ssl/tls13_enc.c

   1 /*
   2  * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdlib.h>
  11 #include "ssl_locl.h"
  12 #include <openssl/evp.h>
  13 #include <openssl/kdf.h>
  14
  15 #define TLS13_MAX_LABEL_LEN     246
  16
  17 /* Always filled with zeros */
  18 static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
  19
  20 /*
  21  * Given a |secret|; a |label| of length |labellen|; and a |hash| of the
  22  * handshake messages, derive a new secret |outlen| bytes long and store it in
  23  * the location pointed to be |out|. The |hash| value may be NULL. Returns 1 on
  24  * success  0 on failure.
  25  */
  26 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
  27                              const unsigned char *label, size_t labellen,
  28                              const unsigned char *hash,
  29                              unsigned char *out, size_t outlen)
  30 {
  31     const unsigned char label_prefix[] = "TLS 1.3, ";
  32     EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
  33     int ret;
  34     size_t hkdflabellen;
  35     size_t hashlen;
  36     /*
  37      * 2 bytes for length of whole HkdfLabel + 1 byte for length of combined
  38      * prefix and label + bytes for the label itself + bytes for the hash
  39      */
  40     unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) +
  41                             + sizeof(label_prefix) + TLS13_MAX_LABEL_LEN
  42                             + EVP_MAX_MD_SIZE];
  43     WPACKET pkt;
  44
  45     if (pctx == NULL)
  46         return 0;
  47
  48     hashlen = EVP_MD_size(md);
  49
  50     if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
  51             || !WPACKET_put_bytes_u16(&pkt, outlen)
  52             || !WPACKET_start_sub_packet_u8(&pkt)
  53             || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
  54             || !WPACKET_memcpy(&pkt, label, labellen)
  55             || !WPACKET_close(&pkt)
  56             || !WPACKET_sub_memcpy_u8(&pkt, hash, (hash == NULL) ? 0 : hashlen)
  57             || !WPACKET_get_total_written(&pkt, &hkdflabellen)
  58             || !WPACKET_finish(&pkt)) {
  59         EVP_PKEY_CTX_free(pctx);
  60         WPACKET_cleanup(&pkt);
  61         return 0;
  62     }
  63
  64     ret = EVP_PKEY_derive_init(pctx) <= 0
  65             || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY)
  66                <= 0
  67             || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
  68             || EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0
  69             || EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0
  70             || EVP_PKEY_derive(pctx, out, &outlen) <= 0;
  71
  72     EVP_PKEY_CTX_free(pctx);
  73
  74     return ret == 0;
  75 }
  76
  77 /*
  78  * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
  79  * success  0 on failure.
  80  */
  81 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
  82                      unsigned char *key, size_t keylen)
  83 {
  84     static const unsigned char keylabel[] = "key";
  85
  86     return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
  87                              NULL, key, keylen);
  88 }
  89
  90 /*
  91  * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
  92  * success  0 on failure.
  93  */
  94 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
  95                     unsigned char *iv, size_t ivlen)
  96 {
  97     static const unsigned char ivlabel[] = "iv";
  98
  99     return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
 100                              NULL, iv, ivlen);
 101 }
 102
 103 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
 104                              const unsigned char *secret,
 105                              unsigned char *fin, size_t finlen)
 106 {
 107     static const unsigned char finishedlabel[] = "finished";
 108
 109     return tls13_hkdf_expand(s, md, secret, finishedlabel,
 110                              sizeof(finishedlabel) - 1, NULL, fin, finlen);
 111 }
 112
 113 /*
 114  * Given the previous secret |prevsecret| and a new input secret |insecret| of
 115  * length |insecretlen|, generate a new secret and store it in the location
 116  * pointed to by |outsecret|. Returns 1 on success  0 on failure.
 117  */
 118 int tls13_generate_secret(SSL *s, const EVP_MD *md,
 119                           const unsigned char *prevsecret,
 120                           const unsigned char *insecret,
 121                           size_t insecretlen,
 122                           unsigned char *outsecret)
 123 {
 124     size_t mdlen, prevsecretlen;
 125     int ret;
 126     EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
 127
 128     if (pctx == NULL)
 129         return 0;
 130
 131     mdlen = EVP_MD_size(md);
 132
 133     if (insecret == NULL) {
 134         insecret = default_zeros;
 135         insecretlen = mdlen;
 136     }
 137     if (prevsecret == NULL) {
 138         prevsecret = default_zeros;
 139         prevsecretlen = 0;
 140     } else {
 141         prevsecretlen = mdlen;
 142     }
 143
 144     ret = EVP_PKEY_derive_init(pctx) <= 0
 145             || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY)
 146                <= 0
 147             || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0
 148             || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0
 149             || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen)
 150                <= 0
 151             || EVP_PKEY_derive(pctx, outsecret, &mdlen)
 152                <= 0;
 153
 154     EVP_PKEY_CTX_free(pctx);
 155     return ret == 0;
 156 }
 157
 158 /*
 159  * Given an input secret |insecret| of length |insecretlen| generate the
 160  * handshake secret. This requires the early secret to already have been
 161  * generated. Returns 1 on success  0 on failure.
 162  */
 163 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
 164                                 size_t insecretlen)
 165 {
 166     return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
 167                                  insecret, insecretlen,
 168                                  (unsigned char *)&s->handshake_secret);
 169 }
 170
 171 /*
 172  * Given the handshake secret |prev| of length |prevlen| generate the master
 173  * secret and store its length in |*secret_size|. Returns 1 on success  0 on
 174  * failure.
 175  */
 176 int tls13_generate_master_secret(SSL *s, unsigned char *out,
 177                                  unsigned char *prev, size_t prevlen,
 178                                  size_t *secret_size)
 179 {
 180     const EVP_MD *md = ssl_handshake_md(s);
 181
 182     *secret_size = EVP_MD_size(md);
 183     return tls13_generate_secret(s, md, prev, NULL, 0, out);
 184 }
 185
 186 /*
 187  * Generates the mac for the Finished message. Returns the length of the MAC or
 188  * 0 on error.
 189  */
 190 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
 191                              unsigned char *out)
 192 {
 193     const EVP_MD *md = ssl_handshake_md(s);
 194     unsigned char hash[EVP_MAX_MD_SIZE];
 195     size_t hashlen, ret = 0;
 196     EVP_PKEY *key = NULL;
 197     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 198
 199     if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen))
 200         goto err;
 201
 202     if (str == s->method->ssl3_enc->server_finished_label)
 203         key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL,
 204                                    s->server_finished_secret, hashlen);
 205     else
 206         key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL,
 207                                    s->client_finished_secret, hashlen);
 208
 209     if (key == NULL
 210             || ctx == NULL
 211             || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0
 212             || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0
 213             || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0)
 214         goto err;
 215
 216     ret = hashlen;
 217  err:
 218     EVP_PKEY_free(key);
 219     EVP_MD_CTX_free(ctx);
 220     return ret;
 221 }
 222
 223 /*
 224  * There isn't really a key block in TLSv1.3, but we still need this function
 225  * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
 226  */
 227 int tls13_setup_key_block(SSL *s)
 228 {
 229     const EVP_CIPHER *c;
 230     const EVP_MD *hash;
 231     int mac_type = NID_undef;
 232
 233     s->session->cipher = s->s3->tmp.new_cipher;
 234     if (!ssl_cipher_get_evp
 235         (s->session, &c, &hash, &mac_type, NULL, NULL, 0)) {
 236         SSLerr(SSL_F_TLS13_SETUP_KEY_BLOCK, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
 237         return 0;
 238     }
 239
 240     s->s3->tmp.new_sym_enc = c;
 241     s->s3->tmp.new_hash = hash;
 242
 243     return 1;
 244 }
 245
 246 static int derive_secret_key_and_iv(SSL *s, int send, const EVP_MD *md,
 247                                     const EVP_CIPHER *ciph,
 248                                     const unsigned char *insecret,
 249                                     const unsigned char *hash,
 250                                     const unsigned char *label,
 251                                     size_t labellen, unsigned char *secret,
 252                                     unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx)
 253 {
 254     unsigned char key[EVP_MAX_KEY_LENGTH];
 255     size_t ivlen, keylen, taglen;
 256     size_t hashlen = EVP_MD_size(md);
 257
 258     if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, secret,
 259                            hashlen)) {
 260         SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR);
 261         goto err;
 262     }
 263
 264     /* TODO(size_t): convert me */
 265     keylen = EVP_CIPHER_key_length(ciph);
 266     if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
 267         uint32_t algenc;
 268
 269         ivlen = EVP_CCM_TLS_IV_LEN;
 270         if (s->s3->tmp.new_cipher == NULL) {
 271             /* We've not selected a cipher yet - we must be doing early data */
 272             algenc = s->session->cipher->algorithm_enc;
 273         } else {
 274             algenc = s->s3->tmp.new_cipher->algorithm_enc;
 275         }
 276         if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
 277             taglen = EVP_CCM8_TLS_TAG_LEN;
 278          else
 279             taglen = EVP_CCM_TLS_TAG_LEN;
 280     } else {
 281         ivlen = EVP_CIPHER_iv_length(ciph);
 282         taglen = 0;
 283     }
 284
 285     if (!tls13_derive_key(s, md, secret, key, keylen)
 286             || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
 287         SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR);
 288         goto err;
 289     }
 290
 291     if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, send) <= 0
 292         || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
 293         || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
 294                                                 taglen, NULL))
 295         || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
 296         SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_EVP_LIB);
 297         goto err;
 298     }
 299
 300 #ifdef OPENSSL_SSL_TRACE_CRYPTO
 301     if (s->msg_callback) {
 302         int wh = send ? TLS1_RT_CRYPTO_WRITE : 0;
 303
 304         if (ciph->key_len)
 305             s->msg_callback(2, s->version, wh | TLS1_RT_CRYPTO_KEY,
 306                             key, ciph->key_len, s, s->msg_callback_arg);
 307
 308         wh |= TLS1_RT_CRYPTO_IV;
 309         s->msg_callback(2, s->version, wh, iv, ivlen, s,
 310                         s->msg_callback_arg);
 311     }
 312 #endif
 313
 314     return 1;
 315  err:
 316     OPENSSL_cleanse(key, sizeof(key));
 317     return 0;
 318 }
 319
 320 int tls13_change_cipher_state(SSL *s, int which)
 321 {
 322     static const unsigned char client_early_traffic[] =
 323         "client early traffic secret";
 324     static const unsigned char client_handshake_traffic[] =
 325         "client handshake traffic secret";
 326     static const unsigned char client_application_traffic[] =
 327         "client application traffic secret";
 328     static const unsigned char server_handshake_traffic[] =
 329         "server handshake traffic secret";
 330     static const unsigned char server_application_traffic[] =
 331         "server application traffic secret";
 332     static const unsigned char resumption_master_secret[] =
 333         "resumption master secret";
 334     unsigned char *iv;
 335     unsigned char secret[EVP_MAX_MD_SIZE];
 336     unsigned char hashval[EVP_MAX_MD_SIZE];
 337     unsigned char *hash = hashval;
 338     unsigned char *insecret;
 339     unsigned char *finsecret = NULL;
 340     const char *log_label = NULL;
 341     EVP_CIPHER_CTX *ciph_ctx;
 342     size_t finsecretlen = 0;
 343     const unsigned char *label;
 344     size_t labellen, hashlen = 0;
 345     int ret = 0;
 346     const EVP_MD *md = NULL;
 347     const EVP_CIPHER *cipher = NULL;
 348
 349     if (which & SSL3_CC_READ) {
 350         if (s->enc_read_ctx != NULL) {
 351             EVP_CIPHER_CTX_reset(s->enc_read_ctx);
 352         } else {
 353             s->enc_read_ctx = EVP_CIPHER_CTX_new();
 354             if (s->enc_read_ctx == NULL) {
 355                 SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 356                 goto err;
 357             }
 358         }
 359         ciph_ctx = s->enc_read_ctx;
 360         iv = s->read_iv;
 361
 362         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 363     } else {
 364         if (s->enc_write_ctx != NULL) {
 365             EVP_CIPHER_CTX_reset(s->enc_write_ctx);
 366         } else {
 367             s->enc_write_ctx = EVP_CIPHER_CTX_new();
 368             if (s->enc_write_ctx == NULL) {
 369                 SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 370                 goto err;
 371             }
 372         }
 373         ciph_ctx = s->enc_write_ctx;
 374         iv = s->write_iv;
 375
 376         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 377     }
 378
 379     if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
 380             || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
 381         if (which & SSL3_CC_EARLY) {
 382             EVP_MD_CTX *mdctx = NULL;
 383             long handlen;
 384             void *hdata;
 385             unsigned int hashlenui;
 386             const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
 387
 388             insecret = s->early_secret;
 389             label = client_early_traffic;
 390             labellen = sizeof(client_early_traffic) - 1;
 391             log_label = CLIENT_EARLY_LABEL;
 392
 393             handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
 394             if (handlen <= 0) {
 395                 SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE,
 396                        SSL_R_BAD_HANDSHAKE_LENGTH);
 397                 goto err;
 398             }
 399             if (sslcipher == NULL) {
 400                 SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 401                 goto err;
 402             }
 403
 404             /*
 405              * We need to calculate the handshake digest using the digest from
 406              * the session. We haven't yet selected our ciphersuite so we can't
 407              * use ssl_handshake_md().
 408              */
 409             mdctx = EVP_MD_CTX_new();
 410             if (mdctx == NULL) {
 411                 SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 412                 goto err;
 413             }
 414             cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
 415             md = ssl_md(sslcipher->algorithm2);
 416             if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
 417                     || !EVP_DigestUpdate(mdctx, hdata, handlen)
 418                     || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
 419                 SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 420                 EVP_MD_CTX_free(mdctx);
 421                 goto err;
 422             }
 423             hashlen = hashlenui;
 424             EVP_MD_CTX_free(mdctx);
 425         } else if (which & SSL3_CC_HANDSHAKE) {
 426             insecret = s->handshake_secret;
 427             finsecret = s->client_finished_secret;
 428             finsecretlen = EVP_MD_size(ssl_handshake_md(s));
 429             label = client_handshake_traffic;
 430             labellen = sizeof(client_handshake_traffic) - 1;
 431             log_label = CLIENT_HANDSHAKE_LABEL;
 432             /*
 433              * The hanshake hash used for the server read/client write handshake
 434              * traffic secret is the same as the hash for the server
 435              * write/client read handshake traffic secret. However, if we
 436              * processed early data then we delay changing the server
 437              * read/client write cipher state until later, and the handshake
 438              * hashes have moved on. Therefore we use the value saved earlier
 439              * when we did the server write/client read change cipher state.
 440              */
 441             hash = s->handshake_traffic_hash;
 442         } else {
 443             insecret = s->master_secret;
 444             label = client_application_traffic;
 445             labellen = sizeof(client_application_traffic) - 1;
 446             log_label = CLIENT_APPLICATION_LABEL;
 447             /*
 448              * For this we only use the handshake hashes up until the server
 449              * Finished hash. We do not include the client's Finished, which is
 450              * what ssl_handshake_hash() would give us. Instead we use the
 451              * previously saved value.
 452              */
 453             hash = s->server_finished_hash;
 454         }
 455     } else {
 456         /* Early data never applies to client-read/server-write */
 457         if (which & SSL3_CC_HANDSHAKE) {
 458             insecret = s->handshake_secret;
 459             finsecret = s->server_finished_secret;
 460             finsecretlen = EVP_MD_size(ssl_handshake_md(s));
 461             label = server_handshake_traffic;
 462             labellen = sizeof(server_handshake_traffic) - 1;
 463             log_label = SERVER_HANDSHAKE_LABEL;
 464         } else {
 465             insecret = s->master_secret;
 466             label = server_application_traffic;
 467             labellen = sizeof(server_application_traffic) - 1;
 468             log_label = SERVER_APPLICATION_LABEL;
 469         }
 470     }
 471
 472     if (!(which & SSL3_CC_EARLY)) {
 473         md = ssl_handshake_md(s);
 474         cipher = s->s3->tmp.new_sym_enc;
 475         if (!ssl3_digest_cached_records(s, 1)
 476                 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
 477             SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 478             goto err;
 479         }
 480     }
 481
 482     /*
 483      * Save the hash of handshakes up to now for use when we calculate the
 484      * client application traffic secret
 485      */
 486     if (label == server_application_traffic)
 487         memcpy(s->server_finished_hash, hashval, hashlen);
 488
 489     if (label == server_handshake_traffic)
 490         memcpy(s->handshake_traffic_hash, hashval, hashlen);
 491
 492     if (label == client_application_traffic) {
 493         /*
 494          * We also create the resumption master secret, but this time use the
 495          * hash for the whole handshake including the Client Finished
 496          */
 497         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 498                                resumption_master_secret,
 499                                sizeof(resumption_master_secret) - 1,
 500                                hashval, s->session->master_key, hashlen)) {
 501             SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 502             goto err;
 503         }
 504         s->session->master_key_length = hashlen;
 505     }
 506
 507     if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
 508                                   insecret, hash, label, labellen, secret, iv,
 509                                   ciph_ctx)) {
 510         goto err;
 511     }
 512
 513     if (label == server_application_traffic)
 514         memcpy(s->server_app_traffic_secret, secret, hashlen);
 515     else if (label == client_application_traffic)
 516         memcpy(s->client_app_traffic_secret, secret, hashlen);
 517
 518     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
 519         SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 520         goto err;
 521     }
 522
 523     if (finsecret != NULL
 524             && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
 525                                          finsecret, finsecretlen)) {
 526         SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 527         goto err;
 528     }
 529
 530     ret = 1;
 531  err:
 532     OPENSSL_cleanse(secret, sizeof(secret));
 533     return ret;
 534 }
 535
 536 int tls13_update_key(SSL *s, int send)
 537 {
 538     static const unsigned char application_traffic[] =
 539         "application traffic secret";
 540     const EVP_MD *md = ssl_handshake_md(s);
 541     size_t hashlen = EVP_MD_size(md);
 542     unsigned char *insecret, *iv;
 543     unsigned char secret[EVP_MAX_MD_SIZE];
 544     EVP_CIPHER_CTX *ciph_ctx;
 545     int ret = 0;
 546
 547     if (s->server == send)
 548         insecret = s->server_app_traffic_secret;
 549     else
 550         insecret = s->client_app_traffic_secret;
 551
 552     if (send) {
 553         iv = s->write_iv;
 554         ciph_ctx = s->enc_write_ctx;
 555         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 556     } else {
 557         iv = s->read_iv;
 558         ciph_ctx = s->enc_read_ctx;
 559         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 560     }
 561
 562     if (!derive_secret_key_and_iv(s, send, ssl_handshake_md(s),
 563                                   s->s3->tmp.new_sym_enc, insecret, NULL,
 564                                   application_traffic,
 565                                   sizeof(application_traffic) - 1, secret, iv,
 566                                   ciph_ctx))
 567         goto err;
 568
 569     memcpy(insecret, secret, hashlen);
 570
 571     ret = 1;
 572  err:
 573     OPENSSL_cleanse(secret, sizeof(secret));
 574     return ret;
 575 }
 576
 577 int tls13_alert_code(int code)
 578 {
 579     if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_END_OF_EARLY_DATA)
 580         return code;
 581
 582     return tls1_alert_code(code);
 583 }