xref: /openbsd-src/lib/libssl/t1_enc.c (revision 24bb5fcea3ed904bc467217bdaadb5dfc618d5bf)
1 /* $OpenBSD: t1_enc.c,v 1.151 2021/07/01 17:53:39 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_locl.h"
147 #include "ssl_locl.h"
148 
149 void
150 tls1_cleanup_key_block(SSL *s)
151 {
152 	tls12_key_block_free(S3I(s)->hs.tls12.key_block);
153 	S3I(s)->hs.tls12.key_block = NULL;
154 }
155 
156 /*
157  * TLS P_hash() data expansion function - see RFC 5246, section 5.
158  */
159 static int
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;
168 	EVP_PKEY *mac_key;
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 	EVP_MD_CTX_init(&ctx);
177 
178 	mac_key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, secret, secret_len);
179 	if (!mac_key)
180 		goto err;
181 	if (!EVP_DigestSignInit(&ctx, NULL, md, NULL, mac_key))
182 		goto err;
183 	if (seed1 && !EVP_DigestSignUpdate(&ctx, seed1, seed1_len))
184 		goto err;
185 	if (seed2 && !EVP_DigestSignUpdate(&ctx, seed2, seed2_len))
186 		goto err;
187 	if (seed3 && !EVP_DigestSignUpdate(&ctx, seed3, seed3_len))
188 		goto err;
189 	if (seed4 && !EVP_DigestSignUpdate(&ctx, seed4, seed4_len))
190 		goto err;
191 	if (seed5 && !EVP_DigestSignUpdate(&ctx, seed5, seed5_len))
192 		goto err;
193 	if (!EVP_DigestSignFinal(&ctx, A1, &A1_len))
194 		goto err;
195 
196 	for (;;) {
197 		if (!EVP_DigestSignInit(&ctx, NULL, md, NULL, mac_key))
198 			goto err;
199 		if (!EVP_DigestSignUpdate(&ctx, A1, A1_len))
200 			goto err;
201 		if (seed1 && !EVP_DigestSignUpdate(&ctx, seed1, seed1_len))
202 			goto err;
203 		if (seed2 && !EVP_DigestSignUpdate(&ctx, seed2, seed2_len))
204 			goto err;
205 		if (seed3 && !EVP_DigestSignUpdate(&ctx, seed3, seed3_len))
206 			goto err;
207 		if (seed4 && !EVP_DigestSignUpdate(&ctx, seed4, seed4_len))
208 			goto err;
209 		if (seed5 && !EVP_DigestSignUpdate(&ctx, seed5, seed5_len))
210 			goto err;
211 		if (!EVP_DigestSignFinal(&ctx, hmac, &hmac_len))
212 			goto err;
213 
214 		if (hmac_len > out_len)
215 			hmac_len = out_len;
216 
217 		for (i = 0; i < hmac_len; i++)
218 			out[i] ^= hmac[i];
219 
220 		out += hmac_len;
221 		out_len -= hmac_len;
222 
223 		if (out_len == 0)
224 			break;
225 
226 		if (!EVP_DigestSignInit(&ctx, NULL, md, NULL, mac_key))
227 			goto err;
228 		if (!EVP_DigestSignUpdate(&ctx, A1, A1_len))
229 			goto err;
230 		if (!EVP_DigestSignFinal(&ctx, A1, &A1_len))
231 			goto err;
232 	}
233 	ret = 1;
234 
235  err:
236 	EVP_PKEY_free(mac_key);
237 	EVP_MD_CTX_cleanup(&ctx);
238 
239 	explicit_bzero(A1, sizeof(A1));
240 	explicit_bzero(hmac, sizeof(hmac));
241 
242 	return ret;
243 }
244 
245 int
246 tls1_PRF(SSL *s, const unsigned char *secret, size_t secret_len,
247     const void *seed1, size_t seed1_len, const void *seed2, size_t seed2_len,
248     const void *seed3, size_t seed3_len, const void *seed4, size_t seed4_len,
249     const void *seed5, size_t seed5_len, unsigned char *out, size_t out_len)
250 {
251 	const EVP_MD *md;
252 	size_t half_len;
253 
254 	memset(out, 0, out_len);
255 
256 	if (!ssl_get_handshake_evp_md(s, &md))
257 		return (0);
258 
259 	if (md->type == NID_md5_sha1) {
260 		/*
261 		 * Partition secret between MD5 and SHA1, then XOR result.
262 		 * If the secret length is odd, a one byte overlap is used.
263 		 */
264 		half_len = secret_len - (secret_len / 2);
265 		if (!tls1_P_hash(EVP_md5(), secret, half_len, seed1, seed1_len,
266 		    seed2, seed2_len, seed3, seed3_len, seed4, seed4_len,
267 		    seed5, seed5_len, out, out_len))
268 			return (0);
269 
270 		secret += secret_len - half_len;
271 		if (!tls1_P_hash(EVP_sha1(), secret, half_len, seed1, seed1_len,
272 		    seed2, seed2_len, seed3, seed3_len, seed4, seed4_len,
273 		    seed5, seed5_len, out, out_len))
274 			return (0);
275 
276 		return (1);
277 	}
278 
279 	if (!tls1_P_hash(md, secret, secret_len, seed1, seed1_len,
280 	    seed2, seed2_len, seed3, seed3_len, seed4, seed4_len,
281 	    seed5, seed5_len, out, out_len))
282 		return (0);
283 
284 	return (1);
285 }
286 
287 int
288 tls1_generate_key_block(SSL *s, uint8_t *key_block, size_t key_block_len)
289 {
290 	return tls1_PRF(s,
291 	    s->session->master_key, s->session->master_key_length,
292 	    TLS_MD_KEY_EXPANSION_CONST, TLS_MD_KEY_EXPANSION_CONST_SIZE,
293 	    s->s3->server_random, SSL3_RANDOM_SIZE,
294 	    s->s3->client_random, SSL3_RANDOM_SIZE,
295 	    NULL, 0, NULL, 0, key_block, key_block_len);
296 }
297 
298 static int
299 tls1_change_cipher_state(SSL *s, int is_write)
300 {
301 	CBS mac_key, key, iv;
302 
303 	/* Use client write keys on client write and server read. */
304 	if ((!s->server && is_write) || (s->server && !is_write)) {
305 		tls12_key_block_client_write(S3I(s)->hs.tls12.key_block,
306 		    &mac_key, &key, &iv);
307 	} else {
308 		tls12_key_block_server_write(S3I(s)->hs.tls12.key_block,
309 		    &mac_key, &key, &iv);
310 	}
311 
312 	if (!is_write) {
313 		if (!tls12_record_layer_change_read_cipher_state(s->internal->rl,
314 		    &mac_key, &key, &iv))
315 			goto err;
316 		if (SSL_is_dtls(s))
317 			dtls1_reset_read_seq_numbers(s);
318 		tls12_record_layer_read_cipher_hash(s->internal->rl,
319 		    &s->enc_read_ctx, &s->read_hash);
320 	} else {
321 		if (!tls12_record_layer_change_write_cipher_state(s->internal->rl,
322 		    &mac_key, &key, &iv))
323 			goto err;
324 	}
325 	return (1);
326 
327  err:
328 	return (0);
329 }
330 
331 int
332 tls1_change_read_cipher_state(SSL *s)
333 {
334 	return tls1_change_cipher_state(s, 0);
335 }
336 
337 int
338 tls1_change_write_cipher_state(SSL *s)
339 {
340 	return tls1_change_cipher_state(s, 1);
341 }
342 
343 int
344 tls1_setup_key_block(SSL *s)
345 {
346 	struct tls12_key_block *key_block;
347 	int mac_type = NID_undef, mac_secret_size = 0;
348 	const EVP_CIPHER *cipher = NULL;
349 	const EVP_AEAD *aead = NULL;
350 	const EVP_MD *handshake_hash = NULL;
351 	const EVP_MD *mac_hash = NULL;
352 	int ret = 0;
353 
354 	/*
355 	 * XXX - callers should be changed so that they only call this
356 	 * function once.
357 	 */
358 	if (S3I(s)->hs.tls12.key_block != NULL)
359 		return (1);
360 
361 	if (s->session->cipher &&
362 	    (s->session->cipher->algorithm_mac & SSL_AEAD)) {
363 		if (!ssl_cipher_get_evp_aead(s->session, &aead)) {
364 			SSLerror(s, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
365 			return (0);
366 		}
367 	} else {
368 		/* XXX - mac_type and mac_secret_size are now unused. */
369 		if (!ssl_cipher_get_evp(s->session, &cipher, &mac_hash,
370 		    &mac_type, &mac_secret_size)) {
371 			SSLerror(s, SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
372 			return (0);
373 		}
374 	}
375 
376 	if (!ssl_get_handshake_evp_md(s, &handshake_hash))
377 		return (0);
378 
379 	tls12_record_layer_set_aead(s->internal->rl, aead);
380 	tls12_record_layer_set_cipher_hash(s->internal->rl, cipher,
381 	    handshake_hash, mac_hash);
382 
383 	if ((key_block = tls12_key_block_new()) == NULL)
384 		goto err;
385 	if (!tls12_key_block_generate(key_block, s, aead, cipher, mac_hash))
386 		goto err;
387 
388 	S3I(s)->hs.tls12.key_block = key_block;
389 	key_block = NULL;
390 
391 	if (!(s->internal->options & SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS) &&
392 	    s->method->version <= TLS1_VERSION) {
393 		/*
394 		 * Enable vulnerability countermeasure for CBC ciphers with
395 		 * known-IV problem (http://www.openssl.org/~bodo/tls-cbc.txt)
396 		 */
397 		S3I(s)->need_empty_fragments = 1;
398 
399 		if (s->session->cipher != NULL) {
400 			if (s->session->cipher->algorithm_enc == SSL_eNULL)
401 				S3I(s)->need_empty_fragments = 0;
402 
403 #ifndef OPENSSL_NO_RC4
404 			if (s->session->cipher->algorithm_enc == SSL_RC4)
405 				S3I(s)->need_empty_fragments = 0;
406 #endif
407 		}
408 	}
409 
410 	ret = 1;
411 
412  err:
413 	tls12_key_block_free(key_block);
414 
415 	return (ret);
416 }
417 
418 int
419 tls1_export_keying_material(SSL *s, unsigned char *out, size_t olen,
420     const char *label, size_t llen, const unsigned char *context,
421     size_t contextlen, int use_context)
422 {
423 	unsigned char *val = NULL;
424 	size_t vallen, currentvalpos;
425 	int rv;
426 
427 	if (!SSL_is_init_finished(s)) {
428 		SSLerror(s, SSL_R_BAD_STATE);
429 		return 0;
430 	}
431 
432 	/* construct PRF arguments
433 	 * we construct the PRF argument ourself rather than passing separate
434 	 * values into the TLS PRF to ensure that the concatenation of values
435 	 * does not create a prohibited label.
436 	 */
437 	vallen = llen + SSL3_RANDOM_SIZE * 2;
438 	if (use_context) {
439 		vallen += 2 + contextlen;
440 	}
441 
442 	val = malloc(vallen);
443 	if (val == NULL)
444 		goto err2;
445 	currentvalpos = 0;
446 	memcpy(val + currentvalpos, (unsigned char *) label, llen);
447 	currentvalpos += llen;
448 	memcpy(val + currentvalpos, s->s3->client_random, SSL3_RANDOM_SIZE);
449 	currentvalpos += SSL3_RANDOM_SIZE;
450 	memcpy(val + currentvalpos, s->s3->server_random, SSL3_RANDOM_SIZE);
451 	currentvalpos += SSL3_RANDOM_SIZE;
452 
453 	if (use_context) {
454 		val[currentvalpos] = (contextlen >> 8) & 0xff;
455 		currentvalpos++;
456 		val[currentvalpos] = contextlen & 0xff;
457 		currentvalpos++;
458 		if ((contextlen > 0) || (context != NULL)) {
459 			memcpy(val + currentvalpos, context, contextlen);
460 		}
461 	}
462 
463 	/* disallow prohibited labels
464 	 * note that SSL3_RANDOM_SIZE > max(prohibited label len) =
465 	 * 15, so size of val > max(prohibited label len) = 15 and the
466 	 * comparisons won't have buffer overflow
467 	 */
468 	if (memcmp(val, TLS_MD_CLIENT_FINISH_CONST,
469 	    TLS_MD_CLIENT_FINISH_CONST_SIZE) == 0)
470 		goto err1;
471 	if (memcmp(val, TLS_MD_SERVER_FINISH_CONST,
472 	    TLS_MD_SERVER_FINISH_CONST_SIZE) == 0)
473 		goto err1;
474 	if (memcmp(val, TLS_MD_MASTER_SECRET_CONST,
475 	    TLS_MD_MASTER_SECRET_CONST_SIZE) == 0)
476 		goto err1;
477 	if (memcmp(val, TLS_MD_KEY_EXPANSION_CONST,
478 	    TLS_MD_KEY_EXPANSION_CONST_SIZE) == 0)
479 		goto err1;
480 
481 	rv = tls1_PRF(s, s->session->master_key, s->session->master_key_length,
482 	    val, vallen, NULL, 0, NULL, 0, NULL, 0, NULL, 0, out, olen);
483 
484 	goto ret;
485  err1:
486 	SSLerror(s, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
487 	rv = 0;
488 	goto ret;
489  err2:
490 	SSLerror(s, ERR_R_MALLOC_FAILURE);
491 	rv = 0;
492  ret:
493 	free(val);
494 
495 	return (rv);
496 }
497