1/*
2 * WPA Supplicant / wrapper functions for libcrypto
3 * Copyright (c) 2004-2009, 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 <openssl/opensslv.h>
17#include <openssl/err.h>
18#include <openssl/des.h>
19#include <openssl/aes.h>
20#include <openssl/bn.h>
21#include <openssl/evp.h>
22#include <openssl/dh.h>
23
24#include "common.h"
25#include "wpabuf.h"
26#include "dh_group5.h"
27#include "crypto.h"
28
29#if OPENSSL_VERSION_NUMBER < 0x00907000
30#define DES_key_schedule des_key_schedule
31#define DES_cblock des_cblock
32#define DES_set_key(key, schedule) des_set_key((key), *(schedule))
33#define DES_ecb_encrypt(input, output, ks, enc) \
34	des_ecb_encrypt((input), (output), *(ks), (enc))
35#endif /* openssl < 0.9.7 */
36
37static BIGNUM * get_group5_prime(void)
38{
39#if OPENSSL_VERSION_NUMBER < 0x00908000
40	static const unsigned char RFC3526_PRIME_1536[] = {
41		0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xC9,0x0F,0xDA,0xA2,
42		0x21,0x68,0xC2,0x34,0xC4,0xC6,0x62,0x8B,0x80,0xDC,0x1C,0xD1,
43		0x29,0x02,0x4E,0x08,0x8A,0x67,0xCC,0x74,0x02,0x0B,0xBE,0xA6,
44		0x3B,0x13,0x9B,0x22,0x51,0x4A,0x08,0x79,0x8E,0x34,0x04,0xDD,
45		0xEF,0x95,0x19,0xB3,0xCD,0x3A,0x43,0x1B,0x30,0x2B,0x0A,0x6D,
46		0xF2,0x5F,0x14,0x37,0x4F,0xE1,0x35,0x6D,0x6D,0x51,0xC2,0x45,
47		0xE4,0x85,0xB5,0x76,0x62,0x5E,0x7E,0xC6,0xF4,0x4C,0x42,0xE9,
48		0xA6,0x37,0xED,0x6B,0x0B,0xFF,0x5C,0xB6,0xF4,0x06,0xB7,0xED,
49		0xEE,0x38,0x6B,0xFB,0x5A,0x89,0x9F,0xA5,0xAE,0x9F,0x24,0x11,
50		0x7C,0x4B,0x1F,0xE6,0x49,0x28,0x66,0x51,0xEC,0xE4,0x5B,0x3D,
51		0xC2,0x00,0x7C,0xB8,0xA1,0x63,0xBF,0x05,0x98,0xDA,0x48,0x36,
52		0x1C,0x55,0xD3,0x9A,0x69,0x16,0x3F,0xA8,0xFD,0x24,0xCF,0x5F,
53		0x83,0x65,0x5D,0x23,0xDC,0xA3,0xAD,0x96,0x1C,0x62,0xF3,0x56,
54		0x20,0x85,0x52,0xBB,0x9E,0xD5,0x29,0x07,0x70,0x96,0x96,0x6D,
55		0x67,0x0C,0x35,0x4E,0x4A,0xBC,0x98,0x04,0xF1,0x74,0x6C,0x08,
56		0xCA,0x23,0x73,0x27,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
57	};
58        return BN_bin2bn(RFC3526_PRIME_1536, sizeof(RFC3526_PRIME_1536), NULL);
59#else /* openssl < 0.9.8 */
60	return get_rfc3526_prime_1536(NULL);
61#endif /* openssl < 0.9.8 */
62}
63
64#if OPENSSL_VERSION_NUMBER < 0x00908000
65#ifndef OPENSSL_NO_SHA256
66#ifndef OPENSSL_FIPS
67#define NO_SHA256_WRAPPER
68#endif
69#endif
70
71#endif /* openssl < 0.9.8 */
72
73#ifdef OPENSSL_NO_SHA256
74#define NO_SHA256_WRAPPER
75#endif
76
77static int openssl_digest_vector(const EVP_MD *type, int non_fips,
78				 size_t num_elem, const u8 *addr[],
79				 const size_t *len, u8 *mac)
80{
81	EVP_MD_CTX ctx;
82	size_t i;
83	unsigned int mac_len;
84
85	EVP_MD_CTX_init(&ctx);
86#ifdef CONFIG_FIPS
87#ifdef OPENSSL_FIPS
88	if (non_fips)
89		EVP_MD_CTX_set_flags(&ctx, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
90#endif /* OPENSSL_FIPS */
91#endif /* CONFIG_FIPS */
92	if (!EVP_DigestInit_ex(&ctx, type, NULL)) {
93		wpa_printf(MSG_ERROR, "OpenSSL: EVP_DigestInit_ex failed: %s",
94			   ERR_error_string(ERR_get_error(), NULL));
95		return -1;
96	}
97	for (i = 0; i < num_elem; i++) {
98		if (!EVP_DigestUpdate(&ctx, addr[i], len[i])) {
99			wpa_printf(MSG_ERROR, "OpenSSL: EVP_DigestUpdate "
100				   "failed: %s",
101				   ERR_error_string(ERR_get_error(), NULL));
102			return -1;
103		}
104	}
105	if (!EVP_DigestFinal(&ctx, mac, &mac_len)) {
106		wpa_printf(MSG_ERROR, "OpenSSL: EVP_DigestFinal failed: %s",
107			   ERR_error_string(ERR_get_error(), NULL));
108		return -1;
109	}
110
111	return 0;
112}
113
114
115int md4_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
116{
117	return openssl_digest_vector(EVP_md4(), 0, num_elem, addr, len, mac);
118}
119
120
121void des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
122{
123	u8 pkey[8], next, tmp;
124	int i;
125	DES_key_schedule ks;
126
127	/* Add parity bits to the key */
128	next = 0;
129	for (i = 0; i < 7; i++) {
130		tmp = key[i];
131		pkey[i] = (tmp >> i) | next | 1;
132		next = tmp << (7 - i);
133	}
134	pkey[i] = next | 1;
135
136	DES_set_key(&pkey, &ks);
137	DES_ecb_encrypt((DES_cblock *) clear, (DES_cblock *) cypher, &ks,
138			DES_ENCRYPT);
139}
140
141
142int rc4_skip(const u8 *key, size_t keylen, size_t skip,
143	     u8 *data, size_t data_len)
144{
145#ifdef OPENSSL_NO_RC4
146	return -1;
147#else /* OPENSSL_NO_RC4 */
148	EVP_CIPHER_CTX ctx;
149	int outl;
150	int res = -1;
151	unsigned char skip_buf[16];
152
153	EVP_CIPHER_CTX_init(&ctx);
154	if (!EVP_CIPHER_CTX_set_padding(&ctx, 0) ||
155	    !EVP_CipherInit_ex(&ctx, EVP_rc4(), NULL, NULL, NULL, 1) ||
156	    !EVP_CIPHER_CTX_set_key_length(&ctx, keylen) ||
157	    !EVP_CipherInit_ex(&ctx, NULL, NULL, key, NULL, 1))
158		goto out;
159
160	while (skip >= sizeof(skip_buf)) {
161		size_t len = skip;
162		if (len > sizeof(skip_buf))
163			len = sizeof(skip_buf);
164		if (!EVP_CipherUpdate(&ctx, skip_buf, &outl, skip_buf, len))
165			goto out;
166		skip -= len;
167	}
168
169	if (EVP_CipherUpdate(&ctx, data, &outl, data, data_len))
170		res = 0;
171
172out:
173	EVP_CIPHER_CTX_cleanup(&ctx);
174	return res;
175#endif /* OPENSSL_NO_RC4 */
176}
177
178
179int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
180{
181	return openssl_digest_vector(EVP_md5(), 0, num_elem, addr, len, mac);
182}
183
184
185#ifdef CONFIG_FIPS
186int md5_vector_non_fips_allow(size_t num_elem, const u8 *addr[],
187			      const size_t *len, u8 *mac)
188{
189	return openssl_digest_vector(EVP_md5(), 1, num_elem, addr, len, mac);
190}
191#endif /* CONFIG_FIPS */
192
193
194int sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
195{
196	return openssl_digest_vector(EVP_sha1(), 0, num_elem, addr, len, mac);
197}
198
199
200#ifndef NO_SHA256_WRAPPER
201int sha256_vector(size_t num_elem, const u8 *addr[], const size_t *len,
202		  u8 *mac)
203{
204	return openssl_digest_vector(EVP_sha256(), 0, num_elem, addr, len,
205				     mac);
206}
207#endif /* NO_SHA256_WRAPPER */
208
209
210void * aes_encrypt_init(const u8 *key, size_t len)
211{
212	AES_KEY *ak;
213	ak = os_malloc(sizeof(*ak));
214	if (ak == NULL)
215		return NULL;
216	if (AES_set_encrypt_key(key, 8 * len, ak) < 0) {
217		os_free(ak);
218		return NULL;
219	}
220	return ak;
221}
222
223
224void aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
225{
226	AES_encrypt(plain, crypt, ctx);
227}
228
229
230void aes_encrypt_deinit(void *ctx)
231{
232	os_free(ctx);
233}
234
235
236void * aes_decrypt_init(const u8 *key, size_t len)
237{
238	AES_KEY *ak;
239	ak = os_malloc(sizeof(*ak));
240	if (ak == NULL)
241		return NULL;
242	if (AES_set_decrypt_key(key, 8 * len, ak) < 0) {
243		os_free(ak);
244		return NULL;
245	}
246	return ak;
247}
248
249
250void aes_decrypt(void *ctx, const u8 *crypt, u8 *plain)
251{
252	AES_decrypt(crypt, plain, ctx);
253}
254
255
256void aes_decrypt_deinit(void *ctx)
257{
258	os_free(ctx);
259}
260
261
262int crypto_mod_exp(const u8 *base, size_t base_len,
263		   const u8 *power, size_t power_len,
264		   const u8 *modulus, size_t modulus_len,
265		   u8 *result, size_t *result_len)
266{
267	BIGNUM *bn_base, *bn_exp, *bn_modulus, *bn_result;
268	int ret = -1;
269	BN_CTX *ctx;
270
271	ctx = BN_CTX_new();
272	if (ctx == NULL)
273		return -1;
274
275	bn_base = BN_bin2bn(base, base_len, NULL);
276	bn_exp = BN_bin2bn(power, power_len, NULL);
277	bn_modulus = BN_bin2bn(modulus, modulus_len, NULL);
278	bn_result = BN_new();
279
280	if (bn_base == NULL || bn_exp == NULL || bn_modulus == NULL ||
281	    bn_result == NULL)
282		goto error;
283
284	if (BN_mod_exp(bn_result, bn_base, bn_exp, bn_modulus, ctx) != 1)
285		goto error;
286
287	*result_len = BN_bn2bin(bn_result, result);
288	ret = 0;
289
290error:
291	BN_free(bn_base);
292	BN_free(bn_exp);
293	BN_free(bn_modulus);
294	BN_free(bn_result);
295	BN_CTX_free(ctx);
296	return ret;
297}
298
299
300struct crypto_cipher {
301	EVP_CIPHER_CTX enc;
302	EVP_CIPHER_CTX dec;
303};
304
305
306struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
307					  const u8 *iv, const u8 *key,
308					  size_t key_len)
309{
310	struct crypto_cipher *ctx;
311	const EVP_CIPHER *cipher;
312
313	ctx = os_zalloc(sizeof(*ctx));
314	if (ctx == NULL)
315		return NULL;
316
317	switch (alg) {
318#ifndef OPENSSL_NO_RC4
319	case CRYPTO_CIPHER_ALG_RC4:
320		cipher = EVP_rc4();
321		break;
322#endif /* OPENSSL_NO_RC4 */
323#ifndef OPENSSL_NO_AES
324	case CRYPTO_CIPHER_ALG_AES:
325		switch (key_len) {
326		case 16:
327			cipher = EVP_aes_128_cbc();
328			break;
329		case 24:
330			cipher = EVP_aes_192_cbc();
331			break;
332		case 32:
333			cipher = EVP_aes_256_cbc();
334			break;
335		default:
336			os_free(ctx);
337			return NULL;
338		}
339		break;
340#endif /* OPENSSL_NO_AES */
341#ifndef OPENSSL_NO_DES
342	case CRYPTO_CIPHER_ALG_3DES:
343		cipher = EVP_des_ede3_cbc();
344		break;
345	case CRYPTO_CIPHER_ALG_DES:
346		cipher = EVP_des_cbc();
347		break;
348#endif /* OPENSSL_NO_DES */
349#ifndef OPENSSL_NO_RC2
350	case CRYPTO_CIPHER_ALG_RC2:
351		cipher = EVP_rc2_ecb();
352		break;
353#endif /* OPENSSL_NO_RC2 */
354	default:
355		os_free(ctx);
356		return NULL;
357	}
358
359	EVP_CIPHER_CTX_init(&ctx->enc);
360	EVP_CIPHER_CTX_set_padding(&ctx->enc, 0);
361	if (!EVP_EncryptInit_ex(&ctx->enc, cipher, NULL, NULL, NULL) ||
362	    !EVP_CIPHER_CTX_set_key_length(&ctx->enc, key_len) ||
363	    !EVP_EncryptInit_ex(&ctx->enc, NULL, NULL, key, iv)) {
364		EVP_CIPHER_CTX_cleanup(&ctx->enc);
365		os_free(ctx);
366		return NULL;
367	}
368
369	EVP_CIPHER_CTX_init(&ctx->dec);
370	EVP_CIPHER_CTX_set_padding(&ctx->dec, 0);
371	if (!EVP_DecryptInit_ex(&ctx->dec, cipher, NULL, NULL, NULL) ||
372	    !EVP_CIPHER_CTX_set_key_length(&ctx->dec, key_len) ||
373	    !EVP_DecryptInit_ex(&ctx->dec, NULL, NULL, key, iv)) {
374		EVP_CIPHER_CTX_cleanup(&ctx->enc);
375		EVP_CIPHER_CTX_cleanup(&ctx->dec);
376		os_free(ctx);
377		return NULL;
378	}
379
380	return ctx;
381}
382
383
384int crypto_cipher_encrypt(struct crypto_cipher *ctx, const u8 *plain,
385			  u8 *crypt, size_t len)
386{
387	int outl;
388	if (!EVP_EncryptUpdate(&ctx->enc, crypt, &outl, plain, len))
389		return -1;
390	return 0;
391}
392
393
394int crypto_cipher_decrypt(struct crypto_cipher *ctx, const u8 *crypt,
395			  u8 *plain, size_t len)
396{
397	int outl;
398	outl = len;
399	if (!EVP_DecryptUpdate(&ctx->dec, plain, &outl, crypt, len))
400		return -1;
401	return 0;
402}
403
404
405void crypto_cipher_deinit(struct crypto_cipher *ctx)
406{
407	EVP_CIPHER_CTX_cleanup(&ctx->enc);
408	EVP_CIPHER_CTX_cleanup(&ctx->dec);
409	os_free(ctx);
410}
411
412
413void * dh5_init(struct wpabuf **priv, struct wpabuf **publ)
414{
415	DH *dh;
416	struct wpabuf *pubkey = NULL, *privkey = NULL;
417	size_t publen, privlen;
418
419	*priv = NULL;
420	*publ = NULL;
421
422	dh = DH_new();
423	if (dh == NULL)
424		return NULL;
425
426	dh->g = BN_new();
427	if (dh->g == NULL || BN_set_word(dh->g, 2) != 1)
428		goto err;
429
430	dh->p = get_group5_prime();
431	if (dh->p == NULL)
432		goto err;
433
434	if (DH_generate_key(dh) != 1)
435		goto err;
436
437	publen = BN_num_bytes(dh->pub_key);
438	pubkey = wpabuf_alloc(publen);
439	if (pubkey == NULL)
440		goto err;
441	privlen = BN_num_bytes(dh->priv_key);
442	privkey = wpabuf_alloc(privlen);
443	if (privkey == NULL)
444		goto err;
445
446	BN_bn2bin(dh->pub_key, wpabuf_put(pubkey, publen));
447	BN_bn2bin(dh->priv_key, wpabuf_put(privkey, privlen));
448
449	*priv = privkey;
450	*publ = pubkey;
451	return dh;
452
453err:
454	wpabuf_free(pubkey);
455	wpabuf_free(privkey);
456	DH_free(dh);
457	return NULL;
458}
459
460
461struct wpabuf * dh5_derive_shared(void *ctx, const struct wpabuf *peer_public,
462				  const struct wpabuf *own_private)
463{
464	BIGNUM *pub_key;
465	struct wpabuf *res = NULL;
466	size_t rlen;
467	DH *dh = ctx;
468	int keylen;
469
470	if (ctx == NULL)
471		return NULL;
472
473	pub_key = BN_bin2bn(wpabuf_head(peer_public), wpabuf_len(peer_public),
474			    NULL);
475	if (pub_key == NULL)
476		return NULL;
477
478	rlen = DH_size(dh);
479	res = wpabuf_alloc(rlen);
480	if (res == NULL)
481		goto err;
482
483	keylen = DH_compute_key(wpabuf_mhead(res), pub_key, dh);
484	if (keylen < 0)
485		goto err;
486	wpabuf_put(res, keylen);
487	BN_free(pub_key);
488
489	return res;
490
491err:
492	BN_free(pub_key);
493	wpabuf_free(res);
494	return NULL;
495}
496
497
498void dh5_free(void *ctx)
499{
500	DH *dh;
501	if (ctx == NULL)
502		return;
503	dh = ctx;
504	DH_free(dh);
505}
506