1 /* 2 * Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <stdlib.h> 11 #include "ssl_locl.h" 12 #include "internal/cryptlib.h" 13 #include <openssl/evp.h> 14 #include <openssl/kdf.h> 15 16 #define TLS13_MAX_LABEL_LEN 249 17 18 /* Always filled with zeros */ 19 static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; 20 21 /* 22 * Given a |secret|; a |label| of length |labellen|; and |data| of length 23 * |datalen| (e.g. typically a hash of the handshake messages), derive a new 24 * secret |outlen| bytes long and store it in the location pointed to be |out|. 25 * The |data| value may be zero length. Any errors will be treated as fatal if 26 * |fatal| is set. Returns 1 on success 0 on failure. 27 */ 28 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, 29 const unsigned char *label, size_t labellen, 30 const unsigned char *data, size_t datalen, 31 unsigned char *out, size_t outlen, int fatal) 32 { 33 #ifdef CHARSET_EBCDIC 34 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 }; 35 #else 36 static const unsigned char label_prefix[] = "tls13 "; 37 #endif 38 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); 39 int ret; 40 size_t hkdflabellen; 41 size_t hashlen; 42 /* 43 * 2 bytes for length of derived secret + 1 byte for length of combined 44 * prefix and label + bytes for the label itself + 1 byte length of hash 45 * + bytes for the hash itself 46 */ 47 unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) + 48 + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN 49 + 1 + EVP_MAX_MD_SIZE]; 50 WPACKET pkt; 51 52 if (pctx == NULL) 53 return 0; 54 55 if (labellen > TLS13_MAX_LABEL_LEN) { 56 if (fatal) { 57 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, 58 ERR_R_INTERNAL_ERROR); 59 } else { 60 /* 61 * Probably we have been called from SSL_export_keying_material(), 62 * or SSL_export_keying_material_early(). 63 */ 64 SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL); 65 } 66 EVP_PKEY_CTX_free(pctx); 67 return 0; 68 } 69 70 hashlen = EVP_MD_size(md); 71 72 if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0) 73 || !WPACKET_put_bytes_u16(&pkt, outlen) 74 || !WPACKET_start_sub_packet_u8(&pkt) 75 || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1) 76 || !WPACKET_memcpy(&pkt, label, labellen) 77 || !WPACKET_close(&pkt) 78 || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen) 79 || !WPACKET_get_total_written(&pkt, &hkdflabellen) 80 || !WPACKET_finish(&pkt)) { 81 EVP_PKEY_CTX_free(pctx); 82 WPACKET_cleanup(&pkt); 83 if (fatal) 84 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, 85 ERR_R_INTERNAL_ERROR); 86 else 87 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); 88 return 0; 89 } 90 91 ret = EVP_PKEY_derive_init(pctx) <= 0 92 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) 93 <= 0 94 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 95 || EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0 96 || EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0 97 || EVP_PKEY_derive(pctx, out, &outlen) <= 0; 98 99 EVP_PKEY_CTX_free(pctx); 100 101 if (ret != 0) { 102 if (fatal) 103 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, 104 ERR_R_INTERNAL_ERROR); 105 else 106 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); 107 } 108 109 return ret == 0; 110 } 111 112 /* 113 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on 114 * success 0 on failure. 115 */ 116 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, 117 unsigned char *key, size_t keylen) 118 { 119 #ifdef CHARSET_EBCDIC 120 static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 }; 121 #else 122 static const unsigned char keylabel[] = "key"; 123 #endif 124 125 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, 126 NULL, 0, key, keylen, 1); 127 } 128 129 /* 130 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on 131 * success 0 on failure. 132 */ 133 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, 134 unsigned char *iv, size_t ivlen) 135 { 136 #ifdef CHARSET_EBCDIC 137 static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 }; 138 #else 139 static const unsigned char ivlabel[] = "iv"; 140 #endif 141 142 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, 143 NULL, 0, iv, ivlen, 1); 144 } 145 146 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, 147 const unsigned char *secret, 148 unsigned char *fin, size_t finlen) 149 { 150 #ifdef CHARSET_EBCDIC 151 static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 }; 152 #else 153 static const unsigned char finishedlabel[] = "finished"; 154 #endif 155 156 return tls13_hkdf_expand(s, md, secret, finishedlabel, 157 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1); 158 } 159 160 /* 161 * Given the previous secret |prevsecret| and a new input secret |insecret| of 162 * length |insecretlen|, generate a new secret and store it in the location 163 * pointed to by |outsecret|. Returns 1 on success 0 on failure. 164 */ 165 int tls13_generate_secret(SSL *s, const EVP_MD *md, 166 const unsigned char *prevsecret, 167 const unsigned char *insecret, 168 size_t insecretlen, 169 unsigned char *outsecret) 170 { 171 size_t mdlen, prevsecretlen; 172 int mdleni; 173 int ret; 174 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); 175 #ifdef CHARSET_EBCDIC 176 static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 }; 177 #else 178 static const char derived_secret_label[] = "derived"; 179 #endif 180 unsigned char preextractsec[EVP_MAX_MD_SIZE]; 181 182 if (pctx == NULL) { 183 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 184 ERR_R_INTERNAL_ERROR); 185 return 0; 186 } 187 188 mdleni = EVP_MD_size(md); 189 /* Ensure cast to size_t is safe */ 190 if (!ossl_assert(mdleni >= 0)) { 191 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 192 ERR_R_INTERNAL_ERROR); 193 return 0; 194 } 195 mdlen = (size_t)mdleni; 196 197 if (insecret == NULL) { 198 insecret = default_zeros; 199 insecretlen = mdlen; 200 } 201 if (prevsecret == NULL) { 202 prevsecret = default_zeros; 203 prevsecretlen = 0; 204 } else { 205 EVP_MD_CTX *mctx = EVP_MD_CTX_new(); 206 unsigned char hash[EVP_MAX_MD_SIZE]; 207 208 /* The pre-extract derive step uses a hash of no messages */ 209 if (mctx == NULL 210 || EVP_DigestInit_ex(mctx, md, NULL) <= 0 211 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { 212 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 213 ERR_R_INTERNAL_ERROR); 214 EVP_MD_CTX_free(mctx); 215 EVP_PKEY_CTX_free(pctx); 216 return 0; 217 } 218 EVP_MD_CTX_free(mctx); 219 220 /* Generate the pre-extract secret */ 221 if (!tls13_hkdf_expand(s, md, prevsecret, 222 (unsigned char *)derived_secret_label, 223 sizeof(derived_secret_label) - 1, hash, mdlen, 224 preextractsec, mdlen, 1)) { 225 /* SSLfatal() already called */ 226 EVP_PKEY_CTX_free(pctx); 227 return 0; 228 } 229 230 prevsecret = preextractsec; 231 prevsecretlen = mdlen; 232 } 233 234 ret = EVP_PKEY_derive_init(pctx) <= 0 235 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) 236 <= 0 237 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 238 || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0 239 || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen) 240 <= 0 241 || EVP_PKEY_derive(pctx, outsecret, &mdlen) 242 <= 0; 243 244 if (ret != 0) 245 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 246 ERR_R_INTERNAL_ERROR); 247 248 EVP_PKEY_CTX_free(pctx); 249 if (prevsecret == preextractsec) 250 OPENSSL_cleanse(preextractsec, mdlen); 251 return ret == 0; 252 } 253 254 /* 255 * Given an input secret |insecret| of length |insecretlen| generate the 256 * handshake secret. This requires the early secret to already have been 257 * generated. Returns 1 on success 0 on failure. 258 */ 259 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, 260 size_t insecretlen) 261 { 262 /* Calls SSLfatal() if required */ 263 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret, 264 insecret, insecretlen, 265 (unsigned char *)&s->handshake_secret); 266 } 267 268 /* 269 * Given the handshake secret |prev| of length |prevlen| generate the master 270 * secret and store its length in |*secret_size|. Returns 1 on success 0 on 271 * failure. 272 */ 273 int tls13_generate_master_secret(SSL *s, unsigned char *out, 274 unsigned char *prev, size_t prevlen, 275 size_t *secret_size) 276 { 277 const EVP_MD *md = ssl_handshake_md(s); 278 279 *secret_size = EVP_MD_size(md); 280 /* Calls SSLfatal() if required */ 281 return tls13_generate_secret(s, md, prev, NULL, 0, out); 282 } 283 284 /* 285 * Generates the mac for the Finished message. Returns the length of the MAC or 286 * 0 on error. 287 */ 288 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen, 289 unsigned char *out) 290 { 291 const EVP_MD *md = ssl_handshake_md(s); 292 unsigned char hash[EVP_MAX_MD_SIZE]; 293 size_t hashlen, ret = 0; 294 EVP_PKEY *key = NULL; 295 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 296 297 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) { 298 /* SSLfatal() already called */ 299 goto err; 300 } 301 302 if (str == s->method->ssl3_enc->server_finished_label) { 303 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 304 s->server_finished_secret, hashlen); 305 } else if (SSL_IS_FIRST_HANDSHAKE(s)) { 306 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 307 s->client_finished_secret, hashlen); 308 } else { 309 unsigned char finsecret[EVP_MAX_MD_SIZE]; 310 311 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s), 312 s->client_app_traffic_secret, 313 finsecret, hashlen)) 314 goto err; 315 316 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret, 317 hashlen); 318 OPENSSL_cleanse(finsecret, sizeof(finsecret)); 319 } 320 321 if (key == NULL 322 || ctx == NULL 323 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0 324 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0 325 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) { 326 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, 327 ERR_R_INTERNAL_ERROR); 328 goto err; 329 } 330 331 ret = hashlen; 332 err: 333 EVP_PKEY_free(key); 334 EVP_MD_CTX_free(ctx); 335 return ret; 336 } 337 338 /* 339 * There isn't really a key block in TLSv1.3, but we still need this function 340 * for initialising the cipher and hash. Returns 1 on success or 0 on failure. 341 */ 342 int tls13_setup_key_block(SSL *s) 343 { 344 const EVP_CIPHER *c; 345 const EVP_MD *hash; 346 347 s->session->cipher = s->s3->tmp.new_cipher; 348 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) { 349 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK, 350 SSL_R_CIPHER_OR_HASH_UNAVAILABLE); 351 return 0; 352 } 353 354 s->s3->tmp.new_sym_enc = c; 355 s->s3->tmp.new_hash = hash; 356 357 return 1; 358 } 359 360 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, 361 const EVP_CIPHER *ciph, 362 const unsigned char *insecret, 363 const unsigned char *hash, 364 const unsigned char *label, 365 size_t labellen, unsigned char *secret, 366 unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx) 367 { 368 unsigned char key[EVP_MAX_KEY_LENGTH]; 369 size_t ivlen, keylen, taglen; 370 int hashleni = EVP_MD_size(md); 371 size_t hashlen; 372 373 /* Ensure cast to size_t is safe */ 374 if (!ossl_assert(hashleni >= 0)) { 375 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 376 ERR_R_EVP_LIB); 377 goto err; 378 } 379 hashlen = (size_t)hashleni; 380 381 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, 382 secret, hashlen, 1)) { 383 /* SSLfatal() already called */ 384 goto err; 385 } 386 387 /* TODO(size_t): convert me */ 388 keylen = EVP_CIPHER_key_length(ciph); 389 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { 390 uint32_t algenc; 391 392 ivlen = EVP_CCM_TLS_IV_LEN; 393 if (s->s3->tmp.new_cipher == NULL) { 394 /* We've not selected a cipher yet - we must be doing early data */ 395 algenc = s->session->cipher->algorithm_enc; 396 } else { 397 algenc = s->s3->tmp.new_cipher->algorithm_enc; 398 } 399 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) 400 taglen = EVP_CCM8_TLS_TAG_LEN; 401 else 402 taglen = EVP_CCM_TLS_TAG_LEN; 403 } else { 404 ivlen = EVP_CIPHER_iv_length(ciph); 405 taglen = 0; 406 } 407 408 if (!tls13_derive_key(s, md, secret, key, keylen) 409 || !tls13_derive_iv(s, md, secret, iv, ivlen)) { 410 /* SSLfatal() already called */ 411 goto err; 412 } 413 414 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 415 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) 416 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, 417 taglen, NULL)) 418 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { 419 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 420 ERR_R_EVP_LIB); 421 goto err; 422 } 423 424 return 1; 425 err: 426 OPENSSL_cleanse(key, sizeof(key)); 427 return 0; 428 } 429 430 int tls13_change_cipher_state(SSL *s, int which) 431 { 432 #ifdef CHARSET_EBCDIC 433 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 434 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 435 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 436 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 437 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 438 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 439 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 440 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 441 #else 442 static const unsigned char client_early_traffic[] = "c e traffic"; 443 static const unsigned char client_handshake_traffic[] = "c hs traffic"; 444 static const unsigned char client_application_traffic[] = "c ap traffic"; 445 static const unsigned char server_handshake_traffic[] = "s hs traffic"; 446 static const unsigned char server_application_traffic[] = "s ap traffic"; 447 static const unsigned char exporter_master_secret[] = "exp master"; 448 static const unsigned char resumption_master_secret[] = "res master"; 449 static const unsigned char early_exporter_master_secret[] = "e exp master"; 450 #endif 451 unsigned char *iv; 452 unsigned char secret[EVP_MAX_MD_SIZE]; 453 unsigned char hashval[EVP_MAX_MD_SIZE]; 454 unsigned char *hash = hashval; 455 unsigned char *insecret; 456 unsigned char *finsecret = NULL; 457 const char *log_label = NULL; 458 EVP_CIPHER_CTX *ciph_ctx; 459 size_t finsecretlen = 0; 460 const unsigned char *label; 461 size_t labellen, hashlen = 0; 462 int ret = 0; 463 const EVP_MD *md = NULL; 464 const EVP_CIPHER *cipher = NULL; 465 466 if (which & SSL3_CC_READ) { 467 if (s->enc_read_ctx != NULL) { 468 EVP_CIPHER_CTX_reset(s->enc_read_ctx); 469 } else { 470 s->enc_read_ctx = EVP_CIPHER_CTX_new(); 471 if (s->enc_read_ctx == NULL) { 472 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 473 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 474 goto err; 475 } 476 } 477 ciph_ctx = s->enc_read_ctx; 478 iv = s->read_iv; 479 480 RECORD_LAYER_reset_read_sequence(&s->rlayer); 481 } else { 482 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 483 if (s->enc_write_ctx != NULL) { 484 EVP_CIPHER_CTX_reset(s->enc_write_ctx); 485 } else { 486 s->enc_write_ctx = EVP_CIPHER_CTX_new(); 487 if (s->enc_write_ctx == NULL) { 488 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 489 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 490 goto err; 491 } 492 } 493 ciph_ctx = s->enc_write_ctx; 494 iv = s->write_iv; 495 496 RECORD_LAYER_reset_write_sequence(&s->rlayer); 497 } 498 499 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) 500 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { 501 if (which & SSL3_CC_EARLY) { 502 EVP_MD_CTX *mdctx = NULL; 503 long handlen; 504 void *hdata; 505 unsigned int hashlenui; 506 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); 507 508 insecret = s->early_secret; 509 label = client_early_traffic; 510 labellen = sizeof(client_early_traffic) - 1; 511 log_label = CLIENT_EARLY_LABEL; 512 513 handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata); 514 if (handlen <= 0) { 515 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 516 SSL_F_TLS13_CHANGE_CIPHER_STATE, 517 SSL_R_BAD_HANDSHAKE_LENGTH); 518 goto err; 519 } 520 521 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING 522 && s->max_early_data > 0 523 && s->session->ext.max_early_data == 0) { 524 /* 525 * If we are attempting to send early data, and we've decided to 526 * actually do it but max_early_data in s->session is 0 then we 527 * must be using an external PSK. 528 */ 529 if (!ossl_assert(s->psksession != NULL 530 && s->max_early_data == 531 s->psksession->ext.max_early_data)) { 532 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 533 SSL_F_TLS13_CHANGE_CIPHER_STATE, 534 ERR_R_INTERNAL_ERROR); 535 goto err; 536 } 537 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 538 } 539 if (sslcipher == NULL) { 540 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 541 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); 542 goto err; 543 } 544 545 /* 546 * We need to calculate the handshake digest using the digest from 547 * the session. We haven't yet selected our ciphersuite so we can't 548 * use ssl_handshake_md(). 549 */ 550 mdctx = EVP_MD_CTX_new(); 551 if (mdctx == NULL) { 552 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 553 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 554 goto err; 555 } 556 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher)); 557 md = ssl_md(sslcipher->algorithm2); 558 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) 559 || !EVP_DigestUpdate(mdctx, hdata, handlen) 560 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { 561 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 562 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 563 EVP_MD_CTX_free(mdctx); 564 goto err; 565 } 566 hashlen = hashlenui; 567 EVP_MD_CTX_free(mdctx); 568 569 if (!tls13_hkdf_expand(s, md, insecret, 570 early_exporter_master_secret, 571 sizeof(early_exporter_master_secret) - 1, 572 hashval, hashlen, 573 s->early_exporter_master_secret, hashlen, 574 1)) { 575 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 576 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 577 goto err; 578 } 579 580 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, 581 s->early_exporter_master_secret, hashlen)) { 582 /* SSLfatal() already called */ 583 goto err; 584 } 585 } else if (which & SSL3_CC_HANDSHAKE) { 586 insecret = s->handshake_secret; 587 finsecret = s->client_finished_secret; 588 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 589 label = client_handshake_traffic; 590 labellen = sizeof(client_handshake_traffic) - 1; 591 log_label = CLIENT_HANDSHAKE_LABEL; 592 /* 593 * The handshake hash used for the server read/client write handshake 594 * traffic secret is the same as the hash for the server 595 * write/client read handshake traffic secret. However, if we 596 * processed early data then we delay changing the server 597 * read/client write cipher state until later, and the handshake 598 * hashes have moved on. Therefore we use the value saved earlier 599 * when we did the server write/client read change cipher state. 600 */ 601 hash = s->handshake_traffic_hash; 602 } else { 603 insecret = s->master_secret; 604 label = client_application_traffic; 605 labellen = sizeof(client_application_traffic) - 1; 606 log_label = CLIENT_APPLICATION_LABEL; 607 /* 608 * For this we only use the handshake hashes up until the server 609 * Finished hash. We do not include the client's Finished, which is 610 * what ssl_handshake_hash() would give us. Instead we use the 611 * previously saved value. 612 */ 613 hash = s->server_finished_hash; 614 } 615 } else { 616 /* Early data never applies to client-read/server-write */ 617 if (which & SSL3_CC_HANDSHAKE) { 618 insecret = s->handshake_secret; 619 finsecret = s->server_finished_secret; 620 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 621 label = server_handshake_traffic; 622 labellen = sizeof(server_handshake_traffic) - 1; 623 log_label = SERVER_HANDSHAKE_LABEL; 624 } else { 625 insecret = s->master_secret; 626 label = server_application_traffic; 627 labellen = sizeof(server_application_traffic) - 1; 628 log_label = SERVER_APPLICATION_LABEL; 629 } 630 } 631 632 if (!(which & SSL3_CC_EARLY)) { 633 md = ssl_handshake_md(s); 634 cipher = s->s3->tmp.new_sym_enc; 635 if (!ssl3_digest_cached_records(s, 1) 636 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { 637 /* SSLfatal() already called */; 638 goto err; 639 } 640 } 641 642 /* 643 * Save the hash of handshakes up to now for use when we calculate the 644 * client application traffic secret 645 */ 646 if (label == server_application_traffic) 647 memcpy(s->server_finished_hash, hashval, hashlen); 648 649 if (label == server_handshake_traffic) 650 memcpy(s->handshake_traffic_hash, hashval, hashlen); 651 652 if (label == client_application_traffic) { 653 /* 654 * We also create the resumption master secret, but this time use the 655 * hash for the whole handshake including the Client Finished 656 */ 657 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 658 resumption_master_secret, 659 sizeof(resumption_master_secret) - 1, 660 hashval, hashlen, s->resumption_master_secret, 661 hashlen, 1)) { 662 /* SSLfatal() already called */ 663 goto err; 664 } 665 } 666 667 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, 668 insecret, hash, label, labellen, secret, iv, 669 ciph_ctx)) { 670 /* SSLfatal() already called */ 671 goto err; 672 } 673 674 if (label == server_application_traffic) { 675 memcpy(s->server_app_traffic_secret, secret, hashlen); 676 /* Now we create the exporter master secret */ 677 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 678 exporter_master_secret, 679 sizeof(exporter_master_secret) - 1, 680 hash, hashlen, s->exporter_master_secret, 681 hashlen, 1)) { 682 /* SSLfatal() already called */ 683 goto err; 684 } 685 686 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, 687 hashlen)) { 688 /* SSLfatal() already called */ 689 goto err; 690 } 691 } else if (label == client_application_traffic) 692 memcpy(s->client_app_traffic_secret, secret, hashlen); 693 694 if (!ssl_log_secret(s, log_label, secret, hashlen)) { 695 /* SSLfatal() already called */ 696 goto err; 697 } 698 699 if (finsecret != NULL 700 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, 701 finsecret, finsecretlen)) { 702 /* SSLfatal() already called */ 703 goto err; 704 } 705 706 if (!s->server && label == client_early_traffic) 707 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; 708 else 709 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 710 ret = 1; 711 err: 712 OPENSSL_cleanse(secret, sizeof(secret)); 713 return ret; 714 } 715 716 int tls13_update_key(SSL *s, int sending) 717 { 718 #ifdef CHARSET_EBCDIC 719 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00}; 720 #else 721 static const unsigned char application_traffic[] = "traffic upd"; 722 #endif 723 const EVP_MD *md = ssl_handshake_md(s); 724 size_t hashlen = EVP_MD_size(md); 725 unsigned char *insecret, *iv; 726 unsigned char secret[EVP_MAX_MD_SIZE]; 727 EVP_CIPHER_CTX *ciph_ctx; 728 int ret = 0; 729 730 if (s->server == sending) 731 insecret = s->server_app_traffic_secret; 732 else 733 insecret = s->client_app_traffic_secret; 734 735 if (sending) { 736 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 737 iv = s->write_iv; 738 ciph_ctx = s->enc_write_ctx; 739 RECORD_LAYER_reset_write_sequence(&s->rlayer); 740 } else { 741 iv = s->read_iv; 742 ciph_ctx = s->enc_read_ctx; 743 RECORD_LAYER_reset_read_sequence(&s->rlayer); 744 } 745 746 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), 747 s->s3->tmp.new_sym_enc, insecret, NULL, 748 application_traffic, 749 sizeof(application_traffic) - 1, secret, iv, 750 ciph_ctx)) { 751 /* SSLfatal() already called */ 752 goto err; 753 } 754 755 memcpy(insecret, secret, hashlen); 756 757 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 758 ret = 1; 759 err: 760 OPENSSL_cleanse(secret, sizeof(secret)); 761 return ret; 762 } 763 764 int tls13_alert_code(int code) 765 { 766 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ 767 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) 768 return code; 769 770 return tls1_alert_code(code); 771 } 772 773 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, 774 const char *label, size_t llen, 775 const unsigned char *context, 776 size_t contextlen, int use_context) 777 { 778 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 779 #ifdef CHARSET_EBCDIC 780 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 781 #else 782 static const unsigned char exporterlabel[] = "exporter"; 783 #endif 784 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 785 const EVP_MD *md = ssl_handshake_md(s); 786 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 787 unsigned int hashsize, datalen; 788 int ret = 0; 789 790 if (ctx == NULL || !ossl_statem_export_allowed(s)) 791 goto err; 792 793 if (!use_context) 794 contextlen = 0; 795 796 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 797 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 798 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 799 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 800 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 801 || !tls13_hkdf_expand(s, md, s->exporter_master_secret, 802 (const unsigned char *)label, llen, 803 data, datalen, exportsecret, hashsize, 0) 804 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 805 sizeof(exporterlabel) - 1, hash, hashsize, 806 out, olen, 0)) 807 goto err; 808 809 ret = 1; 810 err: 811 EVP_MD_CTX_free(ctx); 812 return ret; 813 } 814 815 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, 816 const char *label, size_t llen, 817 const unsigned char *context, 818 size_t contextlen) 819 { 820 #ifdef CHARSET_EBCDIC 821 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 822 #else 823 static const unsigned char exporterlabel[] = "exporter"; 824 #endif 825 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 826 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 827 const EVP_MD *md; 828 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 829 unsigned int hashsize, datalen; 830 int ret = 0; 831 const SSL_CIPHER *sslcipher; 832 833 if (ctx == NULL || !ossl_statem_export_early_allowed(s)) 834 goto err; 835 836 if (!s->server && s->max_early_data > 0 837 && s->session->ext.max_early_data == 0) 838 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 839 else 840 sslcipher = SSL_SESSION_get0_cipher(s->session); 841 842 md = ssl_md(sslcipher->algorithm2); 843 844 /* 845 * Calculate the hash value and store it in |data|. The reason why 846 * the empty string is used is that the definition of TLS-Exporter 847 * is like so: 848 * 849 * TLS-Exporter(label, context_value, key_length) = 850 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), 851 * "exporter", Hash(context_value), key_length) 852 * 853 * Derive-Secret(Secret, Label, Messages) = 854 * HKDF-Expand-Label(Secret, Label, 855 * Transcript-Hash(Messages), Hash.length) 856 * 857 * Here Transcript-Hash is the cipher suite hash algorithm. 858 */ 859 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 860 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 861 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 862 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 863 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 864 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, 865 (const unsigned char *)label, llen, 866 data, datalen, exportsecret, hashsize, 0) 867 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 868 sizeof(exporterlabel) - 1, hash, hashsize, 869 out, olen, 0)) 870 goto err; 871 872 ret = 1; 873 err: 874 EVP_MD_CTX_free(ctx); 875 return ret; 876 } 877