src/crypto/crypto_libtomcrypt.c

   1 /*
   2  * WPA Supplicant / Crypto wrapper for LibTomCrypt (for internal TLSv1)
   3  * Copyright (c) 2005-2006, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10 #include <tomcrypt.h>
  11
  12 #include "common.h"
  13 #include "crypto.h"
  14
  15 #ifndef mp_init_multi
  16 #define mp_init_multi                ltc_init_multi
  17 #define mp_clear_multi               ltc_deinit_multi
  18 #define mp_unsigned_bin_size(a)      ltc_mp.unsigned_size(a)
  19 #define mp_to_unsigned_bin(a, b)     ltc_mp.unsigned_write(a, b)
  20 #define mp_read_unsigned_bin(a, b, c) ltc_mp.unsigned_read(a, b, c)
  21 #define mp_exptmod(a,b,c,d)          ltc_mp.exptmod(a,b,c,d)
  22 #endif
  23
  24
  25 int md4_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
  26 {
  27         hash_state md;
  28         size_t i;
  29
  30         md4_init(&md);
  31         for (i = 0; i < num_elem; i++)
  32                 md4_process(&md, addr[i], len[i]);
  33         md4_done(&md, mac);
  34         return 0;
  35 }
  36
  37
  38 void des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
  39 {
  40         u8 pkey[8], next, tmp;
  41         int i;
  42         symmetric_key skey;
  43
  44         /* Add parity bits to the key */
  45         next = 0;
  46         for (i = 0; i < 7; i++) {
  47                 tmp = key[i];
  48                 pkey[i] = (tmp >> i) | next | 1;
  49                 next = tmp << (7 - i);
  50         }
  51         pkey[i] = next | 1;
  52
  53         des_setup(pkey, 8, 0, &skey);
  54         des_ecb_encrypt(clear, cypher, &skey);
  55         des_done(&skey);
  56 }
  57
  58
  59 int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
  60 {
  61         hash_state md;
  62         size_t i;
  63
  64         md5_init(&md);
  65         for (i = 0; i < num_elem; i++)
  66                 md5_process(&md, addr[i], len[i]);
  67         md5_done(&md, mac);
  68         return 0;
  69 }
  70
  71
  72 int sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
  73 {
  74         hash_state md;
  75         size_t i;
  76
  77         sha1_init(&md);
  78         for (i = 0; i < num_elem; i++)
  79                 sha1_process(&md, addr[i], len[i]);
  80         sha1_done(&md, mac);
  81         return 0;
  82 }
  83
  84
  85 void * aes_encrypt_init(const u8 *key, size_t len)
  86 {
  87         symmetric_key *skey;
  88         skey = os_malloc(sizeof(*skey));
  89         if (skey == NULL)
  90                 return NULL;
  91         if (aes_setup(key, len, 0, skey) != CRYPT_OK) {
  92                 os_free(skey);
  93                 return NULL;
  94         }
  95         return skey;
  96 }
  97
  98
  99 void aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
 100 {
 101         symmetric_key *skey = ctx;
 102         aes_ecb_encrypt(plain, crypt, skey);
 103 }
 104
 105
 106 void aes_encrypt_deinit(void *ctx)
 107 {
 108         symmetric_key *skey = ctx;
 109         aes_done(skey);
 110         os_free(skey);
 111 }
 112
 113
 114 void * aes_decrypt_init(const u8 *key, size_t len)
 115 {
 116         symmetric_key *skey;
 117         skey = os_malloc(sizeof(*skey));
 118         if (skey == NULL)
 119                 return NULL;
 120         if (aes_setup(key, len, 0, skey) != CRYPT_OK) {
 121                 os_free(skey);
 122                 return NULL;
 123         }
 124         return skey;
 125 }
 126
 127
 128 void aes_decrypt(void *ctx, const u8 *crypt, u8 *plain)
 129 {
 130         symmetric_key *skey = ctx;
 131         aes_ecb_encrypt(plain, (u8 *) crypt, skey);
 132 }
 133
 134
 135 void aes_decrypt_deinit(void *ctx)
 136 {
 137         symmetric_key *skey = ctx;
 138         aes_done(skey);
 139         os_free(skey);
 140 }
 141
 142
 143 struct crypto_hash {
 144         enum crypto_hash_alg alg;
 145         int error;
 146         union {
 147                 hash_state md;
 148                 hmac_state hmac;
 149         } u;
 150 };
 151
 152
 153 struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
 154                                       size_t key_len)
 155 {
 156         struct crypto_hash *ctx;
 157
 158         ctx = os_zalloc(sizeof(*ctx));
 159         if (ctx == NULL)
 160                 return NULL;
 161
 162         ctx->alg = alg;
 163
 164         switch (alg) {
 165         case CRYPTO_HASH_ALG_MD5:
 166                 if (md5_init(&ctx->u.md) != CRYPT_OK)
 167                         goto fail;
 168                 break;
 169         case CRYPTO_HASH_ALG_SHA1:
 170                 if (sha1_init(&ctx->u.md) != CRYPT_OK)
 171                         goto fail;
 172                 break;
 173         case CRYPTO_HASH_ALG_HMAC_MD5:
 174                 if (hmac_init(&ctx->u.hmac, find_hash("md5"), key, key_len) !=
 175                     CRYPT_OK)
 176                         goto fail;
 177                 break;
 178         case CRYPTO_HASH_ALG_HMAC_SHA1:
 179                 if (hmac_init(&ctx->u.hmac, find_hash("sha1"), key, key_len) !=
 180                     CRYPT_OK)
 181                         goto fail;
 182                 break;
 183         default:
 184                 goto fail;
 185         }
 186
 187         return ctx;
 188
 189 fail:
 190         os_free(ctx);
 191         return NULL;
 192 }
 193
 194 void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len)
 195 {
 196         if (ctx == NULL || ctx->error)
 197                 return;
 198
 199         switch (ctx->alg) {
 200         case CRYPTO_HASH_ALG_MD5:
 201                 ctx->error = md5_process(&ctx->u.md, data, len) != CRYPT_OK;
 202                 break;
 203         case CRYPTO_HASH_ALG_SHA1:
 204                 ctx->error = sha1_process(&ctx->u.md, data, len) != CRYPT_OK;
 205                 break;
 206         case CRYPTO_HASH_ALG_HMAC_MD5:
 207         case CRYPTO_HASH_ALG_HMAC_SHA1:
 208                 ctx->error = hmac_process(&ctx->u.hmac, data, len) != CRYPT_OK;
 209                 break;
 210         }
 211 }
 212
 213
 214 int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
 215 {
 216         int ret = 0;
 217         unsigned long clen;
 218
 219         if (ctx == NULL)
 220                 return -2;
 221
 222         if (mac == NULL || len == NULL) {
 223                 os_free(ctx);
 224                 return 0;
 225         }
 226
 227         if (ctx->error) {
 228                 os_free(ctx);
 229                 return -2;
 230         }
 231
 232         switch (ctx->alg) {
 233         case CRYPTO_HASH_ALG_MD5:
 234                 if (*len < 16) {
 235                         *len = 16;
 236                         os_free(ctx);
 237                         return -1;
 238                 }
 239                 *len = 16;
 240                 if (md5_done(&ctx->u.md, mac) != CRYPT_OK)
 241                         ret = -2;
 242                 break;
 243         case CRYPTO_HASH_ALG_SHA1:
 244                 if (*len < 20) {
 245                         *len = 20;
 246                         os_free(ctx);
 247                         return -1;
 248                 }
 249                 *len = 20;
 250                 if (sha1_done(&ctx->u.md, mac) != CRYPT_OK)
 251                         ret = -2;
 252                 break;
 253         case CRYPTO_HASH_ALG_HMAC_SHA1:
 254                 if (*len < 20) {
 255                         *len = 20;
 256                         os_free(ctx);
 257                         return -1;
 258                 }
 259                 /* continue */
 260         case CRYPTO_HASH_ALG_HMAC_MD5:
 261                 if (*len < 16) {
 262                         *len = 16;
 263                         os_free(ctx);
 264                         return -1;
 265                 }
 266                 clen = *len;
 267                 if (hmac_done(&ctx->u.hmac, mac, &clen) != CRYPT_OK) {
 268                         os_free(ctx);
 269                         return -1;
 270                 }
 271                 *len = clen;
 272                 break;
 273         default:
 274                 ret = -2;
 275                 break;
 276         }
 277
 278         os_free(ctx);
 279
 280         return ret;
 281 }
 282
 283
 284 struct crypto_cipher {
 285         int rc4;
 286         union {
 287                 symmetric_CBC cbc;
 288                 struct {
 289                         size_t used_bytes;
 290                         u8 key[16];
 291                         size_t keylen;
 292                 } rc4;
 293         } u;
 294 };
 295
 296
 297 struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
 298                                           const u8 *iv, const u8 *key,
 299                                           size_t key_len)
 300 {
 301         struct crypto_cipher *ctx;
 302         int idx, res, rc4 = 0;
 303
 304         switch (alg) {
 305         case CRYPTO_CIPHER_ALG_AES:
 306                 idx = find_cipher("aes");
 307                 break;
 308         case CRYPTO_CIPHER_ALG_3DES:
 309                 idx = find_cipher("3des");
 310                 break;
 311         case CRYPTO_CIPHER_ALG_DES:
 312                 idx = find_cipher("des");
 313                 break;
 314         case CRYPTO_CIPHER_ALG_RC2:
 315                 idx = find_cipher("rc2");
 316                 break;
 317         case CRYPTO_CIPHER_ALG_RC4:
 318                 idx = -1;
 319                 rc4 = 1;
 320                 break;
 321         default:
 322                 return NULL;
 323         }
 324
 325         ctx = os_zalloc(sizeof(*ctx));
 326         if (ctx == NULL)
 327                 return NULL;
 328
 329         if (rc4) {
 330                 ctx->rc4 = 1;
 331                 if (key_len > sizeof(ctx->u.rc4.key)) {
 332                         os_free(ctx);
 333                         return NULL;
 334                 }
 335                 ctx->u.rc4.keylen = key_len;
 336                 os_memcpy(ctx->u.rc4.key, key, key_len);
 337         } else {
 338                 res = cbc_start(idx, iv, key, key_len, 0, &ctx->u.cbc);
 339                 if (res != CRYPT_OK) {
 340                         wpa_printf(MSG_DEBUG, "LibTomCrypt: Cipher start "
 341                                    "failed: %s", error_to_string(res));
 342                         os_free(ctx);
 343                         return NULL;
 344                 }
 345         }
 346
 347         return ctx;
 348 }
 349
 350 int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
 351                           u8 *crypt, size_t len)
 352 {
 353         int res;
 354
 355         if (ctx->rc4) {
 356                 if (plain != crypt)
 357                         os_memcpy(crypt, plain, len);
 358                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 359                          ctx->u.rc4.used_bytes, crypt, len);
 360                 ctx->u.rc4.used_bytes += len;
 361                 return 0;
 362         }
 363
 364         res = cbc_encrypt(plain, crypt, len, &ctx->u.cbc);
 365         if (res != CRYPT_OK) {
 366                 wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC encryption "
 367                            "failed: %s", error_to_string(res));
 368                 return -1;
 369         }
 370         return 0;
 371 }
 372
 373
 374 int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
 375                           u8 *plain, size_t len)
 376 {
 377         int res;
 378
 379         if (ctx->rc4) {
 380                 if (plain != crypt)
 381                         os_memcpy(plain, crypt, len);
 382                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 383                          ctx->u.rc4.used_bytes, plain, len);
 384                 ctx->u.rc4.used_bytes += len;
 385                 return 0;
 386         }
 387
 388         res = cbc_decrypt(crypt, plain, len, &ctx->u.cbc);
 389         if (res != CRYPT_OK) {
 390                 wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC decryption "
 391                            "failed: %s", error_to_string(res));
 392                 return -1;
 393         }
 394
 395         return 0;
 396 }
 397
 398
 399 void crypto_cipher_deinit(struct crypto_cipher *ctx)
 400 {
 401         if (!ctx->rc4)
 402                 cbc_done(&ctx->u.cbc);
 403         os_free(ctx);
 404 }
 405
 406
 407 struct crypto_public_key {
 408         rsa_key rsa;
 409 };
 410
 411 struct crypto_private_key {
 412         rsa_key rsa;
 413 };
 414
 415
 416 struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len)
 417 {
 418         int res;
 419         struct crypto_public_key *pk;
 420
 421         pk = os_zalloc(sizeof(*pk));
 422         if (pk == NULL)
 423                 return NULL;
 424
 425         res = rsa_import(key, len, &pk->rsa);
 426         if (res != CRYPT_OK) {
 427                 wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import "
 428                            "public key (res=%d '%s')",
 429                            res, error_to_string(res));
 430                 os_free(pk);
 431                 return NULL;
 432         }
 433
 434         if (pk->rsa.type != PK_PUBLIC) {
 435                 wpa_printf(MSG_ERROR, "LibTomCrypt: Public key was not of "
 436                            "correct type");
 437                 rsa_free(&pk->rsa);
 438                 os_free(pk);
 439                 return NULL;
 440         }
 441
 442         return pk;
 443 }
 444
 445
 446 struct crypto_private_key * crypto_private_key_import(const u8 *key,
 447                                                       size_t len,
 448                                                       const char *passwd)
 449 {
 450         int res;
 451         struct crypto_private_key *pk;
 452
 453         pk = os_zalloc(sizeof(*pk));
 454         if (pk == NULL)
 455                 return NULL;
 456
 457         res = rsa_import(key, len, &pk->rsa);
 458         if (res != CRYPT_OK) {
 459                 wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import "
 460                            "private key (res=%d '%s')",
 461                            res, error_to_string(res));
 462                 os_free(pk);
 463                 return NULL;
 464         }
 465
 466         if (pk->rsa.type != PK_PRIVATE) {
 467                 wpa_printf(MSG_ERROR, "LibTomCrypt: Private key was not of "
 468                            "correct type");
 469                 rsa_free(&pk->rsa);
 470                 os_free(pk);
 471                 return NULL;
 472         }
 473
 474         return pk;
 475 }
 476
 477
 478 struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf,
 479                                                        size_t len)
 480 {
 481         /* No X.509 support in LibTomCrypt */
 482         return NULL;
 483 }
 484
 485
 486 static int pkcs1_generate_encryption_block(u8 block_type, size_t modlen,
 487                                            const u8 *in, size_t inlen,
 488                                            u8 *out, size_t *outlen)
 489 {
 490         size_t ps_len;
 491         u8 *pos;
 492
 493         /*
 494          * PKCS #1 v1.5, 8.1:
 495          *
 496          * EB = 00 || BT || PS || 00 || D
 497          * BT = 00 or 01 for private-key operation; 02 for public-key operation
 498          * PS = k-3-||D||; at least eight octets
 499          * (BT=0: PS=0x00, BT=1: PS=0xff, BT=2: PS=pseudorandom non-zero)
 500          * k = length of modulus in octets (modlen)
 501          */
 502
 503         if (modlen < 12 || modlen > *outlen || inlen > modlen - 11) {
 504                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Invalid buffer "
 505                            "lengths (modlen=%lu outlen=%lu inlen=%lu)",
 506                            __func__, (unsigned long) modlen,
 507                            (unsigned long) *outlen,
 508                            (unsigned long) inlen);
 509                 return -1;
 510         }
 511
 512         pos = out;
 513         *pos++ = 0x00;
 514         *pos++ = block_type; /* BT */
 515         ps_len = modlen - inlen - 3;
 516         switch (block_type) {
 517         case 0:
 518                 os_memset(pos, 0x00, ps_len);
 519                 pos += ps_len;
 520                 break;
 521         case 1:
 522                 os_memset(pos, 0xff, ps_len);
 523                 pos += ps_len;
 524                 break;
 525         case 2:
 526                 if (os_get_random(pos, ps_len) < 0) {
 527                         wpa_printf(MSG_DEBUG, "PKCS #1: %s - Failed to get "
 528                                    "random data for PS", __func__);
 529                         return -1;
 530                 }
 531                 while (ps_len--) {
 532                         if (*pos == 0x00)
 533                                 *pos = 0x01;
 534                         pos++;
 535                 }
 536                 break;
 537         default:
 538                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Unsupported block type "
 539                            "%d", __func__, block_type);
 540                 return -1;
 541         }
 542         *pos++ = 0x00;
 543         os_memcpy(pos, in, inlen); /* D */
 544
 545         return 0;
 546 }
 547
 548
 549 static int crypto_rsa_encrypt_pkcs1(int block_type, rsa_key *key, int key_type,
 550                                     const u8 *in, size_t inlen,
 551                                     u8 *out, size_t *outlen)
 552 {
 553         unsigned long len, modlen;
 554         int res;
 555
 556         modlen = mp_unsigned_bin_size(key->N);
 557
 558         if (pkcs1_generate_encryption_block(block_type, modlen, in, inlen,
 559                                             out, outlen) < 0)
 560                 return -1;
 561
 562         len = *outlen;
 563         res = rsa_exptmod(out, modlen, out, &len, key_type, key);
 564         if (res != CRYPT_OK) {
 565                 wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s",
 566                            error_to_string(res));
 567                 return -1;
 568         }
 569         *outlen = len;
 570
 571         return 0;
 572 }
 573
 574
 575 int crypto_public_key_encrypt_pkcs1_v15(struct crypto_public_key *key,
 576                                         const u8 *in, size_t inlen,
 577                                         u8 *out, size_t *outlen)
 578 {
 579         return crypto_rsa_encrypt_pkcs1(2, &key->rsa, PK_PUBLIC, in, inlen,
 580                                         out, outlen);
 581 }
 582
 583
 584 int crypto_private_key_sign_pkcs1(struct crypto_private_key *key,
 585                                   const u8 *in, size_t inlen,
 586                                   u8 *out, size_t *outlen)
 587 {
 588         return crypto_rsa_encrypt_pkcs1(1, &key->rsa, PK_PRIVATE, in, inlen,
 589                                         out, outlen);
 590 }
 591
 592
 593 void crypto_public_key_free(struct crypto_public_key *key)
 594 {
 595         if (key) {
 596                 rsa_free(&key->rsa);
 597                 os_free(key);
 598         }
 599 }
 600
 601
 602 void crypto_private_key_free(struct crypto_private_key *key)
 603 {
 604         if (key) {
 605                 rsa_free(&key->rsa);
 606                 os_free(key);
 607         }
 608 }
 609
 610
 611 int crypto_public_key_decrypt_pkcs1(struct crypto_public_key *key,
 612                                     const u8 *crypt, size_t crypt_len,
 613                                     u8 *plain, size_t *plain_len)
 614 {
 615         int res;
 616         unsigned long len;
 617         u8 *pos;
 618
 619         len = *plain_len;
 620         res = rsa_exptmod(crypt, crypt_len, plain, &len, PK_PUBLIC,
 621                           &key->rsa);
 622         if (res != CRYPT_OK) {
 623                 wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s",
 624                            error_to_string(res));
 625                 return -1;
 626         }
 627
 628         /*
 629          * PKCS #1 v1.5, 8.1:
 630          *
 631          * EB = 00 || BT || PS || 00 || D
 632          * BT = 01
 633          * PS = k-3-||D|| times FF
 634          * k = length of modulus in octets
 635          */
 636
 637         if (len < 3 + 8 + 16 /* min hash len */ ||
 638             plain[0] != 0x00 || plain[1] != 0x01 || plain[2] != 0xff) {
 639                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 640                            "structure");
 641                 return -1;
 642         }
 643
 644         pos = plain + 3;
 645         while (pos < plain + len && *pos == 0xff)
 646                 pos++;
 647         if (pos - plain - 2 < 8) {
 648                 /* PKCS #1 v1.5, 8.1: At least eight octets long PS */
 649                 wpa_printf(MSG_INFO, "LibTomCrypt: Too short signature "
 650                            "padding");
 651                 return -1;
 652         }
 653
 654         if (pos + 16 /* min hash len */ >= plain + len || *pos != 0x00) {
 655                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 656                            "structure (2)");
 657                 return -1;
 658         }
 659         pos++;
 660         len -= pos - plain;
 661
 662         /* Strip PKCS #1 header */
 663         os_memmove(plain, pos, len);
 664         *plain_len = len;
 665
 666         return 0;
 667 }
 668
 669
 670 int crypto_global_init(void)
 671 {
 672         ltc_mp = tfm_desc;
 673         /* TODO: only register algorithms that are really needed */
 674         if (register_hash(&md4_desc) < 0 ||
 675             register_hash(&md5_desc) < 0 ||
 676             register_hash(&sha1_desc) < 0 ||
 677             register_cipher(&aes_desc) < 0 ||
 678             register_cipher(&des_desc) < 0 ||
 679             register_cipher(&des3_desc) < 0) {
 680                 wpa_printf(MSG_ERROR, "TLSv1: Failed to register "
 681                            "hash/cipher functions");
 682                 return -1;
 683         }
 684
 685         return 0;
 686 }
 687
 688
 689 void crypto_global_deinit(void)
 690 {
 691 }
 692
 693
 694 #ifdef CONFIG_MODEXP
 695
 696 int crypto_mod_exp(const u8 *base, size_t base_len,
 697                    const u8 *power, size_t power_len,
 698                    const u8 *modulus, size_t modulus_len,
 699                    u8 *result, size_t *result_len)
 700 {
 701         void *b, *p, *m, *r;
 702
 703         if (mp_init_multi(&b, &p, &m, &r, NULL) != CRYPT_OK)
 704                 return -1;
 705
 706         if (mp_read_unsigned_bin(b, (u8 *) base, base_len) != CRYPT_OK ||
 707             mp_read_unsigned_bin(p, (u8 *) power, power_len) != CRYPT_OK ||
 708             mp_read_unsigned_bin(m, (u8 *) modulus, modulus_len) != CRYPT_OK)
 709                 goto fail;
 710
 711         if (mp_exptmod(b, p, m, r) != CRYPT_OK)
 712                 goto fail;
 713
 714         *result_len = mp_unsigned_bin_size(r);
 715         if (mp_to_unsigned_bin(r, result) != CRYPT_OK)
 716                 goto fail;
 717
 718         mp_clear_multi(b, p, m, r, NULL);
 719         return 0;
 720
 721 fail:
 722         mp_clear_multi(b, p, m, r, NULL);
 723         return -1;
 724 }
 725
 726 #endif /* CONFIG_MODEXP */