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
25int 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
38void 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
59int 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
72int 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
85void * 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
99void 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
106void aes_encrypt_deinit(void *ctx)
107{
108	symmetric_key *skey = ctx;
109	aes_done(skey);
110	os_free(skey);
111}
112
113
114void * 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
128void 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
135void aes_decrypt_deinit(void *ctx)
136{
137	symmetric_key *skey = ctx;
138	aes_done(skey);
139	os_free(skey);
140}
141
142
143struct 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
153struct 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
189fail:
190	os_free(ctx);
191	return NULL;
192}
193
194void 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
214int 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
284struct 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
297struct 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
350int 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
374int 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
399void 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
407struct crypto_public_key {
408	rsa_key rsa;
409};
410
411struct crypto_private_key {
412	rsa_key rsa;
413};
414
415
416struct 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
446struct 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
478struct 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
486static 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
549static 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
575int 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
584int 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
593void 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
602void 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
611int 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
670int 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
689void crypto_global_deinit(void)
690{
691}
692
693
694#ifdef CONFIG_MODEXP
695
696int 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
721fail:
722	mp_clear_multi(b, p, m, r, NULL);
723	return -1;
724}
725
726#endif /* CONFIG_MODEXP */
727