1 /* v3_purp.c */
2 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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 no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
75 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
76
77 static int xp_cmp(const X509_PURPOSE * const *a,
78 const X509_PURPOSE * const *b);
79 static void xptable_free(X509_PURPOSE *p);
80
81 static X509_PURPOSE xstandard[] = {
82 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
83 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
84 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
85 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
86 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
87 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
88 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL},
89 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL},
90 };
91
92 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
93
94 IMPLEMENT_STACK_OF(X509_PURPOSE)
95
96 static STACK_OF(X509_PURPOSE) *xptable = NULL;
97
xp_cmp(const X509_PURPOSE * const * a,const X509_PURPOSE * const * b)98 static int xp_cmp(const X509_PURPOSE * const *a,
99 const X509_PURPOSE * const *b)
100 {
101 return (*a)->purpose - (*b)->purpose;
102 }
103
104 /* As much as I'd like to make X509_check_purpose use a "const" X509*
105 * I really can't because it does recalculate hashes and do other non-const
106 * things. */
X509_check_purpose(X509 * x,int id,int ca)107 int X509_check_purpose(X509 *x, int id, int ca)
108 {
109 int idx;
110 const X509_PURPOSE *pt;
111 if(!(x->ex_flags & EXFLAG_SET)) {
112 CRYPTO_w_lock(CRYPTO_LOCK_X509);
113 x509v3_cache_extensions(x);
114 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
115 }
116 if(id == -1) return 1;
117 idx = X509_PURPOSE_get_by_id(id);
118 if(idx == -1) return -1;
119 pt = X509_PURPOSE_get0(idx);
120 return pt->check_purpose(pt, x, ca);
121 }
122
X509_PURPOSE_set(int * p,int purpose)123 int X509_PURPOSE_set(int *p, int purpose)
124 {
125 if(X509_PURPOSE_get_by_id(purpose) == -1) {
126 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
127 return 0;
128 }
129 *p = purpose;
130 return 1;
131 }
132
X509_PURPOSE_get_count(void)133 int X509_PURPOSE_get_count(void)
134 {
135 if(!xptable) return X509_PURPOSE_COUNT;
136 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
137 }
138
X509_PURPOSE_get0(int idx)139 X509_PURPOSE * X509_PURPOSE_get0(int idx)
140 {
141 if(idx < 0) return NULL;
142 if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx;
143 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
144 }
145
X509_PURPOSE_get_by_sname(char * sname)146 int X509_PURPOSE_get_by_sname(char *sname)
147 {
148 int i;
149 X509_PURPOSE *xptmp;
150 for(i = 0; i < X509_PURPOSE_get_count(); i++) {
151 xptmp = X509_PURPOSE_get0(i);
152 if(!strcmp(xptmp->sname, sname)) return i;
153 }
154 return -1;
155 }
156
X509_PURPOSE_get_by_id(int purpose)157 int X509_PURPOSE_get_by_id(int purpose)
158 {
159 X509_PURPOSE tmp;
160 int idx;
161 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
162 return purpose - X509_PURPOSE_MIN;
163 tmp.purpose = purpose;
164 if(!xptable) return -1;
165 idx = sk_X509_PURPOSE_find(xptable, &tmp);
166 if(idx == -1) return -1;
167 return idx + X509_PURPOSE_COUNT;
168 }
169
X509_PURPOSE_add(int id,int trust,int flags,int (* ck)(const X509_PURPOSE *,const X509 *,int),char * name,char * sname,void * arg)170 int X509_PURPOSE_add(int id, int trust, int flags,
171 int (*ck)(const X509_PURPOSE *, const X509 *, int),
172 char *name, char *sname, void *arg)
173 {
174 int idx;
175 X509_PURPOSE *ptmp;
176 /* This is set according to what we change: application can't set it */
177 flags &= ~X509_PURPOSE_DYNAMIC;
178 /* This will always be set for application modified trust entries */
179 flags |= X509_PURPOSE_DYNAMIC_NAME;
180 /* Get existing entry if any */
181 idx = X509_PURPOSE_get_by_id(id);
182 /* Need a new entry */
183 if(idx == -1) {
184 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
185 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
186 return 0;
187 }
188 ptmp->flags = X509_PURPOSE_DYNAMIC;
189 } else ptmp = X509_PURPOSE_get0(idx);
190
191 /* OPENSSL_free existing name if dynamic */
192 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
193 OPENSSL_free(ptmp->name);
194 OPENSSL_free(ptmp->sname);
195 }
196 /* dup supplied name */
197 ptmp->name = BUF_strdup(name);
198 ptmp->sname = BUF_strdup(sname);
199 if(!ptmp->name || !ptmp->sname) {
200 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
201 return 0;
202 }
203 /* Keep the dynamic flag of existing entry */
204 ptmp->flags &= X509_PURPOSE_DYNAMIC;
205 /* Set all other flags */
206 ptmp->flags |= flags;
207
208 ptmp->purpose = id;
209 ptmp->trust = trust;
210 ptmp->check_purpose = ck;
211 ptmp->usr_data = arg;
212
213 /* If its a new entry manage the dynamic table */
214 if(idx == -1) {
215 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
216 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
217 return 0;
218 }
219 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
220 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
221 return 0;
222 }
223 }
224 return 1;
225 }
226
xptable_free(X509_PURPOSE * p)227 static void xptable_free(X509_PURPOSE *p)
228 {
229 if(!p) return;
230 if (p->flags & X509_PURPOSE_DYNAMIC)
231 {
232 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
233 OPENSSL_free(p->name);
234 OPENSSL_free(p->sname);
235 }
236 OPENSSL_free(p);
237 }
238 }
239
X509_PURPOSE_cleanup(void)240 void X509_PURPOSE_cleanup(void)
241 {
242 unsigned int i;
243 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
244 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
245 xptable = NULL;
246 }
247
X509_PURPOSE_get_id(X509_PURPOSE * xp)248 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
249 {
250 return xp->purpose;
251 }
252
X509_PURPOSE_get0_name(X509_PURPOSE * xp)253 char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
254 {
255 return xp->name;
256 }
257
X509_PURPOSE_get0_sname(X509_PURPOSE * xp)258 char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
259 {
260 return xp->sname;
261 }
262
X509_PURPOSE_get_trust(X509_PURPOSE * xp)263 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
264 {
265 return xp->trust;
266 }
267
nid_cmp(int * a,int * b)268 static int nid_cmp(int *a, int *b)
269 {
270 return *a - *b;
271 }
272
X509_supported_extension(X509_EXTENSION * ex)273 int X509_supported_extension(X509_EXTENSION *ex)
274 {
275 /* This table is a list of the NIDs of supported extensions:
276 * that is those which are used by the verify process. If
277 * an extension is critical and doesn't appear in this list
278 * then the verify process will normally reject the certificate.
279 * The list must be kept in numerical order because it will be
280 * searched using bsearch.
281 */
282
283 static int supported_nids[] = {
284 NID_netscape_cert_type, /* 71 */
285 NID_key_usage, /* 83 */
286 NID_subject_alt_name, /* 85 */
287 NID_basic_constraints, /* 87 */
288 NID_certificate_policies, /* 89 */
289 NID_ext_key_usage, /* 126 */
290 #ifndef OPENSSL_NO_RFC3779
291 NID_sbgp_ipAddrBlock, /* 290 */
292 NID_sbgp_autonomousSysNum, /* 291 */
293 #endif
294 NID_proxyCertInfo /* 661 */
295 };
296
297 int ex_nid;
298
299 ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
300
301 if (ex_nid == NID_undef)
302 return 0;
303
304 if (OBJ_bsearch((char *)&ex_nid, (char *)supported_nids,
305 sizeof(supported_nids)/sizeof(int), sizeof(int),
306 (int (*)(const void *, const void *))nid_cmp))
307 return 1;
308 return 0;
309 }
310
311
x509v3_cache_extensions(X509 * x)312 static void x509v3_cache_extensions(X509 *x)
313 {
314 BASIC_CONSTRAINTS *bs;
315 PROXY_CERT_INFO_EXTENSION *pci;
316 ASN1_BIT_STRING *usage;
317 ASN1_BIT_STRING *ns;
318 EXTENDED_KEY_USAGE *extusage;
319 X509_EXTENSION *ex;
320
321 int i;
322 if(x->ex_flags & EXFLAG_SET) return;
323 #ifndef OPENSSL_NO_SHA
324 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
325 #endif
326 /* Does subject name match issuer ? */
327 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
328 x->ex_flags |= EXFLAG_SS;
329 /* V1 should mean no extensions ... */
330 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
331 /* Handle basic constraints */
332 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
333 if(bs->ca) x->ex_flags |= EXFLAG_CA;
334 if(bs->pathlen) {
335 if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
336 || !bs->ca) {
337 x->ex_flags |= EXFLAG_INVALID;
338 x->ex_pathlen = 0;
339 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
340 } else x->ex_pathlen = -1;
341 BASIC_CONSTRAINTS_free(bs);
342 x->ex_flags |= EXFLAG_BCONS;
343 }
344 /* Handle proxy certificates */
345 if((pci=X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
346 if (x->ex_flags & EXFLAG_CA
347 || X509_get_ext_by_NID(x, NID_subject_alt_name, 0) >= 0
348 || X509_get_ext_by_NID(x, NID_issuer_alt_name, 0) >= 0) {
349 x->ex_flags |= EXFLAG_INVALID;
350 }
351 if (pci->pcPathLengthConstraint) {
352 x->ex_pcpathlen =
353 ASN1_INTEGER_get(pci->pcPathLengthConstraint);
354 } else x->ex_pcpathlen = -1;
355 PROXY_CERT_INFO_EXTENSION_free(pci);
356 x->ex_flags |= EXFLAG_PROXY;
357 }
358 /* Handle key usage */
359 if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
360 if(usage->length > 0) {
361 x->ex_kusage = usage->data[0];
362 if(usage->length > 1)
363 x->ex_kusage |= usage->data[1] << 8;
364 } else x->ex_kusage = 0;
365 x->ex_flags |= EXFLAG_KUSAGE;
366 ASN1_BIT_STRING_free(usage);
367 }
368 x->ex_xkusage = 0;
369 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
370 x->ex_flags |= EXFLAG_XKUSAGE;
371 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
372 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
373 case NID_server_auth:
374 x->ex_xkusage |= XKU_SSL_SERVER;
375 break;
376
377 case NID_client_auth:
378 x->ex_xkusage |= XKU_SSL_CLIENT;
379 break;
380
381 case NID_email_protect:
382 x->ex_xkusage |= XKU_SMIME;
383 break;
384
385 case NID_code_sign:
386 x->ex_xkusage |= XKU_CODE_SIGN;
387 break;
388
389 case NID_ms_sgc:
390 case NID_ns_sgc:
391 x->ex_xkusage |= XKU_SGC;
392 break;
393
394 case NID_OCSP_sign:
395 x->ex_xkusage |= XKU_OCSP_SIGN;
396 break;
397
398 case NID_time_stamp:
399 x->ex_xkusage |= XKU_TIMESTAMP;
400 break;
401
402 case NID_dvcs:
403 x->ex_xkusage |= XKU_DVCS;
404 break;
405 }
406 }
407 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
408 }
409
410 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
411 if(ns->length > 0) x->ex_nscert = ns->data[0];
412 else x->ex_nscert = 0;
413 x->ex_flags |= EXFLAG_NSCERT;
414 ASN1_BIT_STRING_free(ns);
415 }
416 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
417 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
418 #ifndef OPENSSL_NO_RFC3779
419 x->rfc3779_addr =X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL);
420 x->rfc3779_asid =X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum,
421 NULL, NULL);
422 #endif
423 for (i = 0; i < X509_get_ext_count(x); i++)
424 {
425 ex = X509_get_ext(x, i);
426 if (!X509_EXTENSION_get_critical(ex))
427 continue;
428 if (!X509_supported_extension(ex))
429 {
430 x->ex_flags |= EXFLAG_CRITICAL;
431 break;
432 }
433 }
434 x->ex_flags |= EXFLAG_SET;
435 }
436
437 /* CA checks common to all purposes
438 * return codes:
439 * 0 not a CA
440 * 1 is a CA
441 * 2 basicConstraints absent so "maybe" a CA
442 * 3 basicConstraints absent but self signed V1.
443 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
444 */
445
446 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
447 #define ku_reject(x, usage) \
448 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
449 #define xku_reject(x, usage) \
450 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
451 #define ns_reject(x, usage) \
452 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
453
check_ca(const X509 * x)454 static int check_ca(const X509 *x)
455 {
456 /* keyUsage if present should allow cert signing */
457 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
458 if(x->ex_flags & EXFLAG_BCONS) {
459 if(x->ex_flags & EXFLAG_CA) return 1;
460 /* If basicConstraints says not a CA then say so */
461 else return 0;
462 } else {
463 /* we support V1 roots for... uh, I don't really know why. */
464 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
465 /* If key usage present it must have certSign so tolerate it */
466 else if (x->ex_flags & EXFLAG_KUSAGE) return 4;
467 /* Older certificates could have Netscape-specific CA types */
468 else if (x->ex_flags & EXFLAG_NSCERT
469 && x->ex_nscert & NS_ANY_CA) return 5;
470 /* can this still be regarded a CA certificate? I doubt it */
471 return 0;
472 }
473 }
474
X509_check_ca(X509 * x)475 int X509_check_ca(X509 *x)
476 {
477 if(!(x->ex_flags & EXFLAG_SET)) {
478 CRYPTO_w_lock(CRYPTO_LOCK_X509);
479 x509v3_cache_extensions(x);
480 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
481 }
482
483 return check_ca(x);
484 }
485
486 /* Check SSL CA: common checks for SSL client and server */
check_ssl_ca(const X509 * x)487 static int check_ssl_ca(const X509 *x)
488 {
489 int ca_ret;
490 ca_ret = check_ca(x);
491 if(!ca_ret) return 0;
492 /* check nsCertType if present */
493 if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret;
494 else return 0;
495 }
496
497
check_purpose_ssl_client(const X509_PURPOSE * xp,const X509 * x,int ca)498 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
499 {
500 if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
501 if(ca) return check_ssl_ca(x);
502 /* We need to do digital signatures with it */
503 if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
504 /* nsCertType if present should allow SSL client use */
505 if(ns_reject(x, NS_SSL_CLIENT)) return 0;
506 return 1;
507 }
508
check_purpose_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)509 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
510 {
511 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
512 if(ca) return check_ssl_ca(x);
513
514 if(ns_reject(x, NS_SSL_SERVER)) return 0;
515 /* Now as for keyUsage: we'll at least need to sign OR encipher */
516 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
517
518 return 1;
519
520 }
521
check_purpose_ns_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)522 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
523 {
524 int ret;
525 ret = check_purpose_ssl_server(xp, x, ca);
526 if(!ret || ca) return ret;
527 /* We need to encipher or Netscape complains */
528 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
529 return ret;
530 }
531
532 /* common S/MIME checks */
purpose_smime(const X509 * x,int ca)533 static int purpose_smime(const X509 *x, int ca)
534 {
535 if(xku_reject(x,XKU_SMIME)) return 0;
536 if(ca) {
537 int ca_ret;
538 ca_ret = check_ca(x);
539 if(!ca_ret) return 0;
540 /* check nsCertType if present */
541 if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret;
542 else return 0;
543 }
544 if(x->ex_flags & EXFLAG_NSCERT) {
545 if(x->ex_nscert & NS_SMIME) return 1;
546 /* Workaround for some buggy certificates */
547 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
548 return 0;
549 }
550 return 1;
551 }
552
check_purpose_smime_sign(const X509_PURPOSE * xp,const X509 * x,int ca)553 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
554 {
555 int ret;
556 ret = purpose_smime(x, ca);
557 if(!ret || ca) return ret;
558 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0;
559 return ret;
560 }
561
check_purpose_smime_encrypt(const X509_PURPOSE * xp,const X509 * x,int ca)562 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
563 {
564 int ret;
565 ret = purpose_smime(x, ca);
566 if(!ret || ca) return ret;
567 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
568 return ret;
569 }
570
check_purpose_crl_sign(const X509_PURPOSE * xp,const X509 * x,int ca)571 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
572 {
573 if(ca) {
574 int ca_ret;
575 if((ca_ret = check_ca(x)) != 2) return ca_ret;
576 else return 0;
577 }
578 if(ku_reject(x, KU_CRL_SIGN)) return 0;
579 return 1;
580 }
581
582 /* OCSP helper: this is *not* a full OCSP check. It just checks that
583 * each CA is valid. Additional checks must be made on the chain.
584 */
585
ocsp_helper(const X509_PURPOSE * xp,const X509 * x,int ca)586 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
587 {
588 /* Must be a valid CA. Should we really support the "I don't know"
589 value (2)? */
590 if(ca) return check_ca(x);
591 /* leaf certificate is checked in OCSP_verify() */
592 return 1;
593 }
594
no_check(const X509_PURPOSE * xp,const X509 * x,int ca)595 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
596 {
597 return 1;
598 }
599
600 /* Various checks to see if one certificate issued the second.
601 * This can be used to prune a set of possible issuer certificates
602 * which have been looked up using some simple method such as by
603 * subject name.
604 * These are:
605 * 1. Check issuer_name(subject) == subject_name(issuer)
606 * 2. If akid(subject) exists check it matches issuer
607 * 3. If key_usage(issuer) exists check it supports certificate signing
608 * returns 0 for OK, positive for reason for mismatch, reasons match
609 * codes for X509_verify_cert()
610 */
611
X509_check_issued(X509 * issuer,X509 * subject)612 int X509_check_issued(X509 *issuer, X509 *subject)
613 {
614 if(X509_NAME_cmp(X509_get_subject_name(issuer),
615 X509_get_issuer_name(subject)))
616 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
617 x509v3_cache_extensions(issuer);
618 x509v3_cache_extensions(subject);
619 if(subject->akid) {
620 /* Check key ids (if present) */
621 if(subject->akid->keyid && issuer->skid &&
622 ASN1_OCTET_STRING_cmp(subject->akid->keyid, issuer->skid) )
623 return X509_V_ERR_AKID_SKID_MISMATCH;
624 /* Check serial number */
625 if(subject->akid->serial &&
626 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer),
627 subject->akid->serial))
628 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
629 /* Check issuer name */
630 if(subject->akid->issuer) {
631 /* Ugh, for some peculiar reason AKID includes
632 * SEQUENCE OF GeneralName. So look for a DirName.
633 * There may be more than one but we only take any
634 * notice of the first.
635 */
636 GENERAL_NAMES *gens;
637 GENERAL_NAME *gen;
638 X509_NAME *nm = NULL;
639 int i;
640 gens = subject->akid->issuer;
641 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
642 gen = sk_GENERAL_NAME_value(gens, i);
643 if(gen->type == GEN_DIRNAME) {
644 nm = gen->d.dirn;
645 break;
646 }
647 }
648 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
649 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
650 }
651 }
652 if(subject->ex_flags & EXFLAG_PROXY)
653 {
654 if(ku_reject(issuer, KU_DIGITAL_SIGNATURE))
655 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
656 }
657 else if(ku_reject(issuer, KU_KEY_CERT_SIGN))
658 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
659 return X509_V_OK;
660 }
661
662