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 static int check_ssl_ca(const X509 *x);
20 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
22 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
24 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
26 static int purpose_smime(const X509 *x, int ca);
27 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
29 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
31 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
33 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
35 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
36 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
38 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
39 static void xptable_free(X509_PURPOSE *p);
41 static X509_PURPOSE xstandard[] = {
42 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
43 check_purpose_ssl_client, "SSL client", "sslclient", NULL},
44 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
45 check_purpose_ssl_server, "SSL server", "sslserver", NULL},
46 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
47 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
48 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
49 "S/MIME signing", "smimesign", NULL},
50 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
51 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
52 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
53 "CRL signing", "crlsign", NULL},
54 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any",
56 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
57 "OCSP helper", "ocsphelper", NULL},
58 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
59 check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
63 #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
65 static STACK_OF(X509_PURPOSE) *xptable = NULL;
67 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
69 return (*a)->purpose - (*b)->purpose;
73 * As much as I'd like to make X509_check_purpose use a "const" X509* I
74 * really can't because it does recalculate hashes and do other non-const
77 int X509_check_purpose(X509 *x, int id, int ca)
80 const X509_PURPOSE *pt;
82 if (!x509v3_cache_extensions(x))
85 /* Return if side-effect only call */
88 idx = X509_PURPOSE_get_by_id(id);
91 pt = X509_PURPOSE_get0(idx);
92 return pt->check_purpose(pt, x, ca);
95 int X509_PURPOSE_set(int *p, int purpose)
97 if (X509_PURPOSE_get_by_id(purpose) == -1) {
98 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
105 int X509_PURPOSE_get_count(void)
108 return X509_PURPOSE_COUNT;
109 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
112 X509_PURPOSE *X509_PURPOSE_get0(int idx)
116 if (idx < (int)X509_PURPOSE_COUNT)
117 return xstandard + idx;
118 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
121 int X509_PURPOSE_get_by_sname(const char *sname)
125 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
126 xptmp = X509_PURPOSE_get0(i);
127 if (strcmp(xptmp->sname, sname) == 0)
133 int X509_PURPOSE_get_by_id(int purpose)
138 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
139 return purpose - X509_PURPOSE_MIN;
142 tmp.purpose = purpose;
143 idx = sk_X509_PURPOSE_find(xptable, &tmp);
146 return idx + X509_PURPOSE_COUNT;
149 int X509_PURPOSE_add(int id, int trust, int flags,
150 int (*ck) (const X509_PURPOSE *, const X509 *, int),
151 const char *name, const char *sname, void *arg)
156 * This is set according to what we change: application can't set it
158 flags &= ~X509_PURPOSE_DYNAMIC;
159 /* This will always be set for application modified trust entries */
160 flags |= X509_PURPOSE_DYNAMIC_NAME;
161 /* Get existing entry if any */
162 idx = X509_PURPOSE_get_by_id(id);
163 /* Need a new entry */
165 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
166 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
169 ptmp->flags = X509_PURPOSE_DYNAMIC;
171 ptmp = X509_PURPOSE_get0(idx);
173 /* OPENSSL_free existing name if dynamic */
174 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
175 OPENSSL_free(ptmp->name);
176 OPENSSL_free(ptmp->sname);
178 /* dup supplied name */
179 ptmp->name = OPENSSL_strdup(name);
180 ptmp->sname = OPENSSL_strdup(sname);
181 if (ptmp->name == NULL|| ptmp->sname == NULL) {
182 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
185 /* Keep the dynamic flag of existing entry */
186 ptmp->flags &= X509_PURPOSE_DYNAMIC;
187 /* Set all other flags */
188 ptmp->flags |= flags;
192 ptmp->check_purpose = ck;
193 ptmp->usr_data = arg;
195 /* If its a new entry manage the dynamic table */
198 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
199 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
202 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
203 X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
210 OPENSSL_free(ptmp->name);
211 OPENSSL_free(ptmp->sname);
217 static void xptable_free(X509_PURPOSE *p)
221 if (p->flags & X509_PURPOSE_DYNAMIC) {
222 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
223 OPENSSL_free(p->name);
224 OPENSSL_free(p->sname);
230 void X509_PURPOSE_cleanup(void)
232 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
236 int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
241 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
246 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
251 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
256 static int nid_cmp(const int *a, const int *b)
261 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
262 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
264 int X509_supported_extension(X509_EXTENSION *ex)
267 * This table is a list of the NIDs of supported extensions: that is
268 * those which are used by the verify process. If an extension is
269 * critical and doesn't appear in this list then the verify process will
270 * normally reject the certificate. The list must be kept in numerical
271 * order because it will be searched using bsearch.
274 static const int supported_nids[] = {
275 NID_netscape_cert_type, /* 71 */
276 NID_key_usage, /* 83 */
277 NID_subject_alt_name, /* 85 */
278 NID_basic_constraints, /* 87 */
279 NID_certificate_policies, /* 89 */
280 NID_crl_distribution_points, /* 103 */
281 NID_ext_key_usage, /* 126 */
282 #ifndef OPENSSL_NO_RFC3779
283 NID_sbgp_ipAddrBlock, /* 290 */
284 NID_sbgp_autonomousSysNum, /* 291 */
286 NID_policy_constraints, /* 401 */
287 NID_proxyCertInfo, /* 663 */
288 NID_name_constraints, /* 666 */
289 NID_policy_mappings, /* 747 */
290 NID_inhibit_any_policy /* 748 */
293 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
295 if (ex_nid == NID_undef)
298 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
303 /* return 1 on success, 0 if x is invalid, -1 on (internal) error */
304 static int setup_dp(const X509 *x, DIST_POINT *dp)
306 const X509_NAME *iname = NULL;
309 if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) {
310 X509err(0, X509_R_INVALID_DISTPOINT);
313 if (dp->reasons != 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;
322 if (dp->distpoint == NULL || dp->distpoint->type != 1)
325 /* handle name fragment given by nameRelativeToCRLIssuer */
327 * Note that the below way of determining iname is not really compliant
328 * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13
329 * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1
330 * and any CRLissuer could be of type different to GEN_DIRNAME.
332 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
333 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
335 if (gen->type == GEN_DIRNAME) {
336 iname = gen->d.directoryName;
341 iname = X509_get_issuer_name(x);
342 return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1;
345 /* return 1 on success, 0 if x is invalid, -1 on (internal) error */
346 static int setup_crldp(X509 *x)
350 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
351 if (x->crldp == NULL && i != -1)
354 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
355 int res = setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
363 /* Check that issuer public key algorithm matches subject signature algorithm */
364 static int check_sig_alg_match(const EVP_PKEY *pkey, const X509 *subject)
369 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
370 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
371 NULL, &pkey_nid) == 0)
372 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
373 if (EVP_PKEY_type(pkey_nid) != EVP_PKEY_base_id(pkey))
374 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
378 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
379 #define ku_reject(x, usage) \
380 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
381 #define xku_reject(x, usage) \
382 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
383 #define ns_reject(x, usage) \
384 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
387 * Cache info on various X.509v3 extensions and further derived information,
388 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
389 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
390 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
392 int x509v3_cache_extensions(X509 *x)
394 BASIC_CONSTRAINTS *bs;
395 PROXY_CERT_INFO_EXTENSION *pci;
396 ASN1_BIT_STRING *usage;
398 EXTENDED_KEY_USAGE *extusage;
403 /* fast lock-free check, see end of the function for details. */
404 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
405 return (x->ex_flags & EXFLAG_INVALID) == 0;
408 CRYPTO_THREAD_write_lock(x->lock);
409 if (x->ex_flags & EXFLAG_SET) { /* cert has already been processed */
410 CRYPTO_THREAD_unlock(x->lock);
411 return (x->ex_flags & EXFLAG_INVALID) == 0;
415 /* Cache the SHA1 digest of the cert */
416 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
418 * Note that the cert is marked invalid also on internal malloc failure
419 * or on failure of EVP_MD_fetch(), potentially called by X509_digest().
421 x->ex_flags |= EXFLAG_INVALID;
423 /* V1 should mean no extensions ... */
424 if (X509_get_version(x) == 0)
425 x->ex_flags |= EXFLAG_V1;
427 /* Handle basic constraints */
429 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
431 x->ex_flags |= EXFLAG_CA;
432 if (bs->pathlen != NULL) {
434 * the error case !bs->ca is checked by check_chain_extensions()
435 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
437 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
438 X509err(0, X509V3_R_NEGATIVE_PATHLEN);
439 x->ex_flags |= EXFLAG_INVALID;
441 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
444 BASIC_CONSTRAINTS_free(bs);
445 x->ex_flags |= EXFLAG_BCONS;
446 } else if (i != -1) {
447 x->ex_flags |= EXFLAG_INVALID;
450 /* Handle proxy certificates */
451 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
452 if (x->ex_flags & EXFLAG_CA
453 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
454 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
455 x->ex_flags |= EXFLAG_INVALID;
457 if (pci->pcPathLengthConstraint != NULL)
458 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
460 x->ex_pcpathlen = -1;
461 PROXY_CERT_INFO_EXTENSION_free(pci);
462 x->ex_flags |= EXFLAG_PROXY;
463 } else if (i != -1) {
464 x->ex_flags |= EXFLAG_INVALID;
467 /* Handle (basic) key usage */
468 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
470 if (usage->length > 0) {
471 x->ex_kusage = usage->data[0];
472 if (usage->length > 1)
473 x->ex_kusage |= usage->data[1] << 8;
475 x->ex_flags |= EXFLAG_KUSAGE;
476 ASN1_BIT_STRING_free(usage);
477 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
478 if (x->ex_kusage == 0) {
479 X509err(0, X509V3_R_EMPTY_KEY_USAGE);
480 x->ex_flags |= EXFLAG_INVALID;
482 } else if (i != -1) {
483 x->ex_flags |= EXFLAG_INVALID;
486 /* Handle extended key usage */
488 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
489 x->ex_flags |= EXFLAG_XKUSAGE;
490 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
491 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
492 case NID_server_auth:
493 x->ex_xkusage |= XKU_SSL_SERVER;
495 case NID_client_auth:
496 x->ex_xkusage |= XKU_SSL_CLIENT;
498 case NID_email_protect:
499 x->ex_xkusage |= XKU_SMIME;
502 x->ex_xkusage |= XKU_CODE_SIGN;
506 x->ex_xkusage |= XKU_SGC;
509 x->ex_xkusage |= XKU_OCSP_SIGN;
512 x->ex_xkusage |= XKU_TIMESTAMP;
515 x->ex_xkusage |= XKU_DVCS;
517 case NID_anyExtendedKeyUsage:
518 x->ex_xkusage |= XKU_ANYEKU;
521 /* ignore unknown extended key usage */
525 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
526 } else if (i != -1) {
527 x->ex_flags |= EXFLAG_INVALID;
530 /* Handle legacy Netscape extension */
531 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
533 x->ex_nscert = ns->data[0];
536 x->ex_flags |= EXFLAG_NSCERT;
537 ASN1_BIT_STRING_free(ns);
538 } else if (i != -1) {
539 x->ex_flags |= EXFLAG_INVALID;
542 /* Handle subject key identifier and issuer/authority key identifier */
543 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
544 if (x->skid == NULL && i != -1)
545 x->ex_flags |= EXFLAG_INVALID;
547 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
548 if (x->akid == NULL && i != -1)
549 x->ex_flags |= EXFLAG_INVALID;
551 /* Check if subject name matches issuer */
552 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
553 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
554 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
555 /* .. and the signature alg matches the PUBKEY alg: */
556 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
557 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
558 /* This is very related to x509_likely_issued(x, x) == X509_V_OK */
561 /* Handle subject alternative names and various other extensions */
562 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
563 if (x->altname == NULL && i != -1)
564 x->ex_flags |= EXFLAG_INVALID;
565 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
566 if (x->nc == NULL && i != -1)
567 x->ex_flags |= EXFLAG_INVALID;
569 /* Handle CRL distribution point entries */
570 res = setup_crldp(x);
572 x->ex_flags |= EXFLAG_INVALID;
576 #ifndef OPENSSL_NO_RFC3779
577 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
578 if (x->rfc3779_addr == NULL && i != -1)
579 x->ex_flags |= EXFLAG_INVALID;
580 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
581 if (x->rfc3779_asid == NULL && i != -1)
582 x->ex_flags |= EXFLAG_INVALID;
584 for (i = 0; i < X509_get_ext_count(x); i++) {
585 X509_EXTENSION *ex = X509_get_ext(x, i);
586 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
588 if (nid == NID_freshest_crl)
589 x->ex_flags |= EXFLAG_FRESHEST;
590 if (!X509_EXTENSION_get_critical(ex))
592 if (!X509_supported_extension(ex)) {
593 x->ex_flags |= EXFLAG_CRITICAL;
597 case NID_basic_constraints:
598 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
600 case NID_authority_key_identifier:
601 x->ex_flags |= EXFLAG_AKID_CRITICAL;
603 case NID_subject_key_identifier:
604 x->ex_flags |= EXFLAG_SKID_CRITICAL;
606 case NID_subject_alt_name:
607 x->ex_flags |= EXFLAG_SAN_CRITICAL;
614 /* Set x->siginf, ignoring errors due to unsupported algos */
615 (void)x509_init_sig_info(x);
617 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
619 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
621 * Above store triggers fast lock-free check in the beginning of the
622 * function. But one has to ensure that the structure is "stable", i.e.
623 * all stores are visible on all processors. Hence the release fence.
627 if ((x->ex_flags & EXFLAG_INVALID) == 0) {
628 CRYPTO_THREAD_unlock(x->lock);
631 X509err(0, X509V3_R_INVALID_CERTIFICATE);
634 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
635 CRYPTO_THREAD_unlock(x->lock);
640 * CA checks common to all purposes
644 * 2 Only possible in older versions of openSSL when basicConstraints are absent
645 * new versions will not return this value. May be a CA
646 * 3 basicConstraints absent but self-signed V1.
647 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
648 * 5 Netscape specific CA Flags present
651 static int check_ca(const X509 *x)
653 /* keyUsage if present should allow cert signing */
654 if (ku_reject(x, KU_KEY_CERT_SIGN))
656 if (x->ex_flags & EXFLAG_BCONS) {
657 if (x->ex_flags & EXFLAG_CA)
659 /* If basicConstraints says not a CA then say so */
663 /* we support V1 roots for... uh, I don't really know why. */
664 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
667 * If key usage present it must have certSign so tolerate it
669 else if (x->ex_flags & EXFLAG_KUSAGE)
671 /* Older certificates could have Netscape-specific CA types */
672 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
674 /* can this still be regarded a CA certificate? I doubt it */
679 void X509_set_proxy_flag(X509 *x)
681 x->ex_flags |= EXFLAG_PROXY;
684 void X509_set_proxy_pathlen(X509 *x, long l)
689 int X509_check_ca(X509 *x)
691 /* Note 0 normally means "not a CA" - but in this case means error. */
692 if (!x509v3_cache_extensions(x))
698 /* Check SSL CA: common checks for SSL client and server */
699 static int check_ssl_ca(const X509 *x)
702 ca_ret = check_ca(x);
705 /* check nsCertType if present */
706 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
712 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
715 if (xku_reject(x, XKU_SSL_CLIENT))
718 return check_ssl_ca(x);
719 /* We need to do digital signatures or key agreement */
720 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
722 /* nsCertType if present should allow SSL client use */
723 if (ns_reject(x, NS_SSL_CLIENT))
729 * Key usage needed for TLS/SSL server: digital signature, encipherment or
730 * key agreement. The ssl code can check this more thoroughly for individual
734 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
736 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
739 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
742 return check_ssl_ca(x);
744 if (ns_reject(x, NS_SSL_SERVER))
746 if (ku_reject(x, KU_TLS))
753 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
757 ret = check_purpose_ssl_server(xp, x, ca);
760 /* We need to encipher or Netscape complains */
761 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
766 /* common S/MIME checks */
767 static int purpose_smime(const X509 *x, int ca)
769 if (xku_reject(x, XKU_SMIME))
773 ca_ret = check_ca(x);
776 /* check nsCertType if present */
777 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
782 if (x->ex_flags & EXFLAG_NSCERT) {
783 if (x->ex_nscert & NS_SMIME)
785 /* Workaround for some buggy certificates */
786 if (x->ex_nscert & NS_SSL_CLIENT)
793 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
797 ret = purpose_smime(x, ca);
800 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
805 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
809 ret = purpose_smime(x, ca);
812 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
817 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
822 if ((ca_ret = check_ca(x)) != 2)
827 if (ku_reject(x, KU_CRL_SIGN))
833 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
834 * is valid. Additional checks must be made on the chain.
837 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
840 * Must be a valid CA. Should we really support the "I don't know" value
845 /* leaf certificate is checked in OCSP_verify() */
849 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
854 /* If ca is true we must return if this is a valid CA certificate. */
859 * Check the optional key usage field:
860 * if Key Usage is present, it must be one of digitalSignature
861 * and/or nonRepudiation (other values are not consistent and shall
864 if ((x->ex_flags & EXFLAG_KUSAGE)
865 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
866 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
869 /* Only time stamp key usage is permitted and it's required. */
870 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
873 /* Extended Key Usage MUST be critical */
874 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
876 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
877 if (!X509_EXTENSION_get_critical(ext))
884 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
890 * Various checks to see if one certificate potentially issued the second.
891 * This can be used to prune a set of possible issuer certificates which
892 * have been looked up using some simple method such as by subject name.
894 * 1. Check issuer_name(subject) == subject_name(issuer)
895 * 2. If akid(subject) exists, check that it matches issuer
896 * 3. Check that issuer public key algorithm matches subject signature algorithm
897 * 4. Check that any key_usage(issuer) allows certificate signing
898 * Note that this does not include actually checking the signature.
899 * Returns 0 for OK, or positive for reason for mismatch
900 * where reason codes match those for X509_verify_cert().
902 int X509_check_issued(X509 *issuer, X509 *subject)
906 if ((ret = x509_likely_issued(issuer, subject)) != X509_V_OK)
908 return x509_signing_allowed(issuer, subject);
911 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
912 int x509_likely_issued(X509 *issuer, X509 *subject)
916 if (X509_NAME_cmp(X509_get_subject_name(issuer),
917 X509_get_issuer_name(subject)) != 0)
918 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
920 /* set issuer->skid and subject->akid */
921 if (!x509v3_cache_extensions(issuer)
922 || !x509v3_cache_extensions(subject))
923 return X509_V_ERR_UNSPECIFIED;
925 ret = X509_check_akid(issuer, subject->akid);
926 if (ret != X509_V_OK)
929 /* check if the subject signature alg matches the issuer's PUBKEY alg */
930 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
934 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
935 * according to the B<keyUsage> field of I<issuer> if present
936 * depending on any proxyCertInfo extension of I<subject>.
937 * Returns 0 for OK, or positive for reason for rejection
938 * where reason codes match those for X509_verify_cert().
940 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
942 if (subject->ex_flags & EXFLAG_PROXY) {
943 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
944 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
945 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
946 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
950 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
955 /* Check key ids (if present) */
956 if (akid->keyid && issuer->skid &&
957 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
958 return X509_V_ERR_AKID_SKID_MISMATCH;
959 /* Check serial number */
961 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
962 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
963 /* Check issuer name */
966 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
967 * GeneralName. So look for a DirName. There may be more than one but
968 * we only take any notice of the first.
972 X509_NAME *nm = NULL;
975 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
976 gen = sk_GENERAL_NAME_value(gens, i);
977 if (gen->type == GEN_DIRNAME) {
982 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
983 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
988 uint32_t X509_get_extension_flags(X509 *x)
990 /* Call for side-effect of computing hash and caching extensions */
991 X509_check_purpose(x, -1, -1);
995 uint32_t X509_get_key_usage(X509 *x)
997 /* Call for side-effect of computing hash and caching extensions */
998 if (X509_check_purpose(x, -1, -1) != 1)
1000 if (x->ex_flags & EXFLAG_KUSAGE)
1001 return x->ex_kusage;
1005 uint32_t X509_get_extended_key_usage(X509 *x)
1007 /* Call for side-effect of computing hash and caching extensions */
1008 if (X509_check_purpose(x, -1, -1) != 1)
1010 if (x->ex_flags & EXFLAG_XKUSAGE)
1011 return x->ex_xkusage;
1015 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1017 /* Call for side-effect of computing hash and caching extensions */
1018 if (X509_check_purpose(x, -1, -1) != 1)
1023 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1025 /* Call for side-effect of computing hash and caching extensions */
1026 if (X509_check_purpose(x, -1, -1) != 1)
1028 return (x->akid != NULL ? x->akid->keyid : NULL);
1031 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1033 /* Call for side-effect of computing hash and caching extensions */
1034 if (X509_check_purpose(x, -1, -1) != 1)
1036 return (x->akid != NULL ? x->akid->issuer : NULL);
1039 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1041 /* Call for side-effect of computing hash and caching extensions */
1042 if (X509_check_purpose(x, -1, -1) != 1)
1044 return (x->akid != NULL ? x->akid->serial : NULL);
1047 long X509_get_pathlen(X509 *x)
1049 /* Called for side effect of caching extensions */
1050 if (X509_check_purpose(x, -1, -1) != 1
1051 || (x->ex_flags & EXFLAG_BCONS) == 0)
1053 return x->ex_pathlen;
1056 long X509_get_proxy_pathlen(X509 *x)
1058 /* Called for side effect of caching extensions */
1059 if (X509_check_purpose(x, -1, -1) != 1
1060 || (x->ex_flags & EXFLAG_PROXY) == 0)
1062 return x->ex_pcpathlen;