/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * Handling of cipher specs.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "ssl.h"

#include "sslproto.h"

#include "pk11func.h"

#include "secitem.h"

#include "sslimpl.h"

/* Record protection algorithms, indexed by SSL3BulkCipher.

 *

 * The |max_records| field (|mr| below) is set to a number that is higher than

 * recommended in some literature (esp. TLS 1.3) because we currently abort the

 * connection when this limit is reached and we want to ensure that we only

 * rarely hit this limit.  See bug 1268745 for details.

 */

#define MR_MAX RECORD_SEQ_MAX  /* 2^48-1 */

#define MR_128 (0x5aULL << 28) /* For AES and similar. */

#define MR_LOW (1ULL << 20)    /* For weak ciphers. */

/* clang-format off */

static const ssl3BulkCipherDef ssl_bulk_cipher_defs[] = {

    /*                                        |--------- Lengths ---------| */

    /* cipher             calg                :  s                        : */

    /*                                        :  e                  b     n */

    /* oid                short_name mr       :  c                  l     o */

    /*                                        k  r                  o  t  n */

    /*                                        e  e               i  c  a  c */

    /*                                        y  t  type         v  k  g  e */

    {cipher_null,         ssl_calg_null,      0, 0, type_stream, 0, 0, 0, 0,

     SEC_OID_NULL_CIPHER, "NULL", MR_MAX},

    {cipher_rc4,          ssl_calg_rc4,      16,16, type_stream, 0, 0, 0, 0,

     SEC_OID_RC4,         "RC4", MR_LOW},

    {cipher_des,          ssl_calg_des,       8, 8, type_block,  8, 8, 0, 0,

     SEC_OID_DES_CBC,     "DES-CBC", MR_LOW},

    {cipher_3des,         ssl_calg_3des,     24,24, type_block,  8, 8, 0, 0,

     SEC_OID_DES_EDE3_CBC, "3DES-EDE-CBC", MR_LOW},

    {cipher_aes_128,      ssl_calg_aes,      16,16, type_block, 16,16, 0, 0,

     SEC_OID_AES_128_CBC, "AES-128", MR_128},

    {cipher_aes_256,      ssl_calg_aes,      32,32, type_block, 16,16, 0, 0,

     SEC_OID_AES_256_CBC, "AES-256", MR_128},

    {cipher_camellia_128, ssl_calg_camellia, 16,16, type_block, 16,16, 0, 0,

     SEC_OID_CAMELLIA_128_CBC, "Camellia-128", MR_128},

    {cipher_camellia_256, ssl_calg_camellia, 32,32, type_block, 16,16, 0, 0,

     SEC_OID_CAMELLIA_256_CBC, "Camellia-256", MR_128},

    {cipher_seed,         ssl_calg_seed,     16,16, type_block, 16,16, 0, 0,

     SEC_OID_SEED_CBC,    "SEED-CBC", MR_128},

    {cipher_aes_128_gcm,  ssl_calg_aes_gcm,  16,16, type_aead,   4, 0,16, 8,

     SEC_OID_AES_128_GCM, "AES-128-GCM", MR_128},

    {cipher_aes_256_gcm,  ssl_calg_aes_gcm,  32,32, type_aead,   4, 0,16, 8,

     SEC_OID_AES_256_GCM, "AES-256-GCM", MR_128},

    {cipher_chacha20,     ssl_calg_chacha20, 32,32, type_aead,  12, 0,16, 0,

     SEC_OID_CHACHA20_POLY1305, "ChaCha20-Poly1305", MR_MAX},

    {cipher_missing,      ssl_calg_null,      0, 0, type_stream, 0, 0, 0, 0,

     SEC_OID_UNKNOWN,     "missing", 0U},

};

/* clang-format on */

const ssl3BulkCipherDef *

ssl_GetBulkCipherDef(const ssl3CipherSuiteDef *suiteDef)

{

    SSL3BulkCipher bulkCipher = suiteDef->bulk_cipher_alg;

    PORT_Assert(bulkCipher < PR_ARRAY_SIZE(ssl_bulk_cipher_defs));

    PORT_Assert(ssl_bulk_cipher_defs[bulkCipher].cipher == bulkCipher);

    return &ssl_bulk_cipher_defs[bulkCipher];

}

/* indexed by SSL3MACAlgorithm */

static const ssl3MACDef ssl_mac_defs[] = {

    /* pad_size is only used for SSL 3.0 MAC. See RFC 6101 Sec. 5.2.3.1. */

    /* mac      mmech       pad_size  mac_size                       */

    { ssl_mac_null, CKM_INVALID_MECHANISM, 0, 0, 0 },

    { ssl_mac_md5, CKM_SSL3_MD5_MAC, 48, MD5_LENGTH, SEC_OID_HMAC_MD5 },

    { ssl_mac_sha, CKM_SSL3_SHA1_MAC, 40, SHA1_LENGTH, SEC_OID_HMAC_SHA1 },

    { ssl_hmac_md5, CKM_MD5_HMAC, 0, MD5_LENGTH, SEC_OID_HMAC_MD5 },

    { ssl_hmac_sha, CKM_SHA_1_HMAC, 0, SHA1_LENGTH, SEC_OID_HMAC_SHA1 },

    { ssl_hmac_sha256, CKM_SHA256_HMAC, 0, SHA256_LENGTH, SEC_OID_HMAC_SHA256 },

    { ssl_mac_aead, CKM_INVALID_MECHANISM, 0, 0, 0 },

    { ssl_hmac_sha384, CKM_SHA384_HMAC, 0, SHA384_LENGTH, SEC_OID_HMAC_SHA384 }

};

const ssl3MACDef *

ssl_GetMacDefByAlg(SSL3MACAlgorithm mac)

{

    /* Cast here for clang: https://bugs.llvm.org/show_bug.cgi?id=16154 */

    PORT_Assert((size_t)mac < PR_ARRAY_SIZE(ssl_mac_defs));

    PORT_Assert(ssl_mac_defs[mac].mac == mac);

    return &ssl_mac_defs[mac];

}

const ssl3MACDef *

ssl_GetMacDef(const sslSocket *ss, const ssl3CipherSuiteDef *suiteDef)

{

    SSL3MACAlgorithm mac = suiteDef->mac_alg;

    if (ss->version > SSL_LIBRARY_VERSION_3_0) {

        switch (mac) {

            case ssl_mac_md5:

                mac = ssl_hmac_md5;

                break;

            case ssl_mac_sha:

                mac = ssl_hmac_sha;

                break;

            default:

                break;

        }

    }

    return ssl_GetMacDefByAlg(mac);

}

ssl3CipherSpec *

ssl_FindCipherSpecByEpoch(sslSocket *ss, CipherSpecDirection direction,

                          DTLSEpoch epoch)

{

    PRCList *cur_p;

    for (cur_p = PR_LIST_HEAD(&ss->ssl3.hs.cipherSpecs);

         cur_p != &ss->ssl3.hs.cipherSpecs;

         cur_p = PR_NEXT_LINK(cur_p)) {

        ssl3CipherSpec *spec = (ssl3CipherSpec *)cur_p;

        if (spec->epoch != epoch) {

            continue;

        }

        if (direction != spec->direction) {

            continue;

        }

        return spec;

    }

    return NULL;

}

ssl3CipherSpec *

ssl_CreateCipherSpec(sslSocket *ss, CipherSpecDirection direction)

{

    ssl3CipherSpec *spec = PORT_ZNew(ssl3CipherSpec);

    if (!spec) {

        return NULL;

    }

    spec->refCt = 1;

    spec->version = ss->version;

    spec->direction = direction;

    spec->recordSizeLimit = MAX_FRAGMENT_LENGTH;

    SSL_TRC(10, ("%d: SSL[%d]: new %s spec %d ct=%d",

                 SSL_GETPID(), ss->fd, SPEC_DIR(spec), spec,

                 spec->refCt));

    return spec;

}

void

ssl_SaveCipherSpec(sslSocket *ss, ssl3CipherSpec *spec)

{

    PR_APPEND_LINK(&spec->link, &ss->ssl3.hs.cipherSpecs);

}

/* Called from ssl3_InitState. */

/* Caller must hold the SpecWriteLock. */

SECStatus

ssl_SetupNullCipherSpec(sslSocket *ss, CipherSpecDirection dir)

{

    ssl3CipherSpec *spec;

    PORT_Assert(ss->opt.noLocks || ssl_HaveSpecWriteLock(ss));

    spec = ssl_CreateCipherSpec(ss, dir);

    if (!spec) {

        return SECFailure;

    }

    /* Set default versions.  This value will be used to generate and send

     * alerts if a version is not negotiated.  These values are overridden when

     * sending a ClientHello and when a version is negotiated. */

    spec->version = SSL_LIBRARY_VERSION_TLS_1_0;

    spec->recordVersion = IS_DTLS(ss)

                              ? SSL_LIBRARY_VERSION_DTLS_1_0_WIRE

                              : SSL_LIBRARY_VERSION_TLS_1_0;

    spec->cipherDef = &ssl_bulk_cipher_defs[cipher_null];

    PORT_Assert(spec->cipherDef->cipher == cipher_null);

    spec->macDef = &ssl_mac_defs[ssl_mac_null];

    PORT_Assert(spec->macDef->mac == ssl_mac_null);

    spec->cipher = Null_Cipher;

    spec->phase = "cleartext";

    dtls_InitRecvdRecords(&spec->recvdRecords);

    ssl_SaveCipherSpec(ss, spec);

    if (dir == CipherSpecRead) {

        ss->ssl3.crSpec = spec;

    } else {

        ss->ssl3.cwSpec = spec;

    }

    return SECSuccess;

}

void

ssl_CipherSpecAddRef(ssl3CipherSpec *spec)

{

    ++spec->refCt;

    SSL_TRC(10, ("%d: SSL[-]: Increment ref ct for %s spec %d. new ct = %d",

                 SSL_GETPID(), SPEC_DIR(spec), spec, spec->refCt));

}

static void

ssl_DestroyKeyMaterial(ssl3KeyMaterial *keyMaterial)

{

    PK11_FreeSymKey(keyMaterial->key);

    PK11_FreeSymKey(keyMaterial->macKey);

    if (keyMaterial->macContext != NULL) {

        PK11_DestroyContext(keyMaterial->macContext, PR_TRUE);

    }

}

static void

ssl_FreeCipherSpec(ssl3CipherSpec *spec)

{

    SSL_TRC(10, ("%d: SSL[-]: Freeing %s spec %d. epoch=%d",

                 SSL_GETPID(), SPEC_DIR(spec), spec, spec->epoch));

    PR_REMOVE_LINK(&spec->link);

    /*  PORT_Assert( ss->opt.noLocks || ssl_HaveSpecWriteLock(ss)); Don't have ss! */

    if (spec->cipherContext) {

        PK11_DestroyContext(spec->cipherContext, PR_TRUE);

    }

    PK11_FreeSymKey(spec->masterSecret);

    ssl_DestroyKeyMaterial(&spec->keyMaterial);

    PORT_ZFree(spec, sizeof(*spec));

}

/* This function is never called on a spec which is on the

 * cipherSpecs list. */

void

ssl_CipherSpecRelease(ssl3CipherSpec *spec)

{

    if (!spec) {

        return;

    }

    PORT_Assert(spec->refCt > 0);

    --spec->refCt;

    SSL_TRC(10, ("%d: SSL[-]: decrement refct for %s spec %d. epoch=%d new ct = %d",

                 SSL_GETPID(), SPEC_DIR(spec), spec, spec->epoch, spec->refCt));

    if (!spec->refCt) {

        ssl_FreeCipherSpec(spec);

    }

}

void

ssl_DestroyCipherSpecs(PRCList *list)

{

    while (!PR_CLIST_IS_EMPTY(list)) {

        ssl3CipherSpec *spec = (ssl3CipherSpec *)PR_LIST_TAIL(list);

        ssl_FreeCipherSpec(spec);

    }

}

void

ssl_CipherSpecReleaseByEpoch(sslSocket *ss, CipherSpecDirection dir,

                             DTLSEpoch epoch)

{

    ssl3CipherSpec *spec;

    SSL_TRC(10, ("%d: SSL[%d]: releasing %s cipher spec for epoch %d",

                 SSL_GETPID(), ss->fd,

                 (dir == CipherSpecRead) ? "read" : "write", epoch));

    spec = ssl_FindCipherSpecByEpoch(ss, dir, epoch);

    if (spec) {

        ssl_CipherSpecRelease(spec);

    }

}