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/ktls.h" 13 #include "record/record_local.h" 14 #include "internal/cryptlib.h" 15 #include <openssl/evp.h> 16 #include <openssl/kdf.h> 17 18 #define TLS13_MAX_LABEL_LEN 249 19 20 /* Always filled with zeros */ 21 static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; 22 23 /* 24 * Given a |secret|; a |label| of length |labellen|; and |data| of length 25 * |datalen| (e.g. typically a hash of the handshake messages), derive a new 26 * secret |outlen| bytes long and store it in the location pointed to be |out|. 27 * The |data| value may be zero length. Any errors will be treated as fatal if 28 * |fatal| is set. Returns 1 on success 0 on failure. 29 */ 30 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, 31 const unsigned char *label, size_t labellen, 32 const unsigned char *data, size_t datalen, 33 unsigned char *out, size_t outlen, int fatal) 34 { 35 #ifdef CHARSET_EBCDIC 36 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 }; 37 #else 38 static const unsigned char label_prefix[] = "tls13 "; 39 #endif 40 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); 41 int ret; 42 size_t hkdflabellen; 43 size_t hashlen; 44 /* 45 * 2 bytes for length of derived secret + 1 byte for length of combined 46 * prefix and label + bytes for the label itself + 1 byte length of hash 47 * + bytes for the hash itself 48 */ 49 unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) 50 + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN 51 + 1 + EVP_MAX_MD_SIZE]; 52 WPACKET pkt; 53 54 if (pctx == NULL) 55 return 0; 56 57 if (labellen > TLS13_MAX_LABEL_LEN) { 58 if (fatal) { 59 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, 60 ERR_R_INTERNAL_ERROR); 61 } else { 62 /* 63 * Probably we have been called from SSL_export_keying_material(), 64 * or SSL_export_keying_material_early(). 65 */ 66 SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL); 67 } 68 EVP_PKEY_CTX_free(pctx); 69 return 0; 70 } 71 72 hashlen = EVP_MD_size(md); 73 74 if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0) 75 || !WPACKET_put_bytes_u16(&pkt, outlen) 76 || !WPACKET_start_sub_packet_u8(&pkt) 77 || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1) 78 || !WPACKET_memcpy(&pkt, label, labellen) 79 || !WPACKET_close(&pkt) 80 || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen) 81 || !WPACKET_get_total_written(&pkt, &hkdflabellen) 82 || !WPACKET_finish(&pkt)) { 83 EVP_PKEY_CTX_free(pctx); 84 WPACKET_cleanup(&pkt); 85 if (fatal) 86 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, 87 ERR_R_INTERNAL_ERROR); 88 else 89 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); 90 return 0; 91 } 92 93 ret = EVP_PKEY_derive_init(pctx) <= 0 94 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) 95 <= 0 96 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 97 || EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0 98 || EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0 99 || EVP_PKEY_derive(pctx, out, &outlen) <= 0; 100 101 EVP_PKEY_CTX_free(pctx); 102 103 if (ret != 0) { 104 if (fatal) 105 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, 106 ERR_R_INTERNAL_ERROR); 107 else 108 SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); 109 } 110 111 return ret == 0; 112 } 113 114 /* 115 * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on 116 * success 0 on failure. 117 */ 118 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, 119 unsigned char *key, size_t keylen) 120 { 121 #ifdef CHARSET_EBCDIC 122 static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 }; 123 #else 124 static const unsigned char keylabel[] = "key"; 125 #endif 126 127 return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, 128 NULL, 0, key, keylen, 1); 129 } 130 131 /* 132 * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on 133 * success 0 on failure. 134 */ 135 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, 136 unsigned char *iv, size_t ivlen) 137 { 138 #ifdef CHARSET_EBCDIC 139 static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 }; 140 #else 141 static const unsigned char ivlabel[] = "iv"; 142 #endif 143 144 return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, 145 NULL, 0, iv, ivlen, 1); 146 } 147 148 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, 149 const unsigned char *secret, 150 unsigned char *fin, size_t finlen) 151 { 152 #ifdef CHARSET_EBCDIC 153 static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 }; 154 #else 155 static const unsigned char finishedlabel[] = "finished"; 156 #endif 157 158 return tls13_hkdf_expand(s, md, secret, finishedlabel, 159 sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1); 160 } 161 162 /* 163 * Given the previous secret |prevsecret| and a new input secret |insecret| of 164 * length |insecretlen|, generate a new secret and store it in the location 165 * pointed to by |outsecret|. Returns 1 on success 0 on failure. 166 */ 167 int tls13_generate_secret(SSL *s, const EVP_MD *md, 168 const unsigned char *prevsecret, 169 const unsigned char *insecret, 170 size_t insecretlen, 171 unsigned char *outsecret) 172 { 173 size_t mdlen, prevsecretlen; 174 int mdleni; 175 int ret; 176 EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); 177 #ifdef CHARSET_EBCDIC 178 static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 }; 179 #else 180 static const char derived_secret_label[] = "derived"; 181 #endif 182 unsigned char preextractsec[EVP_MAX_MD_SIZE]; 183 184 if (pctx == NULL) { 185 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 186 ERR_R_INTERNAL_ERROR); 187 return 0; 188 } 189 190 mdleni = EVP_MD_size(md); 191 /* Ensure cast to size_t is safe */ 192 if (!ossl_assert(mdleni >= 0)) { 193 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 194 ERR_R_INTERNAL_ERROR); 195 EVP_PKEY_CTX_free(pctx); 196 return 0; 197 } 198 mdlen = (size_t)mdleni; 199 200 if (insecret == NULL) { 201 insecret = default_zeros; 202 insecretlen = mdlen; 203 } 204 if (prevsecret == NULL) { 205 prevsecret = default_zeros; 206 prevsecretlen = 0; 207 } else { 208 EVP_MD_CTX *mctx = EVP_MD_CTX_new(); 209 unsigned char hash[EVP_MAX_MD_SIZE]; 210 211 /* The pre-extract derive step uses a hash of no messages */ 212 if (mctx == NULL 213 || EVP_DigestInit_ex(mctx, md, NULL) <= 0 214 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { 215 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 216 ERR_R_INTERNAL_ERROR); 217 EVP_MD_CTX_free(mctx); 218 EVP_PKEY_CTX_free(pctx); 219 return 0; 220 } 221 EVP_MD_CTX_free(mctx); 222 223 /* Generate the pre-extract secret */ 224 if (!tls13_hkdf_expand(s, md, prevsecret, 225 (unsigned char *)derived_secret_label, 226 sizeof(derived_secret_label) - 1, hash, mdlen, 227 preextractsec, mdlen, 1)) { 228 /* SSLfatal() already called */ 229 EVP_PKEY_CTX_free(pctx); 230 return 0; 231 } 232 233 prevsecret = preextractsec; 234 prevsecretlen = mdlen; 235 } 236 237 ret = EVP_PKEY_derive_init(pctx) <= 0 238 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) 239 <= 0 240 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 241 || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0 242 || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen) 243 <= 0 244 || EVP_PKEY_derive(pctx, outsecret, &mdlen) 245 <= 0; 246 247 if (ret != 0) 248 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 249 ERR_R_INTERNAL_ERROR); 250 251 EVP_PKEY_CTX_free(pctx); 252 if (prevsecret == preextractsec) 253 OPENSSL_cleanse(preextractsec, mdlen); 254 return ret == 0; 255 } 256 257 /* 258 * Given an input secret |insecret| of length |insecretlen| generate the 259 * handshake secret. This requires the early secret to already have been 260 * generated. Returns 1 on success 0 on failure. 261 */ 262 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, 263 size_t insecretlen) 264 { 265 /* Calls SSLfatal() if required */ 266 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret, 267 insecret, insecretlen, 268 (unsigned char *)&s->handshake_secret); 269 } 270 271 /* 272 * Given the handshake secret |prev| of length |prevlen| generate the master 273 * secret and store its length in |*secret_size|. Returns 1 on success 0 on 274 * failure. 275 */ 276 int tls13_generate_master_secret(SSL *s, unsigned char *out, 277 unsigned char *prev, size_t prevlen, 278 size_t *secret_size) 279 { 280 const EVP_MD *md = ssl_handshake_md(s); 281 282 *secret_size = EVP_MD_size(md); 283 /* Calls SSLfatal() if required */ 284 return tls13_generate_secret(s, md, prev, NULL, 0, out); 285 } 286 287 /* 288 * Generates the mac for the Finished message. Returns the length of the MAC or 289 * 0 on error. 290 */ 291 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen, 292 unsigned char *out) 293 { 294 const EVP_MD *md = ssl_handshake_md(s); 295 unsigned char hash[EVP_MAX_MD_SIZE]; 296 size_t hashlen, ret = 0; 297 EVP_PKEY *key = NULL; 298 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 299 300 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) { 301 /* SSLfatal() already called */ 302 goto err; 303 } 304 305 if (str == s->method->ssl3_enc->server_finished_label) { 306 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 307 s->server_finished_secret, hashlen); 308 } else if (SSL_IS_FIRST_HANDSHAKE(s)) { 309 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 310 s->client_finished_secret, hashlen); 311 } else { 312 unsigned char finsecret[EVP_MAX_MD_SIZE]; 313 314 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s), 315 s->client_app_traffic_secret, 316 finsecret, hashlen)) 317 goto err; 318 319 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret, 320 hashlen); 321 OPENSSL_cleanse(finsecret, sizeof(finsecret)); 322 } 323 324 if (key == NULL 325 || ctx == NULL 326 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0 327 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0 328 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) { 329 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, 330 ERR_R_INTERNAL_ERROR); 331 goto err; 332 } 333 334 ret = hashlen; 335 err: 336 EVP_PKEY_free(key); 337 EVP_MD_CTX_free(ctx); 338 return ret; 339 } 340 341 /* 342 * There isn't really a key block in TLSv1.3, but we still need this function 343 * for initialising the cipher and hash. Returns 1 on success or 0 on failure. 344 */ 345 int tls13_setup_key_block(SSL *s) 346 { 347 const EVP_CIPHER *c; 348 const EVP_MD *hash; 349 350 s->session->cipher = s->s3->tmp.new_cipher; 351 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) { 352 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK, 353 SSL_R_CIPHER_OR_HASH_UNAVAILABLE); 354 return 0; 355 } 356 357 s->s3->tmp.new_sym_enc = c; 358 s->s3->tmp.new_hash = hash; 359 360 return 1; 361 } 362 363 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, 364 const EVP_CIPHER *ciph, 365 const unsigned char *insecret, 366 const unsigned char *hash, 367 const unsigned char *label, 368 size_t labellen, unsigned char *secret, 369 unsigned char *key, unsigned char *iv, 370 EVP_CIPHER_CTX *ciph_ctx) 371 { 372 size_t ivlen, keylen, taglen; 373 int hashleni = EVP_MD_size(md); 374 size_t hashlen; 375 376 /* Ensure cast to size_t is safe */ 377 if (!ossl_assert(hashleni >= 0)) { 378 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 379 ERR_R_EVP_LIB); 380 return 0; 381 } 382 hashlen = (size_t)hashleni; 383 384 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, 385 secret, hashlen, 1)) { 386 /* SSLfatal() already called */ 387 return 0; 388 } 389 390 /* TODO(size_t): convert me */ 391 keylen = EVP_CIPHER_key_length(ciph); 392 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { 393 uint32_t algenc; 394 395 ivlen = EVP_CCM_TLS_IV_LEN; 396 if (s->s3->tmp.new_cipher != NULL) { 397 algenc = s->s3->tmp.new_cipher->algorithm_enc; 398 } else if (s->session->cipher != NULL) { 399 /* We've not selected a cipher yet - we must be doing early data */ 400 algenc = s->session->cipher->algorithm_enc; 401 } else if (s->psksession != NULL && s->psksession->cipher != NULL) { 402 /* We must be doing early data with out-of-band PSK */ 403 algenc = s->psksession->cipher->algorithm_enc; 404 } else { 405 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 406 ERR_R_EVP_LIB); 407 return 0; 408 } 409 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) 410 taglen = EVP_CCM8_TLS_TAG_LEN; 411 else 412 taglen = EVP_CCM_TLS_TAG_LEN; 413 } else { 414 ivlen = EVP_CIPHER_iv_length(ciph); 415 taglen = 0; 416 } 417 418 if (!tls13_derive_key(s, md, secret, key, keylen) 419 || !tls13_derive_iv(s, md, secret, iv, ivlen)) { 420 /* SSLfatal() already called */ 421 return 0; 422 } 423 424 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 425 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) 426 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, 427 taglen, NULL)) 428 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { 429 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 430 ERR_R_EVP_LIB); 431 return 0; 432 } 433 434 return 1; 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 key[EVP_MAX_KEY_LENGTH]; 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 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13) 474 ktls_crypto_info_t crypto_info; 475 void *rl_sequence; 476 BIO *bio; 477 #endif 478 479 if (which & SSL3_CC_READ) { 480 if (s->enc_read_ctx != NULL) { 481 EVP_CIPHER_CTX_reset(s->enc_read_ctx); 482 } else { 483 s->enc_read_ctx = EVP_CIPHER_CTX_new(); 484 if (s->enc_read_ctx == NULL) { 485 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 486 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 487 goto err; 488 } 489 } 490 ciph_ctx = s->enc_read_ctx; 491 iv = s->read_iv; 492 493 RECORD_LAYER_reset_read_sequence(&s->rlayer); 494 } else { 495 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 496 if (s->enc_write_ctx != NULL) { 497 EVP_CIPHER_CTX_reset(s->enc_write_ctx); 498 } else { 499 s->enc_write_ctx = EVP_CIPHER_CTX_new(); 500 if (s->enc_write_ctx == NULL) { 501 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 502 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 503 goto err; 504 } 505 } 506 ciph_ctx = s->enc_write_ctx; 507 iv = s->write_iv; 508 509 RECORD_LAYER_reset_write_sequence(&s->rlayer); 510 } 511 512 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) 513 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { 514 if (which & SSL3_CC_EARLY) { 515 EVP_MD_CTX *mdctx = NULL; 516 long handlen; 517 void *hdata; 518 unsigned int hashlenui; 519 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); 520 521 insecret = s->early_secret; 522 label = client_early_traffic; 523 labellen = sizeof(client_early_traffic) - 1; 524 log_label = CLIENT_EARLY_LABEL; 525 526 handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata); 527 if (handlen <= 0) { 528 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 529 SSL_F_TLS13_CHANGE_CIPHER_STATE, 530 SSL_R_BAD_HANDSHAKE_LENGTH); 531 goto err; 532 } 533 534 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING 535 && s->max_early_data > 0 536 && s->session->ext.max_early_data == 0) { 537 /* 538 * If we are attempting to send early data, and we've decided to 539 * actually do it but max_early_data in s->session is 0 then we 540 * must be using an external PSK. 541 */ 542 if (!ossl_assert(s->psksession != NULL 543 && s->max_early_data == 544 s->psksession->ext.max_early_data)) { 545 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 546 SSL_F_TLS13_CHANGE_CIPHER_STATE, 547 ERR_R_INTERNAL_ERROR); 548 goto err; 549 } 550 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 551 } 552 if (sslcipher == NULL) { 553 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 554 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); 555 goto err; 556 } 557 558 /* 559 * We need to calculate the handshake digest using the digest from 560 * the session. We haven't yet selected our ciphersuite so we can't 561 * use ssl_handshake_md(). 562 */ 563 mdctx = EVP_MD_CTX_new(); 564 if (mdctx == NULL) { 565 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 566 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 567 goto err; 568 } 569 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher)); 570 md = ssl_md(sslcipher->algorithm2); 571 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) 572 || !EVP_DigestUpdate(mdctx, hdata, handlen) 573 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { 574 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 575 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 576 EVP_MD_CTX_free(mdctx); 577 goto err; 578 } 579 hashlen = hashlenui; 580 EVP_MD_CTX_free(mdctx); 581 582 if (!tls13_hkdf_expand(s, md, insecret, 583 early_exporter_master_secret, 584 sizeof(early_exporter_master_secret) - 1, 585 hashval, hashlen, 586 s->early_exporter_master_secret, hashlen, 587 1)) { 588 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 589 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 590 goto err; 591 } 592 593 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, 594 s->early_exporter_master_secret, hashlen)) { 595 /* SSLfatal() already called */ 596 goto err; 597 } 598 } else if (which & SSL3_CC_HANDSHAKE) { 599 insecret = s->handshake_secret; 600 finsecret = s->client_finished_secret; 601 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 602 label = client_handshake_traffic; 603 labellen = sizeof(client_handshake_traffic) - 1; 604 log_label = CLIENT_HANDSHAKE_LABEL; 605 /* 606 * The handshake hash used for the server read/client write handshake 607 * traffic secret is the same as the hash for the server 608 * write/client read handshake traffic secret. However, if we 609 * processed early data then we delay changing the server 610 * read/client write cipher state until later, and the handshake 611 * hashes have moved on. Therefore we use the value saved earlier 612 * when we did the server write/client read change cipher state. 613 */ 614 hash = s->handshake_traffic_hash; 615 } else { 616 insecret = s->master_secret; 617 label = client_application_traffic; 618 labellen = sizeof(client_application_traffic) - 1; 619 log_label = CLIENT_APPLICATION_LABEL; 620 /* 621 * For this we only use the handshake hashes up until the server 622 * Finished hash. We do not include the client's Finished, which is 623 * what ssl_handshake_hash() would give us. Instead we use the 624 * previously saved value. 625 */ 626 hash = s->server_finished_hash; 627 } 628 } else { 629 /* Early data never applies to client-read/server-write */ 630 if (which & SSL3_CC_HANDSHAKE) { 631 insecret = s->handshake_secret; 632 finsecret = s->server_finished_secret; 633 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 634 label = server_handshake_traffic; 635 labellen = sizeof(server_handshake_traffic) - 1; 636 log_label = SERVER_HANDSHAKE_LABEL; 637 } else { 638 insecret = s->master_secret; 639 label = server_application_traffic; 640 labellen = sizeof(server_application_traffic) - 1; 641 log_label = SERVER_APPLICATION_LABEL; 642 } 643 } 644 645 if (!(which & SSL3_CC_EARLY)) { 646 md = ssl_handshake_md(s); 647 cipher = s->s3->tmp.new_sym_enc; 648 if (!ssl3_digest_cached_records(s, 1) 649 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { 650 /* SSLfatal() already called */; 651 goto err; 652 } 653 } 654 655 /* 656 * Save the hash of handshakes up to now for use when we calculate the 657 * client application traffic secret 658 */ 659 if (label == server_application_traffic) 660 memcpy(s->server_finished_hash, hashval, hashlen); 661 662 if (label == server_handshake_traffic) 663 memcpy(s->handshake_traffic_hash, hashval, hashlen); 664 665 if (label == client_application_traffic) { 666 /* 667 * We also create the resumption master secret, but this time use the 668 * hash for the whole handshake including the Client Finished 669 */ 670 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 671 resumption_master_secret, 672 sizeof(resumption_master_secret) - 1, 673 hashval, hashlen, s->resumption_master_secret, 674 hashlen, 1)) { 675 /* SSLfatal() already called */ 676 goto err; 677 } 678 } 679 680 /* check whether cipher is known */ 681 if(!ossl_assert(cipher != NULL)) 682 goto err; 683 684 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, 685 insecret, hash, label, labellen, secret, key, 686 iv, ciph_ctx)) { 687 /* SSLfatal() already called */ 688 goto err; 689 } 690 691 if (label == server_application_traffic) { 692 memcpy(s->server_app_traffic_secret, secret, hashlen); 693 /* Now we create the exporter master secret */ 694 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 695 exporter_master_secret, 696 sizeof(exporter_master_secret) - 1, 697 hash, hashlen, s->exporter_master_secret, 698 hashlen, 1)) { 699 /* SSLfatal() already called */ 700 goto err; 701 } 702 703 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, 704 hashlen)) { 705 /* SSLfatal() already called */ 706 goto err; 707 } 708 } else if (label == client_application_traffic) 709 memcpy(s->client_app_traffic_secret, secret, hashlen); 710 711 if (!ssl_log_secret(s, log_label, secret, hashlen)) { 712 /* SSLfatal() already called */ 713 goto err; 714 } 715 716 if (finsecret != NULL 717 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, 718 finsecret, finsecretlen)) { 719 /* SSLfatal() already called */ 720 goto err; 721 } 722 723 if (!s->server && label == client_early_traffic) 724 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; 725 else 726 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 727 #ifndef OPENSSL_NO_KTLS 728 # if defined(OPENSSL_KTLS_TLS13) 729 if (!(which & SSL3_CC_APPLICATION) 730 || (s->options & SSL_OP_ENABLE_KTLS) == 0) 731 goto skip_ktls; 732 733 /* ktls supports only the maximum fragment size */ 734 if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH) 735 goto skip_ktls; 736 737 /* ktls does not support record padding */ 738 if (s->record_padding_cb != NULL) 739 goto skip_ktls; 740 741 /* check that cipher is supported */ 742 if (!ktls_check_supported_cipher(s, cipher, ciph_ctx)) 743 goto skip_ktls; 744 745 if (which & SSL3_CC_WRITE) 746 bio = s->wbio; 747 else 748 bio = s->rbio; 749 750 if (!ossl_assert(bio != NULL)) { 751 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_CHANGE_CIPHER_STATE, 752 ERR_R_INTERNAL_ERROR); 753 goto err; 754 } 755 756 /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */ 757 if (which & SSL3_CC_WRITE) { 758 if (BIO_flush(bio) <= 0) 759 goto skip_ktls; 760 } 761 762 /* configure kernel crypto structure */ 763 if (which & SSL3_CC_WRITE) 764 rl_sequence = RECORD_LAYER_get_write_sequence(&s->rlayer); 765 else 766 rl_sequence = RECORD_LAYER_get_read_sequence(&s->rlayer); 767 768 if (!ktls_configure_crypto(s, cipher, ciph_ctx, rl_sequence, &crypto_info, 769 which & SSL3_CC_WRITE, iv, key, NULL, 0)) 770 goto skip_ktls; 771 772 /* ktls works with user provided buffers directly */ 773 if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE)) { 774 if (which & SSL3_CC_WRITE) 775 ssl3_release_write_buffer(s); 776 } 777 skip_ktls: 778 # endif 779 #endif 780 ret = 1; 781 err: 782 OPENSSL_cleanse(key, sizeof(key)); 783 OPENSSL_cleanse(secret, sizeof(secret)); 784 return ret; 785 } 786 787 int tls13_update_key(SSL *s, int sending) 788 { 789 #ifdef CHARSET_EBCDIC 790 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00}; 791 #else 792 static const unsigned char application_traffic[] = "traffic upd"; 793 #endif 794 const EVP_MD *md = ssl_handshake_md(s); 795 size_t hashlen = EVP_MD_size(md); 796 unsigned char key[EVP_MAX_KEY_LENGTH]; 797 unsigned char *insecret, *iv; 798 unsigned char secret[EVP_MAX_MD_SIZE]; 799 EVP_CIPHER_CTX *ciph_ctx; 800 int ret = 0; 801 802 if (s->server == sending) 803 insecret = s->server_app_traffic_secret; 804 else 805 insecret = s->client_app_traffic_secret; 806 807 if (sending) { 808 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 809 iv = s->write_iv; 810 ciph_ctx = s->enc_write_ctx; 811 RECORD_LAYER_reset_write_sequence(&s->rlayer); 812 } else { 813 iv = s->read_iv; 814 ciph_ctx = s->enc_read_ctx; 815 RECORD_LAYER_reset_read_sequence(&s->rlayer); 816 } 817 818 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), 819 s->s3->tmp.new_sym_enc, insecret, NULL, 820 application_traffic, 821 sizeof(application_traffic) - 1, secret, key, 822 iv, ciph_ctx)) { 823 /* SSLfatal() already called */ 824 goto err; 825 } 826 827 memcpy(insecret, secret, hashlen); 828 829 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 830 ret = 1; 831 err: 832 OPENSSL_cleanse(key, sizeof(key)); 833 OPENSSL_cleanse(secret, sizeof(secret)); 834 return ret; 835 } 836 837 int tls13_alert_code(int code) 838 { 839 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ 840 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) 841 return code; 842 843 return tls1_alert_code(code); 844 } 845 846 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, 847 const char *label, size_t llen, 848 const unsigned char *context, 849 size_t contextlen, int use_context) 850 { 851 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 852 #ifdef CHARSET_EBCDIC 853 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 854 #else 855 static const unsigned char exporterlabel[] = "exporter"; 856 #endif 857 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 858 const EVP_MD *md = ssl_handshake_md(s); 859 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 860 unsigned int hashsize, datalen; 861 int ret = 0; 862 863 if (ctx == NULL || !ossl_statem_export_allowed(s)) 864 goto err; 865 866 if (!use_context) 867 contextlen = 0; 868 869 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 870 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 871 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 872 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 873 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 874 || !tls13_hkdf_expand(s, md, s->exporter_master_secret, 875 (const unsigned char *)label, llen, 876 data, datalen, exportsecret, hashsize, 0) 877 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 878 sizeof(exporterlabel) - 1, hash, hashsize, 879 out, olen, 0)) 880 goto err; 881 882 ret = 1; 883 err: 884 EVP_MD_CTX_free(ctx); 885 return ret; 886 } 887 888 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, 889 const char *label, size_t llen, 890 const unsigned char *context, 891 size_t contextlen) 892 { 893 #ifdef CHARSET_EBCDIC 894 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 895 #else 896 static const unsigned char exporterlabel[] = "exporter"; 897 #endif 898 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 899 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 900 const EVP_MD *md; 901 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 902 unsigned int hashsize, datalen; 903 int ret = 0; 904 const SSL_CIPHER *sslcipher; 905 906 if (ctx == NULL || !ossl_statem_export_early_allowed(s)) 907 goto err; 908 909 if (!s->server && s->max_early_data > 0 910 && s->session->ext.max_early_data == 0) 911 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 912 else 913 sslcipher = SSL_SESSION_get0_cipher(s->session); 914 915 md = ssl_md(sslcipher->algorithm2); 916 917 /* 918 * Calculate the hash value and store it in |data|. The reason why 919 * the empty string is used is that the definition of TLS-Exporter 920 * is like so: 921 * 922 * TLS-Exporter(label, context_value, key_length) = 923 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), 924 * "exporter", Hash(context_value), key_length) 925 * 926 * Derive-Secret(Secret, Label, Messages) = 927 * HKDF-Expand-Label(Secret, Label, 928 * Transcript-Hash(Messages), Hash.length) 929 * 930 * Here Transcript-Hash is the cipher suite hash algorithm. 931 */ 932 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 933 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 934 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 935 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 936 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 937 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, 938 (const unsigned char *)label, llen, 939 data, datalen, exportsecret, hashsize, 0) 940 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 941 sizeof(exporterlabel) - 1, hash, hashsize, 942 out, olen, 0)) 943 goto err; 944 945 ret = 1; 946 err: 947 EVP_MD_CTX_free(ctx); 948 return ret; 949 } 950