1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 2 * All rights reserved. 3 * 4 * This package is an SSL implementation written 5 * by Eric Young (eay (at) cryptsoft.com). 6 * The implementation was written so as to conform with Netscapes SSL. 7 * 8 * This library is free for commercial and non-commercial use as long as 9 * the following conditions are aheared to. The following conditions 10 * apply to all code found in this distribution, be it the RC4, RSA, 11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 12 * included with this distribution is covered by the same copyright terms 13 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 14 * 15 * Copyright remains Eric Young's, and as such any Copyright notices in 16 * the code are not to be removed. 17 * If this package is used in a product, Eric Young should be given attribution 18 * as the author of the parts of the library used. 19 * This can be in the form of a textual message at program startup or 20 * in documentation (online or textual) provided with the package. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * "This product includes cryptographic software written by 33 * Eric Young (eay (at) cryptsoft.com)" 34 * The word 'cryptographic' can be left out if the rouines from the library 35 * being used are not cryptographic related :-). 36 * 4. If you include any Windows specific code (or a derivative thereof) from 37 * the apps directory (application code) you must include an acknowledgement: 38 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 50 * SUCH DAMAGE. 51 * 52 * The licence and distribution terms for any publically available version or 53 * derivative of this code cannot be changed. i.e. this code cannot simply be 54 * copied and put under another distribution licence 55 * [including the GNU Public Licence.] 56 */ 57 /* ==================================================================== 58 * Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved. 59 * 60 * Redistribution and use in source and binary forms, with or without 61 * modification, are permitted provided that the following conditions 62 * are met: 63 * 64 * 1. Redistributions of source code must retain the above copyright 65 * notice, this list of conditions and the following disclaimer. 66 * 67 * 2. Redistributions in binary form must reproduce the above copyright 68 * notice, this list of conditions and the following disclaimer in 69 * the documentation and/or other materials provided with the 70 * distribution. 71 * 72 * 3. All advertising materials mentioning features or use of this 73 * software must display the following acknowledgment: 74 * "This product includes software developed by the OpenSSL Project 75 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 76 * 77 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 78 * endorse or promote products derived from this software without 79 * prior written permission. For written permission, please contact 80 * openssl-core (at) openssl.org. 81 * 82 * 5. Products derived from this software may not be called "OpenSSL" 83 * nor may "OpenSSL" appear in their names without prior written 84 * permission of the OpenSSL Project. 85 * 86 * 6. Redistributions of any form whatsoever must retain the following 87 * acknowledgment: 88 * "This product includes software developed by the OpenSSL Project 89 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 90 * 91 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 92 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 93 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 94 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 95 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 96 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 97 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 98 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 99 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 100 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 101 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 102 * OF THE POSSIBILITY OF SUCH DAMAGE. 103 * ==================================================================== 104 * 105 * This product includes cryptographic software written by Eric Young 106 * (eay (at) cryptsoft.com). This product includes software written by Tim 107 * Hudson (tjh (at) cryptsoft.com). 108 * 109 */ 110 /* ==================================================================== 111 * Copyright 2005 Nokia. All rights reserved. 112 * 113 * The portions of the attached software ("Contribution") is developed by 114 * Nokia Corporation and is licensed pursuant to the OpenSSL open source 115 * license. 116 * 117 * The Contribution, originally written by Mika Kousa and Pasi Eronen of 118 * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites 119 * support (see RFC 4279) to OpenSSL. 120 * 121 * No patent licenses or other rights except those expressly stated in 122 * the OpenSSL open source license shall be deemed granted or received 123 * expressly, by implication, estoppel, or otherwise. 124 * 125 * No assurances are provided by Nokia that the Contribution does not 126 * infringe the patent or other intellectual property rights of any third 127 * party or that the license provides you with all the necessary rights 128 * to make use of the Contribution. 129 * 130 * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN 131 * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA 132 * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY 133 * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR 134 * OTHERWISE. */ 135 136 #include <openssl/ssl.h> 137 138 #include <assert.h> 139 #include <string.h> 140 141 #include <openssl/err.h> 142 #include <openssl/evp.h> 143 #include <openssl/hmac.h> 144 #include <openssl/md5.h> 145 #include <openssl/mem.h> 146 #include <openssl/nid.h> 147 #include <openssl/rand.h> 148 149 #include "../crypto/internal.h" 150 #include "internal.h" 151 152 153 /* tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246, 154 * section 5. It XORs |out_len| bytes to |out|, using |md| as the hash and 155 * |secret| as the secret. |seed1| through |seed3| are concatenated to form the 156 * seed parameter. It returns one on success and zero on failure. */ 157 static int tls1_P_hash(uint8_t *out, size_t out_len, const EVP_MD *md, 158 const uint8_t *secret, size_t secret_len, 159 const uint8_t *seed1, size_t seed1_len, 160 const uint8_t *seed2, size_t seed2_len, 161 const uint8_t *seed3, size_t seed3_len) { 162 HMAC_CTX ctx, ctx_tmp, ctx_init; 163 uint8_t A1[EVP_MAX_MD_SIZE]; 164 unsigned A1_len; 165 int ret = 0; 166 167 size_t chunk = EVP_MD_size(md); 168 169 HMAC_CTX_init(&ctx); 170 HMAC_CTX_init(&ctx_tmp); 171 HMAC_CTX_init(&ctx_init); 172 if (!HMAC_Init_ex(&ctx_init, secret, secret_len, md, NULL) || 173 !HMAC_CTX_copy_ex(&ctx, &ctx_init) || 174 !HMAC_Update(&ctx, seed1, seed1_len) || 175 !HMAC_Update(&ctx, seed2, seed2_len) || 176 !HMAC_Update(&ctx, seed3, seed3_len) || 177 !HMAC_Final(&ctx, A1, &A1_len)) { 178 goto err; 179 } 180 181 for (;;) { 182 unsigned len; 183 uint8_t hmac[EVP_MAX_MD_SIZE]; 184 if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) || 185 !HMAC_Update(&ctx, A1, A1_len) || 186 /* Save a copy of |ctx| to compute the next A1 value below. */ 187 (out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) || 188 !HMAC_Update(&ctx, seed1, seed1_len) || 189 !HMAC_Update(&ctx, seed2, seed2_len) || 190 !HMAC_Update(&ctx, seed3, seed3_len) || 191 !HMAC_Final(&ctx, hmac, &len)) { 192 goto err; 193 } 194 assert(len == chunk); 195 196 /* XOR the result into |out|. */ 197 if (len > out_len) { 198 len = out_len; 199 } 200 unsigned i; 201 for (i = 0; i < len; i++) { 202 out[i] ^= hmac[i]; 203 } 204 out += len; 205 out_len -= len; 206 207 if (out_len == 0) { 208 break; 209 } 210 211 /* Calculate the next A1 value. */ 212 if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) { 213 goto err; 214 } 215 } 216 217 ret = 1; 218 219 err: 220 HMAC_CTX_cleanup(&ctx); 221 HMAC_CTX_cleanup(&ctx_tmp); 222 HMAC_CTX_cleanup(&ctx_init); 223 OPENSSL_cleanse(A1, sizeof(A1)); 224 return ret; 225 } 226 227 int tls1_prf(const EVP_MD *digest, uint8_t *out, size_t out_len, 228 const uint8_t *secret, size_t secret_len, const char *label, 229 size_t label_len, const uint8_t *seed1, size_t seed1_len, 230 const uint8_t *seed2, size_t seed2_len) { 231 if (out_len == 0) { 232 return 1; 233 } 234 235 OPENSSL_memset(out, 0, out_len); 236 237 if (digest == EVP_md5_sha1()) { 238 /* If using the MD5/SHA1 PRF, |secret| is partitioned between SHA-1 and 239 * MD5, MD5 first. */ 240 size_t secret_half = secret_len - (secret_len / 2); 241 if (!tls1_P_hash(out, out_len, EVP_md5(), secret, secret_half, 242 (const uint8_t *)label, label_len, seed1, seed1_len, seed2, 243 seed2_len)) { 244 return 0; 245 } 246 247 /* Note that, if |secret_len| is odd, the two halves share a byte. */ 248 secret = secret + (secret_len - secret_half); 249 secret_len = secret_half; 250 251 digest = EVP_sha1(); 252 } 253 254 if (!tls1_P_hash(out, out_len, digest, secret, secret_len, 255 (const uint8_t *)label, label_len, seed1, seed1_len, seed2, 256 seed2_len)) { 257 return 0; 258 } 259 260 return 1; 261 } 262 263 static int ssl3_prf(uint8_t *out, size_t out_len, const uint8_t *secret, 264 size_t secret_len, const char *label, size_t label_len, 265 const uint8_t *seed1, size_t seed1_len, 266 const uint8_t *seed2, size_t seed2_len) { 267 EVP_MD_CTX md5; 268 EVP_MD_CTX sha1; 269 uint8_t buf[16], smd[SHA_DIGEST_LENGTH]; 270 uint8_t c = 'A'; 271 size_t i, j, k; 272 273 k = 0; 274 EVP_MD_CTX_init(&md5); 275 EVP_MD_CTX_init(&sha1); 276 for (i = 0; i < out_len; i += MD5_DIGEST_LENGTH) { 277 k++; 278 if (k > sizeof(buf)) { 279 /* bug: 'buf' is too small for this ciphersuite */ 280 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); 281 return 0; 282 } 283 284 for (j = 0; j < k; j++) { 285 buf[j] = c; 286 } 287 c++; 288 if (!EVP_DigestInit_ex(&sha1, EVP_sha1(), NULL)) { 289 OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP); 290 return 0; 291 } 292 EVP_DigestUpdate(&sha1, buf, k); 293 EVP_DigestUpdate(&sha1, secret, secret_len); 294 /* |label| is ignored for SSLv3. */ 295 if (seed1_len) { 296 EVP_DigestUpdate(&sha1, seed1, seed1_len); 297 } 298 if (seed2_len) { 299 EVP_DigestUpdate(&sha1, seed2, seed2_len); 300 } 301 EVP_DigestFinal_ex(&sha1, smd, NULL); 302 303 if (!EVP_DigestInit_ex(&md5, EVP_md5(), NULL)) { 304 OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP); 305 return 0; 306 } 307 EVP_DigestUpdate(&md5, secret, secret_len); 308 EVP_DigestUpdate(&md5, smd, SHA_DIGEST_LENGTH); 309 if (i + MD5_DIGEST_LENGTH > out_len) { 310 EVP_DigestFinal_ex(&md5, smd, NULL); 311 OPENSSL_memcpy(out, smd, out_len - i); 312 } else { 313 EVP_DigestFinal_ex(&md5, out, NULL); 314 } 315 316 out += MD5_DIGEST_LENGTH; 317 } 318 319 OPENSSL_cleanse(smd, SHA_DIGEST_LENGTH); 320 EVP_MD_CTX_cleanup(&md5); 321 EVP_MD_CTX_cleanup(&sha1); 322 323 return 1; 324 } 325 326 static int tls1_setup_key_block(SSL_HANDSHAKE *hs) { 327 SSL *const ssl = hs->ssl; 328 if (hs->key_block_len != 0) { 329 return 1; 330 } 331 332 SSL_SESSION *session = ssl->session; 333 if (hs->new_session != NULL) { 334 session = hs->new_session; 335 } 336 337 const EVP_AEAD *aead = NULL; 338 size_t mac_secret_len, fixed_iv_len; 339 if (session->cipher == NULL || 340 !ssl_cipher_get_evp_aead(&aead, &mac_secret_len, &fixed_iv_len, 341 session->cipher, ssl3_protocol_version(ssl))) { 342 OPENSSL_PUT_ERROR(SSL, SSL_R_CIPHER_OR_HASH_UNAVAILABLE); 343 return 0; 344 } 345 size_t key_len = EVP_AEAD_key_length(aead); 346 if (mac_secret_len > 0) { 347 /* For "stateful" AEADs (i.e. compatibility with pre-AEAD cipher suites) the 348 * key length reported by |EVP_AEAD_key_length| will include the MAC key 349 * bytes and initial implicit IV. */ 350 if (key_len < mac_secret_len + fixed_iv_len) { 351 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); 352 return 0; 353 } 354 key_len -= mac_secret_len + fixed_iv_len; 355 } 356 357 assert(mac_secret_len < 256); 358 assert(key_len < 256); 359 assert(fixed_iv_len < 256); 360 361 ssl->s3->tmp.new_mac_secret_len = (uint8_t)mac_secret_len; 362 ssl->s3->tmp.new_key_len = (uint8_t)key_len; 363 ssl->s3->tmp.new_fixed_iv_len = (uint8_t)fixed_iv_len; 364 365 size_t key_block_len = SSL_get_key_block_len(ssl); 366 367 uint8_t *keyblock = OPENSSL_malloc(key_block_len); 368 if (keyblock == NULL) { 369 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); 370 return 0; 371 } 372 373 if (!SSL_generate_key_block(ssl, keyblock, key_block_len)) { 374 OPENSSL_free(keyblock); 375 return 0; 376 } 377 378 assert(key_block_len < 256); 379 hs->key_block_len = (uint8_t)key_block_len; 380 hs->key_block = keyblock; 381 return 1; 382 } 383 384 int tls1_change_cipher_state(SSL_HANDSHAKE *hs, int which) { 385 SSL *const ssl = hs->ssl; 386 /* Ensure the key block is set up. */ 387 if (!tls1_setup_key_block(hs)) { 388 return 0; 389 } 390 391 /* is_read is true if we have just read a ChangeCipherSpec message - i.e. we 392 * need to update the read cipherspec. Otherwise we have just written one. */ 393 const char is_read = (which & SSL3_CC_READ) != 0; 394 /* use_client_keys is true if we wish to use the keys for the "client write" 395 * direction. This is the case if we're a client sending a ChangeCipherSpec, 396 * or a server reading a client's ChangeCipherSpec. */ 397 const char use_client_keys = which == SSL3_CHANGE_CIPHER_CLIENT_WRITE || 398 which == SSL3_CHANGE_CIPHER_SERVER_READ; 399 400 size_t mac_secret_len = ssl->s3->tmp.new_mac_secret_len; 401 size_t key_len = ssl->s3->tmp.new_key_len; 402 size_t iv_len = ssl->s3->tmp.new_fixed_iv_len; 403 assert((mac_secret_len + key_len + iv_len) * 2 == hs->key_block_len); 404 405 const uint8_t *key_data = hs->key_block; 406 const uint8_t *client_write_mac_secret = key_data; 407 key_data += mac_secret_len; 408 const uint8_t *server_write_mac_secret = key_data; 409 key_data += mac_secret_len; 410 const uint8_t *client_write_key = key_data; 411 key_data += key_len; 412 const uint8_t *server_write_key = key_data; 413 key_data += key_len; 414 const uint8_t *client_write_iv = key_data; 415 key_data += iv_len; 416 const uint8_t *server_write_iv = key_data; 417 key_data += iv_len; 418 419 const uint8_t *mac_secret, *key, *iv; 420 if (use_client_keys) { 421 mac_secret = client_write_mac_secret; 422 key = client_write_key; 423 iv = client_write_iv; 424 } else { 425 mac_secret = server_write_mac_secret; 426 key = server_write_key; 427 iv = server_write_iv; 428 } 429 430 SSL_AEAD_CTX *aead_ctx = SSL_AEAD_CTX_new( 431 is_read ? evp_aead_open : evp_aead_seal, ssl3_protocol_version(ssl), 432 hs->new_cipher, key, key_len, mac_secret, mac_secret_len, iv, iv_len); 433 if (aead_ctx == NULL) { 434 return 0; 435 } 436 437 if (is_read) { 438 return ssl->method->set_read_state(ssl, aead_ctx); 439 } 440 441 return ssl->method->set_write_state(ssl, aead_ctx); 442 } 443 444 size_t SSL_get_key_block_len(const SSL *ssl) { 445 return 2 * ((size_t)ssl->s3->tmp.new_mac_secret_len + 446 (size_t)ssl->s3->tmp.new_key_len + 447 (size_t)ssl->s3->tmp.new_fixed_iv_len); 448 } 449 450 int SSL_generate_key_block(const SSL *ssl, uint8_t *out, size_t out_len) { 451 if (ssl3_protocol_version(ssl) == SSL3_VERSION) { 452 return ssl3_prf(out, out_len, SSL_get_session(ssl)->master_key, 453 SSL_get_session(ssl)->master_key_length, 454 TLS_MD_KEY_EXPANSION_CONST, TLS_MD_KEY_EXPANSION_CONST_SIZE, 455 ssl->s3->server_random, SSL3_RANDOM_SIZE, 456 ssl->s3->client_random, SSL3_RANDOM_SIZE); 457 } 458 459 const EVP_MD *digest = ssl_get_handshake_digest( 460 SSL_get_session(ssl)->cipher->algorithm_prf, ssl3_protocol_version(ssl)); 461 if (digest == NULL) { 462 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); 463 return 0; 464 } 465 return tls1_prf(digest, out, out_len, SSL_get_session(ssl)->master_key, 466 SSL_get_session(ssl)->master_key_length, 467 TLS_MD_KEY_EXPANSION_CONST, TLS_MD_KEY_EXPANSION_CONST_SIZE, 468 ssl->s3->server_random, SSL3_RANDOM_SIZE, 469 ssl->s3->client_random, SSL3_RANDOM_SIZE); 470 } 471 472 int tls1_generate_master_secret(SSL_HANDSHAKE *hs, uint8_t *out, 473 const uint8_t *premaster, 474 size_t premaster_len) { 475 const SSL *ssl = hs->ssl; 476 if (hs->extended_master_secret) { 477 uint8_t digests[EVP_MAX_MD_SIZE]; 478 size_t digests_len; 479 if (!SSL_TRANSCRIPT_get_hash(&hs->transcript, digests, &digests_len) || 480 !tls1_prf(SSL_TRANSCRIPT_md(&hs->transcript), out, 481 SSL3_MASTER_SECRET_SIZE, premaster, premaster_len, 482 TLS_MD_EXTENDED_MASTER_SECRET_CONST, 483 TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE, digests, 484 digests_len, NULL, 0)) { 485 return 0; 486 } 487 } else { 488 if (ssl3_protocol_version(ssl) == SSL3_VERSION) { 489 if (!ssl3_prf(out, SSL3_MASTER_SECRET_SIZE, premaster, premaster_len, 490 TLS_MD_MASTER_SECRET_CONST, TLS_MD_MASTER_SECRET_CONST_SIZE, 491 ssl->s3->client_random, SSL3_RANDOM_SIZE, 492 ssl->s3->server_random, SSL3_RANDOM_SIZE)) { 493 return 0; 494 } 495 } else { 496 if (!tls1_prf(SSL_TRANSCRIPT_md(&hs->transcript), out, 497 SSL3_MASTER_SECRET_SIZE, premaster, premaster_len, 498 TLS_MD_MASTER_SECRET_CONST, TLS_MD_MASTER_SECRET_CONST_SIZE, 499 ssl->s3->client_random, SSL3_RANDOM_SIZE, 500 ssl->s3->server_random, SSL3_RANDOM_SIZE)) { 501 return 0; 502 } 503 } 504 } 505 506 return SSL3_MASTER_SECRET_SIZE; 507 } 508 509 int SSL_export_keying_material(SSL *ssl, uint8_t *out, size_t out_len, 510 const char *label, size_t label_len, 511 const uint8_t *context, size_t context_len, 512 int use_context) { 513 if (!ssl->s3->have_version || ssl->version == SSL3_VERSION) { 514 return 0; 515 } 516 517 /* Exporters may not be used in the middle of a renegotiation. */ 518 if (SSL_in_init(ssl) && !SSL_in_false_start(ssl)) { 519 return 0; 520 } 521 522 if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) { 523 return tls13_export_keying_material(ssl, out, out_len, label, label_len, 524 context, context_len, use_context); 525 } 526 527 size_t seed_len = 2 * SSL3_RANDOM_SIZE; 528 if (use_context) { 529 if (context_len >= 1u << 16) { 530 OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW); 531 return 0; 532 } 533 seed_len += 2 + context_len; 534 } 535 uint8_t *seed = OPENSSL_malloc(seed_len); 536 if (seed == NULL) { 537 OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE); 538 return 0; 539 } 540 541 OPENSSL_memcpy(seed, ssl->s3->client_random, SSL3_RANDOM_SIZE); 542 OPENSSL_memcpy(seed + SSL3_RANDOM_SIZE, ssl->s3->server_random, 543 SSL3_RANDOM_SIZE); 544 if (use_context) { 545 seed[2 * SSL3_RANDOM_SIZE] = (uint8_t)(context_len >> 8); 546 seed[2 * SSL3_RANDOM_SIZE + 1] = (uint8_t)context_len; 547 OPENSSL_memcpy(seed + 2 * SSL3_RANDOM_SIZE + 2, context, context_len); 548 } 549 550 const EVP_MD *digest = ssl_get_handshake_digest( 551 SSL_get_session(ssl)->cipher->algorithm_prf, ssl3_protocol_version(ssl)); 552 if (digest == NULL) { 553 OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR); 554 return 0; 555 } 556 int ret = tls1_prf(digest, out, out_len, SSL_get_session(ssl)->master_key, 557 SSL_get_session(ssl)->master_key_length, label, label_len, 558 seed, seed_len, NULL, 0); 559 OPENSSL_free(seed); 560 return ret; 561 } 562
