dist/wpa/src/crypto/crypto_internal.c

   1 /*
   2  * WPA Supplicant / Crypto wrapper for internal crypto implementation
   3  * Copyright (c) 2006-2007, 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 "tls/rsa.h"
  24 #include "tls/bignum.h"
  25 #include "tls/asn1.h"
  26
  27
  28 #ifdef EAP_TLS_FUNCS
  29
  30 #ifdef CONFIG_TLS_INTERNAL
  31
  32 /* from des.c */
  33 struct des3_key_s {
  34         u32 ek[3][32];
  35         u32 dk[3][32];
  36 };
  37
  38 void des3_key_setup(const u8 *key, struct des3_key_s *dkey);
  39 void des3_encrypt(const u8 *plain, const struct des3_key_s *key, u8 *crypt);
  40 void des3_decrypt(const u8 *crypt, const struct des3_key_s *key, u8 *plain);
  41
  42
  43 struct MD5Context {
  44         u32 buf[4];
  45         u32 bits[2];
  46         u8 in[64];
  47 };
  48
  49 struct SHA1Context {
  50         u32 state[5];
  51         u32 count[2];
  52         unsigned char buffer[64];
  53 };
  54
  55
  56 struct crypto_hash {
  57         enum crypto_hash_alg alg;
  58         union {
  59                 struct MD5Context md5;
  60                 struct SHA1Context sha1;
  61         } u;
  62         u8 key[64];
  63         size_t key_len;
  64 };
  65
  66
  67 struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
  68                                       size_t key_len)
  69 {
  70         struct crypto_hash *ctx;
  71         u8 k_pad[64];
  72         u8 tk[20];
  73         size_t i;
  74
  75         ctx = os_zalloc(sizeof(*ctx));
  76         if (ctx == NULL)
  77                 return NULL;
  78
  79         ctx->alg = alg;
  80
  81         switch (alg) {
  82         case CRYPTO_HASH_ALG_MD5:
  83                 MD5Init(&ctx->u.md5);
  84                 break;
  85         case CRYPTO_HASH_ALG_SHA1:
  86                 SHA1Init(&ctx->u.sha1);
  87                 break;
  88         case CRYPTO_HASH_ALG_HMAC_MD5:
  89                 if (key_len > sizeof(k_pad)) {
  90                         MD5Init(&ctx->u.md5);
  91                         MD5Update(&ctx->u.md5, key, key_len);
  92                         MD5Final(tk, &ctx->u.md5);
  93                         key = tk;
  94                         key_len = 16;
  95                 }
  96                 os_memcpy(ctx->key, key, key_len);
  97                 ctx->key_len = key_len;
  98
  99                 os_memcpy(k_pad, key, key_len);
 100                 os_memset(k_pad + key_len, 0, sizeof(k_pad) - key_len);
 101                 for (i = 0; i < sizeof(k_pad); i++)
 102                         k_pad[i] ^= 0x36;
 103                 MD5Init(&ctx->u.md5);
 104                 MD5Update(&ctx->u.md5, k_pad, sizeof(k_pad));
 105                 break;
 106         case CRYPTO_HASH_ALG_HMAC_SHA1:
 107                 if (key_len > sizeof(k_pad)) {
 108                         SHA1Init(&ctx->u.sha1);
 109                         SHA1Update(&ctx->u.sha1, key, key_len);
 110                         SHA1Final(tk, &ctx->u.sha1);
 111                         key = tk;
 112                         key_len = 20;
 113                 }
 114                 os_memcpy(ctx->key, key, key_len);
 115                 ctx->key_len = key_len;
 116
 117                 os_memcpy(k_pad, key, key_len);
 118                 os_memset(k_pad + key_len, 0, sizeof(k_pad) - key_len);
 119                 for (i = 0; i < sizeof(k_pad); i++)
 120                         k_pad[i] ^= 0x36;
 121                 SHA1Init(&ctx->u.sha1);
 122                 SHA1Update(&ctx->u.sha1, k_pad, sizeof(k_pad));
 123                 break;
 124         default:
 125                 os_free(ctx);
 126                 return NULL;
 127         }
 128
 129         return ctx;
 130 }
 131
 132
 133 void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len)
 134 {
 135         if (ctx == NULL)
 136                 return;
 137
 138         switch (ctx->alg) {
 139         case CRYPTO_HASH_ALG_MD5:
 140         case CRYPTO_HASH_ALG_HMAC_MD5:
 141                 MD5Update(&ctx->u.md5, data, len);
 142                 break;
 143         case CRYPTO_HASH_ALG_SHA1:
 144         case CRYPTO_HASH_ALG_HMAC_SHA1:
 145                 SHA1Update(&ctx->u.sha1, data, len);
 146                 break;
 147         }
 148 }
 149
 150
 151 int crypto_hash_finish(struct crypto_hash *ctx, u8 *mac, size_t *len)
 152 {
 153         u8 k_pad[64];
 154         size_t i;
 155
 156         if (ctx == NULL)
 157                 return -2;
 158
 159         if (mac == NULL || len == NULL) {
 160                 os_free(ctx);
 161                 return 0;
 162         }
 163
 164         switch (ctx->alg) {
 165         case CRYPTO_HASH_ALG_MD5:
 166                 if (*len < 16) {
 167                         *len = 16;
 168                         os_free(ctx);
 169                         return -1;
 170                 }
 171                 *len = 16;
 172                 MD5Final(mac, &ctx->u.md5);
 173                 break;
 174         case CRYPTO_HASH_ALG_SHA1:
 175                 if (*len < 20) {
 176                         *len = 20;
 177                         os_free(ctx);
 178                         return -1;
 179                 }
 180                 *len = 20;
 181                 SHA1Final(mac, &ctx->u.sha1);
 182                 break;
 183         case CRYPTO_HASH_ALG_HMAC_MD5:
 184                 if (*len < 16) {
 185                         *len = 16;
 186                         os_free(ctx);
 187                         return -1;
 188                 }
 189                 *len = 16;
 190
 191                 MD5Final(mac, &ctx->u.md5);
 192
 193                 os_memcpy(k_pad, ctx->key, ctx->key_len);
 194                 os_memset(k_pad + ctx->key_len, 0,
 195                           sizeof(k_pad) - ctx->key_len);
 196                 for (i = 0; i < sizeof(k_pad); i++)
 197                         k_pad[i] ^= 0x5c;
 198                 MD5Init(&ctx->u.md5);
 199                 MD5Update(&ctx->u.md5, k_pad, sizeof(k_pad));
 200                 MD5Update(&ctx->u.md5, mac, 16);
 201                 MD5Final(mac, &ctx->u.md5);
 202                 break;
 203         case CRYPTO_HASH_ALG_HMAC_SHA1:
 204                 if (*len < 20) {
 205                         *len = 20;
 206                         os_free(ctx);
 207                         return -1;
 208                 }
 209                 *len = 20;
 210
 211                 SHA1Final(mac, &ctx->u.sha1);
 212
 213                 os_memcpy(k_pad, ctx->key, ctx->key_len);
 214                 os_memset(k_pad + ctx->key_len, 0,
 215                           sizeof(k_pad) - ctx->key_len);
 216                 for (i = 0; i < sizeof(k_pad); i++)
 217                         k_pad[i] ^= 0x5c;
 218                 SHA1Init(&ctx->u.sha1);
 219                 SHA1Update(&ctx->u.sha1, k_pad, sizeof(k_pad));
 220                 SHA1Update(&ctx->u.sha1, mac, 20);
 221                 SHA1Final(mac, &ctx->u.sha1);
 222                 break;
 223         }
 224
 225         os_free(ctx);
 226
 227         return 0;
 228 }
 229
 230
 231 struct crypto_cipher {
 232         enum crypto_cipher_alg alg;
 233         union {
 234                 struct {
 235                         size_t used_bytes;
 236                         u8 key[16];
 237                         size_t keylen;
 238                 } rc4;
 239                 struct {
 240                         u8 cbc[32];
 241                         size_t block_size;
 242                         void *ctx_enc;
 243                         void *ctx_dec;
 244                 } aes;
 245                 struct {
 246                         struct des3_key_s key;
 247                         u8 cbc[8];
 248                 } des3;
 249         } u;
 250 };
 251
 252
 253 struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
 254                                           const u8 *iv, const u8 *key,
 255                                           size_t key_len)
 256 {
 257         struct crypto_cipher *ctx;
 258
 259         ctx = os_zalloc(sizeof(*ctx));
 260         if (ctx == NULL)
 261                 return NULL;
 262
 263         ctx->alg = alg;
 264
 265         switch (alg) {
 266         case CRYPTO_CIPHER_ALG_RC4:
 267                 if (key_len > sizeof(ctx->u.rc4.key)) {
 268                         os_free(ctx);
 269                         return NULL;
 270                 }
 271                 ctx->u.rc4.keylen = key_len;
 272                 os_memcpy(ctx->u.rc4.key, key, key_len);
 273                 break;
 274         case CRYPTO_CIPHER_ALG_AES:
 275                 if (key_len > sizeof(ctx->u.aes.cbc)) {
 276                         os_free(ctx);
 277                         return NULL;
 278                 }
 279                 ctx->u.aes.ctx_enc = aes_encrypt_init(key, key_len);
 280                 if (ctx->u.aes.ctx_enc == NULL) {
 281                         os_free(ctx);
 282                         return NULL;
 283                 }
 284                 ctx->u.aes.ctx_dec = aes_decrypt_init(key, key_len);
 285                 if (ctx->u.aes.ctx_dec == NULL) {
 286                         aes_encrypt_deinit(ctx->u.aes.ctx_enc);
 287                         os_free(ctx);
 288                         return NULL;
 289                 }
 290                 ctx->u.aes.block_size = key_len;
 291                 os_memcpy(ctx->u.aes.cbc, iv, ctx->u.aes.block_size);
 292                 break;
 293         case CRYPTO_CIPHER_ALG_3DES:
 294                 if (key_len != 24) {
 295                         os_free(ctx);
 296                         return NULL;
 297                 }
 298                 des3_key_setup(key, &ctx->u.des3.key);
 299                 os_memcpy(ctx->u.des3.cbc, iv, 8);
 300                 break;
 301         default:
 302                 os_free(ctx);
 303                 return NULL;
 304         }
 305
 306         return ctx;
 307 }
 308
 309
 310 int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
 311                           u8 *crypt, size_t len)
 312 {
 313         size_t i, j, blocks;
 314
 315         switch (ctx->alg) {
 316         case CRYPTO_CIPHER_ALG_RC4:
 317                 if (plain != crypt)
 318                         os_memcpy(crypt, plain, len);
 319                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 320                          ctx->u.rc4.used_bytes, crypt, len);
 321                 ctx->u.rc4.used_bytes += len;
 322                 break;
 323         case CRYPTO_CIPHER_ALG_AES:
 324                 if (len % ctx->u.aes.block_size)
 325                         return -1;
 326                 blocks = len / ctx->u.aes.block_size;
 327                 for (i = 0; i < blocks; i++) {
 328                         for (j = 0; j < ctx->u.aes.block_size; j++)
 329                                 ctx->u.aes.cbc[j] ^= plain[j];
 330                         aes_encrypt(ctx->u.aes.ctx_enc, ctx->u.aes.cbc,
 331                                     ctx->u.aes.cbc);
 332                         os_memcpy(crypt, ctx->u.aes.cbc,
 333                                   ctx->u.aes.block_size);
 334                         plain += ctx->u.aes.block_size;
 335                         crypt += ctx->u.aes.block_size;
 336                 }
 337                 break;
 338         case CRYPTO_CIPHER_ALG_3DES:
 339                 if (len % 8)
 340                         return -1;
 341                 blocks = len / 8;
 342                 for (i = 0; i < blocks; i++) {
 343                         for (j = 0; j < 8; j++)
 344                                 ctx->u.des3.cbc[j] ^= plain[j];
 345                         des3_encrypt(ctx->u.des3.cbc, &ctx->u.des3.key,
 346                                      ctx->u.des3.cbc);
 347                         os_memcpy(crypt, ctx->u.des3.cbc, 8);
 348                         plain += 8;
 349                         crypt += 8;
 350                 }
 351                 break;
 352         default:
 353                 return -1;
 354         }
 355
 356         return 0;
 357 }
 358
 359
 360 int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
 361                           u8 *plain, size_t len)
 362 {
 363         size_t i, j, blocks;
 364         u8 tmp[32];
 365
 366         switch (ctx->alg) {
 367         case CRYPTO_CIPHER_ALG_RC4:
 368                 if (plain != crypt)
 369                         os_memcpy(plain, crypt, len);
 370                 rc4_skip(ctx->u.rc4.key, ctx->u.rc4.keylen,
 371                          ctx->u.rc4.used_bytes, plain, len);
 372                 ctx->u.rc4.used_bytes += len;
 373                 break;
 374         case CRYPTO_CIPHER_ALG_AES:
 375                 if (len % ctx->u.aes.block_size)
 376                         return -1;
 377                 blocks = len / ctx->u.aes.block_size;
 378                 for (i = 0; i < blocks; i++) {
 379                         os_memcpy(tmp, crypt, ctx->u.aes.block_size);
 380                         aes_decrypt(ctx->u.aes.ctx_dec, crypt, plain);
 381                         for (j = 0; j < ctx->u.aes.block_size; j++)
 382                                 plain[j] ^= ctx->u.aes.cbc[j];
 383                         os_memcpy(ctx->u.aes.cbc, tmp, ctx->u.aes.block_size);
 384                         plain += ctx->u.aes.block_size;
 385                         crypt += ctx->u.aes.block_size;
 386                 }
 387                 break;
 388         case CRYPTO_CIPHER_ALG_3DES:
 389                 if (len % 8)
 390                         return -1;
 391                 blocks = len / 8;
 392                 for (i = 0; i < blocks; i++) {
 393                         os_memcpy(tmp, crypt, 8);
 394                         des3_decrypt(crypt, &ctx->u.des3.key, plain);
 395                         for (j = 0; j < 8; j++)
 396                                 plain[j] ^= ctx->u.des3.cbc[j];
 397                         os_memcpy(ctx->u.des3.cbc, tmp, 8);
 398                         plain += 8;
 399                         crypt += 8;
 400                 }
 401                 break;
 402         default:
 403                 return -1;
 404         }
 405
 406         return 0;
 407 }
 408
 409
 410 void crypto_cipher_deinit(struct crypto_cipher *ctx)
 411 {
 412         switch (ctx->alg) {
 413         case CRYPTO_CIPHER_ALG_AES:
 414                 aes_encrypt_deinit(ctx->u.aes.ctx_enc);
 415                 aes_decrypt_deinit(ctx->u.aes.ctx_dec);
 416                 break;
 417         case CRYPTO_CIPHER_ALG_3DES:
 418                 break;
 419         default:
 420                 break;
 421         }
 422         os_free(ctx);
 423 }
 424
 425
 426 /* Dummy structures; these are just typecast to struct crypto_rsa_key */
 427 struct crypto_public_key;
 428 struct crypto_private_key;
 429
 430
 431 struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len)
 432 {
 433         return (struct crypto_public_key *)
 434                 crypto_rsa_import_public_key(key, len);
 435 }
 436
 437
 438 static struct crypto_private_key *
 439 crypto_pkcs8_key_import(const u8 *buf, size_t len)
 440 {
 441         struct asn1_hdr hdr;
 442         const u8 *pos, *end;
 443         struct bignum *zero;
 444         struct asn1_oid oid;
 445         char obuf[80];
 446
 447         /* PKCS #8, Chapter 6 */
 448
 449         /* PrivateKeyInfo ::= SEQUENCE */
 450         if (asn1_get_next(buf, len, &hdr) < 0 ||
 451             hdr.class != ASN1_CLASS_UNIVERSAL ||
 452             hdr.tag != ASN1_TAG_SEQUENCE) {
 453                 wpa_printf(MSG_DEBUG, "PKCS #8: Does not start with PKCS #8 "
 454                            "header (SEQUENCE); assume PKCS #8 not used");
 455                 return NULL;
 456         }
 457         pos = hdr.payload;
 458         end = pos + hdr.length;
 459
 460         /* version Version (Version ::= INTEGER) */
 461         if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
 462             hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER) {
 463                 wpa_printf(MSG_DEBUG, "PKCS #8: Expected INTEGER - found "
 464                            "class %d tag 0x%x; assume PKCS #8 not used",
 465                            hdr.class, hdr.tag);
 466                 return NULL;
 467         }
 468
 469         zero = bignum_init();
 470         if (zero == NULL)
 471                 return NULL;
 472
 473         if (bignum_set_unsigned_bin(zero, hdr.payload, hdr.length) < 0) {
 474                 wpa_printf(MSG_DEBUG, "PKCS #8: Failed to parse INTEGER");
 475                 bignum_deinit(zero);
 476                 return NULL;
 477         }
 478         pos = hdr.payload + hdr.length;
 479
 480         if (bignum_cmp_d(zero, 0) != 0) {
 481                 wpa_printf(MSG_DEBUG, "PKCS #8: Expected zero INTEGER in the "
 482                            "beginning of private key; not found; assume "
 483                            "PKCS #8 not used");
 484                 bignum_deinit(zero);
 485                 return NULL;
 486         }
 487         bignum_deinit(zero);
 488
 489         /* privateKeyAlgorithm PrivateKeyAlgorithmIdentifier
 490          * (PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier) */
 491         if (asn1_get_next(pos, len, &hdr) < 0 ||
 492             hdr.class != ASN1_CLASS_UNIVERSAL ||
 493             hdr.tag != ASN1_TAG_SEQUENCE) {
 494                 wpa_printf(MSG_DEBUG, "PKCS #8: Expected SEQUENCE "
 495                            "(AlgorithmIdentifier) - found class %d tag 0x%x; "
 496                            "assume PKCS #8 not used",
 497                            hdr.class, hdr.tag);
 498                 return NULL;
 499         }
 500
 501         if (asn1_get_oid(hdr.payload, hdr.length, &oid, &pos)) {
 502                 wpa_printf(MSG_DEBUG, "PKCS #8: Failed to parse OID "
 503                            "(algorithm); assume PKCS #8 not used");
 504                 return NULL;
 505         }
 506
 507         asn1_oid_to_str(&oid, obuf, sizeof(obuf));
 508         wpa_printf(MSG_DEBUG, "PKCS #8: algorithm=%s", obuf);
 509
 510         if (oid.len != 7 ||
 511             oid.oid[0] != 1 /* iso */ ||
 512             oid.oid[1] != 2 /* member-body */ ||
 513             oid.oid[2] != 840 /* us */ ||
 514             oid.oid[3] != 113549 /* rsadsi */ ||
 515             oid.oid[4] != 1 /* pkcs */ ||
 516             oid.oid[5] != 1 /* pkcs-1 */ ||
 517             oid.oid[6] != 1 /* rsaEncryption */) {
 518                 wpa_printf(MSG_DEBUG, "PKCS #8: Unsupported private key "
 519                            "algorithm %s", obuf);
 520                 return NULL;
 521         }
 522
 523         pos = hdr.payload + hdr.length;
 524
 525         /* privateKey PrivateKey (PrivateKey ::= OCTET STRING) */
 526         if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
 527             hdr.class != ASN1_CLASS_UNIVERSAL ||
 528             hdr.tag != ASN1_TAG_OCTETSTRING) {
 529                 wpa_printf(MSG_DEBUG, "PKCS #8: Expected OCTETSTRING "
 530                            "(privateKey) - found class %d tag 0x%x",
 531                            hdr.class, hdr.tag);
 532                 return NULL;
 533         }
 534         wpa_printf(MSG_DEBUG, "PKCS #8: Try to parse RSAPrivateKey");
 535
 536         return (struct crypto_private_key *)
 537                 crypto_rsa_import_private_key(hdr.payload, hdr.length);
 538 }
 539
 540
 541 struct crypto_private_key * crypto_private_key_import(const u8 *key,
 542                                                       size_t len)
 543 {
 544         struct crypto_private_key *res;
 545
 546         /* First, check for possible PKCS #8 encoding */
 547         res = crypto_pkcs8_key_import(key, len);
 548         if (res)
 549                 return res;
 550
 551         /* Not PKCS#8, so try to import PKCS #1 encoded RSA private key */
 552         wpa_printf(MSG_DEBUG, "Trying to parse PKCS #1 encoded RSA private "
 553                    "key");
 554         return (struct crypto_private_key *)
 555                 crypto_rsa_import_private_key(key, len);
 556 }
 557
 558
 559 struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf,
 560                                                        size_t len)
 561 {
 562         /* No X.509 support in crypto_internal.c */
 563         return NULL;
 564 }
 565
 566
 567 static int pkcs1_generate_encryption_block(u8 block_type, size_t modlen,
 568                                            const u8 *in, size_t inlen,
 569                                            u8 *out, size_t *outlen)
 570 {
 571         size_t ps_len;
 572         u8 *pos;
 573
 574         /*
 575          * PKCS #1 v1.5, 8.1:
 576          *
 577          * EB = 00 || BT || PS || 00 || D
 578          * BT = 00 or 01 for private-key operation; 02 for public-key operation
 579          * PS = k-3-||D||; at least eight octets
 580          * (BT=0: PS=0x00, BT=1: PS=0xff, BT=2: PS=pseudorandom non-zero)
 581          * k = length of modulus in octets (modlen)
 582          */
 583
 584         if (modlen < 12 || modlen > *outlen || inlen > modlen - 11) {
 585                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Invalid buffer "
 586                            "lengths (modlen=%lu outlen=%lu inlen=%lu)",
 587                            __func__, (unsigned long) modlen,
 588                            (unsigned long) *outlen,
 589                            (unsigned long) inlen);
 590                 return -1;
 591         }
 592
 593         pos = out;
 594         *pos++ = 0x00;
 595         *pos++ = block_type; /* BT */
 596         ps_len = modlen - inlen - 3;
 597         switch (block_type) {
 598         case 0:
 599                 os_memset(pos, 0x00, ps_len);
 600                 pos += ps_len;
 601                 break;
 602         case 1:
 603                 os_memset(pos, 0xff, ps_len);
 604                 pos += ps_len;
 605                 break;
 606         case 2:
 607                 if (os_get_random(pos, ps_len) < 0) {
 608                         wpa_printf(MSG_DEBUG, "PKCS #1: %s - Failed to get "
 609                                    "random data for PS", __func__);
 610                         return -1;
 611                 }
 612                 while (ps_len--) {
 613                         if (*pos == 0x00)
 614                                 *pos = 0x01;
 615                         pos++;
 616                 }
 617                 break;
 618         default:
 619                 wpa_printf(MSG_DEBUG, "PKCS #1: %s - Unsupported block type "
 620                            "%d", __func__, block_type);
 621                 return -1;
 622         }
 623         *pos++ = 0x00;
 624         os_memcpy(pos, in, inlen); /* D */
 625
 626         return 0;
 627 }
 628
 629
 630 static int crypto_rsa_encrypt_pkcs1(int block_type, struct crypto_rsa_key *key,
 631                                     int use_private,
 632                                     const u8 *in, size_t inlen,
 633                                     u8 *out, size_t *outlen)
 634 {
 635         size_t modlen;
 636
 637         modlen = crypto_rsa_get_modulus_len(key);
 638
 639         if (pkcs1_generate_encryption_block(block_type, modlen, in, inlen,
 640                                             out, outlen) < 0)
 641                 return -1;
 642
 643         return crypto_rsa_exptmod(out, modlen, out, outlen, key, use_private);
 644 }
 645
 646
 647 int crypto_public_key_encrypt_pkcs1_v15(struct crypto_public_key *key,
 648                                         const u8 *in, size_t inlen,
 649                                         u8 *out, size_t *outlen)
 650 {
 651         return crypto_rsa_encrypt_pkcs1(2, (struct crypto_rsa_key *) key,
 652                                         0, in, inlen, out, outlen);
 653 }
 654
 655
 656 int crypto_private_key_decrypt_pkcs1_v15(struct crypto_private_key *key,
 657                                          const u8 *in, size_t inlen,
 658                                          u8 *out, size_t *outlen)
 659 {
 660         struct crypto_rsa_key *rkey = (struct crypto_rsa_key *) key;
 661         int res;
 662         u8 *pos, *end;
 663
 664         res = crypto_rsa_exptmod(in, inlen, out, outlen, rkey, 1);
 665         if (res)
 666                 return res;
 667
 668         if (*outlen < 2 || out[0] != 0 || out[1] != 2)
 669                 return -1;
 670
 671         /* Skip PS (pseudorandom non-zero octets) */
 672         pos = out + 2;
 673         end = out + *outlen;
 674         while (*pos && pos < end)
 675                 pos++;
 676         if (pos == end)
 677                 return -1;
 678         pos++;
 679
 680         *outlen -= pos - out;
 681
 682         /* Strip PKCS #1 header */
 683         os_memmove(out, pos, *outlen);
 684
 685         return 0;
 686 }
 687
 688
 689 int crypto_private_key_sign_pkcs1(struct crypto_private_key *key,
 690                                   const u8 *in, size_t inlen,
 691                                   u8 *out, size_t *outlen)
 692 {
 693         return crypto_rsa_encrypt_pkcs1(1, (struct crypto_rsa_key *) key,
 694                                         1, in, inlen, out, outlen);
 695 }
 696
 697
 698 void crypto_public_key_free(struct crypto_public_key *key)
 699 {
 700         crypto_rsa_free((struct crypto_rsa_key *) key);
 701 }
 702
 703
 704 void crypto_private_key_free(struct crypto_private_key *key)
 705 {
 706         crypto_rsa_free((struct crypto_rsa_key *) key);
 707 }
 708
 709
 710 int crypto_public_key_decrypt_pkcs1(struct crypto_public_key *key,
 711                                     const u8 *crypt, size_t crypt_len,
 712                                     u8 *plain, size_t *plain_len)
 713 {
 714         size_t len;
 715         u8 *pos;
 716
 717         len = *plain_len;
 718         if (crypto_rsa_exptmod(crypt, crypt_len, plain, &len,
 719                                (struct crypto_rsa_key *) key, 0) < 0)
 720                 return -1;
 721
 722         /*
 723          * PKCS #1 v1.5, 8.1:
 724          *
 725          * EB = 00 || BT || PS || 00 || D
 726          * BT = 00 or 01
 727          * PS = k-3-||D|| times (00 if BT=00) or (FF if BT=01)
 728          * k = length of modulus in octets
 729          */
 730
 731         if (len < 3 + 8 + 16 /* min hash len */ ||
 732             plain[0] != 0x00 || (plain[1] != 0x00 && plain[1] != 0x01)) {
 733                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 734                            "structure");
 735                 return -1;
 736         }
 737
 738         pos = plain + 3;
 739         if (plain[1] == 0x00) {
 740                 /* BT = 00 */
 741                 if (plain[2] != 0x00) {
 742                         wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature "
 743                                    "PS (BT=00)");
 744                         return -1;
 745                 }
 746                 while (pos + 1 < plain + len && *pos == 0x00 && pos[1] == 0x00)
 747                         pos++;
 748         } else {
 749                 /* BT = 01 */
 750                 if (plain[2] != 0xff) {
 751                         wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature "
 752                                    "PS (BT=01)");
 753                         return -1;
 754                 }
 755                 while (pos < plain + len && *pos == 0xff)
 756                         pos++;
 757         }
 758
 759         if (pos - plain - 2 < 8) {
 760                 /* PKCS #1 v1.5, 8.1: At least eight octets long PS */
 761                 wpa_printf(MSG_INFO, "LibTomCrypt: Too short signature "
 762                            "padding");
 763                 return -1;
 764         }
 765
 766         if (pos + 16 /* min hash len */ >= plain + len || *pos != 0x00) {
 767                 wpa_printf(MSG_INFO, "LibTomCrypt: Invalid signature EB "
 768                            "structure (2)");
 769                 return -1;
 770         }
 771         pos++;
 772         len -= pos - plain;
 773
 774         /* Strip PKCS #1 header */
 775         os_memmove(plain, pos, len);
 776         *plain_len = len;
 777
 778         return 0;
 779 }
 780
 781
 782 int crypto_global_init(void)
 783 {
 784         return 0;
 785 }
 786
 787
 788 void crypto_global_deinit(void)
 789 {
 790 }
 791
 792
 793 #ifdef EAP_FAST
 794
 795 int crypto_mod_exp(const u8 *base, size_t base_len,
 796                    const u8 *power, size_t power_len,
 797                    const u8 *modulus, size_t modulus_len,
 798                    u8 *result, size_t *result_len)
 799 {
 800         struct bignum *bn_base, *bn_exp, *bn_modulus, *bn_result;
 801         int ret = -1;
 802
 803         bn_base = bignum_init();
 804         bn_exp = bignum_init();
 805         bn_modulus = bignum_init();
 806         bn_result = bignum_init();
 807
 808         if (bn_base == NULL || bn_exp == NULL || bn_modulus == NULL ||
 809             bn_result == NULL)
 810                 goto error;
 811
 812         if (bignum_set_unsigned_bin(bn_base, base, base_len) < 0 ||
 813             bignum_set_unsigned_bin(bn_exp, power, power_len) < 0 ||
 814             bignum_set_unsigned_bin(bn_modulus, modulus, modulus_len) < 0)
 815                 goto error;
 816
 817         if (bignum_exptmod(bn_base, bn_exp, bn_modulus, bn_result) < 0)
 818                 goto error;
 819
 820         ret = bignum_get_unsigned_bin(bn_result, result, result_len);
 821
 822 error:
 823         bignum_deinit(bn_base);
 824         bignum_deinit(bn_exp);
 825         bignum_deinit(bn_modulus);
 826         bignum_deinit(bn_result);
 827         return ret;
 828 }
 829
 830 #endif /* EAP_FAST */
 831
 832
 833 #endif /* CONFIG_TLS_INTERNAL */
 834
 835 #endif /* EAP_TLS_FUNCS */