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))
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 /* return 1 on success, 0 if x is invalid, -1 on (internal) error */
309 static int setup_dp(const X509 *x, DIST_POINT *dp)
311 const X509_NAME *iname = NULL;
314 if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) {
315 X509err(0, X509_R_INVALID_DISTPOINT);
318 if (dp->reasons != NULL) {
319 if (dp->reasons->length > 0)
320 dp->dp_reasons = dp->reasons->data[0];
321 if (dp->reasons->length > 1)
322 dp->dp_reasons |= (dp->reasons->data[1] << 8);
323 dp->dp_reasons &= CRLDP_ALL_REASONS;
325 dp->dp_reasons = CRLDP_ALL_REASONS;
327 if (dp->distpoint == NULL || dp->distpoint->type != 1)
330 /* handle name fragment given by nameRelativeToCRLIssuer */
332 * Note that the below way of determining iname is not really compliant
333 * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13
334 * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1
335 * and any CRLissuer could be of type different to GEN_DIRNAME.
337 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
338 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
340 if (gen->type == GEN_DIRNAME) {
341 iname = gen->d.directoryName;
346 iname = X509_get_issuer_name(x);
347 return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1;
350 /* return 1 on success, 0 if x is invalid, -1 on (internal) error */
351 static int setup_crldp(X509 *x)
355 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
356 if (x->crldp == NULL && i != -1)
359 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
360 int res = setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
368 /* Check that issuer public key algorithm matches subject signature algorithm */
369 static int check_sig_alg_match(const EVP_PKEY *pkey, const X509 *subject)
374 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
375 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
376 NULL, &pkey_nid) == 0)
377 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
378 if (EVP_PKEY_type(pkey_nid) != EVP_PKEY_base_id(pkey))
379 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
383 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
384 #define ku_reject(x, usage) \
385 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
386 #define xku_reject(x, usage) \
387 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
388 #define ns_reject(x, usage) \
389 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
392 * Cache info on various X.509v3 extensions and further derived information,
393 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
394 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
395 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
397 int x509v3_cache_extensions(X509 *x)
399 BASIC_CONSTRAINTS *bs;
400 PROXY_CERT_INFO_EXTENSION *pci;
401 ASN1_BIT_STRING *usage;
403 EXTENDED_KEY_USAGE *extusage;
409 /* fast lock-free check, see end of the function for details. */
410 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
411 return (x->ex_flags & EXFLAG_INVALID) == 0;
414 CRYPTO_THREAD_write_lock(x->lock);
415 if (x->ex_flags & EXFLAG_SET) { /* cert has already been processed */
416 CRYPTO_THREAD_unlock(x->lock);
417 return (x->ex_flags & EXFLAG_INVALID) == 0;
421 /* Cache the SHA1 digest of the cert */
422 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
424 * Note that the cert is marked invalid also on internal malloc failure
425 * or on failure of EVP_MD_fetch(), potentially called by X509_digest().
427 x->ex_flags |= EXFLAG_INVALID;
429 /* V1 should mean no extensions ... */
430 if (X509_get_version(x) == 0)
431 x->ex_flags |= EXFLAG_V1;
433 /* Handle basic constraints */
435 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
437 x->ex_flags |= EXFLAG_CA;
438 if (bs->pathlen != NULL) {
440 * the error case !bs->ca is checked by check_chain_extensions()
441 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
443 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
444 X509err(0, X509V3_R_NEGATIVE_PATHLEN);
445 x->ex_flags |= EXFLAG_INVALID;
447 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
450 BASIC_CONSTRAINTS_free(bs);
451 x->ex_flags |= EXFLAG_BCONS;
452 } else if (i != -1) {
453 x->ex_flags |= EXFLAG_INVALID;
456 /* Handle proxy certificates */
457 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
458 if (x->ex_flags & EXFLAG_CA
459 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
460 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
461 x->ex_flags |= EXFLAG_INVALID;
463 if (pci->pcPathLengthConstraint != NULL)
464 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
466 x->ex_pcpathlen = -1;
467 PROXY_CERT_INFO_EXTENSION_free(pci);
468 x->ex_flags |= EXFLAG_PROXY;
469 } else if (i != -1) {
470 x->ex_flags |= EXFLAG_INVALID;
473 /* Handle (basic) key usage */
474 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
476 if (usage->length > 0) {
477 x->ex_kusage = usage->data[0];
478 if (usage->length > 1)
479 x->ex_kusage |= usage->data[1] << 8;
481 x->ex_flags |= EXFLAG_KUSAGE;
482 ASN1_BIT_STRING_free(usage);
483 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
484 if (x->ex_kusage == 0) {
485 X509err(0, X509V3_R_EMPTY_KEY_USAGE);
486 x->ex_flags |= EXFLAG_INVALID;
488 } else if (i != -1) {
489 x->ex_flags |= EXFLAG_INVALID;
492 /* Handle extended key usage */
494 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
495 x->ex_flags |= EXFLAG_XKUSAGE;
496 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
497 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
498 case NID_server_auth:
499 x->ex_xkusage |= XKU_SSL_SERVER;
501 case NID_client_auth:
502 x->ex_xkusage |= XKU_SSL_CLIENT;
504 case NID_email_protect:
505 x->ex_xkusage |= XKU_SMIME;
508 x->ex_xkusage |= XKU_CODE_SIGN;
512 x->ex_xkusage |= XKU_SGC;
515 x->ex_xkusage |= XKU_OCSP_SIGN;
518 x->ex_xkusage |= XKU_TIMESTAMP;
521 x->ex_xkusage |= XKU_DVCS;
523 case NID_anyExtendedKeyUsage:
524 x->ex_xkusage |= XKU_ANYEKU;
527 /* ignore unknown extended key usage */
531 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
532 } else if (i != -1) {
533 x->ex_flags |= EXFLAG_INVALID;
536 /* Handle legacy Netscape extension */
537 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
539 x->ex_nscert = ns->data[0];
542 x->ex_flags |= EXFLAG_NSCERT;
543 ASN1_BIT_STRING_free(ns);
544 } else if (i != -1) {
545 x->ex_flags |= EXFLAG_INVALID;
548 /* Handle subject key identifier and issuer/authority key identifier */
549 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
550 if (x->skid == NULL && i != -1)
551 x->ex_flags |= EXFLAG_INVALID;
553 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
554 if (x->akid == NULL && i != -1)
555 x->ex_flags |= EXFLAG_INVALID;
557 /* Check if subject name matches issuer */
558 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
559 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
560 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
561 /* .. and the signature alg matches the PUBKEY alg: */
562 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
563 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
564 /* This is very related to x509_likely_issued(x, x) == X509_V_OK */
567 /* Handle subject alternative names and various other extensions */
568 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
569 if (x->altname == NULL && i != -1)
570 x->ex_flags |= EXFLAG_INVALID;
571 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
572 if (x->nc == NULL && i != -1)
573 x->ex_flags |= EXFLAG_INVALID;
575 /* Handle CRL distribution point entries */
576 res = setup_crldp(x);
578 x->ex_flags |= EXFLAG_INVALID;
582 #ifndef OPENSSL_NO_RFC3779
583 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
584 if (x->rfc3779_addr == NULL && i != -1)
585 x->ex_flags |= EXFLAG_INVALID;
586 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
587 if (x->rfc3779_asid == NULL && i != -1)
588 x->ex_flags |= EXFLAG_INVALID;
590 for (i = 0; i < X509_get_ext_count(x); i++) {
591 ex = X509_get_ext(x, i);
592 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == NID_freshest_crl)
593 x->ex_flags |= EXFLAG_FRESHEST;
594 if (!X509_EXTENSION_get_critical(ex))
596 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == NID_basic_constraints)
597 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
598 if (!X509_supported_extension(ex)) {
599 x->ex_flags |= EXFLAG_CRITICAL;
604 /* Set x->siginf, ignoring errors due to unsupported algos */
605 (void)x509_init_sig_info(x);
607 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
609 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
611 * Above store triggers fast lock-free check in the beginning of the
612 * function. But one has to ensure that the structure is "stable", i.e.
613 * all stores are visible on all processors. Hence the release fence.
617 if ((x->ex_flags & EXFLAG_INVALID) == 0) {
618 CRYPTO_THREAD_unlock(x->lock);
621 X509err(0, X509V3_R_INVALID_CERTIFICATE);
624 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
625 CRYPTO_THREAD_unlock(x->lock);
630 * CA checks common to all purposes
634 * 2 Only possible in older versions of openSSL when basicConstraints are absent
635 * new versions will not return this value. May be a CA
636 * 3 basicConstraints absent but self-signed V1.
637 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
638 * 5 Netscape specific CA Flags present
641 static int check_ca(const X509 *x)
643 /* keyUsage if present should allow cert signing */
644 if (ku_reject(x, KU_KEY_CERT_SIGN))
646 if (x->ex_flags & EXFLAG_BCONS) {
647 if (x->ex_flags & EXFLAG_CA)
649 /* If basicConstraints says not a CA then say so */
653 /* we support V1 roots for... uh, I don't really know why. */
654 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
657 * If key usage present it must have certSign so tolerate it
659 else if (x->ex_flags & EXFLAG_KUSAGE)
661 /* Older certificates could have Netscape-specific CA types */
662 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
664 /* can this still be regarded a CA certificate? I doubt it */
669 void X509_set_proxy_flag(X509 *x)
671 x->ex_flags |= EXFLAG_PROXY;
674 void X509_set_proxy_pathlen(X509 *x, long l)
679 int X509_check_ca(X509 *x)
681 /* Note 0 normally means "not a CA" - but in this case means error. */
682 if (!x509v3_cache_extensions(x))
688 /* Check SSL CA: common checks for SSL client and server */
689 static int check_ssl_ca(const X509 *x)
692 ca_ret = check_ca(x);
695 /* check nsCertType if present */
696 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
702 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
705 if (xku_reject(x, XKU_SSL_CLIENT))
708 return check_ssl_ca(x);
709 /* We need to do digital signatures or key agreement */
710 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
712 /* nsCertType if present should allow SSL client use */
713 if (ns_reject(x, NS_SSL_CLIENT))
719 * Key usage needed for TLS/SSL server: digital signature, encipherment or
720 * key agreement. The ssl code can check this more thoroughly for individual
724 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
726 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
729 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
732 return check_ssl_ca(x);
734 if (ns_reject(x, NS_SSL_SERVER))
736 if (ku_reject(x, KU_TLS))
743 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
747 ret = check_purpose_ssl_server(xp, x, ca);
750 /* We need to encipher or Netscape complains */
751 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
756 /* common S/MIME checks */
757 static int purpose_smime(const X509 *x, int ca)
759 if (xku_reject(x, XKU_SMIME))
763 ca_ret = check_ca(x);
766 /* check nsCertType if present */
767 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
772 if (x->ex_flags & EXFLAG_NSCERT) {
773 if (x->ex_nscert & NS_SMIME)
775 /* Workaround for some buggy certificates */
776 if (x->ex_nscert & NS_SSL_CLIENT)
783 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
787 ret = purpose_smime(x, ca);
790 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
795 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
799 ret = purpose_smime(x, ca);
802 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
807 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
812 if ((ca_ret = check_ca(x)) != 2)
817 if (ku_reject(x, KU_CRL_SIGN))
823 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
824 * is valid. Additional checks must be made on the chain.
827 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
830 * Must be a valid CA. Should we really support the "I don't know" value
835 /* leaf certificate is checked in OCSP_verify() */
839 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
844 /* If ca is true we must return if this is a valid CA certificate. */
849 * Check the optional key usage field:
850 * if Key Usage is present, it must be one of digitalSignature
851 * and/or nonRepudiation (other values are not consistent and shall
854 if ((x->ex_flags & EXFLAG_KUSAGE)
855 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
856 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
859 /* Only time stamp key usage is permitted and it's required. */
860 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
863 /* Extended Key Usage MUST be critical */
864 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
866 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
867 if (!X509_EXTENSION_get_critical(ext))
874 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
880 * Various checks to see if one certificate potentially issued the second.
881 * This can be used to prune a set of possible issuer certificates which
882 * have been looked up using some simple method such as by subject name.
884 * 1. Check issuer_name(subject) == subject_name(issuer)
885 * 2. If akid(subject) exists, check that it matches issuer
886 * 3. Check that issuer public key algorithm matches subject signature algorithm
887 * 4. Check that any key_usage(issuer) allows certificate signing
888 * Note that this does not include actually checking the signature.
889 * Returns 0 for OK, or positive for reason for mismatch
890 * where reason codes match those for X509_verify_cert().
892 int X509_check_issued(X509 *issuer, X509 *subject)
896 if ((ret = x509_likely_issued(issuer, subject)) != X509_V_OK)
898 return x509_signing_allowed(issuer, subject);
901 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
902 int x509_likely_issued(X509 *issuer, X509 *subject)
906 if (X509_NAME_cmp(X509_get_subject_name(issuer),
907 X509_get_issuer_name(subject)) != 0)
908 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
910 /* set issuer->skid and subject->akid */
911 if (!x509v3_cache_extensions(issuer)
912 || !x509v3_cache_extensions(subject))
913 return X509_V_ERR_UNSPECIFIED;
915 ret = X509_check_akid(issuer, subject->akid);
916 if (ret != X509_V_OK)
919 /* check if the subject signature alg matches the issuer's PUBKEY alg */
920 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
924 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
925 * according to the B<keyUsage> field of I<issuer> if present
926 * depending on any proxyCertInfo extension of I<subject>.
927 * Returns 0 for OK, or positive for reason for rejection
928 * where reason codes match those for X509_verify_cert().
930 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
932 if (subject->ex_flags & EXFLAG_PROXY) {
933 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
934 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
935 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
936 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
940 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
945 /* Check key ids (if present) */
946 if (akid->keyid && issuer->skid &&
947 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
948 return X509_V_ERR_AKID_SKID_MISMATCH;
949 /* Check serial number */
951 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
952 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
953 /* Check issuer name */
956 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
957 * GeneralName. So look for a DirName. There may be more than one but
958 * we only take any notice of the first.
962 X509_NAME *nm = NULL;
965 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
966 gen = sk_GENERAL_NAME_value(gens, i);
967 if (gen->type == GEN_DIRNAME) {
972 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
973 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
978 uint32_t X509_get_extension_flags(X509 *x)
980 /* Call for side-effect of computing hash and caching extensions */
981 X509_check_purpose(x, -1, -1);
985 uint32_t X509_get_key_usage(X509 *x)
987 /* Call for side-effect of computing hash and caching extensions */
988 if (X509_check_purpose(x, -1, -1) != 1)
990 if (x->ex_flags & EXFLAG_KUSAGE)
995 uint32_t X509_get_extended_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_XKUSAGE)
1001 return x->ex_xkusage;
1005 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1007 /* Call for side-effect of computing hash and caching extensions */
1008 if (X509_check_purpose(x, -1, -1) != 1)
1013 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1015 /* Call for side-effect of computing hash and caching extensions */
1016 if (X509_check_purpose(x, -1, -1) != 1)
1018 return (x->akid != NULL ? x->akid->keyid : NULL);
1021 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1023 /* Call for side-effect of computing hash and caching extensions */
1024 if (X509_check_purpose(x, -1, -1) != 1)
1026 return (x->akid != NULL ? x->akid->issuer : NULL);
1029 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1031 /* Call for side-effect of computing hash and caching extensions */
1032 if (X509_check_purpose(x, -1, -1) != 1)
1034 return (x->akid != NULL ? x->akid->serial : NULL);
1037 long X509_get_pathlen(X509 *x)
1039 /* Called for side effect of caching extensions */
1040 if (X509_check_purpose(x, -1, -1) != 1
1041 || (x->ex_flags & EXFLAG_BCONS) == 0)
1043 return x->ex_pathlen;
1046 long X509_get_proxy_pathlen(X509 *x)
1048 /* Called for side effect of caching extensions */
1049 if (X509_check_purpose(x, -1, -1) != 1
1050 || (x->ex_flags & EXFLAG_PROXY) == 0)
1052 return x->ex_pcpathlen;