ssl/t1_enc.c

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright 2005 Nokia. All rights reserved.
   4  *
   5  * Licensed under the OpenSSL license (the "License").  You may not use
   6  * this file except in compliance with the License.  You can obtain a copy
   7  * in the file LICENSE in the source distribution or at
   8  * https://www.openssl.org/source/license.html
   9  */
  10
  11 #include <stdio.h>
  12 #include "ssl_locl.h"
  13 #include <openssl/comp.h>
  14 #include <openssl/evp.h>
  15 #include <openssl/kdf.h>
  16 #include <openssl/rand.h>
  17
  18 /* seed1 through seed5 are concatenated */
  19 static int tls1_PRF(SSL *s,
  20                     const void *seed1, size_t seed1_len,
  21                     const void *seed2, size_t seed2_len,
  22                     const void *seed3, size_t seed3_len,
  23                     const void *seed4, size_t seed4_len,
  24                     const void *seed5, size_t seed5_len,
  25                     const unsigned char *sec, size_t slen,
  26                     unsigned char *out, size_t olen)
  27 {
  28     const EVP_MD *md = ssl_prf_md(s);
  29     EVP_PKEY_CTX *pctx = NULL;
  30
  31     int ret = 0;
  32
  33     if (md == NULL) {
  34         /* Should never happen */
  35         SSLerr(SSL_F_TLS1_PRF, ERR_R_INTERNAL_ERROR);
  36         return 0;
  37     }
  38     pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_TLS1_PRF, NULL);
  39     if (pctx == NULL || EVP_PKEY_derive_init(pctx) <= 0
  40         || EVP_PKEY_CTX_set_tls1_prf_md(pctx, md) <= 0
  41         || EVP_PKEY_CTX_set1_tls1_prf_secret(pctx, sec, (int)slen) <= 0)
  42         goto err;
  43
  44     if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed1, (int)seed1_len) <= 0)
  45         goto err;
  46     if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed2, (int)seed2_len) <= 0)
  47         goto err;
  48     if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed3, (int)seed3_len) <= 0)
  49         goto err;
  50     if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed4, (int)seed4_len) <= 0)
  51         goto err;
  52     if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, seed5, (int)seed5_len) <= 0)
  53         goto err;
  54
  55     if (EVP_PKEY_derive(pctx, out, &olen) <= 0)
  56         goto err;
  57     ret = 1;
  58
  59  err:
  60     EVP_PKEY_CTX_free(pctx);
  61     return ret;
  62 }
  63
  64 static int tls1_generate_key_block(SSL *s, unsigned char *km, size_t num)
  65 {
  66     int ret;
  67     ret = tls1_PRF(s,
  68                    TLS_MD_KEY_EXPANSION_CONST,
  69                    TLS_MD_KEY_EXPANSION_CONST_SIZE, s->s3->server_random,
  70                    SSL3_RANDOM_SIZE, s->s3->client_random, SSL3_RANDOM_SIZE,
  71                    NULL, 0, NULL, 0, s->session->master_key,
  72                    s->session->master_key_length, km, num);
  73
  74     return ret;
  75 }
  76
  77 int tls1_change_cipher_state(SSL *s, int which)
  78 {
  79     unsigned char *p, *mac_secret;
  80     unsigned char tmp1[EVP_MAX_KEY_LENGTH];
  81     unsigned char tmp2[EVP_MAX_KEY_LENGTH];
  82     unsigned char iv1[EVP_MAX_IV_LENGTH * 2];
  83     unsigned char iv2[EVP_MAX_IV_LENGTH * 2];
  84     unsigned char *ms, *key, *iv;
  85     EVP_CIPHER_CTX *dd;
  86     const EVP_CIPHER *c;
  87 #ifndef OPENSSL_NO_COMP
  88     const SSL_COMP *comp;
  89 #endif
  90     const EVP_MD *m;
  91     int mac_type;
  92     size_t *mac_secret_size;
  93     EVP_MD_CTX *mac_ctx;
  94     EVP_PKEY *mac_key;
  95     size_t n, i, j, k, cl;
  96     int reuse_dd = 0;
  97
  98     c = s->s3->tmp.new_sym_enc;
  99     m = s->s3->tmp.new_hash;
 100     mac_type = s->s3->tmp.new_mac_pkey_type;
 101 #ifndef OPENSSL_NO_COMP
 102     comp = s->s3->tmp.new_compression;
 103 #endif
 104
 105     if (which & SSL3_CC_READ) {
 106         if (s->ext.use_etm)
 107             s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC_READ;
 108         else
 109             s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC_READ;
 110
 111         if (s->s3->tmp.new_cipher->algorithm2 & TLS1_STREAM_MAC)
 112             s->mac_flags |= SSL_MAC_FLAG_READ_MAC_STREAM;
 113         else
 114             s->mac_flags &= ~SSL_MAC_FLAG_READ_MAC_STREAM;
 115
 116         if (s->enc_read_ctx != NULL)
 117             reuse_dd = 1;
 118         else if ((s->enc_read_ctx = EVP_CIPHER_CTX_new()) == NULL)
 119             goto err;
 120         else
 121             /*
 122              * make sure it's initialised in case we exit later with an error
 123              */
 124             EVP_CIPHER_CTX_reset(s->enc_read_ctx);
 125         dd = s->enc_read_ctx;
 126         mac_ctx = ssl_replace_hash(&s->read_hash, NULL);
 127         if (mac_ctx == NULL)
 128             goto err;
 129 #ifndef OPENSSL_NO_COMP
 130         COMP_CTX_free(s->expand);
 131         s->expand = NULL;
 132         if (comp != NULL) {
 133             s->expand = COMP_CTX_new(comp->method);
 134             if (s->expand == NULL) {
 135                 SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE,
 136                        SSL_R_COMPRESSION_LIBRARY_ERROR);
 137                 goto err2;
 138             }
 139         }
 140 #endif
 141         /*
 142          * this is done by dtls1_reset_seq_numbers for DTLS
 143          */
 144         if (!SSL_IS_DTLS(s))
 145             RECORD_LAYER_reset_read_sequence(&s->rlayer);
 146         mac_secret = &(s->s3->read_mac_secret[0]);
 147         mac_secret_size = &(s->s3->read_mac_secret_size);
 148     } else {
 149         if (s->ext.use_etm)
 150             s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC_WRITE;
 151         else
 152             s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC_WRITE;
 153
 154         if (s->s3->tmp.new_cipher->algorithm2 & TLS1_STREAM_MAC)
 155             s->mac_flags |= SSL_MAC_FLAG_WRITE_MAC_STREAM;
 156         else
 157             s->mac_flags &= ~SSL_MAC_FLAG_WRITE_MAC_STREAM;
 158         if (s->enc_write_ctx != NULL && !SSL_IS_DTLS(s))
 159             reuse_dd = 1;
 160         else if ((s->enc_write_ctx = EVP_CIPHER_CTX_new()) == NULL)
 161             goto err;
 162         dd = s->enc_write_ctx;
 163         if (SSL_IS_DTLS(s)) {
 164             mac_ctx = EVP_MD_CTX_new();
 165             if (mac_ctx == NULL)
 166                 goto err;
 167             s->write_hash = mac_ctx;
 168         } else {
 169             mac_ctx = ssl_replace_hash(&s->write_hash, NULL);
 170             if (mac_ctx == NULL)
 171                 goto err;
 172         }
 173 #ifndef OPENSSL_NO_COMP
 174         COMP_CTX_free(s->compress);
 175         s->compress = NULL;
 176         if (comp != NULL) {
 177             s->compress = COMP_CTX_new(comp->method);
 178             if (s->compress == NULL) {
 179                 SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE,
 180                        SSL_R_COMPRESSION_LIBRARY_ERROR);
 181                 goto err2;
 182             }
 183         }
 184 #endif
 185         /*
 186          * this is done by dtls1_reset_seq_numbers for DTLS
 187          */
 188         if (!SSL_IS_DTLS(s))
 189             RECORD_LAYER_reset_write_sequence(&s->rlayer);
 190         mac_secret = &(s->s3->write_mac_secret[0]);
 191         mac_secret_size = &(s->s3->write_mac_secret_size);
 192     }
 193
 194     if (reuse_dd)
 195         EVP_CIPHER_CTX_reset(dd);
 196
 197     p = s->s3->tmp.key_block;
 198     i = *mac_secret_size = s->s3->tmp.new_mac_secret_size;
 199
 200     /* TODO(size_t): convert me */
 201     cl = EVP_CIPHER_key_length(c);
 202     j = cl;
 203     /* Was j=(exp)?5:EVP_CIPHER_key_length(c); */
 204     /* If GCM/CCM mode only part of IV comes from PRF */
 205     if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE)
 206         k = EVP_GCM_TLS_FIXED_IV_LEN;
 207     else if (EVP_CIPHER_mode(c) == EVP_CIPH_CCM_MODE)
 208         k = EVP_CCM_TLS_FIXED_IV_LEN;
 209     else
 210         k = EVP_CIPHER_iv_length(c);
 211     if ((which == SSL3_CHANGE_CIPHER_CLIENT_WRITE) ||
 212         (which == SSL3_CHANGE_CIPHER_SERVER_READ)) {
 213         ms = &(p[0]);
 214         n = i + i;
 215         key = &(p[n]);
 216         n += j + j;
 217         iv = &(p[n]);
 218         n += k + k;
 219     } else {
 220         n = i;
 221         ms = &(p[n]);
 222         n += i + j;
 223         key = &(p[n]);
 224         n += j + k;
 225         iv = &(p[n]);
 226         n += k;
 227     }
 228
 229     if (n > s->s3->tmp.key_block_length) {
 230         SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 231         goto err2;
 232     }
 233
 234     memcpy(mac_secret, ms, i);
 235
 236     if (!(EVP_CIPHER_flags(c) & EVP_CIPH_FLAG_AEAD_CIPHER)) {
 237         /* TODO(size_t): Convert this function */
 238         mac_key = EVP_PKEY_new_mac_key(mac_type, NULL,
 239                                        mac_secret, (int)*mac_secret_size);
 240         if (mac_key == NULL
 241             || EVP_DigestSignInit(mac_ctx, NULL, m, NULL, mac_key) <= 0) {
 242             EVP_PKEY_free(mac_key);
 243             SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 244             goto err2;
 245         }
 246         EVP_PKEY_free(mac_key);
 247     }
 248 #ifdef SSL_DEBUG
 249     printf("which = %04X\nmac key=", which);
 250     {
 251         size_t z;
 252         for (z = 0; z < i; z++)
 253             printf("%02X%c", ms[z], ((z + 1) % 16) ? ' ' : '\n');
 254     }
 255 #endif
 256
 257     if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE) {
 258         if (!EVP_CipherInit_ex(dd, c, NULL, key, NULL, (which & SSL3_CC_WRITE))
 259             || !EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_GCM_SET_IV_FIXED, (int)k,
 260                                     iv)) {
 261             SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 262             goto err2;
 263         }
 264     } else if (EVP_CIPHER_mode(c) == EVP_CIPH_CCM_MODE) {
 265         int taglen;
 266         if (s->s3->tmp.
 267             new_cipher->algorithm_enc & (SSL_AES128CCM8 | SSL_AES256CCM8))
 268             taglen = EVP_CCM8_TLS_TAG_LEN;
 269         else
 270             taglen = EVP_CCM_TLS_TAG_LEN;
 271         if (!EVP_CipherInit_ex(dd, c, NULL, NULL, NULL, (which & SSL3_CC_WRITE))
 272             || !EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_AEAD_SET_IVLEN, 12, NULL)
 273             || !EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_AEAD_SET_TAG, taglen, NULL)
 274             || !EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_CCM_SET_IV_FIXED, (int)k, iv)
 275             || !EVP_CipherInit_ex(dd, NULL, NULL, key, NULL, -1)) {
 276             SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 277             goto err2;
 278         }
 279     } else {
 280         if (!EVP_CipherInit_ex(dd, c, NULL, key, iv, (which & SSL3_CC_WRITE))) {
 281             SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 282             goto err2;
 283         }
 284     }
 285     /* Needed for "composite" AEADs, such as RC4-HMAC-MD5 */
 286     if ((EVP_CIPHER_flags(c) & EVP_CIPH_FLAG_AEAD_CIPHER) && *mac_secret_size
 287         && !EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_AEAD_SET_MAC_KEY,
 288                                 (int)*mac_secret_size, mac_secret)) {
 289         SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 290         goto err2;
 291     }
 292
 293 #ifdef SSL_DEBUG
 294     printf("which = %04X\nkey=", which);
 295     {
 296         int z;
 297         for (z = 0; z < EVP_CIPHER_key_length(c); z++)
 298             printf("%02X%c", key[z], ((z + 1) % 16) ? ' ' : '\n');
 299     }
 300     printf("\niv=");
 301     {
 302         size_t z;
 303         for (z = 0; z < k; z++)
 304             printf("%02X%c", iv[z], ((z + 1) % 16) ? ' ' : '\n');
 305     }
 306     printf("\n");
 307 #endif
 308
 309     OPENSSL_cleanse(tmp1, sizeof(tmp1));
 310     OPENSSL_cleanse(tmp2, sizeof(tmp1));
 311     OPENSSL_cleanse(iv1, sizeof(iv1));
 312     OPENSSL_cleanse(iv2, sizeof(iv2));
 313     return 1;
 314  err:
 315     SSLerr(SSL_F_TLS1_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 316  err2:
 317     OPENSSL_cleanse(tmp1, sizeof(tmp1));
 318     OPENSSL_cleanse(tmp2, sizeof(tmp1));
 319     OPENSSL_cleanse(iv1, sizeof(iv1));
 320     OPENSSL_cleanse(iv2, sizeof(iv2));
 321     return 0;
 322 }
 323
 324 int tls1_setup_key_block(SSL *s)
 325 {
 326     unsigned char *p;
 327     const EVP_CIPHER *c;
 328     const EVP_MD *hash;
 329     SSL_COMP *comp;
 330     int mac_type = NID_undef;
 331     size_t num, mac_secret_size = 0;
 332     int ret = 0;
 333
 334     if (s->s3->tmp.key_block_length != 0)
 335         return 1;
 336
 337     if (!ssl_cipher_get_evp(s->session, &c, &hash, &mac_type, &mac_secret_size,
 338                             &comp, s->ext.use_etm)) {
 339         SSLerr(SSL_F_TLS1_SETUP_KEY_BLOCK, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
 340         return 0;
 341     }
 342
 343     s->s3->tmp.new_sym_enc = c;
 344     s->s3->tmp.new_hash = hash;
 345     s->s3->tmp.new_mac_pkey_type = mac_type;
 346     s->s3->tmp.new_mac_secret_size = mac_secret_size;
 347     num = EVP_CIPHER_key_length(c) + mac_secret_size + EVP_CIPHER_iv_length(c);
 348     num *= 2;
 349
 350     ssl3_cleanup_key_block(s);
 351
 352     if ((p = OPENSSL_malloc(num)) == NULL) {
 353         SSLerr(SSL_F_TLS1_SETUP_KEY_BLOCK, ERR_R_MALLOC_FAILURE);
 354         goto err;
 355     }
 356
 357     s->s3->tmp.key_block_length = num;
 358     s->s3->tmp.key_block = p;
 359
 360 #ifdef SSL_DEBUG
 361     printf("client random\n");
 362     {
 363         int z;
 364         for (z = 0; z < SSL3_RANDOM_SIZE; z++)
 365             printf("%02X%c", s->s3->client_random[z],
 366                    ((z + 1) % 16) ? ' ' : '\n');
 367     }
 368     printf("server random\n");
 369     {
 370         int z;
 371         for (z = 0; z < SSL3_RANDOM_SIZE; z++)
 372             printf("%02X%c", s->s3->server_random[z],
 373                    ((z + 1) % 16) ? ' ' : '\n');
 374     }
 375     printf("master key\n");
 376     {
 377         size_t z;
 378         for (z = 0; z < s->session->master_key_length; z++)
 379             printf("%02X%c", s->session->master_key[z],
 380                    ((z + 1) % 16) ? ' ' : '\n');
 381     }
 382 #endif
 383     if (!tls1_generate_key_block(s, p, num))
 384         goto err;
 385 #ifdef SSL_DEBUG
 386     printf("\nkey block\n");
 387     {
 388         size_t z;
 389         for (z = 0; z < num; z++)
 390             printf("%02X%c", p[z], ((z + 1) % 16) ? ' ' : '\n');
 391     }
 392 #endif
 393
 394     if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS)
 395         && s->method->version <= TLS1_VERSION) {
 396         /*
 397          * enable vulnerability countermeasure for CBC ciphers with known-IV
 398          * problem (http://www.openssl.org/~bodo/tls-cbc.txt)
 399          */
 400         s->s3->need_empty_fragments = 1;
 401
 402         if (s->session->cipher != NULL) {
 403             if (s->session->cipher->algorithm_enc == SSL_eNULL)
 404                 s->s3->need_empty_fragments = 0;
 405
 406 #ifndef OPENSSL_NO_RC4
 407             if (s->session->cipher->algorithm_enc == SSL_RC4)
 408                 s->s3->need_empty_fragments = 0;
 409 #endif
 410         }
 411     }
 412
 413     ret = 1;
 414  err:
 415     return ret;
 416 }
 417
 418 size_t tls1_final_finish_mac(SSL *s, const char *str, size_t slen,
 419                              unsigned char *out)
 420 {
 421     size_t hashlen;
 422     unsigned char hash[EVP_MAX_MD_SIZE];
 423
 424     if (!ssl3_digest_cached_records(s, 0))
 425         return 0;
 426
 427     if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen))
 428         return 0;
 429
 430     if (!tls1_PRF(s, str, slen, hash, hashlen, NULL, 0, NULL, 0, NULL, 0,
 431                   s->session->master_key, s->session->master_key_length,
 432                   out, TLS1_FINISH_MAC_LENGTH))
 433         return 0;
 434     OPENSSL_cleanse(hash, hashlen);
 435     return TLS1_FINISH_MAC_LENGTH;
 436 }
 437
 438 int tls1_generate_master_secret(SSL *s, unsigned char *out, unsigned char *p,
 439                                 size_t len, size_t *secret_size)
 440 {
 441     if (s->session->flags & SSL_SESS_FLAG_EXTMS) {
 442         unsigned char hash[EVP_MAX_MD_SIZE * 2];
 443         size_t hashlen;
 444         /*
 445          * Digest cached records keeping record buffer (if present): this wont
 446          * affect client auth because we're freezing the buffer at the same
 447          * point (after client key exchange and before certificate verify)
 448          */
 449         if (!ssl3_digest_cached_records(s, 1))
 450             return 0;
 451         if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen))
 452             return 0;
 453 #ifdef SSL_DEBUG
 454         fprintf(stderr, "Handshake hashes:\n");
 455         BIO_dump_fp(stderr, (char *)hash, hashlen);
 456 #endif
 457         tls1_PRF(s,
 458                  TLS_MD_EXTENDED_MASTER_SECRET_CONST,
 459                  TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE,
 460                  hash, hashlen,
 461                  NULL, 0,
 462                  NULL, 0,
 463                  NULL, 0, p, len, out,
 464                  SSL3_MASTER_SECRET_SIZE);
 465         OPENSSL_cleanse(hash, hashlen);
 466     } else {
 467         tls1_PRF(s,
 468                  TLS_MD_MASTER_SECRET_CONST,
 469                  TLS_MD_MASTER_SECRET_CONST_SIZE,
 470                  s->s3->client_random, SSL3_RANDOM_SIZE,
 471                  NULL, 0,
 472                  s->s3->server_random, SSL3_RANDOM_SIZE,
 473                  NULL, 0, p, len, out,
 474                  SSL3_MASTER_SECRET_SIZE);
 475     }
 476 #ifdef SSL_DEBUG
 477     fprintf(stderr, "Premaster Secret:\n");
 478     BIO_dump_fp(stderr, (char *)p, len);
 479     fprintf(stderr, "Client Random:\n");
 480     BIO_dump_fp(stderr, (char *)s->s3->client_random, SSL3_RANDOM_SIZE);
 481     fprintf(stderr, "Server Random:\n");
 482     BIO_dump_fp(stderr, (char *)s->s3->server_random, SSL3_RANDOM_SIZE);
 483     fprintf(stderr, "Master Secret:\n");
 484     BIO_dump_fp(stderr, (char *)s->session->master_key,
 485                 SSL3_MASTER_SECRET_SIZE);
 486 #endif
 487
 488     *secret_size = SSL3_MASTER_SECRET_SIZE;
 489     return 1;
 490 }
 491
 492 int tls1_export_keying_material(SSL *s, unsigned char *out, size_t olen,
 493                                 const char *label, size_t llen,
 494                                 const unsigned char *context,
 495                                 size_t contextlen, int use_context)
 496 {
 497     unsigned char *val = NULL;
 498     size_t vallen = 0, currentvalpos;
 499     int rv;
 500
 501     /*
 502      * construct PRF arguments we construct the PRF argument ourself rather
 503      * than passing separate values into the TLS PRF to ensure that the
 504      * concatenation of values does not create a prohibited label.
 505      */
 506     vallen = llen + SSL3_RANDOM_SIZE * 2;
 507     if (use_context) {
 508         vallen += 2 + contextlen;
 509     }
 510
 511     val = OPENSSL_malloc(vallen);
 512     if (val == NULL)
 513         goto err2;
 514     currentvalpos = 0;
 515     memcpy(val + currentvalpos, (unsigned char *)label, llen);
 516     currentvalpos += llen;
 517     memcpy(val + currentvalpos, s->s3->client_random, SSL3_RANDOM_SIZE);
 518     currentvalpos += SSL3_RANDOM_SIZE;
 519     memcpy(val + currentvalpos, s->s3->server_random, SSL3_RANDOM_SIZE);
 520     currentvalpos += SSL3_RANDOM_SIZE;
 521
 522     if (use_context) {
 523         val[currentvalpos] = (contextlen >> 8) & 0xff;
 524         currentvalpos++;
 525         val[currentvalpos] = contextlen & 0xff;
 526         currentvalpos++;
 527         if ((contextlen > 0) || (context != NULL)) {
 528             memcpy(val + currentvalpos, context, contextlen);
 529         }
 530     }
 531
 532     /*
 533      * disallow prohibited labels note that SSL3_RANDOM_SIZE > max(prohibited
 534      * label len) = 15, so size of val > max(prohibited label len) = 15 and
 535      * the comparisons won't have buffer overflow
 536      */
 537     if (memcmp(val, TLS_MD_CLIENT_FINISH_CONST,
 538                TLS_MD_CLIENT_FINISH_CONST_SIZE) == 0)
 539         goto err1;
 540     if (memcmp(val, TLS_MD_SERVER_FINISH_CONST,
 541                TLS_MD_SERVER_FINISH_CONST_SIZE) == 0)
 542         goto err1;
 543     if (memcmp(val, TLS_MD_MASTER_SECRET_CONST,
 544                TLS_MD_MASTER_SECRET_CONST_SIZE) == 0)
 545         goto err1;
 546     if (memcmp(val, TLS_MD_EXTENDED_MASTER_SECRET_CONST,
 547                TLS_MD_EXTENDED_MASTER_SECRET_CONST_SIZE) == 0)
 548         goto err1;
 549     if (memcmp(val, TLS_MD_KEY_EXPANSION_CONST,
 550                TLS_MD_KEY_EXPANSION_CONST_SIZE) == 0)
 551         goto err1;
 552
 553     rv = tls1_PRF(s,
 554                   val, vallen,
 555                   NULL, 0,
 556                   NULL, 0,
 557                   NULL, 0,
 558                   NULL, 0,
 559                   s->session->master_key, s->session->master_key_length,
 560                   out, olen);
 561
 562     goto ret;
 563  err1:
 564     SSLerr(SSL_F_TLS1_EXPORT_KEYING_MATERIAL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
 565     rv = 0;
 566     goto ret;
 567  err2:
 568     SSLerr(SSL_F_TLS1_EXPORT_KEYING_MATERIAL, ERR_R_MALLOC_FAILURE);
 569     rv = 0;
 570  ret:
 571     OPENSSL_clear_free(val, vallen);
 572     return rv;
 573 }
 574
 575 int tls1_alert_code(int code)
 576 {
 577     switch (code) {
 578     case SSL_AD_CLOSE_NOTIFY:
 579         return SSL3_AD_CLOSE_NOTIFY;
 580     case SSL_AD_UNEXPECTED_MESSAGE:
 581         return SSL3_AD_UNEXPECTED_MESSAGE;
 582     case SSL_AD_BAD_RECORD_MAC:
 583         return SSL3_AD_BAD_RECORD_MAC;
 584     case SSL_AD_DECRYPTION_FAILED:
 585         return TLS1_AD_DECRYPTION_FAILED;
 586     case SSL_AD_RECORD_OVERFLOW:
 587         return TLS1_AD_RECORD_OVERFLOW;
 588     case SSL_AD_DECOMPRESSION_FAILURE:
 589         return SSL3_AD_DECOMPRESSION_FAILURE;
 590     case SSL_AD_HANDSHAKE_FAILURE:
 591         return SSL3_AD_HANDSHAKE_FAILURE;
 592     case SSL_AD_NO_CERTIFICATE:
 593         return -1;
 594     case SSL_AD_BAD_CERTIFICATE:
 595         return SSL3_AD_BAD_CERTIFICATE;
 596     case SSL_AD_UNSUPPORTED_CERTIFICATE:
 597         return SSL3_AD_UNSUPPORTED_CERTIFICATE;
 598     case SSL_AD_CERTIFICATE_REVOKED:
 599         return SSL3_AD_CERTIFICATE_REVOKED;
 600     case SSL_AD_CERTIFICATE_EXPIRED:
 601         return SSL3_AD_CERTIFICATE_EXPIRED;
 602     case SSL_AD_CERTIFICATE_UNKNOWN:
 603         return SSL3_AD_CERTIFICATE_UNKNOWN;
 604     case SSL_AD_ILLEGAL_PARAMETER:
 605         return SSL3_AD_ILLEGAL_PARAMETER;
 606     case SSL_AD_UNKNOWN_CA:
 607         return TLS1_AD_UNKNOWN_CA;
 608     case SSL_AD_ACCESS_DENIED:
 609         return TLS1_AD_ACCESS_DENIED;
 610     case SSL_AD_DECODE_ERROR:
 611         return TLS1_AD_DECODE_ERROR;
 612     case SSL_AD_DECRYPT_ERROR:
 613         return TLS1_AD_DECRYPT_ERROR;
 614     case SSL_AD_EXPORT_RESTRICTION:
 615         return TLS1_AD_EXPORT_RESTRICTION;
 616     case SSL_AD_PROTOCOL_VERSION:
 617         return TLS1_AD_PROTOCOL_VERSION;
 618     case SSL_AD_INSUFFICIENT_SECURITY:
 619         return TLS1_AD_INSUFFICIENT_SECURITY;
 620     case SSL_AD_INTERNAL_ERROR:
 621         return TLS1_AD_INTERNAL_ERROR;
 622     case SSL_AD_USER_CANCELLED:
 623         return TLS1_AD_USER_CANCELLED;
 624     case SSL_AD_NO_RENEGOTIATION:
 625         return TLS1_AD_NO_RENEGOTIATION;
 626     case SSL_AD_UNSUPPORTED_EXTENSION:
 627         return TLS1_AD_UNSUPPORTED_EXTENSION;
 628     case SSL_AD_CERTIFICATE_UNOBTAINABLE:
 629         return TLS1_AD_CERTIFICATE_UNOBTAINABLE;
 630     case SSL_AD_UNRECOGNIZED_NAME:
 631         return TLS1_AD_UNRECOGNIZED_NAME;
 632     case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE:
 633         return TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
 634     case SSL_AD_BAD_CERTIFICATE_HASH_VALUE:
 635         return TLS1_AD_BAD_CERTIFICATE_HASH_VALUE;
 636     case SSL_AD_UNKNOWN_PSK_IDENTITY:
 637         return TLS1_AD_UNKNOWN_PSK_IDENTITY;
 638     case SSL_AD_INAPPROPRIATE_FALLBACK:
 639         return TLS1_AD_INAPPROPRIATE_FALLBACK;
 640     case SSL_AD_NO_APPLICATION_PROTOCOL:
 641         return TLS1_AD_NO_APPLICATION_PROTOCOL;
 642     case SSL_AD_CERTIFICATE_REQUIRED:
 643         return SSL_AD_HANDSHAKE_FAILURE;
 644     default:
 645         return -1;
 646     }
 647 }