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/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 return 0; 196 } 197 mdlen = (size_t)mdleni; 198 199 if (insecret == NULL) { 200 insecret = default_zeros; 201 insecretlen = mdlen; 202 } 203 if (prevsecret == NULL) { 204 prevsecret = default_zeros; 205 prevsecretlen = 0; 206 } else { 207 EVP_MD_CTX *mctx = EVP_MD_CTX_new(); 208 unsigned char hash[EVP_MAX_MD_SIZE]; 209 210 /* The pre-extract derive step uses a hash of no messages */ 211 if (mctx == NULL 212 || EVP_DigestInit_ex(mctx, md, NULL) <= 0 213 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { 214 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 215 ERR_R_INTERNAL_ERROR); 216 EVP_MD_CTX_free(mctx); 217 EVP_PKEY_CTX_free(pctx); 218 return 0; 219 } 220 EVP_MD_CTX_free(mctx); 221 222 /* Generate the pre-extract secret */ 223 if (!tls13_hkdf_expand(s, md, prevsecret, 224 (unsigned char *)derived_secret_label, 225 sizeof(derived_secret_label) - 1, hash, mdlen, 226 preextractsec, mdlen, 1)) { 227 /* SSLfatal() already called */ 228 EVP_PKEY_CTX_free(pctx); 229 return 0; 230 } 231 232 prevsecret = preextractsec; 233 prevsecretlen = mdlen; 234 } 235 236 ret = EVP_PKEY_derive_init(pctx) <= 0 237 || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) 238 <= 0 239 || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 240 || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0 241 || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen) 242 <= 0 243 || EVP_PKEY_derive(pctx, outsecret, &mdlen) 244 <= 0; 245 246 if (ret != 0) 247 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, 248 ERR_R_INTERNAL_ERROR); 249 250 EVP_PKEY_CTX_free(pctx); 251 if (prevsecret == preextractsec) 252 OPENSSL_cleanse(preextractsec, mdlen); 253 return ret == 0; 254 } 255 256 /* 257 * Given an input secret |insecret| of length |insecretlen| generate the 258 * handshake secret. This requires the early secret to already have been 259 * generated. Returns 1 on success 0 on failure. 260 */ 261 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, 262 size_t insecretlen) 263 { 264 /* Calls SSLfatal() if required */ 265 return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret, 266 insecret, insecretlen, 267 (unsigned char *)&s->handshake_secret); 268 } 269 270 /* 271 * Given the handshake secret |prev| of length |prevlen| generate the master 272 * secret and store its length in |*secret_size|. Returns 1 on success 0 on 273 * failure. 274 */ 275 int tls13_generate_master_secret(SSL *s, unsigned char *out, 276 unsigned char *prev, size_t prevlen, 277 size_t *secret_size) 278 { 279 const EVP_MD *md = ssl_handshake_md(s); 280 281 *secret_size = EVP_MD_size(md); 282 /* Calls SSLfatal() if required */ 283 return tls13_generate_secret(s, md, prev, NULL, 0, out); 284 } 285 286 /* 287 * Generates the mac for the Finished message. Returns the length of the MAC or 288 * 0 on error. 289 */ 290 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen, 291 unsigned char *out) 292 { 293 const EVP_MD *md = ssl_handshake_md(s); 294 unsigned char hash[EVP_MAX_MD_SIZE]; 295 size_t hashlen, ret = 0; 296 EVP_PKEY *key = NULL; 297 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 298 299 if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) { 300 /* SSLfatal() already called */ 301 goto err; 302 } 303 304 if (str == s->method->ssl3_enc->server_finished_label) { 305 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 306 s->server_finished_secret, hashlen); 307 } else if (SSL_IS_FIRST_HANDSHAKE(s)) { 308 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, 309 s->client_finished_secret, hashlen); 310 } else { 311 unsigned char finsecret[EVP_MAX_MD_SIZE]; 312 313 if (!tls13_derive_finishedkey(s, ssl_handshake_md(s), 314 s->client_app_traffic_secret, 315 finsecret, hashlen)) 316 goto err; 317 318 key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret, 319 hashlen); 320 OPENSSL_cleanse(finsecret, sizeof(finsecret)); 321 } 322 323 if (key == NULL 324 || ctx == NULL 325 || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0 326 || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0 327 || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) { 328 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, 329 ERR_R_INTERNAL_ERROR); 330 goto err; 331 } 332 333 ret = hashlen; 334 err: 335 EVP_PKEY_free(key); 336 EVP_MD_CTX_free(ctx); 337 return ret; 338 } 339 340 /* 341 * There isn't really a key block in TLSv1.3, but we still need this function 342 * for initialising the cipher and hash. Returns 1 on success or 0 on failure. 343 */ 344 int tls13_setup_key_block(SSL *s) 345 { 346 const EVP_CIPHER *c; 347 const EVP_MD *hash; 348 349 s->session->cipher = s->s3->tmp.new_cipher; 350 if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) { 351 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK, 352 SSL_R_CIPHER_OR_HASH_UNAVAILABLE); 353 return 0; 354 } 355 356 s->s3->tmp.new_sym_enc = c; 357 s->s3->tmp.new_hash = hash; 358 359 return 1; 360 } 361 362 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, 363 const EVP_CIPHER *ciph, 364 const unsigned char *insecret, 365 const unsigned char *hash, 366 const unsigned char *label, 367 size_t labellen, unsigned char *secret, 368 unsigned char *key, unsigned char *iv, 369 EVP_CIPHER_CTX *ciph_ctx) 370 { 371 size_t ivlen, keylen, taglen; 372 int hashleni = EVP_MD_size(md); 373 size_t hashlen; 374 375 /* Ensure cast to size_t is safe */ 376 if (!ossl_assert(hashleni >= 0)) { 377 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 378 ERR_R_EVP_LIB); 379 return 0; 380 } 381 hashlen = (size_t)hashleni; 382 383 if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, 384 secret, hashlen, 1)) { 385 /* SSLfatal() already called */ 386 return 0; 387 } 388 389 /* TODO(size_t): convert me */ 390 keylen = EVP_CIPHER_key_length(ciph); 391 if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { 392 uint32_t algenc; 393 394 ivlen = EVP_CCM_TLS_IV_LEN; 395 if (s->s3->tmp.new_cipher != NULL) { 396 algenc = s->s3->tmp.new_cipher->algorithm_enc; 397 } else if (s->session->cipher != NULL) { 398 /* We've not selected a cipher yet - we must be doing early data */ 399 algenc = s->session->cipher->algorithm_enc; 400 } else if (s->psksession != NULL && s->psksession->cipher != NULL) { 401 /* We must be doing early data with out-of-band PSK */ 402 algenc = s->psksession->cipher->algorithm_enc; 403 } else { 404 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 405 ERR_R_EVP_LIB); 406 return 0; 407 } 408 if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) 409 taglen = EVP_CCM8_TLS_TAG_LEN; 410 else 411 taglen = EVP_CCM_TLS_TAG_LEN; 412 } else { 413 ivlen = EVP_CIPHER_iv_length(ciph); 414 taglen = 0; 415 } 416 417 if (!tls13_derive_key(s, md, secret, key, keylen) 418 || !tls13_derive_iv(s, md, secret, iv, ivlen)) { 419 /* SSLfatal() already called */ 420 return 0; 421 } 422 423 if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 424 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) 425 || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, 426 taglen, NULL)) 427 || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { 428 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, 429 ERR_R_EVP_LIB); 430 return 0; 431 } 432 433 return 1; 434 } 435 436 int tls13_change_cipher_state(SSL *s, int which) 437 { 438 #ifdef CHARSET_EBCDIC 439 static const unsigned char client_early_traffic[] = {0x63, 0x20, 0x65, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 440 static const unsigned char client_handshake_traffic[] = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 441 static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 442 static const unsigned char server_handshake_traffic[] = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 443 static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00}; 444 static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 445 static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 446 static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20, /* master*/ 0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00}; 447 #else 448 static const unsigned char client_early_traffic[] = "c e traffic"; 449 static const unsigned char client_handshake_traffic[] = "c hs traffic"; 450 static const unsigned char client_application_traffic[] = "c ap traffic"; 451 static const unsigned char server_handshake_traffic[] = "s hs traffic"; 452 static const unsigned char server_application_traffic[] = "s ap traffic"; 453 static const unsigned char exporter_master_secret[] = "exp master"; 454 static const unsigned char resumption_master_secret[] = "res master"; 455 static const unsigned char early_exporter_master_secret[] = "e exp master"; 456 #endif 457 unsigned char *iv; 458 unsigned char key[EVP_MAX_KEY_LENGTH]; 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 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13) 473 ktls_crypto_info_t crypto_info; 474 BIO *bio; 475 #endif 476 477 if (which & SSL3_CC_READ) { 478 if (s->enc_read_ctx != NULL) { 479 EVP_CIPHER_CTX_reset(s->enc_read_ctx); 480 } else { 481 s->enc_read_ctx = EVP_CIPHER_CTX_new(); 482 if (s->enc_read_ctx == NULL) { 483 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 484 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 485 goto err; 486 } 487 } 488 ciph_ctx = s->enc_read_ctx; 489 iv = s->read_iv; 490 491 RECORD_LAYER_reset_read_sequence(&s->rlayer); 492 } else { 493 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 494 if (s->enc_write_ctx != NULL) { 495 EVP_CIPHER_CTX_reset(s->enc_write_ctx); 496 } else { 497 s->enc_write_ctx = EVP_CIPHER_CTX_new(); 498 if (s->enc_write_ctx == NULL) { 499 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 500 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 501 goto err; 502 } 503 } 504 ciph_ctx = s->enc_write_ctx; 505 iv = s->write_iv; 506 507 RECORD_LAYER_reset_write_sequence(&s->rlayer); 508 } 509 510 if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) 511 || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { 512 if (which & SSL3_CC_EARLY) { 513 EVP_MD_CTX *mdctx = NULL; 514 long handlen; 515 void *hdata; 516 unsigned int hashlenui; 517 const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); 518 519 insecret = s->early_secret; 520 label = client_early_traffic; 521 labellen = sizeof(client_early_traffic) - 1; 522 log_label = CLIENT_EARLY_LABEL; 523 524 handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata); 525 if (handlen <= 0) { 526 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 527 SSL_F_TLS13_CHANGE_CIPHER_STATE, 528 SSL_R_BAD_HANDSHAKE_LENGTH); 529 goto err; 530 } 531 532 if (s->early_data_state == SSL_EARLY_DATA_CONNECTING 533 && s->max_early_data > 0 534 && s->session->ext.max_early_data == 0) { 535 /* 536 * If we are attempting to send early data, and we've decided to 537 * actually do it but max_early_data in s->session is 0 then we 538 * must be using an external PSK. 539 */ 540 if (!ossl_assert(s->psksession != NULL 541 && s->max_early_data == 542 s->psksession->ext.max_early_data)) { 543 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 544 SSL_F_TLS13_CHANGE_CIPHER_STATE, 545 ERR_R_INTERNAL_ERROR); 546 goto err; 547 } 548 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 549 } 550 if (sslcipher == NULL) { 551 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 552 SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); 553 goto err; 554 } 555 556 /* 557 * We need to calculate the handshake digest using the digest from 558 * the session. We haven't yet selected our ciphersuite so we can't 559 * use ssl_handshake_md(). 560 */ 561 mdctx = EVP_MD_CTX_new(); 562 if (mdctx == NULL) { 563 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 564 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); 565 goto err; 566 } 567 cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher)); 568 md = ssl_md(sslcipher->algorithm2); 569 if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) 570 || !EVP_DigestUpdate(mdctx, hdata, handlen) 571 || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { 572 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 573 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 574 EVP_MD_CTX_free(mdctx); 575 goto err; 576 } 577 hashlen = hashlenui; 578 EVP_MD_CTX_free(mdctx); 579 580 if (!tls13_hkdf_expand(s, md, insecret, 581 early_exporter_master_secret, 582 sizeof(early_exporter_master_secret) - 1, 583 hashval, hashlen, 584 s->early_exporter_master_secret, hashlen, 585 1)) { 586 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 587 SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); 588 goto err; 589 } 590 591 if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, 592 s->early_exporter_master_secret, hashlen)) { 593 /* SSLfatal() already called */ 594 goto err; 595 } 596 } else if (which & SSL3_CC_HANDSHAKE) { 597 insecret = s->handshake_secret; 598 finsecret = s->client_finished_secret; 599 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 600 label = client_handshake_traffic; 601 labellen = sizeof(client_handshake_traffic) - 1; 602 log_label = CLIENT_HANDSHAKE_LABEL; 603 /* 604 * The handshake hash used for the server read/client write handshake 605 * traffic secret is the same as the hash for the server 606 * write/client read handshake traffic secret. However, if we 607 * processed early data then we delay changing the server 608 * read/client write cipher state until later, and the handshake 609 * hashes have moved on. Therefore we use the value saved earlier 610 * when we did the server write/client read change cipher state. 611 */ 612 hash = s->handshake_traffic_hash; 613 } else { 614 insecret = s->master_secret; 615 label = client_application_traffic; 616 labellen = sizeof(client_application_traffic) - 1; 617 log_label = CLIENT_APPLICATION_LABEL; 618 /* 619 * For this we only use the handshake hashes up until the server 620 * Finished hash. We do not include the client's Finished, which is 621 * what ssl_handshake_hash() would give us. Instead we use the 622 * previously saved value. 623 */ 624 hash = s->server_finished_hash; 625 } 626 } else { 627 /* Early data never applies to client-read/server-write */ 628 if (which & SSL3_CC_HANDSHAKE) { 629 insecret = s->handshake_secret; 630 finsecret = s->server_finished_secret; 631 finsecretlen = EVP_MD_size(ssl_handshake_md(s)); 632 label = server_handshake_traffic; 633 labellen = sizeof(server_handshake_traffic) - 1; 634 log_label = SERVER_HANDSHAKE_LABEL; 635 } else { 636 insecret = s->master_secret; 637 label = server_application_traffic; 638 labellen = sizeof(server_application_traffic) - 1; 639 log_label = SERVER_APPLICATION_LABEL; 640 } 641 } 642 643 if (!(which & SSL3_CC_EARLY)) { 644 md = ssl_handshake_md(s); 645 cipher = s->s3->tmp.new_sym_enc; 646 if (!ssl3_digest_cached_records(s, 1) 647 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { 648 /* SSLfatal() already called */; 649 goto err; 650 } 651 } 652 653 /* 654 * Save the hash of handshakes up to now for use when we calculate the 655 * client application traffic secret 656 */ 657 if (label == server_application_traffic) 658 memcpy(s->server_finished_hash, hashval, hashlen); 659 660 if (label == server_handshake_traffic) 661 memcpy(s->handshake_traffic_hash, hashval, hashlen); 662 663 if (label == client_application_traffic) { 664 /* 665 * We also create the resumption master secret, but this time use the 666 * hash for the whole handshake including the Client Finished 667 */ 668 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 669 resumption_master_secret, 670 sizeof(resumption_master_secret) - 1, 671 hashval, hashlen, s->resumption_master_secret, 672 hashlen, 1)) { 673 /* SSLfatal() already called */ 674 goto err; 675 } 676 } 677 678 /* check whether cipher is known */ 679 if(!ossl_assert(cipher != NULL)) 680 goto err; 681 682 if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, 683 insecret, hash, label, labellen, secret, key, 684 iv, ciph_ctx)) { 685 /* SSLfatal() already called */ 686 goto err; 687 } 688 689 if (label == server_application_traffic) { 690 memcpy(s->server_app_traffic_secret, secret, hashlen); 691 /* Now we create the exporter master secret */ 692 if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, 693 exporter_master_secret, 694 sizeof(exporter_master_secret) - 1, 695 hash, hashlen, s->exporter_master_secret, 696 hashlen, 1)) { 697 /* SSLfatal() already called */ 698 goto err; 699 } 700 701 if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, 702 hashlen)) { 703 /* SSLfatal() already called */ 704 goto err; 705 } 706 } else if (label == client_application_traffic) 707 memcpy(s->client_app_traffic_secret, secret, hashlen); 708 709 if (!ssl_log_secret(s, log_label, secret, hashlen)) { 710 /* SSLfatal() already called */ 711 goto err; 712 } 713 714 if (finsecret != NULL 715 && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, 716 finsecret, finsecretlen)) { 717 /* SSLfatal() already called */ 718 goto err; 719 } 720 721 if (!s->server && label == client_early_traffic) 722 s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; 723 else 724 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 725 #ifndef OPENSSL_NO_KTLS 726 # if defined(OPENSSL_KTLS_TLS13) 727 if (!(which & SSL3_CC_WRITE) 728 || !(which & SSL3_CC_APPLICATION) 729 || (s->options & SSL_OP_ENABLE_KTLS) == 0) 730 goto skip_ktls; 731 732 /* ktls supports only the maximum fragment size */ 733 if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH) 734 goto skip_ktls; 735 736 /* ktls does not support record padding */ 737 if (s->record_padding_cb != NULL) 738 goto skip_ktls; 739 740 /* check that cipher is supported */ 741 if (!ktls_check_supported_cipher(s, cipher, ciph_ctx)) 742 goto skip_ktls; 743 744 bio = s->wbio; 745 746 if (!ossl_assert(bio != NULL)) { 747 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_CHANGE_CIPHER_STATE, 748 ERR_R_INTERNAL_ERROR); 749 goto err; 750 } 751 752 /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */ 753 if (BIO_flush(bio) <= 0) 754 goto skip_ktls; 755 756 /* configure kernel crypto structure */ 757 if (!ktls_configure_crypto(s, cipher, ciph_ctx, 758 RECORD_LAYER_get_write_sequence(&s->rlayer), 759 &crypto_info, NULL, iv, key, NULL, 0)) 760 goto skip_ktls; 761 762 /* ktls works with user provided buffers directly */ 763 if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE)) 764 ssl3_release_write_buffer(s); 765 skip_ktls: 766 # endif 767 #endif 768 ret = 1; 769 err: 770 OPENSSL_cleanse(key, sizeof(key)); 771 OPENSSL_cleanse(secret, sizeof(secret)); 772 return ret; 773 } 774 775 int tls13_update_key(SSL *s, int sending) 776 { 777 #ifdef CHARSET_EBCDIC 778 static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00}; 779 #else 780 static const unsigned char application_traffic[] = "traffic upd"; 781 #endif 782 const EVP_MD *md = ssl_handshake_md(s); 783 size_t hashlen = EVP_MD_size(md); 784 unsigned char key[EVP_MAX_KEY_LENGTH]; 785 unsigned char *insecret, *iv; 786 unsigned char secret[EVP_MAX_MD_SIZE]; 787 EVP_CIPHER_CTX *ciph_ctx; 788 int ret = 0; 789 790 if (s->server == sending) 791 insecret = s->server_app_traffic_secret; 792 else 793 insecret = s->client_app_traffic_secret; 794 795 if (sending) { 796 s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; 797 iv = s->write_iv; 798 ciph_ctx = s->enc_write_ctx; 799 RECORD_LAYER_reset_write_sequence(&s->rlayer); 800 } else { 801 iv = s->read_iv; 802 ciph_ctx = s->enc_read_ctx; 803 RECORD_LAYER_reset_read_sequence(&s->rlayer); 804 } 805 806 if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), 807 s->s3->tmp.new_sym_enc, insecret, NULL, 808 application_traffic, 809 sizeof(application_traffic) - 1, secret, key, 810 iv, ciph_ctx)) { 811 /* SSLfatal() already called */ 812 goto err; 813 } 814 815 memcpy(insecret, secret, hashlen); 816 817 s->statem.enc_write_state = ENC_WRITE_STATE_VALID; 818 ret = 1; 819 err: 820 OPENSSL_cleanse(key, sizeof(key)); 821 OPENSSL_cleanse(secret, sizeof(secret)); 822 return ret; 823 } 824 825 int tls13_alert_code(int code) 826 { 827 /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ 828 if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) 829 return code; 830 831 return tls1_alert_code(code); 832 } 833 834 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, 835 const char *label, size_t llen, 836 const unsigned char *context, 837 size_t contextlen, int use_context) 838 { 839 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 840 #ifdef CHARSET_EBCDIC 841 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 842 #else 843 static const unsigned char exporterlabel[] = "exporter"; 844 #endif 845 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 846 const EVP_MD *md = ssl_handshake_md(s); 847 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 848 unsigned int hashsize, datalen; 849 int ret = 0; 850 851 if (ctx == NULL || !ossl_statem_export_allowed(s)) 852 goto err; 853 854 if (!use_context) 855 contextlen = 0; 856 857 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 858 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 859 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 860 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 861 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 862 || !tls13_hkdf_expand(s, md, s->exporter_master_secret, 863 (const unsigned char *)label, llen, 864 data, datalen, exportsecret, hashsize, 0) 865 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 866 sizeof(exporterlabel) - 1, hash, hashsize, 867 out, olen, 0)) 868 goto err; 869 870 ret = 1; 871 err: 872 EVP_MD_CTX_free(ctx); 873 return ret; 874 } 875 876 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, 877 const char *label, size_t llen, 878 const unsigned char *context, 879 size_t contextlen) 880 { 881 #ifdef CHARSET_EBCDIC 882 static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00}; 883 #else 884 static const unsigned char exporterlabel[] = "exporter"; 885 #endif 886 unsigned char exportsecret[EVP_MAX_MD_SIZE]; 887 unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; 888 const EVP_MD *md; 889 EVP_MD_CTX *ctx = EVP_MD_CTX_new(); 890 unsigned int hashsize, datalen; 891 int ret = 0; 892 const SSL_CIPHER *sslcipher; 893 894 if (ctx == NULL || !ossl_statem_export_early_allowed(s)) 895 goto err; 896 897 if (!s->server && s->max_early_data > 0 898 && s->session->ext.max_early_data == 0) 899 sslcipher = SSL_SESSION_get0_cipher(s->psksession); 900 else 901 sslcipher = SSL_SESSION_get0_cipher(s->session); 902 903 md = ssl_md(sslcipher->algorithm2); 904 905 /* 906 * Calculate the hash value and store it in |data|. The reason why 907 * the empty string is used is that the definition of TLS-Exporter 908 * is like so: 909 * 910 * TLS-Exporter(label, context_value, key_length) = 911 * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), 912 * "exporter", Hash(context_value), key_length) 913 * 914 * Derive-Secret(Secret, Label, Messages) = 915 * HKDF-Expand-Label(Secret, Label, 916 * Transcript-Hash(Messages), Hash.length) 917 * 918 * Here Transcript-Hash is the cipher suite hash algorithm. 919 */ 920 if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 921 || EVP_DigestUpdate(ctx, context, contextlen) <= 0 922 || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 923 || EVP_DigestInit_ex(ctx, md, NULL) <= 0 924 || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 925 || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, 926 (const unsigned char *)label, llen, 927 data, datalen, exportsecret, hashsize, 0) 928 || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, 929 sizeof(exporterlabel) - 1, hash, hashsize, 930 out, olen, 0)) 931 goto err; 932 933 ret = 1; 934 err: 935 EVP_MD_CTX_free(ctx); 936 return ret; 937 } 938