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 no_check_purpose(const X509_PURPOSE *xp, const X509 *x,
37 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
40 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
41 static void xptable_free(X509_PURPOSE *p);
43 static X509_PURPOSE xstandard[] = {
44 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
45 check_purpose_ssl_client, "SSL client", "sslclient", NULL},
46 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
47 check_purpose_ssl_server, "SSL server", "sslserver", NULL},
48 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
49 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
50 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
51 "S/MIME signing", "smimesign", NULL},
52 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
53 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
54 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
55 "CRL signing", "crlsign", NULL},
56 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check_purpose,
59 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, check_purpose_ocsp_helper,
60 "OCSP helper", "ocsphelper", NULL},
61 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
62 check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
66 #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
68 static STACK_OF(X509_PURPOSE) *xptable = NULL;
70 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b)
72 return (*a)->purpose - (*b)->purpose;
76 * As much as I'd like to make X509_check_purpose use a "const" X509* I really
77 * can't because it does recalculate hashes and do other non-const things.
78 * If id == -1 it just calls x509v3_cache_extensions() for its side-effect.
79 * Returns 1 on success, 0 if x does not allow purpose, -1 on (internal) error.
81 int X509_check_purpose(X509 *x, int id, int require_ca)
84 const X509_PURPOSE *pt;
86 if (!ossl_x509v3_cache_extensions(x))
91 idx = X509_PURPOSE_get_by_id(id);
94 pt = X509_PURPOSE_get0(idx);
95 return pt->check_purpose(pt, x, require_ca);
98 int X509_PURPOSE_set(int *p, int purpose)
100 if (X509_PURPOSE_get_by_id(purpose) == -1) {
101 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_PURPOSE);
108 int X509_PURPOSE_get_count(void)
111 return X509_PURPOSE_COUNT;
112 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
115 X509_PURPOSE *X509_PURPOSE_get0(int idx)
119 if (idx < (int)X509_PURPOSE_COUNT)
120 return xstandard + idx;
121 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
124 int X509_PURPOSE_get_by_sname(const char *sname)
128 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
129 xptmp = X509_PURPOSE_get0(i);
130 if (strcmp(xptmp->sname, sname) == 0)
136 /* Returns -1 on error, else an index => 0 in standard/extended purpose table */
137 int X509_PURPOSE_get_by_id(int purpose)
142 if (purpose >= X509_PURPOSE_MIN && purpose <= X509_PURPOSE_MAX)
143 return purpose - X509_PURPOSE_MIN;
146 tmp.purpose = purpose;
147 idx = sk_X509_PURPOSE_find(xptable, &tmp);
150 return idx + X509_PURPOSE_COUNT;
153 int X509_PURPOSE_add(int id, int trust, int flags,
154 int (*ck) (const X509_PURPOSE *, const X509 *, int),
155 const char *name, const char *sname, void *arg)
160 /* This is set according to what we change: application can't set it */
161 flags &= ~X509_PURPOSE_DYNAMIC;
162 /* This will always be set for application modified trust entries */
163 flags |= X509_PURPOSE_DYNAMIC_NAME;
164 /* Get existing entry if any */
165 idx = X509_PURPOSE_get_by_id(id);
166 /* Need a new entry */
168 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
169 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
172 ptmp->flags = X509_PURPOSE_DYNAMIC;
174 ptmp = X509_PURPOSE_get0(idx);
176 /* OPENSSL_free existing name if dynamic */
177 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
178 OPENSSL_free(ptmp->name);
179 OPENSSL_free(ptmp->sname);
181 /* Dup supplied name */
182 ptmp->name = OPENSSL_strdup(name);
183 ptmp->sname = OPENSSL_strdup(sname);
184 if (ptmp->name == NULL|| ptmp->sname == NULL) {
185 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
188 /* Keep the dynamic flag of existing entry */
189 ptmp->flags &= X509_PURPOSE_DYNAMIC;
190 /* Set all other flags */
191 ptmp->flags |= flags;
195 ptmp->check_purpose = ck;
196 ptmp->usr_data = arg;
198 /* If its a new entry manage the dynamic table */
201 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
202 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
205 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
206 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE);
213 OPENSSL_free(ptmp->name);
214 OPENSSL_free(ptmp->sname);
220 static void xptable_free(X509_PURPOSE *p)
224 if (p->flags & X509_PURPOSE_DYNAMIC) {
225 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
226 OPENSSL_free(p->name);
227 OPENSSL_free(p->sname);
233 void X509_PURPOSE_cleanup(void)
235 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
239 int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
244 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
249 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
254 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
259 static int nid_cmp(const int *a, const int *b)
264 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
265 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
267 int X509_supported_extension(X509_EXTENSION *ex)
270 * This table is a list of the NIDs of supported extensions: that is
271 * those which are used by the verify process. If an extension is
272 * critical and doesn't appear in this list then the verify process will
273 * normally reject the certificate. The list must be kept in numerical
274 * order because it will be searched using bsearch.
276 static const int supported_nids[] = {
277 NID_netscape_cert_type, /* 71 */
278 NID_key_usage, /* 83 */
279 NID_subject_alt_name, /* 85 */
280 NID_basic_constraints, /* 87 */
281 NID_certificate_policies, /* 89 */
282 NID_crl_distribution_points, /* 103 */
283 NID_ext_key_usage, /* 126 */
284 #ifndef OPENSSL_NO_RFC3779
285 NID_sbgp_ipAddrBlock, /* 290 */
286 NID_sbgp_autonomousSysNum, /* 291 */
288 NID_id_pkix_OCSP_noCheck, /* 369 */
289 NID_policy_constraints, /* 401 */
290 NID_proxyCertInfo, /* 663 */
291 NID_name_constraints, /* 666 */
292 NID_policy_mappings, /* 747 */
293 NID_inhibit_any_policy /* 748 */
296 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
298 if (ex_nid == NID_undef)
301 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
306 /* Returns 1 on success, 0 if x is invalid, -1 on (internal) error. */
307 static int setup_dp(const X509 *x, DIST_POINT *dp)
309 const X509_NAME *iname = NULL;
312 if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) {
313 ERR_raise(ERR_LIB_X509, X509_R_INVALID_DISTPOINT);
316 if (dp->reasons != NULL) {
317 if (dp->reasons->length > 0)
318 dp->dp_reasons = dp->reasons->data[0];
319 if (dp->reasons->length > 1)
320 dp->dp_reasons |= (dp->reasons->data[1] << 8);
321 dp->dp_reasons &= CRLDP_ALL_REASONS;
323 dp->dp_reasons = CRLDP_ALL_REASONS;
325 if (dp->distpoint == NULL || dp->distpoint->type != 1)
328 /* Handle name fragment given by nameRelativeToCRLIssuer */
330 * Note that the below way of determining iname is not really compliant
331 * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13
332 * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1
333 * and any CRLissuer could be of type different to GEN_DIRNAME.
335 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
336 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
338 if (gen->type == GEN_DIRNAME) {
339 iname = gen->d.directoryName;
344 iname = X509_get_issuer_name(x);
345 return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1;
348 /* Return 1 on success, 0 if x is invalid, -1 on (internal) error. */
349 static int setup_crldp(X509 *x)
353 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
354 if (x->crldp == NULL && i != -1)
357 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
358 int res = setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
366 /* Check that issuer public key algorithm matches subject signature algorithm */
367 static int check_sig_alg_match(const EVP_PKEY *issuer_key, const X509 *subject)
371 if (issuer_key == NULL)
372 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
373 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
374 NULL, &subj_sig_nid) == 0)
375 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
376 if (EVP_PKEY_is_a(issuer_key, OBJ_nid2sn(subj_sig_nid))
377 || (EVP_PKEY_is_a(issuer_key, "RSA") && subj_sig_nid == NID_rsassaPss))
379 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
382 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
383 #define ku_reject(x, usage) \
384 (((x)->ex_flags & EXFLAG_KUSAGE) != 0 && ((x)->ex_kusage & (usage)) == 0)
385 #define xku_reject(x, usage) \
386 (((x)->ex_flags & EXFLAG_XKUSAGE) != 0 && ((x)->ex_xkusage & (usage)) == 0)
387 #define ns_reject(x, usage) \
388 (((x)->ex_flags & EXFLAG_NSCERT) != 0 && ((x)->ex_nscert & (usage)) == 0)
391 * Cache info on various X.509v3 extensions and further derived information,
392 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
393 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags.
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 ossl_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 if (!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;
420 /* Cache the SHA1 digest of the cert */
421 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
422 x->ex_flags |= EXFLAG_NO_FINGERPRINT;
426 /* V1 should mean no extensions ... */
427 if (X509_get_version(x) == X509_VERSION_1)
428 x->ex_flags |= EXFLAG_V1;
430 /* Handle basic constraints */
432 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
434 x->ex_flags |= EXFLAG_CA;
435 if (bs->pathlen != NULL) {
437 * The error case !bs->ca is checked by check_chain()
438 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
440 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
441 ERR_raise(ERR_LIB_X509, X509V3_R_NEGATIVE_PATHLEN);
442 x->ex_flags |= EXFLAG_INVALID;
444 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
447 BASIC_CONSTRAINTS_free(bs);
448 x->ex_flags |= EXFLAG_BCONS;
449 } else if (i != -1) {
450 x->ex_flags |= EXFLAG_INVALID;
453 /* Handle proxy certificates */
454 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
455 if (x->ex_flags & EXFLAG_CA
456 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
457 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
458 x->ex_flags |= EXFLAG_INVALID;
460 if (pci->pcPathLengthConstraint != NULL)
461 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
463 x->ex_pcpathlen = -1;
464 PROXY_CERT_INFO_EXTENSION_free(pci);
465 x->ex_flags |= EXFLAG_PROXY;
466 } else if (i != -1) {
467 x->ex_flags |= EXFLAG_INVALID;
470 /* Handle (basic) key usage */
471 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
473 if (usage->length > 0) {
474 x->ex_kusage = usage->data[0];
475 if (usage->length > 1)
476 x->ex_kusage |= usage->data[1] << 8;
478 x->ex_flags |= EXFLAG_KUSAGE;
479 ASN1_BIT_STRING_free(usage);
480 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
481 if (x->ex_kusage == 0) {
482 ERR_raise(ERR_LIB_X509, X509V3_R_EMPTY_KEY_USAGE);
483 x->ex_flags |= EXFLAG_INVALID;
485 } else if (i != -1) {
486 x->ex_flags |= EXFLAG_INVALID;
489 /* Handle extended key usage */
491 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
492 x->ex_flags |= EXFLAG_XKUSAGE;
493 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
494 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
495 case NID_server_auth:
496 x->ex_xkusage |= XKU_SSL_SERVER;
498 case NID_client_auth:
499 x->ex_xkusage |= XKU_SSL_CLIENT;
501 case NID_email_protect:
502 x->ex_xkusage |= XKU_SMIME;
505 x->ex_xkusage |= XKU_CODE_SIGN;
509 x->ex_xkusage |= XKU_SGC;
512 x->ex_xkusage |= XKU_OCSP_SIGN;
515 x->ex_xkusage |= XKU_TIMESTAMP;
518 x->ex_xkusage |= XKU_DVCS;
520 case NID_anyExtendedKeyUsage:
521 x->ex_xkusage |= XKU_ANYEKU;
524 /* Ignore unknown extended key usage */
528 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
529 } else if (i != -1) {
530 x->ex_flags |= EXFLAG_INVALID;
533 /* Handle legacy Netscape extension */
534 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
536 x->ex_nscert = ns->data[0];
539 x->ex_flags |= EXFLAG_NSCERT;
540 ASN1_BIT_STRING_free(ns);
541 } else if (i != -1) {
542 x->ex_flags |= EXFLAG_INVALID;
545 /* Handle subject key identifier and issuer/authority key identifier */
546 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
547 if (x->skid == NULL && i != -1)
548 x->ex_flags |= EXFLAG_INVALID;
550 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
551 if (x->akid == NULL && i != -1)
552 x->ex_flags |= EXFLAG_INVALID;
554 /* Check if subject name matches issuer */
555 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
556 x->ex_flags |= EXFLAG_SI; /* Cert is self-issued */
557 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
558 /* .. and the signature alg matches the PUBKEY alg: */
559 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
560 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
561 /* This is very related to ossl_x509_likely_issued(x, x) == X509_V_OK */
564 /* Handle subject alternative names and various other extensions */
565 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
566 if (x->altname == NULL && i != -1)
567 x->ex_flags |= EXFLAG_INVALID;
568 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
569 if (x->nc == NULL && i != -1)
570 x->ex_flags |= EXFLAG_INVALID;
572 /* Handle CRL distribution point entries */
573 res = setup_crldp(x);
575 x->ex_flags |= EXFLAG_INVALID;
579 #ifndef OPENSSL_NO_RFC3779
580 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
581 if (x->rfc3779_addr == NULL && i != -1)
582 x->ex_flags |= EXFLAG_INVALID;
583 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
584 if (x->rfc3779_asid == NULL && i != -1)
585 x->ex_flags |= EXFLAG_INVALID;
587 for (i = 0; i < X509_get_ext_count(x); i++) {
588 X509_EXTENSION *ex = X509_get_ext(x, i);
589 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
591 if (nid == NID_freshest_crl)
592 x->ex_flags |= EXFLAG_FRESHEST;
593 if (!X509_EXTENSION_get_critical(ex))
595 if (!X509_supported_extension(ex)) {
596 x->ex_flags |= EXFLAG_CRITICAL;
600 case NID_basic_constraints:
601 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
603 case NID_authority_key_identifier:
604 x->ex_flags |= EXFLAG_AKID_CRITICAL;
606 case NID_subject_key_identifier:
607 x->ex_flags |= EXFLAG_SKID_CRITICAL;
609 case NID_subject_alt_name:
610 x->ex_flags |= EXFLAG_SAN_CRITICAL;
617 /* Set x->siginf, ignoring errors due to unsupported algos */
618 (void)ossl_x509_init_sig_info(x);
620 x->ex_flags |= EXFLAG_SET; /* Indicate that cert has been processed */
622 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
624 * Above store triggers fast lock-free check in the beginning of the
625 * function. But one has to ensure that the structure is "stable", i.e.
626 * all stores are visible on all processors. Hence the release fence.
630 if ((x->ex_flags & (EXFLAG_INVALID | EXFLAG_NO_FINGERPRINT)) == 0) {
631 CRYPTO_THREAD_unlock(x->lock);
634 if ((x->ex_flags & EXFLAG_INVALID) != 0)
635 ERR_raise(ERR_LIB_X509, X509V3_R_INVALID_CERTIFICATE);
636 /* If computing sha1_hash failed the error queue already reflects this. */
639 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
640 CRYPTO_THREAD_unlock(x->lock);
645 * CA checks common to all purposes
649 * 2 Only possible in older versions of openSSL when basicConstraints are absent
650 * new versions will not return this value. May be a CA
651 * 3 basicConstraints absent but self-signed V1.
652 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
653 * 5 Netscape specific CA Flags present
656 static int check_ca(const X509 *x)
658 /* keyUsage if present should allow cert signing */
659 if (ku_reject(x, KU_KEY_CERT_SIGN))
661 if ((x->ex_flags & EXFLAG_BCONS) != 0) {
662 /* If basicConstraints says not a CA then say so */
663 return (x->ex_flags & EXFLAG_CA) != 0;
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 if (CRYPTO_THREAD_write_lock(x->lock)) {
684 x->ex_flags |= EXFLAG_PROXY;
685 CRYPTO_THREAD_unlock(x->lock);
689 void X509_set_proxy_pathlen(X509 *x, long l)
694 int X509_check_ca(X509 *x)
696 /* Note 0 normally means "not a CA" - but in this case means error. */
697 if (!ossl_x509v3_cache_extensions(x))
703 /* Check SSL CA: common checks for SSL client and server. */
704 static int check_ssl_ca(const X509 *x)
706 int ca_ret = check_ca(x);
710 /* Check nsCertType if present */
711 return ca_ret != 5 || (x->ex_nscert & NS_SSL_CA) != 0;
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, require_ca);
760 if (!ret || require_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 require_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, require_ca);
800 if (!ret || require_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, require_ca);
812 if (!ret || require_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.
838 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
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_purpose(const X509_PURPOSE *xp, const X509 *x,
893 * Various checks to see if one certificate potentially issued the second.
894 * This can be used to prune a set of possible issuer certificates which
895 * have been looked up using some simple method such as by subject name.
897 * 1. issuer_name(subject) == subject_name(issuer)
898 * 2. If akid(subject) exists, it matches the respective issuer fields.
899 * 3. subject signature algorithm == issuer public key algorithm
900 * 4. If key_usage(issuer) exists, it allows for signing subject.
901 * Note that this does not include actually checking the signature.
902 * Returns 0 for OK, or positive for reason for mismatch
903 * where reason codes match those for X509_verify_cert().
905 int X509_check_issued(X509 *issuer, X509 *subject)
909 if ((ret = ossl_x509_likely_issued(issuer, subject)) != X509_V_OK)
911 return ossl_x509_signing_allowed(issuer, subject);
914 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
915 int ossl_x509_likely_issued(X509 *issuer, X509 *subject)
919 if (X509_NAME_cmp(X509_get_subject_name(issuer),
920 X509_get_issuer_name(subject)) != 0)
921 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
923 /* set issuer->skid and subject->akid */
924 if (!ossl_x509v3_cache_extensions(issuer)
925 || !ossl_x509v3_cache_extensions(subject))
926 return X509_V_ERR_UNSPECIFIED;
928 ret = X509_check_akid(issuer, subject->akid);
929 if (ret != X509_V_OK)
932 /* Check if the subject signature alg matches the issuer's PUBKEY alg */
933 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
937 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
938 * according to the B<keyUsage> field of I<issuer> if present
939 * depending on any proxyCertInfo extension of I<subject>.
940 * Returns 0 for OK, or positive for reason for rejection
941 * where reason codes match those for X509_verify_cert().
943 int ossl_x509_signing_allowed(const X509 *issuer, const X509 *subject)
945 if (subject->ex_flags & EXFLAG_PROXY) {
946 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
947 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
948 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
949 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
953 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
958 /* Check key ids (if present) */
959 if (akid->keyid && issuer->skid &&
960 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
961 return X509_V_ERR_AKID_SKID_MISMATCH;
962 /* Check serial number */
964 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
965 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
966 /* Check issuer name */
969 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
970 * GeneralName. So look for a DirName. There may be more than one but
971 * we only take any notice of the first.
975 X509_NAME *nm = NULL;
978 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
979 gen = sk_GENERAL_NAME_value(gens, i);
980 if (gen->type == GEN_DIRNAME) {
985 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
986 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
991 uint32_t X509_get_extension_flags(X509 *x)
993 /* Call for side-effect of computing hash and caching extensions */
994 X509_check_purpose(x, -1, 0);
998 uint32_t X509_get_key_usage(X509 *x)
1000 /* Call for side-effect of computing hash and caching extensions */
1001 if (X509_check_purpose(x, -1, 0) != 1)
1003 if (x->ex_flags & EXFLAG_KUSAGE)
1004 return x->ex_kusage;
1008 uint32_t X509_get_extended_key_usage(X509 *x)
1010 /* Call for side-effect of computing hash and caching extensions */
1011 if (X509_check_purpose(x, -1, 0) != 1)
1013 if (x->ex_flags & EXFLAG_XKUSAGE)
1014 return x->ex_xkusage;
1018 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1020 /* Call for side-effect of computing hash and caching extensions */
1021 if (X509_check_purpose(x, -1, 0) != 1)
1026 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1028 /* Call for side-effect of computing hash and caching extensions */
1029 if (X509_check_purpose(x, -1, 0) != 1)
1031 return (x->akid != NULL ? x->akid->keyid : NULL);
1034 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1036 /* Call for side-effect of computing hash and caching extensions */
1037 if (X509_check_purpose(x, -1, 0) != 1)
1039 return (x->akid != NULL ? x->akid->issuer : NULL);
1042 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1044 /* Call for side-effect of computing hash and caching extensions */
1045 if (X509_check_purpose(x, -1, 0) != 1)
1047 return (x->akid != NULL ? x->akid->serial : NULL);
1050 long X509_get_pathlen(X509 *x)
1052 /* Called for side effect of caching extensions */
1053 if (X509_check_purpose(x, -1, 0) != 1
1054 || (x->ex_flags & EXFLAG_BCONS) == 0)
1056 return x->ex_pathlen;
1059 long X509_get_proxy_pathlen(X509 *x)
1061 /* Called for side effect of caching extensions */
1062 if (X509_check_purpose(x, -1, 0) != 1
1063 || (x->ex_flags & EXFLAG_PROXY) == 0)
1065 return x->ex_pcpathlen;