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/err.h>
63 #include <openssl/digest.h>
64 #include <openssl/mem.h>
65 #include <openssl/obj.h>
66 #include <openssl/thread.h>
67 #include <openssl/x509_vfy.h>
68 #include <openssl/x509v3.h>
69
70 #include "../internal.h"
71
72 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
73 #define ku_reject(x, usage) \
74 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
75 #define xku_reject(x, usage) \
76 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
77 #define ns_reject(x, usage) \
78 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
79
80 static void x509v3_cache_extensions(X509 *x);
81
82 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
83 int ca);
84 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
85 int ca);
86 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
87 int ca);
88 static int purpose_smime(const X509 *x, int ca);
89 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
90 int ca);
91 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
92 int ca);
93 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
94 int ca);
95 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
96 int ca);
97 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
98 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
99
100 static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b);
101 static void xptable_free(X509_PURPOSE *p);
102
103 static X509_PURPOSE xstandard[] = {
104 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
105 check_purpose_ssl_client, (char *)"SSL client", (char *)"sslclient",
106 NULL},
107 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
108 check_purpose_ssl_server, (char *)"SSL server", (char *)"sslserver",
109 NULL},
110 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
111 check_purpose_ns_ssl_server, (char *)"Netscape SSL server",
112 (char *)"nssslserver", NULL},
113 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
114 (char *)"S/MIME signing", (char *)"smimesign", NULL},
115 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
116 check_purpose_smime_encrypt, (char *)"S/MIME encryption",
117 (char *)"smimeencrypt", NULL},
118 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
119 (char *)"CRL signing", (char *)"crlsign", NULL},
120 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, (char *)"Any Purpose",
121 (char *)"any", NULL},
122 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
123 (char *)"OCSP helper", (char *)"ocsphelper", NULL},
124 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
125 check_purpose_timestamp_sign, (char *)"Time Stamp signing",
126 (char *)"timestampsign", NULL},
127 };
128
129 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
130
131 static STACK_OF(X509_PURPOSE) *xptable = NULL;
132
xp_cmp(const X509_PURPOSE ** a,const X509_PURPOSE ** b)133 static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b)
134 {
135 return (*a)->purpose - (*b)->purpose;
136 }
137
138 /*
139 * As much as I'd like to make X509_check_purpose use a "const" X509* I
140 * really can't because it does recalculate hashes and do other non-const
141 * things.
142 */
X509_check_purpose(X509 * x,int id,int ca)143 int X509_check_purpose(X509 *x, int id, int ca)
144 {
145 int idx;
146 const X509_PURPOSE *pt;
147 x509v3_cache_extensions(x);
148 if (id == -1)
149 return 1;
150 idx = X509_PURPOSE_get_by_id(id);
151 if (idx == -1)
152 return -1;
153 pt = X509_PURPOSE_get0(idx);
154 return pt->check_purpose(pt, x, ca);
155 }
156
X509_PURPOSE_set(int * p,int purpose)157 int X509_PURPOSE_set(int *p, int purpose)
158 {
159 if (X509_PURPOSE_get_by_id(purpose) == -1) {
160 OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_PURPOSE);
161 return 0;
162 }
163 *p = purpose;
164 return 1;
165 }
166
X509_PURPOSE_get_count(void)167 int X509_PURPOSE_get_count(void)
168 {
169 if (!xptable)
170 return X509_PURPOSE_COUNT;
171 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
172 }
173
X509_PURPOSE_get0(int idx)174 X509_PURPOSE *X509_PURPOSE_get0(int idx)
175 {
176 if (idx < 0)
177 return NULL;
178 if (idx < (int)X509_PURPOSE_COUNT)
179 return xstandard + idx;
180 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
181 }
182
X509_PURPOSE_get_by_sname(char * sname)183 int X509_PURPOSE_get_by_sname(char *sname)
184 {
185 int i;
186 X509_PURPOSE *xptmp;
187 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
188 xptmp = X509_PURPOSE_get0(i);
189 if (!strcmp(xptmp->sname, sname))
190 return i;
191 }
192 return -1;
193 }
194
X509_PURPOSE_get_by_id(int purpose)195 int X509_PURPOSE_get_by_id(int purpose)
196 {
197 X509_PURPOSE tmp;
198 size_t idx;
199
200 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
201 return purpose - X509_PURPOSE_MIN;
202 tmp.purpose = purpose;
203 if (!xptable)
204 return -1;
205
206 sk_X509_PURPOSE_sort(xptable);
207 if (!sk_X509_PURPOSE_find(xptable, &idx, &tmp))
208 return -1;
209 return idx + X509_PURPOSE_COUNT;
210 }
211
X509_PURPOSE_add(int id,int trust,int flags,int (* ck)(const X509_PURPOSE *,const X509 *,int),char * name,char * sname,void * arg)212 int X509_PURPOSE_add(int id, int trust, int flags,
213 int (*ck) (const X509_PURPOSE *, const X509 *, int),
214 char *name, char *sname, void *arg)
215 {
216 int idx;
217 X509_PURPOSE *ptmp;
218 char *name_dup, *sname_dup;
219
220 /*
221 * This is set according to what we change: application can't set it
222 */
223 flags &= ~X509_PURPOSE_DYNAMIC;
224 /* This will always be set for application modified trust entries */
225 flags |= X509_PURPOSE_DYNAMIC_NAME;
226 /* Get existing entry if any */
227 idx = X509_PURPOSE_get_by_id(id);
228 /* Need a new entry */
229 if (idx == -1) {
230 if (!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
231 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
232 return 0;
233 }
234 ptmp->flags = X509_PURPOSE_DYNAMIC;
235 } else
236 ptmp = X509_PURPOSE_get0(idx);
237
238 /* Duplicate the supplied names. */
239 name_dup = OPENSSL_strdup(name);
240 sname_dup = OPENSSL_strdup(sname);
241 if (name_dup == NULL || sname_dup == NULL) {
242 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
243 if (name_dup != NULL)
244 OPENSSL_free(name_dup);
245 if (sname_dup != NULL)
246 OPENSSL_free(sname_dup);
247 if (idx == -1)
248 OPENSSL_free(ptmp);
249 return 0;
250 }
251
252 /* OPENSSL_free existing name if dynamic */
253 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
254 OPENSSL_free(ptmp->name);
255 OPENSSL_free(ptmp->sname);
256 }
257 /* dup supplied name */
258 ptmp->name = name_dup;
259 ptmp->sname = sname_dup;
260 /* Keep the dynamic flag of existing entry */
261 ptmp->flags &= X509_PURPOSE_DYNAMIC;
262 /* Set all other flags */
263 ptmp->flags |= flags;
264
265 ptmp->purpose = id;
266 ptmp->trust = trust;
267 ptmp->check_purpose = ck;
268 ptmp->usr_data = arg;
269
270 /* If its a new entry manage the dynamic table */
271 if (idx == -1) {
272 if (!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
273 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
274 xptable_free(ptmp);
275 return 0;
276 }
277 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
278 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
279 xptable_free(ptmp);
280 return 0;
281 }
282 }
283 return 1;
284 }
285
xptable_free(X509_PURPOSE * p)286 static void xptable_free(X509_PURPOSE *p)
287 {
288 if (!p)
289 return;
290 if (p->flags & X509_PURPOSE_DYNAMIC) {
291 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
292 OPENSSL_free(p->name);
293 OPENSSL_free(p->sname);
294 }
295 OPENSSL_free(p);
296 }
297 }
298
X509_PURPOSE_cleanup(void)299 void X509_PURPOSE_cleanup(void)
300 {
301 unsigned int i;
302 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
303 for (i = 0; i < X509_PURPOSE_COUNT; i++)
304 xptable_free(xstandard + i);
305 xptable = NULL;
306 }
307
X509_PURPOSE_get_id(X509_PURPOSE * xp)308 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
309 {
310 return xp->purpose;
311 }
312
X509_PURPOSE_get0_name(X509_PURPOSE * xp)313 char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
314 {
315 return xp->name;
316 }
317
X509_PURPOSE_get0_sname(X509_PURPOSE * xp)318 char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
319 {
320 return xp->sname;
321 }
322
X509_PURPOSE_get_trust(X509_PURPOSE * xp)323 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
324 {
325 return xp->trust;
326 }
327
nid_cmp(const void * void_a,const void * void_b)328 static int nid_cmp(const void *void_a, const void *void_b)
329 {
330 const int *a = void_a, *b = void_b;
331
332 return *a - *b;
333 }
334
X509_supported_extension(X509_EXTENSION * ex)335 int X509_supported_extension(X509_EXTENSION *ex)
336 {
337 /*
338 * This table is a list of the NIDs of supported extensions: that is
339 * those which are used by the verify process. If an extension is
340 * critical and doesn't appear in this list then the verify process will
341 * normally reject the certificate. The list must be kept in numerical
342 * order because it will be searched using bsearch.
343 */
344
345 static const int supported_nids[] = {
346 NID_netscape_cert_type, /* 71 */
347 NID_key_usage, /* 83 */
348 NID_subject_alt_name, /* 85 */
349 NID_basic_constraints, /* 87 */
350 NID_certificate_policies, /* 89 */
351 NID_ext_key_usage, /* 126 */
352 NID_policy_constraints, /* 401 */
353 NID_proxyCertInfo, /* 663 */
354 NID_name_constraints, /* 666 */
355 NID_policy_mappings, /* 747 */
356 NID_inhibit_any_policy /* 748 */
357 };
358
359 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
360
361 if (ex_nid == NID_undef)
362 return 0;
363
364 if (bsearch
365 (&ex_nid, supported_nids, sizeof(supported_nids) / sizeof(int),
366 sizeof(int), nid_cmp) != NULL)
367 return 1;
368 return 0;
369 }
370
setup_dp(X509 * x,DIST_POINT * dp)371 static void setup_dp(X509 *x, DIST_POINT *dp)
372 {
373 X509_NAME *iname = NULL;
374 size_t i;
375 if (dp->reasons) {
376 if (dp->reasons->length > 0)
377 dp->dp_reasons = dp->reasons->data[0];
378 if (dp->reasons->length > 1)
379 dp->dp_reasons |= (dp->reasons->data[1] << 8);
380 dp->dp_reasons &= CRLDP_ALL_REASONS;
381 } else
382 dp->dp_reasons = CRLDP_ALL_REASONS;
383 if (!dp->distpoint || (dp->distpoint->type != 1))
384 return;
385 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
386 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
387 if (gen->type == GEN_DIRNAME) {
388 iname = gen->d.directoryName;
389 break;
390 }
391 }
392 if (!iname)
393 iname = X509_get_issuer_name(x);
394
395 DIST_POINT_set_dpname(dp->distpoint, iname);
396
397 }
398
setup_crldp(X509 * x)399 static void setup_crldp(X509 *x)
400 {
401 size_t i;
402 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
403 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
404 setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
405 }
406
x509v3_cache_extensions(X509 * x)407 static void x509v3_cache_extensions(X509 *x)
408 {
409 BASIC_CONSTRAINTS *bs;
410 PROXY_CERT_INFO_EXTENSION *pci;
411 ASN1_BIT_STRING *usage;
412 ASN1_BIT_STRING *ns;
413 EXTENDED_KEY_USAGE *extusage;
414 X509_EXTENSION *ex;
415 size_t i;
416 int j;
417
418 CRYPTO_MUTEX_lock_read(&x->lock);
419 const int is_set = x->ex_flags & EXFLAG_SET;
420 CRYPTO_MUTEX_unlock_read(&x->lock);
421
422 if (is_set) {
423 return;
424 }
425
426 CRYPTO_MUTEX_lock_write(&x->lock);
427 if (x->ex_flags & EXFLAG_SET) {
428 CRYPTO_MUTEX_unlock_write(&x->lock);
429 return;
430 }
431
432 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
433 /* V1 should mean no extensions ... */
434 if (!X509_get_version(x))
435 x->ex_flags |= EXFLAG_V1;
436 /* Handle basic constraints */
437 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
438 if (bs->ca)
439 x->ex_flags |= EXFLAG_CA;
440 if (bs->pathlen) {
441 if ((bs->pathlen->type == V_ASN1_NEG_INTEGER)
442 || !bs->ca) {
443 x->ex_flags |= EXFLAG_INVALID;
444 x->ex_pathlen = 0;
445 } else
446 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
447 } else
448 x->ex_pathlen = -1;
449 BASIC_CONSTRAINTS_free(bs);
450 x->ex_flags |= EXFLAG_BCONS;
451 }
452 /* Handle proxy certificates */
453 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
454 if (x->ex_flags & EXFLAG_CA
455 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
456 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
457 x->ex_flags |= EXFLAG_INVALID;
458 }
459 if (pci->pcPathLengthConstraint) {
460 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
461 } else
462 x->ex_pcpathlen = -1;
463 PROXY_CERT_INFO_EXTENSION_free(pci);
464 x->ex_flags |= EXFLAG_PROXY;
465 }
466 /* Handle key usage */
467 if ((usage = X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
468 if (usage->length > 0) {
469 x->ex_kusage = usage->data[0];
470 if (usage->length > 1)
471 x->ex_kusage |= usage->data[1] << 8;
472 } else
473 x->ex_kusage = 0;
474 x->ex_flags |= EXFLAG_KUSAGE;
475 ASN1_BIT_STRING_free(usage);
476 }
477 x->ex_xkusage = 0;
478 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
479 x->ex_flags |= EXFLAG_XKUSAGE;
480 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
481 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
482 case NID_server_auth:
483 x->ex_xkusage |= XKU_SSL_SERVER;
484 break;
485
486 case NID_client_auth:
487 x->ex_xkusage |= XKU_SSL_CLIENT;
488 break;
489
490 case NID_email_protect:
491 x->ex_xkusage |= XKU_SMIME;
492 break;
493
494 case NID_code_sign:
495 x->ex_xkusage |= XKU_CODE_SIGN;
496 break;
497
498 case NID_ms_sgc:
499 case NID_ns_sgc:
500 x->ex_xkusage |= XKU_SGC;
501 break;
502
503 case NID_OCSP_sign:
504 x->ex_xkusage |= XKU_OCSP_SIGN;
505 break;
506
507 case NID_time_stamp:
508 x->ex_xkusage |= XKU_TIMESTAMP;
509 break;
510
511 case NID_dvcs:
512 x->ex_xkusage |= XKU_DVCS;
513 break;
514
515 case NID_anyExtendedKeyUsage:
516 x->ex_xkusage |= XKU_ANYEKU;
517 break;
518 }
519 }
520 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
521 }
522
523 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
524 if (ns->length > 0)
525 x->ex_nscert = ns->data[0];
526 else
527 x->ex_nscert = 0;
528 x->ex_flags |= EXFLAG_NSCERT;
529 ASN1_BIT_STRING_free(ns);
530 }
531 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
532 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
533 /* Does subject name match issuer ? */
534 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
535 x->ex_flags |= EXFLAG_SI;
536 /* If SKID matches AKID also indicate self signed */
537 if (X509_check_akid(x, x->akid) == X509_V_OK &&
538 !ku_reject(x, KU_KEY_CERT_SIGN))
539 x->ex_flags |= EXFLAG_SS;
540 }
541 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
542 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &j, NULL);
543 if (!x->nc && (j != -1))
544 x->ex_flags |= EXFLAG_INVALID;
545 setup_crldp(x);
546
547 for (j = 0; j < X509_get_ext_count(x); j++) {
548 ex = X509_get_ext(x, j);
549 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
550 == NID_freshest_crl)
551 x->ex_flags |= EXFLAG_FRESHEST;
552 if (!X509_EXTENSION_get_critical(ex))
553 continue;
554 if (!X509_supported_extension(ex)) {
555 x->ex_flags |= EXFLAG_CRITICAL;
556 break;
557 }
558 }
559 x->ex_flags |= EXFLAG_SET;
560
561 CRYPTO_MUTEX_unlock_write(&x->lock);
562 }
563
564 /* check_ca returns one if |x| should be considered a CA certificate and zero
565 * otherwise. */
check_ca(const X509 * x)566 static int check_ca(const X509 *x)
567 {
568 /* keyUsage if present should allow cert signing */
569 if (ku_reject(x, KU_KEY_CERT_SIGN))
570 return 0;
571 /* Version 1 certificates are considered CAs and don't have extensions. */
572 if ((x->ex_flags & V1_ROOT) == V1_ROOT) {
573 return 1;
574 }
575 /* Otherwise, it's only a CA if basicConstraints says so. */
576 return ((x->ex_flags & EXFLAG_BCONS) &&
577 (x->ex_flags & EXFLAG_CA));
578 }
579
X509_check_ca(X509 * x)580 int X509_check_ca(X509 *x)
581 {
582 x509v3_cache_extensions(x);
583 return check_ca(x);
584 }
585
check_purpose_ssl_client(const X509_PURPOSE * xp,const X509 * x,int ca)586 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
587 int ca)
588 {
589 if (xku_reject(x, XKU_SSL_CLIENT))
590 return 0;
591 if (ca)
592 return check_ca(x);
593 /* We need to do digital signatures or key agreement */
594 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT))
595 return 0;
596 /* nsCertType if present should allow SSL client use */
597 if (ns_reject(x, NS_SSL_CLIENT))
598 return 0;
599 return 1;
600 }
601
602 /*
603 * Key usage needed for TLS/SSL server: digital signature, encipherment or
604 * key agreement. The ssl code can check this more thoroughly for individual
605 * key types.
606 */
607 #define KU_TLS \
608 (KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT)
609
check_purpose_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)610 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
611 int ca)
612 {
613 if (xku_reject(x, XKU_SSL_SERVER))
614 return 0;
615 if (ca)
616 return check_ca(x);
617
618 if (ns_reject(x, NS_SSL_SERVER))
619 return 0;
620 if (ku_reject(x, KU_TLS))
621 return 0;
622
623 return 1;
624
625 }
626
check_purpose_ns_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)627 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
628 int ca)
629 {
630 int ret;
631 ret = check_purpose_ssl_server(xp, x, ca);
632 if (!ret || ca)
633 return ret;
634 /* We need to encipher or Netscape complains */
635 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
636 return 0;
637 return ret;
638 }
639
640 /* purpose_smime returns one if |x| is a valid S/MIME leaf (|ca| is zero) or CA
641 * (|ca| is one) certificate, and zero otherwise. */
purpose_smime(const X509 * x,int ca)642 static int purpose_smime(const X509 *x, int ca)
643 {
644 if (xku_reject(x, XKU_SMIME))
645 return 0;
646 if (ca) {
647 /* check nsCertType if present */
648 if ((x->ex_flags & EXFLAG_NSCERT) &&
649 (x->ex_nscert & NS_SMIME_CA) == 0) {
650 return 0;
651 }
652
653 return check_ca(x);
654 }
655 if (x->ex_flags & EXFLAG_NSCERT) {
656 return (x->ex_nscert & NS_SMIME) == NS_SMIME;
657 }
658 return 1;
659 }
660
check_purpose_smime_sign(const X509_PURPOSE * xp,const X509 * x,int ca)661 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
662 int ca)
663 {
664 int ret;
665 ret = purpose_smime(x, ca);
666 if (!ret || ca)
667 return ret;
668 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION))
669 return 0;
670 return ret;
671 }
672
check_purpose_smime_encrypt(const X509_PURPOSE * xp,const X509 * x,int ca)673 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
674 int ca)
675 {
676 int ret;
677 ret = purpose_smime(x, ca);
678 if (!ret || ca)
679 return ret;
680 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
681 return 0;
682 return ret;
683 }
684
check_purpose_crl_sign(const X509_PURPOSE * xp,const X509 * x,int ca)685 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
686 int ca)
687 {
688 if (ca) {
689 return check_ca(x);
690 }
691 if (ku_reject(x, KU_CRL_SIGN))
692 return 0;
693 return 1;
694 }
695
696 /*
697 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA
698 * is valid. Additional checks must be made on the chain.
699 */
700
ocsp_helper(const X509_PURPOSE * xp,const X509 * x,int ca)701 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
702 {
703 if (ca)
704 return check_ca(x);
705 /* leaf certificate is checked in OCSP_verify() */
706 return 1;
707 }
708
check_purpose_timestamp_sign(const X509_PURPOSE * xp,const X509 * x,int ca)709 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
710 int ca)
711 {
712 int i_ext;
713
714 /* If ca is true we must return if this is a valid CA certificate. */
715 if (ca)
716 return check_ca(x);
717
718 /*
719 * Check the optional key usage field:
720 * if Key Usage is present, it must be one of digitalSignature
721 * and/or nonRepudiation (other values are not consistent and shall
722 * be rejected).
723 */
724 if ((x->ex_flags & EXFLAG_KUSAGE)
725 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
726 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
727 return 0;
728
729 /* Only time stamp key usage is permitted and it's required. */
730 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
731 return 0;
732
733 /* Extended Key Usage MUST be critical */
734 i_ext = X509_get_ext_by_NID((X509 *)x, NID_ext_key_usage, -1);
735 if (i_ext >= 0) {
736 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
737 if (!X509_EXTENSION_get_critical(ext))
738 return 0;
739 }
740
741 return 1;
742 }
743
no_check(const X509_PURPOSE * xp,const X509 * x,int ca)744 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
745 {
746 return 1;
747 }
748
749 /*
750 * Various checks to see if one certificate issued the second. This can be
751 * used to prune a set of possible issuer certificates which have been looked
752 * up using some simple method such as by subject name. These are: 1. Check
753 * issuer_name(subject) == subject_name(issuer) 2. If akid(subject) exists
754 * check it matches issuer 3. If key_usage(issuer) exists check it supports
755 * certificate signing returns 0 for OK, positive for reason for mismatch,
756 * reasons match codes for X509_verify_cert()
757 */
758
X509_check_issued(X509 * issuer,X509 * subject)759 int X509_check_issued(X509 *issuer, X509 *subject)
760 {
761 if (X509_NAME_cmp(X509_get_subject_name(issuer),
762 X509_get_issuer_name(subject)))
763 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
764 x509v3_cache_extensions(issuer);
765 x509v3_cache_extensions(subject);
766
767 if (subject->akid) {
768 int ret = X509_check_akid(issuer, subject->akid);
769 if (ret != X509_V_OK)
770 return ret;
771 }
772
773 if (subject->ex_flags & EXFLAG_PROXY) {
774 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
775 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
776 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
777 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
778 return X509_V_OK;
779 }
780
X509_check_akid(X509 * issuer,AUTHORITY_KEYID * akid)781 int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
782 {
783
784 if (!akid)
785 return X509_V_OK;
786
787 /* Check key ids (if present) */
788 if (akid->keyid && issuer->skid &&
789 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid))
790 return X509_V_ERR_AKID_SKID_MISMATCH;
791 /* Check serial number */
792 if (akid->serial &&
793 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
794 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
795 /* Check issuer name */
796 if (akid->issuer) {
797 /*
798 * Ugh, for some peculiar reason AKID includes SEQUENCE OF
799 * GeneralName. So look for a DirName. There may be more than one but
800 * we only take any notice of the first.
801 */
802 GENERAL_NAMES *gens;
803 GENERAL_NAME *gen;
804 X509_NAME *nm = NULL;
805 size_t i;
806 gens = akid->issuer;
807 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
808 gen = sk_GENERAL_NAME_value(gens, i);
809 if (gen->type == GEN_DIRNAME) {
810 nm = gen->d.dirn;
811 break;
812 }
813 }
814 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
815 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
816 }
817 return X509_V_OK;
818 }
819
X509_get_extension_flags(X509 * x)820 uint32_t X509_get_extension_flags(X509 *x)
821 {
822 /* Call for side-effect of computing hash and caching extensions */
823 X509_check_purpose(x, -1, -1);
824 return x->ex_flags;
825 }
826
X509_get_key_usage(X509 * x)827 uint32_t X509_get_key_usage(X509 *x)
828 {
829 /* Call for side-effect of computing hash and caching extensions */
830 X509_check_purpose(x, -1, -1);
831 if (x->ex_flags & EXFLAG_KUSAGE)
832 return x->ex_kusage;
833 return UINT32_MAX;
834 }
835
X509_get_extended_key_usage(X509 * x)836 uint32_t X509_get_extended_key_usage(X509 *x)
837 {
838 /* Call for side-effect of computing hash and caching extensions */
839 X509_check_purpose(x, -1, -1);
840 if (x->ex_flags & EXFLAG_XKUSAGE)
841 return x->ex_xkusage;
842 return UINT32_MAX;
843 }
844