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 (!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)
369 int signer_nid, subj_sig_nid;
371 if (issuer_key == NULL)
372 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY;
373 signer_nid = EVP_PKEY_base_id(issuer_key);
374 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm),
375 NULL, &subj_sig_nid) == 0)
376 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM;
377 if (signer_nid == EVP_PKEY_type(subj_sig_nid)
378 || (signer_nid == NID_rsaEncryption && subj_sig_nid == NID_rsassaPss))
380 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH;
383 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
384 #define ku_reject(x, usage) \
385 (((x)->ex_flags & EXFLAG_KUSAGE) != 0 && ((x)->ex_kusage & (usage)) == 0)
386 #define xku_reject(x, usage) \
387 (((x)->ex_flags & EXFLAG_XKUSAGE) != 0 && ((x)->ex_xkusage & (usage)) == 0)
388 #define ns_reject(x, usage) \
389 (((x)->ex_flags & EXFLAG_NSCERT) != 0 && ((x)->ex_nscert & (usage)) == 0)
392 * Cache info on various X.509v3 extensions and further derived information,
393 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields.
394 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags.
395 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully.
396 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid.
398 int x509v3_cache_extensions(X509 *x)
400 BASIC_CONSTRAINTS *bs;
401 PROXY_CERT_INFO_EXTENSION *pci;
402 ASN1_BIT_STRING *usage;
404 EXTENDED_KEY_USAGE *extusage;
409 /* Fast lock-free check, see end of the function for details. */
410 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached))
411 return (x->ex_flags & EXFLAG_INVALID) == 0;
414 if (!CRYPTO_THREAD_write_lock(x->lock))
416 if (x->ex_flags & EXFLAG_SET) { /* Cert has already been processed */
417 CRYPTO_THREAD_unlock(x->lock);
418 return (x->ex_flags & EXFLAG_INVALID) == 0;
421 /* Cache the SHA1 digest of the cert */
422 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL))
423 x->ex_flags |= EXFLAG_NO_FINGERPRINT;
427 /* V1 should mean no extensions ... */
428 if (X509_get_version(x) == 0)
429 x->ex_flags |= EXFLAG_V1;
431 /* Handle basic constraints */
433 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) {
435 x->ex_flags |= EXFLAG_CA;
436 if (bs->pathlen != NULL) {
438 * The error case !bs->ca is checked by check_chain()
439 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT
441 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) {
442 ERR_raise(ERR_LIB_X509, X509V3_R_NEGATIVE_PATHLEN);
443 x->ex_flags |= EXFLAG_INVALID;
445 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
448 BASIC_CONSTRAINTS_free(bs);
449 x->ex_flags |= EXFLAG_BCONS;
450 } else if (i != -1) {
451 x->ex_flags |= EXFLAG_INVALID;
454 /* Handle proxy certificates */
455 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) {
456 if (x->ex_flags & EXFLAG_CA
457 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
458 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
459 x->ex_flags |= EXFLAG_INVALID;
461 if (pci->pcPathLengthConstraint != NULL)
462 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
464 x->ex_pcpathlen = -1;
465 PROXY_CERT_INFO_EXTENSION_free(pci);
466 x->ex_flags |= EXFLAG_PROXY;
467 } else if (i != -1) {
468 x->ex_flags |= EXFLAG_INVALID;
471 /* Handle (basic) key usage */
472 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) {
474 if (usage->length > 0) {
475 x->ex_kusage = usage->data[0];
476 if (usage->length > 1)
477 x->ex_kusage |= usage->data[1] << 8;
479 x->ex_flags |= EXFLAG_KUSAGE;
480 ASN1_BIT_STRING_free(usage);
481 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */
482 if (x->ex_kusage == 0) {
483 ERR_raise(ERR_LIB_X509, X509V3_R_EMPTY_KEY_USAGE);
484 x->ex_flags |= EXFLAG_INVALID;
486 } else if (i != -1) {
487 x->ex_flags |= EXFLAG_INVALID;
490 /* Handle extended key usage */
492 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) {
493 x->ex_flags |= EXFLAG_XKUSAGE;
494 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
495 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
496 case NID_server_auth:
497 x->ex_xkusage |= XKU_SSL_SERVER;
499 case NID_client_auth:
500 x->ex_xkusage |= XKU_SSL_CLIENT;
502 case NID_email_protect:
503 x->ex_xkusage |= XKU_SMIME;
506 x->ex_xkusage |= XKU_CODE_SIGN;
510 x->ex_xkusage |= XKU_SGC;
513 x->ex_xkusage |= XKU_OCSP_SIGN;
516 x->ex_xkusage |= XKU_TIMESTAMP;
519 x->ex_xkusage |= XKU_DVCS;
521 case NID_anyExtendedKeyUsage:
522 x->ex_xkusage |= XKU_ANYEKU;
525 /* Ignore unknown extended key usage */
529 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
530 } else if (i != -1) {
531 x->ex_flags |= EXFLAG_INVALID;
534 /* Handle legacy Netscape extension */
535 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) {
537 x->ex_nscert = ns->data[0];
540 x->ex_flags |= EXFLAG_NSCERT;
541 ASN1_BIT_STRING_free(ns);
542 } else if (i != -1) {
543 x->ex_flags |= EXFLAG_INVALID;
546 /* Handle subject key identifier and issuer/authority key identifier */
547 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
548 if (x->skid == NULL && i != -1)
549 x->ex_flags |= EXFLAG_INVALID;
551 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
552 if (x->akid == NULL && i != -1)
553 x->ex_flags |= EXFLAG_INVALID;
555 /* Check if subject name matches issuer */
556 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) {
557 x->ex_flags |= EXFLAG_SI; /* Cert is self-issued */
558 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */
559 /* .. and the signature alg matches the PUBKEY alg: */
560 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK)
561 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */
562 /* This is very related to x509_likely_issued(x, x) == X509_V_OK */
565 /* Handle subject alternative names and various other extensions */
566 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
567 if (x->altname == NULL && i != -1)
568 x->ex_flags |= EXFLAG_INVALID;
569 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
570 if (x->nc == NULL && i != -1)
571 x->ex_flags |= EXFLAG_INVALID;
573 /* Handle CRL distribution point entries */
574 res = setup_crldp(x);
576 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)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.
631 if ((x->ex_flags & (EXFLAG_INVALID | EXFLAG_NO_FINGERPRINT)) == 0) {
632 CRYPTO_THREAD_unlock(x->lock);
635 if ((x->ex_flags & EXFLAG_INVALID) != 0)
636 ERR_raise(ERR_LIB_X509, X509V3_R_INVALID_CERTIFICATE);
637 /* If computing sha1_hash failed the error queue already reflects this. */
640 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */
641 CRYPTO_THREAD_unlock(x->lock);
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)
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)
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,
757 ret = check_purpose_ssl_server(xp, x, require_ca);
758 if (!ret || require_ca)
760 /* We need to encipher or Netscape complains */
761 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
766 /* common S/MIME checks */
767 static int purpose_smime(const X509 *x, int require_ca)
769 if (xku_reject(x, XKU_SMIME))
773 ca_ret = check_ca(x);
776 /* Check nsCertType if present */
777 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
782 if (x->ex_flags & EXFLAG_NSCERT) {
783 if (x->ex_nscert & NS_SMIME)
785 /* Workaround for some buggy certificates */
786 if (x->ex_nscert & NS_SSL_CLIENT)
793 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
797 ret = purpose_smime(x, require_ca);
798 if (!ret || require_ca)
800 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
805 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
809 ret = purpose_smime(x, require_ca);
810 if (!ret || require_ca)
812 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
817 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
822 if ((ca_ret = check_ca(x)) != 2)
827 if (ku_reject(x, KU_CRL_SIGN))
833 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
834 * is valid. Additional checks must be made on the chain.
836 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x,
840 * Must be a valid CA. Should we really support the "I don't know" value
845 /* Leaf certificate is checked in OCSP_verify() */
849 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
854 /* If ca is true we must return if this is a valid CA certificate. */
859 * Check the optional key usage field:
860 * if Key Usage is present, it must be one of digitalSignature
861 * and/or nonRepudiation (other values are not consistent and shall
864 if ((x->ex_flags & EXFLAG_KUSAGE)
865 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
866 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
869 /* Only time stamp key usage is permitted and it's required. */
870 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
873 /* Extended Key Usage MUST be critical */
874 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
876 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
877 if (!X509_EXTENSION_get_critical(ext))
884 static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x,
891 * Various checks to see if one certificate potentially issued the second.
892 * This can be used to prune a set of possible issuer certificates which
893 * have been looked up using some simple method such as by subject name.
895 * 1. Check issuer_name(subject) == subject_name(issuer)
896 * 2. If akid(subject) exists, check that it matches issuer
897 * 3. Check that issuer public key algorithm matches subject signature algorithm
898 * 4. Check that any key_usage(issuer) allows certificate signing
899 * Note that this does not include actually checking the signature.
900 * Returns 0 for OK, or positive for reason for mismatch
901 * where reason codes match those for X509_verify_cert().
903 int X509_check_issued(X509 *issuer, X509 *subject)
907 if ((ret = x509_likely_issued(issuer, subject)) != X509_V_OK)
909 return x509_signing_allowed(issuer, subject);
912 /* Do the checks 1., 2., and 3. as described above for X509_check_issued() */
913 int x509_likely_issued(X509 *issuer, X509 *subject)
917 if (X509_NAME_cmp(X509_get_subject_name(issuer),
918 X509_get_issuer_name(subject)) != 0)
919 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
921 /* Set issuer->skid and subject->akid */
922 if (!x509v3_cache_extensions(issuer)
923 || !x509v3_cache_extensions(subject))
924 return X509_V_ERR_UNSPECIFIED;
926 ret = X509_check_akid(issuer, subject->akid);
927 if (ret != X509_V_OK)
930 /* Check if the subject signature alg matches the issuer's PUBKEY alg */
931 return check_sig_alg_match(X509_get0_pubkey(issuer), subject);
935 * Check if certificate I<issuer> is allowed to issue certificate I<subject>
936 * according to the B<keyUsage> field of I<issuer> if present
937 * depending on any proxyCertInfo extension of I<subject>.
938 * Returns 0 for OK, or positive for reason for rejection
939 * where reason codes match those for X509_verify_cert().
941 int x509_signing_allowed(const X509 *issuer, const X509 *subject)
943 if (subject->ex_flags & EXFLAG_PROXY) {
944 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
945 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
946 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
947 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
951 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid)
956 /* Check key ids (if present) */
957 if (akid->keyid && issuer->skid &&
958 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
959 return X509_V_ERR_AKID_SKID_MISMATCH;
960 /* Check serial number */
962 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial))
963 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
964 /* Check issuer name */
967 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
968 * GeneralName. So look for a DirName. There may be more than one but
969 * we only take any notice of the first.
973 X509_NAME *nm = NULL;
976 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
977 gen = sk_GENERAL_NAME_value(gens, i);
978 if (gen->type == GEN_DIRNAME) {
983 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0)
984 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
989 uint32_t X509_get_extension_flags(X509 *x)
991 /* Call for side-effect of computing hash and caching extensions */
992 X509_check_purpose(x, -1, 0);
996 uint32_t X509_get_key_usage(X509 *x)
998 /* Call for side-effect of computing hash and caching extensions */
999 if (X509_check_purpose(x, -1, 0) != 1)
1001 if (x->ex_flags & EXFLAG_KUSAGE)
1002 return x->ex_kusage;
1006 uint32_t X509_get_extended_key_usage(X509 *x)
1008 /* Call for side-effect of computing hash and caching extensions */
1009 if (X509_check_purpose(x, -1, 0) != 1)
1011 if (x->ex_flags & EXFLAG_XKUSAGE)
1012 return x->ex_xkusage;
1016 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
1018 /* Call for side-effect of computing hash and caching extensions */
1019 if (X509_check_purpose(x, -1, 0) != 1)
1024 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
1026 /* Call for side-effect of computing hash and caching extensions */
1027 if (X509_check_purpose(x, -1, 0) != 1)
1029 return (x->akid != NULL ? x->akid->keyid : NULL);
1032 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x)
1034 /* Call for side-effect of computing hash and caching extensions */
1035 if (X509_check_purpose(x, -1, 0) != 1)
1037 return (x->akid != NULL ? x->akid->issuer : NULL);
1040 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x)
1042 /* Call for side-effect of computing hash and caching extensions */
1043 if (X509_check_purpose(x, -1, 0) != 1)
1045 return (x->akid != NULL ? x->akid->serial : NULL);
1048 long X509_get_pathlen(X509 *x)
1050 /* Called for side effect of caching extensions */
1051 if (X509_check_purpose(x, -1, 0) != 1
1052 || (x->ex_flags & EXFLAG_BCONS) == 0)
1054 return x->ex_pathlen;
1057 long X509_get_proxy_pathlen(X509 *x)
1059 /* Called for side effect of caching extensions */
1060 if (X509_check_purpose(x, -1, 0) != 1
1061 || (x->ex_flags & EXFLAG_PROXY) == 0)
1063 return x->ex_pcpathlen;