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      1 /*
      2  * WPA Supplicant / wrapper functions for libcrypto
      3  * Copyright (c) 2004-2009, Jouni Malinen <j (at) 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 
     37 static 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 
     77 static 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 
    115 int 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 
    121 void 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 
    142 int 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 
    172 out:
    173 	EVP_CIPHER_CTX_cleanup(&ctx);
    174 	return res;
    175 #endif /* OPENSSL_NO_RC4 */
    176 }
    177 
    178 
    179 int 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
    186 int 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 
    194 int 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
    201 int 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 
    210 void * 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 
    224 void aes_encrypt(void *ctx, const u8 *plain, u8 *crypt)
    225 {
    226 	AES_encrypt(plain, crypt, ctx);
    227 }
    228 
    229 
    230 void aes_encrypt_deinit(void *ctx)
    231 {
    232 	os_free(ctx);
    233 }
    234 
    235 
    236 void * 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 
    250 void aes_decrypt(void *ctx, const u8 *crypt, u8 *plain)
    251 {
    252 	AES_decrypt(crypt, plain, ctx);
    253 }
    254 
    255 
    256 void aes_decrypt_deinit(void *ctx)
    257 {
    258 	os_free(ctx);
    259 }
    260 
    261 
    262 int 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 
    290 error:
    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 
    300 struct crypto_cipher {
    301 	EVP_CIPHER_CTX enc;
    302 	EVP_CIPHER_CTX dec;
    303 };
    304 
    305 
    306 struct 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 
    384 int 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 
    394 int 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 
    405 void 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 
    413 void * 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 
    453 err:
    454 	wpabuf_free(pubkey);
    455 	wpabuf_free(privkey);
    456 	DH_free(dh);
    457 	return NULL;
    458 }
    459 
    460 
    461 struct 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 
    491 err:
    492 	BN_free(pub_key);
    493 	wpabuf_free(res);
    494 	return NULL;
    495 }
    496 
    497 
    498 void dh5_free(void *ctx)
    499 {
    500 	DH *dh;
    501 	if (ctx == NULL)
    502 		return;
    503 	dh = ctx;
    504 	DH_free(dh);
    505 }
    506