1 /* 2 * Copyright 2016-2020 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_local.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 algenc = s->s3->tmp.new_cipher->algorithm_enc; 395 } else if (s->session->cipher != NULL) { 396 /* We've not selected a cipher yet - we must be doing early data */ 397 algenc = s->session->cipher->algorithm_enc; 398 } else if (s->psksession != NULL && s->psksession->cipher != NULL) { 399 /* We must be doing early data with out-of-band PSK */ 400 algenc = s->psksession->cipher->algorithm_enc; 401 } else { 402 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 403 ERR_R_EVP_LIB); 404 goto err; 405 } 406 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) 407 taglen = EVP_CCM8_TLS_TAG_LEN; 408 else 409 taglen = EVP_CCM_TLS_TAG_LEN; 410 } else { 411 ivlen = EVP_CIPHER_iv_length(ciph); 412 taglen = 0; 413 } 414 415 if (!tls13_derive_key(s, md, secret, key, keylen) 416 || !tls13_derive_iv(s, md, secret, iv, ivlen)) { 417 /* SSLfatal() already called */ 418 goto err; 419 } 420 421 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 422 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) 423 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, 424 taglen, NULL)) 425 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { 426 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 427 ERR_R_EVP_LIB); 428 goto err; 429 } 430 431 return 1; 432 err: 433 OPENSSL_cleanse(key, sizeof(key)); 434 return 0; 435 } 436 437 int tls13_change_cipher_state(SSL *s, int which) 438 { 439 #ifdef CHARSET_EBCDIC 440 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 441 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 442 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 443 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 444 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 445 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 446 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 447 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 448 #else 449 static const unsigned char client_early_traffic[] = "c e traffic"; 450 static const unsigned char client_handshake_traffic[] = "c hs traffic"; 451 static const unsigned char client_application_traffic[] = "c ap traffic"; 452 static const unsigned char server_handshake_traffic[] = "s hs traffic"; 453 static const unsigned char server_application_traffic[] = "s ap traffic"; 454 static const unsigned char exporter_master_secret[] = "exp master"; 455 static const unsigned char resumption_master_secret[] = "res master"; 456 static const unsigned char early_exporter_master_secret[] = "e exp master"; 457 #endif 458 unsigned char *iv; 459 unsigned char secret[EVP_MAX_MD_SIZE]; 460 unsigned char hashval[EVP_MAX_MD_SIZE]; 461 unsigned char *hash = hashval; 462 unsigned char *insecret; 463 unsigned char *finsecret = NULL; 464 const char *log_label = NULL; 465 EVP_CIPHER_CTX *ciph_ctx; 466 size_t finsecretlen = 0; 467 const unsigned char *label; 468 size_t labellen, hashlen = 0; 469 int ret = 0; 470 const EVP_MD *md = NULL; 471 const EVP_CIPHER *cipher = NULL; 472 473 if (which & SSL3_CC_READ) { 474 if (s->enc_read_ctx != NULL) { 475 EVP_CIPHER_CTX_reset(s->enc_read_ctx); 476 } else { 477 s->enc_read_ctx = EVP_CIPHER_CTX_new(); 478 if (s->enc_read_ctx == NULL) { 479 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 480 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 481 goto err; 482 } 483 } 484 ciph_ctx = s->enc_read_ctx; 485 iv = s->read_iv; 486 487 RECORD_LAYER_reset_read_sequence(&s->rlayer); 488 } else { 489 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 490 if (s->enc_write_ctx != NULL) { 491 EVP_CIPHER_CTX_reset(s->enc_write_ctx); 492 } else { 493 s->enc_write_ctx = EVP_CIPHER_CTX_new(); 494 if (s->enc_write_ctx == NULL) { 495 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 496 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 497 goto err; 498 } 499 } 500 ciph_ctx = s->enc_write_ctx; 501 iv = s->write_iv; 502 503 RECORD_LAYER_reset_write_sequence(&s->rlayer); 504 } 505 506 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) 507 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { 508 if (which & SSL3_CC_EARLY) { 509 EVP_MD_CTX *mdctx = NULL; 510 long handlen; 511 void *hdata; 512 unsigned int hashlenui; 513 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); 514 515 insecret = s->early_secret; 516 label = client_early_traffic; 517 labellen = sizeof(client_early_traffic) - 1; 518 log_label = CLIENT_EARLY_LABEL; 519 520 handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata); 521 if (handlen <= 0) { 522 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 523 SSL_F_TLS13_CHANGE_CIPHER_STATE, 524 SSL_R_BAD_HANDSHAKE_LENGTH); 525 goto err; 526 } 527 528 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING 529 && s->max_early_data > 0 530 && s->session->ext.max_early_data == 0) { 531 /* 532 * If we are attempting to send early data, and we've decided to 533 * actually do it but max_early_data in s->session is 0 then we 534 * must be using an external PSK. 535 */ 536 if (!ossl_assert(s->psksession != NULL 537 && s->max_early_data == 538 s->psksession->ext.max_early_data)) { 539 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 540 SSL_F_TLS13_CHANGE_CIPHER_STATE, 541 ERR_R_INTERNAL_ERROR); 542 goto err; 543 } 544 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 545 } 546 if (sslcipher == NULL) { 547 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 548 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); 549 goto err; 550 } 551 552 /* 553 * We need to calculate the handshake digest using the digest from 554 * the session. We haven't yet selected our ciphersuite so we can't 555 * use ssl_handshake_md(). 556 */ 557 mdctx = EVP_MD_CTX_new(); 558 if (mdctx == NULL) { 559 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 560 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 561 goto err; 562 } 563 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher)); 564 md = ssl_md(sslcipher->algorithm2); 565 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) 566 || !EVP_DigestUpdate(mdctx, hdata, handlen) 567 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { 568 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 569 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 570 EVP_MD_CTX_free(mdctx); 571 goto err; 572 } 573 hashlen = hashlenui; 574 EVP_MD_CTX_free(mdctx); 575 576 if (!tls13_hkdf_expand(s, md, insecret, 577 early_exporter_master_secret, 578 sizeof(early_exporter_master_secret) - 1, 579 hashval, hashlen, 580 s->early_exporter_master_secret, hashlen, 581 1)) { 582 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 583 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 584 goto err; 585 } 586 587 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, 588 s->early_exporter_master_secret, hashlen)) { 589 /* SSLfatal() already called */ 590 goto err; 591 } 592 } else if (which & SSL3_CC_HANDSHAKE) { 593 insecret = s->handshake_secret; 594 finsecret = s->client_finished_secret; 595 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 596 label = client_handshake_traffic; 597 labellen = sizeof(client_handshake_traffic) - 1; 598 log_label = CLIENT_HANDSHAKE_LABEL; 599 /* 600 * The handshake hash used for the server read/client write handshake 601 * traffic secret is the same as the hash for the server 602 * write/client read handshake traffic secret. However, if we 603 * processed early data then we delay changing the server 604 * read/client write cipher state until later, and the handshake 605 * hashes have moved on. Therefore we use the value saved earlier 606 * when we did the server write/client read change cipher state. 607 */ 608 hash = s->handshake_traffic_hash; 609 } else { 610 insecret = s->master_secret; 611 label = client_application_traffic; 612 labellen = sizeof(client_application_traffic) - 1; 613 log_label = CLIENT_APPLICATION_LABEL; 614 /* 615 * For this we only use the handshake hashes up until the server 616 * Finished hash. We do not include the client's Finished, which is 617 * what ssl_handshake_hash() would give us. Instead we use the 618 * previously saved value. 619 */ 620 hash = s->server_finished_hash; 621 } 622 } else { 623 /* Early data never applies to client-read/server-write */ 624 if (which & SSL3_CC_HANDSHAKE) { 625 insecret = s->handshake_secret; 626 finsecret = s->server_finished_secret; 627 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 628 label = server_handshake_traffic; 629 labellen = sizeof(server_handshake_traffic) - 1; 630 log_label = SERVER_HANDSHAKE_LABEL; 631 } else { 632 insecret = s->master_secret; 633 label = server_application_traffic; 634 labellen = sizeof(server_application_traffic) - 1; 635 log_label = SERVER_APPLICATION_LABEL; 636 } 637 } 638 639 if (!(which & SSL3_CC_EARLY)) { 640 md = ssl_handshake_md(s); 641 cipher = s->s3->tmp.new_sym_enc; 642 if (!ssl3_digest_cached_records(s, 1) 643 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { 644 /* SSLfatal() already called */; 645 goto err; 646 } 647 } 648 649 /* 650 * Save the hash of handshakes up to now for use when we calculate the 651 * client application traffic secret 652 */ 653 if (label == server_application_traffic) 654 memcpy(s->server_finished_hash, hashval, hashlen); 655 656 if (label == server_handshake_traffic) 657 memcpy(s->handshake_traffic_hash, hashval, hashlen); 658 659 if (label == client_application_traffic) { 660 /* 661 * We also create the resumption master secret, but this time use the 662 * hash for the whole handshake including the Client Finished 663 */ 664 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 665 resumption_master_secret, 666 sizeof(resumption_master_secret) - 1, 667 hashval, hashlen, s->resumption_master_secret, 668 hashlen, 1)) { 669 /* SSLfatal() already called */ 670 goto err; 671 } 672 } 673 674 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, 675 insecret, hash, label, labellen, secret, iv, 676 ciph_ctx)) { 677 /* SSLfatal() already called */ 678 goto err; 679 } 680 681 if (label == server_application_traffic) { 682 memcpy(s->server_app_traffic_secret, secret, hashlen); 683 /* Now we create the exporter master secret */ 684 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 685 exporter_master_secret, 686 sizeof(exporter_master_secret) - 1, 687 hash, hashlen, s->exporter_master_secret, 688 hashlen, 1)) { 689 /* SSLfatal() already called */ 690 goto err; 691 } 692 693 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, 694 hashlen)) { 695 /* SSLfatal() already called */ 696 goto err; 697 } 698 } else if (label == client_application_traffic) 699 memcpy(s->client_app_traffic_secret, secret, hashlen); 700 701 if (!ssl_log_secret(s, log_label, secret, hashlen)) { 702 /* SSLfatal() already called */ 703 goto err; 704 } 705 706 if (finsecret != NULL 707 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, 708 finsecret, finsecretlen)) { 709 /* SSLfatal() already called */ 710 goto err; 711 } 712 713 if (!s->server && label == client_early_traffic) 714 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; 715 else 716 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 717 ret = 1; 718 err: 719 OPENSSL_cleanse(secret, sizeof(secret)); 720 return ret; 721 } 722 723 int tls13_update_key(SSL *s, int sending) 724 { 725 #ifdef CHARSET_EBCDIC 726 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00}; 727 #else 728 static const unsigned char application_traffic[] = "traffic upd"; 729 #endif 730 const EVP_MD *md = ssl_handshake_md(s); 731 size_t hashlen = EVP_MD_size(md); 732 unsigned char *insecret, *iv; 733 unsigned char secret[EVP_MAX_MD_SIZE]; 734 EVP_CIPHER_CTX *ciph_ctx; 735 int ret = 0; 736 737 if (s->server == sending) 738 insecret = s->server_app_traffic_secret; 739 else 740 insecret = s->client_app_traffic_secret; 741 742 if (sending) { 743 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 744 iv = s->write_iv; 745 ciph_ctx = s->enc_write_ctx; 746 RECORD_LAYER_reset_write_sequence(&s->rlayer); 747 } else { 748 iv = s->read_iv; 749 ciph_ctx = s->enc_read_ctx; 750 RECORD_LAYER_reset_read_sequence(&s->rlayer); 751 } 752 753 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), 754 s->s3->tmp.new_sym_enc, insecret, NULL, 755 application_traffic, 756 sizeof(application_traffic) - 1, secret, iv, 757 ciph_ctx)) { 758 /* SSLfatal() already called */ 759 goto err; 760 } 761 762 memcpy(insecret, secret, hashlen); 763 764 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 765 ret = 1; 766 err: 767 OPENSSL_cleanse(secret, sizeof(secret)); 768 return ret; 769 } 770 771 int tls13_alert_code(int code) 772 { 773 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ 774 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) 775 return code; 776 777 return tls1_alert_code(code); 778 } 779 780 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, 781 const char *label, size_t llen, 782 const unsigned char *context, 783 size_t contextlen, int use_context) 784 { 785 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 786 #ifdef CHARSET_EBCDIC 787 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 788 #else 789 static const unsigned char exporterlabel[] = "exporter"; 790 #endif 791 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 792 const EVP_MD *md = ssl_handshake_md(s); 793 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 794 unsigned int hashsize, datalen; 795 int ret = 0; 796 797 if (ctx == NULL || !ossl_statem_export_allowed(s)) 798 goto err; 799 800 if (!use_context) 801 contextlen = 0; 802 803 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 804 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 805 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 806 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 807 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 808 || !tls13_hkdf_expand(s, md, s->exporter_master_secret, 809 (const unsigned char *)label, llen, 810 data, datalen, exportsecret, hashsize, 0) 811 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 812 sizeof(exporterlabel) - 1, hash, hashsize, 813 out, olen, 0)) 814 goto err; 815 816 ret = 1; 817 err: 818 EVP_MD_CTX_free(ctx); 819 return ret; 820 } 821 822 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, 823 const char *label, size_t llen, 824 const unsigned char *context, 825 size_t contextlen) 826 { 827 #ifdef CHARSET_EBCDIC 828 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 829 #else 830 static const unsigned char exporterlabel[] = "exporter"; 831 #endif 832 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 833 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 834 const EVP_MD *md; 835 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 836 unsigned int hashsize, datalen; 837 int ret = 0; 838 const SSL_CIPHER *sslcipher; 839 840 if (ctx == NULL || !ossl_statem_export_early_allowed(s)) 841 goto err; 842 843 if (!s->server && s->max_early_data > 0 844 && s->session->ext.max_early_data == 0) 845 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 846 else 847 sslcipher = SSL_SESSION_get0_cipher(s->session); 848 849 md = ssl_md(sslcipher->algorithm2); 850 851 /* 852 * Calculate the hash value and store it in |data|. The reason why 853 * the empty string is used is that the definition of TLS-Exporter 854 * is like so: 855 * 856 * TLS-Exporter(label, context_value, key_length) = 857 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), 858 * "exporter", Hash(context_value), key_length) 859 * 860 * Derive-Secret(Secret, Label, Messages) = 861 * HKDF-Expand-Label(Secret, Label, 862 * Transcript-Hash(Messages), Hash.length) 863 * 864 * Here Transcript-Hash is the cipher suite hash algorithm. 865 */ 866 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 867 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 868 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 869 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 870 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 871 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, 872 (const unsigned char *)label, llen, 873 data, datalen, exportsecret, hashsize, 0) 874 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 875 sizeof(exporterlabel) - 1, hash, hashsize, 876 out, olen, 0)) 877 goto err; 878 879 ret = 1; 880 err: 881 EVP_MD_CTX_free(ctx); 882 return ret; 883 } 884