xref: /freebsd/crypto/openssl/ssl/t1_lib.c (revision a25896ca1270e25b657ceaa8d47d5699515f5c25)
1 /*
2  * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <openssl/objects.h>
13 #include <openssl/evp.h>
14 #include <openssl/hmac.h>
15 #include <openssl/ocsp.h>
16 #include <openssl/conf.h>
17 #include <openssl/x509v3.h>
18 #include <openssl/dh.h>
19 #include <openssl/bn.h>
20 #include "internal/nelem.h"
21 #include "ssl_locl.h"
22 #include <openssl/ct.h>
23 
24 SSL3_ENC_METHOD const TLSv1_enc_data = {
25     tls1_enc,
26     tls1_mac,
27     tls1_setup_key_block,
28     tls1_generate_master_secret,
29     tls1_change_cipher_state,
30     tls1_final_finish_mac,
31     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
32     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
33     tls1_alert_code,
34     tls1_export_keying_material,
35     0,
36     ssl3_set_handshake_header,
37     tls_close_construct_packet,
38     ssl3_handshake_write
39 };
40 
41 SSL3_ENC_METHOD const TLSv1_1_enc_data = {
42     tls1_enc,
43     tls1_mac,
44     tls1_setup_key_block,
45     tls1_generate_master_secret,
46     tls1_change_cipher_state,
47     tls1_final_finish_mac,
48     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
49     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
50     tls1_alert_code,
51     tls1_export_keying_material,
52     SSL_ENC_FLAG_EXPLICIT_IV,
53     ssl3_set_handshake_header,
54     tls_close_construct_packet,
55     ssl3_handshake_write
56 };
57 
58 SSL3_ENC_METHOD const TLSv1_2_enc_data = {
59     tls1_enc,
60     tls1_mac,
61     tls1_setup_key_block,
62     tls1_generate_master_secret,
63     tls1_change_cipher_state,
64     tls1_final_finish_mac,
65     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
66     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
67     tls1_alert_code,
68     tls1_export_keying_material,
69     SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF
70         | SSL_ENC_FLAG_TLS1_2_CIPHERS,
71     ssl3_set_handshake_header,
72     tls_close_construct_packet,
73     ssl3_handshake_write
74 };
75 
76 SSL3_ENC_METHOD const TLSv1_3_enc_data = {
77     tls13_enc,
78     tls1_mac,
79     tls13_setup_key_block,
80     tls13_generate_master_secret,
81     tls13_change_cipher_state,
82     tls13_final_finish_mac,
83     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
84     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
85     tls13_alert_code,
86     tls13_export_keying_material,
87     SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF,
88     ssl3_set_handshake_header,
89     tls_close_construct_packet,
90     ssl3_handshake_write
91 };
92 
93 long tls1_default_timeout(void)
94 {
95     /*
96      * 2 hours, the 24 hours mentioned in the TLSv1 spec is way too long for
97      * http, the cache would over fill
98      */
99     return (60 * 60 * 2);
100 }
101 
102 int tls1_new(SSL *s)
103 {
104     if (!ssl3_new(s))
105         return 0;
106     if (!s->method->ssl_clear(s))
107         return 0;
108 
109     return 1;
110 }
111 
112 void tls1_free(SSL *s)
113 {
114     OPENSSL_free(s->ext.session_ticket);
115     ssl3_free(s);
116 }
117 
118 int tls1_clear(SSL *s)
119 {
120     if (!ssl3_clear(s))
121         return 0;
122 
123     if (s->method->version == TLS_ANY_VERSION)
124         s->version = TLS_MAX_VERSION;
125     else
126         s->version = s->method->version;
127 
128     return 1;
129 }
130 
131 #ifndef OPENSSL_NO_EC
132 
133 /*
134  * Table of curve information.
135  * Do not delete entries or reorder this array! It is used as a lookup
136  * table: the index of each entry is one less than the TLS curve id.
137  */
138 static const TLS_GROUP_INFO nid_list[] = {
139     {NID_sect163k1, 80, TLS_CURVE_CHAR2}, /* sect163k1 (1) */
140     {NID_sect163r1, 80, TLS_CURVE_CHAR2}, /* sect163r1 (2) */
141     {NID_sect163r2, 80, TLS_CURVE_CHAR2}, /* sect163r2 (3) */
142     {NID_sect193r1, 80, TLS_CURVE_CHAR2}, /* sect193r1 (4) */
143     {NID_sect193r2, 80, TLS_CURVE_CHAR2}, /* sect193r2 (5) */
144     {NID_sect233k1, 112, TLS_CURVE_CHAR2}, /* sect233k1 (6) */
145     {NID_sect233r1, 112, TLS_CURVE_CHAR2}, /* sect233r1 (7) */
146     {NID_sect239k1, 112, TLS_CURVE_CHAR2}, /* sect239k1 (8) */
147     {NID_sect283k1, 128, TLS_CURVE_CHAR2}, /* sect283k1 (9) */
148     {NID_sect283r1, 128, TLS_CURVE_CHAR2}, /* sect283r1 (10) */
149     {NID_sect409k1, 192, TLS_CURVE_CHAR2}, /* sect409k1 (11) */
150     {NID_sect409r1, 192, TLS_CURVE_CHAR2}, /* sect409r1 (12) */
151     {NID_sect571k1, 256, TLS_CURVE_CHAR2}, /* sect571k1 (13) */
152     {NID_sect571r1, 256, TLS_CURVE_CHAR2}, /* sect571r1 (14) */
153     {NID_secp160k1, 80, TLS_CURVE_PRIME}, /* secp160k1 (15) */
154     {NID_secp160r1, 80, TLS_CURVE_PRIME}, /* secp160r1 (16) */
155     {NID_secp160r2, 80, TLS_CURVE_PRIME}, /* secp160r2 (17) */
156     {NID_secp192k1, 80, TLS_CURVE_PRIME}, /* secp192k1 (18) */
157     {NID_X9_62_prime192v1, 80, TLS_CURVE_PRIME}, /* secp192r1 (19) */
158     {NID_secp224k1, 112, TLS_CURVE_PRIME}, /* secp224k1 (20) */
159     {NID_secp224r1, 112, TLS_CURVE_PRIME}, /* secp224r1 (21) */
160     {NID_secp256k1, 128, TLS_CURVE_PRIME}, /* secp256k1 (22) */
161     {NID_X9_62_prime256v1, 128, TLS_CURVE_PRIME}, /* secp256r1 (23) */
162     {NID_secp384r1, 192, TLS_CURVE_PRIME}, /* secp384r1 (24) */
163     {NID_secp521r1, 256, TLS_CURVE_PRIME}, /* secp521r1 (25) */
164     {NID_brainpoolP256r1, 128, TLS_CURVE_PRIME}, /* brainpoolP256r1 (26) */
165     {NID_brainpoolP384r1, 192, TLS_CURVE_PRIME}, /* brainpoolP384r1 (27) */
166     {NID_brainpoolP512r1, 256, TLS_CURVE_PRIME}, /* brainpool512r1 (28) */
167     {EVP_PKEY_X25519, 128, TLS_CURVE_CUSTOM}, /* X25519 (29) */
168     {EVP_PKEY_X448, 224, TLS_CURVE_CUSTOM}, /* X448 (30) */
169 };
170 
171 static const unsigned char ecformats_default[] = {
172     TLSEXT_ECPOINTFORMAT_uncompressed,
173     TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
174     TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
175 };
176 
177 /* The default curves */
178 static const uint16_t eccurves_default[] = {
179     29,                      /* X25519 (29) */
180     23,                      /* secp256r1 (23) */
181     30,                      /* X448 (30) */
182     25,                      /* secp521r1 (25) */
183     24,                      /* secp384r1 (24) */
184 };
185 
186 static const uint16_t suiteb_curves[] = {
187     TLSEXT_curve_P_256,
188     TLSEXT_curve_P_384
189 };
190 
191 const TLS_GROUP_INFO *tls1_group_id_lookup(uint16_t group_id)
192 {
193     /* ECC curves from RFC 4492 and RFC 7027 */
194     if (group_id < 1 || group_id > OSSL_NELEM(nid_list))
195         return NULL;
196     return &nid_list[group_id - 1];
197 }
198 
199 static uint16_t tls1_nid2group_id(int nid)
200 {
201     size_t i;
202     for (i = 0; i < OSSL_NELEM(nid_list); i++) {
203         if (nid_list[i].nid == nid)
204             return (uint16_t)(i + 1);
205     }
206     return 0;
207 }
208 
209 /*
210  * Set *pgroups to the supported groups list and *pgroupslen to
211  * the number of groups supported.
212  */
213 void tls1_get_supported_groups(SSL *s, const uint16_t **pgroups,
214                                size_t *pgroupslen)
215 {
216 
217     /* For Suite B mode only include P-256, P-384 */
218     switch (tls1_suiteb(s)) {
219     case SSL_CERT_FLAG_SUITEB_128_LOS:
220         *pgroups = suiteb_curves;
221         *pgroupslen = OSSL_NELEM(suiteb_curves);
222         break;
223 
224     case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
225         *pgroups = suiteb_curves;
226         *pgroupslen = 1;
227         break;
228 
229     case SSL_CERT_FLAG_SUITEB_192_LOS:
230         *pgroups = suiteb_curves + 1;
231         *pgroupslen = 1;
232         break;
233 
234     default:
235         if (s->ext.supportedgroups == NULL) {
236             *pgroups = eccurves_default;
237             *pgroupslen = OSSL_NELEM(eccurves_default);
238         } else {
239             *pgroups = s->ext.supportedgroups;
240             *pgroupslen = s->ext.supportedgroups_len;
241         }
242         break;
243     }
244 }
245 
246 /* See if curve is allowed by security callback */
247 int tls_curve_allowed(SSL *s, uint16_t curve, int op)
248 {
249     const TLS_GROUP_INFO *cinfo = tls1_group_id_lookup(curve);
250     unsigned char ctmp[2];
251 
252     if (cinfo == NULL)
253         return 0;
254 # ifdef OPENSSL_NO_EC2M
255     if (cinfo->flags & TLS_CURVE_CHAR2)
256         return 0;
257 # endif
258     ctmp[0] = curve >> 8;
259     ctmp[1] = curve & 0xff;
260     return ssl_security(s, op, cinfo->secbits, cinfo->nid, (void *)ctmp);
261 }
262 
263 /* Return 1 if "id" is in "list" */
264 static int tls1_in_list(uint16_t id, const uint16_t *list, size_t listlen)
265 {
266     size_t i;
267     for (i = 0; i < listlen; i++)
268         if (list[i] == id)
269             return 1;
270     return 0;
271 }
272 
273 /*-
274  * For nmatch >= 0, return the id of the |nmatch|th shared group or 0
275  * if there is no match.
276  * For nmatch == -1, return number of matches
277  * For nmatch == -2, return the id of the group to use for
278  * a tmp key, or 0 if there is no match.
279  */
280 uint16_t tls1_shared_group(SSL *s, int nmatch)
281 {
282     const uint16_t *pref, *supp;
283     size_t num_pref, num_supp, i;
284     int k;
285 
286     /* Can't do anything on client side */
287     if (s->server == 0)
288         return 0;
289     if (nmatch == -2) {
290         if (tls1_suiteb(s)) {
291             /*
292              * For Suite B ciphersuite determines curve: we already know
293              * these are acceptable due to previous checks.
294              */
295             unsigned long cid = s->s3->tmp.new_cipher->id;
296 
297             if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
298                 return TLSEXT_curve_P_256;
299             if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
300                 return TLSEXT_curve_P_384;
301             /* Should never happen */
302             return 0;
303         }
304         /* If not Suite B just return first preference shared curve */
305         nmatch = 0;
306     }
307     /*
308      * If server preference set, our groups are the preference order
309      * otherwise peer decides.
310      */
311     if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
312         tls1_get_supported_groups(s, &pref, &num_pref);
313         tls1_get_peer_groups(s, &supp, &num_supp);
314     } else {
315         tls1_get_peer_groups(s, &pref, &num_pref);
316         tls1_get_supported_groups(s, &supp, &num_supp);
317     }
318 
319     for (k = 0, i = 0; i < num_pref; i++) {
320         uint16_t id = pref[i];
321 
322         if (!tls1_in_list(id, supp, num_supp)
323             || !tls_curve_allowed(s, id, SSL_SECOP_CURVE_SHARED))
324                     continue;
325         if (nmatch == k)
326             return id;
327          k++;
328     }
329     if (nmatch == -1)
330         return k;
331     /* Out of range (nmatch > k). */
332     return 0;
333 }
334 
335 int tls1_set_groups(uint16_t **pext, size_t *pextlen,
336                     int *groups, size_t ngroups)
337 {
338     uint16_t *glist;
339     size_t i;
340     /*
341      * Bitmap of groups included to detect duplicates: only works while group
342      * ids < 32
343      */
344     unsigned long dup_list = 0;
345 
346     if ((glist = OPENSSL_malloc(ngroups * sizeof(*glist))) == NULL) {
347         SSLerr(SSL_F_TLS1_SET_GROUPS, ERR_R_MALLOC_FAILURE);
348         return 0;
349     }
350     for (i = 0; i < ngroups; i++) {
351         unsigned long idmask;
352         uint16_t id;
353         /* TODO(TLS1.3): Convert for DH groups */
354         id = tls1_nid2group_id(groups[i]);
355         idmask = 1L << id;
356         if (!id || (dup_list & idmask)) {
357             OPENSSL_free(glist);
358             return 0;
359         }
360         dup_list |= idmask;
361         glist[i] = id;
362     }
363     OPENSSL_free(*pext);
364     *pext = glist;
365     *pextlen = ngroups;
366     return 1;
367 }
368 
369 # define MAX_CURVELIST   OSSL_NELEM(nid_list)
370 
371 typedef struct {
372     size_t nidcnt;
373     int nid_arr[MAX_CURVELIST];
374 } nid_cb_st;
375 
376 static int nid_cb(const char *elem, int len, void *arg)
377 {
378     nid_cb_st *narg = arg;
379     size_t i;
380     int nid;
381     char etmp[20];
382     if (elem == NULL)
383         return 0;
384     if (narg->nidcnt == MAX_CURVELIST)
385         return 0;
386     if (len > (int)(sizeof(etmp) - 1))
387         return 0;
388     memcpy(etmp, elem, len);
389     etmp[len] = 0;
390     nid = EC_curve_nist2nid(etmp);
391     if (nid == NID_undef)
392         nid = OBJ_sn2nid(etmp);
393     if (nid == NID_undef)
394         nid = OBJ_ln2nid(etmp);
395     if (nid == NID_undef)
396         return 0;
397     for (i = 0; i < narg->nidcnt; i++)
398         if (narg->nid_arr[i] == nid)
399             return 0;
400     narg->nid_arr[narg->nidcnt++] = nid;
401     return 1;
402 }
403 
404 /* Set groups based on a colon separate list */
405 int tls1_set_groups_list(uint16_t **pext, size_t *pextlen, const char *str)
406 {
407     nid_cb_st ncb;
408     ncb.nidcnt = 0;
409     if (!CONF_parse_list(str, ':', 1, nid_cb, &ncb))
410         return 0;
411     if (pext == NULL)
412         return 1;
413     return tls1_set_groups(pext, pextlen, ncb.nid_arr, ncb.nidcnt);
414 }
415 /* Return group id of a key */
416 static uint16_t tls1_get_group_id(EVP_PKEY *pkey)
417 {
418     EC_KEY *ec = EVP_PKEY_get0_EC_KEY(pkey);
419     const EC_GROUP *grp;
420 
421     if (ec == NULL)
422         return 0;
423     grp = EC_KEY_get0_group(ec);
424     return tls1_nid2group_id(EC_GROUP_get_curve_name(grp));
425 }
426 
427 /* Check a key is compatible with compression extension */
428 static int tls1_check_pkey_comp(SSL *s, EVP_PKEY *pkey)
429 {
430     const EC_KEY *ec;
431     const EC_GROUP *grp;
432     unsigned char comp_id;
433     size_t i;
434 
435     /* If not an EC key nothing to check */
436     if (EVP_PKEY_id(pkey) != EVP_PKEY_EC)
437         return 1;
438     ec = EVP_PKEY_get0_EC_KEY(pkey);
439     grp = EC_KEY_get0_group(ec);
440 
441     /* Get required compression id */
442     if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_UNCOMPRESSED) {
443             comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
444     } else if (SSL_IS_TLS13(s)) {
445             /*
446              * ec_point_formats extension is not used in TLSv1.3 so we ignore
447              * this check.
448              */
449             return 1;
450     } else {
451         int field_type = EC_METHOD_get_field_type(EC_GROUP_method_of(grp));
452 
453         if (field_type == NID_X9_62_prime_field)
454             comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
455         else if (field_type == NID_X9_62_characteristic_two_field)
456             comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
457         else
458             return 0;
459     }
460     /*
461      * If point formats extension present check it, otherwise everything is
462      * supported (see RFC4492).
463      */
464     if (s->session->ext.ecpointformats == NULL)
465         return 1;
466 
467     for (i = 0; i < s->session->ext.ecpointformats_len; i++) {
468         if (s->session->ext.ecpointformats[i] == comp_id)
469             return 1;
470     }
471     return 0;
472 }
473 
474 /* Check a group id matches preferences */
475 int tls1_check_group_id(SSL *s, uint16_t group_id, int check_own_groups)
476     {
477     const uint16_t *groups;
478     size_t groups_len;
479 
480     if (group_id == 0)
481         return 0;
482 
483     /* Check for Suite B compliance */
484     if (tls1_suiteb(s) && s->s3->tmp.new_cipher != NULL) {
485         unsigned long cid = s->s3->tmp.new_cipher->id;
486 
487         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256) {
488             if (group_id != TLSEXT_curve_P_256)
489                 return 0;
490         } else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384) {
491             if (group_id != TLSEXT_curve_P_384)
492                 return 0;
493         } else {
494             /* Should never happen */
495             return 0;
496         }
497     }
498 
499     if (check_own_groups) {
500         /* Check group is one of our preferences */
501         tls1_get_supported_groups(s, &groups, &groups_len);
502         if (!tls1_in_list(group_id, groups, groups_len))
503             return 0;
504     }
505 
506     if (!tls_curve_allowed(s, group_id, SSL_SECOP_CURVE_CHECK))
507         return 0;
508 
509     /* For clients, nothing more to check */
510     if (!s->server)
511         return 1;
512 
513     /* Check group is one of peers preferences */
514     tls1_get_peer_groups(s, &groups, &groups_len);
515 
516     /*
517      * RFC 4492 does not require the supported elliptic curves extension
518      * so if it is not sent we can just choose any curve.
519      * It is invalid to send an empty list in the supported groups
520      * extension, so groups_len == 0 always means no extension.
521      */
522     if (groups_len == 0)
523             return 1;
524     return tls1_in_list(group_id, groups, groups_len);
525 }
526 
527 void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
528                          size_t *num_formats)
529 {
530     /*
531      * If we have a custom point format list use it otherwise use default
532      */
533     if (s->ext.ecpointformats) {
534         *pformats = s->ext.ecpointformats;
535         *num_formats = s->ext.ecpointformats_len;
536     } else {
537         *pformats = ecformats_default;
538         /* For Suite B we don't support char2 fields */
539         if (tls1_suiteb(s))
540             *num_formats = sizeof(ecformats_default) - 1;
541         else
542             *num_formats = sizeof(ecformats_default);
543     }
544 }
545 
546 /*
547  * Check cert parameters compatible with extensions: currently just checks EC
548  * certificates have compatible curves and compression.
549  */
550 static int tls1_check_cert_param(SSL *s, X509 *x, int check_ee_md)
551 {
552     uint16_t group_id;
553     EVP_PKEY *pkey;
554     pkey = X509_get0_pubkey(x);
555     if (pkey == NULL)
556         return 0;
557     /* If not EC nothing to do */
558     if (EVP_PKEY_id(pkey) != EVP_PKEY_EC)
559         return 1;
560     /* Check compression */
561     if (!tls1_check_pkey_comp(s, pkey))
562         return 0;
563     group_id = tls1_get_group_id(pkey);
564     /*
565      * For a server we allow the certificate to not be in our list of supported
566      * groups.
567      */
568     if (!tls1_check_group_id(s, group_id, !s->server))
569         return 0;
570     /*
571      * Special case for suite B. We *MUST* sign using SHA256+P-256 or
572      * SHA384+P-384.
573      */
574     if (check_ee_md && tls1_suiteb(s)) {
575         int check_md;
576         size_t i;
577         CERT *c = s->cert;
578 
579         /* Check to see we have necessary signing algorithm */
580         if (group_id == TLSEXT_curve_P_256)
581             check_md = NID_ecdsa_with_SHA256;
582         else if (group_id == TLSEXT_curve_P_384)
583             check_md = NID_ecdsa_with_SHA384;
584         else
585             return 0;           /* Should never happen */
586         for (i = 0; i < c->shared_sigalgslen; i++) {
587             if (check_md == c->shared_sigalgs[i]->sigandhash)
588                 return 1;;
589         }
590         return 0;
591     }
592     return 1;
593 }
594 
595 /*
596  * tls1_check_ec_tmp_key - Check EC temporary key compatibility
597  * @s: SSL connection
598  * @cid: Cipher ID we're considering using
599  *
600  * Checks that the kECDHE cipher suite we're considering using
601  * is compatible with the client extensions.
602  *
603  * Returns 0 when the cipher can't be used or 1 when it can.
604  */
605 int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
606 {
607     /* If not Suite B just need a shared group */
608     if (!tls1_suiteb(s))
609         return tls1_shared_group(s, 0) != 0;
610     /*
611      * If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384, no other
612      * curves permitted.
613      */
614     if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
615         return tls1_check_group_id(s, TLSEXT_curve_P_256, 1);
616     if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
617         return tls1_check_group_id(s, TLSEXT_curve_P_384, 1);
618 
619     return 0;
620 }
621 
622 #else
623 
624 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
625 {
626     return 1;
627 }
628 
629 #endif                          /* OPENSSL_NO_EC */
630 
631 /* Default sigalg schemes */
632 static const uint16_t tls12_sigalgs[] = {
633 #ifndef OPENSSL_NO_EC
634     TLSEXT_SIGALG_ecdsa_secp256r1_sha256,
635     TLSEXT_SIGALG_ecdsa_secp384r1_sha384,
636     TLSEXT_SIGALG_ecdsa_secp521r1_sha512,
637     TLSEXT_SIGALG_ed25519,
638     TLSEXT_SIGALG_ed448,
639 #endif
640 
641     TLSEXT_SIGALG_rsa_pss_pss_sha256,
642     TLSEXT_SIGALG_rsa_pss_pss_sha384,
643     TLSEXT_SIGALG_rsa_pss_pss_sha512,
644     TLSEXT_SIGALG_rsa_pss_rsae_sha256,
645     TLSEXT_SIGALG_rsa_pss_rsae_sha384,
646     TLSEXT_SIGALG_rsa_pss_rsae_sha512,
647 
648     TLSEXT_SIGALG_rsa_pkcs1_sha256,
649     TLSEXT_SIGALG_rsa_pkcs1_sha384,
650     TLSEXT_SIGALG_rsa_pkcs1_sha512,
651 
652 #ifndef OPENSSL_NO_EC
653     TLSEXT_SIGALG_ecdsa_sha224,
654     TLSEXT_SIGALG_ecdsa_sha1,
655 #endif
656     TLSEXT_SIGALG_rsa_pkcs1_sha224,
657     TLSEXT_SIGALG_rsa_pkcs1_sha1,
658 #ifndef OPENSSL_NO_DSA
659     TLSEXT_SIGALG_dsa_sha224,
660     TLSEXT_SIGALG_dsa_sha1,
661 
662     TLSEXT_SIGALG_dsa_sha256,
663     TLSEXT_SIGALG_dsa_sha384,
664     TLSEXT_SIGALG_dsa_sha512,
665 #endif
666 #ifndef OPENSSL_NO_GOST
667     TLSEXT_SIGALG_gostr34102012_256_gostr34112012_256,
668     TLSEXT_SIGALG_gostr34102012_512_gostr34112012_512,
669     TLSEXT_SIGALG_gostr34102001_gostr3411,
670 #endif
671 };
672 
673 #ifndef OPENSSL_NO_EC
674 static const uint16_t suiteb_sigalgs[] = {
675     TLSEXT_SIGALG_ecdsa_secp256r1_sha256,
676     TLSEXT_SIGALG_ecdsa_secp384r1_sha384
677 };
678 #endif
679 
680 static const SIGALG_LOOKUP sigalg_lookup_tbl[] = {
681 #ifndef OPENSSL_NO_EC
682     {"ecdsa_secp256r1_sha256", TLSEXT_SIGALG_ecdsa_secp256r1_sha256,
683      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
684      NID_ecdsa_with_SHA256, NID_X9_62_prime256v1},
685     {"ecdsa_secp384r1_sha384", TLSEXT_SIGALG_ecdsa_secp384r1_sha384,
686      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
687      NID_ecdsa_with_SHA384, NID_secp384r1},
688     {"ecdsa_secp521r1_sha512", TLSEXT_SIGALG_ecdsa_secp521r1_sha512,
689      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
690      NID_ecdsa_with_SHA512, NID_secp521r1},
691     {"ed25519", TLSEXT_SIGALG_ed25519,
692      NID_undef, -1, EVP_PKEY_ED25519, SSL_PKEY_ED25519,
693      NID_undef, NID_undef},
694     {"ed448", TLSEXT_SIGALG_ed448,
695      NID_undef, -1, EVP_PKEY_ED448, SSL_PKEY_ED448,
696      NID_undef, NID_undef},
697     {NULL, TLSEXT_SIGALG_ecdsa_sha224,
698      NID_sha224, SSL_MD_SHA224_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
699      NID_ecdsa_with_SHA224, NID_undef},
700     {NULL, TLSEXT_SIGALG_ecdsa_sha1,
701      NID_sha1, SSL_MD_SHA1_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
702      NID_ecdsa_with_SHA1, NID_undef},
703 #endif
704     {"rsa_pss_rsae_sha256", TLSEXT_SIGALG_rsa_pss_rsae_sha256,
705      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA,
706      NID_undef, NID_undef},
707     {"rsa_pss_rsae_sha384", TLSEXT_SIGALG_rsa_pss_rsae_sha384,
708      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA,
709      NID_undef, NID_undef},
710     {"rsa_pss_rsae_sha512", TLSEXT_SIGALG_rsa_pss_rsae_sha512,
711      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA,
712      NID_undef, NID_undef},
713     {"rsa_pss_pss_sha256", TLSEXT_SIGALG_rsa_pss_pss_sha256,
714      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA_PSS_SIGN,
715      NID_undef, NID_undef},
716     {"rsa_pss_pss_sha384", TLSEXT_SIGALG_rsa_pss_pss_sha384,
717      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA_PSS_SIGN,
718      NID_undef, NID_undef},
719     {"rsa_pss_pss_sha512", TLSEXT_SIGALG_rsa_pss_pss_sha512,
720      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA_PSS_SIGN,
721      NID_undef, NID_undef},
722     {"rsa_pkcs1_sha256", TLSEXT_SIGALG_rsa_pkcs1_sha256,
723      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
724      NID_sha256WithRSAEncryption, NID_undef},
725     {"rsa_pkcs1_sha384", TLSEXT_SIGALG_rsa_pkcs1_sha384,
726      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
727      NID_sha384WithRSAEncryption, NID_undef},
728     {"rsa_pkcs1_sha512", TLSEXT_SIGALG_rsa_pkcs1_sha512,
729      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
730      NID_sha512WithRSAEncryption, NID_undef},
731     {"rsa_pkcs1_sha224", TLSEXT_SIGALG_rsa_pkcs1_sha224,
732      NID_sha224, SSL_MD_SHA224_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
733      NID_sha224WithRSAEncryption, NID_undef},
734     {"rsa_pkcs1_sha1", TLSEXT_SIGALG_rsa_pkcs1_sha1,
735      NID_sha1, SSL_MD_SHA1_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
736      NID_sha1WithRSAEncryption, NID_undef},
737 #ifndef OPENSSL_NO_DSA
738     {NULL, TLSEXT_SIGALG_dsa_sha256,
739      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
740      NID_dsa_with_SHA256, NID_undef},
741     {NULL, TLSEXT_SIGALG_dsa_sha384,
742      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
743      NID_undef, NID_undef},
744     {NULL, TLSEXT_SIGALG_dsa_sha512,
745      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
746      NID_undef, NID_undef},
747     {NULL, TLSEXT_SIGALG_dsa_sha224,
748      NID_sha224, SSL_MD_SHA224_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
749      NID_undef, NID_undef},
750     {NULL, TLSEXT_SIGALG_dsa_sha1,
751      NID_sha1, SSL_MD_SHA1_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
752      NID_dsaWithSHA1, NID_undef},
753 #endif
754 #ifndef OPENSSL_NO_GOST
755     {NULL, TLSEXT_SIGALG_gostr34102012_256_gostr34112012_256,
756      NID_id_GostR3411_2012_256, SSL_MD_GOST12_256_IDX,
757      NID_id_GostR3410_2012_256, SSL_PKEY_GOST12_256,
758      NID_undef, NID_undef},
759     {NULL, TLSEXT_SIGALG_gostr34102012_512_gostr34112012_512,
760      NID_id_GostR3411_2012_512, SSL_MD_GOST12_512_IDX,
761      NID_id_GostR3410_2012_512, SSL_PKEY_GOST12_512,
762      NID_undef, NID_undef},
763     {NULL, TLSEXT_SIGALG_gostr34102001_gostr3411,
764      NID_id_GostR3411_94, SSL_MD_GOST94_IDX,
765      NID_id_GostR3410_2001, SSL_PKEY_GOST01,
766      NID_undef, NID_undef}
767 #endif
768 };
769 /* Legacy sigalgs for TLS < 1.2 RSA TLS signatures */
770 static const SIGALG_LOOKUP legacy_rsa_sigalg = {
771     "rsa_pkcs1_md5_sha1", 0,
772      NID_md5_sha1, SSL_MD_MD5_SHA1_IDX,
773      EVP_PKEY_RSA, SSL_PKEY_RSA,
774      NID_undef, NID_undef
775 };
776 
777 /*
778  * Default signature algorithm values used if signature algorithms not present.
779  * From RFC5246. Note: order must match certificate index order.
780  */
781 static const uint16_t tls_default_sigalg[] = {
782     TLSEXT_SIGALG_rsa_pkcs1_sha1, /* SSL_PKEY_RSA */
783     0, /* SSL_PKEY_RSA_PSS_SIGN */
784     TLSEXT_SIGALG_dsa_sha1, /* SSL_PKEY_DSA_SIGN */
785     TLSEXT_SIGALG_ecdsa_sha1, /* SSL_PKEY_ECC */
786     TLSEXT_SIGALG_gostr34102001_gostr3411, /* SSL_PKEY_GOST01 */
787     TLSEXT_SIGALG_gostr34102012_256_gostr34112012_256, /* SSL_PKEY_GOST12_256 */
788     TLSEXT_SIGALG_gostr34102012_512_gostr34112012_512, /* SSL_PKEY_GOST12_512 */
789     0, /* SSL_PKEY_ED25519 */
790     0, /* SSL_PKEY_ED448 */
791 };
792 
793 /* Lookup TLS signature algorithm */
794 static const SIGALG_LOOKUP *tls1_lookup_sigalg(uint16_t sigalg)
795 {
796     size_t i;
797     const SIGALG_LOOKUP *s;
798 
799     for (i = 0, s = sigalg_lookup_tbl; i < OSSL_NELEM(sigalg_lookup_tbl);
800          i++, s++) {
801         if (s->sigalg == sigalg)
802             return s;
803     }
804     return NULL;
805 }
806 /* Lookup hash: return 0 if invalid or not enabled */
807 int tls1_lookup_md(const SIGALG_LOOKUP *lu, const EVP_MD **pmd)
808 {
809     const EVP_MD *md;
810     if (lu == NULL)
811         return 0;
812     /* lu->hash == NID_undef means no associated digest */
813     if (lu->hash == NID_undef) {
814         md = NULL;
815     } else {
816         md = ssl_md(lu->hash_idx);
817         if (md == NULL)
818             return 0;
819     }
820     if (pmd)
821         *pmd = md;
822     return 1;
823 }
824 
825 /*
826  * Check if key is large enough to generate RSA-PSS signature.
827  *
828  * The key must greater than or equal to 2 * hash length + 2.
829  * SHA512 has a hash length of 64 bytes, which is incompatible
830  * with a 128 byte (1024 bit) key.
831  */
832 #define RSA_PSS_MINIMUM_KEY_SIZE(md) (2 * EVP_MD_size(md) + 2)
833 static int rsa_pss_check_min_key_size(const RSA *rsa, const SIGALG_LOOKUP *lu)
834 {
835     const EVP_MD *md;
836 
837     if (rsa == NULL)
838         return 0;
839     if (!tls1_lookup_md(lu, &md) || md == NULL)
840         return 0;
841     if (RSA_size(rsa) < RSA_PSS_MINIMUM_KEY_SIZE(md))
842         return 0;
843     return 1;
844 }
845 
846 /*
847  * Return a signature algorithm for TLS < 1.2 where the signature type
848  * is fixed by the certificate type.
849  */
850 static const SIGALG_LOOKUP *tls1_get_legacy_sigalg(const SSL *s, int idx)
851 {
852     if (idx == -1) {
853         if (s->server) {
854             size_t i;
855 
856             /* Work out index corresponding to ciphersuite */
857             for (i = 0; i < SSL_PKEY_NUM; i++) {
858                 const SSL_CERT_LOOKUP *clu = ssl_cert_lookup_by_idx(i);
859 
860                 if (clu->amask & s->s3->tmp.new_cipher->algorithm_auth) {
861                     idx = i;
862                     break;
863                 }
864             }
865 
866             /*
867              * Some GOST ciphersuites allow more than one signature algorithms
868              * */
869             if (idx == SSL_PKEY_GOST01 && s->s3->tmp.new_cipher->algorithm_auth != SSL_aGOST01) {
870                 int real_idx;
871 
872                 for (real_idx = SSL_PKEY_GOST12_512; real_idx >= SSL_PKEY_GOST01;
873                      real_idx--) {
874                     if (s->cert->pkeys[real_idx].privatekey != NULL) {
875                         idx = real_idx;
876                         break;
877                     }
878                 }
879             }
880         } else {
881             idx = s->cert->key - s->cert->pkeys;
882         }
883     }
884     if (idx < 0 || idx >= (int)OSSL_NELEM(tls_default_sigalg))
885         return NULL;
886     if (SSL_USE_SIGALGS(s) || idx != SSL_PKEY_RSA) {
887         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(tls_default_sigalg[idx]);
888 
889         if (!tls1_lookup_md(lu, NULL))
890             return NULL;
891         return lu;
892     }
893     return &legacy_rsa_sigalg;
894 }
895 /* Set peer sigalg based key type */
896 int tls1_set_peer_legacy_sigalg(SSL *s, const EVP_PKEY *pkey)
897 {
898     size_t idx;
899     const SIGALG_LOOKUP *lu;
900 
901     if (ssl_cert_lookup_by_pkey(pkey, &idx) == NULL)
902         return 0;
903     lu = tls1_get_legacy_sigalg(s, idx);
904     if (lu == NULL)
905         return 0;
906     s->s3->tmp.peer_sigalg = lu;
907     return 1;
908 }
909 
910 size_t tls12_get_psigalgs(SSL *s, int sent, const uint16_t **psigs)
911 {
912     /*
913      * If Suite B mode use Suite B sigalgs only, ignore any other
914      * preferences.
915      */
916 #ifndef OPENSSL_NO_EC
917     switch (tls1_suiteb(s)) {
918     case SSL_CERT_FLAG_SUITEB_128_LOS:
919         *psigs = suiteb_sigalgs;
920         return OSSL_NELEM(suiteb_sigalgs);
921 
922     case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
923         *psigs = suiteb_sigalgs;
924         return 1;
925 
926     case SSL_CERT_FLAG_SUITEB_192_LOS:
927         *psigs = suiteb_sigalgs + 1;
928         return 1;
929     }
930 #endif
931     /*
932      *  We use client_sigalgs (if not NULL) if we're a server
933      *  and sending a certificate request or if we're a client and
934      *  determining which shared algorithm to use.
935      */
936     if ((s->server == sent) && s->cert->client_sigalgs != NULL) {
937         *psigs = s->cert->client_sigalgs;
938         return s->cert->client_sigalgslen;
939     } else if (s->cert->conf_sigalgs) {
940         *psigs = s->cert->conf_sigalgs;
941         return s->cert->conf_sigalgslen;
942     } else {
943         *psigs = tls12_sigalgs;
944         return OSSL_NELEM(tls12_sigalgs);
945     }
946 }
947 
948 /*
949  * Check signature algorithm is consistent with sent supported signature
950  * algorithms and if so set relevant digest and signature scheme in
951  * s.
952  */
953 int tls12_check_peer_sigalg(SSL *s, uint16_t sig, EVP_PKEY *pkey)
954 {
955     const uint16_t *sent_sigs;
956     const EVP_MD *md = NULL;
957     char sigalgstr[2];
958     size_t sent_sigslen, i, cidx;
959     int pkeyid = EVP_PKEY_id(pkey);
960     const SIGALG_LOOKUP *lu;
961 
962     /* Should never happen */
963     if (pkeyid == -1)
964         return -1;
965     if (SSL_IS_TLS13(s)) {
966         /* Disallow DSA for TLS 1.3 */
967         if (pkeyid == EVP_PKEY_DSA) {
968             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS12_CHECK_PEER_SIGALG,
969                      SSL_R_WRONG_SIGNATURE_TYPE);
970             return 0;
971         }
972         /* Only allow PSS for TLS 1.3 */
973         if (pkeyid == EVP_PKEY_RSA)
974             pkeyid = EVP_PKEY_RSA_PSS;
975     }
976     lu = tls1_lookup_sigalg(sig);
977     /*
978      * Check sigalgs is known. Disallow SHA1/SHA224 with TLS 1.3. Check key type
979      * is consistent with signature: RSA keys can be used for RSA-PSS
980      */
981     if (lu == NULL
982         || (SSL_IS_TLS13(s) && (lu->hash == NID_sha1 || lu->hash == NID_sha224))
983         || (pkeyid != lu->sig
984         && (lu->sig != EVP_PKEY_RSA_PSS || pkeyid != EVP_PKEY_RSA))) {
985         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS12_CHECK_PEER_SIGALG,
986                  SSL_R_WRONG_SIGNATURE_TYPE);
987         return 0;
988     }
989     /* Check the sigalg is consistent with the key OID */
990     if (!ssl_cert_lookup_by_nid(EVP_PKEY_id(pkey), &cidx)
991             || lu->sig_idx != (int)cidx) {
992         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS12_CHECK_PEER_SIGALG,
993                  SSL_R_WRONG_SIGNATURE_TYPE);
994         return 0;
995     }
996 
997 #ifndef OPENSSL_NO_EC
998     if (pkeyid == EVP_PKEY_EC) {
999 
1000         /* Check point compression is permitted */
1001         if (!tls1_check_pkey_comp(s, pkey)) {
1002             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1003                      SSL_F_TLS12_CHECK_PEER_SIGALG,
1004                      SSL_R_ILLEGAL_POINT_COMPRESSION);
1005             return 0;
1006         }
1007 
1008         /* For TLS 1.3 or Suite B check curve matches signature algorithm */
1009         if (SSL_IS_TLS13(s) || tls1_suiteb(s)) {
1010             EC_KEY *ec = EVP_PKEY_get0_EC_KEY(pkey);
1011             int curve = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec));
1012 
1013             if (lu->curve != NID_undef && curve != lu->curve) {
1014                 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1015                          SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_CURVE);
1016                 return 0;
1017             }
1018         }
1019         if (!SSL_IS_TLS13(s)) {
1020             /* Check curve matches extensions */
1021             if (!tls1_check_group_id(s, tls1_get_group_id(pkey), 1)) {
1022                 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1023                          SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_CURVE);
1024                 return 0;
1025             }
1026             if (tls1_suiteb(s)) {
1027                 /* Check sigalg matches a permissible Suite B value */
1028                 if (sig != TLSEXT_SIGALG_ecdsa_secp256r1_sha256
1029                     && sig != TLSEXT_SIGALG_ecdsa_secp384r1_sha384) {
1030                     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
1031                              SSL_F_TLS12_CHECK_PEER_SIGALG,
1032                              SSL_R_WRONG_SIGNATURE_TYPE);
1033                     return 0;
1034                 }
1035             }
1036         }
1037     } else if (tls1_suiteb(s)) {
1038         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS12_CHECK_PEER_SIGALG,
1039                  SSL_R_WRONG_SIGNATURE_TYPE);
1040         return 0;
1041     }
1042 #endif
1043 
1044     /* Check signature matches a type we sent */
1045     sent_sigslen = tls12_get_psigalgs(s, 1, &sent_sigs);
1046     for (i = 0; i < sent_sigslen; i++, sent_sigs++) {
1047         if (sig == *sent_sigs)
1048             break;
1049     }
1050     /* Allow fallback to SHA1 if not strict mode */
1051     if (i == sent_sigslen && (lu->hash != NID_sha1
1052         || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
1053         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS12_CHECK_PEER_SIGALG,
1054                  SSL_R_WRONG_SIGNATURE_TYPE);
1055         return 0;
1056     }
1057     if (!tls1_lookup_md(lu, &md)) {
1058         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS12_CHECK_PEER_SIGALG,
1059                  SSL_R_UNKNOWN_DIGEST);
1060         return 0;
1061     }
1062     if (md != NULL) {
1063         /*
1064          * Make sure security callback allows algorithm. For historical
1065          * reasons we have to pass the sigalg as a two byte char array.
1066          */
1067         sigalgstr[0] = (sig >> 8) & 0xff;
1068         sigalgstr[1] = sig & 0xff;
1069         if (!ssl_security(s, SSL_SECOP_SIGALG_CHECK,
1070                     EVP_MD_size(md) * 4, EVP_MD_type(md),
1071                     (void *)sigalgstr)) {
1072             SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS12_CHECK_PEER_SIGALG,
1073                      SSL_R_WRONG_SIGNATURE_TYPE);
1074             return 0;
1075         }
1076     }
1077     /* Store the sigalg the peer uses */
1078     s->s3->tmp.peer_sigalg = lu;
1079     return 1;
1080 }
1081 
1082 int SSL_get_peer_signature_type_nid(const SSL *s, int *pnid)
1083 {
1084     if (s->s3->tmp.peer_sigalg == NULL)
1085         return 0;
1086     *pnid = s->s3->tmp.peer_sigalg->sig;
1087     return 1;
1088 }
1089 
1090 /*
1091  * Set a mask of disabled algorithms: an algorithm is disabled if it isn't
1092  * supported, doesn't appear in supported signature algorithms, isn't supported
1093  * by the enabled protocol versions or by the security level.
1094  *
1095  * This function should only be used for checking which ciphers are supported
1096  * by the client.
1097  *
1098  * Call ssl_cipher_disabled() to check that it's enabled or not.
1099  */
1100 int ssl_set_client_disabled(SSL *s)
1101 {
1102     s->s3->tmp.mask_a = 0;
1103     s->s3->tmp.mask_k = 0;
1104     ssl_set_sig_mask(&s->s3->tmp.mask_a, s, SSL_SECOP_SIGALG_MASK);
1105     if (ssl_get_min_max_version(s, &s->s3->tmp.min_ver,
1106                                 &s->s3->tmp.max_ver, NULL) != 0)
1107         return 0;
1108 #ifndef OPENSSL_NO_PSK
1109     /* with PSK there must be client callback set */
1110     if (!s->psk_client_callback) {
1111         s->s3->tmp.mask_a |= SSL_aPSK;
1112         s->s3->tmp.mask_k |= SSL_PSK;
1113     }
1114 #endif                          /* OPENSSL_NO_PSK */
1115 #ifndef OPENSSL_NO_SRP
1116     if (!(s->srp_ctx.srp_Mask & SSL_kSRP)) {
1117         s->s3->tmp.mask_a |= SSL_aSRP;
1118         s->s3->tmp.mask_k |= SSL_kSRP;
1119     }
1120 #endif
1121     return 1;
1122 }
1123 
1124 /*
1125  * ssl_cipher_disabled - check that a cipher is disabled or not
1126  * @s: SSL connection that you want to use the cipher on
1127  * @c: cipher to check
1128  * @op: Security check that you want to do
1129  * @ecdhe: If set to 1 then TLSv1 ECDHE ciphers are also allowed in SSLv3
1130  *
1131  * Returns 1 when it's disabled, 0 when enabled.
1132  */
1133 int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op, int ecdhe)
1134 {
1135     if (c->algorithm_mkey & s->s3->tmp.mask_k
1136         || c->algorithm_auth & s->s3->tmp.mask_a)
1137         return 1;
1138     if (s->s3->tmp.max_ver == 0)
1139         return 1;
1140     if (!SSL_IS_DTLS(s)) {
1141         int min_tls = c->min_tls;
1142 
1143         /*
1144          * For historical reasons we will allow ECHDE to be selected by a server
1145          * in SSLv3 if we are a client
1146          */
1147         if (min_tls == TLS1_VERSION && ecdhe
1148                 && (c->algorithm_mkey & (SSL_kECDHE | SSL_kECDHEPSK)) != 0)
1149             min_tls = SSL3_VERSION;
1150 
1151         if ((min_tls > s->s3->tmp.max_ver) || (c->max_tls < s->s3->tmp.min_ver))
1152             return 1;
1153     }
1154     if (SSL_IS_DTLS(s) && (DTLS_VERSION_GT(c->min_dtls, s->s3->tmp.max_ver)
1155                            || DTLS_VERSION_LT(c->max_dtls, s->s3->tmp.min_ver)))
1156         return 1;
1157 
1158     return !ssl_security(s, op, c->strength_bits, 0, (void *)c);
1159 }
1160 
1161 int tls_use_ticket(SSL *s)
1162 {
1163     if ((s->options & SSL_OP_NO_TICKET))
1164         return 0;
1165     return ssl_security(s, SSL_SECOP_TICKET, 0, 0, NULL);
1166 }
1167 
1168 int tls1_set_server_sigalgs(SSL *s)
1169 {
1170     size_t i;
1171 
1172     /* Clear any shared signature algorithms */
1173     OPENSSL_free(s->cert->shared_sigalgs);
1174     s->cert->shared_sigalgs = NULL;
1175     s->cert->shared_sigalgslen = 0;
1176     /* Clear certificate validity flags */
1177     for (i = 0; i < SSL_PKEY_NUM; i++)
1178         s->s3->tmp.valid_flags[i] = 0;
1179     /*
1180      * If peer sent no signature algorithms check to see if we support
1181      * the default algorithm for each certificate type
1182      */
1183     if (s->s3->tmp.peer_cert_sigalgs == NULL
1184             && s->s3->tmp.peer_sigalgs == NULL) {
1185         const uint16_t *sent_sigs;
1186         size_t sent_sigslen = tls12_get_psigalgs(s, 1, &sent_sigs);
1187 
1188         for (i = 0; i < SSL_PKEY_NUM; i++) {
1189             const SIGALG_LOOKUP *lu = tls1_get_legacy_sigalg(s, i);
1190             size_t j;
1191 
1192             if (lu == NULL)
1193                 continue;
1194             /* Check default matches a type we sent */
1195             for (j = 0; j < sent_sigslen; j++) {
1196                 if (lu->sigalg == sent_sigs[j]) {
1197                         s->s3->tmp.valid_flags[i] = CERT_PKEY_SIGN;
1198                         break;
1199                 }
1200             }
1201         }
1202         return 1;
1203     }
1204 
1205     if (!tls1_process_sigalgs(s)) {
1206         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1207                  SSL_F_TLS1_SET_SERVER_SIGALGS, ERR_R_INTERNAL_ERROR);
1208         return 0;
1209     }
1210     if (s->cert->shared_sigalgs != NULL)
1211         return 1;
1212 
1213     /* Fatal error if no shared signature algorithms */
1214     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS1_SET_SERVER_SIGALGS,
1215              SSL_R_NO_SHARED_SIGNATURE_ALGORITHMS);
1216     return 0;
1217 }
1218 
1219 /*-
1220  * Gets the ticket information supplied by the client if any.
1221  *
1222  *   hello: The parsed ClientHello data
1223  *   ret: (output) on return, if a ticket was decrypted, then this is set to
1224  *       point to the resulting session.
1225  */
1226 SSL_TICKET_STATUS tls_get_ticket_from_client(SSL *s, CLIENTHELLO_MSG *hello,
1227                                              SSL_SESSION **ret)
1228 {
1229     size_t size;
1230     RAW_EXTENSION *ticketext;
1231 
1232     *ret = NULL;
1233     s->ext.ticket_expected = 0;
1234 
1235     /*
1236      * If tickets disabled or not supported by the protocol version
1237      * (e.g. TLSv1.3) behave as if no ticket present to permit stateful
1238      * resumption.
1239      */
1240     if (s->version <= SSL3_VERSION || !tls_use_ticket(s))
1241         return SSL_TICKET_NONE;
1242 
1243     ticketext = &hello->pre_proc_exts[TLSEXT_IDX_session_ticket];
1244     if (!ticketext->present)
1245         return SSL_TICKET_NONE;
1246 
1247     size = PACKET_remaining(&ticketext->data);
1248 
1249     return tls_decrypt_ticket(s, PACKET_data(&ticketext->data), size,
1250                               hello->session_id, hello->session_id_len, ret);
1251 }
1252 
1253 /*-
1254  * tls_decrypt_ticket attempts to decrypt a session ticket.
1255  *
1256  * If s->tls_session_secret_cb is set and we're not doing TLSv1.3 then we are
1257  * expecting a pre-shared key ciphersuite, in which case we have no use for
1258  * session tickets and one will never be decrypted, nor will
1259  * s->ext.ticket_expected be set to 1.
1260  *
1261  * Side effects:
1262  *   Sets s->ext.ticket_expected to 1 if the server will have to issue
1263  *   a new session ticket to the client because the client indicated support
1264  *   (and s->tls_session_secret_cb is NULL) but the client either doesn't have
1265  *   a session ticket or we couldn't use the one it gave us, or if
1266  *   s->ctx->ext.ticket_key_cb asked to renew the client's ticket.
1267  *   Otherwise, s->ext.ticket_expected is set to 0.
1268  *
1269  *   etick: points to the body of the session ticket extension.
1270  *   eticklen: the length of the session tickets extension.
1271  *   sess_id: points at the session ID.
1272  *   sesslen: the length of the session ID.
1273  *   psess: (output) on return, if a ticket was decrypted, then this is set to
1274  *       point to the resulting session.
1275  */
1276 SSL_TICKET_STATUS tls_decrypt_ticket(SSL *s, const unsigned char *etick,
1277                                      size_t eticklen, const unsigned char *sess_id,
1278                                      size_t sesslen, SSL_SESSION **psess)
1279 {
1280     SSL_SESSION *sess = NULL;
1281     unsigned char *sdec;
1282     const unsigned char *p;
1283     int slen, renew_ticket = 0, declen;
1284     SSL_TICKET_STATUS ret = SSL_TICKET_FATAL_ERR_OTHER;
1285     size_t mlen;
1286     unsigned char tick_hmac[EVP_MAX_MD_SIZE];
1287     HMAC_CTX *hctx = NULL;
1288     EVP_CIPHER_CTX *ctx = NULL;
1289     SSL_CTX *tctx = s->session_ctx;
1290 
1291     if (eticklen == 0) {
1292         /*
1293          * The client will accept a ticket but doesn't currently have
1294          * one (TLSv1.2 and below), or treated as a fatal error in TLSv1.3
1295          */
1296         ret = SSL_TICKET_EMPTY;
1297         goto end;
1298     }
1299     if (!SSL_IS_TLS13(s) && s->ext.session_secret_cb) {
1300         /*
1301          * Indicate that the ticket couldn't be decrypted rather than
1302          * generating the session from ticket now, trigger
1303          * abbreviated handshake based on external mechanism to
1304          * calculate the master secret later.
1305          */
1306         ret = SSL_TICKET_NO_DECRYPT;
1307         goto end;
1308     }
1309 
1310     /* Need at least keyname + iv */
1311     if (eticklen < TLSEXT_KEYNAME_LENGTH + EVP_MAX_IV_LENGTH) {
1312         ret = SSL_TICKET_NO_DECRYPT;
1313         goto end;
1314     }
1315 
1316     /* Initialize session ticket encryption and HMAC contexts */
1317     hctx = HMAC_CTX_new();
1318     if (hctx == NULL) {
1319         ret = SSL_TICKET_FATAL_ERR_MALLOC;
1320         goto end;
1321     }
1322     ctx = EVP_CIPHER_CTX_new();
1323     if (ctx == NULL) {
1324         ret = SSL_TICKET_FATAL_ERR_MALLOC;
1325         goto end;
1326     }
1327     if (tctx->ext.ticket_key_cb) {
1328         unsigned char *nctick = (unsigned char *)etick;
1329         int rv = tctx->ext.ticket_key_cb(s, nctick,
1330                                          nctick + TLSEXT_KEYNAME_LENGTH,
1331                                          ctx, hctx, 0);
1332         if (rv < 0) {
1333             ret = SSL_TICKET_FATAL_ERR_OTHER;
1334             goto end;
1335         }
1336         if (rv == 0) {
1337             ret = SSL_TICKET_NO_DECRYPT;
1338             goto end;
1339         }
1340         if (rv == 2)
1341             renew_ticket = 1;
1342     } else {
1343         /* Check key name matches */
1344         if (memcmp(etick, tctx->ext.tick_key_name,
1345                    TLSEXT_KEYNAME_LENGTH) != 0) {
1346             ret = SSL_TICKET_NO_DECRYPT;
1347             goto end;
1348         }
1349         if (HMAC_Init_ex(hctx, tctx->ext.secure->tick_hmac_key,
1350                          sizeof(tctx->ext.secure->tick_hmac_key),
1351                          EVP_sha256(), NULL) <= 0
1352             || EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL,
1353                                   tctx->ext.secure->tick_aes_key,
1354                                   etick + TLSEXT_KEYNAME_LENGTH) <= 0) {
1355             ret = SSL_TICKET_FATAL_ERR_OTHER;
1356             goto end;
1357         }
1358         if (SSL_IS_TLS13(s))
1359             renew_ticket = 1;
1360     }
1361     /*
1362      * Attempt to process session ticket, first conduct sanity and integrity
1363      * checks on ticket.
1364      */
1365     mlen = HMAC_size(hctx);
1366     if (mlen == 0) {
1367         ret = SSL_TICKET_FATAL_ERR_OTHER;
1368         goto end;
1369     }
1370 
1371     /* Sanity check ticket length: must exceed keyname + IV + HMAC */
1372     if (eticklen <=
1373         TLSEXT_KEYNAME_LENGTH + EVP_CIPHER_CTX_iv_length(ctx) + mlen) {
1374         ret = SSL_TICKET_NO_DECRYPT;
1375         goto end;
1376     }
1377     eticklen -= mlen;
1378     /* Check HMAC of encrypted ticket */
1379     if (HMAC_Update(hctx, etick, eticklen) <= 0
1380         || HMAC_Final(hctx, tick_hmac, NULL) <= 0) {
1381         ret = SSL_TICKET_FATAL_ERR_OTHER;
1382         goto end;
1383     }
1384 
1385     if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen)) {
1386         ret = SSL_TICKET_NO_DECRYPT;
1387         goto end;
1388     }
1389     /* Attempt to decrypt session data */
1390     /* Move p after IV to start of encrypted ticket, update length */
1391     p = etick + TLSEXT_KEYNAME_LENGTH + EVP_CIPHER_CTX_iv_length(ctx);
1392     eticklen -= TLSEXT_KEYNAME_LENGTH + EVP_CIPHER_CTX_iv_length(ctx);
1393     sdec = OPENSSL_malloc(eticklen);
1394     if (sdec == NULL || EVP_DecryptUpdate(ctx, sdec, &slen, p,
1395                                           (int)eticklen) <= 0) {
1396         OPENSSL_free(sdec);
1397         ret = SSL_TICKET_FATAL_ERR_OTHER;
1398         goto end;
1399     }
1400     if (EVP_DecryptFinal(ctx, sdec + slen, &declen) <= 0) {
1401         OPENSSL_free(sdec);
1402         ret = SSL_TICKET_NO_DECRYPT;
1403         goto end;
1404     }
1405     slen += declen;
1406     p = sdec;
1407 
1408     sess = d2i_SSL_SESSION(NULL, &p, slen);
1409     slen -= p - sdec;
1410     OPENSSL_free(sdec);
1411     if (sess) {
1412         /* Some additional consistency checks */
1413         if (slen != 0) {
1414             SSL_SESSION_free(sess);
1415             sess = NULL;
1416             ret = SSL_TICKET_NO_DECRYPT;
1417             goto end;
1418         }
1419         /*
1420          * The session ID, if non-empty, is used by some clients to detect
1421          * that the ticket has been accepted. So we copy it to the session
1422          * structure. If it is empty set length to zero as required by
1423          * standard.
1424          */
1425         if (sesslen) {
1426             memcpy(sess->session_id, sess_id, sesslen);
1427             sess->session_id_length = sesslen;
1428         }
1429         if (renew_ticket)
1430             ret = SSL_TICKET_SUCCESS_RENEW;
1431         else
1432             ret = SSL_TICKET_SUCCESS;
1433         goto end;
1434     }
1435     ERR_clear_error();
1436     /*
1437      * For session parse failure, indicate that we need to send a new ticket.
1438      */
1439     ret = SSL_TICKET_NO_DECRYPT;
1440 
1441  end:
1442     EVP_CIPHER_CTX_free(ctx);
1443     HMAC_CTX_free(hctx);
1444 
1445     /*
1446      * If set, the decrypt_ticket_cb() is called unless a fatal error was
1447      * detected above. The callback is responsible for checking |ret| before it
1448      * performs any action
1449      */
1450     if (s->session_ctx->decrypt_ticket_cb != NULL
1451             && (ret == SSL_TICKET_EMPTY
1452                 || ret == SSL_TICKET_NO_DECRYPT
1453                 || ret == SSL_TICKET_SUCCESS
1454                 || ret == SSL_TICKET_SUCCESS_RENEW)) {
1455         size_t keyname_len = eticklen;
1456         int retcb;
1457 
1458         if (keyname_len > TLSEXT_KEYNAME_LENGTH)
1459             keyname_len = TLSEXT_KEYNAME_LENGTH;
1460         retcb = s->session_ctx->decrypt_ticket_cb(s, sess, etick, keyname_len,
1461                                                   ret,
1462                                                   s->session_ctx->ticket_cb_data);
1463         switch (retcb) {
1464         case SSL_TICKET_RETURN_ABORT:
1465             ret = SSL_TICKET_FATAL_ERR_OTHER;
1466             break;
1467 
1468         case SSL_TICKET_RETURN_IGNORE:
1469             ret = SSL_TICKET_NONE;
1470             SSL_SESSION_free(sess);
1471             sess = NULL;
1472             break;
1473 
1474         case SSL_TICKET_RETURN_IGNORE_RENEW:
1475             if (ret != SSL_TICKET_EMPTY && ret != SSL_TICKET_NO_DECRYPT)
1476                 ret = SSL_TICKET_NO_DECRYPT;
1477             /* else the value of |ret| will already do the right thing */
1478             SSL_SESSION_free(sess);
1479             sess = NULL;
1480             break;
1481 
1482         case SSL_TICKET_RETURN_USE:
1483         case SSL_TICKET_RETURN_USE_RENEW:
1484             if (ret != SSL_TICKET_SUCCESS
1485                     && ret != SSL_TICKET_SUCCESS_RENEW)
1486                 ret = SSL_TICKET_FATAL_ERR_OTHER;
1487             else if (retcb == SSL_TICKET_RETURN_USE)
1488                 ret = SSL_TICKET_SUCCESS;
1489             else
1490                 ret = SSL_TICKET_SUCCESS_RENEW;
1491             break;
1492 
1493         default:
1494             ret = SSL_TICKET_FATAL_ERR_OTHER;
1495         }
1496     }
1497 
1498     if (s->ext.session_secret_cb == NULL || SSL_IS_TLS13(s)) {
1499         switch (ret) {
1500         case SSL_TICKET_NO_DECRYPT:
1501         case SSL_TICKET_SUCCESS_RENEW:
1502         case SSL_TICKET_EMPTY:
1503             s->ext.ticket_expected = 1;
1504         }
1505     }
1506 
1507     *psess = sess;
1508 
1509     return ret;
1510 }
1511 
1512 /* Check to see if a signature algorithm is allowed */
1513 static int tls12_sigalg_allowed(SSL *s, int op, const SIGALG_LOOKUP *lu)
1514 {
1515     unsigned char sigalgstr[2];
1516     int secbits;
1517 
1518     /* See if sigalgs is recognised and if hash is enabled */
1519     if (!tls1_lookup_md(lu, NULL))
1520         return 0;
1521     /* DSA is not allowed in TLS 1.3 */
1522     if (SSL_IS_TLS13(s) && lu->sig == EVP_PKEY_DSA)
1523         return 0;
1524     /* TODO(OpenSSL1.2) fully axe DSA/etc. in ClientHello per TLS 1.3 spec */
1525     if (!s->server && !SSL_IS_DTLS(s) && s->s3->tmp.min_ver >= TLS1_3_VERSION
1526         && (lu->sig == EVP_PKEY_DSA || lu->hash_idx == SSL_MD_SHA1_IDX
1527             || lu->hash_idx == SSL_MD_MD5_IDX
1528             || lu->hash_idx == SSL_MD_SHA224_IDX))
1529         return 0;
1530 
1531     /* See if public key algorithm allowed */
1532     if (ssl_cert_is_disabled(lu->sig_idx))
1533         return 0;
1534 
1535     if (lu->sig == NID_id_GostR3410_2012_256
1536             || lu->sig == NID_id_GostR3410_2012_512
1537             || lu->sig == NID_id_GostR3410_2001) {
1538         /* We never allow GOST sig algs on the server with TLSv1.3 */
1539         if (s->server && SSL_IS_TLS13(s))
1540             return 0;
1541         if (!s->server
1542                 && s->method->version == TLS_ANY_VERSION
1543                 && s->s3->tmp.max_ver >= TLS1_3_VERSION) {
1544             int i, num;
1545             STACK_OF(SSL_CIPHER) *sk;
1546 
1547             /*
1548              * We're a client that could negotiate TLSv1.3. We only allow GOST
1549              * sig algs if we could negotiate TLSv1.2 or below and we have GOST
1550              * ciphersuites enabled.
1551              */
1552 
1553             if (s->s3->tmp.min_ver >= TLS1_3_VERSION)
1554                 return 0;
1555 
1556             sk = SSL_get_ciphers(s);
1557             num = sk != NULL ? sk_SSL_CIPHER_num(sk) : 0;
1558             for (i = 0; i < num; i++) {
1559                 const SSL_CIPHER *c;
1560 
1561                 c = sk_SSL_CIPHER_value(sk, i);
1562                 /* Skip disabled ciphers */
1563                 if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED, 0))
1564                     continue;
1565 
1566                 if ((c->algorithm_mkey & SSL_kGOST) != 0)
1567                     break;
1568             }
1569             if (i == num)
1570                 return 0;
1571         }
1572     }
1573 
1574     if (lu->hash == NID_undef)
1575         return 1;
1576     /* Security bits: half digest bits */
1577     secbits = EVP_MD_size(ssl_md(lu->hash_idx)) * 4;
1578     /* Finally see if security callback allows it */
1579     sigalgstr[0] = (lu->sigalg >> 8) & 0xff;
1580     sigalgstr[1] = lu->sigalg & 0xff;
1581     return ssl_security(s, op, secbits, lu->hash, (void *)sigalgstr);
1582 }
1583 
1584 /*
1585  * Get a mask of disabled public key algorithms based on supported signature
1586  * algorithms. For example if no signature algorithm supports RSA then RSA is
1587  * disabled.
1588  */
1589 
1590 void ssl_set_sig_mask(uint32_t *pmask_a, SSL *s, int op)
1591 {
1592     const uint16_t *sigalgs;
1593     size_t i, sigalgslen;
1594     uint32_t disabled_mask = SSL_aRSA | SSL_aDSS | SSL_aECDSA;
1595     /*
1596      * Go through all signature algorithms seeing if we support any
1597      * in disabled_mask.
1598      */
1599     sigalgslen = tls12_get_psigalgs(s, 1, &sigalgs);
1600     for (i = 0; i < sigalgslen; i++, sigalgs++) {
1601         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(*sigalgs);
1602         const SSL_CERT_LOOKUP *clu;
1603 
1604         if (lu == NULL)
1605             continue;
1606 
1607         clu = ssl_cert_lookup_by_idx(lu->sig_idx);
1608 	if (clu == NULL)
1609 		continue;
1610 
1611         /* If algorithm is disabled see if we can enable it */
1612         if ((clu->amask & disabled_mask) != 0
1613                 && tls12_sigalg_allowed(s, op, lu))
1614             disabled_mask &= ~clu->amask;
1615     }
1616     *pmask_a |= disabled_mask;
1617 }
1618 
1619 int tls12_copy_sigalgs(SSL *s, WPACKET *pkt,
1620                        const uint16_t *psig, size_t psiglen)
1621 {
1622     size_t i;
1623     int rv = 0;
1624 
1625     for (i = 0; i < psiglen; i++, psig++) {
1626         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(*psig);
1627 
1628         if (!tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SUPPORTED, lu))
1629             continue;
1630         if (!WPACKET_put_bytes_u16(pkt, *psig))
1631             return 0;
1632         /*
1633          * If TLS 1.3 must have at least one valid TLS 1.3 message
1634          * signing algorithm: i.e. neither RSA nor SHA1/SHA224
1635          */
1636         if (rv == 0 && (!SSL_IS_TLS13(s)
1637             || (lu->sig != EVP_PKEY_RSA
1638                 && lu->hash != NID_sha1
1639                 && lu->hash != NID_sha224)))
1640             rv = 1;
1641     }
1642     if (rv == 0)
1643         SSLerr(SSL_F_TLS12_COPY_SIGALGS, SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
1644     return rv;
1645 }
1646 
1647 /* Given preference and allowed sigalgs set shared sigalgs */
1648 static size_t tls12_shared_sigalgs(SSL *s, const SIGALG_LOOKUP **shsig,
1649                                    const uint16_t *pref, size_t preflen,
1650                                    const uint16_t *allow, size_t allowlen)
1651 {
1652     const uint16_t *ptmp, *atmp;
1653     size_t i, j, nmatch = 0;
1654     for (i = 0, ptmp = pref; i < preflen; i++, ptmp++) {
1655         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(*ptmp);
1656 
1657         /* Skip disabled hashes or signature algorithms */
1658         if (!tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SHARED, lu))
1659             continue;
1660         for (j = 0, atmp = allow; j < allowlen; j++, atmp++) {
1661             if (*ptmp == *atmp) {
1662                 nmatch++;
1663                 if (shsig)
1664                     *shsig++ = lu;
1665                 break;
1666             }
1667         }
1668     }
1669     return nmatch;
1670 }
1671 
1672 /* Set shared signature algorithms for SSL structures */
1673 static int tls1_set_shared_sigalgs(SSL *s)
1674 {
1675     const uint16_t *pref, *allow, *conf;
1676     size_t preflen, allowlen, conflen;
1677     size_t nmatch;
1678     const SIGALG_LOOKUP **salgs = NULL;
1679     CERT *c = s->cert;
1680     unsigned int is_suiteb = tls1_suiteb(s);
1681 
1682     OPENSSL_free(c->shared_sigalgs);
1683     c->shared_sigalgs = NULL;
1684     c->shared_sigalgslen = 0;
1685     /* If client use client signature algorithms if not NULL */
1686     if (!s->server && c->client_sigalgs && !is_suiteb) {
1687         conf = c->client_sigalgs;
1688         conflen = c->client_sigalgslen;
1689     } else if (c->conf_sigalgs && !is_suiteb) {
1690         conf = c->conf_sigalgs;
1691         conflen = c->conf_sigalgslen;
1692     } else
1693         conflen = tls12_get_psigalgs(s, 0, &conf);
1694     if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb) {
1695         pref = conf;
1696         preflen = conflen;
1697         allow = s->s3->tmp.peer_sigalgs;
1698         allowlen = s->s3->tmp.peer_sigalgslen;
1699     } else {
1700         allow = conf;
1701         allowlen = conflen;
1702         pref = s->s3->tmp.peer_sigalgs;
1703         preflen = s->s3->tmp.peer_sigalgslen;
1704     }
1705     nmatch = tls12_shared_sigalgs(s, NULL, pref, preflen, allow, allowlen);
1706     if (nmatch) {
1707         if ((salgs = OPENSSL_malloc(nmatch * sizeof(*salgs))) == NULL) {
1708             SSLerr(SSL_F_TLS1_SET_SHARED_SIGALGS, ERR_R_MALLOC_FAILURE);
1709             return 0;
1710         }
1711         nmatch = tls12_shared_sigalgs(s, salgs, pref, preflen, allow, allowlen);
1712     } else {
1713         salgs = NULL;
1714     }
1715     c->shared_sigalgs = salgs;
1716     c->shared_sigalgslen = nmatch;
1717     return 1;
1718 }
1719 
1720 int tls1_save_u16(PACKET *pkt, uint16_t **pdest, size_t *pdestlen)
1721 {
1722     unsigned int stmp;
1723     size_t size, i;
1724     uint16_t *buf;
1725 
1726     size = PACKET_remaining(pkt);
1727 
1728     /* Invalid data length */
1729     if (size == 0 || (size & 1) != 0)
1730         return 0;
1731 
1732     size >>= 1;
1733 
1734     if ((buf = OPENSSL_malloc(size * sizeof(*buf))) == NULL)  {
1735         SSLerr(SSL_F_TLS1_SAVE_U16, ERR_R_MALLOC_FAILURE);
1736         return 0;
1737     }
1738     for (i = 0; i < size && PACKET_get_net_2(pkt, &stmp); i++)
1739         buf[i] = stmp;
1740 
1741     if (i != size) {
1742         OPENSSL_free(buf);
1743         return 0;
1744     }
1745 
1746     OPENSSL_free(*pdest);
1747     *pdest = buf;
1748     *pdestlen = size;
1749 
1750     return 1;
1751 }
1752 
1753 int tls1_save_sigalgs(SSL *s, PACKET *pkt, int cert)
1754 {
1755     /* Extension ignored for inappropriate versions */
1756     if (!SSL_USE_SIGALGS(s))
1757         return 1;
1758     /* Should never happen */
1759     if (s->cert == NULL)
1760         return 0;
1761 
1762     if (cert)
1763         return tls1_save_u16(pkt, &s->s3->tmp.peer_cert_sigalgs,
1764                              &s->s3->tmp.peer_cert_sigalgslen);
1765     else
1766         return tls1_save_u16(pkt, &s->s3->tmp.peer_sigalgs,
1767                              &s->s3->tmp.peer_sigalgslen);
1768 
1769 }
1770 
1771 /* Set preferred digest for each key type */
1772 
1773 int tls1_process_sigalgs(SSL *s)
1774 {
1775     size_t i;
1776     uint32_t *pvalid = s->s3->tmp.valid_flags;
1777     CERT *c = s->cert;
1778 
1779     if (!tls1_set_shared_sigalgs(s))
1780         return 0;
1781 
1782     for (i = 0; i < SSL_PKEY_NUM; i++)
1783         pvalid[i] = 0;
1784 
1785     for (i = 0; i < c->shared_sigalgslen; i++) {
1786         const SIGALG_LOOKUP *sigptr = c->shared_sigalgs[i];
1787         int idx = sigptr->sig_idx;
1788 
1789         /* Ignore PKCS1 based sig algs in TLSv1.3 */
1790         if (SSL_IS_TLS13(s) && sigptr->sig == EVP_PKEY_RSA)
1791             continue;
1792         /* If not disabled indicate we can explicitly sign */
1793         if (pvalid[idx] == 0 && !ssl_cert_is_disabled(idx))
1794             pvalid[idx] = CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN;
1795     }
1796     return 1;
1797 }
1798 
1799 int SSL_get_sigalgs(SSL *s, int idx,
1800                     int *psign, int *phash, int *psignhash,
1801                     unsigned char *rsig, unsigned char *rhash)
1802 {
1803     uint16_t *psig = s->s3->tmp.peer_sigalgs;
1804     size_t numsigalgs = s->s3->tmp.peer_sigalgslen;
1805     if (psig == NULL || numsigalgs > INT_MAX)
1806         return 0;
1807     if (idx >= 0) {
1808         const SIGALG_LOOKUP *lu;
1809 
1810         if (idx >= (int)numsigalgs)
1811             return 0;
1812         psig += idx;
1813         if (rhash != NULL)
1814             *rhash = (unsigned char)((*psig >> 8) & 0xff);
1815         if (rsig != NULL)
1816             *rsig = (unsigned char)(*psig & 0xff);
1817         lu = tls1_lookup_sigalg(*psig);
1818         if (psign != NULL)
1819             *psign = lu != NULL ? lu->sig : NID_undef;
1820         if (phash != NULL)
1821             *phash = lu != NULL ? lu->hash : NID_undef;
1822         if (psignhash != NULL)
1823             *psignhash = lu != NULL ? lu->sigandhash : NID_undef;
1824     }
1825     return (int)numsigalgs;
1826 }
1827 
1828 int SSL_get_shared_sigalgs(SSL *s, int idx,
1829                            int *psign, int *phash, int *psignhash,
1830                            unsigned char *rsig, unsigned char *rhash)
1831 {
1832     const SIGALG_LOOKUP *shsigalgs;
1833     if (s->cert->shared_sigalgs == NULL
1834         || idx < 0
1835         || idx >= (int)s->cert->shared_sigalgslen
1836         || s->cert->shared_sigalgslen > INT_MAX)
1837         return 0;
1838     shsigalgs = s->cert->shared_sigalgs[idx];
1839     if (phash != NULL)
1840         *phash = shsigalgs->hash;
1841     if (psign != NULL)
1842         *psign = shsigalgs->sig;
1843     if (psignhash != NULL)
1844         *psignhash = shsigalgs->sigandhash;
1845     if (rsig != NULL)
1846         *rsig = (unsigned char)(shsigalgs->sigalg & 0xff);
1847     if (rhash != NULL)
1848         *rhash = (unsigned char)((shsigalgs->sigalg >> 8) & 0xff);
1849     return (int)s->cert->shared_sigalgslen;
1850 }
1851 
1852 /* Maximum possible number of unique entries in sigalgs array */
1853 #define TLS_MAX_SIGALGCNT (OSSL_NELEM(sigalg_lookup_tbl) * 2)
1854 
1855 typedef struct {
1856     size_t sigalgcnt;
1857     /* TLSEXT_SIGALG_XXX values */
1858     uint16_t sigalgs[TLS_MAX_SIGALGCNT];
1859 } sig_cb_st;
1860 
1861 static void get_sigorhash(int *psig, int *phash, const char *str)
1862 {
1863     if (strcmp(str, "RSA") == 0) {
1864         *psig = EVP_PKEY_RSA;
1865     } else if (strcmp(str, "RSA-PSS") == 0 || strcmp(str, "PSS") == 0) {
1866         *psig = EVP_PKEY_RSA_PSS;
1867     } else if (strcmp(str, "DSA") == 0) {
1868         *psig = EVP_PKEY_DSA;
1869     } else if (strcmp(str, "ECDSA") == 0) {
1870         *psig = EVP_PKEY_EC;
1871     } else {
1872         *phash = OBJ_sn2nid(str);
1873         if (*phash == NID_undef)
1874             *phash = OBJ_ln2nid(str);
1875     }
1876 }
1877 /* Maximum length of a signature algorithm string component */
1878 #define TLS_MAX_SIGSTRING_LEN   40
1879 
1880 static int sig_cb(const char *elem, int len, void *arg)
1881 {
1882     sig_cb_st *sarg = arg;
1883     size_t i;
1884     const SIGALG_LOOKUP *s;
1885     char etmp[TLS_MAX_SIGSTRING_LEN], *p;
1886     int sig_alg = NID_undef, hash_alg = NID_undef;
1887     if (elem == NULL)
1888         return 0;
1889     if (sarg->sigalgcnt == TLS_MAX_SIGALGCNT)
1890         return 0;
1891     if (len > (int)(sizeof(etmp) - 1))
1892         return 0;
1893     memcpy(etmp, elem, len);
1894     etmp[len] = 0;
1895     p = strchr(etmp, '+');
1896     /*
1897      * We only allow SignatureSchemes listed in the sigalg_lookup_tbl;
1898      * if there's no '+' in the provided name, look for the new-style combined
1899      * name.  If not, match both sig+hash to find the needed SIGALG_LOOKUP.
1900      * Just sig+hash is not unique since TLS 1.3 adds rsa_pss_pss_* and
1901      * rsa_pss_rsae_* that differ only by public key OID; in such cases
1902      * we will pick the _rsae_ variant, by virtue of them appearing earlier
1903      * in the table.
1904      */
1905     if (p == NULL) {
1906         for (i = 0, s = sigalg_lookup_tbl; i < OSSL_NELEM(sigalg_lookup_tbl);
1907              i++, s++) {
1908             if (s->name != NULL && strcmp(etmp, s->name) == 0) {
1909                 sarg->sigalgs[sarg->sigalgcnt++] = s->sigalg;
1910                 break;
1911             }
1912         }
1913         if (i == OSSL_NELEM(sigalg_lookup_tbl))
1914             return 0;
1915     } else {
1916         *p = 0;
1917         p++;
1918         if (*p == 0)
1919             return 0;
1920         get_sigorhash(&sig_alg, &hash_alg, etmp);
1921         get_sigorhash(&sig_alg, &hash_alg, p);
1922         if (sig_alg == NID_undef || hash_alg == NID_undef)
1923             return 0;
1924         for (i = 0, s = sigalg_lookup_tbl; i < OSSL_NELEM(sigalg_lookup_tbl);
1925              i++, s++) {
1926             if (s->hash == hash_alg && s->sig == sig_alg) {
1927                 sarg->sigalgs[sarg->sigalgcnt++] = s->sigalg;
1928                 break;
1929             }
1930         }
1931         if (i == OSSL_NELEM(sigalg_lookup_tbl))
1932             return 0;
1933     }
1934 
1935     /* Reject duplicates */
1936     for (i = 0; i < sarg->sigalgcnt - 1; i++) {
1937         if (sarg->sigalgs[i] == sarg->sigalgs[sarg->sigalgcnt - 1]) {
1938             sarg->sigalgcnt--;
1939             return 0;
1940         }
1941     }
1942     return 1;
1943 }
1944 
1945 /*
1946  * Set supported signature algorithms based on a colon separated list of the
1947  * form sig+hash e.g. RSA+SHA512:DSA+SHA512
1948  */
1949 int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
1950 {
1951     sig_cb_st sig;
1952     sig.sigalgcnt = 0;
1953     if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
1954         return 0;
1955     if (c == NULL)
1956         return 1;
1957     return tls1_set_raw_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
1958 }
1959 
1960 int tls1_set_raw_sigalgs(CERT *c, const uint16_t *psigs, size_t salglen,
1961                      int client)
1962 {
1963     uint16_t *sigalgs;
1964 
1965     if ((sigalgs = OPENSSL_malloc(salglen * sizeof(*sigalgs))) == NULL) {
1966         SSLerr(SSL_F_TLS1_SET_RAW_SIGALGS, ERR_R_MALLOC_FAILURE);
1967         return 0;
1968     }
1969     memcpy(sigalgs, psigs, salglen * sizeof(*sigalgs));
1970 
1971     if (client) {
1972         OPENSSL_free(c->client_sigalgs);
1973         c->client_sigalgs = sigalgs;
1974         c->client_sigalgslen = salglen;
1975     } else {
1976         OPENSSL_free(c->conf_sigalgs);
1977         c->conf_sigalgs = sigalgs;
1978         c->conf_sigalgslen = salglen;
1979     }
1980 
1981     return 1;
1982 }
1983 
1984 int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen, int client)
1985 {
1986     uint16_t *sigalgs, *sptr;
1987     size_t i;
1988 
1989     if (salglen & 1)
1990         return 0;
1991     if ((sigalgs = OPENSSL_malloc((salglen / 2) * sizeof(*sigalgs))) == NULL) {
1992         SSLerr(SSL_F_TLS1_SET_SIGALGS, ERR_R_MALLOC_FAILURE);
1993         return 0;
1994     }
1995     for (i = 0, sptr = sigalgs; i < salglen; i += 2) {
1996         size_t j;
1997         const SIGALG_LOOKUP *curr;
1998         int md_id = *psig_nids++;
1999         int sig_id = *psig_nids++;
2000 
2001         for (j = 0, curr = sigalg_lookup_tbl; j < OSSL_NELEM(sigalg_lookup_tbl);
2002              j++, curr++) {
2003             if (curr->hash == md_id && curr->sig == sig_id) {
2004                 *sptr++ = curr->sigalg;
2005                 break;
2006             }
2007         }
2008 
2009         if (j == OSSL_NELEM(sigalg_lookup_tbl))
2010             goto err;
2011     }
2012 
2013     if (client) {
2014         OPENSSL_free(c->client_sigalgs);
2015         c->client_sigalgs = sigalgs;
2016         c->client_sigalgslen = salglen / 2;
2017     } else {
2018         OPENSSL_free(c->conf_sigalgs);
2019         c->conf_sigalgs = sigalgs;
2020         c->conf_sigalgslen = salglen / 2;
2021     }
2022 
2023     return 1;
2024 
2025  err:
2026     OPENSSL_free(sigalgs);
2027     return 0;
2028 }
2029 
2030 static int tls1_check_sig_alg(CERT *c, X509 *x, int default_nid)
2031 {
2032     int sig_nid;
2033     size_t i;
2034     if (default_nid == -1)
2035         return 1;
2036     sig_nid = X509_get_signature_nid(x);
2037     if (default_nid)
2038         return sig_nid == default_nid ? 1 : 0;
2039     for (i = 0; i < c->shared_sigalgslen; i++)
2040         if (sig_nid == c->shared_sigalgs[i]->sigandhash)
2041             return 1;
2042     return 0;
2043 }
2044 
2045 /* Check to see if a certificate issuer name matches list of CA names */
2046 static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
2047 {
2048     X509_NAME *nm;
2049     int i;
2050     nm = X509_get_issuer_name(x);
2051     for (i = 0; i < sk_X509_NAME_num(names); i++) {
2052         if (!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
2053             return 1;
2054     }
2055     return 0;
2056 }
2057 
2058 /*
2059  * Check certificate chain is consistent with TLS extensions and is usable by
2060  * server. This servers two purposes: it allows users to check chains before
2061  * passing them to the server and it allows the server to check chains before
2062  * attempting to use them.
2063  */
2064 
2065 /* Flags which need to be set for a certificate when strict mode not set */
2066 
2067 #define CERT_PKEY_VALID_FLAGS \
2068         (CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
2069 /* Strict mode flags */
2070 #define CERT_PKEY_STRICT_FLAGS \
2071          (CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
2072          | CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
2073 
2074 int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
2075                      int idx)
2076 {
2077     int i;
2078     int rv = 0;
2079     int check_flags = 0, strict_mode;
2080     CERT_PKEY *cpk = NULL;
2081     CERT *c = s->cert;
2082     uint32_t *pvalid;
2083     unsigned int suiteb_flags = tls1_suiteb(s);
2084     /* idx == -1 means checking server chains */
2085     if (idx != -1) {
2086         /* idx == -2 means checking client certificate chains */
2087         if (idx == -2) {
2088             cpk = c->key;
2089             idx = (int)(cpk - c->pkeys);
2090         } else
2091             cpk = c->pkeys + idx;
2092         pvalid = s->s3->tmp.valid_flags + idx;
2093         x = cpk->x509;
2094         pk = cpk->privatekey;
2095         chain = cpk->chain;
2096         strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
2097         /* If no cert or key, forget it */
2098         if (!x || !pk)
2099             goto end;
2100     } else {
2101         size_t certidx;
2102 
2103         if (!x || !pk)
2104             return 0;
2105 
2106         if (ssl_cert_lookup_by_pkey(pk, &certidx) == NULL)
2107             return 0;
2108         idx = certidx;
2109         pvalid = s->s3->tmp.valid_flags + idx;
2110 
2111         if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
2112             check_flags = CERT_PKEY_STRICT_FLAGS;
2113         else
2114             check_flags = CERT_PKEY_VALID_FLAGS;
2115         strict_mode = 1;
2116     }
2117 
2118     if (suiteb_flags) {
2119         int ok;
2120         if (check_flags)
2121             check_flags |= CERT_PKEY_SUITEB;
2122         ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
2123         if (ok == X509_V_OK)
2124             rv |= CERT_PKEY_SUITEB;
2125         else if (!check_flags)
2126             goto end;
2127     }
2128 
2129     /*
2130      * Check all signature algorithms are consistent with signature
2131      * algorithms extension if TLS 1.2 or later and strict mode.
2132      */
2133     if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode) {
2134         int default_nid;
2135         int rsign = 0;
2136         if (s->s3->tmp.peer_cert_sigalgs != NULL
2137                 || s->s3->tmp.peer_sigalgs != NULL) {
2138             default_nid = 0;
2139         /* If no sigalgs extension use defaults from RFC5246 */
2140         } else {
2141             switch (idx) {
2142             case SSL_PKEY_RSA:
2143                 rsign = EVP_PKEY_RSA;
2144                 default_nid = NID_sha1WithRSAEncryption;
2145                 break;
2146 
2147             case SSL_PKEY_DSA_SIGN:
2148                 rsign = EVP_PKEY_DSA;
2149                 default_nid = NID_dsaWithSHA1;
2150                 break;
2151 
2152             case SSL_PKEY_ECC:
2153                 rsign = EVP_PKEY_EC;
2154                 default_nid = NID_ecdsa_with_SHA1;
2155                 break;
2156 
2157             case SSL_PKEY_GOST01:
2158                 rsign = NID_id_GostR3410_2001;
2159                 default_nid = NID_id_GostR3411_94_with_GostR3410_2001;
2160                 break;
2161 
2162             case SSL_PKEY_GOST12_256:
2163                 rsign = NID_id_GostR3410_2012_256;
2164                 default_nid = NID_id_tc26_signwithdigest_gost3410_2012_256;
2165                 break;
2166 
2167             case SSL_PKEY_GOST12_512:
2168                 rsign = NID_id_GostR3410_2012_512;
2169                 default_nid = NID_id_tc26_signwithdigest_gost3410_2012_512;
2170                 break;
2171 
2172             default:
2173                 default_nid = -1;
2174                 break;
2175             }
2176         }
2177         /*
2178          * If peer sent no signature algorithms extension and we have set
2179          * preferred signature algorithms check we support sha1.
2180          */
2181         if (default_nid > 0 && c->conf_sigalgs) {
2182             size_t j;
2183             const uint16_t *p = c->conf_sigalgs;
2184             for (j = 0; j < c->conf_sigalgslen; j++, p++) {
2185                 const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(*p);
2186 
2187                 if (lu != NULL && lu->hash == NID_sha1 && lu->sig == rsign)
2188                     break;
2189             }
2190             if (j == c->conf_sigalgslen) {
2191                 if (check_flags)
2192                     goto skip_sigs;
2193                 else
2194                     goto end;
2195             }
2196         }
2197         /* Check signature algorithm of each cert in chain */
2198         if (!tls1_check_sig_alg(c, x, default_nid)) {
2199             if (!check_flags)
2200                 goto end;
2201         } else
2202             rv |= CERT_PKEY_EE_SIGNATURE;
2203         rv |= CERT_PKEY_CA_SIGNATURE;
2204         for (i = 0; i < sk_X509_num(chain); i++) {
2205             if (!tls1_check_sig_alg(c, sk_X509_value(chain, i), default_nid)) {
2206                 if (check_flags) {
2207                     rv &= ~CERT_PKEY_CA_SIGNATURE;
2208                     break;
2209                 } else
2210                     goto end;
2211             }
2212         }
2213     }
2214     /* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
2215     else if (check_flags)
2216         rv |= CERT_PKEY_EE_SIGNATURE | CERT_PKEY_CA_SIGNATURE;
2217  skip_sigs:
2218     /* Check cert parameters are consistent */
2219     if (tls1_check_cert_param(s, x, 1))
2220         rv |= CERT_PKEY_EE_PARAM;
2221     else if (!check_flags)
2222         goto end;
2223     if (!s->server)
2224         rv |= CERT_PKEY_CA_PARAM;
2225     /* In strict mode check rest of chain too */
2226     else if (strict_mode) {
2227         rv |= CERT_PKEY_CA_PARAM;
2228         for (i = 0; i < sk_X509_num(chain); i++) {
2229             X509 *ca = sk_X509_value(chain, i);
2230             if (!tls1_check_cert_param(s, ca, 0)) {
2231                 if (check_flags) {
2232                     rv &= ~CERT_PKEY_CA_PARAM;
2233                     break;
2234                 } else
2235                     goto end;
2236             }
2237         }
2238     }
2239     if (!s->server && strict_mode) {
2240         STACK_OF(X509_NAME) *ca_dn;
2241         int check_type = 0;
2242         switch (EVP_PKEY_id(pk)) {
2243         case EVP_PKEY_RSA:
2244             check_type = TLS_CT_RSA_SIGN;
2245             break;
2246         case EVP_PKEY_DSA:
2247             check_type = TLS_CT_DSS_SIGN;
2248             break;
2249         case EVP_PKEY_EC:
2250             check_type = TLS_CT_ECDSA_SIGN;
2251             break;
2252         }
2253         if (check_type) {
2254             const uint8_t *ctypes = s->s3->tmp.ctype;
2255             size_t j;
2256 
2257             for (j = 0; j < s->s3->tmp.ctype_len; j++, ctypes++) {
2258                 if (*ctypes == check_type) {
2259                     rv |= CERT_PKEY_CERT_TYPE;
2260                     break;
2261                 }
2262             }
2263             if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
2264                 goto end;
2265         } else {
2266             rv |= CERT_PKEY_CERT_TYPE;
2267         }
2268 
2269         ca_dn = s->s3->tmp.peer_ca_names;
2270 
2271         if (!sk_X509_NAME_num(ca_dn))
2272             rv |= CERT_PKEY_ISSUER_NAME;
2273 
2274         if (!(rv & CERT_PKEY_ISSUER_NAME)) {
2275             if (ssl_check_ca_name(ca_dn, x))
2276                 rv |= CERT_PKEY_ISSUER_NAME;
2277         }
2278         if (!(rv & CERT_PKEY_ISSUER_NAME)) {
2279             for (i = 0; i < sk_X509_num(chain); i++) {
2280                 X509 *xtmp = sk_X509_value(chain, i);
2281                 if (ssl_check_ca_name(ca_dn, xtmp)) {
2282                     rv |= CERT_PKEY_ISSUER_NAME;
2283                     break;
2284                 }
2285             }
2286         }
2287         if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
2288             goto end;
2289     } else
2290         rv |= CERT_PKEY_ISSUER_NAME | CERT_PKEY_CERT_TYPE;
2291 
2292     if (!check_flags || (rv & check_flags) == check_flags)
2293         rv |= CERT_PKEY_VALID;
2294 
2295  end:
2296 
2297     if (TLS1_get_version(s) >= TLS1_2_VERSION)
2298         rv |= *pvalid & (CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN);
2299     else
2300         rv |= CERT_PKEY_SIGN | CERT_PKEY_EXPLICIT_SIGN;
2301 
2302     /*
2303      * When checking a CERT_PKEY structure all flags are irrelevant if the
2304      * chain is invalid.
2305      */
2306     if (!check_flags) {
2307         if (rv & CERT_PKEY_VALID) {
2308             *pvalid = rv;
2309         } else {
2310             /* Preserve sign and explicit sign flag, clear rest */
2311             *pvalid &= CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN;
2312             return 0;
2313         }
2314     }
2315     return rv;
2316 }
2317 
2318 /* Set validity of certificates in an SSL structure */
2319 void tls1_set_cert_validity(SSL *s)
2320 {
2321     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA);
2322     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_PSS_SIGN);
2323     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DSA_SIGN);
2324     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
2325     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST01);
2326     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_256);
2327     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_512);
2328     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ED25519);
2329     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ED448);
2330 }
2331 
2332 /* User level utility function to check a chain is suitable */
2333 int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
2334 {
2335     return tls1_check_chain(s, x, pk, chain, -1);
2336 }
2337 
2338 #ifndef OPENSSL_NO_DH
2339 DH *ssl_get_auto_dh(SSL *s)
2340 {
2341     int dh_secbits = 80;
2342     if (s->cert->dh_tmp_auto == 2)
2343         return DH_get_1024_160();
2344     if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aPSK)) {
2345         if (s->s3->tmp.new_cipher->strength_bits == 256)
2346             dh_secbits = 128;
2347         else
2348             dh_secbits = 80;
2349     } else {
2350         if (s->s3->tmp.cert == NULL)
2351             return NULL;
2352         dh_secbits = EVP_PKEY_security_bits(s->s3->tmp.cert->privatekey);
2353     }
2354 
2355     if (dh_secbits >= 128) {
2356         DH *dhp = DH_new();
2357         BIGNUM *p, *g;
2358         if (dhp == NULL)
2359             return NULL;
2360         g = BN_new();
2361         if (g == NULL || !BN_set_word(g, 2)) {
2362             DH_free(dhp);
2363             BN_free(g);
2364             return NULL;
2365         }
2366         if (dh_secbits >= 192)
2367             p = BN_get_rfc3526_prime_8192(NULL);
2368         else
2369             p = BN_get_rfc3526_prime_3072(NULL);
2370         if (p == NULL || !DH_set0_pqg(dhp, p, NULL, g)) {
2371             DH_free(dhp);
2372             BN_free(p);
2373             BN_free(g);
2374             return NULL;
2375         }
2376         return dhp;
2377     }
2378     if (dh_secbits >= 112)
2379         return DH_get_2048_224();
2380     return DH_get_1024_160();
2381 }
2382 #endif
2383 
2384 static int ssl_security_cert_key(SSL *s, SSL_CTX *ctx, X509 *x, int op)
2385 {
2386     int secbits = -1;
2387     EVP_PKEY *pkey = X509_get0_pubkey(x);
2388     if (pkey) {
2389         /*
2390          * If no parameters this will return -1 and fail using the default
2391          * security callback for any non-zero security level. This will
2392          * reject keys which omit parameters but this only affects DSA and
2393          * omission of parameters is never (?) done in practice.
2394          */
2395         secbits = EVP_PKEY_security_bits(pkey);
2396     }
2397     if (s)
2398         return ssl_security(s, op, secbits, 0, x);
2399     else
2400         return ssl_ctx_security(ctx, op, secbits, 0, x);
2401 }
2402 
2403 static int ssl_security_cert_sig(SSL *s, SSL_CTX *ctx, X509 *x, int op)
2404 {
2405     /* Lookup signature algorithm digest */
2406     int secbits, nid, pknid;
2407     /* Don't check signature if self signed */
2408     if ((X509_get_extension_flags(x) & EXFLAG_SS) != 0)
2409         return 1;
2410     if (!X509_get_signature_info(x, &nid, &pknid, &secbits, NULL))
2411         secbits = -1;
2412     /* If digest NID not defined use signature NID */
2413     if (nid == NID_undef)
2414         nid = pknid;
2415     if (s)
2416         return ssl_security(s, op, secbits, nid, x);
2417     else
2418         return ssl_ctx_security(ctx, op, secbits, nid, x);
2419 }
2420 
2421 int ssl_security_cert(SSL *s, SSL_CTX *ctx, X509 *x, int vfy, int is_ee)
2422 {
2423     if (vfy)
2424         vfy = SSL_SECOP_PEER;
2425     if (is_ee) {
2426         if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_EE_KEY | vfy))
2427             return SSL_R_EE_KEY_TOO_SMALL;
2428     } else {
2429         if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_CA_KEY | vfy))
2430             return SSL_R_CA_KEY_TOO_SMALL;
2431     }
2432     if (!ssl_security_cert_sig(s, ctx, x, SSL_SECOP_CA_MD | vfy))
2433         return SSL_R_CA_MD_TOO_WEAK;
2434     return 1;
2435 }
2436 
2437 /*
2438  * Check security of a chain, if |sk| includes the end entity certificate then
2439  * |x| is NULL. If |vfy| is 1 then we are verifying a peer chain and not sending
2440  * one to the peer. Return values: 1 if ok otherwise error code to use
2441  */
2442 
2443 int ssl_security_cert_chain(SSL *s, STACK_OF(X509) *sk, X509 *x, int vfy)
2444 {
2445     int rv, start_idx, i;
2446     if (x == NULL) {
2447         x = sk_X509_value(sk, 0);
2448         start_idx = 1;
2449     } else
2450         start_idx = 0;
2451 
2452     rv = ssl_security_cert(s, NULL, x, vfy, 1);
2453     if (rv != 1)
2454         return rv;
2455 
2456     for (i = start_idx; i < sk_X509_num(sk); i++) {
2457         x = sk_X509_value(sk, i);
2458         rv = ssl_security_cert(s, NULL, x, vfy, 0);
2459         if (rv != 1)
2460             return rv;
2461     }
2462     return 1;
2463 }
2464 
2465 /*
2466  * For TLS 1.2 servers check if we have a certificate which can be used
2467  * with the signature algorithm "lu" and return index of certificate.
2468  */
2469 
2470 static int tls12_get_cert_sigalg_idx(const SSL *s, const SIGALG_LOOKUP *lu)
2471 {
2472     int sig_idx = lu->sig_idx;
2473     const SSL_CERT_LOOKUP *clu = ssl_cert_lookup_by_idx(sig_idx);
2474 
2475     /* If not recognised or not supported by cipher mask it is not suitable */
2476     if (clu == NULL
2477             || (clu->amask & s->s3->tmp.new_cipher->algorithm_auth) == 0
2478             || (clu->nid == EVP_PKEY_RSA_PSS
2479                 && (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kRSA) != 0))
2480         return -1;
2481 
2482     return s->s3->tmp.valid_flags[sig_idx] & CERT_PKEY_VALID ? sig_idx : -1;
2483 }
2484 
2485 /*
2486  * Returns true if |s| has a usable certificate configured for use
2487  * with signature scheme |sig|.
2488  * "Usable" includes a check for presence as well as applying
2489  * the signature_algorithm_cert restrictions sent by the peer (if any).
2490  * Returns false if no usable certificate is found.
2491  */
2492 static int has_usable_cert(SSL *s, const SIGALG_LOOKUP *sig, int idx)
2493 {
2494     const SIGALG_LOOKUP *lu;
2495     int mdnid, pknid;
2496     size_t i;
2497 
2498     /* TLS 1.2 callers can override lu->sig_idx, but not TLS 1.3 callers. */
2499     if (idx == -1)
2500         idx = sig->sig_idx;
2501     if (!ssl_has_cert(s, idx))
2502         return 0;
2503     if (s->s3->tmp.peer_cert_sigalgs != NULL) {
2504         for (i = 0; i < s->s3->tmp.peer_cert_sigalgslen; i++) {
2505             lu = tls1_lookup_sigalg(s->s3->tmp.peer_cert_sigalgs[i]);
2506             if (lu == NULL
2507                 || !X509_get_signature_info(s->cert->pkeys[idx].x509, &mdnid,
2508                                             &pknid, NULL, NULL))
2509                 continue;
2510             /*
2511              * TODO this does not differentiate between the
2512              * rsa_pss_pss_* and rsa_pss_rsae_* schemes since we do not
2513              * have a chain here that lets us look at the key OID in the
2514              * signing certificate.
2515              */
2516             if (mdnid == lu->hash && pknid == lu->sig)
2517                 return 1;
2518         }
2519         return 0;
2520     }
2521     return 1;
2522 }
2523 
2524 /*
2525  * Choose an appropriate signature algorithm based on available certificates
2526  * Sets chosen certificate and signature algorithm.
2527  *
2528  * For servers if we fail to find a required certificate it is a fatal error,
2529  * an appropriate error code is set and a TLS alert is sent.
2530  *
2531  * For clients fatalerrs is set to 0. If a certificate is not suitable it is not
2532  * a fatal error: we will either try another certificate or not present one
2533  * to the server. In this case no error is set.
2534  */
2535 int tls_choose_sigalg(SSL *s, int fatalerrs)
2536 {
2537     const SIGALG_LOOKUP *lu = NULL;
2538     int sig_idx = -1;
2539 
2540     s->s3->tmp.cert = NULL;
2541     s->s3->tmp.sigalg = NULL;
2542 
2543     if (SSL_IS_TLS13(s)) {
2544         size_t i;
2545 #ifndef OPENSSL_NO_EC
2546         int curve = -1;
2547 #endif
2548 
2549         /* Look for a certificate matching shared sigalgs */
2550         for (i = 0; i < s->cert->shared_sigalgslen; i++) {
2551             lu = s->cert->shared_sigalgs[i];
2552             sig_idx = -1;
2553 
2554             /* Skip SHA1, SHA224, DSA and RSA if not PSS */
2555             if (lu->hash == NID_sha1
2556                 || lu->hash == NID_sha224
2557                 || lu->sig == EVP_PKEY_DSA
2558                 || lu->sig == EVP_PKEY_RSA)
2559                 continue;
2560             /* Check that we have a cert, and signature_algorithms_cert */
2561             if (!tls1_lookup_md(lu, NULL) || !has_usable_cert(s, lu, -1))
2562                 continue;
2563             if (lu->sig == EVP_PKEY_EC) {
2564 #ifndef OPENSSL_NO_EC
2565                 if (curve == -1) {
2566                     EC_KEY *ec = EVP_PKEY_get0_EC_KEY(s->cert->pkeys[SSL_PKEY_ECC].privatekey);
2567 
2568                     curve = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec));
2569                 }
2570                 if (lu->curve != NID_undef && curve != lu->curve)
2571                     continue;
2572 #else
2573                 continue;
2574 #endif
2575             } else if (lu->sig == EVP_PKEY_RSA_PSS) {
2576                 /* validate that key is large enough for the signature algorithm */
2577                 EVP_PKEY *pkey;
2578 
2579                 pkey = s->cert->pkeys[lu->sig_idx].privatekey;
2580                 if (!rsa_pss_check_min_key_size(EVP_PKEY_get0(pkey), lu))
2581                     continue;
2582             }
2583             break;
2584         }
2585         if (i == s->cert->shared_sigalgslen) {
2586             if (!fatalerrs)
2587                 return 1;
2588             SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_CHOOSE_SIGALG,
2589                      SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
2590             return 0;
2591         }
2592     } else {
2593         /* If ciphersuite doesn't require a cert nothing to do */
2594         if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aCERT))
2595             return 1;
2596         if (!s->server && !ssl_has_cert(s, s->cert->key - s->cert->pkeys))
2597                 return 1;
2598 
2599         if (SSL_USE_SIGALGS(s)) {
2600             size_t i;
2601             if (s->s3->tmp.peer_sigalgs != NULL) {
2602 #ifndef OPENSSL_NO_EC
2603                 int curve;
2604 
2605                 /* For Suite B need to match signature algorithm to curve */
2606                 if (tls1_suiteb(s)) {
2607                     EC_KEY *ec = EVP_PKEY_get0_EC_KEY(s->cert->pkeys[SSL_PKEY_ECC].privatekey);
2608                     curve = EC_GROUP_get_curve_name(EC_KEY_get0_group(ec));
2609                 } else {
2610                     curve = -1;
2611                 }
2612 #endif
2613 
2614                 /*
2615                  * Find highest preference signature algorithm matching
2616                  * cert type
2617                  */
2618                 for (i = 0; i < s->cert->shared_sigalgslen; i++) {
2619                     lu = s->cert->shared_sigalgs[i];
2620 
2621                     if (s->server) {
2622                         if ((sig_idx = tls12_get_cert_sigalg_idx(s, lu)) == -1)
2623                             continue;
2624                     } else {
2625                         int cc_idx = s->cert->key - s->cert->pkeys;
2626 
2627                         sig_idx = lu->sig_idx;
2628                         if (cc_idx != sig_idx)
2629                             continue;
2630                     }
2631                     /* Check that we have a cert, and sig_algs_cert */
2632                     if (!has_usable_cert(s, lu, sig_idx))
2633                         continue;
2634                     if (lu->sig == EVP_PKEY_RSA_PSS) {
2635                         /* validate that key is large enough for the signature algorithm */
2636                         EVP_PKEY *pkey = s->cert->pkeys[sig_idx].privatekey;
2637 
2638                         if (!rsa_pss_check_min_key_size(EVP_PKEY_get0(pkey), lu))
2639                             continue;
2640                     }
2641 #ifndef OPENSSL_NO_EC
2642                     if (curve == -1 || lu->curve == curve)
2643 #endif
2644                         break;
2645                 }
2646                 if (i == s->cert->shared_sigalgslen) {
2647                     if (!fatalerrs)
2648                         return 1;
2649                     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2650                              SSL_F_TLS_CHOOSE_SIGALG,
2651                              SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
2652                     return 0;
2653                 }
2654             } else {
2655                 /*
2656                  * If we have no sigalg use defaults
2657                  */
2658                 const uint16_t *sent_sigs;
2659                 size_t sent_sigslen;
2660 
2661                 if ((lu = tls1_get_legacy_sigalg(s, -1)) == NULL) {
2662                     if (!fatalerrs)
2663                         return 1;
2664                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CHOOSE_SIGALG,
2665                              ERR_R_INTERNAL_ERROR);
2666                     return 0;
2667                 }
2668 
2669                 /* Check signature matches a type we sent */
2670                 sent_sigslen = tls12_get_psigalgs(s, 1, &sent_sigs);
2671                 for (i = 0; i < sent_sigslen; i++, sent_sigs++) {
2672                     if (lu->sigalg == *sent_sigs
2673                             && has_usable_cert(s, lu, lu->sig_idx))
2674                         break;
2675                 }
2676                 if (i == sent_sigslen) {
2677                     if (!fatalerrs)
2678                         return 1;
2679                     SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
2680                              SSL_F_TLS_CHOOSE_SIGALG,
2681                              SSL_R_WRONG_SIGNATURE_TYPE);
2682                     return 0;
2683                 }
2684             }
2685         } else {
2686             if ((lu = tls1_get_legacy_sigalg(s, -1)) == NULL) {
2687                 if (!fatalerrs)
2688                     return 1;
2689                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CHOOSE_SIGALG,
2690                          ERR_R_INTERNAL_ERROR);
2691                 return 0;
2692             }
2693         }
2694     }
2695     if (sig_idx == -1)
2696         sig_idx = lu->sig_idx;
2697     s->s3->tmp.cert = &s->cert->pkeys[sig_idx];
2698     s->cert->key = s->s3->tmp.cert;
2699     s->s3->tmp.sigalg = lu;
2700     return 1;
2701 }
2702 
2703 int SSL_CTX_set_tlsext_max_fragment_length(SSL_CTX *ctx, uint8_t mode)
2704 {
2705     if (mode != TLSEXT_max_fragment_length_DISABLED
2706             && !IS_MAX_FRAGMENT_LENGTH_EXT_VALID(mode)) {
2707         SSLerr(SSL_F_SSL_CTX_SET_TLSEXT_MAX_FRAGMENT_LENGTH,
2708                SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH);
2709         return 0;
2710     }
2711 
2712     ctx->ext.max_fragment_len_mode = mode;
2713     return 1;
2714 }
2715 
2716 int SSL_set_tlsext_max_fragment_length(SSL *ssl, uint8_t mode)
2717 {
2718     if (mode != TLSEXT_max_fragment_length_DISABLED
2719             && !IS_MAX_FRAGMENT_LENGTH_EXT_VALID(mode)) {
2720         SSLerr(SSL_F_SSL_SET_TLSEXT_MAX_FRAGMENT_LENGTH,
2721                SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH);
2722         return 0;
2723     }
2724 
2725     ssl->ext.max_fragment_len_mode = mode;
2726     return 1;
2727 }
2728 
2729 uint8_t SSL_SESSION_get_max_fragment_length(const SSL_SESSION *session)
2730 {
2731     return session->ext.max_fragment_len_mode;
2732 }
2733