2 * Copyright 1999-2020 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
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 "../x509/x509_local.h" /* for x509_signing_allowed() */
17 #include "internal/tsan_assist.h"
19 static void x509v3_cache_extensions(X509 *x);
21 static int check_ssl_ca(const X509 *x);
22 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
24 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
26 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
28 static int purpose_smime(const X509 *x, int ca);
29 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
31 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
33 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
35 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
37 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
38 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
40 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
41 static void xptable_free(X509_PURPOSE *p);
43 static X509_PURPOSE xstandard[] = {
44 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
45 check_purpose_ssl_client, "SSL client", "sslclient", NULL},
46 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
47 check_purpose_ssl_server, "SSL server", "sslserver", NULL},
48 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
49 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
50 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
51 "S/MIME signing", "smimesign", NULL},
52 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
53 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
54 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
55 "CRL signing", "crlsign", NULL},
56 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any",
58 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
59 "OCSP helper", "ocsphelper", NULL},
60 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
61 check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
65 #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
67 static STACK_OF(X509_PURPOSE) *xptable = NULL;
69 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
71 return (*a)->purpose - (*b)->purpose;
75 * As much as I'd like to make X509_check_purpose use a "const" X509* I
76 * really can't because it does recalculate hashes and do other non-const
79 int X509_check_purpose(X509 *x, int id, int ca)
82 const X509_PURPOSE *pt;
84 x509v3_cache_extensions(x);
85 if (x->ex_flags & EXFLAG_INVALID)
88 /* Return if side-effect only call */
91 idx = X509_PURPOSE_get_by_id(id);
94 pt = X509_PURPOSE_get0(idx);
95 return pt->check_purpose(pt, x, ca);
98 int X509_PURPOSE_set(int *p, int purpose)
100 if (X509_PURPOSE_get_by_id(purpose) == -1) {
101 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
108 int X509_PURPOSE_get_count(void)
111 return X509_PURPOSE_COUNT;
112 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
115 X509_PURPOSE *X509_PURPOSE_get0(int idx)
119 if (idx < (int)X509_PURPOSE_COUNT)
120 return xstandard + idx;
121 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
124 int X509_PURPOSE_get_by_sname(const char *sname)
128 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
129 xptmp = X509_PURPOSE_get0(i);
130 if (strcmp(xptmp->sname, sname) == 0)
136 int X509_PURPOSE_get_by_id(int purpose)
141 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
142 return purpose - X509_PURPOSE_MIN;
145 tmp.purpose = purpose;
146 idx = sk_X509_PURPOSE_find(xptable, &tmp);
149 return idx + X509_PURPOSE_COUNT;
152 int X509_PURPOSE_add(int id, int trust, int flags,
153 int (*ck) (const X509_PURPOSE *, const X509 *, int),
154 const char *name, const char *sname, void *arg)
159 * This is set according to what we change: application can't set it
161 flags &= ~X509_PURPOSE_DYNAMIC;
162 /* This will always be set for application modified trust entries */
163 flags |= X509_PURPOSE_DYNAMIC_NAME;
164 /* Get existing entry if any */
165 idx = X509_PURPOSE_get_by_id(id);
166 /* Need a new entry */
168 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
169 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
172 ptmp->flags = X509_PURPOSE_DYNAMIC;
174 ptmp = X509_PURPOSE_get0(idx);
176 /* OPENSSL_free existing name if dynamic */
177 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
178 OPENSSL_free(ptmp->name);
179 OPENSSL_free(ptmp->sname);
181 /* dup supplied name */
182 ptmp->name = OPENSSL_strdup(name);
183 ptmp->sname = OPENSSL_strdup(sname);
184 if (!ptmp->name || !ptmp->sname) {
185 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
188 /* Keep the dynamic flag of existing entry */
189 ptmp->flags &= X509_PURPOSE_DYNAMIC;
190 /* Set all other flags */
191 ptmp->flags |= flags;
195 ptmp->check_purpose = ck;
196 ptmp->usr_data = arg;
198 /* If its a new entry manage the dynamic table */
201 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
202 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
205 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
206 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
213 OPENSSL_free(ptmp->name);
214 OPENSSL_free(ptmp->sname);
220 static void xptable_free(X509_PURPOSE *p)
224 if (p->flags & X509_PURPOSE_DYNAMIC) {
225 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
226 OPENSSL_free(p->name);
227 OPENSSL_free(p->sname);
233 void X509_PURPOSE_cleanup(void)
235 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
239 int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
244 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
249 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
254 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
259 static int nid_cmp(const int *a, const int *b)
264 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
265 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
267 int X509_supported_extension(X509_EXTENSION *ex)
270 * This table is a list of the NIDs of supported extensions: that is
271 * those which are used by the verify process. If an extension is
272 * critical and doesn't appear in this list then the verify process will
273 * normally reject the certificate. The list must be kept in numerical
274 * order because it will be searched using bsearch.
277 static const int supported_nids[] = {
278 NID_netscape_cert_type, /* 71 */
279 NID_key_usage, /* 83 */
280 NID_subject_alt_name, /* 85 */
281 NID_basic_constraints, /* 87 */
282 NID_certificate_policies, /* 89 */
283 NID_crl_distribution_points, /* 103 */
284 NID_ext_key_usage, /* 126 */
285 #ifndef OPENSSL_NO_RFC3779
286 NID_sbgp_ipAddrBlock, /* 290 */
287 NID_sbgp_autonomousSysNum, /* 291 */
289 NID_policy_constraints, /* 401 */
290 NID_proxyCertInfo, /* 663 */
291 NID_name_constraints, /* 666 */
292 NID_policy_mappings, /* 747 */
293 NID_inhibit_any_policy /* 748 */
296 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
298 if (ex_nid == NID_undef)
301 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
306 static int setup_dp(X509 *x, DIST_POINT *dp)
308 X509_NAME *iname = NULL;
312 if (dp->reasons->length > 0)
313 dp->dp_reasons = dp->reasons->data[0];
314 if (dp->reasons->length > 1)
315 dp->dp_reasons |= (dp->reasons->data[1] << 8);
316 dp->dp_reasons &= CRLDP_ALL_REASONS;
318 dp->dp_reasons = CRLDP_ALL_REASONS;
319 if (!dp->distpoint || (dp->distpoint->type != 1))
321 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
322 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
323 if (gen->type == GEN_DIRNAME) {
324 iname = gen->d.directoryName;
329 iname = X509_get_issuer_name(x);
331 return DIST_POINT_set_dpname(dp->distpoint, iname);
334 static int setup_crldp(X509 *x)
338 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
339 if (x->crldp == NULL && i != -1)
341 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
342 if (!setup_dp(x, sk_DIST_POINT_value(x->crldp, i)))
348 /* Check that issuer public key algorithm matches subject signature algorithm */
349 static int check_sig_alg_match(const EVP_PKEY *pkey, const X509 *subject)
354 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
355 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
356 NULL, &pkey_nid) == 0)
357 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
358 if (EVP_PKEY_type(pkey_nid) != EVP_PKEY_base_id(pkey))
359 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
363 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
364 #define ku_reject(x, usage) \
365 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
366 #define xku_reject(x, usage) \
367 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
368 #define ns_reject(x, usage) \
369 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
371 static void x509v3_cache_extensions(X509 *x)
373 BASIC_CONSTRAINTS *bs;
374 PROXY_CERT_INFO_EXTENSION *pci;
375 ASN1_BIT_STRING *usage;
377 EXTENDED_KEY_USAGE *extusage;
382 /* fast lock-free check, see end of the function for details. */
383 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
387 CRYPTO_THREAD_write_lock(x->lock);
388 if (x->ex_flags & EXFLAG_SET) {
389 CRYPTO_THREAD_unlock(x->lock);
393 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
394 x->ex_flags |= EXFLAG_INVALID;
395 /* V1 should mean no extensions ... */
396 if (!X509_get_version(x))
397 x->ex_flags |= EXFLAG_V1;
398 /* Handle basic constraints */
399 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) {
401 x->ex_flags |= EXFLAG_CA;
403 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
404 x->ex_flags |= EXFLAG_INVALID;
407 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
408 if (!bs->ca && x->ex_pathlen != 0) {
409 x->ex_flags |= EXFLAG_INVALID;
415 BASIC_CONSTRAINTS_free(bs);
416 x->ex_flags |= EXFLAG_BCONS;
417 } else if (i != -1) {
418 x->ex_flags |= EXFLAG_INVALID;
420 /* Handle proxy certificates */
421 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL))) {
422 if (x->ex_flags & EXFLAG_CA
423 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
424 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
425 x->ex_flags |= EXFLAG_INVALID;
427 if (pci->pcPathLengthConstraint) {
428 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
430 x->ex_pcpathlen = -1;
431 PROXY_CERT_INFO_EXTENSION_free(pci);
432 x->ex_flags |= EXFLAG_PROXY;
433 } else if (i != -1) {
434 x->ex_flags |= EXFLAG_INVALID;
436 /* Handle key usage */
437 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) {
438 if (usage->length > 0) {
439 x->ex_kusage = usage->data[0];
440 if (usage->length > 1)
441 x->ex_kusage |= usage->data[1] << 8;
444 x->ex_flags |= EXFLAG_KUSAGE;
445 ASN1_BIT_STRING_free(usage);
446 } else if (i != -1) {
447 x->ex_flags |= EXFLAG_INVALID;
450 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) {
451 x->ex_flags |= EXFLAG_XKUSAGE;
452 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
453 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
454 case NID_server_auth:
455 x->ex_xkusage |= XKU_SSL_SERVER;
458 case NID_client_auth:
459 x->ex_xkusage |= XKU_SSL_CLIENT;
462 case NID_email_protect:
463 x->ex_xkusage |= XKU_SMIME;
467 x->ex_xkusage |= XKU_CODE_SIGN;
472 x->ex_xkusage |= XKU_SGC;
476 x->ex_xkusage |= XKU_OCSP_SIGN;
480 x->ex_xkusage |= XKU_TIMESTAMP;
484 x->ex_xkusage |= XKU_DVCS;
487 case NID_anyExtendedKeyUsage:
488 x->ex_xkusage |= XKU_ANYEKU;
492 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
493 } else if (i != -1) {
494 x->ex_flags |= EXFLAG_INVALID;
497 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) {
499 x->ex_nscert = ns->data[0];
502 x->ex_flags |= EXFLAG_NSCERT;
503 ASN1_BIT_STRING_free(ns);
504 } else if (i != -1) {
505 x->ex_flags |= EXFLAG_INVALID;
507 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
508 if (x->skid == NULL && i != -1)
509 x->ex_flags |= EXFLAG_INVALID;
510 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
511 if (x->akid == NULL && i != -1)
512 x->ex_flags |= EXFLAG_INVALID;
513 /* Does subject name match issuer ? */
514 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
515 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
516 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
517 /* .. and the signature alg matches the PUBKEY alg: */
518 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
519 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
521 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
522 if (x->altname == NULL && i != -1)
523 x->ex_flags |= EXFLAG_INVALID;
524 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
525 if (x->nc == NULL && i != -1)
526 x->ex_flags |= EXFLAG_INVALID;
528 x->ex_flags |= EXFLAG_INVALID;
530 #ifndef OPENSSL_NO_RFC3779
531 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
532 if (x->rfc3779_addr == NULL && i != -1)
533 x->ex_flags |= EXFLAG_INVALID;
534 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
535 if (x->rfc3779_asid == NULL && i != -1)
536 x->ex_flags |= EXFLAG_INVALID;
538 for (i = 0; i < X509_get_ext_count(x); i++) {
539 ex = X509_get_ext(x, i);
540 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
542 x->ex_flags |= EXFLAG_FRESHEST;
543 if (!X509_EXTENSION_get_critical(ex))
545 if (!X509_supported_extension(ex)) {
546 x->ex_flags |= EXFLAG_CRITICAL;
550 x509_init_sig_info(x);
551 x->ex_flags |= EXFLAG_SET;
553 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
555 * Above store triggers fast lock-free check in the beginning of the
556 * function. But one has to ensure that the structure is "stable", i.e.
557 * all stores are visible on all processors. Hence the release fence.
560 CRYPTO_THREAD_unlock(x->lock);
564 * CA checks common to all purposes
568 * 2 Only possible in older versions of openSSL when basicConstraints are absent
569 * new versions will not return this value. May be a CA
570 * 3 basicConstraints absent but self signed V1.
571 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
572 * 5 Netscape specific CA Flags present
575 static int check_ca(const X509 *x)
577 /* keyUsage if present should allow cert signing */
578 if (ku_reject(x, KU_KEY_CERT_SIGN))
580 if (x->ex_flags & EXFLAG_BCONS) {
581 if (x->ex_flags & EXFLAG_CA)
583 /* If basicConstraints says not a CA then say so */
587 /* we support V1 roots for... uh, I don't really know why. */
588 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
591 * If key usage present it must have certSign so tolerate it
593 else if (x->ex_flags & EXFLAG_KUSAGE)
595 /* Older certificates could have Netscape-specific CA types */
596 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
598 /* can this still be regarded a CA certificate? I doubt it */
603 void X509_set_proxy_flag(X509 *x)
605 x->ex_flags |= EXFLAG_PROXY;
608 void X509_set_proxy_pathlen(X509 *x, long l)
613 int X509_check_ca(X509 *x)
615 x509v3_cache_extensions(x);
620 /* Check SSL CA: common checks for SSL client and server */
621 static int check_ssl_ca(const X509 *x)
624 ca_ret = check_ca(x);
627 /* check nsCertType if present */
628 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
634 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
637 if (xku_reject(x, XKU_SSL_CLIENT))
640 return check_ssl_ca(x);
641 /* We need to do digital signatures or key agreement */
642 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
644 /* nsCertType if present should allow SSL client use */
645 if (ns_reject(x, NS_SSL_CLIENT))
651 * Key usage needed for TLS/SSL server: digital signature, encipherment or
652 * key agreement. The ssl code can check this more thoroughly for individual
656 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
658 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
661 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
664 return check_ssl_ca(x);
666 if (ns_reject(x, NS_SSL_SERVER))
668 if (ku_reject(x, KU_TLS))
675 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
679 ret = check_purpose_ssl_server(xp, x, ca);
682 /* We need to encipher or Netscape complains */
683 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
688 /* common S/MIME checks */
689 static int purpose_smime(const X509 *x, int ca)
691 if (xku_reject(x, XKU_SMIME))
695 ca_ret = check_ca(x);
698 /* check nsCertType if present */
699 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
704 if (x->ex_flags & EXFLAG_NSCERT) {
705 if (x->ex_nscert & NS_SMIME)
707 /* Workaround for some buggy certificates */
708 if (x->ex_nscert & NS_SSL_CLIENT)
715 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
719 ret = purpose_smime(x, ca);
722 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
727 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
731 ret = purpose_smime(x, ca);
734 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
739 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
744 if ((ca_ret = check_ca(x)) != 2)
749 if (ku_reject(x, KU_CRL_SIGN))
755 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
756 * is valid. Additional checks must be made on the chain.
759 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
762 * Must be a valid CA. Should we really support the "I don't know" value
767 /* leaf certificate is checked in OCSP_verify() */
771 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
776 /* If ca is true we must return if this is a valid CA certificate. */
781 * Check the optional key usage field:
782 * if Key Usage is present, it must be one of digitalSignature
783 * and/or nonRepudiation (other values are not consistent and shall
786 if ((x->ex_flags & EXFLAG_KUSAGE)
787 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
788 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
791 /* Only time stamp key usage is permitted and it's required. */
792 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
795 /* Extended Key Usage MUST be critical */
796 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
798 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
799 if (!X509_EXTENSION_get_critical(ext))
806 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
812 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
813 * according to the B<keyUsage> field of I<issuer> if present
814 * depending on any proxyCertInfo extension of I<subject>.
815 * Returns 0 for OK, or positive for reason for rejection
816 * where reason codes match those for X509_verify_cert().
818 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
820 if (subject->ex_flags & EXFLAG_PROXY) {
821 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
822 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
823 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
824 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
829 * Various checks to see if one certificate issued the second.
830 * This can be used to prune a set of possible issuer certificates
831 * which have been looked up using some simple method such as by
834 * 1. Check issuer_name(subject) == subject_name(issuer)
835 * 2. If akid(subject) exists check it matches issuer
836 * 3. Check that issuer public key algorithm matches subject signature algorithm
837 * 4. If key_usage(issuer) exists check it supports certificate signing
838 * returns 0 for OK, positive for reason for mismatch, reasons match
839 * codes for X509_verify_cert()
842 int X509_check_issued(X509 *issuer, X509 *subject)
846 if ((ret = x509_likely_issued(issuer, subject)) != X509_V_OK)
848 return x509_signing_allowed(issuer, subject);
851 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
852 int x509_likely_issued(X509 *issuer, X509 *subject)
854 if (X509_NAME_cmp(X509_get_subject_name(issuer),
855 X509_get_issuer_name(subject)))
856 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
858 x509v3_cache_extensions(issuer);
859 if (issuer->ex_flags & EXFLAG_INVALID)
860 return X509_V_ERR_UNSPECIFIED;
861 x509v3_cache_extensions(subject);
862 if (subject->ex_flags & EXFLAG_INVALID)
863 return X509_V_ERR_UNSPECIFIED;
866 int ret = X509_check_akid(issuer, subject->akid);
867 if (ret != X509_V_OK)
871 /* check if the subject signature alg matches the issuer's PUBKEY alg */
872 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
875 int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
881 /* Check key ids (if present) */
882 if (akid->keyid && issuer->skid &&
883 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
884 return X509_V_ERR_AKID_SKID_MISMATCH;
885 /* Check serial number */
887 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
888 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
889 /* Check issuer name */
892 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
893 * GeneralName. So look for a DirName. There may be more than one but
894 * we only take any notice of the first.
898 X509_NAME *nm = NULL;
901 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
902 gen = sk_GENERAL_NAME_value(gens, i);
903 if (gen->type == GEN_DIRNAME) {
908 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
909 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
914 uint32_t X509_get_extension_flags(X509 *x)
916 /* Call for side-effect of computing hash and caching extensions */
917 X509_check_purpose(x, -1, -1);
921 uint32_t X509_get_key_usage(X509 *x)
923 /* Call for side-effect of computing hash and caching extensions */
924 if (X509_check_purpose(x, -1, -1) != 1)
926 if (x->ex_flags & EXFLAG_KUSAGE)
931 uint32_t X509_get_extended_key_usage(X509 *x)
933 /* Call for side-effect of computing hash and caching extensions */
934 if (X509_check_purpose(x, -1, -1) != 1)
936 if (x->ex_flags & EXFLAG_XKUSAGE)
937 return x->ex_xkusage;
941 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
943 /* Call for side-effect of computing hash and caching extensions */
944 if (X509_check_purpose(x, -1, -1) != 1)
949 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
951 /* Call for side-effect of computing hash and caching extensions */
952 if (X509_check_purpose(x, -1, -1) != 1)
954 return (x->akid != NULL ? x->akid->keyid : NULL);
957 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
959 /* Call for side-effect of computing hash and caching extensions */
960 if (X509_check_purpose(x, -1, -1) != 1)
962 return (x->akid != NULL ? x->akid->issuer : NULL);
965 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
967 /* Call for side-effect of computing hash and caching extensions */
968 if (X509_check_purpose(x, -1, -1) != 1)
970 return (x->akid != NULL ? x->akid->serial : NULL);
973 long X509_get_pathlen(X509 *x)
975 /* Called for side effect of caching extensions */
976 if (X509_check_purpose(x, -1, -1) != 1
977 || (x->ex_flags & EXFLAG_BCONS) == 0)
979 return x->ex_pathlen;
982 long X509_get_proxy_pathlen(X509 *x)
984 /* Called for side effect of caching extensions */
985 if (X509_check_purpose(x, -1, -1) != 1
986 || (x->ex_flags & EXFLAG_PROXY) == 0)
988 return x->ex_pcpathlen;