1 /* v3_purp.c */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2001.
4 */
5 /* ====================================================================
6 * Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 * acknowledgment:
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58
59 #include <stdio.h>
60 #include "cryptlib.h"
61 #include <openssl/x509v3.h>
62 #include <openssl/x509_vfy.h>
63
64 static void x509v3_cache_extensions(X509 *x);
65
66 static int check_ssl_ca(const X509 *x);
67 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca);
68 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
69 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
70 static int purpose_smime(const X509 *x, int ca);
71 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
72 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca);
73 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
74 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
75 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
76 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
77
78 static int xp_cmp(const X509_PURPOSE * const *a,
79 const X509_PURPOSE * const *b);
80 static void xptable_free(X509_PURPOSE *p);
81
82 static X509_PURPOSE xstandard[] = {
83 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
84 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
85 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
86 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
87 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
88 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
89 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL},
90 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL},
91 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", NULL},
92 };
93
94 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
95
96 IMPLEMENT_STACK_OF(X509_PURPOSE)
97
98 static STACK_OF(X509_PURPOSE) *xptable = NULL;
99
100 static int xp_cmp(const X509_PURPOSE * const *a,
101 const X509_PURPOSE * const *b)
102 {
103 return (*a)->purpose - (*b)->purpose;
104 }
105
106 /* As much as I'd like to make X509_check_purpose use a "const" X509*
107 * I really can't because it does recalculate hashes and do other non-const
108 * things. */
109 int X509_check_purpose(X509 *x, int id, int ca)
110 {
111 int idx;
112 const X509_PURPOSE *pt;
113 if(!(x->ex_flags & EXFLAG_SET)) {
114 CRYPTO_w_lock(CRYPTO_LOCK_X509);
115 x509v3_cache_extensions(x);
116 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
117 }
118 if(id == -1) return 1;
119 idx = X509_PURPOSE_get_by_id(id);
120 if(idx == -1) return -1;
121 pt = X509_PURPOSE_get0(idx);
122 return pt->check_purpose(pt, x, ca);
123 }
124
125 int X509_PURPOSE_set(int *p, int purpose)
126 {
127 if(X509_PURPOSE_get_by_id(purpose) == -1) {
128 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
129 return 0;
130 }
131 *p = purpose;
132 return 1;
133 }
134
135 int X509_PURPOSE_get_count(void)
136 {
137 if(!xptable) return X509_PURPOSE_COUNT;
138 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
139 }
140
141 X509_PURPOSE * X509_PURPOSE_get0(int idx)
142 {
143 if(idx < 0) return NULL;
144 if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx;
145 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
146 }
147
148 int X509_PURPOSE_get_by_sname(char *sname)
149 {
150 int i;
151 X509_PURPOSE *xptmp;
152 for(i = 0; i < X509_PURPOSE_get_count(); i++) {
153 xptmp = X509_PURPOSE_get0(i);
154 if(!strcmp(xptmp->sname, sname)) return i;
155 }
156 return -1;
157 }
158
159 int X509_PURPOSE_get_by_id(int purpose)
160 {
161 X509_PURPOSE tmp;
162 int idx;
163 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
164 return purpose - X509_PURPOSE_MIN;
165 tmp.purpose = purpose;
166 if(!xptable) return -1;
167 idx = sk_X509_PURPOSE_find(xptable, &tmp);
168 if(idx == -1) return -1;
169 return idx + X509_PURPOSE_COUNT;
170 }
171
172 int X509_PURPOSE_add(int id, int trust, int flags,
173 int (*ck)(const X509_PURPOSE *, const X509 *, int),
174 char *name, char *sname, void *arg)
175 {
176 int idx;
177 X509_PURPOSE *ptmp;
178 /* This is set according to what we change: application can't set it */
179 flags &= ~X509_PURPOSE_DYNAMIC;
180 /* This will always be set for application modified trust entries */
181 flags |= X509_PURPOSE_DYNAMIC_NAME;
182 /* Get existing entry if any */
183 idx = X509_PURPOSE_get_by_id(id);
184 /* Need a new entry */
185 if(idx == -1) {
186 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
187 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
188 return 0;
189 }
190 ptmp->flags = X509_PURPOSE_DYNAMIC;
191 } else ptmp = X509_PURPOSE_get0(idx);
192
193 /* OPENSSL_free existing name if dynamic */
194 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
195 OPENSSL_free(ptmp->name);
196 OPENSSL_free(ptmp->sname);
197 }
198 /* dup supplied name */
199 ptmp->name = BUF_strdup(name);
200 ptmp->sname = BUF_strdup(sname);
201 if(!ptmp->name || !ptmp->sname) {
202 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
203 return 0;
204 }
205 /* Keep the dynamic flag of existing entry */
206 ptmp->flags &= X509_PURPOSE_DYNAMIC;
207 /* Set all other flags */
208 ptmp->flags |= flags;
209
210 ptmp->purpose = id;
211 ptmp->trust = trust;
212 ptmp->check_purpose = ck;
213 ptmp->usr_data = arg;
214
215 /* If its a new entry manage the dynamic table */
216 if(idx == -1) {
217 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
218 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
219 return 0;
220 }
221 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
222 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
223 return 0;
224 }
225 }
226 return 1;
227 }
228
229 static void xptable_free(X509_PURPOSE *p)
230 {
231 if(!p) return;
232 if (p->flags & X509_PURPOSE_DYNAMIC)
233 {
234 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
235 OPENSSL_free(p->name);
236 OPENSSL_free(p->sname);
237 }
238 OPENSSL_free(p);
239 }
240 }
241
242 void X509_PURPOSE_cleanup(void)
243 {
244 unsigned int i;
245 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
246 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
247 xptable = NULL;
248 }
249
250 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
251 {
252 return xp->purpose;
253 }
254
255 char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
256 {
257 return xp->name;
258 }
259
260 char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
261 {
262 return xp->sname;
263 }
264
265 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
266 {
267 return xp->trust;
268 }
269
270 static int nid_cmp(const int *a, const int *b)
271 {
272 return *a - *b;
273 }
274
275 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
276 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
277
278 int X509_supported_extension(X509_EXTENSION *ex)
279 {
280 /* This table is a list of the NIDs of supported extensions:
281 * that is those which are used by the verify process. If
282 * an extension is critical and doesn't appear in this list
283 * then the verify process will normally reject the certificate.
284 * The list must be kept in numerical order because it will be
285 * searched using bsearch.
286 */
287
288 static const int supported_nids[] = {
289 NID_netscape_cert_type, /* 71 */
290 NID_key_usage, /* 83 */
291 NID_subject_alt_name, /* 85 */
292 NID_basic_constraints, /* 87 */
293 NID_certificate_policies, /* 89 */
294 NID_ext_key_usage, /* 126 */
295 #ifndef OPENSSL_NO_RFC3779
296 NID_sbgp_ipAddrBlock, /* 290 */
297 NID_sbgp_autonomousSysNum, /* 291 */
298 #endif
299 NID_policy_constraints, /* 401 */
300 NID_proxyCertInfo, /* 663 */
301 NID_name_constraints, /* 666 */
302 NID_policy_mappings, /* 747 */
303 NID_inhibit_any_policy /* 748 */
304 };
305
306 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
307
308 if (ex_nid == NID_undef)
309 return 0;
310
311 if (OBJ_bsearch_nid(&ex_nid, supported_nids,
312 sizeof(supported_nids)/sizeof(int)))
313 return 1;
314 return 0;
315 }
316
317 static void setup_dp(X509 *x, DIST_POINT *dp)
318 {
319 X509_NAME *iname = NULL;
320 int i;
321 if (dp->reasons)
322 {
323 if (dp->reasons->length > 0)
324 dp->dp_reasons = dp->reasons->data[0];
325 if (dp->reasons->length > 1)
326 dp->dp_reasons |= (dp->reasons->data[1] << 8);
327 dp->dp_reasons &= CRLDP_ALL_REASONS;
328 }
329 else
330 dp->dp_reasons = CRLDP_ALL_REASONS;
331 if (!dp->distpoint || (dp->distpoint->type != 1))
332 return;
333 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++)
334 {
335 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
336 if (gen->type == GEN_DIRNAME)
337 {
338 iname = gen->d.directoryName;
339 break;
340 }
341 }
342 if (!iname)
343 iname = X509_get_issuer_name(x);
344
345 DIST_POINT_set_dpname(dp->distpoint, iname);
346
347 }
348
349 static void setup_crldp(X509 *x)
350 {
351 int i;
352 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
353 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
354 setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
355 }
356
357 static void x509v3_cache_extensions(X509 *x)
358 {
359 BASIC_CONSTRAINTS *bs;
360 PROXY_CERT_INFO_EXTENSION *pci;
361 ASN1_BIT_STRING *usage;
362 ASN1_BIT_STRING *ns;
363 EXTENDED_KEY_USAGE *extusage;
364 X509_EXTENSION *ex;
365
366 int i;
367 if(x->ex_flags & EXFLAG_SET) return;
368 #ifndef OPENSSL_NO_SHA
369 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
370 #endif
371 /* Does subject name match issuer ? */
372 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
373 x->ex_flags |= EXFLAG_SI;
374 /* V1 should mean no extensions ... */
375 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
376 /* Handle basic constraints */
377 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
378 if(bs->ca) x->ex_flags |= EXFLAG_CA;
379 if(bs->pathlen) {
380 if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
381 || !bs->ca) {
382 x->ex_flags |= EXFLAG_INVALID;
383 x->ex_pathlen = 0;
384 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
385 } else x->ex_pathlen = -1;
386 BASIC_CONSTRAINTS_free(bs);
387 x->ex_flags |= EXFLAG_BCONS;
388 }
389 /* Handle proxy certificates */
390 if((pci=X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
391 if (x->ex_flags & EXFLAG_CA
392 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
393 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
394 x->ex_flags |= EXFLAG_INVALID;
395 }
396 if (pci->pcPathLengthConstraint) {
397 x->ex_pcpathlen =
398 ASN1_INTEGER_get(pci->pcPathLengthConstraint);
399 } else x->ex_pcpathlen = -1;
400 PROXY_CERT_INFO_EXTENSION_free(pci);
401 x->ex_flags |= EXFLAG_PROXY;
402 }
403 /* Handle key usage */
404 if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
405 if(usage->length > 0) {
406 x->ex_kusage = usage->data[0];
407 if(usage->length > 1)
408 x->ex_kusage |= usage->data[1] << 8;
409 } else x->ex_kusage = 0;
410 x->ex_flags |= EXFLAG_KUSAGE;
411 ASN1_BIT_STRING_free(usage);
412 }
413 x->ex_xkusage = 0;
414 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
415 x->ex_flags |= EXFLAG_XKUSAGE;
416 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
417 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
418 case NID_server_auth:
419 x->ex_xkusage |= XKU_SSL_SERVER;
420 break;
421
422 case NID_client_auth:
423 x->ex_xkusage |= XKU_SSL_CLIENT;
424 break;
425
426 case NID_email_protect:
427 x->ex_xkusage |= XKU_SMIME;
428 break;
429
430 case NID_code_sign:
431 x->ex_xkusage |= XKU_CODE_SIGN;
432 break;
433
434 case NID_ms_sgc:
435 case NID_ns_sgc:
436 x->ex_xkusage |= XKU_SGC;
437 break;
438
439 case NID_OCSP_sign:
440 x->ex_xkusage |= XKU_OCSP_SIGN;
441 break;
442
443 case NID_time_stamp:
444 x->ex_xkusage |= XKU_TIMESTAMP;
445 break;
446
447 case NID_dvcs:
448 x->ex_xkusage |= XKU_DVCS;
449 break;
450 }
451 }
452 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
453 }
454
455 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
456 if(ns->length > 0) x->ex_nscert = ns->data[0];
457 else x->ex_nscert = 0;
458 x->ex_flags |= EXFLAG_NSCERT;
459 ASN1_BIT_STRING_free(ns);
460 }
461 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
462 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
463 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
464 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
465 if (!x->nc && (i != -1))
466 x->ex_flags |= EXFLAG_INVALID;
467 setup_crldp(x);
468
469 #ifndef OPENSSL_NO_RFC3779
470 x->rfc3779_addr =X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL);
471 x->rfc3779_asid =X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum,
472 NULL, NULL);
473 #endif
474 for (i = 0; i < X509_get_ext_count(x); i++)
475 {
476 ex = X509_get_ext(x, i);
477 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
478 == NID_freshest_crl)
479 x->ex_flags |= EXFLAG_FRESHEST;
480 if (!X509_EXTENSION_get_critical(ex))
481 continue;
482 if (!X509_supported_extension(ex))
483 {
484 x->ex_flags |= EXFLAG_CRITICAL;
485 break;
486 }
487 }
488 x->ex_flags |= EXFLAG_SET;
489 }
490
491 /* CA checks common to all purposes
492 * return codes:
493 * 0 not a CA
494 * 1 is a CA
495 * 2 basicConstraints absent so "maybe" a CA
496 * 3 basicConstraints absent but self signed V1.
497 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
498 */
499
500 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
501 #define ku_reject(x, usage) \
502 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
503 #define xku_reject(x, usage) \
504 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
505 #define ns_reject(x, usage) \
506 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
507
508 static int check_ca(const X509 *x)
509 {
510 /* keyUsage if present should allow cert signing */
511 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
512 if(x->ex_flags & EXFLAG_BCONS) {
513 if(x->ex_flags & EXFLAG_CA) return 1;
514 /* If basicConstraints says not a CA then say so */
515 else return 0;
516 } else {
517 /* we support V1 roots for... uh, I don't really know why. */
518 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
519 /* If key usage present it must have certSign so tolerate it */
520 else if (x->ex_flags & EXFLAG_KUSAGE) return 4;
521 /* Older certificates could have Netscape-specific CA types */
522 else if (x->ex_flags & EXFLAG_NSCERT
523 && x->ex_nscert & NS_ANY_CA) return 5;
524 /* can this still be regarded a CA certificate? I doubt it */
525 return 0;
526 }
527 }
528
529 int X509_check_ca(X509 *x)
530 {
531 if(!(x->ex_flags & EXFLAG_SET)) {
532 CRYPTO_w_lock(CRYPTO_LOCK_X509);
533 x509v3_cache_extensions(x);
534 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
535 }
536
537 return check_ca(x);
538 }
539
540 /* Check SSL CA: common checks for SSL client and server */
541 static int check_ssl_ca(const X509 *x)
542 {
543 int ca_ret;
544 ca_ret = check_ca(x);
545 if(!ca_ret) return 0;
546 /* check nsCertType if present */
547 if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret;
548 else return 0;
549 }
550
551
552 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
553 {
554 if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
555 if(ca) return check_ssl_ca(x);
556 /* We need to do digital signatures with it */
557 if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
558 /* nsCertType if present should allow SSL client use */
559 if(ns_reject(x, NS_SSL_CLIENT)) return 0;
560 return 1;
561 }
562
563 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
564 {
565 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
566 if(ca) return check_ssl_ca(x);
567
568 if(ns_reject(x, NS_SSL_SERVER)) return 0;
569 /* Now as for keyUsage: we'll at least need to sign OR encipher */
570 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
571
572 return 1;
573
574 }
575
576 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
577 {
578 int ret;
579 ret = check_purpose_ssl_server(xp, x, ca);
580 if(!ret || ca) return ret;
581 /* We need to encipher or Netscape complains */
582 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
583 return ret;
584 }
585
586 /* common S/MIME checks */
587 static int purpose_smime(const X509 *x, int ca)
588 {
589 if(xku_reject(x,XKU_SMIME)) return 0;
590 if(ca) {
591 int ca_ret;
592 ca_ret = check_ca(x);
593 if(!ca_ret) return 0;
594 /* check nsCertType if present */
595 if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret;
596 else return 0;
597 }
598 if(x->ex_flags & EXFLAG_NSCERT) {
599 if(x->ex_nscert & NS_SMIME) return 1;
600 /* Workaround for some buggy certificates */
601 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
602 return 0;
603 }
604 return 1;
605 }
606
607 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
608 {
609 int ret;
610 ret = purpose_smime(x, ca);
611 if(!ret || ca) return ret;
612 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0;
613 return ret;
614 }
615
616 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
617 {
618 int ret;
619 ret = purpose_smime(x, ca);
620 if(!ret || ca) return ret;
621 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
622 return ret;
623 }
624
625 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
626 {
627 if(ca) {
628 int ca_ret;
629 if((ca_ret = check_ca(x)) != 2) return ca_ret;
630 else return 0;
631 }
632 if(ku_reject(x, KU_CRL_SIGN)) return 0;
633 return 1;
634 }
635
636 /* OCSP helper: this is *not* a full OCSP check. It just checks that
637 * each CA is valid. Additional checks must be made on the chain.
638 */
639
640 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
641 {
642 /* Must be a valid CA. Should we really support the "I don't know"
643 value (2)? */
644 if(ca) return check_ca(x);
645 /* leaf certificate is checked in OCSP_verify() */
646 return 1;
647 }
648
649 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
650 int ca)
651 {
652 int i_ext;
653
654 /* If ca is true we must return if this is a valid CA certificate. */
655 if (ca) return check_ca(x);
656
657 /*
658 * Check the optional key usage field:
659 * if Key Usage is present, it must be one of digitalSignature
660 * and/or nonRepudiation (other values are not consistent and shall
661 * be rejected).
662 */
663 if ((x->ex_flags & EXFLAG_KUSAGE)
664 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
665 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
666 return 0;
667
668 /* Only time stamp key usage is permitted and it's required. */
669 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
670 return 0;
671
672 /* Extended Key Usage MUST be critical */
673 i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1);
674 if (i_ext >= 0)
675 {
676 X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext);
677 if (!X509_EXTENSION_get_critical(ext))
678 return 0;
679 }
680
681 return 1;
682 }
683
684 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
685 {
686 return 1;
687 }
688
689 /* Various checks to see if one certificate issued the second.
690 * This can be used to prune a set of possible issuer certificates
691 * which have been looked up using some simple method such as by
692 * subject name.
693 * These are:
694 * 1. Check issuer_name(subject) == subject_name(issuer)
695 * 2. If akid(subject) exists check it matches issuer
696 * 3. If key_usage(issuer) exists check it supports certificate signing
697 * returns 0 for OK, positive for reason for mismatch, reasons match
698 * codes for X509_verify_cert()
699 */
700
701 int X509_check_issued(X509 *issuer, X509 *subject)
702 {
703 if(X509_NAME_cmp(X509_get_subject_name(issuer),
704 X509_get_issuer_name(subject)))
705 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
706 x509v3_cache_extensions(issuer);
707 x509v3_cache_extensions(subject);
708
709 if(subject->akid)
710 {
711 int ret = X509_check_akid(issuer, subject->akid);
712 if (ret != X509_V_OK)
713 return ret;
714 }
715
716 if(subject->ex_flags & EXFLAG_PROXY)
717 {
718 if(ku_reject(issuer, KU_DIGITAL_SIGNATURE))
719 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
720 }
721 else if(ku_reject(issuer, KU_KEY_CERT_SIGN))
722 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
723 return X509_V_OK;
724 }
725
726 int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
727 {
728
729 if(!akid)
730 return X509_V_OK;
731
732 /* Check key ids (if present) */
733 if(akid->keyid && issuer->skid &&
734 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) )
735 return X509_V_ERR_AKID_SKID_MISMATCH;
736 /* Check serial number */
737 if(akid->serial &&
738 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
739 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
740 /* Check issuer name */
741 if(akid->issuer)
742 {
743 /* Ugh, for some peculiar reason AKID includes
744 * SEQUENCE OF GeneralName. So look for a DirName.
745 * There may be more than one but we only take any
746 * notice of the first.
747 */
748 GENERAL_NAMES *gens;
749 GENERAL_NAME *gen;
750 X509_NAME *nm = NULL;
751 int i;
752 gens = akid->issuer;
753 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++)
754 {
755 gen = sk_GENERAL_NAME_value(gens, i);
756 if(gen->type == GEN_DIRNAME)
757 {
758 nm = gen->d.dirn;
759 break;
760 }
761 }
762 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
763 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
764 }
765 return X509_V_OK;
766 }