2 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
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
15 #include "crypto/ctype.h"
16 #include "internal/cryptlib.h"
17 #include <openssl/crypto.h>
18 #include <openssl/buffer.h>
19 #include <openssl/evp.h>
20 #include <openssl/asn1.h>
21 #include <openssl/x509.h>
22 #include <openssl/x509v3.h>
23 #include <openssl/objects.h>
24 #include "internal/dane.h"
25 #include "crypto/x509.h"
26 #include "x509_local.h"
29 DEFINE_STACK_OF(X509_REVOKED)
30 DEFINE_STACK_OF(GENERAL_NAME)
31 DEFINE_STACK_OF(X509_CRL)
32 DEFINE_STACK_OF(DIST_POINT)
33 DEFINE_STACK_OF_STRING()
35 /* CRL score values */
37 /* No unhandled critical extensions */
39 #define CRL_SCORE_NOCRITICAL 0x100
41 /* certificate is within CRL scope */
43 #define CRL_SCORE_SCOPE 0x080
47 #define CRL_SCORE_TIME 0x040
49 /* Issuer name matches certificate */
51 #define CRL_SCORE_ISSUER_NAME 0x020
53 /* If this score or above CRL is probably valid */
55 #define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE)
57 /* CRL issuer is certificate issuer */
59 #define CRL_SCORE_ISSUER_CERT 0x018
61 /* CRL issuer is on certificate path */
63 #define CRL_SCORE_SAME_PATH 0x008
65 /* CRL issuer matches CRL AKID */
67 #define CRL_SCORE_AKID 0x004
69 /* Have a delta CRL with valid times */
71 #define CRL_SCORE_TIME_DELTA 0x002
73 static int build_chain(X509_STORE_CTX *ctx);
74 static int verify_chain(X509_STORE_CTX *ctx);
75 static int dane_verify(X509_STORE_CTX *ctx);
76 static int null_callback(int ok, X509_STORE_CTX *e);
77 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
78 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
79 static int check_chain_extensions(X509_STORE_CTX *ctx);
80 static int check_name_constraints(X509_STORE_CTX *ctx);
81 static int check_id(X509_STORE_CTX *ctx);
82 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted);
83 static int check_revocation(X509_STORE_CTX *ctx);
84 static int check_cert(X509_STORE_CTX *ctx);
85 static int check_policy(X509_STORE_CTX *ctx);
86 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x);
87 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth);
88 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert);
89 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert);
91 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
92 unsigned int *preasons, X509_CRL *crl, X509 *x);
93 static int get_crl_delta(X509_STORE_CTX *ctx,
94 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x);
95 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl,
96 int *pcrl_score, X509_CRL *base,
97 STACK_OF(X509_CRL) *crls);
98 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
100 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
101 unsigned int *preasons);
102 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
103 static int check_crl_chain(X509_STORE_CTX *ctx,
104 STACK_OF(X509) *cert_path,
105 STACK_OF(X509) *crl_path);
107 static int internal_verify(X509_STORE_CTX *ctx);
109 static int null_callback(int ok, X509_STORE_CTX *e)
115 * Return 1 if given cert is considered self-signed, 0 if not, or -1 on error.
116 * This does not verify self-signedness but relies on x509v3_cache_extensions()
117 * matching issuer and subject names (i.e., the cert being self-issued) and any
118 * present authority key identifier matching the subject key identifier, etc.
120 static int cert_self_signed(X509_STORE_CTX *ctx, X509 *x)
122 if (!X509v3_cache_extensions(x, ctx->libctx, ctx->propq))
125 if (x->ex_flags & EXFLAG_SS)
131 /* Given a certificate try and find an exact match in the store */
133 static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
135 STACK_OF(X509) *certs;
138 /* Lookup all certs with matching subject name */
139 certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
142 /* Look for exact match */
143 for (i = 0; i < sk_X509_num(certs); i++) {
144 xtmp = sk_X509_value(certs, i);
145 if (!X509_cmp(xtmp, x))
149 if (xtmp != NULL && !X509_up_ref(xtmp))
151 sk_X509_pop_free(certs, X509_free);
156 * Inform the verify callback of an error.
157 * If B<x> is not NULL it is the error cert, otherwise use the chain cert at
159 * If B<err> is not X509_V_OK, that's the error value, otherwise leave
160 * unchanged (presumably set by the caller).
162 * Returns 0 to abort verification with an error, non-zero to continue.
164 static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err)
166 ctx->error_depth = depth;
167 ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth);
168 if (err != X509_V_OK)
170 return ctx->verify_cb(0, ctx);
174 * Inform the verify callback of an error, CRL-specific variant. Here, the
175 * error depth and certificate are already set, we just specify the error
178 * Returns 0 to abort verification with an error, non-zero to continue.
180 static int verify_cb_crl(X509_STORE_CTX *ctx, int err)
183 return ctx->verify_cb(0, ctx);
186 static int check_auth_level(X509_STORE_CTX *ctx)
189 int num = sk_X509_num(ctx->chain);
191 if (ctx->param->auth_level <= 0)
194 for (i = 0; i < num; ++i) {
195 X509 *cert = sk_X509_value(ctx->chain, i);
198 * We've already checked the security of the leaf key, so here we only
199 * check the security of issuer keys.
201 if (i > 0 && !check_key_level(ctx, cert) &&
202 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL) == 0)
205 * We also check the signature algorithm security of all certificates
206 * except those of the trust anchor at index num-1.
208 if (i < num - 1 && !check_sig_level(ctx, cert) &&
209 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK) == 0)
215 static int verify_chain(X509_STORE_CTX *ctx)
221 * Before either returning with an error, or continuing with CRL checks,
222 * instantiate chain public key parameters.
224 if ((ok = build_chain(ctx)) == 0 ||
225 (ok = check_chain_extensions(ctx)) == 0 ||
226 (ok = check_auth_level(ctx)) == 0 ||
227 (ok = check_id(ctx)) == 0 || 1)
228 X509_get_pubkey_parameters(NULL, ctx->chain);
229 if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0)
232 err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
234 if (err != X509_V_OK) {
235 if ((ok = verify_cb_cert(ctx, NULL, ctx->error_depth, err)) == 0)
239 /* Verify chain signatures and expiration times */
240 ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx);
244 if ((ok = check_name_constraints(ctx)) == 0)
247 #ifndef OPENSSL_NO_RFC3779
248 /* RFC 3779 path validation, now that CRL check has been done */
249 if ((ok = X509v3_asid_validate_path(ctx)) == 0)
251 if ((ok = X509v3_addr_validate_path(ctx)) == 0)
255 /* If we get this far evaluate policies */
256 if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK)
257 ok = ctx->check_policy(ctx);
261 int X509_verify_cert(X509_STORE_CTX *ctx)
263 SSL_DANE *dane = ctx->dane;
266 if (ctx->cert == NULL) {
267 X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
268 ctx->error = X509_V_ERR_INVALID_CALL;
272 if (ctx->chain != NULL) {
274 * This X509_STORE_CTX has already been used to verify a cert. We
275 * cannot do another one.
277 X509err(X509_F_X509_VERIFY_CERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
278 ctx->error = X509_V_ERR_INVALID_CALL;
282 if (!X509_up_ref(ctx->cert)) {
283 X509err(X509_F_X509_VERIFY_CERT, ERR_R_INTERNAL_ERROR);
284 ctx->error = X509_V_ERR_UNSPECIFIED;
289 * first we make sure the chain we are going to build is present and that
290 * the first entry is in place
292 if ((ctx->chain = sk_X509_new_null()) == NULL
293 || !sk_X509_push(ctx->chain, ctx->cert)) {
294 X509_free(ctx->cert);
295 X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
296 ctx->error = X509_V_ERR_OUT_OF_MEM;
300 ctx->num_untrusted = 1;
302 /* If the peer's public key is too weak, we can stop early. */
303 if (!check_key_level(ctx, ctx->cert) &&
304 !verify_cb_cert(ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL))
307 if (DANETLS_ENABLED(dane))
308 ret = dane_verify(ctx);
310 ret = verify_chain(ctx);
313 * Safety-net. If we are returning an error, we must also set ctx->error,
314 * so that the chain is not considered verified should the error be ignored
315 * (e.g. TLS with SSL_VERIFY_NONE).
317 if (ret <= 0 && ctx->error == X509_V_OK)
318 ctx->error = X509_V_ERR_UNSPECIFIED;
323 * Given a STACK_OF(X509) find the issuer of cert (if any)
325 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
328 X509 *issuer, *rv = NULL;
330 for (i = 0; i < sk_X509_num(sk); i++) {
331 issuer = sk_X509_value(sk, i);
333 * Below check 'issuer != x' is an optimization and safety precaution:
334 * Candidate issuer cert cannot be the same as the subject cert 'x'.
336 if (issuer != x && ctx->check_issued(ctx, x, issuer)) {
338 if (x509_check_cert_time(ctx, rv, -1))
346 * Check that the given certificate 'x' is issued by the certificate 'issuer'
347 * and the issuer is not yet in ctx->chain, where the exceptional case
348 * that 'x' is self-issued and ctx->chain has just one element is allowed.
350 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
352 if (x509_likely_issued(issuer, x, ctx->libctx, ctx->propq) != X509_V_OK)
354 if ((x->ex_flags & EXFLAG_SI) == 0 || sk_X509_num(ctx->chain) != 1) {
358 for (i = 0; i < sk_X509_num(ctx->chain); i++) {
359 ch = sk_X509_value(ctx->chain, i);
360 if (ch == issuer || X509_cmp(ch, issuer) == 0)
367 /* Alternative lookup method: look from a STACK stored in other_ctx */
369 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
371 *issuer = find_issuer(ctx, ctx->other_ctx, x);
373 if (*issuer == NULL || !X509_up_ref(*issuer))
383 static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx,
386 STACK_OF(X509) *sk = NULL;
390 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) {
391 x = sk_X509_value(ctx->other_ctx, i);
392 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) {
393 if (!X509_up_ref(x)) {
394 sk_X509_pop_free(sk, X509_free);
395 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_INTERNAL_ERROR);
396 ctx->error = X509_V_ERR_UNSPECIFIED;
400 sk = sk_X509_new_null();
401 if (sk == NULL || !sk_X509_push(sk, x)) {
403 sk_X509_pop_free(sk, X509_free);
404 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_MALLOC_FAILURE);
405 ctx->error = X509_V_ERR_OUT_OF_MEM;
414 * Check EE or CA certificate purpose. For trusted certificates explicit local
415 * auxiliary trust can be used to override EKU-restrictions.
417 static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth,
420 int tr_ok = X509_TRUST_UNTRUSTED;
423 * For trusted certificates we want to see whether any auxiliary trust
424 * settings trump the purpose constraints.
426 * This is complicated by the fact that the trust ordinals in
427 * ctx->param->trust are entirely independent of the purpose ordinals in
428 * ctx->param->purpose!
430 * What connects them is their mutual initialization via calls from
431 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets
432 * related values of both param->trust and param->purpose. It is however
433 * typically possible to infer associated trust values from a purpose value
434 * via the X509_PURPOSE API.
436 * Therefore, we can only check for trust overrides when the purpose we're
437 * checking is the same as ctx->param->purpose and ctx->param->trust is
440 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose)
441 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT);
444 case X509_TRUST_TRUSTED:
446 case X509_TRUST_REJECTED:
449 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) {
455 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0)
461 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE);
465 * Check a certificate chains extensions for consistency with the supplied
469 static int check_chain_extensions(X509_STORE_CTX *ctx)
471 int i, must_be_ca, plen = 0;
473 int proxy_path_length = 0;
475 int allow_proxy_certs;
476 int num = sk_X509_num(ctx->chain);
479 * must_be_ca can have 1 of 3 values:
480 * -1: we accept both CA and non-CA certificates, to allow direct
481 * use of self-signed certificates (which are marked as CA).
482 * 0: we only accept non-CA certificates. This is currently not
483 * used, but the possibility is present for future extensions.
484 * 1: we only accept CA certificates. This is currently used for
485 * all certificates in the chain except the leaf certificate.
489 /* CRL path validation */
491 allow_proxy_certs = 0;
492 purpose = X509_PURPOSE_CRL_SIGN;
495 ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
496 purpose = ctx->param->purpose;
499 for (i = 0; i < num; i++) {
501 x = sk_X509_value(ctx->chain, i);
502 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
503 && (x->ex_flags & EXFLAG_CRITICAL)) {
504 if (!verify_cb_cert(ctx, x, i,
505 X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION))
508 if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) {
509 if (!verify_cb_cert(ctx, x, i,
510 X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED))
513 ret = X509_check_ca(x);
514 switch (must_be_ca) {
516 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
517 && (ret != 1) && (ret != 0)) {
519 ctx->error = X509_V_ERR_INVALID_CA;
526 ctx->error = X509_V_ERR_INVALID_NON_CA;
531 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */
533 || ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT)
536 ctx->error = X509_V_ERR_INVALID_CA;
541 if ((x->ex_flags & EXFLAG_CA) == 0
542 && x->ex_pathlen != -1
543 && (ctx->param->flags & X509_V_FLAG_X509_STRICT)) {
544 ctx->error = X509_V_ERR_INVALID_EXTENSION;
547 if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK))
549 /* check_purpose() makes the callback as needed */
550 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca))
553 if ((i > 1) && (x->ex_pathlen != -1)
554 && (plen > (x->ex_pathlen + proxy_path_length))) {
555 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED))
558 /* Increment path length if not a self-issued intermediate CA */
559 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0)
562 * If this certificate is a proxy certificate, the next certificate
563 * must be another proxy certificate or a EE certificate. If not,
564 * the next certificate must be a CA certificate.
566 if (x->ex_flags & EXFLAG_PROXY) {
568 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint
569 * is less than max_path_length, the former should be copied to
570 * the latter, and 4.1.4 (a) stipulates that max_path_length
571 * should be verified to be larger than zero and decrement it.
573 * Because we're checking the certs in the reverse order, we start
574 * with verifying that proxy_path_length isn't larger than pcPLC,
575 * and copy the latter to the former if it is, and finally,
576 * increment proxy_path_length.
578 if (x->ex_pcpathlen != -1) {
579 if (proxy_path_length > x->ex_pcpathlen) {
580 if (!verify_cb_cert(ctx, x, i,
581 X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED))
584 proxy_path_length = x->ex_pcpathlen;
594 static int has_san_id(X509 *x, int gtype)
598 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
603 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) {
604 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i);
606 if (g->type == gtype) {
611 GENERAL_NAMES_free(gs);
615 static int check_name_constraints(X509_STORE_CTX *ctx)
619 /* Check name constraints for all certificates */
620 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) {
621 X509 *x = sk_X509_value(ctx->chain, i);
624 /* Ignore self-issued certs unless last in chain */
625 if (i && (x->ex_flags & EXFLAG_SI))
629 * Proxy certificates policy has an extra constraint, where the
630 * certificate subject MUST be the issuer with a single CN entry
632 * (RFC 3820: 3.4, 4.1.3 (a)(4))
634 if (x->ex_flags & EXFLAG_PROXY) {
635 X509_NAME *tmpsubject = X509_get_subject_name(x);
636 X509_NAME *tmpissuer = X509_get_issuer_name(x);
637 X509_NAME_ENTRY *tmpentry = NULL;
638 int last_object_nid = 0;
640 int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1;
642 /* Check that there are at least two RDNs */
643 if (last_object_loc < 1) {
644 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
645 goto proxy_name_done;
649 * Check that there is exactly one more RDN in subject as
650 * there is in issuer.
652 if (X509_NAME_entry_count(tmpsubject)
653 != X509_NAME_entry_count(tmpissuer) + 1) {
654 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
655 goto proxy_name_done;
659 * Check that the last subject component isn't part of a
662 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
664 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
665 last_object_loc - 1))) {
666 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
667 goto proxy_name_done;
671 * Check that the last subject RDN is a commonName, and that
672 * all the previous RDNs match the issuer exactly
674 tmpsubject = X509_NAME_dup(tmpsubject);
675 if (tmpsubject == NULL) {
676 X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
677 ctx->error = X509_V_ERR_OUT_OF_MEM;
682 X509_NAME_delete_entry(tmpsubject, last_object_loc);
684 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry));
686 if (last_object_nid != NID_commonName
687 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) {
688 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
691 X509_NAME_ENTRY_free(tmpentry);
692 X509_NAME_free(tmpsubject);
696 && !verify_cb_cert(ctx, x, i, err))
701 * Check against constraints for all certificates higher in chain
702 * including trust anchor. Trust anchor not strictly speaking needed
703 * but if it includes constraints it is to be assumed it expects them
706 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) {
707 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
710 int rv = NAME_CONSTRAINTS_check(x, nc);
712 /* If EE certificate check commonName too */
713 if (rv == X509_V_OK && i == 0
714 && (ctx->param->hostflags
715 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0
716 && ((ctx->param->hostflags
717 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0
718 || !has_san_id(x, GEN_DNS)))
719 rv = NAME_CONSTRAINTS_check_CN(x, nc);
724 case X509_V_ERR_OUT_OF_MEM:
727 if (!verify_cb_cert(ctx, x, i, rv))
737 static int check_id_error(X509_STORE_CTX *ctx, int errcode)
739 return verify_cb_cert(ctx, ctx->cert, 0, errcode);
742 static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm)
745 int n = sk_OPENSSL_STRING_num(vpm->hosts);
748 if (vpm->peername != NULL) {
749 OPENSSL_free(vpm->peername);
750 vpm->peername = NULL;
752 for (i = 0; i < n; ++i) {
753 name = sk_OPENSSL_STRING_value(vpm->hosts, i);
754 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0)
760 static int check_id(X509_STORE_CTX *ctx)
762 X509_VERIFY_PARAM *vpm = ctx->param;
764 if (vpm->hosts && check_hosts(x, vpm) <= 0) {
765 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
768 if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) {
769 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
772 if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) {
773 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
779 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)
784 SSL_DANE *dane = ctx->dane;
785 int num = sk_X509_num(ctx->chain);
789 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2)
790 * match, we're done, otherwise we'll merely record the match depth.
792 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {
793 switch (trust = check_dane_issuer(ctx, num_untrusted)) {
794 case X509_TRUST_TRUSTED:
795 case X509_TRUST_REJECTED:
801 * Check trusted certificates in chain at depth num_untrusted and up.
802 * Note, that depths 0..num_untrusted-1 may also contain trusted
803 * certificates, but the caller is expected to have already checked those,
804 * and wants to incrementally check just any added since.
806 for (i = num_untrusted; i < num; i++) {
807 x = sk_X509_value(ctx->chain, i);
808 trust = X509_check_trust(x, ctx->param->trust, 0);
809 /* If explicitly trusted return trusted */
810 if (trust == X509_TRUST_TRUSTED)
812 if (trust == X509_TRUST_REJECTED)
817 * If we are looking at a trusted certificate, and accept partial chains,
818 * the chain is PKIX trusted.
820 if (num_untrusted < num) {
821 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
823 return X509_TRUST_UNTRUSTED;
826 if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
828 * Last-resort call with no new trusted certificates, check the leaf
829 * for a direct trust store match.
832 x = sk_X509_value(ctx->chain, i);
833 mx = lookup_cert_match(ctx, x);
835 return X509_TRUST_UNTRUSTED;
838 * Check explicit auxiliary trust/reject settings. If none are set,
839 * we'll accept X509_TRUST_UNTRUSTED when not self-signed.
841 trust = X509_check_trust(mx, ctx->param->trust, 0);
842 if (trust == X509_TRUST_REJECTED) {
847 /* Replace leaf with trusted match */
848 (void) sk_X509_set(ctx->chain, 0, mx);
850 ctx->num_untrusted = 0;
855 * If no trusted certs in chain at all return untrusted and allow
856 * standard (no issuer cert) etc errors to be indicated.
858 return X509_TRUST_UNTRUSTED;
861 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED))
862 return X509_TRUST_REJECTED;
863 return X509_TRUST_UNTRUSTED;
866 if (!DANETLS_ENABLED(dane))
867 return X509_TRUST_TRUSTED;
869 dane->pdpth = num_untrusted;
870 /* With DANE, PKIX alone is not trusted until we have both */
871 if (dane->mdpth >= 0)
872 return X509_TRUST_TRUSTED;
873 return X509_TRUST_UNTRUSTED;
876 static int check_revocation(X509_STORE_CTX *ctx)
878 int i = 0, last = 0, ok = 0;
879 if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
881 if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
882 last = sk_X509_num(ctx->chain) - 1;
884 /* If checking CRL paths this isn't the EE certificate */
889 for (i = 0; i <= last; i++) {
890 ctx->error_depth = i;
891 ok = check_cert(ctx);
898 static int check_cert(X509_STORE_CTX *ctx)
900 X509_CRL *crl = NULL, *dcrl = NULL;
902 int cnum = ctx->error_depth;
903 X509 *x = sk_X509_value(ctx->chain, cnum);
905 ctx->current_cert = x;
906 ctx->current_issuer = NULL;
907 ctx->current_crl_score = 0;
908 ctx->current_reasons = 0;
910 if (x->ex_flags & EXFLAG_PROXY)
913 while (ctx->current_reasons != CRLDP_ALL_REASONS) {
914 unsigned int last_reasons = ctx->current_reasons;
916 /* Try to retrieve relevant CRL */
918 ok = ctx->get_crl(ctx, &crl, x);
920 ok = get_crl_delta(ctx, &crl, &dcrl, x);
922 * If error looking up CRL, nothing we can do except notify callback
925 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
928 ctx->current_crl = crl;
929 ok = ctx->check_crl(ctx, crl);
934 ok = ctx->check_crl(ctx, dcrl);
937 ok = ctx->cert_crl(ctx, dcrl, x);
943 /* Don't look in full CRL if delta reason is removefromCRL */
945 ok = ctx->cert_crl(ctx, crl, x);
955 * If reasons not updated we won't get anywhere by another iteration,
958 if (last_reasons == ctx->current_reasons) {
959 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
967 ctx->current_crl = NULL;
971 /* Check CRL times against values in X509_STORE_CTX */
973 static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
979 ctx->current_crl = crl;
980 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
981 ptime = &ctx->param->check_time;
982 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
987 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime);
991 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD))
998 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID))
1002 if (X509_CRL_get0_nextUpdate(crl)) {
1003 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime);
1008 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD))
1011 /* Ignore expiry of base CRL is delta is valid */
1012 if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) {
1015 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED))
1021 ctx->current_crl = NULL;
1026 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
1027 X509 **pissuer, int *pscore, unsigned int *preasons,
1028 STACK_OF(X509_CRL) *crls)
1030 int i, crl_score, best_score = *pscore;
1031 unsigned int reasons, best_reasons = 0;
1032 X509 *x = ctx->current_cert;
1033 X509_CRL *crl, *best_crl = NULL;
1034 X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
1036 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1037 crl = sk_X509_CRL_value(crls, i);
1038 reasons = *preasons;
1039 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
1040 if (crl_score < best_score || crl_score == 0)
1042 /* If current CRL is equivalent use it if it is newer */
1043 if (crl_score == best_score && best_crl != NULL) {
1045 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl),
1046 X509_CRL_get0_lastUpdate(crl)) == 0)
1049 * ASN1_TIME_diff never returns inconsistent signs for |day|
1052 if (day <= 0 && sec <= 0)
1056 best_crl_issuer = crl_issuer;
1057 best_score = crl_score;
1058 best_reasons = reasons;
1062 X509_CRL_free(*pcrl);
1064 *pissuer = best_crl_issuer;
1065 *pscore = best_score;
1066 *preasons = best_reasons;
1067 X509_CRL_up_ref(best_crl);
1068 X509_CRL_free(*pdcrl);
1070 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
1073 if (best_score >= CRL_SCORE_VALID)
1080 * Compare two CRL extensions for delta checking purposes. They should be
1081 * both present or both absent. If both present all fields must be identical.
1084 static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
1086 ASN1_OCTET_STRING *exta, *extb;
1088 i = X509_CRL_get_ext_by_NID(a, nid, -1);
1090 /* Can't have multiple occurrences */
1091 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1)
1093 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
1097 i = X509_CRL_get_ext_by_NID(b, nid, -1);
1101 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1)
1103 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
1113 if (ASN1_OCTET_STRING_cmp(exta, extb))
1119 /* See if a base and delta are compatible */
1121 static int check_delta_base(X509_CRL *delta, X509_CRL *base)
1123 /* Delta CRL must be a delta */
1124 if (!delta->base_crl_number)
1126 /* Base must have a CRL number */
1127 if (!base->crl_number)
1129 /* Issuer names must match */
1130 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta)))
1132 /* AKID and IDP must match */
1133 if (!crl_extension_match(delta, base, NID_authority_key_identifier))
1135 if (!crl_extension_match(delta, base, NID_issuing_distribution_point))
1137 /* Delta CRL base number must not exceed Full CRL number. */
1138 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0)
1140 /* Delta CRL number must exceed full CRL number */
1141 if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0)
1147 * For a given base CRL find a delta... maybe extend to delta scoring or
1148 * retrieve a chain of deltas...
1151 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore,
1152 X509_CRL *base, STACK_OF(X509_CRL) *crls)
1156 if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS))
1158 if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST))
1160 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1161 delta = sk_X509_CRL_value(crls, i);
1162 if (check_delta_base(delta, base)) {
1163 if (check_crl_time(ctx, delta, 0))
1164 *pscore |= CRL_SCORE_TIME_DELTA;
1165 X509_CRL_up_ref(delta);
1174 * For a given CRL return how suitable it is for the supplied certificate
1175 * 'x'. The return value is a mask of several criteria. If the issuer is not
1176 * the certificate issuer this is returned in *pissuer. The reasons mask is
1177 * also used to determine if the CRL is suitable: if no new reasons the CRL
1178 * is rejected, otherwise reasons is updated.
1181 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
1182 unsigned int *preasons, X509_CRL *crl, X509 *x)
1186 unsigned int tmp_reasons = *preasons, crl_reasons;
1188 /* First see if we can reject CRL straight away */
1190 /* Invalid IDP cannot be processed */
1191 if (crl->idp_flags & IDP_INVALID)
1193 /* Reason codes or indirect CRLs need extended CRL support */
1194 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
1195 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS))
1197 } else if (crl->idp_flags & IDP_REASONS) {
1198 /* If no new reasons reject */
1199 if (!(crl->idp_reasons & ~tmp_reasons))
1202 /* Don't process deltas at this stage */
1203 else if (crl->base_crl_number)
1205 /* If issuer name doesn't match certificate need indirect CRL */
1206 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) {
1207 if (!(crl->idp_flags & IDP_INDIRECT))
1210 crl_score |= CRL_SCORE_ISSUER_NAME;
1212 if (!(crl->flags & EXFLAG_CRITICAL))
1213 crl_score |= CRL_SCORE_NOCRITICAL;
1216 if (check_crl_time(ctx, crl, 0))
1217 crl_score |= CRL_SCORE_TIME;
1219 /* Check authority key ID and locate certificate issuer */
1220 crl_akid_check(ctx, crl, pissuer, &crl_score);
1222 /* If we can't locate certificate issuer at this point forget it */
1224 if (!(crl_score & CRL_SCORE_AKID))
1227 /* Check cert for matching CRL distribution points */
1229 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) {
1230 /* If no new reasons reject */
1231 if (!(crl_reasons & ~tmp_reasons))
1233 tmp_reasons |= crl_reasons;
1234 crl_score |= CRL_SCORE_SCOPE;
1237 *preasons = tmp_reasons;
1243 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl,
1244 X509 **pissuer, int *pcrl_score)
1246 X509 *crl_issuer = NULL;
1247 const X509_NAME *cnm = X509_CRL_get_issuer(crl);
1248 int cidx = ctx->error_depth;
1251 if (cidx != sk_X509_num(ctx->chain) - 1)
1254 crl_issuer = sk_X509_value(ctx->chain, cidx);
1256 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1257 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) {
1258 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT;
1259 *pissuer = crl_issuer;
1264 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) {
1265 crl_issuer = sk_X509_value(ctx->chain, cidx);
1266 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1268 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1269 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH;
1270 *pissuer = crl_issuer;
1275 /* Anything else needs extended CRL support */
1277 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
1281 * Otherwise the CRL issuer is not on the path. Look for it in the set of
1282 * untrusted certificates.
1284 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) {
1285 crl_issuer = sk_X509_value(ctx->untrusted, i);
1286 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1288 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1289 *pissuer = crl_issuer;
1290 *pcrl_score |= CRL_SCORE_AKID;
1297 * Check the path of a CRL issuer certificate. This creates a new
1298 * X509_STORE_CTX and populates it with most of the parameters from the
1299 * parent. This could be optimised somewhat since a lot of path checking will
1300 * be duplicated by the parent, but this will rarely be used in practice.
1303 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x)
1305 X509_STORE_CTX crl_ctx;
1308 /* Don't allow recursive CRL path validation */
1311 if (!X509_STORE_CTX_init(&crl_ctx, ctx->store, x, ctx->untrusted))
1314 crl_ctx.crls = ctx->crls;
1315 /* Copy verify params across */
1316 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
1318 crl_ctx.parent = ctx;
1319 crl_ctx.verify_cb = ctx->verify_cb;
1321 /* Verify CRL issuer */
1322 ret = X509_verify_cert(&crl_ctx);
1326 /* Check chain is acceptable */
1327 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
1329 X509_STORE_CTX_cleanup(&crl_ctx);
1334 * RFC3280 says nothing about the relationship between CRL path and
1335 * certificate path, which could lead to situations where a certificate could
1336 * be revoked or validated by a CA not authorised to do so. RFC5280 is more
1337 * strict and states that the two paths must end in the same trust anchor,
1338 * though some discussions remain... until this is resolved we use the
1342 static int check_crl_chain(X509_STORE_CTX *ctx,
1343 STACK_OF(X509) *cert_path,
1344 STACK_OF(X509) *crl_path)
1346 X509 *cert_ta, *crl_ta;
1347 cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
1348 crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
1349 if (!X509_cmp(cert_ta, crl_ta))
1355 * Check for match between two dist point names: three separate cases.
1356 * 1. Both are relative names and compare X509_NAME types.
1357 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
1358 * 3. Both are full names and compare two GENERAL_NAMES.
1359 * 4. One is NULL: automatic match.
1362 static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
1364 X509_NAME *nm = NULL;
1365 GENERAL_NAMES *gens = NULL;
1366 GENERAL_NAME *gena, *genb;
1373 /* Case 1: two X509_NAME */
1377 if (!X509_NAME_cmp(a->dpname, b->dpname))
1382 /* Case 2: set name and GENERAL_NAMES appropriately */
1384 gens = b->name.fullname;
1385 } else if (b->type == 1) {
1388 /* Case 2: set name and GENERAL_NAMES appropriately */
1389 gens = a->name.fullname;
1393 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */
1395 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1396 gena = sk_GENERAL_NAME_value(gens, i);
1397 if (gena->type != GEN_DIRNAME)
1399 if (!X509_NAME_cmp(nm, gena->d.directoryName))
1405 /* Else case 3: two GENERAL_NAMES */
1407 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) {
1408 gena = sk_GENERAL_NAME_value(a->name.fullname, i);
1409 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) {
1410 genb = sk_GENERAL_NAME_value(b->name.fullname, j);
1411 if (!GENERAL_NAME_cmp(gena, genb))
1420 static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score)
1423 const X509_NAME *nm = X509_CRL_get_issuer(crl);
1424 /* If no CRLissuer return is successful iff don't need a match */
1426 return ! !(crl_score & CRL_SCORE_ISSUER_NAME);
1427 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
1428 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
1429 if (gen->type != GEN_DIRNAME)
1431 if (!X509_NAME_cmp(gen->d.directoryName, nm))
1437 /* Check CRLDP and IDP */
1439 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
1440 unsigned int *preasons)
1443 if (crl->idp_flags & IDP_ONLYATTR)
1445 if (x->ex_flags & EXFLAG_CA) {
1446 if (crl->idp_flags & IDP_ONLYUSER)
1449 if (crl->idp_flags & IDP_ONLYCA)
1452 *preasons = crl->idp_reasons;
1453 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
1454 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
1455 if (crldp_check_crlissuer(dp, crl, crl_score)) {
1456 if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) {
1457 *preasons &= dp->dp_reasons;
1462 if ((!crl->idp || !crl->idp->distpoint)
1463 && (crl_score & CRL_SCORE_ISSUER_NAME))
1469 * Retrieve CRL corresponding to current certificate. If deltas enabled try
1470 * to find a delta CRL too
1473 static int get_crl_delta(X509_STORE_CTX *ctx,
1474 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x)
1477 X509 *issuer = NULL;
1479 unsigned int reasons;
1480 X509_CRL *crl = NULL, *dcrl = NULL;
1481 STACK_OF(X509_CRL) *skcrl;
1482 const X509_NAME *nm = X509_get_issuer_name(x);
1484 reasons = ctx->current_reasons;
1485 ok = get_crl_sk(ctx, &crl, &dcrl,
1486 &issuer, &crl_score, &reasons, ctx->crls);
1490 /* Lookup CRLs from store */
1492 skcrl = ctx->lookup_crls(ctx, nm);
1494 /* If no CRLs found and a near match from get_crl_sk use that */
1498 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
1500 sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
1503 /* If we got any kind of CRL use it and return success */
1505 ctx->current_issuer = issuer;
1506 ctx->current_crl_score = crl_score;
1507 ctx->current_reasons = reasons;
1515 /* Check CRL validity */
1516 static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
1518 X509 *issuer = NULL;
1519 EVP_PKEY *ikey = NULL;
1520 int cnum = ctx->error_depth;
1521 int chnum = sk_X509_num(ctx->chain) - 1;
1523 /* If we have an alternative CRL issuer cert use that */
1524 if (ctx->current_issuer)
1525 issuer = ctx->current_issuer;
1527 * Else find CRL issuer: if not last certificate then issuer is next
1528 * certificate in chain.
1530 else if (cnum < chnum)
1531 issuer = sk_X509_value(ctx->chain, cnum + 1);
1533 issuer = sk_X509_value(ctx->chain, chnum);
1534 /* If not self-issued, can't check signature */
1535 if (!ctx->check_issued(ctx, issuer, issuer) &&
1536 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER))
1544 * Skip most tests for deltas because they have already been done
1546 if (!crl->base_crl_number) {
1547 /* Check for cRLSign bit if keyUsage present */
1548 if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
1549 !(issuer->ex_kusage & KU_CRL_SIGN) &&
1550 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN))
1553 if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) &&
1554 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE))
1557 if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) &&
1558 check_crl_path(ctx, ctx->current_issuer) <= 0 &&
1559 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR))
1562 if ((crl->idp_flags & IDP_INVALID) &&
1563 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION))
1567 if (!(ctx->current_crl_score & CRL_SCORE_TIME) &&
1568 !check_crl_time(ctx, crl, 1))
1571 /* Attempt to get issuer certificate public key */
1572 ikey = X509_get0_pubkey(issuer);
1575 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
1579 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags);
1581 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv))
1583 /* Verify CRL signature */
1584 if (X509_CRL_verify(crl, ikey) <= 0 &&
1585 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE))
1591 /* Check certificate against CRL */
1592 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
1597 * The rules changed for this... previously if a CRL contained unhandled
1598 * critical extensions it could still be used to indicate a certificate
1599 * was revoked. This has since been changed since critical extensions can
1600 * change the meaning of CRL entries.
1602 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
1603 && (crl->flags & EXFLAG_CRITICAL) &&
1604 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION))
1607 * Look for serial number of certificate in CRL. If found, make sure
1608 * reason is not removeFromCRL.
1610 if (X509_CRL_get0_by_cert(crl, &rev, x)) {
1611 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
1613 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED))
1620 static int check_policy(X509_STORE_CTX *ctx)
1627 * With DANE, the trust anchor might be a bare public key, not a
1628 * certificate! In that case our chain does not have the trust anchor
1629 * certificate as a top-most element. This comports well with RFC5280
1630 * chain verification, since there too, the trust anchor is not part of the
1631 * chain to be verified. In particular, X509_policy_check() does not look
1632 * at the TA cert, but assumes that it is present as the top-most chain
1633 * element. We therefore temporarily push a NULL cert onto the chain if it
1634 * was verified via a bare public key, and pop it off right after the
1635 * X509_policy_check() call.
1637 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) {
1638 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
1639 ctx->error = X509_V_ERR_OUT_OF_MEM;
1642 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
1643 ctx->param->policies, ctx->param->flags);
1644 if (ctx->bare_ta_signed)
1645 sk_X509_pop(ctx->chain);
1647 if (ret == X509_PCY_TREE_INTERNAL) {
1648 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
1649 ctx->error = X509_V_ERR_OUT_OF_MEM;
1652 /* Invalid or inconsistent extensions */
1653 if (ret == X509_PCY_TREE_INVALID) {
1656 /* Locate certificates with bad extensions and notify callback. */
1657 for (i = 1; i < sk_X509_num(ctx->chain); i++) {
1658 X509 *x = sk_X509_value(ctx->chain, i);
1660 if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
1662 if (!verify_cb_cert(ctx, x, i,
1663 X509_V_ERR_INVALID_POLICY_EXTENSION))
1668 if (ret == X509_PCY_TREE_FAILURE) {
1669 ctx->current_cert = NULL;
1670 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
1671 return ctx->verify_cb(0, ctx);
1673 if (ret != X509_PCY_TREE_VALID) {
1674 X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR);
1678 if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) {
1679 ctx->current_cert = NULL;
1681 * Verification errors need to be "sticky", a callback may have allowed
1682 * an SSL handshake to continue despite an error, and we must then
1683 * remain in an error state. Therefore, we MUST NOT clear earlier
1684 * verification errors by setting the error to X509_V_OK.
1686 if (!ctx->verify_cb(2, ctx))
1694 * Check certificate validity times.
1695 * If depth >= 0, invoke verification callbacks on error, otherwise just return
1696 * the validation status.
1698 * Return 1 on success, 0 otherwise.
1700 int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth)
1705 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1706 ptime = &ctx->param->check_time;
1707 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1712 i = X509_cmp_time(X509_get0_notBefore(x), ptime);
1713 if (i >= 0 && depth < 0)
1715 if (i == 0 && !verify_cb_cert(ctx, x, depth,
1716 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD))
1718 if (i > 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID))
1721 i = X509_cmp_time(X509_get0_notAfter(x), ptime);
1722 if (i <= 0 && depth < 0)
1724 if (i == 0 && !verify_cb_cert(ctx, x, depth,
1725 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD))
1727 if (i < 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED))
1732 static int internal_verify(X509_STORE_CTX *ctx)
1734 int n = sk_X509_num(ctx->chain) - 1;
1735 X509 *xi = sk_X509_value(ctx->chain, n);
1739 * With DANE-verified bare public key TA signatures, it remains only to
1740 * check the timestamps of the top certificate. We report the issuer as
1741 * NULL, since all we have is a bare key.
1743 if (ctx->bare_ta_signed) {
1749 if (ctx->check_issued(ctx, xi, xi)) /* the last cert appears self-signed */
1752 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
1757 return verify_cb_cert(ctx, xi, 0,
1758 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE);
1760 ctx->error_depth = n;
1761 xs = sk_X509_value(ctx->chain, n);
1765 * Do not clear ctx->error=0, it must be "sticky", only the user's callback
1766 * is allowed to reset errors (at its own peril).
1770 * Skip signature check for self-signed certificates unless explicitly
1771 * asked for because it does not add any security and just wastes time.
1772 * If the issuer's public key is not available or its key usage does
1773 * not support issuing the subject cert, report the issuer certificate
1774 * and its depth (rather than the depth of the subject).
1776 if (xs != xi || (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)) {
1778 int issuer_depth = n + (xi == xs ? 0 : 1);
1779 int ret = x509_signing_allowed(xi, xs);
1781 if (ret != X509_V_OK && !verify_cb_cert(ctx, xi, issuer_depth, ret))
1783 if ((pkey = X509_get0_pubkey(xi)) == NULL) {
1784 if (!verify_cb_cert(ctx, xi, issuer_depth,
1785 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
1787 } else if (X509_verify_ex(xs, pkey, ctx->libctx, ctx->propq) <= 0) {
1788 if (!verify_cb_cert(ctx, xs, n,
1789 X509_V_ERR_CERT_SIGNATURE_FAILURE))
1795 /* Calls verify callback as needed */
1796 if (!x509_check_cert_time(ctx, xs, n))
1800 * Signal success at this depth. However, the previous error (if any)
1803 ctx->current_issuer = xi;
1804 ctx->current_cert = xs;
1805 ctx->error_depth = n;
1806 if (!ctx->verify_cb(1, ctx))
1811 xs = sk_X509_value(ctx->chain, n);
1817 int X509_cmp_current_time(const ASN1_TIME *ctm)
1819 return X509_cmp_time(ctm, NULL);
1822 int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
1824 static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1;
1825 static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1;
1826 ASN1_TIME *asn1_cmp_time = NULL;
1827 int i, day, sec, ret = 0;
1828 #ifdef CHARSET_EBCDIC
1829 const char upper_z = 0x5A;
1831 const char upper_z = 'Z';
1834 * Note that ASN.1 allows much more slack in the time format than RFC5280.
1835 * In RFC5280, the representation is fixed:
1836 * UTCTime: YYMMDDHHMMSSZ
1837 * GeneralizedTime: YYYYMMDDHHMMSSZ
1839 * We do NOT currently enforce the following RFC 5280 requirement:
1840 * "CAs conforming to this profile MUST always encode certificate
1841 * validity dates through the year 2049 as UTCTime; certificate validity
1842 * dates in 2050 or later MUST be encoded as GeneralizedTime."
1844 switch (ctm->type) {
1845 case V_ASN1_UTCTIME:
1846 if (ctm->length != (int)(utctime_length))
1849 case V_ASN1_GENERALIZEDTIME:
1850 if (ctm->length != (int)(generalizedtime_length))
1858 * Verify the format: the ASN.1 functions we use below allow a more
1859 * flexible format than what's mandated by RFC 5280.
1860 * Digit and date ranges will be verified in the conversion methods.
1862 for (i = 0; i < ctm->length - 1; i++) {
1863 if (!ascii_isdigit(ctm->data[i]))
1866 if (ctm->data[ctm->length - 1] != upper_z)
1870 * There is ASN1_UTCTIME_cmp_time_t but no
1871 * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t,
1872 * so we go through ASN.1
1874 asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time);
1875 if (asn1_cmp_time == NULL)
1877 if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time))
1881 * X509_cmp_time comparison is <=.
1882 * The return value 0 is reserved for errors.
1884 ret = (day >= 0 && sec >= 0) ? -1 : 1;
1887 ASN1_TIME_free(asn1_cmp_time);
1892 * Return 0 if time should not be checked or reference time is in range,
1893 * or else 1 if it is past the end, or -1 if it is before the start
1895 int X509_cmp_timeframe(const X509_VERIFY_PARAM *vpm,
1896 const ASN1_TIME *start, const ASN1_TIME *end)
1899 time_t *time = NULL;
1900 unsigned long flags = vpm == NULL ? 0 : X509_VERIFY_PARAM_get_flags(vpm);
1902 if ((flags & X509_V_FLAG_USE_CHECK_TIME) != 0) {
1903 ref_time = X509_VERIFY_PARAM_get_time(vpm);
1905 } else if ((flags & X509_V_FLAG_NO_CHECK_TIME) != 0) {
1906 return 0; /* this means ok */
1907 } /* else reference time is the current time */
1909 if (end != NULL && X509_cmp_time(end, time) < 0)
1911 if (start != NULL && X509_cmp_time(start, time) > 0)
1916 ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj)
1918 return X509_time_adj(s, adj, NULL);
1921 ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm)
1923 return X509_time_adj_ex(s, 0, offset_sec, in_tm);
1926 ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s,
1927 int offset_day, long offset_sec, time_t *in_tm)
1936 if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) {
1937 if (s->type == V_ASN1_UTCTIME)
1938 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec);
1939 if (s->type == V_ASN1_GENERALIZEDTIME)
1940 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec);
1942 return ASN1_TIME_adj(s, t, offset_day, offset_sec);
1945 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
1947 EVP_PKEY *ktmp = NULL, *ktmp2;
1950 if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey))
1953 for (i = 0; i < sk_X509_num(chain); i++) {
1954 ktmp = X509_get0_pubkey(sk_X509_value(chain, i));
1956 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
1957 X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
1960 if (!EVP_PKEY_missing_parameters(ktmp))
1964 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
1965 X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
1969 /* first, populate the other certs */
1970 for (j = i - 1; j >= 0; j--) {
1971 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j));
1972 EVP_PKEY_copy_parameters(ktmp2, ktmp);
1976 EVP_PKEY_copy_parameters(pkey, ktmp);
1980 /* Make a delta CRL as the diff between two full CRLs */
1982 X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer,
1983 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags)
1985 X509_CRL *crl = NULL;
1987 STACK_OF(X509_REVOKED) *revs = NULL;
1988 /* CRLs can't be delta already */
1989 if (base->base_crl_number || newer->base_crl_number) {
1990 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA);
1993 /* Base and new CRL must have a CRL number */
1994 if (!base->crl_number || !newer->crl_number) {
1995 X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER);
1998 /* Issuer names must match */
1999 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) {
2000 X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH);
2003 /* AKID and IDP must match */
2004 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) {
2005 X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH);
2008 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) {
2009 X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH);
2012 /* Newer CRL number must exceed full CRL number */
2013 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) {
2014 X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER);
2017 /* CRLs must verify */
2018 if (skey && (X509_CRL_verify(base, skey) <= 0 ||
2019 X509_CRL_verify(newer, skey) <= 0)) {
2020 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE);
2023 /* Create new CRL */
2024 crl = X509_CRL_new();
2025 if (crl == NULL || !X509_CRL_set_version(crl, 1))
2027 /* Set issuer name */
2028 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer)))
2031 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer)))
2033 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer)))
2036 /* Set base CRL number: must be critical */
2038 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0))
2042 * Copy extensions across from newest CRL to delta: this will set CRL
2043 * number to correct value too.
2046 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) {
2047 X509_EXTENSION *ext;
2048 ext = X509_CRL_get_ext(newer, i);
2049 if (!X509_CRL_add_ext(crl, ext, -1))
2053 /* Go through revoked entries, copying as needed */
2055 revs = X509_CRL_get_REVOKED(newer);
2057 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) {
2058 X509_REVOKED *rvn, *rvtmp;
2059 rvn = sk_X509_REVOKED_value(revs, i);
2061 * Add only if not also in base. TODO: need something cleverer here
2062 * for some more complex CRLs covering multiple CAs.
2064 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) {
2065 rvtmp = X509_REVOKED_dup(rvn);
2068 if (!X509_CRL_add0_revoked(crl, rvtmp)) {
2069 X509_REVOKED_free(rvtmp);
2074 /* TODO: optionally prune deleted entries */
2076 if (skey && md && !X509_CRL_sign(crl, skey, md))
2082 X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE);
2087 int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
2089 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data);
2092 void *X509_STORE_CTX_get_ex_data(const X509_STORE_CTX *ctx, int idx)
2094 return CRYPTO_get_ex_data(&ctx->ex_data, idx);
2097 int X509_STORE_CTX_get_error(const X509_STORE_CTX *ctx)
2102 void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
2107 int X509_STORE_CTX_get_error_depth(const X509_STORE_CTX *ctx)
2109 return ctx->error_depth;
2112 void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth)
2114 ctx->error_depth = depth;
2117 X509 *X509_STORE_CTX_get_current_cert(const X509_STORE_CTX *ctx)
2119 return ctx->current_cert;
2122 void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x)
2124 ctx->current_cert = x;
2127 STACK_OF(X509) *X509_STORE_CTX_get0_chain(const X509_STORE_CTX *ctx)
2132 STACK_OF(X509) *X509_STORE_CTX_get1_chain(const X509_STORE_CTX *ctx)
2136 return X509_chain_up_ref(ctx->chain);
2139 X509 *X509_STORE_CTX_get0_current_issuer(const X509_STORE_CTX *ctx)
2141 return ctx->current_issuer;
2144 X509_CRL *X509_STORE_CTX_get0_current_crl(const X509_STORE_CTX *ctx)
2146 return ctx->current_crl;
2149 X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(const X509_STORE_CTX *ctx)
2154 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
2159 void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
2164 int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
2167 * XXX: Why isn't this function always used to set the associated trust?
2168 * Should there even be a VPM->trust field at all? Or should the trust
2169 * always be inferred from the purpose by X509_STORE_CTX_init().
2171 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
2174 int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
2177 * XXX: See above, this function would only be needed when the default
2178 * trust for the purpose needs an override in a corner case.
2180 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
2184 * This function is used to set the X509_STORE_CTX purpose and trust values.
2185 * This is intended to be used when another structure has its own trust and
2186 * purpose values which (if set) will be inherited by the ctx. If they aren't
2187 * set then we will usually have a default purpose in mind which should then
2188 * be used to set the trust value. An example of this is SSL use: an SSL
2189 * structure will have its own purpose and trust settings which the
2190 * application can set: if they aren't set then we use the default of SSL
2194 int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
2195 int purpose, int trust)
2198 /* If purpose not set use default */
2200 purpose = def_purpose;
2201 /* If we have a purpose then check it is valid */
2204 idx = X509_PURPOSE_get_by_id(purpose);
2206 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2207 X509_R_UNKNOWN_PURPOSE_ID);
2210 ptmp = X509_PURPOSE_get0(idx);
2211 if (ptmp->trust == X509_TRUST_DEFAULT) {
2212 idx = X509_PURPOSE_get_by_id(def_purpose);
2214 * XXX: In the two callers above def_purpose is always 0, which is
2215 * not a known value, so idx will always be -1. How is the
2216 * X509_TRUST_DEFAULT case actually supposed to be handled?
2219 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2220 X509_R_UNKNOWN_PURPOSE_ID);
2223 ptmp = X509_PURPOSE_get0(idx);
2225 /* If trust not set then get from purpose default */
2227 trust = ptmp->trust;
2230 idx = X509_TRUST_get_by_id(trust);
2232 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2233 X509_R_UNKNOWN_TRUST_ID);
2238 if (purpose && !ctx->param->purpose)
2239 ctx->param->purpose = purpose;
2240 if (trust && !ctx->param->trust)
2241 ctx->param->trust = trust;
2245 X509_STORE_CTX *X509_STORE_CTX_new_with_libctx(OPENSSL_CTX *libctx,
2248 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
2251 X509err(0, ERR_R_MALLOC_FAILURE);
2255 ctx->libctx = libctx;
2256 if (propq != NULL) {
2257 ctx->propq = OPENSSL_strdup(propq);
2258 if (ctx->propq == NULL) {
2260 X509err(0, ERR_R_MALLOC_FAILURE);
2268 X509_STORE_CTX *X509_STORE_CTX_new(void)
2270 return X509_STORE_CTX_new_with_libctx(NULL, NULL);
2274 void X509_STORE_CTX_free(X509_STORE_CTX *ctx)
2279 X509_STORE_CTX_cleanup(ctx);
2281 /* libctx and propq survive X509_STORE_CTX_cleanup() */
2282 OPENSSL_free(ctx->propq);
2287 int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
2288 STACK_OF(X509) *chain)
2294 ctx->untrusted = chain;
2296 ctx->num_untrusted = 0;
2297 ctx->other_ctx = NULL;
2301 ctx->explicit_policy = 0;
2302 ctx->error_depth = 0;
2303 ctx->current_cert = NULL;
2304 ctx->current_issuer = NULL;
2305 ctx->current_crl = NULL;
2306 ctx->current_crl_score = 0;
2307 ctx->current_reasons = 0;
2311 ctx->bare_ta_signed = 0;
2312 /* Zero ex_data to make sure we're cleanup-safe */
2313 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2315 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */
2317 ctx->cleanup = store->cleanup;
2321 if (store && store->check_issued)
2322 ctx->check_issued = store->check_issued;
2324 ctx->check_issued = check_issued;
2326 if (store && store->get_issuer)
2327 ctx->get_issuer = store->get_issuer;
2329 ctx->get_issuer = X509_STORE_CTX_get1_issuer;
2331 if (store && store->verify_cb)
2332 ctx->verify_cb = store->verify_cb;
2334 ctx->verify_cb = null_callback;
2336 if (store && store->verify)
2337 ctx->verify = store->verify;
2339 ctx->verify = internal_verify;
2341 if (store && store->check_revocation)
2342 ctx->check_revocation = store->check_revocation;
2344 ctx->check_revocation = check_revocation;
2346 if (store && store->get_crl)
2347 ctx->get_crl = store->get_crl;
2349 ctx->get_crl = NULL;
2351 if (store && store->check_crl)
2352 ctx->check_crl = store->check_crl;
2354 ctx->check_crl = check_crl;
2356 if (store && store->cert_crl)
2357 ctx->cert_crl = store->cert_crl;
2359 ctx->cert_crl = cert_crl;
2361 if (store && store->check_policy)
2362 ctx->check_policy = store->check_policy;
2364 ctx->check_policy = check_policy;
2366 if (store && store->lookup_certs)
2367 ctx->lookup_certs = store->lookup_certs;
2369 ctx->lookup_certs = X509_STORE_CTX_get1_certs;
2371 if (store && store->lookup_crls)
2372 ctx->lookup_crls = store->lookup_crls;
2374 ctx->lookup_crls = X509_STORE_CTX_get1_crls;
2376 ctx->param = X509_VERIFY_PARAM_new();
2377 if (ctx->param == NULL) {
2378 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2383 * Inherit callbacks and flags from X509_STORE if not set use defaults.
2386 ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
2388 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE;
2391 ret = X509_VERIFY_PARAM_inherit(ctx->param,
2392 X509_VERIFY_PARAM_lookup("default"));
2395 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2400 * XXX: For now, continue to inherit trust from VPM, but infer from the
2401 * purpose if this still yields the default value.
2403 if (ctx->param->trust == X509_TRUST_DEFAULT) {
2404 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose);
2405 X509_PURPOSE *xp = X509_PURPOSE_get0(idx);
2408 ctx->param->trust = X509_PURPOSE_get_trust(xp);
2411 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
2414 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2418 * On error clean up allocated storage, if the store context was not
2419 * allocated with X509_STORE_CTX_new() this is our last chance to do so.
2421 X509_STORE_CTX_cleanup(ctx);
2426 * Set alternative lookup method: just a STACK of trusted certificates. This
2427 * avoids X509_STORE nastiness where it isn't needed.
2429 void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2431 ctx->other_ctx = sk;
2432 ctx->get_issuer = get_issuer_sk;
2433 ctx->lookup_certs = lookup_certs_sk;
2436 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
2439 * We need to be idempotent because, unfortunately, free() also calls
2440 * cleanup(), so the natural call sequence new(), init(), cleanup(), free()
2441 * calls cleanup() for the same object twice! Thus we must zero the
2442 * pointers below after they're freed!
2444 /* Seems to always be 0 in OpenSSL, do this at most once. */
2445 if (ctx->cleanup != NULL) {
2447 ctx->cleanup = NULL;
2449 if (ctx->param != NULL) {
2450 if (ctx->parent == NULL)
2451 X509_VERIFY_PARAM_free(ctx->param);
2454 X509_policy_tree_free(ctx->tree);
2456 sk_X509_pop_free(ctx->chain, X509_free);
2458 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
2459 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2462 void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
2464 X509_VERIFY_PARAM_set_depth(ctx->param, depth);
2467 void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
2469 X509_VERIFY_PARAM_set_flags(ctx->param, flags);
2472 void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags,
2475 X509_VERIFY_PARAM_set_time(ctx->param, t);
2478 X509 *X509_STORE_CTX_get0_cert(const X509_STORE_CTX *ctx)
2483 STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(const X509_STORE_CTX *ctx)
2485 return ctx->untrusted;
2488 void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2490 ctx->untrusted = sk;
2493 void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2495 sk_X509_pop_free(ctx->chain, X509_free);
2499 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
2500 X509_STORE_CTX_verify_cb verify_cb)
2502 ctx->verify_cb = verify_cb;
2505 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(const X509_STORE_CTX *ctx)
2507 return ctx->verify_cb;
2510 void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx,
2511 X509_STORE_CTX_verify_fn verify)
2513 ctx->verify = verify;
2516 X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(const X509_STORE_CTX *ctx)
2521 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(const X509_STORE_CTX *ctx)
2523 return ctx->get_issuer;
2526 X509_STORE_CTX_check_issued_fn
2527 X509_STORE_CTX_get_check_issued(const X509_STORE_CTX *ctx)
2529 return ctx->check_issued;
2532 X509_STORE_CTX_check_revocation_fn
2533 X509_STORE_CTX_get_check_revocation(const X509_STORE_CTX *ctx)
2535 return ctx->check_revocation;
2538 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(const X509_STORE_CTX *ctx)
2540 return ctx->get_crl;
2543 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(const X509_STORE_CTX *ctx)
2545 return ctx->check_crl;
2548 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(const X509_STORE_CTX *ctx)
2550 return ctx->cert_crl;
2553 X509_STORE_CTX_check_policy_fn
2554 X509_STORE_CTX_get_check_policy(const X509_STORE_CTX *ctx)
2556 return ctx->check_policy;
2559 X509_STORE_CTX_lookup_certs_fn
2560 X509_STORE_CTX_get_lookup_certs(const X509_STORE_CTX *ctx)
2562 return ctx->lookup_certs;
2565 X509_STORE_CTX_lookup_crls_fn
2566 X509_STORE_CTX_get_lookup_crls(const X509_STORE_CTX *ctx)
2568 return ctx->lookup_crls;
2571 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(const X509_STORE_CTX *ctx)
2573 return ctx->cleanup;
2576 X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(const X509_STORE_CTX *ctx)
2581 int X509_STORE_CTX_get_explicit_policy(const X509_STORE_CTX *ctx)
2583 return ctx->explicit_policy;
2586 int X509_STORE_CTX_get_num_untrusted(const X509_STORE_CTX *ctx)
2588 return ctx->num_untrusted;
2591 int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
2593 const X509_VERIFY_PARAM *param;
2595 param = X509_VERIFY_PARAM_lookup(name);
2598 return X509_VERIFY_PARAM_inherit(ctx->param, param);
2601 X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(const X509_STORE_CTX *ctx)
2606 void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
2608 X509_VERIFY_PARAM_free(ctx->param);
2612 void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane)
2617 static unsigned char *dane_i2d(
2620 unsigned int *i2dlen)
2622 unsigned char *buf = NULL;
2626 * Extract ASN.1 DER form of certificate or public key.
2629 case DANETLS_SELECTOR_CERT:
2630 len = i2d_X509(cert, &buf);
2632 case DANETLS_SELECTOR_SPKI:
2633 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf);
2636 X509err(X509_F_DANE_I2D, X509_R_BAD_SELECTOR);
2640 if (len < 0 || buf == NULL) {
2641 X509err(X509_F_DANE_I2D, ERR_R_MALLOC_FAILURE);
2645 *i2dlen = (unsigned int)len;
2649 #define DANETLS_NONE 256 /* impossible uint8_t */
2651 static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth)
2653 SSL_DANE *dane = ctx->dane;
2654 unsigned usage = DANETLS_NONE;
2655 unsigned selector = DANETLS_NONE;
2656 unsigned ordinal = DANETLS_NONE;
2657 unsigned mtype = DANETLS_NONE;
2658 unsigned char *i2dbuf = NULL;
2659 unsigned int i2dlen = 0;
2660 unsigned char mdbuf[EVP_MAX_MD_SIZE];
2661 unsigned char *cmpbuf = NULL;
2662 unsigned int cmplen = 0;
2666 danetls_record *t = NULL;
2669 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK;
2672 * The trust store is not applicable with DANE-TA(2)
2674 if (depth >= ctx->num_untrusted)
2675 mask &= DANETLS_PKIX_MASK;
2678 * If we've previously matched a PKIX-?? record, no need to test any
2679 * further PKIX-?? records, it remains to just build the PKIX chain.
2680 * Had the match been a DANE-?? record, we'd be done already.
2682 if (dane->mdpth >= 0)
2683 mask &= ~DANETLS_PKIX_MASK;
2686 * https://tools.ietf.org/html/rfc7671#section-5.1
2687 * https://tools.ietf.org/html/rfc7671#section-5.2
2688 * https://tools.ietf.org/html/rfc7671#section-5.3
2689 * https://tools.ietf.org/html/rfc7671#section-5.4
2691 * We handle DANE-EE(3) records first as they require no chain building
2692 * and no expiration or hostname checks. We also process digests with
2693 * higher ordinals first and ignore lower priorities except Full(0) which
2694 * is always processed (last). If none match, we then process PKIX-EE(1).
2696 * NOTE: This relies on DANE usages sorting before the corresponding PKIX
2697 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest
2698 * priorities. See twin comment in ssl/ssl_lib.c.
2700 * We expect that most TLSA RRsets will have just a single usage, so we
2701 * don't go out of our way to cache multiple selector-specific i2d buffers
2702 * across usages, but if the selector happens to remain the same as switch
2703 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1",
2704 * records would result in us generating each of the certificate and public
2705 * key DER forms twice, but more typically we'd just see multiple "3 1 1"
2706 * or multiple "3 0 1" records.
2708 * As soon as we find a match at any given depth, we stop, because either
2709 * we've matched a DANE-?? record and the peer is authenticated, or, after
2710 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is
2711 * sufficient for DANE, and what remains to do is ordinary PKIX validation.
2713 recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0;
2714 for (i = 0; matched == 0 && i < recnum; ++i) {
2715 t = sk_danetls_record_value(dane->trecs, i);
2716 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0)
2718 if (t->usage != usage) {
2721 /* Reset digest agility for each usage/selector pair */
2722 mtype = DANETLS_NONE;
2723 ordinal = dane->dctx->mdord[t->mtype];
2725 if (t->selector != selector) {
2726 selector = t->selector;
2728 /* Update per-selector state */
2729 OPENSSL_free(i2dbuf);
2730 i2dbuf = dane_i2d(cert, selector, &i2dlen);
2734 /* Reset digest agility for each usage/selector pair */
2735 mtype = DANETLS_NONE;
2736 ordinal = dane->dctx->mdord[t->mtype];
2737 } else if (t->mtype != DANETLS_MATCHING_FULL) {
2741 * <https://tools.ietf.org/html/rfc7671#section-9>
2743 * For a fixed selector, after processing all records with the
2744 * highest mtype ordinal, ignore all mtypes with lower ordinals
2745 * other than "Full".
2747 if (dane->dctx->mdord[t->mtype] < ordinal)
2752 * Each time we hit a (new selector or) mtype, re-compute the relevant
2753 * digest, more complex caching is not worth the code space.
2755 if (t->mtype != mtype) {
2756 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype];
2762 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) {
2770 * Squirrel away the certificate and depth if we have a match. Any
2771 * DANE match is dispositive, but with PKIX we still need to build a
2774 if (cmplen == t->dlen &&
2775 memcmp(cmpbuf, t->data, cmplen) == 0) {
2776 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK)
2778 if (matched || dane->mdpth < 0) {
2779 dane->mdpth = depth;
2781 OPENSSL_free(dane->mcert);
2789 /* Clear the one-element DER cache */
2790 OPENSSL_free(i2dbuf);
2794 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth)
2796 SSL_DANE *dane = ctx->dane;
2800 if (!DANETLS_HAS_TA(dane) || depth == 0)
2801 return X509_TRUST_UNTRUSTED;
2804 * Record any DANE trust anchor matches, for the first depth to test, if
2805 * there's one at that depth. (This'll be false for length 1 chains looking
2806 * for an exact match for the leaf certificate).
2808 cert = sk_X509_value(ctx->chain, depth);
2809 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0)
2810 return X509_TRUST_REJECTED;
2812 ctx->num_untrusted = depth - 1;
2813 return X509_TRUST_TRUSTED;
2816 return X509_TRUST_UNTRUSTED;
2819 static int check_dane_pkeys(X509_STORE_CTX *ctx)
2821 SSL_DANE *dane = ctx->dane;
2823 int num = ctx->num_untrusted;
2824 X509 *cert = sk_X509_value(ctx->chain, num - 1);
2825 int recnum = sk_danetls_record_num(dane->trecs);
2828 for (i = 0; i < recnum; ++i) {
2829 t = sk_danetls_record_value(dane->trecs, i);
2830 if (t->usage != DANETLS_USAGE_DANE_TA ||
2831 t->selector != DANETLS_SELECTOR_SPKI ||
2832 t->mtype != DANETLS_MATCHING_FULL ||
2833 X509_verify_ex(cert, t->spki, ctx->libctx, ctx->propq) <= 0)
2836 /* Clear any PKIX-?? matches that failed to extend to a full chain */
2837 X509_free(dane->mcert);
2840 /* Record match via a bare TA public key */
2841 ctx->bare_ta_signed = 1;
2842 dane->mdpth = num - 1;
2845 /* Prune any excess chain certificates */
2846 num = sk_X509_num(ctx->chain);
2847 for (; num > ctx->num_untrusted; --num)
2848 X509_free(sk_X509_pop(ctx->chain));
2850 return X509_TRUST_TRUSTED;
2853 return X509_TRUST_UNTRUSTED;
2856 static void dane_reset(SSL_DANE *dane)
2859 * Reset state to verify another chain, or clear after failure.
2861 X509_free(dane->mcert);
2868 static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert)
2870 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags);
2872 if (err == X509_V_OK)
2874 return verify_cb_cert(ctx, cert, 0, err);
2877 static int dane_verify(X509_STORE_CTX *ctx)
2879 X509 *cert = ctx->cert;
2880 SSL_DANE *dane = ctx->dane;
2887 * When testing the leaf certificate, if we match a DANE-EE(3) record,
2888 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1)
2889 * record, the match depth and matching TLSA record are recorded, but the
2890 * return value is 0, because we still need to find a PKIX trust anchor.
2891 * Therefore, when DANE authentication is enabled (required), we're done
2893 * + matched < 0, internal error.
2894 * + matched == 1, we matched a DANE-EE(3) record
2895 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no
2896 * DANE-TA(2) or PKIX-TA(0) to test.
2898 matched = dane_match(ctx, ctx->cert, 0);
2899 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0);
2902 X509_get_pubkey_parameters(NULL, ctx->chain);
2905 /* Callback invoked as needed */
2906 if (!check_leaf_suiteb(ctx, cert))
2908 /* Callback invoked as needed */
2909 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 &&
2912 /* Bypass internal_verify(), issue depth 0 success callback */
2913 ctx->error_depth = 0;
2914 ctx->current_cert = cert;
2915 return ctx->verify_cb(1, ctx);
2919 ctx->error_depth = 0;
2920 ctx->current_cert = cert;
2921 ctx->error = X509_V_ERR_OUT_OF_MEM;
2926 /* Fail early, TA-based success is not possible */
2927 if (!check_leaf_suiteb(ctx, cert))
2929 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH);
2933 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0
2934 * certificates happens in-line with building the rest of the chain.
2936 return verify_chain(ctx);
2939 /* Get issuer, without duplicate suppression */
2940 static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert)
2942 STACK_OF(X509) *saved_chain = ctx->chain;
2946 ok = ctx->get_issuer(issuer, ctx, cert);
2947 ctx->chain = saved_chain;
2952 static int build_chain(X509_STORE_CTX *ctx)
2954 SSL_DANE *dane = ctx->dane;
2955 int num = sk_X509_num(ctx->chain);
2956 X509 *cert = sk_X509_value(ctx->chain, num - 1);
2957 int self_signed = cert_self_signed(ctx, cert);
2958 STACK_OF(X509) *sktmp = NULL;
2959 unsigned int search;
2960 int may_trusted = 0;
2961 int may_alternate = 0;
2962 int trust = X509_TRUST_UNTRUSTED;
2963 int alt_untrusted = 0;
2968 /* Our chain starts with a single untrusted element. */
2969 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) {
2970 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
2971 ctx->error = X509_V_ERR_UNSPECIFIED;
2975 self_signed = cert_self_signed(ctx, cert);
2976 if (self_signed < 0) {
2977 ctx->error = X509_V_ERR_UNSPECIFIED;
2981 #define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */
2982 #define S_DOTRUSTED (1 << 1) /* Search trusted store */
2983 #define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */
2985 * Set up search policy, untrusted if possible, trusted-first if enabled.
2986 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the
2987 * trust_store, otherwise we might look there first. If not trusted-first,
2988 * and alternate chains are not disabled, try building an alternate chain
2989 * if no luck with untrusted first.
2991 search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0;
2992 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) {
2993 if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)
2994 search |= S_DOTRUSTED;
2995 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS))
3001 * Shallow-copy the stack of untrusted certificates (with TLS, this is
3002 * typically the content of the peer's certificate message) so can make
3003 * multiple passes over it, while free to remove elements as we go.
3005 if (ctx->untrusted && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) {
3006 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3007 ctx->error = X509_V_ERR_OUT_OF_MEM;
3012 * If we got any "DANE-TA(2) Cert(0) Full(0)" trust anchors from DNS, add
3013 * them to our working copy of the untrusted certificate stack. Since the
3014 * caller of X509_STORE_CTX_init() may have provided only a leaf cert with
3015 * no corresponding stack of untrusted certificates, we may need to create
3016 * an empty stack first. [ At present only the ssl library provides DANE
3017 * support, and ssl_verify_cert_chain() always provides a non-null stack
3018 * containing at least the leaf certificate, but we must be prepared for
3021 if (DANETLS_ENABLED(dane) && dane->certs != NULL) {
3022 if (sktmp == NULL && (sktmp = sk_X509_new_null()) == NULL) {
3023 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3024 ctx->error = X509_V_ERR_OUT_OF_MEM;
3027 for (i = 0; i < sk_X509_num(dane->certs); ++i) {
3028 if (!sk_X509_push(sktmp, sk_X509_value(dane->certs, i))) {
3029 sk_X509_free(sktmp);
3030 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3031 ctx->error = X509_V_ERR_OUT_OF_MEM;
3038 * Still absurdly large, but arithmetically safe, a lower hard upper bound
3039 * might be reasonable.
3041 if (ctx->param->depth > INT_MAX/2)
3042 ctx->param->depth = INT_MAX/2;
3045 * Try to extend the chain until we reach an ultimately trusted issuer.
3046 * Build chains up to one longer the limit, later fail if we hit the limit,
3047 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code.
3049 depth = ctx->param->depth + 1;
3051 while (search != 0) {
3056 * Look in the trust store if enabled for first lookup, or we've run
3057 * out of untrusted issuers and search here is not disabled. When we
3058 * reach the depth limit, we stop extending the chain, if by that point
3059 * we've not found a trust anchor, any trusted chain would be too long.
3061 * The error reported to the application verify callback is at the
3062 * maximal valid depth with the current certificate equal to the last
3063 * not ultimately-trusted issuer. For example, with verify_depth = 0,
3064 * the callback will report errors at depth=1 when the immediate issuer
3065 * of the leaf certificate is not a trust anchor. No attempt will be
3066 * made to locate an issuer for that certificate, since such a chain
3067 * would be a-priori too long.
3069 if ((search & S_DOTRUSTED) != 0) {
3070 i = num = sk_X509_num(ctx->chain);
3071 if ((search & S_DOALTERNATE) != 0) {
3073 * As high up the chain as we can, look for an alternative
3074 * trusted issuer of an untrusted certificate that currently
3075 * has an untrusted issuer. We use the alt_untrusted variable
3076 * to track how far up the chain we find the first match. It
3077 * is only if and when we find a match, that we prune the chain
3078 * and reset ctx->num_untrusted to the reduced count of
3079 * untrusted certificates. While we're searching for such a
3080 * match (which may never be found), it is neither safe nor
3081 * wise to preemptively modify either the chain or
3082 * ctx->num_untrusted.
3084 * Note, like ctx->num_untrusted, alt_untrusted is a count of
3085 * untrusted certificates, not a "depth".
3089 x = sk_X509_value(ctx->chain, i-1);
3091 ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x);
3094 trust = X509_TRUST_REJECTED;
3095 ctx->error = X509_V_ERR_STORE_LOOKUP;
3102 * Alternative trusted issuer for a mid-chain untrusted cert?
3103 * Pop the untrusted cert's successors and retry. We might now
3104 * be able to complete a valid chain via the trust store. Note
3105 * that despite the current trust store match we might still
3106 * fail complete the chain to a suitable trust anchor, in which
3107 * case we may prune some more untrusted certificates and try
3108 * again. Thus the S_DOALTERNATE bit may yet be turned on
3109 * again with an even shorter untrusted chain!
3111 * If in the process we threw away our matching PKIX-TA trust
3112 * anchor, reset DANE trust. We might find a suitable trusted
3113 * certificate among the ones from the trust store.
3115 if ((search & S_DOALTERNATE) != 0) {
3116 if (!ossl_assert(num > i && i > 0 && !self_signed)) {
3117 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3119 trust = X509_TRUST_REJECTED;
3120 ctx->error = X509_V_ERR_UNSPECIFIED;
3124 search &= ~S_DOALTERNATE;
3125 for (; num > i; --num)
3126 X509_free(sk_X509_pop(ctx->chain));
3127 ctx->num_untrusted = num;
3129 if (DANETLS_ENABLED(dane) &&
3130 dane->mdpth >= ctx->num_untrusted) {
3132 X509_free(dane->mcert);
3135 if (DANETLS_ENABLED(dane) &&
3136 dane->pdpth >= ctx->num_untrusted)
3141 * Self-signed untrusted certificates get replaced by their
3142 * trusted matching issuer. Otherwise, grow the chain.
3145 if (!sk_X509_push(ctx->chain, x = xtmp)) {
3147 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3148 trust = X509_TRUST_REJECTED;
3149 ctx->error = X509_V_ERR_OUT_OF_MEM;
3153 self_signed = cert_self_signed(ctx, x);
3154 if (self_signed < 0) {
3155 ctx->error = X509_V_ERR_UNSPECIFIED;
3158 } else if (num == ctx->num_untrusted) {
3160 * We have a self-signed certificate that has the same
3161 * subject name (and perhaps keyid and/or serial number) as
3162 * a trust anchor. We must have an exact match to avoid
3163 * possible impersonation via key substitution etc.
3165 if (X509_cmp(x, xtmp) != 0) {
3166 /* Self-signed untrusted mimic. */
3171 ctx->num_untrusted = --num;
3172 (void) sk_X509_set(ctx->chain, num, x = xtmp);
3177 * We've added a new trusted certificate to the chain, recheck
3178 * trust. If not done, and not self-signed look deeper.
3179 * Whether or not we're doing "trusted first", we no longer
3180 * look for untrusted certificates from the peer's chain.
3182 * At this point ctx->num_trusted and num must reflect the
3183 * correct number of untrusted certificates, since the DANE
3184 * logic in check_trust() depends on distinguishing CAs from
3185 * "the wire" from CAs from the trust store. In particular, the
3186 * certificate at depth "num" should be the new trusted
3187 * certificate with ctx->num_untrusted <= num.
3190 if (!ossl_assert(ctx->num_untrusted <= num)) {
3191 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3192 trust = X509_TRUST_REJECTED;
3193 ctx->error = X509_V_ERR_UNSPECIFIED;
3197 search &= ~S_DOUNTRUSTED;
3198 switch (trust = check_trust(ctx, num)) {
3199 case X509_TRUST_TRUSTED:
3200 case X509_TRUST_REJECTED:
3210 * No dispositive decision, and either self-signed or no match, if
3211 * we were doing untrusted-first, and alt-chains are not disabled,
3212 * do that, by repeatedly losing one untrusted element at a time,
3213 * and trying to extend the shorted chain.
3215 if ((search & S_DOUNTRUSTED) == 0) {
3216 /* Continue search for a trusted issuer of a shorter chain? */
3217 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0)
3219 /* Still no luck and no fallbacks left? */
3220 if (!may_alternate || (search & S_DOALTERNATE) != 0 ||
3221 ctx->num_untrusted < 2)
3223 /* Search for a trusted issuer of a shorter chain */
3224 search |= S_DOALTERNATE;
3225 alt_untrusted = ctx->num_untrusted - 1;
3231 * Extend chain with peer-provided certificates
3233 if ((search & S_DOUNTRUSTED) != 0) {
3234 num = sk_X509_num(ctx->chain);
3235 if (!ossl_assert(num == ctx->num_untrusted)) {
3236 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3237 trust = X509_TRUST_REJECTED;
3238 ctx->error = X509_V_ERR_UNSPECIFIED;
3242 x = sk_X509_value(ctx->chain, num-1);
3245 * Once we run out of untrusted issuers, we stop looking for more
3246 * and start looking only in the trust store if enabled.
3248 xtmp = (self_signed || depth < num) ? NULL
3249 : find_issuer(ctx, sktmp, x);
3251 search &= ~S_DOUNTRUSTED;
3253 search |= S_DOTRUSTED;
3257 /* Drop this issuer from future consideration */
3258 (void) sk_X509_delete_ptr(sktmp, xtmp);
3260 if (!X509_up_ref(xtmp)) {
3261 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3262 trust = X509_TRUST_REJECTED;
3263 ctx->error = X509_V_ERR_UNSPECIFIED;
3268 if (!sk_X509_push(ctx->chain, xtmp)) {
3270 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3271 trust = X509_TRUST_REJECTED;
3272 ctx->error = X509_V_ERR_OUT_OF_MEM;
3278 ++ctx->num_untrusted;
3279 self_signed = cert_self_signed(ctx, xtmp);
3280 if (self_signed < 0) {
3281 sk_X509_free(sktmp);
3282 ctx->error = X509_V_ERR_UNSPECIFIED;
3287 * Check for DANE-TA trust of the topmost untrusted certificate.
3289 switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) {
3290 case X509_TRUST_TRUSTED:
3291 case X509_TRUST_REJECTED:
3297 sk_X509_free(sktmp);
3300 * Last chance to make a trusted chain, either bare DANE-TA public-key
3301 * signers, or else direct leaf PKIX trust.
3303 num = sk_X509_num(ctx->chain);
3305 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane))
3306 trust = check_dane_pkeys(ctx);
3307 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted)
3308 trust = check_trust(ctx, num);
3312 case X509_TRUST_TRUSTED:
3314 case X509_TRUST_REJECTED:
3315 /* Callback already issued */
3317 case X509_TRUST_UNTRUSTED:
3319 num = sk_X509_num(ctx->chain);
3321 return verify_cb_cert(ctx, NULL, num-1,
3322 X509_V_ERR_CERT_CHAIN_TOO_LONG);
3323 if (DANETLS_ENABLED(dane) &&
3324 (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0))
3325 return verify_cb_cert(ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH);
3326 if (self_signed && sk_X509_num(ctx->chain) == 1)
3327 return verify_cb_cert(ctx, NULL, num-1,
3328 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
3330 return verify_cb_cert(ctx, NULL, num-1,
3331 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN);
3332 if (ctx->num_untrusted < num)
3333 return verify_cb_cert(ctx, NULL, num-1,
3334 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT);
3335 return verify_cb_cert(ctx, NULL, num-1,
3336 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY);
3340 static const int minbits_table[] = { 80, 112, 128, 192, 256 };
3341 static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table);
3344 * Check whether the public key of ``cert`` meets the security level of
3347 * Returns 1 on success, 0 otherwise.
3349 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert)
3351 EVP_PKEY *pkey = X509_get0_pubkey(cert);
3352 int level = ctx->param->auth_level;
3355 * At security level zero, return without checking for a supported public
3356 * key type. Some engines support key types not understood outside the
3357 * engine, and we only need to understand the key when enforcing a security
3363 /* Unsupported or malformed keys are not secure */
3367 if (level > NUM_AUTH_LEVELS)
3368 level = NUM_AUTH_LEVELS;
3370 return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1];
3374 * Check whether the signature digest algorithm of ``cert`` meets the security
3375 * level of ``ctx``. Should not be checked for trust anchors (whether
3376 * self-signed or otherwise).
3378 * Returns 1 on success, 0 otherwise.
3380 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert)
3383 int level = ctx->param->auth_level;
3387 if (level > NUM_AUTH_LEVELS)
3388 level = NUM_AUTH_LEVELS;
3390 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL))
3393 return secbits >= minbits_table[level - 1];