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 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 *issuer_key, const X509 *subject)
367 int signer_nid, subj_sig_nid;
369 if (issuer_key == NULL)
370 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
371 signer_nid = EVP_PKEY_base_id(issuer_key);
372 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
373 NULL, &subj_sig_nid) == 0)
374 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
375 if (signer_nid == EVP_PKEY_type(subj_sig_nid)
376 || (signer_nid == NID_rsaEncryption && subj_sig_nid == NID_rsassaPss))
378 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
381 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
382 #define ku_reject(x, usage) \
383 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
384 #define xku_reject(x, usage) \
385 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
386 #define ns_reject(x, usage) \
387 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
390 * Cache info on various X.509v3 extensions and further derived information,
391 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
392 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags.
393 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
394 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
396 int x509v3_cache_extensions(X509 *x)
398 BASIC_CONSTRAINTS *bs;
399 PROXY_CERT_INFO_EXTENSION *pci;
400 ASN1_BIT_STRING *usage;
402 EXTENDED_KEY_USAGE *extusage;
407 /* fast lock-free check, see end of the function for details. */
408 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
409 return (x->ex_flags & EXFLAG_INVALID) == 0;
412 CRYPTO_THREAD_write_lock(x->lock);
413 if (x->ex_flags & EXFLAG_SET) { /* cert has already been processed */
414 CRYPTO_THREAD_unlock(x->lock);
415 return (x->ex_flags & EXFLAG_INVALID) == 0;
418 /* Cache the SHA1 digest of the cert */
419 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
420 x->ex_flags |= EXFLAG_NO_FINGERPRINT;
424 /* V1 should mean no extensions ... */
425 if (X509_get_version(x) == 0)
426 x->ex_flags |= EXFLAG_V1;
428 /* Handle basic constraints */
430 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
432 x->ex_flags |= EXFLAG_CA;
433 if (bs->pathlen != NULL) {
435 * the error case !bs->ca is checked by check_chain()
436 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
438 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
439 ERR_raise(ERR_LIB_X509, X509V3_R_NEGATIVE_PATHLEN);
440 x->ex_flags |= EXFLAG_INVALID;
442 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
445 BASIC_CONSTRAINTS_free(bs);
446 x->ex_flags |= EXFLAG_BCONS;
447 } else if (i != -1) {
448 x->ex_flags |= EXFLAG_INVALID;
451 /* Handle proxy certificates */
452 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
453 if (x->ex_flags & EXFLAG_CA
454 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
455 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
456 x->ex_flags |= EXFLAG_INVALID;
458 if (pci->pcPathLengthConstraint != NULL)
459 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
461 x->ex_pcpathlen = -1;
462 PROXY_CERT_INFO_EXTENSION_free(pci);
463 x->ex_flags |= EXFLAG_PROXY;
464 } else if (i != -1) {
465 x->ex_flags |= EXFLAG_INVALID;
468 /* Handle (basic) key usage */
469 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
471 if (usage->length > 0) {
472 x->ex_kusage = usage->data[0];
473 if (usage->length > 1)
474 x->ex_kusage |= usage->data[1] << 8;
476 x->ex_flags |= EXFLAG_KUSAGE;
477 ASN1_BIT_STRING_free(usage);
478 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
479 if (x->ex_kusage == 0) {
480 ERR_raise(ERR_LIB_X509, X509V3_R_EMPTY_KEY_USAGE);
481 x->ex_flags |= EXFLAG_INVALID;
483 } else if (i != -1) {
484 x->ex_flags |= EXFLAG_INVALID;
487 /* Handle extended key usage */
489 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
490 x->ex_flags |= EXFLAG_XKUSAGE;
491 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
492 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
493 case NID_server_auth:
494 x->ex_xkusage |= XKU_SSL_SERVER;
496 case NID_client_auth:
497 x->ex_xkusage |= XKU_SSL_CLIENT;
499 case NID_email_protect:
500 x->ex_xkusage |= XKU_SMIME;
503 x->ex_xkusage |= XKU_CODE_SIGN;
507 x->ex_xkusage |= XKU_SGC;
510 x->ex_xkusage |= XKU_OCSP_SIGN;
513 x->ex_xkusage |= XKU_TIMESTAMP;
516 x->ex_xkusage |= XKU_DVCS;
518 case NID_anyExtendedKeyUsage:
519 x->ex_xkusage |= XKU_ANYEKU;
522 /* ignore unknown extended key usage */
526 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
527 } else if (i != -1) {
528 x->ex_flags |= EXFLAG_INVALID;
531 /* Handle legacy Netscape extension */
532 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
534 x->ex_nscert = ns->data[0];
537 x->ex_flags |= EXFLAG_NSCERT;
538 ASN1_BIT_STRING_free(ns);
539 } else if (i != -1) {
540 x->ex_flags |= EXFLAG_INVALID;
543 /* Handle subject key identifier and issuer/authority key identifier */
544 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
545 if (x->skid == NULL && i != -1)
546 x->ex_flags |= EXFLAG_INVALID;
548 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
549 if (x->akid == NULL && i != -1)
550 x->ex_flags |= EXFLAG_INVALID;
552 /* Check if subject name matches issuer */
553 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
554 x->ex_flags |= EXFLAG_SI; /* cert is self-issued */
555 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
556 /* .. and the signature alg matches the PUBKEY alg: */
557 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
558 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
559 /* This is very related to x509_likely_issued(x, x) == X509_V_OK */
562 /* Handle subject alternative names and various other extensions */
563 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
564 if (x->altname == NULL && i != -1)
565 x->ex_flags |= EXFLAG_INVALID;
566 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
567 if (x->nc == NULL && i != -1)
568 x->ex_flags |= EXFLAG_INVALID;
570 /* Handle CRL distribution point entries */
571 res = setup_crldp(x);
573 x->ex_flags |= EXFLAG_INVALID;
577 #ifndef OPENSSL_NO_RFC3779
578 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
579 if (x->rfc3779_addr == NULL && i != -1)
580 x->ex_flags |= EXFLAG_INVALID;
581 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
582 if (x->rfc3779_asid == NULL && i != -1)
583 x->ex_flags |= EXFLAG_INVALID;
585 for (i = 0; i < X509_get_ext_count(x); i++) {
586 X509_EXTENSION *ex = X509_get_ext(x, i);
587 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
589 if (nid == NID_freshest_crl)
590 x->ex_flags |= EXFLAG_FRESHEST;
591 if (!X509_EXTENSION_get_critical(ex))
593 if (!X509_supported_extension(ex)) {
594 x->ex_flags |= EXFLAG_CRITICAL;
598 case NID_basic_constraints:
599 x->ex_flags |= EXFLAG_BCONS_CRITICAL;
601 case NID_authority_key_identifier:
602 x->ex_flags |= EXFLAG_AKID_CRITICAL;
604 case NID_subject_key_identifier:
605 x->ex_flags |= EXFLAG_SKID_CRITICAL;
607 case NID_subject_alt_name:
608 x->ex_flags |= EXFLAG_SAN_CRITICAL;
615 /* Set x->siginf, ignoring errors due to unsupported algos */
616 (void)x509_init_sig_info(x);
618 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
620 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1);
622 * Above store triggers fast lock-free check in the beginning of the
623 * function. But one has to ensure that the structure is "stable", i.e.
624 * all stores are visible on all processors. Hence the release fence.
628 if ((x->ex_flags & (EXFLAG_INVALID | EXFLAG_NO_FINGERPRINT)) == 0) {
629 CRYPTO_THREAD_unlock(x->lock);
632 if ((x->ex_flags & EXFLAG_INVALID) != 0)
633 ERR_raise(ERR_LIB_X509, X509V3_R_INVALID_CERTIFICATE);
634 /* If computing sha1_hash failed the error queue already reflects this. */
637 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
638 CRYPTO_THREAD_unlock(x->lock);
643 * CA checks common to all purposes
647 * 2 Only possible in older versions of openSSL when basicConstraints are absent
648 * new versions will not return this value. May be a CA
649 * 3 basicConstraints absent but self-signed V1.
650 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
651 * 5 Netscape specific CA Flags present
654 static int check_ca(const X509 *x)
656 /* keyUsage if present should allow cert signing */
657 if (ku_reject(x, KU_KEY_CERT_SIGN))
659 if (x->ex_flags & EXFLAG_BCONS) {
660 if (x->ex_flags & EXFLAG_CA)
662 /* If basicConstraints says not a CA then say so */
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)
674 /* Older certificates could have Netscape-specific CA types */
675 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
677 /* can this still be regarded a CA certificate? I doubt it */
682 void X509_set_proxy_flag(X509 *x)
684 x->ex_flags |= EXFLAG_PROXY;
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 (!x509v3_cache_extensions(x))
701 /* Check SSL CA: common checks for SSL client and server */
702 static int check_ssl_ca(const X509 *x)
705 ca_ret = check_ca(x);
708 /* check nsCertType if present */
709 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
715 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
718 if (xku_reject(x, XKU_SSL_CLIENT))
721 return check_ssl_ca(x);
722 /* We need to do digital signatures or key agreement */
723 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
725 /* nsCertType if present should allow SSL client use */
726 if (ns_reject(x, NS_SSL_CLIENT))
732 * Key usage needed for TLS/SSL server: digital signature, encipherment or
733 * key agreement. The ssl code can check this more thoroughly for individual
737 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
739 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
742 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
745 return check_ssl_ca(x);
747 if (ns_reject(x, NS_SSL_SERVER))
749 if (ku_reject(x, KU_TLS))
756 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
760 ret = check_purpose_ssl_server(xp, x, ca);
763 /* We need to encipher or Netscape complains */
764 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
769 /* common S/MIME checks */
770 static int purpose_smime(const X509 *x, int ca)
772 if (xku_reject(x, XKU_SMIME))
776 ca_ret = check_ca(x);
779 /* check nsCertType if present */
780 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
785 if (x->ex_flags & EXFLAG_NSCERT) {
786 if (x->ex_nscert & NS_SMIME)
788 /* Workaround for some buggy certificates */
789 if (x->ex_nscert & NS_SSL_CLIENT)
796 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
800 ret = purpose_smime(x, ca);
803 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
808 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
812 ret = purpose_smime(x, ca);
815 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
820 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
825 if ((ca_ret = check_ca(x)) != 2)
830 if (ku_reject(x, KU_CRL_SIGN))
836 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
837 * is valid. Additional checks must be made on the chain.
840 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
843 * Must be a valid CA. Should we really support the "I don't know" value
848 /* leaf certificate is checked in OCSP_verify() */
852 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
857 /* If ca is true we must return if this is a valid CA certificate. */
862 * Check the optional key usage field:
863 * if Key Usage is present, it must be one of digitalSignature
864 * and/or nonRepudiation (other values are not consistent and shall
867 if ((x->ex_flags & EXFLAG_KUSAGE)
868 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
869 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
872 /* Only time stamp key usage is permitted and it's required. */
873 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
876 /* Extended Key Usage MUST be critical */
877 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
879 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
880 if (!X509_EXTENSION_get_critical(ext))
887 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
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. Check issuer_name(subject) == subject_name(issuer)
898 * 2. If akid(subject) exists, check that it matches issuer
899 * 3. Check that issuer public key algorithm matches subject signature algorithm
900 * 4. Check that any key_usage(issuer) allows certificate signing
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 = x509_likely_issued(issuer, subject)) != X509_V_OK)
911 return x509_signing_allowed(issuer, subject);
914 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */
915 int 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 (!x509v3_cache_extensions(issuer)
925 || !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 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, -1);
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, -1) != 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, -1) != 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, -1) != 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, -1) != 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, -1) != 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, -1) != 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, -1) != 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, -1) != 1
1063 || (x->ex_flags & EXFLAG_PROXY) == 0)
1065 return x->ex_pcpathlen;