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"
28 DEFINE_STACK_OF(GENERAL_NAME)
29 DEFINE_STACK_OF(DIST_POINT)
30 DEFINE_STACK_OF_STRING()
32 /* CRL score values */
34 /* No unhandled critical extensions */
36 #define CRL_SCORE_NOCRITICAL 0x100
38 /* certificate is within CRL scope */
40 #define CRL_SCORE_SCOPE 0x080
44 #define CRL_SCORE_TIME 0x040
46 /* Issuer name matches certificate */
48 #define CRL_SCORE_ISSUER_NAME 0x020
50 /* If this score or above CRL is probably valid */
52 #define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE)
54 /* CRL issuer is certificate issuer */
56 #define CRL_SCORE_ISSUER_CERT 0x018
58 /* CRL issuer is on certificate path */
60 #define CRL_SCORE_SAME_PATH 0x008
62 /* CRL issuer matches CRL AKID */
64 #define CRL_SCORE_AKID 0x004
66 /* Have a delta CRL with valid times */
68 #define CRL_SCORE_TIME_DELTA 0x002
70 static int build_chain(X509_STORE_CTX *ctx);
71 static int verify_chain(X509_STORE_CTX *ctx);
72 static int dane_verify(X509_STORE_CTX *ctx);
73 static int null_callback(int ok, X509_STORE_CTX *e);
74 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
75 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
76 static int check_chain_extensions(X509_STORE_CTX *ctx);
77 static int check_name_constraints(X509_STORE_CTX *ctx);
78 static int check_id(X509_STORE_CTX *ctx);
79 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted);
80 static int check_revocation(X509_STORE_CTX *ctx);
81 static int check_cert(X509_STORE_CTX *ctx);
82 static int check_policy(X509_STORE_CTX *ctx);
83 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x);
84 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth);
85 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert);
86 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert);
88 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
89 unsigned int *preasons, X509_CRL *crl, X509 *x);
90 static int get_crl_delta(X509_STORE_CTX *ctx,
91 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x);
92 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl,
93 int *pcrl_score, X509_CRL *base,
94 STACK_OF(X509_CRL) *crls);
95 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
97 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
98 unsigned int *preasons);
99 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
100 static int check_crl_chain(X509_STORE_CTX *ctx,
101 STACK_OF(X509) *cert_path,
102 STACK_OF(X509) *crl_path);
104 static int internal_verify(X509_STORE_CTX *ctx);
106 static int null_callback(int ok, X509_STORE_CTX *e)
112 * Return 1 if given cert is considered self-signed, 0 if not, or -1 on error.
113 * This actually verifies self-signedness only if requested.
114 * It calls X509v3_cache_extensions()
115 * to match issuer and subject names (i.e., the cert being self-issued) and any
116 * present authority key identifier to match the subject key identifier, etc.
118 int X509_self_signed(X509 *cert, int verify_signature)
122 if ((pkey = X509_get0_pubkey(cert)) == NULL) { /* handles cert == NULL */
123 X509err(0, X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
126 if (!x509v3_cache_extensions(cert))
128 if ((cert->ex_flags & EXFLAG_SS) == 0)
130 if (!verify_signature)
132 return X509_verify(cert, pkey);
135 /* Given a certificate try and find an exact match in the store */
136 static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
138 STACK_OF(X509) *certs;
141 /* Lookup all certs with matching subject name */
142 certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
145 /* Look for exact match */
146 for (i = 0; i < sk_X509_num(certs); i++) {
147 xtmp = sk_X509_value(certs, i);
148 if (!X509_cmp(xtmp, x))
152 if (xtmp != NULL && !X509_up_ref(xtmp))
154 sk_X509_pop_free(certs, X509_free);
159 * Inform the verify callback of an error.
160 * If B<x> is not NULL it is the error cert, otherwise use the chain cert at
162 * If B<err> is not X509_V_OK, that's the error value, otherwise leave
163 * unchanged (presumably set by the caller).
165 * Returns 0 to abort verification with an error, non-zero to continue.
167 static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err)
169 ctx->error_depth = depth;
170 ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth);
171 if (err != X509_V_OK)
173 return ctx->verify_cb(0, ctx);
177 * Inform the verify callback of an error, CRL-specific variant. Here, the
178 * error depth and certificate are already set, we just specify the error
181 * Returns 0 to abort verification with an error, non-zero to continue.
183 static int verify_cb_crl(X509_STORE_CTX *ctx, int err)
186 return ctx->verify_cb(0, ctx);
189 static int check_auth_level(X509_STORE_CTX *ctx)
192 int num = sk_X509_num(ctx->chain);
194 if (ctx->param->auth_level <= 0)
197 for (i = 0; i < num; ++i) {
198 X509 *cert = sk_X509_value(ctx->chain, i);
201 * We've already checked the security of the leaf key, so here we only
202 * check the security of issuer keys.
204 if (i > 0 && !check_key_level(ctx, cert) &&
205 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL) == 0)
208 * We also check the signature algorithm security of all certificates
209 * except those of the trust anchor at index num-1.
211 if (i < num - 1 && !check_sig_level(ctx, cert) &&
212 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK) == 0)
218 static int verify_chain(X509_STORE_CTX *ctx)
224 * Before either returning with an error, or continuing with CRL checks,
225 * instantiate chain public key parameters.
227 if ((ok = build_chain(ctx)) == 0 ||
228 (ok = check_chain_extensions(ctx)) == 0 ||
229 (ok = check_auth_level(ctx)) == 0 ||
230 (ok = check_id(ctx)) == 0 || 1)
231 X509_get_pubkey_parameters(NULL, ctx->chain);
232 if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0)
235 err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
237 if (err != X509_V_OK) {
238 if ((ok = verify_cb_cert(ctx, NULL, ctx->error_depth, err)) == 0)
242 /* Verify chain signatures and expiration times */
243 ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx);
247 if ((ok = check_name_constraints(ctx)) == 0)
250 #ifndef OPENSSL_NO_RFC3779
251 /* RFC 3779 path validation, now that CRL check has been done */
252 if ((ok = X509v3_asid_validate_path(ctx)) == 0)
254 if ((ok = X509v3_addr_validate_path(ctx)) == 0)
258 /* If we get this far evaluate policies */
259 if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK)
260 ok = ctx->check_policy(ctx);
264 int X509_verify_cert(X509_STORE_CTX *ctx)
266 SSL_DANE *dane = ctx->dane;
269 if (ctx->cert == NULL) {
270 X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
271 ctx->error = X509_V_ERR_INVALID_CALL;
275 if (ctx->chain != NULL) {
277 * This X509_STORE_CTX has already been used to verify a cert. We
278 * cannot do another one.
280 X509err(X509_F_X509_VERIFY_CERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
281 ctx->error = X509_V_ERR_INVALID_CALL;
285 if (!X509_add_cert_new(&ctx->chain, ctx->cert, X509_ADD_FLAG_UP_REF)) {
286 ctx->error = X509_V_ERR_OUT_OF_MEM;
289 ctx->num_untrusted = 1;
291 /* If the peer's public key is too weak, we can stop early. */
292 if (!check_key_level(ctx, ctx->cert) &&
293 !verify_cb_cert(ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL))
296 if (DANETLS_ENABLED(dane))
297 ret = dane_verify(ctx);
299 ret = verify_chain(ctx);
302 * Safety-net. If we are returning an error, we must also set ctx->error,
303 * so that the chain is not considered verified should the error be ignored
304 * (e.g. TLS with SSL_VERIFY_NONE).
306 if (ret <= 0 && ctx->error == X509_V_OK)
307 ctx->error = X509_V_ERR_UNSPECIFIED;
312 * Given a STACK_OF(X509) find the issuer of cert (if any)
314 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
317 X509 *issuer, *rv = NULL;
319 for (i = 0; i < sk_X509_num(sk); i++) {
320 issuer = sk_X509_value(sk, i);
322 * Below check 'issuer != x' is an optimization and safety precaution:
323 * Candidate issuer cert cannot be the same as the subject cert 'x'.
325 if (issuer != x && ctx->check_issued(ctx, x, issuer)) {
327 if (x509_check_cert_time(ctx, rv, -1))
335 * Check that the given certificate 'x' is issued by the certificate 'issuer'
336 * and the issuer is not yet in ctx->chain, where the exceptional case
337 * that 'x' is self-issued and ctx->chain has just one element is allowed.
339 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
341 if (x509_likely_issued(issuer, x) != X509_V_OK)
343 if ((x->ex_flags & EXFLAG_SI) == 0 || sk_X509_num(ctx->chain) != 1) {
347 for (i = 0; i < sk_X509_num(ctx->chain); i++) {
348 ch = sk_X509_value(ctx->chain, i);
349 if (ch == issuer || X509_cmp(ch, issuer) == 0)
356 /* Alternative lookup method: look from a STACK stored in other_ctx */
357 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
359 *issuer = find_issuer(ctx, ctx->other_ctx, x);
361 if (*issuer == NULL || !X509_up_ref(*issuer))
371 static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx,
374 STACK_OF(X509) *sk = NULL;
378 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) {
379 x = sk_X509_value(ctx->other_ctx, i);
380 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) {
381 if (!X509_add_cert_new(&sk, x, X509_ADD_FLAG_UP_REF)) {
382 sk_X509_pop_free(sk, X509_free);
383 ctx->error = X509_V_ERR_OUT_OF_MEM;
392 * Check EE or CA certificate purpose. For trusted certificates explicit local
393 * auxiliary trust can be used to override EKU-restrictions.
395 static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth,
398 int tr_ok = X509_TRUST_UNTRUSTED;
401 * For trusted certificates we want to see whether any auxiliary trust
402 * settings trump the purpose constraints.
404 * This is complicated by the fact that the trust ordinals in
405 * ctx->param->trust are entirely independent of the purpose ordinals in
406 * ctx->param->purpose!
408 * What connects them is their mutual initialization via calls from
409 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets
410 * related values of both param->trust and param->purpose. It is however
411 * typically possible to infer associated trust values from a purpose value
412 * via the X509_PURPOSE API.
414 * Therefore, we can only check for trust overrides when the purpose we're
415 * checking is the same as ctx->param->purpose and ctx->param->trust is
418 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose)
419 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT);
422 case X509_TRUST_TRUSTED:
424 case X509_TRUST_REJECTED:
427 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) {
433 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0)
439 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE);
443 * Check a certificate chains extensions for consistency with the supplied
447 static int check_chain_extensions(X509_STORE_CTX *ctx)
449 int i, must_be_ca, plen = 0;
451 int proxy_path_length = 0;
453 int allow_proxy_certs;
454 int num = sk_X509_num(ctx->chain);
457 * must_be_ca can have 1 of 3 values:
458 * -1: we accept both CA and non-CA certificates, to allow direct
459 * use of self-signed certificates (which are marked as CA).
460 * 0: we only accept non-CA certificates. This is currently not
461 * used, but the possibility is present for future extensions.
462 * 1: we only accept CA certificates. This is currently used for
463 * all certificates in the chain except the leaf certificate.
467 /* CRL path validation */
469 allow_proxy_certs = 0;
470 purpose = X509_PURPOSE_CRL_SIGN;
473 ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
474 purpose = ctx->param->purpose;
477 for (i = 0; i < num; i++) {
480 x = sk_X509_value(ctx->chain, i);
481 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
482 && (x->ex_flags & EXFLAG_CRITICAL)) {
483 if (!verify_cb_cert(ctx, x, i,
484 X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION))
487 if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) {
488 if (!verify_cb_cert(ctx, x, i,
489 X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED))
492 ret = X509_check_ca(x);
493 switch (must_be_ca) {
495 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
496 && (ret != 1) && (ret != 0)) {
498 ctx->error = X509_V_ERR_INVALID_CA;
505 ctx->error = X509_V_ERR_INVALID_NON_CA;
510 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */
512 || ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT)
515 ctx->error = X509_V_ERR_INVALID_CA;
521 * Do the following set of checks only if strict checking is requrested
522 * and not for self-issued (including self-signed) EE (non-CA) certs
523 * because RFC 5280 does not apply to them according RFC 6818 section 2.
525 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0
528 * !(i == 0 && (x->ex_flags & EXFLAG_CA) == 0
529 * && (x->ex_flags & EXFLAG_SI) != 0)
531 /* Check Basic Constraints according to RFC 5280 section 4.2.1.9 */
532 if (x->ex_pathlen != -1) {
533 if ((x->ex_flags & EXFLAG_CA) == 0)
534 ctx->error = X509_V_ERR_PATHLEN_INVALID_FOR_NON_CA;
535 if ((x->ex_kusage & KU_KEY_CERT_SIGN) == 0)
536 ctx->error = X509_V_ERR_PATHLEN_WITHOUT_KU_KEY_CERT_SIGN;
538 if ((x->ex_flags & EXFLAG_CA) != 0
539 && (x->ex_flags & EXFLAG_BCONS) != 0
540 && (x->ex_flags & EXFLAG_BCONS_CRITICAL) == 0)
541 ctx->error = X509_V_ERR_CA_BCONS_NOT_CRITICAL;
542 /* Check Key Usage according to RFC 5280 section 4.2.1.3 */
543 if ((x->ex_flags & EXFLAG_CA) != 0) {
544 if ((x->ex_flags & EXFLAG_KUSAGE) == 0)
545 ctx->error = X509_V_ERR_CA_CERT_MISSING_KEY_USAGE;
547 if ((x->ex_kusage & KU_KEY_CERT_SIGN) != 0)
548 ctx->error = X509_V_ERR_KU_KEY_CERT_SIGN_INVALID_FOR_NON_CA;
550 /* Check issuer is non-empty acc. to RFC 5280 section 4.1.2.4 */
551 if (X509_NAME_entry_count(X509_get_issuer_name(x)) == 0)
552 ctx->error = X509_V_ERR_ISSUER_NAME_EMPTY;
553 /* Check subject is non-empty acc. to RFC 5280 section 4.1.2.6 */
554 if (((x->ex_flags & EXFLAG_CA) != 0
555 || (x->ex_kusage & KU_CRL_SIGN) != 0
556 || x->altname == NULL
557 ) && X509_NAME_entry_count(X509_get_subject_name(x)) == 0)
558 ctx->error = X509_V_ERR_SUBJECT_NAME_EMPTY;
559 if (X509_NAME_entry_count(X509_get_subject_name(x)) == 0
560 && x->altname != NULL
561 && (x->ex_flags & EXFLAG_SAN_CRITICAL) == 0)
562 ctx->error = X509_V_ERR_EMPTY_SUBJECT_SAN_NOT_CRITICAL;
563 /* Check SAN is non-empty according to RFC 5280 section 4.2.1.6 */
564 if (x->altname != NULL && sk_GENERAL_NAME_num(x->altname) <= 0)
565 ctx->error = X509_V_ERR_EMPTY_SUBJECT_ALT_NAME;
566 /* TODO add more checks on SAN entries */
567 /* Check sig alg consistency acc. to RFC 5280 section 4.1.1.2 */
568 if (X509_ALGOR_cmp(&x->sig_alg, &x->cert_info.signature) != 0)
569 ctx->error = X509_V_ERR_SIGNATURE_ALGORITHM_INCONSISTENCY;
570 if (x->akid != NULL && (x->ex_flags & EXFLAG_AKID_CRITICAL) != 0)
571 ctx->error = X509_V_ERR_AUTHORITY_KEY_IDENTIFIER_CRITICAL;
572 if (x->skid != NULL && (x->ex_flags & EXFLAG_SKID_CRITICAL) != 0)
573 ctx->error = X509_V_ERR_SUBJECT_KEY_IDENTIFIER_CRITICAL;
574 if (X509_get_version(x) >= 2) { /* at least X.509v3 */
575 /* Check AKID presence acc. to RFC 5280 section 4.2.1.1 */
577 * this means not last cert in chain,
578 * taken as "generated by conforming CAs"
580 && (x->akid == NULL || x->akid->keyid == NULL))
581 ctx->error = X509_V_ERR_MISSING_AUTHORITY_KEY_IDENTIFIER;
582 /* Check SKID presence acc. to RFC 5280 section 4.2.1.2 */
583 if ((x->ex_flags & EXFLAG_CA) != 0 && x->skid == NULL)
584 ctx->error = X509_V_ERR_MISSING_SUBJECT_KEY_IDENTIFIER;
586 if (sk_X509_EXTENSION_num(X509_get0_extensions(x)) > 0)
587 ctx->error = X509_V_ERR_EXTENSIONS_REQUIRE_VERSION_3;
590 if (ctx->error != X509_V_OK)
592 if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK))
594 /* check_purpose() makes the callback as needed */
595 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca))
598 if ((i > 1) && (x->ex_pathlen != -1)
599 && (plen > (x->ex_pathlen + proxy_path_length))) {
600 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED))
603 /* Increment path length if not a self-issued intermediate CA */
604 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0)
607 * If this certificate is a proxy certificate, the next certificate
608 * must be another proxy certificate or a EE certificate. If not,
609 * the next certificate must be a CA certificate.
611 if (x->ex_flags & EXFLAG_PROXY) {
613 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint
614 * is less than max_path_length, the former should be copied to
615 * the latter, and 4.1.4 (a) stipulates that max_path_length
616 * should be verified to be larger than zero and decrement it.
618 * Because we're checking the certs in the reverse order, we start
619 * with verifying that proxy_path_length isn't larger than pcPLC,
620 * and copy the latter to the former if it is, and finally,
621 * increment proxy_path_length.
623 if (x->ex_pcpathlen != -1) {
624 if (proxy_path_length > x->ex_pcpathlen) {
625 if (!verify_cb_cert(ctx, x, i,
626 X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED))
629 proxy_path_length = x->ex_pcpathlen;
639 static int has_san_id(X509 *x, int gtype)
643 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
648 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) {
649 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i);
651 if (g->type == gtype) {
656 GENERAL_NAMES_free(gs);
660 static int check_name_constraints(X509_STORE_CTX *ctx)
664 /* Check name constraints for all certificates */
665 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) {
666 X509 *x = sk_X509_value(ctx->chain, i);
669 /* Ignore self-issued certs unless last in chain */
670 if (i && (x->ex_flags & EXFLAG_SI))
674 * Proxy certificates policy has an extra constraint, where the
675 * certificate subject MUST be the issuer with a single CN entry
677 * (RFC 3820: 3.4, 4.1.3 (a)(4))
679 if (x->ex_flags & EXFLAG_PROXY) {
680 X509_NAME *tmpsubject = X509_get_subject_name(x);
681 X509_NAME *tmpissuer = X509_get_issuer_name(x);
682 X509_NAME_ENTRY *tmpentry = NULL;
683 int last_object_nid = 0;
685 int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1;
687 /* Check that there are at least two RDNs */
688 if (last_object_loc < 1) {
689 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
690 goto proxy_name_done;
694 * Check that there is exactly one more RDN in subject as
695 * there is in issuer.
697 if (X509_NAME_entry_count(tmpsubject)
698 != X509_NAME_entry_count(tmpissuer) + 1) {
699 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
700 goto proxy_name_done;
704 * Check that the last subject component isn't part of a
707 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
709 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
710 last_object_loc - 1))) {
711 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
712 goto proxy_name_done;
716 * Check that the last subject RDN is a commonName, and that
717 * all the previous RDNs match the issuer exactly
719 tmpsubject = X509_NAME_dup(tmpsubject);
720 if (tmpsubject == NULL) {
721 X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
722 ctx->error = X509_V_ERR_OUT_OF_MEM;
727 X509_NAME_delete_entry(tmpsubject, last_object_loc);
729 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry));
731 if (last_object_nid != NID_commonName
732 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) {
733 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
736 X509_NAME_ENTRY_free(tmpentry);
737 X509_NAME_free(tmpsubject);
741 && !verify_cb_cert(ctx, x, i, err))
746 * Check against constraints for all certificates higher in chain
747 * including trust anchor. Trust anchor not strictly speaking needed
748 * but if it includes constraints it is to be assumed it expects them
751 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) {
752 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
755 int rv = NAME_CONSTRAINTS_check(x, nc);
757 /* If EE certificate check commonName too */
758 if (rv == X509_V_OK && i == 0
759 && (ctx->param->hostflags
760 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0
761 && ((ctx->param->hostflags
762 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0
763 || !has_san_id(x, GEN_DNS)))
764 rv = NAME_CONSTRAINTS_check_CN(x, nc);
769 case X509_V_ERR_OUT_OF_MEM:
772 if (!verify_cb_cert(ctx, x, i, rv))
782 static int check_id_error(X509_STORE_CTX *ctx, int errcode)
784 return verify_cb_cert(ctx, ctx->cert, 0, errcode);
787 static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm)
790 int n = sk_OPENSSL_STRING_num(vpm->hosts);
793 if (vpm->peername != NULL) {
794 OPENSSL_free(vpm->peername);
795 vpm->peername = NULL;
797 for (i = 0; i < n; ++i) {
798 name = sk_OPENSSL_STRING_value(vpm->hosts, i);
799 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0)
805 static int check_id(X509_STORE_CTX *ctx)
807 X509_VERIFY_PARAM *vpm = ctx->param;
809 if (vpm->hosts && check_hosts(x, vpm) <= 0) {
810 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
813 if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) {
814 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
817 if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) {
818 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
824 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)
829 SSL_DANE *dane = ctx->dane;
830 int num = sk_X509_num(ctx->chain);
834 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2)
835 * match, we're done, otherwise we'll merely record the match depth.
837 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {
838 switch (trust = check_dane_issuer(ctx, num_untrusted)) {
839 case X509_TRUST_TRUSTED:
840 case X509_TRUST_REJECTED:
846 * Check trusted certificates in chain at depth num_untrusted and up.
847 * Note, that depths 0..num_untrusted-1 may also contain trusted
848 * certificates, but the caller is expected to have already checked those,
849 * and wants to incrementally check just any added since.
851 for (i = num_untrusted; i < num; i++) {
852 x = sk_X509_value(ctx->chain, i);
853 trust = X509_check_trust(x, ctx->param->trust, 0);
854 /* If explicitly trusted return trusted */
855 if (trust == X509_TRUST_TRUSTED)
857 if (trust == X509_TRUST_REJECTED)
862 * If we are looking at a trusted certificate, and accept partial chains,
863 * the chain is PKIX trusted.
865 if (num_untrusted < num) {
866 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
868 return X509_TRUST_UNTRUSTED;
871 if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
873 * Last-resort call with no new trusted certificates, check the leaf
874 * for a direct trust store match.
877 x = sk_X509_value(ctx->chain, i);
878 mx = lookup_cert_match(ctx, x);
880 return X509_TRUST_UNTRUSTED;
883 * Check explicit auxiliary trust/reject settings. If none are set,
884 * we'll accept X509_TRUST_UNTRUSTED when not self-signed.
886 trust = X509_check_trust(mx, ctx->param->trust, 0);
887 if (trust == X509_TRUST_REJECTED) {
892 /* Replace leaf with trusted match */
893 (void) sk_X509_set(ctx->chain, 0, mx);
895 ctx->num_untrusted = 0;
900 * If no trusted certs in chain at all return untrusted and allow
901 * standard (no issuer cert) etc errors to be indicated.
903 return X509_TRUST_UNTRUSTED;
906 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED))
907 return X509_TRUST_REJECTED;
908 return X509_TRUST_UNTRUSTED;
911 if (!DANETLS_ENABLED(dane))
912 return X509_TRUST_TRUSTED;
914 dane->pdpth = num_untrusted;
915 /* With DANE, PKIX alone is not trusted until we have both */
916 if (dane->mdpth >= 0)
917 return X509_TRUST_TRUSTED;
918 return X509_TRUST_UNTRUSTED;
921 static int check_revocation(X509_STORE_CTX *ctx)
923 int i = 0, last = 0, ok = 0;
924 if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
926 if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
927 last = sk_X509_num(ctx->chain) - 1;
929 /* If checking CRL paths this isn't the EE certificate */
934 for (i = 0; i <= last; i++) {
935 ctx->error_depth = i;
936 ok = check_cert(ctx);
943 static int check_cert(X509_STORE_CTX *ctx)
945 X509_CRL *crl = NULL, *dcrl = NULL;
947 int cnum = ctx->error_depth;
948 X509 *x = sk_X509_value(ctx->chain, cnum);
950 ctx->current_cert = x;
951 ctx->current_issuer = NULL;
952 ctx->current_crl_score = 0;
953 ctx->current_reasons = 0;
955 if (x->ex_flags & EXFLAG_PROXY)
958 while (ctx->current_reasons != CRLDP_ALL_REASONS) {
959 unsigned int last_reasons = ctx->current_reasons;
961 /* Try to retrieve relevant CRL */
963 ok = ctx->get_crl(ctx, &crl, x);
965 ok = get_crl_delta(ctx, &crl, &dcrl, x);
967 * If error looking up CRL, nothing we can do except notify callback
970 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
973 ctx->current_crl = crl;
974 ok = ctx->check_crl(ctx, crl);
979 ok = ctx->check_crl(ctx, dcrl);
982 ok = ctx->cert_crl(ctx, dcrl, x);
988 /* Don't look in full CRL if delta reason is removefromCRL */
990 ok = ctx->cert_crl(ctx, crl, x);
1000 * If reasons not updated we won't get anywhere by another iteration,
1003 if (last_reasons == ctx->current_reasons) {
1004 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
1010 X509_CRL_free(dcrl);
1012 ctx->current_crl = NULL;
1016 /* Check CRL times against values in X509_STORE_CTX */
1018 static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
1024 ctx->current_crl = crl;
1025 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1026 ptime = &ctx->param->check_time;
1027 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1032 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime);
1036 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD))
1043 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID))
1047 if (X509_CRL_get0_nextUpdate(crl)) {
1048 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime);
1053 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD))
1056 /* Ignore expiry of base CRL is delta is valid */
1057 if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) {
1060 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED))
1066 ctx->current_crl = NULL;
1071 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
1072 X509 **pissuer, int *pscore, unsigned int *preasons,
1073 STACK_OF(X509_CRL) *crls)
1075 int i, crl_score, best_score = *pscore;
1076 unsigned int reasons, best_reasons = 0;
1077 X509 *x = ctx->current_cert;
1078 X509_CRL *crl, *best_crl = NULL;
1079 X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
1081 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1082 crl = sk_X509_CRL_value(crls, i);
1083 reasons = *preasons;
1084 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
1085 if (crl_score < best_score || crl_score == 0)
1087 /* If current CRL is equivalent use it if it is newer */
1088 if (crl_score == best_score && best_crl != NULL) {
1090 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl),
1091 X509_CRL_get0_lastUpdate(crl)) == 0)
1094 * ASN1_TIME_diff never returns inconsistent signs for |day|
1097 if (day <= 0 && sec <= 0)
1101 best_crl_issuer = crl_issuer;
1102 best_score = crl_score;
1103 best_reasons = reasons;
1107 X509_CRL_free(*pcrl);
1109 *pissuer = best_crl_issuer;
1110 *pscore = best_score;
1111 *preasons = best_reasons;
1112 X509_CRL_up_ref(best_crl);
1113 X509_CRL_free(*pdcrl);
1115 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
1118 if (best_score >= CRL_SCORE_VALID)
1125 * Compare two CRL extensions for delta checking purposes. They should be
1126 * both present or both absent. If both present all fields must be identical.
1129 static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
1131 ASN1_OCTET_STRING *exta, *extb;
1133 i = X509_CRL_get_ext_by_NID(a, nid, -1);
1135 /* Can't have multiple occurrences */
1136 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1)
1138 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
1142 i = X509_CRL_get_ext_by_NID(b, nid, -1);
1146 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1)
1148 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
1158 if (ASN1_OCTET_STRING_cmp(exta, extb))
1164 /* See if a base and delta are compatible */
1166 static int check_delta_base(X509_CRL *delta, X509_CRL *base)
1168 /* Delta CRL must be a delta */
1169 if (!delta->base_crl_number)
1171 /* Base must have a CRL number */
1172 if (!base->crl_number)
1174 /* Issuer names must match */
1175 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta)))
1177 /* AKID and IDP must match */
1178 if (!crl_extension_match(delta, base, NID_authority_key_identifier))
1180 if (!crl_extension_match(delta, base, NID_issuing_distribution_point))
1182 /* Delta CRL base number must not exceed Full CRL number. */
1183 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0)
1185 /* Delta CRL number must exceed full CRL number */
1186 if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0)
1192 * For a given base CRL find a delta... maybe extend to delta scoring or
1193 * retrieve a chain of deltas...
1196 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore,
1197 X509_CRL *base, STACK_OF(X509_CRL) *crls)
1201 if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS))
1203 if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST))
1205 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1206 delta = sk_X509_CRL_value(crls, i);
1207 if (check_delta_base(delta, base)) {
1208 if (check_crl_time(ctx, delta, 0))
1209 *pscore |= CRL_SCORE_TIME_DELTA;
1210 X509_CRL_up_ref(delta);
1219 * For a given CRL return how suitable it is for the supplied certificate
1220 * 'x'. The return value is a mask of several criteria. If the issuer is not
1221 * the certificate issuer this is returned in *pissuer. The reasons mask is
1222 * also used to determine if the CRL is suitable: if no new reasons the CRL
1223 * is rejected, otherwise reasons is updated.
1226 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
1227 unsigned int *preasons, X509_CRL *crl, X509 *x)
1231 unsigned int tmp_reasons = *preasons, crl_reasons;
1233 /* First see if we can reject CRL straight away */
1235 /* Invalid IDP cannot be processed */
1236 if (crl->idp_flags & IDP_INVALID)
1238 /* Reason codes or indirect CRLs need extended CRL support */
1239 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
1240 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS))
1242 } else if (crl->idp_flags & IDP_REASONS) {
1243 /* If no new reasons reject */
1244 if (!(crl->idp_reasons & ~tmp_reasons))
1247 /* Don't process deltas at this stage */
1248 else if (crl->base_crl_number)
1250 /* If issuer name doesn't match certificate need indirect CRL */
1251 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) {
1252 if (!(crl->idp_flags & IDP_INDIRECT))
1255 crl_score |= CRL_SCORE_ISSUER_NAME;
1257 if (!(crl->flags & EXFLAG_CRITICAL))
1258 crl_score |= CRL_SCORE_NOCRITICAL;
1261 if (check_crl_time(ctx, crl, 0))
1262 crl_score |= CRL_SCORE_TIME;
1264 /* Check authority key ID and locate certificate issuer */
1265 crl_akid_check(ctx, crl, pissuer, &crl_score);
1267 /* If we can't locate certificate issuer at this point forget it */
1269 if (!(crl_score & CRL_SCORE_AKID))
1272 /* Check cert for matching CRL distribution points */
1274 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) {
1275 /* If no new reasons reject */
1276 if (!(crl_reasons & ~tmp_reasons))
1278 tmp_reasons |= crl_reasons;
1279 crl_score |= CRL_SCORE_SCOPE;
1282 *preasons = tmp_reasons;
1288 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl,
1289 X509 **pissuer, int *pcrl_score)
1291 X509 *crl_issuer = NULL;
1292 const X509_NAME *cnm = X509_CRL_get_issuer(crl);
1293 int cidx = ctx->error_depth;
1296 if (cidx != sk_X509_num(ctx->chain) - 1)
1299 crl_issuer = sk_X509_value(ctx->chain, cidx);
1301 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1302 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) {
1303 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT;
1304 *pissuer = crl_issuer;
1309 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) {
1310 crl_issuer = sk_X509_value(ctx->chain, cidx);
1311 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1313 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1314 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH;
1315 *pissuer = crl_issuer;
1320 /* Anything else needs extended CRL support */
1322 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
1326 * Otherwise the CRL issuer is not on the path. Look for it in the set of
1327 * untrusted certificates.
1329 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) {
1330 crl_issuer = sk_X509_value(ctx->untrusted, i);
1331 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1333 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1334 *pissuer = crl_issuer;
1335 *pcrl_score |= CRL_SCORE_AKID;
1342 * Check the path of a CRL issuer certificate. This creates a new
1343 * X509_STORE_CTX and populates it with most of the parameters from the
1344 * parent. This could be optimised somewhat since a lot of path checking will
1345 * be duplicated by the parent, but this will rarely be used in practice.
1348 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x)
1350 X509_STORE_CTX crl_ctx;
1353 /* Don't allow recursive CRL path validation */
1356 if (!X509_STORE_CTX_init(&crl_ctx, ctx->store, x, ctx->untrusted))
1359 crl_ctx.crls = ctx->crls;
1360 /* Copy verify params across */
1361 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
1363 crl_ctx.parent = ctx;
1364 crl_ctx.verify_cb = ctx->verify_cb;
1366 /* Verify CRL issuer */
1367 ret = X509_verify_cert(&crl_ctx);
1371 /* Check chain is acceptable */
1372 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
1374 X509_STORE_CTX_cleanup(&crl_ctx);
1379 * RFC3280 says nothing about the relationship between CRL path and
1380 * certificate path, which could lead to situations where a certificate could
1381 * be revoked or validated by a CA not authorised to do so. RFC5280 is more
1382 * strict and states that the two paths must end in the same trust anchor,
1383 * though some discussions remain... until this is resolved we use the
1387 static int check_crl_chain(X509_STORE_CTX *ctx,
1388 STACK_OF(X509) *cert_path,
1389 STACK_OF(X509) *crl_path)
1391 X509 *cert_ta, *crl_ta;
1392 cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
1393 crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
1394 if (!X509_cmp(cert_ta, crl_ta))
1400 * Check for match between two dist point names: three separate cases.
1401 * 1. Both are relative names and compare X509_NAME types.
1402 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
1403 * 3. Both are full names and compare two GENERAL_NAMES.
1404 * 4. One is NULL: automatic match.
1407 static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
1409 X509_NAME *nm = NULL;
1410 GENERAL_NAMES *gens = NULL;
1411 GENERAL_NAME *gena, *genb;
1418 /* Case 1: two X509_NAME */
1422 if (!X509_NAME_cmp(a->dpname, b->dpname))
1427 /* Case 2: set name and GENERAL_NAMES appropriately */
1429 gens = b->name.fullname;
1430 } else if (b->type == 1) {
1433 /* Case 2: set name and GENERAL_NAMES appropriately */
1434 gens = a->name.fullname;
1438 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */
1440 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1441 gena = sk_GENERAL_NAME_value(gens, i);
1442 if (gena->type != GEN_DIRNAME)
1444 if (!X509_NAME_cmp(nm, gena->d.directoryName))
1450 /* Else case 3: two GENERAL_NAMES */
1452 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) {
1453 gena = sk_GENERAL_NAME_value(a->name.fullname, i);
1454 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) {
1455 genb = sk_GENERAL_NAME_value(b->name.fullname, j);
1456 if (!GENERAL_NAME_cmp(gena, genb))
1465 static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score)
1468 const X509_NAME *nm = X509_CRL_get_issuer(crl);
1469 /* If no CRLissuer return is successful iff don't need a match */
1471 return ! !(crl_score & CRL_SCORE_ISSUER_NAME);
1472 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
1473 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
1474 if (gen->type != GEN_DIRNAME)
1476 if (!X509_NAME_cmp(gen->d.directoryName, nm))
1482 /* Check CRLDP and IDP */
1484 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
1485 unsigned int *preasons)
1488 if (crl->idp_flags & IDP_ONLYATTR)
1490 if (x->ex_flags & EXFLAG_CA) {
1491 if (crl->idp_flags & IDP_ONLYUSER)
1494 if (crl->idp_flags & IDP_ONLYCA)
1497 *preasons = crl->idp_reasons;
1498 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
1499 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
1500 if (crldp_check_crlissuer(dp, crl, crl_score)) {
1501 if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) {
1502 *preasons &= dp->dp_reasons;
1507 if ((!crl->idp || !crl->idp->distpoint)
1508 && (crl_score & CRL_SCORE_ISSUER_NAME))
1514 * Retrieve CRL corresponding to current certificate. If deltas enabled try
1515 * to find a delta CRL too
1518 static int get_crl_delta(X509_STORE_CTX *ctx,
1519 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x)
1522 X509 *issuer = NULL;
1524 unsigned int reasons;
1525 X509_CRL *crl = NULL, *dcrl = NULL;
1526 STACK_OF(X509_CRL) *skcrl;
1527 const X509_NAME *nm = X509_get_issuer_name(x);
1529 reasons = ctx->current_reasons;
1530 ok = get_crl_sk(ctx, &crl, &dcrl,
1531 &issuer, &crl_score, &reasons, ctx->crls);
1535 /* Lookup CRLs from store */
1537 skcrl = ctx->lookup_crls(ctx, nm);
1539 /* If no CRLs found and a near match from get_crl_sk use that */
1543 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
1545 sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
1548 /* If we got any kind of CRL use it and return success */
1550 ctx->current_issuer = issuer;
1551 ctx->current_crl_score = crl_score;
1552 ctx->current_reasons = reasons;
1560 /* Check CRL validity */
1561 static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
1563 X509 *issuer = NULL;
1564 EVP_PKEY *ikey = NULL;
1565 int cnum = ctx->error_depth;
1566 int chnum = sk_X509_num(ctx->chain) - 1;
1568 /* If we have an alternative CRL issuer cert use that */
1569 if (ctx->current_issuer)
1570 issuer = ctx->current_issuer;
1572 * Else find CRL issuer: if not last certificate then issuer is next
1573 * certificate in chain.
1575 else if (cnum < chnum)
1576 issuer = sk_X509_value(ctx->chain, cnum + 1);
1578 issuer = sk_X509_value(ctx->chain, chnum);
1579 /* If not self-issued, can't check signature */
1580 if (!ctx->check_issued(ctx, issuer, issuer) &&
1581 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER))
1589 * Skip most tests for deltas because they have already been done
1591 if (!crl->base_crl_number) {
1592 /* Check for cRLSign bit if keyUsage present */
1593 if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
1594 !(issuer->ex_kusage & KU_CRL_SIGN) &&
1595 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN))
1598 if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) &&
1599 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE))
1602 if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) &&
1603 check_crl_path(ctx, ctx->current_issuer) <= 0 &&
1604 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR))
1607 if ((crl->idp_flags & IDP_INVALID) &&
1608 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION))
1612 if (!(ctx->current_crl_score & CRL_SCORE_TIME) &&
1613 !check_crl_time(ctx, crl, 1))
1616 /* Attempt to get issuer certificate public key */
1617 ikey = X509_get0_pubkey(issuer);
1620 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
1624 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags);
1626 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv))
1628 /* Verify CRL signature */
1629 if (X509_CRL_verify(crl, ikey) <= 0 &&
1630 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE))
1636 /* Check certificate against CRL */
1637 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
1642 * The rules changed for this... previously if a CRL contained unhandled
1643 * critical extensions it could still be used to indicate a certificate
1644 * was revoked. This has since been changed since critical extensions can
1645 * change the meaning of CRL entries.
1647 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
1648 && (crl->flags & EXFLAG_CRITICAL) &&
1649 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION))
1652 * Look for serial number of certificate in CRL. If found, make sure
1653 * reason is not removeFromCRL.
1655 if (X509_CRL_get0_by_cert(crl, &rev, x)) {
1656 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
1658 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED))
1665 static int check_policy(X509_STORE_CTX *ctx)
1672 * With DANE, the trust anchor might be a bare public key, not a
1673 * certificate! In that case our chain does not have the trust anchor
1674 * certificate as a top-most element. This comports well with RFC5280
1675 * chain verification, since there too, the trust anchor is not part of the
1676 * chain to be verified. In particular, X509_policy_check() does not look
1677 * at the TA cert, but assumes that it is present as the top-most chain
1678 * element. We therefore temporarily push a NULL cert onto the chain if it
1679 * was verified via a bare public key, and pop it off right after the
1680 * X509_policy_check() call.
1682 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) {
1683 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
1684 ctx->error = X509_V_ERR_OUT_OF_MEM;
1687 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
1688 ctx->param->policies, ctx->param->flags);
1689 if (ctx->bare_ta_signed)
1690 sk_X509_pop(ctx->chain);
1692 if (ret == X509_PCY_TREE_INTERNAL) {
1693 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE);
1694 ctx->error = X509_V_ERR_OUT_OF_MEM;
1697 /* Invalid or inconsistent extensions */
1698 if (ret == X509_PCY_TREE_INVALID) {
1701 /* Locate certificates with bad extensions and notify callback. */
1702 for (i = 1; i < sk_X509_num(ctx->chain); i++) {
1703 X509 *x = sk_X509_value(ctx->chain, i);
1705 if (!(x->ex_flags & EXFLAG_INVALID_POLICY))
1707 if (!verify_cb_cert(ctx, x, i,
1708 X509_V_ERR_INVALID_POLICY_EXTENSION))
1713 if (ret == X509_PCY_TREE_FAILURE) {
1714 ctx->current_cert = NULL;
1715 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
1716 return ctx->verify_cb(0, ctx);
1718 if (ret != X509_PCY_TREE_VALID) {
1719 X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR);
1723 if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) {
1724 ctx->current_cert = NULL;
1726 * Verification errors need to be "sticky", a callback may have allowed
1727 * an SSL handshake to continue despite an error, and we must then
1728 * remain in an error state. Therefore, we MUST NOT clear earlier
1729 * verification errors by setting the error to X509_V_OK.
1731 if (!ctx->verify_cb(2, ctx))
1739 * Check certificate validity times.
1740 * If depth >= 0, invoke verification callbacks on error, otherwise just return
1741 * the validation status.
1743 * Return 1 on success, 0 otherwise.
1745 int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth)
1750 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1751 ptime = &ctx->param->check_time;
1752 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1757 i = X509_cmp_time(X509_get0_notBefore(x), ptime);
1758 if (i >= 0 && depth < 0)
1760 if (i == 0 && !verify_cb_cert(ctx, x, depth,
1761 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD))
1763 if (i > 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID))
1766 i = X509_cmp_time(X509_get0_notAfter(x), ptime);
1767 if (i <= 0 && depth < 0)
1769 if (i == 0 && !verify_cb_cert(ctx, x, depth,
1770 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD))
1772 if (i < 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED))
1777 /* verify the issuer signatures and cert times of ctx->chain */
1778 static int internal_verify(X509_STORE_CTX *ctx)
1780 int n = sk_X509_num(ctx->chain) - 1;
1781 X509 *xi = sk_X509_value(ctx->chain, n);
1785 * With DANE-verified bare public key TA signatures, it remains only to
1786 * check the timestamps of the top certificate. We report the issuer as
1787 * NULL, since all we have is a bare key.
1789 if (ctx->bare_ta_signed) {
1792 goto check_cert_time;
1795 if (ctx->check_issued(ctx, xi, xi))
1796 xs = xi; /* the typical case: last cert in the chain is self-issued */
1798 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
1800 goto check_cert_time;
1803 return verify_cb_cert(ctx, xi, 0,
1804 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE);
1806 ctx->error_depth = n;
1807 xs = sk_X509_value(ctx->chain, n);
1811 * Do not clear ctx->error=0, it must be "sticky", only the user's callback
1812 * is allowed to reset errors (at its own peril).
1816 * For each iteration of this loop:
1817 * n is the subject depth
1818 * xs is the subject cert, for which the signature is to be checked
1819 * xi is the supposed issuer cert containing the public key to use
1820 * Initially xs == xi if the last cert in the chain is self-issued.
1822 * Skip signature check for self-signed certificates unless explicitly
1823 * asked for because it does not add any security and just wastes time.
1825 if (xs != xi || ((ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)
1826 && (xi->ex_flags & EXFLAG_SS) != 0)) {
1829 * If the issuer's public key is not available or its key usage
1830 * does not support issuing the subject cert, report the issuer
1831 * cert and its depth (rather than n, the depth of the subject).
1833 int issuer_depth = n + (xs == xi ? 0 : 1);
1835 * According to https://tools.ietf.org/html/rfc5280#section-6.1.4
1836 * step (n) we must check any given key usage extension in a CA cert
1837 * when preparing the verification of a certificate issued by it.
1838 * According to https://tools.ietf.org/html/rfc5280#section-4.2.1.3
1839 * we must not verify a certifiate signature if the key usage of the
1840 * CA certificate that issued the certificate prohibits signing.
1841 * In case the 'issuing' certificate is the last in the chain and is
1842 * not a CA certificate but a 'self-issued' end-entity cert (i.e.,
1843 * xs == xi && !(xi->ex_flags & EXFLAG_CA)) RFC 5280 does not apply
1844 * (see https://tools.ietf.org/html/rfc6818#section-2) and thus
1845 * we are free to ignore any key usage restrictions on such certs.
1847 int ret = xs == xi && (xi->ex_flags & EXFLAG_CA) == 0
1848 ? X509_V_OK : x509_signing_allowed(xi, xs);
1850 if (ret != X509_V_OK && !verify_cb_cert(ctx, xi, issuer_depth, ret))
1852 if ((pkey = X509_get0_pubkey(xi)) == NULL) {
1853 ret = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
1854 if (!verify_cb_cert(ctx, xi, issuer_depth, ret))
1856 } else if (X509_verify(xs, pkey) <= 0) {
1857 ret = X509_V_ERR_CERT_SIGNATURE_FAILURE;
1858 if (!verify_cb_cert(ctx, xs, n, ret))
1864 /* Calls verify callback as needed */
1865 if (!x509_check_cert_time(ctx, xs, n))
1869 * Signal success at this depth. However, the previous error (if any)
1872 ctx->current_issuer = xi;
1873 ctx->current_cert = xs;
1874 ctx->error_depth = n;
1875 if (!ctx->verify_cb(1, ctx))
1880 xs = sk_X509_value(ctx->chain, n);
1886 int X509_cmp_current_time(const ASN1_TIME *ctm)
1888 return X509_cmp_time(ctm, NULL);
1891 int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time)
1893 static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1;
1894 static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1;
1895 ASN1_TIME *asn1_cmp_time = NULL;
1896 int i, day, sec, ret = 0;
1897 #ifdef CHARSET_EBCDIC
1898 const char upper_z = 0x5A;
1900 const char upper_z = 'Z';
1903 * Note that ASN.1 allows much more slack in the time format than RFC5280.
1904 * In RFC5280, the representation is fixed:
1905 * UTCTime: YYMMDDHHMMSSZ
1906 * GeneralizedTime: YYYYMMDDHHMMSSZ
1908 * We do NOT currently enforce the following RFC 5280 requirement:
1909 * "CAs conforming to this profile MUST always encode certificate
1910 * validity dates through the year 2049 as UTCTime; certificate validity
1911 * dates in 2050 or later MUST be encoded as GeneralizedTime."
1913 switch (ctm->type) {
1914 case V_ASN1_UTCTIME:
1915 if (ctm->length != (int)(utctime_length))
1918 case V_ASN1_GENERALIZEDTIME:
1919 if (ctm->length != (int)(generalizedtime_length))
1927 * Verify the format: the ASN.1 functions we use below allow a more
1928 * flexible format than what's mandated by RFC 5280.
1929 * Digit and date ranges will be verified in the conversion methods.
1931 for (i = 0; i < ctm->length - 1; i++) {
1932 if (!ascii_isdigit(ctm->data[i]))
1935 if (ctm->data[ctm->length - 1] != upper_z)
1939 * There is ASN1_UTCTIME_cmp_time_t but no
1940 * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t,
1941 * so we go through ASN.1
1943 asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time);
1944 if (asn1_cmp_time == NULL)
1946 if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time))
1950 * X509_cmp_time comparison is <=.
1951 * The return value 0 is reserved for errors.
1953 ret = (day >= 0 && sec >= 0) ? -1 : 1;
1956 ASN1_TIME_free(asn1_cmp_time);
1961 * Return 0 if time should not be checked or reference time is in range,
1962 * or else 1 if it is past the end, or -1 if it is before the start
1964 int X509_cmp_timeframe(const X509_VERIFY_PARAM *vpm,
1965 const ASN1_TIME *start, const ASN1_TIME *end)
1968 time_t *time = NULL;
1969 unsigned long flags = vpm == NULL ? 0 : X509_VERIFY_PARAM_get_flags(vpm);
1971 if ((flags & X509_V_FLAG_USE_CHECK_TIME) != 0) {
1972 ref_time = X509_VERIFY_PARAM_get_time(vpm);
1974 } else if ((flags & X509_V_FLAG_NO_CHECK_TIME) != 0) {
1975 return 0; /* this means ok */
1976 } /* else reference time is the current time */
1978 if (end != NULL && X509_cmp_time(end, time) < 0)
1980 if (start != NULL && X509_cmp_time(start, time) > 0)
1985 ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj)
1987 return X509_time_adj(s, adj, NULL);
1990 ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm)
1992 return X509_time_adj_ex(s, 0, offset_sec, in_tm);
1995 ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s,
1996 int offset_day, long offset_sec, time_t *in_tm)
2005 if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) {
2006 if (s->type == V_ASN1_UTCTIME)
2007 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec);
2008 if (s->type == V_ASN1_GENERALIZEDTIME)
2009 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec);
2011 return ASN1_TIME_adj(s, t, offset_day, offset_sec);
2014 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
2016 EVP_PKEY *ktmp = NULL, *ktmp2;
2019 if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey))
2022 for (i = 0; i < sk_X509_num(chain); i++) {
2023 ktmp = X509_get0_pubkey(sk_X509_value(chain, i));
2025 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
2026 X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
2029 if (!EVP_PKEY_missing_parameters(ktmp))
2033 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
2034 X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
2038 /* first, populate the other certs */
2039 for (j = i - 1; j >= 0; j--) {
2040 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j));
2041 EVP_PKEY_copy_parameters(ktmp2, ktmp);
2045 EVP_PKEY_copy_parameters(pkey, ktmp);
2049 /* Make a delta CRL as the diff between two full CRLs */
2051 X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer,
2052 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags)
2054 X509_CRL *crl = NULL;
2056 STACK_OF(X509_REVOKED) *revs = NULL;
2057 /* CRLs can't be delta already */
2058 if (base->base_crl_number || newer->base_crl_number) {
2059 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA);
2062 /* Base and new CRL must have a CRL number */
2063 if (!base->crl_number || !newer->crl_number) {
2064 X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER);
2067 /* Issuer names must match */
2068 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) {
2069 X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH);
2072 /* AKID and IDP must match */
2073 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) {
2074 X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH);
2077 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) {
2078 X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH);
2081 /* Newer CRL number must exceed full CRL number */
2082 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) {
2083 X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER);
2086 /* CRLs must verify */
2087 if (skey && (X509_CRL_verify(base, skey) <= 0 ||
2088 X509_CRL_verify(newer, skey) <= 0)) {
2089 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE);
2092 /* Create new CRL */
2093 crl = X509_CRL_new();
2094 if (crl == NULL || !X509_CRL_set_version(crl, 1))
2096 /* Set issuer name */
2097 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer)))
2100 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer)))
2102 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer)))
2105 /* Set base CRL number: must be critical */
2107 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0))
2111 * Copy extensions across from newest CRL to delta: this will set CRL
2112 * number to correct value too.
2115 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) {
2116 X509_EXTENSION *ext;
2117 ext = X509_CRL_get_ext(newer, i);
2118 if (!X509_CRL_add_ext(crl, ext, -1))
2122 /* Go through revoked entries, copying as needed */
2124 revs = X509_CRL_get_REVOKED(newer);
2126 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) {
2127 X509_REVOKED *rvn, *rvtmp;
2128 rvn = sk_X509_REVOKED_value(revs, i);
2130 * Add only if not also in base. TODO: need something cleverer here
2131 * for some more complex CRLs covering multiple CAs.
2133 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) {
2134 rvtmp = X509_REVOKED_dup(rvn);
2137 if (!X509_CRL_add0_revoked(crl, rvtmp)) {
2138 X509_REVOKED_free(rvtmp);
2143 /* TODO: optionally prune deleted entries */
2145 if (skey && md && !X509_CRL_sign(crl, skey, md))
2151 X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE);
2156 int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
2158 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data);
2161 void *X509_STORE_CTX_get_ex_data(const X509_STORE_CTX *ctx, int idx)
2163 return CRYPTO_get_ex_data(&ctx->ex_data, idx);
2166 int X509_STORE_CTX_get_error(const X509_STORE_CTX *ctx)
2171 void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
2176 int X509_STORE_CTX_get_error_depth(const X509_STORE_CTX *ctx)
2178 return ctx->error_depth;
2181 void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth)
2183 ctx->error_depth = depth;
2186 X509 *X509_STORE_CTX_get_current_cert(const X509_STORE_CTX *ctx)
2188 return ctx->current_cert;
2191 void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x)
2193 ctx->current_cert = x;
2196 STACK_OF(X509) *X509_STORE_CTX_get0_chain(const X509_STORE_CTX *ctx)
2201 STACK_OF(X509) *X509_STORE_CTX_get1_chain(const X509_STORE_CTX *ctx)
2205 return X509_chain_up_ref(ctx->chain);
2208 X509 *X509_STORE_CTX_get0_current_issuer(const X509_STORE_CTX *ctx)
2210 return ctx->current_issuer;
2213 X509_CRL *X509_STORE_CTX_get0_current_crl(const X509_STORE_CTX *ctx)
2215 return ctx->current_crl;
2218 X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(const X509_STORE_CTX *ctx)
2223 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
2228 void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
2233 int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
2236 * XXX: Why isn't this function always used to set the associated trust?
2237 * Should there even be a VPM->trust field at all? Or should the trust
2238 * always be inferred from the purpose by X509_STORE_CTX_init().
2240 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
2243 int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
2246 * XXX: See above, this function would only be needed when the default
2247 * trust for the purpose needs an override in a corner case.
2249 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
2253 * This function is used to set the X509_STORE_CTX purpose and trust values.
2254 * This is intended to be used when another structure has its own trust and
2255 * purpose values which (if set) will be inherited by the ctx. If they aren't
2256 * set then we will usually have a default purpose in mind which should then
2257 * be used to set the trust value. An example of this is SSL use: an SSL
2258 * structure will have its own purpose and trust settings which the
2259 * application can set: if they aren't set then we use the default of SSL
2263 int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
2264 int purpose, int trust)
2267 /* If purpose not set use default */
2269 purpose = def_purpose;
2270 /* If we have a purpose then check it is valid */
2273 idx = X509_PURPOSE_get_by_id(purpose);
2275 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2276 X509_R_UNKNOWN_PURPOSE_ID);
2279 ptmp = X509_PURPOSE_get0(idx);
2280 if (ptmp->trust == X509_TRUST_DEFAULT) {
2281 idx = X509_PURPOSE_get_by_id(def_purpose);
2283 * XXX: In the two callers above def_purpose is always 0, which is
2284 * not a known value, so idx will always be -1. How is the
2285 * X509_TRUST_DEFAULT case actually supposed to be handled?
2288 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2289 X509_R_UNKNOWN_PURPOSE_ID);
2292 ptmp = X509_PURPOSE_get0(idx);
2294 /* If trust not set then get from purpose default */
2296 trust = ptmp->trust;
2299 idx = X509_TRUST_get_by_id(trust);
2301 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT,
2302 X509_R_UNKNOWN_TRUST_ID);
2307 if (purpose && !ctx->param->purpose)
2308 ctx->param->purpose = purpose;
2309 if (trust && !ctx->param->trust)
2310 ctx->param->trust = trust;
2314 X509_STORE_CTX *X509_STORE_CTX_new_with_libctx(OPENSSL_CTX *libctx,
2317 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
2320 X509err(0, ERR_R_MALLOC_FAILURE);
2324 ctx->libctx = libctx;
2325 if (propq != NULL) {
2326 ctx->propq = OPENSSL_strdup(propq);
2327 if (ctx->propq == NULL) {
2329 X509err(0, ERR_R_MALLOC_FAILURE);
2337 X509_STORE_CTX *X509_STORE_CTX_new(void)
2339 return X509_STORE_CTX_new_with_libctx(NULL, NULL);
2343 void X509_STORE_CTX_free(X509_STORE_CTX *ctx)
2348 X509_STORE_CTX_cleanup(ctx);
2350 /* libctx and propq survive X509_STORE_CTX_cleanup() */
2351 OPENSSL_free(ctx->propq);
2356 int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
2357 STACK_OF(X509) *chain)
2363 ctx->untrusted = chain;
2365 ctx->num_untrusted = 0;
2366 ctx->other_ctx = NULL;
2370 ctx->explicit_policy = 0;
2371 ctx->error_depth = 0;
2372 ctx->current_cert = NULL;
2373 ctx->current_issuer = NULL;
2374 ctx->current_crl = NULL;
2375 ctx->current_crl_score = 0;
2376 ctx->current_reasons = 0;
2380 ctx->bare_ta_signed = 0;
2381 /* Zero ex_data to make sure we're cleanup-safe */
2382 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2384 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */
2386 ctx->cleanup = store->cleanup;
2390 if (store && store->check_issued)
2391 ctx->check_issued = store->check_issued;
2393 ctx->check_issued = check_issued;
2395 if (store && store->get_issuer)
2396 ctx->get_issuer = store->get_issuer;
2398 ctx->get_issuer = X509_STORE_CTX_get1_issuer;
2400 if (store && store->verify_cb)
2401 ctx->verify_cb = store->verify_cb;
2403 ctx->verify_cb = null_callback;
2405 if (store && store->verify)
2406 ctx->verify = store->verify;
2408 ctx->verify = internal_verify;
2410 if (store && store->check_revocation)
2411 ctx->check_revocation = store->check_revocation;
2413 ctx->check_revocation = check_revocation;
2415 if (store && store->get_crl)
2416 ctx->get_crl = store->get_crl;
2418 ctx->get_crl = NULL;
2420 if (store && store->check_crl)
2421 ctx->check_crl = store->check_crl;
2423 ctx->check_crl = check_crl;
2425 if (store && store->cert_crl)
2426 ctx->cert_crl = store->cert_crl;
2428 ctx->cert_crl = cert_crl;
2430 if (store && store->check_policy)
2431 ctx->check_policy = store->check_policy;
2433 ctx->check_policy = check_policy;
2435 if (store && store->lookup_certs)
2436 ctx->lookup_certs = store->lookup_certs;
2438 ctx->lookup_certs = X509_STORE_CTX_get1_certs;
2440 if (store && store->lookup_crls)
2441 ctx->lookup_crls = store->lookup_crls;
2443 ctx->lookup_crls = X509_STORE_CTX_get1_crls;
2445 ctx->param = X509_VERIFY_PARAM_new();
2446 if (ctx->param == NULL) {
2447 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2452 * Inherit callbacks and flags from X509_STORE if not set use defaults.
2455 ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
2457 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE;
2460 ret = X509_VERIFY_PARAM_inherit(ctx->param,
2461 X509_VERIFY_PARAM_lookup("default"));
2464 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2469 * XXX: For now, continue to inherit trust from VPM, but infer from the
2470 * purpose if this still yields the default value.
2472 if (ctx->param->trust == X509_TRUST_DEFAULT) {
2473 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose);
2474 X509_PURPOSE *xp = X509_PURPOSE_get0(idx);
2477 ctx->param->trust = X509_PURPOSE_get_trust(xp);
2480 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
2483 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
2487 * On error clean up allocated storage, if the store context was not
2488 * allocated with X509_STORE_CTX_new() this is our last chance to do so.
2490 X509_STORE_CTX_cleanup(ctx);
2495 * Set alternative lookup method: just a STACK of trusted certificates. This
2496 * avoids X509_STORE nastiness where it isn't needed.
2498 void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2500 ctx->other_ctx = sk;
2501 ctx->get_issuer = get_issuer_sk;
2502 ctx->lookup_certs = lookup_certs_sk;
2505 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
2508 * We need to be idempotent because, unfortunately, free() also calls
2509 * cleanup(), so the natural call sequence new(), init(), cleanup(), free()
2510 * calls cleanup() for the same object twice! Thus we must zero the
2511 * pointers below after they're freed!
2513 /* Seems to always be 0 in OpenSSL, do this at most once. */
2514 if (ctx->cleanup != NULL) {
2516 ctx->cleanup = NULL;
2518 if (ctx->param != NULL) {
2519 if (ctx->parent == NULL)
2520 X509_VERIFY_PARAM_free(ctx->param);
2523 X509_policy_tree_free(ctx->tree);
2525 sk_X509_pop_free(ctx->chain, X509_free);
2527 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
2528 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2531 void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
2533 X509_VERIFY_PARAM_set_depth(ctx->param, depth);
2536 void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
2538 X509_VERIFY_PARAM_set_flags(ctx->param, flags);
2541 void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags,
2544 X509_VERIFY_PARAM_set_time(ctx->param, t);
2547 X509 *X509_STORE_CTX_get0_cert(const X509_STORE_CTX *ctx)
2552 STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(const X509_STORE_CTX *ctx)
2554 return ctx->untrusted;
2557 void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2559 ctx->untrusted = sk;
2562 void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2564 sk_X509_pop_free(ctx->chain, X509_free);
2568 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
2569 X509_STORE_CTX_verify_cb verify_cb)
2571 ctx->verify_cb = verify_cb;
2574 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(const X509_STORE_CTX *ctx)
2576 return ctx->verify_cb;
2579 void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx,
2580 X509_STORE_CTX_verify_fn verify)
2582 ctx->verify = verify;
2585 X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(const X509_STORE_CTX *ctx)
2590 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(const X509_STORE_CTX *ctx)
2592 return ctx->get_issuer;
2595 X509_STORE_CTX_check_issued_fn
2596 X509_STORE_CTX_get_check_issued(const X509_STORE_CTX *ctx)
2598 return ctx->check_issued;
2601 X509_STORE_CTX_check_revocation_fn
2602 X509_STORE_CTX_get_check_revocation(const X509_STORE_CTX *ctx)
2604 return ctx->check_revocation;
2607 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(const X509_STORE_CTX *ctx)
2609 return ctx->get_crl;
2612 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(const X509_STORE_CTX *ctx)
2614 return ctx->check_crl;
2617 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(const X509_STORE_CTX *ctx)
2619 return ctx->cert_crl;
2622 X509_STORE_CTX_check_policy_fn
2623 X509_STORE_CTX_get_check_policy(const X509_STORE_CTX *ctx)
2625 return ctx->check_policy;
2628 X509_STORE_CTX_lookup_certs_fn
2629 X509_STORE_CTX_get_lookup_certs(const X509_STORE_CTX *ctx)
2631 return ctx->lookup_certs;
2634 X509_STORE_CTX_lookup_crls_fn
2635 X509_STORE_CTX_get_lookup_crls(const X509_STORE_CTX *ctx)
2637 return ctx->lookup_crls;
2640 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(const X509_STORE_CTX *ctx)
2642 return ctx->cleanup;
2645 X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(const X509_STORE_CTX *ctx)
2650 int X509_STORE_CTX_get_explicit_policy(const X509_STORE_CTX *ctx)
2652 return ctx->explicit_policy;
2655 int X509_STORE_CTX_get_num_untrusted(const X509_STORE_CTX *ctx)
2657 return ctx->num_untrusted;
2660 int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
2662 const X509_VERIFY_PARAM *param;
2664 param = X509_VERIFY_PARAM_lookup(name);
2667 return X509_VERIFY_PARAM_inherit(ctx->param, param);
2670 X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(const X509_STORE_CTX *ctx)
2675 void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
2677 X509_VERIFY_PARAM_free(ctx->param);
2681 void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane)
2686 static unsigned char *dane_i2d(
2689 unsigned int *i2dlen)
2691 unsigned char *buf = NULL;
2695 * Extract ASN.1 DER form of certificate or public key.
2698 case DANETLS_SELECTOR_CERT:
2699 len = i2d_X509(cert, &buf);
2701 case DANETLS_SELECTOR_SPKI:
2702 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf);
2705 X509err(X509_F_DANE_I2D, X509_R_BAD_SELECTOR);
2709 if (len < 0 || buf == NULL) {
2710 X509err(X509_F_DANE_I2D, ERR_R_MALLOC_FAILURE);
2714 *i2dlen = (unsigned int)len;
2718 #define DANETLS_NONE 256 /* impossible uint8_t */
2720 static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth)
2722 SSL_DANE *dane = ctx->dane;
2723 unsigned usage = DANETLS_NONE;
2724 unsigned selector = DANETLS_NONE;
2725 unsigned ordinal = DANETLS_NONE;
2726 unsigned mtype = DANETLS_NONE;
2727 unsigned char *i2dbuf = NULL;
2728 unsigned int i2dlen = 0;
2729 unsigned char mdbuf[EVP_MAX_MD_SIZE];
2730 unsigned char *cmpbuf = NULL;
2731 unsigned int cmplen = 0;
2735 danetls_record *t = NULL;
2738 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK;
2741 * The trust store is not applicable with DANE-TA(2)
2743 if (depth >= ctx->num_untrusted)
2744 mask &= DANETLS_PKIX_MASK;
2747 * If we've previously matched a PKIX-?? record, no need to test any
2748 * further PKIX-?? records, it remains to just build the PKIX chain.
2749 * Had the match been a DANE-?? record, we'd be done already.
2751 if (dane->mdpth >= 0)
2752 mask &= ~DANETLS_PKIX_MASK;
2755 * https://tools.ietf.org/html/rfc7671#section-5.1
2756 * https://tools.ietf.org/html/rfc7671#section-5.2
2757 * https://tools.ietf.org/html/rfc7671#section-5.3
2758 * https://tools.ietf.org/html/rfc7671#section-5.4
2760 * We handle DANE-EE(3) records first as they require no chain building
2761 * and no expiration or hostname checks. We also process digests with
2762 * higher ordinals first and ignore lower priorities except Full(0) which
2763 * is always processed (last). If none match, we then process PKIX-EE(1).
2765 * NOTE: This relies on DANE usages sorting before the corresponding PKIX
2766 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest
2767 * priorities. See twin comment in ssl/ssl_lib.c.
2769 * We expect that most TLSA RRsets will have just a single usage, so we
2770 * don't go out of our way to cache multiple selector-specific i2d buffers
2771 * across usages, but if the selector happens to remain the same as switch
2772 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1",
2773 * records would result in us generating each of the certificate and public
2774 * key DER forms twice, but more typically we'd just see multiple "3 1 1"
2775 * or multiple "3 0 1" records.
2777 * As soon as we find a match at any given depth, we stop, because either
2778 * we've matched a DANE-?? record and the peer is authenticated, or, after
2779 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is
2780 * sufficient for DANE, and what remains to do is ordinary PKIX validation.
2782 recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0;
2783 for (i = 0; matched == 0 && i < recnum; ++i) {
2784 t = sk_danetls_record_value(dane->trecs, i);
2785 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0)
2787 if (t->usage != usage) {
2790 /* Reset digest agility for each usage/selector pair */
2791 mtype = DANETLS_NONE;
2792 ordinal = dane->dctx->mdord[t->mtype];
2794 if (t->selector != selector) {
2795 selector = t->selector;
2797 /* Update per-selector state */
2798 OPENSSL_free(i2dbuf);
2799 i2dbuf = dane_i2d(cert, selector, &i2dlen);
2803 /* Reset digest agility for each usage/selector pair */
2804 mtype = DANETLS_NONE;
2805 ordinal = dane->dctx->mdord[t->mtype];
2806 } else if (t->mtype != DANETLS_MATCHING_FULL) {
2810 * <https://tools.ietf.org/html/rfc7671#section-9>
2812 * For a fixed selector, after processing all records with the
2813 * highest mtype ordinal, ignore all mtypes with lower ordinals
2814 * other than "Full".
2816 if (dane->dctx->mdord[t->mtype] < ordinal)
2821 * Each time we hit a (new selector or) mtype, re-compute the relevant
2822 * digest, more complex caching is not worth the code space.
2824 if (t->mtype != mtype) {
2825 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype];
2831 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) {
2839 * Squirrel away the certificate and depth if we have a match. Any
2840 * DANE match is dispositive, but with PKIX we still need to build a
2843 if (cmplen == t->dlen &&
2844 memcmp(cmpbuf, t->data, cmplen) == 0) {
2845 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK)
2847 if (matched || dane->mdpth < 0) {
2848 dane->mdpth = depth;
2850 OPENSSL_free(dane->mcert);
2858 /* Clear the one-element DER cache */
2859 OPENSSL_free(i2dbuf);
2863 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth)
2865 SSL_DANE *dane = ctx->dane;
2869 if (!DANETLS_HAS_TA(dane) || depth == 0)
2870 return X509_TRUST_UNTRUSTED;
2873 * Record any DANE trust anchor matches, for the first depth to test, if
2874 * there's one at that depth. (This'll be false for length 1 chains looking
2875 * for an exact match for the leaf certificate).
2877 cert = sk_X509_value(ctx->chain, depth);
2878 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0)
2879 return X509_TRUST_REJECTED;
2881 ctx->num_untrusted = depth - 1;
2882 return X509_TRUST_TRUSTED;
2885 return X509_TRUST_UNTRUSTED;
2888 static int check_dane_pkeys(X509_STORE_CTX *ctx)
2890 SSL_DANE *dane = ctx->dane;
2892 int num = ctx->num_untrusted;
2893 X509 *cert = sk_X509_value(ctx->chain, num - 1);
2894 int recnum = sk_danetls_record_num(dane->trecs);
2897 for (i = 0; i < recnum; ++i) {
2898 t = sk_danetls_record_value(dane->trecs, i);
2899 if (t->usage != DANETLS_USAGE_DANE_TA ||
2900 t->selector != DANETLS_SELECTOR_SPKI ||
2901 t->mtype != DANETLS_MATCHING_FULL ||
2902 X509_verify(cert, t->spki) <= 0)
2905 /* Clear any PKIX-?? matches that failed to extend to a full chain */
2906 X509_free(dane->mcert);
2909 /* Record match via a bare TA public key */
2910 ctx->bare_ta_signed = 1;
2911 dane->mdpth = num - 1;
2914 /* Prune any excess chain certificates */
2915 num = sk_X509_num(ctx->chain);
2916 for (; num > ctx->num_untrusted; --num)
2917 X509_free(sk_X509_pop(ctx->chain));
2919 return X509_TRUST_TRUSTED;
2922 return X509_TRUST_UNTRUSTED;
2925 static void dane_reset(SSL_DANE *dane)
2928 * Reset state to verify another chain, or clear after failure.
2930 X509_free(dane->mcert);
2937 static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert)
2939 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags);
2941 if (err == X509_V_OK)
2943 return verify_cb_cert(ctx, cert, 0, err);
2946 static int dane_verify(X509_STORE_CTX *ctx)
2948 X509 *cert = ctx->cert;
2949 SSL_DANE *dane = ctx->dane;
2956 * When testing the leaf certificate, if we match a DANE-EE(3) record,
2957 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1)
2958 * record, the match depth and matching TLSA record are recorded, but the
2959 * return value is 0, because we still need to find a PKIX trust anchor.
2960 * Therefore, when DANE authentication is enabled (required), we're done
2962 * + matched < 0, internal error.
2963 * + matched == 1, we matched a DANE-EE(3) record
2964 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no
2965 * DANE-TA(2) or PKIX-TA(0) to test.
2967 matched = dane_match(ctx, ctx->cert, 0);
2968 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0);
2971 X509_get_pubkey_parameters(NULL, ctx->chain);
2974 /* Callback invoked as needed */
2975 if (!check_leaf_suiteb(ctx, cert))
2977 /* Callback invoked as needed */
2978 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 &&
2981 /* Bypass internal_verify(), issue depth 0 success callback */
2982 ctx->error_depth = 0;
2983 ctx->current_cert = cert;
2984 return ctx->verify_cb(1, ctx);
2988 ctx->error_depth = 0;
2989 ctx->current_cert = cert;
2990 ctx->error = X509_V_ERR_OUT_OF_MEM;
2995 /* Fail early, TA-based success is not possible */
2996 if (!check_leaf_suiteb(ctx, cert))
2998 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH);
3002 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0
3003 * certificates happens in-line with building the rest of the chain.
3005 return verify_chain(ctx);
3008 /* Get issuer, without duplicate suppression */
3009 static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert)
3011 STACK_OF(X509) *saved_chain = ctx->chain;
3015 ok = ctx->get_issuer(issuer, ctx, cert);
3016 ctx->chain = saved_chain;
3021 static int build_chain(X509_STORE_CTX *ctx)
3023 SSL_DANE *dane = ctx->dane;
3024 int num = sk_X509_num(ctx->chain);
3025 X509 *cert = sk_X509_value(ctx->chain, num - 1);
3027 STACK_OF(X509) *sktmp = NULL;
3028 unsigned int search;
3029 int may_trusted = 0;
3030 int may_alternate = 0;
3031 int trust = X509_TRUST_UNTRUSTED;
3032 int alt_untrusted = 0;
3037 /* Our chain starts with a single untrusted element. */
3038 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) {
3039 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3040 ctx->error = X509_V_ERR_UNSPECIFIED;
3044 self_signed = X509_self_signed(cert, 0);
3045 if (self_signed < 0) {
3046 ctx->error = X509_V_ERR_UNSPECIFIED;
3050 #define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */
3051 #define S_DOTRUSTED (1 << 1) /* Search trusted store */
3052 #define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */
3054 * Set up search policy, untrusted if possible, trusted-first if enabled.
3055 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the
3056 * trust_store, otherwise we might look there first. If not trusted-first,
3057 * and alternate chains are not disabled, try building an alternate chain
3058 * if no luck with untrusted first.
3060 search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0;
3061 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) {
3062 if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)
3063 search |= S_DOTRUSTED;
3064 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS))
3070 * Shallow-copy the stack of untrusted certificates (with TLS, this is
3071 * typically the content of the peer's certificate message) so can make
3072 * multiple passes over it, while free to remove elements as we go.
3074 if (ctx->untrusted && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) {
3075 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3076 ctx->error = X509_V_ERR_OUT_OF_MEM;
3081 * If we got any "DANE-TA(2) Cert(0) Full(0)" trust anchors from DNS, add
3082 * them to our working copy of the untrusted certificate stack. Since the
3083 * caller of X509_STORE_CTX_init() may have provided only a leaf cert with
3084 * no corresponding stack of untrusted certificates, we may need to create
3085 * an empty stack first. [ At present only the ssl library provides DANE
3086 * support, and ssl_verify_cert_chain() always provides a non-null stack
3087 * containing at least the leaf certificate, but we must be prepared for
3090 if (DANETLS_ENABLED(dane) && dane->certs != NULL) {
3091 if (sktmp == NULL && (sktmp = sk_X509_new_null()) == NULL) {
3092 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3093 ctx->error = X509_V_ERR_OUT_OF_MEM;
3096 if (!X509_add_certs(sktmp, dane->certs, X509_ADD_FLAG_DEFAULT)) {
3097 sk_X509_free(sktmp);
3098 ctx->error = X509_V_ERR_OUT_OF_MEM;
3104 * Still absurdly large, but arithmetically safe, a lower hard upper bound
3105 * might be reasonable.
3107 if (ctx->param->depth > INT_MAX/2)
3108 ctx->param->depth = INT_MAX/2;
3111 * Try to extend the chain until we reach an ultimately trusted issuer.
3112 * Build chains up to one longer the limit, later fail if we hit the limit,
3113 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code.
3115 depth = ctx->param->depth + 1;
3117 while (search != 0) {
3122 * Look in the trust store if enabled for first lookup, or we've run
3123 * out of untrusted issuers and search here is not disabled. When we
3124 * reach the depth limit, we stop extending the chain, if by that point
3125 * we've not found a trust anchor, any trusted chain would be too long.
3127 * The error reported to the application verify callback is at the
3128 * maximal valid depth with the current certificate equal to the last
3129 * not ultimately-trusted issuer. For example, with verify_depth = 0,
3130 * the callback will report errors at depth=1 when the immediate issuer
3131 * of the leaf certificate is not a trust anchor. No attempt will be
3132 * made to locate an issuer for that certificate, since such a chain
3133 * would be a-priori too long.
3135 if ((search & S_DOTRUSTED) != 0) {
3136 i = num = sk_X509_num(ctx->chain);
3137 if ((search & S_DOALTERNATE) != 0) {
3139 * As high up the chain as we can, look for an alternative
3140 * trusted issuer of an untrusted certificate that currently
3141 * has an untrusted issuer. We use the alt_untrusted variable
3142 * to track how far up the chain we find the first match. It
3143 * is only if and when we find a match, that we prune the chain
3144 * and reset ctx->num_untrusted to the reduced count of
3145 * untrusted certificates. While we're searching for such a
3146 * match (which may never be found), it is neither safe nor
3147 * wise to preemptively modify either the chain or
3148 * ctx->num_untrusted.
3150 * Note, like ctx->num_untrusted, alt_untrusted is a count of
3151 * untrusted certificates, not a "depth".
3155 x = sk_X509_value(ctx->chain, i-1);
3157 ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x);
3160 trust = X509_TRUST_REJECTED;
3161 ctx->error = X509_V_ERR_STORE_LOOKUP;
3168 * Alternative trusted issuer for a mid-chain untrusted cert?
3169 * Pop the untrusted cert's successors and retry. We might now
3170 * be able to complete a valid chain via the trust store. Note
3171 * that despite the current trust store match we might still
3172 * fail complete the chain to a suitable trust anchor, in which
3173 * case we may prune some more untrusted certificates and try
3174 * again. Thus the S_DOALTERNATE bit may yet be turned on
3175 * again with an even shorter untrusted chain!
3177 * If in the process we threw away our matching PKIX-TA trust
3178 * anchor, reset DANE trust. We might find a suitable trusted
3179 * certificate among the ones from the trust store.
3181 if ((search & S_DOALTERNATE) != 0) {
3182 if (!ossl_assert(num > i && i > 0 && !self_signed)) {
3183 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3185 trust = X509_TRUST_REJECTED;
3186 ctx->error = X509_V_ERR_UNSPECIFIED;
3190 search &= ~S_DOALTERNATE;
3191 for (; num > i; --num)
3192 X509_free(sk_X509_pop(ctx->chain));
3193 ctx->num_untrusted = num;
3195 if (DANETLS_ENABLED(dane) &&
3196 dane->mdpth >= ctx->num_untrusted) {
3198 X509_free(dane->mcert);
3201 if (DANETLS_ENABLED(dane) &&
3202 dane->pdpth >= ctx->num_untrusted)
3207 * Self-signed untrusted certificates get replaced by their
3208 * trusted matching issuer. Otherwise, grow the chain.
3211 if (!sk_X509_push(ctx->chain, x = xtmp)) {
3213 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3214 trust = X509_TRUST_REJECTED;
3215 ctx->error = X509_V_ERR_OUT_OF_MEM;
3219 self_signed = X509_self_signed(x, 0);
3220 if (self_signed < 0) {
3221 ctx->error = X509_V_ERR_UNSPECIFIED;
3224 } else if (num == ctx->num_untrusted) {
3226 * We have a self-signed certificate that has the same
3227 * subject name (and perhaps keyid and/or serial number) as
3228 * a trust anchor. We must have an exact match to avoid
3229 * possible impersonation via key substitution etc.
3231 if (X509_cmp(x, xtmp) != 0) {
3232 /* Self-signed untrusted mimic. */
3237 ctx->num_untrusted = --num;
3238 (void) sk_X509_set(ctx->chain, num, x = xtmp);
3243 * We've added a new trusted certificate to the chain, recheck
3244 * trust. If not done, and not self-signed look deeper.
3245 * Whether or not we're doing "trusted first", we no longer
3246 * look for untrusted certificates from the peer's chain.
3248 * At this point ctx->num_trusted and num must reflect the
3249 * correct number of untrusted certificates, since the DANE
3250 * logic in check_trust() depends on distinguishing CAs from
3251 * "the wire" from CAs from the trust store. In particular, the
3252 * certificate at depth "num" should be the new trusted
3253 * certificate with ctx->num_untrusted <= num.
3256 if (!ossl_assert(ctx->num_untrusted <= num)) {
3257 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3258 trust = X509_TRUST_REJECTED;
3259 ctx->error = X509_V_ERR_UNSPECIFIED;
3263 search &= ~S_DOUNTRUSTED;
3264 switch (trust = check_trust(ctx, num)) {
3265 case X509_TRUST_TRUSTED:
3266 case X509_TRUST_REJECTED:
3276 * No dispositive decision, and either self-signed or no match, if
3277 * we were doing untrusted-first, and alt-chains are not disabled,
3278 * do that, by repeatedly losing one untrusted element at a time,
3279 * and trying to extend the shorted chain.
3281 if ((search & S_DOUNTRUSTED) == 0) {
3282 /* Continue search for a trusted issuer of a shorter chain? */
3283 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0)
3285 /* Still no luck and no fallbacks left? */
3286 if (!may_alternate || (search & S_DOALTERNATE) != 0 ||
3287 ctx->num_untrusted < 2)
3289 /* Search for a trusted issuer of a shorter chain */
3290 search |= S_DOALTERNATE;
3291 alt_untrusted = ctx->num_untrusted - 1;
3297 * Extend chain with peer-provided certificates
3299 if ((search & S_DOUNTRUSTED) != 0) {
3300 num = sk_X509_num(ctx->chain);
3301 if (!ossl_assert(num == ctx->num_untrusted)) {
3302 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3303 trust = X509_TRUST_REJECTED;
3304 ctx->error = X509_V_ERR_UNSPECIFIED;
3308 x = sk_X509_value(ctx->chain, num-1);
3311 * Once we run out of untrusted issuers, we stop looking for more
3312 * and start looking only in the trust store if enabled.
3314 xtmp = (self_signed || depth < num) ? NULL
3315 : find_issuer(ctx, sktmp, x);
3317 search &= ~S_DOUNTRUSTED;
3319 search |= S_DOTRUSTED;
3323 /* Drop this issuer from future consideration */
3324 (void) sk_X509_delete_ptr(sktmp, xtmp);
3326 if (!X509_up_ref(xtmp)) {
3327 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR);
3328 trust = X509_TRUST_REJECTED;
3329 ctx->error = X509_V_ERR_UNSPECIFIED;
3334 if (!sk_X509_push(ctx->chain, xtmp)) {
3336 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE);
3337 trust = X509_TRUST_REJECTED;
3338 ctx->error = X509_V_ERR_OUT_OF_MEM;
3344 ++ctx->num_untrusted;
3345 self_signed = X509_self_signed(xtmp, 0);
3346 if (self_signed < 0) {
3347 sk_X509_free(sktmp);
3348 ctx->error = X509_V_ERR_UNSPECIFIED;
3353 * Check for DANE-TA trust of the topmost untrusted certificate.
3355 switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) {
3356 case X509_TRUST_TRUSTED:
3357 case X509_TRUST_REJECTED:
3363 sk_X509_free(sktmp);
3366 * Last chance to make a trusted chain, either bare DANE-TA public-key
3367 * signers, or else direct leaf PKIX trust.
3369 num = sk_X509_num(ctx->chain);
3371 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane))
3372 trust = check_dane_pkeys(ctx);
3373 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted)
3374 trust = check_trust(ctx, num);
3378 case X509_TRUST_TRUSTED:
3380 case X509_TRUST_REJECTED:
3381 /* Callback already issued */
3383 case X509_TRUST_UNTRUSTED:
3385 num = sk_X509_num(ctx->chain);
3387 return verify_cb_cert(ctx, NULL, num-1,
3388 X509_V_ERR_CERT_CHAIN_TOO_LONG);
3389 if (DANETLS_ENABLED(dane) &&
3390 (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0))
3391 return verify_cb_cert(ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH);
3392 if (self_signed && sk_X509_num(ctx->chain) == 1)
3393 return verify_cb_cert(ctx, NULL, num-1,
3394 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);
3396 return verify_cb_cert(ctx, NULL, num-1,
3397 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN);
3398 if (ctx->num_untrusted < num)
3399 return verify_cb_cert(ctx, NULL, num-1,
3400 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT);
3401 return verify_cb_cert(ctx, NULL, num-1,
3402 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY);
3406 static const int minbits_table[] = { 80, 112, 128, 192, 256 };
3407 static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table);
3410 * Check whether the public key of ``cert`` meets the security level of
3413 * Returns 1 on success, 0 otherwise.
3415 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert)
3417 EVP_PKEY *pkey = X509_get0_pubkey(cert);
3418 int level = ctx->param->auth_level;
3421 * At security level zero, return without checking for a supported public
3422 * key type. Some engines support key types not understood outside the
3423 * engine, and we only need to understand the key when enforcing a security
3429 /* Unsupported or malformed keys are not secure */
3433 if (level > NUM_AUTH_LEVELS)
3434 level = NUM_AUTH_LEVELS;
3436 return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1];
3440 * Check whether the signature digest algorithm of ``cert`` meets the security
3441 * level of ``ctx``. Should not be checked for trust anchors (whether
3442 * self-signed or otherwise).
3444 * Returns 1 on success, 0 otherwise.
3446 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert)
3449 int level = ctx->param->auth_level;
3453 if (level > NUM_AUTH_LEVELS)
3454 level = NUM_AUTH_LEVELS;
3456 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL))
3459 return secbits >= minbits_table[level - 1];