tls13_enc.c revision 1.1.1.1
1 /* 2 * Copyright 2016-2022 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 EVP_PKEY_CTX_free(pctx); 194 return 0; 195 } 196 mdlen = (size_t)mdleni; 197 198 if (insecret == NULL) { 199 insecret = default_zeros; 200 insecretlen = mdlen; 201 } 202 if (prevsecret == NULL) { 203 prevsecret = default_zeros; 204 prevsecretlen = 0; 205 } else { 206 EVP_MD_CTX *mctx = EVP_MD_CTX_new(); 207 unsigned char hash[EVP_MAX_MD_SIZE]; 208 209 /* The pre-extract derive step uses a hash of no messages */ 210 if (mctx == NULL 211 || EVP_DigestInit_ex(mctx, md, NULL) <= 0 212 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { 213 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 214 ERR_R_INTERNAL_ERROR); 215 EVP_MD_CTX_free(mctx); 216 EVP_PKEY_CTX_free(pctx); 217 return 0; 218 } 219 EVP_MD_CTX_free(mctx); 220 221 /* Generate the pre-extract secret */ 222 if (!tls13_hkdf_expand(s, md, prevsecret, 223 (unsigned char *)derived_secret_label, 224 sizeof(derived_secret_label) - 1, hash, mdlen, 225 preextractsec, mdlen, 1)) { 226 /* SSLfatal() already called */ 227 EVP_PKEY_CTX_free(pctx); 228 return 0; 229 } 230 231 prevsecret = preextractsec; 232 prevsecretlen = mdlen; 233 } 234 235 ret = EVP_PKEY_derive_init(pctx) <= 0 236 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) 237 <= 0 238 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 239 || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0 240 || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen) 241 <= 0 242 || EVP_PKEY_derive(pctx, outsecret, &mdlen) 243 <= 0; 244 245 if (ret != 0) 246 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 247 ERR_R_INTERNAL_ERROR); 248 249 EVP_PKEY_CTX_free(pctx); 250 if (prevsecret == preextractsec) 251 OPENSSL_cleanse(preextractsec, mdlen); 252 return ret == 0; 253 } 254 255 /* 256 * Given an input secret |insecret| of length |insecretlen| generate the 257 * handshake secret. This requires the early secret to already have been 258 * generated. Returns 1 on success 0 on failure. 259 */ 260 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, 261 size_t insecretlen) 262 { 263 /* Calls SSLfatal() if required */ 264 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret, 265 insecret, insecretlen, 266 (unsigned char *)&s->handshake_secret); 267 } 268 269 /* 270 * Given the handshake secret |prev| of length |prevlen| generate the master 271 * secret and store its length in |*secret_size|. Returns 1 on success 0 on 272 * failure. 273 */ 274 int tls13_generate_master_secret(SSL *s, unsigned char *out, 275 unsigned char *prev, size_t prevlen, 276 size_t *secret_size) 277 { 278 const EVP_MD *md = ssl_handshake_md(s); 279 280 *secret_size = EVP_MD_size(md); 281 /* Calls SSLfatal() if required */ 282 return tls13_generate_secret(s, md, prev, NULL, 0, out); 283 } 284 285 /* 286 * Generates the mac for the Finished message. Returns the length of the MAC or 287 * 0 on error. 288 */ 289 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen, 290 unsigned char *out) 291 { 292 const EVP_MD *md = ssl_handshake_md(s); 293 unsigned char hash[EVP_MAX_MD_SIZE]; 294 size_t hashlen, ret = 0; 295 EVP_PKEY *key = NULL; 296 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 297 298 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) { 299 /* SSLfatal() already called */ 300 goto err; 301 } 302 303 if (str == s->method->ssl3_enc->server_finished_label) { 304 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 305 s->server_finished_secret, hashlen); 306 } else if (SSL_IS_FIRST_HANDSHAKE(s)) { 307 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 308 s->client_finished_secret, hashlen); 309 } else { 310 unsigned char finsecret[EVP_MAX_MD_SIZE]; 311 312 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s), 313 s->client_app_traffic_secret, 314 finsecret, hashlen)) 315 goto err; 316 317 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret, 318 hashlen); 319 OPENSSL_cleanse(finsecret, sizeof(finsecret)); 320 } 321 322 if (key == NULL 323 || ctx == NULL 324 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0 325 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0 326 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) { 327 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, 328 ERR_R_INTERNAL_ERROR); 329 goto err; 330 } 331 332 ret = hashlen; 333 err: 334 EVP_PKEY_free(key); 335 EVP_MD_CTX_free(ctx); 336 return ret; 337 } 338 339 /* 340 * There isn't really a key block in TLSv1.3, but we still need this function 341 * for initialising the cipher and hash. Returns 1 on success or 0 on failure. 342 */ 343 int tls13_setup_key_block(SSL *s) 344 { 345 const EVP_CIPHER *c; 346 const EVP_MD *hash; 347 348 s->session->cipher = s->s3->tmp.new_cipher; 349 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) { 350 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK, 351 SSL_R_CIPHER_OR_HASH_UNAVAILABLE); 352 return 0; 353 } 354 355 s->s3->tmp.new_sym_enc = c; 356 s->s3->tmp.new_hash = hash; 357 358 return 1; 359 } 360 361 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, 362 const EVP_CIPHER *ciph, 363 const unsigned char *insecret, 364 const unsigned char *hash, 365 const unsigned char *label, 366 size_t labellen, unsigned char *secret, 367 unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx) 368 { 369 unsigned char key[EVP_MAX_KEY_LENGTH]; 370 size_t ivlen, keylen, taglen; 371 int hashleni = EVP_MD_size(md); 372 size_t hashlen; 373 374 /* Ensure cast to size_t is safe */ 375 if (!ossl_assert(hashleni >= 0)) { 376 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 377 ERR_R_EVP_LIB); 378 goto err; 379 } 380 hashlen = (size_t)hashleni; 381 382 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, 383 secret, hashlen, 1)) { 384 /* SSLfatal() already called */ 385 goto err; 386 } 387 388 /* TODO(size_t): convert me */ 389 keylen = EVP_CIPHER_key_length(ciph); 390 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { 391 uint32_t algenc; 392 393 ivlen = EVP_CCM_TLS_IV_LEN; 394 if (s->s3->tmp.new_cipher != NULL) { 395 algenc = s->s3->tmp.new_cipher->algorithm_enc; 396 } else if (s->session->cipher != NULL) { 397 /* We've not selected a cipher yet - we must be doing early data */ 398 algenc = s->session->cipher->algorithm_enc; 399 } else if (s->psksession != NULL && s->psksession->cipher != NULL) { 400 /* We must be doing early data with out-of-band PSK */ 401 algenc = s->psksession->cipher->algorithm_enc; 402 } else { 403 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 404 ERR_R_EVP_LIB); 405 goto err; 406 } 407 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) 408 taglen = EVP_CCM8_TLS_TAG_LEN; 409 else 410 taglen = EVP_CCM_TLS_TAG_LEN; 411 } else { 412 ivlen = EVP_CIPHER_iv_length(ciph); 413 taglen = 0; 414 } 415 416 if (!tls13_derive_key(s, md, secret, key, keylen) 417 || !tls13_derive_iv(s, md, secret, iv, ivlen)) { 418 /* SSLfatal() already called */ 419 goto err; 420 } 421 422 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 423 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) 424 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, 425 taglen, NULL)) 426 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { 427 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 428 ERR_R_EVP_LIB); 429 goto err; 430 } 431 432 return 1; 433 err: 434 OPENSSL_cleanse(key, sizeof(key)); 435 return 0; 436 } 437 438 int tls13_change_cipher_state(SSL *s, int which) 439 { 440 #ifdef CHARSET_EBCDIC 441 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 442 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 443 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 444 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 445 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 446 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 447 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 448 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 449 #else 450 static const unsigned char client_early_traffic[] = "c e traffic"; 451 static const unsigned char client_handshake_traffic[] = "c hs traffic"; 452 static const unsigned char client_application_traffic[] = "c ap traffic"; 453 static const unsigned char server_handshake_traffic[] = "s hs traffic"; 454 static const unsigned char server_application_traffic[] = "s ap traffic"; 455 static const unsigned char exporter_master_secret[] = "exp master"; 456 static const unsigned char resumption_master_secret[] = "res master"; 457 static const unsigned char early_exporter_master_secret[] = "e exp master"; 458 #endif 459 unsigned char *iv; 460 unsigned char secret[EVP_MAX_MD_SIZE]; 461 unsigned char hashval[EVP_MAX_MD_SIZE]; 462 unsigned char *hash = hashval; 463 unsigned char *insecret; 464 unsigned char *finsecret = NULL; 465 const char *log_label = NULL; 466 EVP_CIPHER_CTX *ciph_ctx; 467 size_t finsecretlen = 0; 468 const unsigned char *label; 469 size_t labellen, hashlen = 0; 470 int ret = 0; 471 const EVP_MD *md = NULL; 472 const EVP_CIPHER *cipher = NULL; 473 474 if (which & SSL3_CC_READ) { 475 if (s->enc_read_ctx != NULL) { 476 EVP_CIPHER_CTX_reset(s->enc_read_ctx); 477 } else { 478 s->enc_read_ctx = EVP_CIPHER_CTX_new(); 479 if (s->enc_read_ctx == NULL) { 480 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 481 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 482 goto err; 483 } 484 } 485 ciph_ctx = s->enc_read_ctx; 486 iv = s->read_iv; 487 488 RECORD_LAYER_reset_read_sequence(&s->rlayer); 489 } else { 490 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 491 if (s->enc_write_ctx != NULL) { 492 EVP_CIPHER_CTX_reset(s->enc_write_ctx); 493 } else { 494 s->enc_write_ctx = EVP_CIPHER_CTX_new(); 495 if (s->enc_write_ctx == NULL) { 496 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 497 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 498 goto err; 499 } 500 } 501 ciph_ctx = s->enc_write_ctx; 502 iv = s->write_iv; 503 504 RECORD_LAYER_reset_write_sequence(&s->rlayer); 505 } 506 507 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) 508 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { 509 if (which & SSL3_CC_EARLY) { 510 EVP_MD_CTX *mdctx = NULL; 511 long handlen; 512 void *hdata; 513 unsigned int hashlenui; 514 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); 515 516 insecret = s->early_secret; 517 label = client_early_traffic; 518 labellen = sizeof(client_early_traffic) - 1; 519 log_label = CLIENT_EARLY_LABEL; 520 521 handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata); 522 if (handlen <= 0) { 523 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 524 SSL_F_TLS13_CHANGE_CIPHER_STATE, 525 SSL_R_BAD_HANDSHAKE_LENGTH); 526 goto err; 527 } 528 529 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING 530 && s->max_early_data > 0 531 && s->session->ext.max_early_data == 0) { 532 /* 533 * If we are attempting to send early data, and we've decided to 534 * actually do it but max_early_data in s->session is 0 then we 535 * must be using an external PSK. 536 */ 537 if (!ossl_assert(s->psksession != NULL 538 && s->max_early_data == 539 s->psksession->ext.max_early_data)) { 540 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 541 SSL_F_TLS13_CHANGE_CIPHER_STATE, 542 ERR_R_INTERNAL_ERROR); 543 goto err; 544 } 545 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 546 } 547 if (sslcipher == NULL) { 548 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 549 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); 550 goto err; 551 } 552 553 /* 554 * We need to calculate the handshake digest using the digest from 555 * the session. We haven't yet selected our ciphersuite so we can't 556 * use ssl_handshake_md(). 557 */ 558 mdctx = EVP_MD_CTX_new(); 559 if (mdctx == NULL) { 560 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 561 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 562 goto err; 563 } 564 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher)); 565 md = ssl_md(sslcipher->algorithm2); 566 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) 567 || !EVP_DigestUpdate(mdctx, hdata, handlen) 568 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { 569 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 570 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 571 EVP_MD_CTX_free(mdctx); 572 goto err; 573 } 574 hashlen = hashlenui; 575 EVP_MD_CTX_free(mdctx); 576 577 if (!tls13_hkdf_expand(s, md, insecret, 578 early_exporter_master_secret, 579 sizeof(early_exporter_master_secret) - 1, 580 hashval, hashlen, 581 s->early_exporter_master_secret, hashlen, 582 1)) { 583 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 584 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 585 goto err; 586 } 587 588 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, 589 s->early_exporter_master_secret, hashlen)) { 590 /* SSLfatal() already called */ 591 goto err; 592 } 593 } else if (which & SSL3_CC_HANDSHAKE) { 594 insecret = s->handshake_secret; 595 finsecret = s->client_finished_secret; 596 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 597 label = client_handshake_traffic; 598 labellen = sizeof(client_handshake_traffic) - 1; 599 log_label = CLIENT_HANDSHAKE_LABEL; 600 /* 601 * The handshake hash used for the server read/client write handshake 602 * traffic secret is the same as the hash for the server 603 * write/client read handshake traffic secret. However, if we 604 * processed early data then we delay changing the server 605 * read/client write cipher state until later, and the handshake 606 * hashes have moved on. Therefore we use the value saved earlier 607 * when we did the server write/client read change cipher state. 608 */ 609 hash = s->handshake_traffic_hash; 610 } else { 611 insecret = s->master_secret; 612 label = client_application_traffic; 613 labellen = sizeof(client_application_traffic) - 1; 614 log_label = CLIENT_APPLICATION_LABEL; 615 /* 616 * For this we only use the handshake hashes up until the server 617 * Finished hash. We do not include the client's Finished, which is 618 * what ssl_handshake_hash() would give us. Instead we use the 619 * previously saved value. 620 */ 621 hash = s->server_finished_hash; 622 } 623 } else { 624 /* Early data never applies to client-read/server-write */ 625 if (which & SSL3_CC_HANDSHAKE) { 626 insecret = s->handshake_secret; 627 finsecret = s->server_finished_secret; 628 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 629 label = server_handshake_traffic; 630 labellen = sizeof(server_handshake_traffic) - 1; 631 log_label = SERVER_HANDSHAKE_LABEL; 632 } else { 633 insecret = s->master_secret; 634 label = server_application_traffic; 635 labellen = sizeof(server_application_traffic) - 1; 636 log_label = SERVER_APPLICATION_LABEL; 637 } 638 } 639 640 if (!(which & SSL3_CC_EARLY)) { 641 md = ssl_handshake_md(s); 642 cipher = s->s3->tmp.new_sym_enc; 643 if (!ssl3_digest_cached_records(s, 1) 644 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { 645 /* SSLfatal() already called */; 646 goto err; 647 } 648 } 649 650 /* 651 * Save the hash of handshakes up to now for use when we calculate the 652 * client application traffic secret 653 */ 654 if (label == server_application_traffic) 655 memcpy(s->server_finished_hash, hashval, hashlen); 656 657 if (label == server_handshake_traffic) 658 memcpy(s->handshake_traffic_hash, hashval, hashlen); 659 660 if (label == client_application_traffic) { 661 /* 662 * We also create the resumption master secret, but this time use the 663 * hash for the whole handshake including the Client Finished 664 */ 665 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 666 resumption_master_secret, 667 sizeof(resumption_master_secret) - 1, 668 hashval, hashlen, s->resumption_master_secret, 669 hashlen, 1)) { 670 /* SSLfatal() already called */ 671 goto err; 672 } 673 } 674 675 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, 676 insecret, hash, label, labellen, secret, iv, 677 ciph_ctx)) { 678 /* SSLfatal() already called */ 679 goto err; 680 } 681 682 if (label == server_application_traffic) { 683 memcpy(s->server_app_traffic_secret, secret, hashlen); 684 /* Now we create the exporter master secret */ 685 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 686 exporter_master_secret, 687 sizeof(exporter_master_secret) - 1, 688 hash, hashlen, s->exporter_master_secret, 689 hashlen, 1)) { 690 /* SSLfatal() already called */ 691 goto err; 692 } 693 694 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, 695 hashlen)) { 696 /* SSLfatal() already called */ 697 goto err; 698 } 699 } else if (label == client_application_traffic) 700 memcpy(s->client_app_traffic_secret, secret, hashlen); 701 702 if (!ssl_log_secret(s, log_label, secret, hashlen)) { 703 /* SSLfatal() already called */ 704 goto err; 705 } 706 707 if (finsecret != NULL 708 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, 709 finsecret, finsecretlen)) { 710 /* SSLfatal() already called */ 711 goto err; 712 } 713 714 if (!s->server && label == client_early_traffic) 715 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; 716 else 717 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 718 ret = 1; 719 err: 720 OPENSSL_cleanse(secret, sizeof(secret)); 721 return ret; 722 } 723 724 int tls13_update_key(SSL *s, int sending) 725 { 726 #ifdef CHARSET_EBCDIC 727 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00}; 728 #else 729 static const unsigned char application_traffic[] = "traffic upd"; 730 #endif 731 const EVP_MD *md = ssl_handshake_md(s); 732 size_t hashlen = EVP_MD_size(md); 733 unsigned char *insecret, *iv; 734 unsigned char secret[EVP_MAX_MD_SIZE]; 735 EVP_CIPHER_CTX *ciph_ctx; 736 int ret = 0; 737 738 if (s->server == sending) 739 insecret = s->server_app_traffic_secret; 740 else 741 insecret = s->client_app_traffic_secret; 742 743 if (sending) { 744 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 745 iv = s->write_iv; 746 ciph_ctx = s->enc_write_ctx; 747 RECORD_LAYER_reset_write_sequence(&s->rlayer); 748 } else { 749 iv = s->read_iv; 750 ciph_ctx = s->enc_read_ctx; 751 RECORD_LAYER_reset_read_sequence(&s->rlayer); 752 } 753 754 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), 755 s->s3->tmp.new_sym_enc, insecret, NULL, 756 application_traffic, 757 sizeof(application_traffic) - 1, secret, iv, 758 ciph_ctx)) { 759 /* SSLfatal() already called */ 760 goto err; 761 } 762 763 memcpy(insecret, secret, hashlen); 764 765 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 766 ret = 1; 767 err: 768 OPENSSL_cleanse(secret, sizeof(secret)); 769 return ret; 770 } 771 772 int tls13_alert_code(int code) 773 { 774 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ 775 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) 776 return code; 777 778 return tls1_alert_code(code); 779 } 780 781 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, 782 const char *label, size_t llen, 783 const unsigned char *context, 784 size_t contextlen, int use_context) 785 { 786 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 787 #ifdef CHARSET_EBCDIC 788 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 789 #else 790 static const unsigned char exporterlabel[] = "exporter"; 791 #endif 792 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 793 const EVP_MD *md = ssl_handshake_md(s); 794 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 795 unsigned int hashsize, datalen; 796 int ret = 0; 797 798 if (ctx == NULL || !ossl_statem_export_allowed(s)) 799 goto err; 800 801 if (!use_context) 802 contextlen = 0; 803 804 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 805 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 806 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 807 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 808 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 809 || !tls13_hkdf_expand(s, md, s->exporter_master_secret, 810 (const unsigned char *)label, llen, 811 data, datalen, exportsecret, hashsize, 0) 812 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 813 sizeof(exporterlabel) - 1, hash, hashsize, 814 out, olen, 0)) 815 goto err; 816 817 ret = 1; 818 err: 819 EVP_MD_CTX_free(ctx); 820 return ret; 821 } 822 823 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, 824 const char *label, size_t llen, 825 const unsigned char *context, 826 size_t contextlen) 827 { 828 #ifdef CHARSET_EBCDIC 829 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 830 #else 831 static const unsigned char exporterlabel[] = "exporter"; 832 #endif 833 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 834 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 835 const EVP_MD *md; 836 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 837 unsigned int hashsize, datalen; 838 int ret = 0; 839 const SSL_CIPHER *sslcipher; 840 841 if (ctx == NULL || !ossl_statem_export_early_allowed(s)) 842 goto err; 843 844 if (!s->server && s->max_early_data > 0 845 && s->session->ext.max_early_data == 0) 846 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 847 else 848 sslcipher = SSL_SESSION_get0_cipher(s->session); 849 850 md = ssl_md(sslcipher->algorithm2); 851 852 /* 853 * Calculate the hash value and store it in |data|. The reason why 854 * the empty string is used is that the definition of TLS-Exporter 855 * is like so: 856 * 857 * TLS-Exporter(label, context_value, key_length) = 858 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), 859 * "exporter", Hash(context_value), key_length) 860 * 861 * Derive-Secret(Secret, Label, Messages) = 862 * HKDF-Expand-Label(Secret, Label, 863 * Transcript-Hash(Messages), Hash.length) 864 * 865 * Here Transcript-Hash is the cipher suite hash algorithm. 866 */ 867 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 868 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 869 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 870 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 871 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 872 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, 873 (const unsigned char *)label, llen, 874 data, datalen, exportsecret, hashsize, 0) 875 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 876 sizeof(exporterlabel) - 1, hash, hashsize, 877 out, olen, 0)) 878 goto err; 879 880 ret = 1; 881 err: 882 EVP_MD_CTX_free(ctx); 883 return ret; 884 } 885
Indexes created Fri Jun 26 00:24:39 UTC 2026