyPresent = 0;
                    }
                #endif
                #ifdef HAVE_FALCON
                    else if (ssl->peerFalconKeyPresent &&
                             sa != falcon_level1_sa_algo &&
                             sa != falcon_level5_sa_algo) {
                        FreeKey(ssl, DYNAMIC_TYPE_FALCON,
                                (void**)&ssl->peerFalconKey);
                        ssl->peerFalconKeyPresent = 0;
                    }
                #endif
                    else {
                        ERROR_OUT(PEER_KEY_ERROR, exit_dcv);
                    }
                }
            }
#endif /* WOLFSSL_DUAL_ALG_CERTS */

            /* Check for public key of required type. */
            /* Assume invalid unless signature algo matches the key provided */
            validSigAlgo = 0;
        #ifdef HAVE_ED25519
            if (ssl->options.peerSigAlgo == ed25519_sa_algo) {
                WOLFSSL_MSG("Peer sent ED25519 sig");
                validSigAlgo = (ssl->peerEd25519Key != NULL) &&
                                                     ssl->peerEd25519KeyPresent;
            }
        #endif
        #ifdef HAVE_ED448
            if (ssl->options.peerSigAlgo == ed448_sa_algo) {
                WOLFSSL_MSG("Peer sent ED448 sig");
                validSigAlgo = (ssl->peerEd448Key != NULL) &&
                                                       ssl->peerEd448KeyPresent;
            }
        #endif
        #ifdef HAVE_ECC
            if (ssl->options.peerSigAlgo == ecc_dsa_sa_algo) {
                WOLFSSL_MSG("Peer sent ECC sig");
                validSigAlgo = (ssl->peerEccDsaKey != NULL) &&
                                                      ssl->peerEccDsaKeyPresent;
            }
        #endif
        #if defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
            if (ssl->options.peerSigAlgo == sm2_sa_algo) {
                WOLFSSL_MSG("Peer sent SM2 sig");
                validSigAlgo = (ssl->peerEccDsaKey != NULL) &&
                                                      ssl->peerEccDsaKeyPresent;
            }
        #endif
        #ifdef HAVE_FALCON
            if (ssl->options.peerSigAlgo == falcon_level1_sa_algo) {
                WOLFSSL_MSG("Peer sent Falcon Level 1 sig");
                validSigAlgo = (ssl->peerFalconKey != NULL) &&
                               ssl->peerFalconKeyPresent;
            }
            if (ssl->options.peerSigAlgo == falcon_level5_sa_algo) {
                WOLFSSL_MSG("Peer sent Falcon Level 5 sig");
                validSigAlgo = (ssl->peerFalconKey != NULL) &&
                               ssl->peerFalconKeyPresent;
            }
        #endif
        #ifdef WOLFSSL_HAVE_MLDSA
            if (ssl->options.peerSigAlgo == mldsa_44_sa_algo) {
                WOLFSSL_MSG("Peer sent ML-DSA Level 2 sig");
                validSigAlgo = (ssl->peerMlDsaKey != NULL) &&
                               ssl->peerMlDsaKeyPresent;
            }
            if (ssl->options.peerSigAlgo == mldsa_65_sa_algo) {
                WOLFSSL_MSG("Peer sent ML-DSA Level 3 sig");
                validSigAlgo = (ssl->peerMlDsaKey != NULL) &&
                               ssl->peerMlDsaKeyPresent;
            }
            if (ssl->options.peerSigAlgo == mldsa_87_sa_algo) {
                WOLFSSL_MSG("Peer sent ML-DSA Level 5 sig");
                validSigAlgo = (ssl->peerMlDsaKey != NULL) &&
                               ssl->peerMlDsaKeyPresent;
            }
        #endif
        #ifdef WOLFSSL_HAVE_SLHDSA
            if (IsSlhDsaSigAlgo(ssl->options.peerSigAlgo)) {
                WOLFSSL_MSG("Peer sent SLH-DSA sig");
                validSigAlgo = (ssl->peerSlhDsaKey != NULL) &&
                               ssl->peerSlhDsaKeyPresent;
            }
        #endif
        #ifndef NO_RSA
            if (ssl->options.peerSigAlgo == rsa_sa_algo) {
                WOLFSSL_MSG("Peer sent PKCS#1.5 algo - not valid TLS 1.3");
                ERROR_OUT(INVALID_PARAMETER, exit_dcv);
            }
            if (ssl->options.peerSigAlgo == rsa_pss_sa_algo) {
                WOLFSSL_MSG("Peer sent RSA sig");
                validSigAlgo = (ssl->peerRsaKey != NULL) &&
                                                         ssl->peerRsaKeyPresent;
            }
        #endif
            if (!validSigAlgo) {
                WOLFSSL_MSG("Sig algo doesn't correspond to certificate");
                ERROR_OUT(SIG_VERIFY_E, exit_dcv);
            }

            args->sigSz = args->sz;
#ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                /* In case we received two signatures, both of them are encoded
                 * with their size as 16-bit integeter prior in memory. Hence,
                 * we can decode both lengths here now. */
                word32 tmpIdx = args->idx;
                word16 tmpSz = 0;
                if (args->sz < OPAQUE16_LEN) {
                    ERROR_OUT(BUFFER_ERROR, exit_dcv);
                }
                ato16(input + tmpIdx, &tmpSz);
                args->sigSz = tmpSz;

                tmpIdx += OPAQUE16_LEN + args->sigSz;
                if (tmpIdx - args->idx + OPAQUE16_LEN > args->sz) {
                    ERROR_OUT(BUFFER_ERROR, exit_dcv);
                }
                ato16(input + tmpIdx, &tmpSz);
                args->altSignatureSz = tmpSz;

                if (args->sz != (args->sigSz + args->altSignatureSz +
                                    OPAQUE16_LEN + OPAQUE16_LEN)) {
                    ERROR_OUT(BUFFER_ERROR, exit_dcv);
                }
            }
#endif /* WOLFSSL_DUAL_ALG_CERTS */

        #if !defined(NO_RSA) && defined(WC_RSA_PSS)
            /* In case we have to verify an RSA signature, we have to store the
             * signature in the 'rsaSigBuf' structure for further processing.
             */
            if (ssl->peerRsaKey != NULL && ssl->peerRsaKeyPresent != 0) {
                word32 sigSz = args->sigSz;
                sig = input + args->idx;
            #ifdef WOLFSSL_DUAL_ALG_CERTS
                /* Check if our alternative signature was RSA */
                if (ssl->sigSpec != NULL &&
                    *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                    if (ssl->options.peerSigAlgo != rsa_pss_sa_algo) {
                        /* We have to skip the first signature (length field
                         * and signature itself) and the length field of the
                         * alternative signature. */
                        sig += OPAQUE16_LEN + OPAQUE16_LEN + args->sigSz;
                        sigSz = args->altSignatureSz;
                    }
                    else {
                        /* We have to skip the length field */
                        sig += OPAQUE16_LEN;
                    }
                }
            #endif
                rsaSigBuf->buffer = (byte*)XMALLOC(sigSz, ssl->heap,
                                         DYNAMIC_TYPE_SIGNATURE);
                if (rsaSigBuf->buffer == NULL) {
                    ERROR_OUT(MEMORY_E, exit_dcv);
                }
                rsaSigBuf->length = sigSz;
                XMEMCPY(rsaSigBuf->buffer, sig, rsaSigBuf->length);
            }
        #endif /* !NO_RSA && WC_RSA_PSS */

            args->sigData = (byte*)XMALLOC(MAX_SIG_DATA_SZ, ssl->heap,
                                                    DYNAMIC_TYPE_SIGNATURE);
            if (args->sigData == NULL) {
                ERROR_OUT(MEMORY_E, exit_dcv);
            }

            ret = CreateSigData(ssl, args->sigData, &args->sigDataSz, 1);
            if (ret < 0)
                goto exit_dcv;

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if ((ssl->sigSpec != NULL) &&
                (*ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH)) {
                args->altSigData = (byte*)XMALLOC(MAX_SIG_DATA_SZ, ssl->heap,
                                                        DYNAMIC_TYPE_SIGNATURE);
                if (args->altSigData == NULL) {
                    ERROR_OUT(MEMORY_E, exit_dcv);
                }
                XMEMCPY(args->altSigData, args->sigData, args->sigDataSz);
                args->altSigDataSz = args->sigDataSz;
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */

        #ifdef HAVE_ECC
            if ((ssl->options.peerSigAlgo == ecc_dsa_sa_algo) &&
                (ssl->peerEccDsaKeyPresent)) {
                ret = CreateECCEncodedSig(args->sigData,
                    args->sigDataSz, ssl->options.peerHashAlgo);
                if (ret < 0)
                    goto exit_dcv;
                args->sigDataSz = (word16)ret;
                ret = 0;
            }

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if ((ssl->sigSpec != NULL) &&
                (*ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) &&
                (args->altSigAlgo == ecc_dsa_sa_algo) &&
                (ssl->peerEccDsaKeyPresent)) {
                ret = CreateECCEncodedSig(args->altSigData,
                        args->altSigDataSz, ssl->options.peerHashAlgo);
                    if (ret < 0)
                        goto exit_dcv;
                    args->altSigDataSz = (word16)ret;
                    ret = 0;
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */
        #endif /* HAVE_ECC */

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_DO;
        } /* case TLS_ASYNC_BUILD */
        FALL_THROUGH;

        case TLS_ASYNC_DO:
        {
            sig = input + args->idx;
            (void)sig;
        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                /* As we have two signatures in the message, we stored
                 * the length of each before the actual signature. This
                 * is necessary, as we could have two algorithms with
                 * variable length signatures. */
                sig += OPAQUE16_LEN;
            }
        #endif
        #ifndef NO_RSA
            if ((ssl->options.peerSigAlgo == rsa_pss_sa_algo) &&
                (ssl->peerRsaKey != NULL) && (ssl->peerRsaKeyPresent != 0)) {
                WOLFSSL_MSG("Doing RSA peer cert verify");
                ret = RsaVerify(ssl, rsaSigBuf->buffer,
                                (word32)rsaSigBuf->length, &args->output,
                                ssl->options.peerSigAlgo,
                                ssl->options.peerHashAlgo, ssl->peerRsaKey,
                #ifdef HAVE_PK_CALLBACKS
                                &ssl->buffers.peerRsaKey
                #else
                                NULL
                #endif
                                );
                if (ret >= 0) {
                    args->sendSz = (word32)ret;
                    ret = 0;
                }
            }
        #endif /* !NO_RSA */
        #ifdef HAVE_ECC
            if ((ssl->options.peerSigAlgo == ecc_dsa_sa_algo) &&
                    ssl->peerEccDsaKeyPresent) {
                WOLFSSL_MSG("Doing ECC peer cert verify");
                ret = EccVerify(ssl, sig, args->sigSz,
                    args->sigData, args->sigDataSz,
                    ssl->peerEccDsaKey,
                #ifdef HAVE_PK_CALLBACKS
                    &ssl->buffers.peerEccDsaKey
                #else
                    NULL
                #endif
                    );

                if (ret >= 0) {
                    /* CLIENT/SERVER: data verified with public key from
                     * certificate. */
                    ssl->options.peerAuthGood = 1;

                    FreeKey(ssl, DYNAMIC_TYPE_ECC, (void**)&ssl->peerEccDsaKey);
                    ssl->peerEccDsaKeyPresent = 0;
                }
            }
        #endif /* HAVE_ECC */
        #if defined(HAVE_ECC) && defined(WOLFSSL_SM2) && defined(WOLFSSL_SM3)
            if ((ssl->options.peerSigAlgo == sm2_sa_algo) &&
                   ssl->peerEccDsaKeyPresent) {
                WOLFSSL_MSG("Doing SM2/SM3 peer cert verify");
                ret = Sm2wSm3Verify(ssl, TLS13_SM2_SIG_ID, TLS13_SM2_SIG_ID_SZ,
                    sig, args->sigSz, args->sigData, args->sigDataSz,
                    ssl->peerEccDsaKey, NULL);
                if (ret >= 0) {
                    /* CLIENT/SERVER: data verified with public key from
                     * certificate. */
                    ssl->options.peerAuthGood = 1;

                    FreeKey(ssl, DYNAMIC_TYPE_ECC, (void**)&ssl->peerEccDsaKey);
                    ssl->peerEccDsaKeyPresent = 0;
                }
            }
        #endif
        #ifdef HAVE_ED25519
            if ((ssl->options.peerSigAlgo == ed25519_sa_algo) &&
                (ssl->peerEd25519KeyPresent)) {
                WOLFSSL_MSG("Doing ED25519 peer cert verify");
                ret = Ed25519Verify(ssl, sig, args->sigSz,
                    args->sigData, args->sigDataSz,
                    ssl->peerEd25519Key,
                #ifdef HAVE_PK_CALLBACKS
                    &ssl->buffers.peerEd25519Key
                #else
                    NULL
                #endif
                    );

                if (ret >= 0) {
                    /* CLIENT/SERVER: data verified with public key from
                     * certificate. */
                    ssl->options.peerAuthGood = 1;
                    FreeKey(ssl, DYNAMIC_TYPE_ED25519,
                                                  (void**)&ssl->peerEd25519Key);
                    ssl->peerEd25519KeyPresent = 0;
                }
            }
        #endif
        #ifdef HAVE_ED448
            if ((ssl->options.peerSigAlgo == ed448_sa_algo) &&
                (ssl->peerEd448KeyPresent)) {
                WOLFSSL_MSG("Doing ED448 peer cert verify");
                ret = Ed448Verify(ssl, sig, args->sigSz,
                    args->sigData, args->sigDataSz,
                    ssl->peerEd448Key,
                #ifdef HAVE_PK_CALLBACKS
                    &ssl->buffers.peerEd448Key
                #else
                    NULL
                #endif
                );

                if (ret >= 0) {
                    /* CLIENT/SERVER: data verified with public key from
                     * certificate. */
                    ssl->options.peerAuthGood = 1;
                    FreeKey(ssl, DYNAMIC_TYPE_ED448,
                                                    (void**)&ssl->peerEd448Key);
                    ssl->peerEd448KeyPresent = 0;
                }
            }
        #endif
        #if defined(HAVE_FALCON)
            if (((ssl->options.peerSigAlgo == falcon_level1_sa_algo) ||
                 (ssl->options.peerSigAlgo == falcon_level5_sa_algo)) &&
                (ssl->peerFalconKeyPresent)) {
                int res = 0;
                WOLFSSL_MSG("Doing Falcon peer cert verify");
                ret = wc_falcon_verify_msg(sig, args->sigSz,
                                           args->sigData, args->sigDataSz,
                                           &res, ssl->peerFalconKey);

                if ((ret >= 0) && (res == 1)) {
                    /* CLIENT/SERVER: data verified with public key from
                     * certificate. */
                    ssl->options.peerAuthGood = 1;

                    FreeKey(ssl, DYNAMIC_TYPE_FALCON,
                                                   (void**)&ssl->peerFalconKey);
                    ssl->peerFalconKeyPresent = 0;
                }
                else if ((ret >= 0) && (res == 0)) {
                    WOLFSSL_MSG("Falcon signature verification failed");
                    ret = SIG_VERIFY_E;
                }
            }
        #endif /* HAVE_FALCON */
        #if defined(WOLFSSL_HAVE_MLDSA) && !defined(WOLFSSL_MLDSA_NO_VERIFY)
            if (((ssl->options.peerSigAlgo == mldsa_44_sa_algo) ||
                 (ssl->options.peerSigAlgo == mldsa_65_sa_algo) ||
                 (ssl->options.peerSigAlgo == mldsa_87_sa_algo)) &&
                (ssl->peerMlDsaKeyPresent)) {
                int res = 0;
                WOLFSSL_MSG("Doing ML-DSA peer cert verify");
                ret = wc_MlDsaKey_VerifyCtx(ssl->peerMlDsaKey, sig, args->sigSz,
                                            NULL, 0, args->sigData,
                                            args->sigDataSz, &res);

                if ((ret >= 0) && (res == 1)) {
                    /* CLIENT/SERVER: data verified with public key from
                     * certificate. */
                    ssl->options.peerAuthGood = 1;

                    FreeKey(ssl, DYNAMIC_TYPE_MLDSA,
                            (void**)&ssl->peerMlDsaKey);
                    ssl->peerMlDsaKeyPresent = 0;
                }
                else if ((ret >= 0) && (res == 0)) {
                    WOLFSSL_MSG("ML-DSA signature verification failed");
                    ret = SIG_VERIFY_E;
                }
            }
        #endif /* WOLFSSL_HAVE_MLDSA */
        #if defined(WOLFSSL_HAVE_SLHDSA)
            if (IsSlhDsaSigAlgo(ssl->options.peerSigAlgo) &&
                (ssl->peerSlhDsaKeyPresent)) {
                WOLFSSL_MSG("Doing SLH-DSA peer cert verify");

                /* The advertised signature scheme must match the parameter set
                 * of the peer's certificate key (RFC 8446 4.4.3). The key
                 * params come from the certificate OID, so a mismatch means the
                 * peer is over-claiming its security level; reject it. */
                if ((ssl->peerSlhDsaKey->params == NULL) ||
                    (SlhDsaParamToType((int)ssl->peerSlhDsaKey->params->param)
                        != ssl->options.peerSigAlgo)) {
                    ERROR_OUT(SIG_VERIFY_E, exit_dcv);
                }

                /* wc_SlhDsaKey_Verify returns 0 for a valid signature. */
                ret = wc_SlhDsaKey_Verify(ssl->peerSlhDsaKey, NULL, 0,
                                          args->sigData, args->sigDataSz,
                                          sig, args->sigSz);

                if (ret == 0) {
                    /* CLIENT/SERVER: data verified with public key from
                     * certificate. */
                    ssl->options.peerAuthGood = 1;

                    FreeKey(ssl, DYNAMIC_TYPE_SLHDSA,
                            (void**)&ssl->peerSlhDsaKey);
                    ssl->peerSlhDsaKeyPresent = 0;
                }
                else {
                    /* wc_SlhDsaKey_Verify already returns SIG_VERIFY_E on a
                     * signature mismatch and propagates real errors verbatim
                     * (WC_PENDING_E on the async crypto-callback path, MEMORY_E,
                     * ...), so leave ret unchanged. Flattening everything to
                     * SIG_VERIFY_E would break async resume and mask
                     * diagnostics; the ML-DSA/Falcon blocks above likewise
                     * preserve non-completion return codes. */
                    WOLFSSL_MSG("SLH-DSA signature verification failed");
                }
            }
        #endif /* WOLFSSL_HAVE_SLHDSA */

            /* Check for error */
            if (ret != 0) {
                goto exit_dcv;
            }

        #ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                /* Move forward to the alternative signature. */
                sig += args->sigSz + OPAQUE16_LEN;

                /* Verify the alternative signature */
            #ifndef NO_RSA
                if ((args->altSigAlgo == rsa_pss_sa_algo) &&
                    (ssl->peerRsaKey != NULL) &&
                    (ssl->peerRsaKeyPresent != 0)) {
                    WOLFSSL_MSG("Doing RSA peer cert alt verify");
                    ret = RsaVerify(ssl, rsaSigBuf->buffer,
                                    (word32)rsaSigBuf->length,
                                    &args->output, args->altSigAlgo,
                                    ssl->options.peerHashAlgo, ssl->peerRsaKey,
                    #ifdef HAVE_PK_CALLBACKS
                                    &ssl->buffers.peerRsaKey
                    #else
                                    NULL
                    #endif
                                    );
                    if (ret >= 0) {
                        args->sendSz = ret;
                        ret = 0;
                    }
                }
            #endif /* !NO_RSA */
            #ifdef HAVE_ECC
                if ((args->altSigAlgo == ecc_dsa_sa_algo) &&
                    (ssl->peerEccDsaKeyPresent)) {
                    WOLFSSL_MSG("Doing ECC peer cert alt verify");
                    ret = EccVerify(ssl, sig, args->altSignatureSz,
                                args->altSigData, args->altSigDataSz,
                                ssl->peerEccDsaKey,
                    #ifdef HAVE_PK_CALLBACKS
                                &ssl->buffers.peerEccDsaKey
                    #else
                                NULL
                    #endif
                                );

                    if (ret >= 0) {
                        /* CLIENT/SERVER: data verified with public key from
                        * certificate. */
                        args->altPeerAuthGood = 1;

                        FreeKey(ssl, DYNAMIC_TYPE_ECC,
                                                (void**)&ssl->peerEccDsaKey);
                        ssl->peerEccDsaKeyPresent = 0;
                    }
                }
            #endif /* HAVE_ECC */
            #if defined(HAVE_FALCON)
                if (((args->altSigAlgo == falcon_level1_sa_algo) ||
                     (args->altSigAlgo == falcon_level5_sa_algo)) &&
                    (ssl->peerFalconKeyPresent)) {
                    int res = 0;
                    WOLFSSL_MSG("Doing Falcon peer cert alt verify");
                    ret = wc_falcon_verify_msg(sig, args->altSignatureSz,
                                        args->altSigData, args->altSigDataSz,
                                        &res, ssl->peerFalconKey);

                    if ((ret >= 0) && (res == 1)) {
                        /* CLIENT/SERVER: data verified with public key from
                        * certificate. */
                        args->altPeerAuthGood = 1;

                        FreeKey(ssl, DYNAMIC_TYPE_FALCON,
                                                (void**)&ssl->peerFalconKey);
                        ssl->peerFalconKeyPresent = 0;
                    }
                    else if ((ret >= 0) && (res == 0)) {
                        WOLFSSL_MSG("Falcon signature verification failed");
                        ret = SIG_VERIFY_E;
                    }
                }
            #endif /* HAVE_FALCON */
            #if defined(WOLFSSL_HAVE_MLDSA) && !defined(WOLFSSL_MLDSA_NO_VERIFY)
                if (((args->altSigAlgo == mldsa_44_sa_algo) ||
                     (args->altSigAlgo == mldsa_65_sa_algo) ||
                     (args->altSigAlgo == mldsa_87_sa_algo)) &&
                    (ssl->peerMlDsaKeyPresent)) {
                    int res = 0;
                    WOLFSSL_MSG("Doing ML-DSA peer cert alt verify");
                    ret = wc_MlDsaKey_VerifyCtx(ssl->peerMlDsaKey, sig,
                                        args->altSignatureSz, NULL, 0,
                                        args->altSigData,
                                        args->altSigDataSz, &res);

                    if ((ret >= 0) && (res == 1)) {
                        /* CLIENT/SERVER: data verified with public key from
                        * certificate. */
                        args->altPeerAuthGood = 1;

                        FreeKey(ssl, DYNAMIC_TYPE_MLDSA,
                                            (void**)&ssl->peerMlDsaKey);
                        ssl->peerMlDsaKeyPresent = 0;
                    }
                    else if ((ret >= 0) && (res == 0)) {
                        WOLFSSL_MSG("ML-DSA signature verification failed");
                        ret = SIG_VERIFY_E;
                    }
                }
            #endif /* WOLFSSL_HAVE_MLDSA */

                /* Check for error */
                if (ret != 0) {
                    goto exit_dcv;
                }
            }
        #endif /* WOLFSSL_DUAL_ALG_CERTS */

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_VERIFY;
        } /* case TLS_ASYNC_DO */
        FALL_THROUGH;

        case TLS_ASYNC_VERIFY:
        {
        #if !defined(NO_RSA) && defined(WC_RSA_PSS)
            if (ssl->peerRsaKey != NULL && ssl->peerRsaKeyPresent != 0) {
                int sigAlgo = ssl->options.peerSigAlgo;
            #ifdef WOLFSSL_DUAL_ALG_CERTS
                /* Check if our alternative signature was RSA */
                if (ssl->sigSpec != NULL &&
                    *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH &&
                    ssl->options.peerSigAlgo != rsa_pss_sa_algo) {
                    sigAlgo = args->altSigAlgo;
                }
            #endif
                ret = CheckRSASignature(ssl, sigAlgo,
                        ssl->options.peerHashAlgo, args->output, args->sendSz);
                if (ret != 0)
                    goto exit_dcv;

                /* CLIENT/SERVER: data verified with public key from
                 * certificate. */
                ssl->peerRsaKeyPresent = 0;
                FreeKey(ssl, DYNAMIC_TYPE_RSA, (void**)&ssl->peerRsaKey);
            #ifdef WOLFSSL_DUAL_ALG_CERTS
                /* Check if our alternative signature was RSA */
                if (ssl->sigSpec != NULL &&
                    *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH &&
                    ssl->options.peerSigAlgo != rsa_pss_sa_algo) {
                    args->altPeerAuthGood = 1;
                }
                else
            #endif
                    ssl->options.peerAuthGood = 1;
            }
        #endif /* !NO_RSA && WC_RSA_PSS */

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_FINALIZE;
        } /* case TLS_ASYNC_VERIFY */
        FALL_THROUGH;

        case TLS_ASYNC_FINALIZE:
        {
#ifdef WOLFSSL_DUAL_ALG_CERTS
            if (ssl->options.peerAuthGood &&
                ssl->sigSpec != NULL &&
                *ssl->sigSpec == WOLFSSL_CKS_SIGSPEC_BOTH) {
                ssl->options.peerAuthGood = args->altPeerAuthGood;
            }
#endif /* WOLFSSL_DUAL_ALG_CERTS */
            ssl->options.havePeerVerify = 1;

            /* Set final index */
            args->idx += args->sz;
            *inOutIdx = args->idx;

            /* Advance state and proceed */
            ssl->options.asyncState = TLS_ASYNC_END;

        #if !defined(NO_WOLFSSL_CLIENT)
            if (ssl->options.side == WOLFSSL_CLIENT_END)
                ssl->options.serverState = SERVER_CERT_VERIFY_COMPLETE;
        #endif
        } /* case TLS_ASYNC_FINALIZE */
        FALL_THROUGH;

        case TLS_ASYNC_END:
        {
            break;
        }

        default:
            ret = INPUT_CASE_ERROR;
    } /* switch(ssl->options.asyncState) */

exit_dcv:

    WOLFSSL_LEAVE("DoTls13CertificateVerify", ret);
    WOLFSSL_END(WC_FUNC_CERTIFICATE_VERIFY_DO);

#ifdef WOLFSSL_ASYNC_CRYPT
    /* Handle async operation */
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E)) {
        /* Mark message as not received so it can process again */
        ssl->msgsReceived.got_certificate_verify = 0;

        return ret;
    }
    else
#endif /* WOLFSSL_ASYNC_CRYPT */
    if (ret != 0) {
        WOLFSSL_ERROR_VERBOSE(ret);

        if (ret != WC_NO_ERR_TRACE(INVALID_PARAMETER)) {
            SendAlert(ssl, alert_fatal, decrypt_error);
        }
    }

    /* Final cleanup */
    FreeDcv13Args(ssl, args);
    FreeKeyExchange(ssl);
#ifdef WOLFSSL_ASYNC_IO
    /* Cleanup async */
    FreeAsyncCtx(ssl, 0);
#endif
#ifdef WOLFSSL_ASYNC_CRYPT
    /* Replays skip the sanity check that re-sets got_certificate_verify;
     * restore on completion or Finished reports out-of-order. */
    if (ret == 0 && ssl->msgsReceived.got_certificate_verify == 0) {
        ssl->msgsReceived.got_certificate_verify = 1;
    }
#endif

    return ret;
}
#endif /* !NO_RSA || HAVE_ECC || HAVE_ED25519 || HAVE_ED448 ||
        * HAVE_FALCON || WOLFSSL_HAVE_MLDSA || WOLFSSL_HAVE_SLHDSA */
#endif /* !NO_CERTS */

#ifdef WOLFSSL_POST_HANDSHAKE_AUTH
/* Message is being processed after the enclosing handshake completed. Whatever
 * resumption, PSK or deferred (post-handshake) verification excused during that
 * handshake, a later post-handshake exchange has to stand on its own. */
#define TLS13_AFTER_HANDSHAKE(ssl)  ((ssl)->options.handShakeDone)
#else
#define TLS13_AFTER_HANDSHAKE(ssl)  0
#endif

/* Parse and handle a TLS v1.3 Finished message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of Finished.
 *           On exit, the index of byte after the Finished message and padding.
 * size      Length of message data.
 * totalSz   Length of remaining data in the message buffer.
 * sniff     Indicates whether we are sniffing packets.
 * returns 0 on success and otherwise failure.
 */
int DoTls13Finished(WOLFSSL* ssl, const byte* input, word32* inOutIdx,
                           word32 size, word32 totalSz, int sniff)
{
    int    ret;
    word32 finishedSz = 0;
    byte*  secret;
    byte   mac[WC_MAX_DIGEST_SIZE];

    WOLFSSL_START(WC_FUNC_FINISHED_DO);
    WOLFSSL_ENTER("DoTls13Finished");

#if !defined(NO_CERTS) && !defined(WOLFSSL_NO_CLIENT_AUTH)
    /* verify the client sent certificate if required */
    if (ssl->options.side == WOLFSSL_SERVER_END &&
            (!ssl->options.resuming || TLS13_AFTER_HANDSHAKE(ssl)) &&
            (ssl->options.mutualAuth || ssl->options.failNoCert)) {
#ifdef OPENSSL_COMPATIBLE_DEFAULTS
        if (ssl->options.isPSK && !TLS13_AFTER_HANDSHAKE(ssl)) {
            WOLFSSL_MSG("TLS v1.3 client used PSK but cert required. Allowing "
                        "for OpenSSL compatibility");
        }
        else
#endif
        if (
        #ifdef WOLFSSL_POST_HANDSHAKE_AUTH
            /* Exempt only the enclosing handshake; a post-handshake exchange
             * still requires a peer certificate and a valid
             * CertificateVerify. */
            (!ssl->options.verifyPostHandshake || TLS13_AFTER_HANDSHAKE(ssl)) &&
        #endif
            (!ssl->options.havePeerCert || !ssl->options.havePeerVerify)) {
            ret = NO_PEER_CERT; /* NO_PEER_VERIFY */
            WOLFSSL_MSG("TLS v1.3 client did not present peer cert");
            DoCertFatalAlert(ssl, ret);
            goto cleanup;
        }
    }
#endif

#if !defined(NO_CERTS) && !defined(NO_PSK) && \
    defined(WOLFSSL_CERT_WITH_EXTERN_PSK)
    /* Verify the server sent a certificate if requested */
    if (ssl->options.side == WOLFSSL_CLIENT_END && ssl->options.pskNegotiated &&
            ssl->options.failNoCert) {
        if ((TLSX_Find(ssl->extensions, TLSX_CERT_WITH_EXTERN_PSK) != NULL) &&
                (!ssl->options.havePeerCert || !ssl->options.havePeerVerify)) {
            ret = NO_PEER_CERT;
            WOLFSSL_MSG("TLS v1.3 server did not present peer cert");
            DoCertFatalAlert(ssl, ret);
            goto cleanup;
        }
    }
#endif

    /* check against totalSz */
    if (*inOutIdx + size > totalSz) {
        ret = BUFFER_E;
        goto cleanup;
    }

#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    ret = tsip_Tls13HandleFinished(ssl, input, inOutIdx, size, totalSz);
    if (ret == 0) {
        ssl->options.serverState = SERVER_FINISHED_COMPLETE;
        goto cleanup;
    }
    if (ret == WC_NO_ERR_TRACE(VERIFY_FINISHED_ERROR)) {
        SendAlert(ssl, alert_fatal, decrypt_error);
        goto cleanup;
    }
    if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE)) {
        /* other errors */
        goto cleanup;
    }
    ret = 0;
#endif /* WOLFSSL_RENESAS_TSIP_TLS */

    if (ssl->options.handShakeDone) {
        ret = DeriveFinishedSecret(ssl, ssl->clientSecret,
                                   ssl->keys.client_write_MAC_secret,
                                   WOLFSSL_CLIENT_END);
        if (ret != 0)
            goto cleanup;

        secret = ssl->keys.client_write_MAC_secret;
    }
    else if (ssl->options.side == WOLFSSL_CLIENT_END) {
        /* All the handshake messages have been received to calculate
         * client and server finished keys.
         */
        ret = DeriveFinishedSecret(ssl, ssl->clientSecret,
                                   ssl->keys.client_write_MAC_secret,
                                   WOLFSSL_CLIENT_END);
        if (ret != 0)
            goto cleanup;

        ret = DeriveFinishedSecret(ssl, ssl->serverSecret,
                                   ssl->keys.server_write_MAC_secret,
                                   WOLFSSL_SERVER_END);
        if (ret != 0)
            goto cleanup;

        secret = ssl->keys.server_write_MAC_secret;
    }
    else {
        secret = ssl->keys.client_write_MAC_secret;
    }

    if (sniff == NO_SNIFF) {

        ret = BuildTls13HandshakeHmac(ssl, secret, mac, &finishedSz);
    #ifdef WOLFSSL_HAVE_TLS_UNIQUE
        if (finishedSz > TLS_FINISHED_SZ_MAX) {
            ret = BUFFER_ERROR;
            goto cleanup;
        }
        if (ssl->options.side == WOLFSSL_CLIENT_END) {
            XMEMCPY(ssl->serverFinished, mac, finishedSz);
            ssl->serverFinished_len = (byte)finishedSz;
        }
        else {
            XMEMCPY(ssl->clientFinished, mac, finishedSz);
            ssl->clientFinished_len = (byte)finishedSz;
        }
    #endif /* WOLFSSL_HAVE_TLS_UNIQUE */
        if (ret != 0)
            goto cleanup;
        if (size != finishedSz) {
            ret = BUFFER_ERROR;
            goto cleanup;
        }
    }

#ifdef WOLFSSL_CALLBACKS
    if (ssl->hsInfoOn) AddPacketName(ssl, "Finished");
    if (ssl->toInfoOn) AddLateName("Finished", &ssl->timeoutInfo);
#endif

    if (sniff == NO_SNIFF) {
        /* Actually check verify data. */
        if (size > WC_MAX_DIGEST_SIZE ||
                ConstantCompare(input + *inOutIdx, mac, size) != 0){
            WOLFSSL_MSG("Verify finished error on hashes");
            SendAlert(ssl, alert_fatal, decrypt_error);
            WOLFSSL_ERROR_VERBOSE(VERIFY_FINISHED_ERROR);
            ret = VERIFY_FINISHED_ERROR;
            goto cleanup;
        }
    }

    *inOutIdx += size;

#ifndef NO_WOLFSSL_SERVER
    if (ssl->options.side == WOLFSSL_SERVER_END &&
                                                  !ssl->options.handShakeDone) {
#ifdef WOLFSSL_EARLY_DATA
        if (ssl->earlyData != no_early_data) {
            if ((ret = DeriveTls13Keys(ssl, no_key, DECRYPT_SIDE_ONLY, 1)) != 0)
                goto cleanup;
        }
#endif
        /* Setup keys for application data messages from client. */
        if ((ret = SetKeysSide(ssl, DECRYPT_SIDE_ONLY)) != 0)
            goto cleanup;
    }
#endif

#ifndef NO_WOLFSSL_CLIENT
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        ssl->options.serverState = SERVER_FINISHED_COMPLETE;
#endif
#ifndef NO_WOLFSSL_SERVER
    if (ssl->options.side == WOLFSSL_SERVER_END) {
        ssl->options.clientState = CLIENT_FINISHED_COMPLETE;
        ssl->options.handShakeState = HANDSHAKE_DONE;
        ssl->options.handShakeDone  = 1;
    }
#endif

#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_EARLY_DATA)
    if (ssl->options.dtls && ssl->earlyData > early_data_ext) {
        /* DTLSv1.3 has no EndOfearlydata messages. We stop processing EarlyData
           as soon we receive the client's finished message */
        ssl->earlyData = done_early_data;
    }
#endif /* WOLFSSL_DTLS13 && WOLFSSL_EARLY_DATA */
#if defined(WOLFSSL_QUIC) && defined(WOLFSSL_EARLY_DATA)
    if (WOLFSSL_IS_QUIC(ssl) && ssl->earlyData > early_data_ext) {
        /* QUIC has no EndOfEarlyData messages. We stop processing EarlyData
           as soon we receive the client's finished message */
        ssl->earlyData = done_early_data;
    }
#endif /* WOLFSSL_QUIC && WOLFSSL_EARLY_DATA */

    ret = 0;
cleanup:
    ForceZero(mac, sizeof(mac));
    WOLFSSL_LEAVE("DoTls13Finished", ret);
    WOLFSSL_END(WC_FUNC_FINISHED_DO);

    return ret;
}

#if !defined(NO_WOLFSSL_CLIENT) || !defined(NO_WOLFSSL_SERVER)
/* Send the TLS v1.3 Finished message.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
static int SendTls13Finished(WOLFSSL* ssl)
{
    byte  finishedSz = ssl->specs.hash_size;
    byte* input;
    byte* output;
    int   ret = 0; /* the resume goto can skip every build-phase assign */
    int   headerSz = HANDSHAKE_HEADER_SZ;
    int   outputSz;
    byte* secret;

#ifdef WOLFSSL_DTLS13
    int dtlsRet = 0, isDtls = 0;
#endif /* WOLFSSL_DTLS13 */

    WOLFSSL_START(WC_FUNC_FINISHED_SEND);
    WOLFSSL_ENTER("SendTls13Finished");

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        headerSz = DTLS_HANDSHAKE_HEADER_SZ;
        /* using isDtls instead of ssl->options.dtls will abide clang static
           analyzer on using an uninitialized value */
        isDtls = 1;
    }
#endif /* WOLFSSL_DTLS13 */

    /* Post-send key-schedule resume: the Finished record is already
     * queued, so skip the build phase (re-running would queue it twice). */
    if (ssl->kdfDeriveStep > 0)
        goto tls13_send_finished_derives;

    ssl->options.buildingMsg = 1;

    outputSz = WC_MAX_DIGEST_SIZE + headerSz + MAX_MSG_EXTRA;
#ifdef WOLFSSL_DTLS13
    /* MAX_MSG_EXTRA reserves RECORD_HEADER_SZ, which is the size of the DTLS
     * 1.3 unified header without the CID, so only the CID is missing. */
    if (isDtls)
        outputSz += DtlsGetCidTxSize(ssl);
#endif /* WOLFSSL_DTLS13 */
    /* Check buffers are big enough and grow if needed. */
    if ((ret = CheckAvailableSize(ssl, outputSz)) != 0)
        return ret;

    /* get output buffer */
    output = GetOutputBuffer(ssl);
    input = output + RECORD_HEADER_SZ;

#ifdef WOLFSSL_DTLS13
    if (isDtls)
        input = output + Dtls13GetRlHeaderLength(ssl, 1);
#endif /* WOLFSSL_DTLS13 */

    AddTls13HandShakeHeader(input, (word32)finishedSz, 0, (word32)finishedSz,
            finished, ssl);

#ifdef WOLFSSL_ASYNC_CRYPT
    /* A suspended build already wrote the verify data and hashed it;
     * recomputing would hash the body twice. */
    if (ssl->options.buildArgs13Set)
        goto tls13_send_finished_encrypt;
#endif

#if defined(WOLFSSL_RENESAS_TSIP_TLS)
    if (ssl->options.side == WOLFSSL_CLIENT_END) {
        ret = tsip_Tls13SendFinished(ssl, output, outputSz, input, 1);
        if (ret != WC_NO_ERR_TRACE(CRYPTOCB_UNAVAILABLE)) {
            return ret;
        }
        ret = 0;
    }
#endif /* WOLFSSL_RENESAS_TSIP_TLS */

    /* make finished hashes */
    if (ssl->options.handShakeDone) {
        ret = DeriveFinishedSecret(ssl, ssl->clientSecret,
                                   ssl->keys.client_write_MAC_secret,
                                   WOLFSSL_CLIENT_END);
        if (ret != 0)
            return ret;

        secret = ssl->keys.client_write_MAC_secret;
    }
    else if (ssl->options.side == WOLFSSL_CLIENT_END)
        secret = ssl->keys.client_write_MAC_secret;
    else {
        /* All the handshake messages have been done to calculate client and
         * server finished keys.
         */
        ret = DeriveFinishedSecret(ssl, ssl->clientSecret,
                                   ssl->keys.client_write_MAC_secret,
                                   WOLFSSL_CLIENT_END);
        if (ret != 0)
            return ret;

        ret = DeriveFinishedSecret(ssl, ssl->serverSecret,
                                   ssl->keys.server_write_MAC_secret,
                                   WOLFSSL_SERVER_END);
        if (ret != 0)
            return ret;

        secret = ssl->keys.server_write_MAC_secret;
    }
    ret = BuildTls13HandshakeHmac(ssl, secret, &input[headerSz], NULL);
    if (ret != 0)
        return ret;
    #ifdef WOLFSSL_HAVE_TLS_UNIQUE
        if (ssl->options.side == WOLFSSL_CLIENT_END) {
            XMEMCPY(ssl->clientFinished, &input[headerSz], finishedSz);
            ssl->clientFinished_len = finishedSz;
        }
        else {
            XMEMCPY(ssl->serverFinished, &input[headerSz], finishedSz);
            ssl->serverFinished_len = finishedSz;
        }
    #endif /* WOLFSSL_HAVE_TLS_UNIQUE */

#ifdef WOLFSSL_ASYNC_CRYPT
tls13_send_finished_encrypt:
#endif

#ifdef WOLFSSL_DTLS13
    if (isDtls) {
        dtlsRet = Dtls13HandshakeSend(ssl, output, (word16)outputSz,
            (word16)(Dtls13GetRlHeaderLength(ssl, 1) + headerSz + finishedSz), finished,
            1);
        if (dtlsRet != 0 && dtlsRet != WC_NO_ERR_TRACE(WANT_WRITE))
            return dtlsRet;

    } else
#endif /* WOLFSSL_DTLS13 */
    {
        /* This message is always encrypted. */
        int sendSz = BuildTls13Message(ssl, output, outputSz, input,
                                   headerSz + finishedSz, handshake, 1, 0,
                                   TLS13_HS_ASYNC_OKAY);
        if (sendSz < 0) {
        #ifdef WOLFSSL_ASYNC_CRYPT
            /* Propagate a pending record encryption rather than reporting it
             * as a build failure: the retry resumes the record. */
            if (sendSz == WC_NO_ERR_TRACE(WC_PENDING_E))
                return sendSz;
        #endif
            WOLFSSL_ERROR_VERBOSE(BUILD_MSG_ERROR);
            return BUILD_MSG_ERROR;
        }

        #if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
            if (ssl->hsInfoOn) AddPacketName(ssl, "Finished");
            if (ssl->toInfoOn) {
                ret = AddPacketInfo(ssl, "Finished", handshake, output, sendSz,
                              WRITE_PROTO, 0, ssl->heap);
                if (ret != 0)
                    return ret;
            }
        #endif

        ssl->buffers.outputBuffer.length += (word32)sendSz;
        ssl->options.buildingMsg = 0;
    }

    /* Build phase complete; steps below are individually resumable. */
    ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_ENTERED;
tls13_send_finished_derives:

    if (ssl->options.side == WOLFSSL_SERVER_END) {
#ifdef WOLFSSL_EARLY_DATA
        byte storeTrafficDecKeys = ssl->earlyData == no_early_data;
#endif
        /* Can send application data now. */
        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_ENTERED) {
            ret = DeriveMasterSecret(ssl);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_MASTER_SECRET;
        }
        /* Last use of preMasterSecret - zeroize as soon as possible. */
        ForceZero(ssl->arrays->preMasterSecret, ssl->arrays->preMasterSz);
#ifdef WOLFSSL_EARLY_DATA

#ifdef WOLFSSL_DTLS13
        /* DTLS13 dynamically change keys and it needs all
           the keys in ssl->keys to save the keying material */
        if (isDtls)
            storeTrafficDecKeys = 1;
#endif /* WOLFSSL_DTLS13 */

        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_MASTER_SECRET) {
            ret = DeriveTls13Keys(ssl, traffic_key, ENCRYPT_SIDE_ONLY, 1);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_ENC_TRAFFIC_KEYS;
        }
        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_ENC_TRAFFIC_KEYS) {
            ret = DeriveTls13Keys(ssl, traffic_key, DECRYPT_SIDE_ONLY,
                                  storeTrafficDecKeys);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_TRAFFIC_KEYS;
        }
#else
        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_ENC_TRAFFIC_KEYS) {
            ret = DeriveTls13Keys(ssl, traffic_key, ENCRYPT_AND_DECRYPT_SIDE,
                                  1);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_TRAFFIC_KEYS;
        }
#endif
        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_TRAFFIC_KEYS) {
            ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_ENC_KEYS_SET;
        }

#ifdef WOLFSSL_DTLS13
        if (isDtls) {
            w64wrapper epochTraffic0;
            epochTraffic0 = w64From32(0, DTLS13_EPOCH_TRAFFIC0);
            ssl->dtls13Epoch = epochTraffic0;
            ssl->dtls13PeerEpoch = epochTraffic0;

            if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_ENC_KEYS_SET) {
                ret = Dtls13SetEpochKeys(ssl, epochTraffic0,
                                         ENCRYPT_AND_DECRYPT_SIDE);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                    return ret;
                }
                ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_DTLS_TRAFFIC_EPOCH;
            }
        }
#endif /* WOLFSSL_DTLS13 */

    }

    if (ssl->options.side == WOLFSSL_CLIENT_END &&
                                                  !ssl->options.handShakeDone) {
#ifdef WOLFSSL_EARLY_DATA
        if (ssl->earlyData != no_early_data) {
            if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_DTLS_TRAFFIC_EPOCH) {
                ret = DeriveTls13Keys(ssl, no_key, ENCRYPT_SIDE_ONLY, 1);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                    return ret;
                }
                ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_EARLY_ENC_KEYS;
            }
        }
#endif
        /* Setup keys for application data messages. */
        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_EARLY_ENC_KEYS) {
            ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_EARLY_KEYS_SET;
        }

#if defined(HAVE_SESSION_TICKET)
        if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_EARLY_KEYS_SET) {
            ret = DeriveResumptionSecret(ssl, ssl->session->masterSecret);
            if (ret != 0) {
                if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                return ret;
            }
            ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_RESUMPTION_SECRET;
        }
#endif

#ifdef WOLFSSL_DTLS13
        if (isDtls) {
            w64wrapper epochTraffic0;
            epochTraffic0 = w64From32(0, DTLS13_EPOCH_TRAFFIC0);
            ssl->dtls13Epoch = epochTraffic0;
            ssl->dtls13PeerEpoch = epochTraffic0;

            /* Step-guarded like every other derive in this function, so a
             * pend resumes here and a real error clears the resume state. */
            if (ssl->kdfDeriveStep <= TLS13_SEND_KDF_FIN_RESUMPTION_SECRET) {
                ret = Dtls13SetEpochKeys(
                    ssl, epochTraffic0, ENCRYPT_AND_DECRYPT_SIDE);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;
                    return ret;
                }
                ssl->kdfDeriveStep = TLS13_SEND_KDF_FIN_DTLS_EPOCH_SET;
            }
        }
#endif /* WOLFSSL_DTLS13 */
    }

    ssl->kdfDeriveStep = TLS13_SEND_KDF_NONE;

#ifndef NO_WOLFSSL_CLIENT
    if (ssl->options.side == WOLFSSL_CLIENT_END) {
        ssl->options.clientState = CLIENT_FINISHED_COMPLETE;
        ssl->options.handShakeState = HANDSHAKE_DONE;
        ssl->options.handShakeDone  = 1;
    }
#endif
#ifndef NO_WOLFSSL_SERVER
    if (ssl->options.side == WOLFSSL_SERVER_END) {
        ssl->options.serverState = SERVER_FINISHED_COMPLETE;
    }
#endif

#ifdef WOLFSSL_DTLS13
    if (isDtls) {
        WOLFSSL_LEAVE("SendTls13Finished", ret);
        WOLFSSL_END(WC_FUNC_FINISHED_SEND);

        return dtlsRet;
    }
#endif /* WOLFSSL_DTLS13 */

    if ((ret = SendBuffered(ssl)) != 0)
        return ret;

    WOLFSSL_LEAVE("SendTls13Finished", ret);
    WOLFSSL_END(WC_FUNC_FINISHED_SEND);

    return ret;
}
#endif /* !NO_WOLFSSL_CLIENT || !NO_WOLFSSL_SERVER */

/* RFC 9846 Section 4.7.3: a TLS 1.3 sender MUST NOT allow its number of key
 * updates to exceed 2^48-1. DTLS 1.3 bounds the epoch instead (RFC 9147
 * Section 4.2.1), so this only covers TLS.
 *
 * ssl  The SSL/TLS object.
 * returns 1 when a further KeyUpdate would exceed the limit, 0 otherwise.
 */
int Tls13KeyUpdateLimitReached(WOLFSSL* ssl)
{
    if (ssl->options.dtls)
        return 0;

    return w64GTE(ssl->keys.keyUpdateCount,
                  w64From32(TLS13_KEY_UPDATE_MAX_HI32,
                            TLS13_KEY_UPDATE_MAX_LO32));
}

/* handle generation TLS v1.3 key_update (24) */
/* Send the TLS v1.3 KeyUpdate message.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
int SendTls13KeyUpdate(WOLFSSL* ssl)
{
    byte*  input;
    byte*  output;
    int    ret;
    int    headerSz = HANDSHAKE_HEADER_SZ;
    int    outputSz;
    word32 i = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;

    WOLFSSL_START(WC_FUNC_KEY_UPDATE_SEND);
    WOLFSSL_ENTER("SendTls13KeyUpdate");

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        /* RFC 9147 Section 4.2.1: do not send a KeyUpdate that would advance
         * the sending epoch beyond 2^48-1. */
        if (w64GTE(ssl->dtls13Epoch,
                   w64From32(DTLS13_EPOCH_MAX_HI32, DTLS13_EPOCH_MAX_LO32))) {
            WOLFSSL_MSG("DTLS 1.3 sending epoch at maximum; refusing KeyUpdate");
            return BAD_STATE_E;
        }
        i = Dtls13GetRlHeaderLength(ssl, 1) + DTLS_HANDSHAKE_HEADER_SZ;
    }
#endif /* WOLFSSL_DTLS13 */

    /* RFC 9846 Section 4.7.3: a sending implementation MUST NOT allow its
     * number of key updates to exceed 2^48-1. Receivers MUST NOT enforce this
     * on the peer. */
    if (Tls13KeyUpdateLimitReached(ssl)) {
        WOLFSSL_MSG("TLS 1.3 key update count at maximum; refusing KeyUpdate");
        return BAD_STATE_E;
    }

    /* i already carries the real record and handshake header lengths.
     * MAX_MSG_EXTRA only budgets RECORD_HEADER_SZ. */
    outputSz = (int)i + OPAQUE8_LEN + MAX_MSG_EXTRA;
    /* Check buffers are big enough and grow if needed. */
    if ((ret = CheckAvailableSize(ssl, outputSz)) != 0)
        return ret;

    /* get output buffer */
    output = GetOutputBuffer(ssl);
    input = output + RECORD_HEADER_SZ;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        input = output + Dtls13GetRlHeaderLength(ssl, 1);
#endif /* WOLFSSL_DTLS13 */

    AddTls13Headers(output, OPAQUE8_LEN, key_update, ssl);

    /* If:
     *   1. I haven't sent a KeyUpdate requesting a response and
     *   2. This isn't responding to peer KeyUpdate requiring a response then,
     * I want a response.
     */
    ssl->keys.updateResponseReq = output[i++] =
         !ssl->keys.updateResponseReq && !ssl->keys.keyUpdateRespond;
    /* Sent response, no longer need to respond. */
    ssl->keys.keyUpdateRespond = 0;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        ret = Dtls13HandshakeSend(ssl, output, (word16)outputSz,
            OPAQUE8_LEN + Dtls13GetRlHeaderLength(ssl, 1) +
                DTLS_HANDSHAKE_HEADER_SZ,
            key_update, 0);
    }
    else
#endif /* WOLFSSL_DTLS13 */
    {
        /* This message is always encrypted. */
        int sendSz = BuildTls13Message(ssl, output, outputSz, input,
                                   headerSz + OPAQUE8_LEN, handshake, 0, 0, 0);
        if (sendSz < 0)
            return BUILD_MSG_ERROR;

        #if defined(WOLFSSL_CALLBACKS) || defined(OPENSSL_EXTRA)
            if (ssl->hsInfoOn) AddPacketName(ssl, "KeyUpdate");
            if (ssl->toInfoOn) {
                ret = AddPacketInfo(ssl, "KeyUpdate", handshake, output, sendSz,
                              WRITE_PROTO, 0, ssl->heap);
                if (ret != 0)
                    return ret;
            }
        #endif

        ssl->buffers.outputBuffer.length += (word32)sendSz;

        ret = SendBuffered(ssl);


        if (ret != 0 && ret != WC_NO_ERR_TRACE(WANT_WRITE))
            return ret;
    }

    /* In DTLS we must wait for the ack before setting up the new keys */
    if (!ssl->options.dtls) {

        /* Future traffic uses new encryption keys. */
        if ((ret = DeriveTls13Keys(
                       ssl, update_traffic_key, ENCRYPT_SIDE_ONLY, 1))
            != 0)
            return ret;
        if ((ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY)) != 0)
            return ret;

        /* Count this key update against the RFC 9846 sender limit. */
        w64Increment(&ssl->keys.keyUpdateCount);
    }


    WOLFSSL_LEAVE("SendTls13KeyUpdate", ret);
    WOLFSSL_END(WC_FUNC_KEY_UPDATE_SEND);

    return ret;
}

/* handle processing TLS v1.3 key_update (24) */
/* Parse and handle a TLS v1.3 KeyUpdate message.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of Finished.
 *           On exit, the index of byte after the Finished message and padding.
 * totalSz   The length of the current handshake message.
 * returns 0 on success and otherwise failure.
 */
static int DoTls13KeyUpdate(WOLFSSL* ssl, const byte* input, word32* inOutIdx,
                            word32 totalSz)
{
    int    ret;
    word32 i = *inOutIdx;

    WOLFSSL_START(WC_FUNC_KEY_UPDATE_DO);
    WOLFSSL_ENTER("DoTls13KeyUpdate");

    /* check against totalSz */
    if (OPAQUE8_LEN != totalSz)
        return BUFFER_E;

    switch (input[i]) {
        case update_not_requested:
            /* This message in response to any outstanding request. */
            ssl->keys.keyUpdateRespond = 0;
            ssl->keys.updateResponseReq = 0;
            break;
        case update_requested:
            /* New key update requiring a response. */
            ssl->keys.keyUpdateRespond = 1;
            break;
        default:
            WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
            return INVALID_PARAMETER;
    }

    /* Move index to byte after message. */
    *inOutIdx += totalSz;

    /* Future traffic uses new decryption keys. */
    if ((ret = DeriveTls13Keys(ssl, update_traffic_key, DECRYPT_SIDE_ONLY, 1))
                                                                         != 0) {
        return ret;
    }
    if ((ret = SetKeysSide(ssl, DECRYPT_SIDE_ONLY)) != 0)
        return ret;

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls) {
        /* Increment on a local copy so ssl->dtls13PeerEpoch is left
         * untouched when the check fails. */
        w64wrapper newEpoch = ssl->dtls13PeerEpoch;
        w64Increment(&newEpoch);

        /* RFC 9147 Section 8: the 2^48-1 cap is sender-only; receivers MUST
         * NOT enforce it. Guard only the wrap-to-zero (Section 4.2.1). */
        if (w64IsZero(newEpoch))
            return BAD_STATE_E;

        ssl->dtls13PeerEpoch = newEpoch;

        ret = Dtls13SetEpochKeys(ssl, ssl->dtls13PeerEpoch, DECRYPT_SIDE_ONLY);
        if (ret != 0)
            return ret;
    }
#endif /* WOLFSSL_DTLS13 */

    if (ssl->keys.keyUpdateRespond) {

#ifdef WOLFSSL_DTLS13
        /* we already sent a keyUpdate (either in response to a previous
           KeyUpdate or initiated by the application) and we are waiting for the
           ack. We can't send a new KeyUpdate right away but to honor the RFC we
           should send another KeyUpdate after the one in-flight is acked. We
           don't do that as it looks redundant, it will make the code more
           complex and I don't see a good use case for that. */
        if (ssl->options.dtls && ssl->dtls13WaitKeyUpdateAck) {
            ssl->keys.keyUpdateRespond = 0;
            return 0;
        }
#endif /* WOLFSSL_DTLS13 */

#if defined(HAVE_WRITE_DUP) && defined(WOLFSSL_TLS13)
        /* Read side cannot write; delegate the response to the write side.
         * The key update cap is deliberately not checked here: the two sides
         * are separate WOLFSSL objects with separate keys, and only the write
         * side ever sends a KeyUpdate, so this object's keyUpdateCount is not
         * the one the limit applies to. The check is applied on the write side
         * in wolfssl_write_dup_do_tls13_work(). */
        if (ssl->dupWrite != NULL && ssl->dupSide == READ_DUP_SIDE) {
            if (wc_LockMutex(&ssl->dupWrite->dupMutex) != 0)
                return BAD_MUTEX_E;
            ssl->dupWrite->keyUpdateRespond = 1;
            wc_UnLockMutex(&ssl->dupWrite->dupMutex);
            ssl->keys.keyUpdateRespond = 0;
            return 0;
        }
#endif /* HAVE_WRITE_DUP && WOLFSSL_TLS13 */

        /* RFC 9846 Section 4.7.3: a sender that would exceed the key update
         * limit "MUST NOT send its own KeyUpdate ... and SHOULD instead ignore
         * the 'update_requested' flag". Dropping the response rather than
         * failing keeps the connection alive on the current keys until the
         * Section 5.5 data limits eventually force it closed. */
        if (Tls13KeyUpdateLimitReached(ssl)) {
            WOLFSSL_MSG("Key update limit reached; ignoring update_requested");
            ssl->keys.keyUpdateRespond = 0;
            return 0;
        }

#ifndef WOLFSSL_RW_THREADED
        return SendTls13KeyUpdate(ssl);
#else
        ssl->options.sendKeyUpdate = 1;
        return 0;
#endif
    }

    WOLFSSL_LEAVE("DoTls13KeyUpdate", ret);
    WOLFSSL_END(WC_FUNC_KEY_UPDATE_DO);

    return 0;
}

#ifdef WOLFSSL_EARLY_DATA
#ifndef NO_WOLFSSL_CLIENT
/* Send the TLS v1.3 EndOfEarlyData message to indicate that there will be no
 * more early application data.
 * The encryption key now changes to the pre-calculated handshake key.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success and otherwise failure.
 */
static int SendTls13EndOfEarlyData(WOLFSSL* ssl)
{
    byte*  output;
    int    ret;
    int    sendSz;
    word32 length;
    word32 idx = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;

    WOLFSSL_START(WC_FUNC_END_OF_EARLY_DATA_SEND);
    WOLFSSL_ENTER("SendTls13EndOfEarlyData");

    length = 0;
    sendSz = (int)(idx + length + MAX_MSG_EXTRA);
    ssl->options.buildingMsg = 1;

    /* Check buffers are big enough and grow if needed. */
    if ((ret = CheckAvailableSize(ssl, sendSz)) != 0)
        return ret;

    /* Get position in output buffer to write new message to. */
    output = GetOutputBuffer(ssl);

    /* Put the record and handshake headers on. */
    AddTls13Headers(output, length, end_of_early_data, ssl);

    /* This message is always encrypted. */
    sendSz = BuildTls13Message(ssl, output, sendSz, output + RECORD_HEADER_SZ,
                               idx - RECORD_HEADER_SZ, handshake, 1, 0, 0);
    if (sendSz < 0)
        return sendSz;

    ssl->buffers.outputBuffer.length += sendSz;

    if ((ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY)) != 0)
        return ret;

    ssl->options.buildingMsg = 0;
    if (!ssl->options.groupMessages)
        ret = SendBuffered(ssl);

    ssl->earlyData = done_early_data;

    WOLFSSL_LEAVE("SendTls13EndOfEarlyData", ret);
    WOLFSSL_END(WC_FUNC_END_OF_EARLY_DATA_SEND);

    return ret;
}
#endif /* !NO_WOLFSSL_CLIENT */

#ifndef NO_WOLFSSL_SERVER
/* handle processing of TLS 1.3 end_of_early_data (5) */
/* Parse the TLS v1.3 EndOfEarlyData message that indicates that there will be
 * no more early application data.
 * The decryption key now changes to the pre-calculated handshake key.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success and otherwise failure.
 */
static int DoTls13EndOfEarlyData(WOLFSSL* ssl, const byte* input,
                                 word32* inOutIdx, word32 size)
{
    int    ret;
    word32 begin = *inOutIdx;

    (void)input;

    WOLFSSL_START(WC_FUNC_END_OF_EARLY_DATA_DO);
    WOLFSSL_ENTER("DoTls13EndOfEarlyData");

    if ((*inOutIdx - begin) != size)
        return BUFFER_ERROR;

    if (ssl->earlyData == no_early_data) {
        WOLFSSL_MSG("EndOfEarlyData received unexpectedly");
        SendAlert(ssl, alert_fatal, unexpected_message);
        WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
        return OUT_OF_ORDER_E;
    }

    ssl->earlyData = done_early_data;

    ret = SetKeysSide(ssl, DECRYPT_SIDE_ONLY);

    WOLFSSL_LEAVE("DoTls13EndOfEarlyData", ret);
    WOLFSSL_END(WC_FUNC_END_OF_EARLY_DATA_DO);

    return ret;
}
#endif /* !NO_WOLFSSL_SERVER */
#endif /* WOLFSSL_EARLY_DATA */

#if defined(HAVE_SESSION_TICKET) && defined(WOLFSSL_TICKET_NONCE_MALLOC) &&    \
    (!defined(HAVE_FIPS) || (defined(FIPS_VERSION_GE) && FIPS_VERSION_GE(5,3)))
int SessionTicketNoncePopulate(WOLFSSL_SESSION *session, const byte *nonce,
    byte len)
{
    if (session->ticketNonce.data
            != session->ticketNonce.dataStatic) {
         XFREE(session->ticketNonce.data, session->heap,
             DYNAMIC_TYPE_SESSION_TICK);
         session->ticketNonce.data = session->ticketNonce.dataStatic;
         session->ticketNonce.len = 0;
    }

    if (len > MAX_TICKET_NONCE_STATIC_SZ) {
        WOLFSSL_MSG("Using dynamic nonce buffer");
        session->ticketNonce.data = (byte*)XMALLOC(len,
            session->heap, DYNAMIC_TYPE_SESSION_TICK);
        if (session->ticketNonce.data == NULL)
            return MEMORY_ERROR;
    }
    XMEMCPY(session->ticketNonce.data, nonce, len);
    session->ticketNonce.len = len;
    return 0;
}
#endif
#ifndef NO_WOLFSSL_CLIENT
/* Handle a New Session Ticket handshake message.
 * Message contains the information required to perform resumption.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the message buffer of Finished.
 *           On exit, the index of byte after the Finished message and padding.
 * size      The length of the current handshake message.
 * returns 0 on success, otherwise failure.
 */
static int DoTls13NewSessionTicket(WOLFSSL* ssl, const byte* input,
                                   word32* inOutIdx, word32 size)
{
#ifdef HAVE_SESSION_TICKET
    int    ret;
    word32 begin = *inOutIdx;
    word32 lifetime;
    word32 ageAdd;
    word16 length;
#ifdef WOLFSSL_32BIT_MILLI_TIME
    word32 now;
#else
    sword64 now;
#endif
    const byte* nonce;
    byte        nonceLength;

    WOLFSSL_START(WC_FUNC_NEW_SESSION_TICKET_DO);
    WOLFSSL_ENTER("DoTls13NewSessionTicket");

#ifdef HAVE_ECH
    /* ignore session ticket when ECH is rejected */
    if (ssl->echConfigs != NULL && !ssl->options.disableECH &&
            !ssl->options.echAccepted) {
        *inOutIdx += size + ssl->keys.padSz;
        return 0;
    }
#endif

    /* Lifetime hint. */
    if ((*inOutIdx - begin) + SESSION_HINT_SZ > size)
        return BUFFER_ERROR;
    ato32(input + *inOutIdx, &lifetime);
    *inOutIdx += SESSION_HINT_SZ;
    if (lifetime > MAX_LIFETIME) {
        WOLFSSL_ERROR_VERBOSE(SERVER_HINT_ERROR);
        return SERVER_HINT_ERROR;
    }

    /* Age add. */
    if ((*inOutIdx - begin) + SESSION_ADD_SZ > size)
        return BUFFER_ERROR;
    ato32(input + *inOutIdx, &ageAdd);
    *inOutIdx += SESSION_ADD_SZ;

    /* Ticket nonce. */
    if ((*inOutIdx - begin) + 1 > size)
        return BUFFER_ERROR;
    nonceLength = input[*inOutIdx];
#if !defined(WOLFSSL_TICKET_NONCE_MALLOC) &&                                   \
    (!defined(HAVE_FIPS) || FIPS_VERSION_GE(5,3))
    if (nonceLength > MAX_TICKET_NONCE_STATIC_SZ) {
        WOLFSSL_MSG("Nonce length not supported");
        WOLFSSL_ERROR_VERBOSE(INVALID_PARAMETER);
        return INVALID_PARAMETER;
    }
#endif /* WOLFSSL_TICKET_NONCE_MALLOC && FIPS_VERSION_GE(5,3) */
    *inOutIdx += 1;
    if ((*inOutIdx - begin) + nonceLength > size)
        return BUFFER_ERROR;
    nonce = input + *inOutIdx;
    *inOutIdx += nonceLength;

    /* Ticket length. */
    if ((*inOutIdx - begin) + LENGTH_SZ > size)
        return BUFFER_ERROR;
    ato16(input + *inOutIdx, &length);
    *inOutIdx += LENGTH_SZ;
    if ((*inOutIdx - begin) + length > size)
        return BUFFER_ERROR;
    /* note: we reject zero length ticket here, and not in SetTicket(),
     * because zero length is valid for TLS 1.2 */
    if (length == 0)
        return BUFFER_ERROR;

    if ((ret = SetTicket(ssl, input + *inOutIdx, length)) != 0)
        return ret;
    *inOutIdx += length;

    now = TimeNowInMilliseconds();
    if (now == 0)
        return GETTIME_ERROR;
    /* Copy in ticket data (server identity). */
    ssl->timeout                  = lifetime;
    ssl->session->timeout         = lifetime;
    ssl->session->cipherSuite0    = ssl->options.cipherSuite0;
    ssl->session->cipherSuite     = ssl->options.cipherSuite;
    ssl->session->ticketSeen      = now;
    ssl->session->ticketAdd       = ageAdd;
    #ifdef WOLFSSL_EARLY_DATA
    ssl->session->maxEarlyDataSz  = ssl->options.maxEarlyDataSz;
    #endif

#if defined(WOLFSSL_TICKET_NONCE_MALLOC) &&                                    \
    (!defined(HAVE_FIPS) || (defined(FIPS_VERSION_GE) && FIPS_VERSION_GE(5,3)))
    ret = SessionTicketNoncePopulate(ssl->session, nonce, nonceLength);
    if (ret != 0)
        return ret;
#else
    ssl->session->ticketNonce.len = nonceLength;
    if (nonceLength > MAX_TICKET_NONCE_STATIC_SZ) {
        ret = BUFFER_ERROR;
        return ret;
    }
    if (nonceLength > 0)
        XMEMCPY(ssl->session->ticketNonce.data, nonce, nonceLength);
#endif /* defined(WOLFSSL_TICKET_NONCE_MALLOC) && FIPS_VERSION_GE(5,3) */

    ssl->session->namedGroup      = ssl->namedGroup;

    if ((*inOutIdx - begin) + EXTS_SZ > size)
        return BUFFER_ERROR;
    ato16(input + *inOutIdx, &length);
    *inOutIdx += EXTS_SZ;
    if ((*inOutIdx - begin) + length != size)
        return BUFFER_ERROR;
    /* RFC 9846 Section 4.7.1: the extensions are Section 4.3 Extension TLVs.
     * Malformed framing is a syntax error even when no extension in the list
     * is one we act on. */
    ret = TLSX_Parse(ssl, input + *inOutIdx, length, session_ticket, NULL);
    if (ret != 0)
        return ret;
    *inOutIdx += length;

    SetupSession(ssl);
    #ifndef NO_SESSION_CACHE
        AddSession(ssl);
    #endif

    ssl->expect_session_ticket = 0;
#else
    (void)ssl;
    (void)input;

    WOLFSSL_ENTER("DoTls13NewSessionTicket");

    *inOutIdx += size;
#endif /* HAVE_SESSION_TICKET */

    WOLFSSL_LEAVE("DoTls13NewSessionTicket", 0);
    WOLFSSL_END(WC_FUNC_NEW_SESSION_TICKET_DO);

    return 0;
}
#endif /* NO_WOLFSSL_CLIENT */

#ifndef NO_WOLFSSL_SERVER
    #ifdef HAVE_SESSION_TICKET

#ifdef WOLFSSL_TLS13_TICKET_BEFORE_FINISHED
/* Offset of the MAC size in the finished message. */
#define FINISHED_MSG_SIZE_OFFSET    3

/* Calculate the resumption secret which includes the unseen client finished
 * message.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
static int ExpectedResumptionSecret(WOLFSSL* ssl)
{
    int         ret;
    int         saveRet = 0;
    word32      finishedSz = 0;
    byte        mac[WC_MAX_DIGEST_SIZE];
    Digest      digest;
    byte header[] = { 0x14, 0x00, 0x00, 0x00 };

    XMEMSET(&digest, 0, sizeof(Digest));

    /* Copy the running hash so we can restore it after. */
    switch (ssl->specs.mac_algorithm) {
    #ifndef NO_SHA256
        case sha256_mac:
            ret = wc_Sha256Copy(&ssl->hsHashes->hashSha256, &digest.sha256);
            if (ret != 0)
                return ret;
            break;
    #endif
    #ifdef WOLFSSL_SHA384
        case sha384_mac:
            ret = wc_Sha384Copy(&ssl->hsHashes->hashSha384, &digest.sha384);
            if (ret != 0)
                return ret;
            break;
    #endif
    #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            ret = wc_Sha512Copy(&ssl->hsHashes->hashSha512, &digest.sha512);
            if (ret != 0)
                return ret;
            break;
    #endif
    #ifdef WOLFSSL_SM3
        case sm3_mac:
            ret = wc_Sm3Copy(&ssl->hsHashes->hashSm3, &digest.sm3);
            if (ret != 0)
                return ret;
            break;
    #endif
    }

    /* Generate the Client's Finished message and hash it. */
    ret = BuildTls13HandshakeHmac(ssl, ssl->keys.client_write_MAC_secret, mac,
                                  &finishedSz);
    if (ret != 0)
        goto restore;
    header[FINISHED_MSG_SIZE_OFFSET] = finishedSz;
#ifdef WOLFSSL_EARLY_DATA
    if (ssl->earlyData != no_early_data) {
        static byte endOfEarlyData[] = { 0x05, 0x00, 0x00, 0x00 };
        ret = HashRaw(ssl, endOfEarlyData, sizeof(endOfEarlyData));
        if (ret != 0)
            goto restore;
    }
#endif
    if ((ret = HashRaw(ssl, header, sizeof(header))) != 0)
        goto restore;
    if ((ret = HashRaw(ssl, mac, finishedSz)) != 0)
        goto restore;

    if ((ret = DeriveResumptionSecret(ssl, ssl->session->masterSecret)) != 0)
        goto restore;

    /* Restore the hash inline with currently seen messages. */
restore:
    /* The restore result must not mask the error that got here, or a
     * WC_PENDING_E would be reported as success with the derive skipped. */
    saveRet = ret;
    switch (ssl->specs.mac_algorithm) {
    #ifndef NO_SHA256
        case sha256_mac:
            wc_Sha256Free(&ssl->hsHashes->hashSha256);
            ret = wc_Sha256Copy(&digest.sha256, &ssl->hsHashes->hashSha256);
            wc_Sha256Free(&digest.sha256);
            break;
    #endif
    #ifdef WOLFSSL_SHA384
        case sha384_mac:
            wc_Sha384Free(&ssl->hsHashes->hashSha384);
            ret = wc_Sha384Copy(&digest.sha384, &ssl->hsHashes->hashSha384);
            wc_Sha384Free(&digest.sha384);
            break;
    #endif
    #ifdef WOLFSSL_TLS13_SHA512
        case sha512_mac:
            wc_Sha512Free(&ssl->hsHashes->hashSha512);
            ret = wc_Sha512Copy(&digest.sha512, &ssl->hsHashes->hashSha512);
            wc_Sha512Free(&digest.sha512);
            break;
    #endif
    #ifdef WOLFSSL_SM3
        case sm3_mac:
            wc_Sm3Free(&ssl->hsHashes->hashSm3);
            ret = wc_Sm3Copy(&digest.sm3, &ssl->hsHashes->hashSm3);
            wc_Sm3Free(&digest.sm3);
            break;
    #endif
    }
    if (saveRet != 0)
        ret = saveRet;

    ForceZero(mac, sizeof(mac));
    return ret;
}
#endif

/* Check the client advertised a PSK key exchange mode a resumption ticket can
 * be used with.
 *
 * RFC 9846 Section 4.3.9: psk_key_exchange_modes restricts both the PSKs
 * offered in the ClientHello and those the server might supply through
 * NewSessionTicket, and servers should not send tickets that are incompatible
 * with the advertised modes. RFC 9846 Section 4.7.1 makes sending a ticket
 * conditional on the client's hello carrying a suitable extension.
 *
 * ssl  The SSL/TLS object.
 * returns 0 when a ticket may be sent, MISSING_HANDSHAKE_DATA when the
 *         extension was not received and PSK_KEY_ERROR when none of the
 *         advertised modes is usable.
 */
static int CheckTls13TicketPskModes(WOLFSSL* ssl)
{
#ifdef WOLFSSL_TLS13_TICKET_CHECK_PSK_MODES
    if (!ssl->options.pskKeModesRecvd) {
        WOLFSSL_MSG("No psk_key_exchange_modes in ClientHello");
        return MISSING_HANDSHAKE_DATA;
    }

    if ((ssl->options.pskKeModes & (1 << PSK_KE)) != 0
    #ifdef HAVE_SUPPORTED_CURVES
        && !ssl->options.onlyPskDheKe
    #endif
        ) {
        return 0;
    }
    /* The configured policy, not noPskDheKe - a certificate handshake clears
     * that one before the ticket is sent, which would make this always true. */
    if ((ssl->options.pskKeModes & (1 << PSK_DHE_KE)) != 0 &&
            !ssl->options.noPskDheKePolicy) {
        return 0;
    }

    WOLFSSL_MSG("No usable psk_key_exchange_modes advertised by client");
    return PSK_KEY_ERROR;
#else
    (void)ssl;
    return 0;
#endif
}

/* Send New Session Ticket handshake message.
 * Message contains the information required to perform resumption.
 *
 * ssl  The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
static int SendTls13NewSessionTicket(WOLFSSL* ssl)
{
    byte*  output;
    int    ret;
    word32 length;
    int    sendSz;
    word16 extSz;
    word32 idx = RECORD_HEADER_SZ + HANDSHAKE_HEADER_SZ;

    WOLFSSL_START(WC_FUNC_NEW_SESSION_TICKET_SEND);
    WOLFSSL_ENTER("SendTls13NewSessionTicket");

    if (DefTicketHintTooLarge(ssl)) {
        WOLFSSL_MSG("Ticket hint exceeds half the ticket key lifetime; "
                    "skipping ticket");
        return 0;
    }

    if (CheckTls13TicketPskModes(ssl) != 0) {
        WOLFSSL_MSG("Client advertised no usable PSK key exchange mode; "
                    "skipping ticket");
        return 0;
    }

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        idx = Dtls13GetRlHeaderLength(ssl, 1) + DTLS_HANDSHAKE_HEADER_SZ;
#endif /* WOLFSSL_DTLS13 */

#ifdef WOLFSSL_TLS13_TICKET_BEFORE_FINISHED
    if (!ssl->msgsReceived.got_finished) {
        if ((ret = ExpectedResumptionSecret(ssl)) != 0)
            return ret;
    }
#endif

    /* Start ticket nonce at 0 and go up to 255. */
    if (ssl->session->ticketNonce.len == 0) {
        ssl->session->ticketNonce.len = DEF_TICKET_NONCE_SZ;
        ssl->session->ticketNonce.data[0] = 0;
    }
    else
    #ifdef WOLFSSL_ASYNC_CRYPT
        if (ssl->error != WC_NO_ERR_TRACE(WC_PENDING_E))
    #endif
    {
        if (ssl->session->ticketNonce.data[0] == 255) {
            /* RFC8446 Section 4.6.1: Each ticket must have a unique nonce
             * value. As the nonce is only a single byte, we have to prevent
             * the overflow and abort. */
            return SESSION_TICKET_NONCE_OVERFLOW;
        }
        else
            ssl->session->ticketNonce.data[0]++;
    }

    if ((ssl->options.mask & WOLFSSL_OP_NO_TICKET) != 0) {
        /* In this case we only send the ID as the ticket. Let's generate a new
         * ID for the new ticket so that we don't overwrite any old ones */
        ret = wc_RNG_GenerateBlock(ssl->rng, ssl->session->altSessionID,
                                   ID_LEN);
        if (ret != 0)
            return ret;
        ssl->session->haveAltSessionID = 1;
    }

    if (!ssl->options.noTicketTls13) {
        if ((ret = SetupTicket(ssl)) != 0)
            return ret;
        /* No need to create the ticket if we only send the ID */
        if ((ssl->options.mask & WOLFSSL_OP_NO_TICKET) == 0) {
            if ((ret = CreateTicket(ssl)) != 0)
                return ret;
        }
    }

#ifdef WOLFSSL_EARLY_DATA
    ssl->session->maxEarlyDataSz = ssl->options.maxEarlyDataSz;
    if (ssl->session->maxEarlyDataSz > 0)
        TLSX_EarlyData_Use(ssl, ssl->session->maxEarlyDataSz, 1);
    extSz = 0;
    ret = TLSX_GetResponseSize(ssl, session_ticket, &extSz);
    if (ret != 0)
        return ret;
#else
    extSz = EXTS_SZ;
#endif
    /* Lifetime | Age Add | Ticket session ID | Extensions */
    length = SESSION_HINT_SZ + SESSION_ADD_SZ + LENGTH_SZ;
    if ((ssl->options.mask & WOLFSSL_OP_NO_TICKET) != 0)
        length += ID_LEN + extSz;
    else
        length += ssl->session->ticketLen + extSz;
    /* Nonce */
    length += TICKET_NONCE_LEN_SZ + DEF_TICKET_NONCE_SZ;

    sendSz = (int)(idx + length + MAX_MSG_EXTRA);

    /* Check buffers are big enough and grow if needed. */
    if ((ret = CheckAvailableSize(ssl, sendSz)) != 0)
        return ret;

    /* Get position in output buffer to write new message to. */
    output = GetOutputBuffer(ssl);

    /* Put the record and handshake headers on. */
    AddTls13Headers(output, length, session_ticket, ssl);

    /* Lifetime hint */
    c32toa(ssl->ctx->ticketHint, output + idx);
    idx += SESSION_HINT_SZ;
    /* Age add - obfuscator */
    c32toa(ssl->session->ticketAdd, output + idx);
    idx += SESSION_ADD_SZ;

    output[idx++] = ssl->session->ticketNonce.len;
    output[idx++] = ssl->session->ticketNonce.data[0];

    /* length */
    if ((ssl->options.mask & WOLFSSL_OP_NO_TICKET) != 0) {
        c16toa(ID_LEN, output + idx);
    }
    else {
        c16toa(ssl->session->ticketLen, output + idx);
    }

    idx += LENGTH_SZ;
    /* ticket */
    if ((ssl->options.mask & WOLFSSL_OP_NO_TICKET) != 0) {
        if (ssl->session->haveAltSessionID)
            XMEMCPY(output + idx, ssl->session->altSessionID, ID_LEN);
        else
            return BAD_FUNC_ARG; /* Should not happen */
        idx += ID_LEN;
    }
    else {
        XMEMCPY(output + idx, ssl->session->ticket, ssl->session->ticketLen);
        idx += ssl->session->ticketLen;
    }

#ifdef WOLFSSL_EARLY_DATA
    extSz = 0;
    ret = TLSX_WriteResponse(ssl, output + idx, session_ticket, &extSz);
    if (ret != 0)
        return ret;
    idx += extSz;
#else
    /* No extension support - empty extensions. */
    c16toa(0, output + idx);
    idx += EXTS_SZ;
#endif

    if (idx > WOLFSSL_MAX_16BIT ||
        sendSz > (int)WOLFSSL_MAX_16BIT) {
        return BAD_LENGTH_E;
    }

    ssl->options.haveSessionId = 1;

    SetupSession(ssl);
    /* Only add to cache when support built in and when the ticket contains
     * an ID. Otherwise we have no way to actually retrieve the ticket from the
     * cache. */
#if !defined(NO_SESSION_CACHE) && defined(WOLFSSL_TICKET_HAVE_ID)
    AddSession(ssl);
#endif

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        return Dtls13HandshakeSend(ssl, output, (word16)sendSz,
                                   (word16)idx, session_ticket, 0);
#endif /* WOLFSSL_DTLS13 */

    /* This message is always encrypted. */
    sendSz = BuildTls13Message(ssl, output, sendSz,
                               output + RECORD_HEADER_SZ,
                               (word16)idx - RECORD_HEADER_SZ,
                               handshake, 0, 0, 0);
    if (sendSz < 0)
        return sendSz;

    ssl->buffers.outputBuffer.length += sendSz;

    /* Always send as this is either directly after server's Finished or only
     * message after client's Finished.
     */
    ret = SendBuffered(ssl);

    WOLFSSL_LEAVE("SendTls13NewSessionTicket", 0);
    WOLFSSL_END(WC_FUNC_NEW_SESSION_TICKET_SEND);

    return ret;
}
    #endif /* HAVE_SESSION_TICKET */
#endif /* NO_WOLFSSL_SERVER */

/* Make sure no duplicates, no fast forward, or other problems
 *
 * ssl   The SSL/TLS object.
 * type  Type of handshake message received.
 * returns 0 on success, otherwise failure.
 */
static int SanityCheckTls13MsgReceived(WOLFSSL* ssl, byte type)
{
    /* verify not a duplicate, mark received, check state */
    switch (type) {

#ifndef NO_WOLFSSL_SERVER
        case client_hello:
        #ifndef NO_WOLFSSL_CLIENT
            /* Only valid when received on SERVER side. */
            if (ssl->options.side == WOLFSSL_CLIENT_END) {
                WOLFSSL_MSG("ClientHello received by client");
                WOLFSSL_ERROR_VERBOSE(SIDE_ERROR);
                return SIDE_ERROR;
            }
        #endif
            /* A replay after a pend arrives with got_client_hello cleared
             * (see exit_dch); a genuine duplicate arrives with it set. */
            if (ssl->options.clientState >= CLIENT_HELLO_COMPLETE
        #ifdef WOLFSSL_ASYNC_CRYPT
                && ssl->msgsReceived.got_client_hello != 0
        #endif
                ) {
                WOLFSSL_MSG("ClientHello received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            /* Check previously seen. */
            /* Initial and after HelloRetryRequest - no more than 2. */
            if (ssl->msgsReceived.got_client_hello == 2) {
                WOLFSSL_MSG("Too many ClientHello received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            /* Second only after HelloRetryRequest seen. */
            if (ssl->msgsReceived.got_client_hello == 1 &&
                ssl->options.serverState !=
                                          SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
                WOLFSSL_MSG("Duplicate ClientHello received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_client_hello++;

            break;
#endif

#ifndef NO_WOLFSSL_CLIENT
        case server_hello:
        #ifndef NO_WOLFSSL_SERVER
            /* Only valid when received on CLIENT side. */
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                WOLFSSL_MSG("ServerHello received by server");
                WOLFSSL_ERROR_VERBOSE(SIDE_ERROR);
                return SIDE_ERROR;
            }
        #endif
            /* Check state. */
            if (ssl->options.serverState >= SERVER_HELLO_COMPLETE) {
                WOLFSSL_MSG("ServerHello received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            /* Check previously seen. */
            /* Only once after ClientHello.
             * HelloRetryRequest has ServerHello type but count fixed up later
             * - see DoTls13ServerHello().
             */
            if (ssl->msgsReceived.got_server_hello) {
                WOLFSSL_MSG("Duplicate ServerHello received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_server_hello = 1;

            break;
#endif

#ifndef NO_WOLFSSL_CLIENT
        case session_ticket:
        #ifndef NO_WOLFSSL_SERVER
            /* Only valid when received on CLIENT side. */
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                WOLFSSL_MSG("NewSessionTicket received by server");
                WOLFSSL_ERROR_VERBOSE(SIDE_ERROR);
                return SIDE_ERROR;
            }
        #endif
            /* Check state. */
        #ifdef WOLFSSL_TLS13_TICKET_BEFORE_FINISHED
            /* Only allowed after server's Finished message. */
            if (ssl->options.serverState < SERVER_FINISHED_COMPLETE) {
                WOLFSSL_MSG("NewSessionTicket received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
        #else
            /* Only allowed after client's Finished message. */
            if (ssl->options.clientState < CLIENT_FINISHED_COMPLETE) {
                WOLFSSL_MSG("NewSessionTicket received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
        #endif
            /* Many SessionTickets can be sent. */
            ssl->msgsReceived.got_session_ticket = 1;

            break;
#endif

#ifndef NO_WOLFSSL_SERVER
    #ifdef WOLFSSL_EARLY_DATA
        case end_of_early_data:
        #ifndef NO_WOLFSSL_CLIENT
            /* Only valid when received on SERVER side. */
            if (ssl->options.side == WOLFSSL_CLIENT_END) {
                WOLFSSL_MSG("EndOfEarlyData received by client");
                WOLFSSL_ERROR_VERBOSE(SIDE_ERROR);
                return SIDE_ERROR;
            }
        #endif
            /* Check state. */
            /* Only after server's Finished and before client's Finished. */
            if (ssl->options.serverState < SERVER_FINISHED_COMPLETE) {
                WOLFSSL_MSG("EndOfEarlyData received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            if (ssl->options.clientState >= CLIENT_FINISHED_COMPLETE) {
                WOLFSSL_MSG("EndOfEarlyData received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            /* Check previously seen. */
            if (ssl->msgsReceived.got_end_of_early_data) {
                WOLFSSL_MSG("Too many EndOfEarlyData received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_end_of_early_data = 1;

            break;
    #endif
#endif

#ifndef NO_WOLFSSL_CLIENT
        case encrypted_extensions:
        #ifndef NO_WOLFSSL_SERVER
            /* Only valid when received on CLIENT side. */
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                WOLFSSL_MSG("EncryptedExtensions received by server");
                WOLFSSL_ERROR_VERBOSE(SIDE_ERROR);
                return SIDE_ERROR;
            }
        #endif
            /* Check state. */
            /* Must be received directly after ServerHello.
             * DoTls13EncryptedExtensions() changes state to:
             *   SERVER_ENCRYPTED_EXTENSIONS_COMPLETE.
             */
            if (ssl->options.serverState != SERVER_HELLO_COMPLETE) {
                WOLFSSL_MSG("EncryptedExtensions received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            /* Check previously seen. */
            if (ssl->msgsReceived.got_encrypted_extensions) {
                WOLFSSL_MSG("Duplicate EncryptedExtensions received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_encrypted_extensions = 1;

            break;
#endif

        case certificate:
            /* Valid on both sides. */
    #ifndef NO_WOLFSSL_CLIENT
            /* Check state. */
            /* On client, seen after EncryptedExtension and CertificateRequest
             * (if sent) and before CertificateVerify and Finished.
             * DoTls13Certificate() sets serverState to SERVER_CERT_COMPLETE.
             */
            if (ssl->options.side == WOLFSSL_CLIENT_END &&
                ssl->options.serverState !=
                                         SERVER_ENCRYPTED_EXTENSIONS_COMPLETE) {
                WOLFSSL_MSG("Certificate received out of order - Client");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
        #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
            /* Server's authenticating with PSK must not send this. */
            if (ssl->options.side == WOLFSSL_CLIENT_END &&
                             ssl->options.serverState == SERVER_CERT_COMPLETE &&
                             ssl->options.pskNegotiated
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
                             && !ssl->options.certWithExternPsk
#endif
               ) {
                WOLFSSL_MSG("Certificate received while using PSK");
                WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                return SANITY_MSG_E;
            }
        #endif
    #endif
    #ifndef NO_WOLFSSL_SERVER
            /* Check state. */
            /* On Server, valid after ClientHello received and ServerFinished
             * sent. */
            if (ssl->options.side == WOLFSSL_SERVER_END &&
                ssl->options.clientState != CLIENT_HELLO_COMPLETE &&
                ssl->options.serverState < SERVER_FINISHED_COMPLETE) {
                WOLFSSL_MSG("Certificate received out of order - Server");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
        #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
            /* RFC 8446 4.4.2: the client only sends this in response to a
             * CertificateRequest, which a server authenticating with a PSK
             * does not send in the main handshake (but may post-handshake). */
            if (ssl->options.side == WOLFSSL_SERVER_END &&
                ssl->options.pskNegotiated && !TLS13_AFTER_HANDSHAKE(ssl)
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
                && !ssl->options.certWithExternPsk
#endif
               ) {
                WOLFSSL_MSG("Certificate received while using PSK - Server");
                WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                return SANITY_MSG_E;
            }
        #endif
    #endif
            /* Check previously seen. */
            if (ssl->msgsReceived.got_certificate) {
                WOLFSSL_MSG("Duplicate Certificate received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_certificate = 1;

            break;

#ifndef NO_WOLFSSL_CLIENT
        case certificate_request:
        #ifndef NO_WOLFSSL_SERVER
            /* Only valid when received on CLIENT side. */
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                WOLFSSL_MSG("CertificateRequest received by server");
                WOLFSSL_ERROR_VERBOSE(SIDE_ERROR);
                return SIDE_ERROR;
            }
        #endif
            /* Check state. */
        #ifndef WOLFSSL_POST_HANDSHAKE_AUTH
            /* Only valid when sent after EncryptedExtensions and before
             * Certificate. */
            if (ssl->options.serverState !=
                                         SERVER_ENCRYPTED_EXTENSIONS_COMPLETE) {
                WOLFSSL_MSG("CertificateRequest received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
        #else
            /* Valid when sent after EncryptedExtensions and before Certificate
             * and after both client and server have sent Finished (Post
             * Handshake Authentication). */
            if (ssl->options.serverState !=
                                         SERVER_ENCRYPTED_EXTENSIONS_COMPLETE &&
                       (ssl->options.serverState < SERVER_FINISHED_COMPLETE ||
                        ssl->options.clientState != CLIENT_FINISHED_COMPLETE)) {
                WOLFSSL_MSG("CertificateRequest received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            /* RFC 8446 4.6.2: A client that receives a post-handshake
             * CertificateRequest message without having sent the
             * "post_handshake_auth" extension MUST send an
             * "unexpected_message" fatal alert. wolfSSL_allow_post_handshake_auth()
             * must be called before wolfSSL_connect() so postHandshakeAuth
             * reflects whether the extension was offered. */
            if (ssl->options.serverState >= SERVER_FINISHED_COMPLETE &&
                ssl->options.clientState == CLIENT_FINISHED_COMPLETE &&
                !ssl->options.postHandshakeAuth) {
                WOLFSSL_MSG("Post-handshake CertificateRequest received "
                            "without having sent post_handshake_auth "
                            "extension");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
        #endif
        #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
            /* RFC 8446 4.3.2: a server authenticating with a PSK must not send
             * this in the main handshake, but may send it post-handshake. */
            if (ssl->options.pskNegotiated && !TLS13_AFTER_HANDSHAKE(ssl)
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
                && !ssl->options.certWithExternPsk
#endif
               ) {
                WOLFSSL_MSG("CertificateRequest received while using PSK");
                WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                return SANITY_MSG_E;
            }
        #endif
            /* Check previously seen. */
        #ifndef WOLFSSL_POST_HANDSHAKE_AUTH
            /* Only once during handshake. */
            if (ssl->msgsReceived.got_certificate_request) {
                WOLFSSL_MSG("Duplicate CertificateRequest received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
        #else
            /* Only once during handshake. */
            if (ssl->msgsReceived.got_certificate_request &&
                ssl->options.clientState != CLIENT_FINISHED_COMPLETE) {
                WOLFSSL_MSG("Duplicate CertificateRequest received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
        #endif
            ssl->msgsReceived.got_certificate_request = 1;

            break;
#endif

        case certificate_verify:
            /* Valid on both sides. */
    #ifndef NO_WOLFSSL_CLIENT
            /* Check state on client.
             * Valid only directly after a Certificate message. */
            if (ssl->options.side == WOLFSSL_CLIENT_END) {
                if (ssl->options.serverState != SERVER_CERT_COMPLETE) {
                    WOLFSSL_MSG("No Cert before CertVerify");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
            #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
                /* Server's authenticating with PSK must not send this. */
                if (ssl->options.pskNegotiated
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
                    && !ssl->options.certWithExternPsk
#endif
                   ) {
                    WOLFSSL_MSG("CertificateVerify received while using PSK");
                    WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                    return SANITY_MSG_E;
                }
            #endif
            }
    #endif
    #ifndef NO_WOLFSSL_SERVER
            /* Check state on server. */
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                /* Server must have sent Finished message. */
                if (ssl->options.serverState < SERVER_FINISHED_COMPLETE) {
                    WOLFSSL_MSG("CertificateVerify received out of order");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
                /* Valid only directly after a Certificate message. */
                if (ssl->options.clientState < CLIENT_HELLO_COMPLETE) {
                    WOLFSSL_MSG("CertificateVerify before ClientHello done");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
                if (!ssl->msgsReceived.got_certificate) {
                    WOLFSSL_MSG("No Cert before CertificateVerify");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
            }
    #endif
            /* Check previously seen. */
            if (ssl->msgsReceived.got_certificate_verify) {
                WOLFSSL_MSG("Duplicate CertificateVerify received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_certificate_verify = 1;

            break;

        case finished:
            /* Valid on both sides. */
        #ifndef NO_WOLFSSL_CLIENT
            /* Check state on client. */
            if (ssl->options.side == WOLFSSL_CLIENT_END) {
                /* After sending ClientHello */
                if (ssl->options.clientState < CLIENT_HELLO_COMPLETE) {
                    WOLFSSL_MSG("Finished received out of order - clientState");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
                /* Must have seen certificate and verify from server except when
                 * using PSK. */
            #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
                if (ssl->options.pskNegotiated) {
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
                    if (ssl->options.certWithExternPsk) {
                        if (ssl->options.serverState !=
                                                SERVER_CERT_VERIFY_COMPLETE) {
                            WOLFSSL_MSG("Finished received out of order - "
                                        "cert_with_extern_psk");
                            WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                            return OUT_OF_ORDER_E;
                        }
                    }
                    else
#endif
                    {
                        if (ssl->options.serverState !=
                                         SERVER_ENCRYPTED_EXTENSIONS_COMPLETE) {
                            WOLFSSL_MSG("Finished received out of order - PSK");
                            WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                            return OUT_OF_ORDER_E;
                        }
                    }
                }
                else
            #endif
                if (ssl->options.serverState != SERVER_CERT_VERIFY_COMPLETE) {
                    WOLFSSL_MSG("Finished received out of order - serverState");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
            }
        #endif
        #ifndef NO_WOLFSSL_SERVER
            /* Check state on server. */
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                if (ssl->options.serverState < SERVER_FINISHED_COMPLETE) {
                    WOLFSSL_MSG("Finished received out of order - serverState");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
                if (ssl->options.clientState < CLIENT_HELLO_COMPLETE) {
                    WOLFSSL_MSG("Finished received out of order - clientState");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
            #ifdef WOLFSSL_EARLY_DATA
                if (ssl->earlyData == process_early_data &&
                    /* early data may be lost when using DTLS */
                    !ssl->options.dtls
                    /* QUIC does not use EndOfEarlyData records */
                    && !WOLFSSL_IS_QUIC(ssl)) {
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
            #endif
            }
        #endif
        #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
            if (!ssl->options.pskNegotiated ||
                (ssl->options.side == WOLFSSL_SERVER_END &&
                 TLS13_AFTER_HANDSHAKE(ssl))
#ifdef WOLFSSL_CERT_WITH_EXTERN_PSK
                || ssl->options.certWithExternPsk
#endif
            )
        #endif
            {
                /* Must have received a Certificate message from client if
                 * verifying the peer. Empty certificate message indicates
                 * no certificate available.
                 */
                if (ssl->options.verifyPeer &&
                #ifdef WOLFSSL_POST_HANDSHAKE_AUTH
                    /* The post-handshake-auth exemption is only valid during
                     * the enclosing handshake. Once the server has requested a
                     * certificate post-handshake, one is required again.
                     * Whether an empty Certificate is then accepted follows the
                     * verify mode (FAIL_IF_NO_PEER_CERT), exactly as for
                     * first-handshake client authentication. */
                    (!ssl->options.verifyPostHandshake ||
                     TLS13_AFTER_HANDSHAKE(ssl)) &&
                #endif
                                           !ssl->msgsReceived.got_certificate) {
                    WOLFSSL_MSG("Finished received out of order - "
                                "missing Certificate message");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
                /* Mutual authentication on server requires a certificate from
                 * peer. Verify peer set on client side requires a certificate
                 * from peer as not doing PSK.
                 */
                if ((ssl->options.mutualAuth ||
                    (ssl->options.side == WOLFSSL_CLIENT_END &&
                     ssl->options.verifyPeer)) && !ssl->options.havePeerCert) {
                    WOLFSSL_MSG("Finished received out of order - "
                                "no valid certificate");
                    WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                    return OUT_OF_ORDER_E;
                }
            }
            /* Must have received a valid CertificateVerify if got a peer
             * certificate. A certificate without proof of possession is never
             * acceptable, regardless of how the handshake was authenticated.
             */
            if (ssl->options.havePeerCert && !ssl->options.havePeerVerify) {
                WOLFSSL_MSG("Finished received out of order - "
                            "Certificate message but no CertificateVerify");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            /* Check previously seen. */
            if (ssl->msgsReceived.got_finished) {
                WOLFSSL_MSG("Duplicate Finished received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_finished = 1;

            break;

        case key_update:
            /* Valid on both sides. */
#ifdef WOLFSSL_QUIC
            /* RFC 9001 Section 6: QUIC performs key updates at the QUIC
             * packet-protection layer, so a TLS KeyUpdate message must be
             * rejected as a fatal unexpected_message connection error. */
            if (WOLFSSL_IS_QUIC(ssl)) {
                WOLFSSL_MSG("KeyUpdate received over QUIC");
                WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                return SANITY_MSG_E;
            }
#endif
            /* Check state.
             * Client and server must have received finished message from other
             * side.
             */
            if (!ssl->msgsReceived.got_finished) {
                WOLFSSL_MSG("No KeyUpdate before Finished");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            /* Multiple KeyUpdates can be sent. */
            break;
#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_NO_TLS12)
        case hello_verify_request:
            if (!ssl->options.dtls) {
                WOLFSSL_MSG("HelloVerifyRequest when not in DTLS");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            if (ssl->msgsReceived.got_hello_verify_request) {
                WOLFSSL_MSG("Duplicate HelloVerifyRequest received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            ssl->msgsReceived.got_hello_verify_request = 1;
            if (ssl->msgsReceived.got_hello_retry_request) {
                WOLFSSL_MSG(
                    "Both HelloVerifyRequest and HelloRetryRequest received");
                WOLFSSL_ERROR_VERBOSE(DUPLICATE_MSG_E);
                return DUPLICATE_MSG_E;
            }
            if (ssl->options.serverState >=
                    SERVER_HELLO_RETRY_REQUEST_COMPLETE ||
                ssl->options.connectState != CLIENT_HELLO_SENT) {
                WOLFSSL_MSG("HelloVerifyRequest received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            if (ssl->options.side == WOLFSSL_SERVER_END) {
                WOLFSSL_MSG("HelloVerifyRequest received on the server");
                WOLFSSL_ERROR_VERBOSE(SIDE_ERROR);
                return SIDE_ERROR;
            }
            if (!ssl->options.downgrade ||
                ssl->options.minDowngrade < DTLSv1_2_MINOR) {
                WOLFSSL_MSG(
                    "HelloVerifyRequest received but not DTLSv1.2 allowed");
                WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
                return VERSION_ERROR;
            }
            break;
#endif /* WOLFSSL_DTLS13 && !WOLFSSL_NO_TLS12*/

#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_DTLS_CID)
        case request_connection_id:
        case new_connection_id:
        {
            CIDInfo* cidInfo = ssl->dtlsCidInfo;

            /* DTLS 1.3 only (RFC 9147) */
            if (!ssl->options.dtls) {
                WOLFSSL_MSG("CID message received but not DTLS");
                WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                return SANITY_MSG_E;
            }
            /* RFC 9147 Section 9: if CIDs were not negotiated, MUST abort
             * with an unexpected_message alert */
            if (cidInfo == NULL || !cidInfo->negotiated) {
                WOLFSSL_MSG("CID message received but CID not negotiated");
                WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                return SANITY_MSG_E;
            }
            if (ssl->options.handShakeState != HANDSHAKE_DONE) {
                WOLFSSL_MSG("CID message received out of order");
                WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
                return OUT_OF_ORDER_E;
            }
            if (type == request_connection_id) {
                /* the peer MUST NOT request CIDs while sending an empty
                 * CID itself */
                if (cidInfo->rx == NULL || cidInfo->rx->length == 0) {
                    WOLFSSL_MSG("RequestConnectionId from peer sending an "
                                "empty CID");
                    WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                    return SANITY_MSG_E;
                }
            }
            else {
                /* the peer MUST NOT issue CIDs after negotiating receiving
                 * an empty CID */
                if (cidInfo->tx == NULL || cidInfo->tx->length == 0) {
                    WOLFSSL_MSG("NewConnectionId from peer that negotiated "
                                "an empty CID");
                    WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
                    return SANITY_MSG_E;
                }
            }
            break;
        }
#endif /* WOLFSSL_DTLS13 && WOLFSSL_DTLS_CID */

        default:
            WOLFSSL_MSG("Unknown message type");
            WOLFSSL_ERROR_VERBOSE(SANITY_MSG_E);
            return SANITY_MSG_E;
    }

    return 0;
}

/* Handle a type of handshake message that has been received.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the buffer of the current message.
 *           On exit, the index into the buffer of the next message.
 * size      The length of the current handshake message.
 * totalSz   Length of remaining data in the message buffer.
 * returns 0 on success and otherwise failure.
 */
/* Run the key schedule belonging to a just-processed handshake message.
 * A pend here cannot replay the message (its handler already advanced
 * state); the record is consumed and this is called again from
 * DoProcessReplyEx() entry, pre-dispatch, or the reply-loop exits.
 * Returns 0, WC_PENDING_E while the device is busy, else an error. */
int DoTls13MsgDerives(WOLFSSL* ssl, byte type)
{
    int ret = 0;

    (void)ssl;
    (void)type;

#ifndef NO_WOLFSSL_CLIENT
    if (ssl->options.side == WOLFSSL_CLIENT_END) {
        if (type == server_hello) {
            /* Entered before the first derive, or a pend there would
             * route the retry back to the message handler. */
            if (ssl->kdfMsgStep == TLS13_MSG_KDF_NONE) {
                ssl->kdfMsgStep = TLS13_MSG_KDF_SH_ENTERED;
                ssl->kdfMsgType = type;
            }

            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_SH_ENTERED) {
                ret = DeriveEarlySecret(ssl);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_SH_EARLY_SECRET;
            }
            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_SH_EARLY_SECRET) {
                ret = DeriveHandshakeSecret(ssl);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_SH_HS_SECRET;
            }
            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_SH_HS_SECRET) {
                ret = DeriveTls13Keys(ssl, handshake_key,
                                      ENCRYPT_AND_DECRYPT_SIDE, 1);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_SH_HS_KEYS;
            }
    #ifdef WOLFSSL_EARLY_DATA
            if (ssl->earlyData != no_early_data) {
                if (ssl->kdfMsgStep <= TLS13_MSG_KDF_SH_HS_KEYS) {
                    ret = SetKeysSide(ssl, DECRYPT_SIDE_ONLY);
                    if (ret != 0) {
                        if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                        return ret;
                    }
                    ssl->kdfMsgStep = TLS13_MSG_KDF_SH_KEYS_SET;
                }
            }
            else
    #endif
            {
                if (ssl->kdfMsgStep <= TLS13_MSG_KDF_SH_HS_KEYS) {
                    ret = SetKeysSide(ssl, ENCRYPT_AND_DECRYPT_SIDE);
                    if (ret != 0) {
                        if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                        return ret;
                    }
                    ssl->kdfMsgStep = TLS13_MSG_KDF_SH_KEYS_SET;
                }
            }

#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls) {
                w64wrapper epochHandshake;
                epochHandshake = w64From32(0, DTLS13_EPOCH_HANDSHAKE);
                ssl->dtls13Epoch = epochHandshake;
                ssl->dtls13PeerEpoch = epochHandshake;

                if (ssl->kdfMsgStep <= TLS13_MSG_KDF_SH_KEYS_SET) {
                    ret = Dtls13SetEpochKeys(ssl, epochHandshake,
                                             ENCRYPT_AND_DECRYPT_SIDE);
                    if (ret != 0) {
                        if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                        return ret;
                    }
                    ssl->kdfMsgStep = TLS13_MSG_KDF_SH_DTLS_EPOCH;
                }
            }
#endif /* WOLFSSL_DTLS13 */
            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
        }

        if (type == finished) {
            /* Mark the phase entered before the first derive, so a pending
             * there still routes the retry back here. */
            if (ssl->kdfMsgStep == TLS13_MSG_KDF_NONE) {
                ssl->kdfMsgStep = TLS13_MSG_KDF_FIN_ENTERED;
                ssl->kdfMsgType = type;
            }

            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_FIN_ENTERED) {
                if ((ret = DeriveMasterSecret(ssl)) != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                /* Zeroized only after the derive completed: a pend retry
                 * still reads preMasterSecret. */
                ForceZero(ssl->arrays->preMasterSecret,
                    ssl->arrays->preMasterSz);
                ssl->kdfMsgStep = TLS13_MSG_KDF_FIN_MASTER_SECRET;
            }
    #ifdef WOLFSSL_EARLY_DATA
    #ifdef WOLFSSL_QUIC
            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_FIN_MASTER_SECRET) {
                if (WOLFSSL_IS_QUIC(ssl) &&
                        ssl->earlyData != no_early_data) {
                    /* QUIC never sends/receives EndOfEarlyData, but
                     * having early data means the last encryption keys
                     * had not been set yet. */
                    if ((ret = SetKeysSide(ssl, ENCRYPT_SIDE_ONLY)) != 0) {
                        if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                        return ret;
                    }
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_FIN_QUIC_EARLY_KEYS;
            }
    #endif
            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_FIN_QUIC_EARLY_KEYS) {
                ret = DeriveTls13Keys(ssl, traffic_key,
                            ENCRYPT_AND_DECRYPT_SIDE,
                            ssl->earlyData == no_early_data);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_FIN_TRAFFIC_KEYS;
            }
            if (ssl->earlyData != no_early_data) {
                if (ssl->kdfMsgStep <= TLS13_MSG_KDF_FIN_TRAFFIC_KEYS) {
                    if ((ret = DeriveTls13Keys(ssl, no_key,
                                            DECRYPT_SIDE_ONLY, 1)) != 0) {
                        if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                        return ret;
                    }
                    ssl->kdfMsgStep = TLS13_MSG_KDF_FIN_TRAFFIC_DONE;
                }
            }
    #else
            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_FIN_QUIC_EARLY_KEYS) {
                ret = DeriveTls13Keys(ssl, traffic_key,
                            ENCRYPT_AND_DECRYPT_SIDE, 1);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_FIN_TRAFFIC_DONE;
            }
    #endif
            /* Setup keys for application data messages. */
            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_FIN_TRAFFIC_DONE) {
                if ((ret = SetKeysSide(ssl, DECRYPT_SIDE_ONLY)) != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_FIN_KEYS_SET;
            }
            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
        }
    }
#endif /* NO_WOLFSSL_CLIENT */

#ifndef NO_WOLFSSL_SERVER
    #if defined(HAVE_SESSION_TICKET)
        if (ssl->options.side == WOLFSSL_SERVER_END && type == finished) {
            if (ssl->kdfMsgStep == TLS13_MSG_KDF_NONE) {
                ssl->kdfMsgStep = TLS13_MSG_KDF_SFIN_ENTERED;
                ssl->kdfMsgType = type;
            }
            if (ssl->kdfMsgStep <= TLS13_MSG_KDF_SFIN_ENTERED) {
                ret = DeriveResumptionSecret(ssl, ssl->session->masterSecret);
                if (ret != 0) {
                    if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                        ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
                    return ret;
                }
                ssl->kdfMsgStep = TLS13_MSG_KDF_SFIN_RESUMPTION_SECRET;
            }
            ssl->kdfMsgStep = TLS13_MSG_KDF_NONE;
        }
    #endif
#endif /* NO_WOLFSSL_SERVER */

    return ret;
}

int DoTls13HandShakeMsgType(WOLFSSL* ssl, byte* input, word32* inOutIdx,
                            byte type, word32 size, word32 totalSz)
{
    int ret = 0, tmp;
    word32 inIdx = *inOutIdx;
    int alertType;
    int skipSanity = 0;
#if defined(HAVE_ECH) && !defined(NO_WOLFSSL_SERVER)
    TLSX* echX = NULL;
    word32 echInOutIdx;
#endif

    (void)totalSz;

    WOLFSSL_ENTER("DoTls13HandShakeMsgType");

    /* make sure we can read the message */
    if (*inOutIdx + size > totalSz)
        return INCOMPLETE_DATA;

#ifdef WOLFSSL_ASYNC_CRYPT
    /* A message being replayed after its own handler pended has already
     * passed its sanity check and advanced the got_* state on the first
     * pass; the handler restores its cleared marker on completion. Consume
     * the one-shot marker here so only that replayed message skips the
     * check - messages dispatched after it (ssl->error may still read
     * WC_PENDING_E from a trailing key-schedule pend) are still checked. */
    skipSanity = ssl->options.asyncReplayMsg;
    ssl->options.asyncReplayMsg = 0;
#endif

    /* Sanity check msg received. Skipped on a WC_PENDING_E resume (it
     * would reject the replay against already-advanced state); handlers
     * restore their cleared got_* markers on completion instead. */
    if (!skipSanity &&
            (ret = SanityCheckTls13MsgReceived(ssl, type)) != 0) {
        WOLFSSL_MSG("Sanity Check on handshake message type received failed");
        if (ret == WC_NO_ERR_TRACE(VERSION_ERROR))
            SendAlert(ssl, alert_fatal, wolfssl_alert_protocol_version);
        else
            SendAlert(ssl, alert_fatal, unexpected_message);
        return ret;
    }

#if defined(WOLFSSL_CALLBACKS)
    /* add name later, add on record and handshake header part back on */
    if (ssl->toInfoOn) {
        ret = AddPacketInfo(ssl, 0, handshake, input + *inOutIdx -
            HANDSHAKE_HEADER_SZ, size + HANDSHAKE_HEADER_SZ, READ_PROTO,
            RECORD_HEADER_SZ, ssl->heap);
        if (ret != 0)
            return ret;
        AddLateRecordHeader(&ssl->curRL, &ssl->timeoutInfo);
    }
#endif

    if (ssl->options.handShakeState == HANDSHAKE_DONE &&
            type != session_ticket && type != certificate_request &&
            type != certificate && type != key_update && type != finished
#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_DTLS_CID)
            && type != request_connection_id && type != new_connection_id
#endif
            ) {
        WOLFSSL_MSG("HandShake message after handshake complete");
        SendAlert(ssl, alert_fatal, unexpected_message);
        WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
        return OUT_OF_ORDER_E;
    }

    if (ssl->options.side == WOLFSSL_CLIENT_END &&
               ssl->options.serverState == NULL_STATE &&
               type != server_hello && type != hello_retry_request
#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_NO_TLS12)
        && (!ssl->options.dtls || type != hello_verify_request)
#endif /* defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_NO_TLS12) */
        ) {
        WOLFSSL_MSG("First server message not server hello");
        SendAlert(ssl, alert_fatal, unexpected_message);
        WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
        return OUT_OF_ORDER_E;
    }

    if (ssl->options.side == WOLFSSL_SERVER_END &&
               ssl->options.clientState == NULL_STATE && type != client_hello) {
        WOLFSSL_MSG("First client message not client hello");
        SendAlert(ssl, alert_fatal, unexpected_message);
        WOLFSSL_ERROR_VERBOSE(OUT_OF_ORDER_E);
        return OUT_OF_ORDER_E;
    }

    /* above checks handshake state */
    /* Finish an earlier message's key schedule before this message is
     * judged: it installs state this one is checked against. */
    if (ssl->kdfMsgStep > 0) {
        ret = DoTls13MsgDerives(ssl, ssl->kdfMsgType);
        if (ret != 0)
            return ret;
        /* A resolved pend must not suppress the next sanity check. */
        if (ssl->error == WC_NO_ERR_TRACE(WC_PENDING_E)) {
            ssl->error = 0;
        }
    }

    switch (type) {
#ifndef NO_WOLFSSL_CLIENT
    /* Messages only received by client. */
    case server_hello:
        WOLFSSL_MSG("processing server hello");
        ret = DoTls13ServerHello(ssl, input, inOutIdx, size, &type);
    #if !defined(WOLFSSL_NO_CLIENT_AUTH) && \
               ((defined(HAVE_ED25519) && !defined(NO_ED25519_CLIENT_AUTH)) || \
                (defined(HAVE_ED448) && !defined(NO_ED448_CLIENT_AUTH)))
        if (ssl->options.resuming || !IsAtLeastTLSv1_2(ssl) ||
                                               IsAtLeastTLSv1_3(ssl->version)) {
            ssl->options.cacheMessages = 0;
            if ((ssl->hsHashes != NULL) && (ssl->hsHashes->messages != NULL)) {
                ForceZero(ssl->hsHashes->messages, ssl->hsHashes->length);
                XFREE(ssl->hsHashes->messages, ssl->heap, DYNAMIC_TYPE_HASHES);
                ssl->hsHashes->messages = NULL;
            }
        }
    #endif
        break;

    case encrypted_extensions:
        WOLFSSL_MSG("processing encrypted extensions");
        ret = DoTls13EncryptedExtensions(ssl, input, inOutIdx, size);
        break;

    #ifndef NO_CERTS
    case certificate_request:
        WOLFSSL_MSG("processing certificate request");
        ret = DoTls13CertificateRequest(ssl, input, inOutIdx, size);
        break;
    #endif

    case session_ticket:
        WOLFSSL_MSG("processing new session ticket");
        ret = DoTls13NewSessionTicket(ssl, input, inOutIdx, size);
        break;
#endif /* !NO_WOLFSSL_CLIENT */

#ifndef NO_WOLFSSL_SERVER
    /* Messages only received by server. */
    case client_hello:
        WOLFSSL_MSG("processing client hello");
#if defined(HAVE_ECH)
        /* keep the start idx so we can restore it for the inner call */
        echInOutIdx = *inOutIdx;
#endif
        ret = DoTls13ClientHello(ssl, input, inOutIdx, size);
    #if !defined(WOLFSSL_NO_CLIENT_AUTH) && \
               ((defined(HAVE_ED25519) && !defined(NO_ED25519_CLIENT_AUTH)) || \
                (defined(HAVE_ED448) && !defined(NO_ED448_CLIENT_AUTH)))
        if ((ssl->options.resuming || !ssl->options.verifyPeer ||
               !IsAtLeastTLSv1_2(ssl) || IsAtLeastTLSv1_3(ssl->version))
        #ifdef WOLFSSL_DTLS13
               && (!ssl->options.dtls)
        #endif
               ) {
        #if defined(WOLFSSL_ASYNC_CRYPT) || defined(WOLFSSL_NONBLOCK_OCSP)
            if (ret != WC_NO_ERR_TRACE(WC_PENDING_E) &&
                ret != WC_NO_ERR_TRACE(OCSP_WANT_READ))
        #endif
            {
                ssl->options.cacheMessages = 0;
                if ((ssl->hsHashes != NULL) &&
                        (ssl->hsHashes->messages != NULL)) {
                    ForceZero(ssl->hsHashes->messages, ssl->hsHashes->length);
                    XFREE(ssl->hsHashes->messages, ssl->heap,
                        DYNAMIC_TYPE_HASHES);
                    ssl->hsHashes->messages = NULL;
                }
            }
        }
    #endif
#if defined(HAVE_ECH)
        if (ret == 0) {
            echX = TLSX_Find(ssl->extensions, TLSX_ECH);

            if (echX != NULL &&
                    ((WOLFSSL_ECH*)echX->data)->state == ECH_WRITE_NONE &&
                    ((WOLFSSL_ECH*)echX->data)->innerClientHello != NULL) {
                byte copyRandom = ((WOLFSSL_ECH*)echX->data)->innerCount == 0;
                /* reset the inOutIdx to the outer start */
                *inOutIdx = echInOutIdx;
                /* call again with the inner hello */
                if (ret == 0) {
                    echInOutIdx = HANDSHAKE_HEADER_SZ;
#ifdef WOLFSSL_DTLS13
                    if (ssl->options.dtls)
                        echInOutIdx = DTLS13_HANDSHAKE_HEADER_SZ;
#endif
                    ssl->options.echProcessingInner = 1;
                    ret = DoTls13ClientHello(ssl,
                        ((WOLFSSL_ECH*)echX->data)->innerClientHello,
                        &echInOutIdx,
                        ((WOLFSSL_ECH*)echX->data)->innerClientHelloLen);
                    ssl->options.echProcessingInner = 0;
                }
                if (ret == 0 && ((WOLFSSL_ECH*)echX->data)->state !=
                        ECH_PARSED_INTERNAL) {
                    WOLFSSL_MSG("ECH: inner ClientHello missing ECH extension");
                    ret = INVALID_PARAMETER;
                }
                /* if the inner ech parsed successfully we have successfully
                 * handled the hello and can skip the whole message */
                if (ret == 0) {
                    /* Copy inner client random for ECH acceptance calculation.
                     * Only on first inner ClientHello (before HRR), not CH2. */
                    if (copyRandom) {
                        XMEMCPY(ssl->arrays->clientRandomInner,
                                ssl->arrays->clientRandom, RAN_LEN);
                    }
                    *inOutIdx += size;
                }
            }
        }
#endif /* HAVE_ECH */
        break;

    #ifdef WOLFSSL_EARLY_DATA
    case end_of_early_data:
        WOLFSSL_MSG("processing end of early data");
        ret = DoTls13EndOfEarlyData(ssl, input, inOutIdx, size);
        break;
    #endif
#endif /* !NO_WOLFSSL_SERVER */

    /* Messages received by both client and server. */
#if !defined(NO_CERTS) && (!defined(NO_WOLFSSL_CLIENT) || \
                           !defined(WOLFSSL_NO_CLIENT_AUTH))
    case certificate:
        WOLFSSL_MSG("processing certificate");
        ret = DoTls13Certificate(ssl, input, inOutIdx, size);
        break;
#endif

#if (!defined(NO_RSA) || defined(HAVE_ECC) || defined(HAVE_ED25519) || \
     defined(HAVE_ED448) || defined(HAVE_FALCON) || \
     defined(WOLFSSL_HAVE_MLDSA) || defined(WOLFSSL_HAVE_SLHDSA)) && \
    !defined(NO_CERTS)
    case certificate_verify:
        WOLFSSL_MSG("processing certificate verify");
        ret = DoTls13CertificateVerify(ssl, input, inOutIdx, size);
        break;
#endif
    case finished:
        WOLFSSL_MSG("processing finished");
        ret = DoTls13Finished(ssl, input, inOutIdx, size, totalSz, NO_SNIFF);
        break;

    case key_update:
        WOLFSSL_MSG("processing key update");
        ret = DoTls13KeyUpdate(ssl, input, inOutIdx, size);
        break;

#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_DTLS_CID)
    case request_connection_id:
        WOLFSSL_MSG("processing request connection id");
        ret = DoDtls13RequestConnectionId(ssl, input, inOutIdx, size);
        break;

    case new_connection_id:
        WOLFSSL_MSG("processing new connection id");
        ret = DoDtls13NewConnectionId(ssl, input, inOutIdx, size);
        break;
#endif /* WOLFSSL_DTLS13 && WOLFSSL_DTLS_CID */

#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_NO_TLS12) && \
    !defined(NO_WOLFSSL_CLIENT)
    case hello_verify_request:
        WOLFSSL_MSG("processing hello verify request");
        ret = DoHelloVerifyRequest(ssl, input, inOutIdx, size);
        break;
#endif
    default:
        WOLFSSL_MSG("Unknown handshake message type");
        ret = UNKNOWN_HANDSHAKE_TYPE;
        break;
    }

#ifdef WOLFSSL_ASYNC_CRYPT
    /* Handler pended: this exact message will be replayed. Mark it so the
     * replay skips its sanity check (it already passed and advanced state).
     * Set from the handler's own ret, before the trailing key-schedule
     * derive below can re-raise WC_PENDING_E for an already-done message. */
    if (ret == WC_NO_ERR_TRACE(WC_PENDING_E))
        ssl->options.asyncReplayMsg = 1;
#endif

#if defined(WOLFSSL_ASYNC_CRYPT) || defined(WOLFSSL_ASYNC_IO)
    /* if async, offset index so this msg will be processed again */
    /* NOTE: check this now before other calls can overwrite ret */
    if ((ret == WC_NO_ERR_TRACE(WC_PENDING_E) ||
         ret == WC_NO_ERR_TRACE(OCSP_WANT_READ)) && *inOutIdx > 0) {
        /* DTLS always stores a message in a buffer when async is enable, so we
         * don't need to adjust for the extra bytes here (*inOutIdx is always
         * == 0) */
        *inOutIdx -= HANDSHAKE_HEADER_SZ;
    }

    /* make sure async error is cleared */
    if (ret == 0 &&
        (ssl->error == WC_NO_ERR_TRACE(WC_PENDING_E) ||
         ssl->error == WC_NO_ERR_TRACE(OCSP_WANT_READ))) {
        ssl->error = 0;
    }
#endif
#if defined(HAVE_WRITE_DUP) && defined(WOLFSSL_POST_HANDSHAKE_AUTH)
    /* Read side: a fresh PHA CertificateRequest. Resume from the transcript
     * the write side published after the previous PHA response, so this CR is
     * hashed onto the same base the server has. */
    if (ret == 0 && type == certificate_request &&
            ssl->options.side == WOLFSSL_CLIENT_END &&
            ssl->dupSide == READ_DUP_SIDE &&
            ssl->options.handShakeState == HANDSHAKE_DONE &&
            ssl->dupWrite != NULL) {
        if (wc_LockMutex(&ssl->dupWrite->dupMutex) != 0)
            return BAD_MUTEX_E;
        if (ssl->dupWrite->postHandshakeSyncedHashState != NULL) {
            FreeHandshakeHashes(ssl);
            ssl->hsHashes = ssl->dupWrite->postHandshakeSyncedHashState;
            ssl->dupWrite->postHandshakeSyncedHashState = NULL;
        }
        wc_UnLockMutex(&ssl->dupWrite->dupMutex);
    }
#endif /* HAVE_WRITE_DUP && WOLFSSL_POST_HANDSHAKE_AUTH */
    if (ret == 0 && type != client_hello && type != session_ticket &&
                                                           type != key_update
#if defined(WOLFSSL_DTLS13) && defined(WOLFSSL_DTLS_CID)
            && type != request_connection_id && type != new_connection_id
#endif
            ) {
        ret = HashInput(ssl, input + inIdx, (int)size);
    }

    alertType = TranslateErrorToAlert(ret);

    /* Skip when a fatal alert already went out for this error. The message
     * handlers reached above send their own, more specific alert before
     * returning (a protocol_version from the version checks in DoClientHello,
     * decode_error, illegal_parameter, inappropriate_fallback), and a second
     * fatal alert on a connection that is already being torn down is not a
     * message the peer can act on. Matches the guard in
     * SendFatalAlertOnly(). */
    if (alertType != invalid_alert &&
            ssl->alert_history.last_tx.level != alert_fatal) {
#ifdef WOLFSSL_DTLS13
        if (type == client_hello && ssl->options.dtls)
            DtlsSetSeqNumForReply(ssl);
#endif
        tmp = SendAlert(ssl, alert_fatal, alertType);
        /* propagate socket error instead of tls error to be sure the error is
         * not ignored by DTLS code */
        if (tmp == WC_NO_ERR_TRACE(SOCKET_ERROR_E))
            ret = SOCKET_ERROR_E;
    }

    if (ret == 0 && ssl->options.tls1_3) {
        /* The message is hashed by now; run the key schedule that belongs to
         * it. */
        ret = DoTls13MsgDerives(ssl, type);
        if (ret != 0)
            return ret;

    #if !defined(NO_WOLFSSL_CLIENT) && defined(WOLFSSL_POST_HANDSHAKE_AUTH)
        if (ssl->options.side == WOLFSSL_CLIENT_END) {
            if (type == certificate_request &&
                                ssl->options.handShakeState == HANDSHAKE_DONE) {
#if defined(HAVE_WRITE_DUP)
                /* Read side cannot write; delegate the cert response to the
                 * write side by saving auth state in the shared WriteDup. */
                if (ssl->dupSide == READ_DUP_SIDE) {
                    if (ssl->dupWrite == NULL)
                        return BAD_STATE_E;
                    if (wc_LockMutex(&ssl->dupWrite->dupMutex) != 0)
                        return BAD_MUTEX_E;
                    /* Copy the current transcript so the write side can
                     * compute the correct Finished MAC. */
                    ret = InitHandshakeHashesAndCopy(ssl, ssl->hsHashes,
                                      &ssl->dupWrite->postHandshakeHashState);
                    if (ret == 0) {
                        /* Copy the cert request context. */
                        CertReqCtx** tail = &ssl->certReqCtx;
                        while (*tail != NULL)
                            tail = &(*tail)->next;
                        *tail = ssl->dupWrite->postHandshakeCertReqCtx;
                        ssl->dupWrite->postHandshakeCertReqCtx = ssl->certReqCtx;
                        ssl->certReqCtx = NULL;
                        ssl->dupWrite->postHandshakeSendVerify =
                            ssl->options.sendVerify;
                        ssl->dupWrite->postHandshakeSigAlgo =
                            ssl->options.sigAlgo;
                        ssl->dupWrite->postHandshakeHashAlgo =
                            ssl->options.hashAlgo;
                    #if !defined(NO_CERTS) && !defined(WOLFSSL_NO_SIGALG)
                        /* The request just parsed decides whether the chain
                         * about to be sent may be SHA-1 signed. */
                        ssl->dupWrite->postHandshakeSha1CertOk =
                            (byte)ssl->options.peerSha1CertOk;
                    #endif
                        ssl->dupWrite->postHandshakeAuthPending = 1;
                    }
                    wc_UnLockMutex(&ssl->dupWrite->dupMutex);
                    /* Leave ssl->options unchanged: read side must not reset
                     * its states or call wolfSSL_connect_TLSv13. */
                }
                else
#endif /* HAVE_WRITE_DUP */
                {
                    /* reset handshake states */
                    ssl->options.clientState = CLIENT_HELLO_COMPLETE;
                    ssl->options.connectState  = FIRST_REPLY_DONE;
                    ssl->options.handShakeState = CLIENT_HELLO_COMPLETE;
                    ssl->options.processReply = 0; /* doProcessInit */

                    /*
                       DTLSv1.3 note: We can't reset serverState to
                       SERVER_FINISHED_COMPLETE with the goal that this connect
                       blocks until the cert/cert_verify/finished flight gets ACKed
                       by the server. The problem is that we will invoke
                       ProcessReplyEx() in that case, but we came here from
                       ProcessReplyEx() and it is not re-entrant safe (the input
                       buffer would still have the certificate_request message). */

                    if (wolfSSL_connect_TLSv13(ssl) != WOLFSSL_SUCCESS) {
                        ret = ssl->error;
                        if (ret != WC_NO_ERR_TRACE(WC_PENDING_E))
                            ret = POST_HAND_AUTH_ERROR;
                    }
                }
            }
        }
    #endif /* !NO_WOLFSSL_CLIENT && WOLFSSL_POST_HANDSHAKE_AUTH */
    }

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls && !ssl->options.dtlsStateful) {
        DtlsResetState(ssl);
        if (DtlsIgnoreError(ret))
            ret = 0;
    }
#endif

    WOLFSSL_LEAVE("DoTls13HandShakeMsgType()", ret);
    return ret;
}


/* Handle a handshake message that has been received.
 *
 * ssl       The SSL/TLS object.
 * input     The message buffer.
 * inOutIdx  On entry, the index into the buffer of the current message.
 *           On exit, the index into the buffer of the next message.
 * totalSz   Length of remaining data in the message buffer.
 * returns 0 on success and otherwise failure.
 */
int DoTls13HandShakeMsg(WOLFSSL* ssl, byte* input, word32* inOutIdx,
                        word32 totalSz)
{
    int    ret = 0;
    word32 inputLength;
    byte   type;
    word32 size = 0;
#if defined(WOLFSSL_ASYNC_CRYPT) || defined(WOLFSSL_NONBLOCK_OCSP)
    /* Nonzero on entry: an earlier message's schedule is unfinished, so a
     * pend from its pre-dispatch drain must re-present this message. */
    byte   kdfStepEntry = ssl->kdfMsgStep;
#endif

    WOLFSSL_ENTER("DoTls13HandShakeMsg");

    /* totalSz is now curStartIdx + curSize (content-only, padSz already
     * subtracted in ProcessReply). */
    if (*inOutIdx > totalSz)
        return BUFFER_ERROR;
    inputLength = totalSz - *inOutIdx;

    /* If there is a pending fragmented handshake message,
     * pending message size will be non-zero. */
    if (ssl->pendingMsgSz == 0) {
    #if defined(WOLFSSL_ASYNC_CRYPT) || defined(WOLFSSL_NONBLOCK_OCSP)
        word32 startIdx = *inOutIdx;
    #endif

        if (GetHandshakeHeader(ssl, input, inOutIdx, &type, &size,
                               totalSz) != 0) {
            WOLFSSL_ERROR_VERBOSE(PARSE_ERROR);
            return PARSE_ERROR;
        }

        ret = EarlySanityCheckMsgReceived(ssl, type,
                (inputLength > HANDSHAKE_HEADER_SZ) ?
                min(inputLength - HANDSHAKE_HEADER_SZ, size) : 0);
        if (ret != 0) {
            WOLFSSL_ERROR(ret);
            return ret;
        }

        /* Cap the maximum size of a handshake message to something reasonable.
         * By default is the maximum size of a certificate message assuming
         * nine 2048-bit RSA certificates in the chain. */
        if (size > MAX_HANDSHAKE_SZ) {
            WOLFSSL_MSG("Handshake message too large");
            WOLFSSL_ERROR_VERBOSE(HANDSHAKE_SIZE_ERROR);
            return HANDSHAKE_SIZE_ERROR;
        }

        /* size is the size of the certificate message payload */
        if (inputLength - HANDSHAKE_HEADER_SZ < size) {
            /* Commit pending state only after the allocation succeeds. */
            ssl->pendingMsg = (byte*)XMALLOC(size + HANDSHAKE_HEADER_SZ,
                                             ssl->heap, DYNAMIC_TYPE_ARRAYS);
            if (ssl->pendingMsg == NULL)
                return MEMORY_E;
            ssl->pendingMsgType = type;
            ssl->pendingMsgSz = size + HANDSHAKE_HEADER_SZ;
            XMEMCPY(ssl->pendingMsg,
                    input + *inOutIdx - HANDSHAKE_HEADER_SZ,
                    inputLength);
            ssl->pendingMsgOffset = inputLength;
            *inOutIdx += inputLength - HANDSHAKE_HEADER_SZ;
            return 0;
        }

        ret = DoTls13HandShakeMsgType(ssl, input, inOutIdx, type, size,
                                      totalSz);
    #if defined(WOLFSSL_ASYNC_CRYPT) || defined(WOLFSSL_NONBLOCK_OCSP)
        if ((ret == WC_NO_ERR_TRACE(WC_PENDING_E) &&
                 (ssl->kdfMsgStep == 0 || kdfStepEntry != 0) &&
                 ssl->options.processReply != 0 /* doProcessInit */) ||
                ret == WC_NO_ERR_TRACE(OCSP_WANT_READ)) {
            /* Re-present for in-handler pends and pre-dispatch drain pends.
             * Not for post-handler pends, which committed the message: a
             * key-schedule pend (kdfMsgStep != 0) resumes through
             * DoTls13MsgDerives(), and a post-handshake-auth send pend
             * (processReply reset to doProcessInit) resumes through
             * wolfSSL_negotiate(). */
            *inOutIdx = startIdx;
        }
    #endif
    }
    else {
        if (inputLength + ssl->pendingMsgOffset > ssl->pendingMsgSz) {
            inputLength = ssl->pendingMsgSz - ssl->pendingMsgOffset;
        }

        ret = EarlySanityCheckMsgReceived(ssl, ssl->pendingMsgType,
                inputLength);
        if (ret != 0) {
            WOLFSSL_ERROR(ret);
            return ret;
        }

        XMEMCPY(ssl->pendingMsg + ssl->pendingMsgOffset,
                input + *inOutIdx, inputLength);
        ssl->pendingMsgOffset += inputLength;
        *inOutIdx += inputLength;

        if (ssl->pendingMsgOffset == ssl->pendingMsgSz)
        {
            word32 idx = 0;
            ret = DoTls13HandShakeMsgType(ssl,
                                ssl->pendingMsg + HANDSHAKE_HEADER_SZ,
                                &idx, ssl->pendingMsgType,
                                ssl->pendingMsgSz - HANDSHAKE_HEADER_SZ,
                                ssl->pendingMsgSz);
        #if defined(WOLFSSL_ASYNC_CRYPT) || defined(WOLFSSL_NONBLOCK_OCSP)
            if ((ret == WC_NO_ERR_TRACE(WC_PENDING_E) &&
                 (ssl->kdfMsgStep == 0 || kdfStepEntry != 0) &&
                 ssl->options.processReply != 0 /* doProcessInit */) ||
                ret == WC_NO_ERR_TRACE(OCSP_WANT_READ)) {
                /* Re-present the fragment; a post-handler pend falls
                 * through and consumes the message. */
                ssl->pendingMsgOffset -= inputLength;
                *inOutIdx -= inputLength;
            }
            else
        #endif
            {
                XFREE(ssl->pendingMsg, ssl->heap, DYNAMIC_TYPE_ARRAYS);
                ssl->pendingMsg = NULL;
                ssl->pendingMsgSz = 0;
            }
        }
    }

    WOLFSSL_LEAVE("DoTls13HandShakeMsg", ret);
    return ret;
}

#ifndef NO_WOLFSSL_CLIENT

/* The client connecting to the server.
 * The protocol version is expecting to be TLS v1.3.
 * If the server downgrades, and older versions of the protocol are compiled
 * in, the client will fallback to wolfSSL_connect().
 * Please see note at top of README if you get an error from connect.
 *
 * ssl  The SSL/TLS object.
 * returns WOLFSSL_SUCCESS on successful handshake, WOLFSSL_FATAL_ERROR when
 * unrecoverable error occurs and 0 otherwise.
 * For more error information use wolfSSL_get_error().
 */
int wolfSSL_connect_TLSv13(WOLFSSL* ssl)
{
    int advanceState;
    int ret = 0;

    WOLFSSL_ENTER("wolfSSL_connect_TLSv13");

#ifdef HAVE_ERRNO_H
    errno = 0;
#endif

    if (ssl == NULL)
        return BAD_FUNC_ARG;

    if (ssl->options.side != WOLFSSL_CLIENT_END) {
        ssl->error = SIDE_ERROR;
        WOLFSSL_ERROR(ssl->error);
        return WOLFSSL_FATAL_ERROR;
    }

    /* make sure this wolfSSL object has arrays and rng setup. Protects
     * case where the WOLFSSL object is reused via wolfSSL_clear() */
    if ((ret = ReinitSSL(ssl, ssl->ctx, 0)) != 0) {
        return ret;
    }

#ifdef WOLFSSL_DTLS
    if (ssl->version.major == DTLS_MAJOR) {
        ssl->options.dtls   = 1;
        ssl->options.dtlsStateful = 1;
    }
#endif

#ifdef WOLFSSL_WOLFSENTRY_HOOKS
    if ((ssl->ConnectFilter != NULL) &&
        (ssl->options.connectState == CONNECT_BEGIN))
    {
        wolfSSL_netfilter_decision_t res;
        if ((ssl->ConnectFilter(ssl, ssl->ConnectFilter_arg, &res) ==
             WOLFSSL_SUCCESS) &&
            (res == WOLFSSL_NETFILTER_REJECT)) {
            ssl->error = SOCKET_FILTERED_E;
            WOLFSSL_ERROR(ssl->error);
            return WOLFSSL_FATAL_ERROR;
        }
    }
#endif /* WOLFSSL_WOLFSENTRY_HOOKS */

    /* fragOffset is non-zero when sending fragments. On the last
     * fragment, fragOffset is zero again, and the state can be
     * advanced. Also, only advance from states in which we send data */
    advanceState = (ssl->options.connectState == CONNECT_BEGIN ||
            ssl->options.connectState == HELLO_AGAIN ||
            (ssl->options.connectState >= FIRST_REPLY_DONE &&
             ssl->options.connectState <= FIRST_REPLY_FOURTH));

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls)
        advanceState = advanceState && !ssl->dtls13SendingFragments
            && !ssl->dtls13SendingAckOrRtx;
#endif /* WOLFSSL_DTLS13 */

    if (ssl->buffers.outputBuffer.length > 0
    #ifdef WOLFSSL_ASYNC_CRYPT
        /* do not send buffered or advance state if last error was an
            async pending operation */
        && ssl->error != WC_NO_ERR_TRACE(WC_PENDING_E)
    #endif
    ) {
        if ((ret = SendBuffered(ssl)) == 0) {
            if (ssl->fragOffset == 0 && !ssl->options.buildingMsg) {
                if (advanceState) {
#ifdef WOLFSSL_DTLS13
                    if (ssl->options.dtls && IsAtLeastTLSv1_3(ssl->version) &&
                        ssl->options.connectState == FIRST_REPLY_FOURTH) {
                    /* WAIT_FINISHED_ACK is a state added afterwards, but it
                       can't follow FIRST_REPLY_FOURTH in the enum order. Indeed
                       the value of the enum ConnectState is stored in
                       serialized session. This would make importing serialized
                       session from other wolfSSL version incompatible */
                        ssl->options.connectState = WAIT_FINISHED_ACK;
                    }
                    else
#endif /* WOLFSSL_DTLS13 */
                    {
                        ssl->options.connectState++;
                    }
                    WOLFSSL_MSG("connect state: "
                                "Advanced from last buffered fragment send");
#ifdef WOLFSSL_ASYNC_IO
                    FreeAsyncCtx(ssl, 0);
#endif

                }
            }
            else {
                WOLFSSL_MSG("connect state: "
                            "Not advanced, more fragments to send");
            }
#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls)
                ssl->dtls13SendingAckOrRtx = 0;
#endif /* WOLFSSL_DTLS13 */

        }
        else {
            ssl->error = ret;
            WOLFSSL_ERROR(ssl->error);
            return WOLFSSL_FATAL_ERROR;
        }
    }

    ret = RetrySendAlert(ssl);
    if (ret != 0) {
        ssl->error = ret;
        WOLFSSL_ERROR(ssl->error);
        return WOLFSSL_FATAL_ERROR;
    }

#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls && ssl->dtls13SendingFragments) {
        if ((ssl->error = Dtls13FragmentsContinue(ssl)) != 0) {
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
        }

        /* we sent all the fragments. Advance state. */
        ssl->options.connectState++;
    }
#endif /* WOLFSSL_DTLS13 */

    switch (ssl->options.connectState) {

        case CONNECT_BEGIN:
            /* Always send client hello first. */
            if ((ssl->error = SendTls13ClientHello(ssl)) != 0) {
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
            }

            ssl->options.connectState = CLIENT_HELLO_SENT;
            WOLFSSL_MSG("TLSv13 connect state: CLIENT_HELLO_SENT");
            FALL_THROUGH;

        case CLIENT_HELLO_SENT:
    #ifdef WOLFSSL_EARLY_DATA
            if (ssl->earlyData != no_early_data &&
                ssl->options.handShakeState != CLIENT_HELLO_COMPLETE) {
        #if defined(WOLFSSL_TLS13_MIDDLEBOX_COMPAT)
                    if (!ssl->options.dtls && !ssl->options.sentChangeCipher
                            && ssl->options.tls13MiddleBoxCompat) {
                        ssl->error = SendChangeCipher(ssl);
                        /* A short send leaves the record queued in the output
                         * buffer, so a resumed connect must not build a second
                         * one. Same on every other site. */
                        if (ssl->error == 0 ||
                                ssl->error == WC_NO_ERR_TRACE(WANT_WRITE)) {
                            ssl->options.sentChangeCipher = 1;
                        }
                        if (ssl->error != 0) {
                            WOLFSSL_ERROR(ssl->error);
                            return WOLFSSL_FATAL_ERROR;
                        }
                    }
        #endif
                ssl->options.handShakeState = CLIENT_HELLO_COMPLETE;
                return WOLFSSL_SUCCESS;
            }
    #endif
            /* Get the response/s from the server. */
            while (ssl->options.serverState <
                    SERVER_HELLOVERIFYREQUEST_COMPLETE) {
                if ((ssl->error = ProcessReply(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                }

#ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls) {
                    if ((ssl->error = Dtls13DoScheduledWork(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
#endif /* WOLFSSL_DTLS13 */
            }

            if (!ssl->options.tls1_3) {
    #ifndef WOLFSSL_NO_TLS12
                if (ssl->options.downgrade)
                    return wolfSSL_connect(ssl);
    #endif
                WOLFSSL_MSG("Client using higher version, fatal error");
                WOLFSSL_ERROR_VERBOSE(VERSION_ERROR);
                return VERSION_ERROR;
            }

            ssl->options.connectState = HELLO_AGAIN;
            WOLFSSL_MSG("connect state: HELLO_AGAIN");
            FALL_THROUGH;

        case HELLO_AGAIN:

            if (ssl->options.serverState ==
                                          SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
        #if defined(WOLFSSL_TLS13_MIDDLEBOX_COMPAT)
                if (!ssl->options.dtls && !ssl->options.sentChangeCipher
                    && ssl->options.tls13MiddleBoxCompat) {
                    ssl->error = SendChangeCipher(ssl);
                    if (ssl->error == 0 ||
                            ssl->error == WC_NO_ERR_TRACE(WANT_WRITE)) {
                        ssl->options.sentChangeCipher = 1;
                    }
                    if (ssl->error != 0) {
                        /* The second ClientHello still has to follow, so hold
                         * the state machine on this case while the record
                         * drains. */
                        ssl->options.buildingMsg = 1;
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
        #endif
                /* Try again with different security parameters. */
                if ((ssl->error = SendTls13ClientHello(ssl)) != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }

            ssl->options.connectState = HELLO_AGAIN_REPLY;
            WOLFSSL_MSG("connect state: HELLO_AGAIN_REPLY");
            FALL_THROUGH;

        case HELLO_AGAIN_REPLY:
            /* Get the response/s from the server. */
            while (ssl->options.serverState < SERVER_FINISHED_COMPLETE) {
#ifdef WOLFSSL_DTLS13
                if (!IsAtLeastTLSv1_3(ssl->version)) {
        #ifndef WOLFSSL_NO_TLS12
                    if (ssl->options.downgrade)
                        return wolfSSL_connect(ssl);
        #endif
                }
#endif /* WOLFSSL_DTLS13 */
                if ((ssl->error = ProcessReply(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                }

#ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls) {
                    if ((ssl->error = Dtls13DoScheduledWork(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
#endif /* WOLFSSL_DTLS13 */
            }

            /* Finish a key schedule the Finished handler left pending:
             * it must complete before this side's sends advance the
             * transcript the traffic secrets hash. */
            if (ssl->kdfMsgStep > 0) {
                ssl->error = DoTls13MsgDerives(ssl, ssl->kdfMsgType);
                if (ssl->error != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }

            ssl->options.connectState = FIRST_REPLY_DONE;
            WOLFSSL_MSG("connect state: FIRST_REPLY_DONE");
            FALL_THROUGH;

        case FIRST_REPLY_DONE:
            if (ssl->options.certOnly)
                return WOLFSSL_SUCCESS;
        #ifdef WOLFSSL_EARLY_DATA
            if (!ssl->options.dtls && ssl->earlyData != no_early_data
                && !WOLFSSL_IS_QUIC(ssl)) {
                if ((ssl->error = SendTls13EndOfEarlyData(ssl)) != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
                WOLFSSL_MSG("sent: end_of_early_data");
            }
        #endif

            ssl->options.connectState = FIRST_REPLY_FIRST;
            WOLFSSL_MSG("connect state: FIRST_REPLY_FIRST");
            FALL_THROUGH;

        case FIRST_REPLY_FIRST:
        #if defined(WOLFSSL_TLS13_MIDDLEBOX_COMPAT)
            if (!ssl->options.sentChangeCipher && !ssl->options.dtls
                && ssl->options.tls13MiddleBoxCompat) {
                ssl->error = SendChangeCipher(ssl);
                if (ssl->error == 0 ||
                        ssl->error == WC_NO_ERR_TRACE(WANT_WRITE)) {
                    ssl->options.sentChangeCipher = 1;
                }
                if (ssl->error != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }
        #endif

            ssl->options.connectState = FIRST_REPLY_SECOND;
            WOLFSSL_MSG("connect state: FIRST_REPLY_SECOND");
            FALL_THROUGH;

        case FIRST_REPLY_SECOND:
            /* CLIENT: check peer authentication. */
            if (!ssl->options.peerAuthGood) {
                WOLFSSL_MSG("Server authentication did not happen");
                WOLFSSL_ERROR_VERBOSE(WOLFSSL_FATAL_ERROR);
                return WOLFSSL_FATAL_ERROR;
            }
        #ifndef NO_CERTS
            if ((!ssl->options.resuming || TLS13_AFTER_HANDSHAKE(ssl)) &&
                    ssl->options.sendVerify) {
                ssl->error = SendTls13Certificate(ssl);
                if (ssl->error != 0) {
                    wolfssl_local_MaybeCheckAlertOnErr(ssl, ssl->error);
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
                WOLFSSL_MSG("sent: certificate");
            }
        #endif

            ssl->options.connectState = FIRST_REPLY_THIRD;
            WOLFSSL_MSG("connect state: FIRST_REPLY_THIRD");
            FALL_THROUGH;

        case FIRST_REPLY_THIRD:
        #if (!defined(NO_CERTS) && (!defined(NO_RSA) || defined(HAVE_ECC) || \
             defined(HAVE_ED25519) || defined(HAVE_ED448) || \
             defined(HAVE_FALCON) || defined(WOLFSSL_HAVE_MLDSA) || \
             defined(WOLFSSL_HAVE_SLHDSA))) && \
             (!defined(NO_WOLFSSL_SERVER) || !defined(WOLFSSL_NO_CLIENT_AUTH))
            if ((!ssl->options.resuming || TLS13_AFTER_HANDSHAKE(ssl)) &&
                    ssl->options.sendVerify) {
                ssl->error = SendTls13CertificateVerify(ssl);
                if (ssl->error != 0) {
                    wolfssl_local_MaybeCheckAlertOnErr(ssl, ssl->error);
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
                WOLFSSL_MSG("sent: certificate verify");
            }
        #endif

            ssl->options.connectState = FIRST_REPLY_FOURTH;
            WOLFSSL_MSG("connect state: FIRST_REPLY_FOURTH");
            FALL_THROUGH;

        case FIRST_REPLY_FOURTH:
            if ((ssl->error = SendTls13Finished(ssl)) != 0) {
                wolfssl_local_MaybeCheckAlertOnErr(ssl, ssl->error);
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
            }
            WOLFSSL_MSG("sent: finished");

#ifdef WOLFSSL_DTLS13
            ssl->options.connectState = WAIT_FINISHED_ACK;
            WOLFSSL_MSG("connect state: WAIT_FINISHED_ACK");
            FALL_THROUGH;

        case WAIT_FINISHED_ACK:
            if (ssl->options.dtls) {
                while (ssl->options.serverState != SERVER_FINISHED_ACKED) {
                    if ((ssl->error = ProcessReply(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }

                    if ((ssl->error = Dtls13DoScheduledWork(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
            }
#endif /* WOLFSSL_DTLS13 */
            ssl->options.connectState = FINISHED_DONE;
            WOLFSSL_MSG("connect state: FINISHED_DONE");
            FALL_THROUGH;

        case FINISHED_DONE:
        #ifndef NO_HANDSHAKE_DONE_CB
            if (ssl->hsDoneCb != NULL) {
                int cbret = ssl->hsDoneCb(ssl, ssl->hsDoneCtx);
                if (cbret < 0) {
                    ssl->error = cbret;
                    WOLFSSL_ERROR_VERBOSE(ssl->error);
                    WOLFSSL_MSG("HandShake Done Cb don't continue error");
                    return WOLFSSL_FATAL_ERROR;
                }
            }
        #endif /* NO_HANDSHAKE_DONE_CB */

        #if defined(HAVE_ECH)
            /* RFC 9849 s6.1.6: if we offered ECH but the server rejected it,
             * send ech_required alert and abort before returning to the app */
            if (ssl->echConfigs != NULL && !ssl->options.disableECH &&
                    !ssl->options.echAccepted) {
                if (ssl->echRetryConfigs != NULL) {
                    ssl->options.echRetryConfigsAccepted = 1;
                }
                SendAlert(ssl, alert_fatal, ech_required);
                ssl->error = ECH_REQUIRED_E;
                WOLFSSL_ERROR_VERBOSE(ECH_REQUIRED_E);
                return WOLFSSL_FATAL_ERROR;
            }
        #endif /* HAVE_ECH */

            if (!ssl->options.keepResources) {
                FreeHandshakeResources(ssl);
            }
        #if defined(WOLFSSL_ASYNC_IO) && !defined(WOLFSSL_ASYNC_CRYPT)
            /* Free the remaining async context if not using it for crypto */
            FreeAsyncCtx(ssl, 1);
        #endif

            ssl->error = 0; /* clear the error */

            WOLFSSL_LEAVE("wolfSSL_connect_TLSv13", WOLFSSL_SUCCESS);
            return WOLFSSL_SUCCESS;

        default:
            WOLFSSL_MSG("Unknown connect state ERROR");
            return WOLFSSL_FATAL_ERROR; /* unknown connect state */
    }
}
#endif

#if defined(WOLFSSL_SEND_HRR_COOKIE)
/* Send a cookie with the HelloRetryRequest to avoid storing state.
 *
 * ssl       SSL/TLS object.
 * secret    Secret to use when generating integrity check for cookie.
 *           A value of NULL indicates to generate a new random secret.
 * secretSz  Size of secret data in bytes.
 *           Use a value of 0 to indicate use of default size.
 * returns BAD_FUNC_ARG when ssl is NULL or not using TLS v1.3, SIDE_ERROR when
 * called on a client; WOLFSSL_SUCCESS on success and otherwise failure.
 */
int wolfSSL_send_hrr_cookie(WOLFSSL* ssl, const unsigned char* secret,
                            unsigned int secretSz)
{
    int ret;

    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;
 #ifndef NO_WOLFSSL_SERVER
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

    if (secretSz == 0) {
    #ifndef NO_SHA256
        secretSz = WC_SHA256_DIGEST_SIZE;
    #elif defined(WOLFSSL_SHA384)
        secretSz = WC_SHA384_DIGEST_SIZE;
    #elif defined(WOLFSSL_TLS13_SHA512)
        secretSz = WC_SHA512_DIGEST_SIZE;
    #elif defined(WOLFSSL_SM3)
        secretSz = WC_SM3_DIGEST_SIZE;
    #else
        #error "No digest to available to use with HMAC for cookies."
    #endif /* NO_SHA */
    }

    if (secretSz != ssl->buffers.tls13CookieSecret.length) {
        byte* newSecret;

        if (ssl->buffers.tls13CookieSecret.buffer != NULL) {
            ForceZero(ssl->buffers.tls13CookieSecret.buffer,
                      ssl->buffers.tls13CookieSecret.length);
            XFREE(ssl->buffers.tls13CookieSecret.buffer,
                  ssl->heap, DYNAMIC_TYPE_COOKIE_PWD);
        }

        newSecret = (byte*)XMALLOC(secretSz, ssl->heap,
                                   DYNAMIC_TYPE_COOKIE_PWD);
        if (newSecret == NULL) {
            ssl->buffers.tls13CookieSecret.buffer = NULL;
            ssl->buffers.tls13CookieSecret.length = 0;
            WOLFSSL_MSG("couldn't allocate new cookie secret");
            return MEMORY_ERROR;
        }
        ssl->buffers.tls13CookieSecret.buffer = newSecret;
        ssl->buffers.tls13CookieSecret.length = secretSz;
    #ifdef WOLFSSL_CHECK_MEM_ZERO
        wc_MemZero_Add("wolfSSL_send_hrr_cookie secret",
            ssl->buffers.tls13CookieSecret.buffer,
            ssl->buffers.tls13CookieSecret.length);
    #endif
    }

    /* If the supplied secret is NULL, randomly generate a new secret. */
    if (secret == NULL) {
        ret = wc_RNG_GenerateBlock(ssl->rng,
                               ssl->buffers.tls13CookieSecret.buffer, secretSz);
        if (ret < 0)
            return ret;
    }
    else
        XMEMCPY(ssl->buffers.tls13CookieSecret.buffer, secret, secretSz);

    ssl->options.sendCookie = 1;

    ret = WOLFSSL_SUCCESS;
#else
    (void)secret;
    (void)secretSz;

    ret = SIDE_ERROR;
#endif

    return ret;
}

int wolfSSL_disable_hrr_cookie(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

#ifdef NO_WOLFSSL_SERVER
    return SIDE_ERROR;
#else
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

    if (ssl->buffers.tls13CookieSecret.buffer != NULL) {
        ForceZero(ssl->buffers.tls13CookieSecret.buffer,
            ssl->buffers.tls13CookieSecret.length);
        XFREE(ssl->buffers.tls13CookieSecret.buffer, ssl->heap,
            DYNAMIC_TYPE_COOKIE_PWD);
        ssl->buffers.tls13CookieSecret.buffer = NULL;
        ssl->buffers.tls13CookieSecret.length = 0;
    }

    if (ssl->buffers.tls13CookieSecretSecondary.buffer != NULL) {
        ForceZero(ssl->buffers.tls13CookieSecretSecondary.buffer,
            ssl->buffers.tls13CookieSecretSecondary.length);
        XFREE(ssl->buffers.tls13CookieSecretSecondary.buffer, ssl->heap,
            DYNAMIC_TYPE_COOKIE_PWD);
        ssl->buffers.tls13CookieSecretSecondary.buffer = NULL;
        ssl->buffers.tls13CookieSecretSecondary.length = 0;
    }

    ssl->options.sendCookie = 0;
    return WOLFSSL_SUCCESS;
#endif /* NO_WOLFSSL_SERVER */
}

/* Set a secondary HelloRetryRequest cookie secret used only when verifying a
 * received cookie, and only if the primary secret (set by
 * wolfSSL_send_hrr_cookie()) fails to verify it.
 *
 * This supports an application-driven cookie-secret rotation on a stateless
 * DTLS 1.3 server: after rotating the primary secret, install the previous
 * secret here so that cookies already issued under it are still accepted for
 * an overlap window.  It is never used to issue cookies.
 *
 * This API is DTLS only - TLS 1.3 over a reliable transport does not operate
 * statelessly across the HelloRetryRequest exchange, so a secondary cookie
 * secret has no use there.
 *
 * ssl       SSL/TLS object.
 * secret    Secondary secret to verify cookies against.  A value of NULL (or a
 *           secretSz of 0) clears any previously set secondary secret.
 * secretSz  Size of secret data in bytes.
 * returns BAD_FUNC_ARG when ssl is NULL, not TLS v1.3 or not DTLS; SIDE_ERROR
 * when called on a client; WOLFSSL_SUCCESS on success and otherwise failure.
 */
int wolfSSL_set_hrr_cookie_secret_secondary(WOLFSSL* ssl,
    const unsigned char* secret, unsigned int secretSz)
{
    int ret;

    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;
#ifndef NO_WOLFSSL_SERVER
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;
    /* DTLS only - TLS 1.3 does not verify cookies statelessly. */
    if (!ssl->options.dtls) {
        WOLFSSL_MSG("Secondary HRR cookie secret is DTLS only");
        return BAD_FUNC_ARG;
    }

    /* Clear any existing secondary secret. */
    if (ssl->buffers.tls13CookieSecretSecondary.buffer != NULL) {
        ForceZero(ssl->buffers.tls13CookieSecretSecondary.buffer,
                  ssl->buffers.tls13CookieSecretSecondary.length);
        XFREE(ssl->buffers.tls13CookieSecretSecondary.buffer, ssl->heap,
              DYNAMIC_TYPE_COOKIE_PWD);
        ssl->buffers.tls13CookieSecretSecondary.buffer = NULL;
        ssl->buffers.tls13CookieSecretSecondary.length = 0;
    }

    /* A NULL/empty secret just clears the secondary secret. */
    if (secret == NULL || secretSz == 0) {
        ret = WOLFSSL_SUCCESS;
    }
    else {
        byte* newSecret = (byte*)XMALLOC(secretSz, ssl->heap,
                                         DYNAMIC_TYPE_COOKIE_PWD);
        if (newSecret == NULL) {
            WOLFSSL_MSG("couldn't allocate secondary cookie secret");
            ret = MEMORY_ERROR;
        }
        else {
            XMEMCPY(newSecret, secret, secretSz);
            ssl->buffers.tls13CookieSecretSecondary.buffer = newSecret;
            ssl->buffers.tls13CookieSecretSecondary.length = secretSz;
        #ifdef WOLFSSL_CHECK_MEM_ZERO
            wc_MemZero_Add("wolfSSL_set_hrr_cookie_secret_secondary secret",
                ssl->buffers.tls13CookieSecretSecondary.buffer,
                ssl->buffers.tls13CookieSecretSecondary.length);
        #endif
            ret = WOLFSSL_SUCCESS;
        }
    }
#else
    (void)secret;
    (void)secretSz;

    ret = SIDE_ERROR;
#endif

    return ret;
}

#endif /* defined(WOLFSSL_SEND_HRR_COOKIE) */

#ifdef HAVE_SUPPORTED_CURVES
/* Create a key share entry from group.
 * Generates a key pair.
 *
 * ssl    The SSL/TLS object.
 * group  The named group.
 * returns 0 on success, otherwise failure.
 *   for async can return WC_PENDING_E and should be called again
 */
int wolfSSL_UseKeyShare(WOLFSSL* ssl, word16 group)
{
    int ret;

    if (ssl == NULL)
        return BAD_FUNC_ARG;

#ifdef WOLFSSL_ASYNC_CRYPT
    ret = wolfSSL_AsyncPop(ssl, NULL);
    if (ret != WC_NO_ERR_TRACE(WC_NO_PENDING_E)) {
        /* Check for error */
        if (ret < 0)
            return ret;
    }
#endif

#if defined(WOLFSSL_HAVE_MLKEM)
    if (WOLFSSL_NAMED_GROUP_IS_PQC(group) ||
        WOLFSSL_NAMED_GROUP_IS_PQC_HYBRID(group)) {

        if (!IsAtLeastTLSv1_3(ssl->version)) {
            return BAD_FUNC_ARG;
        }

        if (ssl->options.side == WOLFSSL_SERVER_END) {
            /* If I am the server of a KEM connection, do not do keygen because
             * I'm going to encapsulate with the client's public key. Note that
             * I might be the client and ssl->option.side has not been properly
             * set yet. In that case the KeyGen operation will be deferred to
             * connection time. */
            return WOLFSSL_SUCCESS;
        }
    }
#endif
#if defined(NO_TLS)
    (void)ret;
    (void)group;
#else
    /* Check if the group is supported. */
    if (!TLSX_IsGroupSupported(group, ssl->options.side)) {
        WOLFSSL_MSG("Group not supported.");
        return BAD_FUNC_ARG;
    }

    ret = TLSX_KeyShare_Use(ssl, group, 0, NULL, NULL, &ssl->extensions);
    if (ret != 0)
        return ret;
#endif /* NO_TLS */
    return WOLFSSL_SUCCESS;
}

/* Send no key share entries - use HelloRetryRequest to negotiate shared group.
 *
 * ssl    The SSL/TLS object.
 * returns 0 on success, otherwise failure.
 */
int wolfSSL_NoKeyShares(WOLFSSL* ssl)
{
    int ret;

    if (ssl == NULL)
        return BAD_FUNC_ARG;
    if (ssl->options.side == WOLFSSL_SERVER_END)
        return SIDE_ERROR;
#if defined(NO_TLS)
    (void)ret;
#else
    ret = TLSX_KeyShare_Empty(ssl);
    if (ret != 0)
        return ret;
#endif /* NO_TLS */
    return WOLFSSL_SUCCESS;
}
#endif

#ifdef WOLFSSL_DUAL_ALG_CERTS
int wolfSSL_UseCKS(WOLFSSL* ssl, byte *sigSpec, word16 sigSpecSz)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->ctx->method->version) ||
        sigSpec == NULL || sigSpecSz == 0)
        return BAD_FUNC_ARG;

    ssl->sigSpec = sigSpec;
    ssl->sigSpecSz = sigSpecSz;
    return WOLFSSL_SUCCESS;
}

int wolfSSL_CTX_UseCKS(WOLFSSL_CTX* ctx, byte *sigSpec, word16 sigSpecSz)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version) ||
        sigSpec == NULL || sigSpecSz == 0)
        return BAD_FUNC_ARG;

    ctx->sigSpec = sigSpec;
    ctx->sigSpecSz = sigSpecSz;
    return WOLFSSL_SUCCESS;
}
#endif /* WOLFSSL_DUAL_ALG_CERTS */

/* Do not send a ticket after TLS v1.3 handshake for resumption.
 *
 * ctx  The SSL/TLS CTX object.
 * returns BAD_FUNC_ARG when ctx is NULL and 0 on success.
 */
int wolfSSL_CTX_no_ticket_TLSv13(WOLFSSL_CTX* ctx)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;
    if (ctx->method->side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

#ifdef HAVE_SESSION_TICKET
    ctx->noTicketTls13 = 1;
#endif

    return 0;
}

/* Do not send a ticket after TLS v1.3 handshake for resumption.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL, not using TLS v1.3, or called on
 * a client and 0 on success.
 */
int wolfSSL_no_ticket_TLSv13(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

#ifdef HAVE_SESSION_TICKET
    ssl->options.noTicketTls13 = 1;
#endif

    return 0;
}

/* Disallow (EC)DHE key exchange when using pre-shared keys.
 *
 * ctx  The SSL/TLS CTX object.
 * returns BAD_FUNC_ARG when ctx is NULL and 0 on success.
 */
int wolfSSL_CTX_no_dhe_psk(WOLFSSL_CTX* ctx)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ctx->noPskDheKe = 1;
#endif

    return 0;
}

/* Disallow (EC)DHE key exchange when using pre-shared keys.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL, or not using TLS v1.3 and 0 on
 * success.
 */
int wolfSSL_no_dhe_psk(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ssl->options.noPskDheKe = 1;
    ssl->options.noPskDheKePolicy = 1;
#endif

    return 0;
}

#ifdef HAVE_SUPPORTED_CURVES
/* Only allow (EC)DHE key exchange when using pre-shared keys.
 *
 * ctx  The SSL/TLS CTX object.
 * returns BAD_FUNC_ARG when ctx is NULL and 0 on success.
 */
int wolfSSL_CTX_only_dhe_psk(WOLFSSL_CTX* ctx)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ctx->onlyPskDheKe = 1;
#endif

    return 0;
}

/* Only allow (EC)DHE key exchange when using pre-shared keys.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL, or not using TLS v1.3 and 0 on
 * success.
 */
int wolfSSL_only_dhe_psk(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ssl->options.onlyPskDheKe = 1;
#endif

    return 0;
}
#endif /* HAVE_SUPPORTED_CURVES */

/* Require that an external Pre-Shared Key is negotiated for the handshake to
 * succeed. TLS 1.3 / DTLS 1.3 only - in (D)TLS 1.2 the use of a PSK is
 * determined by the negotiated cipher suite, so a mandatory PSK is configured
 * there by restricting the cipher suite list to PSK suites.
 *
 * ctx  The SSL/TLS CTX object.
 * returns BAD_FUNC_ARG when ctx is NULL or not at least TLS v1.3, 0 on success.
 */
int wolfSSL_CTX_require_psk(WOLFSSL_CTX* ctx)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ctx->failNoPSK = 1;
    /* The requirement can only be enforced for (D)TLS 1.3, so keep it
     * fail-closed by disabling a version downgrade. Otherwise a
     * downgrade-capable context (e.g. from a v23 method) could silently fall
     * back to (D)TLS 1.2 and complete without any PSK. */
    ctx->method->downgrade = 0;
#endif

    return 0;
}

/* Require that an external Pre-Shared Key is negotiated for the handshake to
 * succeed. See wolfSSL_CTX_require_psk().
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL or not at least TLS v1.3, 0 on success.
 */
int wolfSSL_require_psk(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    ssl->options.failNoPSK = 1;
    /* See wolfSSL_CTX_require_psk() - keep the requirement fail-closed by
     * disabling a version downgrade to (D)TLS 1.2. */
    ssl->options.downgrade = 0;
#endif

    return 0;
}

int Tls13UpdateKeys(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

#ifdef WOLFSSL_QUIC
    /* RFC 9001 Section 6: a QUIC connection must not send a TLS KeyUpdate;
     * key updates are handled at the QUIC packet-protection layer. */
    if (WOLFSSL_IS_QUIC(ssl))
        return BAD_FUNC_ARG;
#endif

#ifdef WOLFSSL_DTLS13
    /* we are already waiting for the ack of a sent key update message. We can't
       send another one before receiving its ack. Either wolfSSL_update_keys()
       was invoked multiple times over a short period of time or we replied to a
       KeyUpdate with update request. We'll just ignore sending this
       KeyUpdate. */
    /* TODO: add WOLFSSL_ERROR_ALREADY_IN_PROGRESS type of error here */
    if (ssl->options.dtls && ssl->dtls13WaitKeyUpdateAck)
        return 0;
#endif /* WOLFSSL_DTLS13 */

    return SendTls13KeyUpdate(ssl);
}

/* Update the keys for encryption and decryption.
 * If using non-blocking I/O and WOLFSSL_ERROR_WANT_WRITE is returned then
 * calling wolfSSL_write() will have the message sent when ready.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL, not using TLS v1.3, or running over
 * QUIC (RFC 9001 handles key updates at the QUIC packet-protection layer),
 * WOLFSSL_ERROR_WANT_WRITE when non-blocking I/O is not ready to write,
 * WOLFSSL_SUCCESS on success and otherwise failure.
 */
int wolfSSL_update_keys(WOLFSSL* ssl)
{
    int ret;
    ret = Tls13UpdateKeys(ssl);
    if (ret == WC_NO_ERR_TRACE(WANT_WRITE))
        ret = WOLFSSL_ERROR_WANT_WRITE;
    else if (ret == 0)
        ret = WOLFSSL_SUCCESS;
    return ret;
}

/* Whether a response is waiting for key update request.
 *
 * ssl        The SSL/TLS object.
 * required   0 when no key update response required.
 *            1 when no key update response required.
 * return  0 on success.
 * return  BAD_FUNC_ARG when ssl is NULL or not using TLS v1.3
 */
int wolfSSL_key_update_response(WOLFSSL* ssl, int* required)
{
    if (required == NULL || ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

    *required = ssl->keys.updateResponseReq;

    return 0;
}

#if !defined(NO_CERTS) && defined(WOLFSSL_POST_HANDSHAKE_AUTH)
/* Allow post-handshake authentication in TLS v1.3 connections.
 *
 * ctx  The SSL/TLS CTX object.
 * returns BAD_FUNC_ARG when ctx is NULL, SIDE_ERROR when not a client and
 * 0 on success.
 */
int wolfSSL_CTX_allow_post_handshake_auth(WOLFSSL_CTX* ctx)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;
    if (ctx->method->side == WOLFSSL_SERVER_END)
        return SIDE_ERROR;

    ctx->postHandshakeAuth = 1;

    return 0;
}

/* Allow post-handshake authentication in TLS v1.3 connection.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL, not using TLS v1.3, or running over
 * QUIC, SIDE_ERROR when not a client, BAD_STATE_E when called after the
 * handshake has started, and 0 on success.
 *
 * Must be called before wolfSSL_connect() so the post_handshake_auth
 * extension can be included in the ClientHello.
 */
int wolfSSL_allow_post_handshake_auth(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;
#ifdef WOLFSSL_QUIC
    if (WOLFSSL_IS_QUIC(ssl))
        return BAD_FUNC_ARG;
#endif
    if (ssl->options.side == WOLFSSL_SERVER_END)
        return SIDE_ERROR;
    if (ssl->options.handShakeState != NULL_STATE)
        return BAD_STATE_E;

    ssl->options.postHandshakeAuth = 1;

    return 0;
}

/* Request a certificate of the client.
 * Can be called any time after handshake completion.
 * A maximum of 256 requests can be sent on a connection.
 *
 * ssl  SSL/TLS object.
 */
int wolfSSL_request_certificate(WOLFSSL* ssl)
{
    int         ret;
#ifndef NO_WOLFSSL_SERVER
    CertReqCtx* certReqCtx;
#endif

    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;
#ifdef WOLFSSL_QUIC
    if (WOLFSSL_IS_QUIC(ssl))
        return BAD_FUNC_ARG;
#endif
#ifndef NO_WOLFSSL_SERVER
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;
    if (ssl->options.handShakeState != HANDSHAKE_DONE)
        return NOT_READY_ERROR;
    if (!ssl->options.postHandshakeAuth)
        return POST_HAND_AUTH_ERROR;
    if (ssl->certReqCtx != NULL) {
        if (ssl->certReqCtx->len != 1)
            return BAD_STATE_E;
        /* We support sending up to 255 certificate requests */
        if (ssl->certReqCtx->ctx == 255)
            return BAD_STATE_E;
    }

    certReqCtx = (CertReqCtx*)XMALLOC(sizeof(CertReqCtx), ssl->heap,
                                                       DYNAMIC_TYPE_TMP_BUFFER);
    if (certReqCtx == NULL)
        return MEMORY_E;
    XMEMSET(certReqCtx, 0, sizeof(CertReqCtx));
    certReqCtx->next = ssl->certReqCtx;
    certReqCtx->len = 1;
    if (certReqCtx->next != NULL)
        certReqCtx->ctx = certReqCtx->next->ctx + 1;
    ssl->certReqCtx = certReqCtx;

    ssl->msgsReceived.got_certificate = 0;
    ssl->msgsReceived.got_certificate_verify = 0;
    ssl->msgsReceived.got_finished = 0;
    /* Each round must prove possession again; these are only ever set to 1. */
    ssl->options.havePeerCert = 0;
    ssl->options.havePeerVerify = 0;

    ret = SendTls13CertificateRequest(ssl, &certReqCtx->ctx, certReqCtx->len);
    if (ret == WC_NO_ERR_TRACE(WANT_WRITE))
        ret = WOLFSSL_ERROR_WANT_WRITE;
    else if (ret == 0)
        ret = WOLFSSL_SUCCESS;
#else
    ret = SIDE_ERROR;
#endif

    return ret;
}
#endif /* !NO_CERTS && WOLFSSL_POST_HANDSHAKE_AUTH */

#if !defined(WOLFSSL_NO_SERVER_GROUPS_EXT)
/* Get the preferred key exchange group.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL or not using TLS v1.3,
 * SIDE_ERROR when not a client, NOT_READY_ERROR when handshake not complete
 * and group number on success.
 */
int wolfSSL_preferred_group(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;
#ifndef NO_WOLFSSL_CLIENT
    if (ssl->options.side == WOLFSSL_SERVER_END)
        return SIDE_ERROR;
    if (ssl->options.handShakeState != HANDSHAKE_DONE)
        return NOT_READY_ERROR;

#ifdef HAVE_SUPPORTED_CURVES
    /* Return supported groups only. */
    return TLSX_SupportedCurve_Preferred(ssl, 1);
#else
    return 0;
#endif
#else
    return SIDE_ERROR;
#endif
}
#endif

#ifndef NO_PSK
/* Set the PSK callback, that is passed the cipher suite, for a client to use
 * against context object.
 *
 * @param [in, out] ctx  SSL/TLS context object.
 * @param [in]      cb   Client PSK callback passed a cipher suite.
 */
void wolfSSL_CTX_set_psk_client_cs_callback(WOLFSSL_CTX* ctx,
                                            wc_psk_client_cs_callback cb)
{
    WOLFSSL_ENTER("wolfSSL_CTX_set_psk_client_cs_callback");

    if (ctx == NULL)
        return;

    ctx->havePSK = 1;
    ctx->client_psk_cs_cb = cb;
}

/* Set the PSK callback, that is passed the cipher suite, for a client to use
 * against SSL object.
 *
 * @param [in, out] ssl  SSL/TLS object.
 * @param [in]      cb   Client PSK callback passed a cipher suite.
 */
void wolfSSL_set_psk_client_cs_callback(WOLFSSL* ssl,
                                        wc_psk_client_cs_callback cb)
{
    byte haveRSA = 1;
    int  keySz   = 0;

    WOLFSSL_ENTER("wolfSSL_set_psk_client_cs_callback");

    if (ssl == NULL)
        return;

    ssl->options.havePSK = 1;
    ssl->options.client_psk_cs_cb = cb;

    #ifdef NO_RSA
        haveRSA = 0;
    #endif
    #ifndef NO_CERTS
        keySz = ssl->buffers.keySz;
    #endif
    if (AllocateSuites(ssl) != 0)
        return;
    InitSuites(ssl->suites, ssl->version, keySz, haveRSA, TRUE,
               ssl->options.haveDH, ssl->options.haveECDSAsig,
               ssl->options.haveECC, TRUE, ssl->options.haveStaticECC,
               ssl->options.useAnon, TRUE, TRUE, TRUE, TRUE, ssl->options.side);
}

/* Set the PSK callback that returns the cipher suite for a client to use
 * against context object.
 *
 * @param [in, out] ctx  SSL/TLS context object.
 * @param [in]      cb   Client PSK callback returning cipher suite.
 */
void wolfSSL_CTX_set_psk_client_tls13_callback(WOLFSSL_CTX* ctx,
                                               wc_psk_client_tls13_callback cb)
{
    WOLFSSL_ENTER("wolfSSL_CTX_set_psk_client_tls13_callback");

    if (ctx == NULL)
        return;

    ctx->havePSK = 1;
    ctx->client_psk_tls13_cb = cb;
}

/* Set the PSK callback that returns the cipher suite for a client to use
 * against SSL object.
 *
 * @param [in, out] ssl  SSL/TLS object.
 * @param [in]      cb   Client PSK callback returning cipher suite.
 */
void wolfSSL_set_psk_client_tls13_callback(WOLFSSL* ssl,
                                           wc_psk_client_tls13_callback cb)
{
    byte haveRSA = 1;
    int  keySz   = 0;

    WOLFSSL_ENTER("wolfSSL_set_psk_client_tls13_callback");

    if (ssl == NULL)
        return;

    ssl->options.havePSK = 1;
    ssl->options.client_psk_tls13_cb = cb;

    #ifdef NO_RSA
        haveRSA = 0;
    #endif
    #ifndef NO_CERTS
        keySz = ssl->buffers.keySz;
    #endif
    if (AllocateSuites(ssl) != 0)
        return;
    InitSuites(ssl->suites, ssl->version, keySz, haveRSA, TRUE,
               ssl->options.haveDH, ssl->options.haveECDSAsig,
               ssl->options.haveECC, TRUE, ssl->options.haveStaticECC,
               ssl->options.useAnon, TRUE, TRUE, TRUE, TRUE, ssl->options.side);
}

/* Set the PSK callback that returns the cipher suite for a server to use
 * against context object.
 *
 * @param [in, out] ctx  SSL/TLS context object.
 * @param [in]      cb   Server PSK callback returning cipher suite.
 */
void wolfSSL_CTX_set_psk_server_tls13_callback(WOLFSSL_CTX* ctx,
                                               wc_psk_server_tls13_callback cb)
{
    WOLFSSL_ENTER("wolfSSL_CTX_set_psk_server_tls13_callback");
    if (ctx == NULL)
        return;
    ctx->havePSK = 1;
    ctx->server_psk_tls13_cb = cb;
}

/* Set the PSK callback that returns the cipher suite for a server to use
 * against SSL object.
 *
 * @param [in, out] ssl  SSL/TLS object.
 * @param [in]      cb   Server PSK callback returning cipher suite.
 */
void wolfSSL_set_psk_server_tls13_callback(WOLFSSL* ssl,
                                           wc_psk_server_tls13_callback cb)
{
    byte haveRSA = 1;
    int  keySz   = 0;

    WOLFSSL_ENTER("wolfSSL_set_psk_server_tls13_callback");
    if (ssl == NULL)
        return;

    ssl->options.havePSK = 1;
    ssl->options.server_psk_tls13_cb = cb;

    #ifdef NO_RSA
        haveRSA = 0;
    #endif
    #ifndef NO_CERTS
        keySz = ssl->buffers.keySz;
    #endif
    if (AllocateSuites(ssl) != 0)
        return;
    InitSuites(ssl->suites, ssl->version, keySz, haveRSA, TRUE,
               ssl->options.haveDH, ssl->options.haveECDSAsig,
               ssl->options.haveECC, TRUE, ssl->options.haveStaticECC,
               ssl->options.useAnon, TRUE, TRUE, TRUE, TRUE, ssl->options.side);
}

/* Get name of first supported cipher suite that uses the hash indicated.
 *
 * @param [in] ssl   SSL/TLS object.
 * @param [in] hash  Name of hash algorithm. e.g. "SHA256", "SHA384"
 * @return  Name of cipher suite.
 * @return  NULL on failure.
 */
const char* wolfSSL_get_cipher_name_by_hash(WOLFSSL* ssl, const char* hash)
{
    const char* name = NULL;
    byte mac = no_mac;
    int i;
    const Suites* suites;

    if (hash == NULL || ssl == NULL ||
        (ssl->suites == NULL && ssl->ctx == NULL))
        return NULL;

    suites = WOLFSSL_SUITES(ssl);
    if (suites == NULL)
        return NULL;

    if (XSTRCMP(hash, "SHA256") == 0) {
        mac = sha256_mac;
    }
    else if (XSTRCMP(hash, "SHA384") == 0) {
        mac = sha384_mac;
    }
    if (mac != no_mac) {
        for (i = 0; i < suites->suiteSz; i += 2) {
            if (SuiteMac(suites->suites + i) == mac) {
                name = GetCipherNameInternal(suites->suites[i + 0],
                                             suites->suites[i + 1]);
                break;
            }
        }
    }
    return name;
}
#endif /* !NO_PSK */


#ifndef NO_WOLFSSL_SERVER

/* Send the RFC 8446 Appendix D.4 ChangeCipherSpec a server owes a client that
 * offered a non-empty legacy_session_id.
 *
 * ssl    The SSL/TLS object.
 * flush  Force the record out on its own. A HelloRetryRequest needs this
 *        because SendTls13ServerHello has already sent it, unlike a
 *        ServerHello, which waits for the rest of its flight.
 * returns 0 on success.
 */
static int SendTls13ServerChangeCipher(WOLFSSL* ssl, int flush)
{
    int ret;

    /* DoTls13ClientHello clears tls13MiddleBoxCompat for a QUIC peer, so the
     * check here is a local backstop, 0 when QUIC is not built. */
    if (ssl->options.dtls || WOLFSSL_IS_QUIC(ssl)
            || !ssl->options.tls13MiddleBoxCompat
            || ssl->options.sentChangeCipher) {
        return 0;
    }

    ret = SendChangeCipher(ssl);
    /* A short send leaves the record queued in the output buffer. Mark it sent
     * anyway, or the resumed accept, which comes back in at the ServerHello
     * case, puts a second record on the wire. */
    if (ret == 0 || ret == WC_NO_ERR_TRACE(WANT_WRITE))
        ssl->options.sentChangeCipher = 1;
    if (ret == 0 && flush && ssl->options.groupMessages)
        ret = SendBuffered(ssl);

    return ret;
}

/* The server accepting a connection from a client.
 * The protocol version is expecting to be TLS v1.3.
 * If the client downgrades, and older versions of the protocol are compiled
 * in, the server will fallback to wolfSSL_accept().
 * Please see note at top of README if you get an error from accept.
 *
 * ssl  The SSL/TLS object.
 * returns WOLFSSL_SUCCESS on successful handshake, WOLFSSL_FATAL_ERROR when
 * unrecoverable error occurs and 0 otherwise.
 * For more error information use wolfSSL_get_error().
 */
int wolfSSL_accept_TLSv13(WOLFSSL* ssl)
{
#if !defined(NO_CERTS) && (defined(HAVE_SESSION_TICKET) || !defined(NO_PSK))
    word16 havePSK = 0;
#endif
    int ret = 0;

    WOLFSSL_ENTER("wolfSSL_accept_TLSv13");

#ifdef HAVE_ERRNO_H
    errno = 0;
#endif

    if (ssl == NULL)
        return WOLFSSL_FATAL_ERROR;

#if !defined(NO_CERTS) && (defined(HAVE_SESSION_TICKET) || !defined(NO_PSK))
    havePSK = ssl->options.havePSK;
#endif

    if (ssl->options.side != WOLFSSL_SERVER_END) {
        ssl->error = SIDE_ERROR;
        WOLFSSL_ERROR(ssl->error);
        return WOLFSSL_FATAL_ERROR;
    }

    /* make sure this wolfSSL object has arrays and rng setup. Protects
     * case where the WOLFSSL object is reused via wolfSSL_clear() */
    if ((ret = ReinitSSL(ssl, ssl->ctx, 0)) != 0) {
        return ret;
    }

#ifdef WOLFSSL_DTLS
    if (ssl->version.major == DTLS_MAJOR) {
        ssl->options.dtls   = 1;
        if (!IsDtlsNotSctpMode(ssl) || !ssl->options.sendCookie)
            ssl->options.dtlsStateful = 1;
    }
#endif

#ifdef WOLFSSL_WOLFSENTRY_HOOKS
    if ((ssl->AcceptFilter != NULL) &&
            ((ssl->options.acceptState == TLS13_ACCEPT_BEGIN)
#ifdef HAVE_SECURE_RENEGOTIATION
             || (ssl->options.acceptState == TLS13_ACCEPT_BEGIN_RENEG)
#endif
                ))
    {
        wolfSSL_netfilter_decision_t res;
        if ((ssl->AcceptFilter(ssl, ssl->AcceptFilter_arg, &res) ==
             WOLFSSL_SUCCESS) &&
            (res == WOLFSSL_NETFILTER_REJECT)) {
            ssl->error = SOCKET_FILTERED_E;
            WOLFSSL_ERROR(ssl->error);
            return WOLFSSL_FATAL_ERROR;
        }
    }
#endif /* WOLFSSL_WOLFSENTRY_HOOKS */

#ifndef NO_CERTS
#if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
    if (!havePSK)
#endif
    {
    #if defined(OPENSSL_ALL) || defined(OPENSSL_EXTRA) || \
        defined(WOLFSSL_NGINX) || defined (WOLFSSL_HAPROXY)
        if (ssl->ctx->certSetupCb != NULL) {
            WOLFSSL_MSG("CertSetupCb set. server cert and "
                        "key not checked");
        }
        else
    #endif
        {
            if (!ssl->buffers.certificate ||
                !ssl->buffers.certificate->buffer) {

                WOLFSSL_MSG("accept error: server cert required");
                ssl->error = NO_PRIVATE_KEY;
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
            }

            if (!ssl->buffers.key || !ssl->buffers.key->buffer) {
                /* allow no private key if using existing key */
            #ifdef WOLF_PRIVATE_KEY_ID
                if (ssl->devId != INVALID_DEVID
                #ifdef HAVE_PK_CALLBACKS
                    || wolfSSL_CTX_IsPrivatePkSet(ssl->ctx)
                #endif
                ) {
                    WOLFSSL_MSG("Allowing no server private key (external)");
                }
                else
            #endif
                {
                    WOLFSSL_MSG("accept error: server key required");
                    ssl->error = NO_PRIVATE_KEY;
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }
        }
    }
#endif /* NO_CERTS */

    if (ssl->buffers.outputBuffer.length > 0
    #ifdef WOLFSSL_ASYNC_CRYPT
        /* do not send buffered or advance state if last error was an
            async pending operation */
        && ssl->error != WC_NO_ERR_TRACE(WC_PENDING_E)
    #endif
    ) {

        /* fragOffset is non-zero when sending fragments. On the last
         * fragment, fragOffset is zero again, and the state can be
         * advanced. */
        int advanceState =
            (ssl->options.acceptState == TLS13_ACCEPT_CLIENT_HELLO_DONE ||
                ssl->options.acceptState ==
                    TLS13_ACCEPT_HELLO_RETRY_REQUEST_DONE ||
                ssl->options.acceptState == TLS13_ACCEPT_SECOND_REPLY_DONE ||
                ssl->options.acceptState == TLS13_SERVER_HELLO_SENT ||
                ssl->options.acceptState == TLS13_ACCEPT_THIRD_REPLY_DONE ||
                ssl->options.acceptState == TLS13_SERVER_EXTENSIONS_SENT ||
                ssl->options.acceptState == TLS13_CERT_REQ_SENT ||
                ssl->options.acceptState == TLS13_CERT_SENT ||
                ssl->options.acceptState == TLS13_CERT_VERIFY_SENT ||
                ssl->options.acceptState == TLS13_ACCEPT_FINISHED_SENT ||
                ssl->options.acceptState == TLS13_ACCEPT_FINISHED_DONE);

#ifdef WOLFSSL_DTLS13
        if (ssl->options.dtls)
            advanceState = advanceState && !ssl->dtls13SendingFragments
                && !ssl->dtls13SendingAckOrRtx;
#endif /* WOLFSSL_DTLS13 */

        ret = SendBuffered(ssl);
        if (ret == 0) {
            if (ssl->fragOffset == 0 && !ssl->options.buildingMsg) {
                if (advanceState) {
                    ssl->options.acceptState++;
                    WOLFSSL_MSG("accept state: "
                                "Advanced from last buffered fragment send");
#ifdef WOLFSSL_ASYNC_IO
                    FreeAsyncCtx(ssl, 0);
#endif
                }
            }
            else {
                WOLFSSL_MSG("accept state: "
                            "Not advanced, more fragments to send");
            }

#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls)
                ssl->dtls13SendingAckOrRtx = 0;
#endif /* WOLFSSL_DTLS13 */

        }
        else {
            ssl->error = ret;
            WOLFSSL_ERROR(ssl->error);
            return WOLFSSL_FATAL_ERROR;
        }
    }

    ret = RetrySendAlert(ssl);
    if (ret != 0) {
        ssl->error = ret;
        WOLFSSL_ERROR(ssl->error);
        return WOLFSSL_FATAL_ERROR;
    }
#ifdef WOLFSSL_DTLS13
    if (ssl->options.dtls && ssl->dtls13SendingFragments) {
        if ((ssl->error = Dtls13FragmentsContinue(ssl)) != 0) {
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
        }

        /* we sent all the fragments. Advance state. */
        ssl->options.acceptState++;
    }
#endif /* WOLFSSL_DTLS13 */

    switch (ssl->options.acceptState) {

#ifdef HAVE_SECURE_RENEGOTIATION
        case TLS13_ACCEPT_BEGIN_RENEG:
#endif
        case TLS13_ACCEPT_BEGIN :
            /* get client_hello */

            while (ssl->options.clientState < CLIENT_HELLO_COMPLETE) {
                if ((ssl->error = ProcessReply(ssl)) < 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }

#ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls) {
                    if ((ssl->error = Dtls13DoScheduledWork(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
#endif /* WOLFSSL_DTLS13 */

            }

            ssl->options.acceptState = TLS13_ACCEPT_CLIENT_HELLO_DONE;
            WOLFSSL_MSG("accept state ACCEPT_CLIENT_HELLO_DONE");
            if (!IsAtLeastTLSv1_3(ssl->version))
                return wolfSSL_accept(ssl);
            FALL_THROUGH;

        case TLS13_ACCEPT_CLIENT_HELLO_DONE :
            if (ssl->options.serverState ==
                                          SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
                if ((ssl->error = SendTls13ServerHello(ssl,
                                                   hello_retry_request)) != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }

            ssl->options.acceptState = TLS13_ACCEPT_HELLO_RETRY_REQUEST_DONE;
            WOLFSSL_MSG("accept state ACCEPT_HELLO_RETRY_REQUEST_DONE");
            FALL_THROUGH;

        case TLS13_ACCEPT_HELLO_RETRY_REQUEST_DONE :
            if (ssl->options.serverState ==
                                          SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
                ssl->error = SendTls13ServerChangeCipher(ssl, 1);
                if (ssl->error != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }
            ssl->options.acceptState = TLS13_ACCEPT_FIRST_REPLY_DONE;
            WOLFSSL_MSG("accept state ACCEPT_FIRST_REPLY_DONE");
            FALL_THROUGH;

        case TLS13_ACCEPT_FIRST_REPLY_DONE :
            if (ssl->options.serverState ==
                                          SERVER_HELLO_RETRY_REQUEST_COMPLETE) {
                ssl->options.clientState = CLIENT_HELLO_RETRY;
                while (ssl->options.clientState < CLIENT_HELLO_COMPLETE) {
                    if ((ssl->error = ProcessReply(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }

#ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls) {
                    if ((ssl->error = Dtls13DoScheduledWork(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
#endif /* WOLFSSL_DTLS13 */

                }
            }

            ssl->options.acceptState = TLS13_ACCEPT_SECOND_REPLY_DONE;
            WOLFSSL_MSG("accept state ACCEPT_SECOND_REPLY_DONE");
            FALL_THROUGH;

        case TLS13_ACCEPT_SECOND_REPLY_DONE :
            if (ssl->options.returnOnGoodCh) {
                /* Higher level in stack wants us to return. Simulate a
                 * WANT_WRITE to accomplish this. */
                ssl->error = WANT_WRITE;
                return WOLFSSL_FATAL_ERROR;
            }

            if ((ssl->error = SendTls13ServerHello(ssl, server_hello)) != 0) {
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
            }
            ssl->options.acceptState = TLS13_SERVER_HELLO_SENT;
            WOLFSSL_MSG("accept state SERVER_HELLO_SENT");
            FALL_THROUGH;

        case TLS13_SERVER_HELLO_SENT :
            ssl->error = SendTls13ServerChangeCipher(ssl, 0);
            if (ssl->error != 0) {
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
            }

            ssl->options.acceptState = TLS13_ACCEPT_THIRD_REPLY_DONE;
            WOLFSSL_MSG("accept state ACCEPT_THIRD_REPLY_DONE");
            FALL_THROUGH;

        case TLS13_ACCEPT_THIRD_REPLY_DONE :
    #ifdef HAVE_SUPPORTED_CURVES
        #if defined(HAVE_SESSION_TICKET) || !defined(NO_PSK)
            if (!ssl->options.noPskDheKe)
        #endif
            {
                ssl->error = TLSX_KeyShare_DeriveSecret(ssl);
                if (ssl->error != 0)
                    return WOLFSSL_FATAL_ERROR;
            }
    #endif

            if ((ssl->error = SendTls13EncryptedExtensions(ssl)) != 0) {
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
            }
            ssl->options.acceptState = TLS13_SERVER_EXTENSIONS_SENT;
            WOLFSSL_MSG("accept state SERVER_EXTENSIONS_SENT");
            FALL_THROUGH;

        case TLS13_SERVER_EXTENSIONS_SENT :
#ifndef NO_CERTS
            if (!ssl->options.resuming) {
                if (ssl->options.verifyPeer
    #ifdef WOLFSSL_POST_HANDSHAKE_AUTH
                    && !ssl->options.verifyPostHandshake
    #endif
                   ) {
                    ssl->error = SendTls13CertificateRequest(ssl, NULL, 0);
                    if (ssl->error != 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
                else {
                    /* SERVER: Peer auth good if not verifying client. */
                    ssl->options.peerAuthGood = 1;
                }
            }
#endif
            ssl->options.acceptState = TLS13_CERT_REQ_SENT;
            WOLFSSL_MSG("accept state CERT_REQ_SENT");
            FALL_THROUGH;

        case TLS13_CERT_REQ_SENT :
#ifndef NO_CERTS
            if (!ssl->options.resuming && ssl->options.sendVerify) {
                if ((ssl->error = SendTls13Certificate(ssl)) != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }
#endif
            ssl->options.acceptState = TLS13_CERT_SENT;
            WOLFSSL_MSG("accept state CERT_SENT");
            FALL_THROUGH;

        case TLS13_CERT_SENT :
#if !defined(NO_CERTS) && (!defined(NO_RSA) || defined(HAVE_ECC) || \
     defined(HAVE_ED25519) || defined(HAVE_ED448) || defined(HAVE_FALCON) || \
     defined(WOLFSSL_HAVE_MLDSA) || defined(WOLFSSL_HAVE_SLHDSA))
            if (!ssl->options.resuming && ssl->options.sendVerify) {
                if ((ssl->error = SendTls13CertificateVerify(ssl)) != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }
#endif
            ssl->options.acceptState = TLS13_CERT_VERIFY_SENT;
            WOLFSSL_MSG("accept state CERT_VERIFY_SENT");
            FALL_THROUGH;

        case TLS13_CERT_VERIFY_SENT :
            if ((ssl->error = SendTls13Finished(ssl)) != 0) {
                WOLFSSL_ERROR(ssl->error);
                return WOLFSSL_FATAL_ERROR;
            }

            ssl->options.acceptState = TLS13_ACCEPT_FINISHED_SENT;
            WOLFSSL_MSG("accept state ACCEPT_FINISHED_SENT");
            FALL_THROUGH;

        case TLS13_ACCEPT_FINISHED_SENT:
#ifdef WOLFSSL_EARLY_DATA
            if (ssl->earlyData != no_early_data &&
                    ssl->options.handShakeState != SERVER_FINISHED_COMPLETE) {
                ssl->options.handShakeState = SERVER_FINISHED_COMPLETE;
                return WOLFSSL_SUCCESS;
            }
#endif
#ifdef HAVE_SESSION_TICKET
    #ifdef WOLFSSL_TLS13_TICKET_BEFORE_FINISHED
            if (!ssl->options.verifyPeer && !ssl->options.noTicketTls13 &&
                    ssl->ctx->ticketEncCb != NULL &&
                    ssl->options.maxTicketTls13 > 0) {
                if ((ssl->error = SendTls13NewSessionTicket(ssl)) != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
                ssl->options.ticketsSent = 1;
            }
    #endif
#endif /* HAVE_SESSION_TICKET */
            ssl->options.acceptState = TLS13_PRE_TICKET_SENT;
            WOLFSSL_MSG("accept state  TICKET_SENT");
            FALL_THROUGH;

        case TLS13_PRE_TICKET_SENT :
            while (ssl->options.clientState < CLIENT_FINISHED_COMPLETE) {
                if ( (ssl->error = ProcessReply(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }

#ifdef WOLFSSL_DTLS13
                if (ssl->options.dtls) {
                    if ((ssl->error = Dtls13DoScheduledWork(ssl)) < 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
#endif /* WOLFSSL_DTLS13 */
            }

            /* Finish a key schedule the Finished handler left pending:
             * it must complete before this side's sends advance the
             * transcript the traffic secrets hash. */
            if (ssl->kdfMsgStep > 0) {
                ssl->error = DoTls13MsgDerives(ssl, ssl->kdfMsgType);
                if (ssl->error != 0) {
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }

            ssl->options.acceptState = TLS13_ACCEPT_FINISHED_DONE;
            WOLFSSL_MSG("accept state ACCEPT_FINISHED_DONE");
            FALL_THROUGH;

        case TLS13_ACCEPT_FINISHED_DONE :
            /* SERVER: When not resuming and verifying peer but no certificate
             * received and not failing when not received then peer auth good.
             */
            if (!ssl->options.resuming && ssl->options.verifyPeer &&
        #ifdef WOLFSSL_POST_HANDSHAKE_AUTH
                !ssl->options.verifyPostHandshake &&
        #endif
                !ssl->options.havePeerCert && !ssl->options.failNoCert) {
                ssl->options.peerAuthGood = 1;
            }
            /* SERVER: check peer authentication. */
            if (!ssl->options.peerAuthGood) {
                WOLFSSL_MSG("Client authentication did not happen");
                return WOLFSSL_FATAL_ERROR;
            }
#ifdef HAVE_SESSION_TICKET
            while (ssl->options.ticketsSent < ssl->options.maxTicketTls13) {
                if (!ssl->options.noTicketTls13 && ssl->ctx->ticketEncCb
                        != NULL) {
                    if ((ssl->error = SendTls13NewSessionTicket(ssl)) != 0) {
                        WOLFSSL_ERROR(ssl->error);
                        return WOLFSSL_FATAL_ERROR;
                    }
                }
                ssl->options.ticketsSent++;

                /* only one session ticket is sent on session resumption */
                if (ssl->options.resuming) {
                    break;
                }
            }
#endif /* HAVE_SESSION_TICKET */
            ssl->options.acceptState = TLS13_TICKET_SENT;
            WOLFSSL_MSG("accept state TICKET_SENT");
            FALL_THROUGH;

        case TLS13_TICKET_SENT :
#ifndef NO_HANDSHAKE_DONE_CB
            if (ssl->hsDoneCb) {
                int cbret = ssl->hsDoneCb(ssl, ssl->hsDoneCtx);
                if (cbret < 0) {
                    ssl->error = cbret;
                    WOLFSSL_MSG("HandShake Done Cb don't continue error");
                    return WOLFSSL_FATAL_ERROR;
                }
            }
#endif /* NO_HANDSHAKE_DONE_CB */

            if (!ssl->options.keepResources) {
                FreeHandshakeResources(ssl);
            }

#if defined(WOLFSSL_ASYNC_IO) && !defined(WOLFSSL_ASYNC_CRYPT)
            /* Free the remaining async context if not using it for crypto */
            FreeAsyncCtx(ssl, 1);
#endif

            ssl->error = 0; /* clear the error */

            WOLFSSL_LEAVE("wolfSSL_accept", WOLFSSL_SUCCESS);
            return WOLFSSL_SUCCESS;

        default:
            WOLFSSL_MSG("Unknown accept state ERROR");
            return WOLFSSL_FATAL_ERROR;
    }
}
#endif

#if !defined(NO_WOLFSSL_SERVER) && defined(HAVE_SESSION_TICKET)
/* Server sends a session ticket to the peer.
 *
 * RFC 8446, section 4.6.1, para 1.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL, or not using TLS v1.3,
 *         SIDE_ERROR when not a server,
 *         NOT_READY_ERROR when handshake not complete,
 *         MISSING_HANDSHAKE_DATA when the ClientHello had no
 *         psk_key_exchange_modes extension and
 *         WOLFSSL_TLS13_TICKET_CHECK_PSK_MODES is defined,
 *         PSK_KEY_ERROR when no advertised PSK key exchange mode is usable and
 *         WOLFSSL_TLS13_TICKET_CHECK_PSK_MODES is defined,
 *         WOLFSSL_FATAL_ERROR when creating or sending message fails, and
 *         WOLFSSL_SUCCESS on success.
 */
int wolfSSL_send_SessionTicket(WOLFSSL* ssl)
{
    int ret;

    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;
    if (ssl->options.handShakeState != HANDSHAKE_DONE)
        return NOT_READY_ERROR;
    ret = CheckTls13TicketPskModes(ssl);
    if (ret != 0) {
        WOLFSSL_ERROR_VERBOSE(ret);
        return ret;
    }

    if ((ssl->error = SendTls13NewSessionTicket(ssl)) != 0) {
        WOLFSSL_ERROR(ssl->error);
        return WOLFSSL_FATAL_ERROR;
    }
    ssl->options.ticketsSent++;

    return WOLFSSL_SUCCESS;
}
#endif

#ifdef WOLFSSL_EARLY_DATA
/* Sets the maximum amount of early data that can be seen by server when using
 * session tickets for resumption.
 * A value of zero indicates no early data is to be sent by client using session
 * tickets.
 *
 * The default value is zero: per RFC 8446 Appendix E.5, TLS implementations
 * "MUST NOT enable 0-RTT (either sending or accepting) unless specifically
 * requested by the application." Servers must explicitly opt in by calling
 * this function (or the per-SSL equivalent) with a non-zero value.
 *
 * ctx  The SSL/TLS CTX object.
 * sz   Maximum size of the early data.
 * returns BAD_FUNC_ARG when ctx is NULL, SIDE_ERROR when not a server and
 * 0 on success.
 */
int wolfSSL_CTX_set_max_early_data(WOLFSSL_CTX* ctx, unsigned int sz)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;
    if (ctx->method->side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

    ctx->maxEarlyDataSz = sz;

#if defined(OPENSSL_EXTRA) || defined(WOLFSSL_ERROR_CODE_OPENSSL)
    /* 1 on success in OpenSSL*/
    return WOLFSSL_SUCCESS;
#else
    return 0;
#endif
}

/* Disable the RFC 8446 Section 8.2 fresh start protection. Early data is
 * then accepted for tickets minted before this ctx was created. Only use
 * this when the anti-replay state reliably survives server restarts.
 *
 * The check needs TimeNowInMilliseconds() to be comparable across restarts.
 * On ports where it counts from boot the check never fires for tickets
 * minted before a reboot.
 *
 * ctx  The SSL/TLS CTX object.
 * returns BAD_FUNC_ARG when ctx is NULL or not TLS v1.3, SIDE_ERROR when
 * called with a client and 0 on success.
 */
int wolfSSL_CTX_no_early_data_fresh_start_check(WOLFSSL_CTX* ctx)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;
    if (ctx->method->side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

#ifdef HAVE_SESSION_TICKET
    ctx->noFreshStartCheck = 1;
#endif

    return 0;
}

/* Sets the maximum amount of early data that a client or server would like
 * to exchange. Servers will advertise this value in session tickets sent
 * to a client.
 * A value of zero indicates no early data will be sent by a client, or
 * no early data is accepted by a server (and announced as such in send out
 * session tickets).
 *
 * ssl  The SSL/TLS object.
 * sz   Maximum size of the early data.
 * returns BAD_FUNC_ARG when ssl is NULL, or not using TLS v1.3,
 * and 0 on success.
 */
int wolfSSL_set_max_early_data(WOLFSSL* ssl, unsigned int sz)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

    ssl->options.maxEarlyDataSz = sz;
#if defined(OPENSSL_EXTRA) || defined(WOLFSSL_ERROR_CODE_OPENSSL)
    /* 1 on success in OpenSSL*/
    return WOLFSSL_SUCCESS;
#else
    return 0;
#endif
}

/* Gets the maximum amount of early data that can be seen by server when using
 * session tickets for resumption.
 * A value of zero indicates no early data is to be sent by client using session
 * tickets.
 *
 * ctx  The SSL/TLS CTX object.
 * returns BAD_FUNC_ARG when ctx is NULL, SIDE_ERROR when not a server and
 * returns the maximum amount of early data to be set
 */
int wolfSSL_CTX_get_max_early_data(WOLFSSL_CTX* ctx)
{
    if (ctx == NULL || !IsAtLeastTLSv1_3(ctx->method->version))
        return BAD_FUNC_ARG;
    if (ctx->method->side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

    return ctx->maxEarlyDataSz;
}

/* Gets the maximum amount of early data that can be seen by server when using
 * session tickets for resumption.
 * A value of zero indicates no early data is to be sent by client using session
 * tickets.
 *
 * ssl  The SSL/TLS object.
 * returns BAD_FUNC_ARG when ssl is NULL, or not using TLS v1.3,
 * SIDE_ERROR when not a server and
 * returns the maximum amount of early data to be set
 */
int wolfSSL_get_max_early_data(WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

    return ssl->options.maxEarlyDataSz;
}

/* Write early data to the server.
 *
 * ssl    The SSL/TLS object.
 * data   Early data to write
 * sz     The size of the early data in bytes.
 * outSz  The number of early data bytes written.
 * returns BAD_FUNC_ARG when: ssl, data or outSz is NULL; sz is negative;
 * or not using TLS v1.3. SIDE ERROR when not a server. BAD_STATE_E if invoked
 * without a valid session or without a valid PSK CB.
 * Otherwise the number of early data bytes written.
 */
int wolfSSL_write_early_data(WOLFSSL* ssl, const void* data, int sz, int* outSz)
{
    int ret = 0;

    WOLFSSL_ENTER("wolfSSL_write_early_data");

    if (ssl == NULL || data == NULL || sz < 0 || outSz == NULL)
        return BAD_FUNC_ARG;
    if (!IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

    *outSz = 0;

#ifndef NO_WOLFSSL_CLIENT
    if (ssl->options.side == WOLFSSL_SERVER_END)
        return SIDE_ERROR;

    /* Early data requires PSK or session resumption */
    if (!EarlyDataPossible(ssl)) {
        return BAD_STATE_E;
    }

    if (ssl->options.handShakeState == NULL_STATE) {
        /* avoid re-setting ssl->earlyData if we re-enter the function because
         * of WC_PENDING_E, WANT_WRITE or WANT_READ */
        if (ssl->error == 0)
            ssl->earlyData = expecting_early_data;
        ret = wolfSSL_connect_TLSv13(ssl);
        if (ret != WOLFSSL_SUCCESS)
            return WOLFSSL_FATAL_ERROR;
        /* on client side, status is set to rejected        */
        /* until sever accepts the early data extension.    */
        ssl->earlyDataStatus = WOLFSSL_EARLY_DATA_REJECTED;
    }
    if (ssl->options.handShakeState == CLIENT_HELLO_COMPLETE) {
#ifdef OPENSSL_EXTRA
        /* when processed early data exceeds max size */
        if (ssl->session->maxEarlyDataSz > 0 &&
            (ssl->earlyDataSz + sz > ssl->session->maxEarlyDataSz)) {
            ssl->error = TOO_MUCH_EARLY_DATA;
            return WOLFSSL_FATAL_ERROR;
        }
#endif
        ret = SendData(ssl, data, sz);
        if (ret > 0) {
            *outSz = ret;
            /* store amount of processed early data from client */
            ssl->earlyDataSz += ret;
        }
    }
#else
    return SIDE_ERROR;
#endif

    WOLFSSL_LEAVE("wolfSSL_write_early_data", ret);

    if (ret < 0)
        ret = WOLFSSL_FATAL_ERROR;
    return ret;
}

/* Read the any early data from the client.
 *
 * ssl    The SSL/TLS object.
 * data   Buffer to put the early data into.
 * sz     The size of the buffer in bytes.
 * outSz  The number of early data bytes read.
 * returns BAD_FUNC_ARG when: ssl, data or outSz is NULL; sz is negative;
 * or not using TLS v1.3. SIDE ERROR when not a server. Otherwise the number of
 * early data bytes read.
 */
int wolfSSL_read_early_data(WOLFSSL* ssl, void* data, int sz, int* outSz)
{
    int ret = 0;

    WOLFSSL_ENTER("wolfSSL_read_early_data");


    if (ssl == NULL || data == NULL || sz < 0 || outSz == NULL)
        return BAD_FUNC_ARG;
    if (!IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

    *outSz = 0;
#ifndef NO_WOLFSSL_SERVER
    if (ssl->options.side == WOLFSSL_CLIENT_END)
        return SIDE_ERROR;

    if (ssl->options.handShakeState == NULL_STATE) {
        /* the server flight can return WANT_WRITE and we re-enter here after
         * setting ssl->earlyData = process_early_data, set earlyData to
         * expecting_early_data just once */
        if (ssl->earlyData < expecting_early_data)
            ssl->earlyData = expecting_early_data;
        /* this used to be: ret = wolfSSL_accept_TLSv13(ssl);
         * However, wolfSSL_accept_TLSv13() expects a certificate to
         * be installed already, which is not the case in servers
         * such as HAProxy. They do it after inspecting the ClientHello.
         * The common wolfssl_accept() allows that. */
        ret = wolfSSL_accept(ssl);
        if (ret <= 0)
            return WOLFSSL_FATAL_ERROR;
    }
    if (ssl->options.handShakeState == SERVER_FINISHED_COMPLETE) {
        ssl->options.clientInEarlyData = 1;
        ret = ReceiveData(ssl, (byte*)data, (size_t)sz, FALSE);
        ssl->options.clientInEarlyData = 0;
        if (ret > 0)
            *outSz = ret;
        if (ssl->error == WC_NO_ERR_TRACE(APP_DATA_READY)) {
            ret = 0;
            ssl->error = WOLFSSL_ERROR_NONE;
#ifdef WOLFSSL_DTLS13
            if (ssl->options.dtls) {
                ret = Dtls13DoScheduledWork(ssl);
                if (ret  < 0) {
                    ssl->error = ret;
                    WOLFSSL_ERROR(ssl->error);
                    return WOLFSSL_FATAL_ERROR;
                }
            }
#endif /* WOLFSSL_DTLS13 */
        }
    }
#ifdef WOLFSSL_DTLS13
    else if (ssl->buffers.outputBuffer.length > 0 &&
        ssl->options.dtls && ssl->dtls13SendingAckOrRtx) {
        ret = SendBuffered(ssl);
        if (ret == 0) {
            ssl->dtls13SendingAckOrRtx = 0;
        }
        else {
            ssl->error = ret;
            WOLFSSL_ERROR(ssl->error);
            return WOLFSSL_FATAL_ERROR;
        }
    }
#endif /* WOLFSSL_DTLS13 */
    else
        ret = 0;
#else
    return SIDE_ERROR;
#endif

    WOLFSSL_LEAVE("wolfSSL_read_early_data", ret);

    if (ret < 0)
        ret = WOLFSSL_FATAL_ERROR;
    return ret;
}

/* Returns early data status
 *
 * ssl    The SSL/TLS object.
 * returns WOLFSSL_EARLY_DATA_ACCEPTED if the data was accepted
 *         WOLFSSL_EARLY_DATA_REJECTED if the data was rejected
 *         WOLFSSL_EARLY_DATA_NOT_SENT if no early data was sent
 */
int wolfSSL_get_early_data_status(const WOLFSSL* ssl)
{
    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
        return BAD_FUNC_ARG;

    return ssl->earlyDataStatus;
}
#endif

#ifdef HAVE_SECRET_CALLBACK
int wolfSSL_set_tls13_secret_cb(WOLFSSL* ssl, Tls13SecretCb cb, void* ctx)
{
    WOLFSSL_ENTER("wolfSSL_set_tls13_secret_cb");
    if (ssl == NULL)
        return WOLFSSL_FATAL_ERROR;

    ssl->tls13SecretCb = cb;
    ssl->tls13SecretCtx = ctx;

    return WOLFSSL_SUCCESS;
}

#if defined(SHOW_SECRETS) && defined(WOLFSSL_SSLKEYLOGFILE)
int tls13ShowSecrets(WOLFSSL* ssl, int id, const unsigned char* secret,
    int secretSz, void* ctx)
{
    int i;
    const char* str = NULL;
    byte clientRandom[RAN_LEN];
    int clientRandomSz;
    XFILE fp;
#if defined(WOLFSSL_SSLKEYLOGFILE_OUTPUT) && defined(WOLFSSL_SSLKEYLOGFILE_USE_ENV)
    const char* keyLogFile;
#endif

    (void) ctx;
#ifdef WOLFSSL_SSLKEYLOGFILE_OUTPUT
#ifdef WOLFSSL_SSLKEYLOGFILE_USE_ENV
    /* RFC 9850: prefer the SSLKEYLOGFILE environment variable so tools such as
     * curl and Wireshark can share the path, else use the compile-time path.
     * XGETENV resolves to NULL where environment access is unavailable. Opt-in
     * so a build with the variable exported for other applications is not
     * affected. */
    keyLogFile = XGETENV("SSLKEYLOGFILE");
    if (keyLogFile == NULL || keyLogFile[0] == '\0')
        keyLogFile = WOLFSSL_SSLKEYLOGFILE_OUTPUT;
    fp = XFOPEN(keyLogFile, "ab");
#else
    fp = XFOPEN(WOLFSSL_SSLKEYLOGFILE_OUTPUT, "ab");
#endif
    if (fp == XBADFILE) {
        return BAD_FUNC_ARG;
    }
#else
    fp = stderr;
#endif

    clientRandomSz = (int)wolfSSL_get_client_random(ssl, clientRandom,
        sizeof(clientRandom));

    if (clientRandomSz <= 0) {
        printf("Error getting server random %d\n", clientRandomSz);
        return BAD_FUNC_ARG;
    }

#if 0
    printf("TLS Server Secret CB: Rand %d, Secret %d\n",
        serverRandomSz, secretSz);
#endif

    switch (id) {
        case CLIENT_EARLY_TRAFFIC_SECRET:
            str = "CLIENT_EARLY_TRAFFIC_SECRET"; break;
        case EARLY_EXPORTER_SECRET:
            str = "EARLY_EXPORTER_SECRET"; break;
        case CLIENT_HANDSHAKE_TRAFFIC_SECRET:
            str = "CLIENT_HANDSHAKE_TRAFFIC_SECRET"; break;
        case SERVER_HANDSHAKE_TRAFFIC_SECRET:
            str = "SERVER_HANDSHAKE_TRAFFIC_SECRET"; break;
        case CLIENT_TRAFFIC_SECRET:
            str = "CLIENT_TRAFFIC_SECRET_0"; break;
        case SERVER_TRAFFIC_SECRET:
            str = "SERVER_TRAFFIC_SECRET_0"; break;
        case EXPORTER_SECRET:
            str = "EXPORTER_SECRET"; break;
#ifdef HAVE_ECH
        case ECH_SECRET:
            str = "ECH_SECRET"; break;
        case ECH_CONFIG:
            str = "ECH_CONFIG"; break;
#endif
        default:
#ifdef WOLFSSL_SSLKEYLOGFILE_OUTPUT
            XFCLOSE(fp);
#endif
            return BAD_FUNC_ARG;
            break;
    }

    fprintf(fp, "%s ", str);
    for (i = 0; i < (int)clientRandomSz; i++) {
        fprintf(fp, "%02x", clientRandom[i]);
    }
    fprintf(fp, " ");
    for (i = 0; i < secretSz; i++) {
        fprintf(fp, "%02x", secret[i]);
    }
    fprintf(fp, "\n");

#ifdef WOLFSSL_SSLKEYLOGFILE_OUTPUT
    XFCLOSE(fp);
#endif

    return 0;
}
#endif
#endif

#undef ERROR_OUT

#endif /* !WOLFCRYPT_ONLY */

#endif /* !NO_TLS && WOLFSSL_TLS13 */

Coverage Report

Created: 2026-09-20 06:33