1/* v3_purp.c */
2/*
3 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
4 * 2001.
5 */
6/* ====================================================================
7 * Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com). */
57
58#include <stdio.h>
59
60#include <string.h>
61
62#include <openssl/buf.h>
63#include <openssl/err.h>
64#include <openssl/digest.h>
65#include <openssl/mem.h>
66#include <openssl/obj.h>
67#include <openssl/thread.h>
68#include <openssl/x509_vfy.h>
69#include <openssl/x509v3.h>
70
71#include "../internal.h"
72
73#define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
74#define ku_reject(x, usage) \
75 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
76#define xku_reject(x, usage) \
77 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
78#define ns_reject(x, usage) \
79 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
80
81static void x509v3_cache_extensions(X509 *x);
82
83static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
84 int ca);
85static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
86 int ca);
87static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
88 int ca);
89static int purpose_smime(const X509 *x, int ca);
90static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
91 int ca);
92static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
93 int ca);
94static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
95 int ca);
96static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
97 int ca);
98static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
99static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
100
101static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b);
102static void xptable_free(X509_PURPOSE *p);
103
104static X509_PURPOSE xstandard[] = {
105 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
106 check_purpose_ssl_client, (char *)"SSL client", (char *)"sslclient",
107 NULL},
108 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
109 check_purpose_ssl_server, (char *)"SSL server", (char *)"sslserver",
110 NULL},
111 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
112 check_purpose_ns_ssl_server, (char *)"Netscape SSL server",
113 (char *)"nssslserver", NULL},
114 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
115 (char *)"S/MIME signing", (char *)"smimesign", NULL},
116 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
117 check_purpose_smime_encrypt, (char *)"S/MIME encryption",
118 (char *)"smimeencrypt", NULL},
119 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
120 (char *)"CRL signing", (char *)"crlsign", NULL},
121 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, (char *)"Any Purpose",
122 (char *)"any", NULL},
123 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
124 (char *)"OCSP helper", (char *)"ocsphelper", NULL},
125 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
126 check_purpose_timestamp_sign, (char *)"Time Stamp signing",
127 (char *)"timestampsign", NULL},
128};
129
130#define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
131
132static STACK_OF(X509_PURPOSE) *xptable = NULL;
133
134static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b)
135{
136 return (*a)->purpose - (*b)->purpose;
137}
138
139/*
140 * As much as I'd like to make X509_check_purpose use a "const" X509* I
141 * really can't because it does recalculate hashes and do other non-const
142 * things.
143 */
144int X509_check_purpose(X509 *x, int id, int ca)
145{
146 int idx;
147 const X509_PURPOSE *pt;
148 x509v3_cache_extensions(x);
149 if (id == -1)
150 return 1;
151 idx = X509_PURPOSE_get_by_id(id);
152 if (idx == -1)
153 return -1;
154 pt = X509_PURPOSE_get0(idx);
155 return pt->check_purpose(pt, x, ca);
156}
157
158int X509_PURPOSE_set(int *p, int purpose)
159{
160 if (X509_PURPOSE_get_by_id(purpose) == -1) {
161 OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_PURPOSE);
162 return 0;
163 }
164 *p = purpose;
165 return 1;
166}
167
168int X509_PURPOSE_get_count(void)
169{
170 if (!xptable)
171 return X509_PURPOSE_COUNT;
172 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
173}
174
175X509_PURPOSE *X509_PURPOSE_get0(int idx)
176{
177 if (idx < 0)
178 return NULL;
179 if (idx < (int)X509_PURPOSE_COUNT)
180 return xstandard + idx;
181 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
182}
183
184int X509_PURPOSE_get_by_sname(char *sname)
185{
186 int i;
187 X509_PURPOSE *xptmp;
188 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
189 xptmp = X509_PURPOSE_get0(i);
190 if (!strcmp(xptmp->sname, sname))
191 return i;
192 }
193 return -1;
194}
195
196int X509_PURPOSE_get_by_id(int purpose)
197{
198 X509_PURPOSE tmp;
199 size_t idx;
200
201 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
202 return purpose - X509_PURPOSE_MIN;
203 tmp.purpose = purpose;
204 if (!xptable)
205 return -1;
206
207 sk_X509_PURPOSE_sort(xptable);
208 if (!sk_X509_PURPOSE_find(xptable, &idx, &tmp))
209 return -1;
210 return idx + X509_PURPOSE_COUNT;
211}
212
213int X509_PURPOSE_add(int id, int trust, int flags,
214 int (*ck) (const X509_PURPOSE *, const X509 *, int),
215 char *name, char *sname, void *arg)
216{
217 int idx;
218 X509_PURPOSE *ptmp;
219 char *name_dup, *sname_dup;
220
221 /*
222 * This is set according to what we change: application can't set it
223 */
224 flags &= ~X509_PURPOSE_DYNAMIC;
225 /* This will always be set for application modified trust entries */
226 flags |= X509_PURPOSE_DYNAMIC_NAME;
227 /* Get existing entry if any */
228 idx = X509_PURPOSE_get_by_id(id);
229 /* Need a new entry */
230 if (idx == -1) {
231 if (!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
232 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
233 return 0;
234 }
235 ptmp->flags = X509_PURPOSE_DYNAMIC;
236 } else
237 ptmp = X509_PURPOSE_get0(idx);
238
239 /* Duplicate the supplied names. */
240 name_dup = BUF_strdup(name);
241 sname_dup = BUF_strdup(sname);
242 if (name_dup == NULL || sname_dup == NULL) {
243 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
244 if (name_dup != NULL)
245 OPENSSL_free(name_dup);
246 if (sname_dup != NULL)
247 OPENSSL_free(sname_dup);
248 if (idx == -1)
249 OPENSSL_free(ptmp);
250 return 0;
251 }
252
253 /* OPENSSL_free existing name if dynamic */
254 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
255 OPENSSL_free(ptmp->name);
256 OPENSSL_free(ptmp->sname);
257 }
258 /* dup supplied name */
259 ptmp->name = name_dup;
260 ptmp->sname = sname_dup;
261 /* Keep the dynamic flag of existing entry */
262 ptmp->flags &= X509_PURPOSE_DYNAMIC;
263 /* Set all other flags */
264 ptmp->flags |= flags;
265
266 ptmp->purpose = id;
267 ptmp->trust = trust;
268 ptmp->check_purpose = ck;
269 ptmp->usr_data = arg;
270
271 /* If its a new entry manage the dynamic table */
272 if (idx == -1) {
273 if (!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
274 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
275 xptable_free(ptmp);
276 return 0;
277 }
278 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
279 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
280 xptable_free(ptmp);
281 return 0;
282 }
283 }
284 return 1;
285}
286
287static void xptable_free(X509_PURPOSE *p)
288{
289 if (!p)
290 return;
291 if (p->flags & X509_PURPOSE_DYNAMIC) {
292 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
293 OPENSSL_free(p->name);
294 OPENSSL_free(p->sname);
295 }
296 OPENSSL_free(p);
297 }
298}
299
300void X509_PURPOSE_cleanup(void)
301{
302 unsigned int i;
303 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
304 for (i = 0; i < X509_PURPOSE_COUNT; i++)
305 xptable_free(xstandard + i);
306 xptable = NULL;
307}
308
309int X509_PURPOSE_get_id(X509_PURPOSE *xp)
310{
311 return xp->purpose;
312}
313
314char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
315{
316 return xp->name;
317}
318
319char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
320{
321 return xp->sname;
322}
323
324int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
325{
326 return xp->trust;
327}
328
329static int nid_cmp(const void *void_a, const void *void_b)
330{
331 const int *a = void_a, *b = void_b;
332
333 return *a - *b;
334}
335
336int X509_supported_extension(X509_EXTENSION *ex)
337{
338 /*
339 * This table is a list of the NIDs of supported extensions: that is
340 * those which are used by the verify process. If an extension is
341 * critical and doesn't appear in this list then the verify process will
342 * normally reject the certificate. The list must be kept in numerical
343 * order because it will be searched using bsearch.
344 */
345
346 static const int supported_nids[] = {
347 NID_netscape_cert_type, /* 71 */
348 NID_key_usage, /* 83 */
349 NID_subject_alt_name, /* 85 */
350 NID_basic_constraints, /* 87 */
351 NID_certificate_policies, /* 89 */
352 NID_ext_key_usage, /* 126 */
353 NID_policy_constraints, /* 401 */
354 NID_proxyCertInfo, /* 663 */
355 NID_name_constraints, /* 666 */
356 NID_policy_mappings, /* 747 */
357 NID_inhibit_any_policy /* 748 */
358 };
359
360 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
361
362 if (ex_nid == NID_undef)
363 return 0;
364
365 if (bsearch
366 (&ex_nid, supported_nids, sizeof(supported_nids) / sizeof(int),
367 sizeof(int), nid_cmp) != NULL)
368 return 1;
369 return 0;
370}
371
372static void setup_dp(X509 *x, DIST_POINT *dp)
373{
374 X509_NAME *iname = NULL;
375 size_t i;
376 if (dp->reasons) {
377 if (dp->reasons->length > 0)
378 dp->dp_reasons = dp->reasons->data[0];
379 if (dp->reasons->length > 1)
380 dp->dp_reasons |= (dp->reasons->data[1] << 8);
381 dp->dp_reasons &= CRLDP_ALL_REASONS;
382 } else
383 dp->dp_reasons = CRLDP_ALL_REASONS;
384 if (!dp->distpoint || (dp->distpoint->type != 1))
385 return;
386 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
387 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
388 if (gen->type == GEN_DIRNAME) {
389 iname = gen->d.directoryName;
390 break;
391 }
392 }
393 if (!iname)
394 iname = X509_get_issuer_name(x);
395
396 DIST_POINT_set_dpname(dp->distpoint, iname);
397
398}
399
400static void setup_crldp(X509 *x)
401{
402 size_t i;
403 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
404 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
405 setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
406}
407
408static void x509v3_cache_extensions(X509 *x)
409{
410 BASIC_CONSTRAINTS *bs;
411 PROXY_CERT_INFO_EXTENSION *pci;
412 ASN1_BIT_STRING *usage;
413 ASN1_BIT_STRING *ns;
414 EXTENDED_KEY_USAGE *extusage;
415 X509_EXTENSION *ex;
416 size_t i;
417 int j;
418
419 CRYPTO_MUTEX_lock_read(&x->lock);
420 const int is_set = x->ex_flags & EXFLAG_SET;
421 CRYPTO_MUTEX_unlock_read(&x->lock);
422
423 if (is_set) {
424 return;
425 }
426
427 CRYPTO_MUTEX_lock_write(&x->lock);
428 if (x->ex_flags & EXFLAG_SET) {
429 CRYPTO_MUTEX_unlock_write(&x->lock);
430 return;
431 }
432
433 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
434 /* V1 should mean no extensions ... */
435 if (!X509_get_version(x))
436 x->ex_flags |= EXFLAG_V1;
437 /* Handle basic constraints */
438 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
439 if (bs->ca)
440 x->ex_flags |= EXFLAG_CA;
441 if (bs->pathlen) {
442 if ((bs->pathlen->type == V_ASN1_NEG_INTEGER)
443 || !bs->ca) {
444 x->ex_flags |= EXFLAG_INVALID;
445 x->ex_pathlen = 0;
446 } else
447 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
448 } else
449 x->ex_pathlen = -1;
450 BASIC_CONSTRAINTS_free(bs);
451 x->ex_flags |= EXFLAG_BCONS;
452 }
453 /* Handle proxy certificates */
454 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, 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;
459 }
460 if (pci->pcPathLengthConstraint) {
461 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
462 } else
463 x->ex_pcpathlen = -1;
464 PROXY_CERT_INFO_EXTENSION_free(pci);
465 x->ex_flags |= EXFLAG_PROXY;
466 }
467 /* Handle key usage */
468 if ((usage = X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
469 if (usage->length > 0) {
470 x->ex_kusage = usage->data[0];
471 if (usage->length > 1)
472 x->ex_kusage |= usage->data[1] << 8;
473 } else
474 x->ex_kusage = 0;
475 x->ex_flags |= EXFLAG_KUSAGE;
476 ASN1_BIT_STRING_free(usage);
477 }
478 x->ex_xkusage = 0;
479 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
480 x->ex_flags |= EXFLAG_XKUSAGE;
481 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
482 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
483 case NID_server_auth:
484 x->ex_xkusage |= XKU_SSL_SERVER;
485 break;
486
487 case NID_client_auth:
488 x->ex_xkusage |= XKU_SSL_CLIENT;
489 break;
490
491 case NID_email_protect:
492 x->ex_xkusage |= XKU_SMIME;
493 break;
494
495 case NID_code_sign:
496 x->ex_xkusage |= XKU_CODE_SIGN;
497 break;
498
499 case NID_ms_sgc:
500 case NID_ns_sgc:
501 x->ex_xkusage |= XKU_SGC;
502 break;
503
504 case NID_OCSP_sign:
505 x->ex_xkusage |= XKU_OCSP_SIGN;
506 break;
507
508 case NID_time_stamp:
509 x->ex_xkusage |= XKU_TIMESTAMP;
510 break;
511
512 case NID_dvcs:
513 x->ex_xkusage |= XKU_DVCS;
514 break;
515
516 case NID_anyExtendedKeyUsage:
517 x->ex_xkusage |= XKU_ANYEKU;
518 break;
519 }
520 }
521 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
522 }
523
524 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
525 if (ns->length > 0)
526 x->ex_nscert = ns->data[0];
527 else
528 x->ex_nscert = 0;
529 x->ex_flags |= EXFLAG_NSCERT;
530 ASN1_BIT_STRING_free(ns);
531 }
532 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
533 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
534 /* Does subject name match issuer ? */
535 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
536 x->ex_flags |= EXFLAG_SI;
537 /* If SKID matches AKID also indicate self signed */
538 if (X509_check_akid(x, x->akid) == X509_V_OK &&
539 !ku_reject(x, KU_KEY_CERT_SIGN))
540 x->ex_flags |= EXFLAG_SS;
541 }
542 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
543 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &j, NULL);
544 if (!x->nc && (j != -1))
545 x->ex_flags |= EXFLAG_INVALID;
546 setup_crldp(x);
547
548 for (j = 0; j < X509_get_ext_count(x); j++) {
549 ex = X509_get_ext(x, j);
550 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
551 == NID_freshest_crl)
552 x->ex_flags |= EXFLAG_FRESHEST;
553 if (!X509_EXTENSION_get_critical(ex))
554 continue;
555 if (!X509_supported_extension(ex)) {
556 x->ex_flags |= EXFLAG_CRITICAL;
557 break;
558 }
559 }
560 x->ex_flags |= EXFLAG_SET;
561
562 CRYPTO_MUTEX_unlock_write(&x->lock);
563}
564
565/* check_ca returns one if |x| should be considered a CA certificate and zero
566 * otherwise. */
567static int check_ca(const X509 *x)
568{
569 /* keyUsage if present should allow cert signing */
570 if (ku_reject(x, KU_KEY_CERT_SIGN))
571 return 0;
572 /* Version 1 certificates are considered CAs and don't have extensions. */
573 if ((x->ex_flags & V1_ROOT) == V1_ROOT) {
574 return 1;
575 }
576 /* Otherwise, it's only a CA if basicConstraints says so. */
577 return ((x->ex_flags & EXFLAG_BCONS) &&
578 (x->ex_flags & EXFLAG_CA));
579}
580
581int X509_check_ca(X509 *x)
582{
583 x509v3_cache_extensions(x);
584 return check_ca(x);
585}
586
587static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
588 int ca)
589{
590 if (xku_reject(x, XKU_SSL_CLIENT))
591 return 0;
592 if (ca)
593 return check_ca(x);
594 /* We need to do digital signatures or key agreement */
595 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
596 return 0;
597 /* nsCertType if present should allow SSL client use */
598 if (ns_reject(x, NS_SSL_CLIENT))
599 return 0;
600 return 1;
601}
602
603/*
604 * Key usage needed for TLS/SSL server: digital signature, encipherment or
605 * key agreement. The ssl code can check this more thoroughly for individual
606 * key types.
607 */
608#define KU_TLS \
609 (KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT)
610
611static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
612 int ca)
613{
614 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC))
615 return 0;
616 if (ca)
617 return check_ca(x);
618
619 if (ns_reject(x, NS_SSL_SERVER))
620 return 0;
621 if (ku_reject(x, KU_TLS))
622 return 0;
623
624 return 1;
625
626}
627
628static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
629 int ca)
630{
631 int ret;
632 ret = check_purpose_ssl_server(xp, x, ca);
633 if (!ret || ca)
634 return ret;
635 /* We need to encipher or Netscape complains */
636 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
637 return 0;
638 return ret;
639}
640
641/* purpose_smime returns one if |x| is a valid S/MIME leaf (|ca| is zero) or CA
642 * (|ca| is one) certificate, and zero otherwise. */
643static int purpose_smime(const X509 *x, int ca)
644{
645 if (xku_reject(x, XKU_SMIME))
646 return 0;
647 if (ca) {
648 /* check nsCertType if present */
649 if ((x->ex_flags & EXFLAG_NSCERT) &&
650 (x->ex_nscert & NS_SMIME_CA) == 0) {
651 return 0;
652 }
653
654 return check_ca(x);
655 }
656 if (x->ex_flags & EXFLAG_NSCERT) {
657 return (x->ex_nscert & NS_SMIME) == NS_SMIME;
658 }
659 return 1;
660}
661
662static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
663 int ca)
664{
665 int ret;
666 ret = purpose_smime(x, ca);
667 if (!ret || ca)
668 return ret;
669 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
670 return 0;
671 return ret;
672}
673
674static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
675 int ca)
676{
677 int ret;
678 ret = purpose_smime(x, ca);
679 if (!ret || ca)
680 return ret;
681 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
682 return 0;
683 return ret;
684}
685
686static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
687 int ca)
688{
689 if (ca) {
690 return check_ca(x);
691 }
692 if (ku_reject(x, KU_CRL_SIGN))
693 return 0;
694 return 1;
695}
696
697/*
698 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
699 * is valid. Additional checks must be made on the chain.
700 */
701
702static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
703{
704 if (ca)
705 return check_ca(x);
706 /* leaf certificate is checked in OCSP_verify() */
707 return 1;
708}
709
710static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
711 int ca)
712{
713 int i_ext;
714
715 /* If ca is true we must return if this is a valid CA certificate. */
716 if (ca)
717 return check_ca(x);
718
719 /*
720 * Check the optional key usage field:
721 * if Key Usage is present, it must be one of digitalSignature
722 * and/or nonRepudiation (other values are not consistent and shall
723 * be rejected).
724 */
725 if ((x->ex_flags & EXFLAG_KUSAGE)
726 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
727 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
728 return 0;
729
730 /* Only time stamp key usage is permitted and it's required. */
731 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
732 return 0;
733
734 /* Extended Key Usage MUST be critical */
735 i_ext = X509_get_ext_by_NID((X509 *)x, NID_ext_key_usage, -1);
736 if (i_ext >= 0) {
737 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
738 if (!X509_EXTENSION_get_critical(ext))
739 return 0;
740 }
741
742 return 1;
743}
744
745static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
746{
747 return 1;
748}
749
750/*
751 * Various checks to see if one certificate issued the second. This can be
752 * used to prune a set of possible issuer certificates which have been looked
753 * up using some simple method such as by subject name. These are: 1. Check
754 * issuer_name(subject) == subject_name(issuer) 2. If akid(subject) exists
755 * check it matches issuer 3. If key_usage(issuer) exists check it supports
756 * certificate signing returns 0 for OK, positive for reason for mismatch,
757 * reasons match codes for X509_verify_cert()
758 */
759
760int X509_check_issued(X509 *issuer, X509 *subject)
761{
762 if (X509_NAME_cmp(X509_get_subject_name(issuer),
763 X509_get_issuer_name(subject)))
764 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
765 x509v3_cache_extensions(issuer);
766 x509v3_cache_extensions(subject);
767
768 if (subject->akid) {
769 int ret = X509_check_akid(issuer, subject->akid);
770 if (ret != X509_V_OK)
771 return ret;
772 }
773
774 if (subject->ex_flags & EXFLAG_PROXY) {
775 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
776 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
777 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
778 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
779 return X509_V_OK;
780}
781
782int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
783{
784
785 if (!akid)
786 return X509_V_OK;
787
788 /* Check key ids (if present) */
789 if (akid->keyid && issuer->skid &&
790 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
791 return X509_V_ERR_AKID_SKID_MISMATCH;
792 /* Check serial number */
793 if (akid->serial &&
794 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
795 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
796 /* Check issuer name */
797 if (akid->issuer) {
798 /*
799 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
800 * GeneralName. So look for a DirName. There may be more than one but
801 * we only take any notice of the first.
802 */
803 GENERAL_NAMES *gens;
804 GENERAL_NAME *gen;
805 X509_NAME *nm = NULL;
806 size_t i;
807 gens = akid->issuer;
808 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
809 gen = sk_GENERAL_NAME_value(gens, i);
810 if (gen->type == GEN_DIRNAME) {
811 nm = gen->d.dirn;
812 break;
813 }
814 }
815 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
816 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
817 }
818 return X509_V_OK;
819}
820
821uint32_t X509_get_extension_flags(X509 *x)
822{
823 /* Call for side-effect of computing hash and caching extensions */
824 X509_check_purpose(x, -1, -1);
825 return x->ex_flags;
826}
827
828uint32_t X509_get_key_usage(X509 *x)
829{
830 /* Call for side-effect of computing hash and caching extensions */
831 X509_check_purpose(x, -1, -1);
832 if (x->ex_flags & EXFLAG_KUSAGE)
833 return x->ex_kusage;
834 return UINT32_MAX;
835}
836
837uint32_t X509_get_extended_key_usage(X509 *x)
838{
839 /* Call for side-effect of computing hash and caching extensions */
840 X509_check_purpose(x, -1, -1);
841 if (x->ex_flags & EXFLAG_XKUSAGE)
842 return x->ex_xkusage;
843 return UINT32_MAX;
844}
845