2 * Copyright 1999-2023 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 non_leaf);
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 non_leaf)
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, non_leaf);
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)
176 ptmp->flags = X509_PURPOSE_DYNAMIC;
178 ptmp = X509_PURPOSE_get0(idx);
181 /* OPENSSL_free existing name if dynamic */
182 if ((ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) != 0) {
183 OPENSSL_free(ptmp->name);
184 OPENSSL_free(ptmp->sname);
186 /* Dup supplied name */
187 ptmp->name = OPENSSL_strdup(name);
188 ptmp->sname = OPENSSL_strdup(sname);
189 if (ptmp->name == NULL || ptmp->sname == NULL)
191 /* Keep the dynamic flag of existing entry */
192 ptmp->flags &= X509_PURPOSE_DYNAMIC;
193 /* Set all other flags */
194 ptmp->flags |= flags;
198 ptmp->check_purpose = ck;
199 ptmp->usr_data = arg;
201 /* If its a new entry manage the dynamic table */
204 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
205 ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB);
208 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
209 ERR_raise(ERR_LIB_X509V3, ERR_R_CRYPTO_LIB);
216 OPENSSL_free(ptmp->name);
217 OPENSSL_free(ptmp->sname);
223 static void xptable_free(X509_PURPOSE *p)
227 if ((p->flags & X509_PURPOSE_DYNAMIC) != 0) {
228 if ((p->flags & X509_PURPOSE_DYNAMIC_NAME) != 0) {
229 OPENSSL_free(p->name);
230 OPENSSL_free(p->sname);
236 void X509_PURPOSE_cleanup(void)
238 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
242 int X509_PURPOSE_get_id(const X509_PURPOSE *xp)
247 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
252 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
257 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
262 static int nid_cmp(const int *a, const int *b)
267 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
268 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
270 int X509_supported_extension(X509_EXTENSION *ex)
273 * This table is a list of the NIDs of supported extensions: that is
274 * those which are used by the verify process. If an extension is
275 * critical and doesn't appear in this list then the verify process will
276 * normally reject the certificate. The list must be kept in numerical
277 * 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_id_pkix_OCSP_noCheck, /* 369 */
292 NID_policy_constraints, /* 401 */
293 NID_proxyCertInfo, /* 663 */
294 NID_name_constraints, /* 666 */
295 NID_policy_mappings, /* 747 */
296 NID_inhibit_any_policy /* 748 */
299 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
301 if (ex_nid == NID_undef)
304 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
309 /* Returns 1 on success, 0 if x is invalid, -1 on (internal) error. */
310 static int setup_dp(const X509 *x, DIST_POINT *dp)
312 const X509_NAME *iname = NULL;
315 if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) {
316 ERR_raise(ERR_LIB_X509, X509_R_INVALID_DISTPOINT);
319 if (dp->reasons != NULL) {
320 if (dp->reasons->length > 0)
321 dp->dp_reasons = dp->reasons->data[0];
322 if (dp->reasons->length > 1)
323 dp->dp_reasons |= (dp->reasons->data[1] << 8);
324 dp->dp_reasons &= CRLDP_ALL_REASONS;
326 dp->dp_reasons = CRLDP_ALL_REASONS;
328 if (dp->distpoint == NULL || dp->distpoint->type != 1)
331 /* Handle name fragment given by nameRelativeToCRLIssuer */
333 * Note that the below way of determining iname is not really compliant
334 * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13
335 * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1
336 * and any CRLissuer could be of type different to GEN_DIRNAME.
338 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
339 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
341 if (gen->type == GEN_DIRNAME) {
342 iname = gen->d.directoryName;
347 iname = X509_get_issuer_name(x);
348 return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1;
351 /* Return 1 on success, 0 if x is invalid, -1 on (internal) error. */
352 static int setup_crldp(X509 *x)
356 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
357 if (x->crldp == NULL && i != -1)
360 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
361 int res = setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
369 /* Check that issuer public key algorithm matches subject signature algorithm */
370 static int check_sig_alg_match(const EVP_PKEY *issuer_key, const X509 *subject)
374 if (issuer_key == NULL)
375 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
376 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
377 NULL, &subj_sig_nid) == 0)
378 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
379 if (EVP_PKEY_is_a(issuer_key, OBJ_nid2sn(subj_sig_nid))
380 || (EVP_PKEY_is_a(issuer_key, "RSA") && subj_sig_nid == NID_rsassaPss))
382 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
385 #define V1_ROOT (EXFLAG_V1 | EXFLAG_SS)
386 #define ku_reject(x, usage) \
387 (((x)->ex_flags & EXFLAG_KUSAGE) != 0 && ((x)->ex_kusage & (usage)) == 0)
388 #define xku_reject(x, usage) \
389 (((x)->ex_flags & EXFLAG_XKUSAGE) != 0 && ((x)->ex_xkusage & (usage)) == 0)
390 #define ns_reject(x, usage) \
391 (((x)->ex_flags & EXFLAG_NSCERT) != 0 && ((x)->ex_nscert & (usage)) == 0)
394 * Cache info on various X.509v3 extensions and further derived information,
395 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
396 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags.
397 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
398 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
400 int ossl_x509v3_cache_extensions(X509 *x)
402 BASIC_CONSTRAINTS *bs;
403 PROXY_CERT_INFO_EXTENSION *pci;
404 ASN1_BIT_STRING *usage;
406 EXTENDED_KEY_USAGE *extusage;
411 /* Fast lock-free check, see end of the function for details. */
412 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
413 return (x->ex_flags & EXFLAG_INVALID) == 0;
416 if (!CRYPTO_THREAD_write_lock(x->lock))
418 if ((x->ex_flags & EXFLAG_SET) != 0) { /* Cert has already been processed */
419 CRYPTO_THREAD_unlock(x->lock);
420 return (x->ex_flags & EXFLAG_INVALID) == 0;
425 /* Cache the SHA1 digest of the cert */
426 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
427 x->ex_flags |= EXFLAG_NO_FINGERPRINT;
429 /* V1 should mean no extensions ... */
430 if (X509_get_version(x) == X509_VERSION_1)
431 x->ex_flags |= EXFLAG_V1;
433 /* Handle basic constraints */
435 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
437 x->ex_flags |= EXFLAG_CA;
438 if (bs->pathlen != NULL) {
440 * The error case !bs->ca is checked by check_chain()
441 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
443 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
444 ERR_raise(ERR_LIB_X509V3, X509V3_R_NEGATIVE_PATHLEN);
445 x->ex_flags |= EXFLAG_INVALID;
447 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
450 BASIC_CONSTRAINTS_free(bs);
451 x->ex_flags |= EXFLAG_BCONS;
452 } else if (i != -1) {
453 x->ex_flags |= EXFLAG_INVALID;
456 /* Handle proxy certificates */
457 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
458 if ((x->ex_flags & EXFLAG_CA) != 0
459 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
460 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
461 x->ex_flags |= EXFLAG_INVALID;
463 if (pci->pcPathLengthConstraint != NULL)
464 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
466 x->ex_pcpathlen = -1;
467 PROXY_CERT_INFO_EXTENSION_free(pci);
468 x->ex_flags |= EXFLAG_PROXY;
469 } else if (i != -1) {
470 x->ex_flags |= EXFLAG_INVALID;
473 /* Handle (basic) key usage */
474 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
476 if (usage->length > 0) {
477 x->ex_kusage = usage->data[0];
478 if (usage->length > 1)
479 x->ex_kusage |= usage->data[1] << 8;
481 x->ex_flags |= EXFLAG_KUSAGE;
482 ASN1_BIT_STRING_free(usage);
483 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
484 if (x->ex_kusage == 0) {
485 ERR_raise(ERR_LIB_X509V3, X509V3_R_EMPTY_KEY_USAGE);
486 x->ex_flags |= EXFLAG_INVALID;
488 } else if (i != -1) {
489 x->ex_flags |= EXFLAG_INVALID;
492 /* Handle extended key usage */
494 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
495 x->ex_flags |= EXFLAG_XKUSAGE;
496 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
497 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
498 case NID_server_auth:
499 x->ex_xkusage |= XKU_SSL_SERVER;
501 case NID_client_auth:
502 x->ex_xkusage |= XKU_SSL_CLIENT;
504 case NID_email_protect:
505 x->ex_xkusage |= XKU_SMIME;
508 x->ex_xkusage |= XKU_CODE_SIGN;
512 x->ex_xkusage |= XKU_SGC;
515 x->ex_xkusage |= XKU_OCSP_SIGN;
518 x->ex_xkusage |= XKU_TIMESTAMP;
521 x->ex_xkusage |= XKU_DVCS;
523 case NID_anyExtendedKeyUsage:
524 x->ex_xkusage |= XKU_ANYEKU;
527 /* Ignore unknown extended key usage */
531 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
532 } else if (i != -1) {
533 x->ex_flags |= EXFLAG_INVALID;
536 /* Handle legacy Netscape extension */
537 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
539 x->ex_nscert = ns->data[0];
542 x->ex_flags |= EXFLAG_NSCERT;
543 ASN1_BIT_STRING_free(ns);
544 } else if (i != -1) {
545 x->ex_flags |= EXFLAG_INVALID;
548 /* Handle subject key identifier and issuer/authority key identifier */
549 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
550 if (x->skid == NULL && i != -1)
551 x->ex_flags |= EXFLAG_INVALID;
553 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
554 if (x->akid == NULL && i != -1)
555 x->ex_flags |= EXFLAG_INVALID;
557 /* Check if subject name matches issuer */
558 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
559 x->ex_flags |= EXFLAG_SI; /* Cert is self-issued */
560 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
561 /* .. and the signature alg matches the PUBKEY alg: */
562 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
563 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
564 /* This is very related to ossl_x509_likely_issued(x, x) == X509_V_OK */
567 /* Handle subject alternative names and various other extensions */
568 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
569 if (x->altname == NULL && i != -1)
570 x->ex_flags |= EXFLAG_INVALID;
571 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
572 if (x->nc == NULL && i != -1)
573 x->ex_flags |= EXFLAG_INVALID;
575 /* Handle CRL distribution point entries */
576 res = setup_crldp(x);
578 x->ex_flags |= EXFLAG_INVALID;
580 #ifndef OPENSSL_NO_RFC3779
581 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
582 if (x->rfc3779_addr == NULL && i != -1)
583 x->ex_flags |= EXFLAG_INVALID;
584 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
585 if (x->rfc3779_asid == NULL && i != -1)
586 x->ex_flags |= EXFLAG_INVALID;
588 for (i = 0; i < X509_get_ext_count(x); i++) {
589 X509_EXTENSION *ex = X509_get_ext(x, i);
590 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
592 if (nid == NID_freshest_crl)
593 x->ex_flags |= EXFLAG_FRESHEST;
594 if (!X509_EXTENSION_get_critical(ex))
596 if (!X509_supported_extension(ex)) {
597 x->ex_flags |= EXFLAG_CRITICAL;
601 case NID_basic_constraints:
602 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
604 case NID_authority_key_identifier:
605 x->ex_flags |= EXFLAG_AKID_CRITICAL;
607 case NID_subject_key_identifier:
608 x->ex_flags |= EXFLAG_SKID_CRITICAL;
610 case NID_subject_alt_name:
611 x->ex_flags |= EXFLAG_SAN_CRITICAL;
618 /* Set x->siginf, ignoring errors due to unsupported algos */
619 (void)ossl_x509_init_sig_info(x);
621 x->ex_flags |= EXFLAG_SET; /* Indicate that cert has been processed */
623 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
625 * Above store triggers fast lock-free check in the beginning of the
626 * function. But one has to ensure that the structure is "stable", i.e.
627 * all stores are visible on all processors. Hence the release fence.
632 if ((x->ex_flags & EXFLAG_INVALID) == 0) {
633 CRYPTO_THREAD_unlock(x->lock);
636 CRYPTO_THREAD_unlock(x->lock);
637 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_CERTIFICATE);
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) != 0) {
659 /* If basicConstraints says not a CA then say so */
660 return (x->ex_flags & EXFLAG_CA) != 0;
662 /* We support V1 roots for... uh, I don't really know why. */
663 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
666 * If key usage present it must have certSign so tolerate it
668 else if ((x->ex_flags & EXFLAG_KUSAGE) != 0)
670 /* Older certificates could have Netscape-specific CA types */
671 else if ((x->ex_flags & EXFLAG_NSCERT) != 0
672 && (x->ex_nscert & NS_ANY_CA) != 0)
674 /* Can this still be regarded a CA certificate? I doubt it. */
679 void X509_set_proxy_flag(X509 *x)
681 if (CRYPTO_THREAD_write_lock(x->lock)) {
682 x->ex_flags |= EXFLAG_PROXY;
683 CRYPTO_THREAD_unlock(x->lock);
687 void X509_set_proxy_pathlen(X509 *x, long l)
692 int X509_check_ca(X509 *x)
694 /* Note 0 normally means "not a CA" - but in this case means error. */
695 if (!ossl_x509v3_cache_extensions(x))
701 /* Check SSL CA: common checks for SSL client and server. */
702 static int check_ssl_ca(const X509 *x)
704 int ca_ret = check_ca(x);
708 /* Check nsCertType if present */
709 return ca_ret != 5 || (x->ex_nscert & NS_SSL_CA) != 0;
712 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
715 if (xku_reject(x, XKU_SSL_CLIENT))
718 return check_ssl_ca(x);
719 /* We need to do digital signatures or key agreement */
720 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
722 /* nsCertType if present should allow SSL client use */
723 if (ns_reject(x, NS_SSL_CLIENT))
729 * Key usage needed for TLS/SSL server: digital signature, encipherment or
730 * key agreement. The ssl code can check this more thoroughly for individual
734 KU_DIGITAL_SIGNATURE | KU_KEY_ENCIPHERMENT | KU_KEY_AGREEMENT
736 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
739 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
742 return check_ssl_ca(x);
744 if (ns_reject(x, NS_SSL_SERVER))
746 if (ku_reject(x, KU_TLS))
753 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
756 int ret = check_purpose_ssl_server(xp, x, non_leaf);
758 if (!ret || non_leaf)
760 /* We need to encipher or Netscape complains */
761 return ku_reject(x, KU_KEY_ENCIPHERMENT) ? 0 : ret;
764 /* common S/MIME checks */
765 static int purpose_smime(const X509 *x, int non_leaf)
767 if (xku_reject(x, XKU_SMIME))
770 int ca_ret = check_ca(x);
774 /* Check nsCertType if present */
775 if (ca_ret != 5 || (x->ex_nscert & NS_SMIME_CA) != 0)
780 if ((x->ex_flags & EXFLAG_NSCERT) != 0) {
781 if ((x->ex_nscert & NS_SMIME) != 0)
783 /* Workaround for some buggy certificates */
784 return (x->ex_nscert & NS_SSL_CLIENT) != 0 ? 2 : 0;
789 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
792 int ret = purpose_smime(x, non_leaf);
794 if (!ret || non_leaf)
796 return ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION) ? 0 : ret;
799 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
802 int ret = purpose_smime(x, non_leaf);
804 if (!ret || non_leaf)
806 return ku_reject(x, KU_KEY_ENCIPHERMENT) ? 0 : ret;
809 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
813 int ca_ret = check_ca(x);
815 return ca_ret == 2 ? 0 : ca_ret;
817 return !ku_reject(x, KU_CRL_SIGN);
821 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
822 * is valid. Additional checks must be made on the chain.
824 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
828 * Must be a valid CA. Should we really support the "I don't know" value
833 /* Leaf certificate is checked in OCSP_verify() */
837 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
843 * If non_leaf is true we must check if this is a valid CA certificate.
844 * The extra requirements by the CA/Browser Forum are not checked.
850 * Key Usage is checked according to RFC 5280 and
851 * Extended Key Usage attributes is checked according to RFC 3161.
852 * The extra (and somewhat conflicting) CA/Browser Forum
853 * Baseline Requirements for the Issuance and Management of
854 * PubliclyâTrusted Code Signing Certificates, Version 3.0.0,
855 * Section 7.1.2.3: Code signing and Timestamp Certificate are not checked.
858 * Check the optional key usage field:
859 * if Key Usage is present, it must be one of digitalSignature
860 * and/or nonRepudiation (other values are not consistent and shall
863 if ((x->ex_flags & EXFLAG_KUSAGE) != 0
864 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
865 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
868 /* Only timestamp key usage is permitted and it's required. */
869 if ((x->ex_flags & EXFLAG_XKUSAGE) == 0 || x->ex_xkusage != XKU_TIMESTAMP)
872 /* Extended Key Usage MUST be critical */
873 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
875 && !X509_EXTENSION_get_critical(X509_get_ext((X509 *)x, i_ext)))
880 static int check_purpose_code_sign(const X509_PURPOSE *xp, const X509 *x,
886 * If non_leaf is true we must check if this is a valid CA certificate.
887 * The extra requirements by the CA/Browser Forum are not checked.
893 * Check the key usage and extended key usage fields:
895 * Reference: CA/Browser Forum,
896 * Baseline Requirements for the Issuance and Management of
897 * PubliclyâTrusted Code Signing Certificates, Version 3.0.0,
898 * Section 7.1.2.3: Code signing and Timestamp Certificate
900 * Checking covers Key Usage and Extended Key Usage attributes.
901 * The certificatePolicies, cRLDistributionPoints (CDP), and
902 * authorityInformationAccess (AIA) extensions are so far not checked.
905 if ((x->ex_flags & EXFLAG_KUSAGE) == 0)
907 if ((x->ex_kusage & KU_DIGITAL_SIGNATURE) == 0)
909 if ((x->ex_kusage & (KU_KEY_CERT_SIGN | KU_CRL_SIGN)) != 0)
912 /* Key Usage MUST be critical */
913 i_ext = X509_get_ext_by_NID(x, NID_key_usage, -1);
917 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
918 if (!X509_EXTENSION_get_critical(ext))
922 /* Extended Key Usage */
923 if ((x->ex_flags & EXFLAG_XKUSAGE) == 0)
925 if ((x->ex_xkusage & XKU_CODE_SIGN) == 0)
927 if ((x->ex_xkusage & (XKU_ANYEKU | XKU_SSL_SERVER)) != 0)
934 static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x,
941 * Various checks to see if one certificate potentially issued the second.
942 * This can be used to prune a set of possible issuer certificates which
943 * have been looked up using some simple method such as by subject name.
945 * 1. issuer_name(subject) == subject_name(issuer)
946 * 2. If akid(subject) exists, it matches the respective issuer fields.
947 * 3. subject signature algorithm == issuer public key algorithm
948 * 4. If key_usage(issuer) exists, it allows for signing subject.
949 * Note that this does not include actually checking the signature.
950 * Returns 0 for OK, or positive for reason for mismatch
951 * where reason codes match those for X509_verify_cert().
953 int X509_check_issued(X509 *issuer, X509 *subject)
957 if ((ret = ossl_x509_likely_issued(issuer, subject)) != X509_V_OK)
959 return ossl_x509_signing_allowed(issuer, subject);
962 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
963 int ossl_x509_likely_issued(X509 *issuer, X509 *subject)
967 if (X509_NAME_cmp(X509_get_subject_name(issuer),
968 X509_get_issuer_name(subject)) != 0)
969 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
971 /* set issuer->skid and subject->akid */
972 if (!ossl_x509v3_cache_extensions(issuer)
973 || !ossl_x509v3_cache_extensions(subject))
974 return X509_V_ERR_UNSPECIFIED;
976 ret = X509_check_akid(issuer, subject->akid);
977 if (ret != X509_V_OK)
980 /* Check if the subject signature alg matches the issuer's PUBKEY alg */
981 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
985 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
986 * according to the B<keyUsage> field of I<issuer> if present
987 * depending on any proxyCertInfo extension of I<subject>.
988 * Returns 0 for OK, or positive for reason for rejection
989 * where reason codes match those for X509_verify_cert().
991 int ossl_x509_signing_allowed(const X509 *issuer, const X509 *subject)
993 if ((subject->ex_flags & EXFLAG_PROXY) != 0) {
994 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
995 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
996 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) {
997 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
1002 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
1007 /* Check key ids (if present) */
1008 if (akid->keyid && issuer->skid &&
1009 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
1010 return X509_V_ERR_AKID_SKID_MISMATCH;
1011 /* Check serial number */
1013 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
1014 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
1015 /* Check issuer name */
1018 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
1019 * GeneralName. So look for a DirName. There may be more than one but
1020 * we only take any notice of the first.
1022 GENERAL_NAMES *gens = akid->issuer;
1024 X509_NAME *nm = NULL;
1027 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
1028 gen = sk_GENERAL_NAME_value(gens, i);
1029 if (gen->type == GEN_DIRNAME) {
1034 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
1035 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
1040 uint32_t X509_get_extension_flags(X509 *x)
1042 /* Call for side-effect of computing hash and caching extensions */
1043 X509_check_purpose(x, -1, 0);
1047 uint32_t X509_get_key_usage(X509 *x)
1049 /* Call for side-effect of computing hash and caching extensions */
1050 if (X509_check_purpose(x, -1, 0) != 1)
1052 return (x->ex_flags & EXFLAG_KUSAGE) != 0 ? x->ex_kusage : UINT32_MAX;
1055 uint32_t X509_get_extended_key_usage(X509 *x)
1057 /* Call for side-effect of computing hash and caching extensions */
1058 if (X509_check_purpose(x, -1, 0) != 1)
1060 return (x->ex_flags & EXFLAG_XKUSAGE) != 0 ? x->ex_xkusage : UINT32_MAX;
1063 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1065 /* Call for side-effect of computing hash and caching extensions */
1066 if (X509_check_purpose(x, -1, 0) != 1)
1071 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1073 /* Call for side-effect of computing hash and caching extensions */
1074 if (X509_check_purpose(x, -1, 0) != 1)
1076 return (x->akid != NULL ? x->akid->keyid : NULL);
1079 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1081 /* Call for side-effect of computing hash and caching extensions */
1082 if (X509_check_purpose(x, -1, 0) != 1)
1084 return (x->akid != NULL ? x->akid->issuer : NULL);
1087 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1089 /* Call for side-effect of computing hash and caching extensions */
1090 if (X509_check_purpose(x, -1, 0) != 1)
1092 return (x->akid != NULL ? x->akid->serial : NULL);
1095 long X509_get_pathlen(X509 *x)
1097 /* Called for side effect of caching extensions */
1098 if (X509_check_purpose(x, -1, 0) != 1
1099 || (x->ex_flags & EXFLAG_BCONS) == 0)
1101 return x->ex_pathlen;
1104 long X509_get_proxy_pathlen(X509 *x)
1106 /* Called for side effect of caching extensions */
1107 if (X509_check_purpose(x, -1, 0) != 1
1108 || (x->ex_flags & EXFLAG_PROXY) == 0)
1110 return x->ex_pcpathlen;