2 * Copyright 1999-2021 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 require_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 check_purpose_code_sign(const X509_PURPOSE *xp, const X509 *x,
37 static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x,
39 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
42 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
43 static void xptable_free(X509_PURPOSE *p);
45 static X509_PURPOSE xstandard[] = {
46 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
47 check_purpose_ssl_client, "SSL client", "sslclient", NULL},
48 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
49 check_purpose_ssl_server, "SSL server", "sslserver", NULL},
50 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
51 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
52 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
53 "S/MIME signing", "smimesign", NULL},
54 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
55 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
56 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
57 "CRL signing", "crlsign", NULL},
58 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check_purpose,
61 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, check_purpose_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",
66 {X509_PURPOSE_CODE_SIGN, X509_TRUST_OBJECT_SIGN, 0,
67 check_purpose_code_sign, "Code signing", "codesign",
71 #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
73 static STACK_OF(X509_PURPOSE) *xptable = NULL;
75 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
77 return (*a)->purpose - (*b)->purpose;
81 * As much as I'd like to make X509_check_purpose use a "const" X509* I really
82 * can't because it does recalculate hashes and do other non-const things.
83 * If id == -1 it just calls x509v3_cache_extensions() for its side-effect.
84 * Returns 1 on success, 0 if x does not allow purpose, -1 on (internal) error.
86 int X509_check_purpose(X509 *x, int id, int require_ca)
89 const X509_PURPOSE *pt;
91 if (!ossl_x509v3_cache_extensions(x))
96 idx = X509_PURPOSE_get_by_id(id);
99 pt = X509_PURPOSE_get0(idx);
100 return pt->check_purpose(pt, x, require_ca);
103 int X509_PURPOSE_set(int *p, int purpose)
105 if (X509_PURPOSE_get_by_id(purpose) == -1) {
106 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_PURPOSE);
113 int X509_PURPOSE_get_count(void)
116 return X509_PURPOSE_COUNT;
117 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
120 X509_PURPOSE *X509_PURPOSE_get0(int idx)
124 if (idx < (int)X509_PURPOSE_COUNT)
125 return xstandard + idx;
126 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
129 int X509_PURPOSE_get_by_sname(const char *sname)
134 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
135 xptmp = X509_PURPOSE_get0(i);
136 if (strcmp(xptmp->sname, sname) == 0)
142 /* Returns -1 on error, else an index => 0 in standard/extended purpose table */
143 int X509_PURPOSE_get_by_id(int purpose)
148 if (purpose >= X509_PURPOSE_MIN && purpose <= X509_PURPOSE_MAX)
149 return purpose - X509_PURPOSE_MIN;
152 tmp.purpose = purpose;
153 idx = sk_X509_PURPOSE_find(xptable, &tmp);
156 return idx + X509_PURPOSE_COUNT;
159 int X509_PURPOSE_add(int id, int trust, int flags,
160 int (*ck) (const X509_PURPOSE *, const X509 *, int),
161 const char *name, const char *sname, void *arg)
166 /* This is set according to what we change: application can't set it */
167 flags &= ~X509_PURPOSE_DYNAMIC;
168 /* This will always be set for application modified trust entries */
169 flags |= X509_PURPOSE_DYNAMIC_NAME;
170 /* Get existing entry if any */
171 idx = X509_PURPOSE_get_by_id(id);
172 /* Need a new entry */
174 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
175 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
178 ptmp->flags = X509_PURPOSE_DYNAMIC;
180 ptmp = X509_PURPOSE_get0(idx);
183 /* OPENSSL_free existing name if dynamic */
184 if ((ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) != 0) {
185 OPENSSL_free(ptmp->name);
186 OPENSSL_free(ptmp->sname);
188 /* Dup supplied name */
189 ptmp->name = OPENSSL_strdup(name);
190 ptmp->sname = OPENSSL_strdup(sname);
191 if (ptmp->name == NULL || ptmp->sname == NULL) {
192 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
195 /* Keep the dynamic flag of existing entry */
196 ptmp->flags &= X509_PURPOSE_DYNAMIC;
197 /* Set all other flags */
198 ptmp->flags |= flags;
202 ptmp->check_purpose = ck;
203 ptmp->usr_data = arg;
205 /* If its a new entry manage the dynamic table */
208 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
209 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
212 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
213 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
220 OPENSSL_free(ptmp->name);
221 OPENSSL_free(ptmp->sname);
227 static void xptable_free(X509_PURPOSE *p)
231 if ((p->flags & X509_PURPOSE_DYNAMIC) != 0) {
232 if ((p->flags & X509_PURPOSE_DYNAMIC_NAME) != 0) {
233 OPENSSL_free(p->name);
234 OPENSSL_free(p->sname);
240 void X509_PURPOSE_cleanup(void)
242 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
246 int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
251 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
256 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
261 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
266 static int nid_cmp(const int *a, const int *b)
271 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
272 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
274 int X509_supported_extension(X509_EXTENSION *ex)
277 * This table is a list of the NIDs of supported extensions: that is
278 * those which are used by the verify process. If an extension is
279 * critical and doesn't appear in this list then the verify process will
280 * normally reject the certificate. The list must be kept in numerical
281 * order because it will be searched using bsearch.
283 static const int supported_nids[] = {
284 NID_netscape_cert_type, /* 71 */
285 NID_key_usage, /* 83 */
286 NID_subject_alt_name, /* 85 */
287 NID_basic_constraints, /* 87 */
288 NID_certificate_policies, /* 89 */
289 NID_crl_distribution_points, /* 103 */
290 NID_ext_key_usage, /* 126 */
291 #ifndef OPENSSL_NO_RFC3779
292 NID_sbgp_ipAddrBlock, /* 290 */
293 NID_sbgp_autonomousSysNum, /* 291 */
295 NID_id_pkix_OCSP_noCheck, /* 369 */
296 NID_policy_constraints, /* 401 */
297 NID_proxyCertInfo, /* 663 */
298 NID_name_constraints, /* 666 */
299 NID_policy_mappings, /* 747 */
300 NID_inhibit_any_policy /* 748 */
303 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
305 if (ex_nid == NID_undef)
308 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
313 /* Returns 1 on success, 0 if x is invalid, -1 on (internal) error. */
314 static int setup_dp(const X509 *x, DIST_POINT *dp)
316 const X509_NAME *iname = NULL;
319 if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) {
320 ERR_raise(ERR_LIB_X509, X509_R_INVALID_DISTPOINT);
323 if (dp->reasons != NULL) {
324 if (dp->reasons->length > 0)
325 dp->dp_reasons = dp->reasons->data[0];
326 if (dp->reasons->length > 1)
327 dp->dp_reasons |= (dp->reasons->data[1] << 8);
328 dp->dp_reasons &= CRLDP_ALL_REASONS;
330 dp->dp_reasons = CRLDP_ALL_REASONS;
332 if (dp->distpoint == NULL || dp->distpoint->type != 1)
335 /* Handle name fragment given by nameRelativeToCRLIssuer */
337 * Note that the below way of determining iname is not really compliant
338 * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13
339 * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1
340 * and any CRLissuer could be of type different to GEN_DIRNAME.
342 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
343 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
345 if (gen->type == GEN_DIRNAME) {
346 iname = gen->d.directoryName;
351 iname = X509_get_issuer_name(x);
352 return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1;
355 /* Return 1 on success, 0 if x is invalid, -1 on (internal) error. */
356 static int setup_crldp(X509 *x)
360 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
361 if (x->crldp == NULL && i != -1)
364 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
365 int res = setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
373 /* Check that issuer public key algorithm matches subject signature algorithm */
374 static int check_sig_alg_match(const EVP_PKEY *issuer_key, const X509 *subject)
378 if (issuer_key == NULL)
379 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
380 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
381 NULL, &subj_sig_nid) == 0)
382 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
383 if (EVP_PKEY_is_a(issuer_key, OBJ_nid2sn(subj_sig_nid))
384 || (EVP_PKEY_is_a(issuer_key, "RSA") && subj_sig_nid == NID_rsassaPss))
386 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
389 #define V1_ROOT (EXFLAG_V1 | EXFLAG_SS)
390 #define ku_reject(x, usage) \
391 (((x)->ex_flags & EXFLAG_KUSAGE) != 0 && ((x)->ex_kusage & (usage)) == 0)
392 #define xku_reject(x, usage) \
393 (((x)->ex_flags & EXFLAG_XKUSAGE) != 0 && ((x)->ex_xkusage & (usage)) == 0)
394 #define ns_reject(x, usage) \
395 (((x)->ex_flags & EXFLAG_NSCERT) != 0 && ((x)->ex_nscert & (usage)) == 0)
398 * Cache info on various X.509v3 extensions and further derived information,
399 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
400 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags.
401 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
402 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
404 int ossl_x509v3_cache_extensions(X509 *x)
406 BASIC_CONSTRAINTS *bs;
407 PROXY_CERT_INFO_EXTENSION *pci;
408 ASN1_BIT_STRING *usage;
410 EXTENDED_KEY_USAGE *extusage;
415 /* Fast lock-free check, see end of the function for details. */
416 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
417 return (x->ex_flags & EXFLAG_INVALID) == 0;
420 if (!CRYPTO_THREAD_write_lock(x->lock))
422 if ((x->ex_flags & EXFLAG_SET) != 0) { /* Cert has already been processed */
423 CRYPTO_THREAD_unlock(x->lock);
424 return (x->ex_flags & EXFLAG_INVALID) == 0;
429 /* Cache the SHA1 digest of the cert */
430 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
431 x->ex_flags |= EXFLAG_NO_FINGERPRINT;
433 /* V1 should mean no extensions ... */
434 if (X509_get_version(x) == X509_VERSION_1)
435 x->ex_flags |= EXFLAG_V1;
437 /* Handle basic constraints */
439 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
441 x->ex_flags |= EXFLAG_CA;
442 if (bs->pathlen != NULL) {
444 * The error case !bs->ca is checked by check_chain()
445 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
447 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
448 ERR_raise(ERR_LIB_X509, X509V3_R_NEGATIVE_PATHLEN);
449 x->ex_flags |= EXFLAG_INVALID;
451 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
454 BASIC_CONSTRAINTS_free(bs);
455 x->ex_flags |= EXFLAG_BCONS;
456 } else if (i != -1) {
457 x->ex_flags |= EXFLAG_INVALID;
460 /* Handle proxy certificates */
461 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
462 if ((x->ex_flags & EXFLAG_CA) != 0
463 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
464 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
465 x->ex_flags |= EXFLAG_INVALID;
467 if (pci->pcPathLengthConstraint != NULL)
468 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
470 x->ex_pcpathlen = -1;
471 PROXY_CERT_INFO_EXTENSION_free(pci);
472 x->ex_flags |= EXFLAG_PROXY;
473 } else if (i != -1) {
474 x->ex_flags |= EXFLAG_INVALID;
477 /* Handle (basic) key usage */
478 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
480 if (usage->length > 0) {
481 x->ex_kusage = usage->data[0];
482 if (usage->length > 1)
483 x->ex_kusage |= usage->data[1] << 8;
485 x->ex_flags |= EXFLAG_KUSAGE;
486 ASN1_BIT_STRING_free(usage);
487 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
488 if (x->ex_kusage == 0) {
489 ERR_raise(ERR_LIB_X509, X509V3_R_EMPTY_KEY_USAGE);
490 x->ex_flags |= EXFLAG_INVALID;
492 } else if (i != -1) {
493 x->ex_flags |= EXFLAG_INVALID;
496 /* Handle extended key usage */
498 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
499 x->ex_flags |= EXFLAG_XKUSAGE;
500 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
501 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
502 case NID_server_auth:
503 x->ex_xkusage |= XKU_SSL_SERVER;
505 case NID_client_auth:
506 x->ex_xkusage |= XKU_SSL_CLIENT;
508 case NID_email_protect:
509 x->ex_xkusage |= XKU_SMIME;
512 x->ex_xkusage |= XKU_CODE_SIGN;
516 x->ex_xkusage |= XKU_SGC;
519 x->ex_xkusage |= XKU_OCSP_SIGN;
522 x->ex_xkusage |= XKU_TIMESTAMP;
525 x->ex_xkusage |= XKU_DVCS;
527 case NID_anyExtendedKeyUsage:
528 x->ex_xkusage |= XKU_ANYEKU;
531 /* Ignore unknown extended key usage */
535 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
536 } else if (i != -1) {
537 x->ex_flags |= EXFLAG_INVALID;
540 /* Handle legacy Netscape extension */
541 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
543 x->ex_nscert = ns->data[0];
546 x->ex_flags |= EXFLAG_NSCERT;
547 ASN1_BIT_STRING_free(ns);
548 } else if (i != -1) {
549 x->ex_flags |= EXFLAG_INVALID;
552 /* Handle subject key identifier and issuer/authority key identifier */
553 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
554 if (x->skid == NULL && i != -1)
555 x->ex_flags |= EXFLAG_INVALID;
557 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
558 if (x->akid == NULL && i != -1)
559 x->ex_flags |= EXFLAG_INVALID;
561 /* Check if subject name matches issuer */
562 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
563 x->ex_flags |= EXFLAG_SI; /* Cert is self-issued */
564 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
565 /* .. and the signature alg matches the PUBKEY alg: */
566 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
567 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
568 /* This is very related to ossl_x509_likely_issued(x, x) == X509_V_OK */
571 /* Handle subject alternative names and various other extensions */
572 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
573 if (x->altname == NULL && i != -1)
574 x->ex_flags |= EXFLAG_INVALID;
575 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
576 if (x->nc == NULL && i != -1)
577 x->ex_flags |= EXFLAG_INVALID;
579 /* Handle CRL distribution point entries */
580 res = setup_crldp(x);
582 x->ex_flags |= EXFLAG_INVALID;
584 #ifndef OPENSSL_NO_RFC3779
585 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
586 if (x->rfc3779_addr == NULL && i != -1)
587 x->ex_flags |= EXFLAG_INVALID;
588 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
589 if (x->rfc3779_asid == NULL && i != -1)
590 x->ex_flags |= EXFLAG_INVALID;
592 for (i = 0; i < X509_get_ext_count(x); i++) {
593 X509_EXTENSION *ex = X509_get_ext(x, i);
594 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
596 if (nid == NID_freshest_crl)
597 x->ex_flags |= EXFLAG_FRESHEST;
598 if (!X509_EXTENSION_get_critical(ex))
600 if (!X509_supported_extension(ex)) {
601 x->ex_flags |= EXFLAG_CRITICAL;
605 case NID_basic_constraints:
606 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
608 case NID_authority_key_identifier:
609 x->ex_flags |= EXFLAG_AKID_CRITICAL;
611 case NID_subject_key_identifier:
612 x->ex_flags |= EXFLAG_SKID_CRITICAL;
614 case NID_subject_alt_name:
615 x->ex_flags |= EXFLAG_SAN_CRITICAL;
622 /* Set x->siginf, ignoring errors due to unsupported algos */
623 (void)ossl_x509_init_sig_info(x);
625 x->ex_flags |= EXFLAG_SET; /* Indicate that cert has been processed */
627 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
629 * Above store triggers fast lock-free check in the beginning of the
630 * function. But one has to ensure that the structure is "stable", i.e.
631 * all stores are visible on all processors. Hence the release fence.
636 if ((x->ex_flags & EXFLAG_INVALID) == 0) {
637 CRYPTO_THREAD_unlock(x->lock);
640 CRYPTO_THREAD_unlock(x->lock);
641 ERR_raise(ERR_LIB_X509, X509V3_R_INVALID_CERTIFICATE);
646 * CA checks common to all purposes
650 * 2 Only possible in older versions of openSSL when basicConstraints are absent
651 * new versions will not return this value. May be a CA
652 * 3 basicConstraints absent but self-signed V1.
653 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
654 * 5 Netscape specific CA Flags present
657 static int check_ca(const X509 *x)
659 /* keyUsage if present should allow cert signing */
660 if (ku_reject(x, KU_KEY_CERT_SIGN))
662 if ((x->ex_flags & EXFLAG_BCONS) != 0) {
663 /* If basicConstraints says not a CA then say so */
664 return (x->ex_flags & EXFLAG_CA) != 0;
666 /* We support V1 roots for... uh, I don't really know why. */
667 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
670 * If key usage present it must have certSign so tolerate it
672 else if ((x->ex_flags & EXFLAG_KUSAGE) != 0)
674 /* Older certificates could have Netscape-specific CA types */
675 else if ((x->ex_flags & EXFLAG_NSCERT) != 0
676 && (x->ex_nscert & NS_ANY_CA) != 0)
678 /* Can this still be regarded a CA certificate? I doubt it. */
683 void X509_set_proxy_flag(X509 *x)
685 if (CRYPTO_THREAD_write_lock(x->lock)) {
686 x->ex_flags |= EXFLAG_PROXY;
687 CRYPTO_THREAD_unlock(x->lock);
691 void X509_set_proxy_pathlen(X509 *x, long l)
696 int X509_check_ca(X509 *x)
698 /* Note 0 normally means "not a CA" - but in this case means error. */
699 if (!ossl_x509v3_cache_extensions(x))
705 /* Check SSL CA: common checks for SSL client and server. */
706 static int check_ssl_ca(const X509 *x)
708 int ca_ret = check_ca(x);
712 /* Check nsCertType if present */
713 return ca_ret != 5 || (x->ex_nscert & NS_SSL_CA) != 0;
716 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
719 if (xku_reject(x, XKU_SSL_CLIENT))
722 return check_ssl_ca(x);
723 /* We need to do digital signatures or key agreement */
724 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
726 /* nsCertType if present should allow SSL client use */
727 if (ns_reject(x, NS_SSL_CLIENT))
733 * Key usage needed for TLS/SSL server: digital signature, encipherment or
734 * key agreement. The ssl code can check this more thoroughly for individual
738 KU_DIGITAL_SIGNATURE | KU_KEY_ENCIPHERMENT | KU_KEY_AGREEMENT
740 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
743 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
746 return check_ssl_ca(x);
748 if (ns_reject(x, NS_SSL_SERVER))
750 if (ku_reject(x, KU_TLS))
757 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
760 int ret = check_purpose_ssl_server(xp, x, require_ca);
762 if (!ret || require_ca)
764 /* We need to encipher or Netscape complains */
765 return ku_reject(x, KU_KEY_ENCIPHERMENT) ? 0 : ret;
768 /* common S/MIME checks */
769 static int purpose_smime(const X509 *x, int require_ca)
771 if (xku_reject(x, XKU_SMIME))
774 int ca_ret = check_ca(x);
778 /* Check nsCertType if present */
779 if (ca_ret != 5 || (x->ex_nscert & NS_SMIME_CA) != 0)
784 if ((x->ex_flags & EXFLAG_NSCERT) != 0) {
785 if ((x->ex_nscert & NS_SMIME) != 0)
787 /* Workaround for some buggy certificates */
788 return (x->ex_nscert & NS_SSL_CLIENT) != 0 ? 2 : 0;
793 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
796 int ret = purpose_smime(x, require_ca);
798 if (!ret || require_ca)
800 return ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION) ? 0 : ret;
803 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
806 int ret = purpose_smime(x, require_ca);
808 if (!ret || require_ca)
810 return ku_reject(x, KU_KEY_ENCIPHERMENT) ? 0 : ret;
813 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
817 int ca_ret = check_ca(x);
819 return ca_ret == 2 ? 0 : ca_ret;
821 return !ku_reject(x, KU_CRL_SIGN);
825 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
826 * is valid. Additional checks must be made on the chain.
828 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
832 * Must be a valid CA. Should we really support the "I don't know" value
837 /* Leaf certificate is checked in OCSP_verify() */
841 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
846 /* If ca is true we must return if this is a valid CA certificate. */
851 * Check the optional key usage field:
852 * if Key Usage is present, it must be one of digitalSignature
853 * and/or nonRepudiation (other values are not consistent and shall
856 if ((x->ex_flags & EXFLAG_KUSAGE) != 0
857 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
858 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
861 /* Only time stamp key usage is permitted and it's required. */
862 if ((x->ex_flags & EXFLAG_XKUSAGE) == 0 || x->ex_xkusage != XKU_TIMESTAMP)
865 /* Extended Key Usage MUST be critical */
866 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
868 && !X509_EXTENSION_get_critical(X509_get_ext((X509 *)x, i_ext)))
873 static int check_purpose_code_sign(const X509_PURPOSE *xp, const X509 *x,
878 /* If ca is true we must return if this is a valid CA certificate. */
883 * Check the key usage and extended key usage fields:
885 * Reference: CA Browser Forum,
886 * Baseline Requirements for the Issuance and Management of
887 * PubliclyâTrusted Code Signing Certificates, Version 3.0.0,
888 * Section 7.1.2.3: Code signing and Timestamp Certificate
890 * Checking covers Key Usage and Extended Key Usage attributes.
891 * Other properties like CRL Distribution Points and Authoriy
892 * Information Access (AIA) are not checked.
895 if ((x->ex_flags & EXFLAG_KUSAGE) == 0)
897 if ((x->ex_kusage & KU_DIGITAL_SIGNATURE) == 0)
899 if ((x->ex_kusage & (KU_KEY_CERT_SIGN | KU_CRL_SIGN)) != 0)
902 /* Key Usage MUST be critical */
903 i_ext = X509_get_ext_by_NID(x, NID_key_usage, -1);
907 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
908 if (!X509_EXTENSION_get_critical(ext))
912 /* Extended Key Usage */
913 if ((x->ex_flags & EXFLAG_XKUSAGE) == 0)
915 if ((x->ex_xkusage & XKU_CODE_SIGN) == 0)
917 if ((x->ex_xkusage & (XKU_ANYEKU | XKU_SSL_SERVER)) != 0)
924 static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x,
931 * Various checks to see if one certificate potentially issued the second.
932 * This can be used to prune a set of possible issuer certificates which
933 * have been looked up using some simple method such as by subject name.
935 * 1. issuer_name(subject) == subject_name(issuer)
936 * 2. If akid(subject) exists, it matches the respective issuer fields.
937 * 3. subject signature algorithm == issuer public key algorithm
938 * 4. If key_usage(issuer) exists, it allows for signing subject.
939 * Note that this does not include actually checking the signature.
940 * Returns 0 for OK, or positive for reason for mismatch
941 * where reason codes match those for X509_verify_cert().
943 int X509_check_issued(X509 *issuer, X509 *subject)
947 if ((ret = ossl_x509_likely_issued(issuer, subject)) != X509_V_OK)
949 return ossl_x509_signing_allowed(issuer, subject);
952 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
953 int ossl_x509_likely_issued(X509 *issuer, X509 *subject)
957 if (X509_NAME_cmp(X509_get_subject_name(issuer),
958 X509_get_issuer_name(subject)) != 0)
959 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
961 /* set issuer->skid and subject->akid */
962 if (!ossl_x509v3_cache_extensions(issuer)
963 || !ossl_x509v3_cache_extensions(subject))
964 return X509_V_ERR_UNSPECIFIED;
966 ret = X509_check_akid(issuer, subject->akid);
967 if (ret != X509_V_OK)
970 /* Check if the subject signature alg matches the issuer's PUBKEY alg */
971 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
975 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
976 * according to the B<keyUsage> field of I<issuer> if present
977 * depending on any proxyCertInfo extension of I<subject>.
978 * Returns 0 for OK, or positive for reason for rejection
979 * where reason codes match those for X509_verify_cert().
981 int ossl_x509_signing_allowed(const X509 *issuer, const X509 *subject)
983 if ((subject->ex_flags & EXFLAG_PROXY) != 0) {
984 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
985 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
986 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) {
987 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
992 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
997 /* Check key ids (if present) */
998 if (akid->keyid && issuer->skid &&
999 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
1000 return X509_V_ERR_AKID_SKID_MISMATCH;
1001 /* Check serial number */
1003 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
1004 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
1005 /* Check issuer name */
1008 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
1009 * GeneralName. So look for a DirName. There may be more than one but
1010 * we only take any notice of the first.
1012 GENERAL_NAMES *gens = akid->issuer;
1014 X509_NAME *nm = NULL;
1017 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1018 gen = sk_GENERAL_NAME_value(gens, i);
1019 if (gen->type == GEN_DIRNAME) {
1024 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
1025 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
1030 uint32_t X509_get_extension_flags(X509 *x)
1032 /* Call for side-effect of computing hash and caching extensions */
1033 X509_check_purpose(x, -1, 0);
1037 uint32_t X509_get_key_usage(X509 *x)
1039 /* Call for side-effect of computing hash and caching extensions */
1040 if (X509_check_purpose(x, -1, 0) != 1)
1042 return (x->ex_flags & EXFLAG_KUSAGE) != 0 ? x->ex_kusage : UINT32_MAX;
1045 uint32_t X509_get_extended_key_usage(X509 *x)
1047 /* Call for side-effect of computing hash and caching extensions */
1048 if (X509_check_purpose(x, -1, 0) != 1)
1050 return (x->ex_flags & EXFLAG_XKUSAGE) != 0 ? x->ex_xkusage : UINT32_MAX;
1053 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1055 /* Call for side-effect of computing hash and caching extensions */
1056 if (X509_check_purpose(x, -1, 0) != 1)
1061 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1063 /* Call for side-effect of computing hash and caching extensions */
1064 if (X509_check_purpose(x, -1, 0) != 1)
1066 return (x->akid != NULL ? x->akid->keyid : NULL);
1069 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1071 /* Call for side-effect of computing hash and caching extensions */
1072 if (X509_check_purpose(x, -1, 0) != 1)
1074 return (x->akid != NULL ? x->akid->issuer : NULL);
1077 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1079 /* Call for side-effect of computing hash and caching extensions */
1080 if (X509_check_purpose(x, -1, 0) != 1)
1082 return (x->akid != NULL ? x->akid->serial : NULL);
1085 long X509_get_pathlen(X509 *x)
1087 /* Called for side effect of caching extensions */
1088 if (X509_check_purpose(x, -1, 0) != 1
1089 || (x->ex_flags & EXFLAG_BCONS) == 0)
1091 return x->ex_pathlen;
1094 long X509_get_proxy_pathlen(X509 *x)
1096 /* Called for side effect of caching extensions */
1097 if (X509_check_purpose(x, -1, 0) != 1
1098 || (x->ex_flags & EXFLAG_PROXY) == 0)
1100 return x->ex_pcpathlen;