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 program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16 #include <tomcrypt.h>
  17
  18 #include "common.h"
  19 #include "crypto.h"
  20
  21 #ifndef mp_init_multi
  22 #define mp_init_multi                ltc_init_multi
  23 #define mp_clear_multi               ltc_deinit_multi
  24 #define mp_unsigned_bin_size(a)      ltc_mp.unsigned_size(a)
  25 #define mp_to_unsigned_bin(a, b)     ltc_mp.unsigned_write(a, b)
  26 #define mp_read_unsigned_bin(a, b, c) ltc_mp.unsigned_read(a, b, c)
  27 #define mp_exptmod(a,b,c,d)          ltc_mp.exptmod(a,b,c,d)
  28 #endif
  29
  30
  31 int md4_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
  32 {
  33         hash_state md;
  34         size_t i;
  35
  36         md4_init(&md);
  37         for (i = 0; i < num_elem; i++)
  38                 md4_process(&md, addr[i], len[i]);
  39         md4_done(&md, mac);
  40         return 0;
  41 }
  42
  43
  44 void des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
  45 {
  46         u8 pkey[8], next, tmp;
  47         int i;
  48         symmetric_key skey;
  49
  50         /* Add parity bits to the key */
  51         next = 0;
  52         for (i = 0; i < 7; i++) {
  53                 tmp = key[i];
  54                 pkey[i] = (tmp >> i) | next | 1;
  55                 next = tmp << (7 - i);
  56         }
  57         pkey[i] = next | 1;
  58
  59         des_setup(pkey, 8, 0, &skey);
  60         des_ecb_encrypt(clear, cypher, &skey);
  61         des_done(&skey);
  62 }
  63
  64
  65 int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
  66 {
  67         hash_state md;
  68         size_t i;
  69
  70         md5_init(&md);
  71         for (i = 0; i < num_elem; i++)
  72                 md5_process(&md, addr[i], len[i]);
  73         md5_done(&md, mac);
  74         return 0;
  75 }
  76
  77
  78 int sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
  79 {
  80         hash_state md;
  81         size_t i;
  82
  83         sha1_init(&md);
  84         for (i = 0; i < num_elem; i++)
  85                 sha1_process(&md, addr[i], len[i]);
  86         sha1_done(&md, mac);
  87         return 0;
  88 }
  89
  90
  91 void * aes_encrypt_init(const u8 *key, size_t len)
  92 {
  93         symmetric_key *skey;
  94         skey = os_malloc(sizeof(*skey));
  95         if (skey == NULL)
  96                 return NULL;
  97         if (aes_setup(key, len, 0, skey) != CRYPT_OK) {
  98                 os_free(skey);
  99                 return NULL;
 100         }
 101         return skey;
 102 }
 103
 104
 105 void aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
 106 {
 107         symmetric_key *skey = ctx;
 108         aes_ecb_encrypt(plain, crypt, skey);
 109 }
 110
 111
 112 void aes_encrypt_deinit(void *ctx)
 113 {
 114         symmetric_key *skey = ctx;
 115         aes_done(skey);
 116         os_free(skey);
 117 }
 118
 119
 120 void * aes_decrypt_init(const u8 *key, size_t len)
 121 {
 122         symmetric_key *skey;
 123         skey = os_malloc(sizeof(*skey));
 124         if (skey == NULL)
 125                 return NULL;
 126         if (aes_setup(key, len, 0, skey) != CRYPT_OK) {
 127                 os_free(skey);
 128                 return NULL;
 129         }
 130         return skey;
 131 }
 132
 133
 134 void aes_decrypt(void *ctx, const u8 *crypt, u8 *plain)
 135 {
 136         symmetric_key *skey = ctx;
 137         aes_ecb_encrypt(plain, (u8 *) crypt, skey);
 138 }
 139
 140
 141 void aes_decrypt_deinit(void *ctx)
 142 {
 143         symmetric_key *skey = ctx;
 144         aes_done(skey);
 145         os_free(skey);
 146 }
 147
 148
 149 struct crypto_hash {
 150         enum crypto_hash_alg alg;
 151         int error;
 152         union {
 153                 hash_state md;
 154                 hmac_state hmac;
 155         } u;
 156 };
 157
 158
 159 struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
 160                                       size_t key_len)
 161 {
 162         struct crypto_hash *ctx;
 163
 164         ctx = os_zalloc(sizeof(*ctx));
 165         if (ctx == NULL)
 166                 return NULL;
 167
 168         ctx->alg = alg;
 169
 170         switch (alg) {
 171         case CRYPTO_HASH_ALG_MD5:
 172                 if (md5_init(&ctx->u.md) != CRYPT_OK)
 173                         goto fail;
 174                 break;
 175         case CRYPTO_HASH_ALG_SHA1:
 176                 if (sha1_init(&ctx->u.md) != CRYPT_OK)
 177                         goto fail;
 178                 break;
 179         case CRYPTO_HASH_ALG_HMAC_MD5:
 180                 if (hmac_init(&ctx->u.hmac, find_hash("md5"), key, key_len) !=
 181                     CRYPT_OK)
 182                         goto fail;
 183                 break;
 184         case CRYPTO_HASH_ALG_HMAC_SHA1:
 185                 if (hmac_init(&ctx->u.hmac, find_hash("sha1"), key, key_len) !=
 186                     CRYPT_OK)
 187                         goto fail;
 188                 break;
 189         default:
 190                 goto fail;
 191         }
 192
 193         return ctx;
 194
 195 fail:
 196         os_free(ctx);
 197         return NULL;
 198 }
 199
 200 void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len)
 201 {
 202         if (ctx == NULL || ctx->error)
 203                 return;
 204
 205         switch (ctx->alg) {
 206         case CRYPTO_HASH_ALG_MD5:
 207                 ctx->error = md5_process(&ctx->u.md, data, len) != CRYPT_OK;
 208                 break;
 209         case CRYPTO_HASH_ALG_SHA1:
 210                 ctx->error = sha1_process(&ctx->u.md, data, len) != CRYPT_OK;
 211                 break;
 212         case CRYPTO_HASH_ALG_HMAC_MD5:
 213         case CRYPTO_HASH_ALG_HMAC_SHA1:
 214                 ctx->error = hmac_process(&ctx->u.hmac, data, len) != CRYPT_OK;
 215                 break;
 216         }
 217 }
 218
 219
 220 int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
 221 {
 222         int ret = 0;
 223         unsigned long clen;
 224
 225         if (ctx == NULL)
 226                 return -2;
 227
 228         if (mac == NULL || len == NULL) {
 229                 os_free(ctx);
 230                 return 0;
 231         }
 232
 233         if (ctx->error) {
 234                 os_free(ctx);
 235                 return -2;
 236         }
 237
 238         switch (ctx->alg) {
 239         case CRYPTO_HASH_ALG_MD5:
 240                 if (*len < 16) {
 241                         *len = 16;
 242                         os_free(ctx);
 243                         return -1;
 244                 }
 245                 *len = 16;
 246                 if (md5_done(&ctx->u.md, mac) != CRYPT_OK)
 247                         ret = -2;
 248                 break;
 249         case CRYPTO_HASH_ALG_SHA1:
 250                 if (*len < 20) {
 251                         *len = 20;
 252                         os_free(ctx);
 253                         return -1;
 254                 }
 255                 *len = 20;
 256                 if (sha1_done(&ctx->u.md, mac) != CRYPT_OK)
 257                         ret = -2;
 258                 break;
 259         case CRYPTO_HASH_ALG_HMAC_SHA1:
 260                 if (*len < 20) {
 261                         *len = 20;
 262                         os_free(ctx);
 263                         return -1;
 264                 }
 265                 /* continue */
 266         case CRYPTO_HASH_ALG_HMAC_MD5:
 267                 if (*len < 16) {
 268                         *len = 16;
 269                         os_free(ctx);
 270                         return -1;
 271                 }
 272                 clen = *len;
 273                 if (hmac_done(&ctx->u.hmac, mac, &clen) != CRYPT_OK) {
 274                         os_free(ctx);
 275                         return -1;
 276                 }
 277                 *len = clen;
 278                 break;
 279         default:
 280                 ret = -2;
 281                 break;
 282         }
 283
 284         os_free(ctx);
 285
 286         return ret;
 287 }
 288
 289
 290 struct crypto_cipher {
 291         int rc4;
 292         union {
 293                 symmetric_CBC cbc;
 294                 struct {
 295                         size_t used_bytes;
 296                         u8 key[16];
 297                         size_t keylen;
 298                 } rc4;
 299         } u;
 300 };
 301
 302
 303 struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
 304                                           const u8 *iv, const u8 *key,
 305                                           size_t key_len)
 306 {
 307         struct crypto_cipher *ctx;
 308         int idx, res, rc4 = 0;
 309
 310         switch (alg) {
 311         case CRYPTO_CIPHER_ALG_AES:
 312                 idx = find_cipher("aes");
 313                 break;
 314         case CRYPTO_CIPHER_ALG_3DES:
 315                 idx = find_cipher("3des");
 316                 break;
 317         case CRYPTO_CIPHER_ALG_DES:
 318                 idx = find_cipher("des");
 319                 break;
 320         case CRYPTO_CIPHER_ALG_RC2:
 321                 idx = find_cipher("rc2");
 322                 break;
 323         case CRYPTO_CIPHER_ALG_RC4:
 324                 idx = -1;
 325                 rc4 = 1;
 326                 break;
 327         default:
 328                 return NULL;
 329         }
 330
 331         ctx = os_zalloc(sizeof(*ctx));
 332         if (ctx == NULL)
 333                 return NULL;
 334
 335         if (rc4) {
 336                 ctx->rc4 = 1;
 337                 if (key_len > sizeof(ctx->u.rc4.key)) {
 338                         os_free(ctx);
 339                         return NULL;
 340                 }
 341                 ctx->u.rc4.keylen = key_len;
 342                 os_memcpy(ctx->u.rc4.key, key, key_len);
 343         } else {
 344                 res = cbc_start(idx, iv, key, key_len, 0, &ctx->u.cbc);
 345                 if (res != CRYPT_OK) {
 346                         wpa_printf(MSG_DEBUG, "LibTomCrypt: Cipher start "
 347                                    "failed: %s", error_to_string(res));
 348                         os_free(ctx);
 349                         return NULL;
 350                 }
 351         }
 352
 353         return ctx;
 354 }
 355
 356 int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
 357                           u8 *crypt, size_t len)
 358 {
 359         int res;
 360
 361         if (ctx->rc4) {
 362                 if (plain != crypt)
 363                         os_memcpy(crypt, plain, len);
 364                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 365                          ctx->u.rc4.used_bytes, crypt, len);
 366                 ctx->u.rc4.used_bytes += len;
 367                 return 0;
 368         }
 369
 370         res = cbc_encrypt(plain, crypt, len, &ctx->u.cbc);
 371         if (res != CRYPT_OK) {
 372                 wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC encryption "
 373                            "failed: %s", error_to_string(res));
 374                 return -1;
 375         }
 376         return 0;
 377 }
 378
 379
 380 int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
 381                           u8 *plain, size_t len)
 382 {
 383         int res;
 384
 385         if (ctx->rc4) {
 386                 if (plain != crypt)
 387                         os_memcpy(plain, crypt, len);
 388                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 389                          ctx->u.rc4.used_bytes, plain, len);
 390                 ctx->u.rc4.used_bytes += len;
 391                 return 0;
 392         }
 393
 394         res = cbc_decrypt(crypt, plain, len, &ctx->u.cbc);
 395         if (res != CRYPT_OK) {
 396                 wpa_printf(MSG_DEBUG, "LibTomCrypt: CBC decryption "
 397                            "failed: %s", error_to_string(res));
 398                 return -1;
 399         }
 400
 401         return 0;
 402 }
 403
 404
 405 void crypto_cipher_deinit(struct crypto_cipher *ctx)
 406 {
 407         if (!ctx->rc4)
 408                 cbc_done(&ctx->u.cbc);
 409         os_free(ctx);
 410 }
 411
 412
 413 struct crypto_public_key {
 414         rsa_key rsa;
 415 };
 416
 417 struct crypto_private_key {
 418         rsa_key rsa;
 419 };
 420
 421
 422 struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len)
 423 {
 424         int res;
 425         struct crypto_public_key *pk;
 426
 427         pk = os_zalloc(sizeof(*pk));
 428         if (pk == NULL)
 429                 return NULL;
 430
 431         res = rsa_import(key, len, &pk->rsa);
 432         if (res != CRYPT_OK) {
 433                 wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import "
 434                            "public key (res=%d '%s')",
 435                            res, error_to_string(res));
 436                 os_free(pk);
 437                 return NULL;
 438         }
 439
 440         if (pk->rsa.type != PK_PUBLIC) {
 441                 wpa_printf(MSG_ERROR, "LibTomCrypt: Public key was not of "
 442                            "correct type");
 443                 rsa_free(&pk->rsa);
 444                 os_free(pk);
 445                 return NULL;
 446         }
 447
 448         return pk;
 449 }
 450
 451
 452 struct crypto_private_key * crypto_private_key_import(const u8 *key,
 453                                                       size_t len,
 454                                                       const char *passwd)
 455 {
 456         int res;
 457         struct crypto_private_key *pk;
 458
 459         pk = os_zalloc(sizeof(*pk));
 460         if (pk == NULL)
 461                 return NULL;
 462
 463         res = rsa_import(key, len, &pk->rsa);
 464         if (res != CRYPT_OK) {
 465                 wpa_printf(MSG_ERROR, "LibTomCrypt: Failed to import "
 466                            "private key (res=%d '%s')",
 467                            res, error_to_string(res));
 468                 os_free(pk);
 469                 return NULL;
 470         }
 471
 472         if (pk->rsa.type != PK_PRIVATE) {
 473                 wpa_printf(MSG_ERROR, "LibTomCrypt: Private key was not of "
 474                            "correct type");
 475                 rsa_free(&pk->rsa);
 476                 os_free(pk);
 477                 return NULL;
 478         }
 479
 480         return pk;
 481 }
 482
 483
 484 struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf,
 485                                                        size_t len)
 486 {
 487         /* No X.509 support in LibTomCrypt */
 488         return NULL;
 489 }
 490
 491
 492 static int pkcs1_generate_encryption_block(u8 block_type, size_t modlen,
 493                                            const u8 *in, size_t inlen,
 494                                            u8 *out, size_t *outlen)
 495 {
 496         size_t ps_len;
 497         u8 *pos;
 498
 499         /*
 500          * PKCS #1 v1.5, 8.1:
 501          *
 502          * EB = 00 || BT || PS || 00 || D
 503          * BT = 00 or 01 for private-key operation; 02 for public-key operation
 504          * PS = k-3-||D||; at least eight octets
 505          * (BT=0: PS=0x00, BT=1: PS=0xff, BT=2: PS=pseudorandom non-zero)
 506          * k = length of modulus in octets (modlen)
 507          */
 508
 509         if (modlen < 12 || modlen > *outlen || inlen > modlen - 11) {
 510                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Invalid buffer "
 511                            "lengths (modlen=%lu outlen=%lu inlen=%lu)",
 512                            __func__, (unsigned long) modlen,
 513                            (unsigned long) *outlen,
 514                            (unsigned long) inlen);
 515                 return -1;
 516         }
 517
 518         pos = out;
 519         *pos++ = 0x00;
 520         *pos++ = block_type; /* BT */
 521         ps_len = modlen - inlen - 3;
 522         switch (block_type) {
 523         case 0:
 524                 os_memset(pos, 0x00, ps_len);
 525                 pos += ps_len;
 526                 break;
 527         case 1:
 528                 os_memset(pos, 0xff, ps_len);
 529                 pos += ps_len;
 530                 break;
 531         case 2:
 532                 if (os_get_random(pos, ps_len) < 0) {
 533                         wpa_printf(MSG_DEBUG, "PKCS #1: %s - Failed to get "
 534                                    "random data for PS", __func__);
 535                         return -1;
 536                 }
 537                 while (ps_len--) {
 538                         if (*pos == 0x00)
 539                                 *pos = 0x01;
 540                         pos++;
 541                 }
 542                 break;
 543         default:
 544                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Unsupported block type "
 545                            "%d", __func__, block_type);
 546                 return -1;
 547         }
 548         *pos++ = 0x00;
 549         os_memcpy(pos, in, inlen); /* D */
 550
 551         return 0;
 552 }
 553
 554
 555 static int crypto_rsa_encrypt_pkcs1(int block_type, rsa_key *key, int key_type,
 556                                     const u8 *in, size_t inlen,
 557                                     u8 *out, size_t *outlen)
 558 {
 559         unsigned long len, modlen;
 560         int res;
 561
 562         modlen = mp_unsigned_bin_size(key->N);
 563
 564         if (pkcs1_generate_encryption_block(block_type, modlen, in, inlen,
 565                                             out, outlen) < 0)
 566                 return -1;
 567
 568         len = *outlen;
 569         res = rsa_exptmod(out, modlen, out, &len, key_type, key);
 570         if (res != CRYPT_OK) {
 571                 wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s",
 572                            error_to_string(res));
 573                 return -1;
 574         }
 575         *outlen = len;
 576
 577         return 0;
 578 }
 579
 580
 581 int crypto_public_key_encrypt_pkcs1_v15(struct crypto_public_key *key,
 582                                         const u8 *in, size_t inlen,
 583                                         u8 *out, size_t *outlen)
 584 {
 585         return crypto_rsa_encrypt_pkcs1(2, &key->rsa, PK_PUBLIC, in, inlen,
 586                                         out, outlen);
 587 }
 588
 589
 590 int crypto_private_key_sign_pkcs1(struct crypto_private_key *key,
 591                                   const u8 *in, size_t inlen,
 592                                   u8 *out, size_t *outlen)
 593 {
 594         return crypto_rsa_encrypt_pkcs1(1, &key->rsa, PK_PRIVATE, in, inlen,
 595                                         out, outlen);
 596 }
 597
 598
 599 void crypto_public_key_free(struct crypto_public_key *key)
 600 {
 601         if (key) {
 602                 rsa_free(&key->rsa);
 603                 os_free(key);
 604         }
 605 }
 606
 607
 608 void crypto_private_key_free(struct crypto_private_key *key)
 609 {
 610         if (key) {
 611                 rsa_free(&key->rsa);
 612                 os_free(key);
 613         }
 614 }
 615
 616
 617 int crypto_public_key_decrypt_pkcs1(struct crypto_public_key *key,
 618                                     const u8 *crypt, size_t crypt_len,
 619                                     u8 *plain, size_t *plain_len)
 620 {
 621         int res;
 622         unsigned long len;
 623         u8 *pos;
 624
 625         len = *plain_len;
 626         res = rsa_exptmod(crypt, crypt_len, plain, &len, PK_PUBLIC,
 627                           &key->rsa);
 628         if (res != CRYPT_OK) {
 629                 wpa_printf(MSG_DEBUG, "LibTomCrypt: rsa_exptmod failed: %s",
 630                            error_to_string(res));
 631                 return -1;
 632         }
 633
 634         /*
 635          * PKCS #1 v1.5, 8.1:
 636          *
 637          * EB = 00 || BT || PS || 00 || D
 638          * BT = 01
 639          * PS = k-3-||D|| times FF
 640          * k = length of modulus in octets
 641          */
 642
 643         if (len < 3 + 8 + 16 /* min hash len */ ||
 644             plain[0] != 0x00 || plain[1] != 0x01 || plain[2] != 0xff) {
 645                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 646                            "structure");
 647                 return -1;
 648         }
 649
 650         pos = plain + 3;
 651         while (pos < plain + len && *pos == 0xff)
 652                 pos++;
 653         if (pos - plain - 2 < 8) {
 654                 /* PKCS #1 v1.5, 8.1: At least eight octets long PS */
 655                 wpa_printf(MSG_INFO, "LibTomCrypt: Too short signature "
 656                            "padding");
 657                 return -1;
 658         }
 659
 660         if (pos + 16 /* min hash len */ >= plain + len || *pos != 0x00) {
 661                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 662                            "structure (2)");
 663                 return -1;
 664         }
 665         pos++;
 666         len -= pos - plain;
 667
 668         /* Strip PKCS #1 header */
 669         os_memmove(plain, pos, len);
 670         *plain_len = len;
 671
 672         return 0;
 673 }
 674
 675
 676 int crypto_global_init(void)
 677 {
 678         ltc_mp = tfm_desc;
 679         /* TODO: only register algorithms that are really needed */
 680         if (register_hash(&md4_desc) < 0 ||
 681             register_hash(&md5_desc) < 0 ||
 682             register_hash(&sha1_desc) < 0 ||
 683             register_cipher(&aes_desc) < 0 ||
 684             register_cipher(&des_desc) < 0 ||
 685             register_cipher(&des3_desc) < 0) {
 686                 wpa_printf(MSG_ERROR, "TLSv1: Failed to register "
 687                            "hash/cipher functions");
 688                 return -1;
 689         }
 690
 691         return 0;
 692 }
 693
 694
 695 void crypto_global_deinit(void)
 696 {
 697 }
 698
 699
 700 #ifdef CONFIG_MODEXP
 701
 702 int crypto_mod_exp(const u8 *base, size_t base_len,
 703                    const u8 *power, size_t power_len,
 704                    const u8 *modulus, size_t modulus_len,
 705                    u8 *result, size_t *result_len)
 706 {
 707         void *b, *p, *m, *r;
 708
 709         if (mp_init_multi(&b, &p, &m, &r, NULL) != CRYPT_OK)
 710                 return -1;
 711
 712         if (mp_read_unsigned_bin(b, (u8 *) base, base_len) != CRYPT_OK ||
 713             mp_read_unsigned_bin(p, (u8 *) power, power_len) != CRYPT_OK ||
 714             mp_read_unsigned_bin(m, (u8 *) modulus, modulus_len) != CRYPT_OK)
 715                 goto fail;
 716
 717         if (mp_exptmod(b, p, m, r) != CRYPT_OK)
 718                 goto fail;
 719
 720         *result_len = mp_unsigned_bin_size(r);
 721         if (mp_to_unsigned_bin(r, result) != CRYPT_OK)
 722                 goto fail;
 723
 724         mp_clear_multi(b, p, m, r, NULL);
 725         return 0;
 726
 727 fail:
 728         mp_clear_multi(b, p, m, r, NULL);
 729         return -1;
 730 }
 731
 732 #endif /* CONFIG_MODEXP */