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