ssl/s3_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/evp.h>
  14 #include <openssl/md5.h>
  15
  16 static int ssl3_generate_key_block(SSL *s, unsigned char *km, int num)
  17 {
  18     EVP_MD_CTX *m5;
  19     EVP_MD_CTX *s1;
  20     unsigned char buf[16], smd[SHA_DIGEST_LENGTH];
  21     unsigned char c = 'A';
  22     unsigned int i, j, k;
  23     int ret = 0;
  24
  25 #ifdef CHARSET_EBCDIC
  26     c = os_toascii[c];          /* 'A' in ASCII */
  27 #endif
  28     k = 0;
  29     m5 = EVP_MD_CTX_new();
  30     s1 = EVP_MD_CTX_new();
  31     if (m5 == NULL || s1 == NULL) {
  32         SSLerr(SSL_F_SSL3_GENERATE_KEY_BLOCK, ERR_R_MALLOC_FAILURE);
  33         goto err;
  34     }
  35     EVP_MD_CTX_set_flags(m5, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
  36     for (i = 0; (int)i < num; i += MD5_DIGEST_LENGTH) {
  37         k++;
  38         if (k > sizeof(buf)) {
  39             /* bug: 'buf' is too small for this ciphersuite */
  40             SSLerr(SSL_F_SSL3_GENERATE_KEY_BLOCK, ERR_R_INTERNAL_ERROR);
  41             goto err;
  42         }
  43
  44         for (j = 0; j < k; j++)
  45             buf[j] = c;
  46         c++;
  47         if (!EVP_DigestInit_ex(s1, EVP_sha1(), NULL)
  48             || !EVP_DigestUpdate(s1, buf, k)
  49             || !EVP_DigestUpdate(s1, s->session->master_key,
  50                                  s->session->master_key_length)
  51             || !EVP_DigestUpdate(s1, s->s3->server_random, SSL3_RANDOM_SIZE)
  52             || !EVP_DigestUpdate(s1, s->s3->client_random, SSL3_RANDOM_SIZE)
  53             || !EVP_DigestFinal_ex(s1, smd, NULL)
  54             || !EVP_DigestInit_ex(m5, EVP_md5(), NULL)
  55             || !EVP_DigestUpdate(m5, s->session->master_key,
  56                                  s->session->master_key_length)
  57             || !EVP_DigestUpdate(m5, smd, SHA_DIGEST_LENGTH))
  58             goto err;
  59         if ((int)(i + MD5_DIGEST_LENGTH) > num) {
  60             if (!EVP_DigestFinal_ex(m5, smd, NULL))
  61                 goto err;
  62             memcpy(km, smd, (num - i));
  63         } else {
  64             if (!EVP_DigestFinal_ex(m5, km, NULL))
  65                 goto err;
  66         }
  67
  68         km += MD5_DIGEST_LENGTH;
  69     }
  70     OPENSSL_cleanse(smd, sizeof(smd));
  71     ret = 1;
  72  err:
  73     EVP_MD_CTX_free(m5);
  74     EVP_MD_CTX_free(s1);
  75     return ret;
  76 }
  77
  78 int ssl3_change_cipher_state(SSL *s, int which)
  79 {
  80     unsigned char *p, *mac_secret;
  81     unsigned char exp_key[EVP_MAX_KEY_LENGTH];
  82     unsigned char exp_iv[EVP_MAX_IV_LENGTH];
  83     unsigned char *ms, *key, *iv;
  84     EVP_CIPHER_CTX *dd;
  85     const EVP_CIPHER *c;
  86 #ifndef OPENSSL_NO_COMP
  87     COMP_METHOD *comp;
  88 #endif
  89     const EVP_MD *m;
  90     int mdi;
  91     size_t n, i, j, k, cl;
  92     int reuse_dd = 0;
  93
  94     c = s->s3->tmp.new_sym_enc;
  95     m = s->s3->tmp.new_hash;
  96     /* m == NULL will lead to a crash later */
  97     if (!ossl_assert(m != NULL)) {
  98         SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
  99         goto err2;
 100     }
 101 #ifndef OPENSSL_NO_COMP
 102     if (s->s3->tmp.new_compression == NULL)
 103         comp = NULL;
 104     else
 105         comp = s->s3->tmp.new_compression->method;
 106 #endif
 107
 108     if (which & SSL3_CC_READ) {
 109         if (s->enc_read_ctx != NULL)
 110             reuse_dd = 1;
 111         else if ((s->enc_read_ctx = EVP_CIPHER_CTX_new()) == NULL)
 112             goto err;
 113         else
 114             /*
 115              * make sure it's initialised in case we exit later with an error
 116              */
 117             EVP_CIPHER_CTX_reset(s->enc_read_ctx);
 118         dd = s->enc_read_ctx;
 119
 120         if (ssl_replace_hash(&s->read_hash, m) == NULL) {
 121             SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 122             goto err2;
 123         }
 124 #ifndef OPENSSL_NO_COMP
 125         /* COMPRESS */
 126         COMP_CTX_free(s->expand);
 127         s->expand = NULL;
 128         if (comp != NULL) {
 129             s->expand = COMP_CTX_new(comp);
 130             if (s->expand == NULL) {
 131                 SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,
 132                        SSL_R_COMPRESSION_LIBRARY_ERROR);
 133                 goto err2;
 134             }
 135         }
 136 #endif
 137         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 138         mac_secret = &(s->s3->read_mac_secret[0]);
 139     } else {
 140         if (s->enc_write_ctx != NULL)
 141             reuse_dd = 1;
 142         else if ((s->enc_write_ctx = EVP_CIPHER_CTX_new()) == NULL)
 143             goto err;
 144         else
 145             /*
 146              * make sure it's initialised in case we exit later with an error
 147              */
 148             EVP_CIPHER_CTX_reset(s->enc_write_ctx);
 149         dd = s->enc_write_ctx;
 150         if (ssl_replace_hash(&s->write_hash, m) == NULL) {
 151             SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 152             goto err2;
 153         }
 154 #ifndef OPENSSL_NO_COMP
 155         /* COMPRESS */
 156         COMP_CTX_free(s->compress);
 157         s->compress = NULL;
 158         if (comp != NULL) {
 159             s->compress = COMP_CTX_new(comp);
 160             if (s->compress == NULL) {
 161                 SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,
 162                        SSL_R_COMPRESSION_LIBRARY_ERROR);
 163                 goto err2;
 164             }
 165         }
 166 #endif
 167         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 168         mac_secret = &(s->s3->write_mac_secret[0]);
 169     }
 170
 171     if (reuse_dd)
 172         EVP_CIPHER_CTX_reset(dd);
 173
 174     p = s->s3->tmp.key_block;
 175     mdi = EVP_MD_size(m);
 176     if (mdi < 0)
 177         goto err2;
 178     i = mdi;
 179     cl = EVP_CIPHER_key_length(c);
 180     j = cl;
 181     k = EVP_CIPHER_iv_length(c);
 182     if ((which == SSL3_CHANGE_CIPHER_CLIENT_WRITE) ||
 183         (which == SSL3_CHANGE_CIPHER_SERVER_READ)) {
 184         ms = &(p[0]);
 185         n = i + i;
 186         key = &(p[n]);
 187         n += j + j;
 188         iv = &(p[n]);
 189         n += k + k;
 190     } else {
 191         n = i;
 192         ms = &(p[n]);
 193         n += i + j;
 194         key = &(p[n]);
 195         n += j + k;
 196         iv = &(p[n]);
 197         n += k;
 198     }
 199
 200     if (n > s->s3->tmp.key_block_length) {
 201         SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 202         goto err2;
 203     }
 204
 205     memcpy(mac_secret, ms, i);
 206
 207     if (!EVP_CipherInit_ex(dd, c, NULL, key, iv, (which & SSL3_CC_WRITE)))
 208         goto err2;
 209
 210     OPENSSL_cleanse(exp_key, sizeof(exp_key));
 211     OPENSSL_cleanse(exp_iv, sizeof(exp_iv));
 212     return (1);
 213  err:
 214     SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 215  err2:
 216     OPENSSL_cleanse(exp_key, sizeof(exp_key));
 217     OPENSSL_cleanse(exp_iv, sizeof(exp_iv));
 218     return (0);
 219 }
 220
 221 int ssl3_setup_key_block(SSL *s)
 222 {
 223     unsigned char *p;
 224     const EVP_CIPHER *c;
 225     const EVP_MD *hash;
 226     int num;
 227     int ret = 0;
 228     SSL_COMP *comp;
 229
 230     if (s->s3->tmp.key_block_length != 0)
 231         return (1);
 232
 233     if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, &comp, 0)) {
 234         SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
 235         return (0);
 236     }
 237
 238     s->s3->tmp.new_sym_enc = c;
 239     s->s3->tmp.new_hash = hash;
 240 #ifdef OPENSSL_NO_COMP
 241     s->s3->tmp.new_compression = NULL;
 242 #else
 243     s->s3->tmp.new_compression = comp;
 244 #endif
 245
 246     num = EVP_MD_size(hash);
 247     if (num < 0)
 248         return 0;
 249
 250     num = EVP_CIPHER_key_length(c) + num + EVP_CIPHER_iv_length(c);
 251     num *= 2;
 252
 253     ssl3_cleanup_key_block(s);
 254
 255     if ((p = OPENSSL_malloc(num)) == NULL)
 256         goto err;
 257
 258     s->s3->tmp.key_block_length = num;
 259     s->s3->tmp.key_block = p;
 260
 261     ret = ssl3_generate_key_block(s, p, num);
 262
 263     if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS)) {
 264         /*
 265          * enable vulnerability countermeasure for CBC ciphers with known-IV
 266          * problem (http://www.openssl.org/~bodo/tls-cbc.txt)
 267          */
 268         s->s3->need_empty_fragments = 1;
 269
 270         if (s->session->cipher != NULL) {
 271             if (s->session->cipher->algorithm_enc == SSL_eNULL)
 272                 s->s3->need_empty_fragments = 0;
 273
 274 #ifndef OPENSSL_NO_RC4
 275             if (s->session->cipher->algorithm_enc == SSL_RC4)
 276                 s->s3->need_empty_fragments = 0;
 277 #endif
 278         }
 279     }
 280
 281     return ret;
 282
 283  err:
 284     SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK, ERR_R_MALLOC_FAILURE);
 285     return (0);
 286 }
 287
 288 void ssl3_cleanup_key_block(SSL *s)
 289 {
 290     OPENSSL_clear_free(s->s3->tmp.key_block, s->s3->tmp.key_block_length);
 291     s->s3->tmp.key_block = NULL;
 292     s->s3->tmp.key_block_length = 0;
 293 }
 294
 295 int ssl3_init_finished_mac(SSL *s)
 296 {
 297     BIO *buf = BIO_new(BIO_s_mem());
 298
 299     if (buf == NULL) {
 300         SSLerr(SSL_F_SSL3_INIT_FINISHED_MAC, ERR_R_MALLOC_FAILURE);
 301         return 0;
 302     }
 303     ssl3_free_digest_list(s);
 304     s->s3->handshake_buffer = buf;
 305     (void)BIO_set_close(s->s3->handshake_buffer, BIO_CLOSE);
 306     return 1;
 307 }
 308
 309 /*
 310  * Free digest list. Also frees handshake buffer since they are always freed
 311  * together.
 312  */
 313
 314 void ssl3_free_digest_list(SSL *s)
 315 {
 316     BIO_free(s->s3->handshake_buffer);
 317     s->s3->handshake_buffer = NULL;
 318     EVP_MD_CTX_free(s->s3->handshake_dgst);
 319     s->s3->handshake_dgst = NULL;
 320 }
 321
 322 int ssl3_finish_mac(SSL *s, const unsigned char *buf, size_t len)
 323 {
 324     if (s->s3->handshake_dgst == NULL) {
 325         int ret;
 326         /* Note: this writes to a memory BIO so a failure is a fatal error */
 327         if (len > INT_MAX)
 328             return 0;
 329         ret = BIO_write(s->s3->handshake_buffer, (void *)buf, (int)len);
 330         return ret > 0 && ret == (int)len;
 331     } else {
 332         return EVP_DigestUpdate(s->s3->handshake_dgst, buf, len);
 333     }
 334 }
 335
 336 int ssl3_digest_cached_records(SSL *s, int keep)
 337 {
 338     const EVP_MD *md;
 339     long hdatalen;
 340     void *hdata;
 341
 342     if (s->s3->handshake_dgst == NULL) {
 343         hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
 344         if (hdatalen <= 0) {
 345             SSLerr(SSL_F_SSL3_DIGEST_CACHED_RECORDS,
 346                    SSL_R_BAD_HANDSHAKE_LENGTH);
 347             return 0;
 348         }
 349
 350         s->s3->handshake_dgst = EVP_MD_CTX_new();
 351         if (s->s3->handshake_dgst == NULL) {
 352             SSLerr(SSL_F_SSL3_DIGEST_CACHED_RECORDS, ERR_R_MALLOC_FAILURE);
 353             return 0;
 354         }
 355
 356         md = ssl_handshake_md(s);
 357         if (md == NULL || !EVP_DigestInit_ex(s->s3->handshake_dgst, md, NULL)
 358             || !EVP_DigestUpdate(s->s3->handshake_dgst, hdata, hdatalen)) {
 359             SSLerr(SSL_F_SSL3_DIGEST_CACHED_RECORDS, ERR_R_INTERNAL_ERROR);
 360             return 0;
 361         }
 362     }
 363     if (keep == 0) {
 364         BIO_free(s->s3->handshake_buffer);
 365         s->s3->handshake_buffer = NULL;
 366     }
 367
 368     return 1;
 369 }
 370
 371 size_t ssl3_final_finish_mac(SSL *s, const char *sender, size_t len,
 372                              unsigned char *p)
 373 {
 374     int ret;
 375     EVP_MD_CTX *ctx = NULL;
 376
 377     if (!ssl3_digest_cached_records(s, 0))
 378         return 0;
 379
 380     if (EVP_MD_CTX_type(s->s3->handshake_dgst) != NID_md5_sha1) {
 381         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, SSL_R_NO_REQUIRED_DIGEST);
 382         return 0;
 383     }
 384
 385     ctx = EVP_MD_CTX_new();
 386     if (ctx == NULL) {
 387         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, ERR_R_MALLOC_FAILURE);
 388         return 0;
 389     }
 390     if (!EVP_MD_CTX_copy_ex(ctx, s->s3->handshake_dgst)) {
 391         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, ERR_R_INTERNAL_ERROR);
 392         return 0;
 393     }
 394
 395     ret = EVP_MD_CTX_size(ctx);
 396     if (ret < 0) {
 397         EVP_MD_CTX_reset(ctx);
 398         return 0;
 399     }
 400
 401     if ((sender != NULL && EVP_DigestUpdate(ctx, sender, len) <= 0)
 402         || EVP_MD_CTX_ctrl(ctx, EVP_CTRL_SSL3_MASTER_SECRET,
 403                            (int)s->session->master_key_length,
 404                            s->session->master_key) <= 0
 405         || EVP_DigestFinal_ex(ctx, p, NULL) <= 0) {
 406         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, ERR_R_INTERNAL_ERROR);
 407         ret = 0;
 408     }
 409
 410     EVP_MD_CTX_free(ctx);
 411
 412     return ret;
 413 }
 414
 415 int ssl3_generate_master_secret(SSL *s, unsigned char *out, unsigned char *p,
 416                                 size_t len, size_t *secret_size)
 417 {
 418     static const unsigned char *salt[3] = {
 419 #ifndef CHARSET_EBCDIC
 420         (const unsigned char *)"A",
 421         (const unsigned char *)"BB",
 422         (const unsigned char *)"CCC",
 423 #else
 424         (const unsigned char *)"\x41",
 425         (const unsigned char *)"\x42\x42",
 426         (const unsigned char *)"\x43\x43\x43",
 427 #endif
 428     };
 429     unsigned char buf[EVP_MAX_MD_SIZE];
 430     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 431     int i, ret = 1;
 432     unsigned int n;
 433     size_t ret_secret_size = 0;
 434
 435     if (ctx == NULL) {
 436         SSLerr(SSL_F_SSL3_GENERATE_MASTER_SECRET, ERR_R_MALLOC_FAILURE);
 437         return 0;
 438     }
 439     for (i = 0; i < 3; i++) {
 440         if (EVP_DigestInit_ex(ctx, s->ctx->sha1, NULL) <= 0
 441             || EVP_DigestUpdate(ctx, salt[i],
 442                                 strlen((const char *)salt[i])) <= 0
 443             || EVP_DigestUpdate(ctx, p, len) <= 0
 444             || EVP_DigestUpdate(ctx, &(s->s3->client_random[0]),
 445                                 SSL3_RANDOM_SIZE) <= 0
 446             || EVP_DigestUpdate(ctx, &(s->s3->server_random[0]),
 447                                 SSL3_RANDOM_SIZE) <= 0
 448                /* TODO(size_t) : convert me */
 449             || EVP_DigestFinal_ex(ctx, buf, &n) <= 0
 450             || EVP_DigestInit_ex(ctx, s->ctx->md5, NULL) <= 0
 451             || EVP_DigestUpdate(ctx, p, len) <= 0
 452             || EVP_DigestUpdate(ctx, buf, n) <= 0
 453             || EVP_DigestFinal_ex(ctx, out, &n) <= 0) {
 454             SSLerr(SSL_F_SSL3_GENERATE_MASTER_SECRET, ERR_R_INTERNAL_ERROR);
 455             ret = 0;
 456             break;
 457         }
 458         out += n;
 459         ret_secret_size += n;
 460     }
 461     EVP_MD_CTX_free(ctx);
 462
 463     OPENSSL_cleanse(buf, sizeof(buf));
 464     if (ret)
 465         *secret_size = ret_secret_size;
 466     return ret;
 467 }
 468
 469 int ssl3_alert_code(int code)
 470 {
 471     switch (code) {
 472     case SSL_AD_CLOSE_NOTIFY:
 473         return (SSL3_AD_CLOSE_NOTIFY);
 474     case SSL_AD_UNEXPECTED_MESSAGE:
 475         return (SSL3_AD_UNEXPECTED_MESSAGE);
 476     case SSL_AD_BAD_RECORD_MAC:
 477         return (SSL3_AD_BAD_RECORD_MAC);
 478     case SSL_AD_DECRYPTION_FAILED:
 479         return (SSL3_AD_BAD_RECORD_MAC);
 480     case SSL_AD_RECORD_OVERFLOW:
 481         return (SSL3_AD_BAD_RECORD_MAC);
 482     case SSL_AD_DECOMPRESSION_FAILURE:
 483         return (SSL3_AD_DECOMPRESSION_FAILURE);
 484     case SSL_AD_HANDSHAKE_FAILURE:
 485         return (SSL3_AD_HANDSHAKE_FAILURE);
 486     case SSL_AD_NO_CERTIFICATE:
 487         return (SSL3_AD_NO_CERTIFICATE);
 488     case SSL_AD_BAD_CERTIFICATE:
 489         return (SSL3_AD_BAD_CERTIFICATE);
 490     case SSL_AD_UNSUPPORTED_CERTIFICATE:
 491         return (SSL3_AD_UNSUPPORTED_CERTIFICATE);
 492     case SSL_AD_CERTIFICATE_REVOKED:
 493         return (SSL3_AD_CERTIFICATE_REVOKED);
 494     case SSL_AD_CERTIFICATE_EXPIRED:
 495         return (SSL3_AD_CERTIFICATE_EXPIRED);
 496     case SSL_AD_CERTIFICATE_UNKNOWN:
 497         return (SSL3_AD_CERTIFICATE_UNKNOWN);
 498     case SSL_AD_ILLEGAL_PARAMETER:
 499         return (SSL3_AD_ILLEGAL_PARAMETER);
 500     case SSL_AD_UNKNOWN_CA:
 501         return (SSL3_AD_BAD_CERTIFICATE);
 502     case SSL_AD_ACCESS_DENIED:
 503         return (SSL3_AD_HANDSHAKE_FAILURE);
 504     case SSL_AD_DECODE_ERROR:
 505         return (SSL3_AD_HANDSHAKE_FAILURE);
 506     case SSL_AD_DECRYPT_ERROR:
 507         return (SSL3_AD_HANDSHAKE_FAILURE);
 508     case SSL_AD_EXPORT_RESTRICTION:
 509         return (SSL3_AD_HANDSHAKE_FAILURE);
 510     case SSL_AD_PROTOCOL_VERSION:
 511         return (SSL3_AD_HANDSHAKE_FAILURE);
 512     case SSL_AD_INSUFFICIENT_SECURITY:
 513         return (SSL3_AD_HANDSHAKE_FAILURE);
 514     case SSL_AD_INTERNAL_ERROR:
 515         return (SSL3_AD_HANDSHAKE_FAILURE);
 516     case SSL_AD_USER_CANCELLED:
 517         return (SSL3_AD_HANDSHAKE_FAILURE);
 518     case SSL_AD_NO_RENEGOTIATION:
 519         return (-1);            /* Don't send it :-) */
 520     case SSL_AD_UNSUPPORTED_EXTENSION:
 521         return (SSL3_AD_HANDSHAKE_FAILURE);
 522     case SSL_AD_CERTIFICATE_UNOBTAINABLE:
 523         return (SSL3_AD_HANDSHAKE_FAILURE);
 524     case SSL_AD_UNRECOGNIZED_NAME:
 525         return (SSL3_AD_HANDSHAKE_FAILURE);
 526     case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE:
 527         return (SSL3_AD_HANDSHAKE_FAILURE);
 528     case SSL_AD_BAD_CERTIFICATE_HASH_VALUE:
 529         return (SSL3_AD_HANDSHAKE_FAILURE);
 530     case SSL_AD_UNKNOWN_PSK_IDENTITY:
 531         return (TLS1_AD_UNKNOWN_PSK_IDENTITY);
 532     case SSL_AD_INAPPROPRIATE_FALLBACK:
 533         return (TLS1_AD_INAPPROPRIATE_FALLBACK);
 534     case SSL_AD_NO_APPLICATION_PROTOCOL:
 535         return (TLS1_AD_NO_APPLICATION_PROTOCOL);
 536     case SSL_AD_CERTIFICATE_REQUIRED:
 537         return SSL_AD_HANDSHAKE_FAILURE;
 538     default:
 539         return (-1);
 540     }
 541 }