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 /* 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(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 -1 on error.
110 * This actually verifies self-signedness only if requested.
111 * It calls X509v3_cache_extensions()
112 * to match issuer and subject names (i.e., the cert being self-issued) and any
113 * present authority key identifier to match the subject key identifier, etc.
115 int X509_self_signed(X509 *cert, int verify_signature)
119 if ((pkey = X509_get0_pubkey(cert)) == NULL) { /* handles cert == NULL */
120 ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
123 if (!x509v3_cache_extensions(cert))
125 if ((cert->ex_flags & EXFLAG_SS) == 0)
127 if (!verify_signature)
129 return X509_verify(cert, pkey);
132 /* Given a certificate try and find an exact match in the store */
133 static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
135 STACK_OF(X509) *certs;
138 /* Lookup all certs with matching subject name */
140 certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
144 /* Look for exact match */
145 for (i = 0; i < sk_X509_num(certs); i++) {
146 xtmp = sk_X509_value(certs, i);
147 if (!X509_cmp(xtmp, x))
151 if (xtmp != NULL && !X509_up_ref(xtmp))
153 sk_X509_pop_free(certs, X509_free);
158 * Inform the verify callback of an error.
159 * If 'x' is not NULL it is the error cert, otherwise use the chain cert at
161 * If 'err' is not X509_V_OK, that's the error value, otherwise leave
162 * unchanged (presumably set by the caller).
164 * Returns 0 to abort verification with an error, non-zero to continue.
166 static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err)
168 ctx->error_depth = depth;
169 ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth);
170 if (err != X509_V_OK)
172 return ctx->verify_cb(0, ctx);
175 #define CHECK_CB(cond, ctx, cert, depth, err) \
176 if ((cond) && verify_cb_cert(ctx, cert, depth, err) == 0) \
180 * Inform the verify callback of an error, CRL-specific variant. Here, the
181 * error depth and certificate are already set, we just specify the error
184 * Returns 0 to abort verification with an error, non-zero to continue.
186 static int verify_cb_crl(X509_STORE_CTX *ctx, int err)
189 return ctx->verify_cb(0, ctx);
192 static int check_auth_level(X509_STORE_CTX *ctx)
195 int num = sk_X509_num(ctx->chain);
197 if (ctx->param->auth_level <= 0)
200 for (i = 0; i < num; ++i) {
201 X509 *cert = sk_X509_value(ctx->chain, i);
204 * We've already checked the security of the leaf key, so here we only
205 * check the security of issuer keys.
207 CHECK_CB(i > 0 && !check_key_level(ctx, cert),
208 ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL);
210 * We also check the signature algorithm security of all certificates
211 * except those of the trust anchor at index num-1.
213 CHECK_CB(i < num - 1 && !check_sig_level(ctx, cert),
214 ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK);
219 static int verify_chain(X509_STORE_CTX *ctx)
225 * Before either returning with an error, or continuing with CRL checks,
226 * instantiate chain public key parameters.
228 if ((ok = build_chain(ctx)) == 0 ||
229 (ok = check_chain(ctx)) == 0 ||
230 (ok = check_auth_level(ctx)) == 0 ||
231 (ok = check_id(ctx)) == 0 || 1)
232 X509_get_pubkey_parameters(NULL, ctx->chain);
233 if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0)
236 err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
238 CHECK_CB(err != X509_V_OK, ctx, NULL, ctx->error_depth, err);
240 /* Verify chain signatures and expiration times */
241 ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx);
245 if ((ok = check_name_constraints(ctx)) == 0)
248 #ifndef OPENSSL_NO_RFC3779
249 /* RFC 3779 path validation, now that CRL check has been done */
250 if ((ok = X509v3_asid_validate_path(ctx)) == 0)
252 if ((ok = X509v3_addr_validate_path(ctx)) == 0)
256 /* If we get this far evaluate policies */
257 if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK)
258 ok = ctx->check_policy(ctx);
262 int X509_verify_cert(X509_STORE_CTX *ctx)
264 SSL_DANE *dane = ctx->dane;
267 if (ctx->cert == NULL) {
268 ERR_raise(ERR_LIB_X509, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
269 ctx->error = X509_V_ERR_INVALID_CALL;
273 if (ctx->chain != NULL) {
275 * This X509_STORE_CTX has already been used to verify a cert. We
276 * cannot do another one.
278 ERR_raise(ERR_LIB_X509, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
279 ctx->error = X509_V_ERR_INVALID_CALL;
283 if (!X509_add_cert_new(&ctx->chain, ctx->cert, X509_ADD_FLAG_UP_REF)) {
284 ctx->error = X509_V_ERR_OUT_OF_MEM;
287 ctx->num_untrusted = 1;
289 /* If the peer's public key is too weak, we can stop early. */
290 CHECK_CB(!check_key_level(ctx, ctx->cert),
291 ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL);
293 if (DANETLS_ENABLED(dane))
294 ret = dane_verify(ctx);
296 ret = verify_chain(ctx);
299 * Safety-net. If we are returning an error, we must also set ctx->error,
300 * so that the chain is not considered verified should the error be ignored
301 * (e.g. TLS with SSL_VERIFY_NONE).
303 if (ret <= 0 && ctx->error == X509_V_OK)
304 ctx->error = X509_V_ERR_UNSPECIFIED;
308 static int sk_X509_contains(STACK_OF(X509) *sk, X509 *cert)
310 int i, n = sk_X509_num(sk);
312 for (i = 0; i < n; i++)
313 if (X509_cmp(sk_X509_value(sk, i), cert) == 0)
319 * Find in given STACK_OF(X509) |sk| an issuer cert (if any) of given cert |x|.
320 * The issuer must not yet be in |ctx->chain|, yet allowing the exception that
321 * |x| is self-issued and |ctx->chain| has just one element.
322 * Prefer the first non-expired one, else take the most recently expired one.
324 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
327 X509 *issuer, *rv = NULL;
329 for (i = 0; i < sk_X509_num(sk); i++) {
330 issuer = sk_X509_value(sk, i);
331 if (ctx->check_issued(ctx, x, issuer)
332 && (((x->ex_flags & EXFLAG_SI) != 0 && sk_X509_num(ctx->chain) == 1)
333 || !sk_X509_contains(ctx->chain, issuer))) {
334 if (x509_check_cert_time(ctx, issuer, -1))
336 if (rv == NULL || ASN1_TIME_compare(X509_get0_notAfter(issuer),
337 X509_get0_notAfter(rv)) > 0)
344 /* Check that the given certificate 'x' is issued by the certificate 'issuer' */
345 static int check_issued(ossl_unused X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
347 return x509_likely_issued(issuer, x) == X509_V_OK;
350 /* Alternative lookup method: look from a STACK stored in other_ctx */
351 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
353 *issuer = find_issuer(ctx, ctx->other_ctx, x);
355 if (*issuer == NULL || !X509_up_ref(*issuer))
365 static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx,
368 STACK_OF(X509) *sk = NULL;
372 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) {
373 x = sk_X509_value(ctx->other_ctx, i);
374 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) {
375 if (!X509_add_cert_new(&sk, x, X509_ADD_FLAG_UP_REF)) {
376 sk_X509_pop_free(sk, X509_free);
377 ctx->error = X509_V_ERR_OUT_OF_MEM;
386 * Check EE or CA certificate purpose. For trusted certificates explicit local
387 * auxiliary trust can be used to override EKU-restrictions.
389 static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth,
392 int tr_ok = X509_TRUST_UNTRUSTED;
395 * For trusted certificates we want to see whether any auxiliary trust
396 * settings trump the purpose constraints.
398 * This is complicated by the fact that the trust ordinals in
399 * ctx->param->trust are entirely independent of the purpose ordinals in
400 * ctx->param->purpose!
402 * What connects them is their mutual initialization via calls from
403 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets
404 * related values of both param->trust and param->purpose. It is however
405 * typically possible to infer associated trust values from a purpose value
406 * via the X509_PURPOSE API.
408 * Therefore, we can only check for trust overrides when the purpose we're
409 * checking is the same as ctx->param->purpose and ctx->param->trust is
412 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose)
413 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT);
416 case X509_TRUST_TRUSTED:
418 case X509_TRUST_REJECTED:
421 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) {
427 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0)
433 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE);
437 * Check a certificate chains extensions for consistency with the supplied
441 static int check_chain(X509_STORE_CTX *ctx)
443 int i, must_be_ca, plen = 0;
445 int proxy_path_length = 0;
447 int allow_proxy_certs;
448 int num = sk_X509_num(ctx->chain);
451 * must_be_ca can have 1 of 3 values:
452 * -1: we accept both CA and non-CA certificates, to allow direct
453 * use of self-signed certificates (which are marked as CA).
454 * 0: we only accept non-CA certificates. This is currently not
455 * used, but the possibility is present for future extensions.
456 * 1: we only accept CA certificates. This is currently used for
457 * all certificates in the chain except the leaf certificate.
461 /* CRL path validation */
463 allow_proxy_certs = 0;
464 purpose = X509_PURPOSE_CRL_SIGN;
467 ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
468 purpose = ctx->param->purpose;
471 for (i = 0; i < num; i++) {
474 x = sk_X509_value(ctx->chain, i);
475 CHECK_CB((ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) == 0
476 && (x->ex_flags & EXFLAG_CRITICAL) != 0,
477 ctx, x, i, X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION);
478 CHECK_CB(!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY),
479 ctx, x, i, X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED);
480 ret = X509_check_ca(x);
481 switch (must_be_ca) {
483 CHECK_CB((ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0
484 && ret != 1 && ret != 0,
485 ctx, x, i, X509_V_ERR_INVALID_CA);
488 CHECK_CB(ret != 0, ctx, x, i, X509_V_ERR_INVALID_NON_CA);
491 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */
494 || ctx->param->flags & X509_V_FLAG_X509_STRICT)
495 && ret != 1), ctx, x, i, X509_V_ERR_INVALID_CA);
499 /* Check for presence of explicit elliptic curve parameters */
500 ret = check_curve(x);
501 CHECK_CB(ret < 0, ctx, x, i, X509_V_ERR_UNSPECIFIED);
502 CHECK_CB(ret == 0, ctx, x, i, X509_V_ERR_EC_KEY_EXPLICIT_PARAMS);
505 * Do the following set of checks only if strict checking is requested
506 * and not for self-issued (including self-signed) EE (non-CA) certs
507 * because RFC 5280 does not apply to them according RFC 6818 section 2.
509 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0
512 * !(i == 0 && (x->ex_flags & EXFLAG_CA) == 0
513 * && (x->ex_flags & EXFLAG_SI) != 0)
515 /* Check Basic Constraints according to RFC 5280 section 4.2.1.9 */
516 if (x->ex_pathlen != -1) {
517 CHECK_CB((x->ex_flags & EXFLAG_CA) == 0,
518 ctx, x, i, X509_V_ERR_PATHLEN_INVALID_FOR_NON_CA);
519 CHECK_CB((x->ex_kusage & KU_KEY_CERT_SIGN) == 0, ctx, x, i,
520 X509_V_ERR_PATHLEN_WITHOUT_KU_KEY_CERT_SIGN);
522 CHECK_CB((x->ex_flags & EXFLAG_CA) != 0
523 && (x->ex_flags & EXFLAG_BCONS) != 0
524 && (x->ex_flags & EXFLAG_BCONS_CRITICAL) == 0,
525 ctx, x, i, X509_V_ERR_CA_BCONS_NOT_CRITICAL);
526 /* Check Key Usage according to RFC 5280 section 4.2.1.3 */
527 if ((x->ex_flags & EXFLAG_CA) != 0) {
528 CHECK_CB((x->ex_flags & EXFLAG_KUSAGE) == 0,
529 ctx, x, i, X509_V_ERR_CA_CERT_MISSING_KEY_USAGE);
531 CHECK_CB((x->ex_kusage & KU_KEY_CERT_SIGN) != 0, ctx, x, i,
532 X509_V_ERR_KU_KEY_CERT_SIGN_INVALID_FOR_NON_CA);
534 /* Check issuer is non-empty acc. to RFC 5280 section 4.1.2.4 */
535 CHECK_CB(X509_NAME_entry_count(X509_get_issuer_name(x)) == 0,
536 ctx, x, i, X509_V_ERR_ISSUER_NAME_EMPTY);
537 /* Check subject is non-empty acc. to RFC 5280 section 4.1.2.6 */
538 CHECK_CB(((x->ex_flags & EXFLAG_CA) != 0
539 || (x->ex_kusage & KU_CRL_SIGN) != 0
540 || x->altname == NULL
541 ) && X509_NAME_entry_count(X509_get_subject_name(x)) == 0,
542 ctx, x, i, X509_V_ERR_SUBJECT_NAME_EMPTY);
543 CHECK_CB(X509_NAME_entry_count(X509_get_subject_name(x)) == 0
544 && x->altname != NULL
545 && (x->ex_flags & EXFLAG_SAN_CRITICAL) == 0,
546 ctx, x, i, X509_V_ERR_EMPTY_SUBJECT_SAN_NOT_CRITICAL);
547 /* Check SAN is non-empty according to RFC 5280 section 4.2.1.6 */
548 CHECK_CB(x->altname != NULL && sk_GENERAL_NAME_num(x->altname) <= 0,
549 ctx, x, i, X509_V_ERR_EMPTY_SUBJECT_ALT_NAME);
550 /* TODO add more checks on SAN entries */
551 /* Check sig alg consistency acc. to RFC 5280 section 4.1.1.2 */
552 CHECK_CB(X509_ALGOR_cmp(&x->sig_alg, &x->cert_info.signature) != 0,
553 ctx, x, i, X509_V_ERR_SIGNATURE_ALGORITHM_INCONSISTENCY);
554 CHECK_CB(x->akid != NULL
555 && (x->ex_flags & EXFLAG_AKID_CRITICAL) != 0,
556 ctx, x, i, X509_V_ERR_AUTHORITY_KEY_IDENTIFIER_CRITICAL);
557 CHECK_CB(x->skid != NULL
558 && (x->ex_flags & EXFLAG_SKID_CRITICAL) != 0,
559 ctx, x, i, X509_V_ERR_SUBJECT_KEY_IDENTIFIER_CRITICAL);
560 if (X509_get_version(x) >= 2) { /* at least X.509v3 */
561 /* Check AKID presence acc. to RFC 5280 section 4.2.1.1 */
562 CHECK_CB(i + 1 < num /*
563 * this means not last cert in chain,
564 * taken as "generated by conforming CAs"
566 && (x->akid == NULL || x->akid->keyid == NULL), ctx,
567 x, i, X509_V_ERR_MISSING_AUTHORITY_KEY_IDENTIFIER);
568 /* Check SKID presence acc. to RFC 5280 section 4.2.1.2 */
569 CHECK_CB((x->ex_flags & EXFLAG_CA) != 0 && x->skid == NULL,
570 ctx, x, i, X509_V_ERR_MISSING_SUBJECT_KEY_IDENTIFIER);
572 CHECK_CB(sk_X509_EXTENSION_num(X509_get0_extensions(x)) > 0,
573 ctx, x, i, X509_V_ERR_EXTENSIONS_REQUIRE_VERSION_3);
577 /* check_purpose() makes the callback as needed */
578 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca))
580 /* Check path length */
581 CHECK_CB(i > 1 && x->ex_pathlen != -1
582 && plen > x->ex_pathlen + proxy_path_length,
583 ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED);
584 /* Increment path length if not a self-issued intermediate CA */
585 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0)
588 * If this certificate is a proxy certificate, the next certificate
589 * must be another proxy certificate or a EE certificate. If not,
590 * the next certificate must be a CA certificate.
592 if (x->ex_flags & EXFLAG_PROXY) {
594 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint
595 * is less than max_path_length, the former should be copied to
596 * the latter, and 4.1.4 (a) stipulates that max_path_length
597 * should be verified to be larger than zero and decrement it.
599 * Because we're checking the certs in the reverse order, we start
600 * with verifying that proxy_path_length isn't larger than pcPLC,
601 * and copy the latter to the former if it is, and finally,
602 * increment proxy_path_length.
604 if (x->ex_pcpathlen != -1) {
605 CHECK_CB(proxy_path_length > x->ex_pcpathlen,
606 ctx, x, i, X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED);
607 proxy_path_length = x->ex_pcpathlen;
617 static int has_san_id(X509 *x, int gtype)
621 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
626 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) {
627 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i);
629 if (g->type == gtype) {
634 GENERAL_NAMES_free(gs);
638 static int check_name_constraints(X509_STORE_CTX *ctx)
642 /* Check name constraints for all certificates */
643 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) {
644 X509 *x = sk_X509_value(ctx->chain, i);
647 /* Ignore self-issued certs unless last in chain */
648 if (i && (x->ex_flags & EXFLAG_SI))
652 * Proxy certificates policy has an extra constraint, where the
653 * certificate subject MUST be the issuer with a single CN entry
655 * (RFC 3820: 3.4, 4.1.3 (a)(4))
657 if (x->ex_flags & EXFLAG_PROXY) {
658 X509_NAME *tmpsubject = X509_get_subject_name(x);
659 X509_NAME *tmpissuer = X509_get_issuer_name(x);
660 X509_NAME_ENTRY *tmpentry = NULL;
661 int last_object_nid = 0;
663 int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1;
665 /* Check that there are at least two RDNs */
666 if (last_object_loc < 1) {
667 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
668 goto proxy_name_done;
672 * Check that there is exactly one more RDN in subject as
673 * there is in issuer.
675 if (X509_NAME_entry_count(tmpsubject)
676 != X509_NAME_entry_count(tmpissuer) + 1) {
677 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
678 goto proxy_name_done;
682 * Check that the last subject component isn't part of a
685 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
687 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
688 last_object_loc - 1))) {
689 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
690 goto proxy_name_done;
694 * Check that the last subject RDN is a commonName, and that
695 * all the previous RDNs match the issuer exactly
697 tmpsubject = X509_NAME_dup(tmpsubject);
698 if (tmpsubject == NULL) {
699 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
700 ctx->error = X509_V_ERR_OUT_OF_MEM;
705 X509_NAME_delete_entry(tmpsubject, last_object_loc);
707 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry));
709 if (last_object_nid != NID_commonName
710 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) {
711 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
714 X509_NAME_ENTRY_free(tmpentry);
715 X509_NAME_free(tmpsubject);
718 CHECK_CB(err != X509_V_OK, ctx, x, i, err);
722 * Check against constraints for all certificates higher in chain
723 * including trust anchor. Trust anchor not strictly speaking needed
724 * but if it includes constraints it is to be assumed it expects them
727 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) {
728 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
731 int rv = NAME_CONSTRAINTS_check(x, nc);
733 /* If EE certificate check commonName too */
734 if (rv == X509_V_OK && i == 0
735 && (ctx->param->hostflags
736 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0
737 && ((ctx->param->hostflags
738 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0
739 || !has_san_id(x, GEN_DNS)))
740 rv = NAME_CONSTRAINTS_check_CN(x, nc);
745 case X509_V_ERR_OUT_OF_MEM:
748 CHECK_CB(1, ctx, x, i, rv);
757 static int check_id_error(X509_STORE_CTX *ctx, int errcode)
759 return verify_cb_cert(ctx, ctx->cert, 0, errcode);
762 static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm)
765 int n = sk_OPENSSL_STRING_num(vpm->hosts);
768 if (vpm->peername != NULL) {
769 OPENSSL_free(vpm->peername);
770 vpm->peername = NULL;
772 for (i = 0; i < n; ++i) {
773 name = sk_OPENSSL_STRING_value(vpm->hosts, i);
774 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0)
780 static int check_id(X509_STORE_CTX *ctx)
782 X509_VERIFY_PARAM *vpm = ctx->param;
784 if (vpm->hosts && check_hosts(x, vpm) <= 0) {
785 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
788 if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) {
789 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
792 if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) {
793 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
799 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)
804 SSL_DANE *dane = ctx->dane;
805 int num = sk_X509_num(ctx->chain);
809 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2)
810 * match, we're done, otherwise we'll merely record the match depth.
812 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {
813 switch (trust = check_dane_issuer(ctx, num_untrusted)) {
814 case X509_TRUST_TRUSTED:
815 case X509_TRUST_REJECTED:
821 * Check trusted certificates in chain at depth num_untrusted and up.
822 * Note, that depths 0..num_untrusted-1 may also contain trusted
823 * certificates, but the caller is expected to have already checked those,
824 * and wants to incrementally check just any added since.
826 for (i = num_untrusted; i < num; i++) {
827 x = sk_X509_value(ctx->chain, i);
828 trust = X509_check_trust(x, ctx->param->trust, 0);
829 /* If explicitly trusted return trusted */
830 if (trust == X509_TRUST_TRUSTED)
832 if (trust == X509_TRUST_REJECTED)
837 * If we are looking at a trusted certificate, and accept partial chains,
838 * the chain is PKIX trusted.
840 if (num_untrusted < num) {
841 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
843 return X509_TRUST_UNTRUSTED;
846 if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
848 * Last-resort call with no new trusted certificates, check the leaf
849 * for a direct trust store match.
852 x = sk_X509_value(ctx->chain, i);
853 mx = lookup_cert_match(ctx, x);
855 return X509_TRUST_UNTRUSTED;
858 * Check explicit auxiliary trust/reject settings. If none are set,
859 * we'll accept X509_TRUST_UNTRUSTED when not self-signed.
861 trust = X509_check_trust(mx, ctx->param->trust, 0);
862 if (trust == X509_TRUST_REJECTED) {
867 /* Replace leaf with trusted match */
868 (void) sk_X509_set(ctx->chain, 0, mx);
870 ctx->num_untrusted = 0;
875 * If no trusted certs in chain at all return untrusted and allow
876 * standard (no issuer cert) etc errors to be indicated.
878 return X509_TRUST_UNTRUSTED;
881 return verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED) == 0
882 ? X509_TRUST_REJECTED : X509_TRUST_UNTRUSTED;
885 if (!DANETLS_ENABLED(dane))
886 return X509_TRUST_TRUSTED;
888 dane->pdpth = num_untrusted;
889 /* With DANE, PKIX alone is not trusted until we have both */
890 if (dane->mdpth >= 0)
891 return X509_TRUST_TRUSTED;
892 return X509_TRUST_UNTRUSTED;
895 static int check_revocation(X509_STORE_CTX *ctx)
897 int i = 0, last = 0, ok = 0;
898 if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
900 if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
901 last = sk_X509_num(ctx->chain) - 1;
903 /* If checking CRL paths this isn't the EE certificate */
908 for (i = 0; i <= last; i++) {
909 ctx->error_depth = i;
910 ok = check_cert(ctx);
917 static int check_cert(X509_STORE_CTX *ctx)
919 X509_CRL *crl = NULL, *dcrl = NULL;
921 int cnum = ctx->error_depth;
922 X509 *x = sk_X509_value(ctx->chain, cnum);
924 ctx->current_cert = x;
925 ctx->current_issuer = NULL;
926 ctx->current_crl_score = 0;
927 ctx->current_reasons = 0;
929 if (x->ex_flags & EXFLAG_PROXY)
932 while (ctx->current_reasons != CRLDP_ALL_REASONS) {
933 unsigned int last_reasons = ctx->current_reasons;
935 /* Try to retrieve relevant CRL */
937 ok = ctx->get_crl(ctx, &crl, x);
939 ok = get_crl_delta(ctx, &crl, &dcrl, x);
941 * If error looking up CRL, nothing we can do except notify callback
944 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
947 ctx->current_crl = crl;
948 ok = ctx->check_crl(ctx, crl);
953 ok = ctx->check_crl(ctx, dcrl);
956 ok = ctx->cert_crl(ctx, dcrl, x);
962 /* Don't look in full CRL if delta reason is removefromCRL */
964 ok = ctx->cert_crl(ctx, crl, x);
974 * If reasons not updated we won't get anywhere by another iteration,
977 if (last_reasons == ctx->current_reasons) {
978 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
986 ctx->current_crl = NULL;
990 /* Check CRL times against values in X509_STORE_CTX */
992 static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
998 ctx->current_crl = crl;
999 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1000 ptime = &ctx->param->check_time;
1001 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1006 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime);
1010 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD))
1017 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID))
1021 if (X509_CRL_get0_nextUpdate(crl)) {
1022 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime);
1027 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD))
1030 /* Ignore expiration of base CRL is delta is valid */
1031 if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) {
1034 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED))
1040 ctx->current_crl = NULL;
1045 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
1046 X509 **pissuer, int *pscore, unsigned int *preasons,
1047 STACK_OF(X509_CRL) *crls)
1049 int i, crl_score, best_score = *pscore;
1050 unsigned int reasons, best_reasons = 0;
1051 X509 *x = ctx->current_cert;
1052 X509_CRL *crl, *best_crl = NULL;
1053 X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
1055 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1056 crl = sk_X509_CRL_value(crls, i);
1057 reasons = *preasons;
1058 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
1059 if (crl_score < best_score || crl_score == 0)
1061 /* If current CRL is equivalent use it if it is newer */
1062 if (crl_score == best_score && best_crl != NULL) {
1064 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl),
1065 X509_CRL_get0_lastUpdate(crl)) == 0)
1068 * ASN1_TIME_diff never returns inconsistent signs for |day|
1071 if (day <= 0 && sec <= 0)
1075 best_crl_issuer = crl_issuer;
1076 best_score = crl_score;
1077 best_reasons = reasons;
1081 X509_CRL_free(*pcrl);
1083 *pissuer = best_crl_issuer;
1084 *pscore = best_score;
1085 *preasons = best_reasons;
1086 X509_CRL_up_ref(best_crl);
1087 X509_CRL_free(*pdcrl);
1089 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
1092 if (best_score >= CRL_SCORE_VALID)
1099 * Compare two CRL extensions for delta checking purposes. They should be
1100 * both present or both absent. If both present all fields must be identical.
1103 static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid)
1105 ASN1_OCTET_STRING *exta, *extb;
1107 i = X509_CRL_get_ext_by_NID(a, nid, -1);
1109 /* Can't have multiple occurrences */
1110 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1)
1112 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
1116 i = X509_CRL_get_ext_by_NID(b, nid, -1);
1120 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1)
1122 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
1132 if (ASN1_OCTET_STRING_cmp(exta, extb))
1138 /* See if a base and delta are compatible */
1140 static int check_delta_base(X509_CRL *delta, X509_CRL *base)
1142 /* Delta CRL must be a delta */
1143 if (!delta->base_crl_number)
1145 /* Base must have a CRL number */
1146 if (!base->crl_number)
1148 /* Issuer names must match */
1149 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta)))
1151 /* AKID and IDP must match */
1152 if (!crl_extension_match(delta, base, NID_authority_key_identifier))
1154 if (!crl_extension_match(delta, base, NID_issuing_distribution_point))
1156 /* Delta CRL base number must not exceed Full CRL number. */
1157 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0)
1159 /* Delta CRL number must exceed full CRL number */
1160 if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0)
1166 * For a given base CRL find a delta... maybe extend to delta scoring or
1167 * retrieve a chain of deltas...
1170 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore,
1171 X509_CRL *base, STACK_OF(X509_CRL) *crls)
1175 if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS))
1177 if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST))
1179 for (i = 0; i < sk_X509_CRL_num(crls); i++) {
1180 delta = sk_X509_CRL_value(crls, i);
1181 if (check_delta_base(delta, base)) {
1182 if (check_crl_time(ctx, delta, 0))
1183 *pscore |= CRL_SCORE_TIME_DELTA;
1184 X509_CRL_up_ref(delta);
1193 * For a given CRL return how suitable it is for the supplied certificate
1194 * 'x'. The return value is a mask of several criteria. If the issuer is not
1195 * the certificate issuer this is returned in *pissuer. The reasons mask is
1196 * also used to determine if the CRL is suitable: if no new reasons the CRL
1197 * is rejected, otherwise reasons is updated.
1200 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
1201 unsigned int *preasons, X509_CRL *crl, X509 *x)
1205 unsigned int tmp_reasons = *preasons, crl_reasons;
1207 /* First see if we can reject CRL straight away */
1209 /* Invalid IDP cannot be processed */
1210 if (crl->idp_flags & IDP_INVALID)
1212 /* Reason codes or indirect CRLs need extended CRL support */
1213 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
1214 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS))
1216 } else if (crl->idp_flags & IDP_REASONS) {
1217 /* If no new reasons reject */
1218 if (!(crl->idp_reasons & ~tmp_reasons))
1221 /* Don't process deltas at this stage */
1222 else if (crl->base_crl_number)
1224 /* If issuer name doesn't match certificate need indirect CRL */
1225 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) {
1226 if (!(crl->idp_flags & IDP_INDIRECT))
1229 crl_score |= CRL_SCORE_ISSUER_NAME;
1231 if (!(crl->flags & EXFLAG_CRITICAL))
1232 crl_score |= CRL_SCORE_NOCRITICAL;
1234 /* Check expiration */
1235 if (check_crl_time(ctx, crl, 0))
1236 crl_score |= CRL_SCORE_TIME;
1238 /* Check authority key ID and locate certificate issuer */
1239 crl_akid_check(ctx, crl, pissuer, &crl_score);
1241 /* If we can't locate certificate issuer at this point forget it */
1243 if (!(crl_score & CRL_SCORE_AKID))
1246 /* Check cert for matching CRL distribution points */
1248 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) {
1249 /* If no new reasons reject */
1250 if (!(crl_reasons & ~tmp_reasons))
1252 tmp_reasons |= crl_reasons;
1253 crl_score |= CRL_SCORE_SCOPE;
1256 *preasons = tmp_reasons;
1262 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl,
1263 X509 **pissuer, int *pcrl_score)
1265 X509 *crl_issuer = NULL;
1266 const X509_NAME *cnm = X509_CRL_get_issuer(crl);
1267 int cidx = ctx->error_depth;
1270 if (cidx != sk_X509_num(ctx->chain) - 1)
1273 crl_issuer = sk_X509_value(ctx->chain, cidx);
1275 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1276 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) {
1277 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT;
1278 *pissuer = crl_issuer;
1283 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) {
1284 crl_issuer = sk_X509_value(ctx->chain, cidx);
1285 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1287 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1288 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH;
1289 *pissuer = crl_issuer;
1294 /* Anything else needs extended CRL support */
1296 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
1300 * Otherwise the CRL issuer is not on the path. Look for it in the set of
1301 * untrusted certificates.
1303 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) {
1304 crl_issuer = sk_X509_value(ctx->untrusted, i);
1305 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
1307 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
1308 *pissuer = crl_issuer;
1309 *pcrl_score |= CRL_SCORE_AKID;
1316 * Check the path of a CRL issuer certificate. This creates a new
1317 * X509_STORE_CTX and populates it with most of the parameters from the
1318 * parent. This could be optimised somewhat since a lot of path checking will
1319 * be duplicated by the parent, but this will rarely be used in practice.
1322 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x)
1324 X509_STORE_CTX crl_ctx;
1327 /* Don't allow recursive CRL path validation */
1330 if (!X509_STORE_CTX_init(&crl_ctx, ctx->store, x, ctx->untrusted))
1333 crl_ctx.crls = ctx->crls;
1334 /* Copy verify params across */
1335 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
1337 crl_ctx.parent = ctx;
1338 crl_ctx.verify_cb = ctx->verify_cb;
1340 /* Verify CRL issuer */
1341 ret = X509_verify_cert(&crl_ctx);
1345 /* Check chain is acceptable */
1346 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
1348 X509_STORE_CTX_cleanup(&crl_ctx);
1353 * RFC3280 says nothing about the relationship between CRL path and
1354 * certificate path, which could lead to situations where a certificate could
1355 * be revoked or validated by a CA not authorized to do so. RFC5280 is more
1356 * strict and states that the two paths must end in the same trust anchor,
1357 * though some discussions remain... until this is resolved we use the
1361 static int check_crl_chain(X509_STORE_CTX *ctx,
1362 STACK_OF(X509) *cert_path,
1363 STACK_OF(X509) *crl_path)
1365 X509 *cert_ta, *crl_ta;
1366 cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
1367 crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
1368 if (!X509_cmp(cert_ta, crl_ta))
1374 * Check for match between two dist point names: three separate cases.
1375 * 1. Both are relative names and compare X509_NAME types.
1376 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
1377 * 3. Both are full names and compare two GENERAL_NAMES.
1378 * 4. One is NULL: automatic match.
1381 static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
1383 X509_NAME *nm = NULL;
1384 GENERAL_NAMES *gens = NULL;
1385 GENERAL_NAME *gena, *genb;
1392 /* Case 1: two X509_NAME */
1396 if (!X509_NAME_cmp(a->dpname, b->dpname))
1401 /* Case 2: set name and GENERAL_NAMES appropriately */
1403 gens = b->name.fullname;
1404 } else if (b->type == 1) {
1407 /* Case 2: set name and GENERAL_NAMES appropriately */
1408 gens = a->name.fullname;
1412 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */
1414 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1415 gena = sk_GENERAL_NAME_value(gens, i);
1416 if (gena->type != GEN_DIRNAME)
1418 if (!X509_NAME_cmp(nm, gena->d.directoryName))
1424 /* Else case 3: two GENERAL_NAMES */
1426 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) {
1427 gena = sk_GENERAL_NAME_value(a->name.fullname, i);
1428 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) {
1429 genb = sk_GENERAL_NAME_value(b->name.fullname, j);
1430 if (!GENERAL_NAME_cmp(gena, genb))
1439 static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score)
1442 const X509_NAME *nm = X509_CRL_get_issuer(crl);
1443 /* If no CRLissuer return is successful iff don't need a match */
1445 return ! !(crl_score & CRL_SCORE_ISSUER_NAME);
1446 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
1447 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
1448 if (gen->type != GEN_DIRNAME)
1450 if (!X509_NAME_cmp(gen->d.directoryName, nm))
1456 /* Check CRLDP and IDP */
1458 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
1459 unsigned int *preasons)
1462 if (crl->idp_flags & IDP_ONLYATTR)
1464 if (x->ex_flags & EXFLAG_CA) {
1465 if (crl->idp_flags & IDP_ONLYUSER)
1468 if (crl->idp_flags & IDP_ONLYCA)
1471 *preasons = crl->idp_reasons;
1472 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
1473 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
1474 if (crldp_check_crlissuer(dp, crl, crl_score)) {
1475 if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) {
1476 *preasons &= dp->dp_reasons;
1481 if ((!crl->idp || !crl->idp->distpoint)
1482 && (crl_score & CRL_SCORE_ISSUER_NAME))
1488 * Retrieve CRL corresponding to current certificate. If deltas enabled try
1489 * to find a delta CRL too
1492 static int get_crl_delta(X509_STORE_CTX *ctx,
1493 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x)
1496 X509 *issuer = NULL;
1498 unsigned int reasons;
1499 X509_CRL *crl = NULL, *dcrl = NULL;
1500 STACK_OF(X509_CRL) *skcrl;
1501 const X509_NAME *nm = X509_get_issuer_name(x);
1503 reasons = ctx->current_reasons;
1504 ok = get_crl_sk(ctx, &crl, &dcrl,
1505 &issuer, &crl_score, &reasons, ctx->crls);
1509 /* Lookup CRLs from store */
1511 skcrl = ctx->lookup_crls(ctx, nm);
1513 /* If no CRLs found and a near match from get_crl_sk use that */
1517 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
1519 sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
1522 /* If we got any kind of CRL use it and return success */
1524 ctx->current_issuer = issuer;
1525 ctx->current_crl_score = crl_score;
1526 ctx->current_reasons = reasons;
1534 /* Check CRL validity */
1535 static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
1537 X509 *issuer = NULL;
1538 EVP_PKEY *ikey = NULL;
1539 int cnum = ctx->error_depth;
1540 int chnum = sk_X509_num(ctx->chain) - 1;
1542 /* If we have an alternative CRL issuer cert use that */
1543 if (ctx->current_issuer)
1544 issuer = ctx->current_issuer;
1546 * Else find CRL issuer: if not last certificate then issuer is next
1547 * certificate in chain.
1549 else if (cnum < chnum)
1550 issuer = sk_X509_value(ctx->chain, cnum + 1);
1552 issuer = sk_X509_value(ctx->chain, chnum);
1553 /* If not self-issued, can't check signature */
1554 if (!ctx->check_issued(ctx, issuer, issuer) &&
1555 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER))
1563 * Skip most tests for deltas because they have already been done
1565 if (!crl->base_crl_number) {
1566 /* Check for cRLSign bit if keyUsage present */
1567 if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
1568 !(issuer->ex_kusage & KU_CRL_SIGN) &&
1569 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN))
1572 if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) &&
1573 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE))
1576 if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) &&
1577 check_crl_path(ctx, ctx->current_issuer) <= 0 &&
1578 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR))
1581 if ((crl->idp_flags & IDP_INVALID) &&
1582 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION))
1586 if (!(ctx->current_crl_score & CRL_SCORE_TIME) &&
1587 !check_crl_time(ctx, crl, 1))
1590 /* Attempt to get issuer certificate public key */
1591 ikey = X509_get0_pubkey(issuer);
1594 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY))
1598 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags);
1600 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv))
1602 /* Verify CRL signature */
1603 if (X509_CRL_verify(crl, ikey) <= 0 &&
1604 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE))
1610 /* Check certificate against CRL */
1611 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
1616 * The rules changed for this... previously if a CRL contained unhandled
1617 * critical extensions it could still be used to indicate a certificate
1618 * was revoked. This has since been changed since critical extensions can
1619 * change the meaning of CRL entries.
1621 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
1622 && (crl->flags & EXFLAG_CRITICAL) &&
1623 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION))
1626 * Look for serial number of certificate in CRL. If found, make sure
1627 * reason is not removeFromCRL.
1629 if (X509_CRL_get0_by_cert(crl, &rev, x)) {
1630 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)
1632 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED))
1639 static int check_policy(X509_STORE_CTX *ctx)
1646 * With DANE, the trust anchor might be a bare public key, not a
1647 * certificate! In that case our chain does not have the trust anchor
1648 * certificate as a top-most element. This comports well with RFC5280
1649 * chain verification, since there too, the trust anchor is not part of the
1650 * chain to be verified. In particular, X509_policy_check() does not look
1651 * at the TA cert, but assumes that it is present as the top-most chain
1652 * element. We therefore temporarily push a NULL cert onto the chain if it
1653 * was verified via a bare public key, and pop it off right after the
1654 * X509_policy_check() call.
1656 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) {
1657 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
1658 ctx->error = X509_V_ERR_OUT_OF_MEM;
1661 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain,
1662 ctx->param->policies, ctx->param->flags);
1663 if (ctx->bare_ta_signed)
1664 (void)sk_X509_pop(ctx->chain);
1666 if (ret == X509_PCY_TREE_INTERNAL) {
1667 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
1668 ctx->error = X509_V_ERR_OUT_OF_MEM;
1671 /* Invalid or inconsistent extensions */
1672 if (ret == X509_PCY_TREE_INVALID) {
1675 /* Locate certificates with bad extensions and notify callback. */
1676 for (i = 1; i < sk_X509_num(ctx->chain); i++) {
1677 X509 *x = sk_X509_value(ctx->chain, i);
1679 CHECK_CB((x->ex_flags & EXFLAG_INVALID_POLICY) != 0,
1680 ctx, x, i, X509_V_ERR_INVALID_POLICY_EXTENSION);
1684 if (ret == X509_PCY_TREE_FAILURE) {
1685 ctx->current_cert = NULL;
1686 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY;
1687 return ctx->verify_cb(0, ctx);
1689 if (ret != X509_PCY_TREE_VALID) {
1690 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
1694 if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) {
1695 ctx->current_cert = NULL;
1697 * Verification errors need to be "sticky", a callback may have allowed
1698 * an SSL handshake to continue despite an error, and we must then
1699 * remain in an error state. Therefore, we MUST NOT clear earlier
1700 * verification errors by setting the error to X509_V_OK.
1702 if (!ctx->verify_cb(2, ctx))
1710 * Check certificate validity times.
1711 * If depth >= 0, invoke verification callbacks on error, otherwise just return
1712 * the validation status.
1714 * Return 1 on success, 0 otherwise.
1716 int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth)
1721 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
1722 ptime = &ctx->param->check_time;
1723 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
1728 i = X509_cmp_time(X509_get0_notBefore(x), ptime);
1729 if (i >= 0 && depth < 0)
1731 CHECK_CB(i == 0, ctx, x, depth, X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD);
1732 CHECK_CB(i > 0, ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID);
1734 i = X509_cmp_time(X509_get0_notAfter(x), ptime);
1735 if (i <= 0 && depth < 0)
1737 CHECK_CB(i == 0, ctx, x, depth, X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD);
1738 CHECK_CB(i < 0, ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED);
1742 /* verify the issuer signatures and cert times of ctx->chain */
1743 static int internal_verify(X509_STORE_CTX *ctx)
1745 int n = sk_X509_num(ctx->chain) - 1;
1746 X509 *xi = sk_X509_value(ctx->chain, n);
1750 * With DANE-verified bare public key TA signatures, it remains only to
1751 * check the timestamps of the top certificate. We report the issuer as
1752 * NULL, since all we have is a bare key.
1754 if (ctx->bare_ta_signed) {
1757 goto check_cert_time;
1760 if (ctx->check_issued(ctx, xi, xi))
1761 xs = xi; /* the typical case: last cert in the chain is self-issued */
1763 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
1765 goto check_cert_time;
1768 CHECK_CB(1, ctx, xi, 0, X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE);
1771 goto check_cert_time;
1775 ctx->error_depth = n;
1776 xs = sk_X509_value(ctx->chain, n);
1780 * Do not clear ctx->error=0, it must be "sticky", only the user's callback
1781 * is allowed to reset errors (at its own peril).
1785 * For each iteration of this loop:
1786 * n is the subject depth
1787 * xs is the subject cert, for which the signature is to be checked
1788 * xi is the supposed issuer cert containing the public key to use
1789 * Initially xs == xi if the last cert in the chain is self-issued.
1791 * Skip signature check for self-signed certificates unless explicitly
1792 * asked for because it does not add any security and just wastes time.
1794 if (xs != xi || ((ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)
1795 && (xi->ex_flags & EXFLAG_SS) != 0)) {
1798 * If the issuer's public key is not available or its key usage
1799 * does not support issuing the subject cert, report the issuer
1800 * cert and its depth (rather than n, the depth of the subject).
1802 int issuer_depth = n + (xs == xi ? 0 : 1);
1804 * According to https://tools.ietf.org/html/rfc5280#section-6.1.4
1805 * step (n) we must check any given key usage extension in a CA cert
1806 * when preparing the verification of a certificate issued by it.
1807 * According to https://tools.ietf.org/html/rfc5280#section-4.2.1.3
1808 * we must not verify a certificate signature if the key usage of
1809 * the CA certificate that issued the certificate prohibits signing.
1810 * In case the 'issuing' certificate is the last in the chain and is
1811 * not a CA certificate but a 'self-issued' end-entity cert (i.e.,
1812 * xs == xi && !(xi->ex_flags & EXFLAG_CA)) RFC 5280 does not apply
1813 * (see https://tools.ietf.org/html/rfc6818#section-2) and thus
1814 * we are free to ignore any key usage restrictions on such certs.
1816 int ret = xs == xi && (xi->ex_flags & EXFLAG_CA) == 0
1817 ? X509_V_OK : x509_signing_allowed(xi, xs);
1819 CHECK_CB(ret != X509_V_OK, ctx, xi, issuer_depth, ret);
1820 if ((pkey = X509_get0_pubkey(xi)) == NULL) {
1821 CHECK_CB(1, ctx, xi, issuer_depth,
1822 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY);
1824 CHECK_CB(X509_verify(xs, pkey) <= 0,
1825 ctx, xs, n, X509_V_ERR_CERT_SIGNATURE_FAILURE);
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);
1927 * Return 0 if time should not be checked or reference time is in range,
1928 * or else 1 if it is past the end, or -1 if it is before the start
1930 int X509_cmp_timeframe(const X509_VERIFY_PARAM *vpm,
1931 const ASN1_TIME *start, const ASN1_TIME *end)
1934 time_t *time = NULL;
1935 unsigned long flags = vpm == NULL ? 0 : X509_VERIFY_PARAM_get_flags(vpm);
1937 if ((flags & X509_V_FLAG_USE_CHECK_TIME) != 0) {
1938 ref_time = X509_VERIFY_PARAM_get_time(vpm);
1940 } else if ((flags & X509_V_FLAG_NO_CHECK_TIME) != 0) {
1941 return 0; /* this means ok */
1942 } /* else reference time is the current time */
1944 if (end != NULL && X509_cmp_time(end, time) < 0)
1946 if (start != NULL && X509_cmp_time(start, time) > 0)
1951 ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj)
1953 return X509_time_adj(s, adj, NULL);
1956 ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm)
1958 return X509_time_adj_ex(s, 0, offset_sec, in_tm);
1961 ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s,
1962 int offset_day, long offset_sec, time_t *in_tm)
1971 if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) {
1972 if (s->type == V_ASN1_UTCTIME)
1973 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec);
1974 if (s->type == V_ASN1_GENERALIZEDTIME)
1975 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec);
1977 return ASN1_TIME_adj(s, t, offset_day, offset_sec);
1980 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
1982 EVP_PKEY *ktmp = NULL, *ktmp2;
1985 if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey))
1988 for (i = 0; i < sk_X509_num(chain); i++) {
1989 ktmp = X509_get0_pubkey(sk_X509_value(chain, i));
1991 ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
1994 if (!EVP_PKEY_missing_parameters(ktmp))
1998 ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
2002 /* first, populate the other certs */
2003 for (j = i - 1; j >= 0; j--) {
2004 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j));
2005 EVP_PKEY_copy_parameters(ktmp2, ktmp);
2009 EVP_PKEY_copy_parameters(pkey, ktmp);
2013 /* Make a delta CRL as the difference between two full CRLs */
2015 X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer,
2016 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags)
2018 X509_CRL *crl = NULL;
2020 STACK_OF(X509_REVOKED) *revs = NULL;
2021 /* CRLs can't be delta already */
2022 if (base->base_crl_number || newer->base_crl_number) {
2023 ERR_raise(ERR_LIB_X509, X509_R_CRL_ALREADY_DELTA);
2026 /* Base and new CRL must have a CRL number */
2027 if (!base->crl_number || !newer->crl_number) {
2028 ERR_raise(ERR_LIB_X509, X509_R_NO_CRL_NUMBER);
2031 /* Issuer names must match */
2032 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) {
2033 ERR_raise(ERR_LIB_X509, X509_R_ISSUER_MISMATCH);
2036 /* AKID and IDP must match */
2037 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) {
2038 ERR_raise(ERR_LIB_X509, X509_R_AKID_MISMATCH);
2041 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) {
2042 ERR_raise(ERR_LIB_X509, X509_R_IDP_MISMATCH);
2045 /* Newer CRL number must exceed full CRL number */
2046 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) {
2047 ERR_raise(ERR_LIB_X509, X509_R_NEWER_CRL_NOT_NEWER);
2050 /* CRLs must verify */
2051 if (skey && (X509_CRL_verify(base, skey) <= 0 ||
2052 X509_CRL_verify(newer, skey) <= 0)) {
2053 ERR_raise(ERR_LIB_X509, X509_R_CRL_VERIFY_FAILURE);
2056 /* Create new CRL */
2057 crl = X509_CRL_new();
2058 if (crl == NULL || !X509_CRL_set_version(crl, 1))
2060 /* Set issuer name */
2061 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer)))
2064 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer)))
2066 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer)))
2069 /* Set base CRL number: must be critical */
2071 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0))
2075 * Copy extensions across from newest CRL to delta: this will set CRL
2076 * number to correct value too.
2079 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) {
2080 X509_EXTENSION *ext;
2081 ext = X509_CRL_get_ext(newer, i);
2082 if (!X509_CRL_add_ext(crl, ext, -1))
2086 /* Go through revoked entries, copying as needed */
2088 revs = X509_CRL_get_REVOKED(newer);
2090 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) {
2091 X509_REVOKED *rvn, *rvtmp;
2092 rvn = sk_X509_REVOKED_value(revs, i);
2094 * Add only if not also in base. TODO: need something cleverer here
2095 * for some more complex CRLs covering multiple CAs.
2097 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) {
2098 rvtmp = X509_REVOKED_dup(rvn);
2101 if (!X509_CRL_add0_revoked(crl, rvtmp)) {
2102 X509_REVOKED_free(rvtmp);
2107 /* TODO: optionally prune deleted entries */
2109 if (skey && md && !X509_CRL_sign(crl, skey, md))
2115 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
2120 int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data)
2122 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data);
2125 void *X509_STORE_CTX_get_ex_data(const X509_STORE_CTX *ctx, int idx)
2127 return CRYPTO_get_ex_data(&ctx->ex_data, idx);
2130 int X509_STORE_CTX_get_error(const X509_STORE_CTX *ctx)
2135 void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err)
2140 int X509_STORE_CTX_get_error_depth(const X509_STORE_CTX *ctx)
2142 return ctx->error_depth;
2145 void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth)
2147 ctx->error_depth = depth;
2150 X509 *X509_STORE_CTX_get_current_cert(const X509_STORE_CTX *ctx)
2152 return ctx->current_cert;
2155 void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x)
2157 ctx->current_cert = x;
2160 STACK_OF(X509) *X509_STORE_CTX_get0_chain(const X509_STORE_CTX *ctx)
2165 STACK_OF(X509) *X509_STORE_CTX_get1_chain(const X509_STORE_CTX *ctx)
2169 return X509_chain_up_ref(ctx->chain);
2172 X509 *X509_STORE_CTX_get0_current_issuer(const X509_STORE_CTX *ctx)
2174 return ctx->current_issuer;
2177 X509_CRL *X509_STORE_CTX_get0_current_crl(const X509_STORE_CTX *ctx)
2179 return ctx->current_crl;
2182 X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(const X509_STORE_CTX *ctx)
2187 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x)
2192 void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk)
2197 int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose)
2200 * XXX: Why isn't this function always used to set the associated trust?
2201 * Should there even be a VPM->trust field at all? Or should the trust
2202 * always be inferred from the purpose by X509_STORE_CTX_init().
2204 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
2207 int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust)
2210 * XXX: See above, this function would only be needed when the default
2211 * trust for the purpose needs an override in a corner case.
2213 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
2217 * This function is used to set the X509_STORE_CTX purpose and trust values.
2218 * This is intended to be used when another structure has its own trust and
2219 * purpose values which (if set) will be inherited by the ctx. If they aren't
2220 * set then we will usually have a default purpose in mind which should then
2221 * be used to set the trust value. An example of this is SSL use: an SSL
2222 * structure will have its own purpose and trust settings which the
2223 * application can set: if they aren't set then we use the default of SSL
2227 int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
2228 int purpose, int trust)
2231 /* If purpose not set use default */
2233 purpose = def_purpose;
2234 /* If we have a purpose then check it is valid */
2237 idx = X509_PURPOSE_get_by_id(purpose);
2239 ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID);
2242 ptmp = X509_PURPOSE_get0(idx);
2243 if (ptmp->trust == X509_TRUST_DEFAULT) {
2244 idx = X509_PURPOSE_get_by_id(def_purpose);
2246 * XXX: In the two callers above def_purpose is always 0, which is
2247 * not a known value, so idx will always be -1. How is the
2248 * X509_TRUST_DEFAULT case actually supposed to be handled?
2251 ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID);
2254 ptmp = X509_PURPOSE_get0(idx);
2256 /* If trust not set then get from purpose default */
2258 trust = ptmp->trust;
2261 idx = X509_TRUST_get_by_id(trust);
2263 ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_TRUST_ID);
2268 if (purpose && !ctx->param->purpose)
2269 ctx->param->purpose = purpose;
2270 if (trust && !ctx->param->trust)
2271 ctx->param->trust = trust;
2275 X509_STORE_CTX *X509_STORE_CTX_new_ex(OSSL_LIB_CTX *libctx, const char *propq)
2277 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
2280 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
2284 ctx->libctx = libctx;
2285 if (propq != NULL) {
2286 ctx->propq = OPENSSL_strdup(propq);
2287 if (ctx->propq == NULL) {
2289 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
2297 X509_STORE_CTX *X509_STORE_CTX_new(void)
2299 return X509_STORE_CTX_new_ex(NULL, NULL);
2303 void X509_STORE_CTX_free(X509_STORE_CTX *ctx)
2308 X509_STORE_CTX_cleanup(ctx);
2310 /* libctx and propq survive X509_STORE_CTX_cleanup() */
2311 OPENSSL_free(ctx->propq);
2316 int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
2317 STACK_OF(X509) *chain)
2323 ctx->untrusted = chain;
2325 ctx->num_untrusted = 0;
2326 ctx->other_ctx = NULL;
2330 ctx->explicit_policy = 0;
2331 ctx->error_depth = 0;
2332 ctx->current_cert = NULL;
2333 ctx->current_issuer = NULL;
2334 ctx->current_crl = NULL;
2335 ctx->current_crl_score = 0;
2336 ctx->current_reasons = 0;
2340 ctx->bare_ta_signed = 0;
2341 /* Zero ex_data to make sure we're cleanup-safe */
2342 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2344 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */
2346 ctx->cleanup = store->cleanup;
2350 if (store && store->check_issued)
2351 ctx->check_issued = store->check_issued;
2353 ctx->check_issued = check_issued;
2355 if (store && store->get_issuer)
2356 ctx->get_issuer = store->get_issuer;
2358 ctx->get_issuer = X509_STORE_CTX_get1_issuer;
2360 if (store && store->verify_cb)
2361 ctx->verify_cb = store->verify_cb;
2363 ctx->verify_cb = null_callback;
2365 if (store && store->verify)
2366 ctx->verify = store->verify;
2368 ctx->verify = internal_verify;
2370 if (store && store->check_revocation)
2371 ctx->check_revocation = store->check_revocation;
2373 ctx->check_revocation = check_revocation;
2375 if (store && store->get_crl)
2376 ctx->get_crl = store->get_crl;
2378 ctx->get_crl = NULL;
2380 if (store && store->check_crl)
2381 ctx->check_crl = store->check_crl;
2383 ctx->check_crl = check_crl;
2385 if (store && store->cert_crl)
2386 ctx->cert_crl = store->cert_crl;
2388 ctx->cert_crl = cert_crl;
2390 if (store && store->check_policy)
2391 ctx->check_policy = store->check_policy;
2393 ctx->check_policy = check_policy;
2395 if (store && store->lookup_certs)
2396 ctx->lookup_certs = store->lookup_certs;
2398 ctx->lookup_certs = X509_STORE_CTX_get1_certs;
2400 if (store && store->lookup_crls)
2401 ctx->lookup_crls = store->lookup_crls;
2403 ctx->lookup_crls = X509_STORE_CTX_get1_crls;
2405 ctx->param = X509_VERIFY_PARAM_new();
2406 if (ctx->param == NULL) {
2407 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
2412 * Inherit callbacks and flags from X509_STORE if not set use defaults.
2415 ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
2417 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE;
2420 ret = X509_VERIFY_PARAM_inherit(ctx->param,
2421 X509_VERIFY_PARAM_lookup("default"));
2424 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
2429 * XXX: For now, continue to inherit trust from VPM, but infer from the
2430 * purpose if this still yields the default value.
2432 if (ctx->param->trust == X509_TRUST_DEFAULT) {
2433 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose);
2434 X509_PURPOSE *xp = X509_PURPOSE_get0(idx);
2437 ctx->param->trust = X509_PURPOSE_get_trust(xp);
2440 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
2443 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
2447 * On error clean up allocated storage, if the store context was not
2448 * allocated with X509_STORE_CTX_new() this is our last chance to do so.
2450 X509_STORE_CTX_cleanup(ctx);
2455 * Set alternative lookup method: just a STACK of trusted certificates. This
2456 * avoids X509_STORE nastiness where it isn't needed.
2458 void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2460 ctx->other_ctx = sk;
2461 ctx->get_issuer = get_issuer_sk;
2462 ctx->lookup_certs = lookup_certs_sk;
2465 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
2468 * We need to be idempotent because, unfortunately, free() also calls
2469 * cleanup(), so the natural call sequence new(), init(), cleanup(), free()
2470 * calls cleanup() for the same object twice! Thus we must zero the
2471 * pointers below after they're freed!
2473 /* Seems to always be 0 in OpenSSL, do this at most once. */
2474 if (ctx->cleanup != NULL) {
2476 ctx->cleanup = NULL;
2478 if (ctx->param != NULL) {
2479 if (ctx->parent == NULL)
2480 X509_VERIFY_PARAM_free(ctx->param);
2483 X509_policy_tree_free(ctx->tree);
2485 sk_X509_pop_free(ctx->chain, X509_free);
2487 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
2488 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
2491 void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth)
2493 X509_VERIFY_PARAM_set_depth(ctx->param, depth);
2496 void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags)
2498 X509_VERIFY_PARAM_set_flags(ctx->param, flags);
2501 void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags,
2504 X509_VERIFY_PARAM_set_time(ctx->param, t);
2507 X509 *X509_STORE_CTX_get0_cert(const X509_STORE_CTX *ctx)
2512 STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(const X509_STORE_CTX *ctx)
2514 return ctx->untrusted;
2517 void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2519 ctx->untrusted = sk;
2522 void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk)
2524 sk_X509_pop_free(ctx->chain, X509_free);
2528 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
2529 X509_STORE_CTX_verify_cb verify_cb)
2531 ctx->verify_cb = verify_cb;
2534 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(const X509_STORE_CTX *ctx)
2536 return ctx->verify_cb;
2539 void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx,
2540 X509_STORE_CTX_verify_fn verify)
2542 ctx->verify = verify;
2545 X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(const X509_STORE_CTX *ctx)
2550 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(const X509_STORE_CTX *ctx)
2552 return ctx->get_issuer;
2555 X509_STORE_CTX_check_issued_fn
2556 X509_STORE_CTX_get_check_issued(const X509_STORE_CTX *ctx)
2558 return ctx->check_issued;
2561 X509_STORE_CTX_check_revocation_fn
2562 X509_STORE_CTX_get_check_revocation(const X509_STORE_CTX *ctx)
2564 return ctx->check_revocation;
2567 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(const X509_STORE_CTX *ctx)
2569 return ctx->get_crl;
2572 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(const X509_STORE_CTX *ctx)
2574 return ctx->check_crl;
2577 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(const X509_STORE_CTX *ctx)
2579 return ctx->cert_crl;
2582 X509_STORE_CTX_check_policy_fn
2583 X509_STORE_CTX_get_check_policy(const X509_STORE_CTX *ctx)
2585 return ctx->check_policy;
2588 X509_STORE_CTX_lookup_certs_fn
2589 X509_STORE_CTX_get_lookup_certs(const X509_STORE_CTX *ctx)
2591 return ctx->lookup_certs;
2594 X509_STORE_CTX_lookup_crls_fn
2595 X509_STORE_CTX_get_lookup_crls(const X509_STORE_CTX *ctx)
2597 return ctx->lookup_crls;
2600 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(const X509_STORE_CTX *ctx)
2602 return ctx->cleanup;
2605 X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(const X509_STORE_CTX *ctx)
2610 int X509_STORE_CTX_get_explicit_policy(const X509_STORE_CTX *ctx)
2612 return ctx->explicit_policy;
2615 int X509_STORE_CTX_get_num_untrusted(const X509_STORE_CTX *ctx)
2617 return ctx->num_untrusted;
2620 int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name)
2622 const X509_VERIFY_PARAM *param;
2624 param = X509_VERIFY_PARAM_lookup(name);
2627 return X509_VERIFY_PARAM_inherit(ctx->param, param);
2630 X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(const X509_STORE_CTX *ctx)
2635 void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
2637 X509_VERIFY_PARAM_free(ctx->param);
2641 void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane)
2646 static unsigned char *dane_i2d(
2649 unsigned int *i2dlen)
2651 unsigned char *buf = NULL;
2655 * Extract ASN.1 DER form of certificate or public key.
2658 case DANETLS_SELECTOR_CERT:
2659 len = i2d_X509(cert, &buf);
2661 case DANETLS_SELECTOR_SPKI:
2662 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf);
2665 ERR_raise(ERR_LIB_X509, X509_R_BAD_SELECTOR);
2669 if (len < 0 || buf == NULL) {
2670 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
2674 *i2dlen = (unsigned int)len;
2678 #define DANETLS_NONE 256 /* impossible uint8_t */
2680 static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth)
2682 SSL_DANE *dane = ctx->dane;
2683 unsigned usage = DANETLS_NONE;
2684 unsigned selector = DANETLS_NONE;
2685 unsigned ordinal = DANETLS_NONE;
2686 unsigned mtype = DANETLS_NONE;
2687 unsigned char *i2dbuf = NULL;
2688 unsigned int i2dlen = 0;
2689 unsigned char mdbuf[EVP_MAX_MD_SIZE];
2690 unsigned char *cmpbuf = NULL;
2691 unsigned int cmplen = 0;
2695 danetls_record *t = NULL;
2698 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK;
2701 * The trust store is not applicable with DANE-TA(2)
2703 if (depth >= ctx->num_untrusted)
2704 mask &= DANETLS_PKIX_MASK;
2707 * If we've previously matched a PKIX-?? record, no need to test any
2708 * further PKIX-?? records, it remains to just build the PKIX chain.
2709 * Had the match been a DANE-?? record, we'd be done already.
2711 if (dane->mdpth >= 0)
2712 mask &= ~DANETLS_PKIX_MASK;
2715 * https://tools.ietf.org/html/rfc7671#section-5.1
2716 * https://tools.ietf.org/html/rfc7671#section-5.2
2717 * https://tools.ietf.org/html/rfc7671#section-5.3
2718 * https://tools.ietf.org/html/rfc7671#section-5.4
2720 * We handle DANE-EE(3) records first as they require no chain building
2721 * and no expiration or hostname checks. We also process digests with
2722 * higher ordinals first and ignore lower priorities except Full(0) which
2723 * is always processed (last). If none match, we then process PKIX-EE(1).
2725 * NOTE: This relies on DANE usages sorting before the corresponding PKIX
2726 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest
2727 * priorities. See twin comment in ssl/ssl_lib.c.
2729 * We expect that most TLSA RRsets will have just a single usage, so we
2730 * don't go out of our way to cache multiple selector-specific i2d buffers
2731 * across usages, but if the selector happens to remain the same as switch
2732 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1",
2733 * records would result in us generating each of the certificate and public
2734 * key DER forms twice, but more typically we'd just see multiple "3 1 1"
2735 * or multiple "3 0 1" records.
2737 * As soon as we find a match at any given depth, we stop, because either
2738 * we've matched a DANE-?? record and the peer is authenticated, or, after
2739 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is
2740 * sufficient for DANE, and what remains to do is ordinary PKIX validation.
2742 recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0;
2743 for (i = 0; matched == 0 && i < recnum; ++i) {
2744 t = sk_danetls_record_value(dane->trecs, i);
2745 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0)
2747 if (t->usage != usage) {
2750 /* Reset digest agility for each usage/selector pair */
2751 mtype = DANETLS_NONE;
2752 ordinal = dane->dctx->mdord[t->mtype];
2754 if (t->selector != selector) {
2755 selector = t->selector;
2757 /* Update per-selector state */
2758 OPENSSL_free(i2dbuf);
2759 i2dbuf = dane_i2d(cert, selector, &i2dlen);
2763 /* Reset digest agility for each usage/selector pair */
2764 mtype = DANETLS_NONE;
2765 ordinal = dane->dctx->mdord[t->mtype];
2766 } else if (t->mtype != DANETLS_MATCHING_FULL) {
2770 * <https://tools.ietf.org/html/rfc7671#section-9>
2772 * For a fixed selector, after processing all records with the
2773 * highest mtype ordinal, ignore all mtypes with lower ordinals
2774 * other than "Full".
2776 if (dane->dctx->mdord[t->mtype] < ordinal)
2781 * Each time we hit a (new selector or) mtype, re-compute the relevant
2782 * digest, more complex caching is not worth the code space.
2784 if (t->mtype != mtype) {
2785 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype];
2791 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) {
2799 * Squirrel away the certificate and depth if we have a match. Any
2800 * DANE match is dispositive, but with PKIX we still need to build a
2803 if (cmplen == t->dlen &&
2804 memcmp(cmpbuf, t->data, cmplen) == 0) {
2805 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK)
2807 if (matched || dane->mdpth < 0) {
2808 dane->mdpth = depth;
2810 OPENSSL_free(dane->mcert);
2818 /* Clear the one-element DER cache */
2819 OPENSSL_free(i2dbuf);
2823 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth)
2825 SSL_DANE *dane = ctx->dane;
2829 if (!DANETLS_HAS_TA(dane) || depth == 0)
2830 return X509_TRUST_UNTRUSTED;
2833 * Record any DANE trust anchor matches, for the first depth to test, if
2834 * there's one at that depth. (This'll be false for length 1 chains looking
2835 * for an exact match for the leaf certificate).
2837 cert = sk_X509_value(ctx->chain, depth);
2838 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0)
2839 return X509_TRUST_REJECTED;
2841 ctx->num_untrusted = depth - 1;
2842 return X509_TRUST_TRUSTED;
2845 return X509_TRUST_UNTRUSTED;
2848 static int check_dane_pkeys(X509_STORE_CTX *ctx)
2850 SSL_DANE *dane = ctx->dane;
2852 int num = ctx->num_untrusted;
2853 X509 *cert = sk_X509_value(ctx->chain, num - 1);
2854 int recnum = sk_danetls_record_num(dane->trecs);
2857 for (i = 0; i < recnum; ++i) {
2858 t = sk_danetls_record_value(dane->trecs, i);
2859 if (t->usage != DANETLS_USAGE_DANE_TA ||
2860 t->selector != DANETLS_SELECTOR_SPKI ||
2861 t->mtype != DANETLS_MATCHING_FULL ||
2862 X509_verify(cert, t->spki) <= 0)
2865 /* Clear any PKIX-?? matches that failed to extend to a full chain */
2866 X509_free(dane->mcert);
2869 /* Record match via a bare TA public key */
2870 ctx->bare_ta_signed = 1;
2871 dane->mdpth = num - 1;
2874 /* Prune any excess chain certificates */
2875 num = sk_X509_num(ctx->chain);
2876 for (; num > ctx->num_untrusted; --num)
2877 X509_free(sk_X509_pop(ctx->chain));
2879 return X509_TRUST_TRUSTED;
2882 return X509_TRUST_UNTRUSTED;
2885 static void dane_reset(SSL_DANE *dane)
2888 * Reset state to verify another chain, or clear after failure.
2890 X509_free(dane->mcert);
2897 static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert)
2899 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags);
2901 CHECK_CB(err != X509_V_OK, ctx, cert, 0, err);
2905 static int dane_verify(X509_STORE_CTX *ctx)
2907 X509 *cert = ctx->cert;
2908 SSL_DANE *dane = ctx->dane;
2915 * When testing the leaf certificate, if we match a DANE-EE(3) record,
2916 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1)
2917 * record, the match depth and matching TLSA record are recorded, but the
2918 * return value is 0, because we still need to find a PKIX trust anchor.
2919 * Therefore, when DANE authentication is enabled (required), we're done
2921 * + matched < 0, internal error.
2922 * + matched == 1, we matched a DANE-EE(3) record
2923 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no
2924 * DANE-TA(2) or PKIX-TA(0) to test.
2926 matched = dane_match(ctx, ctx->cert, 0);
2927 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0);
2930 X509_get_pubkey_parameters(NULL, ctx->chain);
2933 /* Callback invoked as needed */
2934 if (!check_leaf_suiteb(ctx, cert))
2936 /* Callback invoked as needed */
2937 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 &&
2940 /* Bypass internal_verify(), issue depth 0 success callback */
2941 ctx->error_depth = 0;
2942 ctx->current_cert = cert;
2943 return ctx->verify_cb(1, ctx);
2947 ctx->error_depth = 0;
2948 ctx->current_cert = cert;
2949 ctx->error = X509_V_ERR_OUT_OF_MEM;
2954 /* Fail early, TA-based success is not possible */
2955 if (!check_leaf_suiteb(ctx, cert))
2957 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH);
2961 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0
2962 * certificates happens in-line with building the rest of the chain.
2964 return verify_chain(ctx);
2967 /* Get issuer, without duplicate suppression */
2968 static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert)
2970 STACK_OF(X509) *saved_chain = ctx->chain;
2974 ok = ctx->get_issuer(issuer, ctx, cert);
2975 ctx->chain = saved_chain;
2980 static int build_chain(X509_STORE_CTX *ctx)
2982 SSL_DANE *dane = ctx->dane;
2983 int num = sk_X509_num(ctx->chain);
2984 X509 *cert = sk_X509_value(ctx->chain, num - 1);
2986 STACK_OF(X509) *sktmp = NULL;
2987 unsigned int search;
2988 int may_trusted = 0;
2989 int may_alternate = 0;
2990 int trust = X509_TRUST_UNTRUSTED;
2991 int alt_untrusted = 0;
2996 /* Our chain starts with a single untrusted element. */
2997 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) {
2998 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
2999 ctx->error = X509_V_ERR_UNSPECIFIED;
3003 self_signed = X509_self_signed(cert, 0);
3004 if (self_signed < 0) {
3005 ctx->error = X509_V_ERR_UNSPECIFIED;
3009 #define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */
3010 #define S_DOTRUSTED (1 << 1) /* Search trusted store */
3011 #define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */
3013 * Set up search policy, untrusted if possible, trusted-first if enabled.
3014 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the
3015 * trust_store, otherwise we might look there first. If not trusted-first,
3016 * and alternate chains are not disabled, try building an alternate chain
3017 * if no luck with untrusted first.
3019 search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0;
3020 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) {
3021 if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)
3022 search |= S_DOTRUSTED;
3023 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS))
3029 * Shallow-copy the stack of untrusted certificates (with TLS, this is
3030 * typically the content of the peer's certificate message) so can make
3031 * multiple passes over it, while free to remove elements as we go.
3033 if (ctx->untrusted && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) {
3034 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
3035 ctx->error = X509_V_ERR_OUT_OF_MEM;
3040 * If we got any "DANE-TA(2) Cert(0) Full(0)" trust anchors from DNS, add
3041 * them to our working copy of the untrusted certificate stack. Since the
3042 * caller of X509_STORE_CTX_init() may have provided only a leaf cert with
3043 * no corresponding stack of untrusted certificates, we may need to create
3044 * an empty stack first. [ At present only the ssl library provides DANE
3045 * support, and ssl_verify_cert_chain() always provides a non-null stack
3046 * containing at least the leaf certificate, but we must be prepared for
3049 if (DANETLS_ENABLED(dane) && dane->certs != NULL) {
3050 if (sktmp == NULL && (sktmp = sk_X509_new_null()) == NULL) {
3051 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
3052 ctx->error = X509_V_ERR_OUT_OF_MEM;
3055 if (!X509_add_certs(sktmp, dane->certs, X509_ADD_FLAG_DEFAULT)) {
3056 sk_X509_free(sktmp);
3057 ctx->error = X509_V_ERR_OUT_OF_MEM;
3063 * Still absurdly large, but arithmetically safe, a lower hard upper bound
3064 * might be reasonable.
3066 if (ctx->param->depth > INT_MAX/2)
3067 ctx->param->depth = INT_MAX/2;
3070 * Try to extend the chain until we reach an ultimately trusted issuer.
3071 * Build chains up to one longer the limit, later fail if we hit the limit,
3072 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code.
3074 depth = ctx->param->depth + 1;
3076 while (search != 0) {
3081 * Look in the trust store if enabled for first lookup, or we've run
3082 * out of untrusted issuers and search here is not disabled. When we
3083 * reach the depth limit, we stop extending the chain, if by that point
3084 * we've not found a trust anchor, any trusted chain would be too long.
3086 * The error reported to the application verify callback is at the
3087 * maximal valid depth with the current certificate equal to the last
3088 * not ultimately-trusted issuer. For example, with verify_depth = 0,
3089 * the callback will report errors at depth=1 when the immediate issuer
3090 * of the leaf certificate is not a trust anchor. No attempt will be
3091 * made to locate an issuer for that certificate, since such a chain
3092 * would be a-priori too long.
3094 if ((search & S_DOTRUSTED) != 0) {
3095 i = num = sk_X509_num(ctx->chain);
3096 if ((search & S_DOALTERNATE) != 0) {
3098 * As high up the chain as we can, look for an alternative
3099 * trusted issuer of an untrusted certificate that currently
3100 * has an untrusted issuer. We use the alt_untrusted variable
3101 * to track how far up the chain we find the first match. It
3102 * is only if and when we find a match, that we prune the chain
3103 * and reset ctx->num_untrusted to the reduced count of
3104 * untrusted certificates. While we're searching for such a
3105 * match (which may never be found), it is neither safe nor
3106 * wise to preemptively modify either the chain or
3107 * ctx->num_untrusted.
3109 * Note, like ctx->num_untrusted, alt_untrusted is a count of
3110 * untrusted certificates, not a "depth".
3114 x = sk_X509_value(ctx->chain, i-1);
3116 ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x);
3119 trust = X509_TRUST_REJECTED;
3120 ctx->error = X509_V_ERR_STORE_LOOKUP;
3127 * Alternative trusted issuer for a mid-chain untrusted cert?
3128 * Pop the untrusted cert's successors and retry. We might now
3129 * be able to complete a valid chain via the trust store. Note
3130 * that despite the current trust store match we might still
3131 * fail complete the chain to a suitable trust anchor, in which
3132 * case we may prune some more untrusted certificates and try
3133 * again. Thus the S_DOALTERNATE bit may yet be turned on
3134 * again with an even shorter untrusted chain!
3136 * If in the process we threw away our matching PKIX-TA trust
3137 * anchor, reset DANE trust. We might find a suitable trusted
3138 * certificate among the ones from the trust store.
3140 if ((search & S_DOALTERNATE) != 0) {
3141 if (!ossl_assert(num > i && i > 0 && !self_signed)) {
3142 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
3144 trust = X509_TRUST_REJECTED;
3145 ctx->error = X509_V_ERR_UNSPECIFIED;
3149 search &= ~S_DOALTERNATE;
3150 for (; num > i; --num)
3151 X509_free(sk_X509_pop(ctx->chain));
3152 ctx->num_untrusted = num;
3154 if (DANETLS_ENABLED(dane) &&
3155 dane->mdpth >= ctx->num_untrusted) {
3157 X509_free(dane->mcert);
3160 if (DANETLS_ENABLED(dane) &&
3161 dane->pdpth >= ctx->num_untrusted)
3166 * Self-signed untrusted certificates get replaced by their
3167 * trusted matching issuer. Otherwise, grow the chain.
3170 if (!sk_X509_push(ctx->chain, x = xtmp)) {
3172 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
3173 trust = X509_TRUST_REJECTED;
3174 ctx->error = X509_V_ERR_OUT_OF_MEM;
3178 self_signed = X509_self_signed(x, 0);
3179 if (self_signed < 0) {
3180 sk_X509_free(sktmp);
3181 ctx->error = X509_V_ERR_UNSPECIFIED;
3184 } else if (num == ctx->num_untrusted) {
3186 * We have a self-signed certificate that has the same
3187 * subject name (and perhaps keyid and/or serial number) as
3188 * a trust anchor. We must have an exact match to avoid
3189 * possible impersonation via key substitution etc.
3191 if (X509_cmp(x, xtmp) != 0) {
3192 /* Self-signed untrusted mimic. */
3197 ctx->num_untrusted = --num;
3198 (void) sk_X509_set(ctx->chain, num, x = xtmp);
3203 * We've added a new trusted certificate to the chain, re-check
3204 * trust. If not done, and not self-signed look deeper.
3205 * Whether or not we're doing "trusted first", we no longer
3206 * look for untrusted certificates from the peer's chain.
3208 * At this point ctx->num_trusted and num must reflect the
3209 * correct number of untrusted certificates, since the DANE
3210 * logic in check_trust() depends on distinguishing CAs from
3211 * "the wire" from CAs from the trust store. In particular, the
3212 * certificate at depth "num" should be the new trusted
3213 * certificate with ctx->num_untrusted <= num.
3216 if (!ossl_assert(ctx->num_untrusted <= num)) {
3217 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
3218 trust = X509_TRUST_REJECTED;
3219 ctx->error = X509_V_ERR_UNSPECIFIED;
3223 search &= ~S_DOUNTRUSTED;
3224 switch (trust = check_trust(ctx, num)) {
3225 case X509_TRUST_TRUSTED:
3226 case X509_TRUST_REJECTED:
3236 * No dispositive decision, and either self-signed or no match, if
3237 * we were doing untrusted-first, and alt-chains are not disabled,
3238 * do that, by repeatedly losing one untrusted element at a time,
3239 * and trying to extend the shorted chain.
3241 if ((search & S_DOUNTRUSTED) == 0) {
3242 /* Continue search for a trusted issuer of a shorter chain? */
3243 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0)
3245 /* Still no luck and no fallbacks left? */
3246 if (!may_alternate || (search & S_DOALTERNATE) != 0 ||
3247 ctx->num_untrusted < 2)
3249 /* Search for a trusted issuer of a shorter chain */
3250 search |= S_DOALTERNATE;
3251 alt_untrusted = ctx->num_untrusted - 1;
3257 * Extend chain with peer-provided certificates
3259 if ((search & S_DOUNTRUSTED) != 0) {
3260 num = sk_X509_num(ctx->chain);
3261 if (!ossl_assert(num == ctx->num_untrusted)) {
3262 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
3263 trust = X509_TRUST_REJECTED;
3264 ctx->error = X509_V_ERR_UNSPECIFIED;
3268 x = sk_X509_value(ctx->chain, num-1);
3271 * Once we run out of untrusted issuers, we stop looking for more
3272 * and start looking only in the trust store if enabled.
3274 xtmp = (self_signed || depth < num) ? NULL
3275 : find_issuer(ctx, sktmp, x);
3277 search &= ~S_DOUNTRUSTED;
3279 search |= S_DOTRUSTED;
3283 /* Drop this issuer from future consideration */
3284 (void) sk_X509_delete_ptr(sktmp, xtmp);
3286 if (!X509_up_ref(xtmp)) {
3287 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR);
3288 trust = X509_TRUST_REJECTED;
3289 ctx->error = X509_V_ERR_UNSPECIFIED;
3294 if (!sk_X509_push(ctx->chain, xtmp)) {
3296 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
3297 trust = X509_TRUST_REJECTED;
3298 ctx->error = X509_V_ERR_OUT_OF_MEM;
3304 ++ctx->num_untrusted;
3305 self_signed = X509_self_signed(x, 0);
3306 if (self_signed < 0) {
3307 sk_X509_free(sktmp);
3308 ctx->error = X509_V_ERR_UNSPECIFIED;
3313 * Check for DANE-TA trust of the topmost untrusted certificate.
3315 switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) {
3316 case X509_TRUST_TRUSTED:
3317 case X509_TRUST_REJECTED:
3323 sk_X509_free(sktmp);
3326 * Last chance to make a trusted chain, either bare DANE-TA public-key
3327 * signers, or else direct leaf PKIX trust.
3329 num = sk_X509_num(ctx->chain);
3331 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane))
3332 trust = check_dane_pkeys(ctx);
3333 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted)
3334 trust = check_trust(ctx, num);
3338 case X509_TRUST_TRUSTED:
3340 case X509_TRUST_REJECTED:
3341 /* Callback already issued */
3343 case X509_TRUST_UNTRUSTED:
3345 num = sk_X509_num(ctx->chain);
3346 CHECK_CB(num > depth, ctx, NULL, num-1, X509_V_ERR_CERT_CHAIN_TOO_LONG);
3347 CHECK_CB(DANETLS_ENABLED(dane)
3348 && (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0),
3349 ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH);
3351 return verify_cb_cert(ctx, NULL, num-1,
3352 sk_X509_num(ctx->chain) == 1
3353 ? X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
3354 : X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN);
3355 return verify_cb_cert(ctx, NULL, num-1,
3356 ctx->num_untrusted < num
3357 ? X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT
3358 : X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY);
3362 static const int minbits_table[] = { 80, 112, 128, 192, 256 };
3363 static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table);
3366 * Check whether the public key of ``cert`` meets the security level of
3369 * Returns 1 on success, 0 otherwise.
3371 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert)
3373 EVP_PKEY *pkey = X509_get0_pubkey(cert);
3374 int level = ctx->param->auth_level;
3377 * At security level zero, return without checking for a supported public
3378 * key type. Some engines support key types not understood outside the
3379 * engine, and we only need to understand the key when enforcing a security
3385 /* Unsupported or malformed keys are not secure */
3389 if (level > NUM_AUTH_LEVELS)
3390 level = NUM_AUTH_LEVELS;
3392 return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1];
3396 * Check whether the public key of ``cert`` does not use explicit params
3397 * for an elliptic curve.
3399 * Returns 1 on success, 0 if check fails, -1 for other errors.
3401 static int check_curve(X509 *cert)
3403 #ifndef OPENSSL_NO_EC
3404 EVP_PKEY *pkey = X509_get0_pubkey(cert);
3406 /* Unsupported or malformed key */
3410 if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) {
3413 ret = EC_KEY_decoded_from_explicit_params(EVP_PKEY_get0_EC_KEY(pkey));
3414 return ret < 0 ? ret : !ret;
3422 * Check whether the signature digest algorithm of ``cert`` meets the security
3423 * level of ``ctx``. Should not be checked for trust anchors (whether
3424 * self-signed or otherwise).
3426 * Returns 1 on success, 0 otherwise.
3428 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert)
3431 int level = ctx->param->auth_level;
3435 if (level > NUM_AUTH_LEVELS)
3436 level = NUM_AUTH_LEVELS;
3438 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL))
3441 return secbits >= minbits_table[level - 1];