xref: /openbsd-src/lib/libssl/ssl_ciph.c (revision 68dd5bb1859285b71cb62a10bf107b8ad54064d9)
1 /* $OpenBSD: ssl_ciph.c,v 1.138 2024/01/04 20:02:10 tb 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 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
113  * ECC cipher suite support in OpenSSL originally developed by
114  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
115  */
116 /* ====================================================================
117  * Copyright 2005 Nokia. All rights reserved.
118  *
119  * The portions of the attached software ("Contribution") is developed by
120  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
121  * license.
122  *
123  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
124  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
125  * support (see RFC 4279) to OpenSSL.
126  *
127  * No patent licenses or other rights except those expressly stated in
128  * the OpenSSL open source license shall be deemed granted or received
129  * expressly, by implication, estoppel, or otherwise.
130  *
131  * No assurances are provided by Nokia that the Contribution does not
132  * infringe the patent or other intellectual property rights of any third
133  * party or that the license provides you with all the necessary rights
134  * to make use of the Contribution.
135  *
136  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
137  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
138  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
139  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
140  * OTHERWISE.
141  */
142 
143 #include <stdio.h>
144 
145 #include <openssl/evp.h>
146 #include <openssl/objects.h>
147 #include <openssl/opensslconf.h>
148 
149 #include "ssl_local.h"
150 
151 #define CIPHER_ADD	1
152 #define CIPHER_KILL	2
153 #define CIPHER_DEL	3
154 #define CIPHER_ORD	4
155 #define CIPHER_SPECIAL	5
156 
157 typedef struct cipher_order_st {
158 	const SSL_CIPHER *cipher;
159 	int active;
160 	int dead;
161 	struct cipher_order_st *next, *prev;
162 } CIPHER_ORDER;
163 
164 static const SSL_CIPHER cipher_aliases[] = {
165 
166 	/* "ALL" doesn't include eNULL (must be specifically enabled) */
167 	{
168 		.name = SSL_TXT_ALL,
169 		.algorithm_enc = ~SSL_eNULL,
170 	},
171 
172 	/* "COMPLEMENTOFALL" */
173 	{
174 		.name = SSL_TXT_CMPALL,
175 		.algorithm_enc = SSL_eNULL,
176 	},
177 
178 	/*
179 	 * "COMPLEMENTOFDEFAULT"
180 	 * (does *not* include ciphersuites not found in ALL!)
181 	 */
182 	{
183 		.name = SSL_TXT_CMPDEF,
184 		.algorithm_mkey = SSL_kDHE|SSL_kECDHE,
185 		.algorithm_auth = SSL_aNULL,
186 		.algorithm_enc = ~SSL_eNULL,
187 	},
188 
189 	/*
190 	 * key exchange aliases
191 	 * (some of those using only a single bit here combine multiple key
192 	 * exchange algs according to the RFCs, e.g. kEDH combines DHE_DSS
193 	 * and DHE_RSA)
194 	 */
195 	{
196 		.name = SSL_TXT_kRSA,
197 		.algorithm_mkey = SSL_kRSA,
198 	},
199 	{
200 		.name = SSL_TXT_kEDH,
201 		.algorithm_mkey = SSL_kDHE,
202 	},
203 	{
204 		.name = SSL_TXT_DH,
205 		.algorithm_mkey = SSL_kDHE,
206 	},
207 	{
208 		.name = SSL_TXT_kEECDH,
209 		.algorithm_mkey = SSL_kECDHE,
210 	},
211 	{
212 		.name = SSL_TXT_ECDH,
213 		.algorithm_mkey = SSL_kECDHE,
214 	},
215 	{
216 		.name = SSL_TXT_kGOST,
217 		.algorithm_mkey = SSL_kGOST,
218 	},
219 
220 	/* server authentication aliases */
221 	{
222 		.name = SSL_TXT_aRSA,
223 		.algorithm_auth = SSL_aRSA,
224 	},
225 	{
226 		.name = SSL_TXT_aDSS,
227 		.algorithm_auth = SSL_aDSS,
228 	},
229 	{
230 		.name = SSL_TXT_DSS,
231 		.algorithm_auth = SSL_aDSS,
232 	},
233 	{
234 		.name = SSL_TXT_aNULL,
235 		.algorithm_auth = SSL_aNULL,
236 	},
237 	{
238 		.name = SSL_TXT_aECDSA,
239 		.algorithm_auth = SSL_aECDSA,
240 	},
241 	{
242 		.name = SSL_TXT_ECDSA,
243 		.algorithm_auth = SSL_aECDSA,
244 	},
245 	{
246 		.name = SSL_TXT_aGOST01,
247 		.algorithm_auth = SSL_aGOST01,
248 	},
249 	{
250 		.name = SSL_TXT_aGOST,
251 		.algorithm_auth = SSL_aGOST01,
252 	},
253 
254 	/* aliases combining key exchange and server authentication */
255 	{
256 		.name = SSL_TXT_DHE,
257 		.algorithm_mkey = SSL_kDHE,
258 		.algorithm_auth = ~SSL_aNULL,
259 	},
260 	{
261 		.name = SSL_TXT_EDH,
262 		.algorithm_mkey = SSL_kDHE,
263 		.algorithm_auth = ~SSL_aNULL,
264 	},
265 	{
266 		.name = SSL_TXT_ECDHE,
267 		.algorithm_mkey = SSL_kECDHE,
268 		.algorithm_auth = ~SSL_aNULL,
269 	},
270 	{
271 		.name = SSL_TXT_EECDH,
272 		.algorithm_mkey = SSL_kECDHE,
273 		.algorithm_auth = ~SSL_aNULL,
274 	},
275 	{
276 		.name = SSL_TXT_NULL,
277 		.algorithm_enc = SSL_eNULL,
278 	},
279 	{
280 		.name = SSL_TXT_RSA,
281 		.algorithm_mkey = SSL_kRSA,
282 		.algorithm_auth = SSL_aRSA,
283 	},
284 	{
285 		.name = SSL_TXT_ADH,
286 		.algorithm_mkey = SSL_kDHE,
287 		.algorithm_auth = SSL_aNULL,
288 	},
289 	{
290 		.name = SSL_TXT_AECDH,
291 		.algorithm_mkey = SSL_kECDHE,
292 		.algorithm_auth = SSL_aNULL,
293 	},
294 
295 	/* symmetric encryption aliases */
296 	{
297 		.name = SSL_TXT_3DES,
298 		.algorithm_enc = SSL_3DES,
299 	},
300 	{
301 		.name = SSL_TXT_RC4,
302 		.algorithm_enc = SSL_RC4,
303 	},
304 	{
305 		.name = SSL_TXT_eNULL,
306 		.algorithm_enc = SSL_eNULL,
307 	},
308 	{
309 		.name = SSL_TXT_AES128,
310 		.algorithm_enc = SSL_AES128|SSL_AES128GCM,
311 	},
312 	{
313 		.name = SSL_TXT_AES256,
314 		.algorithm_enc = SSL_AES256|SSL_AES256GCM,
315 	},
316 	{
317 		.name = SSL_TXT_AES,
318 		.algorithm_enc = SSL_AES,
319 	},
320 	{
321 		.name = SSL_TXT_AES_GCM,
322 		.algorithm_enc = SSL_AES128GCM|SSL_AES256GCM,
323 	},
324 	{
325 		.name = SSL_TXT_CAMELLIA128,
326 		.algorithm_enc = SSL_CAMELLIA128,
327 	},
328 	{
329 		.name = SSL_TXT_CAMELLIA256,
330 		.algorithm_enc = SSL_CAMELLIA256,
331 	},
332 	{
333 		.name = SSL_TXT_CAMELLIA,
334 		.algorithm_enc = SSL_CAMELLIA128|SSL_CAMELLIA256,
335 	},
336 	{
337 		.name = SSL_TXT_CHACHA20,
338 		.algorithm_enc = SSL_CHACHA20POLY1305,
339 	},
340 
341 	/* MAC aliases */
342 	{
343 		.name = SSL_TXT_AEAD,
344 		.algorithm_mac = SSL_AEAD,
345 	},
346 	{
347 		.name = SSL_TXT_MD5,
348 		.algorithm_mac = SSL_MD5,
349 	},
350 	{
351 		.name = SSL_TXT_SHA1,
352 		.algorithm_mac = SSL_SHA1,
353 	},
354 	{
355 		.name = SSL_TXT_SHA,
356 		.algorithm_mac = SSL_SHA1,
357 	},
358 	{
359 		.name = SSL_TXT_GOST94,
360 		.algorithm_mac = SSL_GOST94,
361 	},
362 	{
363 		.name = SSL_TXT_GOST89MAC,
364 		.algorithm_mac = SSL_GOST89MAC,
365 	},
366 	{
367 		.name = SSL_TXT_SHA256,
368 		.algorithm_mac = SSL_SHA256,
369 	},
370 	{
371 		.name = SSL_TXT_SHA384,
372 		.algorithm_mac = SSL_SHA384,
373 	},
374 	{
375 		.name = SSL_TXT_STREEBOG256,
376 		.algorithm_mac = SSL_STREEBOG256,
377 	},
378 
379 	/* protocol version aliases */
380 	{
381 		.name = SSL_TXT_SSLV3,
382 		.algorithm_ssl = SSL_SSLV3,
383 	},
384 	{
385 		.name = SSL_TXT_TLSV1,
386 		.algorithm_ssl = SSL_TLSV1,
387 	},
388 	{
389 		.name = SSL_TXT_TLSV1_2,
390 		.algorithm_ssl = SSL_TLSV1_2,
391 	},
392 	{
393 		.name = SSL_TXT_TLSV1_3,
394 		.algorithm_ssl = SSL_TLSV1_3,
395 	},
396 
397 	/* cipher suite aliases */
398 #ifdef LIBRESSL_HAS_TLS1_3
399 	{
400 		.valid = 1,
401 		.name = "TLS_AES_128_GCM_SHA256",
402 		.id = TLS1_3_CK_AES_128_GCM_SHA256,
403 		.algorithm_ssl = SSL_TLSV1_3,
404 	},
405 	{
406 		.valid = 1,
407 		.name = "TLS_AES_256_GCM_SHA384",
408 		.id = TLS1_3_CK_AES_256_GCM_SHA384,
409 		.algorithm_ssl = SSL_TLSV1_3,
410 	},
411 	{
412 		.valid = 1,
413 		.name = "TLS_CHACHA20_POLY1305_SHA256",
414 		.id = TLS1_3_CK_CHACHA20_POLY1305_SHA256,
415 		.algorithm_ssl = SSL_TLSV1_3,
416 	},
417 #endif
418 
419 	/* strength classes */
420 	{
421 		.name = SSL_TXT_LOW,
422 		.algo_strength = SSL_LOW,
423 	},
424 	{
425 		.name = SSL_TXT_MEDIUM,
426 		.algo_strength = SSL_MEDIUM,
427 	},
428 	{
429 		.name = SSL_TXT_HIGH,
430 		.algo_strength = SSL_HIGH,
431 	},
432 };
433 
434 int
435 ssl_cipher_get_evp(const SSL_SESSION *ss, const EVP_CIPHER **enc,
436     const EVP_MD **md, int *mac_pkey_type, int *mac_secret_size)
437 {
438 	*enc = NULL;
439 	*md = NULL;
440 	*mac_pkey_type = NID_undef;
441 	*mac_secret_size = 0;
442 
443 	if (ss->cipher == NULL)
444 		return 0;
445 
446 	/*
447 	 * This function does not handle EVP_AEAD.
448 	 * See ssl_cipher_get_evp_aead instead.
449 	 */
450 	if (ss->cipher->algorithm_mac & SSL_AEAD)
451 		return 0;
452 
453 	switch (ss->cipher->algorithm_enc) {
454 	case SSL_3DES:
455 		*enc = EVP_des_ede3_cbc();
456 		break;
457 	case SSL_RC4:
458 		*enc = EVP_rc4();
459 		break;
460 	case SSL_eNULL:
461 		*enc = EVP_enc_null();
462 		break;
463 	case SSL_AES128:
464 		*enc = EVP_aes_128_cbc();
465 		break;
466 	case SSL_AES256:
467 		*enc = EVP_aes_256_cbc();
468 		break;
469 	case SSL_CAMELLIA128:
470 		*enc = EVP_camellia_128_cbc();
471 		break;
472 	case SSL_CAMELLIA256:
473 		*enc = EVP_camellia_256_cbc();
474 		break;
475 #ifndef OPENSSL_NO_GOST
476 	case SSL_eGOST2814789CNT:
477 		*enc = EVP_gost2814789_cnt();
478 		break;
479 #endif
480 	}
481 
482 	switch (ss->cipher->algorithm_mac) {
483 	case SSL_MD5:
484 		*md = EVP_md5();
485 		break;
486 	case SSL_SHA1:
487 		*md = EVP_sha1();
488 		break;
489 	case SSL_SHA256:
490 		*md = EVP_sha256();
491 		break;
492 	case SSL_SHA384:
493 		*md = EVP_sha384();
494 		break;
495 #ifndef OPENSSL_NO_GOST
496 	case SSL_GOST89MAC:
497 		*md = EVP_gost2814789imit();
498 		break;
499 	case SSL_GOST94:
500 		*md = EVP_gostr341194();
501 		break;
502 	case SSL_STREEBOG256:
503 		*md = EVP_streebog256();
504 		break;
505 #endif
506 	}
507 	if (*enc == NULL || *md == NULL)
508 		return 0;
509 
510 	/*
511 	 * EVP_CIPH_FLAG_AEAD_CIPHER and EVP_CIPH_GCM_MODE ciphers are not
512 	 * supported via EVP_CIPHER (they should be using EVP_AEAD instead).
513 	 */
514 	if (EVP_CIPHER_flags(*enc) & EVP_CIPH_FLAG_AEAD_CIPHER)
515 		return 0;
516 	if (EVP_CIPHER_mode(*enc) == EVP_CIPH_GCM_MODE)
517 		return 0;
518 #ifndef OPENSSL_NO_GOST
519 	/* XXX JFC. die in fire already */
520 	if (ss->cipher->algorithm_mac == SSL_GOST89MAC) {
521 		*mac_pkey_type = EVP_PKEY_GOSTIMIT;
522 		*mac_secret_size = 32; /* XXX */
523 	} else {
524 #endif
525 		*mac_pkey_type = EVP_PKEY_HMAC;
526 		*mac_secret_size = EVP_MD_size(*md);
527 #ifndef OPENSSL_NO_GOST
528 	}
529 #endif
530 	return 1;
531 }
532 
533 /*
534  * ssl_cipher_get_evp_aead sets aead to point to the correct EVP_AEAD object
535  * for s->cipher. It returns 1 on success and 0 on error.
536  */
537 int
538 ssl_cipher_get_evp_aead(const SSL_SESSION *ss, const EVP_AEAD **aead)
539 {
540 	*aead = NULL;
541 
542 	if (ss->cipher == NULL)
543 		return 0;
544 	if ((ss->cipher->algorithm_mac & SSL_AEAD) == 0)
545 		return 0;
546 
547 	switch (ss->cipher->algorithm_enc) {
548 	case SSL_AES128GCM:
549 		*aead = EVP_aead_aes_128_gcm();
550 		return 1;
551 	case SSL_AES256GCM:
552 		*aead = EVP_aead_aes_256_gcm();
553 		return 1;
554 	case SSL_CHACHA20POLY1305:
555 		*aead = EVP_aead_chacha20_poly1305();
556 		return 1;
557 	default:
558 		break;
559 	}
560 	return 0;
561 }
562 
563 int
564 ssl_get_handshake_evp_md(SSL *s, const EVP_MD **md)
565 {
566 	unsigned long handshake_mac;
567 
568 	*md = NULL;
569 
570 	if (s->s3->hs.cipher == NULL)
571 		return 0;
572 
573 	handshake_mac = s->s3->hs.cipher->algorithm2 &
574 	    SSL_HANDSHAKE_MAC_MASK;
575 
576 	/* For TLSv1.2 we upgrade the default MD5+SHA1 MAC to SHA256. */
577 	if (SSL_USE_SHA256_PRF(s) && handshake_mac == SSL_HANDSHAKE_MAC_DEFAULT)
578 		handshake_mac = SSL_HANDSHAKE_MAC_SHA256;
579 
580 	switch (handshake_mac) {
581 	case SSL_HANDSHAKE_MAC_DEFAULT:
582 		*md = EVP_md5_sha1();
583 		return 1;
584 #ifndef OPENSSL_NO_GOST
585 	case SSL_HANDSHAKE_MAC_GOST94:
586 		*md = EVP_gostr341194();
587 		return 1;
588 	case SSL_HANDSHAKE_MAC_STREEBOG256:
589 		*md = EVP_streebog256();
590 		return 1;
591 #endif
592 	case SSL_HANDSHAKE_MAC_SHA256:
593 		*md = EVP_sha256();
594 		return 1;
595 	case SSL_HANDSHAKE_MAC_SHA384:
596 		*md = EVP_sha384();
597 		return 1;
598 	default:
599 		break;
600 	}
601 
602 	return 0;
603 }
604 
605 #define ITEM_SEP(a) \
606 	(((a) == ':') || ((a) == ' ') || ((a) == ';') || ((a) == ','))
607 
608 static void
609 ll_append_tail(CIPHER_ORDER **head, CIPHER_ORDER *curr,
610     CIPHER_ORDER **tail)
611 {
612 	if (curr == *tail)
613 		return;
614 	if (curr == *head)
615 		*head = curr->next;
616 	if (curr->prev != NULL)
617 		curr->prev->next = curr->next;
618 	if (curr->next != NULL)
619 		curr->next->prev = curr->prev;
620 	(*tail)->next = curr;
621 	curr->prev= *tail;
622 	curr->next = NULL;
623 	*tail = curr;
624 }
625 
626 static void
627 ll_append_head(CIPHER_ORDER **head, CIPHER_ORDER *curr,
628     CIPHER_ORDER **tail)
629 {
630 	if (curr == *head)
631 		return;
632 	if (curr == *tail)
633 		*tail = curr->prev;
634 	if (curr->next != NULL)
635 		curr->next->prev = curr->prev;
636 	if (curr->prev != NULL)
637 		curr->prev->next = curr->next;
638 	(*head)->prev = curr;
639 	curr->next= *head;
640 	curr->prev = NULL;
641 	*head = curr;
642 }
643 
644 static void
645 ssl_cipher_get_disabled(unsigned long *mkey, unsigned long *auth,
646     unsigned long *enc, unsigned long *mac, unsigned long *ssl)
647 {
648 	*mkey = 0;
649 	*auth = 0;
650 	*enc = 0;
651 	*mac = 0;
652 	*ssl = 0;
653 
654 	/*
655 	 * Check for the availability of GOST 34.10 public/private key
656 	 * algorithms. If they are not available disable the associated
657 	 * authentication and key exchange algorithms.
658 	 */
659 #if defined(OPENSSL_NO_GOST) || !defined(EVP_PKEY_GOSTR01)
660 	*auth |= SSL_aGOST01;
661 	*mkey |= SSL_kGOST;
662 #endif
663 
664 #ifdef SSL_FORBID_ENULL
665 	*enc |= SSL_eNULL;
666 #endif
667 }
668 
669 static void
670 ssl_cipher_collect_ciphers(const SSL_METHOD *ssl_method, int num_of_ciphers,
671     unsigned long disabled_mkey, unsigned long disabled_auth,
672     unsigned long disabled_enc, unsigned long disabled_mac,
673     unsigned long disabled_ssl, CIPHER_ORDER *co_list,
674     CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
675 {
676 	int i, co_list_num;
677 	const SSL_CIPHER *c;
678 
679 	/*
680 	 * We have num_of_ciphers descriptions compiled in, depending on the
681 	 * method selected (SSLv3, TLSv1, etc). These will later be sorted in
682 	 * a linked list with at most num entries.
683 	 */
684 
685 	/* Get the initial list of ciphers */
686 	co_list_num = 0;	/* actual count of ciphers */
687 	for (i = 0; i < num_of_ciphers; i++) {
688 		c = ssl_method->get_cipher(i);
689 		/*
690 		 * Drop any invalid ciphers and any which use unavailable
691 		 * algorithms.
692 		 */
693 		if ((c != NULL) && c->valid &&
694 		    !(c->algorithm_mkey & disabled_mkey) &&
695 		    !(c->algorithm_auth & disabled_auth) &&
696 		    !(c->algorithm_enc & disabled_enc) &&
697 		    !(c->algorithm_mac & disabled_mac) &&
698 		    !(c->algorithm_ssl & disabled_ssl)) {
699 			co_list[co_list_num].cipher = c;
700 			co_list[co_list_num].next = NULL;
701 			co_list[co_list_num].prev = NULL;
702 			co_list[co_list_num].active = 0;
703 			co_list_num++;
704 		}
705 	}
706 
707 	/*
708 	 * Prepare linked list from list entries
709 	 */
710 	if (co_list_num > 0) {
711 		co_list[0].prev = NULL;
712 
713 		if (co_list_num > 1) {
714 			co_list[0].next = &co_list[1];
715 
716 			for (i = 1; i < co_list_num - 1; i++) {
717 				co_list[i].prev = &co_list[i - 1];
718 				co_list[i].next = &co_list[i + 1];
719 			}
720 
721 			co_list[co_list_num - 1].prev =
722 			    &co_list[co_list_num - 2];
723 		}
724 
725 		co_list[co_list_num - 1].next = NULL;
726 
727 		*head_p = &co_list[0];
728 		*tail_p = &co_list[co_list_num - 1];
729 	}
730 }
731 
732 static void
733 ssl_cipher_collect_aliases(const SSL_CIPHER **ca_list, int num_of_group_aliases,
734     unsigned long disabled_mkey, unsigned long disabled_auth,
735     unsigned long disabled_enc, unsigned long disabled_mac,
736     unsigned long disabled_ssl, CIPHER_ORDER *head)
737 {
738 	CIPHER_ORDER *ciph_curr;
739 	const SSL_CIPHER **ca_curr;
740 	int i;
741 	unsigned long mask_mkey = ~disabled_mkey;
742 	unsigned long mask_auth = ~disabled_auth;
743 	unsigned long mask_enc = ~disabled_enc;
744 	unsigned long mask_mac = ~disabled_mac;
745 	unsigned long mask_ssl = ~disabled_ssl;
746 
747 	/*
748 	 * First, add the real ciphers as already collected
749 	 */
750 	ciph_curr = head;
751 	ca_curr = ca_list;
752 	while (ciph_curr != NULL) {
753 		*ca_curr = ciph_curr->cipher;
754 		ca_curr++;
755 		ciph_curr = ciph_curr->next;
756 	}
757 
758 	/*
759 	 * Now we add the available ones from the cipher_aliases[] table.
760 	 * They represent either one or more algorithms, some of which
761 	 * in any affected category must be supported (set in enabled_mask),
762 	 * or represent a cipher strength value (will be added in any case because algorithms=0).
763 	 */
764 	for (i = 0; i < num_of_group_aliases; i++) {
765 		unsigned long algorithm_mkey = cipher_aliases[i].algorithm_mkey;
766 		unsigned long algorithm_auth = cipher_aliases[i].algorithm_auth;
767 		unsigned long algorithm_enc = cipher_aliases[i].algorithm_enc;
768 		unsigned long algorithm_mac = cipher_aliases[i].algorithm_mac;
769 		unsigned long algorithm_ssl = cipher_aliases[i].algorithm_ssl;
770 
771 		if (algorithm_mkey)
772 			if ((algorithm_mkey & mask_mkey) == 0)
773 				continue;
774 
775 		if (algorithm_auth)
776 			if ((algorithm_auth & mask_auth) == 0)
777 				continue;
778 
779 		if (algorithm_enc)
780 			if ((algorithm_enc & mask_enc) == 0)
781 				continue;
782 
783 		if (algorithm_mac)
784 			if ((algorithm_mac & mask_mac) == 0)
785 				continue;
786 
787 		if (algorithm_ssl)
788 			if ((algorithm_ssl & mask_ssl) == 0)
789 				continue;
790 
791 		*ca_curr = (SSL_CIPHER *)(cipher_aliases + i);
792 		ca_curr++;
793 	}
794 
795 	*ca_curr = NULL;	/* end of list */
796 }
797 
798 static void
799 ssl_cipher_apply_rule(unsigned long cipher_id, unsigned long alg_mkey,
800     unsigned long alg_auth, unsigned long alg_enc, unsigned long alg_mac,
801     unsigned long alg_ssl, unsigned long algo_strength, int rule,
802     int strength_bits, CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
803 {
804 	CIPHER_ORDER *head, *tail, *curr, *next, *last;
805 	const SSL_CIPHER *cp;
806 	int reverse = 0;
807 
808 	if (rule == CIPHER_DEL)
809 		reverse = 1; /* needed to maintain sorting between currently deleted ciphers */
810 
811 	head = *head_p;
812 	tail = *tail_p;
813 
814 	if (reverse) {
815 		next = tail;
816 		last = head;
817 	} else {
818 		next = head;
819 		last = tail;
820 	}
821 
822 	curr = NULL;
823 	for (;;) {
824 		if (curr == last)
825 			break;
826 		curr = next;
827 		next = reverse ? curr->prev : curr->next;
828 
829 		cp = curr->cipher;
830 
831 		if (cipher_id && cp->id != cipher_id)
832 			continue;
833 
834 		/*
835 		 * Selection criteria is either the value of strength_bits
836 		 * or the algorithms used.
837 		 */
838 		if (strength_bits >= 0) {
839 			if (strength_bits != cp->strength_bits)
840 				continue;
841 		} else {
842 			if (alg_mkey && !(alg_mkey & cp->algorithm_mkey))
843 				continue;
844 			if (alg_auth && !(alg_auth & cp->algorithm_auth))
845 				continue;
846 			if (alg_enc && !(alg_enc & cp->algorithm_enc))
847 				continue;
848 			if (alg_mac && !(alg_mac & cp->algorithm_mac))
849 				continue;
850 			if (alg_ssl && !(alg_ssl & cp->algorithm_ssl))
851 				continue;
852 			if ((algo_strength & SSL_STRONG_MASK) && !(algo_strength & SSL_STRONG_MASK & cp->algo_strength))
853 				continue;
854 		}
855 
856 		/* add the cipher if it has not been added yet. */
857 		if (rule == CIPHER_ADD) {
858 			/* reverse == 0 */
859 			if (!curr->active) {
860 				ll_append_tail(&head, curr, &tail);
861 				curr->active = 1;
862 			}
863 		}
864 		/* Move the added cipher to this location */
865 		else if (rule == CIPHER_ORD) {
866 			/* reverse == 0 */
867 			if (curr->active) {
868 				ll_append_tail(&head, curr, &tail);
869 			}
870 		} else if (rule == CIPHER_DEL) {
871 			/* reverse == 1 */
872 			if (curr->active) {
873 				/* most recently deleted ciphersuites get best positions
874 				 * for any future CIPHER_ADD (note that the CIPHER_DEL loop
875 				 * works in reverse to maintain the order) */
876 				ll_append_head(&head, curr, &tail);
877 				curr->active = 0;
878 			}
879 		} else if (rule == CIPHER_KILL) {
880 			/* reverse == 0 */
881 			if (head == curr)
882 				head = curr->next;
883 			else
884 				curr->prev->next = curr->next;
885 			if (tail == curr)
886 				tail = curr->prev;
887 			curr->active = 0;
888 			if (curr->next != NULL)
889 				curr->next->prev = curr->prev;
890 			if (curr->prev != NULL)
891 				curr->prev->next = curr->next;
892 			curr->next = NULL;
893 			curr->prev = NULL;
894 		}
895 	}
896 
897 	*head_p = head;
898 	*tail_p = tail;
899 }
900 
901 static int
902 ssl_cipher_strength_sort(CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
903 {
904 	int max_strength_bits, i, *number_uses;
905 	CIPHER_ORDER *curr;
906 
907 	/*
908 	 * This routine sorts the ciphers with descending strength. The sorting
909 	 * must keep the pre-sorted sequence, so we apply the normal sorting
910 	 * routine as '+' movement to the end of the list.
911 	 */
912 	max_strength_bits = 0;
913 	curr = *head_p;
914 	while (curr != NULL) {
915 		if (curr->active &&
916 		    (curr->cipher->strength_bits > max_strength_bits))
917 			max_strength_bits = curr->cipher->strength_bits;
918 		curr = curr->next;
919 	}
920 
921 	number_uses = calloc((max_strength_bits + 1), sizeof(int));
922 	if (!number_uses) {
923 		SSLerrorx(ERR_R_MALLOC_FAILURE);
924 		return (0);
925 	}
926 
927 	/*
928 	 * Now find the strength_bits values actually used
929 	 */
930 	curr = *head_p;
931 	while (curr != NULL) {
932 		if (curr->active)
933 			number_uses[curr->cipher->strength_bits]++;
934 		curr = curr->next;
935 	}
936 	/*
937 	 * Go through the list of used strength_bits values in descending
938 	 * order.
939 	 */
940 	for (i = max_strength_bits; i >= 0; i--)
941 		if (number_uses[i] > 0)
942 			ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ORD, i, head_p, tail_p);
943 
944 	free(number_uses);
945 	return (1);
946 }
947 
948 static int
949 ssl_cipher_process_rulestr(const char *rule_str, CIPHER_ORDER **head_p,
950     CIPHER_ORDER **tail_p, const SSL_CIPHER **ca_list, SSL_CERT *cert,
951     int *tls13_seen)
952 {
953 	unsigned long alg_mkey, alg_auth, alg_enc, alg_mac, alg_ssl;
954 	unsigned long algo_strength;
955 	int j, multi, found, rule, retval, ok, buflen;
956 	unsigned long cipher_id = 0;
957 	const char *l, *buf;
958 	char ch;
959 
960 	*tls13_seen = 0;
961 
962 	retval = 1;
963 	l = rule_str;
964 	for (;;) {
965 		ch = *l;
966 
967 		if (ch == '\0')
968 			break;
969 
970 		if (ch == '-') {
971 			rule = CIPHER_DEL;
972 			l++;
973 		} else if (ch == '+') {
974 			rule = CIPHER_ORD;
975 			l++;
976 		} else if (ch == '!') {
977 			rule = CIPHER_KILL;
978 			l++;
979 		} else if (ch == '@') {
980 			rule = CIPHER_SPECIAL;
981 			l++;
982 		} else {
983 			rule = CIPHER_ADD;
984 		}
985 
986 		if (ITEM_SEP(ch)) {
987 			l++;
988 			continue;
989 		}
990 
991 		alg_mkey = 0;
992 		alg_auth = 0;
993 		alg_enc = 0;
994 		alg_mac = 0;
995 		alg_ssl = 0;
996 		algo_strength = 0;
997 
998 		for (;;) {
999 			ch = *l;
1000 			buf = l;
1001 			buflen = 0;
1002 			while (((ch >= 'A') && (ch <= 'Z')) ||
1003 			    ((ch >= '0') && (ch <= '9')) ||
1004 			    ((ch >= 'a') && (ch <= 'z')) ||
1005 			    (ch == '-') || (ch == '.') ||
1006 			    (ch == '_') || (ch == '=')) {
1007 				ch = *(++l);
1008 				buflen++;
1009 			}
1010 
1011 			if (buflen == 0) {
1012 				/*
1013 				 * We hit something we cannot deal with,
1014 				 * it is no command or separator nor
1015 				 * alphanumeric, so we call this an error.
1016 				 */
1017 				SSLerrorx(SSL_R_INVALID_COMMAND);
1018 				return 0;
1019 			}
1020 
1021 			if (rule == CIPHER_SPECIAL) {
1022 				 /* unused -- avoid compiler warning */
1023 				found = 0;
1024 				/* special treatment */
1025 				break;
1026 			}
1027 
1028 			/* check for multi-part specification */
1029 			if (ch == '+') {
1030 				multi = 1;
1031 				l++;
1032 			} else
1033 				multi = 0;
1034 
1035 			/*
1036 			 * Now search for the cipher alias in the ca_list.
1037 			 * Be careful with the strncmp, because the "buflen"
1038 			 * limitation will make the rule "ADH:SOME" and the
1039 			 * cipher "ADH-MY-CIPHER" look like a match for
1040 			 * buflen=3. So additionally check whether the cipher
1041 			 * name found has the correct length. We can save a
1042 			 * strlen() call: just checking for the '\0' at the
1043 			 * right place is sufficient, we have to strncmp()
1044 			 * anyway (we cannot use strcmp(), because buf is not
1045 			 * '\0' terminated.)
1046 			 */
1047 			j = found = 0;
1048 			cipher_id = 0;
1049 			while (ca_list[j]) {
1050 				if (!strncmp(buf, ca_list[j]->name, buflen) &&
1051 				    (ca_list[j]->name[buflen] == '\0')) {
1052 					found = 1;
1053 					break;
1054 				} else
1055 					j++;
1056 			}
1057 
1058 			if (!found)
1059 				break;	/* ignore this entry */
1060 
1061 			if (ca_list[j]->algorithm_mkey) {
1062 				if (alg_mkey) {
1063 					alg_mkey &= ca_list[j]->algorithm_mkey;
1064 					if (!alg_mkey) {
1065 						found = 0;
1066 						break;
1067 					}
1068 				} else
1069 					alg_mkey = ca_list[j]->algorithm_mkey;
1070 			}
1071 
1072 			if (ca_list[j]->algorithm_auth) {
1073 				if (alg_auth) {
1074 					alg_auth &= ca_list[j]->algorithm_auth;
1075 					if (!alg_auth) {
1076 						found = 0;
1077 						break;
1078 					}
1079 				} else
1080 					alg_auth = ca_list[j]->algorithm_auth;
1081 			}
1082 
1083 			if (ca_list[j]->algorithm_enc) {
1084 				if (alg_enc) {
1085 					alg_enc &= ca_list[j]->algorithm_enc;
1086 					if (!alg_enc) {
1087 						found = 0;
1088 						break;
1089 					}
1090 				} else
1091 					alg_enc = ca_list[j]->algorithm_enc;
1092 			}
1093 
1094 			if (ca_list[j]->algorithm_mac) {
1095 				if (alg_mac) {
1096 					alg_mac &= ca_list[j]->algorithm_mac;
1097 					if (!alg_mac) {
1098 						found = 0;
1099 						break;
1100 					}
1101 				} else
1102 					alg_mac = ca_list[j]->algorithm_mac;
1103 			}
1104 
1105 			if (ca_list[j]->algo_strength & SSL_STRONG_MASK) {
1106 				if (algo_strength & SSL_STRONG_MASK) {
1107 					algo_strength &=
1108 					    (ca_list[j]->algo_strength &
1109 					    SSL_STRONG_MASK) | ~SSL_STRONG_MASK;
1110 					if (!(algo_strength &
1111 					    SSL_STRONG_MASK)) {
1112 						found = 0;
1113 						break;
1114 					}
1115 				} else
1116 					algo_strength |=
1117 					    ca_list[j]->algo_strength &
1118 					    SSL_STRONG_MASK;
1119 			}
1120 
1121 			if (ca_list[j]->valid) {
1122 				/*
1123 				 * explicit ciphersuite found; its protocol
1124 				 * version does not become part of the search
1125 				 * pattern!
1126 				 */
1127 				cipher_id = ca_list[j]->id;
1128 				if (ca_list[j]->algorithm_ssl == SSL_TLSV1_3)
1129 					*tls13_seen = 1;
1130 			} else {
1131 				/*
1132 				 * not an explicit ciphersuite; only in this
1133 				 * case, the protocol version is considered
1134 				 * part of the search pattern
1135 				 */
1136 				if (ca_list[j]->algorithm_ssl) {
1137 					if (alg_ssl) {
1138 						alg_ssl &=
1139 						    ca_list[j]->algorithm_ssl;
1140 						if (!alg_ssl) {
1141 							found = 0;
1142 							break;
1143 						}
1144 					} else
1145 						alg_ssl =
1146 						    ca_list[j]->algorithm_ssl;
1147 				}
1148 			}
1149 
1150 			if (!multi)
1151 				break;
1152 		}
1153 
1154 		/*
1155 		 * Ok, we have the rule, now apply it
1156 		 */
1157 		if (rule == CIPHER_SPECIAL) {
1158 			/* special command */
1159 			ok = 0;
1160 			if (buflen == 8 && strncmp(buf, "STRENGTH", 8) == 0) {
1161 				ok = ssl_cipher_strength_sort(head_p, tail_p);
1162 			} else if (buflen == 10 &&
1163 			    strncmp(buf, "SECLEVEL=", 9) == 0) {
1164 				int level = buf[9] - '0';
1165 
1166 				if (level >= 0 && level <= 5) {
1167 					cert->security_level = level;
1168 					ok = 1;
1169 				} else {
1170 					SSLerrorx(SSL_R_INVALID_COMMAND);
1171 				}
1172 			} else {
1173 				SSLerrorx(SSL_R_INVALID_COMMAND);
1174 			}
1175 			if (ok == 0)
1176 				retval = 0;
1177 
1178 			while ((*l != '\0') && !ITEM_SEP(*l))
1179 				l++;
1180 		} else if (found) {
1181 			if (alg_ssl == SSL_TLSV1_3)
1182 				*tls13_seen = 1;
1183 			ssl_cipher_apply_rule(cipher_id, alg_mkey, alg_auth,
1184 			    alg_enc, alg_mac, alg_ssl, algo_strength, rule,
1185 			    -1, head_p, tail_p);
1186 		} else {
1187 			while ((*l != '\0') && !ITEM_SEP(*l))
1188 				l++;
1189 		}
1190 		if (*l == '\0')
1191 			break; /* done */
1192 	}
1193 
1194 	return (retval);
1195 }
1196 
1197 static inline int
1198 ssl_aes_is_accelerated(void)
1199 {
1200 #if defined(__i386__) || defined(__x86_64__)
1201 	return ((OPENSSL_cpu_caps() & (1ULL << 57)) != 0);
1202 #else
1203 	return (0);
1204 #endif
1205 }
1206 
1207 STACK_OF(SSL_CIPHER) *
1208 ssl_create_cipher_list(const SSL_METHOD *ssl_method,
1209     STACK_OF(SSL_CIPHER) **cipher_list,
1210     STACK_OF(SSL_CIPHER) *cipher_list_tls13,
1211     const char *rule_str, SSL_CERT *cert)
1212 {
1213 	int ok, num_of_ciphers, num_of_alias_max, num_of_group_aliases;
1214 	unsigned long disabled_mkey, disabled_auth, disabled_enc, disabled_mac, disabled_ssl;
1215 	STACK_OF(SSL_CIPHER) *cipherstack = NULL, *ret = NULL;
1216 	const char *rule_p;
1217 	CIPHER_ORDER *co_list = NULL, *head = NULL, *tail = NULL, *curr;
1218 	const SSL_CIPHER **ca_list = NULL;
1219 	const SSL_CIPHER *cipher;
1220 	int tls13_seen = 0;
1221 	int any_active;
1222 	int i;
1223 
1224 	/*
1225 	 * Return with error if nothing to do.
1226 	 */
1227 	if (rule_str == NULL || cipher_list == NULL)
1228 		goto err;
1229 
1230 	/*
1231 	 * To reduce the work to do we only want to process the compiled
1232 	 * in algorithms, so we first get the mask of disabled ciphers.
1233 	 */
1234 	ssl_cipher_get_disabled(&disabled_mkey, &disabled_auth, &disabled_enc, &disabled_mac, &disabled_ssl);
1235 
1236 	/*
1237 	 * Now we have to collect the available ciphers from the compiled
1238 	 * in ciphers. We cannot get more than the number compiled in, so
1239 	 * it is used for allocation.
1240 	 */
1241 	num_of_ciphers = ssl3_num_ciphers();
1242 	co_list = reallocarray(NULL, num_of_ciphers, sizeof(CIPHER_ORDER));
1243 	if (co_list == NULL) {
1244 		SSLerrorx(ERR_R_MALLOC_FAILURE);
1245 		goto err;
1246 	}
1247 
1248 	ssl_cipher_collect_ciphers(ssl_method, num_of_ciphers,
1249 	    disabled_mkey, disabled_auth, disabled_enc, disabled_mac, disabled_ssl,
1250 	    co_list, &head, &tail);
1251 
1252 
1253 	/* Now arrange all ciphers by preference: */
1254 
1255 	/* Everything else being equal, prefer ephemeral ECDH over other key exchange mechanisms */
1256 	ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1257 	ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_DEL, -1, &head, &tail);
1258 
1259 	if (ssl_aes_is_accelerated()) {
1260 		/*
1261 		 * We have hardware assisted AES - prefer AES as a symmetric
1262 		 * cipher, with CHACHA20 second.
1263 		 */
1264 		ssl_cipher_apply_rule(0, 0, 0, SSL_AES, 0, 0, 0,
1265 		    CIPHER_ADD, -1, &head, &tail);
1266 		ssl_cipher_apply_rule(0, 0, 0, SSL_CHACHA20POLY1305,
1267 		    0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1268 	} else {
1269 		/*
1270 		 * CHACHA20 is fast and safe on all hardware and is thus our
1271 		 * preferred symmetric cipher, with AES second.
1272 		 */
1273 		ssl_cipher_apply_rule(0, 0, 0, SSL_CHACHA20POLY1305,
1274 		    0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1275 		ssl_cipher_apply_rule(0, 0, 0, SSL_AES, 0, 0, 0,
1276 		    CIPHER_ADD, -1, &head, &tail);
1277 	}
1278 
1279 	/* Temporarily enable everything else for sorting */
1280 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1281 
1282 	/* Low priority for MD5 */
1283 	ssl_cipher_apply_rule(0, 0, 0, 0, SSL_MD5, 0, 0, CIPHER_ORD, -1, &head, &tail);
1284 
1285 	/* Move anonymous ciphers to the end.  Usually, these will remain disabled.
1286 	 * (For applications that allow them, they aren't too bad, but we prefer
1287 	 * authenticated ciphers.) */
1288 	ssl_cipher_apply_rule(0, 0, SSL_aNULL, 0, 0, 0, 0, CIPHER_ORD, -1, &head, &tail);
1289 
1290 	/* Move ciphers without forward secrecy to the end */
1291 	ssl_cipher_apply_rule(0, SSL_kRSA, 0, 0, 0, 0, 0, CIPHER_ORD, -1, &head, &tail);
1292 
1293 	/* RC4 is sort of broken - move it to the end */
1294 	ssl_cipher_apply_rule(0, 0, 0, SSL_RC4, 0, 0, 0, CIPHER_ORD, -1, &head, &tail);
1295 
1296 	/* Now sort by symmetric encryption strength.  The above ordering remains
1297 	 * in force within each class */
1298 	if (!ssl_cipher_strength_sort(&head, &tail))
1299 		goto err;
1300 
1301 	/* Now disable everything (maintaining the ordering!) */
1302 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_DEL, -1, &head, &tail);
1303 
1304 	/* TLSv1.3 first. */
1305 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, SSL_TLSV1_3, 0, CIPHER_ADD, -1, &head, &tail);
1306 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, SSL_TLSV1_3, 0, CIPHER_DEL, -1, &head, &tail);
1307 
1308 	/*
1309 	 * We also need cipher aliases for selecting based on the rule_str.
1310 	 * There might be two types of entries in the rule_str: 1) names
1311 	 * of ciphers themselves 2) aliases for groups of ciphers.
1312 	 * For 1) we need the available ciphers and for 2) the cipher
1313 	 * groups of cipher_aliases added together in one list (otherwise
1314 	 * we would be happy with just the cipher_aliases table).
1315 	 */
1316 	num_of_group_aliases = sizeof(cipher_aliases) / sizeof(SSL_CIPHER);
1317 	num_of_alias_max = num_of_ciphers + num_of_group_aliases + 1;
1318 	ca_list = reallocarray(NULL, num_of_alias_max, sizeof(SSL_CIPHER *));
1319 	if (ca_list == NULL) {
1320 		SSLerrorx(ERR_R_MALLOC_FAILURE);
1321 		goto err;
1322 	}
1323 	ssl_cipher_collect_aliases(ca_list, num_of_group_aliases, disabled_mkey,
1324 	    disabled_auth, disabled_enc, disabled_mac, disabled_ssl, head);
1325 
1326 	/*
1327 	 * If the rule_string begins with DEFAULT, apply the default rule
1328 	 * before using the (possibly available) additional rules.
1329 	 */
1330 	ok = 1;
1331 	rule_p = rule_str;
1332 	if (strncmp(rule_str, "DEFAULT", 7) == 0) {
1333 		ok = ssl_cipher_process_rulestr(SSL_DEFAULT_CIPHER_LIST,
1334 		    &head, &tail, ca_list, cert, &tls13_seen);
1335 		rule_p += 7;
1336 		if (*rule_p == ':')
1337 			rule_p++;
1338 	}
1339 
1340 	if (ok && (strlen(rule_p) > 0))
1341 		ok = ssl_cipher_process_rulestr(rule_p, &head, &tail, ca_list,
1342 		    cert, &tls13_seen);
1343 
1344 	if (!ok) {
1345 		/* Rule processing failure */
1346 		goto err;
1347 	}
1348 
1349 	/*
1350 	 * Allocate new "cipherstack" for the result, return with error
1351 	 * if we cannot get one.
1352 	 */
1353 	if ((cipherstack = sk_SSL_CIPHER_new_null()) == NULL) {
1354 		SSLerrorx(ERR_R_MALLOC_FAILURE);
1355 		goto err;
1356 	}
1357 
1358 	/* Prefer TLSv1.3 cipher suites. */
1359 	if (cipher_list_tls13 != NULL) {
1360 		for (i = 0; i < sk_SSL_CIPHER_num(cipher_list_tls13); i++) {
1361 			cipher = sk_SSL_CIPHER_value(cipher_list_tls13, i);
1362 			if (!sk_SSL_CIPHER_push(cipherstack, cipher)) {
1363 				SSLerrorx(ERR_R_MALLOC_FAILURE);
1364 				goto err;
1365 			}
1366 		}
1367 		tls13_seen = 1;
1368 	}
1369 
1370 	/*
1371 	 * The cipher selection for the list is done. The ciphers are added
1372 	 * to the resulting precedence to the STACK_OF(SSL_CIPHER).
1373 	 *
1374 	 * If the rule string did not contain any references to TLSv1.3 and
1375 	 * TLSv1.3 cipher suites have not been configured separately,
1376 	 * include inactive TLSv1.3 cipher suites. This avoids attempts to
1377 	 * use TLSv1.3 with an older rule string that does not include
1378 	 * TLSv1.3 cipher suites. If the rule string resulted in no active
1379 	 * cipher suites then we return an empty stack.
1380 	 */
1381 	any_active = 0;
1382 	for (curr = head; curr != NULL; curr = curr->next) {
1383 		if (curr->active ||
1384 		    (!tls13_seen && curr->cipher->algorithm_ssl == SSL_TLSV1_3)) {
1385 			if (!sk_SSL_CIPHER_push(cipherstack, curr->cipher)) {
1386 				SSLerrorx(ERR_R_MALLOC_FAILURE);
1387 				goto err;
1388 			}
1389 		}
1390 		any_active |= curr->active;
1391 	}
1392 	if (!any_active)
1393 		sk_SSL_CIPHER_zero(cipherstack);
1394 
1395 	sk_SSL_CIPHER_free(*cipher_list);
1396 	*cipher_list = cipherstack;
1397 	cipherstack = NULL;
1398 
1399 	ret = *cipher_list;
1400 
1401  err:
1402 	sk_SSL_CIPHER_free(cipherstack);
1403 	free((void *)ca_list);
1404 	free(co_list);
1405 
1406 	return ret;
1407 }
1408 
1409 const SSL_CIPHER *
1410 SSL_CIPHER_get_by_id(unsigned int id)
1411 {
1412 	return ssl3_get_cipher_by_id(id);
1413 }
1414 LSSL_ALIAS(SSL_CIPHER_get_by_id);
1415 
1416 const SSL_CIPHER *
1417 SSL_CIPHER_get_by_value(uint16_t value)
1418 {
1419 	return ssl3_get_cipher_by_value(value);
1420 }
1421 LSSL_ALIAS(SSL_CIPHER_get_by_value);
1422 
1423 char *
1424 SSL_CIPHER_description(const SSL_CIPHER *cipher, char *buf, int len)
1425 {
1426 	unsigned long alg_mkey, alg_auth, alg_enc, alg_mac, alg_ssl, alg2;
1427 	const char *ver, *kx, *au, *enc, *mac;
1428 	char *ret;
1429 	int l;
1430 
1431 	alg_mkey = cipher->algorithm_mkey;
1432 	alg_auth = cipher->algorithm_auth;
1433 	alg_enc = cipher->algorithm_enc;
1434 	alg_mac = cipher->algorithm_mac;
1435 	alg_ssl = cipher->algorithm_ssl;
1436 
1437 	alg2 = cipher->algorithm2;
1438 
1439 	if (alg_ssl & SSL_SSLV3)
1440 		ver = "SSLv3";
1441 	else if (alg_ssl & SSL_TLSV1_2)
1442 		ver = "TLSv1.2";
1443 	else if (alg_ssl & SSL_TLSV1_3)
1444 		ver = "TLSv1.3";
1445 	else
1446 		ver = "unknown";
1447 
1448 	switch (alg_mkey) {
1449 	case SSL_kRSA:
1450 		kx = "RSA";
1451 		break;
1452 	case SSL_kDHE:
1453 		kx = "DH";
1454 		break;
1455 	case SSL_kECDHE:
1456 		kx = "ECDH";
1457 		break;
1458 	case SSL_kGOST:
1459 		kx = "GOST";
1460 		break;
1461 	case SSL_kTLS1_3:
1462 		kx = "TLSv1.3";
1463 		break;
1464 	default:
1465 		kx = "unknown";
1466 	}
1467 
1468 	switch (alg_auth) {
1469 	case SSL_aRSA:
1470 		au = "RSA";
1471 		break;
1472 	case SSL_aDSS:
1473 		au = "DSS";
1474 		break;
1475 	case SSL_aNULL:
1476 		au = "None";
1477 		break;
1478 	case SSL_aECDSA:
1479 		au = "ECDSA";
1480 		break;
1481 	case SSL_aGOST01:
1482 		au = "GOST01";
1483 		break;
1484 	case SSL_aTLS1_3:
1485 		au = "TLSv1.3";
1486 		break;
1487 	default:
1488 		au = "unknown";
1489 		break;
1490 	}
1491 
1492 	switch (alg_enc) {
1493 	case SSL_3DES:
1494 		enc = "3DES(168)";
1495 		break;
1496 	case SSL_RC4:
1497 		enc = alg2 & SSL2_CF_8_BYTE_ENC ? "RC4(64)" : "RC4(128)";
1498 		break;
1499 	case SSL_eNULL:
1500 		enc = "None";
1501 		break;
1502 	case SSL_AES128:
1503 		enc = "AES(128)";
1504 		break;
1505 	case SSL_AES256:
1506 		enc = "AES(256)";
1507 		break;
1508 	case SSL_AES128GCM:
1509 		enc = "AESGCM(128)";
1510 		break;
1511 	case SSL_AES256GCM:
1512 		enc = "AESGCM(256)";
1513 		break;
1514 	case SSL_CAMELLIA128:
1515 		enc = "Camellia(128)";
1516 		break;
1517 	case SSL_CAMELLIA256:
1518 		enc = "Camellia(256)";
1519 		break;
1520 	case SSL_CHACHA20POLY1305:
1521 		enc = "ChaCha20-Poly1305";
1522 		break;
1523 	case SSL_eGOST2814789CNT:
1524 		enc = "GOST-28178-89-CNT";
1525 		break;
1526 	default:
1527 		enc = "unknown";
1528 		break;
1529 	}
1530 
1531 	switch (alg_mac) {
1532 	case SSL_MD5:
1533 		mac = "MD5";
1534 		break;
1535 	case SSL_SHA1:
1536 		mac = "SHA1";
1537 		break;
1538 	case SSL_SHA256:
1539 		mac = "SHA256";
1540 		break;
1541 	case SSL_SHA384:
1542 		mac = "SHA384";
1543 		break;
1544 	case SSL_AEAD:
1545 		mac = "AEAD";
1546 		break;
1547 	case SSL_GOST94:
1548 		mac = "GOST94";
1549 		break;
1550 	case SSL_GOST89MAC:
1551 		mac = "GOST89IMIT";
1552 		break;
1553 	case SSL_STREEBOG256:
1554 		mac = "STREEBOG256";
1555 		break;
1556 	default:
1557 		mac = "unknown";
1558 		break;
1559 	}
1560 
1561 	if (asprintf(&ret, "%-23s %s Kx=%-8s Au=%-4s Enc=%-9s Mac=%-4s\n",
1562 	    cipher->name, ver, kx, au, enc, mac) == -1)
1563 		return "OPENSSL_malloc Error";
1564 
1565 	if (buf != NULL) {
1566 		l = strlcpy(buf, ret, len);
1567 		free(ret);
1568 		ret = buf;
1569 		if (l >= len)
1570 			ret = "Buffer too small";
1571 	}
1572 
1573 	return (ret);
1574 }
1575 LSSL_ALIAS(SSL_CIPHER_description);
1576 
1577 const char *
1578 SSL_CIPHER_get_version(const SSL_CIPHER *c)
1579 {
1580 	if (c == NULL)
1581 		return("(NONE)");
1582 	if ((c->id >> 24) == 3)
1583 		return("TLSv1/SSLv3");
1584 	else
1585 		return("unknown");
1586 }
1587 LSSL_ALIAS(SSL_CIPHER_get_version);
1588 
1589 /* return the actual cipher being used */
1590 const char *
1591 SSL_CIPHER_get_name(const SSL_CIPHER *c)
1592 {
1593 	if (c != NULL)
1594 		return (c->name);
1595 	return("(NONE)");
1596 }
1597 LSSL_ALIAS(SSL_CIPHER_get_name);
1598 
1599 /* number of bits for symmetric cipher */
1600 int
1601 SSL_CIPHER_get_bits(const SSL_CIPHER *c, int *alg_bits)
1602 {
1603 	int ret = 0;
1604 
1605 	if (c != NULL) {
1606 		if (alg_bits != NULL)
1607 			*alg_bits = c->alg_bits;
1608 		ret = c->strength_bits;
1609 	}
1610 	return (ret);
1611 }
1612 LSSL_ALIAS(SSL_CIPHER_get_bits);
1613 
1614 unsigned long
1615 SSL_CIPHER_get_id(const SSL_CIPHER *c)
1616 {
1617 	return c->id;
1618 }
1619 LSSL_ALIAS(SSL_CIPHER_get_id);
1620 
1621 uint16_t
1622 SSL_CIPHER_get_value(const SSL_CIPHER *c)
1623 {
1624 	return ssl3_cipher_get_value(c);
1625 }
1626 LSSL_ALIAS(SSL_CIPHER_get_value);
1627 
1628 const SSL_CIPHER *
1629 SSL_CIPHER_find(SSL *ssl, const unsigned char *ptr)
1630 {
1631 	uint16_t cipher_value;
1632 	CBS cbs;
1633 
1634 	/* This API is documented with ptr being an array of length two. */
1635 	CBS_init(&cbs, ptr, 2);
1636 	if (!CBS_get_u16(&cbs, &cipher_value))
1637 		return NULL;
1638 
1639 	return ssl3_get_cipher_by_value(cipher_value);
1640 }
1641 LSSL_ALIAS(SSL_CIPHER_find);
1642 
1643 int
1644 SSL_CIPHER_get_cipher_nid(const SSL_CIPHER *c)
1645 {
1646 	switch (c->algorithm_enc) {
1647 	case SSL_eNULL:
1648 		return NID_undef;
1649 	case SSL_3DES:
1650 		return NID_des_ede3_cbc;
1651 	case SSL_AES128:
1652 		return NID_aes_128_cbc;
1653 	case SSL_AES128GCM:
1654 		return NID_aes_128_gcm;
1655 	case SSL_AES256:
1656 		return NID_aes_256_cbc;
1657 	case SSL_AES256GCM:
1658 		return NID_aes_256_gcm;
1659 	case SSL_CAMELLIA128:
1660 		return NID_camellia_128_cbc;
1661 	case SSL_CAMELLIA256:
1662 		return NID_camellia_256_cbc;
1663 	case SSL_CHACHA20POLY1305:
1664 		return NID_chacha20_poly1305;
1665 	case SSL_DES:
1666 		return NID_des_cbc;
1667 	case SSL_RC4:
1668 		return NID_rc4;
1669 	case SSL_eGOST2814789CNT:
1670 		return NID_gost89_cnt;
1671 	default:
1672 		return NID_undef;
1673 	}
1674 }
1675 LSSL_ALIAS(SSL_CIPHER_get_cipher_nid);
1676 
1677 int
1678 SSL_CIPHER_get_digest_nid(const SSL_CIPHER *c)
1679 {
1680 	switch (c->algorithm_mac) {
1681 	case SSL_AEAD:
1682 		return NID_undef;
1683 	case SSL_GOST89MAC:
1684 		return NID_id_Gost28147_89_MAC;
1685 	case SSL_GOST94:
1686 		return NID_id_GostR3411_94;
1687 	case SSL_MD5:
1688 		return NID_md5;
1689 	case SSL_SHA1:
1690 		return NID_sha1;
1691 	case SSL_SHA256:
1692 		return NID_sha256;
1693 	case SSL_SHA384:
1694 		return NID_sha384;
1695 	case SSL_STREEBOG256:
1696 		return NID_id_tc26_gost3411_2012_256;
1697 	default:
1698 		return NID_undef;
1699 	}
1700 }
1701 LSSL_ALIAS(SSL_CIPHER_get_digest_nid);
1702 
1703 int
1704 SSL_CIPHER_get_kx_nid(const SSL_CIPHER *c)
1705 {
1706 	switch (c->algorithm_mkey) {
1707 	case SSL_kDHE:
1708 		return NID_kx_dhe;
1709 	case SSL_kECDHE:
1710 		return NID_kx_ecdhe;
1711 	case SSL_kGOST:
1712 		return NID_kx_gost;
1713 	case SSL_kRSA:
1714 		return NID_kx_rsa;
1715 	default:
1716 		return NID_undef;
1717 	}
1718 }
1719 LSSL_ALIAS(SSL_CIPHER_get_kx_nid);
1720 
1721 int
1722 SSL_CIPHER_get_auth_nid(const SSL_CIPHER *c)
1723 {
1724 	switch (c->algorithm_auth) {
1725 	case SSL_aNULL:
1726 		return NID_auth_null;
1727 	case SSL_aECDSA:
1728 		return NID_auth_ecdsa;
1729 	case SSL_aGOST01:
1730 		return NID_auth_gost01;
1731 	case SSL_aRSA:
1732 		return NID_auth_rsa;
1733 	default:
1734 		return NID_undef;
1735 	}
1736 }
1737 LSSL_ALIAS(SSL_CIPHER_get_auth_nid);
1738 
1739 int
1740 SSL_CIPHER_is_aead(const SSL_CIPHER *c)
1741 {
1742 	return (c->algorithm_mac & SSL_AEAD) == SSL_AEAD;
1743 }
1744 LSSL_ALIAS(SSL_CIPHER_is_aead);
1745 
1746 void *
1747 SSL_COMP_get_compression_methods(void)
1748 {
1749 	return NULL;
1750 }
1751 LSSL_ALIAS(SSL_COMP_get_compression_methods);
1752 
1753 int
1754 SSL_COMP_add_compression_method(int id, void *cm)
1755 {
1756 	return 1;
1757 }
1758 LSSL_ALIAS(SSL_COMP_add_compression_method);
1759 
1760 const char *
1761 SSL_COMP_get_name(const void *comp)
1762 {
1763 	return NULL;
1764 }
1765 LSSL_ALIAS(SSL_COMP_get_name);
1766