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 int 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 return 0; 57 } 58 59 60 int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac) 61 { 62 hash_state md; 63 size_t i; 64 65 md5_init(&md); 66 for (i = 0; i < num_elem; i++) 67 md5_process(&md, addr[i], len[i]); 68 md5_done(&md, mac); 69 return 0; 70 } 71 72 73 int sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac) 74 { 75 hash_state md; 76 size_t i; 77 78 sha1_init(&md); 79 for (i = 0; i < num_elem; i++) 80 sha1_process(&md, addr[i], len[i]); 81 sha1_done(&md, mac); 82 return 0; 83 } 84 85 86 void * aes_encrypt_init(const u8 *key, size_t len) 87 { 88 symmetric_key *skey; 89 skey = os_malloc(sizeof(*skey)); 90 if (skey == NULL) 91 return NULL; 92 if (aes_setup(key, len, 0, skey) != CRYPT_OK) { 93 os_free(skey); 94 return NULL; 95 } 96 return skey; 97 } 98 99 100 int aes_encrypt(void *ctx, const u8 *plain, u8 *crypt) 101 { 102 symmetric_key *skey = ctx; 103 return aes_ecb_encrypt(plain, crypt, skey) == CRYPT_OK ? 0 : -1; 104 } 105 106 107 void aes_encrypt_deinit(void *ctx) 108 { 109 symmetric_key *skey = ctx; 110 aes_done(skey); 111 os_free(skey); 112 } 113 114 115 void * aes_decrypt_init(const u8 *key, size_t len) 116 { 117 symmetric_key *skey; 118 skey = os_malloc(sizeof(*skey)); 119 if (skey == NULL) 120 return NULL; 121 if (aes_setup(key, len, 0, skey) != CRYPT_OK) { 122 os_free(skey); 123 return NULL; 124 } 125 return skey; 126 } 127 128 129 int aes_decrypt(void *ctx, const u8 *crypt, u8 *plain) 130 { 131 symmetric_key *skey = ctx; 132 return aes_ecb_encrypt(plain, (u8 *) crypt, skey) == CRYPT_OK ? 0 : -1; 133 } 134 135 136 void aes_decrypt_deinit(void *ctx) 137 { 138 symmetric_key *skey = ctx; 139 aes_done(skey); 140 os_free(skey); 141 } 142 143 144 struct crypto_hash { 145 enum crypto_hash_alg alg; 146 int error; 147 union { 148 hash_state md; 149 hmac_state hmac; 150 } u; 151 }; 152 153 154 struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key, 155 size_t key_len) 156 { 157 struct crypto_hash *ctx; 158 159 ctx = os_zalloc(sizeof(*ctx)); 160 if (ctx == NULL) 161 return NULL; 162 163 ctx->alg = alg; 164 165 switch (alg) { 166 case CRYPTO_HASH_ALG_MD5: 167 if (md5_init(&ctx->u.md) != CRYPT_OK) 168 goto fail; 169 break; 170 case CRYPTO_HASH_ALG_SHA1: 171 if (sha1_init(&ctx->u.md) != CRYPT_OK) 172 goto fail; 173 break; 174 case CRYPTO_HASH_ALG_HMAC_MD5: 175 if (hmac_init(&ctx->u.hmac, find_hash("md5"), key, key_len) != 176 CRYPT_OK) 177 goto fail; 178 break; 179 case CRYPTO_HASH_ALG_HMAC_SHA1: 180 if (hmac_init(&ctx->u.hmac, find_hash("sha1"), key, key_len) != 181 CRYPT_OK) 182 goto fail; 183 break; 184 default: 185 goto fail; 186 } 187 188 return ctx; 189 190 fail: 191 os_free(ctx); 192 return NULL; 193 } 194 195 void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len) 196 { 197 if (ctx == NULL || ctx->error) 198 return; 199 200 switch (ctx->alg) { 201 case CRYPTO_HASH_ALG_MD5: 202 ctx->error = md5_process(&ctx->u.md, data, len) != CRYPT_OK; 203 break; 204 case CRYPTO_HASH_ALG_SHA1: 205 ctx->error = sha1_process(&ctx->u.md, data, len) != CRYPT_OK; 206 break; 207 case CRYPTO_HASH_ALG_HMAC_MD5: 208 case CRYPTO_HASH_ALG_HMAC_SHA1: 209 ctx->error = hmac_process(&ctx->u.hmac, data, len) != CRYPT_OK; 210 break; 211 } 212 } 213 214 215 int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len) 216 { 217 int ret = 0; 218 unsigned long clen; 219 220 if (ctx == NULL) 221 return -2; 222 223 if (mac == NULL || len == NULL) { 224 os_free(ctx); 225 return 0; 226 } 227 228 if (ctx->error) { 229 os_free(ctx); 230 return -2; 231 } 232 233 switch (ctx->alg) { 234 case CRYPTO_HASH_ALG_MD5: 235 if (*len < 16) { 236 *len = 16; 237 os_free(ctx); 238 return -1; 239 } 240 *len = 16; 241 if (md5_done(&ctx->u.md, mac) != CRYPT_OK) 242 ret = -2; 243 break; 244 case CRYPTO_HASH_ALG_SHA1: 245 if (*len < 20) { 246 *len = 20; 247 os_free(ctx); 248 return -1; 249 } 250 *len = 20; 251 if (sha1_done(&ctx->u.md, mac) != CRYPT_OK) 252 ret = -2; 253 break; 254 case CRYPTO_HASH_ALG_HMAC_SHA1: 255 if (*len < 20) { 256 *len = 20; 257 os_free(ctx); 258 return -1; 259 } 260 /* continue */ 261 case CRYPTO_HASH_ALG_HMAC_MD5: 262 if (*len < 16) { 263 *len = 16; 264 os_free(ctx); 265 return -1; 266 } 267 clen = *len; 268 if (hmac_done(&ctx->u.hmac, mac, &clen) != CRYPT_OK) { 269 os_free(ctx); 270 return -1; 271 } 272 *len = clen; 273 break; 274 default: 275 ret = -2; 276 break; 277 } 278 279 os_free(ctx); 280 281 return ret; 282 } 283 284 285 struct crypto_cipher { 286 int rc4; 287 union { 288 symmetric_CBC cbc; 289 struct { 290 size_t used_bytes; 291 u8 key[16]; 292 size_t keylen; 293 } rc4; 294 } u; 295 }; 296 297 298 struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg, 299 const u8 *iv, const u8 *key, 300 size_t key_len) 301 { 302 struct crypto_cipher *ctx; 303 int idx, res, rc4 = 0; 304 305 switch (alg) { 306 case CRYPTO_CIPHER_ALG_AES: 307 idx = find_cipher("aes"); 308 break; 309 case CRYPTO_CIPHER_ALG_3DES: 310 idx = find_cipher("3des"); 311 break; 312 case CRYPTO_CIPHER_ALG_DES: 313 idx = find_cipher("des"); 314 break; 315 case CRYPTO_CIPHER_ALG_RC2: 316 idx = find_cipher("rc2"); 317 break; 318 case CRYPTO_CIPHER_ALG_RC4: 319 idx = -1; 320 rc4 = 1; 321 break; 322 default: 323 return NULL; 324 } 325 326 ctx = os_zalloc(sizeof(*ctx)); 327 if (ctx == NULL) 328 return NULL; 329 330 if (rc4) { 331 ctx->rc4 = 1; 332 if (key_len > sizeof(ctx->u.rc4.key)) { 333 os_free(ctx); 334 return NULL; 335 } 336 ctx->u.rc4.keylen = key_len; 337 os_memcpy(ctx->u.rc4.key, key, key_len); 338 } else { 339 res = cbc_start(idx, iv, key, key_len, 0, &ctx->u.cbc); 340 if (res != CRYPT_OK) { 341 wpa_printf(MSG_DEBUG, "LibTomCrypt: Cipher start " 342 "failed: %s", error_to_string(res)); 343 os_free(ctx); 344 return NULL; 345 } 346 } 347 348 return ctx; 349 } 350 351 int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain, 352 u8 *crypt, size_t len) 353 { 354 int res; 355 356 if (ctx->rc4) { 357 if (plain != crypt) 358 os_memcpy(crypt, plain, len); 359 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen, 360 ctx->u.rc4.used_bytes, crypt, len); 361 ctx->u.rc4.used_bytes += len; 362 return 0; 363 } 364 365 res = cbc_encrypt(plain, crypt, len, &ctx->u.cbc); 366 if (res != CRYPT_OK) { 367 wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC encryption " 368 "failed: %s", error_to_string(res)); 369 return -1; 370 } 371 return 0; 372 } 373 374 375 int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt, 376 u8 *plain, size_t len) 377 { 378 int res; 379 380 if (ctx->rc4) { 381 if (plain != crypt) 382 os_memcpy(plain, crypt, len); 383 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen, 384 ctx->u.rc4.used_bytes, plain, len); 385 ctx->u.rc4.used_bytes += len; 386 return 0; 387 } 388 389 res = cbc_decrypt(crypt, plain, len, &ctx->u.cbc); 390 if (res != CRYPT_OK) { 391 wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC decryption " 392 "failed: %s", error_to_string(res)); 393 return -1; 394 } 395 396 return 0; 397 } 398 399 400 void crypto_cipher_deinit(struct crypto_cipher *ctx) 401 { 402 if (!ctx->rc4) 403 cbc_done(&ctx->u.cbc); 404 os_free(ctx); 405 } 406 407 408 struct crypto_public_key { 409 rsa_key rsa; 410 }; 411 412 struct crypto_private_key { 413 rsa_key rsa; 414 }; 415 416 417 struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len) 418 { 419 int res; 420 struct crypto_public_key *pk; 421 422 pk = os_zalloc(sizeof(*pk)); 423 if (pk == NULL) 424 return NULL; 425 426 res = rsa_import(key, len, &pk->rsa); 427 if (res != CRYPT_OK) { 428 wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import " 429 "public key (res=%d '%s')", 430 res, error_to_string(res)); 431 os_free(pk); 432 return NULL; 433 } 434 435 if (pk->rsa.type != PK_PUBLIC) { 436 wpa_printf(MSG_ERROR, "LibTomCrypt: Public key was not of " 437 "correct type"); 438 rsa_free(&pk->rsa); 439 os_free(pk); 440 return NULL; 441 } 442 443 return pk; 444 } 445 446 447 struct crypto_private_key * crypto_private_key_import(const u8 *key, 448 size_t len, 449 const char *passwd) 450 { 451 int res; 452 struct crypto_private_key *pk; 453 454 pk = os_zalloc(sizeof(*pk)); 455 if (pk == NULL) 456 return NULL; 457 458 res = rsa_import(key, len, &pk->rsa); 459 if (res != CRYPT_OK) { 460 wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import " 461 "private key (res=%d '%s')", 462 res, error_to_string(res)); 463 os_free(pk); 464 return NULL; 465 } 466 467 if (pk->rsa.type != PK_PRIVATE) { 468 wpa_printf(MSG_ERROR, "LibTomCrypt: Private key was not of " 469 "correct type"); 470 rsa_free(&pk->rsa); 471 os_free(pk); 472 return NULL; 473 } 474 475 return pk; 476 } 477 478 479 struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf, 480 size_t len) 481 { 482 /* No X.509 support in LibTomCrypt */ 483 return NULL; 484 } 485 486 487 static int pkcs1_generate_encryption_block(u8 block_type, size_t modlen, 488 const u8 *in, size_t inlen, 489 u8 *out, size_t *outlen) 490 { 491 size_t ps_len; 492 u8 *pos; 493 494 /* 495 * PKCS #1 v1.5, 8.1: 496 * 497 * EB = 00 || BT || PS || 00 || D 498 * BT = 00 or 01 for private-key operation; 02 for public-key operation 499 * PS = k-3-||D||; at least eight octets 500 * (BT=0: PS=0x00, BT=1: PS=0xff, BT=2: PS=pseudorandom non-zero) 501 * k = length of modulus in octets (modlen) 502 */ 503 504 if (modlen < 12 || modlen > *outlen || inlen > modlen - 11) { 505 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Invalid buffer " 506 "lengths (modlen=%lu outlen=%lu inlen=%lu)", 507 __func__, (unsigned long) modlen, 508 (unsigned long) *outlen, 509 (unsigned long) inlen); 510 return -1; 511 } 512 513 pos = out; 514 *pos++ = 0x00; 515 *pos++ = block_type; /* BT */ 516 ps_len = modlen - inlen - 3; 517 switch (block_type) { 518 case 0: 519 os_memset(pos, 0x00, ps_len); 520 pos += ps_len; 521 break; 522 case 1: 523 os_memset(pos, 0xff, ps_len); 524 pos += ps_len; 525 break; 526 case 2: 527 if (os_get_random(pos, ps_len) < 0) { 528 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Failed to get " 529 "random data for PS", __func__); 530 return -1; 531 } 532 while (ps_len--) { 533 if (*pos == 0x00) 534 *pos = 0x01; 535 pos++; 536 } 537 break; 538 default: 539 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Unsupported block type " 540 "%d", __func__, block_type); 541 return -1; 542 } 543 *pos++ = 0x00; 544 os_memcpy(pos, in, inlen); /* D */ 545 546 return 0; 547 } 548 549 550 static int crypto_rsa_encrypt_pkcs1(int block_type, rsa_key *key, int key_type, 551 const u8 *in, size_t inlen, 552 u8 *out, size_t *outlen) 553 { 554 unsigned long len, modlen; 555 int res; 556 557 modlen = mp_unsigned_bin_size(key->N); 558 559 if (pkcs1_generate_encryption_block(block_type, modlen, in, inlen, 560 out, outlen) < 0) 561 return -1; 562 563 len = *outlen; 564 res = rsa_exptmod(out, modlen, out, &len, key_type, key); 565 if (res != CRYPT_OK) { 566 wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s", 567 error_to_string(res)); 568 return -1; 569 } 570 *outlen = len; 571 572 return 0; 573 } 574 575 576 int crypto_public_key_encrypt_pkcs1_v15(struct crypto_public_key *key, 577 const u8 *in, size_t inlen, 578 u8 *out, size_t *outlen) 579 { 580 return crypto_rsa_encrypt_pkcs1(2, &key->rsa, PK_PUBLIC, in, inlen, 581 out, outlen); 582 } 583 584 585 int crypto_private_key_sign_pkcs1(struct crypto_private_key *key, 586 const u8 *in, size_t inlen, 587 u8 *out, size_t *outlen) 588 { 589 return crypto_rsa_encrypt_pkcs1(1, &key->rsa, PK_PRIVATE, in, inlen, 590 out, outlen); 591 } 592 593 594 void crypto_public_key_free(struct crypto_public_key *key) 595 { 596 if (key) { 597 rsa_free(&key->rsa); 598 os_free(key); 599 } 600 } 601 602 603 void crypto_private_key_free(struct crypto_private_key *key) 604 { 605 if (key) { 606 rsa_free(&key->rsa); 607 os_free(key); 608 } 609 } 610 611 612 int crypto_public_key_decrypt_pkcs1(struct crypto_public_key *key, 613 const u8 *crypt, size_t crypt_len, 614 u8 *plain, size_t *plain_len) 615 { 616 int res; 617 unsigned long len; 618 u8 *pos; 619 620 len = *plain_len; 621 res = rsa_exptmod(crypt, crypt_len, plain, &len, PK_PUBLIC, 622 &key->rsa); 623 if (res != CRYPT_OK) { 624 wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s", 625 error_to_string(res)); 626 return -1; 627 } 628 629 /* 630 * PKCS #1 v1.5, 8.1: 631 * 632 * EB = 00 || BT || PS || 00 || D 633 * BT = 01 634 * PS = k-3-||D|| times FF 635 * k = length of modulus in octets 636 */ 637 638 if (len < 3 + 8 + 16 /* min hash len */ || 639 plain[0] != 0x00 || plain[1] != 0x01 || plain[2] != 0xff) { 640 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB " 641 "structure"); 642 return -1; 643 } 644 645 pos = plain + 3; 646 while (pos < plain + len && *pos == 0xff) 647 pos++; 648 if (pos - plain - 2 < 8) { 649 /* PKCS #1 v1.5, 8.1: At least eight octets long PS */ 650 wpa_printf(MSG_INFO, "LibTomCrypt: Too short signature " 651 "padding"); 652 return -1; 653 } 654 655 if (pos + 16 /* min hash len */ >= plain + len || *pos != 0x00) { 656 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB " 657 "structure (2)"); 658 return -1; 659 } 660 pos++; 661 len -= pos - plain; 662 663 /* Strip PKCS #1 header */ 664 os_memmove(plain, pos, len); 665 *plain_len = len; 666 667 return 0; 668 } 669 670 671 int crypto_global_init(void) 672 { 673 ltc_mp = tfm_desc; 674 /* TODO: only register algorithms that are really needed */ 675 if (register_hash(&md4_desc) < 0 || 676 register_hash(&md5_desc) < 0 || 677 register_hash(&sha1_desc) < 0 || 678 register_cipher(&aes_desc) < 0 || 679 register_cipher(&des_desc) < 0 || 680 register_cipher(&des3_desc) < 0) { 681 wpa_printf(MSG_ERROR, "TLSv1: Failed to register " 682 "hash/cipher functions"); 683 return -1; 684 } 685 686 return 0; 687 } 688 689 690 void crypto_global_deinit(void) 691 { 692 } 693 694 695 #ifdef CONFIG_MODEXP 696 697 int crypto_dh_init(u8 generator, const u8 *prime, size_t prime_len, u8 *privkey, 698 u8 *pubkey) 699 { 700 size_t pubkey_len, pad; 701 702 if (os_get_random(privkey, prime_len) < 0) 703 return -1; 704 if (os_memcmp(privkey, prime, prime_len) > 0) { 705 /* Make sure private value is smaller than prime */ 706 privkey[0] = 0; 707 } 708 709 pubkey_len = prime_len; 710 if (crypto_mod_exp(&generator, 1, privkey, prime_len, prime, prime_len, 711 pubkey, &pubkey_len) < 0) 712 return -1; 713 if (pubkey_len < prime_len) { 714 pad = prime_len - pubkey_len; 715 os_memmove(pubkey + pad, pubkey, pubkey_len); 716 os_memset(pubkey, 0, pad); 717 } 718 719 return 0; 720 } 721 722 723 int crypto_dh_derive_secret(u8 generator, const u8 *prime, size_t prime_len, 724 const u8 *privkey, size_t privkey_len, 725 const u8 *pubkey, size_t pubkey_len, 726 u8 *secret, size_t *len) 727 { 728 return crypto_mod_exp(pubkey, pubkey_len, privkey, privkey_len, 729 prime, prime_len, secret, len); 730 } 731 732 733 int crypto_mod_exp(const u8 *base, size_t base_len, 734 const u8 *power, size_t power_len, 735 const u8 *modulus, size_t modulus_len, 736 u8 *result, size_t *result_len) 737 { 738 void *b, *p, *m, *r; 739 740 if (mp_init_multi(&b, &p, &m, &r, NULL) != CRYPT_OK) 741 return -1; 742 743 if (mp_read_unsigned_bin(b, (u8 *) base, base_len) != CRYPT_OK || 744 mp_read_unsigned_bin(p, (u8 *) power, power_len) != CRYPT_OK || 745 mp_read_unsigned_bin(m, (u8 *) modulus, modulus_len) != CRYPT_OK) 746 goto fail; 747 748 if (mp_exptmod(b, p, m, r) != CRYPT_OK) 749 goto fail; 750 751 *result_len = mp_unsigned_bin_size(r); 752 if (mp_to_unsigned_bin(r, result) != CRYPT_OK) 753 goto fail; 754 755 mp_clear_multi(b, p, m, r, NULL); 756 return 0; 757 758 fail: 759 mp_clear_multi(b, p, m, r, NULL); 760 return -1; 761 } 762 763 #endif /* CONFIG_MODEXP */ 764