ssl/t1_enc.c - boringssl - Git at Google

 /* 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 <openssl/ssl.h>

 #include <assert.h>
 #include <string.h>

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

 #include "../crypto/internal.h"
 #include "internal.h"


 /* tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
  * section 5. It XORs |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) {
   HMAC_CTX ctx, ctx_tmp, ctx_init;
   uint8_t A1[EVP_MAX_MD_SIZE];
   unsigned A1_len;
   int ret = 0;

   size_t 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) ||
       !HMAC_Update(&ctx, seed1, seed1_len) ||
       !HMAC_Update(&ctx, seed2, seed2_len) ||
       !HMAC_Update(&ctx, seed3, seed3_len) ||
       !HMAC_Final(&ctx, A1, &A1_len)) {
     goto err;
   }

   for (;;) {
     unsigned len;
     uint8_t hmac[EVP_MAX_MD_SIZE];
     if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
         !HMAC_Update(&ctx, A1, A1_len) ||
         /* Save a copy of |ctx| to compute the next A1 value below. */
         (out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) ||
         !HMAC_Update(&ctx, seed1, seed1_len) ||
         !HMAC_Update(&ctx, seed2, seed2_len) ||
         !HMAC_Update(&ctx, seed3, seed3_len) ||
         !HMAC_Final(&ctx, hmac, &len)) {
       goto err;
     }
     assert(len == chunk);

     /* XOR the result into |out|. */
     if (len > out_len) {
       len = out_len;
     }
     unsigned i;
     for (i = 0; i < len; i++) {
       out[i] ^= hmac[i];
     }
     out += len;
     out_len -= len;

     if (out_len == 0) {
       break;
     }

     /* Calculate the next A1 value. */
     if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) {
       goto err;
     }
   }

   ret = 1;

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

 static int tls1_prf(const SSL *ssl, uint8_t *out, size_t out_len,
                     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) {
   if (out_len == 0) {
     return 1;
   }

   OPENSSL_memset(out, 0, out_len);

   uint32_t algorithm_prf = ssl_get_algorithm_prf(ssl);
   if (algorithm_prf == SSL_HANDSHAKE_MAC_DEFAULT) {
     /* If using the MD5/SHA1 PRF, |secret| is partitioned between SHA-1 and
      * MD5, MD5 first. */
     size_t secret_half = secret_len - (secret_len / 2);
     if (!tls1_P_hash(out, out_len, EVP_md5(), secret, secret_half,
                      (const uint8_t *)label, label_len, seed1, seed1_len, seed2,
                      seed2_len)) {
       return 0;
     }

     /* Note that, if |secret_len| is odd, the two halves share a byte. */
     secret = secret + (secret_len - secret_half);
     secret_len = secret_half;
   }

   if (!tls1_P_hash(out, out_len, ssl_get_handshake_digest(algorithm_prf),
                    secret, secret_len, (const uint8_t *)label, label_len,
                    seed1, seed1_len, seed2, seed2_len)) {
     return 0;
   }

   return 1;
 }

 static int tls1_setup_key_block(SSL_HANDSHAKE *hs) {
   SSL *const ssl = hs->ssl;
   if (hs->key_block_len != 0) {
     return 1;
   }

   SSL_SESSION *session = ssl->session;
   if (ssl->s3->new_session != NULL) {
     session = ssl->s3->new_session;
   }

   const EVP_AEAD *aead = NULL;
   size_t mac_secret_len, fixed_iv_len;
   if (session->cipher == NULL ||
       !ssl_cipher_get_evp_aead(&aead, &mac_secret_len, &fixed_iv_len,
                                session->cipher, ssl3_protocol_version(ssl))) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
     return 0;
   }
   size_t 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 key
      * bytes and initial implicit IV. */
     if (key_len < mac_secret_len + fixed_iv_len) {
       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
       return 0;
     }
     key_len -= mac_secret_len + fixed_iv_len;
   }

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

   ssl->s3->tmp.new_mac_secret_len = (uint8_t)mac_secret_len;
   ssl->s3->tmp.new_key_len = (uint8_t)key_len;
   ssl->s3->tmp.new_fixed_iv_len = (uint8_t)fixed_iv_len;

   size_t key_block_len = SSL_get_key_block_len(ssl);

   uint8_t *keyblock = OPENSSL_malloc(key_block_len);
   if (keyblock == NULL) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
     return 0;
   }

   if (!SSL_generate_key_block(ssl, keyblock, key_block_len)) {
     OPENSSL_free(keyblock);
     return 0;
   }

   assert(key_block_len < 256);
   hs->key_block_len = (uint8_t)key_block_len;
   hs->key_block = keyblock;
   return 1;
 }

 int tls1_change_cipher_state(SSL_HANDSHAKE *hs, int which) {
   SSL *const ssl = hs->ssl;
   /* Ensure the key block is set up. */
   if (!tls1_setup_key_block(hs)) {
     return 0;
   }

   /* 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;

   size_t mac_secret_len = ssl->s3->tmp.new_mac_secret_len;
   size_t key_len = ssl->s3->tmp.new_key_len;
   size_t iv_len = ssl->s3->tmp.new_fixed_iv_len;
   assert((mac_secret_len + key_len + iv_len) * 2 == hs->key_block_len);

   const uint8_t *key_data = hs->key_block;
   const uint8_t *client_write_mac_secret = key_data;
   key_data += mac_secret_len;
   const uint8_t *server_write_mac_secret = key_data;
   key_data += mac_secret_len;
   const uint8_t *client_write_key = key_data;
   key_data += key_len;
   const uint8_t *server_write_key = key_data;
   key_data += key_len;
   const uint8_t *client_write_iv = key_data;
   key_data += iv_len;
   const uint8_t *server_write_iv = key_data;
   key_data += iv_len;

   const uint8_t *mac_secret, *key, *iv;
   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;
   }

   SSL_AEAD_CTX *aead_ctx =
       SSL_AEAD_CTX_new(is_read ? evp_aead_open : evp_aead_seal,
                        ssl3_protocol_version(ssl), ssl->s3->tmp.new_cipher, key,
                        key_len, mac_secret, mac_secret_len, iv, iv_len);
   if (aead_ctx == NULL) {
     return 0;
   }

   if (is_read) {
     return ssl->method->set_read_state(ssl, aead_ctx);
   }

   return ssl->method->set_write_state(ssl, aead_ctx);
 }

 size_t SSL_get_key_block_len(const SSL *ssl) {
   return 2 * ((size_t)ssl->s3->tmp.new_mac_secret_len +
               (size_t)ssl->s3->tmp.new_key_len +
               (size_t)ssl->s3->tmp.new_fixed_iv_len);
 }

 int SSL_generate_key_block(const SSL *ssl, uint8_t *out, size_t out_len) {
   return ssl->s3->enc_method->prf(
       ssl, out, out_len, SSL_get_session(ssl)->master_key,
       SSL_get_session(ssl)->master_key_length, TLS_MD_KEY_EXPANSION_CONST,
       TLS_MD_KEY_EXPANSION_CONST_SIZE, ssl->s3->server_random, SSL3_RANDOM_SIZE,
       ssl->s3->client_random, SSL3_RANDOM_SIZE);
 }

 static int append_digest(const EVP_MD_CTX *ctx, uint8_t *out, size_t *out_len,
                          size_t max_out) {
   int ret = 0;
   EVP_MD_CTX ctx_copy;
   EVP_MD_CTX_init(&ctx_copy);

   if (EVP_MD_CTX_size(ctx) > max_out) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
     goto err;
   }
   unsigned len;
   if (!EVP_MD_CTX_copy_ex(&ctx_copy, ctx) ||
       !EVP_DigestFinal_ex(&ctx_copy, out, &len)) {
     goto err;
   }
   assert(len == EVP_MD_CTX_size(ctx));

   *out_len = len;
   ret = 1;

 err:
   EVP_MD_CTX_cleanup(&ctx_copy);
   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 *ssl, uint8_t *out, size_t out_len) {
   size_t md5_len = 0;
   if (EVP_MD_CTX_md(&ssl->s3->handshake_md5) != NULL &&
       !append_digest(&ssl->s3->handshake_md5, out, &md5_len, out_len)) {
     return -1;
   }

   size_t len;
   if (!append_digest(&ssl->s3->handshake_hash, out + md5_len, &len,
                      out_len - md5_len)) {
     return -1;
   }

   return (int)(md5_len + len);
 }

 static int tls1_final_finish_mac(SSL *ssl, int from_server, uint8_t *out) {
   /* At this point, the handshake should have released the handshake buffer on
    * its own. */
   assert(ssl->s3->handshake_buffer == NULL);

   const char *label = TLS_MD_CLIENT_FINISH_CONST;
   size_t label_len = TLS_MD_SERVER_FINISH_CONST_SIZE;
   if (from_server) {
     label = TLS_MD_SERVER_FINISH_CONST;
     label_len = TLS_MD_SERVER_FINISH_CONST_SIZE;
   }

   uint8_t buf[EVP_MAX_MD_SIZE];
   int digests_len = tls1_handshake_digest(ssl, buf, sizeof(buf));
   if (digests_len < 0) {
     return 0;
   }

   static const size_t kFinishedLen = 12;
   if (!ssl->s3->enc_method->prf(ssl, out, kFinishedLen,
                                 SSL_get_session(ssl)->master_key,
                                 SSL_get_session(ssl)->master_key_length, label,
                                 label_len, buf, digests_len, NULL, 0)) {
     return 0;
   }

   return (int)kFinishedLen;
 }

 int tls1_generate_master_secret(SSL *ssl, uint8_t *out,
                                 const uint8_t *premaster,
                                 size_t premaster_len) {
   if (ssl->s3->tmp.extended_master_secret) {
     uint8_t digests[EVP_MAX_MD_SIZE];
     int digests_len = tls1_handshake_digest(ssl, digests, sizeof(digests));
     if (digests_len == -1) {
       return 0;
     }

     if (!ssl->s3->enc_method->prf(ssl, out, SSL3_MASTER_SECRET_SIZE, 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 (!ssl->s3->enc_method->prf(ssl, out, SSL3_MASTER_SECRET_SIZE, premaster,
                                   premaster_len, TLS_MD_MASTER_SECRET_CONST,
                                   TLS_MD_MASTER_SECRET_CONST_SIZE,
                                   ssl->s3->client_random, SSL3_RANDOM_SIZE,
                                   ssl->s3->server_random, SSL3_RANDOM_SIZE)) {
       return 0;
     }
   }

   return SSL3_MASTER_SECRET_SIZE;
 }

 int SSL_export_keying_material(SSL *ssl, uint8_t *out, size_t out_len,
                                const char *label, size_t label_len,
                                const uint8_t *context, size_t context_len,
                                int use_context) {
   if (!ssl->s3->have_version || ssl->version == SSL3_VERSION) {
     return 0;
   }

   /* Exporters may not be used in the middle of a renegotiation. */
   if (SSL_in_init(ssl) && !SSL_in_false_start(ssl)) {
     return 0;
   }

   if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
     return tls13_export_keying_material(ssl, out, out_len, label, label_len,
                                         context, context_len, use_context);
   }

   size_t seed_len = 2 * SSL3_RANDOM_SIZE;
   if (use_context) {
     if (context_len >= 1u << 16) {
       OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
       return 0;
     }
     seed_len += 2 + context_len;
   }
   uint8_t *seed = OPENSSL_malloc(seed_len);
   if (seed == NULL) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
     return 0;
   }

   OPENSSL_memcpy(seed, ssl->s3->client_random, SSL3_RANDOM_SIZE);
   OPENSSL_memcpy(seed + SSL3_RANDOM_SIZE, ssl->s3->server_random,
                  SSL3_RANDOM_SIZE);
   if (use_context) {
     seed[2 * SSL3_RANDOM_SIZE] = (uint8_t)(context_len >> 8);
     seed[2 * SSL3_RANDOM_SIZE + 1] = (uint8_t)context_len;
     OPENSSL_memcpy(seed + 2 * SSL3_RANDOM_SIZE + 2, context, context_len);
   }

   int ret =
       ssl->s3->enc_method->prf(ssl, out, out_len,
                                SSL_get_session(ssl)->master_key,
                                SSL_get_session(ssl)->master_key_length, label,
                                label_len, seed, seed_len, NULL, 0);
   OPENSSL_free(seed);
   return ret;
 }

 const SSL3_ENC_METHOD TLSv1_enc_data = {
     tls1_prf,
     tls1_final_finish_mac,
 };
	/* 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 <openssl/ssl.h>

	#include <assert.h>
	#include <string.h>

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

	#include "../crypto/internal.h"
	#include "internal.h"


	/* tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
	* section 5. It XORs \|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) {
	HMAC_CTX ctx, ctx_tmp, ctx_init;
	uint8_t A1[EVP_MAX_MD_SIZE];
	unsigned A1_len;
	int ret = 0;

	size_t 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) \|\|
	!HMAC_Update(&ctx, seed1, seed1_len) \|\|
	!HMAC_Update(&ctx, seed2, seed2_len) \|\|
	!HMAC_Update(&ctx, seed3, seed3_len) \|\|
	!HMAC_Final(&ctx, A1, &A1_len)) {
	goto err;
	}

	for (;;) {
	unsigned len;
	uint8_t hmac[EVP_MAX_MD_SIZE];
	if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) \|\|
	!HMAC_Update(&ctx, A1, A1_len) \|\|
	/* Save a copy of \|ctx\| to compute the next A1 value below. */
	(out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) \|\|
	!HMAC_Update(&ctx, seed1, seed1_len) \|\|
	!HMAC_Update(&ctx, seed2, seed2_len) \|\|
	!HMAC_Update(&ctx, seed3, seed3_len) \|\|
	!HMAC_Final(&ctx, hmac, &len)) {
	goto err;
	}
	assert(len == chunk);

	/* XOR the result into \|out\|. */
	if (len > out_len) {
	len = out_len;
	}
	unsigned i;
	for (i = 0; i < len; i++) {
	out[i] ^= hmac[i];
	}
	out += len;
	out_len -= len;

	if (out_len == 0) {
	break;
	}

	/* Calculate the next A1 value. */
	if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) {
	goto err;
	}
	}

	ret = 1;

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

	static int tls1_prf(const SSL ssl, uint8_t out, size_t out_len,
	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) {
	if (out_len == 0) {
	return 1;
	}

	OPENSSL_memset(out, 0, out_len);

	uint32_t algorithm_prf = ssl_get_algorithm_prf(ssl);
	if (algorithm_prf == SSL_HANDSHAKE_MAC_DEFAULT) {
	/* If using the MD5/SHA1 PRF, \|secret\| is partitioned between SHA-1 and
	* MD5, MD5 first. */
	size_t secret_half = secret_len - (secret_len / 2);
	if (!tls1_P_hash(out, out_len, EVP_md5(), secret, secret_half,
	(const uint8_t *)label, label_len, seed1, seed1_len, seed2,
	seed2_len)) {
	return 0;
	}

	/* Note that, if \|secret_len\| is odd, the two halves share a byte. */
	secret = secret + (secret_len - secret_half);
	secret_len = secret_half;
	}

	if (!tls1_P_hash(out, out_len, ssl_get_handshake_digest(algorithm_prf),
	secret, secret_len, (const uint8_t *)label, label_len,
	seed1, seed1_len, seed2, seed2_len)) {
	return 0;
	}

	return 1;
	}

	static int tls1_setup_key_block(SSL_HANDSHAKE *hs) {
	SSL *const ssl = hs->ssl;
	if (hs->key_block_len != 0) {
	return 1;
	}

	SSL_SESSION *session = ssl->session;
	if (ssl->s3->new_session != NULL) {
	session = ssl->s3->new_session;
	}

	const EVP_AEAD *aead = NULL;
	size_t mac_secret_len, fixed_iv_len;
	if (session->cipher == NULL \|\|
	!ssl_cipher_get_evp_aead(&aead, &mac_secret_len, &fixed_iv_len,
	session->cipher, ssl3_protocol_version(ssl))) {
	OPENSSL_PUT_ERROR(SSL, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
	return 0;
	}
	size_t 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 key
	* bytes and initial implicit IV. */
	if (key_len < mac_secret_len + fixed_iv_len) {
	OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
	return 0;
	}
	key_len -= mac_secret_len + fixed_iv_len;
	}

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

	ssl->s3->tmp.new_mac_secret_len = (uint8_t)mac_secret_len;
	ssl->s3->tmp.new_key_len = (uint8_t)key_len;
	ssl->s3->tmp.new_fixed_iv_len = (uint8_t)fixed_iv_len;

	size_t key_block_len = SSL_get_key_block_len(ssl);

	uint8_t *keyblock = OPENSSL_malloc(key_block_len);
	if (keyblock == NULL) {
	OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
	return 0;
	}

	if (!SSL_generate_key_block(ssl, keyblock, key_block_len)) {
	OPENSSL_free(keyblock);
	return 0;
	}

	assert(key_block_len < 256);
	hs->key_block_len = (uint8_t)key_block_len;
	hs->key_block = keyblock;
	return 1;
	}

	int tls1_change_cipher_state(SSL_HANDSHAKE *hs, int which) {
	SSL *const ssl = hs->ssl;
	/* Ensure the key block is set up. */
	if (!tls1_setup_key_block(hs)) {
	return 0;
	}

	/* 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;

	size_t mac_secret_len = ssl->s3->tmp.new_mac_secret_len;
	size_t key_len = ssl->s3->tmp.new_key_len;
	size_t iv_len = ssl->s3->tmp.new_fixed_iv_len;
	assert((mac_secret_len + key_len + iv_len) * 2 == hs->key_block_len);

	const uint8_t *key_data = hs->key_block;
	const uint8_t *client_write_mac_secret = key_data;
	key_data += mac_secret_len;
	const uint8_t *server_write_mac_secret = key_data;
	key_data += mac_secret_len;
	const uint8_t *client_write_key = key_data;
	key_data += key_len;
	const uint8_t *server_write_key = key_data;
	key_data += key_len;
	const uint8_t *client_write_iv = key_data;
	key_data += iv_len;
	const uint8_t *server_write_iv = key_data;
	key_data += iv_len;

	const uint8_t mac_secret, key, *iv;
	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;
	}

	SSL_AEAD_CTX *aead_ctx =
	SSL_AEAD_CTX_new(is_read ? evp_aead_open : evp_aead_seal,
	ssl3_protocol_version(ssl), ssl->s3->tmp.new_cipher, key,
	key_len, mac_secret, mac_secret_len, iv, iv_len);
	if (aead_ctx == NULL) {
	return 0;
	}

	if (is_read) {
	return ssl->method->set_read_state(ssl, aead_ctx);
	}

	return ssl->method->set_write_state(ssl, aead_ctx);
	}

	size_t SSL_get_key_block_len(const SSL *ssl) {
	return 2 * ((size_t)ssl->s3->tmp.new_mac_secret_len +
	(size_t)ssl->s3->tmp.new_key_len +
	(size_t)ssl->s3->tmp.new_fixed_iv_len);
	}

	int SSL_generate_key_block(const SSL ssl, uint8_t out, size_t out_len) {
	return ssl->s3->enc_method->prf(
	ssl, out, out_len, SSL_get_session(ssl)->master_key,
	SSL_get_session(ssl)->master_key_length, TLS_MD_KEY_EXPANSION_CONST,
	TLS_MD_KEY_EXPANSION_CONST_SIZE, ssl->s3->server_random, SSL3_RANDOM_SIZE,
	ssl->s3->client_random, SSL3_RANDOM_SIZE);
	}

	static int append_digest(const EVP_MD_CTX ctx, uint8_t out, size_t *out_len,
	size_t max_out) {
	int ret = 0;
	EVP_MD_CTX ctx_copy;
	EVP_MD_CTX_init(&ctx_copy);

	if (EVP_MD_CTX_size(ctx) > max_out) {
	OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFER_TOO_SMALL);
	goto err;
	}
	unsigned len;
	if (!EVP_MD_CTX_copy_ex(&ctx_copy, ctx) \|\|
	!EVP_DigestFinal_ex(&ctx_copy, out, &len)) {
	goto err;
	}
	assert(len == EVP_MD_CTX_size(ctx));

	*out_len = len;
	ret = 1;

	err:
	EVP_MD_CTX_cleanup(&ctx_copy);
	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 ssl, uint8_t out, size_t out_len) {
	size_t md5_len = 0;
	if (EVP_MD_CTX_md(&ssl->s3->handshake_md5) != NULL &&
	!append_digest(&ssl->s3->handshake_md5, out, &md5_len, out_len)) {
	return -1;
	}

	size_t len;
	if (!append_digest(&ssl->s3->handshake_hash, out + md5_len, &len,
	out_len - md5_len)) {
	return -1;
	}

	return (int)(md5_len + len);
	}

	static int tls1_final_finish_mac(SSL ssl, int from_server, uint8_t out) {
	/* At this point, the handshake should have released the handshake buffer on
	* its own. */
	assert(ssl->s3->handshake_buffer == NULL);

	const char *label = TLS_MD_CLIENT_FINISH_CONST;
	size_t label_len = TLS_MD_SERVER_FINISH_CONST_SIZE;
	if (from_server) {
	label = TLS_MD_SERVER_FINISH_CONST;
	label_len = TLS_MD_SERVER_FINISH_CONST_SIZE;
	}

	uint8_t buf[EVP_MAX_MD_SIZE];
	int digests_len = tls1_handshake_digest(ssl, buf, sizeof(buf));
	if (digests_len < 0) {
	return 0;
	}

	static const size_t kFinishedLen = 12;
	if (!ssl->s3->enc_method->prf(ssl, out, kFinishedLen,
	SSL_get_session(ssl)->master_key,
	SSL_get_session(ssl)->master_key_length, label,
	label_len, buf, digests_len, NULL, 0)) {
	return 0;
	}

	return (int)kFinishedLen;
	}

	int tls1_generate_master_secret(SSL ssl, uint8_t out,
	const uint8_t *premaster,
	size_t premaster_len) {
	if (ssl->s3->tmp.extended_master_secret) {
	uint8_t digests[EVP_MAX_MD_SIZE];
	int digests_len = tls1_handshake_digest(ssl, digests, sizeof(digests));
	if (digests_len == -1) {
	return 0;
	}

	if (!ssl->s3->enc_method->prf(ssl, out, SSL3_MASTER_SECRET_SIZE, 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 (!ssl->s3->enc_method->prf(ssl, out, SSL3_MASTER_SECRET_SIZE, premaster,
	premaster_len, TLS_MD_MASTER_SECRET_CONST,
	TLS_MD_MASTER_SECRET_CONST_SIZE,
	ssl->s3->client_random, SSL3_RANDOM_SIZE,
	ssl->s3->server_random, SSL3_RANDOM_SIZE)) {
	return 0;
	}
	}

	return SSL3_MASTER_SECRET_SIZE;
	}

	int SSL_export_keying_material(SSL ssl, uint8_t out, size_t out_len,
	const char *label, size_t label_len,
	const uint8_t *context, size_t context_len,
	int use_context) {
	if (!ssl->s3->have_version \|\| ssl->version == SSL3_VERSION) {
	return 0;
	}

	/* Exporters may not be used in the middle of a renegotiation. */
	if (SSL_in_init(ssl) && !SSL_in_false_start(ssl)) {
	return 0;
	}

	if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
	return tls13_export_keying_material(ssl, out, out_len, label, label_len,
	context, context_len, use_context);
	}

	size_t seed_len = 2 * SSL3_RANDOM_SIZE;
	if (use_context) {
	if (context_len >= 1u << 16) {
	OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
	return 0;
	}
	seed_len += 2 + context_len;
	}
	uint8_t *seed = OPENSSL_malloc(seed_len);
	if (seed == NULL) {
	OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
	return 0;
	}

	OPENSSL_memcpy(seed, ssl->s3->client_random, SSL3_RANDOM_SIZE);
	OPENSSL_memcpy(seed + SSL3_RANDOM_SIZE, ssl->s3->server_random,
	SSL3_RANDOM_SIZE);
	if (use_context) {
	seed[2 * SSL3_RANDOM_SIZE] = (uint8_t)(context_len >> 8);
	seed[2 * SSL3_RANDOM_SIZE + 1] = (uint8_t)context_len;
	OPENSSL_memcpy(seed + 2 * SSL3_RANDOM_SIZE + 2, context, context_len);
	}

	int ret =
	ssl->s3->enc_method->prf(ssl, out, out_len,
	SSL_get_session(ssl)->master_key,
	SSL_get_session(ssl)->master_key_length, label,
	label_len, seed, seed_len, NULL, 0);
	OPENSSL_free(seed);
	return ret;
	}

	const SSL3_ENC_METHOD TLSv1_enc_data = {
	tls1_prf,
	tls1_final_finish_mac,
	};