/*

 * Copyright 1995-2025 The OpenSSL Project Authors. All Rights Reserved.

 * Copyright 2005 Nokia. All rights reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <stdio.h>

#include "ssl_local.h"

#include "record/record_local.h"

#include "internal/ktls.h"

#include "internal/cryptlib.h"

#include "internal/ssl_unwrap.h"

#include <openssl/comp.h>

#include <openssl/evp.h>

#include <openssl/kdf.h>

#include <openssl/rand.h>

#include <openssl/obj_mac.h>

#include <openssl/core_names.h>

#include <openssl/trace.h>

/* seed1 through seed5 are concatenated */

static int tls1_PRF(SSL_CONNECTION *s,

                    const void *seed1, size_t seed1_len,

                    const void *seed2, size_t seed2_len,

                    const void *seed3, size_t seed3_len,

                    const void *seed4, size_t seed4_len,

                    const void *seed5, size_t seed5_len,

                    const unsigned char *sec, size_t slen,

                    unsigned char *out, size_t olen, int fatal)

{

    const EVP_MD *md = ssl_prf_md(s);

    EVP_KDF *kdf;

    EVP_KDF_CTX *kctx = NULL;

    OSSL_PARAM params[9], *p = params;

    const char *mdname;

    if (md == NULL) {

        /* Should never happen */

        if (fatal)

            SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);

        else

            ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);

        return 0;

    }

    kdf = EVP_KDF_fetch(SSL_CONNECTION_GET_CTX(s)->libctx,

                        OSSL_KDF_NAME_TLS1_PRF,

                        SSL_CONNECTION_GET_CTX(s)->propq);

    if (kdf == NULL)

        goto err;

    kctx = EVP_KDF_CTX_new(kdf);

    EVP_KDF_free(kdf);

    if (kctx == NULL)

        goto err;

    mdname = EVP_MD_get0_name(md);

    *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,

                                            (char *)mdname, 0);

    *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SECRET,

                                             (unsigned char *)sec,

                                             (size_t)slen);

    *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SEED,

                                             (void *)seed1, (size_t)seed1_len);

    *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SEED,

                                             (void *)seed2, (size_t)seed2_len);

    *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SEED,

                                             (void *)seed3, (size_t)seed3_len);

    *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SEED,

                                             (void *)seed4, (size_t)seed4_len);

    *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SEED,

                                             (void *)seed5, (size_t)seed5_len);

    /*

     * If we have a property query string, the kdf needs to know about it in the event

     * the specific kdf in use allocated a digest as part of its implementation

     */

    if (SSL_CONNECTION_GET_CTX(s)->propq != NULL)

        *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_PROPERTIES,

                                                (char *)SSL_CONNECTION_GET_CTX(s)->propq, 0);

    *p = OSSL_PARAM_construct_end();

    if (EVP_KDF_derive(kctx, out, olen, params)) {

        EVP_KDF_CTX_free(kctx);

        return 1;

    }

 err:

    if (fatal)

        SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);

    else

        ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);

    EVP_KDF_CTX_free(kctx);

    return 0;

}

static int tls1_generate_key_block(SSL_CONNECTION *s, unsigned char *km,

                                   size_t num)

{

    int ret;

    /* Calls SSLfatal() as required */

    ret = tls1_PRF(s,

                   TLS_MD_KEY_EXPANSION_CONST,

                   TLS_MD_KEY_EXPANSION_CONST_SIZE, s->s3.server_random,

                   SSL3_RANDOM_SIZE, s->s3.client_random, SSL3_RANDOM_SIZE,

                   NULL, 0, NULL, 0, s->session->master_key,

                   s->session->master_key_length, km, num, 1);

    return ret;

}

static int tls_iv_length_within_key_block(const EVP_CIPHER *c)

{

    /* If GCM/CCM mode only part of IV comes from PRF */

    if (EVP_CIPHER_get_mode(c) == EVP_CIPH_GCM_MODE)

        return EVP_GCM_TLS_FIXED_IV_LEN;

    else if (EVP_CIPHER_get_mode(c) == EVP_CIPH_CCM_MODE)

        return EVP_CCM_TLS_FIXED_IV_LEN;

    else

        return EVP_CIPHER_get_iv_length(c);

}

int tls1_change_cipher_state(SSL_CONNECTION *s, int which)

{

    unsigned char *p, *mac_secret;

    unsigned char *key, *iv;

    const EVP_CIPHER *c;

    const SSL_COMP *comp = NULL;

    const EVP_MD *m;

    int mac_type;

    size_t mac_secret_size;

    size_t n, i, j, k, cl;

    int iivlen;

    /*

     * Taglen is only relevant for CCM ciphersuites. Other ciphersuites

     * ignore this value so we can default it to 0.

     */

    size_t taglen = 0;

    int direction;

    c = s->s3.tmp.new_sym_enc;

    m = s->s3.tmp.new_hash;

    mac_type = s->s3.tmp.new_mac_pkey_type;

#ifndef OPENSSL_NO_COMP

    comp = s->s3.tmp.new_compression;

#endif

    p = s->s3.tmp.key_block;

    i = mac_secret_size = s->s3.tmp.new_mac_secret_size;

    cl = EVP_CIPHER_get_key_length(c);

    j = cl;

    iivlen = tls_iv_length_within_key_block(c);

    if (iivlen < 0) {

        SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);

        goto err;

    }

    k = iivlen;

    if ((which == SSL3_CHANGE_CIPHER_CLIENT_WRITE) ||

        (which == SSL3_CHANGE_CIPHER_SERVER_READ)) {

        mac_secret = &(p[0]);

        n = i + i;

        key = &(p[n]);

        n += j + j;

        iv = &(p[n]);

        n += k + k;

    } else {

        n = i;

        mac_secret = &(p[n]);

        n += i + j;

        key = &(p[n]);

        n += j + k;

        iv = &(p[n]);

        n += k;

    }

    if (n > s->s3.tmp.key_block_length) {

        SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);

        goto err;

    }

    switch (EVP_CIPHER_get_mode(c)) {

    case EVP_CIPH_GCM_MODE:

        taglen = EVP_GCM_TLS_TAG_LEN;

        break;

    case EVP_CIPH_CCM_MODE:

        if ((s->s3.tmp.new_cipher->algorithm_enc

                & (SSL_AES128CCM8 | SSL_AES256CCM8)) != 0)

            taglen = EVP_CCM8_TLS_TAG_LEN;

        else

            taglen = EVP_CCM_TLS_TAG_LEN;

        break;

    default:

        if (EVP_CIPHER_is_a(c, "CHACHA20-POLY1305")) {

            taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;

        } else {

            /* MAC secret size corresponds to the MAC output size */

            taglen = s->s3.tmp.new_mac_secret_size;

        }

        break;

    }

    if (which & SSL3_CC_READ) {

        if (s->ext.use_etm)

            s->s3.flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC_READ;

        else

            s->s3.flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC_READ;

        if (s->s3.tmp.new_cipher->algorithm2 & TLS1_STREAM_MAC)

            s->mac_flags |= SSL_MAC_FLAG_READ_MAC_STREAM;

        else

            s->mac_flags &= ~SSL_MAC_FLAG_READ_MAC_STREAM;

        if (s->s3.tmp.new_cipher->algorithm2 & TLS1_TLSTREE)

            s->mac_flags |= SSL_MAC_FLAG_READ_MAC_TLSTREE;

        else

            s->mac_flags &= ~SSL_MAC_FLAG_READ_MAC_TLSTREE;

        direction = OSSL_RECORD_DIRECTION_READ;

    } else {

        if (s->ext.use_etm)

            s->s3.flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC_WRITE;

        else

            s->s3.flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC_WRITE;

        if (s->s3.tmp.new_cipher->algorithm2 & TLS1_STREAM_MAC)

            s->mac_flags |= SSL_MAC_FLAG_WRITE_MAC_STREAM;

        else

            s->mac_flags &= ~SSL_MAC_FLAG_WRITE_MAC_STREAM;

        if (s->s3.tmp.new_cipher->algorithm2 & TLS1_TLSTREE)

            s->mac_flags |= SSL_MAC_FLAG_WRITE_MAC_TLSTREE;

        else

            s->mac_flags &= ~SSL_MAC_FLAG_WRITE_MAC_TLSTREE;

        direction = OSSL_RECORD_DIRECTION_WRITE;

    }

    if (SSL_CONNECTION_IS_DTLS(s))

        dtls1_increment_epoch(s, which);

    if (!ssl_set_new_record_layer(s, s->version, direction,

                                    OSSL_RECORD_PROTECTION_LEVEL_APPLICATION,

                                    NULL, 0, key, cl, iv, (size_t)k, mac_secret,

                                    mac_secret_size, c, taglen, mac_type,

                                    m, comp, NULL)) {

        /* SSLfatal already called */

        goto err;

    }

    OSSL_TRACE_BEGIN(TLS) {

        BIO_printf(trc_out, "which = %04X, key:\n", which);

        BIO_dump_indent(trc_out, key, EVP_CIPHER_get_key_length(c), 4);

        BIO_printf(trc_out, "iv:\n");

        BIO_dump_indent(trc_out, iv, (int)k, 4);

    } OSSL_TRACE_END(TLS);

    return 1;

 err:

    return 0;

}

int tls1_setup_key_block(SSL_CONNECTION *s)

{

    unsigned char *p;

    const EVP_CIPHER *c;

    const EVP_MD *hash;

    SSL_COMP *comp;

    int mac_type = NID_undef;

    size_t num, mac_secret_size = 0;

    int ret = 0;

    int ivlen;

    if (s->s3.tmp.key_block_length != 0)

        return 1;

    if (!ssl_cipher_get_evp(SSL_CONNECTION_GET_CTX(s), s->session, &c, &hash,

                            &mac_type, &mac_secret_size, &comp,

                            s->ext.use_etm)) {

        /* Error is already recorded */

        SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);

        return 0;

    }

    ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);

    s->s3.tmp.new_sym_enc = c;

    ssl_evp_md_free(s->s3.tmp.new_hash);

    s->s3.tmp.new_hash = hash;

    s->s3.tmp.new_mac_pkey_type = mac_type;

    s->s3.tmp.new_mac_secret_size = mac_secret_size;

    ivlen = tls_iv_length_within_key_block(c);

    if (ivlen < 0) {

        SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);

        return 0;

    }

    num = mac_secret_size + EVP_CIPHER_get_key_length(c) + ivlen;

    num *= 2;

    ssl3_cleanup_key_block(s);

    if ((p = OPENSSL_malloc(num)) == NULL) {

        SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_CRYPTO_LIB);

        goto err;

    }

    s->s3.tmp.key_block_length = num;

    s->s3.tmp.key_block = p;

    OSSL_TRACE_BEGIN(TLS) {

        BIO_printf(trc_out, "key block length: %zu\n", num);

        BIO_printf(trc_out, "client random\n");

        BIO_dump_indent(trc_out, s->s3.client_random, SSL3_RANDOM_SIZE, 4);

        BIO_printf(trc_out, "server random\n");

        BIO_dump_indent(trc_out, s->s3.server_random, SSL3_RANDOM_SIZE, 4);

        BIO_printf(trc_out, "master key\n");

        BIO_dump_indent(trc_out,

                        s->session->master_key,

                        (int)s->session->master_key_length, 4);

    } OSSL_TRACE_END(TLS);

    if (!tls1_generate_key_block(s, p, num)) {

        /* SSLfatal() already called */

        goto err;

    }

    OSSL_TRACE_BEGIN(TLS) {

        BIO_printf(trc_out, "key block\n");

        BIO_dump_indent(trc_out, p, (int)num, 4);

    } OSSL_TRACE_END(TLS);

    ret = 1;

 err:

    return ret;

}

size_t tls1_final_finish_mac(SSL_CONNECTION *s, const char *str,

                             size_t slen, unsigned char *out)

{

    size_t hashlen;

    unsigned char hash[EVP_MAX_MD_SIZE];

    size_t finished_size = TLS1_FINISH_MAC_LENGTH;

    if (s->s3.tmp.new_cipher->algorithm_mkey & SSL_kGOST18)

        finished_size = 32;

    if (!ssl3_digest_cached_records(s, 0)) {

        /* SSLfatal() already called */

        return 0;

    }

    if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {

        /* SSLfatal() already called */

        return 0;

    }

    if (!tls1_PRF(s, str, slen, hash, hashlen, NULL, 0, NULL, 0, NULL, 0,

                  s->session->master_key, s->session->master_key_length,

                  out, finished_size, 1)) {

        /* SSLfatal() already called */

        return 0;

    }

    OPENSSL_cleanse(hash, hashlen);

    return finished_size;

}

int tls1_generate_master_secret(SSL_CONNECTION *s, unsigned char *out,

                                unsigned char *p, size_t len,

                                size_t *secret_size)

{

    if (s->session->flags & SSL_SESS_FLAG_EXTMS) {

        unsigned char hash[EVP_MAX_MD_SIZE * 2];

        size_t hashlen;

        /*

         * Digest cached records keeping record buffer (if present): this won't

         * affect client auth because we're freezing the buffer at the same

         * point (after client key exchange and before certificate verify)

         */

        if (!ssl3_digest_cached_records(s, 1)

                || !ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {

            /* SSLfatal() already called */

            return 0;

        }

        OSSL_TRACE_BEGIN(TLS) {

            BIO_printf(trc_out, "Handshake hashes:\n");

            BIO_dump(trc_out, (char *)hash, (int)hashlen);

        } OSSL_TRACE_END(TLS);

        if (!tls1_PRF(s,

                      TLS_MD_EXTENDED_MASTER_SECRET_CONST,

                      TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE,

                      hash, hashlen,

                      NULL, 0,

                      NULL, 0,

                      NULL, 0, p, len, out,

                      SSL3_MASTER_SECRET_SIZE, 1)) {

            /* SSLfatal() already called */

            return 0;

        }

        OPENSSL_cleanse(hash, hashlen);

    } else {

        if (!tls1_PRF(s,

                      TLS_MD_MASTER_SECRET_CONST,

                      TLS_MD_MASTER_SECRET_CONST_SIZE,

                      s->s3.client_random, SSL3_RANDOM_SIZE,

                      NULL, 0,

                      s->s3.server_random, SSL3_RANDOM_SIZE,

                      NULL, 0, p, len, out,

                      SSL3_MASTER_SECRET_SIZE, 1)) {

           /* SSLfatal() already called */

            return 0;

        }

    }

    OSSL_TRACE_BEGIN(TLS) {

        BIO_printf(trc_out, "Premaster Secret:\n");

        BIO_dump_indent(trc_out, p, (int)len, 4);

        BIO_printf(trc_out, "Client Random:\n");

        BIO_dump_indent(trc_out, s->s3.client_random, SSL3_RANDOM_SIZE, 4);

        BIO_printf(trc_out, "Server Random:\n");

        BIO_dump_indent(trc_out, s->s3.server_random, SSL3_RANDOM_SIZE, 4);

        BIO_printf(trc_out, "Master Secret:\n");

        BIO_dump_indent(trc_out,

                        s->session->master_key,

                        SSL3_MASTER_SECRET_SIZE, 4);

    } OSSL_TRACE_END(TLS);

    *secret_size = SSL3_MASTER_SECRET_SIZE;

    return 1;

}

int tls1_export_keying_material(SSL_CONNECTION *s, unsigned char *out,

                                size_t olen, const char *label, size_t llen,

                                const unsigned char *context,

                                size_t contextlen, int use_context)

{

    unsigned char *val = NULL;

    size_t vallen = 0, currentvalpos;

    int rv = 0;

    /*

     * RFC 5705 embeds context length as uint16; reject longer context

     * before proceeding.

     */

    if (contextlen > 0xffff) {

        ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

    /*

     * construct PRF arguments we construct the PRF argument ourself rather

     * than passing separate values into the TLS PRF to ensure that the

     * concatenation of values does not create a prohibited label.

     */

    vallen = llen + SSL3_RANDOM_SIZE * 2;

    if (use_context) {

        vallen += 2 + contextlen;

    }

    val = OPENSSL_malloc(vallen);

    if (val == NULL)

        goto ret;

    currentvalpos = 0;

    memcpy(val + currentvalpos, (unsigned char *)label, llen);

    currentvalpos += llen;

    memcpy(val + currentvalpos, s->s3.client_random, SSL3_RANDOM_SIZE);

    currentvalpos += SSL3_RANDOM_SIZE;

    memcpy(val + currentvalpos, s->s3.server_random, SSL3_RANDOM_SIZE);

    currentvalpos += SSL3_RANDOM_SIZE;

    if (use_context) {

        val[currentvalpos] = (contextlen >> 8) & 0xff;

        currentvalpos++;

        val[currentvalpos] = contextlen & 0xff;

        currentvalpos++;

        if ((contextlen > 0) || (context != NULL)) {

            memcpy(val + currentvalpos, context, contextlen);

        }

    }

    /*

     * disallow prohibited labels note that SSL3_RANDOM_SIZE > max(prohibited

     * label len) = 15, so size of val > max(prohibited label len) = 15 and

     * the comparisons won't have buffer overflow

     */

    if (memcmp(val, TLS_MD_CLIENT_FINISH_CONST,

               TLS_MD_CLIENT_FINISH_CONST_SIZE) == 0)

        goto err1;

    if (memcmp(val, TLS_MD_SERVER_FINISH_CONST,

               TLS_MD_SERVER_FINISH_CONST_SIZE) == 0)

        goto err1;

    if (memcmp(val, TLS_MD_MASTER_SECRET_CONST,

               TLS_MD_MASTER_SECRET_CONST_SIZE) == 0)

        goto err1;

    if (memcmp(val, TLS_MD_EXTENDED_MASTER_SECRET_CONST,

               TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE) == 0)

        goto err1;

    if (memcmp(val, TLS_MD_KEY_EXPANSION_CONST,

               TLS_MD_KEY_EXPANSION_CONST_SIZE) == 0)

        goto err1;

    rv = tls1_PRF(s,

                  val, vallen,

                  NULL, 0,

                  NULL, 0,

                  NULL, 0,

                  NULL, 0,

                  s->session->master_key, s->session->master_key_length,

                  out, olen, 0);

    goto ret;

 err1:

    ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);

 ret:

    OPENSSL_clear_free(val, vallen);

    return rv;

}

int tls1_alert_code(int code)

{

    switch (code) {

    case SSL_AD_CLOSE_NOTIFY:

        return SSL3_AD_CLOSE_NOTIFY;

    case SSL_AD_UNEXPECTED_MESSAGE:

        return SSL3_AD_UNEXPECTED_MESSAGE;

    case SSL_AD_BAD_RECORD_MAC:

        return SSL3_AD_BAD_RECORD_MAC;

    case SSL_AD_DECRYPTION_FAILED:

        return TLS1_AD_DECRYPTION_FAILED;

    case SSL_AD_RECORD_OVERFLOW:

        return TLS1_AD_RECORD_OVERFLOW;

    case SSL_AD_DECOMPRESSION_FAILURE:

        return SSL3_AD_DECOMPRESSION_FAILURE;

    case SSL_AD_HANDSHAKE_FAILURE:

        return SSL3_AD_HANDSHAKE_FAILURE;

    case SSL_AD_NO_CERTIFICATE:

        return -1;

    case SSL_AD_BAD_CERTIFICATE:

        return SSL3_AD_BAD_CERTIFICATE;

    case SSL_AD_UNSUPPORTED_CERTIFICATE:

        return SSL3_AD_UNSUPPORTED_CERTIFICATE;

    case SSL_AD_CERTIFICATE_REVOKED:

        return SSL3_AD_CERTIFICATE_REVOKED;

    case SSL_AD_CERTIFICATE_EXPIRED:

        return SSL3_AD_CERTIFICATE_EXPIRED;

    case SSL_AD_CERTIFICATE_UNKNOWN:

        return SSL3_AD_CERTIFICATE_UNKNOWN;

    case SSL_AD_ILLEGAL_PARAMETER:

        return SSL3_AD_ILLEGAL_PARAMETER;

    case SSL_AD_UNKNOWN_CA:

        return TLS1_AD_UNKNOWN_CA;

    case SSL_AD_ACCESS_DENIED:

        return TLS1_AD_ACCESS_DENIED;

    case SSL_AD_DECODE_ERROR:

        return TLS1_AD_DECODE_ERROR;

    case SSL_AD_DECRYPT_ERROR:

        return TLS1_AD_DECRYPT_ERROR;

    case SSL_AD_EXPORT_RESTRICTION:

        return TLS1_AD_EXPORT_RESTRICTION;

    case SSL_AD_PROTOCOL_VERSION:

        return TLS1_AD_PROTOCOL_VERSION;

    case SSL_AD_INSUFFICIENT_SECURITY:

        return TLS1_AD_INSUFFICIENT_SECURITY;

    case SSL_AD_INTERNAL_ERROR:

        return TLS1_AD_INTERNAL_ERROR;

    case SSL_AD_USER_CANCELLED:

        return TLS1_AD_USER_CANCELLED;

    case SSL_AD_NO_RENEGOTIATION:

        return TLS1_AD_NO_RENEGOTIATION;

    case SSL_AD_UNSUPPORTED_EXTENSION:

        return TLS1_AD_UNSUPPORTED_EXTENSION;

    case SSL_AD_CERTIFICATE_UNOBTAINABLE:

        return TLS1_AD_CERTIFICATE_UNOBTAINABLE;

    case SSL_AD_UNRECOGNIZED_NAME:

        return TLS1_AD_UNRECOGNIZED_NAME;

    case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE:

        return TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE;

    case SSL_AD_BAD_CERTIFICATE_HASH_VALUE:

        return TLS1_AD_BAD_CERTIFICATE_HASH_VALUE;

    case SSL_AD_UNKNOWN_PSK_IDENTITY:

        return TLS1_AD_UNKNOWN_PSK_IDENTITY;

    case SSL_AD_INAPPROPRIATE_FALLBACK:

        return TLS1_AD_INAPPROPRIATE_FALLBACK;

    case SSL_AD_NO_APPLICATION_PROTOCOL:

        return TLS1_AD_NO_APPLICATION_PROTOCOL;

    case SSL_AD_CERTIFICATE_REQUIRED:

        return SSL_AD_HANDSHAKE_FAILURE;

    case TLS13_AD_MISSING_EXTENSION:

        return SSL_AD_HANDSHAKE_FAILURE;

    default:

        return -1;

    }

}