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 #include "internal/cryptlib.h"
  16
  17 static int ssl3_generate_key_block(SSL *s, unsigned char *km, int num)
  18 {
  19     EVP_MD_CTX *m5;
  20     EVP_MD_CTX *s1;
  21     unsigned char buf[16], smd[SHA_DIGEST_LENGTH];
  22     unsigned char c = 'A';
  23     unsigned int i, j, k;
  24     int ret = 0;
  25
  26 #ifdef CHARSET_EBCDIC
  27     c = os_toascii[c];          /* 'A' in ASCII */
  28 #endif
  29     k = 0;
  30     m5 = EVP_MD_CTX_new();
  31     s1 = EVP_MD_CTX_new();
  32     if (m5 == NULL || s1 == NULL) {
  33         SSLerr(SSL_F_SSL3_GENERATE_KEY_BLOCK, ERR_R_MALLOC_FAILURE);
  34         goto err;
  35     }
  36     EVP_MD_CTX_set_flags(m5, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
  37     for (i = 0; (int)i < num; i += MD5_DIGEST_LENGTH) {
  38         k++;
  39         if (k > sizeof(buf)) {
  40             /* bug: 'buf' is too small for this ciphersuite */
  41             SSLerr(SSL_F_SSL3_GENERATE_KEY_BLOCK, ERR_R_INTERNAL_ERROR);
  42             goto err;
  43         }
  44
  45         for (j = 0; j < k; j++)
  46             buf[j] = c;
  47         c++;
  48         if (!EVP_DigestInit_ex(s1, EVP_sha1(), NULL)
  49             || !EVP_DigestUpdate(s1, buf, k)
  50             || !EVP_DigestUpdate(s1, s->session->master_key,
  51                                  s->session->master_key_length)
  52             || !EVP_DigestUpdate(s1, s->s3->server_random, SSL3_RANDOM_SIZE)
  53             || !EVP_DigestUpdate(s1, s->s3->client_random, SSL3_RANDOM_SIZE)
  54             || !EVP_DigestFinal_ex(s1, smd, NULL)
  55             || !EVP_DigestInit_ex(m5, EVP_md5(), NULL)
  56             || !EVP_DigestUpdate(m5, s->session->master_key,
  57                                  s->session->master_key_length)
  58             || !EVP_DigestUpdate(m5, smd, SHA_DIGEST_LENGTH))
  59             goto err;
  60         if ((int)(i + MD5_DIGEST_LENGTH) > num) {
  61             if (!EVP_DigestFinal_ex(m5, smd, NULL))
  62                 goto err;
  63             memcpy(km, smd, (num - i));
  64         } else {
  65             if (!EVP_DigestFinal_ex(m5, km, NULL))
  66                 goto err;
  67         }
  68
  69         km += MD5_DIGEST_LENGTH;
  70     }
  71     OPENSSL_cleanse(smd, sizeof(smd));
  72     ret = 1;
  73  err:
  74     EVP_MD_CTX_free(m5);
  75     EVP_MD_CTX_free(s1);
  76     return ret;
  77 }
  78
  79 int ssl3_change_cipher_state(SSL *s, int which)
  80 {
  81     unsigned char *p, *mac_secret;
  82     unsigned char exp_key[EVP_MAX_KEY_LENGTH];
  83     unsigned char exp_iv[EVP_MAX_IV_LENGTH];
  84     unsigned char *ms, *key, *iv;
  85     EVP_CIPHER_CTX *dd;
  86     const EVP_CIPHER *c;
  87 #ifndef OPENSSL_NO_COMP
  88     COMP_METHOD *comp;
  89 #endif
  90     const EVP_MD *m;
  91     int mdi;
  92     size_t n, i, j, k, cl;
  93     int reuse_dd = 0;
  94
  95     c = s->s3->tmp.new_sym_enc;
  96     m = s->s3->tmp.new_hash;
  97     /* m == NULL will lead to a crash later */
  98     if (!ossl_assert(m != NULL)) {
  99         SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 100         goto err2;
 101     }
 102 #ifndef OPENSSL_NO_COMP
 103     if (s->s3->tmp.new_compression == NULL)
 104         comp = NULL;
 105     else
 106         comp = s->s3->tmp.new_compression->method;
 107 #endif
 108
 109     if (which & SSL3_CC_READ) {
 110         if (s->enc_read_ctx != NULL)
 111             reuse_dd = 1;
 112         else if ((s->enc_read_ctx = EVP_CIPHER_CTX_new()) == NULL)
 113             goto err;
 114         else
 115             /*
 116              * make sure it's initialised in case we exit later with an error
 117              */
 118             EVP_CIPHER_CTX_reset(s->enc_read_ctx);
 119         dd = s->enc_read_ctx;
 120
 121         if (ssl_replace_hash(&s->read_hash, m) == NULL) {
 122             SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 123             goto err2;
 124         }
 125 #ifndef OPENSSL_NO_COMP
 126         /* COMPRESS */
 127         COMP_CTX_free(s->expand);
 128         s->expand = NULL;
 129         if (comp != NULL) {
 130             s->expand = COMP_CTX_new(comp);
 131             if (s->expand == NULL) {
 132                 SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,
 133                        SSL_R_COMPRESSION_LIBRARY_ERROR);
 134                 goto err2;
 135             }
 136         }
 137 #endif
 138         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 139         mac_secret = &(s->s3->read_mac_secret[0]);
 140     } else {
 141         if (s->enc_write_ctx != NULL)
 142             reuse_dd = 1;
 143         else if ((s->enc_write_ctx = EVP_CIPHER_CTX_new()) == NULL)
 144             goto err;
 145         else
 146             /*
 147              * make sure it's initialised in case we exit later with an error
 148              */
 149             EVP_CIPHER_CTX_reset(s->enc_write_ctx);
 150         dd = s->enc_write_ctx;
 151         if (ssl_replace_hash(&s->write_hash, m) == NULL) {
 152             SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 153             goto err2;
 154         }
 155 #ifndef OPENSSL_NO_COMP
 156         /* COMPRESS */
 157         COMP_CTX_free(s->compress);
 158         s->compress = NULL;
 159         if (comp != NULL) {
 160             s->compress = COMP_CTX_new(comp);
 161             if (s->compress == NULL) {
 162                 SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE,
 163                        SSL_R_COMPRESSION_LIBRARY_ERROR);
 164                 goto err2;
 165             }
 166         }
 167 #endif
 168         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 169         mac_secret = &(s->s3->write_mac_secret[0]);
 170     }
 171
 172     if (reuse_dd)
 173         EVP_CIPHER_CTX_reset(dd);
 174
 175     p = s->s3->tmp.key_block;
 176     mdi = EVP_MD_size(m);
 177     if (mdi < 0)
 178         goto err2;
 179     i = mdi;
 180     cl = EVP_CIPHER_key_length(c);
 181     j = cl;
 182     k = EVP_CIPHER_iv_length(c);
 183     if ((which == SSL3_CHANGE_CIPHER_CLIENT_WRITE) ||
 184         (which == SSL3_CHANGE_CIPHER_SERVER_READ)) {
 185         ms = &(p[0]);
 186         n = i + i;
 187         key = &(p[n]);
 188         n += j + j;
 189         iv = &(p[n]);
 190         n += k + k;
 191     } else {
 192         n = i;
 193         ms = &(p[n]);
 194         n += i + j;
 195         key = &(p[n]);
 196         n += j + k;
 197         iv = &(p[n]);
 198         n += k;
 199     }
 200
 201     if (n > s->s3->tmp.key_block_length) {
 202         SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 203         goto err2;
 204     }
 205
 206     memcpy(mac_secret, ms, i);
 207
 208     if (!EVP_CipherInit_ex(dd, c, NULL, key, iv, (which & SSL3_CC_WRITE)))
 209         goto err2;
 210
 211     OPENSSL_cleanse(exp_key, sizeof(exp_key));
 212     OPENSSL_cleanse(exp_iv, sizeof(exp_iv));
 213     return (1);
 214  err:
 215     SSLerr(SSL_F_SSL3_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 216  err2:
 217     OPENSSL_cleanse(exp_key, sizeof(exp_key));
 218     OPENSSL_cleanse(exp_iv, sizeof(exp_iv));
 219     return (0);
 220 }
 221
 222 int ssl3_setup_key_block(SSL *s)
 223 {
 224     unsigned char *p;
 225     const EVP_CIPHER *c;
 226     const EVP_MD *hash;
 227     int num;
 228     int ret = 0;
 229     SSL_COMP *comp;
 230
 231     if (s->s3->tmp.key_block_length != 0)
 232         return (1);
 233
 234     if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, &comp, 0)) {
 235         SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
 236         return (0);
 237     }
 238
 239     s->s3->tmp.new_sym_enc = c;
 240     s->s3->tmp.new_hash = hash;
 241 #ifdef OPENSSL_NO_COMP
 242     s->s3->tmp.new_compression = NULL;
 243 #else
 244     s->s3->tmp.new_compression = comp;
 245 #endif
 246
 247     num = EVP_MD_size(hash);
 248     if (num < 0)
 249         return 0;
 250
 251     num = EVP_CIPHER_key_length(c) + num + EVP_CIPHER_iv_length(c);
 252     num *= 2;
 253
 254     ssl3_cleanup_key_block(s);
 255
 256     if ((p = OPENSSL_malloc(num)) == NULL)
 257         goto err;
 258
 259     s->s3->tmp.key_block_length = num;
 260     s->s3->tmp.key_block = p;
 261
 262     ret = ssl3_generate_key_block(s, p, num);
 263
 264     if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS)) {
 265         /*
 266          * enable vulnerability countermeasure for CBC ciphers with known-IV
 267          * problem (http://www.openssl.org/~bodo/tls-cbc.txt)
 268          */
 269         s->s3->need_empty_fragments = 1;
 270
 271         if (s->session->cipher != NULL) {
 272             if (s->session->cipher->algorithm_enc == SSL_eNULL)
 273                 s->s3->need_empty_fragments = 0;
 274
 275 #ifndef OPENSSL_NO_RC4
 276             if (s->session->cipher->algorithm_enc == SSL_RC4)
 277                 s->s3->need_empty_fragments = 0;
 278 #endif
 279         }
 280     }
 281
 282     return ret;
 283
 284  err:
 285     SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK, ERR_R_MALLOC_FAILURE);
 286     return (0);
 287 }
 288
 289 void ssl3_cleanup_key_block(SSL *s)
 290 {
 291     OPENSSL_clear_free(s->s3->tmp.key_block, s->s3->tmp.key_block_length);
 292     s->s3->tmp.key_block = NULL;
 293     s->s3->tmp.key_block_length = 0;
 294 }
 295
 296 int ssl3_init_finished_mac(SSL *s)
 297 {
 298     BIO *buf = BIO_new(BIO_s_mem());
 299
 300     if (buf == NULL) {
 301         SSLerr(SSL_F_SSL3_INIT_FINISHED_MAC, ERR_R_MALLOC_FAILURE);
 302         return 0;
 303     }
 304     ssl3_free_digest_list(s);
 305     s->s3->handshake_buffer = buf;
 306     (void)BIO_set_close(s->s3->handshake_buffer, BIO_CLOSE);
 307     return 1;
 308 }
 309
 310 /*
 311  * Free digest list. Also frees handshake buffer since they are always freed
 312  * together.
 313  */
 314
 315 void ssl3_free_digest_list(SSL *s)
 316 {
 317     BIO_free(s->s3->handshake_buffer);
 318     s->s3->handshake_buffer = NULL;
 319     EVP_MD_CTX_free(s->s3->handshake_dgst);
 320     s->s3->handshake_dgst = NULL;
 321 }
 322
 323 int ssl3_finish_mac(SSL *s, const unsigned char *buf, size_t len)
 324 {
 325     if (s->s3->handshake_dgst == NULL) {
 326         int ret;
 327         /* Note: this writes to a memory BIO so a failure is a fatal error */
 328         if (len > INT_MAX)
 329             return 0;
 330         ret = BIO_write(s->s3->handshake_buffer, (void *)buf, (int)len);
 331         return ret > 0 && ret == (int)len;
 332     } else {
 333         return EVP_DigestUpdate(s->s3->handshake_dgst, buf, len);
 334     }
 335 }
 336
 337 int ssl3_digest_cached_records(SSL *s, int keep)
 338 {
 339     const EVP_MD *md;
 340     long hdatalen;
 341     void *hdata;
 342
 343     if (s->s3->handshake_dgst == NULL) {
 344         hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
 345         if (hdatalen <= 0) {
 346             SSLerr(SSL_F_SSL3_DIGEST_CACHED_RECORDS,
 347                    SSL_R_BAD_HANDSHAKE_LENGTH);
 348             return 0;
 349         }
 350
 351         s->s3->handshake_dgst = EVP_MD_CTX_new();
 352         if (s->s3->handshake_dgst == NULL) {
 353             SSLerr(SSL_F_SSL3_DIGEST_CACHED_RECORDS, ERR_R_MALLOC_FAILURE);
 354             return 0;
 355         }
 356
 357         md = ssl_handshake_md(s);
 358         if (md == NULL || !EVP_DigestInit_ex(s->s3->handshake_dgst, md, NULL)
 359             || !EVP_DigestUpdate(s->s3->handshake_dgst, hdata, hdatalen)) {
 360             SSLerr(SSL_F_SSL3_DIGEST_CACHED_RECORDS, ERR_R_INTERNAL_ERROR);
 361             return 0;
 362         }
 363     }
 364     if (keep == 0) {
 365         BIO_free(s->s3->handshake_buffer);
 366         s->s3->handshake_buffer = NULL;
 367     }
 368
 369     return 1;
 370 }
 371
 372 size_t ssl3_final_finish_mac(SSL *s, const char *sender, size_t len,
 373                              unsigned char *p)
 374 {
 375     int ret;
 376     EVP_MD_CTX *ctx = NULL;
 377
 378     if (!ssl3_digest_cached_records(s, 0))
 379         return 0;
 380
 381     if (EVP_MD_CTX_type(s->s3->handshake_dgst) != NID_md5_sha1) {
 382         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, SSL_R_NO_REQUIRED_DIGEST);
 383         return 0;
 384     }
 385
 386     ctx = EVP_MD_CTX_new();
 387     if (ctx == NULL) {
 388         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, ERR_R_MALLOC_FAILURE);
 389         return 0;
 390     }
 391     if (!EVP_MD_CTX_copy_ex(ctx, s->s3->handshake_dgst)) {
 392         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, ERR_R_INTERNAL_ERROR);
 393         return 0;
 394     }
 395
 396     ret = EVP_MD_CTX_size(ctx);
 397     if (ret < 0) {
 398         EVP_MD_CTX_reset(ctx);
 399         return 0;
 400     }
 401
 402     if ((sender != NULL && EVP_DigestUpdate(ctx, sender, len) <= 0)
 403         || EVP_MD_CTX_ctrl(ctx, EVP_CTRL_SSL3_MASTER_SECRET,
 404                            (int)s->session->master_key_length,
 405                            s->session->master_key) <= 0
 406         || EVP_DigestFinal_ex(ctx, p, NULL) <= 0) {
 407         SSLerr(SSL_F_SSL3_FINAL_FINISH_MAC, ERR_R_INTERNAL_ERROR);
 408         ret = 0;
 409     }
 410
 411     EVP_MD_CTX_free(ctx);
 412
 413     return ret;
 414 }
 415
 416 int ssl3_generate_master_secret(SSL *s, unsigned char *out, unsigned char *p,
 417                                 size_t len, size_t *secret_size)
 418 {
 419     static const unsigned char *salt[3] = {
 420 #ifndef CHARSET_EBCDIC
 421         (const unsigned char *)"A",
 422         (const unsigned char *)"BB",
 423         (const unsigned char *)"CCC",
 424 #else
 425         (const unsigned char *)"\x41",
 426         (const unsigned char *)"\x42\x42",
 427         (const unsigned char *)"\x43\x43\x43",
 428 #endif
 429     };
 430     unsigned char buf[EVP_MAX_MD_SIZE];
 431     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 432     int i, ret = 1;
 433     unsigned int n;
 434     size_t ret_secret_size = 0;
 435
 436     if (ctx == NULL) {
 437         SSLerr(SSL_F_SSL3_GENERATE_MASTER_SECRET, ERR_R_MALLOC_FAILURE);
 438         return 0;
 439     }
 440     for (i = 0; i < 3; i++) {
 441         if (EVP_DigestInit_ex(ctx, s->ctx->sha1, NULL) <= 0
 442             || EVP_DigestUpdate(ctx, salt[i],
 443                                 strlen((const char *)salt[i])) <= 0
 444             || EVP_DigestUpdate(ctx, p, len) <= 0
 445             || EVP_DigestUpdate(ctx, &(s->s3->client_random[0]),
 446                                 SSL3_RANDOM_SIZE) <= 0
 447             || EVP_DigestUpdate(ctx, &(s->s3->server_random[0]),
 448                                 SSL3_RANDOM_SIZE) <= 0
 449                /* TODO(size_t) : convert me */
 450             || EVP_DigestFinal_ex(ctx, buf, &n) <= 0
 451             || EVP_DigestInit_ex(ctx, s->ctx->md5, NULL) <= 0
 452             || EVP_DigestUpdate(ctx, p, len) <= 0
 453             || EVP_DigestUpdate(ctx, buf, n) <= 0
 454             || EVP_DigestFinal_ex(ctx, out, &n) <= 0) {
 455             SSLerr(SSL_F_SSL3_GENERATE_MASTER_SECRET, ERR_R_INTERNAL_ERROR);
 456             ret = 0;
 457             break;
 458         }
 459         out += n;
 460         ret_secret_size += n;
 461     }
 462     EVP_MD_CTX_free(ctx);
 463
 464     OPENSSL_cleanse(buf, sizeof(buf));
 465     if (ret)
 466         *secret_size = ret_secret_size;
 467     return ret;
 468 }
 469
 470 int ssl3_alert_code(int code)
 471 {
 472     switch (code) {
 473     case SSL_AD_CLOSE_NOTIFY:
 474         return (SSL3_AD_CLOSE_NOTIFY);
 475     case SSL_AD_UNEXPECTED_MESSAGE:
 476         return (SSL3_AD_UNEXPECTED_MESSAGE);
 477     case SSL_AD_BAD_RECORD_MAC:
 478         return (SSL3_AD_BAD_RECORD_MAC);
 479     case SSL_AD_DECRYPTION_FAILED:
 480         return (SSL3_AD_BAD_RECORD_MAC);
 481     case SSL_AD_RECORD_OVERFLOW:
 482         return (SSL3_AD_BAD_RECORD_MAC);
 483     case SSL_AD_DECOMPRESSION_FAILURE:
 484         return (SSL3_AD_DECOMPRESSION_FAILURE);
 485     case SSL_AD_HANDSHAKE_FAILURE:
 486         return (SSL3_AD_HANDSHAKE_FAILURE);
 487     case SSL_AD_NO_CERTIFICATE:
 488         return (SSL3_AD_NO_CERTIFICATE);
 489     case SSL_AD_BAD_CERTIFICATE:
 490         return (SSL3_AD_BAD_CERTIFICATE);
 491     case SSL_AD_UNSUPPORTED_CERTIFICATE:
 492         return (SSL3_AD_UNSUPPORTED_CERTIFICATE);
 493     case SSL_AD_CERTIFICATE_REVOKED:
 494         return (SSL3_AD_CERTIFICATE_REVOKED);
 495     case SSL_AD_CERTIFICATE_EXPIRED:
 496         return (SSL3_AD_CERTIFICATE_EXPIRED);
 497     case SSL_AD_CERTIFICATE_UNKNOWN:
 498         return (SSL3_AD_CERTIFICATE_UNKNOWN);
 499     case SSL_AD_ILLEGAL_PARAMETER:
 500         return (SSL3_AD_ILLEGAL_PARAMETER);
 501     case SSL_AD_UNKNOWN_CA:
 502         return (SSL3_AD_BAD_CERTIFICATE);
 503     case SSL_AD_ACCESS_DENIED:
 504         return (SSL3_AD_HANDSHAKE_FAILURE);
 505     case SSL_AD_DECODE_ERROR:
 506         return (SSL3_AD_HANDSHAKE_FAILURE);
 507     case SSL_AD_DECRYPT_ERROR:
 508         return (SSL3_AD_HANDSHAKE_FAILURE);
 509     case SSL_AD_EXPORT_RESTRICTION:
 510         return (SSL3_AD_HANDSHAKE_FAILURE);
 511     case SSL_AD_PROTOCOL_VERSION:
 512         return (SSL3_AD_HANDSHAKE_FAILURE);
 513     case SSL_AD_INSUFFICIENT_SECURITY:
 514         return (SSL3_AD_HANDSHAKE_FAILURE);
 515     case SSL_AD_INTERNAL_ERROR:
 516         return (SSL3_AD_HANDSHAKE_FAILURE);
 517     case SSL_AD_USER_CANCELLED:
 518         return (SSL3_AD_HANDSHAKE_FAILURE);
 519     case SSL_AD_NO_RENEGOTIATION:
 520         return (-1);            /* Don't send it :-) */
 521     case SSL_AD_UNSUPPORTED_EXTENSION:
 522         return (SSL3_AD_HANDSHAKE_FAILURE);
 523     case SSL_AD_CERTIFICATE_UNOBTAINABLE:
 524         return (SSL3_AD_HANDSHAKE_FAILURE);
 525     case SSL_AD_UNRECOGNIZED_NAME:
 526         return (SSL3_AD_HANDSHAKE_FAILURE);
 527     case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE:
 528         return (SSL3_AD_HANDSHAKE_FAILURE);
 529     case SSL_AD_BAD_CERTIFICATE_HASH_VALUE:
 530         return (SSL3_AD_HANDSHAKE_FAILURE);
 531     case SSL_AD_UNKNOWN_PSK_IDENTITY:
 532         return (TLS1_AD_UNKNOWN_PSK_IDENTITY);
 533     case SSL_AD_INAPPROPRIATE_FALLBACK:
 534         return (TLS1_AD_INAPPROPRIATE_FALLBACK);
 535     case SSL_AD_NO_APPLICATION_PROTOCOL:
 536         return (TLS1_AD_NO_APPLICATION_PROTOCOL);
 537     case SSL_AD_CERTIFICATE_REQUIRED:
 538         return SSL_AD_HANDSHAKE_FAILURE;
 539     default:
 540         return (-1);
 541     }
 542 }