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 ERR_raise(ERR_LIB_X509V3, 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 ERR_raise(ERR_LIB_X509V3, 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 ERR_raise(ERR_LIB_X509V3, 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 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
202 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
203 ERR_raise(ERR_LIB_X509V3, 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_id_pkix_OCSP_noCheck, /* 369 */
287 NID_policy_constraints, /* 401 */
288 NID_proxyCertInfo, /* 663 */
289 NID_name_constraints, /* 666 */
290 NID_policy_mappings, /* 747 */
291 NID_inhibit_any_policy /* 748 */
294 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
296 if (ex_nid == NID_undef)
299 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
304 /* return 1 on success, 0 if x is invalid, -1 on (internal) error */
305 static int setup_dp(const X509 *x, DIST_POINT *dp)
307 const X509_NAME *iname = NULL;
310 if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) {
311 ERR_raise(ERR_LIB_X509, X509_R_INVALID_DISTPOINT);
314 if (dp->reasons != NULL) {
315 if (dp->reasons->length > 0)
316 dp->dp_reasons = dp->reasons->data[0];
317 if (dp->reasons->length > 1)
318 dp->dp_reasons |= (dp->reasons->data[1] << 8);
319 dp->dp_reasons &= CRLDP_ALL_REASONS;
321 dp->dp_reasons = CRLDP_ALL_REASONS;
323 if (dp->distpoint == NULL || dp->distpoint->type != 1)
326 /* handle name fragment given by nameRelativeToCRLIssuer */
328 * Note that the below way of determining iname is not really compliant
329 * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13
330 * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1
331 * and any CRLissuer could be of type different to GEN_DIRNAME.
333 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
334 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
336 if (gen->type == GEN_DIRNAME) {
337 iname = gen->d.directoryName;
342 iname = X509_get_issuer_name(x);
343 return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1;
346 /* return 1 on success, 0 if x is invalid, -1 on (internal) error */
347 static int setup_crldp(X509 *x)
351 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
352 if (x->crldp == NULL && i != -1)
355 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
356 int res = setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
364 /* Check that issuer public key algorithm matches subject signature algorithm */
365 static int check_sig_alg_match(const EVP_PKEY *pkey, const X509 *subject)
370 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
371 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
372 NULL, &pkey_nid) == 0)
373 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
374 if (EVP_PKEY_type(pkey_nid) != EVP_PKEY_base_id(pkey))
375 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
379 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
380 #define ku_reject(x, usage) \
381 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
382 #define xku_reject(x, usage) \
383 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
384 #define ns_reject(x, usage) \
385 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
388 * Cache info on various X.509v3 extensions and further derived information,
389 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
390 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags.
391 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
392 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
394 int x509v3_cache_extensions(X509 *x)
396 BASIC_CONSTRAINTS *bs;
397 PROXY_CERT_INFO_EXTENSION *pci;
398 ASN1_BIT_STRING *usage;
400 EXTENDED_KEY_USAGE *extusage;
405 /* fast lock-free check, see end of the function for details. */
406 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
407 return (x->ex_flags & EXFLAG_INVALID) == 0;
410 CRYPTO_THREAD_write_lock(x->lock);
411 if (x->ex_flags & EXFLAG_SET) { /* cert has already been processed */
412 CRYPTO_THREAD_unlock(x->lock);
413 return (x->ex_flags & EXFLAG_INVALID) == 0;
416 /* Cache the SHA1 digest of the cert */
417 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
418 x->ex_flags |= EXFLAG_NO_FINGERPRINT;
422 /* V1 should mean no extensions ... */
423 if (X509_get_version(x) == 0)
424 x->ex_flags |= EXFLAG_V1;
426 /* Handle basic constraints */
428 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
430 x->ex_flags |= EXFLAG_CA;
431 if (bs->pathlen != NULL) {
433 * the error case !bs->ca is checked by check_chain()
434 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
436 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
437 ERR_raise(ERR_LIB_X509, X509V3_R_NEGATIVE_PATHLEN);
438 x->ex_flags |= EXFLAG_INVALID;
440 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
443 BASIC_CONSTRAINTS_free(bs);
444 x->ex_flags |= EXFLAG_BCONS;
445 } else if (i != -1) {
446 x->ex_flags |= EXFLAG_INVALID;
449 /* Handle proxy certificates */
450 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
451 if (x->ex_flags & EXFLAG_CA
452 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
453 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
454 x->ex_flags |= EXFLAG_INVALID;
456 if (pci->pcPathLengthConstraint != NULL)
457 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
459 x->ex_pcpathlen = -1;
460 PROXY_CERT_INFO_EXTENSION_free(pci);
461 x->ex_flags |= EXFLAG_PROXY;
462 } else if (i != -1) {
463 x->ex_flags |= EXFLAG_INVALID;
466 /* Handle (basic) key usage */
467 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
469 if (usage->length > 0) {
470 x->ex_kusage = usage->data[0];
471 if (usage->length > 1)
472 x->ex_kusage |= usage->data[1] << 8;
474 x->ex_flags |= EXFLAG_KUSAGE;
475 ASN1_BIT_STRING_free(usage);
476 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
477 if (x->ex_kusage == 0) {
478 ERR_raise(ERR_LIB_X509, X509V3_R_EMPTY_KEY_USAGE);
479 x->ex_flags |= EXFLAG_INVALID;
481 } else if (i != -1) {
482 x->ex_flags |= EXFLAG_INVALID;
485 /* Handle extended key usage */
487 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
488 x->ex_flags |= EXFLAG_XKUSAGE;
489 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
490 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
491 case NID_server_auth:
492 x->ex_xkusage |= XKU_SSL_SERVER;
494 case NID_client_auth:
495 x->ex_xkusage |= XKU_SSL_CLIENT;
497 case NID_email_protect:
498 x->ex_xkusage |= XKU_SMIME;
501 x->ex_xkusage |= XKU_CODE_SIGN;
505 x->ex_xkusage |= XKU_SGC;
508 x->ex_xkusage |= XKU_OCSP_SIGN;
511 x->ex_xkusage |= XKU_TIMESTAMP;
514 x->ex_xkusage |= XKU_DVCS;
516 case NID_anyExtendedKeyUsage:
517 x->ex_xkusage |= XKU_ANYEKU;
520 /* ignore unknown extended key usage */
524 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
525 } else if (i != -1) {
526 x->ex_flags |= EXFLAG_INVALID;
529 /* Handle legacy Netscape extension */
530 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
532 x->ex_nscert = ns->data[0];
535 x->ex_flags |= EXFLAG_NSCERT;
536 ASN1_BIT_STRING_free(ns);
537 } else if (i != -1) {
538 x->ex_flags |= EXFLAG_INVALID;
541 /* Handle subject key identifier and issuer/authority key identifier */
542 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
543 if (x->skid == NULL && i != -1)
544 x->ex_flags |= EXFLAG_INVALID;
546 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
547 if (x->akid == NULL && i != -1)
548 x->ex_flags |= EXFLAG_INVALID;
550 /* Check if subject name matches issuer */
551 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
552 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
553 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
554 /* .. and the signature alg matches the PUBKEY alg: */
555 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
556 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
557 /* This is very related to x509_likely_issued(x, x) == X509_V_OK */
560 /* Handle subject alternative names and various other extensions */
561 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
562 if (x->altname == NULL && i != -1)
563 x->ex_flags |= EXFLAG_INVALID;
564 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
565 if (x->nc == NULL && i != -1)
566 x->ex_flags |= EXFLAG_INVALID;
568 /* Handle CRL distribution point entries */
569 res = setup_crldp(x);
571 x->ex_flags |= EXFLAG_INVALID;
575 #ifndef OPENSSL_NO_RFC3779
576 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
577 if (x->rfc3779_addr == NULL && i != -1)
578 x->ex_flags |= EXFLAG_INVALID;
579 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
580 if (x->rfc3779_asid == NULL && i != -1)
581 x->ex_flags |= EXFLAG_INVALID;
583 for (i = 0; i < X509_get_ext_count(x); i++) {
584 X509_EXTENSION *ex = X509_get_ext(x, i);
585 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
587 if (nid == NID_freshest_crl)
588 x->ex_flags |= EXFLAG_FRESHEST;
589 if (!X509_EXTENSION_get_critical(ex))
591 if (!X509_supported_extension(ex)) {
592 x->ex_flags |= EXFLAG_CRITICAL;
596 case NID_basic_constraints:
597 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
599 case NID_authority_key_identifier:
600 x->ex_flags |= EXFLAG_AKID_CRITICAL;
602 case NID_subject_key_identifier:
603 x->ex_flags |= EXFLAG_SKID_CRITICAL;
605 case NID_subject_alt_name:
606 x->ex_flags |= EXFLAG_SAN_CRITICAL;
613 /* Set x->siginf, ignoring errors due to unsupported algos */
614 (void)x509_init_sig_info(x);
616 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
618 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
620 * Above store triggers fast lock-free check in the beginning of the
621 * function. But one has to ensure that the structure is "stable", i.e.
622 * all stores are visible on all processors. Hence the release fence.
626 if ((x->ex_flags & (EXFLAG_INVALID | EXFLAG_NO_FINGERPRINT)) == 0) {
627 CRYPTO_THREAD_unlock(x->lock);
630 if ((x->ex_flags & EXFLAG_INVALID) != 0)
631 ERR_raise(ERR_LIB_X509, X509V3_R_INVALID_CERTIFICATE);
632 /* If computing sha1_hash failed the error queue already reflects this. */
635 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
636 CRYPTO_THREAD_unlock(x->lock);
641 * CA checks common to all purposes
645 * 2 Only possible in older versions of openSSL when basicConstraints are absent
646 * new versions will not return this value. May be a CA
647 * 3 basicConstraints absent but self-signed V1.
648 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
649 * 5 Netscape specific CA Flags present
652 static int check_ca(const X509 *x)
654 /* keyUsage if present should allow cert signing */
655 if (ku_reject(x, KU_KEY_CERT_SIGN))
657 if (x->ex_flags & EXFLAG_BCONS) {
658 if (x->ex_flags & EXFLAG_CA)
660 /* If basicConstraints says not a CA then say so */
664 /* we support V1 roots for... uh, I don't really know why. */
665 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
668 * If key usage present it must have certSign so tolerate it
670 else if (x->ex_flags & EXFLAG_KUSAGE)
672 /* Older certificates could have Netscape-specific CA types */
673 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
675 /* can this still be regarded a CA certificate? I doubt it */
680 void X509_set_proxy_flag(X509 *x)
682 x->ex_flags |= EXFLAG_PROXY;
685 void X509_set_proxy_pathlen(X509 *x, long l)
690 int X509_check_ca(X509 *x)
692 /* Note 0 normally means "not a CA" - but in this case means error. */
693 if (!x509v3_cache_extensions(x))
699 /* Check SSL CA: common checks for SSL client and server */
700 static int check_ssl_ca(const X509 *x)
703 ca_ret = check_ca(x);
706 /* check nsCertType if present */
707 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
713 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
716 if (xku_reject(x, XKU_SSL_CLIENT))
719 return check_ssl_ca(x);
720 /* We need to do digital signatures or key agreement */
721 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
723 /* nsCertType if present should allow SSL client use */
724 if (ns_reject(x, NS_SSL_CLIENT))
730 * Key usage needed for TLS/SSL server: digital signature, encipherment or
731 * key agreement. The ssl code can check this more thoroughly for individual
735 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
737 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
740 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
743 return check_ssl_ca(x);
745 if (ns_reject(x, NS_SSL_SERVER))
747 if (ku_reject(x, KU_TLS))
754 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
758 ret = check_purpose_ssl_server(xp, x, ca);
761 /* We need to encipher or Netscape complains */
762 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
767 /* common S/MIME checks */
768 static int purpose_smime(const X509 *x, int ca)
770 if (xku_reject(x, XKU_SMIME))
774 ca_ret = check_ca(x);
777 /* check nsCertType if present */
778 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
783 if (x->ex_flags & EXFLAG_NSCERT) {
784 if (x->ex_nscert & NS_SMIME)
786 /* Workaround for some buggy certificates */
787 if (x->ex_nscert & NS_SSL_CLIENT)
794 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
798 ret = purpose_smime(x, ca);
801 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
806 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
810 ret = purpose_smime(x, ca);
813 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
818 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
823 if ((ca_ret = check_ca(x)) != 2)
828 if (ku_reject(x, KU_CRL_SIGN))
834 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
835 * is valid. Additional checks must be made on the chain.
838 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
841 * Must be a valid CA. Should we really support the "I don't know" value
846 /* leaf certificate is checked in OCSP_verify() */
850 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
855 /* If ca is true we must return if this is a valid CA certificate. */
860 * Check the optional key usage field:
861 * if Key Usage is present, it must be one of digitalSignature
862 * and/or nonRepudiation (other values are not consistent and shall
865 if ((x->ex_flags & EXFLAG_KUSAGE)
866 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
867 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
870 /* Only time stamp key usage is permitted and it's required. */
871 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
874 /* Extended Key Usage MUST be critical */
875 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
877 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
878 if (!X509_EXTENSION_get_critical(ext))
885 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
891 * Various checks to see if one certificate potentially issued the second.
892 * This can be used to prune a set of possible issuer certificates which
893 * have been looked up using some simple method such as by subject name.
895 * 1. Check issuer_name(subject) == subject_name(issuer)
896 * 2. If akid(subject) exists, check that it matches issuer
897 * 3. Check that issuer public key algorithm matches subject signature algorithm
898 * 4. Check that any key_usage(issuer) allows certificate signing
899 * Note that this does not include actually checking the signature.
900 * Returns 0 for OK, or positive for reason for mismatch
901 * where reason codes match those for X509_verify_cert().
903 int X509_check_issued(X509 *issuer, X509 *subject)
907 if ((ret = x509_likely_issued(issuer, subject)) != X509_V_OK)
909 return x509_signing_allowed(issuer, subject);
912 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
913 int x509_likely_issued(X509 *issuer, X509 *subject)
917 if (X509_NAME_cmp(X509_get_subject_name(issuer),
918 X509_get_issuer_name(subject)) != 0)
919 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
921 /* set issuer->skid and subject->akid */
922 if (!x509v3_cache_extensions(issuer)
923 || !x509v3_cache_extensions(subject))
924 return X509_V_ERR_UNSPECIFIED;
926 ret = X509_check_akid(issuer, subject->akid);
927 if (ret != X509_V_OK)
930 /* check if the subject signature alg matches the issuer's PUBKEY alg */
931 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
935 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
936 * according to the B<keyUsage> field of I<issuer> if present
937 * depending on any proxyCertInfo extension of I<subject>.
938 * Returns 0 for OK, or positive for reason for rejection
939 * where reason codes match those for X509_verify_cert().
941 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
943 if (subject->ex_flags & EXFLAG_PROXY) {
944 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
945 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
946 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
947 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
951 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
956 /* Check key ids (if present) */
957 if (akid->keyid && issuer->skid &&
958 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
959 return X509_V_ERR_AKID_SKID_MISMATCH;
960 /* Check serial number */
962 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
963 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
964 /* Check issuer name */
967 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
968 * GeneralName. So look for a DirName. There may be more than one but
969 * we only take any notice of the first.
973 X509_NAME *nm = NULL;
976 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
977 gen = sk_GENERAL_NAME_value(gens, i);
978 if (gen->type == GEN_DIRNAME) {
983 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
984 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
989 uint32_t X509_get_extension_flags(X509 *x)
991 /* Call for side-effect of computing hash and caching extensions */
992 X509_check_purpose(x, -1, -1);
996 uint32_t X509_get_key_usage(X509 *x)
998 /* Call for side-effect of computing hash and caching extensions */
999 if (X509_check_purpose(x, -1, -1) != 1)
1001 if (x->ex_flags & EXFLAG_KUSAGE)
1002 return x->ex_kusage;
1006 uint32_t X509_get_extended_key_usage(X509 *x)
1008 /* Call for side-effect of computing hash and caching extensions */
1009 if (X509_check_purpose(x, -1, -1) != 1)
1011 if (x->ex_flags & EXFLAG_XKUSAGE)
1012 return x->ex_xkusage;
1016 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1018 /* Call for side-effect of computing hash and caching extensions */
1019 if (X509_check_purpose(x, -1, -1) != 1)
1024 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1026 /* Call for side-effect of computing hash and caching extensions */
1027 if (X509_check_purpose(x, -1, -1) != 1)
1029 return (x->akid != NULL ? x->akid->keyid : NULL);
1032 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1034 /* Call for side-effect of computing hash and caching extensions */
1035 if (X509_check_purpose(x, -1, -1) != 1)
1037 return (x->akid != NULL ? x->akid->issuer : NULL);
1040 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1042 /* Call for side-effect of computing hash and caching extensions */
1043 if (X509_check_purpose(x, -1, -1) != 1)
1045 return (x->akid != NULL ? x->akid->serial : NULL);
1048 long X509_get_pathlen(X509 *x)
1050 /* Called for side effect of caching extensions */
1051 if (X509_check_purpose(x, -1, -1) != 1
1052 || (x->ex_flags & EXFLAG_BCONS) == 0)
1054 return x->ex_pathlen;
1057 long X509_get_proxy_pathlen(X509 *x)
1059 /* Called for side effect of caching extensions */
1060 if (X509_check_purpose(x, -1, -1) != 1
1061 || (x->ex_flags & EXFLAG_PROXY) == 0)
1063 return x->ex_pcpathlen;