xref: /openbsd-src/lib/libssl/ssl_ciph.c (revision 1ad61ae0a79a724d2d3ec69e69c8e1d1ff6b53a0)
1 /* $OpenBSD: ssl_ciph.c,v 1.136 2023/07/08 16:40:13 beck 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/objects.h>
146 #include <openssl/opensslconf.h>
147 
148 #ifndef OPENSSL_NO_ENGINE
149 #include <openssl/engine.h>
150 #endif
151 
152 #include "ssl_local.h"
153 
154 #define CIPHER_ADD	1
155 #define CIPHER_KILL	2
156 #define CIPHER_DEL	3
157 #define CIPHER_ORD	4
158 #define CIPHER_SPECIAL	5
159 
160 typedef struct cipher_order_st {
161 	const SSL_CIPHER *cipher;
162 	int active;
163 	int dead;
164 	struct cipher_order_st *next, *prev;
165 } CIPHER_ORDER;
166 
167 static const SSL_CIPHER cipher_aliases[] = {
168 
169 	/* "ALL" doesn't include eNULL (must be specifically enabled) */
170 	{
171 		.name = SSL_TXT_ALL,
172 		.algorithm_enc = ~SSL_eNULL,
173 	},
174 
175 	/* "COMPLEMENTOFALL" */
176 	{
177 		.name = SSL_TXT_CMPALL,
178 		.algorithm_enc = SSL_eNULL,
179 	},
180 
181 	/*
182 	 * "COMPLEMENTOFDEFAULT"
183 	 * (does *not* include ciphersuites not found in ALL!)
184 	 */
185 	{
186 		.name = SSL_TXT_CMPDEF,
187 		.algorithm_mkey = SSL_kDHE|SSL_kECDHE,
188 		.algorithm_auth = SSL_aNULL,
189 		.algorithm_enc = ~SSL_eNULL,
190 	},
191 
192 	/*
193 	 * key exchange aliases
194 	 * (some of those using only a single bit here combine multiple key
195 	 * exchange algs according to the RFCs, e.g. kEDH combines DHE_DSS
196 	 * and DHE_RSA)
197 	 */
198 	{
199 		.name = SSL_TXT_kRSA,
200 		.algorithm_mkey = SSL_kRSA,
201 	},
202 	{
203 		.name = SSL_TXT_kEDH,
204 		.algorithm_mkey = SSL_kDHE,
205 	},
206 	{
207 		.name = SSL_TXT_DH,
208 		.algorithm_mkey = SSL_kDHE,
209 	},
210 	{
211 		.name = SSL_TXT_kEECDH,
212 		.algorithm_mkey = SSL_kECDHE,
213 	},
214 	{
215 		.name = SSL_TXT_ECDH,
216 		.algorithm_mkey = SSL_kECDHE,
217 	},
218 	{
219 		.name = SSL_TXT_kGOST,
220 		.algorithm_mkey = SSL_kGOST,
221 	},
222 
223 	/* server authentication aliases */
224 	{
225 		.name = SSL_TXT_aRSA,
226 		.algorithm_auth = SSL_aRSA,
227 	},
228 	{
229 		.name = SSL_TXT_aDSS,
230 		.algorithm_auth = SSL_aDSS,
231 	},
232 	{
233 		.name = SSL_TXT_DSS,
234 		.algorithm_auth = SSL_aDSS,
235 	},
236 	{
237 		.name = SSL_TXT_aNULL,
238 		.algorithm_auth = SSL_aNULL,
239 	},
240 	{
241 		.name = SSL_TXT_aECDSA,
242 		.algorithm_auth = SSL_aECDSA,
243 	},
244 	{
245 		.name = SSL_TXT_ECDSA,
246 		.algorithm_auth = SSL_aECDSA,
247 	},
248 	{
249 		.name = SSL_TXT_aGOST01,
250 		.algorithm_auth = SSL_aGOST01,
251 	},
252 	{
253 		.name = SSL_TXT_aGOST,
254 		.algorithm_auth = SSL_aGOST01,
255 	},
256 
257 	/* aliases combining key exchange and server authentication */
258 	{
259 		.name = SSL_TXT_DHE,
260 		.algorithm_mkey = SSL_kDHE,
261 		.algorithm_auth = ~SSL_aNULL,
262 	},
263 	{
264 		.name = SSL_TXT_EDH,
265 		.algorithm_mkey = SSL_kDHE,
266 		.algorithm_auth = ~SSL_aNULL,
267 	},
268 	{
269 		.name = SSL_TXT_ECDHE,
270 		.algorithm_mkey = SSL_kECDHE,
271 		.algorithm_auth = ~SSL_aNULL,
272 	},
273 	{
274 		.name = SSL_TXT_EECDH,
275 		.algorithm_mkey = SSL_kECDHE,
276 		.algorithm_auth = ~SSL_aNULL,
277 	},
278 	{
279 		.name = SSL_TXT_NULL,
280 		.algorithm_enc = SSL_eNULL,
281 	},
282 	{
283 		.name = SSL_TXT_RSA,
284 		.algorithm_mkey = SSL_kRSA,
285 		.algorithm_auth = SSL_aRSA,
286 	},
287 	{
288 		.name = SSL_TXT_ADH,
289 		.algorithm_mkey = SSL_kDHE,
290 		.algorithm_auth = SSL_aNULL,
291 	},
292 	{
293 		.name = SSL_TXT_AECDH,
294 		.algorithm_mkey = SSL_kECDHE,
295 		.algorithm_auth = SSL_aNULL,
296 	},
297 
298 	/* symmetric encryption aliases */
299 	{
300 		.name = SSL_TXT_3DES,
301 		.algorithm_enc = SSL_3DES,
302 	},
303 	{
304 		.name = SSL_TXT_RC4,
305 		.algorithm_enc = SSL_RC4,
306 	},
307 	{
308 		.name = SSL_TXT_eNULL,
309 		.algorithm_enc = SSL_eNULL,
310 	},
311 	{
312 		.name = SSL_TXT_AES128,
313 		.algorithm_enc = SSL_AES128|SSL_AES128GCM,
314 	},
315 	{
316 		.name = SSL_TXT_AES256,
317 		.algorithm_enc = SSL_AES256|SSL_AES256GCM,
318 	},
319 	{
320 		.name = SSL_TXT_AES,
321 		.algorithm_enc = SSL_AES,
322 	},
323 	{
324 		.name = SSL_TXT_AES_GCM,
325 		.algorithm_enc = SSL_AES128GCM|SSL_AES256GCM,
326 	},
327 	{
328 		.name = SSL_TXT_CAMELLIA128,
329 		.algorithm_enc = SSL_CAMELLIA128,
330 	},
331 	{
332 		.name = SSL_TXT_CAMELLIA256,
333 		.algorithm_enc = SSL_CAMELLIA256,
334 	},
335 	{
336 		.name = SSL_TXT_CAMELLIA,
337 		.algorithm_enc = SSL_CAMELLIA128|SSL_CAMELLIA256,
338 	},
339 	{
340 		.name = SSL_TXT_CHACHA20,
341 		.algorithm_enc = SSL_CHACHA20POLY1305,
342 	},
343 
344 	/* MAC aliases */
345 	{
346 		.name = SSL_TXT_AEAD,
347 		.algorithm_mac = SSL_AEAD,
348 	},
349 	{
350 		.name = SSL_TXT_MD5,
351 		.algorithm_mac = SSL_MD5,
352 	},
353 	{
354 		.name = SSL_TXT_SHA1,
355 		.algorithm_mac = SSL_SHA1,
356 	},
357 	{
358 		.name = SSL_TXT_SHA,
359 		.algorithm_mac = SSL_SHA1,
360 	},
361 	{
362 		.name = SSL_TXT_GOST94,
363 		.algorithm_mac = SSL_GOST94,
364 	},
365 	{
366 		.name = SSL_TXT_GOST89MAC,
367 		.algorithm_mac = SSL_GOST89MAC,
368 	},
369 	{
370 		.name = SSL_TXT_SHA256,
371 		.algorithm_mac = SSL_SHA256,
372 	},
373 	{
374 		.name = SSL_TXT_SHA384,
375 		.algorithm_mac = SSL_SHA384,
376 	},
377 	{
378 		.name = SSL_TXT_STREEBOG256,
379 		.algorithm_mac = SSL_STREEBOG256,
380 	},
381 
382 	/* protocol version aliases */
383 	{
384 		.name = SSL_TXT_SSLV3,
385 		.algorithm_ssl = SSL_SSLV3,
386 	},
387 	{
388 		.name = SSL_TXT_TLSV1,
389 		.algorithm_ssl = SSL_TLSV1,
390 	},
391 	{
392 		.name = SSL_TXT_TLSV1_2,
393 		.algorithm_ssl = SSL_TLSV1_2,
394 	},
395 	{
396 		.name = SSL_TXT_TLSV1_3,
397 		.algorithm_ssl = SSL_TLSV1_3,
398 	},
399 
400 	/* cipher suite aliases */
401 #ifdef LIBRESSL_HAS_TLS1_3
402 	{
403 		.valid = 1,
404 		.name = "TLS_AES_128_GCM_SHA256",
405 		.id = TLS1_3_CK_AES_128_GCM_SHA256,
406 		.algorithm_ssl = SSL_TLSV1_3,
407 	},
408 	{
409 		.valid = 1,
410 		.name = "TLS_AES_256_GCM_SHA384",
411 		.id = TLS1_3_CK_AES_256_GCM_SHA384,
412 		.algorithm_ssl = SSL_TLSV1_3,
413 	},
414 	{
415 		.valid = 1,
416 		.name = "TLS_CHACHA20_POLY1305_SHA256",
417 		.id = TLS1_3_CK_CHACHA20_POLY1305_SHA256,
418 		.algorithm_ssl = SSL_TLSV1_3,
419 	},
420 #endif
421 
422 	/* strength classes */
423 	{
424 		.name = SSL_TXT_LOW,
425 		.algo_strength = SSL_LOW,
426 	},
427 	{
428 		.name = SSL_TXT_MEDIUM,
429 		.algo_strength = SSL_MEDIUM,
430 	},
431 	{
432 		.name = SSL_TXT_HIGH,
433 		.algo_strength = SSL_HIGH,
434 	},
435 };
436 
437 int
438 ssl_cipher_get_evp(const SSL_SESSION *ss, const EVP_CIPHER **enc,
439     const EVP_MD **md, int *mac_pkey_type, int *mac_secret_size)
440 {
441 	*enc = NULL;
442 	*md = NULL;
443 	*mac_pkey_type = NID_undef;
444 	*mac_secret_size = 0;
445 
446 	if (ss->cipher == NULL)
447 		return 0;
448 
449 	/*
450 	 * This function does not handle EVP_AEAD.
451 	 * See ssl_cipher_get_evp_aead instead.
452 	 */
453 	if (ss->cipher->algorithm_mac & SSL_AEAD)
454 		return 0;
455 
456 	switch (ss->cipher->algorithm_enc) {
457 	case SSL_3DES:
458 		*enc = EVP_des_ede3_cbc();
459 		break;
460 	case SSL_RC4:
461 		*enc = EVP_rc4();
462 		break;
463 	case SSL_eNULL:
464 		*enc = EVP_enc_null();
465 		break;
466 	case SSL_AES128:
467 		*enc = EVP_aes_128_cbc();
468 		break;
469 	case SSL_AES256:
470 		*enc = EVP_aes_256_cbc();
471 		break;
472 	case SSL_CAMELLIA128:
473 		*enc = EVP_camellia_128_cbc();
474 		break;
475 	case SSL_CAMELLIA256:
476 		*enc = EVP_camellia_256_cbc();
477 		break;
478 #ifndef OPENSSL_NO_GOST
479 	case SSL_eGOST2814789CNT:
480 		*enc = EVP_gost2814789_cnt();
481 		break;
482 #endif
483 	}
484 
485 	switch (ss->cipher->algorithm_mac) {
486 	case SSL_MD5:
487 		*md = EVP_md5();
488 		break;
489 	case SSL_SHA1:
490 		*md = EVP_sha1();
491 		break;
492 	case SSL_SHA256:
493 		*md = EVP_sha256();
494 		break;
495 	case SSL_SHA384:
496 		*md = EVP_sha384();
497 		break;
498 #ifndef OPENSSL_NO_GOST
499 	case SSL_GOST89MAC:
500 		*md = EVP_gost2814789imit();
501 		break;
502 	case SSL_GOST94:
503 		*md = EVP_gostr341194();
504 		break;
505 	case SSL_STREEBOG256:
506 		*md = EVP_streebog256();
507 		break;
508 #endif
509 	}
510 	if (*enc == NULL || *md == NULL)
511 		return 0;
512 
513 	/*
514 	 * EVP_CIPH_FLAG_AEAD_CIPHER and EVP_CIPH_GCM_MODE ciphers are not
515 	 * supported via EVP_CIPHER (they should be using EVP_AEAD instead).
516 	 */
517 	if (EVP_CIPHER_flags(*enc) & EVP_CIPH_FLAG_AEAD_CIPHER)
518 		return 0;
519 	if (EVP_CIPHER_mode(*enc) == EVP_CIPH_GCM_MODE)
520 		return 0;
521 #ifndef OPENSSL_NO_GOST
522 	/* XXX JFC. die in fire already */
523 	if (ss->cipher->algorithm_mac == SSL_GOST89MAC) {
524 		*mac_pkey_type = EVP_PKEY_GOSTIMIT;
525 		*mac_secret_size = 32; /* XXX */
526 	} else {
527 #endif
528 		*mac_pkey_type = EVP_PKEY_HMAC;
529 		*mac_secret_size = EVP_MD_size(*md);
530 #ifndef OPENSSL_NO_GOST
531 	}
532 #endif
533 	return 1;
534 }
535 
536 /*
537  * ssl_cipher_get_evp_aead sets aead to point to the correct EVP_AEAD object
538  * for s->cipher. It returns 1 on success and 0 on error.
539  */
540 int
541 ssl_cipher_get_evp_aead(const SSL_SESSION *ss, const EVP_AEAD **aead)
542 {
543 	*aead = NULL;
544 
545 	if (ss->cipher == NULL)
546 		return 0;
547 	if ((ss->cipher->algorithm_mac & SSL_AEAD) == 0)
548 		return 0;
549 
550 	switch (ss->cipher->algorithm_enc) {
551 	case SSL_AES128GCM:
552 		*aead = EVP_aead_aes_128_gcm();
553 		return 1;
554 	case SSL_AES256GCM:
555 		*aead = EVP_aead_aes_256_gcm();
556 		return 1;
557 	case SSL_CHACHA20POLY1305:
558 		*aead = EVP_aead_chacha20_poly1305();
559 		return 1;
560 	default:
561 		break;
562 	}
563 	return 0;
564 }
565 
566 int
567 ssl_get_handshake_evp_md(SSL *s, const EVP_MD **md)
568 {
569 	unsigned long handshake_mac;
570 
571 	*md = NULL;
572 
573 	if (s->s3->hs.cipher == NULL)
574 		return 0;
575 
576 	handshake_mac = s->s3->hs.cipher->algorithm2 &
577 	    SSL_HANDSHAKE_MAC_MASK;
578 
579 	/* For TLSv1.2 we upgrade the default MD5+SHA1 MAC to SHA256. */
580 	if (SSL_USE_SHA256_PRF(s) && handshake_mac == SSL_HANDSHAKE_MAC_DEFAULT)
581 		handshake_mac = SSL_HANDSHAKE_MAC_SHA256;
582 
583 	switch (handshake_mac) {
584 	case SSL_HANDSHAKE_MAC_DEFAULT:
585 		*md = EVP_md5_sha1();
586 		return 1;
587 #ifndef OPENSSL_NO_GOST
588 	case SSL_HANDSHAKE_MAC_GOST94:
589 		*md = EVP_gostr341194();
590 		return 1;
591 	case SSL_HANDSHAKE_MAC_STREEBOG256:
592 		*md = EVP_streebog256();
593 		return 1;
594 #endif
595 	case SSL_HANDSHAKE_MAC_SHA256:
596 		*md = EVP_sha256();
597 		return 1;
598 	case SSL_HANDSHAKE_MAC_SHA384:
599 		*md = EVP_sha384();
600 		return 1;
601 	default:
602 		break;
603 	}
604 
605 	return 0;
606 }
607 
608 #define ITEM_SEP(a) \
609 	(((a) == ':') || ((a) == ' ') || ((a) == ';') || ((a) == ','))
610 
611 static void
612 ll_append_tail(CIPHER_ORDER **head, CIPHER_ORDER *curr,
613     CIPHER_ORDER **tail)
614 {
615 	if (curr == *tail)
616 		return;
617 	if (curr == *head)
618 		*head = curr->next;
619 	if (curr->prev != NULL)
620 		curr->prev->next = curr->next;
621 	if (curr->next != NULL)
622 		curr->next->prev = curr->prev;
623 	(*tail)->next = curr;
624 	curr->prev= *tail;
625 	curr->next = NULL;
626 	*tail = curr;
627 }
628 
629 static void
630 ll_append_head(CIPHER_ORDER **head, CIPHER_ORDER *curr,
631     CIPHER_ORDER **tail)
632 {
633 	if (curr == *head)
634 		return;
635 	if (curr == *tail)
636 		*tail = curr->prev;
637 	if (curr->next != NULL)
638 		curr->next->prev = curr->prev;
639 	if (curr->prev != NULL)
640 		curr->prev->next = curr->next;
641 	(*head)->prev = curr;
642 	curr->next= *head;
643 	curr->prev = NULL;
644 	*head = curr;
645 }
646 
647 static void
648 ssl_cipher_get_disabled(unsigned long *mkey, unsigned long *auth,
649     unsigned long *enc, unsigned long *mac, unsigned long *ssl)
650 {
651 	*mkey = 0;
652 	*auth = 0;
653 	*enc = 0;
654 	*mac = 0;
655 	*ssl = 0;
656 
657 	/*
658 	 * Check for the availability of GOST 34.10 public/private key
659 	 * algorithms. If they are not available disable the associated
660 	 * authentication and key exchange algorithms.
661 	 */
662 	if (EVP_PKEY_meth_find(NID_id_GostR3410_2001) == NULL) {
663 		*auth |= SSL_aGOST01;
664 		*mkey |= SSL_kGOST;
665 	}
666 
667 #ifdef SSL_FORBID_ENULL
668 	*enc |= SSL_eNULL;
669 #endif
670 }
671 
672 static void
673 ssl_cipher_collect_ciphers(const SSL_METHOD *ssl_method, int num_of_ciphers,
674     unsigned long disabled_mkey, unsigned long disabled_auth,
675     unsigned long disabled_enc, unsigned long disabled_mac,
676     unsigned long disabled_ssl, CIPHER_ORDER *co_list,
677     CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
678 {
679 	int i, co_list_num;
680 	const SSL_CIPHER *c;
681 
682 	/*
683 	 * We have num_of_ciphers descriptions compiled in, depending on the
684 	 * method selected (SSLv3, TLSv1, etc). These will later be sorted in
685 	 * a linked list with at most num entries.
686 	 */
687 
688 	/* Get the initial list of ciphers */
689 	co_list_num = 0;	/* actual count of ciphers */
690 	for (i = 0; i < num_of_ciphers; i++) {
691 		c = ssl_method->get_cipher(i);
692 		/*
693 		 * Drop any invalid ciphers and any which use unavailable
694 		 * algorithms.
695 		 */
696 		if ((c != NULL) && c->valid &&
697 		    !(c->algorithm_mkey & disabled_mkey) &&
698 		    !(c->algorithm_auth & disabled_auth) &&
699 		    !(c->algorithm_enc & disabled_enc) &&
700 		    !(c->algorithm_mac & disabled_mac) &&
701 		    !(c->algorithm_ssl & disabled_ssl)) {
702 			co_list[co_list_num].cipher = c;
703 			co_list[co_list_num].next = NULL;
704 			co_list[co_list_num].prev = NULL;
705 			co_list[co_list_num].active = 0;
706 			co_list_num++;
707 		}
708 	}
709 
710 	/*
711 	 * Prepare linked list from list entries
712 	 */
713 	if (co_list_num > 0) {
714 		co_list[0].prev = NULL;
715 
716 		if (co_list_num > 1) {
717 			co_list[0].next = &co_list[1];
718 
719 			for (i = 1; i < co_list_num - 1; i++) {
720 				co_list[i].prev = &co_list[i - 1];
721 				co_list[i].next = &co_list[i + 1];
722 			}
723 
724 			co_list[co_list_num - 1].prev =
725 			    &co_list[co_list_num - 2];
726 		}
727 
728 		co_list[co_list_num - 1].next = NULL;
729 
730 		*head_p = &co_list[0];
731 		*tail_p = &co_list[co_list_num - 1];
732 	}
733 }
734 
735 static void
736 ssl_cipher_collect_aliases(const SSL_CIPHER **ca_list, int num_of_group_aliases,
737     unsigned long disabled_mkey, unsigned long disabled_auth,
738     unsigned long disabled_enc, unsigned long disabled_mac,
739     unsigned long disabled_ssl, CIPHER_ORDER *head)
740 {
741 	CIPHER_ORDER *ciph_curr;
742 	const SSL_CIPHER **ca_curr;
743 	int i;
744 	unsigned long mask_mkey = ~disabled_mkey;
745 	unsigned long mask_auth = ~disabled_auth;
746 	unsigned long mask_enc = ~disabled_enc;
747 	unsigned long mask_mac = ~disabled_mac;
748 	unsigned long mask_ssl = ~disabled_ssl;
749 
750 	/*
751 	 * First, add the real ciphers as already collected
752 	 */
753 	ciph_curr = head;
754 	ca_curr = ca_list;
755 	while (ciph_curr != NULL) {
756 		*ca_curr = ciph_curr->cipher;
757 		ca_curr++;
758 		ciph_curr = ciph_curr->next;
759 	}
760 
761 	/*
762 	 * Now we add the available ones from the cipher_aliases[] table.
763 	 * They represent either one or more algorithms, some of which
764 	 * in any affected category must be supported (set in enabled_mask),
765 	 * or represent a cipher strength value (will be added in any case because algorithms=0).
766 	 */
767 	for (i = 0; i < num_of_group_aliases; i++) {
768 		unsigned long algorithm_mkey = cipher_aliases[i].algorithm_mkey;
769 		unsigned long algorithm_auth = cipher_aliases[i].algorithm_auth;
770 		unsigned long algorithm_enc = cipher_aliases[i].algorithm_enc;
771 		unsigned long algorithm_mac = cipher_aliases[i].algorithm_mac;
772 		unsigned long algorithm_ssl = cipher_aliases[i].algorithm_ssl;
773 
774 		if (algorithm_mkey)
775 			if ((algorithm_mkey & mask_mkey) == 0)
776 				continue;
777 
778 		if (algorithm_auth)
779 			if ((algorithm_auth & mask_auth) == 0)
780 				continue;
781 
782 		if (algorithm_enc)
783 			if ((algorithm_enc & mask_enc) == 0)
784 				continue;
785 
786 		if (algorithm_mac)
787 			if ((algorithm_mac & mask_mac) == 0)
788 				continue;
789 
790 		if (algorithm_ssl)
791 			if ((algorithm_ssl & mask_ssl) == 0)
792 				continue;
793 
794 		*ca_curr = (SSL_CIPHER *)(cipher_aliases + i);
795 		ca_curr++;
796 	}
797 
798 	*ca_curr = NULL;	/* end of list */
799 }
800 
801 static void
802 ssl_cipher_apply_rule(unsigned long cipher_id, unsigned long alg_mkey,
803     unsigned long alg_auth, unsigned long alg_enc, unsigned long alg_mac,
804     unsigned long alg_ssl, unsigned long algo_strength, int rule,
805     int strength_bits, CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
806 {
807 	CIPHER_ORDER *head, *tail, *curr, *next, *last;
808 	const SSL_CIPHER *cp;
809 	int reverse = 0;
810 
811 	if (rule == CIPHER_DEL)
812 		reverse = 1; /* needed to maintain sorting between currently deleted ciphers */
813 
814 	head = *head_p;
815 	tail = *tail_p;
816 
817 	if (reverse) {
818 		next = tail;
819 		last = head;
820 	} else {
821 		next = head;
822 		last = tail;
823 	}
824 
825 	curr = NULL;
826 	for (;;) {
827 		if (curr == last)
828 			break;
829 		curr = next;
830 		next = reverse ? curr->prev : curr->next;
831 
832 		cp = curr->cipher;
833 
834 		if (cipher_id && cp->id != cipher_id)
835 			continue;
836 
837 		/*
838 		 * Selection criteria is either the value of strength_bits
839 		 * or the algorithms used.
840 		 */
841 		if (strength_bits >= 0) {
842 			if (strength_bits != cp->strength_bits)
843 				continue;
844 		} else {
845 			if (alg_mkey && !(alg_mkey & cp->algorithm_mkey))
846 				continue;
847 			if (alg_auth && !(alg_auth & cp->algorithm_auth))
848 				continue;
849 			if (alg_enc && !(alg_enc & cp->algorithm_enc))
850 				continue;
851 			if (alg_mac && !(alg_mac & cp->algorithm_mac))
852 				continue;
853 			if (alg_ssl && !(alg_ssl & cp->algorithm_ssl))
854 				continue;
855 			if ((algo_strength & SSL_STRONG_MASK) && !(algo_strength & SSL_STRONG_MASK & cp->algo_strength))
856 				continue;
857 		}
858 
859 		/* add the cipher if it has not been added yet. */
860 		if (rule == CIPHER_ADD) {
861 			/* reverse == 0 */
862 			if (!curr->active) {
863 				ll_append_tail(&head, curr, &tail);
864 				curr->active = 1;
865 			}
866 		}
867 		/* Move the added cipher to this location */
868 		else if (rule == CIPHER_ORD) {
869 			/* reverse == 0 */
870 			if (curr->active) {
871 				ll_append_tail(&head, curr, &tail);
872 			}
873 		} else if (rule == CIPHER_DEL) {
874 			/* reverse == 1 */
875 			if (curr->active) {
876 				/* most recently deleted ciphersuites get best positions
877 				 * for any future CIPHER_ADD (note that the CIPHER_DEL loop
878 				 * works in reverse to maintain the order) */
879 				ll_append_head(&head, curr, &tail);
880 				curr->active = 0;
881 			}
882 		} else if (rule == CIPHER_KILL) {
883 			/* reverse == 0 */
884 			if (head == curr)
885 				head = curr->next;
886 			else
887 				curr->prev->next = curr->next;
888 			if (tail == curr)
889 				tail = curr->prev;
890 			curr->active = 0;
891 			if (curr->next != NULL)
892 				curr->next->prev = curr->prev;
893 			if (curr->prev != NULL)
894 				curr->prev->next = curr->next;
895 			curr->next = NULL;
896 			curr->prev = NULL;
897 		}
898 	}
899 
900 	*head_p = head;
901 	*tail_p = tail;
902 }
903 
904 static int
905 ssl_cipher_strength_sort(CIPHER_ORDER **head_p, CIPHER_ORDER **tail_p)
906 {
907 	int max_strength_bits, i, *number_uses;
908 	CIPHER_ORDER *curr;
909 
910 	/*
911 	 * This routine sorts the ciphers with descending strength. The sorting
912 	 * must keep the pre-sorted sequence, so we apply the normal sorting
913 	 * routine as '+' movement to the end of the list.
914 	 */
915 	max_strength_bits = 0;
916 	curr = *head_p;
917 	while (curr != NULL) {
918 		if (curr->active &&
919 		    (curr->cipher->strength_bits > max_strength_bits))
920 			max_strength_bits = curr->cipher->strength_bits;
921 		curr = curr->next;
922 	}
923 
924 	number_uses = calloc((max_strength_bits + 1), sizeof(int));
925 	if (!number_uses) {
926 		SSLerrorx(ERR_R_MALLOC_FAILURE);
927 		return (0);
928 	}
929 
930 	/*
931 	 * Now find the strength_bits values actually used
932 	 */
933 	curr = *head_p;
934 	while (curr != NULL) {
935 		if (curr->active)
936 			number_uses[curr->cipher->strength_bits]++;
937 		curr = curr->next;
938 	}
939 	/*
940 	 * Go through the list of used strength_bits values in descending
941 	 * order.
942 	 */
943 	for (i = max_strength_bits; i >= 0; i--)
944 		if (number_uses[i] > 0)
945 			ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ORD, i, head_p, tail_p);
946 
947 	free(number_uses);
948 	return (1);
949 }
950 
951 static int
952 ssl_cipher_process_rulestr(const char *rule_str, CIPHER_ORDER **head_p,
953     CIPHER_ORDER **tail_p, const SSL_CIPHER **ca_list, SSL_CERT *cert,
954     int *tls13_seen)
955 {
956 	unsigned long alg_mkey, alg_auth, alg_enc, alg_mac, alg_ssl;
957 	unsigned long algo_strength;
958 	int j, multi, found, rule, retval, ok, buflen;
959 	unsigned long cipher_id = 0;
960 	const char *l, *buf;
961 	char ch;
962 
963 	*tls13_seen = 0;
964 
965 	retval = 1;
966 	l = rule_str;
967 	for (;;) {
968 		ch = *l;
969 
970 		if (ch == '\0')
971 			break;
972 
973 		if (ch == '-') {
974 			rule = CIPHER_DEL;
975 			l++;
976 		} else if (ch == '+') {
977 			rule = CIPHER_ORD;
978 			l++;
979 		} else if (ch == '!') {
980 			rule = CIPHER_KILL;
981 			l++;
982 		} else if (ch == '@') {
983 			rule = CIPHER_SPECIAL;
984 			l++;
985 		} else {
986 			rule = CIPHER_ADD;
987 		}
988 
989 		if (ITEM_SEP(ch)) {
990 			l++;
991 			continue;
992 		}
993 
994 		alg_mkey = 0;
995 		alg_auth = 0;
996 		alg_enc = 0;
997 		alg_mac = 0;
998 		alg_ssl = 0;
999 		algo_strength = 0;
1000 
1001 		for (;;) {
1002 			ch = *l;
1003 			buf = l;
1004 			buflen = 0;
1005 			while (((ch >= 'A') && (ch <= 'Z')) ||
1006 			    ((ch >= '0') && (ch <= '9')) ||
1007 			    ((ch >= 'a') && (ch <= 'z')) ||
1008 			    (ch == '-') || (ch == '.') ||
1009 			    (ch == '_') || (ch == '=')) {
1010 				ch = *(++l);
1011 				buflen++;
1012 			}
1013 
1014 			if (buflen == 0) {
1015 				/*
1016 				 * We hit something we cannot deal with,
1017 				 * it is no command or separator nor
1018 				 * alphanumeric, so we call this an error.
1019 				 */
1020 				SSLerrorx(SSL_R_INVALID_COMMAND);
1021 				return 0;
1022 			}
1023 
1024 			if (rule == CIPHER_SPECIAL) {
1025 				 /* unused -- avoid compiler warning */
1026 				found = 0;
1027 				/* special treatment */
1028 				break;
1029 			}
1030 
1031 			/* check for multi-part specification */
1032 			if (ch == '+') {
1033 				multi = 1;
1034 				l++;
1035 			} else
1036 				multi = 0;
1037 
1038 			/*
1039 			 * Now search for the cipher alias in the ca_list.
1040 			 * Be careful with the strncmp, because the "buflen"
1041 			 * limitation will make the rule "ADH:SOME" and the
1042 			 * cipher "ADH-MY-CIPHER" look like a match for
1043 			 * buflen=3. So additionally check whether the cipher
1044 			 * name found has the correct length. We can save a
1045 			 * strlen() call: just checking for the '\0' at the
1046 			 * right place is sufficient, we have to strncmp()
1047 			 * anyway (we cannot use strcmp(), because buf is not
1048 			 * '\0' terminated.)
1049 			 */
1050 			j = found = 0;
1051 			cipher_id = 0;
1052 			while (ca_list[j]) {
1053 				if (!strncmp(buf, ca_list[j]->name, buflen) &&
1054 				    (ca_list[j]->name[buflen] == '\0')) {
1055 					found = 1;
1056 					break;
1057 				} else
1058 					j++;
1059 			}
1060 
1061 			if (!found)
1062 				break;	/* ignore this entry */
1063 
1064 			if (ca_list[j]->algorithm_mkey) {
1065 				if (alg_mkey) {
1066 					alg_mkey &= ca_list[j]->algorithm_mkey;
1067 					if (!alg_mkey) {
1068 						found = 0;
1069 						break;
1070 					}
1071 				} else
1072 					alg_mkey = ca_list[j]->algorithm_mkey;
1073 			}
1074 
1075 			if (ca_list[j]->algorithm_auth) {
1076 				if (alg_auth) {
1077 					alg_auth &= ca_list[j]->algorithm_auth;
1078 					if (!alg_auth) {
1079 						found = 0;
1080 						break;
1081 					}
1082 				} else
1083 					alg_auth = ca_list[j]->algorithm_auth;
1084 			}
1085 
1086 			if (ca_list[j]->algorithm_enc) {
1087 				if (alg_enc) {
1088 					alg_enc &= ca_list[j]->algorithm_enc;
1089 					if (!alg_enc) {
1090 						found = 0;
1091 						break;
1092 					}
1093 				} else
1094 					alg_enc = ca_list[j]->algorithm_enc;
1095 			}
1096 
1097 			if (ca_list[j]->algorithm_mac) {
1098 				if (alg_mac) {
1099 					alg_mac &= ca_list[j]->algorithm_mac;
1100 					if (!alg_mac) {
1101 						found = 0;
1102 						break;
1103 					}
1104 				} else
1105 					alg_mac = ca_list[j]->algorithm_mac;
1106 			}
1107 
1108 			if (ca_list[j]->algo_strength & SSL_STRONG_MASK) {
1109 				if (algo_strength & SSL_STRONG_MASK) {
1110 					algo_strength &=
1111 					    (ca_list[j]->algo_strength &
1112 					    SSL_STRONG_MASK) | ~SSL_STRONG_MASK;
1113 					if (!(algo_strength &
1114 					    SSL_STRONG_MASK)) {
1115 						found = 0;
1116 						break;
1117 					}
1118 				} else
1119 					algo_strength |=
1120 					    ca_list[j]->algo_strength &
1121 					    SSL_STRONG_MASK;
1122 			}
1123 
1124 			if (ca_list[j]->valid) {
1125 				/*
1126 				 * explicit ciphersuite found; its protocol
1127 				 * version does not become part of the search
1128 				 * pattern!
1129 				 */
1130 				cipher_id = ca_list[j]->id;
1131 				if (ca_list[j]->algorithm_ssl == SSL_TLSV1_3)
1132 					*tls13_seen = 1;
1133 			} else {
1134 				/*
1135 				 * not an explicit ciphersuite; only in this
1136 				 * case, the protocol version is considered
1137 				 * part of the search pattern
1138 				 */
1139 				if (ca_list[j]->algorithm_ssl) {
1140 					if (alg_ssl) {
1141 						alg_ssl &=
1142 						    ca_list[j]->algorithm_ssl;
1143 						if (!alg_ssl) {
1144 							found = 0;
1145 							break;
1146 						}
1147 					} else
1148 						alg_ssl =
1149 						    ca_list[j]->algorithm_ssl;
1150 				}
1151 			}
1152 
1153 			if (!multi)
1154 				break;
1155 		}
1156 
1157 		/*
1158 		 * Ok, we have the rule, now apply it
1159 		 */
1160 		if (rule == CIPHER_SPECIAL) {
1161 			/* special command */
1162 			ok = 0;
1163 			if (buflen == 8 && strncmp(buf, "STRENGTH", 8) == 0) {
1164 				ok = ssl_cipher_strength_sort(head_p, tail_p);
1165 			} else if (buflen == 10 &&
1166 			    strncmp(buf, "SECLEVEL=", 9) == 0) {
1167 				int level = buf[9] - '0';
1168 
1169 				if (level >= 0 && level <= 5) {
1170 					cert->security_level = level;
1171 					ok = 1;
1172 				} else {
1173 					SSLerrorx(SSL_R_INVALID_COMMAND);
1174 				}
1175 			} else {
1176 				SSLerrorx(SSL_R_INVALID_COMMAND);
1177 			}
1178 			if (ok == 0)
1179 				retval = 0;
1180 
1181 			while ((*l != '\0') && !ITEM_SEP(*l))
1182 				l++;
1183 		} else if (found) {
1184 			if (alg_ssl == SSL_TLSV1_3)
1185 				*tls13_seen = 1;
1186 			ssl_cipher_apply_rule(cipher_id, alg_mkey, alg_auth,
1187 			    alg_enc, alg_mac, alg_ssl, algo_strength, rule,
1188 			    -1, head_p, tail_p);
1189 		} else {
1190 			while ((*l != '\0') && !ITEM_SEP(*l))
1191 				l++;
1192 		}
1193 		if (*l == '\0')
1194 			break; /* done */
1195 	}
1196 
1197 	return (retval);
1198 }
1199 
1200 static inline int
1201 ssl_aes_is_accelerated(void)
1202 {
1203 #if defined(__i386__) || defined(__x86_64__)
1204 	return ((OPENSSL_cpu_caps() & (1ULL << 57)) != 0);
1205 #else
1206 	return (0);
1207 #endif
1208 }
1209 
1210 STACK_OF(SSL_CIPHER) *
1211 ssl_create_cipher_list(const SSL_METHOD *ssl_method,
1212     STACK_OF(SSL_CIPHER) **cipher_list,
1213     STACK_OF(SSL_CIPHER) *cipher_list_tls13,
1214     const char *rule_str, SSL_CERT *cert)
1215 {
1216 	int ok, num_of_ciphers, num_of_alias_max, num_of_group_aliases;
1217 	unsigned long disabled_mkey, disabled_auth, disabled_enc, disabled_mac, disabled_ssl;
1218 	STACK_OF(SSL_CIPHER) *cipherstack = NULL, *ret = NULL;
1219 	const char *rule_p;
1220 	CIPHER_ORDER *co_list = NULL, *head = NULL, *tail = NULL, *curr;
1221 	const SSL_CIPHER **ca_list = NULL;
1222 	const SSL_CIPHER *cipher;
1223 	int tls13_seen = 0;
1224 	int any_active;
1225 	int i;
1226 
1227 	/*
1228 	 * Return with error if nothing to do.
1229 	 */
1230 	if (rule_str == NULL || cipher_list == NULL)
1231 		goto err;
1232 
1233 	/*
1234 	 * To reduce the work to do we only want to process the compiled
1235 	 * in algorithms, so we first get the mask of disabled ciphers.
1236 	 */
1237 	ssl_cipher_get_disabled(&disabled_mkey, &disabled_auth, &disabled_enc, &disabled_mac, &disabled_ssl);
1238 
1239 	/*
1240 	 * Now we have to collect the available ciphers from the compiled
1241 	 * in ciphers. We cannot get more than the number compiled in, so
1242 	 * it is used for allocation.
1243 	 */
1244 	num_of_ciphers = ssl3_num_ciphers();
1245 	co_list = reallocarray(NULL, num_of_ciphers, sizeof(CIPHER_ORDER));
1246 	if (co_list == NULL) {
1247 		SSLerrorx(ERR_R_MALLOC_FAILURE);
1248 		goto err;
1249 	}
1250 
1251 	ssl_cipher_collect_ciphers(ssl_method, num_of_ciphers,
1252 	    disabled_mkey, disabled_auth, disabled_enc, disabled_mac, disabled_ssl,
1253 	    co_list, &head, &tail);
1254 
1255 
1256 	/* Now arrange all ciphers by preference: */
1257 
1258 	/* Everything else being equal, prefer ephemeral ECDH over other key exchange mechanisms */
1259 	ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1260 	ssl_cipher_apply_rule(0, SSL_kECDHE, 0, 0, 0, 0, 0, CIPHER_DEL, -1, &head, &tail);
1261 
1262 	if (ssl_aes_is_accelerated()) {
1263 		/*
1264 		 * We have hardware assisted AES - prefer AES as a symmetric
1265 		 * cipher, with CHACHA20 second.
1266 		 */
1267 		ssl_cipher_apply_rule(0, 0, 0, SSL_AES, 0, 0, 0,
1268 		    CIPHER_ADD, -1, &head, &tail);
1269 		ssl_cipher_apply_rule(0, 0, 0, SSL_CHACHA20POLY1305,
1270 		    0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1271 	} else {
1272 		/*
1273 		 * CHACHA20 is fast and safe on all hardware and is thus our
1274 		 * preferred symmetric cipher, with AES second.
1275 		 */
1276 		ssl_cipher_apply_rule(0, 0, 0, SSL_CHACHA20POLY1305,
1277 		    0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1278 		ssl_cipher_apply_rule(0, 0, 0, SSL_AES, 0, 0, 0,
1279 		    CIPHER_ADD, -1, &head, &tail);
1280 	}
1281 
1282 	/* Temporarily enable everything else for sorting */
1283 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_ADD, -1, &head, &tail);
1284 
1285 	/* Low priority for MD5 */
1286 	ssl_cipher_apply_rule(0, 0, 0, 0, SSL_MD5, 0, 0, CIPHER_ORD, -1, &head, &tail);
1287 
1288 	/* Move anonymous ciphers to the end.  Usually, these will remain disabled.
1289 	 * (For applications that allow them, they aren't too bad, but we prefer
1290 	 * authenticated ciphers.) */
1291 	ssl_cipher_apply_rule(0, 0, SSL_aNULL, 0, 0, 0, 0, CIPHER_ORD, -1, &head, &tail);
1292 
1293 	/* Move ciphers without forward secrecy to the end */
1294 	ssl_cipher_apply_rule(0, SSL_kRSA, 0, 0, 0, 0, 0, CIPHER_ORD, -1, &head, &tail);
1295 
1296 	/* RC4 is sort of broken - move it to the end */
1297 	ssl_cipher_apply_rule(0, 0, 0, SSL_RC4, 0, 0, 0, CIPHER_ORD, -1, &head, &tail);
1298 
1299 	/* Now sort by symmetric encryption strength.  The above ordering remains
1300 	 * in force within each class */
1301 	if (!ssl_cipher_strength_sort(&head, &tail))
1302 		goto err;
1303 
1304 	/* Now disable everything (maintaining the ordering!) */
1305 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, 0, 0, CIPHER_DEL, -1, &head, &tail);
1306 
1307 	/* TLSv1.3 first. */
1308 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, SSL_TLSV1_3, 0, CIPHER_ADD, -1, &head, &tail);
1309 	ssl_cipher_apply_rule(0, 0, 0, 0, 0, SSL_TLSV1_3, 0, CIPHER_DEL, -1, &head, &tail);
1310 
1311 	/*
1312 	 * We also need cipher aliases for selecting based on the rule_str.
1313 	 * There might be two types of entries in the rule_str: 1) names
1314 	 * of ciphers themselves 2) aliases for groups of ciphers.
1315 	 * For 1) we need the available ciphers and for 2) the cipher
1316 	 * groups of cipher_aliases added together in one list (otherwise
1317 	 * we would be happy with just the cipher_aliases table).
1318 	 */
1319 	num_of_group_aliases = sizeof(cipher_aliases) / sizeof(SSL_CIPHER);
1320 	num_of_alias_max = num_of_ciphers + num_of_group_aliases + 1;
1321 	ca_list = reallocarray(NULL, num_of_alias_max, sizeof(SSL_CIPHER *));
1322 	if (ca_list == NULL) {
1323 		SSLerrorx(ERR_R_MALLOC_FAILURE);
1324 		goto err;
1325 	}
1326 	ssl_cipher_collect_aliases(ca_list, num_of_group_aliases, disabled_mkey,
1327 	    disabled_auth, disabled_enc, disabled_mac, disabled_ssl, head);
1328 
1329 	/*
1330 	 * If the rule_string begins with DEFAULT, apply the default rule
1331 	 * before using the (possibly available) additional rules.
1332 	 */
1333 	ok = 1;
1334 	rule_p = rule_str;
1335 	if (strncmp(rule_str, "DEFAULT", 7) == 0) {
1336 		ok = ssl_cipher_process_rulestr(SSL_DEFAULT_CIPHER_LIST,
1337 		    &head, &tail, ca_list, cert, &tls13_seen);
1338 		rule_p += 7;
1339 		if (*rule_p == ':')
1340 			rule_p++;
1341 	}
1342 
1343 	if (ok && (strlen(rule_p) > 0))
1344 		ok = ssl_cipher_process_rulestr(rule_p, &head, &tail, ca_list,
1345 		    cert, &tls13_seen);
1346 
1347 	if (!ok) {
1348 		/* Rule processing failure */
1349 		goto err;
1350 	}
1351 
1352 	/*
1353 	 * Allocate new "cipherstack" for the result, return with error
1354 	 * if we cannot get one.
1355 	 */
1356 	if ((cipherstack = sk_SSL_CIPHER_new_null()) == NULL) {
1357 		SSLerrorx(ERR_R_MALLOC_FAILURE);
1358 		goto err;
1359 	}
1360 
1361 	/* Prefer TLSv1.3 cipher suites. */
1362 	if (cipher_list_tls13 != NULL) {
1363 		for (i = 0; i < sk_SSL_CIPHER_num(cipher_list_tls13); i++) {
1364 			cipher = sk_SSL_CIPHER_value(cipher_list_tls13, i);
1365 			if (!sk_SSL_CIPHER_push(cipherstack, cipher)) {
1366 				SSLerrorx(ERR_R_MALLOC_FAILURE);
1367 				goto err;
1368 			}
1369 		}
1370 		tls13_seen = 1;
1371 	}
1372 
1373 	/*
1374 	 * The cipher selection for the list is done. The ciphers are added
1375 	 * to the resulting precedence to the STACK_OF(SSL_CIPHER).
1376 	 *
1377 	 * If the rule string did not contain any references to TLSv1.3 and
1378 	 * TLSv1.3 cipher suites have not been configured separately,
1379 	 * include inactive TLSv1.3 cipher suites. This avoids attempts to
1380 	 * use TLSv1.3 with an older rule string that does not include
1381 	 * TLSv1.3 cipher suites. If the rule string resulted in no active
1382 	 * cipher suites then we return an empty stack.
1383 	 */
1384 	any_active = 0;
1385 	for (curr = head; curr != NULL; curr = curr->next) {
1386 		if (curr->active ||
1387 		    (!tls13_seen && curr->cipher->algorithm_ssl == SSL_TLSV1_3)) {
1388 			if (!sk_SSL_CIPHER_push(cipherstack, curr->cipher)) {
1389 				SSLerrorx(ERR_R_MALLOC_FAILURE);
1390 				goto err;
1391 			}
1392 		}
1393 		any_active |= curr->active;
1394 	}
1395 	if (!any_active)
1396 		sk_SSL_CIPHER_zero(cipherstack);
1397 
1398 	sk_SSL_CIPHER_free(*cipher_list);
1399 	*cipher_list = cipherstack;
1400 	cipherstack = NULL;
1401 
1402 	ret = *cipher_list;
1403 
1404  err:
1405 	sk_SSL_CIPHER_free(cipherstack);
1406 	free((void *)ca_list);
1407 	free(co_list);
1408 
1409 	return ret;
1410 }
1411 
1412 const SSL_CIPHER *
1413 SSL_CIPHER_get_by_id(unsigned int id)
1414 {
1415 	return ssl3_get_cipher_by_id(id);
1416 }
1417 LSSL_ALIAS(SSL_CIPHER_get_by_id);
1418 
1419 const SSL_CIPHER *
1420 SSL_CIPHER_get_by_value(uint16_t value)
1421 {
1422 	return ssl3_get_cipher_by_value(value);
1423 }
1424 LSSL_ALIAS(SSL_CIPHER_get_by_value);
1425 
1426 char *
1427 SSL_CIPHER_description(const SSL_CIPHER *cipher, char *buf, int len)
1428 {
1429 	unsigned long alg_mkey, alg_auth, alg_enc, alg_mac, alg_ssl, alg2;
1430 	const char *ver, *kx, *au, *enc, *mac;
1431 	char *ret;
1432 	int l;
1433 
1434 	alg_mkey = cipher->algorithm_mkey;
1435 	alg_auth = cipher->algorithm_auth;
1436 	alg_enc = cipher->algorithm_enc;
1437 	alg_mac = cipher->algorithm_mac;
1438 	alg_ssl = cipher->algorithm_ssl;
1439 
1440 	alg2 = cipher->algorithm2;
1441 
1442 	if (alg_ssl & SSL_SSLV3)
1443 		ver = "SSLv3";
1444 	else if (alg_ssl & SSL_TLSV1_2)
1445 		ver = "TLSv1.2";
1446 	else if (alg_ssl & SSL_TLSV1_3)
1447 		ver = "TLSv1.3";
1448 	else
1449 		ver = "unknown";
1450 
1451 	switch (alg_mkey) {
1452 	case SSL_kRSA:
1453 		kx = "RSA";
1454 		break;
1455 	case SSL_kDHE:
1456 		kx = "DH";
1457 		break;
1458 	case SSL_kECDHE:
1459 		kx = "ECDH";
1460 		break;
1461 	case SSL_kGOST:
1462 		kx = "GOST";
1463 		break;
1464 	case SSL_kTLS1_3:
1465 		kx = "TLSv1.3";
1466 		break;
1467 	default:
1468 		kx = "unknown";
1469 	}
1470 
1471 	switch (alg_auth) {
1472 	case SSL_aRSA:
1473 		au = "RSA";
1474 		break;
1475 	case SSL_aDSS:
1476 		au = "DSS";
1477 		break;
1478 	case SSL_aNULL:
1479 		au = "None";
1480 		break;
1481 	case SSL_aECDSA:
1482 		au = "ECDSA";
1483 		break;
1484 	case SSL_aGOST01:
1485 		au = "GOST01";
1486 		break;
1487 	case SSL_aTLS1_3:
1488 		au = "TLSv1.3";
1489 		break;
1490 	default:
1491 		au = "unknown";
1492 		break;
1493 	}
1494 
1495 	switch (alg_enc) {
1496 	case SSL_3DES:
1497 		enc = "3DES(168)";
1498 		break;
1499 	case SSL_RC4:
1500 		enc = alg2 & SSL2_CF_8_BYTE_ENC ? "RC4(64)" : "RC4(128)";
1501 		break;
1502 	case SSL_eNULL:
1503 		enc = "None";
1504 		break;
1505 	case SSL_AES128:
1506 		enc = "AES(128)";
1507 		break;
1508 	case SSL_AES256:
1509 		enc = "AES(256)";
1510 		break;
1511 	case SSL_AES128GCM:
1512 		enc = "AESGCM(128)";
1513 		break;
1514 	case SSL_AES256GCM:
1515 		enc = "AESGCM(256)";
1516 		break;
1517 	case SSL_CAMELLIA128:
1518 		enc = "Camellia(128)";
1519 		break;
1520 	case SSL_CAMELLIA256:
1521 		enc = "Camellia(256)";
1522 		break;
1523 	case SSL_CHACHA20POLY1305:
1524 		enc = "ChaCha20-Poly1305";
1525 		break;
1526 	case SSL_eGOST2814789CNT:
1527 		enc = "GOST-28178-89-CNT";
1528 		break;
1529 	default:
1530 		enc = "unknown";
1531 		break;
1532 	}
1533 
1534 	switch (alg_mac) {
1535 	case SSL_MD5:
1536 		mac = "MD5";
1537 		break;
1538 	case SSL_SHA1:
1539 		mac = "SHA1";
1540 		break;
1541 	case SSL_SHA256:
1542 		mac = "SHA256";
1543 		break;
1544 	case SSL_SHA384:
1545 		mac = "SHA384";
1546 		break;
1547 	case SSL_AEAD:
1548 		mac = "AEAD";
1549 		break;
1550 	case SSL_GOST94:
1551 		mac = "GOST94";
1552 		break;
1553 	case SSL_GOST89MAC:
1554 		mac = "GOST89IMIT";
1555 		break;
1556 	case SSL_STREEBOG256:
1557 		mac = "STREEBOG256";
1558 		break;
1559 	default:
1560 		mac = "unknown";
1561 		break;
1562 	}
1563 
1564 	if (asprintf(&ret, "%-23s %s Kx=%-8s Au=%-4s Enc=%-9s Mac=%-4s\n",
1565 	    cipher->name, ver, kx, au, enc, mac) == -1)
1566 		return "OPENSSL_malloc Error";
1567 
1568 	if (buf != NULL) {
1569 		l = strlcpy(buf, ret, len);
1570 		free(ret);
1571 		ret = buf;
1572 		if (l >= len)
1573 			ret = "Buffer too small";
1574 	}
1575 
1576 	return (ret);
1577 }
1578 LSSL_ALIAS(SSL_CIPHER_description);
1579 
1580 const char *
1581 SSL_CIPHER_get_version(const SSL_CIPHER *c)
1582 {
1583 	if (c == NULL)
1584 		return("(NONE)");
1585 	if ((c->id >> 24) == 3)
1586 		return("TLSv1/SSLv3");
1587 	else
1588 		return("unknown");
1589 }
1590 LSSL_ALIAS(SSL_CIPHER_get_version);
1591 
1592 /* return the actual cipher being used */
1593 const char *
1594 SSL_CIPHER_get_name(const SSL_CIPHER *c)
1595 {
1596 	if (c != NULL)
1597 		return (c->name);
1598 	return("(NONE)");
1599 }
1600 LSSL_ALIAS(SSL_CIPHER_get_name);
1601 
1602 /* number of bits for symmetric cipher */
1603 int
1604 SSL_CIPHER_get_bits(const SSL_CIPHER *c, int *alg_bits)
1605 {
1606 	int ret = 0;
1607 
1608 	if (c != NULL) {
1609 		if (alg_bits != NULL)
1610 			*alg_bits = c->alg_bits;
1611 		ret = c->strength_bits;
1612 	}
1613 	return (ret);
1614 }
1615 LSSL_ALIAS(SSL_CIPHER_get_bits);
1616 
1617 unsigned long
1618 SSL_CIPHER_get_id(const SSL_CIPHER *c)
1619 {
1620 	return c->id;
1621 }
1622 LSSL_ALIAS(SSL_CIPHER_get_id);
1623 
1624 uint16_t
1625 SSL_CIPHER_get_value(const SSL_CIPHER *c)
1626 {
1627 	return ssl3_cipher_get_value(c);
1628 }
1629 LSSL_ALIAS(SSL_CIPHER_get_value);
1630 
1631 const SSL_CIPHER *
1632 SSL_CIPHER_find(SSL *ssl, const unsigned char *ptr)
1633 {
1634 	uint16_t cipher_value;
1635 	CBS cbs;
1636 
1637 	/* This API is documented with ptr being an array of length two. */
1638 	CBS_init(&cbs, ptr, 2);
1639 	if (!CBS_get_u16(&cbs, &cipher_value))
1640 		return NULL;
1641 
1642 	return ssl3_get_cipher_by_value(cipher_value);
1643 }
1644 LSSL_ALIAS(SSL_CIPHER_find);
1645 
1646 int
1647 SSL_CIPHER_get_cipher_nid(const SSL_CIPHER *c)
1648 {
1649 	switch (c->algorithm_enc) {
1650 	case SSL_eNULL:
1651 		return NID_undef;
1652 	case SSL_3DES:
1653 		return NID_des_ede3_cbc;
1654 	case SSL_AES128:
1655 		return NID_aes_128_cbc;
1656 	case SSL_AES128GCM:
1657 		return NID_aes_128_gcm;
1658 	case SSL_AES256:
1659 		return NID_aes_256_cbc;
1660 	case SSL_AES256GCM:
1661 		return NID_aes_256_gcm;
1662 	case SSL_CAMELLIA128:
1663 		return NID_camellia_128_cbc;
1664 	case SSL_CAMELLIA256:
1665 		return NID_camellia_256_cbc;
1666 	case SSL_CHACHA20POLY1305:
1667 		return NID_chacha20_poly1305;
1668 	case SSL_DES:
1669 		return NID_des_cbc;
1670 	case SSL_RC4:
1671 		return NID_rc4;
1672 	case SSL_eGOST2814789CNT:
1673 		return NID_gost89_cnt;
1674 	default:
1675 		return NID_undef;
1676 	}
1677 }
1678 LSSL_ALIAS(SSL_CIPHER_get_cipher_nid);
1679 
1680 int
1681 SSL_CIPHER_get_digest_nid(const SSL_CIPHER *c)
1682 {
1683 	switch (c->algorithm_mac) {
1684 	case SSL_AEAD:
1685 		return NID_undef;
1686 	case SSL_GOST89MAC:
1687 		return NID_id_Gost28147_89_MAC;
1688 	case SSL_GOST94:
1689 		return NID_id_GostR3411_94;
1690 	case SSL_MD5:
1691 		return NID_md5;
1692 	case SSL_SHA1:
1693 		return NID_sha1;
1694 	case SSL_SHA256:
1695 		return NID_sha256;
1696 	case SSL_SHA384:
1697 		return NID_sha384;
1698 	case SSL_STREEBOG256:
1699 		return NID_id_tc26_gost3411_2012_256;
1700 	default:
1701 		return NID_undef;
1702 	}
1703 }
1704 LSSL_ALIAS(SSL_CIPHER_get_digest_nid);
1705 
1706 int
1707 SSL_CIPHER_get_kx_nid(const SSL_CIPHER *c)
1708 {
1709 	switch (c->algorithm_mkey) {
1710 	case SSL_kDHE:
1711 		return NID_kx_dhe;
1712 	case SSL_kECDHE:
1713 		return NID_kx_ecdhe;
1714 	case SSL_kGOST:
1715 		return NID_kx_gost;
1716 	case SSL_kRSA:
1717 		return NID_kx_rsa;
1718 	default:
1719 		return NID_undef;
1720 	}
1721 }
1722 LSSL_ALIAS(SSL_CIPHER_get_kx_nid);
1723 
1724 int
1725 SSL_CIPHER_get_auth_nid(const SSL_CIPHER *c)
1726 {
1727 	switch (c->algorithm_auth) {
1728 	case SSL_aNULL:
1729 		return NID_auth_null;
1730 	case SSL_aECDSA:
1731 		return NID_auth_ecdsa;
1732 	case SSL_aGOST01:
1733 		return NID_auth_gost01;
1734 	case SSL_aRSA:
1735 		return NID_auth_rsa;
1736 	default:
1737 		return NID_undef;
1738 	}
1739 }
1740 LSSL_ALIAS(SSL_CIPHER_get_auth_nid);
1741 
1742 int
1743 SSL_CIPHER_is_aead(const SSL_CIPHER *c)
1744 {
1745 	return (c->algorithm_mac & SSL_AEAD) == SSL_AEAD;
1746 }
1747 LSSL_ALIAS(SSL_CIPHER_is_aead);
1748 
1749 void *
1750 SSL_COMP_get_compression_methods(void)
1751 {
1752 	return NULL;
1753 }
1754 LSSL_ALIAS(SSL_COMP_get_compression_methods);
1755 
1756 int
1757 SSL_COMP_add_compression_method(int id, void *cm)
1758 {
1759 	return 1;
1760 }
1761 LSSL_ALIAS(SSL_COMP_add_compression_method);
1762 
1763 const char *
1764 SSL_COMP_get_name(const void *comp)
1765 {
1766 	return NULL;
1767 }
1768 LSSL_ALIAS(SSL_COMP_get_name);
1769