2 * Copyright 1999-2020 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
11 #include "internal/cryptlib.h"
12 #include "internal/numbers.h"
13 #include <openssl/x509v3.h>
14 #include <openssl/x509_vfy.h>
15 #include "crypto/x509.h"
16 #include "internal/tsan_assist.h"
17 #include "x509_local.h"
19 DEFINE_STACK_OF(GENERAL_NAME)
20 DEFINE_STACK_OF(DIST_POINT)
21 DEFINE_STACK_OF(X509_PURPOSE)
22 DEFINE_STACK_OF(ASN1_OBJECT)
24 static int check_ssl_ca(const X509 *x);
25 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
27 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
29 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
31 static int purpose_smime(const X509 *x, int ca);
32 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
34 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
36 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
38 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
40 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
41 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
43 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
44 static void xptable_free(X509_PURPOSE *p);
46 static X509_PURPOSE xstandard[] = {
47 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
48 check_purpose_ssl_client, "SSL client", "sslclient", NULL},
49 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
50 check_purpose_ssl_server, "SSL server", "sslserver", NULL},
51 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
52 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
53 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
54 "S/MIME signing", "smimesign", NULL},
55 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
56 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
57 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
58 "CRL signing", "crlsign", NULL},
59 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any",
61 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
62 "OCSP helper", "ocsphelper", NULL},
63 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
64 check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
68 #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
70 static STACK_OF(X509_PURPOSE) *xptable = NULL;
72 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
74 return (*a)->purpose - (*b)->purpose;
78 * As much as I'd like to make X509_check_purpose use a "const" X509* I
79 * really can't because it does recalculate hashes and do other non-const
82 int X509_check_purpose(X509 *x, int id, int ca)
85 const X509_PURPOSE *pt;
87 if (!X509v3_cache_extensions(x, NULL, NULL))
90 /* Return if side-effect only call */
93 idx = X509_PURPOSE_get_by_id(id);
96 pt = X509_PURPOSE_get0(idx);
97 return pt->check_purpose(pt, x, ca);
100 int X509_PURPOSE_set(int *p, int purpose)
102 if (X509_PURPOSE_get_by_id(purpose) == -1) {
103 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
110 int X509_PURPOSE_get_count(void)
113 return X509_PURPOSE_COUNT;
114 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
117 X509_PURPOSE *X509_PURPOSE_get0(int idx)
121 if (idx < (int)X509_PURPOSE_COUNT)
122 return xstandard + idx;
123 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
126 int X509_PURPOSE_get_by_sname(const char *sname)
130 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
131 xptmp = X509_PURPOSE_get0(i);
132 if (strcmp(xptmp->sname, sname) == 0)
138 int X509_PURPOSE_get_by_id(int purpose)
143 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
144 return purpose - X509_PURPOSE_MIN;
147 tmp.purpose = purpose;
148 idx = sk_X509_PURPOSE_find(xptable, &tmp);
151 return idx + X509_PURPOSE_COUNT;
154 int X509_PURPOSE_add(int id, int trust, int flags,
155 int (*ck) (const X509_PURPOSE *, const X509 *, int),
156 const char *name, const char *sname, void *arg)
161 * This is set according to what we change: application can't set it
163 flags &= ~X509_PURPOSE_DYNAMIC;
164 /* This will always be set for application modified trust entries */
165 flags |= X509_PURPOSE_DYNAMIC_NAME;
166 /* Get existing entry if any */
167 idx = X509_PURPOSE_get_by_id(id);
168 /* Need a new entry */
170 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
171 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
174 ptmp->flags = X509_PURPOSE_DYNAMIC;
176 ptmp = X509_PURPOSE_get0(idx);
178 /* OPENSSL_free existing name if dynamic */
179 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
180 OPENSSL_free(ptmp->name);
181 OPENSSL_free(ptmp->sname);
183 /* dup supplied name */
184 ptmp->name = OPENSSL_strdup(name);
185 ptmp->sname = OPENSSL_strdup(sname);
186 if (ptmp->name == NULL|| ptmp->sname == NULL) {
187 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
190 /* Keep the dynamic flag of existing entry */
191 ptmp->flags &= X509_PURPOSE_DYNAMIC;
192 /* Set all other flags */
193 ptmp->flags |= flags;
197 ptmp->check_purpose = ck;
198 ptmp->usr_data = arg;
200 /* If its a new entry manage the dynamic table */
203 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
204 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
207 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
208 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
215 OPENSSL_free(ptmp->name);
216 OPENSSL_free(ptmp->sname);
222 static void xptable_free(X509_PURPOSE *p)
226 if (p->flags & X509_PURPOSE_DYNAMIC) {
227 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
228 OPENSSL_free(p->name);
229 OPENSSL_free(p->sname);
235 void X509_PURPOSE_cleanup(void)
237 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
241 int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
246 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
251 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
256 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
261 static int nid_cmp(const int *a, const int *b)
266 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
267 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
269 int X509_supported_extension(X509_EXTENSION *ex)
272 * This table is a list of the NIDs of supported extensions: that is
273 * those which are used by the verify process. If an extension is
274 * critical and doesn't appear in this list then the verify process will
275 * normally reject the certificate. The list must be kept in numerical
276 * order because it will be searched using bsearch.
279 static const int supported_nids[] = {
280 NID_netscape_cert_type, /* 71 */
281 NID_key_usage, /* 83 */
282 NID_subject_alt_name, /* 85 */
283 NID_basic_constraints, /* 87 */
284 NID_certificate_policies, /* 89 */
285 NID_crl_distribution_points, /* 103 */
286 NID_ext_key_usage, /* 126 */
287 #ifndef OPENSSL_NO_RFC3779
288 NID_sbgp_ipAddrBlock, /* 290 */
289 NID_sbgp_autonomousSysNum, /* 291 */
291 NID_policy_constraints, /* 401 */
292 NID_proxyCertInfo, /* 663 */
293 NID_name_constraints, /* 666 */
294 NID_policy_mappings, /* 747 */
295 NID_inhibit_any_policy /* 748 */
298 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
300 if (ex_nid == NID_undef)
303 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
308 static int setup_dp(X509 *x, DIST_POINT *dp)
310 const X509_NAME *iname = NULL;
314 if (dp->reasons->length > 0)
315 dp->dp_reasons = dp->reasons->data[0];
316 if (dp->reasons->length > 1)
317 dp->dp_reasons |= (dp->reasons->data[1] << 8);
318 dp->dp_reasons &= CRLDP_ALL_REASONS;
320 dp->dp_reasons = CRLDP_ALL_REASONS;
321 if (!dp->distpoint || (dp->distpoint->type != 1))
323 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
324 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
325 if (gen->type == GEN_DIRNAME) {
326 iname = gen->d.directoryName;
331 iname = X509_get_issuer_name(x);
333 return DIST_POINT_set_dpname(dp->distpoint, iname);
336 static int setup_crldp(X509 *x)
340 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
341 if (x->crldp == NULL && i != -1)
343 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
344 if (!setup_dp(x, sk_DIST_POINT_value(x->crldp, i)))
350 /* Check that issuer public key algorithm matches subject signature algorithm */
351 static int check_sig_alg_match(const EVP_PKEY *pkey, const X509 *subject)
356 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
357 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
358 NULL, &pkey_nid) == 0)
359 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
360 if (EVP_PKEY_type(pkey_nid) != EVP_PKEY_base_id(pkey))
361 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
365 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
366 #define ku_reject(x, usage) \
367 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
368 #define xku_reject(x, usage) \
369 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
370 #define ns_reject(x, usage) \
371 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
373 /* this caches also further information, e.g., if the cert is self-issued */
374 int X509v3_cache_extensions(X509 *x, OPENSSL_CTX *libctx, const char *propq)
376 BASIC_CONSTRAINTS *bs;
377 PROXY_CERT_INFO_EXTENSION *pci;
378 ASN1_BIT_STRING *usage;
380 EXTENDED_KEY_USAGE *extusage;
386 /* fast lock-free check, see end of the function for details. */
387 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
388 return (x->ex_flags & EXFLAG_INVALID) == 0;
391 CRYPTO_THREAD_write_lock(x->lock);
392 if (x->ex_flags & EXFLAG_SET) {
393 CRYPTO_THREAD_unlock(x->lock);
394 return (x->ex_flags & EXFLAG_INVALID) == 0;
397 sha1 = EVP_MD_fetch(libctx, "SHA1", propq);
398 if (sha1 == NULL || !X509_digest(x, sha1, x->sha1_hash, NULL))
399 x->ex_flags |= EXFLAG_INVALID;
402 /* V1 should mean no extensions ... */
403 if (!X509_get_version(x))
404 x->ex_flags |= EXFLAG_V1;
405 /* Handle basic constraints */
406 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) {
408 x->ex_flags |= EXFLAG_CA;
410 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
411 x->ex_flags |= EXFLAG_INVALID;
414 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
415 if (!bs->ca && x->ex_pathlen != 0) {
416 x->ex_flags |= EXFLAG_INVALID;
422 BASIC_CONSTRAINTS_free(bs);
423 x->ex_flags |= EXFLAG_BCONS;
424 } else if (i != -1) {
425 x->ex_flags |= EXFLAG_INVALID;
427 /* Handle proxy certificates */
428 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL))) {
429 if (x->ex_flags & EXFLAG_CA
430 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
431 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
432 x->ex_flags |= EXFLAG_INVALID;
434 if (pci->pcPathLengthConstraint) {
435 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
437 x->ex_pcpathlen = -1;
438 PROXY_CERT_INFO_EXTENSION_free(pci);
439 x->ex_flags |= EXFLAG_PROXY;
440 } else if (i != -1) {
441 x->ex_flags |= EXFLAG_INVALID;
443 /* Handle key usage */
444 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) {
445 if (usage->length > 0) {
446 x->ex_kusage = usage->data[0];
447 if (usage->length > 1)
448 x->ex_kusage |= usage->data[1] << 8;
451 x->ex_flags |= EXFLAG_KUSAGE;
452 ASN1_BIT_STRING_free(usage);
453 } else if (i != -1) {
454 x->ex_flags |= EXFLAG_INVALID;
457 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) {
458 x->ex_flags |= EXFLAG_XKUSAGE;
459 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
460 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
461 case NID_server_auth:
462 x->ex_xkusage |= XKU_SSL_SERVER;
465 case NID_client_auth:
466 x->ex_xkusage |= XKU_SSL_CLIENT;
469 case NID_email_protect:
470 x->ex_xkusage |= XKU_SMIME;
474 x->ex_xkusage |= XKU_CODE_SIGN;
479 x->ex_xkusage |= XKU_SGC;
483 x->ex_xkusage |= XKU_OCSP_SIGN;
487 x->ex_xkusage |= XKU_TIMESTAMP;
491 x->ex_xkusage |= XKU_DVCS;
494 case NID_anyExtendedKeyUsage:
495 x->ex_xkusage |= XKU_ANYEKU;
499 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
500 } else if (i != -1) {
501 x->ex_flags |= EXFLAG_INVALID;
504 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) {
506 x->ex_nscert = ns->data[0];
509 x->ex_flags |= EXFLAG_NSCERT;
510 ASN1_BIT_STRING_free(ns);
511 } else if (i != -1) {
512 x->ex_flags |= EXFLAG_INVALID;
514 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
515 if (x->skid == NULL && i != -1)
516 x->ex_flags |= EXFLAG_INVALID;
517 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
518 if (x->akid == NULL && i != -1)
519 x->ex_flags |= EXFLAG_INVALID;
520 /* Does subject name match issuer ? */
521 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
522 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
523 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
524 /* .. and the signature alg matches the PUBKEY alg: */
525 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
526 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
528 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
529 if (x->altname == NULL && i != -1)
530 x->ex_flags |= EXFLAG_INVALID;
531 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
532 if (x->nc == NULL && i != -1)
533 x->ex_flags |= EXFLAG_INVALID;
535 x->ex_flags |= EXFLAG_INVALID;
537 #ifndef OPENSSL_NO_RFC3779
538 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
539 if (x->rfc3779_addr == NULL && i != -1)
540 x->ex_flags |= EXFLAG_INVALID;
541 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
542 if (x->rfc3779_asid == NULL && i != -1)
543 x->ex_flags |= EXFLAG_INVALID;
545 for (i = 0; i < X509_get_ext_count(x); i++) {
546 ex = X509_get_ext(x, i);
547 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
549 x->ex_flags |= EXFLAG_FRESHEST;
550 if (!X509_EXTENSION_get_critical(ex))
552 if (!X509_supported_extension(ex)) {
553 x->ex_flags |= EXFLAG_CRITICAL;
557 x509_init_sig_info(x);
558 x->ex_flags |= EXFLAG_SET;
560 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
562 * Above store triggers fast lock-free check in the beginning of the
563 * function. But one has to ensure that the structure is "stable", i.e.
564 * all stores are visible on all processors. Hence the release fence.
567 CRYPTO_THREAD_unlock(x->lock);
569 return (x->ex_flags & EXFLAG_INVALID) == 0;
573 * CA checks common to all purposes
577 * 2 Only possible in older versions of openSSL when basicConstraints are absent
578 * new versions will not return this value. May be a CA
579 * 3 basicConstraints absent but self-signed V1.
580 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
581 * 5 Netscape specific CA Flags present
584 static int check_ca(const X509 *x)
586 /* keyUsage if present should allow cert signing */
587 if (ku_reject(x, KU_KEY_CERT_SIGN))
589 if (x->ex_flags & EXFLAG_BCONS) {
590 if (x->ex_flags & EXFLAG_CA)
592 /* If basicConstraints says not a CA then say so */
596 /* we support V1 roots for... uh, I don't really know why. */
597 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
600 * If key usage present it must have certSign so tolerate it
602 else if (x->ex_flags & EXFLAG_KUSAGE)
604 /* Older certificates could have Netscape-specific CA types */
605 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
607 /* can this still be regarded a CA certificate? I doubt it */
612 void X509_set_proxy_flag(X509 *x)
614 x->ex_flags |= EXFLAG_PROXY;
617 void X509_set_proxy_pathlen(X509 *x, long l)
622 int X509_check_ca(X509 *x)
624 /* Note 0 normally means "not a CA" - but in this case means error. */
625 if (!X509v3_cache_extensions(x, NULL, NULL))
631 /* Check SSL CA: common checks for SSL client and server */
632 static int check_ssl_ca(const X509 *x)
635 ca_ret = check_ca(x);
638 /* check nsCertType if present */
639 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
645 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
648 if (xku_reject(x, XKU_SSL_CLIENT))
651 return check_ssl_ca(x);
652 /* We need to do digital signatures or key agreement */
653 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
655 /* nsCertType if present should allow SSL client use */
656 if (ns_reject(x, NS_SSL_CLIENT))
662 * Key usage needed for TLS/SSL server: digital signature, encipherment or
663 * key agreement. The ssl code can check this more thoroughly for individual
667 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
669 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
672 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
675 return check_ssl_ca(x);
677 if (ns_reject(x, NS_SSL_SERVER))
679 if (ku_reject(x, KU_TLS))
686 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
690 ret = check_purpose_ssl_server(xp, x, ca);
693 /* We need to encipher or Netscape complains */
694 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
699 /* common S/MIME checks */
700 static int purpose_smime(const X509 *x, int ca)
702 if (xku_reject(x, XKU_SMIME))
706 ca_ret = check_ca(x);
709 /* check nsCertType if present */
710 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
715 if (x->ex_flags & EXFLAG_NSCERT) {
716 if (x->ex_nscert & NS_SMIME)
718 /* Workaround for some buggy certificates */
719 if (x->ex_nscert & NS_SSL_CLIENT)
726 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
730 ret = purpose_smime(x, ca);
733 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
738 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
742 ret = purpose_smime(x, ca);
745 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
750 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
755 if ((ca_ret = check_ca(x)) != 2)
760 if (ku_reject(x, KU_CRL_SIGN))
766 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
767 * is valid. Additional checks must be made on the chain.
770 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
773 * Must be a valid CA. Should we really support the "I don't know" value
778 /* leaf certificate is checked in OCSP_verify() */
782 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
787 /* If ca is true we must return if this is a valid CA certificate. */
792 * Check the optional key usage field:
793 * if Key Usage is present, it must be one of digitalSignature
794 * and/or nonRepudiation (other values are not consistent and shall
797 if ((x->ex_flags & EXFLAG_KUSAGE)
798 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
799 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
802 /* Only time stamp key usage is permitted and it's required. */
803 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
806 /* Extended Key Usage MUST be critical */
807 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
809 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
810 if (!X509_EXTENSION_get_critical(ext))
817 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
823 * Various checks to see if one certificate potentially issued the second.
824 * This can be used to prune a set of possible issuer certificates which
825 * have been looked up using some simple method such as by subject name.
827 * 1. Check issuer_name(subject) == subject_name(issuer)
828 * 2. If akid(subject) exists, check that it matches issuer
829 * 3. Check that issuer public key algorithm matches subject signature algorithm
830 * 4. Check that any key_usage(issuer) allows certificate signing
831 * Note that this does not include actually checking the signature.
832 * Returns 0 for OK, or positive for reason for mismatch
833 * where reason codes match those for X509_verify_cert().
835 int x509_check_issued_int(X509 *issuer, X509 *subject,
836 OPENSSL_CTX *libctx, const char *propq)
840 if ((ret = x509_likely_issued(issuer, subject, libctx, propq)) != X509_V_OK)
842 return x509_signing_allowed(issuer, subject);
845 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
846 int x509_likely_issued(X509 *issuer, X509 *subject,
847 OPENSSL_CTX *libctx, const char *propq)
851 if (X509_NAME_cmp(X509_get_subject_name(issuer),
852 X509_get_issuer_name(subject)) != 0)
853 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
855 if (!X509v3_cache_extensions(issuer, libctx, propq)
856 || !X509v3_cache_extensions(subject, libctx, propq))
857 return X509_V_ERR_UNSPECIFIED;
859 ret = X509_check_akid(issuer, subject->akid);
860 if (ret != X509_V_OK)
863 /* check if the subject signature alg matches the issuer's PUBKEY alg */
864 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
868 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
869 * according to the B<keyUsage> field of I<issuer> if present
870 * depending on any proxyCertInfo extension of I<subject>.
871 * Returns 0 for OK, or positive for reason for rejection
872 * where reason codes match those for X509_verify_cert().
874 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
876 if (subject->ex_flags & EXFLAG_PROXY) {
877 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
878 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
879 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
880 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
884 int X509_check_issued(X509 *issuer, X509 *subject)
886 return x509_check_issued_int(issuer, subject, NULL, NULL);
889 int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
894 /* Check key ids (if present) */
895 if (akid->keyid && issuer->skid &&
896 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
897 return X509_V_ERR_AKID_SKID_MISMATCH;
898 /* Check serial number */
900 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
901 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
902 /* Check issuer name */
905 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
906 * GeneralName. So look for a DirName. There may be more than one but
907 * we only take any notice of the first.
911 X509_NAME *nm = NULL;
914 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
915 gen = sk_GENERAL_NAME_value(gens, i);
916 if (gen->type == GEN_DIRNAME) {
921 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
922 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
927 uint32_t X509_get_extension_flags(X509 *x)
929 /* Call for side-effect of computing hash and caching extensions */
930 X509_check_purpose(x, -1, -1);
934 uint32_t X509_get_key_usage(X509 *x)
936 /* Call for side-effect of computing hash and caching extensions */
937 if (X509_check_purpose(x, -1, -1) != 1)
939 if (x->ex_flags & EXFLAG_KUSAGE)
944 uint32_t X509_get_extended_key_usage(X509 *x)
946 /* Call for side-effect of computing hash and caching extensions */
947 if (X509_check_purpose(x, -1, -1) != 1)
949 if (x->ex_flags & EXFLAG_XKUSAGE)
950 return x->ex_xkusage;
954 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
956 /* Call for side-effect of computing hash and caching extensions */
957 if (X509_check_purpose(x, -1, -1) != 1)
962 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
964 /* Call for side-effect of computing hash and caching extensions */
965 if (X509_check_purpose(x, -1, -1) != 1)
967 return (x->akid != NULL ? x->akid->keyid : NULL);
970 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
972 /* Call for side-effect of computing hash and caching extensions */
973 if (X509_check_purpose(x, -1, -1) != 1)
975 return (x->akid != NULL ? x->akid->issuer : NULL);
978 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
980 /* Call for side-effect of computing hash and caching extensions */
981 if (X509_check_purpose(x, -1, -1) != 1)
983 return (x->akid != NULL ? x->akid->serial : NULL);
986 long X509_get_pathlen(X509 *x)
988 /* Called for side effect of caching extensions */
989 if (X509_check_purpose(x, -1, -1) != 1
990 || (x->ex_flags & EXFLAG_BCONS) == 0)
992 return x->ex_pathlen;
995 long X509_get_proxy_pathlen(X509 *x)
997 /* Called for side effect of caching extensions */
998 if (X509_check_purpose(x, -1, -1) != 1
999 || (x->ex_flags & EXFLAG_PROXY) == 0)
1001 return x->ex_pcpathlen;