ssl/t1_enc.cc - 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 <utility>

 #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"


 namespace bssl {

 // tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
 // section 5. It XORs |out.size()| bytes to |out|, using |md| as the hash and
 // |secret| as the secret. |label|, |seed1|, and |seed2| are concatenated to
 // form the seed parameter. It returns true on success and false on failure.
 static bool tls1_P_hash(Span<uint8_t> out, const EVP_MD *md,
                         Span<const uint8_t> secret, Span<const char> label,
                         Span<const uint8_t> seed1, Span<const uint8_t> seed2) {
   ScopedHMAC_CTX ctx, ctx_tmp, ctx_init;
   uint8_t A1[EVP_MAX_MD_SIZE];
   unsigned A1_len;
   bool ret = false;

   size_t chunk = EVP_MD_size(md);

   if (!HMAC_Init_ex(ctx_init.get(), secret.data(), secret.size(), md,
                     nullptr) ||
       !HMAC_CTX_copy_ex(ctx.get(), ctx_init.get()) ||
       !HMAC_Update(ctx.get(), reinterpret_cast<const uint8_t *>(label.data()),
                    label.size()) ||
       !HMAC_Update(ctx.get(), seed1.data(), seed1.size()) ||
       !HMAC_Update(ctx.get(), seed2.data(), seed2.size()) ||
       !HMAC_Final(ctx.get(), A1, &A1_len)) {
     goto err;
   }

   for (;;) {
     unsigned len;
     uint8_t hmac[EVP_MAX_MD_SIZE];
     if (!HMAC_CTX_copy_ex(ctx.get(), ctx_init.get()) ||
         !HMAC_Update(ctx.get(), A1, A1_len) ||
         // Save a copy of |ctx| to compute the next A1 value below.
         (out.size() > chunk && !HMAC_CTX_copy_ex(ctx_tmp.get(), ctx.get())) ||
         !HMAC_Update(ctx.get(), reinterpret_cast<const uint8_t *>(label.data()),
                      label.size()) ||
         !HMAC_Update(ctx.get(), seed1.data(), seed1.size()) ||
         !HMAC_Update(ctx.get(), seed2.data(), seed2.size()) ||
         !HMAC_Final(ctx.get(), hmac, &len)) {
       goto err;
     }
     assert(len == chunk);

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

     if (out.empty()) {
       break;
     }

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

   ret = true;

 err:
   OPENSSL_cleanse(A1, sizeof(A1));
   return ret;
 }

 bool tls1_prf(const EVP_MD *digest, Span<uint8_t> out,
               Span<const uint8_t> secret, Span<const char> label,
               Span<const uint8_t> seed1, Span<const uint8_t> seed2) {
   if (out.empty()) {
     return true;
   }

   OPENSSL_memset(out.data(), 0, out.size());

   if (digest == EVP_md5_sha1()) {
     // If using the MD5/SHA1 PRF, |secret| is partitioned between MD5 and SHA-1.
     size_t secret_half = secret.size() - (secret.size() / 2);
     if (!tls1_P_hash(out, EVP_md5(), secret.subspan(0, secret_half), label,
                      seed1, seed2)) {
       return false;
     }

     // Note that, if |secret.size()| is odd, the two halves share a byte.
     secret = secret.subspan(secret.size() - secret_half);
     digest = EVP_sha1();
   }

   return tls1_P_hash(out, digest, secret, label, seed1, seed2);
 }

 static bool ssl3_prf(Span<uint8_t> out, Span<const uint8_t> secret,
                      Span<const char> label, Span<const uint8_t> seed1,
                      Span<const uint8_t> seed2) {
   ScopedEVP_MD_CTX md5;
   ScopedEVP_MD_CTX sha1;
   uint8_t buf[16], smd[SHA_DIGEST_LENGTH];
   uint8_t c = 'A';
   size_t k = 0;
   while (!out.empty()) {
     k++;
     if (k > sizeof(buf)) {
       // bug: 'buf' is too small for this ciphersuite
       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
       return false;
     }

     for (size_t j = 0; j < k; j++) {
       buf[j] = c;
     }
     c++;
     if (!EVP_DigestInit_ex(sha1.get(), EVP_sha1(), NULL)) {
       OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP);
       return false;
     }
     EVP_DigestUpdate(sha1.get(), buf, k);
     EVP_DigestUpdate(sha1.get(), secret.data(), secret.size());
     // |label| is ignored for SSLv3.
     EVP_DigestUpdate(sha1.get(), seed1.data(), seed1.size());
     EVP_DigestUpdate(sha1.get(), seed2.data(), seed2.size());
     EVP_DigestFinal_ex(sha1.get(), smd, NULL);

     if (!EVP_DigestInit_ex(md5.get(), EVP_md5(), NULL)) {
       OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP);
       return false;
     }
     EVP_DigestUpdate(md5.get(), secret.data(), secret.size());
     EVP_DigestUpdate(md5.get(), smd, SHA_DIGEST_LENGTH);
     if (out.size() < MD5_DIGEST_LENGTH) {
       EVP_DigestFinal_ex(md5.get(), smd, NULL);
       OPENSSL_memcpy(out.data(), smd, out.size());
       break;
     }
     EVP_DigestFinal_ex(md5.get(), out.data(), NULL);
     out = out.subspan(MD5_DIGEST_LENGTH);
   }

   OPENSSL_cleanse(smd, SHA_DIGEST_LENGTH);
   return true;
 }

 static bool get_key_block_lengths(const SSL *ssl, size_t *out_mac_secret_len,
                                   size_t *out_key_len, size_t *out_iv_len,
                                   const SSL_CIPHER *cipher) {
   const EVP_AEAD *aead = NULL;
   if (!ssl_cipher_get_evp_aead(&aead, out_mac_secret_len, out_iv_len, cipher,
                                ssl_protocol_version(ssl), SSL_is_dtls(ssl))) {
     OPENSSL_PUT_ERROR(SSL, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
     return false;
   }

   *out_key_len = EVP_AEAD_key_length(aead);
   if (*out_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 (*out_key_len < *out_mac_secret_len + *out_iv_len) {
       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
       return false;
     }
     *out_key_len -= *out_mac_secret_len + *out_iv_len;
   }

   return true;
 }

 static bool setup_key_block(SSL_HANDSHAKE *hs) {
   SSL *const ssl = hs->ssl;
   if (!hs->key_block.empty()) {
     return true;
   }

   size_t mac_secret_len, key_len, fixed_iv_len;
   Array<uint8_t> key_block;
   if (!get_key_block_lengths(ssl, &mac_secret_len, &key_len, &fixed_iv_len,
                              hs->new_cipher) ||
       !key_block.Init(2 * (mac_secret_len + key_len + fixed_iv_len)) ||
       !SSL_generate_key_block(ssl, key_block.data(), key_block.size())) {
     return false;
   }

   hs->key_block = std::move(key_block);
   return true;
 }

 int tls1_change_cipher_state(SSL_HANDSHAKE *hs,
                              evp_aead_direction_t direction) {
   SSL *const ssl = hs->ssl;
   // Ensure the key block is set up.
   size_t mac_secret_len, key_len, iv_len;
   if (!setup_key_block(hs) ||
       !get_key_block_lengths(ssl, &mac_secret_len, &key_len, &iv_len,
                              hs->new_cipher)) {
     return 0;
   }

   if ((mac_secret_len + key_len + iv_len) * 2 != hs->key_block.size()) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
     return 0;
   }

   Span<const uint8_t> key_block = hs->key_block;
   Span<const uint8_t> mac_secret, key, iv;
   if (direction == (ssl->server ? evp_aead_open : evp_aead_seal)) {
     // Use the client write (server read) keys.
     mac_secret = key_block.subspan(0, mac_secret_len);
     key = key_block.subspan(2 * mac_secret_len, key_len);
     iv = key_block.subspan(2 * mac_secret_len + 2 * key_len, iv_len);
   } else {
     // Use the server write (client read) keys.
     mac_secret = key_block.subspan(mac_secret_len, mac_secret_len);
     key = key_block.subspan(2 * mac_secret_len + key_len, key_len);
     iv = key_block.subspan(2 * mac_secret_len + 2 * key_len + iv_len, iv_len);
   }

   UniquePtr<SSLAEADContext> aead_ctx =
       SSLAEADContext::Create(direction, ssl->version, SSL_is_dtls(ssl),
                              hs->new_cipher, key, mac_secret, iv);
   if (!aead_ctx) {
     return 0;
   }

   if (direction == evp_aead_open) {
     return ssl->method->set_read_state(ssl, std::move(aead_ctx));
   }

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

 int tls1_generate_master_secret(SSL_HANDSHAKE *hs, uint8_t *out,
                                 Span<const uint8_t> premaster) {
   static const char kMasterSecretLabel[] = "master secret";
   static const char kExtendedMasterSecretLabel[] = "extended master secret";

   const SSL *ssl = hs->ssl;
   auto out_span = MakeSpan(out, SSL3_MASTER_SECRET_SIZE);
   if (hs->extended_master_secret) {
     auto label = MakeConstSpan(kExtendedMasterSecretLabel,
                                sizeof(kExtendedMasterSecretLabel) - 1);
     uint8_t digests[EVP_MAX_MD_SIZE];
     size_t digests_len;
     if (!hs->transcript.GetHash(digests, &digests_len) ||
         !tls1_prf(hs->transcript.Digest(), out_span, premaster, label,
                   MakeConstSpan(digests, digests_len), {})) {
       return 0;
     }
   } else {
     auto label =
         MakeConstSpan(kMasterSecretLabel, sizeof(kMasterSecretLabel) - 1);
     if (ssl_protocol_version(ssl) == SSL3_VERSION) {
       if (!ssl3_prf(out_span, premaster, label, ssl->s3->client_random,
                     ssl->s3->server_random)) {
         return 0;
       }
     } else {
       if (!tls1_prf(hs->transcript.Digest(), out_span, premaster, label,
                     ssl->s3->client_random, ssl->s3->server_random)) {
         return 0;
       }
     }
   }

   return SSL3_MASTER_SECRET_SIZE;
 }

 }  // namespace bssl

 using namespace bssl;

 size_t SSL_get_key_block_len(const SSL *ssl) {
   size_t mac_secret_len, key_len, fixed_iv_len;
   if (!get_key_block_lengths(ssl, &mac_secret_len, &key_len, &fixed_iv_len,
                              SSL_get_current_cipher(ssl))) {
     ERR_clear_error();
     return 0;
   }

   return 2 * (mac_secret_len + key_len + fixed_iv_len);
 }

 int SSL_generate_key_block(const SSL *ssl, uint8_t *out, size_t out_len) {
   const SSL_SESSION *session = SSL_get_session(ssl);
   auto out_span = MakeSpan(out, out_len);
   auto master_key =
       MakeConstSpan(session->master_key, session->master_key_length);
   static const char kLabel[] = "key expansion";
   auto label = MakeConstSpan(kLabel, sizeof(kLabel) - 1);

   if (ssl_protocol_version(ssl) == SSL3_VERSION) {
     return ssl3_prf(out_span, master_key, label, ssl->s3->server_random,
                     ssl->s3->client_random);
   }

   const EVP_MD *digest = ssl_session_get_digest(session);
   return tls1_prf(digest, out_span, master_key, label, ssl->s3->server_random,
                   ssl->s3->client_random);
 }

 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 (ssl_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;
   }
   Array<uint8_t> seed;
   if (!seed.Init(seed_len)) {
     OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
     return 0;
   }

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

   const SSL_SESSION *session = SSL_get_session(ssl);
   const EVP_MD *digest = ssl_session_get_digest(session);
   return tls1_prf(
       digest, MakeSpan(out, out_len),
       MakeConstSpan(session->master_key, session->master_key_length),
       MakeConstSpan(label, label_len), seed, {});
 }
	/* 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 <utility>

	#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"


	namespace bssl {

	// tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
	// section 5. It XORs \|out.size()\| bytes to \|out\|, using \|md\| as the hash and
	// \|secret\| as the secret. \|label\|, \|seed1\|, and \|seed2\| are concatenated to
	// form the seed parameter. It returns true on success and false on failure.
	static bool tls1_P_hash(Span<uint8_t> out, const EVP_MD *md,
	Span<const uint8_t> secret, Span<const char> label,
	Span<const uint8_t> seed1, Span<const uint8_t> seed2) {
	ScopedHMAC_CTX ctx, ctx_tmp, ctx_init;
	uint8_t A1[EVP_MAX_MD_SIZE];
	unsigned A1_len;
	bool ret = false;

	size_t chunk = EVP_MD_size(md);

	if (!HMAC_Init_ex(ctx_init.get(), secret.data(), secret.size(), md,
	nullptr) \|\|
	!HMAC_CTX_copy_ex(ctx.get(), ctx_init.get()) \|\|
	!HMAC_Update(ctx.get(), reinterpret_cast<const uint8_t *>(label.data()),
	label.size()) \|\|
	!HMAC_Update(ctx.get(), seed1.data(), seed1.size()) \|\|
	!HMAC_Update(ctx.get(), seed2.data(), seed2.size()) \|\|
	!HMAC_Final(ctx.get(), A1, &A1_len)) {
	goto err;
	}

	for (;;) {
	unsigned len;
	uint8_t hmac[EVP_MAX_MD_SIZE];
	if (!HMAC_CTX_copy_ex(ctx.get(), ctx_init.get()) \|\|
	!HMAC_Update(ctx.get(), A1, A1_len) \|\|
	// Save a copy of \|ctx\| to compute the next A1 value below.
	(out.size() > chunk && !HMAC_CTX_copy_ex(ctx_tmp.get(), ctx.get())) \|\|
	!HMAC_Update(ctx.get(), reinterpret_cast<const uint8_t *>(label.data()),
	label.size()) \|\|
	!HMAC_Update(ctx.get(), seed1.data(), seed1.size()) \|\|
	!HMAC_Update(ctx.get(), seed2.data(), seed2.size()) \|\|
	!HMAC_Final(ctx.get(), hmac, &len)) {
	goto err;
	}
	assert(len == chunk);

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

	if (out.empty()) {
	break;
	}

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

	ret = true;

	err:
	OPENSSL_cleanse(A1, sizeof(A1));
	return ret;
	}

	bool tls1_prf(const EVP_MD *digest, Span<uint8_t> out,
	Span<const uint8_t> secret, Span<const char> label,
	Span<const uint8_t> seed1, Span<const uint8_t> seed2) {
	if (out.empty()) {
	return true;
	}

	OPENSSL_memset(out.data(), 0, out.size());

	if (digest == EVP_md5_sha1()) {
	// If using the MD5/SHA1 PRF, \|secret\| is partitioned between MD5 and SHA-1.
	size_t secret_half = secret.size() - (secret.size() / 2);
	if (!tls1_P_hash(out, EVP_md5(), secret.subspan(0, secret_half), label,
	seed1, seed2)) {
	return false;
	}

	// Note that, if \|secret.size()\| is odd, the two halves share a byte.
	secret = secret.subspan(secret.size() - secret_half);
	digest = EVP_sha1();
	}

	return tls1_P_hash(out, digest, secret, label, seed1, seed2);
	}

	static bool ssl3_prf(Span<uint8_t> out, Span<const uint8_t> secret,
	Span<const char> label, Span<const uint8_t> seed1,
	Span<const uint8_t> seed2) {
	ScopedEVP_MD_CTX md5;
	ScopedEVP_MD_CTX sha1;
	uint8_t buf[16], smd[SHA_DIGEST_LENGTH];
	uint8_t c = 'A';
	size_t k = 0;
	while (!out.empty()) {
	k++;
	if (k > sizeof(buf)) {
	// bug: 'buf' is too small for this ciphersuite
	OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
	return false;
	}

	for (size_t j = 0; j < k; j++) {
	buf[j] = c;
	}
	c++;
	if (!EVP_DigestInit_ex(sha1.get(), EVP_sha1(), NULL)) {
	OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP);
	return false;
	}
	EVP_DigestUpdate(sha1.get(), buf, k);
	EVP_DigestUpdate(sha1.get(), secret.data(), secret.size());
	// \|label\| is ignored for SSLv3.
	EVP_DigestUpdate(sha1.get(), seed1.data(), seed1.size());
	EVP_DigestUpdate(sha1.get(), seed2.data(), seed2.size());
	EVP_DigestFinal_ex(sha1.get(), smd, NULL);

	if (!EVP_DigestInit_ex(md5.get(), EVP_md5(), NULL)) {
	OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP);
	return false;
	}
	EVP_DigestUpdate(md5.get(), secret.data(), secret.size());
	EVP_DigestUpdate(md5.get(), smd, SHA_DIGEST_LENGTH);
	if (out.size() < MD5_DIGEST_LENGTH) {
	EVP_DigestFinal_ex(md5.get(), smd, NULL);
	OPENSSL_memcpy(out.data(), smd, out.size());
	break;
	}
	EVP_DigestFinal_ex(md5.get(), out.data(), NULL);
	out = out.subspan(MD5_DIGEST_LENGTH);
	}

	OPENSSL_cleanse(smd, SHA_DIGEST_LENGTH);
	return true;
	}

	static bool get_key_block_lengths(const SSL ssl, size_t out_mac_secret_len,
	size_t out_key_len, size_t out_iv_len,
	const SSL_CIPHER *cipher) {
	const EVP_AEAD *aead = NULL;
	if (!ssl_cipher_get_evp_aead(&aead, out_mac_secret_len, out_iv_len, cipher,
	ssl_protocol_version(ssl), SSL_is_dtls(ssl))) {
	OPENSSL_PUT_ERROR(SSL, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
	return false;
	}

	*out_key_len = EVP_AEAD_key_length(aead);
	if (*out_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 (out_key_len < out_mac_secret_len + *out_iv_len) {
	OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
	return false;
	}
	out_key_len -= out_mac_secret_len + *out_iv_len;
	}

	return true;
	}

	static bool setup_key_block(SSL_HANDSHAKE *hs) {
	SSL *const ssl = hs->ssl;
	if (!hs->key_block.empty()) {
	return true;
	}

	size_t mac_secret_len, key_len, fixed_iv_len;
	Array<uint8_t> key_block;
	if (!get_key_block_lengths(ssl, &mac_secret_len, &key_len, &fixed_iv_len,
	hs->new_cipher) \|\|
	!key_block.Init(2 * (mac_secret_len + key_len + fixed_iv_len)) \|\|
	!SSL_generate_key_block(ssl, key_block.data(), key_block.size())) {
	return false;
	}

	hs->key_block = std::move(key_block);
	return true;
	}

	int tls1_change_cipher_state(SSL_HANDSHAKE *hs,
	evp_aead_direction_t direction) {
	SSL *const ssl = hs->ssl;
	// Ensure the key block is set up.
	size_t mac_secret_len, key_len, iv_len;
	if (!setup_key_block(hs) \|\|
	!get_key_block_lengths(ssl, &mac_secret_len, &key_len, &iv_len,
	hs->new_cipher)) {
	return 0;
	}

	if ((mac_secret_len + key_len + iv_len) * 2 != hs->key_block.size()) {
	OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
	return 0;
	}

	Span<const uint8_t> key_block = hs->key_block;
	Span<const uint8_t> mac_secret, key, iv;
	if (direction == (ssl->server ? evp_aead_open : evp_aead_seal)) {
	// Use the client write (server read) keys.
	mac_secret = key_block.subspan(0, mac_secret_len);
	key = key_block.subspan(2 * mac_secret_len, key_len);
	iv = key_block.subspan(2 * mac_secret_len + 2 * key_len, iv_len);
	} else {
	// Use the server write (client read) keys.
	mac_secret = key_block.subspan(mac_secret_len, mac_secret_len);
	key = key_block.subspan(2 * mac_secret_len + key_len, key_len);
	iv = key_block.subspan(2 * mac_secret_len + 2 * key_len + iv_len, iv_len);
	}

	UniquePtr<SSLAEADContext> aead_ctx =
	SSLAEADContext::Create(direction, ssl->version, SSL_is_dtls(ssl),
	hs->new_cipher, key, mac_secret, iv);
	if (!aead_ctx) {
	return 0;
	}

	if (direction == evp_aead_open) {
	return ssl->method->set_read_state(ssl, std::move(aead_ctx));
	}

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

	int tls1_generate_master_secret(SSL_HANDSHAKE hs, uint8_t out,
	Span<const uint8_t> premaster) {
	static const char kMasterSecretLabel[] = "master secret";
	static const char kExtendedMasterSecretLabel[] = "extended master secret";

	const SSL *ssl = hs->ssl;
	auto out_span = MakeSpan(out, SSL3_MASTER_SECRET_SIZE);
	if (hs->extended_master_secret) {
	auto label = MakeConstSpan(kExtendedMasterSecretLabel,
	sizeof(kExtendedMasterSecretLabel) - 1);
	uint8_t digests[EVP_MAX_MD_SIZE];
	size_t digests_len;
	if (!hs->transcript.GetHash(digests, &digests_len) \|\|
	!tls1_prf(hs->transcript.Digest(), out_span, premaster, label,
	MakeConstSpan(digests, digests_len), {})) {
	return 0;
	}
	} else {
	auto label =
	MakeConstSpan(kMasterSecretLabel, sizeof(kMasterSecretLabel) - 1);
	if (ssl_protocol_version(ssl) == SSL3_VERSION) {
	if (!ssl3_prf(out_span, premaster, label, ssl->s3->client_random,
	ssl->s3->server_random)) {
	return 0;
	}
	} else {
	if (!tls1_prf(hs->transcript.Digest(), out_span, premaster, label,
	ssl->s3->client_random, ssl->s3->server_random)) {
	return 0;
	}
	}
	}

	return SSL3_MASTER_SECRET_SIZE;
	}

	} // namespace bssl

	using namespace bssl;

	size_t SSL_get_key_block_len(const SSL *ssl) {
	size_t mac_secret_len, key_len, fixed_iv_len;
	if (!get_key_block_lengths(ssl, &mac_secret_len, &key_len, &fixed_iv_len,
	SSL_get_current_cipher(ssl))) {
	ERR_clear_error();
	return 0;
	}

	return 2 * (mac_secret_len + key_len + fixed_iv_len);
	}

	int SSL_generate_key_block(const SSL ssl, uint8_t out, size_t out_len) {
	const SSL_SESSION *session = SSL_get_session(ssl);
	auto out_span = MakeSpan(out, out_len);
	auto master_key =
	MakeConstSpan(session->master_key, session->master_key_length);
	static const char kLabel[] = "key expansion";
	auto label = MakeConstSpan(kLabel, sizeof(kLabel) - 1);

	if (ssl_protocol_version(ssl) == SSL3_VERSION) {
	return ssl3_prf(out_span, master_key, label, ssl->s3->server_random,
	ssl->s3->client_random);
	}

	const EVP_MD *digest = ssl_session_get_digest(session);
	return tls1_prf(digest, out_span, master_key, label, ssl->s3->server_random,
	ssl->s3->client_random);
	}

	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 (ssl_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;
	}
	Array<uint8_t> seed;
	if (!seed.Init(seed_len)) {
	OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
	return 0;
	}

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

	const SSL_SESSION *session = SSL_get_session(ssl);
	const EVP_MD *digest = ssl_session_get_digest(session);
	return tls1_prf(
	digest, MakeSpan(out, out_len),
	MakeConstSpan(session->master_key, session->master_key_length),
	MakeConstSpan(label, label_len), seed, {});
	}