xref: /openbsd/lib/libssl/t1_enc.c (revision 387303bb)
1 /* $OpenBSD: t1_enc.c,v 1.158 2024/07/20 04:04:23 jsing Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 /* ====================================================================
59  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  *
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  *
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in
70  *    the documentation and/or other materials provided with the
71  *    distribution.
72  *
73  * 3. All advertising materials mentioning features or use of this
74  *    software must display the following acknowledgment:
75  *    "This product includes software developed by the OpenSSL Project
76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77  *
78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79  *    endorse or promote products derived from this software without
80  *    prior written permission. For written permission, please contact
81  *    openssl-core@openssl.org.
82  *
83  * 5. Products derived from this software may not be called "OpenSSL"
84  *    nor may "OpenSSL" appear in their names without prior written
85  *    permission of the OpenSSL Project.
86  *
87  * 6. Redistributions of any form whatsoever must retain the following
88  *    acknowledgment:
89  *    "This product includes software developed by the OpenSSL Project
90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91  *
92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103  * OF THE POSSIBILITY OF SUCH DAMAGE.
104  * ====================================================================
105  *
106  * This product includes cryptographic software written by Eric Young
107  * (eay@cryptsoft.com).  This product includes software written by Tim
108  * Hudson (tjh@cryptsoft.com).
109  *
110  */
111 /* ====================================================================
112  * Copyright 2005 Nokia. All rights reserved.
113  *
114  * The portions of the attached software ("Contribution") is developed by
115  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
116  * license.
117  *
118  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
119  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
120  * support (see RFC 4279) to OpenSSL.
121  *
122  * No patent licenses or other rights except those expressly stated in
123  * the OpenSSL open source license shall be deemed granted or received
124  * expressly, by implication, estoppel, or otherwise.
125  *
126  * No assurances are provided by Nokia that the Contribution does not
127  * infringe the patent or other intellectual property rights of any third
128  * party or that the license provides you with all the necessary rights
129  * to make use of the Contribution.
130  *
131  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
132  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
133  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
134  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
135  * OTHERWISE.
136  */
137 
138 #include <limits.h>
139 #include <stdio.h>
140 
141 #include <openssl/evp.h>
142 #include <openssl/hmac.h>
143 #include <openssl/md5.h>
144 #include <openssl/opensslconf.h>
145 
146 #include "dtls_local.h"
147 #include "ssl_local.h"
148 
149 void
tls1_cleanup_key_block(SSL * s)150 tls1_cleanup_key_block(SSL *s)
151 {
152 	tls12_key_block_free(s->s3->hs.tls12.key_block);
153 	s->s3->hs.tls12.key_block = NULL;
154 }
155 
156 /*
157  * TLS P_hash() data expansion function - see RFC 5246, section 5.
158  */
159 static int
tls1_P_hash(const EVP_MD * md,const unsigned char * secret,size_t secret_len,const void * seed1,size_t seed1_len,const void * seed2,size_t seed2_len,const void * seed3,size_t seed3_len,const void * seed4,size_t seed4_len,const void * seed5,size_t seed5_len,unsigned char * out,size_t out_len)160 tls1_P_hash(const EVP_MD *md, const unsigned char *secret, size_t secret_len,
161     const void *seed1, size_t seed1_len, const void *seed2, size_t seed2_len,
162     const void *seed3, size_t seed3_len, const void *seed4, size_t seed4_len,
163     const void *seed5, size_t seed5_len, unsigned char *out, size_t out_len)
164 {
165 	unsigned char A1[EVP_MAX_MD_SIZE], hmac[EVP_MAX_MD_SIZE];
166 	size_t A1_len, hmac_len;
167 	EVP_MD_CTX *ctx = NULL;
168 	EVP_PKEY *mac_key = NULL;
169 	int ret = 0;
170 	int chunk;
171 	size_t i;
172 
173 	chunk = EVP_MD_size(md);
174 	OPENSSL_assert(chunk >= 0);
175 
176 	if ((ctx = EVP_MD_CTX_new()) == NULL)
177 		goto err;
178 
179 	mac_key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, secret, secret_len);
180 	if (mac_key == NULL)
181 		goto err;
182 	if (!EVP_DigestSignInit(ctx, NULL, md, NULL, mac_key))
183 		goto err;
184 	if (seed1 && !EVP_DigestSignUpdate(ctx, seed1, seed1_len))
185 		goto err;
186 	if (seed2 && !EVP_DigestSignUpdate(ctx, seed2, seed2_len))
187 		goto err;
188 	if (seed3 && !EVP_DigestSignUpdate(ctx, seed3, seed3_len))
189 		goto err;
190 	if (seed4 && !EVP_DigestSignUpdate(ctx, seed4, seed4_len))
191 		goto err;
192 	if (seed5 && !EVP_DigestSignUpdate(ctx, seed5, seed5_len))
193 		goto err;
194 	if (!EVP_DigestSignFinal(ctx, A1, &A1_len))
195 		goto err;
196 
197 	for (;;) {
198 		if (!EVP_DigestSignInit(ctx, NULL, md, NULL, mac_key))
199 			goto err;
200 		if (!EVP_DigestSignUpdate(ctx, A1, A1_len))
201 			goto err;
202 		if (seed1 && !EVP_DigestSignUpdate(ctx, seed1, seed1_len))
203 			goto err;
204 		if (seed2 && !EVP_DigestSignUpdate(ctx, seed2, seed2_len))
205 			goto err;
206 		if (seed3 && !EVP_DigestSignUpdate(ctx, seed3, seed3_len))
207 			goto err;
208 		if (seed4 && !EVP_DigestSignUpdate(ctx, seed4, seed4_len))
209 			goto err;
210 		if (seed5 && !EVP_DigestSignUpdate(ctx, seed5, seed5_len))
211 			goto err;
212 		if (!EVP_DigestSignFinal(ctx, hmac, &hmac_len))
213 			goto err;
214 
215 		if (hmac_len > out_len)
216 			hmac_len = out_len;
217 
218 		for (i = 0; i < hmac_len; i++)
219 			out[i] ^= hmac[i];
220 
221 		out += hmac_len;
222 		out_len -= hmac_len;
223 
224 		if (out_len == 0)
225 			break;
226 
227 		if (!EVP_DigestSignInit(ctx, NULL, md, NULL, mac_key))
228 			goto err;
229 		if (!EVP_DigestSignUpdate(ctx, A1, A1_len))
230 			goto err;
231 		if (!EVP_DigestSignFinal(ctx, A1, &A1_len))
232 			goto err;
233 	}
234 	ret = 1;
235 
236  err:
237 	EVP_PKEY_free(mac_key);
238 	EVP_MD_CTX_free(ctx);
239 
240 	explicit_bzero(A1, sizeof(A1));
241 	explicit_bzero(hmac, sizeof(hmac));
242 
243 	return ret;
244 }
245 
246 int
tls1_PRF(SSL * s,const unsigned char * secret,size_t secret_len,const void * seed1,size_t seed1_len,const void * seed2,size_t seed2_len,const void * seed3,size_t seed3_len,const void * seed4,size_t seed4_len,const void * seed5,size_t seed5_len,unsigned char * out,size_t out_len)247 tls1_PRF(SSL *s, const unsigned char *secret, size_t secret_len,
248     const void *seed1, size_t seed1_len, const void *seed2, size_t seed2_len,
249     const void *seed3, size_t seed3_len, const void *seed4, size_t seed4_len,
250     const void *seed5, size_t seed5_len, unsigned char *out, size_t out_len)
251 {
252 	const EVP_MD *md;
253 	size_t half_len;
254 
255 	memset(out, 0, out_len);
256 
257 	if (!ssl_get_handshake_evp_md(s, &md))
258 		return (0);
259 
260 	if (EVP_MD_type(md) == NID_md5_sha1) {
261 		/*
262 		 * Partition secret between MD5 and SHA1, then XOR result.
263 		 * If the secret length is odd, a one byte overlap is used.
264 		 */
265 		half_len = secret_len - (secret_len / 2);
266 		if (!tls1_P_hash(EVP_md5(), secret, half_len, seed1, seed1_len,
267 		    seed2, seed2_len, seed3, seed3_len, seed4, seed4_len,
268 		    seed5, seed5_len, out, out_len))
269 			return (0);
270 
271 		secret += secret_len - half_len;
272 		if (!tls1_P_hash(EVP_sha1(), secret, half_len, seed1, seed1_len,
273 		    seed2, seed2_len, seed3, seed3_len, seed4, seed4_len,
274 		    seed5, seed5_len, out, out_len))
275 			return (0);
276 
277 		return (1);
278 	}
279 
280 	if (!tls1_P_hash(md, secret, secret_len, seed1, seed1_len,
281 	    seed2, seed2_len, seed3, seed3_len, seed4, seed4_len,
282 	    seed5, seed5_len, out, out_len))
283 		return (0);
284 
285 	return (1);
286 }
287 
288 int
tls1_generate_key_block(SSL * s,uint8_t * key_block,size_t key_block_len)289 tls1_generate_key_block(SSL *s, uint8_t *key_block, size_t key_block_len)
290 {
291 	return tls1_PRF(s,
292 	    s->session->master_key, s->session->master_key_length,
293 	    TLS_MD_KEY_EXPANSION_CONST, TLS_MD_KEY_EXPANSION_CONST_SIZE,
294 	    s->s3->server_random, SSL3_RANDOM_SIZE,
295 	    s->s3->client_random, SSL3_RANDOM_SIZE,
296 	    NULL, 0, NULL, 0, key_block, key_block_len);
297 }
298 
299 static int
tls1_change_cipher_state(SSL * s,int is_write)300 tls1_change_cipher_state(SSL *s, int is_write)
301 {
302 	CBS mac_key, key, iv;
303 
304 	/* Use client write keys on client write and server read. */
305 	if ((!s->server && is_write) || (s->server && !is_write)) {
306 		tls12_key_block_client_write(s->s3->hs.tls12.key_block,
307 		    &mac_key, &key, &iv);
308 	} else {
309 		tls12_key_block_server_write(s->s3->hs.tls12.key_block,
310 		    &mac_key, &key, &iv);
311 	}
312 
313 	if (!is_write) {
314 		if (!tls12_record_layer_change_read_cipher_state(s->rl,
315 		    &mac_key, &key, &iv))
316 			goto err;
317 		if (SSL_is_dtls(s))
318 			dtls1_reset_read_seq_numbers(s);
319 	} else {
320 		if (!tls12_record_layer_change_write_cipher_state(s->rl,
321 		    &mac_key, &key, &iv))
322 			goto err;
323 	}
324 	return (1);
325 
326  err:
327 	return (0);
328 }
329 
330 int
tls1_change_read_cipher_state(SSL * s)331 tls1_change_read_cipher_state(SSL *s)
332 {
333 	return tls1_change_cipher_state(s, 0);
334 }
335 
336 int
tls1_change_write_cipher_state(SSL * s)337 tls1_change_write_cipher_state(SSL *s)
338 {
339 	return tls1_change_cipher_state(s, 1);
340 }
341 
342 int
tls1_setup_key_block(SSL * s)343 tls1_setup_key_block(SSL *s)
344 {
345 	struct tls12_key_block *key_block;
346 	int mac_type = NID_undef, mac_secret_size = 0;
347 	const EVP_CIPHER *cipher = NULL;
348 	const EVP_AEAD *aead = NULL;
349 	const EVP_MD *handshake_hash = NULL;
350 	const EVP_MD *mac_hash = NULL;
351 	int ret = 0;
352 
353 	/*
354 	 * XXX - callers should be changed so that they only call this
355 	 * function once.
356 	 */
357 	if (s->s3->hs.tls12.key_block != NULL)
358 		return (1);
359 
360 	if (s->s3->hs.cipher == NULL)
361 		return (0);
362 
363 	if ((s->s3->hs.cipher->algorithm_mac & SSL_AEAD) != 0) {
364 		if (!ssl_cipher_get_evp_aead(s, &aead)) {
365 			SSLerror(s, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
366 			return (0);
367 		}
368 	} else {
369 		/* XXX - mac_type and mac_secret_size are now unused. */
370 		if (!ssl_cipher_get_evp(s, &cipher, &mac_hash,
371 		    &mac_type, &mac_secret_size)) {
372 			SSLerror(s, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
373 			return (0);
374 		}
375 	}
376 
377 	if (!ssl_get_handshake_evp_md(s, &handshake_hash))
378 		return (0);
379 
380 	tls12_record_layer_set_aead(s->rl, aead);
381 	tls12_record_layer_set_cipher_hash(s->rl, cipher,
382 	    handshake_hash, mac_hash);
383 
384 	if ((key_block = tls12_key_block_new()) == NULL)
385 		goto err;
386 	if (!tls12_key_block_generate(key_block, s, aead, cipher, mac_hash))
387 		goto err;
388 
389 	s->s3->hs.tls12.key_block = key_block;
390 	key_block = NULL;
391 
392 	if (!(s->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS) &&
393 	    s->method->version <= TLS1_VERSION) {
394 		/*
395 		 * Enable vulnerability countermeasure for CBC ciphers with
396 		 * known-IV problem (http://www.openssl.org/~bodo/tls-cbc.txt)
397 		 */
398 		s->s3->need_empty_fragments = 1;
399 
400 		if (s->s3->hs.cipher != NULL) {
401 			if (s->s3->hs.cipher->algorithm_enc == SSL_eNULL)
402 				s->s3->need_empty_fragments = 0;
403 
404 #ifndef OPENSSL_NO_RC4
405 			if (s->s3->hs.cipher->algorithm_enc == SSL_RC4)
406 				s->s3->need_empty_fragments = 0;
407 #endif
408 		}
409 	}
410 
411 	ret = 1;
412 
413  err:
414 	tls12_key_block_free(key_block);
415 
416 	return (ret);
417 }
418