contrib/wpa_supplicant-0.5.8/crypto_internal.c

   1 /*
   2  * WPA Supplicant / Crypto wrapper for internal crypto implementation
   3  * Copyright (c) 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
  17 #include "common.h"
  18 #include "crypto.h"
  19 #include "md5.h"
  20 #include "sha1.h"
  21 #include "rc4.h"
  22 #include "aes.h"
  23 #include "rsa.h"
  24 #include "bignum.h"
  25
  26
  27 #ifdef EAP_TLS_FUNCS
  28
  29 #ifdef CONFIG_TLS_INTERNAL
  30
  31 /* from des.c */
  32 struct des3_key_s {
  33         u32 ek[3][32];
  34         u32 dk[3][32];
  35 };
  36
  37 void des3_key_setup(const u8 *key, struct des3_key_s *dkey);
  38 void des3_encrypt(const u8 *plain, const struct des3_key_s *key, u8 *crypt);
  39 void des3_decrypt(const u8 *crypt, const struct des3_key_s *key, u8 *plain);
  40
  41
  42 struct MD5Context {
  43         u32 buf[4];
  44         u32 bits[2];
  45         u8 in[64];
  46 };
  47
  48 struct SHA1Context {
  49         u32 state[5];
  50         u32 count[2];
  51         unsigned char buffer[64];
  52 };
  53
  54
  55 struct crypto_hash {
  56         enum crypto_hash_alg alg;
  57         union {
  58                 struct MD5Context md5;
  59                 struct SHA1Context sha1;
  60         } u;
  61         u8 key[64];
  62         size_t key_len;
  63 };
  64
  65
  66 struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
  67                                       size_t key_len)
  68 {
  69         struct crypto_hash *ctx;
  70         u8 k_pad[64];
  71         u8 tk[20];
  72         size_t i;
  73
  74         ctx = os_zalloc(sizeof(*ctx));
  75         if (ctx == NULL)
  76                 return NULL;
  77
  78         ctx->alg = alg;
  79
  80         switch (alg) {
  81         case CRYPTO_HASH_ALG_MD5:
  82                 MD5Init(&ctx->u.md5);
  83                 break;
  84         case CRYPTO_HASH_ALG_SHA1:
  85                 SHA1Init(&ctx->u.sha1);
  86                 break;
  87         case CRYPTO_HASH_ALG_HMAC_MD5:
  88                 if (key_len > sizeof(k_pad)) {
  89                         MD5Init(&ctx->u.md5);
  90                         MD5Update(&ctx->u.md5, key, key_len);
  91                         MD5Final(tk, &ctx->u.md5);
  92                         key = tk;
  93                         key_len = 16;
  94                 }
  95                 os_memcpy(ctx->key, key, key_len);
  96                 ctx->key_len = key_len;
  97
  98                 os_memcpy(k_pad, key, key_len);
  99                 os_memset(k_pad + key_len, 0, sizeof(k_pad) - key_len);
 100                 for (i = 0; i < sizeof(k_pad); i++)
 101                         k_pad[i] ^= 0x36;
 102                 MD5Init(&ctx->u.md5);
 103                 MD5Update(&ctx->u.md5, k_pad, sizeof(k_pad));
 104                 break;
 105         case CRYPTO_HASH_ALG_HMAC_SHA1:
 106                 if (key_len > sizeof(k_pad)) {
 107                         SHA1Init(&ctx->u.sha1);
 108                         SHA1Update(&ctx->u.sha1, key, key_len);
 109                         SHA1Final(tk, &ctx->u.sha1);
 110                         key = tk;
 111                         key_len = 20;
 112                 }
 113                 os_memcpy(ctx->key, key, key_len);
 114                 ctx->key_len = key_len;
 115
 116                 os_memcpy(k_pad, key, key_len);
 117                 os_memset(k_pad + key_len, 0, sizeof(k_pad) - key_len);
 118                 for (i = 0; i < sizeof(k_pad); i++)
 119                         k_pad[i] ^= 0x36;
 120                 SHA1Init(&ctx->u.sha1);
 121                 SHA1Update(&ctx->u.sha1, k_pad, sizeof(k_pad));
 122                 break;
 123         default:
 124                 os_free(ctx);
 125                 return NULL;
 126         }
 127
 128         return ctx;
 129 }
 130
 131
 132 void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len)
 133 {
 134         if (ctx == NULL)
 135                 return;
 136
 137         switch (ctx->alg) {
 138         case CRYPTO_HASH_ALG_MD5:
 139         case CRYPTO_HASH_ALG_HMAC_MD5:
 140                 MD5Update(&ctx->u.md5, data, len);
 141                 break;
 142         case CRYPTO_HASH_ALG_SHA1:
 143         case CRYPTO_HASH_ALG_HMAC_SHA1:
 144                 SHA1Update(&ctx->u.sha1, data, len);
 145                 break;
 146         }
 147 }
 148
 149
 150 int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
 151 {
 152         u8 k_pad[64];
 153         size_t i;
 154
 155         if (ctx == NULL)
 156                 return -2;
 157
 158         if (mac == NULL || len == NULL) {
 159                 os_free(ctx);
 160                 return 0;
 161         }
 162
 163         switch (ctx->alg) {
 164         case CRYPTO_HASH_ALG_MD5:
 165                 if (*len < 16) {
 166                         *len = 16;
 167                         os_free(ctx);
 168                         return -1;
 169                 }
 170                 *len = 16;
 171                 MD5Final(mac, &ctx->u.md5);
 172                 break;
 173         case CRYPTO_HASH_ALG_SHA1:
 174                 if (*len < 20) {
 175                         *len = 20;
 176                         os_free(ctx);
 177                         return -1;
 178                 }
 179                 *len = 20;
 180                 SHA1Final(mac, &ctx->u.sha1);
 181                 break;
 182         case CRYPTO_HASH_ALG_HMAC_MD5:
 183                 if (*len < 16) {
 184                         *len = 16;
 185                         os_free(ctx);
 186                         return -1;
 187                 }
 188                 *len = 16;
 189
 190                 MD5Final(mac, &ctx->u.md5);
 191
 192                 os_memcpy(k_pad, ctx->key, ctx->key_len);
 193                 os_memset(k_pad + ctx->key_len, 0,
 194                           sizeof(k_pad) - ctx->key_len);
 195                 for (i = 0; i < sizeof(k_pad); i++)
 196                         k_pad[i] ^= 0x5c;
 197                 MD5Init(&ctx->u.md5);
 198                 MD5Update(&ctx->u.md5, k_pad, sizeof(k_pad));
 199                 MD5Update(&ctx->u.md5, mac, 16);
 200                 MD5Final(mac, &ctx->u.md5);
 201                 break;
 202         case CRYPTO_HASH_ALG_HMAC_SHA1:
 203                 if (*len < 20) {
 204                         *len = 20;
 205                         os_free(ctx);
 206                         return -1;
 207                 }
 208                 *len = 20;
 209
 210                 SHA1Final(mac, &ctx->u.sha1);
 211
 212                 os_memcpy(k_pad, ctx->key, ctx->key_len);
 213                 os_memset(k_pad + ctx->key_len, 0,
 214                           sizeof(k_pad) - ctx->key_len);
 215                 for (i = 0; i < sizeof(k_pad); i++)
 216                         k_pad[i] ^= 0x5c;
 217                 SHA1Init(&ctx->u.sha1);
 218                 SHA1Update(&ctx->u.sha1, k_pad, sizeof(k_pad));
 219                 SHA1Update(&ctx->u.sha1, mac, 20);
 220                 SHA1Final(mac, &ctx->u.sha1);
 221                 break;
 222         }
 223
 224         os_free(ctx);
 225
 226         return 0;
 227 }
 228
 229
 230 struct crypto_cipher {
 231         enum crypto_cipher_alg alg;
 232         union {
 233                 struct {
 234                         size_t used_bytes;
 235                         u8 key[16];
 236                         size_t keylen;
 237                 } rc4;
 238                 struct {
 239                         u8 cbc[32];
 240                         size_t block_size;
 241                         void *ctx_enc;
 242                         void *ctx_dec;
 243                 } aes;
 244                 struct {
 245                         struct des3_key_s key;
 246                         u8 cbc[8];
 247                 } des3;
 248         } u;
 249 };
 250
 251
 252 struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
 253                                           const u8 *iv, const u8 *key,
 254                                           size_t key_len)
 255 {
 256         struct crypto_cipher *ctx;
 257
 258         ctx = os_zalloc(sizeof(*ctx));
 259         if (ctx == NULL)
 260                 return NULL;
 261
 262         ctx->alg = alg;
 263
 264         switch (alg) {
 265         case CRYPTO_CIPHER_ALG_RC4:
 266                 if (key_len > sizeof(ctx->u.rc4.key)) {
 267                         os_free(ctx);
 268                         return NULL;
 269                 }
 270                 ctx->u.rc4.keylen = key_len;
 271                 os_memcpy(ctx->u.rc4.key, key, key_len);
 272                 break;
 273         case CRYPTO_CIPHER_ALG_AES:
 274                 if (key_len > sizeof(ctx->u.aes.cbc)) {
 275                         os_free(ctx);
 276                         return NULL;
 277                 }
 278                 ctx->u.aes.ctx_enc = aes_encrypt_init(key, key_len);
 279                 if (ctx->u.aes.ctx_enc == NULL) {
 280                         os_free(ctx);
 281                         return NULL;
 282                 }
 283                 ctx->u.aes.ctx_dec = aes_decrypt_init(key, key_len);
 284                 if (ctx->u.aes.ctx_dec == NULL) {
 285                         aes_encrypt_deinit(ctx->u.aes.ctx_enc);
 286                         os_free(ctx);
 287                         return NULL;
 288                 }
 289                 ctx->u.aes.block_size = key_len;
 290                 os_memcpy(ctx->u.aes.cbc, iv, ctx->u.aes.block_size);
 291                 break;
 292         case CRYPTO_CIPHER_ALG_3DES:
 293                 if (key_len != 24) {
 294                         os_free(ctx);
 295                         return NULL;
 296                 }
 297                 des3_key_setup(key, &ctx->u.des3.key);
 298                 os_memcpy(ctx->u.des3.cbc, iv, 8);
 299                 break;
 300         default:
 301                 os_free(ctx);
 302                 return NULL;
 303         }
 304
 305         return ctx;
 306 }
 307
 308
 309 int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
 310                           u8 *crypt, size_t len)
 311 {
 312         size_t i, j, blocks;
 313
 314         switch (ctx->alg) {
 315         case CRYPTO_CIPHER_ALG_RC4:
 316                 if (plain != crypt)
 317                         os_memcpy(crypt, plain, len);
 318                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 319                          ctx->u.rc4.used_bytes, crypt, len);
 320                 ctx->u.rc4.used_bytes += len;
 321                 break;
 322         case CRYPTO_CIPHER_ALG_AES:
 323                 if (len % ctx->u.aes.block_size)
 324                         return -1;
 325                 blocks = len / ctx->u.aes.block_size;
 326                 for (i = 0; i < blocks; i++) {
 327                         for (j = 0; j < ctx->u.aes.block_size; j++)
 328                                 ctx->u.aes.cbc[j] ^= plain[j];
 329                         aes_encrypt(ctx->u.aes.ctx_enc, ctx->u.aes.cbc,
 330                                     ctx->u.aes.cbc);
 331                         os_memcpy(crypt, ctx->u.aes.cbc,
 332                                   ctx->u.aes.block_size);
 333                         plain += ctx->u.aes.block_size;
 334                         crypt += ctx->u.aes.block_size;
 335                 }
 336                 break;
 337         case CRYPTO_CIPHER_ALG_3DES:
 338                 if (len % 8)
 339                         return -1;
 340                 blocks = len / 8;
 341                 for (i = 0; i < blocks; i++) {
 342                         for (j = 0; j < 8; j++)
 343                                 ctx->u.des3.cbc[j] ^= plain[j];
 344                         des3_encrypt(ctx->u.des3.cbc, &ctx->u.des3.key,
 345                                      ctx->u.des3.cbc);
 346                         os_memcpy(crypt, ctx->u.des3.cbc, 8);
 347                         plain += 8;
 348                         crypt += 8;
 349                 }
 350                 break;
 351         default:
 352                 return -1;
 353         }
 354
 355         return 0;
 356 }
 357
 358
 359 int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
 360                           u8 *plain, size_t len)
 361 {
 362         size_t i, j, blocks;
 363         u8 tmp[32];
 364
 365         switch (ctx->alg) {
 366         case CRYPTO_CIPHER_ALG_RC4:
 367                 if (plain != crypt)
 368                         os_memcpy(plain, crypt, len);
 369                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 370                          ctx->u.rc4.used_bytes, plain, len);
 371                 ctx->u.rc4.used_bytes += len;
 372                 break;
 373         case CRYPTO_CIPHER_ALG_AES:
 374                 if (len % ctx->u.aes.block_size)
 375                         return -1;
 376                 blocks = len / ctx->u.aes.block_size;
 377                 for (i = 0; i < blocks; i++) {
 378                         os_memcpy(tmp, crypt, ctx->u.aes.block_size);
 379                         aes_decrypt(ctx->u.aes.ctx_dec, crypt, plain);
 380                         for (j = 0; j < ctx->u.aes.block_size; j++)
 381                                 plain[j] ^= ctx->u.aes.cbc[j];
 382                         os_memcpy(ctx->u.aes.cbc, tmp, ctx->u.aes.block_size);
 383                         plain += ctx->u.aes.block_size;
 384                         crypt += ctx->u.aes.block_size;
 385                 }
 386                 break;
 387         case CRYPTO_CIPHER_ALG_3DES:
 388                 if (len % 8)
 389                         return -1;
 390                 blocks = len / 8;
 391                 for (i = 0; i < blocks; i++) {
 392                         os_memcpy(tmp, crypt, 8);
 393                         des3_decrypt(crypt, &ctx->u.des3.key, plain);
 394                         for (j = 0; j < 8; j++)
 395                                 plain[j] ^= ctx->u.des3.cbc[j];
 396                         os_memcpy(ctx->u.des3.cbc, tmp, 8);
 397                         plain += 8;
 398                         crypt += 8;
 399                 }
 400                 break;
 401         default:
 402                 return -1;
 403         }
 404
 405         return 0;
 406 }
 407
 408
 409 void crypto_cipher_deinit(struct crypto_cipher *ctx)
 410 {
 411         switch (ctx->alg) {
 412         case CRYPTO_CIPHER_ALG_AES:
 413                 aes_encrypt_deinit(ctx->u.aes.ctx_enc);
 414                 aes_decrypt_deinit(ctx->u.aes.ctx_dec);
 415                 break;
 416         case CRYPTO_CIPHER_ALG_3DES:
 417                 break;
 418         default:
 419                 break;
 420         }
 421         os_free(ctx);
 422 }
 423
 424
 425 /* Dummy structures; these are just typecast to struct crypto_rsa_key */
 426 struct crypto_public_key;
 427 struct crypto_private_key;
 428
 429
 430 struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len)
 431 {
 432         return (struct crypto_public_key *)
 433                 crypto_rsa_import_public_key(key, len);
 434 }
 435
 436
 437 struct crypto_private_key * crypto_private_key_import(const u8 *key,
 438                                                       size_t len)
 439 {
 440         return (struct crypto_private_key *)
 441                 crypto_rsa_import_private_key(key, len);
 442 }
 443
 444
 445 struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf,
 446                                                        size_t len)
 447 {
 448         /* No X.509 support in crypto_internal.c */
 449         return NULL;
 450 }
 451
 452
 453 static int pkcs1_generate_encryption_block(u8 block_type, size_t modlen,
 454                                            const u8 *in, size_t inlen,
 455                                            u8 *out, size_t *outlen)
 456 {
 457         size_t ps_len;
 458         u8 *pos;
 459
 460         /*
 461          * PKCS #1 v1.5, 8.1:
 462          *
 463          * EB = 00 || BT || PS || 00 || D
 464          * BT = 00 or 01 for private-key operation; 02 for public-key operation
 465          * PS = k-3-||D||; at least eight octets
 466          * (BT=0: PS=0x00, BT=1: PS=0xff, BT=2: PS=pseudorandom non-zero)
 467          * k = length of modulus in octets (modlen)
 468          */
 469
 470         if (modlen < 12 || modlen > *outlen || inlen > modlen - 11) {
 471                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Invalid buffer "
 472                            "lengths (modlen=%lu outlen=%lu inlen=%lu)",
 473                            __func__, (unsigned long) modlen,
 474                            (unsigned long) *outlen,
 475                            (unsigned long) inlen);
 476                 return -1;
 477         }
 478
 479         pos = out;
 480         *pos++ = 0x00;
 481         *pos++ = block_type; /* BT */
 482         ps_len = modlen - inlen - 3;
 483         switch (block_type) {
 484         case 0:
 485                 os_memset(pos, 0x00, ps_len);
 486                 pos += ps_len;
 487                 break;
 488         case 1:
 489                 os_memset(pos, 0xff, ps_len);
 490                 pos += ps_len;
 491                 break;
 492         case 2:
 493                 if (os_get_random(pos, ps_len) < 0) {
 494                         wpa_printf(MSG_DEBUG, "PKCS #1: %s - Failed to get "
 495                                    "random data for PS", __func__);
 496                         return -1;
 497                 }
 498                 while (ps_len--) {
 499                         if (*pos == 0x00)
 500                                 *pos = 0x01;
 501                         pos++;
 502                 }
 503                 break;
 504         default:
 505                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Unsupported block type "
 506                            "%d", __func__, block_type);
 507                 return -1;
 508         }
 509         *pos++ = 0x00;
 510         os_memcpy(pos, in, inlen); /* D */
 511
 512         return 0;
 513 }
 514
 515
 516 static int crypto_rsa_encrypt_pkcs1(int block_type, struct crypto_rsa_key *key,
 517                                     int use_private,
 518                                     const u8 *in, size_t inlen,
 519                                     u8 *out, size_t *outlen)
 520 {
 521         size_t modlen;
 522
 523         modlen = crypto_rsa_get_modulus_len(key);
 524
 525         if (pkcs1_generate_encryption_block(block_type, modlen, in, inlen,
 526                                             out, outlen) < 0)
 527                 return -1;
 528
 529         return crypto_rsa_exptmod(out, modlen, out, outlen, key, use_private);
 530 }
 531
 532
 533 int crypto_public_key_encrypt_pkcs1_v15(struct crypto_public_key *key,
 534                                         const u8 *in, size_t inlen,
 535                                         u8 *out, size_t *outlen)
 536 {
 537         return crypto_rsa_encrypt_pkcs1(2, (struct crypto_rsa_key *) key,
 538                                         0, in, inlen, out, outlen);
 539 }
 540
 541
 542 int crypto_private_key_sign_pkcs1(struct crypto_private_key *key,
 543                                   const u8 *in, size_t inlen,
 544                                   u8 *out, size_t *outlen)
 545 {
 546         return crypto_rsa_encrypt_pkcs1(1, (struct crypto_rsa_key *) key,
 547                                         1, in, inlen, out, outlen);
 548 }
 549
 550
 551 void crypto_public_key_free(struct crypto_public_key *key)
 552 {
 553         crypto_rsa_free((struct crypto_rsa_key *) key);
 554 }
 555
 556
 557 void crypto_private_key_free(struct crypto_private_key *key)
 558 {
 559         crypto_rsa_free((struct crypto_rsa_key *) key);
 560 }
 561
 562
 563 int crypto_public_key_decrypt_pkcs1(struct crypto_public_key *key,
 564                                     const u8 *crypt, size_t crypt_len,
 565                                     u8 *plain, size_t *plain_len)
 566 {
 567         size_t len;
 568         u8 *pos;
 569
 570         len = *plain_len;
 571         if (crypto_rsa_exptmod(crypt, crypt_len, plain, &len,
 572                                (struct crypto_rsa_key *) key, 0) < 0)
 573                 return -1;
 574
 575         /*
 576          * PKCS #1 v1.5, 8.1:
 577          *
 578          * EB = 00 || BT || PS || 00 || D
 579          * BT = 01
 580          * PS = k-3-||D|| times FF
 581          * k = length of modulus in octets
 582          */
 583
 584         if (len < 3 + 8 + 16 /* min hash len */ ||
 585             plain[0] != 0x00 || plain[1] != 0x01 || plain[2] != 0xff) {
 586                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 587                            "structure");
 588                 return -1;
 589         }
 590
 591         pos = plain + 3;
 592         while (pos < plain + len && *pos == 0xff)
 593                 pos++;
 594         if (pos - plain - 2 < 8) {
 595                 /* PKCS #1 v1.5, 8.1: At least eight octets long PS */
 596                 wpa_printf(MSG_INFO, "LibTomCrypt: Too short signature "
 597                            "padding");
 598                 return -1;
 599         }
 600
 601         if (pos + 16 /* min hash len */ >= plain + len || *pos != 0x00) {
 602                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 603                            "structure (2)");
 604                 return -1;
 605         }
 606         pos++;
 607         len -= pos - plain;
 608
 609         /* Strip PKCS #1 header */
 610         os_memmove(plain, pos, len);
 611         *plain_len = len;
 612
 613         return 0;
 614 }
 615
 616
 617 int crypto_global_init(void)
 618 {
 619         return 0;
 620 }
 621
 622
 623 void crypto_global_deinit(void)
 624 {
 625 }
 626
 627
 628 #ifdef EAP_FAST
 629
 630 int crypto_mod_exp(const u8 *base, size_t base_len,
 631                    const u8 *power, size_t power_len,
 632                    const u8 *modulus, size_t modulus_len,
 633                    u8 *result, size_t *result_len)
 634 {
 635         struct bignum *bn_base, *bn_exp, *bn_modulus, *bn_result;
 636         int ret = 0;
 637
 638         bn_base = bignum_init();
 639         bn_exp = bignum_init();
 640         bn_modulus = bignum_init();
 641         bn_result = bignum_init();
 642
 643         if (bn_base == NULL || bn_exp == NULL || bn_modulus == NULL ||
 644             bn_result == NULL)
 645                 goto error;
 646
 647         if (bignum_set_unsigned_bin(bn_base, base, base_len) < 0 ||
 648             bignum_set_unsigned_bin(bn_exp, power, power_len) < 0 ||
 649             bignum_set_unsigned_bin(bn_modulus, modulus, modulus_len) < 0)
 650                 goto error;
 651
 652         if (bignum_exptmod(bn_base, bn_exp, bn_modulus, bn_result) < 0)
 653                 goto error;
 654
 655         ret = bignum_get_unsigned_bin(bn_result, result, result_len);
 656
 657 error:
 658         bignum_deinit(bn_base);
 659         bignum_deinit(bn_exp);
 660         bignum_deinit(bn_modulus);
 661         bignum_deinit(bn_result);
 662         return ret;
 663 }
 664
 665 #endif /* EAP_FAST */
 666
 667
 668 #endif /* CONFIG_TLS_INTERNAL */
 669
 670 #endif /* EAP_TLS_FUNCS */