ssl/t1_enc.c

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */
/* ====================================================================
 * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* ====================================================================
 * Copyright 2005 Nokia. All rights reserved.
 *
 * The portions of the attached software ("Contribution") is developed by
 * Nokia Corporation and is licensed pursuant to the OpenSSL open source
 * license.
 *
 * The Contribution, originally written by Mika Kousa and Pasi Eronen of
 * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
 * support (see RFC 4279) to OpenSSL.
 *
 * No patent licenses or other rights except those expressly stated in
 * the OpenSSL open source license shall be deemed granted or received
 * expressly, by implication, estoppel, or otherwise.
 *
 * No assurances are provided by Nokia that the Contribution does not
 * infringe the patent or other intellectual property rights of any third
 * party or that the license provides you with all the necessary rights
 * to make use of the Contribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
 * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
 * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
 * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
 * OTHERWISE. */

#include <stdio.h>
#include <assert.h>

#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/md5.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/rand.h>

#include "ssl_locl.h"


/* tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
 * section 5. It writes |out_len| bytes to |out|, using |md| as the hash and
 * |secret| as the secret. |seed1| through |seed3| are concatenated to form the
 * seed parameter. It returns one on success and zero on failure. */
static int tls1_P_hash(uint8_t *out, size_t out_len, const EVP_MD *md,
                       const uint8_t *secret, size_t secret_len,
                       const uint8_t *seed1, size_t seed1_len,
                       const uint8_t *seed2, size_t seed2_len,
                       const uint8_t *seed3, size_t seed3_len) {
  size_t chunk;
  HMAC_CTX ctx, ctx_tmp, ctx_init;
  uint8_t A1[EVP_MAX_MD_SIZE];
  unsigned A1_len;
  int ret = 0;

  chunk = EVP_MD_size(md);

  HMAC_CTX_init(&ctx);
  HMAC_CTX_init(&ctx_tmp);
  HMAC_CTX_init(&ctx_init);
  if (!HMAC_Init_ex(&ctx_init, secret, secret_len, md, NULL) ||
      !HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
      (seed1_len && !HMAC_Update(&ctx, seed1, seed1_len)) ||
      (seed2_len && !HMAC_Update(&ctx, seed2, seed2_len)) ||
      (seed3_len && !HMAC_Update(&ctx, seed3, seed3_len)) ||
      !HMAC_Final(&ctx, A1, &A1_len)) {
    goto err;
  }

  for (;;) {
    /* Reinit mac contexts. */
    if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
        !HMAC_Update(&ctx, A1, A1_len) ||
        (out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) ||
        (seed1_len && !HMAC_Update(&ctx, seed1, seed1_len)) ||
        (seed2_len && !HMAC_Update(&ctx, seed2, seed2_len)) ||
        (seed3_len && !HMAC_Update(&ctx, seed3, seed3_len))) {
      goto err;
    }

    if (out_len > chunk) {
      unsigned len;
      if (!HMAC_Final(&ctx, out, &len)) {
        goto err;
      }
      assert(len == chunk);
      out += len;
      out_len -= len;
      /* Calculate the next A1 value. */
      if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) {
        goto err;
      }
    } else {
      /* Last chunk. */
      if (!HMAC_Final(&ctx, A1, &A1_len)) {
        goto err;
      }
      memcpy(out, A1, out_len);
      break;
    }
  }

  ret = 1;

err:
  HMAC_CTX_cleanup(&ctx);
  HMAC_CTX_cleanup(&ctx_tmp);
  HMAC_CTX_cleanup(&ctx_init);
  OPENSSL_cleanse(A1, sizeof(A1));
  return ret;
}

/* tls1_PRF computes the TLS PRF function as described in RFC 5246, section 5
 * and RFC 2246 section 5. It writes |out_len| bytes to |out|, using
 * |digest_mask| to select the hash functions, |secret| as the secret, and
 * |label| as the label. |seed1| and |seed2| are concatenated to form the seed
 * parameter. It returns one on success and zero on failure. */
static int tls1_PRF(uint8_t *out, size_t out_len, long digest_mask,
                    const uint8_t *secret, size_t secret_len,
                    const char *label, size_t label_len,
                    const uint8_t *seed1, size_t seed1_len,
                    const uint8_t *seed2, size_t seed2_len) {
  size_t idx, len, count, i;
  const uint8_t *S1;
  long m;
  const EVP_MD *md;
  int ret = 0;
  uint8_t *tmp;

  if (out_len == 0) {
    return 1;
  }

  /* Allocate a temporary buffer. */
  tmp = OPENSSL_malloc(out_len);
  if (tmp == NULL) {
    OPENSSL_PUT_ERROR(SSL, tls1_PRF, ERR_R_MALLOC_FAILURE);
    return 0;
  }

  /* Count number of digests and partition |secret| evenly. */
  count = 0;
  for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) {
    if ((m << TLS1_PRF_DGST_SHIFT) & digest_mask) {
      count++;
    }
  }
  /* TODO(davidben): The only case where count isn't 1 is the old MD5/SHA-1
   * combination. The logic around multiple handshake digests can probably be
   * simplified. */
  assert(count == 1 || count == 2);
  len = secret_len / count;
  if (count == 1) {
    secret_len = 0;
  }
  S1 = secret;
  memset(out, 0, out_len);
  for (idx = 0; ssl_get_handshake_digest(idx, &m, &md); idx++) {
    if ((m << TLS1_PRF_DGST_SHIFT) & digest_mask) {
      /* If |count| is 2 and |secret_len| is odd, |secret| is partitioned into
       * two halves with an overlapping byte. */
      if (!tls1_P_hash(tmp, out_len, md, S1, len + (secret_len & 1),
                       (const uint8_t *)label, label_len, seed1, seed1_len,
                       seed2, seed2_len)) {
        goto err;
      }
      S1 += len;
      for (i = 0; i < out_len; i++) {
        out[i] ^= tmp[i];
      }
    }
  }
  ret = 1;

err:
  OPENSSL_cleanse(tmp, out_len);
  OPENSSL_free(tmp);
  return ret;
}

static int tls1_generate_key_block(SSL *s, uint8_t *out, size_t out_len) {
  return tls1_PRF(out, out_len, ssl_get_algorithm2(s),
                  s->session->master_key, s->session->master_key_length,
                  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);
}

/* tls1_aead_ctx_init allocates |*aead_ctx|, if needed and returns 1. It
 * returns 0 on malloc error. */
static int tls1_aead_ctx_init(SSL_AEAD_CTX **aead_ctx) {
  if (*aead_ctx != NULL) {
    EVP_AEAD_CTX_cleanup(&(*aead_ctx)->ctx);
  } else {
    *aead_ctx = (SSL_AEAD_CTX *)OPENSSL_malloc(sizeof(SSL_AEAD_CTX));
    if (*aead_ctx == NULL) {
      OPENSSL_PUT_ERROR(SSL, tls1_aead_ctx_init, ERR_R_MALLOC_FAILURE);
      return 0;
    }
  }

  return 1;
}

static void tls1_cleanup_enc_ctx(EVP_CIPHER_CTX **ctx) {
  if (*ctx != NULL) {
    EVP_CIPHER_CTX_free(*ctx);
  }
  *ctx = NULL;
}

static void tls1_cleanup_hash_ctx(EVP_MD_CTX **ctx) {
  if (*ctx != NULL) {
    EVP_MD_CTX_destroy(*ctx);
  }
  *ctx = NULL;
}

static int tls1_change_cipher_state_aead(SSL *s, char is_read,
                                         const uint8_t *key, unsigned key_len,
                                         const uint8_t *iv, unsigned iv_len,
                                         const uint8_t *mac_secret,
                                         unsigned mac_secret_len) {
  const EVP_AEAD *aead = s->s3->tmp.new_aead;
  SSL_AEAD_CTX *aead_ctx;
  /* merged_key is used to merge the MAC, cipher, and IV keys for an AEAD which
   * simulates pre-AEAD cipher suites. */
  uint8_t merged_key[EVP_AEAD_MAX_KEY_LENGTH];

  if (is_read) {
    tls1_cleanup_enc_ctx(&s->enc_read_ctx);
    tls1_cleanup_hash_ctx(&s->read_hash);
  } else {
    tls1_cleanup_enc_ctx(&s->enc_write_ctx);
    tls1_cleanup_hash_ctx(&s->write_hash);
  }

  if (mac_secret_len > 0) {
    /* This is a "stateful" AEAD (for compatibility with pre-AEAD cipher
     * suites). */
    if (mac_secret_len + key_len + iv_len > sizeof(merged_key)) {
      OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead,
                        ERR_R_INTERNAL_ERROR);
      return 0;
    }
    memcpy(merged_key, mac_secret, mac_secret_len);
    memcpy(merged_key + mac_secret_len, key, key_len);
    memcpy(merged_key + mac_secret_len + key_len, iv, iv_len);
    key = merged_key;
    key_len += mac_secret_len;
    key_len += iv_len;
  }

  if (is_read) {
    if (!tls1_aead_ctx_init(&s->aead_read_ctx)) {
      return 0;
    }
    aead_ctx = s->aead_read_ctx;
  } else {
    if (!tls1_aead_ctx_init(&s->aead_write_ctx)) {
      return 0;
    }
    aead_ctx = s->aead_write_ctx;
  }

  if (!EVP_AEAD_CTX_init(&aead_ctx->ctx, aead, key, key_len,
                         EVP_AEAD_DEFAULT_TAG_LENGTH, NULL /* engine */)) {
    OPENSSL_free(aead_ctx);
    if (is_read) {
      s->aead_read_ctx = NULL;
    } else {
      s->aead_write_ctx = NULL;
    }

    return 0;
  }

  if (mac_secret_len == 0) {
    /* For a real AEAD, the IV is the fixed part of the nonce. */
    if (iv_len > sizeof(aead_ctx->fixed_nonce)) {
      OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
      return 0;
    }

    memcpy(aead_ctx->fixed_nonce, iv, iv_len);
    aead_ctx->fixed_nonce_len = iv_len;
    aead_ctx->variable_nonce_included_in_record =
      (s->s3->tmp.new_cipher->algorithm2 &
       SSL_CIPHER_ALGORITHM2_VARIABLE_NONCE_INCLUDED_IN_RECORD) != 0;
    aead_ctx->random_variable_nonce = 0;
    aead_ctx->omit_length_in_ad = 0;
  } else {
    aead_ctx->fixed_nonce_len = 0;
    aead_ctx->variable_nonce_included_in_record = 1;
    aead_ctx->random_variable_nonce = 1;
    aead_ctx->omit_length_in_ad = 1;
  }
  aead_ctx->variable_nonce_len = s->s3->tmp.new_variable_iv_len;

  if (aead_ctx->variable_nonce_len + aead_ctx->fixed_nonce_len !=
      EVP_AEAD_nonce_length(aead)) {
    OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_aead, ERR_R_INTERNAL_ERROR);
    return 0;
  }
  aead_ctx->tag_len = EVP_AEAD_max_overhead(aead);

  return 1;
}

static void tls1_cleanup_aead_ctx(SSL_AEAD_CTX **ctx) {
  if (*ctx != NULL) {
    EVP_AEAD_CTX_cleanup(&(*ctx)->ctx);
    OPENSSL_free(*ctx);
  }
  *ctx = NULL;
}

/* tls1_change_cipher_state_cipher performs the work needed to switch cipher
 * states when using EVP_CIPHER. The argument |is_read| is true iff this
 * function is being called due to reading, as opposed to writing, a
 * ChangeCipherSpec message. In order to support export ciphersuites,
 * use_client_keys indicates whether the key material provided is in the
 * "client write" direction. */
static int tls1_change_cipher_state_cipher(SSL *s, char is_read,
                                           char use_client_keys,
                                           const uint8_t *mac_secret,
                                           unsigned mac_secret_len,
                                           const uint8_t *key, unsigned key_len,
                                           const uint8_t *iv, unsigned iv_len) {
  const EVP_CIPHER *cipher = s->s3->tmp.new_sym_enc;
  EVP_CIPHER_CTX *cipher_ctx;
  EVP_MD_CTX *mac_ctx;

  if (is_read) {
    tls1_cleanup_aead_ctx(&s->aead_read_ctx);
  } else {
    tls1_cleanup_aead_ctx(&s->aead_write_ctx);
  }

  if (is_read) {
    if (s->enc_read_ctx != NULL && !SSL_IS_DTLS(s)) {
      EVP_CIPHER_CTX_cleanup(s->enc_read_ctx);
    } else if ((s->enc_read_ctx = EVP_CIPHER_CTX_new()) == NULL) {
      goto err;
    }

    cipher_ctx = s->enc_read_ctx;
    mac_ctx = ssl_replace_hash(&s->read_hash, NULL);
    if (mac_ctx == NULL) {
      goto err;
    }

    memcpy(s->s3->read_mac_secret, mac_secret, mac_secret_len);
    s->s3->read_mac_secret_size = mac_secret_len;
  } else {
    /* When updating the write contexts for DTLS, we do not wish to free the
     * old ones because DTLS stores pointers to them in order to implement
     * retransmission. */

    if (s->enc_write_ctx != NULL && !SSL_IS_DTLS(s)) {
      EVP_CIPHER_CTX_cleanup(s->enc_write_ctx);
    } else {
      s->enc_write_ctx = OPENSSL_malloc(sizeof(EVP_CIPHER_CTX));
      if (s->enc_write_ctx == NULL) {
        goto err;
      }
    }
    EVP_CIPHER_CTX_init(s->enc_write_ctx);

    cipher_ctx = s->enc_write_ctx;
    if (SSL_IS_DTLS(s)) {
      /* This is the same as ssl_replace_hash, but doesn't
       * free the old |s->write_hash|. */
      mac_ctx = EVP_MD_CTX_create();
      if (!mac_ctx) {
        goto err;
      }
      s->write_hash = mac_ctx;
    } else {
      mac_ctx = ssl_replace_hash(&s->write_hash, NULL);
      if (mac_ctx == NULL) {
        goto err;
      }
    }

    memcpy(s->s3->write_mac_secret, mac_secret, mac_secret_len);
    s->s3->write_mac_secret_size = mac_secret_len;
  }

  EVP_PKEY *mac_key = EVP_PKEY_new_mac_key(s->s3->tmp.new_mac_pkey_type, NULL,
                                           mac_secret, mac_secret_len);
  if (!mac_key) {
    return 0;
  }

  if (!EVP_DigestSignInit(mac_ctx, NULL, s->s3->tmp.new_hash, NULL, mac_key)) {
    EVP_PKEY_free(mac_key);
    goto err;
  }
  EVP_PKEY_free(mac_key);

  if (!EVP_CipherInit_ex(cipher_ctx, cipher, NULL /* engine */, key, iv,
                         !is_read)) {
    goto err;
  }

  return 1;

err:
  OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_cipher, ERR_R_MALLOC_FAILURE);
  return 0;
}

int tls1_change_cipher_state(SSL *s, int which) {
  /* is_read is true if we have just read a ChangeCipherSpec message - i.e. we
   * need to update the read cipherspec. Otherwise we have just written one. */
  const char is_read = (which & SSL3_CC_READ) != 0;
  /* use_client_keys is true if we wish to use the keys for the "client write"
   * direction. This is the case if we're a client sending a ChangeCipherSpec,
   * or a server reading a client's ChangeCipherSpec. */
  const char use_client_keys = which == SSL3_CHANGE_CIPHER_CLIENT_WRITE ||
                               which == SSL3_CHANGE_CIPHER_SERVER_READ;
  const uint8_t *client_write_mac_secret, *server_write_mac_secret, *mac_secret;
  const uint8_t *client_write_key, *server_write_key, *key;
  const uint8_t *client_write_iv, *server_write_iv, *iv;
  const EVP_CIPHER *cipher = s->s3->tmp.new_sym_enc;
  const EVP_AEAD *aead = s->s3->tmp.new_aead;
  size_t key_len, iv_len, mac_secret_len;
  const uint8_t *key_data;

  /* Reset sequence number to zero. */
  if (!SSL_IS_DTLS(s)) {
    memset(is_read ? s->s3->read_sequence : s->s3->write_sequence, 0, 8);
  }

  mac_secret_len = s->s3->tmp.new_mac_secret_len;
  iv_len = s->s3->tmp.new_fixed_iv_len;

  if (aead != NULL) {
    key_len = EVP_AEAD_key_length(aead);
    if (mac_secret_len > 0) {
      /* For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher suites)
       * the key length reported by |EVP_AEAD_key_length| will include the MAC
       * and IV key bytes. */
      if (key_len < mac_secret_len + iv_len) {
        OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR);
        return 0;
      }
      key_len -= mac_secret_len + iv_len;
    }
  } else {
    key_len = EVP_CIPHER_key_length(cipher);
  }

  key_data = s->s3->tmp.key_block;
  client_write_mac_secret = key_data;
  key_data += mac_secret_len;
  server_write_mac_secret = key_data;
  key_data += mac_secret_len;
  client_write_key = key_data;
  key_data += key_len;
  server_write_key = key_data;
  key_data += key_len;
  client_write_iv = key_data;
  key_data += iv_len;
  server_write_iv = key_data;
  key_data += iv_len;

  if (use_client_keys) {
    mac_secret = client_write_mac_secret;
    key = client_write_key;
    iv = client_write_iv;
  } else {
    mac_secret = server_write_mac_secret;
    key = server_write_key;
    iv = server_write_iv;
  }

  if (key_data - s->s3->tmp.key_block != s->s3->tmp.key_block_length) {
    OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR);
    return 0;
  }

  if (aead != NULL) {
    if (!tls1_change_cipher_state_aead(s, is_read, key, key_len, iv, iv_len,
                                       mac_secret, mac_secret_len)) {
      return 0;
    }
  } else {
    if (!tls1_change_cipher_state_cipher(s, is_read, use_client_keys,
                                         mac_secret, mac_secret_len, key,
                                         key_len, iv, iv_len)) {
      return 0;
    }
  }

  return 1;
}

int tls1_setup_key_block(SSL *s) {
  uint8_t *p;
  const EVP_CIPHER *c = NULL;
  const EVP_MD *hash = NULL;
  const EVP_AEAD *aead = NULL;
  int mac_type = NID_undef;
  int ret = 0;
  size_t mac_secret_len, fixed_iv_len, variable_iv_len, key_len;
  size_t key_block_len;


  if (s->s3->tmp.key_block_length != 0) {
    return 1;
  }

  if (s->session->cipher == NULL) {
    goto cipher_unavailable_err;
  }

  /* TODO(davidben): Make DTLS record-layer code EVP_AEAD-aware. */
  if (!SSL_IS_DTLS(s)) {
    if (!ssl_cipher_get_evp_aead(&aead, &mac_secret_len, &fixed_iv_len,
                                 s->session->cipher,
                                 ssl3_version_from_wire(s, s->version))) {
      goto cipher_unavailable_err;
    }
    key_len = EVP_AEAD_key_length(aead);
    variable_iv_len = EVP_AEAD_nonce_length(aead);
    if (mac_secret_len > 0) {
      /* For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher suites)
       * the key length reported by |EVP_AEAD_key_length| will include the MAC
       * key bytes and initial implicit IV. */
      if (key_len < mac_secret_len + fixed_iv_len) {
        OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_INTERNAL_ERROR);
        return 0;
      }
      key_len -= mac_secret_len + fixed_iv_len;
    } else {
      /* The nonce is split into a fixed portion and a variable portion. */
      if (variable_iv_len < fixed_iv_len) {
        OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_INTERNAL_ERROR);
        return 0;
      }
      variable_iv_len -= fixed_iv_len;
    }
  } else {
    if (!ssl_cipher_get_evp(s->session, &c, &hash, &mac_type,
                            &mac_secret_len)) {
      goto cipher_unavailable_err;
    }
    key_len = EVP_CIPHER_key_length(c);
    fixed_iv_len = EVP_CIPHER_iv_length(c);
    variable_iv_len = 0;
  }

  assert(mac_secret_len < 256);
  assert(fixed_iv_len < 256);
  assert(variable_iv_len < 256);

  s->s3->tmp.new_aead = aead;
  s->s3->tmp.new_sym_enc = c;
  s->s3->tmp.new_hash = hash;
  s->s3->tmp.new_mac_pkey_type = mac_type;
  s->s3->tmp.new_mac_secret_len = (uint8_t)mac_secret_len;
  s->s3->tmp.new_fixed_iv_len = (uint8_t)fixed_iv_len;
  s->s3->tmp.new_variable_iv_len = (uint8_t)variable_iv_len;

  key_block_len = key_len + mac_secret_len + fixed_iv_len;
  key_block_len *= 2;

  ssl3_cleanup_key_block(s);

  p = (uint8_t *)OPENSSL_malloc(key_block_len);
  if (p == NULL) {
    OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block, ERR_R_MALLOC_FAILURE);
    goto err;
  }

  s->s3->tmp.key_block_length = key_block_len;
  s->s3->tmp.key_block = p;

  if (!tls1_generate_key_block(s, p, key_block_len)) {
    goto err;
  }

  if (!SSL_USE_EXPLICIT_IV(s) &&
      (s->mode & SSL_MODE_CBC_RECORD_SPLITTING) != 0) {
    /* enable vulnerability countermeasure for CBC ciphers with known-IV
     * problem (http://www.openssl.org/~bodo/tls-cbc.txt). */
    s->s3->need_record_splitting = 1;

    if (s->session->cipher != NULL &&
        s->session->cipher->algorithm_enc == SSL_RC4) {
      s->s3->need_record_splitting = 0;
    }
  }

  ret = 1;

err:
  return ret;

cipher_unavailable_err:
  OPENSSL_PUT_ERROR(SSL, tls1_setup_key_block,
                    SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
  return 0;
}

/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|,
 * respectively.
 *
 * Returns:
 *   0: (in non-constant time) if the record is publically invalid (i.e. too
 *       short etc).
 *   1: if the record's padding is valid / the encryption was successful.
 *   -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
 *       an internal error occured. */
int tls1_enc(SSL *s, int send) {
  SSL3_RECORD *rec;
  EVP_CIPHER_CTX *ds;
  unsigned long l;
  int bs, i, j, k, pad = 0, ret, mac_size = 0;
  const EVP_CIPHER *enc;
  const SSL_AEAD_CTX *aead;

  if (send) {
    rec = &s->s3->wrec;
    aead = s->aead_write_ctx;
  } else {
    rec = &s->s3->rrec;
    aead = s->aead_read_ctx;
  }

  if (aead) {
    uint8_t ad[13], *seq, *in, *out, nonce[EVP_AEAD_MAX_NONCE_LENGTH];
    unsigned nonce_used;
    size_t n, ad_len;

    seq = send ? s->s3->write_sequence : s->s3->read_sequence;

    if (SSL_IS_DTLS(s)) {
      uint8_t dtlsseq[9], *p = dtlsseq;

      s2n(send ? s->d1->w_epoch : s->d1->r_epoch, p);
      memcpy(p, &seq[2], 6);
      memcpy(ad, dtlsseq, 8);
    } else {
      memcpy(ad, seq, 8);
      for (i = 7; i >= 0; i--) {
        ++seq[i];
        if (seq[i] != 0) {
          break;
        }
      }
    }

    ad[8] = rec->type;
    ad[9] = (uint8_t)(s->version >> 8);
    ad[10] = (uint8_t)(s->version);

    if (aead->fixed_nonce_len + aead->variable_nonce_len > sizeof(nonce)) {
      OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR);
      return -1; /* internal error - should never happen. */
    }

    memcpy(nonce, aead->fixed_nonce, aead->fixed_nonce_len);
    nonce_used = aead->fixed_nonce_len;

    if (send) {
      size_t len = rec->length;
      size_t eivlen = 0;
      in = rec->input;
      out = rec->data;

      uint8_t *variable_nonce = nonce + nonce_used;
      if (aead->random_variable_nonce) {
        assert(aead->variable_nonce_included_in_record);
        if (!RAND_bytes(nonce + nonce_used, aead->variable_nonce_len)) {
          return -1;
        }
      } else {
        /* When sending we use the sequence number as the variable part of the
         * nonce. */
        if (aead->variable_nonce_len != 8) {
          OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR);
          return -1;
        }
        memcpy(nonce + nonce_used, ad, aead->variable_nonce_len);
      }
      nonce_used += aead->variable_nonce_len;

      /* in do_ssl3_write, rec->input is moved forward by variable_nonce_len in
       * order to leave space for the variable nonce. Thus we can copy the
       * sequence number bytes into place without overwriting any of the
       * plaintext. */
      if (aead->variable_nonce_included_in_record) {
        memcpy(out, variable_nonce, aead->variable_nonce_len);
        len -= aead->variable_nonce_len;
        eivlen = aead->variable_nonce_len;
      }

      if (aead->omit_length_in_ad) {
        ad_len = 11;
      } else {
        ad[11] = len >> 8;
        ad[12] = len & 0xff;
        ad_len = 13;
      }

      if (!EVP_AEAD_CTX_seal(&aead->ctx, out + eivlen, &n, len + aead->tag_len,
                             nonce, nonce_used, in + eivlen, len, ad, ad_len)) {
        return -1;
      }

      if (aead->variable_nonce_included_in_record) {
        n += aead->variable_nonce_len;
      }
    } else {
      /* receive */
      size_t len = rec->length;

      if (rec->data != rec->input) {
        OPENSSL_PUT_ERROR(SSL, tls1_enc, ERR_R_INTERNAL_ERROR);
        return -1; /* internal error - should never happen. */
      }
      out = in = rec->input;

      if (len < aead->variable_nonce_len) {
        return 0;
      }
      memcpy(nonce + nonce_used,
             aead->variable_nonce_included_in_record ? in : ad,
             aead->variable_nonce_len);
      nonce_used += aead->variable_nonce_len;

      if (aead->variable_nonce_included_in_record) {
        in += aead->variable_nonce_len;
        len -= aead->variable_nonce_len;
        out += aead->variable_nonce_len;
      }

      if (aead->omit_length_in_ad) {
        ad_len = 11;
      } else {
        if (len < aead->tag_len) {
          return 0;
        }
        size_t plaintext_len = len - aead->tag_len;

        ad[11] = plaintext_len >> 8;
        ad[12] = plaintext_len & 0xff;
        ad_len = 13;
      }

      if (!EVP_AEAD_CTX_open(&aead->ctx, out, &n, rec->length, nonce, nonce_used, in,
                             len, ad, ad_len)) {
        return -1;
      }

      rec->data = rec->input = out;
    }

    rec->length = n;
    return 1;
  }

  if (send) {
    ds = s->enc_write_ctx;
    rec = &(s->s3->wrec);
    if (s->enc_write_ctx == NULL) {
      enc = NULL;
    } else {
      int ivlen;
      enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
      /* For TLSv1.1 and later explicit IV */
      if (SSL_USE_EXPLICIT_IV(s) && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE) {
        ivlen = EVP_CIPHER_iv_length(enc);
      } else {
        ivlen = 0;
      }

      if (ivlen > 1) {
        if (rec->data != rec->input) {
          /* we can't write into the input stream:
           * Can this ever happen?? (steve)
           */
          fprintf(stderr, "%s:%d: rec->data != rec->input\n", __FILE__,
                  __LINE__);
        } else if (!RAND_bytes(rec->input, ivlen)) {
          return -1;
        }
      }
    }
  } else {
    ds = s->enc_read_ctx;
    rec = &(s->s3->rrec);
    if (s->enc_read_ctx == NULL) {
      enc = NULL;
    } else {
      enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
    }
  }

  if (s->session == NULL || ds == NULL || enc == NULL) {
    memmove(rec->data, rec->input, rec->length);
    rec->input = rec->data;
    ret = 1;
  } else {
    l = rec->length;
    bs = EVP_CIPHER_block_size(ds->cipher);

    if (bs != 1 && send) {
      i = bs - ((int)l % bs);

      /* Add weird padding of upto 256 bytes */
      /* we need to add 'i' padding bytes of value j */
      j = i - 1;
      for (k = (int)l; k < (int)(l + i); k++) {
        rec->input[k] = j;
      }
      l += i;
      rec->length += i;
    }

    if (!send && (l == 0 || l % bs != 0)) {
      return 0;
    }

    if (!EVP_Cipher(ds, rec->data, rec->input, l)) {
      return -1;
    }

    ret = 1;
    if (EVP_MD_CTX_md(s->read_hash) != NULL) {
      mac_size = EVP_MD_CTX_size(s->read_hash);
    }

    if (bs != 1 && !send) {
      ret = tls1_cbc_remove_padding(s, rec, bs, mac_size);
    }
    if (pad && !send) {
      rec->length -= pad;
    }
  }
  return ret;
}

int tls1_cert_verify_mac(SSL *s, int md_nid, uint8_t *out) {
  unsigned int ret;
  EVP_MD_CTX ctx, *d = NULL;
  int i;

  if (s->s3->handshake_buffer &&
      !ssl3_digest_cached_records(s, free_handshake_buffer)) {
    return 0;
  }

  for (i = 0; i < SSL_MAX_DIGEST; i++) {
    if (s->s3->handshake_dgst[i] &&
        EVP_MD_CTX_type(s->s3->handshake_dgst[i]) == md_nid) {
      d = s->s3->handshake_dgst[i];
      break;
    }
  }

  if (!d) {
    OPENSSL_PUT_ERROR(SSL, tls1_cert_verify_mac, SSL_R_NO_REQUIRED_DIGEST);
    return 0;
  }

  EVP_MD_CTX_init(&ctx);
  EVP_MD_CTX_copy_ex(&ctx, d);
  EVP_DigestFinal_ex(&ctx, out, &ret);
  EVP_MD_CTX_cleanup(&ctx);

  return ret;
}

/* tls1_handshake_digest calculates the current handshake hash and writes it to
 * |out|, which has space for |out_len| bytes. It returns the number of bytes
 * written or -1 in the event of an error. This function works on a copy of the
 * underlying digests so can be called multiple times and prior to the final
 * update etc. */
int tls1_handshake_digest(SSL *s, uint8_t *out, size_t out_len) {
  const EVP_MD *md;
  EVP_MD_CTX ctx;
  int err = 0, len = 0;
  size_t i;
  long mask;

  EVP_MD_CTX_init(&ctx);

  for (i = 0; ssl_get_handshake_digest(i, &mask, &md); i++) {
    size_t hash_size;
    unsigned int digest_len;
    EVP_MD_CTX *hdgst = s->s3->handshake_dgst[i];

    if ((mask & ssl_get_algorithm2(s)) == 0) {
      continue;
    }

    hash_size = EVP_MD_size(md);
    if (!hdgst ||
        hash_size > out_len ||
        !EVP_MD_CTX_copy_ex(&ctx, hdgst) ||
        !EVP_DigestFinal_ex(&ctx, out, &digest_len) ||
        digest_len != hash_size /* internal error */) {
      err = 1;
      break;
    }

    out += digest_len;
    out_len -= digest_len;
    len += digest_len;
  }

  EVP_MD_CTX_cleanup(&ctx);

  if (err != 0) {
    return -1;
  }
  return len;
}

int tls1_final_finish_mac(SSL *s, const char *str, int slen, uint8_t *out) {
  uint8_t buf[2 * EVP_MAX_MD_SIZE];
  int err = 0;
  int digests_len;

  if (s->s3->handshake_buffer &&
      !ssl3_digest_cached_records(s, free_handshake_buffer)) {
    return 0;
  }

  digests_len = tls1_handshake_digest(s, buf, sizeof(buf));
  if (digests_len < 0) {
    err = 1;
    digests_len = 0;
  }

  if (!tls1_PRF(out, 12, ssl_get_algorithm2(s), s->session->master_key,
                s->session->master_key_length, str, slen, buf, digests_len,
                NULL, 0)) {
    err = 1;
  }

  if (err) {
    return 0;
  } else {
    return 12;
  }
}

int tls1_mac(SSL *ssl, uint8_t *md, int send) {
  SSL3_RECORD *rec;
  uint8_t *seq;
  EVP_MD_CTX *hash;
  size_t md_size, orig_len;
  int i, ok;
  EVP_MD_CTX hmac, *mac_ctx;
  uint8_t header[13];
  int t;

  if (send) {
    rec = &ssl->s3->wrec;
    seq = &ssl->s3->write_sequence[0];
    hash = ssl->write_hash;
  } else {
    rec = &ssl->s3->rrec;
    seq = &ssl->s3->read_sequence[0];
    hash = ssl->read_hash;
  }

  t = EVP_MD_CTX_size(hash);
  assert(t >= 0);
  md_size = t;

  mac_ctx = &hmac;
  if (!EVP_MD_CTX_copy(mac_ctx, hash)) {
    return -1;
  }

  if (SSL_IS_DTLS(ssl)) {
    uint8_t dtlsseq[8], *p = dtlsseq;

    s2n(send ? ssl->d1->w_epoch : ssl->d1->r_epoch, p);
    memcpy(p, &seq[2], 6);

    memcpy(header, dtlsseq, 8);
  } else {
    memcpy(header, seq, 8);
  }

  /* kludge: tls1_cbc_remove_padding passes padding length in rec->type */
  orig_len = rec->length + md_size + ((unsigned int)rec->type >> 8);
  rec->type &= 0xff;

  header[8] = rec->type;
  header[9] = (uint8_t)(ssl->version >> 8);
  header[10] = (uint8_t)(ssl->version);
  header[11] = (rec->length) >> 8;
  header[12] = (rec->length) & 0xff;

  if (!send && EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
      ssl3_cbc_record_digest_supported(mac_ctx)) {
    /* This is a CBC-encrypted record. We must avoid leaking any timing-side
     * channel information about how many blocks of data we are hashing because
     * that gives an attacker a timing-oracle. */
    ok = ssl3_cbc_digest_record(
        mac_ctx, md, &md_size, header, rec->input, rec->length + md_size,
        orig_len, ssl->s3->read_mac_secret, ssl->s3->read_mac_secret_size,
        0 /* not SSLv3 */);
  } else {
    EVP_DigestSignUpdate(mac_ctx, header, sizeof(header));
    EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length);
    ok = EVP_DigestSignFinal(mac_ctx, md, &md_size);
  }

  EVP_MD_CTX_cleanup(mac_ctx);

  if (!ok) {
    return -1;
  }

  if (!SSL_IS_DTLS(ssl)) {
    for (i = 7; i >= 0; i--) {
      ++seq[i];
      if (seq[i] != 0) {
        break;
      }
    }
  }

  return md_size;
}

int tls1_generate_master_secret(SSL *s, uint8_t *out, uint8_t *premaster,
                                int premaster_len) {
  if (s->s3->tmp.extended_master_secret) {
    uint8_t digests[2 * EVP_MAX_MD_SIZE];
    int digests_len;

    /* The master secret is based on the handshake hash just after sending the
     * ClientKeyExchange. However, we might have a client certificate to send,
     * in which case we might need different hashes for the verification and
     * thus still need the handshake buffer around. Keeping both a handshake
     * buffer *and* running hashes isn't yet supported so, when it comes to
     * calculating the Finished hash, we'll have to hash the handshake buffer
     * again. */
    if (s->s3->handshake_buffer &&
        !ssl3_digest_cached_records(s, dont_free_handshake_buffer)) {
      return 0;
    }

    digests_len = tls1_handshake_digest(s, digests, sizeof(digests));
    if (digests_len == -1) {
      return 0;
    }

    if (!tls1_PRF(out, SSL3_MASTER_SECRET_SIZE, ssl_get_algorithm2(s),
                  premaster, premaster_len, TLS_MD_EXTENDED_MASTER_SECRET_CONST,
                  TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE, digests,
                  digests_len, NULL, 0)) {
      return 0;
    }
  } else {
    if (!tls1_PRF(out, SSL3_MASTER_SECRET_SIZE, ssl_get_algorithm2(s),
                  premaster, premaster_len, TLS_MD_MASTER_SECRET_CONST,
                  TLS_MD_MASTER_SECRET_CONST_SIZE, s->s3->client_random,
                  SSL3_RANDOM_SIZE, s->s3->server_random,
                  SSL3_RANDOM_SIZE)) {
      return 0;
    }
  }

  return SSL3_MASTER_SECRET_SIZE;
}

int tls1_export_keying_material(SSL *s, uint8_t *out, size_t olen,
                                const char *label, size_t llen,
                                const uint8_t *context, size_t contextlen,
                                int use_context) {
  uint8_t *val = NULL;
  size_t vallen, currentvalpos;
  int ret;

  /* 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 err2;
  }

  currentvalpos = 0;
  memcpy(val + currentvalpos, (uint8_t *)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 ||
      memcmp(val, TLS_MD_SERVER_FINISH_CONST,
             TLS_MD_SERVER_FINISH_CONST_SIZE) == 0 ||
      memcmp(val, TLS_MD_MASTER_SECRET_CONST,
             TLS_MD_MASTER_SECRET_CONST_SIZE) == 0 ||
      memcmp(val, TLS_MD_KEY_EXPANSION_CONST,
             TLS_MD_KEY_EXPANSION_CONST_SIZE) == 0) {
    goto err1;
  }

  ret = tls1_PRF(out, olen, ssl_get_algorithm2(s), s->session->master_key,
                 s->session->master_key_length, (const char *)val, vallen, NULL,
                 0, NULL, 0);
  goto out;

err1:
  OPENSSL_PUT_ERROR(SSL, tls1_export_keying_material,
                    SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
  ret = 0;
  goto out;

err2:
  OPENSSL_PUT_ERROR(SSL, tls1_export_keying_material, ERR_R_MALLOC_FAILURE);
  ret = 0;

out:
  if (val != NULL) {
    OPENSSL_free(val);
  }

  return ret;
}

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 SSL3_AD_INAPPROPRIATE_FALLBACK;

    default:
      return -1;
  }
}