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;
408 /* fast lock-free check, see end of the function for details. */
409 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
410 return (x->ex_flags & EXFLAG_INVALID) == 0;
413 CRYPTO_THREAD_write_lock(x->lock);
414 if (x->ex_flags & EXFLAG_SET) { /* cert has already been processed */
415 CRYPTO_THREAD_unlock(x->lock);
416 return (x->ex_flags & EXFLAG_INVALID) == 0;
420 /* Cache the SHA1 digest of the cert */
421 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
423 * Note that the cert is marked invalid also on internal malloc failure
424 * or on failure of EVP_MD_fetch(), potentially called by X509_digest().
426 x->ex_flags |= EXFLAG_INVALID;
428 /* V1 should mean no extensions ... */
429 if (X509_get_version(x) == 0)
430 x->ex_flags |= EXFLAG_V1;
432 /* Handle basic constraints */
434 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
436 x->ex_flags |= EXFLAG_CA;
437 if (bs->pathlen != NULL) {
439 * the error case !bs->ca is checked by check_chain_extensions()
440 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
442 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
443 X509err(0, X509V3_R_NEGATIVE_PATHLEN);
444 x->ex_flags |= EXFLAG_INVALID;
446 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
449 BASIC_CONSTRAINTS_free(bs);
450 x->ex_flags |= EXFLAG_BCONS;
451 } else if (i != -1) {
452 x->ex_flags |= EXFLAG_INVALID;
455 /* Handle proxy certificates */
456 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
457 if (x->ex_flags & EXFLAG_CA
458 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
459 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
460 x->ex_flags |= EXFLAG_INVALID;
462 if (pci->pcPathLengthConstraint != NULL)
463 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
465 x->ex_pcpathlen = -1;
466 PROXY_CERT_INFO_EXTENSION_free(pci);
467 x->ex_flags |= EXFLAG_PROXY;
468 } else if (i != -1) {
469 x->ex_flags |= EXFLAG_INVALID;
472 /* Handle (basic) key usage */
473 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
475 if (usage->length > 0) {
476 x->ex_kusage = usage->data[0];
477 if (usage->length > 1)
478 x->ex_kusage |= usage->data[1] << 8;
480 x->ex_flags |= EXFLAG_KUSAGE;
481 ASN1_BIT_STRING_free(usage);
482 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
483 if (x->ex_kusage == 0) {
484 X509err(0, X509V3_R_EMPTY_KEY_USAGE);
485 x->ex_flags |= EXFLAG_INVALID;
487 } else if (i != -1) {
488 x->ex_flags |= EXFLAG_INVALID;
491 /* Handle extended key usage */
493 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
494 x->ex_flags |= EXFLAG_XKUSAGE;
495 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
496 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
497 case NID_server_auth:
498 x->ex_xkusage |= XKU_SSL_SERVER;
500 case NID_client_auth:
501 x->ex_xkusage |= XKU_SSL_CLIENT;
503 case NID_email_protect:
504 x->ex_xkusage |= XKU_SMIME;
507 x->ex_xkusage |= XKU_CODE_SIGN;
511 x->ex_xkusage |= XKU_SGC;
514 x->ex_xkusage |= XKU_OCSP_SIGN;
517 x->ex_xkusage |= XKU_TIMESTAMP;
520 x->ex_xkusage |= XKU_DVCS;
522 case NID_anyExtendedKeyUsage:
523 x->ex_xkusage |= XKU_ANYEKU;
526 /* ignore unknown extended key usage */
530 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
531 } else if (i != -1) {
532 x->ex_flags |= EXFLAG_INVALID;
535 /* Handle legacy Netscape extension */
536 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
538 x->ex_nscert = ns->data[0];
541 x->ex_flags |= EXFLAG_NSCERT;
542 ASN1_BIT_STRING_free(ns);
543 } else if (i != -1) {
544 x->ex_flags |= EXFLAG_INVALID;
547 /* Handle subject key identifier and issuer/authority key identifier */
548 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
549 if (x->skid == NULL && i != -1)
550 x->ex_flags |= EXFLAG_INVALID;
552 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
553 if (x->akid == NULL && i != -1)
554 x->ex_flags |= EXFLAG_INVALID;
556 /* Check if subject name matches issuer */
557 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
558 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
559 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
560 /* .. and the signature alg matches the PUBKEY alg: */
561 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
562 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
563 /* This is very related to x509_likely_issued(x, x) == X509_V_OK */
566 /* Handle subject alternative names and various other extensions */
567 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
568 if (x->altname == NULL && i != -1)
569 x->ex_flags |= EXFLAG_INVALID;
570 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
571 if (x->nc == NULL && i != -1)
572 x->ex_flags |= EXFLAG_INVALID;
574 /* Handle CRL distribution point entries */
575 res = setup_crldp(x);
577 x->ex_flags |= EXFLAG_INVALID;
581 #ifndef OPENSSL_NO_RFC3779
582 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
583 if (x->rfc3779_addr == NULL && i != -1)
584 x->ex_flags |= EXFLAG_INVALID;
585 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
586 if (x->rfc3779_asid == NULL && i != -1)
587 x->ex_flags |= EXFLAG_INVALID;
589 for (i = 0; i < X509_get_ext_count(x); i++) {
590 X509_EXTENSION *ex = X509_get_ext(x, i);
591 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
593 if (nid == NID_freshest_crl)
594 x->ex_flags |= EXFLAG_FRESHEST;
595 if (!X509_EXTENSION_get_critical(ex))
597 if (!X509_supported_extension(ex)) {
598 x->ex_flags |= EXFLAG_CRITICAL;
602 case NID_basic_constraints:
603 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
605 case NID_authority_key_identifier:
606 x->ex_flags |= EXFLAG_AKID_CRITICAL;
608 case NID_subject_key_identifier:
609 x->ex_flags |= EXFLAG_SKID_CRITICAL;
616 /* Set x->siginf, ignoring errors due to unsupported algos */
617 (void)x509_init_sig_info(x);
619 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
621 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
623 * Above store triggers fast lock-free check in the beginning of the
624 * function. But one has to ensure that the structure is "stable", i.e.
625 * all stores are visible on all processors. Hence the release fence.
629 if ((x->ex_flags & EXFLAG_INVALID) == 0) {
630 CRYPTO_THREAD_unlock(x->lock);
633 X509err(0, X509V3_R_INVALID_CERTIFICATE);
636 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
637 CRYPTO_THREAD_unlock(x->lock);
642 * CA checks common to all purposes
646 * 2 Only possible in older versions of openSSL when basicConstraints are absent
647 * new versions will not return this value. May be a CA
648 * 3 basicConstraints absent but self-signed V1.
649 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
650 * 5 Netscape specific CA Flags present
653 static int check_ca(const X509 *x)
655 /* keyUsage if present should allow cert signing */
656 if (ku_reject(x, KU_KEY_CERT_SIGN))
658 if (x->ex_flags & EXFLAG_BCONS) {
659 if (x->ex_flags & EXFLAG_CA)
661 /* If basicConstraints says not a CA then say so */
665 /* we support V1 roots for... uh, I don't really know why. */
666 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
669 * If key usage present it must have certSign so tolerate it
671 else if (x->ex_flags & EXFLAG_KUSAGE)
673 /* Older certificates could have Netscape-specific CA types */
674 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
676 /* can this still be regarded a CA certificate? I doubt it */
681 void X509_set_proxy_flag(X509 *x)
683 x->ex_flags |= EXFLAG_PROXY;
686 void X509_set_proxy_pathlen(X509 *x, long l)
691 int X509_check_ca(X509 *x)
693 /* Note 0 normally means "not a CA" - but in this case means error. */
694 if (!x509v3_cache_extensions(x))
700 /* Check SSL CA: common checks for SSL client and server */
701 static int check_ssl_ca(const X509 *x)
704 ca_ret = check_ca(x);
707 /* check nsCertType if present */
708 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
714 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
717 if (xku_reject(x, XKU_SSL_CLIENT))
720 return check_ssl_ca(x);
721 /* We need to do digital signatures or key agreement */
722 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
724 /* nsCertType if present should allow SSL client use */
725 if (ns_reject(x, NS_SSL_CLIENT))
731 * Key usage needed for TLS/SSL server: digital signature, encipherment or
732 * key agreement. The ssl code can check this more thoroughly for individual
736 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
738 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
741 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
744 return check_ssl_ca(x);
746 if (ns_reject(x, NS_SSL_SERVER))
748 if (ku_reject(x, KU_TLS))
755 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
759 ret = check_purpose_ssl_server(xp, x, ca);
762 /* We need to encipher or Netscape complains */
763 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
768 /* common S/MIME checks */
769 static int purpose_smime(const X509 *x, int ca)
771 if (xku_reject(x, XKU_SMIME))
775 ca_ret = check_ca(x);
778 /* check nsCertType if present */
779 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
784 if (x->ex_flags & EXFLAG_NSCERT) {
785 if (x->ex_nscert & NS_SMIME)
787 /* Workaround for some buggy certificates */
788 if (x->ex_nscert & NS_SSL_CLIENT)
795 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
799 ret = purpose_smime(x, ca);
802 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
807 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
811 ret = purpose_smime(x, ca);
814 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
819 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
824 if ((ca_ret = check_ca(x)) != 2)
829 if (ku_reject(x, KU_CRL_SIGN))
835 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
836 * is valid. Additional checks must be made on the chain.
839 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
842 * Must be a valid CA. Should we really support the "I don't know" value
847 /* leaf certificate is checked in OCSP_verify() */
851 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
856 /* If ca is true we must return if this is a valid CA certificate. */
861 * Check the optional key usage field:
862 * if Key Usage is present, it must be one of digitalSignature
863 * and/or nonRepudiation (other values are not consistent and shall
866 if ((x->ex_flags & EXFLAG_KUSAGE)
867 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
868 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
871 /* Only time stamp key usage is permitted and it's required. */
872 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
875 /* Extended Key Usage MUST be critical */
876 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
878 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
879 if (!X509_EXTENSION_get_critical(ext))
886 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
892 * Various checks to see if one certificate potentially issued the second.
893 * This can be used to prune a set of possible issuer certificates which
894 * have been looked up using some simple method such as by subject name.
896 * 1. Check issuer_name(subject) == subject_name(issuer)
897 * 2. If akid(subject) exists, check that it matches issuer
898 * 3. Check that issuer public key algorithm matches subject signature algorithm
899 * 4. Check that any key_usage(issuer) allows certificate signing
900 * Note that this does not include actually checking the signature.
901 * Returns 0 for OK, or positive for reason for mismatch
902 * where reason codes match those for X509_verify_cert().
904 int X509_check_issued(X509 *issuer, X509 *subject)
908 if ((ret = x509_likely_issued(issuer, subject)) != X509_V_OK)
910 return x509_signing_allowed(issuer, subject);
913 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
914 int x509_likely_issued(X509 *issuer, X509 *subject)
918 if (X509_NAME_cmp(X509_get_subject_name(issuer),
919 X509_get_issuer_name(subject)) != 0)
920 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
922 /* set issuer->skid and subject->akid */
923 if (!x509v3_cache_extensions(issuer)
924 || !x509v3_cache_extensions(subject))
925 return X509_V_ERR_UNSPECIFIED;
927 ret = X509_check_akid(issuer, subject->akid);
928 if (ret != X509_V_OK)
931 /* check if the subject signature alg matches the issuer's PUBKEY alg */
932 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
936 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
937 * according to the B<keyUsage> field of I<issuer> if present
938 * depending on any proxyCertInfo extension of I<subject>.
939 * Returns 0 for OK, or positive for reason for rejection
940 * where reason codes match those for X509_verify_cert().
942 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
944 if (subject->ex_flags & EXFLAG_PROXY) {
945 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
946 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
947 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
948 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
952 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
957 /* Check key ids (if present) */
958 if (akid->keyid && issuer->skid &&
959 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
960 return X509_V_ERR_AKID_SKID_MISMATCH;
961 /* Check serial number */
963 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
964 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
965 /* Check issuer name */
968 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
969 * GeneralName. So look for a DirName. There may be more than one but
970 * we only take any notice of the first.
974 X509_NAME *nm = NULL;
977 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
978 gen = sk_GENERAL_NAME_value(gens, i);
979 if (gen->type == GEN_DIRNAME) {
984 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
985 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
990 uint32_t X509_get_extension_flags(X509 *x)
992 /* Call for side-effect of computing hash and caching extensions */
993 X509_check_purpose(x, -1, -1);
997 uint32_t X509_get_key_usage(X509 *x)
999 /* Call for side-effect of computing hash and caching extensions */
1000 if (X509_check_purpose(x, -1, -1) != 1)
1002 if (x->ex_flags & EXFLAG_KUSAGE)
1003 return x->ex_kusage;
1007 uint32_t X509_get_extended_key_usage(X509 *x)
1009 /* Call for side-effect of computing hash and caching extensions */
1010 if (X509_check_purpose(x, -1, -1) != 1)
1012 if (x->ex_flags & EXFLAG_XKUSAGE)
1013 return x->ex_xkusage;
1017 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1019 /* Call for side-effect of computing hash and caching extensions */
1020 if (X509_check_purpose(x, -1, -1) != 1)
1025 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1027 /* Call for side-effect of computing hash and caching extensions */
1028 if (X509_check_purpose(x, -1, -1) != 1)
1030 return (x->akid != NULL ? x->akid->keyid : NULL);
1033 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1035 /* Call for side-effect of computing hash and caching extensions */
1036 if (X509_check_purpose(x, -1, -1) != 1)
1038 return (x->akid != NULL ? x->akid->issuer : NULL);
1041 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1043 /* Call for side-effect of computing hash and caching extensions */
1044 if (X509_check_purpose(x, -1, -1) != 1)
1046 return (x->akid != NULL ? x->akid->serial : NULL);
1049 long X509_get_pathlen(X509 *x)
1051 /* Called for side effect of caching extensions */
1052 if (X509_check_purpose(x, -1, -1) != 1
1053 || (x->ex_flags & EXFLAG_BCONS) == 0)
1055 return x->ex_pathlen;
1058 long X509_get_proxy_pathlen(X509 *x)
1060 /* Called for side effect of caching extensions */
1061 if (X509_check_purpose(x, -1, -1) != 1
1062 || (x->ex_flags & EXFLAG_PROXY) == 0)
1064 return x->ex_pcpathlen;