1 /*
2  * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (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/core_names.h>
16 #include <openssl/ocsp.h>
17 #include <openssl/conf.h>
18 #include <openssl/x509v3.h>
19 #include <openssl/dh.h>
20 #include <openssl/bn.h>
21 #include <openssl/provider.h>
22 #include <openssl/param_build.h>
23 #include "internal/nelem.h"
24 #include "internal/sizes.h"
25 #include "internal/tlsgroups.h"
26 #include "ssl_local.h"
27 #include <openssl/ct.h>
28 
29 static const SIGALG_LOOKUP *find_sig_alg(SSL *s, X509 *x, EVP_PKEY *pkey);
30 static int tls12_sigalg_allowed(const SSL *s, int op, const SIGALG_LOOKUP *lu);
31 
32 SSL3_ENC_METHOD const TLSv1_enc_data = {
33     tls1_enc,
34     tls1_mac,
35     tls1_setup_key_block,
36     tls1_generate_master_secret,
37     tls1_change_cipher_state,
38     tls1_final_finish_mac,
39     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
40     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
41     tls1_alert_code,
42     tls1_export_keying_material,
43     0,
44     ssl3_set_handshake_header,
45     tls_close_construct_packet,
46     ssl3_handshake_write
47 };
48 
49 SSL3_ENC_METHOD const TLSv1_1_enc_data = {
50     tls1_enc,
51     tls1_mac,
52     tls1_setup_key_block,
53     tls1_generate_master_secret,
54     tls1_change_cipher_state,
55     tls1_final_finish_mac,
56     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
57     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
58     tls1_alert_code,
59     tls1_export_keying_material,
60     SSL_ENC_FLAG_EXPLICIT_IV,
61     ssl3_set_handshake_header,
62     tls_close_construct_packet,
63     ssl3_handshake_write
64 };
65 
66 SSL3_ENC_METHOD const TLSv1_2_enc_data = {
67     tls1_enc,
68     tls1_mac,
69     tls1_setup_key_block,
70     tls1_generate_master_secret,
71     tls1_change_cipher_state,
72     tls1_final_finish_mac,
73     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
74     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
75     tls1_alert_code,
76     tls1_export_keying_material,
77     SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF
78         | SSL_ENC_FLAG_TLS1_2_CIPHERS,
79     ssl3_set_handshake_header,
80     tls_close_construct_packet,
81     ssl3_handshake_write
82 };
83 
84 SSL3_ENC_METHOD const TLSv1_3_enc_data = {
85     tls13_enc,
86     tls1_mac,
87     tls13_setup_key_block,
88     tls13_generate_master_secret,
89     tls13_change_cipher_state,
90     tls13_final_finish_mac,
91     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
92     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
93     tls13_alert_code,
94     tls13_export_keying_material,
95     SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF,
96     ssl3_set_handshake_header,
97     tls_close_construct_packet,
98     ssl3_handshake_write
99 };
100 
tls1_default_timeout(void)101 long tls1_default_timeout(void)
102 {
103     /*
104      * 2 hours, the 24 hours mentioned in the TLSv1 spec is way too long for
105      * http, the cache would over fill
106      */
107     return (60 * 60 * 2);
108 }
109 
tls1_new(SSL *s)110 int tls1_new(SSL *s)
111 {
112     if (!ssl3_new(s))
113         return 0;
114     if (!s->method->ssl_clear(s))
115         return 0;
116 
117     return 1;
118 }
119 
tls1_free(SSL *s)120 void tls1_free(SSL *s)
121 {
122     OPENSSL_free(s->ext.session_ticket);
123     ssl3_free(s);
124 }
125 
tls1_clear(SSL *s)126 int tls1_clear(SSL *s)
127 {
128     if (!ssl3_clear(s))
129         return 0;
130 
131     if (s->method->version == TLS_ANY_VERSION)
132         s->version = TLS_MAX_VERSION_INTERNAL;
133     else
134         s->version = s->method->version;
135 
136     return 1;
137 }
138 
139 /* Legacy NID to group_id mapping. Only works for groups we know about */
140 static struct {
141     int nid;
142     uint16_t group_id;
143 } nid_to_group[] = {
144     {NID_sect163k1, OSSL_TLS_GROUP_ID_sect163k1},
145     {NID_sect163r1, OSSL_TLS_GROUP_ID_sect163r1},
146     {NID_sect163r2, OSSL_TLS_GROUP_ID_sect163r2},
147     {NID_sect193r1, OSSL_TLS_GROUP_ID_sect193r1},
148     {NID_sect193r2, OSSL_TLS_GROUP_ID_sect193r2},
149     {NID_sect233k1, OSSL_TLS_GROUP_ID_sect233k1},
150     {NID_sect233r1, OSSL_TLS_GROUP_ID_sect233r1},
151     {NID_sect239k1, OSSL_TLS_GROUP_ID_sect239k1},
152     {NID_sect283k1, OSSL_TLS_GROUP_ID_sect283k1},
153     {NID_sect283r1, OSSL_TLS_GROUP_ID_sect283r1},
154     {NID_sect409k1, OSSL_TLS_GROUP_ID_sect409k1},
155     {NID_sect409r1, OSSL_TLS_GROUP_ID_sect409r1},
156     {NID_sect571k1, OSSL_TLS_GROUP_ID_sect571k1},
157     {NID_sect571r1, OSSL_TLS_GROUP_ID_sect571r1},
158     {NID_secp160k1, OSSL_TLS_GROUP_ID_secp160k1},
159     {NID_secp160r1, OSSL_TLS_GROUP_ID_secp160r1},
160     {NID_secp160r2, OSSL_TLS_GROUP_ID_secp160r2},
161     {NID_secp192k1, OSSL_TLS_GROUP_ID_secp192k1},
162     {NID_X9_62_prime192v1, OSSL_TLS_GROUP_ID_secp192r1},
163     {NID_secp224k1, OSSL_TLS_GROUP_ID_secp224k1},
164     {NID_secp224r1, OSSL_TLS_GROUP_ID_secp224r1},
165     {NID_secp256k1, OSSL_TLS_GROUP_ID_secp256k1},
166     {NID_X9_62_prime256v1, OSSL_TLS_GROUP_ID_secp256r1},
167     {NID_secp384r1, OSSL_TLS_GROUP_ID_secp384r1},
168     {NID_secp521r1, OSSL_TLS_GROUP_ID_secp521r1},
169     {NID_brainpoolP256r1, OSSL_TLS_GROUP_ID_brainpoolP256r1},
170     {NID_brainpoolP384r1, OSSL_TLS_GROUP_ID_brainpoolP384r1},
171     {NID_brainpoolP512r1, OSSL_TLS_GROUP_ID_brainpoolP512r1},
172     {EVP_PKEY_X25519, OSSL_TLS_GROUP_ID_x25519},
173     {EVP_PKEY_X448, OSSL_TLS_GROUP_ID_x448},
174     {NID_id_tc26_gost_3410_2012_256_paramSetA, 0x0022},
175     {NID_id_tc26_gost_3410_2012_256_paramSetB, 0x0023},
176     {NID_id_tc26_gost_3410_2012_256_paramSetC, 0x0024},
177     {NID_id_tc26_gost_3410_2012_256_paramSetD, 0x0025},
178     {NID_id_tc26_gost_3410_2012_512_paramSetA, 0x0026},
179     {NID_id_tc26_gost_3410_2012_512_paramSetB, 0x0027},
180     {NID_id_tc26_gost_3410_2012_512_paramSetC, 0x0028},
181     {NID_ffdhe2048, OSSL_TLS_GROUP_ID_ffdhe2048},
182     {NID_ffdhe3072, OSSL_TLS_GROUP_ID_ffdhe3072},
183     {NID_ffdhe4096, OSSL_TLS_GROUP_ID_ffdhe4096},
184     {NID_ffdhe6144, OSSL_TLS_GROUP_ID_ffdhe6144},
185     {NID_ffdhe8192, OSSL_TLS_GROUP_ID_ffdhe8192}
186 };
187 
188 static const unsigned char ecformats_default[] = {
189     TLSEXT_ECPOINTFORMAT_uncompressed,
190     TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
191     TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
192 };
193 
194 /* The default curves */
195 static const uint16_t supported_groups_default[] = {
196     29,                      /* X25519 (29) */
197     23,                      /* secp256r1 (23) */
198     30,                      /* X448 (30) */
199     25,                      /* secp521r1 (25) */
200     24,                      /* secp384r1 (24) */
201     34,                      /* GC256A (34) */
202     35,                      /* GC256B (35) */
203     36,                      /* GC256C (36) */
204     37,                      /* GC256D (37) */
205     38,                      /* GC512A (38) */
206     39,                      /* GC512B (39) */
207     40,                      /* GC512C (40) */
208     0x100,                   /* ffdhe2048 (0x100) */
209     0x101,                   /* ffdhe3072 (0x101) */
210     0x102,                   /* ffdhe4096 (0x102) */
211     0x103,                   /* ffdhe6144 (0x103) */
212     0x104,                   /* ffdhe8192 (0x104) */
213 };
214 
215 static const uint16_t suiteb_curves[] = {
216     TLSEXT_curve_P_256,
217     TLSEXT_curve_P_384
218 };
219 
220 struct provider_group_data_st {
221     SSL_CTX *ctx;
222     OSSL_PROVIDER *provider;
223 };
224 
225 #define TLS_GROUP_LIST_MALLOC_BLOCK_SIZE        10
226 static OSSL_CALLBACK add_provider_groups;
add_provider_groups(const OSSL_PARAM params[], void *data)227 static int add_provider_groups(const OSSL_PARAM params[], void *data)
228 {
229     struct provider_group_data_st *pgd = data;
230     SSL_CTX *ctx = pgd->ctx;
231     OSSL_PROVIDER *provider = pgd->provider;
232     const OSSL_PARAM *p;
233     TLS_GROUP_INFO *ginf = NULL;
234     EVP_KEYMGMT *keymgmt;
235     unsigned int gid;
236     unsigned int is_kem = 0;
237     int ret = 0;
238 
239     if (ctx->group_list_max_len == ctx->group_list_len) {
240         TLS_GROUP_INFO *tmp = NULL;
241 
242         if (ctx->group_list_max_len == 0)
243             tmp = OPENSSL_malloc(sizeof(TLS_GROUP_INFO)
244                                  * TLS_GROUP_LIST_MALLOC_BLOCK_SIZE);
245         else
246             tmp = OPENSSL_realloc(ctx->group_list,
247                                   (ctx->group_list_max_len
248                                    + TLS_GROUP_LIST_MALLOC_BLOCK_SIZE)
249                                   * sizeof(TLS_GROUP_INFO));
250         if (tmp == NULL) {
251             ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
252             return 0;
253         }
254         ctx->group_list = tmp;
255         memset(tmp + ctx->group_list_max_len,
256                0,
257                sizeof(TLS_GROUP_INFO) * TLS_GROUP_LIST_MALLOC_BLOCK_SIZE);
258         ctx->group_list_max_len += TLS_GROUP_LIST_MALLOC_BLOCK_SIZE;
259     }
260 
261     ginf = &ctx->group_list[ctx->group_list_len];
262 
263     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_NAME);
264     if (p == NULL || p->data_type != OSSL_PARAM_UTF8_STRING) {
265         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
266         goto err;
267     }
268     ginf->tlsname = OPENSSL_strdup(p->data);
269     if (ginf->tlsname == NULL) {
270         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
271         goto err;
272     }
273 
274     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_NAME_INTERNAL);
275     if (p == NULL || p->data_type != OSSL_PARAM_UTF8_STRING) {
276         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
277         goto err;
278     }
279     ginf->realname = OPENSSL_strdup(p->data);
280     if (ginf->realname == NULL) {
281         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
282         goto err;
283     }
284 
285     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_ID);
286     if (p == NULL || !OSSL_PARAM_get_uint(p, &gid) || gid > UINT16_MAX) {
287         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
288         goto err;
289     }
290     ginf->group_id = (uint16_t)gid;
291 
292     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_ALG);
293     if (p == NULL || p->data_type != OSSL_PARAM_UTF8_STRING) {
294         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
295         goto err;
296     }
297     ginf->algorithm = OPENSSL_strdup(p->data);
298     if (ginf->algorithm == NULL) {
299         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
300         goto err;
301     }
302 
303     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_SECURITY_BITS);
304     if (p == NULL || !OSSL_PARAM_get_uint(p, &ginf->secbits)) {
305         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
306         goto err;
307     }
308 
309     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_IS_KEM);
310     if (p != NULL && (!OSSL_PARAM_get_uint(p, &is_kem) || is_kem > 1)) {
311         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
312         goto err;
313     }
314     ginf->is_kem = 1 & is_kem;
315 
316     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_MIN_TLS);
317     if (p == NULL || !OSSL_PARAM_get_int(p, &ginf->mintls)) {
318         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
319         goto err;
320     }
321 
322     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_MAX_TLS);
323     if (p == NULL || !OSSL_PARAM_get_int(p, &ginf->maxtls)) {
324         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
325         goto err;
326     }
327 
328     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_MIN_DTLS);
329     if (p == NULL || !OSSL_PARAM_get_int(p, &ginf->mindtls)) {
330         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
331         goto err;
332     }
333 
334     p = OSSL_PARAM_locate_const(params, OSSL_CAPABILITY_TLS_GROUP_MAX_DTLS);
335     if (p == NULL || !OSSL_PARAM_get_int(p, &ginf->maxdtls)) {
336         ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT);
337         goto err;
338     }
339     /*
340      * Now check that the algorithm is actually usable for our property query
341      * string. Regardless of the result we still return success because we have
342      * successfully processed this group, even though we may decide not to use
343      * it.
344      */
345     ret = 1;
346     ERR_set_mark();
347     keymgmt = EVP_KEYMGMT_fetch(ctx->libctx, ginf->algorithm, ctx->propq);
348     if (keymgmt != NULL) {
349         /*
350          * We have successfully fetched the algorithm - however if the provider
351          * doesn't match this one then we ignore it.
352          *
353          * Note: We're cheating a little here. Technically if the same algorithm
354          * is available from more than one provider then it is undefined which
355          * implementation you will get back. Theoretically this could be
356          * different every time...we assume here that you'll always get the
357          * same one back if you repeat the exact same fetch. Is this a reasonable
358          * assumption to make (in which case perhaps we should document this
359          * behaviour)?
360          */
361         if (EVP_KEYMGMT_get0_provider(keymgmt) == provider) {
362             /* We have a match - so we will use this group */
363             ctx->group_list_len++;
364             ginf = NULL;
365         }
366         EVP_KEYMGMT_free(keymgmt);
367     }
368     ERR_pop_to_mark();
369  err:
370     if (ginf != NULL) {
371         OPENSSL_free(ginf->tlsname);
372         OPENSSL_free(ginf->realname);
373         OPENSSL_free(ginf->algorithm);
374         ginf->algorithm = ginf->tlsname = ginf->realname = NULL;
375     }
376     return ret;
377 }
378 
discover_provider_groups(OSSL_PROVIDER *provider, void *vctx)379 static int discover_provider_groups(OSSL_PROVIDER *provider, void *vctx)
380 {
381     struct provider_group_data_st pgd;
382 
383     pgd.ctx = vctx;
384     pgd.provider = provider;
385     return OSSL_PROVIDER_get_capabilities(provider, "TLS-GROUP",
386                                           add_provider_groups, &pgd);
387 }
388 
ssl_load_groups(SSL_CTX *ctx)389 int ssl_load_groups(SSL_CTX *ctx)
390 {
391     size_t i, j, num_deflt_grps = 0;
392     uint16_t tmp_supp_groups[OSSL_NELEM(supported_groups_default)];
393 
394     if (!OSSL_PROVIDER_do_all(ctx->libctx, discover_provider_groups, ctx))
395         return 0;
396 
397     for (i = 0; i < OSSL_NELEM(supported_groups_default); i++) {
398         for (j = 0; j < ctx->group_list_len; j++) {
399             if (ctx->group_list[j].group_id == supported_groups_default[i]) {
400                 tmp_supp_groups[num_deflt_grps++] = ctx->group_list[j].group_id;
401                 break;
402             }
403         }
404     }
405 
406     if (num_deflt_grps == 0)
407         return 1;
408 
409     ctx->ext.supported_groups_default
410         = OPENSSL_malloc(sizeof(uint16_t) * num_deflt_grps);
411 
412     if (ctx->ext.supported_groups_default == NULL) {
413         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
414         return 0;
415     }
416 
417     memcpy(ctx->ext.supported_groups_default,
418            tmp_supp_groups,
419            num_deflt_grps * sizeof(tmp_supp_groups[0]));
420     ctx->ext.supported_groups_default_len = num_deflt_grps;
421 
422     return 1;
423 }
424 
tls1_group_name2id(SSL_CTX *ctx, const char *name)425 static uint16_t tls1_group_name2id(SSL_CTX *ctx, const char *name)
426 {
427     size_t i;
428 
429     for (i = 0; i < ctx->group_list_len; i++) {
430         if (strcmp(ctx->group_list[i].tlsname, name) == 0
431                 || strcmp(ctx->group_list[i].realname, name) == 0)
432             return ctx->group_list[i].group_id;
433     }
434 
435     return 0;
436 }
437 
tls1_group_id_lookup(SSL_CTX *ctx, uint16_t group_id)438 const TLS_GROUP_INFO *tls1_group_id_lookup(SSL_CTX *ctx, uint16_t group_id)
439 {
440     size_t i;
441 
442     for (i = 0; i < ctx->group_list_len; i++) {
443         if (ctx->group_list[i].group_id == group_id)
444             return &ctx->group_list[i];
445     }
446 
447     return NULL;
448 }
449 
tls1_group_id2nid(uint16_t group_id, int include_unknown)450 int tls1_group_id2nid(uint16_t group_id, int include_unknown)
451 {
452     size_t i;
453 
454     if (group_id == 0)
455         return NID_undef;
456 
457     /*
458      * Return well known Group NIDs - for backwards compatibility. This won't
459      * work for groups we don't know about.
460      */
461     for (i = 0; i < OSSL_NELEM(nid_to_group); i++)
462     {
463         if (nid_to_group[i].group_id == group_id)
464             return nid_to_group[i].nid;
465     }
466     if (!include_unknown)
467         return NID_undef;
468     return TLSEXT_nid_unknown | (int)group_id;
469 }
470 
tls1_nid2group_id(int nid)471 uint16_t tls1_nid2group_id(int nid)
472 {
473     size_t i;
474 
475     /*
476      * Return well known Group ids - for backwards compatibility. This won't
477      * work for groups we don't know about.
478      */
479     for (i = 0; i < OSSL_NELEM(nid_to_group); i++)
480     {
481         if (nid_to_group[i].nid == nid)
482             return nid_to_group[i].group_id;
483     }
484 
485     return 0;
486 }
487 
488 /*
489  * Set *pgroups to the supported groups list and *pgroupslen to
490  * the number of groups supported.
491  */
tls1_get_supported_groups(SSL *s, const uint16_t **pgroups, size_t *pgroupslen)492 void tls1_get_supported_groups(SSL *s, const uint16_t **pgroups,
493                                size_t *pgroupslen)
494 {
495     /* For Suite B mode only include P-256, P-384 */
496     switch (tls1_suiteb(s)) {
497     case SSL_CERT_FLAG_SUITEB_128_LOS:
498         *pgroups = suiteb_curves;
499         *pgroupslen = OSSL_NELEM(suiteb_curves);
500         break;
501 
502     case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
503         *pgroups = suiteb_curves;
504         *pgroupslen = 1;
505         break;
506 
507     case SSL_CERT_FLAG_SUITEB_192_LOS:
508         *pgroups = suiteb_curves + 1;
509         *pgroupslen = 1;
510         break;
511 
512     default:
513         if (s->ext.supportedgroups == NULL) {
514             *pgroups = s->ctx->ext.supported_groups_default;
515             *pgroupslen = s->ctx->ext.supported_groups_default_len;
516         } else {
517             *pgroups = s->ext.supportedgroups;
518             *pgroupslen = s->ext.supportedgroups_len;
519         }
520         break;
521     }
522 }
523 
tls_valid_group(SSL *s, uint16_t group_id, int minversion, int maxversion, int isec, int *okfortls13)524 int tls_valid_group(SSL *s, uint16_t group_id, int minversion, int maxversion,
525                     int isec, int *okfortls13)
526 {
527     const TLS_GROUP_INFO *ginfo = tls1_group_id_lookup(s->ctx, group_id);
528     int ret;
529 
530     if (okfortls13 != NULL)
531         *okfortls13 = 0;
532 
533     if (ginfo == NULL)
534         return 0;
535 
536     if (SSL_IS_DTLS(s)) {
537         if (ginfo->mindtls < 0 || ginfo->maxdtls < 0)
538             return 0;
539         if (ginfo->maxdtls == 0)
540             ret = 1;
541         else
542             ret = DTLS_VERSION_LE(minversion, ginfo->maxdtls);
543         if (ginfo->mindtls > 0)
544             ret &= DTLS_VERSION_GE(maxversion, ginfo->mindtls);
545     } else {
546         if (ginfo->mintls < 0 || ginfo->maxtls < 0)
547             return 0;
548         if (ginfo->maxtls == 0)
549             ret = 1;
550         else
551             ret = (minversion <= ginfo->maxtls);
552         if (ginfo->mintls > 0)
553             ret &= (maxversion >= ginfo->mintls);
554         if (ret && okfortls13 != NULL && maxversion == TLS1_3_VERSION)
555             *okfortls13 = (ginfo->maxtls == 0)
556                           || (ginfo->maxtls >= TLS1_3_VERSION);
557     }
558     ret &= !isec
559            || strcmp(ginfo->algorithm, "EC") == 0
560            || strcmp(ginfo->algorithm, "X25519") == 0
561            || strcmp(ginfo->algorithm, "X448") == 0;
562 
563     return ret;
564 }
565 
566 /* See if group is allowed by security callback */
tls_group_allowed(SSL *s, uint16_t group, int op)567 int tls_group_allowed(SSL *s, uint16_t group, int op)
568 {
569     const TLS_GROUP_INFO *ginfo = tls1_group_id_lookup(s->ctx, group);
570     unsigned char gtmp[2];
571 
572     if (ginfo == NULL)
573         return 0;
574 
575     gtmp[0] = group >> 8;
576     gtmp[1] = group & 0xff;
577     return ssl_security(s, op, ginfo->secbits,
578                         tls1_group_id2nid(ginfo->group_id, 0), (void *)gtmp);
579 }
580 
581 /* Return 1 if "id" is in "list" */
tls1_in_list(uint16_t id, const uint16_t *list, size_t listlen)582 static int tls1_in_list(uint16_t id, const uint16_t *list, size_t listlen)
583 {
584     size_t i;
585     for (i = 0; i < listlen; i++)
586         if (list[i] == id)
587             return 1;
588     return 0;
589 }
590 
591 /*-
592  * For nmatch >= 0, return the id of the |nmatch|th shared group or 0
593  * if there is no match.
594  * For nmatch == -1, return number of matches
595  * For nmatch == -2, return the id of the group to use for
596  * a tmp key, or 0 if there is no match.
597  */
tls1_shared_group(SSL *s, int nmatch)598 uint16_t tls1_shared_group(SSL *s, int nmatch)
599 {
600     const uint16_t *pref, *supp;
601     size_t num_pref, num_supp, i;
602     int k;
603 
604     /* Can't do anything on client side */
605     if (s->server == 0)
606         return 0;
607     if (nmatch == -2) {
608         if (tls1_suiteb(s)) {
609             /*
610              * For Suite B ciphersuite determines curve: we already know
611              * these are acceptable due to previous checks.
612              */
613             unsigned long cid = s->s3.tmp.new_cipher->id;
614 
615             if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
616                 return TLSEXT_curve_P_256;
617             if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
618                 return TLSEXT_curve_P_384;
619             /* Should never happen */
620             return 0;
621         }
622         /* If not Suite B just return first preference shared curve */
623         nmatch = 0;
624     }
625     /*
626      * If server preference set, our groups are the preference order
627      * otherwise peer decides.
628      */
629     if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
630         tls1_get_supported_groups(s, &pref, &num_pref);
631         tls1_get_peer_groups(s, &supp, &num_supp);
632     } else {
633         tls1_get_peer_groups(s, &pref, &num_pref);
634         tls1_get_supported_groups(s, &supp, &num_supp);
635     }
636 
637     for (k = 0, i = 0; i < num_pref; i++) {
638         uint16_t id = pref[i];
639 
640         if (!tls1_in_list(id, supp, num_supp)
641             || !tls_group_allowed(s, id, SSL_SECOP_CURVE_SHARED))
642                     continue;
643         if (nmatch == k)
644             return id;
645          k++;
646     }
647     if (nmatch == -1)
648         return k;
649     /* Out of range (nmatch > k). */
650     return 0;
651 }
652 
tls1_set_groups(uint16_t **pext, size_t *pextlen, int *groups, size_t ngroups)653 int tls1_set_groups(uint16_t **pext, size_t *pextlen,
654                     int *groups, size_t ngroups)
655 {
656     uint16_t *glist;
657     size_t i;
658     /*
659      * Bitmap of groups included to detect duplicates: two variables are added
660      * to detect duplicates as some values are more than 32.
661      */
662     unsigned long *dup_list = NULL;
663     unsigned long dup_list_egrp = 0;
664     unsigned long dup_list_dhgrp = 0;
665 
666     if (ngroups == 0) {
667         ERR_raise(ERR_LIB_SSL, SSL_R_BAD_LENGTH);
668         return 0;
669     }
670     if ((glist = OPENSSL_malloc(ngroups * sizeof(*glist))) == NULL) {
671         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
672         return 0;
673     }
674     for (i = 0; i < ngroups; i++) {
675         unsigned long idmask;
676         uint16_t id;
677         id = tls1_nid2group_id(groups[i]);
678         if ((id & 0x00FF) >= (sizeof(unsigned long) * 8))
679             goto err;
680         idmask = 1L << (id & 0x00FF);
681         dup_list = (id < 0x100) ? &dup_list_egrp : &dup_list_dhgrp;
682         if (!id || ((*dup_list) & idmask))
683             goto err;
684         *dup_list |= idmask;
685         glist[i] = id;
686     }
687     OPENSSL_free(*pext);
688     *pext = glist;
689     *pextlen = ngroups;
690     return 1;
691 err:
692     OPENSSL_free(glist);
693     return 0;
694 }
695 
696 # define GROUPLIST_INCREMENT   40
697 # define GROUP_NAME_BUFFER_LENGTH 64
698 typedef struct {
699     SSL_CTX *ctx;
700     size_t gidcnt;
701     size_t gidmax;
702     uint16_t *gid_arr;
703 } gid_cb_st;
704 
gid_cb(const char *elem, int len, void *arg)705 static int gid_cb(const char *elem, int len, void *arg)
706 {
707     gid_cb_st *garg = arg;
708     size_t i;
709     uint16_t gid = 0;
710     char etmp[GROUP_NAME_BUFFER_LENGTH];
711 
712     if (elem == NULL)
713         return 0;
714     if (garg->gidcnt == garg->gidmax) {
715         uint16_t *tmp =
716             OPENSSL_realloc(garg->gid_arr,
717                             (garg->gidmax + GROUPLIST_INCREMENT) * sizeof(*garg->gid_arr));
718         if (tmp == NULL)
719             return 0;
720         garg->gidmax += GROUPLIST_INCREMENT;
721         garg->gid_arr = tmp;
722     }
723     if (len > (int)(sizeof(etmp) - 1))
724         return 0;
725     memcpy(etmp, elem, len);
726     etmp[len] = 0;
727 
728     gid = tls1_group_name2id(garg->ctx, etmp);
729     if (gid == 0) {
730         ERR_raise_data(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT,
731                        "group '%s' cannot be set", etmp);
732         return 0;
733     }
734     for (i = 0; i < garg->gidcnt; i++)
735         if (garg->gid_arr[i] == gid)
736             return 0;
737     garg->gid_arr[garg->gidcnt++] = gid;
738     return 1;
739 }
740 
741 /* Set groups based on a colon separated list */
tls1_set_groups_list(SSL_CTX *ctx, uint16_t **pext, size_t *pextlen, const char *str)742 int tls1_set_groups_list(SSL_CTX *ctx, uint16_t **pext, size_t *pextlen,
743                          const char *str)
744 {
745     gid_cb_st gcb;
746     uint16_t *tmparr;
747     int ret = 0;
748 
749     gcb.gidcnt = 0;
750     gcb.gidmax = GROUPLIST_INCREMENT;
751     gcb.gid_arr = OPENSSL_malloc(gcb.gidmax * sizeof(*gcb.gid_arr));
752     if (gcb.gid_arr == NULL)
753         return 0;
754     gcb.ctx = ctx;
755     if (!CONF_parse_list(str, ':', 1, gid_cb, &gcb))
756         goto end;
757     if (pext == NULL) {
758         ret = 1;
759         goto end;
760     }
761 
762     /*
763      * gid_cb ensurse there are no duplicates so we can just go ahead and set
764      * the result
765      */
766     tmparr = OPENSSL_memdup(gcb.gid_arr, gcb.gidcnt * sizeof(*tmparr));
767     if (tmparr == NULL)
768         goto end;
769     OPENSSL_free(*pext);
770     *pext = tmparr;
771     *pextlen = gcb.gidcnt;
772     ret = 1;
773  end:
774     OPENSSL_free(gcb.gid_arr);
775     return ret;
776 }
777 
778 /* Check a group id matches preferences */
tls1_check_group_id(SSL *s, uint16_t group_id, int check_own_groups)779 int tls1_check_group_id(SSL *s, uint16_t group_id, int check_own_groups)
780     {
781     const uint16_t *groups;
782     size_t groups_len;
783 
784     if (group_id == 0)
785         return 0;
786 
787     /* Check for Suite B compliance */
788     if (tls1_suiteb(s) && s->s3.tmp.new_cipher != NULL) {
789         unsigned long cid = s->s3.tmp.new_cipher->id;
790 
791         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256) {
792             if (group_id != TLSEXT_curve_P_256)
793                 return 0;
794         } else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384) {
795             if (group_id != TLSEXT_curve_P_384)
796                 return 0;
797         } else {
798             /* Should never happen */
799             return 0;
800         }
801     }
802 
803     if (check_own_groups) {
804         /* Check group is one of our preferences */
805         tls1_get_supported_groups(s, &groups, &groups_len);
806         if (!tls1_in_list(group_id, groups, groups_len))
807             return 0;
808     }
809 
810     if (!tls_group_allowed(s, group_id, SSL_SECOP_CURVE_CHECK))
811         return 0;
812 
813     /* For clients, nothing more to check */
814     if (!s->server)
815         return 1;
816 
817     /* Check group is one of peers preferences */
818     tls1_get_peer_groups(s, &groups, &groups_len);
819 
820     /*
821      * RFC 4492 does not require the supported elliptic curves extension
822      * so if it is not sent we can just choose any curve.
823      * It is invalid to send an empty list in the supported groups
824      * extension, so groups_len == 0 always means no extension.
825      */
826     if (groups_len == 0)
827             return 1;
828     return tls1_in_list(group_id, groups, groups_len);
829 }
830 
tls1_get_formatlist(SSL *s, const unsigned char **pformats, size_t *num_formats)831 void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
832                          size_t *num_formats)
833 {
834     /*
835      * If we have a custom point format list use it otherwise use default
836      */
837     if (s->ext.ecpointformats) {
838         *pformats = s->ext.ecpointformats;
839         *num_formats = s->ext.ecpointformats_len;
840     } else {
841         *pformats = ecformats_default;
842         /* For Suite B we don't support char2 fields */
843         if (tls1_suiteb(s))
844             *num_formats = sizeof(ecformats_default) - 1;
845         else
846             *num_formats = sizeof(ecformats_default);
847     }
848 }
849 
850 /* Check a key is compatible with compression extension */
tls1_check_pkey_comp(SSL *s, EVP_PKEY *pkey)851 static int tls1_check_pkey_comp(SSL *s, EVP_PKEY *pkey)
852 {
853     unsigned char comp_id;
854     size_t i;
855     int point_conv;
856 
857     /* If not an EC key nothing to check */
858     if (!EVP_PKEY_is_a(pkey, "EC"))
859         return 1;
860 
861 
862     /* Get required compression id */
863     point_conv = EVP_PKEY_get_ec_point_conv_form(pkey);
864     if (point_conv == 0)
865         return 0;
866     if (point_conv == POINT_CONVERSION_UNCOMPRESSED) {
867             comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
868     } else if (SSL_IS_TLS13(s)) {
869         /*
870          * ec_point_formats extension is not used in TLSv1.3 so we ignore
871          * this check.
872          */
873         return 1;
874     } else {
875         int field_type = EVP_PKEY_get_field_type(pkey);
876 
877         if (field_type == NID_X9_62_prime_field)
878             comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
879         else if (field_type == NID_X9_62_characteristic_two_field)
880             comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
881         else
882             return 0;
883     }
884     /*
885      * If point formats extension present check it, otherwise everything is
886      * supported (see RFC4492).
887      */
888     if (s->ext.peer_ecpointformats == NULL)
889         return 1;
890 
891     for (i = 0; i < s->ext.peer_ecpointformats_len; i++) {
892         if (s->ext.peer_ecpointformats[i] == comp_id)
893             return 1;
894     }
895     return 0;
896 }
897 
898 /* Return group id of a key */
tls1_get_group_id(EVP_PKEY *pkey)899 static uint16_t tls1_get_group_id(EVP_PKEY *pkey)
900 {
901     int curve_nid = ssl_get_EC_curve_nid(pkey);
902 
903     if (curve_nid == NID_undef)
904         return 0;
905     return tls1_nid2group_id(curve_nid);
906 }
907 
908 /*
909  * Check cert parameters compatible with extensions: currently just checks EC
910  * certificates have compatible curves and compression.
911  */
tls1_check_cert_param(SSL *s, X509 *x, int check_ee_md)912 static int tls1_check_cert_param(SSL *s, X509 *x, int check_ee_md)
913 {
914     uint16_t group_id;
915     EVP_PKEY *pkey;
916     pkey = X509_get0_pubkey(x);
917     if (pkey == NULL)
918         return 0;
919     /* If not EC nothing to do */
920     if (!EVP_PKEY_is_a(pkey, "EC"))
921         return 1;
922     /* Check compression */
923     if (!tls1_check_pkey_comp(s, pkey))
924         return 0;
925     group_id = tls1_get_group_id(pkey);
926     /*
927      * For a server we allow the certificate to not be in our list of supported
928      * groups.
929      */
930     if (!tls1_check_group_id(s, group_id, !s->server))
931         return 0;
932     /*
933      * Special case for suite B. We *MUST* sign using SHA256+P-256 or
934      * SHA384+P-384.
935      */
936     if (check_ee_md && tls1_suiteb(s)) {
937         int check_md;
938         size_t i;
939 
940         /* Check to see we have necessary signing algorithm */
941         if (group_id == TLSEXT_curve_P_256)
942             check_md = NID_ecdsa_with_SHA256;
943         else if (group_id == TLSEXT_curve_P_384)
944             check_md = NID_ecdsa_with_SHA384;
945         else
946             return 0;           /* Should never happen */
947         for (i = 0; i < s->shared_sigalgslen; i++) {
948             if (check_md == s->shared_sigalgs[i]->sigandhash)
949                 return 1;;
950         }
951         return 0;
952     }
953     return 1;
954 }
955 
956 /*
957  * tls1_check_ec_tmp_key - Check EC temporary key compatibility
958  * @s: SSL connection
959  * @cid: Cipher ID we're considering using
960  *
961  * Checks that the kECDHE cipher suite we're considering using
962  * is compatible with the client extensions.
963  *
964  * Returns 0 when the cipher can't be used or 1 when it can.
965  */
tls1_check_ec_tmp_key(SSL *s, unsigned long cid)966 int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
967 {
968     /* If not Suite B just need a shared group */
969     if (!tls1_suiteb(s))
970         return tls1_shared_group(s, 0) != 0;
971     /*
972      * If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384, no other
973      * curves permitted.
974      */
975     if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
976         return tls1_check_group_id(s, TLSEXT_curve_P_256, 1);
977     if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
978         return tls1_check_group_id(s, TLSEXT_curve_P_384, 1);
979 
980     return 0;
981 }
982 
983 /* Default sigalg schemes */
984 static const uint16_t tls12_sigalgs[] = {
985     TLSEXT_SIGALG_ecdsa_secp256r1_sha256,
986     TLSEXT_SIGALG_ecdsa_secp384r1_sha384,
987     TLSEXT_SIGALG_ecdsa_secp521r1_sha512,
988     TLSEXT_SIGALG_ed25519,
989     TLSEXT_SIGALG_ed448,
990 
991     TLSEXT_SIGALG_rsa_pss_pss_sha256,
992     TLSEXT_SIGALG_rsa_pss_pss_sha384,
993     TLSEXT_SIGALG_rsa_pss_pss_sha512,
994     TLSEXT_SIGALG_rsa_pss_rsae_sha256,
995     TLSEXT_SIGALG_rsa_pss_rsae_sha384,
996     TLSEXT_SIGALG_rsa_pss_rsae_sha512,
997 
998     TLSEXT_SIGALG_rsa_pkcs1_sha256,
999     TLSEXT_SIGALG_rsa_pkcs1_sha384,
1000     TLSEXT_SIGALG_rsa_pkcs1_sha512,
1001 
1002     TLSEXT_SIGALG_ecdsa_sha224,
1003     TLSEXT_SIGALG_ecdsa_sha1,
1004 
1005     TLSEXT_SIGALG_rsa_pkcs1_sha224,
1006     TLSEXT_SIGALG_rsa_pkcs1_sha1,
1007 
1008     TLSEXT_SIGALG_dsa_sha224,
1009     TLSEXT_SIGALG_dsa_sha1,
1010 
1011     TLSEXT_SIGALG_dsa_sha256,
1012     TLSEXT_SIGALG_dsa_sha384,
1013     TLSEXT_SIGALG_dsa_sha512,
1014 
1015 #ifndef OPENSSL_NO_GOST
1016     TLSEXT_SIGALG_gostr34102012_256_intrinsic,
1017     TLSEXT_SIGALG_gostr34102012_512_intrinsic,
1018     TLSEXT_SIGALG_gostr34102012_256_gostr34112012_256,
1019     TLSEXT_SIGALG_gostr34102012_512_gostr34112012_512,
1020     TLSEXT_SIGALG_gostr34102001_gostr3411,
1021 #endif
1022 };
1023 
1024 
1025 static const uint16_t suiteb_sigalgs[] = {
1026     TLSEXT_SIGALG_ecdsa_secp256r1_sha256,
1027     TLSEXT_SIGALG_ecdsa_secp384r1_sha384
1028 };
1029 
1030 static const SIGALG_LOOKUP sigalg_lookup_tbl[] = {
1031     {"ecdsa_secp256r1_sha256", TLSEXT_SIGALG_ecdsa_secp256r1_sha256,
1032      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
1033      NID_ecdsa_with_SHA256, NID_X9_62_prime256v1, 1},
1034     {"ecdsa_secp384r1_sha384", TLSEXT_SIGALG_ecdsa_secp384r1_sha384,
1035      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
1036      NID_ecdsa_with_SHA384, NID_secp384r1, 1},
1037     {"ecdsa_secp521r1_sha512", TLSEXT_SIGALG_ecdsa_secp521r1_sha512,
1038      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
1039      NID_ecdsa_with_SHA512, NID_secp521r1, 1},
1040     {"ed25519", TLSEXT_SIGALG_ed25519,
1041      NID_undef, -1, EVP_PKEY_ED25519, SSL_PKEY_ED25519,
1042      NID_undef, NID_undef, 1},
1043     {"ed448", TLSEXT_SIGALG_ed448,
1044      NID_undef, -1, EVP_PKEY_ED448, SSL_PKEY_ED448,
1045      NID_undef, NID_undef, 1},
1046     {NULL, TLSEXT_SIGALG_ecdsa_sha224,
1047      NID_sha224, SSL_MD_SHA224_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
1048      NID_ecdsa_with_SHA224, NID_undef, 1},
1049     {NULL, TLSEXT_SIGALG_ecdsa_sha1,
1050      NID_sha1, SSL_MD_SHA1_IDX, EVP_PKEY_EC, SSL_PKEY_ECC,
1051      NID_ecdsa_with_SHA1, NID_undef, 1},
1052     {"rsa_pss_rsae_sha256", TLSEXT_SIGALG_rsa_pss_rsae_sha256,
1053      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA,
1054      NID_undef, NID_undef, 1},
1055     {"rsa_pss_rsae_sha384", TLSEXT_SIGALG_rsa_pss_rsae_sha384,
1056      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA,
1057      NID_undef, NID_undef, 1},
1058     {"rsa_pss_rsae_sha512", TLSEXT_SIGALG_rsa_pss_rsae_sha512,
1059      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA,
1060      NID_undef, NID_undef, 1},
1061     {"rsa_pss_pss_sha256", TLSEXT_SIGALG_rsa_pss_pss_sha256,
1062      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA_PSS_SIGN,
1063      NID_undef, NID_undef, 1},
1064     {"rsa_pss_pss_sha384", TLSEXT_SIGALG_rsa_pss_pss_sha384,
1065      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA_PSS_SIGN,
1066      NID_undef, NID_undef, 1},
1067     {"rsa_pss_pss_sha512", TLSEXT_SIGALG_rsa_pss_pss_sha512,
1068      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_RSA_PSS, SSL_PKEY_RSA_PSS_SIGN,
1069      NID_undef, NID_undef, 1},
1070     {"rsa_pkcs1_sha256", TLSEXT_SIGALG_rsa_pkcs1_sha256,
1071      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
1072      NID_sha256WithRSAEncryption, NID_undef, 1},
1073     {"rsa_pkcs1_sha384", TLSEXT_SIGALG_rsa_pkcs1_sha384,
1074      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
1075      NID_sha384WithRSAEncryption, NID_undef, 1},
1076     {"rsa_pkcs1_sha512", TLSEXT_SIGALG_rsa_pkcs1_sha512,
1077      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
1078      NID_sha512WithRSAEncryption, NID_undef, 1},
1079     {"rsa_pkcs1_sha224", TLSEXT_SIGALG_rsa_pkcs1_sha224,
1080      NID_sha224, SSL_MD_SHA224_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
1081      NID_sha224WithRSAEncryption, NID_undef, 1},
1082     {"rsa_pkcs1_sha1", TLSEXT_SIGALG_rsa_pkcs1_sha1,
1083      NID_sha1, SSL_MD_SHA1_IDX, EVP_PKEY_RSA, SSL_PKEY_RSA,
1084      NID_sha1WithRSAEncryption, NID_undef, 1},
1085     {NULL, TLSEXT_SIGALG_dsa_sha256,
1086      NID_sha256, SSL_MD_SHA256_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
1087      NID_dsa_with_SHA256, NID_undef, 1},
1088     {NULL, TLSEXT_SIGALG_dsa_sha384,
1089      NID_sha384, SSL_MD_SHA384_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
1090      NID_undef, NID_undef, 1},
1091     {NULL, TLSEXT_SIGALG_dsa_sha512,
1092      NID_sha512, SSL_MD_SHA512_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
1093      NID_undef, NID_undef, 1},
1094     {NULL, TLSEXT_SIGALG_dsa_sha224,
1095      NID_sha224, SSL_MD_SHA224_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
1096      NID_undef, NID_undef, 1},
1097     {NULL, TLSEXT_SIGALG_dsa_sha1,
1098      NID_sha1, SSL_MD_SHA1_IDX, EVP_PKEY_DSA, SSL_PKEY_DSA_SIGN,
1099      NID_dsaWithSHA1, NID_undef, 1},
1100 #ifndef OPENSSL_NO_GOST
1101     {NULL, TLSEXT_SIGALG_gostr34102012_256_intrinsic,
1102      NID_id_GostR3411_2012_256, SSL_MD_GOST12_256_IDX,
1103      NID_id_GostR3410_2012_256, SSL_PKEY_GOST12_256,
1104      NID_undef, NID_undef, 1},
1105     {NULL, TLSEXT_SIGALG_gostr34102012_512_intrinsic,
1106      NID_id_GostR3411_2012_512, SSL_MD_GOST12_512_IDX,
1107      NID_id_GostR3410_2012_512, SSL_PKEY_GOST12_512,
1108      NID_undef, NID_undef, 1},
1109     {NULL, TLSEXT_SIGALG_gostr34102012_256_gostr34112012_256,
1110      NID_id_GostR3411_2012_256, SSL_MD_GOST12_256_IDX,
1111      NID_id_GostR3410_2012_256, SSL_PKEY_GOST12_256,
1112      NID_undef, NID_undef, 1},
1113     {NULL, TLSEXT_SIGALG_gostr34102012_512_gostr34112012_512,
1114      NID_id_GostR3411_2012_512, SSL_MD_GOST12_512_IDX,
1115      NID_id_GostR3410_2012_512, SSL_PKEY_GOST12_512,
1116      NID_undef, NID_undef, 1},
1117     {NULL, TLSEXT_SIGALG_gostr34102001_gostr3411,
1118      NID_id_GostR3411_94, SSL_MD_GOST94_IDX,
1119      NID_id_GostR3410_2001, SSL_PKEY_GOST01,
1120      NID_undef, NID_undef, 1}
1121 #endif
1122 };
1123 /* Legacy sigalgs for TLS < 1.2 RSA TLS signatures */
1124 static const SIGALG_LOOKUP legacy_rsa_sigalg = {
1125     "rsa_pkcs1_md5_sha1", 0,
1126      NID_md5_sha1, SSL_MD_MD5_SHA1_IDX,
1127      EVP_PKEY_RSA, SSL_PKEY_RSA,
1128      NID_undef, NID_undef, 1
1129 };
1130 
1131 /*
1132  * Default signature algorithm values used if signature algorithms not present.
1133  * From RFC5246. Note: order must match certificate index order.
1134  */
1135 static const uint16_t tls_default_sigalg[] = {
1136     TLSEXT_SIGALG_rsa_pkcs1_sha1, /* SSL_PKEY_RSA */
1137     0, /* SSL_PKEY_RSA_PSS_SIGN */
1138     TLSEXT_SIGALG_dsa_sha1, /* SSL_PKEY_DSA_SIGN */
1139     TLSEXT_SIGALG_ecdsa_sha1, /* SSL_PKEY_ECC */
1140     TLSEXT_SIGALG_gostr34102001_gostr3411, /* SSL_PKEY_GOST01 */
1141     TLSEXT_SIGALG_gostr34102012_256_intrinsic, /* SSL_PKEY_GOST12_256 */
1142     TLSEXT_SIGALG_gostr34102012_512_intrinsic, /* SSL_PKEY_GOST12_512 */
1143     0, /* SSL_PKEY_ED25519 */
1144     0, /* SSL_PKEY_ED448 */
1145 };
1146 
ssl_setup_sig_algs(SSL_CTX *ctx)1147 int ssl_setup_sig_algs(SSL_CTX *ctx)
1148 {
1149     size_t i;
1150     const SIGALG_LOOKUP *lu;
1151     SIGALG_LOOKUP *cache
1152         = OPENSSL_malloc(sizeof(*lu) * OSSL_NELEM(sigalg_lookup_tbl));
1153     EVP_PKEY *tmpkey = EVP_PKEY_new();
1154     int ret = 0;
1155 
1156     if (cache == NULL || tmpkey == NULL)
1157         goto err;
1158 
1159     ERR_set_mark();
1160     for (i = 0, lu = sigalg_lookup_tbl;
1161          i < OSSL_NELEM(sigalg_lookup_tbl); lu++, i++) {
1162         EVP_PKEY_CTX *pctx;
1163 
1164         cache[i] = *lu;
1165 
1166         /*
1167          * Check hash is available.
1168          * This test is not perfect. A provider could have support
1169          * for a signature scheme, but not a particular hash. However the hash
1170          * could be available from some other loaded provider. In that case it
1171          * could be that the signature is available, and the hash is available
1172          * independently - but not as a combination. We ignore this for now.
1173          */
1174         if (lu->hash != NID_undef
1175                 && ctx->ssl_digest_methods[lu->hash_idx] == NULL) {
1176             cache[i].enabled = 0;
1177             continue;
1178         }
1179 
1180         if (!EVP_PKEY_set_type(tmpkey, lu->sig)) {
1181             cache[i].enabled = 0;
1182             continue;
1183         }
1184         pctx = EVP_PKEY_CTX_new_from_pkey(ctx->libctx, tmpkey, ctx->propq);
1185         /* If unable to create pctx we assume the sig algorithm is unavailable */
1186         if (pctx == NULL)
1187             cache[i].enabled = 0;
1188         EVP_PKEY_CTX_free(pctx);
1189     }
1190     ERR_pop_to_mark();
1191     ctx->sigalg_lookup_cache = cache;
1192     cache = NULL;
1193 
1194     ret = 1;
1195  err:
1196     OPENSSL_free(cache);
1197     EVP_PKEY_free(tmpkey);
1198     return ret;
1199 }
1200 
1201 /* Lookup TLS signature algorithm */
tls1_lookup_sigalg(const SSL *s, uint16_t sigalg)1202 static const SIGALG_LOOKUP *tls1_lookup_sigalg(const SSL *s, uint16_t sigalg)
1203 {
1204     size_t i;
1205     const SIGALG_LOOKUP *lu;
1206 
1207     for (i = 0, lu = s->ctx->sigalg_lookup_cache;
1208          /* cache should have the same number of elements as sigalg_lookup_tbl */
1209          i < OSSL_NELEM(sigalg_lookup_tbl);
1210          lu++, i++) {
1211         if (lu->sigalg == sigalg) {
1212             if (!lu->enabled)
1213                 return NULL;
1214             return lu;
1215         }
1216     }
1217     return NULL;
1218 }
1219 /* Lookup hash: return 0 if invalid or not enabled */
tls1_lookup_md(SSL_CTX *ctx, const SIGALG_LOOKUP *lu, const EVP_MD **pmd)1220 int tls1_lookup_md(SSL_CTX *ctx, const SIGALG_LOOKUP *lu, const EVP_MD **pmd)
1221 {
1222     const EVP_MD *md;
1223     if (lu == NULL)
1224         return 0;
1225     /* lu->hash == NID_undef means no associated digest */
1226     if (lu->hash == NID_undef) {
1227         md = NULL;
1228     } else {
1229         md = ssl_md(ctx, lu->hash_idx);
1230         if (md == NULL)
1231             return 0;
1232     }
1233     if (pmd)
1234         *pmd = md;
1235     return 1;
1236 }
1237 
1238 /*
1239  * Check if key is large enough to generate RSA-PSS signature.
1240  *
1241  * The key must greater than or equal to 2 * hash length + 2.
1242  * SHA512 has a hash length of 64 bytes, which is incompatible
1243  * with a 128 byte (1024 bit) key.
1244  */
1245 #define RSA_PSS_MINIMUM_KEY_SIZE(md) (2 * EVP_MD_get_size(md) + 2)
rsa_pss_check_min_key_size(SSL_CTX *ctx, const EVP_PKEY *pkey, const SIGALG_LOOKUP *lu)1246 static int rsa_pss_check_min_key_size(SSL_CTX *ctx, const EVP_PKEY *pkey,
1247                                       const SIGALG_LOOKUP *lu)
1248 {
1249     const EVP_MD *md;
1250 
1251     if (pkey == NULL)
1252         return 0;
1253     if (!tls1_lookup_md(ctx, lu, &md) || md == NULL)
1254         return 0;
1255     if (EVP_PKEY_get_size(pkey) < RSA_PSS_MINIMUM_KEY_SIZE(md))
1256         return 0;
1257     return 1;
1258 }
1259 
1260 /*
1261  * Returns a signature algorithm when the peer did not send a list of supported
1262  * signature algorithms. The signature algorithm is fixed for the certificate
1263  * type. |idx| is a certificate type index (SSL_PKEY_*). When |idx| is -1 the
1264  * certificate type from |s| will be used.
1265  * Returns the signature algorithm to use, or NULL on error.
1266  */
tls1_get_legacy_sigalg(const SSL *s, int idx)1267 static const SIGALG_LOOKUP *tls1_get_legacy_sigalg(const SSL *s, int idx)
1268 {
1269     if (idx == -1) {
1270         if (s->server) {
1271             size_t i;
1272 
1273             /* Work out index corresponding to ciphersuite */
1274             for (i = 0; i < SSL_PKEY_NUM; i++) {
1275                 const SSL_CERT_LOOKUP *clu = ssl_cert_lookup_by_idx(i);
1276 
1277                 if (clu == NULL)
1278                     continue;
1279                 if (clu->amask & s->s3.tmp.new_cipher->algorithm_auth) {
1280                     idx = i;
1281                     break;
1282                 }
1283             }
1284 
1285             /*
1286              * Some GOST ciphersuites allow more than one signature algorithms
1287              * */
1288             if (idx == SSL_PKEY_GOST01 && s->s3.tmp.new_cipher->algorithm_auth != SSL_aGOST01) {
1289                 int real_idx;
1290 
1291                 for (real_idx = SSL_PKEY_GOST12_512; real_idx >= SSL_PKEY_GOST01;
1292                      real_idx--) {
1293                     if (s->cert->pkeys[real_idx].privatekey != NULL) {
1294                         idx = real_idx;
1295                         break;
1296                     }
1297                 }
1298             }
1299             /*
1300              * As both SSL_PKEY_GOST12_512 and SSL_PKEY_GOST12_256 indices can be used
1301              * with new (aGOST12-only) ciphersuites, we should find out which one is available really.
1302              */
1303             else if (idx == SSL_PKEY_GOST12_256) {
1304                 int real_idx;
1305 
1306                 for (real_idx = SSL_PKEY_GOST12_512; real_idx >= SSL_PKEY_GOST12_256;
1307                      real_idx--) {
1308                      if (s->cert->pkeys[real_idx].privatekey != NULL) {
1309                          idx = real_idx;
1310                          break;
1311                      }
1312                 }
1313             }
1314         } else {
1315             idx = s->cert->key - s->cert->pkeys;
1316         }
1317     }
1318     if (idx < 0 || idx >= (int)OSSL_NELEM(tls_default_sigalg))
1319         return NULL;
1320     if (SSL_USE_SIGALGS(s) || idx != SSL_PKEY_RSA) {
1321         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(s, tls_default_sigalg[idx]);
1322 
1323         if (lu == NULL)
1324             return NULL;
1325         if (!tls1_lookup_md(s->ctx, lu, NULL))
1326             return NULL;
1327         if (!tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SUPPORTED, lu))
1328             return NULL;
1329         return lu;
1330     }
1331     if (!tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SUPPORTED, &legacy_rsa_sigalg))
1332         return NULL;
1333     return &legacy_rsa_sigalg;
1334 }
1335 /* Set peer sigalg based key type */
tls1_set_peer_legacy_sigalg(SSL *s, const EVP_PKEY *pkey)1336 int tls1_set_peer_legacy_sigalg(SSL *s, const EVP_PKEY *pkey)
1337 {
1338     size_t idx;
1339     const SIGALG_LOOKUP *lu;
1340 
1341     if (ssl_cert_lookup_by_pkey(pkey, &idx) == NULL)
1342         return 0;
1343     lu = tls1_get_legacy_sigalg(s, idx);
1344     if (lu == NULL)
1345         return 0;
1346     s->s3.tmp.peer_sigalg = lu;
1347     return 1;
1348 }
1349 
tls12_get_psigalgs(SSL *s, int sent, const uint16_t **psigs)1350 size_t tls12_get_psigalgs(SSL *s, int sent, const uint16_t **psigs)
1351 {
1352     /*
1353      * If Suite B mode use Suite B sigalgs only, ignore any other
1354      * preferences.
1355      */
1356     switch (tls1_suiteb(s)) {
1357     case SSL_CERT_FLAG_SUITEB_128_LOS:
1358         *psigs = suiteb_sigalgs;
1359         return OSSL_NELEM(suiteb_sigalgs);
1360 
1361     case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
1362         *psigs = suiteb_sigalgs;
1363         return 1;
1364 
1365     case SSL_CERT_FLAG_SUITEB_192_LOS:
1366         *psigs = suiteb_sigalgs + 1;
1367         return 1;
1368     }
1369     /*
1370      *  We use client_sigalgs (if not NULL) if we're a server
1371      *  and sending a certificate request or if we're a client and
1372      *  determining which shared algorithm to use.
1373      */
1374     if ((s->server == sent) && s->cert->client_sigalgs != NULL) {
1375         *psigs = s->cert->client_sigalgs;
1376         return s->cert->client_sigalgslen;
1377     } else if (s->cert->conf_sigalgs) {
1378         *psigs = s->cert->conf_sigalgs;
1379         return s->cert->conf_sigalgslen;
1380     } else {
1381         *psigs = tls12_sigalgs;
1382         return OSSL_NELEM(tls12_sigalgs);
1383     }
1384 }
1385 
1386 /*
1387  * Called by servers only. Checks that we have a sig alg that supports the
1388  * specified EC curve.
1389  */
tls_check_sigalg_curve(const SSL *s, int curve)1390 int tls_check_sigalg_curve(const SSL *s, int curve)
1391 {
1392    const uint16_t *sigs;
1393    size_t siglen, i;
1394 
1395     if (s->cert->conf_sigalgs) {
1396         sigs = s->cert->conf_sigalgs;
1397         siglen = s->cert->conf_sigalgslen;
1398     } else {
1399         sigs = tls12_sigalgs;
1400         siglen = OSSL_NELEM(tls12_sigalgs);
1401     }
1402 
1403     for (i = 0; i < siglen; i++) {
1404         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(s, sigs[i]);
1405 
1406         if (lu == NULL)
1407             continue;
1408         if (lu->sig == EVP_PKEY_EC
1409                 && lu->curve != NID_undef
1410                 && curve == lu->curve)
1411             return 1;
1412     }
1413 
1414     return 0;
1415 }
1416 
1417 /*
1418  * Return the number of security bits for the signature algorithm, or 0 on
1419  * error.
1420  */
sigalg_security_bits(SSL_CTX *ctx, const SIGALG_LOOKUP *lu)1421 static int sigalg_security_bits(SSL_CTX *ctx, const SIGALG_LOOKUP *lu)
1422 {
1423     const EVP_MD *md = NULL;
1424     int secbits = 0;
1425 
1426     if (!tls1_lookup_md(ctx, lu, &md))
1427         return 0;
1428     if (md != NULL)
1429     {
1430         int md_type = EVP_MD_get_type(md);
1431 
1432         /* Security bits: half digest bits */
1433         secbits = EVP_MD_get_size(md) * 4;
1434         /*
1435          * SHA1 and MD5 are known to be broken. Reduce security bits so that
1436          * they're no longer accepted at security level 1. The real values don't
1437          * really matter as long as they're lower than 80, which is our
1438          * security level 1.
1439          * https://eprint.iacr.org/2020/014 puts a chosen-prefix attack for
1440          * SHA1 at 2^63.4 and MD5+SHA1 at 2^67.2
1441          * https://documents.epfl.ch/users/l/le/lenstra/public/papers/lat.pdf
1442          * puts a chosen-prefix attack for MD5 at 2^39.
1443          */
1444         if (md_type == NID_sha1)
1445             secbits = 64;
1446         else if (md_type == NID_md5_sha1)
1447             secbits = 67;
1448         else if (md_type == NID_md5)
1449             secbits = 39;
1450     } else {
1451         /* Values from https://tools.ietf.org/html/rfc8032#section-8.5 */
1452         if (lu->sigalg == TLSEXT_SIGALG_ed25519)
1453             secbits = 128;
1454         else if (lu->sigalg == TLSEXT_SIGALG_ed448)
1455             secbits = 224;
1456     }
1457     return secbits;
1458 }
1459 
1460 /*
1461  * Check signature algorithm is consistent with sent supported signature
1462  * algorithms and if so set relevant digest and signature scheme in
1463  * s.
1464  */
tls12_check_peer_sigalg(SSL *s, uint16_t sig, EVP_PKEY *pkey)1465 int tls12_check_peer_sigalg(SSL *s, uint16_t sig, EVP_PKEY *pkey)
1466 {
1467     const uint16_t *sent_sigs;
1468     const EVP_MD *md = NULL;
1469     char sigalgstr[2];
1470     size_t sent_sigslen, i, cidx;
1471     int pkeyid = -1;
1472     const SIGALG_LOOKUP *lu;
1473     int secbits = 0;
1474 
1475     pkeyid = EVP_PKEY_get_id(pkey);
1476     /* Should never happen */
1477     if (pkeyid == -1)
1478         return -1;
1479     if (SSL_IS_TLS13(s)) {
1480         /* Disallow DSA for TLS 1.3 */
1481         if (pkeyid == EVP_PKEY_DSA) {
1482             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_WRONG_SIGNATURE_TYPE);
1483             return 0;
1484         }
1485         /* Only allow PSS for TLS 1.3 */
1486         if (pkeyid == EVP_PKEY_RSA)
1487             pkeyid = EVP_PKEY_RSA_PSS;
1488     }
1489     lu = tls1_lookup_sigalg(s, sig);
1490     /*
1491      * Check sigalgs is known. Disallow SHA1/SHA224 with TLS 1.3. Check key type
1492      * is consistent with signature: RSA keys can be used for RSA-PSS
1493      */
1494     if (lu == NULL
1495         || (SSL_IS_TLS13(s) && (lu->hash == NID_sha1 || lu->hash == NID_sha224))
1496         || (pkeyid != lu->sig
1497         && (lu->sig != EVP_PKEY_RSA_PSS || pkeyid != EVP_PKEY_RSA))) {
1498         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_WRONG_SIGNATURE_TYPE);
1499         return 0;
1500     }
1501     /* Check the sigalg is consistent with the key OID */
1502     if (!ssl_cert_lookup_by_nid(EVP_PKEY_get_id(pkey), &cidx)
1503             || lu->sig_idx != (int)cidx) {
1504         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_WRONG_SIGNATURE_TYPE);
1505         return 0;
1506     }
1507 
1508     if (pkeyid == EVP_PKEY_EC) {
1509 
1510         /* Check point compression is permitted */
1511         if (!tls1_check_pkey_comp(s, pkey)) {
1512             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1513                      SSL_R_ILLEGAL_POINT_COMPRESSION);
1514             return 0;
1515         }
1516 
1517         /* For TLS 1.3 or Suite B check curve matches signature algorithm */
1518         if (SSL_IS_TLS13(s) || tls1_suiteb(s)) {
1519             int curve = ssl_get_EC_curve_nid(pkey);
1520 
1521             if (lu->curve != NID_undef && curve != lu->curve) {
1522                 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_WRONG_CURVE);
1523                 return 0;
1524             }
1525         }
1526         if (!SSL_IS_TLS13(s)) {
1527             /* Check curve matches extensions */
1528             if (!tls1_check_group_id(s, tls1_get_group_id(pkey), 1)) {
1529                 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_WRONG_CURVE);
1530                 return 0;
1531             }
1532             if (tls1_suiteb(s)) {
1533                 /* Check sigalg matches a permissible Suite B value */
1534                 if (sig != TLSEXT_SIGALG_ecdsa_secp256r1_sha256
1535                     && sig != TLSEXT_SIGALG_ecdsa_secp384r1_sha384) {
1536                     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
1537                              SSL_R_WRONG_SIGNATURE_TYPE);
1538                     return 0;
1539                 }
1540             }
1541         }
1542     } else if (tls1_suiteb(s)) {
1543         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_R_WRONG_SIGNATURE_TYPE);
1544         return 0;
1545     }
1546 
1547     /* Check signature matches a type we sent */
1548     sent_sigslen = tls12_get_psigalgs(s, 1, &sent_sigs);
1549     for (i = 0; i < sent_sigslen; i++, sent_sigs++) {
1550         if (sig == *sent_sigs)
1551             break;
1552     }
1553     /* Allow fallback to SHA1 if not strict mode */
1554     if (i == sent_sigslen && (lu->hash != NID_sha1
1555         || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
1556         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_R_WRONG_SIGNATURE_TYPE);
1557         return 0;
1558     }
1559     if (!tls1_lookup_md(s->ctx, lu, &md)) {
1560         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_R_UNKNOWN_DIGEST);
1561         return 0;
1562     }
1563     /*
1564      * Make sure security callback allows algorithm. For historical
1565      * reasons we have to pass the sigalg as a two byte char array.
1566      */
1567     sigalgstr[0] = (sig >> 8) & 0xff;
1568     sigalgstr[1] = sig & 0xff;
1569     secbits = sigalg_security_bits(s->ctx, lu);
1570     if (secbits == 0 ||
1571         !ssl_security(s, SSL_SECOP_SIGALG_CHECK, secbits,
1572                       md != NULL ? EVP_MD_get_type(md) : NID_undef,
1573                       (void *)sigalgstr)) {
1574         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_R_WRONG_SIGNATURE_TYPE);
1575         return 0;
1576     }
1577     /* Store the sigalg the peer uses */
1578     s->s3.tmp.peer_sigalg = lu;
1579     return 1;
1580 }
1581 
SSL_get_peer_signature_type_nid(const SSL *s, int *pnid)1582 int SSL_get_peer_signature_type_nid(const SSL *s, int *pnid)
1583 {
1584     if (s->s3.tmp.peer_sigalg == NULL)
1585         return 0;
1586     *pnid = s->s3.tmp.peer_sigalg->sig;
1587     return 1;
1588 }
1589 
SSL_get_signature_type_nid(const SSL *s, int *pnid)1590 int SSL_get_signature_type_nid(const SSL *s, int *pnid)
1591 {
1592     if (s->s3.tmp.sigalg == NULL)
1593         return 0;
1594     *pnid = s->s3.tmp.sigalg->sig;
1595     return 1;
1596 }
1597 
1598 /*
1599  * Set a mask of disabled algorithms: an algorithm is disabled if it isn't
1600  * supported, doesn't appear in supported signature algorithms, isn't supported
1601  * by the enabled protocol versions or by the security level.
1602  *
1603  * This function should only be used for checking which ciphers are supported
1604  * by the client.
1605  *
1606  * Call ssl_cipher_disabled() to check that it's enabled or not.
1607  */
ssl_set_client_disabled(SSL *s)1608 int ssl_set_client_disabled(SSL *s)
1609 {
1610     s->s3.tmp.mask_a = 0;
1611     s->s3.tmp.mask_k = 0;
1612     ssl_set_sig_mask(&s->s3.tmp.mask_a, s, SSL_SECOP_SIGALG_MASK);
1613     if (ssl_get_min_max_version(s, &s->s3.tmp.min_ver,
1614                                 &s->s3.tmp.max_ver, NULL) != 0)
1615         return 0;
1616 #ifndef OPENSSL_NO_PSK
1617     /* with PSK there must be client callback set */
1618     if (!s->psk_client_callback) {
1619         s->s3.tmp.mask_a |= SSL_aPSK;
1620         s->s3.tmp.mask_k |= SSL_PSK;
1621     }
1622 #endif                          /* OPENSSL_NO_PSK */
1623 #ifndef OPENSSL_NO_SRP
1624     if (!(s->srp_ctx.srp_Mask & SSL_kSRP)) {
1625         s->s3.tmp.mask_a |= SSL_aSRP;
1626         s->s3.tmp.mask_k |= SSL_kSRP;
1627     }
1628 #endif
1629     return 1;
1630 }
1631 
1632 /*
1633  * ssl_cipher_disabled - check that a cipher is disabled or not
1634  * @s: SSL connection that you want to use the cipher on
1635  * @c: cipher to check
1636  * @op: Security check that you want to do
1637  * @ecdhe: If set to 1 then TLSv1 ECDHE ciphers are also allowed in SSLv3
1638  *
1639  * Returns 1 when it's disabled, 0 when enabled.
1640  */
ssl_cipher_disabled(const SSL *s, const SSL_CIPHER *c, int op, int ecdhe)1641 int ssl_cipher_disabled(const SSL *s, const SSL_CIPHER *c, int op, int ecdhe)
1642 {
1643     if (c->algorithm_mkey & s->s3.tmp.mask_k
1644         || c->algorithm_auth & s->s3.tmp.mask_a)
1645         return 1;
1646     if (s->s3.tmp.max_ver == 0)
1647         return 1;
1648     if (!SSL_IS_DTLS(s)) {
1649         int min_tls = c->min_tls;
1650 
1651         /*
1652          * For historical reasons we will allow ECHDE to be selected by a server
1653          * in SSLv3 if we are a client
1654          */
1655         if (min_tls == TLS1_VERSION && ecdhe
1656                 && (c->algorithm_mkey & (SSL_kECDHE | SSL_kECDHEPSK)) != 0)
1657             min_tls = SSL3_VERSION;
1658 
1659         if ((min_tls > s->s3.tmp.max_ver) || (c->max_tls < s->s3.tmp.min_ver))
1660             return 1;
1661     }
1662     if (SSL_IS_DTLS(s) && (DTLS_VERSION_GT(c->min_dtls, s->s3.tmp.max_ver)
1663                            || DTLS_VERSION_LT(c->max_dtls, s->s3.tmp.min_ver)))
1664         return 1;
1665 
1666     return !ssl_security(s, op, c->strength_bits, 0, (void *)c);
1667 }
1668 
tls_use_ticket(SSL *s)1669 int tls_use_ticket(SSL *s)
1670 {
1671     if ((s->options & SSL_OP_NO_TICKET))
1672         return 0;
1673     return ssl_security(s, SSL_SECOP_TICKET, 0, 0, NULL);
1674 }
1675 
tls1_set_server_sigalgs(SSL *s)1676 int tls1_set_server_sigalgs(SSL *s)
1677 {
1678     size_t i;
1679 
1680     /* Clear any shared signature algorithms */
1681     OPENSSL_free(s->shared_sigalgs);
1682     s->shared_sigalgs = NULL;
1683     s->shared_sigalgslen = 0;
1684     /* Clear certificate validity flags */
1685     for (i = 0; i < SSL_PKEY_NUM; i++)
1686         s->s3.tmp.valid_flags[i] = 0;
1687     /*
1688      * If peer sent no signature algorithms check to see if we support
1689      * the default algorithm for each certificate type
1690      */
1691     if (s->s3.tmp.peer_cert_sigalgs == NULL
1692             && s->s3.tmp.peer_sigalgs == NULL) {
1693         const uint16_t *sent_sigs;
1694         size_t sent_sigslen = tls12_get_psigalgs(s, 1, &sent_sigs);
1695 
1696         for (i = 0; i < SSL_PKEY_NUM; i++) {
1697             const SIGALG_LOOKUP *lu = tls1_get_legacy_sigalg(s, i);
1698             size_t j;
1699 
1700             if (lu == NULL)
1701                 continue;
1702             /* Check default matches a type we sent */
1703             for (j = 0; j < sent_sigslen; j++) {
1704                 if (lu->sigalg == sent_sigs[j]) {
1705                         s->s3.tmp.valid_flags[i] = CERT_PKEY_SIGN;
1706                         break;
1707                 }
1708             }
1709         }
1710         return 1;
1711     }
1712 
1713     if (!tls1_process_sigalgs(s)) {
1714         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1715         return 0;
1716     }
1717     if (s->shared_sigalgs != NULL)
1718         return 1;
1719 
1720     /* Fatal error if no shared signature algorithms */
1721     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
1722              SSL_R_NO_SHARED_SIGNATURE_ALGORITHMS);
1723     return 0;
1724 }
1725 
1726 /*-
1727  * Gets the ticket information supplied by the client if any.
1728  *
1729  *   hello: The parsed ClientHello data
1730  *   ret: (output) on return, if a ticket was decrypted, then this is set to
1731  *       point to the resulting session.
1732  */
tls_get_ticket_from_client(SSL *s, CLIENTHELLO_MSG *hello, SSL_SESSION **ret)1733 SSL_TICKET_STATUS tls_get_ticket_from_client(SSL *s, CLIENTHELLO_MSG *hello,
1734                                              SSL_SESSION **ret)
1735 {
1736     size_t size;
1737     RAW_EXTENSION *ticketext;
1738 
1739     *ret = NULL;
1740     s->ext.ticket_expected = 0;
1741 
1742     /*
1743      * If tickets disabled or not supported by the protocol version
1744      * (e.g. TLSv1.3) behave as if no ticket present to permit stateful
1745      * resumption.
1746      */
1747     if (s->version <= SSL3_VERSION || !tls_use_ticket(s))
1748         return SSL_TICKET_NONE;
1749 
1750     ticketext = &hello->pre_proc_exts[TLSEXT_IDX_session_ticket];
1751     if (!ticketext->present)
1752         return SSL_TICKET_NONE;
1753 
1754     size = PACKET_remaining(&ticketext->data);
1755 
1756     return tls_decrypt_ticket(s, PACKET_data(&ticketext->data), size,
1757                               hello->session_id, hello->session_id_len, ret);
1758 }
1759 
1760 /*-
1761  * tls_decrypt_ticket attempts to decrypt a session ticket.
1762  *
1763  * If s->tls_session_secret_cb is set and we're not doing TLSv1.3 then we are
1764  * expecting a pre-shared key ciphersuite, in which case we have no use for
1765  * session tickets and one will never be decrypted, nor will
1766  * s->ext.ticket_expected be set to 1.
1767  *
1768  * Side effects:
1769  *   Sets s->ext.ticket_expected to 1 if the server will have to issue
1770  *   a new session ticket to the client because the client indicated support
1771  *   (and s->tls_session_secret_cb is NULL) but the client either doesn't have
1772  *   a session ticket or we couldn't use the one it gave us, or if
1773  *   s->ctx->ext.ticket_key_cb asked to renew the client's ticket.
1774  *   Otherwise, s->ext.ticket_expected is set to 0.
1775  *
1776  *   etick: points to the body of the session ticket extension.
1777  *   eticklen: the length of the session tickets extension.
1778  *   sess_id: points at the session ID.
1779  *   sesslen: the length of the session ID.
1780  *   psess: (output) on return, if a ticket was decrypted, then this is set to
1781  *       point to the resulting session.
1782  */
tls_decrypt_ticket(SSL *s, const unsigned char *etick, size_t eticklen, const unsigned char *sess_id, size_t sesslen, SSL_SESSION **psess)1783 SSL_TICKET_STATUS tls_decrypt_ticket(SSL *s, const unsigned char *etick,
1784                                      size_t eticklen, const unsigned char *sess_id,
1785                                      size_t sesslen, SSL_SESSION **psess)
1786 {
1787     SSL_SESSION *sess = NULL;
1788     unsigned char *sdec;
1789     const unsigned char *p;
1790     int slen, ivlen, renew_ticket = 0, declen;
1791     SSL_TICKET_STATUS ret = SSL_TICKET_FATAL_ERR_OTHER;
1792     size_t mlen;
1793     unsigned char tick_hmac[EVP_MAX_MD_SIZE];
1794     SSL_HMAC *hctx = NULL;
1795     EVP_CIPHER_CTX *ctx = NULL;
1796     SSL_CTX *tctx = s->session_ctx;
1797 
1798     if (eticklen == 0) {
1799         /*
1800          * The client will accept a ticket but doesn't currently have
1801          * one (TLSv1.2 and below), or treated as a fatal error in TLSv1.3
1802          */
1803         ret = SSL_TICKET_EMPTY;
1804         goto end;
1805     }
1806     if (!SSL_IS_TLS13(s) && s->ext.session_secret_cb) {
1807         /*
1808          * Indicate that the ticket couldn't be decrypted rather than
1809          * generating the session from ticket now, trigger
1810          * abbreviated handshake based on external mechanism to
1811          * calculate the master secret later.
1812          */
1813         ret = SSL_TICKET_NO_DECRYPT;
1814         goto end;
1815     }
1816 
1817     /* Need at least keyname + iv */
1818     if (eticklen < TLSEXT_KEYNAME_LENGTH + EVP_MAX_IV_LENGTH) {
1819         ret = SSL_TICKET_NO_DECRYPT;
1820         goto end;
1821     }
1822 
1823     /* Initialize session ticket encryption and HMAC contexts */
1824     hctx = ssl_hmac_new(tctx);
1825     if (hctx == NULL) {
1826         ret = SSL_TICKET_FATAL_ERR_MALLOC;
1827         goto end;
1828     }
1829     ctx = EVP_CIPHER_CTX_new();
1830     if (ctx == NULL) {
1831         ret = SSL_TICKET_FATAL_ERR_MALLOC;
1832         goto end;
1833     }
1834 #ifndef OPENSSL_NO_DEPRECATED_3_0
1835     if (tctx->ext.ticket_key_evp_cb != NULL || tctx->ext.ticket_key_cb != NULL)
1836 #else
1837     if (tctx->ext.ticket_key_evp_cb != NULL)
1838 #endif
1839     {
1840         unsigned char *nctick = (unsigned char *)etick;
1841         int rv = 0;
1842 
1843         if (tctx->ext.ticket_key_evp_cb != NULL)
1844             rv = tctx->ext.ticket_key_evp_cb(s, nctick,
1845                                              nctick + TLSEXT_KEYNAME_LENGTH,
1846                                              ctx,
1847                                              ssl_hmac_get0_EVP_MAC_CTX(hctx),
1848                                              0);
1849 #ifndef OPENSSL_NO_DEPRECATED_3_0
1850         else if (tctx->ext.ticket_key_cb != NULL)
1851             /* if 0 is returned, write an empty ticket */
1852             rv = tctx->ext.ticket_key_cb(s, nctick,
1853                                          nctick + TLSEXT_KEYNAME_LENGTH,
1854                                          ctx, ssl_hmac_get0_HMAC_CTX(hctx), 0);
1855 #endif
1856         if (rv < 0) {
1857             ret = SSL_TICKET_FATAL_ERR_OTHER;
1858             goto end;
1859         }
1860         if (rv == 0) {
1861             ret = SSL_TICKET_NO_DECRYPT;
1862             goto end;
1863         }
1864         if (rv == 2)
1865             renew_ticket = 1;
1866     } else {
1867         EVP_CIPHER *aes256cbc = NULL;
1868 
1869         /* Check key name matches */
1870         if (memcmp(etick, tctx->ext.tick_key_name,
1871                    TLSEXT_KEYNAME_LENGTH) != 0) {
1872             ret = SSL_TICKET_NO_DECRYPT;
1873             goto end;
1874         }
1875 
1876         aes256cbc = EVP_CIPHER_fetch(s->ctx->libctx, "AES-256-CBC",
1877                                      s->ctx->propq);
1878         if (aes256cbc == NULL
1879             || ssl_hmac_init(hctx, tctx->ext.secure->tick_hmac_key,
1880                              sizeof(tctx->ext.secure->tick_hmac_key),
1881                              "SHA256") <= 0
1882             || EVP_DecryptInit_ex(ctx, aes256cbc, NULL,
1883                                   tctx->ext.secure->tick_aes_key,
1884                                   etick + TLSEXT_KEYNAME_LENGTH) <= 0) {
1885             EVP_CIPHER_free(aes256cbc);
1886             ret = SSL_TICKET_FATAL_ERR_OTHER;
1887             goto end;
1888         }
1889         EVP_CIPHER_free(aes256cbc);
1890         if (SSL_IS_TLS13(s))
1891             renew_ticket = 1;
1892     }
1893     /*
1894      * Attempt to process session ticket, first conduct sanity and integrity
1895      * checks on ticket.
1896      */
1897     mlen = ssl_hmac_size(hctx);
1898     if (mlen == 0) {
1899         ret = SSL_TICKET_FATAL_ERR_OTHER;
1900         goto end;
1901     }
1902 
1903     ivlen = EVP_CIPHER_CTX_get_iv_length(ctx);
1904     if (ivlen < 0) {
1905         ret = SSL_TICKET_FATAL_ERR_OTHER;
1906         goto end;
1907     }
1908 
1909     /* Sanity check ticket length: must exceed keyname + IV + HMAC */
1910     if (eticklen <= TLSEXT_KEYNAME_LENGTH + ivlen + mlen) {
1911         ret = SSL_TICKET_NO_DECRYPT;
1912         goto end;
1913     }
1914     eticklen -= mlen;
1915     /* Check HMAC of encrypted ticket */
1916     if (ssl_hmac_update(hctx, etick, eticklen) <= 0
1917         || ssl_hmac_final(hctx, tick_hmac, NULL, sizeof(tick_hmac)) <= 0) {
1918         ret = SSL_TICKET_FATAL_ERR_OTHER;
1919         goto end;
1920     }
1921 
1922     if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen)) {
1923         ret = SSL_TICKET_NO_DECRYPT;
1924         goto end;
1925     }
1926     /* Attempt to decrypt session data */
1927     /* Move p after IV to start of encrypted ticket, update length */
1928     p = etick + TLSEXT_KEYNAME_LENGTH + ivlen;
1929     eticklen -= TLSEXT_KEYNAME_LENGTH + ivlen;
1930     sdec = OPENSSL_malloc(eticklen);
1931     if (sdec == NULL || EVP_DecryptUpdate(ctx, sdec, &slen, p,
1932                                           (int)eticklen) <= 0) {
1933         OPENSSL_free(sdec);
1934         ret = SSL_TICKET_FATAL_ERR_OTHER;
1935         goto end;
1936     }
1937     if (EVP_DecryptFinal(ctx, sdec + slen, &declen) <= 0) {
1938         OPENSSL_free(sdec);
1939         ret = SSL_TICKET_NO_DECRYPT;
1940         goto end;
1941     }
1942     slen += declen;
1943     p = sdec;
1944 
1945     sess = d2i_SSL_SESSION(NULL, &p, slen);
1946     slen -= p - sdec;
1947     OPENSSL_free(sdec);
1948     if (sess) {
1949         /* Some additional consistency checks */
1950         if (slen != 0) {
1951             SSL_SESSION_free(sess);
1952             sess = NULL;
1953             ret = SSL_TICKET_NO_DECRYPT;
1954             goto end;
1955         }
1956         /*
1957          * The session ID, if non-empty, is used by some clients to detect
1958          * that the ticket has been accepted. So we copy it to the session
1959          * structure. If it is empty set length to zero as required by
1960          * standard.
1961          */
1962         if (sesslen) {
1963             memcpy(sess->session_id, sess_id, sesslen);
1964             sess->session_id_length = sesslen;
1965         }
1966         if (renew_ticket)
1967             ret = SSL_TICKET_SUCCESS_RENEW;
1968         else
1969             ret = SSL_TICKET_SUCCESS;
1970         goto end;
1971     }
1972     ERR_clear_error();
1973     /*
1974      * For session parse failure, indicate that we need to send a new ticket.
1975      */
1976     ret = SSL_TICKET_NO_DECRYPT;
1977 
1978  end:
1979     EVP_CIPHER_CTX_free(ctx);
1980     ssl_hmac_free(hctx);
1981 
1982     /*
1983      * If set, the decrypt_ticket_cb() is called unless a fatal error was
1984      * detected above. The callback is responsible for checking |ret| before it
1985      * performs any action
1986      */
1987     if (s->session_ctx->decrypt_ticket_cb != NULL
1988             && (ret == SSL_TICKET_EMPTY
1989                 || ret == SSL_TICKET_NO_DECRYPT
1990                 || ret == SSL_TICKET_SUCCESS
1991                 || ret == SSL_TICKET_SUCCESS_RENEW)) {
1992         size_t keyname_len = eticklen;
1993         int retcb;
1994 
1995         if (keyname_len > TLSEXT_KEYNAME_LENGTH)
1996             keyname_len = TLSEXT_KEYNAME_LENGTH;
1997         retcb = s->session_ctx->decrypt_ticket_cb(s, sess, etick, keyname_len,
1998                                                   ret,
1999                                                   s->session_ctx->ticket_cb_data);
2000         switch (retcb) {
2001         case SSL_TICKET_RETURN_ABORT:
2002             ret = SSL_TICKET_FATAL_ERR_OTHER;
2003             break;
2004 
2005         case SSL_TICKET_RETURN_IGNORE:
2006             ret = SSL_TICKET_NONE;
2007             SSL_SESSION_free(sess);
2008             sess = NULL;
2009             break;
2010 
2011         case SSL_TICKET_RETURN_IGNORE_RENEW:
2012             if (ret != SSL_TICKET_EMPTY && ret != SSL_TICKET_NO_DECRYPT)
2013                 ret = SSL_TICKET_NO_DECRYPT;
2014             /* else the value of |ret| will already do the right thing */
2015             SSL_SESSION_free(sess);
2016             sess = NULL;
2017             break;
2018 
2019         case SSL_TICKET_RETURN_USE:
2020         case SSL_TICKET_RETURN_USE_RENEW:
2021             if (ret != SSL_TICKET_SUCCESS
2022                     && ret != SSL_TICKET_SUCCESS_RENEW)
2023                 ret = SSL_TICKET_FATAL_ERR_OTHER;
2024             else if (retcb == SSL_TICKET_RETURN_USE)
2025                 ret = SSL_TICKET_SUCCESS;
2026             else
2027                 ret = SSL_TICKET_SUCCESS_RENEW;
2028             break;
2029 
2030         default:
2031             ret = SSL_TICKET_FATAL_ERR_OTHER;
2032         }
2033     }
2034 
2035     if (s->ext.session_secret_cb == NULL || SSL_IS_TLS13(s)) {
2036         switch (ret) {
2037         case SSL_TICKET_NO_DECRYPT:
2038         case SSL_TICKET_SUCCESS_RENEW:
2039         case SSL_TICKET_EMPTY:
2040             s->ext.ticket_expected = 1;
2041         }
2042     }
2043 
2044     *psess = sess;
2045 
2046     return ret;
2047 }
2048 
2049 /* Check to see if a signature algorithm is allowed */
tls12_sigalg_allowed(const SSL *s, int op, const SIGALG_LOOKUP *lu)2050 static int tls12_sigalg_allowed(const SSL *s, int op, const SIGALG_LOOKUP *lu)
2051 {
2052     unsigned char sigalgstr[2];
2053     int secbits;
2054 
2055     if (lu == NULL || !lu->enabled)
2056         return 0;
2057     /* DSA is not allowed in TLS 1.3 */
2058     if (SSL_IS_TLS13(s) && lu->sig == EVP_PKEY_DSA)
2059         return 0;
2060     /*
2061      * At some point we should fully axe DSA/etc. in ClientHello as per TLS 1.3
2062      * spec
2063      */
2064     if (!s->server && !SSL_IS_DTLS(s) && s->s3.tmp.min_ver >= TLS1_3_VERSION
2065         && (lu->sig == EVP_PKEY_DSA || lu->hash_idx == SSL_MD_SHA1_IDX
2066             || lu->hash_idx == SSL_MD_MD5_IDX
2067             || lu->hash_idx == SSL_MD_SHA224_IDX))
2068         return 0;
2069 
2070     /* See if public key algorithm allowed */
2071     if (ssl_cert_is_disabled(s->ctx, lu->sig_idx))
2072         return 0;
2073 
2074     if (lu->sig == NID_id_GostR3410_2012_256
2075             || lu->sig == NID_id_GostR3410_2012_512
2076             || lu->sig == NID_id_GostR3410_2001) {
2077         /* We never allow GOST sig algs on the server with TLSv1.3 */
2078         if (s->server && SSL_IS_TLS13(s))
2079             return 0;
2080         if (!s->server
2081                 && s->method->version == TLS_ANY_VERSION
2082                 && s->s3.tmp.max_ver >= TLS1_3_VERSION) {
2083             int i, num;
2084             STACK_OF(SSL_CIPHER) *sk;
2085 
2086             /*
2087              * We're a client that could negotiate TLSv1.3. We only allow GOST
2088              * sig algs if we could negotiate TLSv1.2 or below and we have GOST
2089              * ciphersuites enabled.
2090              */
2091 
2092             if (s->s3.tmp.min_ver >= TLS1_3_VERSION)
2093                 return 0;
2094 
2095             sk = SSL_get_ciphers(s);
2096             num = sk != NULL ? sk_SSL_CIPHER_num(sk) : 0;
2097             for (i = 0; i < num; i++) {
2098                 const SSL_CIPHER *c;
2099 
2100                 c = sk_SSL_CIPHER_value(sk, i);
2101                 /* Skip disabled ciphers */
2102                 if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED, 0))
2103                     continue;
2104 
2105                 if ((c->algorithm_mkey & (SSL_kGOST | SSL_kGOST18)) != 0)
2106                     break;
2107             }
2108             if (i == num)
2109                 return 0;
2110         }
2111     }
2112 
2113     /* Finally see if security callback allows it */
2114     secbits = sigalg_security_bits(s->ctx, lu);
2115     sigalgstr[0] = (lu->sigalg >> 8) & 0xff;
2116     sigalgstr[1] = lu->sigalg & 0xff;
2117     return ssl_security(s, op, secbits, lu->hash, (void *)sigalgstr);
2118 }
2119 
2120 /*
2121  * Get a mask of disabled public key algorithms based on supported signature
2122  * algorithms. For example if no signature algorithm supports RSA then RSA is
2123  * disabled.
2124  */
2125 
ssl_set_sig_mask(uint32_t *pmask_a, SSL *s, int op)2126 void ssl_set_sig_mask(uint32_t *pmask_a, SSL *s, int op)
2127 {
2128     const uint16_t *sigalgs;
2129     size_t i, sigalgslen;
2130     uint32_t disabled_mask = SSL_aRSA | SSL_aDSS | SSL_aECDSA;
2131     /*
2132      * Go through all signature algorithms seeing if we support any
2133      * in disabled_mask.
2134      */
2135     sigalgslen = tls12_get_psigalgs(s, 1, &sigalgs);
2136     for (i = 0; i < sigalgslen; i++, sigalgs++) {
2137         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(s, *sigalgs);
2138         const SSL_CERT_LOOKUP *clu;
2139 
2140         if (lu == NULL)
2141             continue;
2142 
2143         clu = ssl_cert_lookup_by_idx(lu->sig_idx);
2144         if (clu == NULL)
2145                 continue;
2146 
2147         /* If algorithm is disabled see if we can enable it */
2148         if ((clu->amask & disabled_mask) != 0
2149                 && tls12_sigalg_allowed(s, op, lu))
2150             disabled_mask &= ~clu->amask;
2151     }
2152     *pmask_a |= disabled_mask;
2153 }
2154 
tls12_copy_sigalgs(SSL *s, WPACKET *pkt, const uint16_t *psig, size_t psiglen)2155 int tls12_copy_sigalgs(SSL *s, WPACKET *pkt,
2156                        const uint16_t *psig, size_t psiglen)
2157 {
2158     size_t i;
2159     int rv = 0;
2160 
2161     for (i = 0; i < psiglen; i++, psig++) {
2162         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(s, *psig);
2163 
2164         if (lu == NULL
2165                 || !tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SUPPORTED, lu))
2166             continue;
2167         if (!WPACKET_put_bytes_u16(pkt, *psig))
2168             return 0;
2169         /*
2170          * If TLS 1.3 must have at least one valid TLS 1.3 message
2171          * signing algorithm: i.e. neither RSA nor SHA1/SHA224
2172          */
2173         if (rv == 0 && (!SSL_IS_TLS13(s)
2174             || (lu->sig != EVP_PKEY_RSA
2175                 && lu->hash != NID_sha1
2176                 && lu->hash != NID_sha224)))
2177             rv = 1;
2178     }
2179     if (rv == 0)
2180         ERR_raise(ERR_LIB_SSL, SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
2181     return rv;
2182 }
2183 
2184 /* Given preference and allowed sigalgs set shared sigalgs */
tls12_shared_sigalgs(SSL *s, const SIGALG_LOOKUP **shsig, const uint16_t *pref, size_t preflen, const uint16_t *allow, size_t allowlen)2185 static size_t tls12_shared_sigalgs(SSL *s, const SIGALG_LOOKUP **shsig,
2186                                    const uint16_t *pref, size_t preflen,
2187                                    const uint16_t *allow, size_t allowlen)
2188 {
2189     const uint16_t *ptmp, *atmp;
2190     size_t i, j, nmatch = 0;
2191     for (i = 0, ptmp = pref; i < preflen; i++, ptmp++) {
2192         const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(s, *ptmp);
2193 
2194         /* Skip disabled hashes or signature algorithms */
2195         if (lu == NULL
2196                 || !tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SHARED, lu))
2197             continue;
2198         for (j = 0, atmp = allow; j < allowlen; j++, atmp++) {
2199             if (*ptmp == *atmp) {
2200                 nmatch++;
2201                 if (shsig)
2202                     *shsig++ = lu;
2203                 break;
2204             }
2205         }
2206     }
2207     return nmatch;
2208 }
2209 
2210 /* Set shared signature algorithms for SSL structures */
tls1_set_shared_sigalgs(SSL *s)2211 static int tls1_set_shared_sigalgs(SSL *s)
2212 {
2213     const uint16_t *pref, *allow, *conf;
2214     size_t preflen, allowlen, conflen;
2215     size_t nmatch;
2216     const SIGALG_LOOKUP **salgs = NULL;
2217     CERT *c = s->cert;
2218     unsigned int is_suiteb = tls1_suiteb(s);
2219 
2220     OPENSSL_free(s->shared_sigalgs);
2221     s->shared_sigalgs = NULL;
2222     s->shared_sigalgslen = 0;
2223     /* If client use client signature algorithms if not NULL */
2224     if (!s->server && c->client_sigalgs && !is_suiteb) {
2225         conf = c->client_sigalgs;
2226         conflen = c->client_sigalgslen;
2227     } else if (c->conf_sigalgs && !is_suiteb) {
2228         conf = c->conf_sigalgs;
2229         conflen = c->conf_sigalgslen;
2230     } else
2231         conflen = tls12_get_psigalgs(s, 0, &conf);
2232     if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb) {
2233         pref = conf;
2234         preflen = conflen;
2235         allow = s->s3.tmp.peer_sigalgs;
2236         allowlen = s->s3.tmp.peer_sigalgslen;
2237     } else {
2238         allow = conf;
2239         allowlen = conflen;
2240         pref = s->s3.tmp.peer_sigalgs;
2241         preflen = s->s3.tmp.peer_sigalgslen;
2242     }
2243     nmatch = tls12_shared_sigalgs(s, NULL, pref, preflen, allow, allowlen);
2244     if (nmatch) {
2245         if ((salgs = OPENSSL_malloc(nmatch * sizeof(*salgs))) == NULL) {
2246             ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
2247             return 0;
2248         }
2249         nmatch = tls12_shared_sigalgs(s, salgs, pref, preflen, allow, allowlen);
2250     } else {
2251         salgs = NULL;
2252     }
2253     s->shared_sigalgs = salgs;
2254     s->shared_sigalgslen = nmatch;
2255     return 1;
2256 }
2257 
tls1_save_u16(PACKET *pkt, uint16_t **pdest, size_t *pdestlen)2258 int tls1_save_u16(PACKET *pkt, uint16_t **pdest, size_t *pdestlen)
2259 {
2260     unsigned int stmp;
2261     size_t size, i;
2262     uint16_t *buf;
2263 
2264     size = PACKET_remaining(pkt);
2265 
2266     /* Invalid data length */
2267     if (size == 0 || (size & 1) != 0)
2268         return 0;
2269 
2270     size >>= 1;
2271 
2272     if ((buf = OPENSSL_malloc(size * sizeof(*buf))) == NULL)  {
2273         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
2274         return 0;
2275     }
2276     for (i = 0; i < size && PACKET_get_net_2(pkt, &stmp); i++)
2277         buf[i] = stmp;
2278 
2279     if (i != size) {
2280         OPENSSL_free(buf);
2281         return 0;
2282     }
2283 
2284     OPENSSL_free(*pdest);
2285     *pdest = buf;
2286     *pdestlen = size;
2287 
2288     return 1;
2289 }
2290 
tls1_save_sigalgs(SSL *s, PACKET *pkt, int cert)2291 int tls1_save_sigalgs(SSL *s, PACKET *pkt, int cert)
2292 {
2293     /* Extension ignored for inappropriate versions */
2294     if (!SSL_USE_SIGALGS(s))
2295         return 1;
2296     /* Should never happen */
2297     if (s->cert == NULL)
2298         return 0;
2299 
2300     if (cert)
2301         return tls1_save_u16(pkt, &s->s3.tmp.peer_cert_sigalgs,
2302                              &s->s3.tmp.peer_cert_sigalgslen);
2303     else
2304         return tls1_save_u16(pkt, &s->s3.tmp.peer_sigalgs,
2305                              &s->s3.tmp.peer_sigalgslen);
2306 
2307 }
2308 
2309 /* Set preferred digest for each key type */
2310 
tls1_process_sigalgs(SSL *s)2311 int tls1_process_sigalgs(SSL *s)
2312 {
2313     size_t i;
2314     uint32_t *pvalid = s->s3.tmp.valid_flags;
2315 
2316     if (!tls1_set_shared_sigalgs(s))
2317         return 0;
2318 
2319     for (i = 0; i < SSL_PKEY_NUM; i++)
2320         pvalid[i] = 0;
2321 
2322     for (i = 0; i < s->shared_sigalgslen; i++) {
2323         const SIGALG_LOOKUP *sigptr = s->shared_sigalgs[i];
2324         int idx = sigptr->sig_idx;
2325 
2326         /* Ignore PKCS1 based sig algs in TLSv1.3 */
2327         if (SSL_IS_TLS13(s) && sigptr->sig == EVP_PKEY_RSA)
2328             continue;
2329         /* If not disabled indicate we can explicitly sign */
2330         if (pvalid[idx] == 0 && !ssl_cert_is_disabled(s->ctx, idx))
2331             pvalid[idx] = CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN;
2332     }
2333     return 1;
2334 }
2335 
SSL_get_sigalgs(SSL *s, int idx, int *psign, int *phash, int *psignhash, unsigned char *rsig, unsigned char *rhash)2336 int SSL_get_sigalgs(SSL *s, int idx,
2337                     int *psign, int *phash, int *psignhash,
2338                     unsigned char *rsig, unsigned char *rhash)
2339 {
2340     uint16_t *psig = s->s3.tmp.peer_sigalgs;
2341     size_t numsigalgs = s->s3.tmp.peer_sigalgslen;
2342     if (psig == NULL || numsigalgs > INT_MAX)
2343         return 0;
2344     if (idx >= 0) {
2345         const SIGALG_LOOKUP *lu;
2346 
2347         if (idx >= (int)numsigalgs)
2348             return 0;
2349         psig += idx;
2350         if (rhash != NULL)
2351             *rhash = (unsigned char)((*psig >> 8) & 0xff);
2352         if (rsig != NULL)
2353             *rsig = (unsigned char)(*psig & 0xff);
2354         lu = tls1_lookup_sigalg(s, *psig);
2355         if (psign != NULL)
2356             *psign = lu != NULL ? lu->sig : NID_undef;
2357         if (phash != NULL)
2358             *phash = lu != NULL ? lu->hash : NID_undef;
2359         if (psignhash != NULL)
2360             *psignhash = lu != NULL ? lu->sigandhash : NID_undef;
2361     }
2362     return (int)numsigalgs;
2363 }
2364 
SSL_get_shared_sigalgs(SSL *s, int idx, int *psign, int *phash, int *psignhash, unsigned char *rsig, unsigned char *rhash)2365 int SSL_get_shared_sigalgs(SSL *s, int idx,
2366                            int *psign, int *phash, int *psignhash,
2367                            unsigned char *rsig, unsigned char *rhash)
2368 {
2369     const SIGALG_LOOKUP *shsigalgs;
2370     if (s->shared_sigalgs == NULL
2371         || idx < 0
2372         || idx >= (int)s->shared_sigalgslen
2373         || s->shared_sigalgslen > INT_MAX)
2374         return 0;
2375     shsigalgs = s->shared_sigalgs[idx];
2376     if (phash != NULL)
2377         *phash = shsigalgs->hash;
2378     if (psign != NULL)
2379         *psign = shsigalgs->sig;
2380     if (psignhash != NULL)
2381         *psignhash = shsigalgs->sigandhash;
2382     if (rsig != NULL)
2383         *rsig = (unsigned char)(shsigalgs->sigalg & 0xff);
2384     if (rhash != NULL)
2385         *rhash = (unsigned char)((shsigalgs->sigalg >> 8) & 0xff);
2386     return (int)s->shared_sigalgslen;
2387 }
2388 
2389 /* Maximum possible number of unique entries in sigalgs array */
2390 #define TLS_MAX_SIGALGCNT (OSSL_NELEM(sigalg_lookup_tbl) * 2)
2391 
2392 typedef struct {
2393     size_t sigalgcnt;
2394     /* TLSEXT_SIGALG_XXX values */
2395     uint16_t sigalgs[TLS_MAX_SIGALGCNT];
2396 } sig_cb_st;
2397 
get_sigorhash(int *psig, int *phash, const char *str)2398 static void get_sigorhash(int *psig, int *phash, const char *str)
2399 {
2400     if (strcmp(str, "RSA") == 0) {
2401         *psig = EVP_PKEY_RSA;
2402     } else if (strcmp(str, "RSA-PSS") == 0 || strcmp(str, "PSS") == 0) {
2403         *psig = EVP_PKEY_RSA_PSS;
2404     } else if (strcmp(str, "DSA") == 0) {
2405         *psig = EVP_PKEY_DSA;
2406     } else if (strcmp(str, "ECDSA") == 0) {
2407         *psig = EVP_PKEY_EC;
2408     } else {
2409         *phash = OBJ_sn2nid(str);
2410         if (*phash == NID_undef)
2411             *phash = OBJ_ln2nid(str);
2412     }
2413 }
2414 /* Maximum length of a signature algorithm string component */
2415 #define TLS_MAX_SIGSTRING_LEN   40
2416 
sig_cb(const char *elem, int len, void *arg)2417 static int sig_cb(const char *elem, int len, void *arg)
2418 {
2419     sig_cb_st *sarg = arg;
2420     size_t i;
2421     const SIGALG_LOOKUP *s;
2422     char etmp[TLS_MAX_SIGSTRING_LEN], *p;
2423     int sig_alg = NID_undef, hash_alg = NID_undef;
2424     if (elem == NULL)
2425         return 0;
2426     if (sarg->sigalgcnt == TLS_MAX_SIGALGCNT)
2427         return 0;
2428     if (len > (int)(sizeof(etmp) - 1))
2429         return 0;
2430     memcpy(etmp, elem, len);
2431     etmp[len] = 0;
2432     p = strchr(etmp, '+');
2433     /*
2434      * We only allow SignatureSchemes listed in the sigalg_lookup_tbl;
2435      * if there's no '+' in the provided name, look for the new-style combined
2436      * name.  If not, match both sig+hash to find the needed SIGALG_LOOKUP.
2437      * Just sig+hash is not unique since TLS 1.3 adds rsa_pss_pss_* and
2438      * rsa_pss_rsae_* that differ only by public key OID; in such cases
2439      * we will pick the _rsae_ variant, by virtue of them appearing earlier
2440      * in the table.
2441      */
2442     if (p == NULL) {
2443         for (i = 0, s = sigalg_lookup_tbl; i < OSSL_NELEM(sigalg_lookup_tbl);
2444              i++, s++) {
2445             if (s->name != NULL && strcmp(etmp, s->name) == 0) {
2446                 sarg->sigalgs[sarg->sigalgcnt++] = s->sigalg;
2447                 break;
2448             }
2449         }
2450         if (i == OSSL_NELEM(sigalg_lookup_tbl))
2451             return 0;
2452     } else {
2453         *p = 0;
2454         p++;
2455         if (*p == 0)
2456             return 0;
2457         get_sigorhash(&sig_alg, &hash_alg, etmp);
2458         get_sigorhash(&sig_alg, &hash_alg, p);
2459         if (sig_alg == NID_undef || hash_alg == NID_undef)
2460             return 0;
2461         for (i = 0, s = sigalg_lookup_tbl; i < OSSL_NELEM(sigalg_lookup_tbl);
2462              i++, s++) {
2463             if (s->hash == hash_alg && s->sig == sig_alg) {
2464                 sarg->sigalgs[sarg->sigalgcnt++] = s->sigalg;
2465                 break;
2466             }
2467         }
2468         if (i == OSSL_NELEM(sigalg_lookup_tbl))
2469             return 0;
2470     }
2471 
2472     /* Reject duplicates */
2473     for (i = 0; i < sarg->sigalgcnt - 1; i++) {
2474         if (sarg->sigalgs[i] == sarg->sigalgs[sarg->sigalgcnt - 1]) {
2475             sarg->sigalgcnt--;
2476             return 0;
2477         }
2478     }
2479     return 1;
2480 }
2481 
2482 /*
2483  * Set supported signature algorithms based on a colon separated list of the
2484  * form sig+hash e.g. RSA+SHA512:DSA+SHA512
2485  */
tls1_set_sigalgs_list(CERT *c, const char *str, int client)2486 int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
2487 {
2488     sig_cb_st sig;
2489     sig.sigalgcnt = 0;
2490     if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
2491         return 0;
2492     if (c == NULL)
2493         return 1;
2494     return tls1_set_raw_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
2495 }
2496 
tls1_set_raw_sigalgs(CERT *c, const uint16_t *psigs, size_t salglen, int client)2497 int tls1_set_raw_sigalgs(CERT *c, const uint16_t *psigs, size_t salglen,
2498                      int client)
2499 {
2500     uint16_t *sigalgs;
2501 
2502     if ((sigalgs = OPENSSL_malloc(salglen * sizeof(*sigalgs))) == NULL) {
2503         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
2504         return 0;
2505     }
2506     memcpy(sigalgs, psigs, salglen * sizeof(*sigalgs));
2507 
2508     if (client) {
2509         OPENSSL_free(c->client_sigalgs);
2510         c->client_sigalgs = sigalgs;
2511         c->client_sigalgslen = salglen;
2512     } else {
2513         OPENSSL_free(c->conf_sigalgs);
2514         c->conf_sigalgs = sigalgs;
2515         c->conf_sigalgslen = salglen;
2516     }
2517 
2518     return 1;
2519 }
2520 
tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen, int client)2521 int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen, int client)
2522 {
2523     uint16_t *sigalgs, *sptr;
2524     size_t i;
2525 
2526     if (salglen & 1)
2527         return 0;
2528     if ((sigalgs = OPENSSL_malloc((salglen / 2) * sizeof(*sigalgs))) == NULL) {
2529         ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
2530         return 0;
2531     }
2532     for (i = 0, sptr = sigalgs; i < salglen; i += 2) {
2533         size_t j;
2534         const SIGALG_LOOKUP *curr;
2535         int md_id = *psig_nids++;
2536         int sig_id = *psig_nids++;
2537 
2538         for (j = 0, curr = sigalg_lookup_tbl; j < OSSL_NELEM(sigalg_lookup_tbl);
2539              j++, curr++) {
2540             if (curr->hash == md_id && curr->sig == sig_id) {
2541                 *sptr++ = curr->sigalg;
2542                 break;
2543             }
2544         }
2545 
2546         if (j == OSSL_NELEM(sigalg_lookup_tbl))
2547             goto err;
2548     }
2549 
2550     if (client) {
2551         OPENSSL_free(c->client_sigalgs);
2552         c->client_sigalgs = sigalgs;
2553         c->client_sigalgslen = salglen / 2;
2554     } else {
2555         OPENSSL_free(c->conf_sigalgs);
2556         c->conf_sigalgs = sigalgs;
2557         c->conf_sigalgslen = salglen / 2;
2558     }
2559 
2560     return 1;
2561 
2562  err:
2563     OPENSSL_free(sigalgs);
2564     return 0;
2565 }
2566 
tls1_check_sig_alg(SSL *s, X509 *x, int default_nid)2567 static int tls1_check_sig_alg(SSL *s, X509 *x, int default_nid)
2568 {
2569     int sig_nid, use_pc_sigalgs = 0;
2570     size_t i;
2571     const SIGALG_LOOKUP *sigalg;
2572     size_t sigalgslen;
2573     if (default_nid == -1)
2574         return 1;
2575     sig_nid = X509_get_signature_nid(x);
2576     if (default_nid)
2577         return sig_nid == default_nid ? 1 : 0;
2578 
2579     if (SSL_IS_TLS13(s) && s->s3.tmp.peer_cert_sigalgs != NULL) {
2580         /*
2581          * If we're in TLSv1.3 then we only get here if we're checking the
2582          * chain. If the peer has specified peer_cert_sigalgs then we use them
2583          * otherwise we default to normal sigalgs.
2584          */
2585         sigalgslen = s->s3.tmp.peer_cert_sigalgslen;
2586         use_pc_sigalgs = 1;
2587     } else {
2588         sigalgslen = s->shared_sigalgslen;
2589     }
2590     for (i = 0; i < sigalgslen; i++) {
2591         sigalg = use_pc_sigalgs
2592                  ? tls1_lookup_sigalg(s, s->s3.tmp.peer_cert_sigalgs[i])
2593                  : s->shared_sigalgs[i];
2594         if (sigalg != NULL && sig_nid == sigalg->sigandhash)
2595             return 1;
2596     }
2597     return 0;
2598 }
2599 
2600 /* Check to see if a certificate issuer name matches list of CA names */
STACK_OFnull2601 static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
2602 {
2603     const X509_NAME *nm;
2604     int i;
2605     nm = X509_get_issuer_name(x);
2606     for (i = 0; i < sk_X509_NAME_num(names); i++) {
2607         if (!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
2608             return 1;
2609     }
2610     return 0;
2611 }
2612 
2613 /*
2614  * Check certificate chain is consistent with TLS extensions and is usable by
2615  * server. This servers two purposes: it allows users to check chains before
2616  * passing them to the server and it allows the server to check chains before
2617  * attempting to use them.
2618  */
2619 
2620 /* Flags which need to be set for a certificate when strict mode not set */
2621 
2622 #define CERT_PKEY_VALID_FLAGS \
2623         (CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
2624 /* Strict mode flags */
2625 #define CERT_PKEY_STRICT_FLAGS \
2626          (CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
2627          | CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
2628 
tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain, int idx)2629 int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
2630                      int idx)
2631 {
2632     int i;
2633     int rv = 0;
2634     int check_flags = 0, strict_mode;
2635     CERT_PKEY *cpk = NULL;
2636     CERT *c = s->cert;
2637     uint32_t *pvalid;
2638     unsigned int suiteb_flags = tls1_suiteb(s);
2639     /* idx == -1 means checking server chains */
2640     if (idx != -1) {
2641         /* idx == -2 means checking client certificate chains */
2642         if (idx == -2) {
2643             cpk = c->key;
2644             idx = (int)(cpk - c->pkeys);
2645         } else
2646             cpk = c->pkeys + idx;
2647         pvalid = s->s3.tmp.valid_flags + idx;
2648         x = cpk->x509;
2649         pk = cpk->privatekey;
2650         chain = cpk->chain;
2651         strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
2652         /* If no cert or key, forget it */
2653         if (!x || !pk)
2654             goto end;
2655     } else {
2656         size_t certidx;
2657 
2658         if (!x || !pk)
2659             return 0;
2660 
2661         if (ssl_cert_lookup_by_pkey(pk, &certidx) == NULL)
2662             return 0;
2663         idx = certidx;
2664         pvalid = s->s3.tmp.valid_flags + idx;
2665 
2666         if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
2667             check_flags = CERT_PKEY_STRICT_FLAGS;
2668         else
2669             check_flags = CERT_PKEY_VALID_FLAGS;
2670         strict_mode = 1;
2671     }
2672 
2673     if (suiteb_flags) {
2674         int ok;
2675         if (check_flags)
2676             check_flags |= CERT_PKEY_SUITEB;
2677         ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
2678         if (ok == X509_V_OK)
2679             rv |= CERT_PKEY_SUITEB;
2680         else if (!check_flags)
2681             goto end;
2682     }
2683 
2684     /*
2685      * Check all signature algorithms are consistent with signature
2686      * algorithms extension if TLS 1.2 or later and strict mode.
2687      */
2688     if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode) {
2689         int default_nid;
2690         int rsign = 0;
2691         if (s->s3.tmp.peer_cert_sigalgs != NULL
2692                 || s->s3.tmp.peer_sigalgs != NULL) {
2693             default_nid = 0;
2694         /* If no sigalgs extension use defaults from RFC5246 */
2695         } else {
2696             switch (idx) {
2697             case SSL_PKEY_RSA:
2698                 rsign = EVP_PKEY_RSA;
2699                 default_nid = NID_sha1WithRSAEncryption;
2700                 break;
2701 
2702             case SSL_PKEY_DSA_SIGN:
2703                 rsign = EVP_PKEY_DSA;
2704                 default_nid = NID_dsaWithSHA1;
2705                 break;
2706 
2707             case SSL_PKEY_ECC:
2708                 rsign = EVP_PKEY_EC;
2709                 default_nid = NID_ecdsa_with_SHA1;
2710                 break;
2711 
2712             case SSL_PKEY_GOST01:
2713                 rsign = NID_id_GostR3410_2001;
2714                 default_nid = NID_id_GostR3411_94_with_GostR3410_2001;
2715                 break;
2716 
2717             case SSL_PKEY_GOST12_256:
2718                 rsign = NID_id_GostR3410_2012_256;
2719                 default_nid = NID_id_tc26_signwithdigest_gost3410_2012_256;
2720                 break;
2721 
2722             case SSL_PKEY_GOST12_512:
2723                 rsign = NID_id_GostR3410_2012_512;
2724                 default_nid = NID_id_tc26_signwithdigest_gost3410_2012_512;
2725                 break;
2726 
2727             default:
2728                 default_nid = -1;
2729                 break;
2730             }
2731         }
2732         /*
2733          * If peer sent no signature algorithms extension and we have set
2734          * preferred signature algorithms check we support sha1.
2735          */
2736         if (default_nid > 0 && c->conf_sigalgs) {
2737             size_t j;
2738             const uint16_t *p = c->conf_sigalgs;
2739             for (j = 0; j < c->conf_sigalgslen; j++, p++) {
2740                 const SIGALG_LOOKUP *lu = tls1_lookup_sigalg(s, *p);
2741 
2742                 if (lu != NULL && lu->hash == NID_sha1 && lu->sig == rsign)
2743                     break;
2744             }
2745             if (j == c->conf_sigalgslen) {
2746                 if (check_flags)
2747                     goto skip_sigs;
2748                 else
2749                     goto end;
2750             }
2751         }
2752         /* Check signature algorithm of each cert in chain */
2753         if (SSL_IS_TLS13(s)) {
2754             /*
2755              * We only get here if the application has called SSL_check_chain(),
2756              * so check_flags is always set.
2757              */
2758             if (find_sig_alg(s, x, pk) != NULL)
2759                 rv |= CERT_PKEY_EE_SIGNATURE;
2760         } else if (!tls1_check_sig_alg(s, x, default_nid)) {
2761             if (!check_flags)
2762                 goto end;
2763         } else
2764             rv |= CERT_PKEY_EE_SIGNATURE;
2765         rv |= CERT_PKEY_CA_SIGNATURE;
2766         for (i = 0; i < sk_X509_num(chain); i++) {
2767             if (!tls1_check_sig_alg(s, sk_X509_value(chain, i), default_nid)) {
2768                 if (check_flags) {
2769                     rv &= ~CERT_PKEY_CA_SIGNATURE;
2770                     break;
2771                 } else
2772                     goto end;
2773             }
2774         }
2775     }
2776     /* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
2777     else if (check_flags)
2778         rv |= CERT_PKEY_EE_SIGNATURE | CERT_PKEY_CA_SIGNATURE;
2779  skip_sigs:
2780     /* Check cert parameters are consistent */
2781     if (tls1_check_cert_param(s, x, 1))
2782         rv |= CERT_PKEY_EE_PARAM;
2783     else if (!check_flags)
2784         goto end;
2785     if (!s->server)
2786         rv |= CERT_PKEY_CA_PARAM;
2787     /* In strict mode check rest of chain too */
2788     else if (strict_mode) {
2789         rv |= CERT_PKEY_CA_PARAM;
2790         for (i = 0; i < sk_X509_num(chain); i++) {
2791             X509 *ca = sk_X509_value(chain, i);
2792             if (!tls1_check_cert_param(s, ca, 0)) {
2793                 if (check_flags) {
2794                     rv &= ~CERT_PKEY_CA_PARAM;
2795                     break;
2796                 } else
2797                     goto end;
2798             }
2799         }
2800     }
2801     if (!s->server && strict_mode) {
2802         STACK_OF(X509_NAME) *ca_dn;
2803         int check_type = 0;
2804 
2805         if (EVP_PKEY_is_a(pk, "RSA"))
2806             check_type = TLS_CT_RSA_SIGN;
2807         else if (EVP_PKEY_is_a(pk, "DSA"))
2808             check_type = TLS_CT_DSS_SIGN;
2809         else if (EVP_PKEY_is_a(pk, "EC"))
2810             check_type = TLS_CT_ECDSA_SIGN;
2811 
2812         if (check_type) {
2813             const uint8_t *ctypes = s->s3.tmp.ctype;
2814             size_t j;
2815 
2816             for (j = 0; j < s->s3.tmp.ctype_len; j++, ctypes++) {
2817                 if (*ctypes == check_type) {
2818                     rv |= CERT_PKEY_CERT_TYPE;
2819                     break;
2820                 }
2821             }
2822             if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
2823                 goto end;
2824         } else {
2825             rv |= CERT_PKEY_CERT_TYPE;
2826         }
2827 
2828         ca_dn = s->s3.tmp.peer_ca_names;
2829 
2830         if (ca_dn == NULL
2831             || sk_X509_NAME_num(ca_dn) == 0
2832             || ssl_check_ca_name(ca_dn, x))
2833             rv |= CERT_PKEY_ISSUER_NAME;
2834         else
2835             for (i = 0; i < sk_X509_num(chain); i++) {
2836                 X509 *xtmp = sk_X509_value(chain, i);
2837 
2838                 if (ssl_check_ca_name(ca_dn, xtmp)) {
2839                     rv |= CERT_PKEY_ISSUER_NAME;
2840                     break;
2841                 }
2842             }
2843 
2844         if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
2845             goto end;
2846     } else
2847         rv |= CERT_PKEY_ISSUER_NAME | CERT_PKEY_CERT_TYPE;
2848 
2849     if (!check_flags || (rv & check_flags) == check_flags)
2850         rv |= CERT_PKEY_VALID;
2851 
2852  end:
2853 
2854     if (TLS1_get_version(s) >= TLS1_2_VERSION)
2855         rv |= *pvalid & (CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN);
2856     else
2857         rv |= CERT_PKEY_SIGN | CERT_PKEY_EXPLICIT_SIGN;
2858 
2859     /*
2860      * When checking a CERT_PKEY structure all flags are irrelevant if the
2861      * chain is invalid.
2862      */
2863     if (!check_flags) {
2864         if (rv & CERT_PKEY_VALID) {
2865             *pvalid = rv;
2866         } else {
2867             /* Preserve sign and explicit sign flag, clear rest */
2868             *pvalid &= CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN;
2869             return 0;
2870         }
2871     }
2872     return rv;
2873 }
2874 
2875 /* Set validity of certificates in an SSL structure */
tls1_set_cert_validity(SSL *s)2876 void tls1_set_cert_validity(SSL *s)
2877 {
2878     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA);
2879     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_PSS_SIGN);
2880     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DSA_SIGN);
2881     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
2882     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST01);
2883     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_256);
2884     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_512);
2885     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ED25519);
2886     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ED448);
2887 }
2888 
2889 /* User level utility function to check a chain is suitable */
SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)2890 int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
2891 {
2892     return tls1_check_chain(s, x, pk, chain, -1);
2893 }
2894 
ssl_get_auto_dh(SSL *s)2895 EVP_PKEY *ssl_get_auto_dh(SSL *s)
2896 {
2897     EVP_PKEY *dhp = NULL;
2898     BIGNUM *p;
2899     int dh_secbits = 80, sec_level_bits;
2900     EVP_PKEY_CTX *pctx = NULL;
2901     OSSL_PARAM_BLD *tmpl = NULL;
2902     OSSL_PARAM *params = NULL;
2903 
2904     if (s->cert->dh_tmp_auto != 2) {
2905         if (s->s3.tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aPSK)) {
2906             if (s->s3.tmp.new_cipher->strength_bits == 256)
2907                 dh_secbits = 128;
2908             else
2909                 dh_secbits = 80;
2910         } else {
2911             if (s->s3.tmp.cert == NULL)
2912                 return NULL;
2913             dh_secbits = EVP_PKEY_get_security_bits(s->s3.tmp.cert->privatekey);
2914         }
2915     }
2916 
2917     /* Do not pick a prime that is too weak for the current security level */
2918     sec_level_bits = ssl_get_security_level_bits(s, NULL, NULL);
2919     if (dh_secbits < sec_level_bits)
2920         dh_secbits = sec_level_bits;
2921 
2922     if (dh_secbits >= 192)
2923         p = BN_get_rfc3526_prime_8192(NULL);
2924     else if (dh_secbits >= 152)
2925         p = BN_get_rfc3526_prime_4096(NULL);
2926     else if (dh_secbits >= 128)
2927         p = BN_get_rfc3526_prime_3072(NULL);
2928     else if (dh_secbits >= 112)
2929         p = BN_get_rfc3526_prime_2048(NULL);
2930     else
2931         p = BN_get_rfc2409_prime_1024(NULL);
2932     if (p == NULL)
2933         goto err;
2934 
2935     pctx = EVP_PKEY_CTX_new_from_name(s->ctx->libctx, "DH", s->ctx->propq);
2936     if (pctx == NULL
2937             || EVP_PKEY_fromdata_init(pctx) != 1)
2938         goto err;
2939 
2940     tmpl = OSSL_PARAM_BLD_new();
2941     if (tmpl == NULL
2942             || !OSSL_PARAM_BLD_push_BN(tmpl, OSSL_PKEY_PARAM_FFC_P, p)
2943             || !OSSL_PARAM_BLD_push_uint(tmpl, OSSL_PKEY_PARAM_FFC_G, 2))
2944         goto err;
2945 
2946     params = OSSL_PARAM_BLD_to_param(tmpl);
2947     if (params == NULL
2948             || EVP_PKEY_fromdata(pctx, &dhp, EVP_PKEY_KEY_PARAMETERS, params) != 1)
2949         goto err;
2950 
2951 err:
2952     OSSL_PARAM_free(params);
2953     OSSL_PARAM_BLD_free(tmpl);
2954     EVP_PKEY_CTX_free(pctx);
2955     BN_free(p);
2956     return dhp;
2957 }
2958 
ssl_security_cert_key(SSL *s, SSL_CTX *ctx, X509 *x, int op)2959 static int ssl_security_cert_key(SSL *s, SSL_CTX *ctx, X509 *x, int op)
2960 {
2961     int secbits = -1;
2962     EVP_PKEY *pkey = X509_get0_pubkey(x);
2963     if (pkey) {
2964         /*
2965          * If no parameters this will return -1 and fail using the default
2966          * security callback for any non-zero security level. This will
2967          * reject keys which omit parameters but this only affects DSA and
2968          * omission of parameters is never (?) done in practice.
2969          */
2970         secbits = EVP_PKEY_get_security_bits(pkey);
2971     }
2972     if (s)
2973         return ssl_security(s, op, secbits, 0, x);
2974     else
2975         return ssl_ctx_security(ctx, op, secbits, 0, x);
2976 }
2977 
ssl_security_cert_sig(SSL *s, SSL_CTX *ctx, X509 *x, int op)2978 static int ssl_security_cert_sig(SSL *s, SSL_CTX *ctx, X509 *x, int op)
2979 {
2980     /* Lookup signature algorithm digest */
2981     int secbits, nid, pknid;
2982     /* Don't check signature if self signed */
2983     if ((X509_get_extension_flags(x) & EXFLAG_SS) != 0)
2984         return 1;
2985     if (!X509_get_signature_info(x, &nid, &pknid, &secbits, NULL))
2986         secbits = -1;
2987     /* If digest NID not defined use signature NID */
2988     if (nid == NID_undef)
2989         nid = pknid;
2990     if (s)
2991         return ssl_security(s, op, secbits, nid, x);
2992     else
2993         return ssl_ctx_security(ctx, op, secbits, nid, x);
2994 }
2995 
ssl_security_cert(SSL *s, SSL_CTX *ctx, X509 *x, int vfy, int is_ee)2996 int ssl_security_cert(SSL *s, SSL_CTX *ctx, X509 *x, int vfy, int is_ee)
2997 {
2998     if (vfy)
2999         vfy = SSL_SECOP_PEER;
3000     if (is_ee) {
3001         if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_EE_KEY | vfy))
3002             return SSL_R_EE_KEY_TOO_SMALL;
3003     } else {
3004         if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_CA_KEY | vfy))
3005             return SSL_R_CA_KEY_TOO_SMALL;
3006     }
3007     if (!ssl_security_cert_sig(s, ctx, x, SSL_SECOP_CA_MD | vfy))
3008         return SSL_R_CA_MD_TOO_WEAK;
3009     return 1;
3010 }
3011 
3012 /*
3013  * Check security of a chain, if |sk| includes the end entity certificate then
3014  * |x| is NULL. If |vfy| is 1 then we are verifying a peer chain and not sending
3015  * one to the peer. Return values: 1 if ok otherwise error code to use
3016  */
3017 
ssl_security_cert_chain(SSL *s, STACK_OF(X509) *sk, X509 *x, int vfy)3018 int ssl_security_cert_chain(SSL *s, STACK_OF(X509) *sk, X509 *x, int vfy)
3019 {
3020     int rv, start_idx, i;
3021     if (x == NULL) {
3022         x = sk_X509_value(sk, 0);
3023         if (x == NULL)
3024             return ERR_R_INTERNAL_ERROR;
3025         start_idx = 1;
3026     } else
3027         start_idx = 0;
3028 
3029     rv = ssl_security_cert(s, NULL, x, vfy, 1);
3030     if (rv != 1)
3031         return rv;
3032 
3033     for (i = start_idx; i < sk_X509_num(sk); i++) {
3034         x = sk_X509_value(sk, i);
3035         rv = ssl_security_cert(s, NULL, x, vfy, 0);
3036         if (rv != 1)
3037             return rv;
3038     }
3039     return 1;
3040 }
3041 
3042 /*
3043  * For TLS 1.2 servers check if we have a certificate which can be used
3044  * with the signature algorithm "lu" and return index of certificate.
3045  */
3046 
tls12_get_cert_sigalg_idx(const SSL *s, const SIGALG_LOOKUP *lu)3047 static int tls12_get_cert_sigalg_idx(const SSL *s, const SIGALG_LOOKUP *lu)
3048 {
3049     int sig_idx = lu->sig_idx;
3050     const SSL_CERT_LOOKUP *clu = ssl_cert_lookup_by_idx(sig_idx);
3051 
3052     /* If not recognised or not supported by cipher mask it is not suitable */
3053     if (clu == NULL
3054             || (clu->amask & s->s3.tmp.new_cipher->algorithm_auth) == 0
3055             || (clu->nid == EVP_PKEY_RSA_PSS
3056                 && (s->s3.tmp.new_cipher->algorithm_mkey & SSL_kRSA) != 0))
3057         return -1;
3058 
3059     return s->s3.tmp.valid_flags[sig_idx] & CERT_PKEY_VALID ? sig_idx : -1;
3060 }
3061 
3062 /*
3063  * Checks the given cert against signature_algorithm_cert restrictions sent by
3064  * the peer (if any) as well as whether the hash from the sigalg is usable with
3065  * the key.
3066  * Returns true if the cert is usable and false otherwise.
3067  */
check_cert_usable(SSL *s, const SIGALG_LOOKUP *sig, X509 *x, EVP_PKEY *pkey)3068 static int check_cert_usable(SSL *s, const SIGALG_LOOKUP *sig, X509 *x,
3069                              EVP_PKEY *pkey)
3070 {
3071     const SIGALG_LOOKUP *lu;
3072     int mdnid, pknid, supported;
3073     size_t i;
3074     const char *mdname = NULL;
3075 
3076     /*
3077      * If the given EVP_PKEY cannot support signing with this digest,
3078      * the answer is simply 'no'.
3079      */
3080     if (sig->hash != NID_undef)
3081         mdname = OBJ_nid2sn(sig->hash);
3082     supported = EVP_PKEY_digestsign_supports_digest(pkey, s->ctx->libctx,
3083                                                     mdname,
3084                                                     s->ctx->propq);
3085     if (supported <= 0)
3086         return 0;
3087 
3088     /*
3089      * The TLS 1.3 signature_algorithms_cert extension places restrictions
3090      * on the sigalg with which the certificate was signed (by its issuer).
3091      */
3092     if (s->s3.tmp.peer_cert_sigalgs != NULL) {
3093         if (!X509_get_signature_info(x, &mdnid, &pknid, NULL, NULL))
3094             return 0;
3095         for (i = 0; i < s->s3.tmp.peer_cert_sigalgslen; i++) {
3096             lu = tls1_lookup_sigalg(s, s->s3.tmp.peer_cert_sigalgs[i]);
3097             if (lu == NULL)
3098                 continue;
3099 
3100             /*
3101              * This does not differentiate between the
3102              * rsa_pss_pss_* and rsa_pss_rsae_* schemes since we do not
3103              * have a chain here that lets us look at the key OID in the
3104              * signing certificate.
3105              */
3106             if (mdnid == lu->hash && pknid == lu->sig)
3107                 return 1;
3108         }
3109         return 0;
3110     }
3111 
3112     /*
3113      * Without signat_algorithms_cert, any certificate for which we have
3114      * a viable public key is permitted.
3115      */
3116     return 1;
3117 }
3118 
3119 /*
3120  * Returns true if |s| has a usable certificate configured for use
3121  * with signature scheme |sig|.
3122  * "Usable" includes a check for presence as well as applying
3123  * the signature_algorithm_cert restrictions sent by the peer (if any).
3124  * Returns false if no usable certificate is found.
3125  */
has_usable_cert(SSL *s, const SIGALG_LOOKUP *sig, int idx)3126 static int has_usable_cert(SSL *s, const SIGALG_LOOKUP *sig, int idx)
3127 {
3128     /* TLS 1.2 callers can override sig->sig_idx, but not TLS 1.3 callers. */
3129     if (idx == -1)
3130         idx = sig->sig_idx;
3131     if (!ssl_has_cert(s, idx))
3132         return 0;
3133 
3134     return check_cert_usable(s, sig, s->cert->pkeys[idx].x509,
3135                              s->cert->pkeys[idx].privatekey);
3136 }
3137 
3138 /*
3139  * Returns true if the supplied cert |x| and key |pkey| is usable with the
3140  * specified signature scheme |sig|, or false otherwise.
3141  */
is_cert_usable(SSL *s, const SIGALG_LOOKUP *sig, X509 *x, EVP_PKEY *pkey)3142 static int is_cert_usable(SSL *s, const SIGALG_LOOKUP *sig, X509 *x,
3143                           EVP_PKEY *pkey)
3144 {
3145     size_t idx;
3146 
3147     if (ssl_cert_lookup_by_pkey(pkey, &idx) == NULL)
3148         return 0;
3149 
3150     /* Check the key is consistent with the sig alg */
3151     if ((int)idx != sig->sig_idx)
3152         return 0;
3153 
3154     return check_cert_usable(s, sig, x, pkey);
3155 }
3156 
3157 /*
3158  * Find a signature scheme that works with the supplied certificate |x| and key
3159  * |pkey|. |x| and |pkey| may be NULL in which case we additionally look at our
3160  * available certs/keys to find one that works.
3161  */
find_sig_alg(SSL *s, X509 *x, EVP_PKEY *pkey)3162 static const SIGALG_LOOKUP *find_sig_alg(SSL *s, X509 *x, EVP_PKEY *pkey)
3163 {
3164     const SIGALG_LOOKUP *lu = NULL;
3165     size_t i;
3166     int curve = -1;
3167     EVP_PKEY *tmppkey;
3168 
3169     /* Look for a shared sigalgs matching possible certificates */
3170     for (i = 0; i < s->shared_sigalgslen; i++) {
3171         lu = s->shared_sigalgs[i];
3172 
3173         /* Skip SHA1, SHA224, DSA and RSA if not PSS */
3174         if (lu->hash == NID_sha1
3175             || lu->hash == NID_sha224
3176             || lu->sig == EVP_PKEY_DSA
3177             || lu->sig == EVP_PKEY_RSA)
3178             continue;
3179         /* Check that we have a cert, and signature_algorithms_cert */
3180         if (!tls1_lookup_md(s->ctx, lu, NULL))
3181             continue;
3182         if ((pkey == NULL && !has_usable_cert(s, lu, -1))
3183                 || (pkey != NULL && !is_cert_usable(s, lu, x, pkey)))
3184             continue;
3185 
3186         tmppkey = (pkey != NULL) ? pkey
3187                                  : s->cert->pkeys[lu->sig_idx].privatekey;
3188 
3189         if (lu->sig == EVP_PKEY_EC) {
3190             if (curve == -1)
3191                 curve = ssl_get_EC_curve_nid(tmppkey);
3192             if (lu->curve != NID_undef && curve != lu->curve)
3193                 continue;
3194         } else if (lu->sig == EVP_PKEY_RSA_PSS) {
3195             /* validate that key is large enough for the signature algorithm */
3196             if (!rsa_pss_check_min_key_size(s->ctx, tmppkey, lu))
3197                 continue;
3198         }
3199         break;
3200     }
3201 
3202     if (i == s->shared_sigalgslen)
3203         return NULL;
3204 
3205     return lu;
3206 }
3207 
3208 /*
3209  * Choose an appropriate signature algorithm based on available certificates
3210  * Sets chosen certificate and signature algorithm.
3211  *
3212  * For servers if we fail to find a required certificate it is a fatal error,
3213  * an appropriate error code is set and a TLS alert is sent.
3214  *
3215  * For clients fatalerrs is set to 0. If a certificate is not suitable it is not
3216  * a fatal error: we will either try another certificate or not present one
3217  * to the server. In this case no error is set.
3218  */
tls_choose_sigalg(SSL *s, int fatalerrs)3219 int tls_choose_sigalg(SSL *s, int fatalerrs)
3220 {
3221     const SIGALG_LOOKUP *lu = NULL;
3222     int sig_idx = -1;
3223 
3224     s->s3.tmp.cert = NULL;
3225     s->s3.tmp.sigalg = NULL;
3226 
3227     if (SSL_IS_TLS13(s)) {
3228         lu = find_sig_alg(s, NULL, NULL);
3229         if (lu == NULL) {
3230             if (!fatalerrs)
3231                 return 1;
3232             SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3233                      SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
3234             return 0;
3235         }
3236     } else {
3237         /* If ciphersuite doesn't require a cert nothing to do */
3238         if (!(s->s3.tmp.new_cipher->algorithm_auth & SSL_aCERT))
3239             return 1;
3240         if (!s->server && !ssl_has_cert(s, s->cert->key - s->cert->pkeys))
3241                 return 1;
3242 
3243         if (SSL_USE_SIGALGS(s)) {
3244             size_t i;
3245             if (s->s3.tmp.peer_sigalgs != NULL) {
3246                 int curve = -1;
3247 
3248                 /* For Suite B need to match signature algorithm to curve */
3249                 if (tls1_suiteb(s))
3250                     curve = ssl_get_EC_curve_nid(s->cert->pkeys[SSL_PKEY_ECC]
3251                                                  .privatekey);
3252 
3253                 /*
3254                  * Find highest preference signature algorithm matching
3255                  * cert type
3256                  */
3257                 for (i = 0; i < s->shared_sigalgslen; i++) {
3258                     lu = s->shared_sigalgs[i];
3259 
3260                     if (s->server) {
3261                         if ((sig_idx = tls12_get_cert_sigalg_idx(s, lu)) == -1)
3262                             continue;
3263                     } else {
3264                         int cc_idx = s->cert->key - s->cert->pkeys;
3265 
3266                         sig_idx = lu->sig_idx;
3267                         if (cc_idx != sig_idx)
3268                             continue;
3269                     }
3270                     /* Check that we have a cert, and sig_algs_cert */
3271                     if (!has_usable_cert(s, lu, sig_idx))
3272                         continue;
3273                     if (lu->sig == EVP_PKEY_RSA_PSS) {
3274                         /* validate that key is large enough for the signature algorithm */
3275                         EVP_PKEY *pkey = s->cert->pkeys[sig_idx].privatekey;
3276 
3277                         if (!rsa_pss_check_min_key_size(s->ctx, pkey, lu))
3278                             continue;
3279                     }
3280                     if (curve == -1 || lu->curve == curve)
3281                         break;
3282                 }
3283 #ifndef OPENSSL_NO_GOST
3284                 /*
3285                  * Some Windows-based implementations do not send GOST algorithms indication
3286                  * in supported_algorithms extension, so when we have GOST-based ciphersuite,
3287                  * we have to assume GOST support.
3288                  */
3289                 if (i == s->shared_sigalgslen && s->s3.tmp.new_cipher->algorithm_auth & (SSL_aGOST01 | SSL_aGOST12)) {
3290                   if ((lu = tls1_get_legacy_sigalg(s, -1)) == NULL) {
3291                     if (!fatalerrs)
3292                       return 1;
3293                     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3294                              SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
3295                     return 0;
3296                   } else {
3297                     i = 0;
3298                     sig_idx = lu->sig_idx;
3299                   }
3300                 }
3301 #endif
3302                 if (i == s->shared_sigalgslen) {
3303                     if (!fatalerrs)
3304                         return 1;
3305                     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3306                              SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
3307                     return 0;
3308                 }
3309             } else {
3310                 /*
3311                  * If we have no sigalg use defaults
3312                  */
3313                 const uint16_t *sent_sigs;
3314                 size_t sent_sigslen;
3315 
3316                 if ((lu = tls1_get_legacy_sigalg(s, -1)) == NULL) {
3317                     if (!fatalerrs)
3318                         return 1;
3319                     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3320                              SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
3321                     return 0;
3322                 }
3323 
3324                 /* Check signature matches a type we sent */
3325                 sent_sigslen = tls12_get_psigalgs(s, 1, &sent_sigs);
3326                 for (i = 0; i < sent_sigslen; i++, sent_sigs++) {
3327                     if (lu->sigalg == *sent_sigs
3328                             && has_usable_cert(s, lu, lu->sig_idx))
3329                         break;
3330                 }
3331                 if (i == sent_sigslen) {
3332                     if (!fatalerrs)
3333                         return 1;
3334                     SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3335                              SSL_R_WRONG_SIGNATURE_TYPE);
3336                     return 0;
3337                 }
3338             }
3339         } else {
3340             if ((lu = tls1_get_legacy_sigalg(s, -1)) == NULL) {
3341                 if (!fatalerrs)
3342                     return 1;
3343                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3344                          SSL_R_NO_SUITABLE_SIGNATURE_ALGORITHM);
3345                 return 0;
3346             }
3347         }
3348     }
3349     if (sig_idx == -1)
3350         sig_idx = lu->sig_idx;
3351     s->s3.tmp.cert = &s->cert->pkeys[sig_idx];
3352     s->cert->key = s->s3.tmp.cert;
3353     s->s3.tmp.sigalg = lu;
3354     return 1;
3355 }
3356 
SSL_CTX_set_tlsext_max_fragment_length(SSL_CTX *ctx, uint8_t mode)3357 int SSL_CTX_set_tlsext_max_fragment_length(SSL_CTX *ctx, uint8_t mode)
3358 {
3359     if (mode != TLSEXT_max_fragment_length_DISABLED
3360             && !IS_MAX_FRAGMENT_LENGTH_EXT_VALID(mode)) {
3361         ERR_raise(ERR_LIB_SSL, SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH);
3362         return 0;
3363     }
3364 
3365     ctx->ext.max_fragment_len_mode = mode;
3366     return 1;
3367 }
3368 
SSL_set_tlsext_max_fragment_length(SSL *ssl, uint8_t mode)3369 int SSL_set_tlsext_max_fragment_length(SSL *ssl, uint8_t mode)
3370 {
3371     if (mode != TLSEXT_max_fragment_length_DISABLED
3372             && !IS_MAX_FRAGMENT_LENGTH_EXT_VALID(mode)) {
3373         ERR_raise(ERR_LIB_SSL, SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH);
3374         return 0;
3375     }
3376 
3377     ssl->ext.max_fragment_len_mode = mode;
3378     return 1;
3379 }
3380 
SSL_SESSION_get_max_fragment_length(const SSL_SESSION *session)3381 uint8_t SSL_SESSION_get_max_fragment_length(const SSL_SESSION *session)
3382 {
3383     return session->ext.max_fragment_len_mode;
3384 }
3385 
3386 /*
3387  * Helper functions for HMAC access with legacy support included.
3388  */
ssl_hmac_new(const SSL_CTX *ctx)3389 SSL_HMAC *ssl_hmac_new(const SSL_CTX *ctx)
3390 {
3391     SSL_HMAC *ret = OPENSSL_zalloc(sizeof(*ret));
3392     EVP_MAC *mac = NULL;
3393 
3394     if (ret == NULL)
3395         return NULL;
3396 #ifndef OPENSSL_NO_DEPRECATED_3_0
3397     if (ctx->ext.ticket_key_evp_cb == NULL
3398             && ctx->ext.ticket_key_cb != NULL) {
3399         if (!ssl_hmac_old_new(ret))
3400             goto err;
3401         return ret;
3402     }
3403 #endif
3404     mac = EVP_MAC_fetch(ctx->libctx, "HMAC", ctx->propq);
3405     if (mac == NULL || (ret->ctx = EVP_MAC_CTX_new(mac)) == NULL)
3406         goto err;
3407     EVP_MAC_free(mac);
3408     return ret;
3409  err:
3410     EVP_MAC_CTX_free(ret->ctx);
3411     EVP_MAC_free(mac);
3412     OPENSSL_free(ret);
3413     return NULL;
3414 }
3415 
ssl_hmac_free(SSL_HMAC *ctx)3416 void ssl_hmac_free(SSL_HMAC *ctx)
3417 {
3418     if (ctx != NULL) {
3419         EVP_MAC_CTX_free(ctx->ctx);
3420 #ifndef OPENSSL_NO_DEPRECATED_3_0
3421         ssl_hmac_old_free(ctx);
3422 #endif
3423         OPENSSL_free(ctx);
3424     }
3425 }
3426 
ssl_hmac_get0_EVP_MAC_CTX(SSL_HMAC *ctx)3427 EVP_MAC_CTX *ssl_hmac_get0_EVP_MAC_CTX(SSL_HMAC *ctx)
3428 {
3429     return ctx->ctx;
3430 }
3431 
ssl_hmac_init(SSL_HMAC *ctx, void *key, size_t len, char *md)3432 int ssl_hmac_init(SSL_HMAC *ctx, void *key, size_t len, char *md)
3433 {
3434     OSSL_PARAM params[2], *p = params;
3435 
3436     if (ctx->ctx != NULL) {
3437         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_DIGEST, md, 0);
3438         *p = OSSL_PARAM_construct_end();
3439         if (EVP_MAC_init(ctx->ctx, key, len, params))
3440             return 1;
3441     }
3442 #ifndef OPENSSL_NO_DEPRECATED_3_0
3443     if (ctx->old_ctx != NULL)
3444         return ssl_hmac_old_init(ctx, key, len, md);
3445 #endif
3446     return 0;
3447 }
3448 
ssl_hmac_update(SSL_HMAC *ctx, const unsigned char *data, size_t len)3449 int ssl_hmac_update(SSL_HMAC *ctx, const unsigned char *data, size_t len)
3450 {
3451     if (ctx->ctx != NULL)
3452         return EVP_MAC_update(ctx->ctx, data, len);
3453 #ifndef OPENSSL_NO_DEPRECATED_3_0
3454     if (ctx->old_ctx != NULL)
3455         return ssl_hmac_old_update(ctx, data, len);
3456 #endif
3457     return 0;
3458 }
3459 
ssl_hmac_final(SSL_HMAC *ctx, unsigned char *md, size_t *len, size_t max_size)3460 int ssl_hmac_final(SSL_HMAC *ctx, unsigned char *md, size_t *len,
3461                    size_t max_size)
3462 {
3463     if (ctx->ctx != NULL)
3464         return EVP_MAC_final(ctx->ctx, md, len, max_size);
3465 #ifndef OPENSSL_NO_DEPRECATED_3_0
3466     if (ctx->old_ctx != NULL)
3467         return ssl_hmac_old_final(ctx, md, len);
3468 #endif
3469     return 0;
3470 }
3471 
ssl_hmac_size(const SSL_HMAC *ctx)3472 size_t ssl_hmac_size(const SSL_HMAC *ctx)
3473 {
3474     if (ctx->ctx != NULL)
3475         return EVP_MAC_CTX_get_mac_size(ctx->ctx);
3476 #ifndef OPENSSL_NO_DEPRECATED_3_0
3477     if (ctx->old_ctx != NULL)
3478         return ssl_hmac_old_size(ctx);
3479 #endif
3480     return 0;
3481 }
3482 
ssl_get_EC_curve_nid(const EVP_PKEY *pkey)3483 int ssl_get_EC_curve_nid(const EVP_PKEY *pkey)
3484 {
3485     char gname[OSSL_MAX_NAME_SIZE];
3486 
3487     if (EVP_PKEY_get_group_name(pkey, gname, sizeof(gname), NULL) > 0)
3488         return OBJ_txt2nid(gname);
3489 
3490     return NID_undef;
3491 }
3492 
tls13_set_encoded_pub_key(EVP_PKEY *pkey, const unsigned char *enckey, size_t enckeylen)3493 __owur int tls13_set_encoded_pub_key(EVP_PKEY *pkey,
3494                                      const unsigned char *enckey,
3495                                      size_t enckeylen)
3496 {
3497     if (EVP_PKEY_is_a(pkey, "DH")) {
3498         int bits = EVP_PKEY_get_bits(pkey);
3499 
3500         if (bits <= 0 || enckeylen != (size_t)bits / 8)
3501             /* the encoded key must be padded to the length of the p */
3502             return 0;
3503     } else if (EVP_PKEY_is_a(pkey, "EC")) {
3504         if (enckeylen < 3 /* point format and at least 1 byte for x and y */
3505             || enckey[0] != 0x04)
3506             return 0;
3507     }
3508 
3509     return EVP_PKEY_set1_encoded_public_key(pkey, enckey, enckeylen);
3510 }
3511