2 * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
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"
28 /* CRL score values */
30 /* No unhandled critical extensions */
32 #define CRL_SCORE_NOCRITICAL 0x100
34 /* certificate is within CRL scope */
36 #define CRL_SCORE_SCOPE 0x080
40 #define CRL_SCORE_TIME 0x040
42 /* Issuer name matches certificate */
44 #define CRL_SCORE_ISSUER_NAME 0x020
46 /* If this score or above CRL is probably valid */
48 #define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE)
50 /* CRL issuer is certificate issuer */
52 #define CRL_SCORE_ISSUER_CERT 0x018
54 /* CRL issuer is on certificate path */
56 #define CRL_SCORE_SAME_PATH 0x008
58 /* CRL issuer matches CRL AKID */
60 #define CRL_SCORE_AKID 0x004
62 /* Have a delta CRL with valid times */
64 #define CRL_SCORE_TIME_DELTA 0x002
66 static int build_chain(X509_STORE_CTX *ctx);
67 static int verify_chain(X509_STORE_CTX *ctx);
68 static int dane_verify(X509_STORE_CTX *ctx);
69 static int null_callback(int ok, X509_STORE_CTX *e);
70 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
71 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
72 static int check_chain_extensions(X509_STORE_CTX *ctx);
73 static int check_name_constraints(X509_STORE_CTX *ctx);
74 static int check_id(X509_STORE_CTX *ctx);
75 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted);
76 static int check_revocation(X509_STORE_CTX *ctx);
77 static int check_cert(X509_STORE_CTX *ctx);
78 static int check_policy(X509_STORE_CTX *ctx);
79 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x);
80 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth);
81 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert);
82 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert);
83 static int check_curve(X509 *cert);
85 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
86 unsigned int *preasons, X509_CRL *crl, X509 *x);
87 static int get_crl_delta(X509_STORE_CTX *ctx,
88 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x);
89 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl,
90 int *pcrl_score, X509_CRL *base,
91 STACK_OF(X509_CRL) *crls);
92 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
94 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
95 unsigned int *preasons);
96 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
97 static int check_crl_chain(X509_STORE_CTX *ctx,
98 STACK_OF(X509) *cert_path,
99 STACK_OF(X509) *crl_path);
101 static int internal_verify(X509_STORE_CTX *ctx);
103 static int null_callback(int ok, X509_STORE_CTX *e)
109 * Return 1 if given cert is considered self-signed, 0 if not or on error.
110 * This does not verify self-signedness but relies on x509v3_cache_extensions()
111 * matching issuer and subject names (i.e., the cert being self-issued) and any
112 * present authority key identifier matching the subject key identifier, etc.
114 static int cert_self_signed(X509 *x)
116 if (X509_check_purpose(x, -1, 0) != 1)
118 if (x->ex_flags & EXFLAG_SS)
124 /* Given a certificate try and find an exact match in the store */
126 static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
128 STACK_OF(X509) *certs;
131 /* Lookup all certs with matching subject name */
132 certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
135 /* Look for exact match */
136 for (i = 0; i < sk_X509_num(certs); i++) {
137 xtmp = sk_X509_value(certs, i);
138 if (!X509_cmp(xtmp, x))
142 if (xtmp != NULL && !X509_up_ref(xtmp))
144 sk_X509_pop_free(certs, X509_free);
149 * Inform the verify callback of an error.
150 * If B<x> is not NULL it is the error cert, otherwise use the chain cert at
152 * If B<err> is not X509_V_OK, that's the error value, otherwise leave
153 * unchanged (presumably set by the caller).
155 * Returns 0 to abort verification with an error, non-zero to continue.
157 static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err)
159 ctx->error_depth = depth;
160 ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth);
161 if (err != X509_V_OK)
163 return ctx->verify_cb(0, ctx);
167 * Inform the verify callback of an error, CRL-specific variant. Here, the
168 * error depth and certificate are already set, we just specify the error
171 * Returns 0 to abort verification with an error, non-zero to continue.
173 static int verify_cb_crl(X509_STORE_CTX *ctx, int err)
176 return ctx->verify_cb(0, ctx);
179 static int check_auth_level(X509_STORE_CTX *ctx)
182 int num = sk_X509_num(ctx->chain);
184 if (ctx->param->auth_level <= 0)
187 for (i = 0; i < num; ++i) {
188 X509 *cert = sk_X509_value(ctx->chain, i);
191 * We've already checked the security of the leaf key, so here we only
192 * check the security of issuer keys.
194 if (i > 0 && !check_key_level(ctx, cert) &&
195 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL) == 0)
198 * We also check the signature algorithm security of all certificates
199 * except those of the trust anchor at index num-1.
201 if (i < num - 1 && !check_sig_level(ctx, cert) &&
202 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK) == 0)
208 static int verify_chain(X509_STORE_CTX *ctx)
214 * Before either returning with an error, or continuing with CRL checks,
215 * instantiate chain public key parameters.
217 if ((ok = build_chain(ctx)) == 0 ||
218 (ok = check_chain_extensions(ctx)) == 0 ||
219 (ok = check_auth_level(ctx)) == 0 ||
220 (ok = check_id(ctx)) == 0 || 1)
221 X509_get_pubkey_parameters(NULL, ctx->chain);
222 if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0)
225 err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
227 if (err != X509_V_OK) {
228 if ((ok = verify_cb_cert(ctx, NULL, ctx->error_depth, err)) == 0)
232 /* Verify chain signatures and expiration times */
233 ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx);
237 if ((ok = check_name_constraints(ctx)) == 0)
240 #ifndef OPENSSL_NO_RFC3779
241 /* RFC 3779 path validation, now that CRL check has been done */
242 if ((ok = X509v3_asid_validate_path(ctx)) == 0)
244 if ((ok = X509v3_addr_validate_path(ctx)) == 0)
248 /* If we get this far evaluate policies */
249 if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK)
250 ok = ctx->check_policy(ctx);
254 int X509_verify_cert(X509_STORE_CTX *ctx)
256 SSL_DANE *dane = ctx->dane;
259 if (ctx->cert == NULL) {
260 X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
261 ctx->error = X509_V_ERR_INVALID_CALL;
265 if (ctx->chain != NULL) {
267 * This X509_STORE_CTX has already been used to verify a cert. We
268 * cannot do another one.
270 X509err(X509_F_X509_VERIFY_CERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
271 ctx->error = X509_V_ERR_INVALID_CALL;
275 if (!X509_up_ref(ctx->cert)) {
276 X509err(X509_F_X509_VERIFY_CERT, ERR_R_INTERNAL_ERROR);
277 ctx->error = X509_V_ERR_UNSPECIFIED;
282 * first we make sure the chain we are going to build is present and that
283 * the first entry is in place
285 if ((ctx->chain = sk_X509_new_null()) == NULL
286 || !sk_X509_push(ctx->chain, ctx->cert)) {
287 X509_free(ctx->cert);
288 X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
289 ctx->error = X509_V_ERR_OUT_OF_MEM;
293 ctx->num_untrusted = 1;
295 /* If the peer's public key is too weak, we can stop early. */
296 if (!check_key_level(ctx, ctx->cert) &&
297 !verify_cb_cert(ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL))
300 if (DANETLS_ENABLED(dane))
301 ret = dane_verify(ctx);
303 ret = verify_chain(ctx);
306 * Safety-net. If we are returning an error, we must also set ctx->error,
307 * so that the chain is not considered verified should the error be ignored
308 * (e.g. TLS with SSL_VERIFY_NONE).
310 if (ret <= 0 && ctx->error == X509_V_OK)
311 ctx->error = X509_V_ERR_UNSPECIFIED;
315 static int sk_X509_contains(STACK_OF(X509) *sk, X509 *cert)
317 int i, n = sk_X509_num(sk);
319 for (i = 0; i < n; i++)
320 if (X509_cmp(sk_X509_value(sk, i), cert) == 0)
326 * Find in given STACK_OF(X509) sk an issuer cert of given cert x.
327 * The issuer must not yet be in ctx->chain, where the exceptional case
328 * that x is self-issued and ctx->chain has just one element is allowed.
329 * Prefer the first one that is not expired, else take the last expired one.
331 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
334 X509 *issuer, *rv = NULL;
336 for (i = 0; i < sk_X509_num(sk); i++) {
337 issuer = sk_X509_value(sk, i);
338 if (ctx->check_issued(ctx, x, issuer)
339 && (((x->ex_flags & EXFLAG_SI) != 0 && sk_X509_num(ctx->chain) == 1)
340 || !sk_X509_contains(ctx->chain, issuer))) {
342 if (x509_check_cert_time(ctx, rv, -1))
349 /* Check that the given certificate 'x' is issued by the certificate 'issuer' */
350 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
352 return x509_likely_issued(issuer, x) == X509_V_OK;
355 /* Alternative lookup method: look from a STACK stored in other_ctx */
356 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
358 *issuer = find_issuer(ctx, ctx->other_ctx, x);
360 if (*issuer == NULL || !X509_up_ref(*issuer))
370 static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, X509_NAME *nm)
372 STACK_OF(X509) *sk = NULL;
376 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) {
377 x = sk_X509_value(ctx->other_ctx, i);
378 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) {
379 if (!X509_up_ref(x)) {
380 sk_X509_pop_free(sk, X509_free);
381 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_INTERNAL_ERROR);
382 ctx->error = X509_V_ERR_UNSPECIFIED;
386 sk = sk_X509_new_null();
387 if (sk == NULL || !sk_X509_push(sk, x)) {
389 sk_X509_pop_free(sk, X509_free);
390 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_MALLOC_FAILURE);
391 ctx->error = X509_V_ERR_OUT_OF_MEM;
400 * Check EE or CA certificate purpose. For trusted certificates explicit local
401 * auxiliary trust can be used to override EKU-restrictions.
403 static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth,
406 int tr_ok = X509_TRUST_UNTRUSTED;
409 * For trusted certificates we want to see whether any auxiliary trust
410 * settings trump the purpose constraints.
412 * This is complicated by the fact that the trust ordinals in
413 * ctx->param->trust are entirely independent of the purpose ordinals in
414 * ctx->param->purpose!
416 * What connects them is their mutual initialization via calls from
417 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets
418 * related values of both param->trust and param->purpose. It is however
419 * typically possible to infer associated trust values from a purpose value
420 * via the X509_PURPOSE API.
422 * Therefore, we can only check for trust overrides when the purpose we're
423 * checking is the same as ctx->param->purpose and ctx->param->trust is
426 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose)
427 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT);
430 case X509_TRUST_TRUSTED:
432 case X509_TRUST_REJECTED:
435 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) {
441 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0)
447 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE);
451 * Check a certificate chains extensions for consistency with the supplied
455 static int check_chain_extensions(X509_STORE_CTX *ctx)
457 int i, must_be_ca, plen = 0;
459 int proxy_path_length = 0;
461 int allow_proxy_certs;
462 int num = sk_X509_num(ctx->chain);
465 * must_be_ca can have 1 of 3 values:
466 * -1: we accept both CA and non-CA certificates, to allow direct
467 * use of self-signed certificates (which are marked as CA).
468 * 0: we only accept non-CA certificates. This is currently not
469 * used, but the possibility is present for future extensions.
470 * 1: we only accept CA certificates. This is currently used for
471 * all certificates in the chain except the leaf certificate.
475 /* CRL path validation */
477 allow_proxy_certs = 0;
478 purpose = X509_PURPOSE_CRL_SIGN;
481 ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
482 purpose = ctx->param->purpose;
485 for (i = 0; i < num; i++) {
487 x = sk_X509_value(ctx->chain, i);
488 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
489 && (x->ex_flags & EXFLAG_CRITICAL)) {
490 if (!verify_cb_cert(ctx, x, i,
491 X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION))
494 if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) {
495 if (!verify_cb_cert(ctx, x, i,
496 X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED))
499 ret = X509_check_ca(x);
500 switch (must_be_ca) {
502 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
503 && (ret != 1) && (ret != 0)) {
505 ctx->error = X509_V_ERR_INVALID_CA;
512 ctx->error = X509_V_ERR_INVALID_NON_CA;
517 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */
519 || ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT)
522 ctx->error = X509_V_ERR_INVALID_CA;
528 && (ctx->param->flags & X509_V_FLAG_X509_STRICT) && num > 1) {
529 /* Check for presence of explicit elliptic curve parameters */
530 ret = check_curve(x);
532 ctx->error = X509_V_ERR_UNSPECIFIED;
534 } else if (ret == 0) {
535 ctx->error = X509_V_ERR_EC_KEY_EXPLICIT_PARAMS;
539 && (x->ex_flags & EXFLAG_CA) == 0
540 && x->ex_pathlen != -1
541 && (ctx->param->flags & X509_V_FLAG_X509_STRICT)) {
542 ctx->error = X509_V_ERR_INVALID_EXTENSION;
545 if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK))
547 /* check_purpose() makes the callback as needed */
548 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca))
551 if ((i > 1) && (x->ex_pathlen != -1)
552 && (plen > (x->ex_pathlen + proxy_path_length))) {
553 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED))
556 /* Increment path length if not a self issued intermediate CA */
557 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0)
560 * If this certificate is a proxy certificate, the next certificate
561 * must be another proxy certificate or a EE certificate. If not,
562 * the next certificate must be a CA certificate.
564 if (x->ex_flags & EXFLAG_PROXY) {
566 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint
567 * is less than max_path_length, the former should be copied to
568 * the latter, and 4.1.4 (a) stipulates that max_path_length
569 * should be verified to be larger than zero and decrement it.
571 * Because we're checking the certs in the reverse order, we start
572 * with verifying that proxy_path_length isn't larger than pcPLC,
573 * and copy the latter to the former if it is, and finally,
574 * increment proxy_path_length.
576 if (x->ex_pcpathlen != -1) {
577 if (proxy_path_length > x->ex_pcpathlen) {
578 if (!verify_cb_cert(ctx, x, i,
579 X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED))
582 proxy_path_length = x->ex_pcpathlen;
592 static int has_san_id(X509 *x, int gtype)
596 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
601 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) {
602 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i);
604 if (g->type == gtype) {
609 GENERAL_NAMES_free(gs);
613 static int check_name_constraints(X509_STORE_CTX *ctx)
617 /* Check name constraints for all certificates */
618 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) {
619 X509 *x = sk_X509_value(ctx->chain, i);
622 /* Ignore self issued certs unless last in chain */
623 if (i && (x->ex_flags & EXFLAG_SI))
627 * Proxy certificates policy has an extra constraint, where the
628 * certificate subject MUST be the issuer with a single CN entry
630 * (RFC 3820: 3.4, 4.1.3 (a)(4))
632 if (x->ex_flags & EXFLAG_PROXY) {
633 X509_NAME *tmpsubject = X509_get_subject_name(x);
634 X509_NAME *tmpissuer = X509_get_issuer_name(x);
635 X509_NAME_ENTRY *tmpentry = NULL;
636 int last_object_nid = 0;
638 int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1;
640 /* Check that there are at least two RDNs */
641 if (last_object_loc < 1) {
642 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
643 goto proxy_name_done;
647 * Check that there is exactly one more RDN in subject as
648 * there is in issuer.
650 if (X509_NAME_entry_count(tmpsubject)
651 != X509_NAME_entry_count(tmpissuer) + 1) {
652 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
653 goto proxy_name_done;
657 * Check that the last subject component isn't part of a
660 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
662 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
663 last_object_loc - 1))) {
664 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
665 goto proxy_name_done;
669 * Check that the last subject RDN is a commonName, and that
670 * all the previous RDNs match the issuer exactly
672 tmpsubject = X509_NAME_dup(tmpsubject);
673 if (tmpsubject == NULL) {
674 X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
675 ctx->error = X509_V_ERR_OUT_OF_MEM;
680 X509_NAME_delete_entry(tmpsubject, last_object_loc);
682 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry));
684 if (last_object_nid != NID_commonName
685 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) {
686 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
689 X509_NAME_ENTRY_free(tmpentry);
690 X509_NAME_free(tmpsubject);
694 && !verify_cb_cert(ctx, x, i, err))
699 * Check against constraints for all certificates higher in chain
700 * including trust anchor. Trust anchor not strictly speaking needed
701 * but if it includes constraints it is to be assumed it expects them
704 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) {
705 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
708 int rv = NAME_CONSTRAINTS_check(x, nc);
710 /* If EE certificate check commonName too */
711 if (rv == X509_V_OK && i == 0
712 && (ctx->param->hostflags
713 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0
714 && ((ctx->param->hostflags
715 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0
716 || !has_san_id(x, GEN_DNS)))
717 rv = NAME_CONSTRAINTS_check_CN(x, nc);
722 case X509_V_ERR_OUT_OF_MEM:
725 if (!verify_cb_cert(ctx, x, i, rv))
735 static int check_id_error(X509_STORE_CTX *ctx, int errcode)
737 return verify_cb_cert(ctx, ctx->cert, 0, errcode);
740 static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm)
743 int n = sk_OPENSSL_STRING_num(vpm->hosts);
746 if (vpm->peername != NULL) {
747 OPENSSL_free(vpm->peername);
748 vpm->peername = NULL;
750 for (i = 0; i < n; ++i) {
751 name = sk_OPENSSL_STRING_value(vpm->hosts, i);
752 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0)
758 static int check_id(X509_STORE_CTX *ctx)
760 X509_VERIFY_PARAM *vpm = ctx->param;
762 if (vpm->hosts && check_hosts(x, vpm) <= 0) {
763 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
766 if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) {
767 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
770 if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) {
771 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
777 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)
782 SSL_DANE *dane = ctx->dane;
783 int num = sk_X509_num(ctx->chain);
787 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2)
788 * match, we're done, otherwise we'll merely record the match depth.
790 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {
791 switch (trust = check_dane_issuer(ctx, num_untrusted)) {
792 case X509_TRUST_TRUSTED:
793 case X509_TRUST_REJECTED:
799 * Check trusted certificates in chain at depth num_untrusted and up.
800 * Note, that depths 0..num_untrusted-1 may also contain trusted
801 * certificates, but the caller is expected to have already checked those,
802 * and wants to incrementally check just any added since.
804 for (i = num_untrusted; i < num; i++) {
805 x = sk_X509_value(ctx->chain, i);
806 trust = X509_check_trust(x, ctx->param->trust, 0);
807 /* If explicitly trusted return trusted */
808 if (trust == X509_TRUST_TRUSTED)
810 if (trust == X509_TRUST_REJECTED)
815 * If we are looking at a trusted certificate, and accept partial chains,
816 * the chain is PKIX trusted.
818 if (num_untrusted < num) {
819 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
821 return X509_TRUST_UNTRUSTED;
824 if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
826 * Last-resort call with no new trusted certificates, check the leaf
827 * for a direct trust store match.
830 x = sk_X509_value(ctx->chain, i);
831 mx = lookup_cert_match(ctx, x);
833 return X509_TRUST_UNTRUSTED;
836 * Check explicit auxiliary trust/reject settings. If none are set,
837 * we'll accept X509_TRUST_UNTRUSTED when not self-signed.
839 trust = X509_check_trust(mx, ctx->param->trust, 0);
840 if (trust == X509_TRUST_REJECTED) {
845 /* Replace leaf with trusted match */
846 (void) sk_X509_set(ctx->chain, 0, mx);
848 ctx->num_untrusted = 0;
853 * If no trusted certs in chain at all return untrusted and allow
854 * standard (no issuer cert) etc errors to be indicated.
856 return X509_TRUST_UNTRUSTED;
859 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED))
860 return X509_TRUST_REJECTED;
861 return X509_TRUST_UNTRUSTED;
864 if (!DANETLS_ENABLED(dane))
865 return X509_TRUST_TRUSTED;
867 dane->pdpth = num_untrusted;
868 /* With DANE, PKIX alone is not trusted until we have both */
869 if (dane->mdpth >= 0)
870 return X509_TRUST_TRUSTED;
871 return X509_TRUST_UNTRUSTED;
874 static int check_revocation(X509_STORE_CTX *ctx)
876 int i = 0, last = 0, ok = 0;
877 if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
879 if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
880 last = sk_X509_num(ctx->chain) - 1;
882 /* If checking CRL paths this isn't the EE certificate */
887 for (i = 0; i <= last; i++) {
888 ctx->error_depth = i;
889 ok = check_cert(ctx);
896 static int check_cert(X509_STORE_CTX *ctx)
898 X509_CRL *crl = NULL, *dcrl = NULL;
900 int cnum = ctx->error_depth;
901 X509 *x = sk_X509_value(ctx->chain, cnum);
903 ctx->current_cert = x;
904 ctx->current_issuer = NULL;
905 ctx->current_crl_score = 0;
906 ctx->current_reasons = 0;
908 if (x->ex_flags & EXFLAG_PROXY)
911 while (ctx->current_reasons != CRLDP_ALL_REASONS) {
912 unsigned int last_reasons = ctx->current_reasons;
914 /* Try to retrieve relevant CRL */
916 ok = ctx->get_crl(ctx, &crl, x);
918 ok = get_crl_delta(ctx, &crl, &dcrl, x);
920 * If error looking up CRL, nothing we can do except notify callback
923 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
926 ctx->current_crl = crl;
927 ok = ctx->check_crl(ctx, crl);
932 ok = ctx->check_crl(ctx, dcrl);
935 ok = ctx->cert_crl(ctx, dcrl, x);
941 /* Don't look in full CRL if delta reason is removefromCRL */
943 ok = ctx->cert_crl(ctx, crl, x);
953 * If reasons not updated we won't get anywhere by another iteration,
956 if (last_reasons == ctx->current_reasons) {
957 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
965 ctx->current_crl = NULL;
969 /* Check CRL times against values in X509_STORE_CTX */
971 static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
976 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
977 ptime = &ctx->param->check_time;
978 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
983 ctx->current_crl = crl;
985 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime);
989 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD))
996 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID))
1000 if (X509_CRL_get0_nextUpdate(crl)) {
1001 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime);
1006 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD))
1009 /* Ignore expiry of base CRL is delta is valid */
1010 if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) {
1013 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED))
1019 ctx->current_crl = NULL;
1024 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
1025 X509 **pissuer, int *pscore, unsigned int *preasons,
1026 STACK_OF(X509_CRL) *crls)
1028 int i, crl_score, best_score = *pscore;
1029 unsigned int reasons, best_reasons = 0;
1030 X509 *x = ctx->current_cert;
1031 X509_CRL *crl, *best_crl = NULL;
1032 X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
1034 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1035 crl = sk_X509_CRL_value(crls, i);
1036 reasons = *preasons;
1037 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
1038 if (crl_score < best_score || crl_score == 0)
1040 /* If current CRL is equivalent use it if it is newer */
1041 if (crl_score == best_score && best_crl != NULL) {
1043 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl),
1044 X509_CRL_get0_lastUpdate(crl)) == 0)
1047 * ASN1_TIME_diff never returns inconsistent signs for |day|
1050 if (day <= 0 && sec <= 0)
1054 best_crl_issuer = crl_issuer;
1055 best_score = crl_score;
1056 best_reasons = reasons;
1060 X509_CRL_free(*pcrl);
1062 *pissuer = best_crl_issuer;
1063 *pscore = best_score;
1064 *preasons = best_reasons;
1065 X509_CRL_up_ref(best_crl);
1066 X509_CRL_free(*pdcrl);
1068 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
1071 if (best_score >= CRL_SCORE_VALID)
1078 * Compare two CRL extensions for delta checking purposes. They should be
1079 * both present or both absent. If both present all fields must be identical.
1082 static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
1084 ASN1_OCTET_STRING *exta, *extb;
1086 i = X509_CRL_get_ext_by_NID(a, nid, -1);
1088 /* Can't have multiple occurrences */
1089 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1)
1091 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
1095 i = X509_CRL_get_ext_by_NID(b, nid, -1);
1099 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1)
1101 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
1111 if (ASN1_OCTET_STRING_cmp(exta, extb))
1117 /* See if a base and delta are compatible */
1119 static int check_delta_base(X509_CRL *delta, X509_CRL *base)
1121 /* Delta CRL must be a delta */
1122 if (!delta->base_crl_number)
1124 /* Base must have a CRL number */
1125 if (!base->crl_number)
1127 /* Issuer names must match */
1128 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta)))
1130 /* AKID and IDP must match */
1131 if (!crl_extension_match(delta, base, NID_authority_key_identifier))
1133 if (!crl_extension_match(delta, base, NID_issuing_distribution_point))
1135 /* Delta CRL base number must not exceed Full CRL number. */
1136 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0)
1138 /* Delta CRL number must exceed full CRL number */
1139 if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0)
1145 * For a given base CRL find a delta... maybe extend to delta scoring or
1146 * retrieve a chain of deltas...
1149 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore,
1150 X509_CRL *base, STACK_OF(X509_CRL) *crls)
1154 if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS))
1156 if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST))
1158 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1159 delta = sk_X509_CRL_value(crls, i);
1160 if (check_delta_base(delta, base)) {
1161 if (check_crl_time(ctx, delta, 0))
1162 *pscore |= CRL_SCORE_TIME_DELTA;
1163 X509_CRL_up_ref(delta);
1172 * For a given CRL return how suitable it is for the supplied certificate
1173 * 'x'. The return value is a mask of several criteria. If the issuer is not
1174 * the certificate issuer this is returned in *pissuer. The reasons mask is
1175 * also used to determine if the CRL is suitable: if no new reasons the CRL
1176 * is rejected, otherwise reasons is updated.
1179 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
1180 unsigned int *preasons, X509_CRL *crl, X509 *x)
1184 unsigned int tmp_reasons = *preasons, crl_reasons;
1186 /* First see if we can reject CRL straight away */
1188 /* Invalid IDP cannot be processed */
1189 if (crl->idp_flags & IDP_INVALID)
1191 /* Reason codes or indirect CRLs need extended CRL support */
1192 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
1193 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS))
1195 } else if (crl->idp_flags & IDP_REASONS) {
1196 /* If no new reasons reject */
1197 if (!(crl->idp_reasons & ~tmp_reasons))
1200 /* Don't process deltas at this stage */
1201 else if (crl->base_crl_number)
1203 /* If issuer name doesn't match certificate need indirect CRL */
1204 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) {
1205 if (!(crl->idp_flags & IDP_INDIRECT))
1208 crl_score |= CRL_SCORE_ISSUER_NAME;
1210 if (!(crl->flags & EXFLAG_CRITICAL))
1211 crl_score |= CRL_SCORE_NOCRITICAL;
1214 if (check_crl_time(ctx, crl, 0))
1215 crl_score |= CRL_SCORE_TIME;
1217 /* Check authority key ID and locate certificate issuer */
1218 crl_akid_check(ctx, crl, pissuer, &crl_score);
1220 /* If we can't locate certificate issuer at this point forget it */
1222 if (!(crl_score & CRL_SCORE_AKID))
1225 /* Check cert for matching CRL distribution points */
1227 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) {
1228 /* If no new reasons reject */
1229 if (!(crl_reasons & ~tmp_reasons))
1231 tmp_reasons |= crl_reasons;
1232 crl_score |= CRL_SCORE_SCOPE;
1235 *preasons = tmp_reasons;
1241 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl,
1242 X509 **pissuer, int *pcrl_score)
1244 X509 *crl_issuer = NULL;
1245 X509_NAME *cnm = X509_CRL_get_issuer(crl);
1246 int cidx = ctx->error_depth;
1249 if (cidx != sk_X509_num(ctx->chain) - 1)
1252 crl_issuer = sk_X509_value(ctx->chain, cidx);
1254 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1255 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) {
1256 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT;
1257 *pissuer = crl_issuer;
1262 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) {
1263 crl_issuer = sk_X509_value(ctx->chain, cidx);
1264 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1266 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1267 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH;
1268 *pissuer = crl_issuer;
1273 /* Anything else needs extended CRL support */
1275 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
1279 * Otherwise the CRL issuer is not on the path. Look for it in the set of
1280 * untrusted certificates.
1282 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) {
1283 crl_issuer = sk_X509_value(ctx->untrusted, i);
1284 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1286 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1287 *pissuer = crl_issuer;
1288 *pcrl_score |= CRL_SCORE_AKID;
1295 * Check the path of a CRL issuer certificate. This creates a new
1296 * X509_STORE_CTX and populates it with most of the parameters from the
1297 * parent. This could be optimised somewhat since a lot of path checking will
1298 * be duplicated by the parent, but this will rarely be used in practice.
1301 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x)
1303 X509_STORE_CTX crl_ctx;
1306 /* Don't allow recursive CRL path validation */
1309 if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted))
1312 crl_ctx.crls = ctx->crls;
1313 /* Copy verify params across */
1314 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
1316 crl_ctx.parent = ctx;
1317 crl_ctx.verify_cb = ctx->verify_cb;
1319 /* Verify CRL issuer */
1320 ret = X509_verify_cert(&crl_ctx);
1324 /* Check chain is acceptable */
1325 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
1327 X509_STORE_CTX_cleanup(&crl_ctx);
1332 * RFC3280 says nothing about the relationship between CRL path and
1333 * certificate path, which could lead to situations where a certificate could
1334 * be revoked or validated by a CA not authorised to do so. RFC5280 is more
1335 * strict and states that the two paths must end in the same trust anchor,
1336 * though some discussions remain... until this is resolved we use the
1340 static int check_crl_chain(X509_STORE_CTX *ctx,
1341 STACK_OF(X509) *cert_path,
1342 STACK_OF(X509) *crl_path)
1344 X509 *cert_ta, *crl_ta;
1345 cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
1346 crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
1347 if (!X509_cmp(cert_ta, crl_ta))
1353 * Check for match between two dist point names: three separate cases.
1354 * 1. Both are relative names and compare X509_NAME types.
1355 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
1356 * 3. Both are full names and compare two GENERAL_NAMES.
1357 * 4. One is NULL: automatic match.
1360 static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
1362 X509_NAME *nm = NULL;
1363 GENERAL_NAMES *gens = NULL;
1364 GENERAL_NAME *gena, *genb;
1371 /* Case 1: two X509_NAME */
1375 if (!X509_NAME_cmp(a->dpname, b->dpname))
1380 /* Case 2: set name and GENERAL_NAMES appropriately */
1382 gens = b->name.fullname;
1383 } else if (b->type == 1) {
1386 /* Case 2: set name and GENERAL_NAMES appropriately */
1387 gens = a->name.fullname;
1391 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */
1393 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1394 gena = sk_GENERAL_NAME_value(gens, i);
1395 if (gena->type != GEN_DIRNAME)
1397 if (!X509_NAME_cmp(nm, gena->d.directoryName))
1403 /* Else case 3: two GENERAL_NAMES */
1405 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) {
1406 gena = sk_GENERAL_NAME_value(a->name.fullname, i);
1407 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) {
1408 genb = sk_GENERAL_NAME_value(b->name.fullname, j);
1409 if (!GENERAL_NAME_cmp(gena, genb))
1418 static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score)
1421 X509_NAME *nm = X509_CRL_get_issuer(crl);
1422 /* If no CRLissuer return is successful iff don't need a match */
1424 return ! !(crl_score & CRL_SCORE_ISSUER_NAME);
1425 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
1426 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
1427 if (gen->type != GEN_DIRNAME)
1429 if (!X509_NAME_cmp(gen->d.directoryName, nm))
1435 /* Check CRLDP and IDP */
1437 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
1438 unsigned int *preasons)
1441 if (crl->idp_flags & IDP_ONLYATTR)
1443 if (x->ex_flags & EXFLAG_CA) {
1444 if (crl->idp_flags & IDP_ONLYUSER)
1447 if (crl->idp_flags & IDP_ONLYCA)
1450 *preasons = crl->idp_reasons;
1451 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
1452 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
1453 if (crldp_check_crlissuer(dp, crl, crl_score)) {
1454 if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) {
1455 *preasons &= dp->dp_reasons;
1460 if ((!crl->idp || !crl->idp->distpoint)
1461 && (crl_score & CRL_SCORE_ISSUER_NAME))
1467 * Retrieve CRL corresponding to current certificate. If deltas enabled try
1468 * to find a delta CRL too
1471 static int get_crl_delta(X509_STORE_CTX *ctx,
1472 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x)
1475 X509 *issuer = NULL;
1477 unsigned int reasons;
1478 X509_CRL *crl = NULL, *dcrl = NULL;
1479 STACK_OF(X509_CRL) *skcrl;
1480 X509_NAME *nm = X509_get_issuer_name(x);
1482 reasons = ctx->current_reasons;
1483 ok = get_crl_sk(ctx, &crl, &dcrl,
1484 &issuer, &crl_score, &reasons, ctx->crls);
1488 /* Lookup CRLs from store */
1490 skcrl = ctx->lookup_crls(ctx, nm);
1492 /* If no CRLs found and a near match from get_crl_sk use that */
1496 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
1498 sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
1501 /* If we got any kind of CRL use it and return success */
1503 ctx->current_issuer = issuer;
1504 ctx->current_crl_score = crl_score;
1505 ctx->current_reasons = reasons;
1513 /* Check CRL validity */
1514 static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
1516 X509 *issuer = NULL;
1517 EVP_PKEY *ikey = NULL;
1518 int cnum = ctx->error_depth;
1519 int chnum = sk_X509_num(ctx->chain) - 1;
1521 /* if we have an alternative CRL issuer cert use that */
1522 if (ctx->current_issuer)
1523 issuer = ctx->current_issuer;
1525 * Else find CRL issuer: if not last certificate then issuer is next
1526 * certificate in chain.
1528 else if (cnum < chnum)
1529 issuer = sk_X509_value(ctx->chain, cnum + 1);
1531 issuer = sk_X509_value(ctx->chain, chnum);
1532 /* If not self signed, can't check signature */
1533 if (!ctx->check_issued(ctx, issuer, issuer) &&
1534 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER))
1542 * Skip most tests for deltas because they have already been done
1544 if (!crl->base_crl_number) {
1545 /* Check for cRLSign bit if keyUsage present */
1546 if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
1547 !(issuer->ex_kusage & KU_CRL_SIGN) &&
1548 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN))
1551 if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) &&
1552 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE))
1555 if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) &&
1556 check_crl_path(ctx, ctx->current_issuer) <= 0 &&
1557 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR))
1560 if ((crl->idp_flags & IDP_INVALID) &&
1561 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION))
1565 if (!(ctx->current_crl_score & CRL_SCORE_TIME) &&
1566 !check_crl_time(ctx, crl, 1))
1569 /* Attempt to get issuer certificate public key */
1570 ikey = X509_get0_pubkey(issuer);
1573 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
1577 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags);
1579 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv))
1581 /* Verify CRL signature */
1582 if (X509_CRL_verify(crl, ikey) <= 0 &&
1583 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE))
1589 /* Check certificate against CRL */
1590 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
1595 * The rules changed for this... previously if a CRL contained unhandled
1596 * critical extensions it could still be used to indicate a certificate
1597 * was revoked. This has since been changed since critical extensions can
1598 * change the meaning of CRL entries.
1600 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
1601 && (crl->flags & EXFLAG_CRITICAL) &&
1602 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION))
1605 * Look for serial number of certificate in CRL. If found, make sure
1606 * reason is not removeFromCRL.
1608 if (X509_CRL_get0_by_cert(crl, &rev, x)) {
1609 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
1611 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED))
1618 static int check_policy(X509_STORE_CTX *ctx)
1625 * With DANE, the trust anchor might be a bare public key, not a
1626 * certificate! In that case our chain does not have the trust anchor
1627 * certificate as a top-most element. This comports well with RFC5280
1628 * chain verification, since there too, the trust anchor is not part of the
1629 * chain to be verified. In particular, X509_policy_check() does not look
1630 * at the TA cert, but assumes that it is present as the top-most chain
1631 * element. We therefore temporarily push a NULL cert onto the chain if it
1632 * was verified via a bare public key, and pop it off right after the
1633 * X509_policy_check() call.
1635 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) {
1636 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
1637 ctx->error = X509_V_ERR_OUT_OF_MEM;
1640 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
1641 ctx->param->policies, ctx->param->flags);
1642 if (ctx->bare_ta_signed)
1643 sk_X509_pop(ctx->chain);
1645 if (ret == X509_PCY_TREE_INTERNAL) {
1646 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
1647 ctx->error = X509_V_ERR_OUT_OF_MEM;
1650 /* Invalid or inconsistent extensions */
1651 if (ret == X509_PCY_TREE_INVALID) {
1652 int i, cbcalled = 0;
1654 /* Locate certificates with bad extensions and notify callback. */
1655 for (i = 0; i < sk_X509_num(ctx->chain); i++) {
1656 X509 *x = sk_X509_value(ctx->chain, i);
1658 if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
1661 if (!verify_cb_cert(ctx, x, i,
1662 X509_V_ERR_INVALID_POLICY_EXTENSION))
1666 /* Should not be able to get here */
1667 X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR);
1670 /* The callback ignored the error so we return success */
1673 if (ret == X509_PCY_TREE_FAILURE) {
1674 ctx->current_cert = NULL;
1675 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
1676 return ctx->verify_cb(0, ctx);
1678 if (ret != X509_PCY_TREE_VALID) {
1679 X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR);
1683 if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) {
1684 ctx->current_cert = NULL;
1686 * Verification errors need to be "sticky", a callback may have allowed
1687 * an SSL handshake to continue despite an error, and we must then
1688 * remain in an error state. Therefore, we MUST NOT clear earlier
1689 * verification errors by setting the error to X509_V_OK.
1691 if (!ctx->verify_cb(2, ctx))
1699 * Check certificate validity times.
1700 * If depth >= 0, invoke verification callbacks on error, otherwise just return
1701 * the validation status.
1703 * Return 1 on success, 0 otherwise.
1705 int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth)
1710 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1711 ptime = &ctx->param->check_time;
1712 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1717 i = X509_cmp_time(X509_get0_notBefore(x), ptime);
1718 if (i >= 0 && depth < 0)
1720 if (i == 0 && !verify_cb_cert(ctx, x, depth,
1721 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD))
1723 if (i > 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID))
1726 i = X509_cmp_time(X509_get0_notAfter(x), ptime);
1727 if (i <= 0 && depth < 0)
1729 if (i == 0 && !verify_cb_cert(ctx, x, depth,
1730 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD))
1732 if (i < 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED))
1737 /* verify the issuer signatures and cert times of ctx->chain */
1738 static int internal_verify(X509_STORE_CTX *ctx)
1740 int n = sk_X509_num(ctx->chain) - 1;
1741 X509 *xi = sk_X509_value(ctx->chain, n);
1745 * With DANE-verified bare public key TA signatures, it remains only to
1746 * check the timestamps of the top certificate. We report the issuer as
1747 * NULL, since all we have is a bare key.
1749 if (ctx->bare_ta_signed) {
1752 goto check_cert_time;
1755 if (ctx->check_issued(ctx, xi, xi))
1756 xs = xi; /* the typical case: last cert in the chain is self-issued */
1758 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
1760 goto check_cert_time;
1763 if (!verify_cb_cert(ctx, xi, 0,
1764 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE))
1768 goto check_cert_time;
1772 ctx->error_depth = n;
1773 xs = sk_X509_value(ctx->chain, n);
1777 * Do not clear ctx->error=0, it must be "sticky", only the user's callback
1778 * is allowed to reset errors (at its own peril).
1782 * For each iteration of this loop:
1783 * n is the subject depth
1784 * xs is the subject cert, for which the signature is to be checked
1785 * xi is the supposed issuer cert containing the public key to use
1786 * Initially xs == xi if the last cert in the chain is self-issued.
1788 * Skip signature check for self-signed certificates unless explicitly
1789 * asked for because it does not add any security and just wastes time.
1791 if (xs != xi || ((ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)
1792 && (xi->ex_flags & EXFLAG_SS) != 0)) {
1795 * If the issuer's public key is not available or its key usage
1796 * does not support issuing the subject cert, report the issuer
1797 * cert and its depth (rather than n, the depth of the subject).
1799 int issuer_depth = n + (xs == xi ? 0 : 1);
1801 * According to https://tools.ietf.org/html/rfc5280#section-6.1.4
1802 * step (n) we must check any given key usage extension in a CA cert
1803 * when preparing the verification of a certificate issued by it.
1804 * According to https://tools.ietf.org/html/rfc5280#section-4.2.1.3
1805 * we must not verify a certifiate signature if the key usage of the
1806 * CA certificate that issued the certificate prohibits signing.
1807 * In case the 'issuing' certificate is the last in the chain and is
1808 * not a CA certificate but a 'self-issued' end-entity cert (i.e.,
1809 * xs == xi && !(xi->ex_flags & EXFLAG_CA)) RFC 5280 does not apply
1810 * (see https://tools.ietf.org/html/rfc6818#section-2) and thus
1811 * we are free to ignore any key usage restrictions on such certs.
1813 int ret = xs == xi && (xi->ex_flags & EXFLAG_CA) == 0
1814 ? X509_V_OK : x509_signing_allowed(xi, xs);
1816 if (ret != X509_V_OK && !verify_cb_cert(ctx, xi, issuer_depth, ret))
1818 if ((pkey = X509_get0_pubkey(xi)) == NULL) {
1819 ret = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
1820 if (!verify_cb_cert(ctx, xi, issuer_depth, ret))
1822 } else if (X509_verify(xs, pkey) <= 0) {
1823 ret = X509_V_ERR_CERT_SIGNATURE_FAILURE;
1824 if (!verify_cb_cert(ctx, xs, n, ret))
1829 check_cert_time: /* in addition to RFC 5280, do also for trusted (root) cert */
1830 /* Calls verify callback as needed */
1831 if (!x509_check_cert_time(ctx, xs, n))
1835 * Signal success at this depth. However, the previous error (if any)
1838 ctx->current_issuer = xi;
1839 ctx->current_cert = xs;
1840 ctx->error_depth = n;
1841 if (!ctx->verify_cb(1, ctx))
1846 xs = sk_X509_value(ctx->chain, n);
1852 int X509_cmp_current_time(const ASN1_TIME *ctm)
1854 return X509_cmp_time(ctm, NULL);
1857 int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
1859 static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1;
1860 static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1;
1861 ASN1_TIME *asn1_cmp_time = NULL;
1862 int i, day, sec, ret = 0;
1863 #ifdef CHARSET_EBCDIC
1864 const char upper_z = 0x5A;
1866 const char upper_z = 'Z';
1869 * Note that ASN.1 allows much more slack in the time format than RFC5280.
1870 * In RFC5280, the representation is fixed:
1871 * UTCTime: YYMMDDHHMMSSZ
1872 * GeneralizedTime: YYYYMMDDHHMMSSZ
1874 * We do NOT currently enforce the following RFC 5280 requirement:
1875 * "CAs conforming to this profile MUST always encode certificate
1876 * validity dates through the year 2049 as UTCTime; certificate validity
1877 * dates in 2050 or later MUST be encoded as GeneralizedTime."
1879 switch (ctm->type) {
1880 case V_ASN1_UTCTIME:
1881 if (ctm->length != (int)(utctime_length))
1884 case V_ASN1_GENERALIZEDTIME:
1885 if (ctm->length != (int)(generalizedtime_length))
1893 * Verify the format: the ASN.1 functions we use below allow a more
1894 * flexible format than what's mandated by RFC 5280.
1895 * Digit and date ranges will be verified in the conversion methods.
1897 for (i = 0; i < ctm->length - 1; i++) {
1898 if (!ascii_isdigit(ctm->data[i]))
1901 if (ctm->data[ctm->length - 1] != upper_z)
1905 * There is ASN1_UTCTIME_cmp_time_t but no
1906 * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t,
1907 * so we go through ASN.1
1909 asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time);
1910 if (asn1_cmp_time == NULL)
1912 if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time))
1916 * X509_cmp_time comparison is <=.
1917 * The return value 0 is reserved for errors.
1919 ret = (day >= 0 && sec >= 0) ? -1 : 1;
1922 ASN1_TIME_free(asn1_cmp_time);
1926 ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj)
1928 return X509_time_adj(s, adj, NULL);
1931 ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm)
1933 return X509_time_adj_ex(s, 0, offset_sec, in_tm);
1936 ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s,
1937 int offset_day, long offset_sec, time_t *in_tm)
1946 if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) {
1947 if (s->type == V_ASN1_UTCTIME)
1948 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec);
1949 if (s->type == V_ASN1_GENERALIZEDTIME)
1950 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec);
1952 return ASN1_TIME_adj(s, t, offset_day, offset_sec);
1955 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
1957 EVP_PKEY *ktmp = NULL, *ktmp2;
1960 if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey))
1963 for (i = 0; i < sk_X509_num(chain); i++) {
1964 ktmp = X509_get0_pubkey(sk_X509_value(chain, i));
1966 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
1967 X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
1970 if (!EVP_PKEY_missing_parameters(ktmp))
1974 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
1975 X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
1979 /* first, populate the other certs */
1980 for (j = i - 1; j >= 0; j--) {
1981 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j));
1982 EVP_PKEY_copy_parameters(ktmp2, ktmp);
1986 EVP_PKEY_copy_parameters(pkey, ktmp);
1990 /* Make a delta CRL as the diff between two full CRLs */
1992 X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer,
1993 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags)
1995 X509_CRL *crl = NULL;
1997 STACK_OF(X509_REVOKED) *revs = NULL;
1998 /* CRLs can't be delta already */
1999 if (base->base_crl_number || newer->base_crl_number) {
2000 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA);
2003 /* Base and new CRL must have a CRL number */
2004 if (!base->crl_number || !newer->crl_number) {
2005 X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER);
2008 /* Issuer names must match */
2009 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) {
2010 X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH);
2013 /* AKID and IDP must match */
2014 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) {
2015 X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH);
2018 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) {
2019 X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH);
2022 /* Newer CRL number must exceed full CRL number */
2023 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) {
2024 X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER);
2027 /* CRLs must verify */
2028 if (skey && (X509_CRL_verify(base, skey) <= 0 ||
2029 X509_CRL_verify(newer, skey) <= 0)) {
2030 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE);
2033 /* Create new CRL */
2034 crl = X509_CRL_new();
2035 if (crl == NULL || !X509_CRL_set_version(crl, 1))
2037 /* Set issuer name */
2038 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer)))
2041 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer)))
2043 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer)))
2046 /* Set base CRL number: must be critical */
2048 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0))
2052 * Copy extensions across from newest CRL to delta: this will set CRL
2053 * number to correct value too.
2056 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) {
2057 X509_EXTENSION *ext;
2058 ext = X509_CRL_get_ext(newer, i);
2059 if (!X509_CRL_add_ext(crl, ext, -1))
2063 /* Go through revoked entries, copying as needed */
2065 revs = X509_CRL_get_REVOKED(newer);
2067 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) {
2068 X509_REVOKED *rvn, *rvtmp;
2069 rvn = sk_X509_REVOKED_value(revs, i);
2071 * Add only if not also in base. TODO: need something cleverer here
2072 * for some more complex CRLs covering multiple CAs.
2074 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) {
2075 rvtmp = X509_REVOKED_dup(rvn);
2078 if (!X509_CRL_add0_revoked(crl, rvtmp)) {
2079 X509_REVOKED_free(rvtmp);
2084 /* TODO: optionally prune deleted entries */
2086 if (skey && md && !X509_CRL_sign(crl, skey, md))
2092 X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE);
2097 int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
2099 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data);
2102 void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx)
2104 return CRYPTO_get_ex_data(&ctx->ex_data, idx);
2107 int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx)
2112 void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
2117 int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx)
2119 return ctx->error_depth;
2122 void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth)
2124 ctx->error_depth = depth;
2127 X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx)
2129 return ctx->current_cert;
2132 void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x)
2134 ctx->current_cert = x;
2137 STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx)
2142 STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx)
2146 return X509_chain_up_ref(ctx->chain);
2149 X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx)
2151 return ctx->current_issuer;
2154 X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx)
2156 return ctx->current_crl;
2159 X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx)
2164 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
2169 void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
2174 int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
2177 * XXX: Why isn't this function always used to set the associated trust?
2178 * Should there even be a VPM->trust field at all? Or should the trust
2179 * always be inferred from the purpose by X509_STORE_CTX_init().
2181 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
2184 int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
2187 * XXX: See above, this function would only be needed when the default
2188 * trust for the purpose needs an override in a corner case.
2190 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
2194 * This function is used to set the X509_STORE_CTX purpose and trust values.
2195 * This is intended to be used when another structure has its own trust and
2196 * purpose values which (if set) will be inherited by the ctx. If they aren't
2197 * set then we will usually have a default purpose in mind which should then
2198 * be used to set the trust value. An example of this is SSL use: an SSL
2199 * structure will have its own purpose and trust settings which the
2200 * application can set: if they aren't set then we use the default of SSL
2204 int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
2205 int purpose, int trust)
2208 /* If purpose not set use default */
2210 purpose = def_purpose;
2212 * If purpose is set but we don't have a default then set the default to
2213 * the current purpose
2215 else if (def_purpose == 0)
2216 def_purpose = purpose;
2217 /* If we have a purpose then check it is valid */
2220 idx = X509_PURPOSE_get_by_id(purpose);
2222 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2223 X509_R_UNKNOWN_PURPOSE_ID);
2226 ptmp = X509_PURPOSE_get0(idx);
2227 if (ptmp->trust == X509_TRUST_DEFAULT) {
2228 idx = X509_PURPOSE_get_by_id(def_purpose);
2230 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2231 X509_R_UNKNOWN_PURPOSE_ID);
2234 ptmp = X509_PURPOSE_get0(idx);
2236 /* If trust not set then get from purpose default */
2238 trust = ptmp->trust;
2241 idx = X509_TRUST_get_by_id(trust);
2243 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2244 X509_R_UNKNOWN_TRUST_ID);
2249 if (purpose && !ctx->param->purpose)
2250 ctx->param->purpose = purpose;
2251 if (trust && !ctx->param->trust)
2252 ctx->param->trust = trust;
2256 X509_STORE_CTX *X509_STORE_CTX_new(void)
2258 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
2261 X509err(X509_F_X509_STORE_CTX_NEW, ERR_R_MALLOC_FAILURE);
2267 void X509_STORE_CTX_free(X509_STORE_CTX *ctx)
2272 X509_STORE_CTX_cleanup(ctx);
2276 int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
2277 STACK_OF(X509) *chain)
2283 ctx->untrusted = chain;
2285 ctx->num_untrusted = 0;
2286 ctx->other_ctx = NULL;
2290 ctx->explicit_policy = 0;
2291 ctx->error_depth = 0;
2292 ctx->current_cert = NULL;
2293 ctx->current_issuer = NULL;
2294 ctx->current_crl = NULL;
2295 ctx->current_crl_score = 0;
2296 ctx->current_reasons = 0;
2300 ctx->bare_ta_signed = 0;
2301 /* Zero ex_data to make sure we're cleanup-safe */
2302 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2304 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */
2306 ctx->cleanup = store->cleanup;
2310 if (store && store->check_issued)
2311 ctx->check_issued = store->check_issued;
2313 ctx->check_issued = check_issued;
2315 if (store && store->get_issuer)
2316 ctx->get_issuer = store->get_issuer;
2318 ctx->get_issuer = X509_STORE_CTX_get1_issuer;
2320 if (store && store->verify_cb)
2321 ctx->verify_cb = store->verify_cb;
2323 ctx->verify_cb = null_callback;
2325 if (store && store->verify)
2326 ctx->verify = store->verify;
2328 ctx->verify = internal_verify;
2330 if (store && store->check_revocation)
2331 ctx->check_revocation = store->check_revocation;
2333 ctx->check_revocation = check_revocation;
2335 if (store && store->get_crl)
2336 ctx->get_crl = store->get_crl;
2338 ctx->get_crl = NULL;
2340 if (store && store->check_crl)
2341 ctx->check_crl = store->check_crl;
2343 ctx->check_crl = check_crl;
2345 if (store && store->cert_crl)
2346 ctx->cert_crl = store->cert_crl;
2348 ctx->cert_crl = cert_crl;
2350 if (store && store->check_policy)
2351 ctx->check_policy = store->check_policy;
2353 ctx->check_policy = check_policy;
2355 if (store && store->lookup_certs)
2356 ctx->lookup_certs = store->lookup_certs;
2358 ctx->lookup_certs = X509_STORE_CTX_get1_certs;
2360 if (store && store->lookup_crls)
2361 ctx->lookup_crls = store->lookup_crls;
2363 ctx->lookup_crls = X509_STORE_CTX_get1_crls;
2365 ctx->param = X509_VERIFY_PARAM_new();
2366 if (ctx->param == NULL) {
2367 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2372 * Inherit callbacks and flags from X509_STORE if not set use defaults.
2375 ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
2377 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE;
2380 ret = X509_VERIFY_PARAM_inherit(ctx->param,
2381 X509_VERIFY_PARAM_lookup("default"));
2384 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2389 * XXX: For now, continue to inherit trust from VPM, but infer from the
2390 * purpose if this still yields the default value.
2392 if (ctx->param->trust == X509_TRUST_DEFAULT) {
2393 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose);
2394 X509_PURPOSE *xp = X509_PURPOSE_get0(idx);
2397 ctx->param->trust = X509_PURPOSE_get_trust(xp);
2400 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
2403 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2407 * On error clean up allocated storage, if the store context was not
2408 * allocated with X509_STORE_CTX_new() this is our last chance to do so.
2410 X509_STORE_CTX_cleanup(ctx);
2415 * Set alternative lookup method: just a STACK of trusted certificates. This
2416 * avoids X509_STORE nastiness where it isn't needed.
2418 void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2420 ctx->other_ctx = sk;
2421 ctx->get_issuer = get_issuer_sk;
2422 ctx->lookup_certs = lookup_certs_sk;
2425 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
2428 * We need to be idempotent because, unfortunately, free() also calls
2429 * cleanup(), so the natural call sequence new(), init(), cleanup(), free()
2430 * calls cleanup() for the same object twice! Thus we must zero the
2431 * pointers below after they're freed!
2433 /* Seems to always be 0 in OpenSSL, do this at most once. */
2434 if (ctx->cleanup != NULL) {
2436 ctx->cleanup = NULL;
2438 if (ctx->param != NULL) {
2439 if (ctx->parent == NULL)
2440 X509_VERIFY_PARAM_free(ctx->param);
2443 X509_policy_tree_free(ctx->tree);
2445 sk_X509_pop_free(ctx->chain, X509_free);
2447 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
2448 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2451 void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
2453 X509_VERIFY_PARAM_set_depth(ctx->param, depth);
2456 void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
2458 X509_VERIFY_PARAM_set_flags(ctx->param, flags);
2461 void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags,
2464 X509_VERIFY_PARAM_set_time(ctx->param, t);
2467 X509 *X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx)
2472 STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx)
2474 return ctx->untrusted;
2477 void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2479 ctx->untrusted = sk;
2482 void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2484 sk_X509_pop_free(ctx->chain, X509_free);
2488 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
2489 X509_STORE_CTX_verify_cb verify_cb)
2491 ctx->verify_cb = verify_cb;
2494 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx)
2496 return ctx->verify_cb;
2499 void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx,
2500 X509_STORE_CTX_verify_fn verify)
2502 ctx->verify = verify;
2505 X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(X509_STORE_CTX *ctx)
2510 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx)
2512 return ctx->get_issuer;
2515 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx)
2517 return ctx->check_issued;
2520 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx)
2522 return ctx->check_revocation;
2525 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx)
2527 return ctx->get_crl;
2530 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx)
2532 return ctx->check_crl;
2535 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx)
2537 return ctx->cert_crl;
2540 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx)
2542 return ctx->check_policy;
2545 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx)
2547 return ctx->lookup_certs;
2550 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx)
2552 return ctx->lookup_crls;
2555 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx)
2557 return ctx->cleanup;
2560 X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx)
2565 int X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx)
2567 return ctx->explicit_policy;
2570 int X509_STORE_CTX_get_num_untrusted(X509_STORE_CTX *ctx)
2572 return ctx->num_untrusted;
2575 int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
2577 const X509_VERIFY_PARAM *param;
2578 param = X509_VERIFY_PARAM_lookup(name);
2581 return X509_VERIFY_PARAM_inherit(ctx->param, param);
2584 X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx)
2589 void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
2591 X509_VERIFY_PARAM_free(ctx->param);
2595 void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane)
2600 static unsigned char *dane_i2d(
2603 unsigned int *i2dlen)
2605 unsigned char *buf = NULL;
2609 * Extract ASN.1 DER form of certificate or public key.
2612 case DANETLS_SELECTOR_CERT:
2613 len = i2d_X509(cert, &buf);
2615 case DANETLS_SELECTOR_SPKI:
2616 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf);
2619 X509err(X509_F_DANE_I2D, X509_R_BAD_SELECTOR);
2623 if (len < 0 || buf == NULL) {
2624 X509err(X509_F_DANE_I2D, ERR_R_MALLOC_FAILURE);
2628 *i2dlen = (unsigned int)len;
2632 #define DANETLS_NONE 256 /* impossible uint8_t */
2634 static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth)
2636 SSL_DANE *dane = ctx->dane;
2637 unsigned usage = DANETLS_NONE;
2638 unsigned selector = DANETLS_NONE;
2639 unsigned ordinal = DANETLS_NONE;
2640 unsigned mtype = DANETLS_NONE;
2641 unsigned char *i2dbuf = NULL;
2642 unsigned int i2dlen = 0;
2643 unsigned char mdbuf[EVP_MAX_MD_SIZE];
2644 unsigned char *cmpbuf = NULL;
2645 unsigned int cmplen = 0;
2649 danetls_record *t = NULL;
2652 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK;
2655 * The trust store is not applicable with DANE-TA(2)
2657 if (depth >= ctx->num_untrusted)
2658 mask &= DANETLS_PKIX_MASK;
2661 * If we've previously matched a PKIX-?? record, no need to test any
2662 * further PKIX-?? records, it remains to just build the PKIX chain.
2663 * Had the match been a DANE-?? record, we'd be done already.
2665 if (dane->mdpth >= 0)
2666 mask &= ~DANETLS_PKIX_MASK;
2669 * https://tools.ietf.org/html/rfc7671#section-5.1
2670 * https://tools.ietf.org/html/rfc7671#section-5.2
2671 * https://tools.ietf.org/html/rfc7671#section-5.3
2672 * https://tools.ietf.org/html/rfc7671#section-5.4
2674 * We handle DANE-EE(3) records first as they require no chain building
2675 * and no expiration or hostname checks. We also process digests with
2676 * higher ordinals first and ignore lower priorities except Full(0) which
2677 * is always processed (last). If none match, we then process PKIX-EE(1).
2679 * NOTE: This relies on DANE usages sorting before the corresponding PKIX
2680 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest
2681 * priorities. See twin comment in ssl/ssl_lib.c.
2683 * We expect that most TLSA RRsets will have just a single usage, so we
2684 * don't go out of our way to cache multiple selector-specific i2d buffers
2685 * across usages, but if the selector happens to remain the same as switch
2686 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1",
2687 * records would result in us generating each of the certificate and public
2688 * key DER forms twice, but more typically we'd just see multiple "3 1 1"
2689 * or multiple "3 0 1" records.
2691 * As soon as we find a match at any given depth, we stop, because either
2692 * we've matched a DANE-?? record and the peer is authenticated, or, after
2693 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is
2694 * sufficient for DANE, and what remains to do is ordinary PKIX validation.
2696 recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0;
2697 for (i = 0; matched == 0 && i < recnum; ++i) {
2698 t = sk_danetls_record_value(dane->trecs, i);
2699 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0)
2701 if (t->usage != usage) {
2704 /* Reset digest agility for each usage/selector pair */
2705 mtype = DANETLS_NONE;
2706 ordinal = dane->dctx->mdord[t->mtype];
2708 if (t->selector != selector) {
2709 selector = t->selector;
2711 /* Update per-selector state */
2712 OPENSSL_free(i2dbuf);
2713 i2dbuf = dane_i2d(cert, selector, &i2dlen);
2717 /* Reset digest agility for each usage/selector pair */
2718 mtype = DANETLS_NONE;
2719 ordinal = dane->dctx->mdord[t->mtype];
2720 } else if (t->mtype != DANETLS_MATCHING_FULL) {
2724 * <https://tools.ietf.org/html/rfc7671#section-9>
2726 * For a fixed selector, after processing all records with the
2727 * highest mtype ordinal, ignore all mtypes with lower ordinals
2728 * other than "Full".
2730 if (dane->dctx->mdord[t->mtype] < ordinal)
2735 * Each time we hit a (new selector or) mtype, re-compute the relevant
2736 * digest, more complex caching is not worth the code space.
2738 if (t->mtype != mtype) {
2739 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype];
2745 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) {
2753 * Squirrel away the certificate and depth if we have a match. Any
2754 * DANE match is dispositive, but with PKIX we still need to build a
2757 if (cmplen == t->dlen &&
2758 memcmp(cmpbuf, t->data, cmplen) == 0) {
2759 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK)
2761 if (matched || dane->mdpth < 0) {
2762 dane->mdpth = depth;
2764 OPENSSL_free(dane->mcert);
2772 /* Clear the one-element DER cache */
2773 OPENSSL_free(i2dbuf);
2777 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth)
2779 SSL_DANE *dane = ctx->dane;
2783 if (!DANETLS_HAS_TA(dane) || depth == 0)
2784 return X509_TRUST_UNTRUSTED;
2787 * Record any DANE trust-anchor matches, for the first depth to test, if
2788 * there's one at that depth. (This'll be false for length 1 chains looking
2789 * for an exact match for the leaf certificate).
2791 cert = sk_X509_value(ctx->chain, depth);
2792 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0)
2793 return X509_TRUST_REJECTED;
2795 ctx->num_untrusted = depth - 1;
2796 return X509_TRUST_TRUSTED;
2799 return X509_TRUST_UNTRUSTED;
2802 static int check_dane_pkeys(X509_STORE_CTX *ctx)
2804 SSL_DANE *dane = ctx->dane;
2806 int num = ctx->num_untrusted;
2807 X509 *cert = sk_X509_value(ctx->chain, num - 1);
2808 int recnum = sk_danetls_record_num(dane->trecs);
2811 for (i = 0; i < recnum; ++i) {
2812 t = sk_danetls_record_value(dane->trecs, i);
2813 if (t->usage != DANETLS_USAGE_DANE_TA ||
2814 t->selector != DANETLS_SELECTOR_SPKI ||
2815 t->mtype != DANETLS_MATCHING_FULL ||
2816 X509_verify(cert, t->spki) <= 0)
2819 /* Clear any PKIX-?? matches that failed to extend to a full chain */
2820 X509_free(dane->mcert);
2823 /* Record match via a bare TA public key */
2824 ctx->bare_ta_signed = 1;
2825 dane->mdpth = num - 1;
2828 /* Prune any excess chain certificates */
2829 num = sk_X509_num(ctx->chain);
2830 for (; num > ctx->num_untrusted; --num)
2831 X509_free(sk_X509_pop(ctx->chain));
2833 return X509_TRUST_TRUSTED;
2836 return X509_TRUST_UNTRUSTED;
2839 static void dane_reset(SSL_DANE *dane)
2842 * Reset state to verify another chain, or clear after failure.
2844 X509_free(dane->mcert);
2851 static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert)
2853 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags);
2855 if (err == X509_V_OK)
2857 return verify_cb_cert(ctx, cert, 0, err);
2860 static int dane_verify(X509_STORE_CTX *ctx)
2862 X509 *cert = ctx->cert;
2863 SSL_DANE *dane = ctx->dane;
2870 * When testing the leaf certificate, if we match a DANE-EE(3) record,
2871 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1)
2872 * record, the match depth and matching TLSA record are recorded, but the
2873 * return value is 0, because we still need to find a PKIX trust-anchor.
2874 * Therefore, when DANE authentication is enabled (required), we're done
2876 * + matched < 0, internal error.
2877 * + matched == 1, we matched a DANE-EE(3) record
2878 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no
2879 * DANE-TA(2) or PKIX-TA(0) to test.
2881 matched = dane_match(ctx, ctx->cert, 0);
2882 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0);
2885 X509_get_pubkey_parameters(NULL, ctx->chain);
2888 /* Callback invoked as needed */
2889 if (!check_leaf_suiteb(ctx, cert))
2891 /* Callback invoked as needed */
2892 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 &&
2895 /* Bypass internal_verify(), issue depth 0 success callback */
2896 ctx->error_depth = 0;
2897 ctx->current_cert = cert;
2898 return ctx->verify_cb(1, ctx);
2902 ctx->error_depth = 0;
2903 ctx->current_cert = cert;
2904 ctx->error = X509_V_ERR_OUT_OF_MEM;
2909 /* Fail early, TA-based success is not possible */
2910 if (!check_leaf_suiteb(ctx, cert))
2912 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH);
2916 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0
2917 * certificates happens in-line with building the rest of the chain.
2919 return verify_chain(ctx);
2922 /* Get issuer, without duplicate suppression */
2923 static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert)
2925 STACK_OF(X509) *saved_chain = ctx->chain;
2929 ok = ctx->get_issuer(issuer, ctx, cert);
2930 ctx->chain = saved_chain;
2935 static int augment_stack(STACK_OF(X509) *src, STACK_OF(X509) **dstPtr)
2938 STACK_OF(X509) *dst;
2941 if (*dstPtr == NULL)
2942 return ((*dstPtr = sk_X509_dup(src)) != NULL);
2944 for (dst = *dstPtr, i = 0; i < sk_X509_num(src); ++i) {
2945 if (!sk_X509_push(dst, sk_X509_value(src, i))) {
2955 static int build_chain(X509_STORE_CTX *ctx)
2957 SSL_DANE *dane = ctx->dane;
2958 int num = sk_X509_num(ctx->chain);
2959 X509 *cert = sk_X509_value(ctx->chain, num - 1);
2960 int ss = cert_self_signed(cert);
2961 STACK_OF(X509) *sktmp = NULL;
2962 unsigned int search;
2963 int may_trusted = 0;
2964 int may_alternate = 0;
2965 int trust = X509_TRUST_UNTRUSTED;
2966 int alt_untrusted = 0;
2971 /* Our chain starts with a single untrusted element. */
2972 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) {
2973 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
2974 ctx->error = X509_V_ERR_UNSPECIFIED;
2978 #define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */
2979 #define S_DOTRUSTED (1 << 1) /* Search trusted store */
2980 #define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */
2982 * Set up search policy, untrusted if possible, trusted-first if enabled.
2983 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the
2984 * trust_store, otherwise we might look there first. If not trusted-first,
2985 * and alternate chains are not disabled, try building an alternate chain
2986 * if no luck with untrusted first.
2988 search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0;
2989 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) {
2990 if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)
2991 search |= S_DOTRUSTED;
2992 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS))
2998 * If we got any "Cert(0) Full(0)" issuer certificates from DNS, *prepend*
2999 * them to our working copy of the untrusted certificate stack. Since the
3000 * caller of X509_STORE_CTX_init() may have provided only a leaf cert with
3001 * no corresponding stack of untrusted certificates, we may need to create
3002 * an empty stack first. [ At present only the ssl library provides DANE
3003 * support, and ssl_verify_cert_chain() always provides a non-null stack
3004 * containing at least the leaf certificate, but we must be prepared for
3007 if (DANETLS_ENABLED(dane) && !augment_stack(dane->certs, &sktmp)) {
3008 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3009 ctx->error = X509_V_ERR_OUT_OF_MEM;
3014 * Shallow-copy the stack of untrusted certificates (with TLS, this is
3015 * typically the content of the peer's certificate message) so can make
3016 * multiple passes over it, while free to remove elements as we go.
3018 if (!augment_stack(ctx->untrusted, &sktmp)) {
3019 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3020 ctx->error = X509_V_ERR_OUT_OF_MEM;
3025 * Still absurdly large, but arithmetically safe, a lower hard upper bound
3026 * might be reasonable.
3028 if (ctx->param->depth > INT_MAX/2)
3029 ctx->param->depth = INT_MAX/2;
3032 * Try to Extend the chain until we reach an ultimately trusted issuer.
3033 * Build chains up to one longer the limit, later fail if we hit the limit,
3034 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code.
3036 depth = ctx->param->depth + 1;
3038 while (search != 0) {
3043 * Look in the trust store if enabled for first lookup, or we've run
3044 * out of untrusted issuers and search here is not disabled. When we
3045 * reach the depth limit, we stop extending the chain, if by that point
3046 * we've not found a trust-anchor, any trusted chain would be too long.
3048 * The error reported to the application verify callback is at the
3049 * maximal valid depth with the current certificate equal to the last
3050 * not ultimately-trusted issuer. For example, with verify_depth = 0,
3051 * the callback will report errors at depth=1 when the immediate issuer
3052 * of the leaf certificate is not a trust anchor. No attempt will be
3053 * made to locate an issuer for that certificate, since such a chain
3054 * would be a-priori too long.
3056 if ((search & S_DOTRUSTED) != 0) {
3057 i = num = sk_X509_num(ctx->chain);
3058 if ((search & S_DOALTERNATE) != 0) {
3060 * As high up the chain as we can, look for an alternative
3061 * trusted issuer of an untrusted certificate that currently
3062 * has an untrusted issuer. We use the alt_untrusted variable
3063 * to track how far up the chain we find the first match. It
3064 * is only if and when we find a match, that we prune the chain
3065 * and reset ctx->num_untrusted to the reduced count of
3066 * untrusted certificates. While we're searching for such a
3067 * match (which may never be found), it is neither safe nor
3068 * wise to preemptively modify either the chain or
3069 * ctx->num_untrusted.
3071 * Note, like ctx->num_untrusted, alt_untrusted is a count of
3072 * untrusted certificates, not a "depth".
3076 x = sk_X509_value(ctx->chain, i-1);
3078 ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x);
3081 trust = X509_TRUST_REJECTED;
3082 ctx->error = X509_V_ERR_STORE_LOOKUP;
3089 * Alternative trusted issuer for a mid-chain untrusted cert?
3090 * Pop the untrusted cert's successors and retry. We might now
3091 * be able to complete a valid chain via the trust store. Note
3092 * that despite the current trust-store match we might still
3093 * fail complete the chain to a suitable trust-anchor, in which
3094 * case we may prune some more untrusted certificates and try
3095 * again. Thus the S_DOALTERNATE bit may yet be turned on
3096 * again with an even shorter untrusted chain!
3098 * If in the process we threw away our matching PKIX-TA trust
3099 * anchor, reset DANE trust. We might find a suitable trusted
3100 * certificate among the ones from the trust store.
3102 if ((search & S_DOALTERNATE) != 0) {
3103 if (!ossl_assert(num > i && i > 0 && ss == 0)) {
3104 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3106 trust = X509_TRUST_REJECTED;
3107 ctx->error = X509_V_ERR_UNSPECIFIED;
3111 search &= ~S_DOALTERNATE;
3112 for (; num > i; --num)
3113 X509_free(sk_X509_pop(ctx->chain));
3114 ctx->num_untrusted = num;
3116 if (DANETLS_ENABLED(dane) &&
3117 dane->mdpth >= ctx->num_untrusted) {
3119 X509_free(dane->mcert);
3122 if (DANETLS_ENABLED(dane) &&
3123 dane->pdpth >= ctx->num_untrusted)
3128 * Self-signed untrusted certificates get replaced by their
3129 * trusted matching issuer. Otherwise, grow the chain.
3132 if (!sk_X509_push(ctx->chain, x = xtmp)) {
3134 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3135 trust = X509_TRUST_REJECTED;
3136 ctx->error = X509_V_ERR_OUT_OF_MEM;
3140 ss = cert_self_signed(x);
3141 } else if (num == ctx->num_untrusted) {
3143 * We have a self-signed certificate that has the same
3144 * subject name (and perhaps keyid and/or serial number) as
3145 * a trust-anchor. We must have an exact match to avoid
3146 * possible impersonation via key substitution etc.
3148 if (X509_cmp(x, xtmp) != 0) {
3149 /* Self-signed untrusted mimic. */
3154 ctx->num_untrusted = --num;
3155 (void) sk_X509_set(ctx->chain, num, x = xtmp);
3160 * We've added a new trusted certificate to the chain, recheck
3161 * trust. If not done, and not self-signed look deeper.
3162 * Whether or not we're doing "trusted first", we no longer
3163 * look for untrusted certificates from the peer's chain.
3165 * At this point ctx->num_trusted and num must reflect the
3166 * correct number of untrusted certificates, since the DANE
3167 * logic in check_trust() depends on distinguishing CAs from
3168 * "the wire" from CAs from the trust store. In particular, the
3169 * certificate at depth "num" should be the new trusted
3170 * certificate with ctx->num_untrusted <= num.
3173 if (!ossl_assert(ctx->num_untrusted <= num)) {
3174 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3175 trust = X509_TRUST_REJECTED;
3176 ctx->error = X509_V_ERR_UNSPECIFIED;
3180 search &= ~S_DOUNTRUSTED;
3181 switch (trust = check_trust(ctx, num)) {
3182 case X509_TRUST_TRUSTED:
3183 case X509_TRUST_REJECTED:
3193 * No dispositive decision, and either self-signed or no match, if
3194 * we were doing untrusted-first, and alt-chains are not disabled,
3195 * do that, by repeatedly losing one untrusted element at a time,
3196 * and trying to extend the shorted chain.
3198 if ((search & S_DOUNTRUSTED) == 0) {
3199 /* Continue search for a trusted issuer of a shorter chain? */
3200 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0)
3202 /* Still no luck and no fallbacks left? */
3203 if (!may_alternate || (search & S_DOALTERNATE) != 0 ||
3204 ctx->num_untrusted < 2)
3206 /* Search for a trusted issuer of a shorter chain */
3207 search |= S_DOALTERNATE;
3208 alt_untrusted = ctx->num_untrusted - 1;
3214 * Extend chain with peer-provided certificates
3216 if ((search & S_DOUNTRUSTED) != 0) {
3217 num = sk_X509_num(ctx->chain);
3218 if (!ossl_assert(num == ctx->num_untrusted)) {
3219 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3220 trust = X509_TRUST_REJECTED;
3221 ctx->error = X509_V_ERR_UNSPECIFIED;
3225 x = sk_X509_value(ctx->chain, num-1);
3228 * Once we run out of untrusted issuers, we stop looking for more
3229 * and start looking only in the trust store if enabled.
3231 xtmp = (ss || depth < num) ? NULL : find_issuer(ctx, sktmp, x);
3233 search &= ~S_DOUNTRUSTED;
3235 search |= S_DOTRUSTED;
3239 /* Drop this issuer from future consideration */
3240 (void) sk_X509_delete_ptr(sktmp, xtmp);
3242 if (!X509_up_ref(xtmp)) {
3243 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3244 trust = X509_TRUST_REJECTED;
3245 ctx->error = X509_V_ERR_UNSPECIFIED;
3250 if (!sk_X509_push(ctx->chain, xtmp)) {
3252 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3253 trust = X509_TRUST_REJECTED;
3254 ctx->error = X509_V_ERR_OUT_OF_MEM;
3260 ++ctx->num_untrusted;
3261 ss = cert_self_signed(xtmp);
3264 * Check for DANE-TA trust of the topmost untrusted certificate.
3266 switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) {
3267 case X509_TRUST_TRUSTED:
3268 case X509_TRUST_REJECTED:
3274 sk_X509_free(sktmp);
3277 * Last chance to make a trusted chain, either bare DANE-TA public-key
3278 * signers, or else direct leaf PKIX trust.
3280 num = sk_X509_num(ctx->chain);
3282 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane))
3283 trust = check_dane_pkeys(ctx);
3284 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted)
3285 trust = check_trust(ctx, num);
3289 case X509_TRUST_TRUSTED:
3291 case X509_TRUST_REJECTED:
3292 /* Callback already issued */
3294 case X509_TRUST_UNTRUSTED:
3296 num = sk_X509_num(ctx->chain);
3298 return verify_cb_cert(ctx, NULL, num-1,
3299 X509_V_ERR_CERT_CHAIN_TOO_LONG);
3300 if (DANETLS_ENABLED(dane) &&
3301 (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0))
3302 return verify_cb_cert(ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH);
3303 if (ss && sk_X509_num(ctx->chain) == 1)
3304 return verify_cb_cert(ctx, NULL, num-1,
3305 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
3307 return verify_cb_cert(ctx, NULL, num-1,
3308 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN);
3309 if (ctx->num_untrusted < num)
3310 return verify_cb_cert(ctx, NULL, num-1,
3311 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT);
3312 return verify_cb_cert(ctx, NULL, num-1,
3313 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY);
3317 static const int minbits_table[] = { 80, 112, 128, 192, 256 };
3318 static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table);
3321 * Check whether the public key of ``cert`` meets the security level of
3324 * Returns 1 on success, 0 otherwise.
3326 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert)
3328 EVP_PKEY *pkey = X509_get0_pubkey(cert);
3329 int level = ctx->param->auth_level;
3332 * At security level zero, return without checking for a supported public
3333 * key type. Some engines support key types not understood outside the
3334 * engine, and we only need to understand the key when enforcing a security
3340 /* Unsupported or malformed keys are not secure */
3344 if (level > NUM_AUTH_LEVELS)
3345 level = NUM_AUTH_LEVELS;
3347 return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1];
3351 * Check whether the public key of ``cert`` does not use explicit params
3352 * for an elliptic curve.
3354 * Returns 1 on success, 0 if check fails, -1 for other errors.
3356 static int check_curve(X509 *cert)
3358 #ifndef OPENSSL_NO_EC
3359 EVP_PKEY *pkey = X509_get0_pubkey(cert);
3361 /* Unsupported or malformed key */
3365 if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) {
3368 ret = EC_KEY_decoded_from_explicit_params(EVP_PKEY_get0_EC_KEY(pkey));
3369 return ret < 0 ? ret : !ret;
3377 * Check whether the signature digest algorithm of ``cert`` meets the security
3378 * level of ``ctx``. Should not be checked for trust anchors (whether
3379 * self-signed or otherwise).
3381 * Returns 1 on success, 0 otherwise.
3383 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert)
3386 int level = ctx->param->auth_level;
3390 if (level > NUM_AUTH_LEVELS)
3391 level = NUM_AUTH_LEVELS;
3393 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL))
3396 return secbits >= minbits_table[level - 1];