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 #include <stdio.h>
58
59 #include <string.h>
60
61 #include <openssl/buf.h>
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
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
81 static void x509v3_cache_extensions(X509 *x);
82
83 static int check_ssl_ca(const X509 *x);
84 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca);
85 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
86 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
87 static int purpose_smime(const X509 *x, int ca);
88 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
89 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca);
90 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
91 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
92 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
93 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
94
95 static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b);
96 static void xptable_free(X509_PURPOSE *p);
97
98 static X509_PURPOSE xstandard[] = {
99 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, (char *) "SSL client", (char *) "sslclient", NULL},
100 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, (char *) "SSL server", (char *) "sslserver", NULL},
101 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, (char *) "Netscape SSL server", (char *) "nssslserver", NULL},
102 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, (char *) "S/MIME signing", (char *) "smimesign", NULL},
103 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, (char *) "S/MIME encryption", (char *) "smimeencrypt", NULL},
104 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, (char *) "CRL signing", (char *) "crlsign", NULL},
105 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, (char *) "Any Purpose", (char *) "any", NULL},
106 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, (char *) "OCSP helper", (char *) "ocsphelper", NULL},
107 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, (char *) "Time Stamp signing", (char *) "timestampsign", NULL},
108 };
109
110 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
111
112 static STACK_OF(X509_PURPOSE) *xptable = NULL;
113
xp_cmp(const X509_PURPOSE ** a,const X509_PURPOSE ** b)114 static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b)
115 {
116 return (*a)->purpose - (*b)->purpose;
117 }
118
119 /* As much as I'd like to make X509_check_purpose use a "const" X509*
120 * I really can't because it does recalculate hashes and do other non-const
121 * things. */
X509_check_purpose(X509 * x,int id,int ca)122 int X509_check_purpose(X509 *x, int id, int ca)
123 {
124 int idx;
125 const X509_PURPOSE *pt;
126 if(!(x->ex_flags & EXFLAG_SET)) {
127 x509v3_cache_extensions(x);
128 }
129 if(id == -1) return 1;
130 idx = X509_PURPOSE_get_by_id(id);
131 if(idx == -1) return -1;
132 pt = X509_PURPOSE_get0(idx);
133 return pt->check_purpose(pt, x, ca);
134 }
135
X509_PURPOSE_set(int * p,int purpose)136 int X509_PURPOSE_set(int *p, int purpose)
137 {
138 if(X509_PURPOSE_get_by_id(purpose) == -1) {
139 OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_PURPOSE);
140 return 0;
141 }
142 *p = purpose;
143 return 1;
144 }
145
X509_PURPOSE_get_count(void)146 int X509_PURPOSE_get_count(void)
147 {
148 if(!xptable) return X509_PURPOSE_COUNT;
149 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
150 }
151
X509_PURPOSE_get0(int idx)152 X509_PURPOSE * X509_PURPOSE_get0(int idx)
153 {
154 if(idx < 0) return NULL;
155 if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx;
156 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
157 }
158
X509_PURPOSE_get_by_sname(char * sname)159 int X509_PURPOSE_get_by_sname(char *sname)
160 {
161 int i;
162 X509_PURPOSE *xptmp;
163 for(i = 0; i < X509_PURPOSE_get_count(); i++) {
164 xptmp = X509_PURPOSE_get0(i);
165 if(!strcmp(xptmp->sname, sname)) return i;
166 }
167 return -1;
168 }
169
X509_PURPOSE_get_by_id(int purpose)170 int X509_PURPOSE_get_by_id(int purpose)
171 {
172 X509_PURPOSE tmp;
173 size_t idx;
174
175 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
176 return purpose - X509_PURPOSE_MIN;
177 tmp.purpose = purpose;
178 if(!xptable) return -1;
179
180 if (!sk_X509_PURPOSE_find(xptable, &idx, &tmp))
181 return -1;
182 return idx + X509_PURPOSE_COUNT;
183 }
184
X509_PURPOSE_add(int id,int trust,int flags,int (* ck)(const X509_PURPOSE *,const X509 *,int),char * name,char * sname,void * arg)185 int X509_PURPOSE_add(int id, int trust, int flags,
186 int (*ck)(const X509_PURPOSE *, const X509 *, int),
187 char *name, char *sname, void *arg)
188 {
189 int idx;
190 X509_PURPOSE *ptmp;
191 char *name_dup, *sname_dup;
192
193 /* This is set according to what we change: application can't set it */
194 flags &= ~X509_PURPOSE_DYNAMIC;
195 /* This will always be set for application modified trust entries */
196 flags |= X509_PURPOSE_DYNAMIC_NAME;
197 /* Get existing entry if any */
198 idx = X509_PURPOSE_get_by_id(id);
199 /* Need a new entry */
200 if(idx == -1) {
201 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
202 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
203 return 0;
204 }
205 ptmp->flags = X509_PURPOSE_DYNAMIC;
206 } else ptmp = X509_PURPOSE_get0(idx);
207
208 /* Duplicate the supplied names. */
209 name_dup = BUF_strdup(name);
210 sname_dup = BUF_strdup(sname);
211 if (name_dup == NULL || sname_dup == NULL) {
212 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
213 if (name_dup != NULL)
214 OPENSSL_free(name_dup);
215 if (sname_dup != NULL)
216 OPENSSL_free(sname_dup);
217 if (idx == -1)
218 OPENSSL_free(ptmp);
219 return 0;
220 }
221
222 /* OPENSSL_free existing name if dynamic */
223 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
224 OPENSSL_free(ptmp->name);
225 OPENSSL_free(ptmp->sname);
226 }
227 /* dup supplied name */
228 ptmp->name = name_dup;
229 ptmp->sname = sname_dup;
230 /* Keep the dynamic flag of existing entry */
231 ptmp->flags &= X509_PURPOSE_DYNAMIC;
232 /* Set all other flags */
233 ptmp->flags |= flags;
234
235 ptmp->purpose = id;
236 ptmp->trust = trust;
237 ptmp->check_purpose = ck;
238 ptmp->usr_data = arg;
239
240 /* If its a new entry manage the dynamic table */
241 if(idx == -1) {
242 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
243 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
244 xptable_free(ptmp);
245 return 0;
246 }
247 if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
248 OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE);
249 xptable_free(ptmp);
250 return 0;
251 }
252 }
253 return 1;
254 }
255
xptable_free(X509_PURPOSE * p)256 static void xptable_free(X509_PURPOSE *p)
257 {
258 if(!p) return;
259 if (p->flags & X509_PURPOSE_DYNAMIC)
260 {
261 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
262 OPENSSL_free(p->name);
263 OPENSSL_free(p->sname);
264 }
265 OPENSSL_free(p);
266 }
267 }
268
X509_PURPOSE_cleanup(void)269 void X509_PURPOSE_cleanup(void)
270 {
271 unsigned int i;
272 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
273 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
274 xptable = NULL;
275 }
276
X509_PURPOSE_get_id(X509_PURPOSE * xp)277 int X509_PURPOSE_get_id(X509_PURPOSE *xp)
278 {
279 return xp->purpose;
280 }
281
X509_PURPOSE_get0_name(X509_PURPOSE * xp)282 char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
283 {
284 return xp->name;
285 }
286
X509_PURPOSE_get0_sname(X509_PURPOSE * xp)287 char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
288 {
289 return xp->sname;
290 }
291
X509_PURPOSE_get_trust(X509_PURPOSE * xp)292 int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
293 {
294 return xp->trust;
295 }
296
nid_cmp(const void * void_a,const void * void_b)297 static int nid_cmp(const void *void_a, const void *void_b)
298 {
299 const int *a = void_a, *b = void_b;
300
301 return *a - *b;
302 }
303
X509_supported_extension(X509_EXTENSION * ex)304 int X509_supported_extension(X509_EXTENSION *ex)
305 {
306 /* This table is a list of the NIDs of supported extensions:
307 * that is those which are used by the verify process. If
308 * an extension is critical and doesn't appear in this list
309 * then the verify process will normally reject the certificate.
310 * The list must be kept in numerical order because it will be
311 * searched using bsearch.
312 */
313
314 static const int supported_nids[] = {
315 NID_netscape_cert_type, /* 71 */
316 NID_key_usage, /* 83 */
317 NID_subject_alt_name, /* 85 */
318 NID_basic_constraints, /* 87 */
319 NID_certificate_policies, /* 89 */
320 NID_ext_key_usage, /* 126 */
321 NID_policy_constraints, /* 401 */
322 NID_proxyCertInfo, /* 663 */
323 NID_name_constraints, /* 666 */
324 NID_policy_mappings, /* 747 */
325 NID_inhibit_any_policy /* 748 */
326 };
327
328 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
329
330 if (ex_nid == NID_undef)
331 return 0;
332
333 if (bsearch(&ex_nid, supported_nids, sizeof(supported_nids)/sizeof(int), sizeof(int), nid_cmp) != NULL)
334 return 1;
335 return 0;
336 }
337
setup_dp(X509 * x,DIST_POINT * dp)338 static void setup_dp(X509 *x, DIST_POINT *dp)
339 {
340 X509_NAME *iname = NULL;
341 size_t i;
342 if (dp->reasons)
343 {
344 if (dp->reasons->length > 0)
345 dp->dp_reasons = dp->reasons->data[0];
346 if (dp->reasons->length > 1)
347 dp->dp_reasons |= (dp->reasons->data[1] << 8);
348 dp->dp_reasons &= CRLDP_ALL_REASONS;
349 }
350 else
351 dp->dp_reasons = CRLDP_ALL_REASONS;
352 if (!dp->distpoint || (dp->distpoint->type != 1))
353 return;
354 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++)
355 {
356 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
357 if (gen->type == GEN_DIRNAME)
358 {
359 iname = gen->d.directoryName;
360 break;
361 }
362 }
363 if (!iname)
364 iname = X509_get_issuer_name(x);
365
366 DIST_POINT_set_dpname(dp->distpoint, iname);
367
368 }
369
setup_crldp(X509 * x)370 static void setup_crldp(X509 *x)
371 {
372 size_t i;
373 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
374 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
375 setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
376 }
377
378 /* g_x509_cache_extensions_lock is used to protect against concurrent calls to
379 * |x509v3_cache_extensions|. Ideally this would be done with a |CRYPTO_once_t|
380 * in the |X509| structure, but |CRYPTO_once_t| isn't public.
381 *
382 * Note: it's not entirely clear whether this lock is needed. Not all paths to
383 * this function took a lock in OpenSSL. */
384 static struct CRYPTO_STATIC_MUTEX g_x509_cache_extensions_lock =
385 CRYPTO_STATIC_MUTEX_INIT;
386
x509v3_cache_extensions(X509 * x)387 static void x509v3_cache_extensions(X509 *x)
388 {
389 BASIC_CONSTRAINTS *bs;
390 PROXY_CERT_INFO_EXTENSION *pci;
391 ASN1_BIT_STRING *usage;
392 ASN1_BIT_STRING *ns;
393 EXTENDED_KEY_USAGE *extusage;
394 X509_EXTENSION *ex;
395 size_t i;
396 int j;
397
398 CRYPTO_STATIC_MUTEX_lock_write(&g_x509_cache_extensions_lock);
399
400 if(x->ex_flags & EXFLAG_SET)
401 {
402 CRYPTO_STATIC_MUTEX_unlock(&g_x509_cache_extensions_lock);
403 return;
404 }
405
406 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
407 /* V1 should mean no extensions ... */
408 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
409 /* Handle basic constraints */
410 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
411 if(bs->ca) x->ex_flags |= EXFLAG_CA;
412 if(bs->pathlen) {
413 if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
414 || !bs->ca) {
415 x->ex_flags |= EXFLAG_INVALID;
416 x->ex_pathlen = 0;
417 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
418 } else x->ex_pathlen = -1;
419 BASIC_CONSTRAINTS_free(bs);
420 x->ex_flags |= EXFLAG_BCONS;
421 }
422 /* Handle proxy certificates */
423 if((pci=X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
424 if (x->ex_flags & EXFLAG_CA
425 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
426 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
427 x->ex_flags |= EXFLAG_INVALID;
428 }
429 if (pci->pcPathLengthConstraint) {
430 x->ex_pcpathlen =
431 ASN1_INTEGER_get(pci->pcPathLengthConstraint);
432 } else x->ex_pcpathlen = -1;
433 PROXY_CERT_INFO_EXTENSION_free(pci);
434 x->ex_flags |= EXFLAG_PROXY;
435 }
436 /* Handle key usage */
437 if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
438 if(usage->length > 0) {
439 x->ex_kusage = usage->data[0];
440 if(usage->length > 1)
441 x->ex_kusage |= usage->data[1] << 8;
442 } else x->ex_kusage = 0;
443 x->ex_flags |= EXFLAG_KUSAGE;
444 ASN1_BIT_STRING_free(usage);
445 }
446 x->ex_xkusage = 0;
447 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
448 x->ex_flags |= EXFLAG_XKUSAGE;
449 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
450 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
451 case NID_server_auth:
452 x->ex_xkusage |= XKU_SSL_SERVER;
453 break;
454
455 case NID_client_auth:
456 x->ex_xkusage |= XKU_SSL_CLIENT;
457 break;
458
459 case NID_email_protect:
460 x->ex_xkusage |= XKU_SMIME;
461 break;
462
463 case NID_code_sign:
464 x->ex_xkusage |= XKU_CODE_SIGN;
465 break;
466
467 case NID_ms_sgc:
468 case NID_ns_sgc:
469 x->ex_xkusage |= XKU_SGC;
470 break;
471
472 case NID_OCSP_sign:
473 x->ex_xkusage |= XKU_OCSP_SIGN;
474 break;
475
476 case NID_time_stamp:
477 x->ex_xkusage |= XKU_TIMESTAMP;
478 break;
479
480 case NID_dvcs:
481 x->ex_xkusage |= XKU_DVCS;
482 break;
483
484 case NID_anyExtendedKeyUsage:
485 x->ex_xkusage |= XKU_ANYEKU;
486 break;
487 }
488 }
489 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
490 }
491
492 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
493 if(ns->length > 0) x->ex_nscert = ns->data[0];
494 else x->ex_nscert = 0;
495 x->ex_flags |= EXFLAG_NSCERT;
496 ASN1_BIT_STRING_free(ns);
497 }
498 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
499 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
500 /* Does subject name match issuer ? */
501 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
502 {
503 x->ex_flags |= EXFLAG_SI;
504 /* If SKID matches AKID also indicate self signed */
505 if (X509_check_akid(x, x->akid) == X509_V_OK &&
506 !ku_reject(x, KU_KEY_CERT_SIGN))
507 x->ex_flags |= EXFLAG_SS;
508 }
509 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
510 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &j, NULL);
511 if (!x->nc && (j != -1))
512 x->ex_flags |= EXFLAG_INVALID;
513 setup_crldp(x);
514
515 for (j = 0; j < X509_get_ext_count(x); j++)
516 {
517 ex = X509_get_ext(x, j);
518 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
519 == NID_freshest_crl)
520 x->ex_flags |= EXFLAG_FRESHEST;
521 if (!X509_EXTENSION_get_critical(ex))
522 continue;
523 if (!X509_supported_extension(ex))
524 {
525 x->ex_flags |= EXFLAG_CRITICAL;
526 break;
527 }
528 }
529 x->ex_flags |= EXFLAG_SET;
530
531 CRYPTO_STATIC_MUTEX_unlock(&g_x509_cache_extensions_lock);
532 }
533
534 /* CA checks common to all purposes
535 * return codes:
536 * 0 not a CA
537 * 1 is a CA
538 * 2 basicConstraints absent so "maybe" a CA
539 * 3 basicConstraints absent but self signed V1.
540 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
541 */
542
check_ca(const X509 * x)543 static int check_ca(const X509 *x)
544 {
545 /* keyUsage if present should allow cert signing */
546 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
547 if(x->ex_flags & EXFLAG_BCONS) {
548 if(x->ex_flags & EXFLAG_CA) return 1;
549 /* If basicConstraints says not a CA then say so */
550 else return 0;
551 } else {
552 /* we support V1 roots for... uh, I don't really know why. */
553 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
554 /* If key usage present it must have certSign so tolerate it */
555 else if (x->ex_flags & EXFLAG_KUSAGE) return 4;
556 /* Older certificates could have Netscape-specific CA types */
557 else if (x->ex_flags & EXFLAG_NSCERT
558 && x->ex_nscert & NS_ANY_CA) return 5;
559 /* can this still be regarded a CA certificate? I doubt it */
560 return 0;
561 }
562 }
563
X509_check_ca(X509 * x)564 int X509_check_ca(X509 *x)
565 {
566 if(!(x->ex_flags & EXFLAG_SET)) {
567 x509v3_cache_extensions(x);
568 }
569
570 return check_ca(x);
571 }
572
573 /* Check SSL CA: common checks for SSL client and server */
check_ssl_ca(const X509 * x)574 static int check_ssl_ca(const X509 *x)
575 {
576 int ca_ret;
577 ca_ret = check_ca(x);
578 if(!ca_ret) return 0;
579 /* check nsCertType if present */
580 if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret;
581 else return 0;
582 }
583
584
check_purpose_ssl_client(const X509_PURPOSE * xp,const X509 * x,int ca)585 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
586 {
587 if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
588 if(ca) return check_ssl_ca(x);
589 /* We need to do digital signatures or key agreement */
590 if(ku_reject(x,KU_DIGITAL_SIGNATURE|KU_KEY_AGREEMENT)) return 0;
591 /* nsCertType if present should allow SSL client use */
592 if(ns_reject(x, NS_SSL_CLIENT)) return 0;
593 return 1;
594 }
595 /* Key usage needed for TLS/SSL server: digital signature, encipherment or
596 * key agreement. The ssl code can check this more thoroughly for individual
597 * key types.
598 */
599 #define KU_TLS \
600 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT
601
check_purpose_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)602 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
603 {
604 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
605 if(ca) return check_ssl_ca(x);
606
607 if(ns_reject(x, NS_SSL_SERVER)) return 0;
608 if(ku_reject(x, KU_TLS)) return 0;
609
610 return 1;
611
612 }
613
check_purpose_ns_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)614 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
615 {
616 int ret;
617 ret = check_purpose_ssl_server(xp, x, ca);
618 if(!ret || ca) return ret;
619 /* We need to encipher or Netscape complains */
620 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
621 return ret;
622 }
623
624 /* common S/MIME checks */
purpose_smime(const X509 * x,int ca)625 static int purpose_smime(const X509 *x, int ca)
626 {
627 if(xku_reject(x,XKU_SMIME)) return 0;
628 if(ca) {
629 int ca_ret;
630 ca_ret = check_ca(x);
631 if(!ca_ret) return 0;
632 /* check nsCertType if present */
633 if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret;
634 else return 0;
635 }
636 if(x->ex_flags & EXFLAG_NSCERT) {
637 if(x->ex_nscert & NS_SMIME) return 1;
638 /* Workaround for some buggy certificates */
639 if(x->ex_nscert & NS_SSL_CLIENT) return 2;
640 return 0;
641 }
642 return 1;
643 }
644
check_purpose_smime_sign(const X509_PURPOSE * xp,const X509 * x,int ca)645 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
646 {
647 int ret;
648 ret = purpose_smime(x, ca);
649 if(!ret || ca) return ret;
650 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0;
651 return ret;
652 }
653
check_purpose_smime_encrypt(const X509_PURPOSE * xp,const X509 * x,int ca)654 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
655 {
656 int ret;
657 ret = purpose_smime(x, ca);
658 if(!ret || ca) return ret;
659 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
660 return ret;
661 }
662
check_purpose_crl_sign(const X509_PURPOSE * xp,const X509 * x,int ca)663 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
664 {
665 if(ca) {
666 int ca_ret;
667 if((ca_ret = check_ca(x)) != 2) return ca_ret;
668 else return 0;
669 }
670 if(ku_reject(x, KU_CRL_SIGN)) return 0;
671 return 1;
672 }
673
674 /* OCSP helper: this is *not* a full OCSP check. It just checks that
675 * each CA is valid. Additional checks must be made on the chain.
676 */
677
ocsp_helper(const X509_PURPOSE * xp,const X509 * x,int ca)678 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
679 {
680 /* Must be a valid CA. Should we really support the "I don't know"
681 value (2)? */
682 if(ca) return check_ca(x);
683 /* leaf certificate is checked in OCSP_verify() */
684 return 1;
685 }
686
check_purpose_timestamp_sign(const X509_PURPOSE * xp,const X509 * x,int ca)687 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
688 int ca)
689 {
690 int i_ext;
691
692 /* If ca is true we must return if this is a valid CA certificate. */
693 if (ca) return check_ca(x);
694
695 /*
696 * Check the optional key usage field:
697 * if Key Usage is present, it must be one of digitalSignature
698 * and/or nonRepudiation (other values are not consistent and shall
699 * be rejected).
700 */
701 if ((x->ex_flags & EXFLAG_KUSAGE)
702 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
703 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
704 return 0;
705
706 /* Only time stamp key usage is permitted and it's required. */
707 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
708 return 0;
709
710 /* Extended Key Usage MUST be critical */
711 i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1);
712 if (i_ext >= 0)
713 {
714 X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext);
715 if (!X509_EXTENSION_get_critical(ext))
716 return 0;
717 }
718
719 return 1;
720 }
721
no_check(const X509_PURPOSE * xp,const X509 * x,int ca)722 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
723 {
724 return 1;
725 }
726
727 /* Various checks to see if one certificate issued the second.
728 * This can be used to prune a set of possible issuer certificates
729 * which have been looked up using some simple method such as by
730 * subject name.
731 * These are:
732 * 1. Check issuer_name(subject) == subject_name(issuer)
733 * 2. If akid(subject) exists check it matches issuer
734 * 3. If key_usage(issuer) exists check it supports certificate signing
735 * returns 0 for OK, positive for reason for mismatch, reasons match
736 * codes for X509_verify_cert()
737 */
738
X509_check_issued(X509 * issuer,X509 * subject)739 int X509_check_issued(X509 *issuer, X509 *subject)
740 {
741 if(X509_NAME_cmp(X509_get_subject_name(issuer),
742 X509_get_issuer_name(subject)))
743 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
744 x509v3_cache_extensions(issuer);
745 x509v3_cache_extensions(subject);
746
747 if(subject->akid)
748 {
749 int ret = X509_check_akid(issuer, subject->akid);
750 if (ret != X509_V_OK)
751 return ret;
752 }
753
754 if(subject->ex_flags & EXFLAG_PROXY)
755 {
756 if(ku_reject(issuer, KU_DIGITAL_SIGNATURE))
757 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
758 }
759 else if(ku_reject(issuer, KU_KEY_CERT_SIGN))
760 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
761 return X509_V_OK;
762 }
763
X509_check_akid(X509 * issuer,AUTHORITY_KEYID * akid)764 int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
765 {
766
767 if(!akid)
768 return X509_V_OK;
769
770 /* Check key ids (if present) */
771 if(akid->keyid && issuer->skid &&
772 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) )
773 return X509_V_ERR_AKID_SKID_MISMATCH;
774 /* Check serial number */
775 if(akid->serial &&
776 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
777 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
778 /* Check issuer name */
779 if(akid->issuer)
780 {
781 /* Ugh, for some peculiar reason AKID includes
782 * SEQUENCE OF GeneralName. So look for a DirName.
783 * There may be more than one but we only take any
784 * notice of the first.
785 */
786 GENERAL_NAMES *gens;
787 GENERAL_NAME *gen;
788 X509_NAME *nm = NULL;
789 size_t i;
790 gens = akid->issuer;
791 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++)
792 {
793 gen = sk_GENERAL_NAME_value(gens, i);
794 if(gen->type == GEN_DIRNAME)
795 {
796 nm = gen->d.dirn;
797 break;
798 }
799 }
800 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
801 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
802 }
803 return X509_V_OK;
804 }
805
806