1 /* $OpenBSD: x509_purp.c,v 1.16 2022/05/10 19:42:52 tb Exp $ */
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 <string.h>
61
62 #include <openssl/opensslconf.h>
63
64 #include <openssl/err.h>
65 #include <openssl/x509v3.h>
66 #include <openssl/x509_vfy.h>
67
68 #include "x509_internal.h"
69 #include "x509_lcl.h"
70
71 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
72 #define ku_reject(x, usage) \
73 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
74 #define xku_reject(x, usage) \
75 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
76 #define ns_reject(x, usage) \
77 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
78
79 void x509v3_cache_extensions(X509 *x);
80
81 static int check_ssl_ca(const X509 *x);
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 * const *a, const X509_PURPOSE * const *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, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
105 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
106 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
107 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
108 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
109 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
110 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL},
111 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL},
112 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", NULL},
113 };
114
115 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
116
117 static STACK_OF(X509_PURPOSE) *xptable = NULL;
118
119 static int
xp_cmp(const X509_PURPOSE * const * a,const X509_PURPOSE * const * b)120 xp_cmp(const X509_PURPOSE * const *a, const X509_PURPOSE * const *b)
121 {
122 return (*a)->purpose - (*b)->purpose;
123 }
124
125 /* As much as I'd like to make X509_check_purpose use a "const" X509*
126 * I really can't because it does recalculate hashes and do other non-const
127 * things. */
128 int
X509_check_purpose(X509 * x,int id,int ca)129 X509_check_purpose(X509 *x, int id, int ca)
130 {
131 int idx;
132 const X509_PURPOSE *pt;
133
134 if (!(x->ex_flags & EXFLAG_SET)) {
135 CRYPTO_w_lock(CRYPTO_LOCK_X509);
136 x509v3_cache_extensions(x);
137 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
138 if (x->ex_flags & EXFLAG_INVALID)
139 return -1;
140 }
141 if (id == -1)
142 return 1;
143 idx = X509_PURPOSE_get_by_id(id);
144 if (idx == -1)
145 return -1;
146 pt = X509_PURPOSE_get0(idx);
147 return pt->check_purpose(pt, x, ca);
148 }
149
150 int
X509_PURPOSE_set(int * p,int purpose)151 X509_PURPOSE_set(int *p, int purpose)
152 {
153 if (X509_PURPOSE_get_by_id(purpose) == -1) {
154 X509V3error(X509V3_R_INVALID_PURPOSE);
155 return 0;
156 }
157 *p = purpose;
158 return 1;
159 }
160
161 int
X509_PURPOSE_get_count(void)162 X509_PURPOSE_get_count(void)
163 {
164 if (!xptable)
165 return X509_PURPOSE_COUNT;
166 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
167 }
168
169 X509_PURPOSE *
X509_PURPOSE_get0(int idx)170 X509_PURPOSE_get0(int idx)
171 {
172 if (idx < 0)
173 return NULL;
174 if (idx < (int)X509_PURPOSE_COUNT)
175 return xstandard + idx;
176 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
177 }
178
179 int
X509_PURPOSE_get_by_sname(const char * sname)180 X509_PURPOSE_get_by_sname(const char *sname)
181 {
182 int i;
183 X509_PURPOSE *xptmp;
184
185 for (i = 0; i < X509_PURPOSE_get_count(); i++) {
186 xptmp = X509_PURPOSE_get0(i);
187 if (!strcmp(xptmp->sname, sname))
188 return i;
189 }
190 return -1;
191 }
192
193 int
X509_PURPOSE_get_by_id(int purpose)194 X509_PURPOSE_get_by_id(int purpose)
195 {
196 X509_PURPOSE tmp;
197 int idx;
198
199 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
200 return purpose - X509_PURPOSE_MIN;
201 tmp.purpose = purpose;
202 if (!xptable)
203 return -1;
204 idx = sk_X509_PURPOSE_find(xptable, &tmp);
205 if (idx == -1)
206 return -1;
207 return idx + X509_PURPOSE_COUNT;
208 }
209
210 int
X509_PURPOSE_add(int id,int trust,int flags,int (* ck)(const X509_PURPOSE *,const X509 *,int),const char * name,const char * sname,void * arg)211 X509_PURPOSE_add(int id, int trust, int flags,
212 int (*ck)(const X509_PURPOSE *, const X509 *, int), const char *name,
213 const char *sname, void *arg)
214 {
215 int idx;
216 X509_PURPOSE *ptmp;
217 char *name_dup, *sname_dup;
218
219 name_dup = sname_dup = NULL;
220
221 if (name == NULL || sname == NULL) {
222 X509V3error(X509V3_R_INVALID_NULL_ARGUMENT);
223 return 0;
224 }
225
226 /* This is set according to what we change: application can't set it */
227 flags &= ~X509_PURPOSE_DYNAMIC;
228 /* This will always be set for application modified trust entries */
229 flags |= X509_PURPOSE_DYNAMIC_NAME;
230 /* Get existing entry if any */
231 idx = X509_PURPOSE_get_by_id(id);
232 /* Need a new entry */
233 if (idx == -1) {
234 if ((ptmp = malloc(sizeof(X509_PURPOSE))) == NULL) {
235 X509V3error(ERR_R_MALLOC_FAILURE);
236 return 0;
237 }
238 ptmp->flags = X509_PURPOSE_DYNAMIC;
239 } else
240 ptmp = X509_PURPOSE_get0(idx);
241
242 if ((name_dup = strdup(name)) == NULL)
243 goto err;
244 if ((sname_dup = strdup(sname)) == NULL)
245 goto err;
246
247 /* free existing name if dynamic */
248 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
249 free(ptmp->name);
250 free(ptmp->sname);
251 }
252 /* dup supplied name */
253 ptmp->name = name_dup;
254 ptmp->sname = sname_dup;
255 /* Keep the dynamic flag of existing entry */
256 ptmp->flags &= X509_PURPOSE_DYNAMIC;
257 /* Set all other flags */
258 ptmp->flags |= flags;
259
260 ptmp->purpose = id;
261 ptmp->trust = trust;
262 ptmp->check_purpose = ck;
263 ptmp->usr_data = arg;
264
265 /* If its a new entry manage the dynamic table */
266 if (idx == -1) {
267 if (xptable == NULL &&
268 (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL)
269 goto err;
270 if (sk_X509_PURPOSE_push(xptable, ptmp) == 0)
271 goto err;
272 }
273 return 1;
274
275 err:
276 free(name_dup);
277 free(sname_dup);
278 if (idx == -1)
279 free(ptmp);
280 X509V3error(ERR_R_MALLOC_FAILURE);
281 return 0;
282 }
283
284 static void
xptable_free(X509_PURPOSE * p)285 xptable_free(X509_PURPOSE *p)
286 {
287 if (!p)
288 return;
289 if (p->flags & X509_PURPOSE_DYNAMIC) {
290 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
291 free(p->name);
292 free(p->sname);
293 }
294 free(p);
295 }
296 }
297
298 void
X509_PURPOSE_cleanup(void)299 X509_PURPOSE_cleanup(void)
300 {
301 sk_X509_PURPOSE_pop_free(xptable, xptable_free);
302 xptable = NULL;
303 }
304
305 int
X509_PURPOSE_get_id(const X509_PURPOSE * xp)306 X509_PURPOSE_get_id(const X509_PURPOSE *xp)
307 {
308 return xp->purpose;
309 }
310
311 char *
X509_PURPOSE_get0_name(const X509_PURPOSE * xp)312 X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
313 {
314 return xp->name;
315 }
316
317 char *
X509_PURPOSE_get0_sname(const X509_PURPOSE * xp)318 X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
319 {
320 return xp->sname;
321 }
322
323 int
X509_PURPOSE_get_trust(const X509_PURPOSE * xp)324 X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
325 {
326 return xp->trust;
327 }
328
329 static int
nid_cmp(const int * a,const int * b)330 nid_cmp(const int *a, const int *b)
331 {
332 return *a - *b;
333 }
334
335 static int nid_cmp_BSEARCH_CMP_FN(const void *, const void *);
336 static int nid_cmp(int const *, int const *);
337 static int *OBJ_bsearch_nid(int *key, int const *base, int num);
338
339 static int
nid_cmp_BSEARCH_CMP_FN(const void * a_,const void * b_)340 nid_cmp_BSEARCH_CMP_FN(const void *a_, const void *b_)
341 {
342 int const *a = a_;
343 int const *b = b_;
344 return nid_cmp(a, b);
345 }
346
347 static int *
OBJ_bsearch_nid(int * key,int const * base,int num)348 OBJ_bsearch_nid(int *key, int const *base, int num)
349 {
350 return (int *)OBJ_bsearch_(key, base, num, sizeof(int),
351 nid_cmp_BSEARCH_CMP_FN);
352 }
353
354 int
X509_supported_extension(X509_EXTENSION * ex)355 X509_supported_extension(X509_EXTENSION *ex)
356 {
357 /* This table is a list of the NIDs of supported extensions:
358 * that is those which are used by the verify process. If
359 * an extension is critical and doesn't appear in this list
360 * then the verify process will normally reject the certificate.
361 * The list must be kept in numerical order because it will be
362 * searched using bsearch.
363 */
364
365 static const int supported_nids[] = {
366 NID_netscape_cert_type, /* 71 */
367 NID_key_usage, /* 83 */
368 NID_subject_alt_name, /* 85 */
369 NID_basic_constraints, /* 87 */
370 NID_certificate_policies, /* 89 */
371 NID_ext_key_usage, /* 126 */
372 #ifndef OPENSSL_NO_RFC3779
373 NID_sbgp_ipAddrBlock, /* 290 */
374 NID_sbgp_autonomousSysNum, /* 291 */
375 #endif
376 NID_policy_constraints, /* 401 */
377 NID_proxyCertInfo, /* 663 */
378 NID_name_constraints, /* 666 */
379 NID_policy_mappings, /* 747 */
380 NID_inhibit_any_policy /* 748 */
381 };
382
383 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
384
385 if (ex_nid == NID_undef)
386 return 0;
387
388 if (OBJ_bsearch_nid(&ex_nid, supported_nids,
389 sizeof(supported_nids) / sizeof(int)))
390 return 1;
391 return 0;
392 }
393
394 static void
setup_dp(X509 * x,DIST_POINT * dp)395 setup_dp(X509 *x, DIST_POINT *dp)
396 {
397 X509_NAME *iname = NULL;
398 int i;
399
400 if (dp->reasons) {
401 if (dp->reasons->length > 0)
402 dp->dp_reasons = dp->reasons->data[0];
403 if (dp->reasons->length > 1)
404 dp->dp_reasons |= (dp->reasons->data[1] << 8);
405 dp->dp_reasons &= CRLDP_ALL_REASONS;
406 } else
407 dp->dp_reasons = CRLDP_ALL_REASONS;
408 if (!dp->distpoint || (dp->distpoint->type != 1))
409 return;
410 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
411 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
412 if (gen->type == GEN_DIRNAME) {
413 iname = gen->d.directoryName;
414 break;
415 }
416 }
417 if (!iname)
418 iname = X509_get_issuer_name(x);
419
420 DIST_POINT_set_dpname(dp->distpoint, iname);
421
422 }
423
424 static void
setup_crldp(X509 * x)425 setup_crldp(X509 *x)
426 {
427 int i;
428
429 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL);
430 if (x->crldp == NULL && i != -1) {
431 x->ex_flags |= EXFLAG_INVALID;
432 return;
433 }
434
435 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
436 setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
437 }
438
439 void
x509v3_cache_extensions(X509 * x)440 x509v3_cache_extensions(X509 *x)
441 {
442 BASIC_CONSTRAINTS *bs;
443 PROXY_CERT_INFO_EXTENSION *pci;
444 ASN1_BIT_STRING *usage;
445 ASN1_BIT_STRING *ns;
446 EXTENDED_KEY_USAGE *extusage;
447 X509_EXTENSION *ex;
448 int i;
449
450 if (x->ex_flags & EXFLAG_SET)
451 return;
452
453 X509_digest(x, X509_CERT_HASH_EVP, x->hash, NULL);
454
455 /* V1 should mean no extensions ... */
456 if (!X509_get_version(x))
457 x->ex_flags |= EXFLAG_V1;
458
459 /* Handle basic constraints */
460 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) {
461 if (bs->ca)
462 x->ex_flags |= EXFLAG_CA;
463 if (bs->pathlen) {
464 if ((bs->pathlen->type == V_ASN1_NEG_INTEGER) ||
465 !bs->ca) {
466 x->ex_flags |= EXFLAG_INVALID;
467 x->ex_pathlen = 0;
468 } else
469 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
470 } else
471 x->ex_pathlen = -1;
472 BASIC_CONSTRAINTS_free(bs);
473 x->ex_flags |= EXFLAG_BCONS;
474 } else if (i != -1) {
475 x->ex_flags |= EXFLAG_INVALID;
476 }
477
478 /* Handle proxy certificates */
479 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL))) {
480 if (x->ex_flags & EXFLAG_CA ||
481 X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 ||
482 X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
483 x->ex_flags |= EXFLAG_INVALID;
484 }
485 if (pci->pcPathLengthConstraint) {
486 if (pci->pcPathLengthConstraint->type ==
487 V_ASN1_NEG_INTEGER) {
488 x->ex_flags |= EXFLAG_INVALID;
489 x->ex_pcpathlen = 0;
490 } else
491 x->ex_pcpathlen =
492 ASN1_INTEGER_get(pci->
493 pcPathLengthConstraint);
494 } else
495 x->ex_pcpathlen = -1;
496 PROXY_CERT_INFO_EXTENSION_free(pci);
497 x->ex_flags |= EXFLAG_PROXY;
498 } else if (i != -1) {
499 x->ex_flags |= EXFLAG_INVALID;
500 }
501
502 /* Handle key usage */
503 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) {
504 if (usage->length > 0) {
505 x->ex_kusage = usage->data[0];
506 if (usage->length > 1)
507 x->ex_kusage |= usage->data[1] << 8;
508 } else
509 x->ex_kusage = 0;
510 x->ex_flags |= EXFLAG_KUSAGE;
511 ASN1_BIT_STRING_free(usage);
512 } else if (i != -1) {
513 x->ex_flags |= EXFLAG_INVALID;
514 }
515
516 x->ex_xkusage = 0;
517 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) {
518 x->ex_flags |= EXFLAG_XKUSAGE;
519 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
520 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
521 case NID_server_auth:
522 x->ex_xkusage |= XKU_SSL_SERVER;
523 break;
524
525 case NID_client_auth:
526 x->ex_xkusage |= XKU_SSL_CLIENT;
527 break;
528
529 case NID_email_protect:
530 x->ex_xkusage |= XKU_SMIME;
531 break;
532
533 case NID_code_sign:
534 x->ex_xkusage |= XKU_CODE_SIGN;
535 break;
536
537 case NID_ms_sgc:
538 case NID_ns_sgc:
539 x->ex_xkusage |= XKU_SGC;
540 break;
541
542 case NID_OCSP_sign:
543 x->ex_xkusage |= XKU_OCSP_SIGN;
544 break;
545
546 case NID_time_stamp:
547 x->ex_xkusage |= XKU_TIMESTAMP;
548 break;
549
550 case NID_dvcs:
551 x->ex_xkusage |= XKU_DVCS;
552 break;
553
554 case NID_anyExtendedKeyUsage:
555 x->ex_xkusage |= XKU_ANYEKU;
556 break;
557 }
558 }
559 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
560 } else if (i != -1) {
561 x->ex_flags |= EXFLAG_INVALID;
562 }
563
564 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) {
565 if (ns->length > 0)
566 x->ex_nscert = ns->data[0];
567 else
568 x->ex_nscert = 0;
569 x->ex_flags |= EXFLAG_NSCERT;
570 ASN1_BIT_STRING_free(ns);
571 } else if (i != -1) {
572 x->ex_flags |= EXFLAG_INVALID;
573 }
574
575 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
576 if (x->skid == NULL && i != -1)
577 x->ex_flags |= EXFLAG_INVALID;
578 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
579 if (x->akid == NULL && i != -1)
580 x->ex_flags |= EXFLAG_INVALID;
581
582 /* Does subject name match issuer? */
583 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
584 x->ex_flags |= EXFLAG_SI;
585 /* If SKID matches AKID also indicate self signed. */
586 if (X509_check_akid(x, x->akid) == X509_V_OK &&
587 !ku_reject(x, KU_KEY_CERT_SIGN))
588 x->ex_flags |= EXFLAG_SS;
589 }
590
591 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL);
592 if (x->altname == NULL && i != -1)
593 x->ex_flags |= EXFLAG_INVALID;
594 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
595 if (!x->nc && (i != -1))
596 x->ex_flags |= EXFLAG_INVALID;
597 setup_crldp(x);
598
599 #ifndef OPENSSL_NO_RFC3779
600 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL);
601 if (x->rfc3779_addr == NULL && i != -1)
602 x->ex_flags |= EXFLAG_INVALID;
603 if (!X509v3_addr_is_canonical(x->rfc3779_addr))
604 x->ex_flags |= EXFLAG_INVALID;
605 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
606 if (x->rfc3779_asid == NULL && i != -1)
607 x->ex_flags |= EXFLAG_INVALID;
608 if (!X509v3_asid_is_canonical(x->rfc3779_asid))
609 x->ex_flags |= EXFLAG_INVALID;
610 #endif
611
612 for (i = 0; i < X509_get_ext_count(x); i++) {
613 ex = X509_get_ext(x, i);
614 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) ==
615 NID_freshest_crl)
616 x->ex_flags |= EXFLAG_FRESHEST;
617 if (!X509_EXTENSION_get_critical(ex))
618 continue;
619 if (!X509_supported_extension(ex)) {
620 x->ex_flags |= EXFLAG_CRITICAL;
621 break;
622 }
623 }
624
625 x509_verify_cert_info_populate(x);
626
627 x->ex_flags |= EXFLAG_SET;
628 }
629
630 /* CA checks common to all purposes
631 * return codes:
632 * 0 not a CA
633 * 1 is a CA
634 * 2 basicConstraints absent so "maybe" a CA
635 * 3 basicConstraints absent but self signed V1.
636 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
637 */
638
639 static int
check_ca(const X509 * x)640 check_ca(const X509 *x)
641 {
642 /* keyUsage if present should allow cert signing */
643 if (ku_reject(x, KU_KEY_CERT_SIGN))
644 return 0;
645 if (x->ex_flags & EXFLAG_BCONS) {
646 if (x->ex_flags & EXFLAG_CA)
647 return 1;
648 /* If basicConstraints says not a CA then say so */
649 else
650 return 0;
651 } else {
652 /* we support V1 roots for... uh, I don't really know why. */
653 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
654 return 3;
655 /* If key usage present it must have certSign so tolerate it */
656 else if (x->ex_flags & EXFLAG_KUSAGE)
657 return 4;
658 /* Older certificates could have Netscape-specific CA types */
659 else if (x->ex_flags & EXFLAG_NSCERT &&
660 x->ex_nscert & NS_ANY_CA)
661 return 5;
662 /* can this still be regarded a CA certificate? I doubt it */
663 return 0;
664 }
665 }
666
667 int
X509_check_ca(X509 * x)668 X509_check_ca(X509 *x)
669 {
670 if (!(x->ex_flags & EXFLAG_SET)) {
671 CRYPTO_w_lock(CRYPTO_LOCK_X509);
672 x509v3_cache_extensions(x);
673 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
674 }
675
676 return check_ca(x);
677 }
678
679 /* Check SSL CA: common checks for SSL client and server */
680 static int
check_ssl_ca(const X509 * x)681 check_ssl_ca(const X509 *x)
682 {
683 int ca_ret;
684
685 ca_ret = check_ca(x);
686 if (!ca_ret)
687 return 0;
688 /* check nsCertType if present */
689 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
690 return ca_ret;
691 else
692 return 0;
693 }
694
695 static int
check_purpose_ssl_client(const X509_PURPOSE * xp,const X509 * x,int ca)696 check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
697 {
698 if (xku_reject(x, XKU_SSL_CLIENT))
699 return 0;
700 if (ca)
701 return check_ssl_ca(x);
702 /* We need to do digital signatures with it */
703 if (ku_reject(x, KU_DIGITAL_SIGNATURE))
704 return 0;
705 /* nsCertType if present should allow SSL client use */
706 if (ns_reject(x, NS_SSL_CLIENT))
707 return 0;
708 return 1;
709 }
710
711 static int
check_purpose_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)712 check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
713 {
714 if (xku_reject(x, XKU_SSL_SERVER|XKU_SGC))
715 return 0;
716 if (ca)
717 return check_ssl_ca(x);
718
719 if (ns_reject(x, NS_SSL_SERVER))
720 return 0;
721 /* Now as for keyUsage: we'll at least need to sign OR encipher */
722 if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT))
723 return 0;
724
725 return 1;
726 }
727
728 static int
check_purpose_ns_ssl_server(const X509_PURPOSE * xp,const X509 * x,int ca)729 check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
730 {
731 int ret;
732
733 ret = check_purpose_ssl_server(xp, x, ca);
734 if (!ret || ca)
735 return ret;
736 /* We need to encipher or Netscape complains */
737 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
738 return 0;
739 return ret;
740 }
741
742 /* common S/MIME checks */
743 static int
purpose_smime(const X509 * x,int ca)744 purpose_smime(const X509 *x, int ca)
745 {
746 if (xku_reject(x, XKU_SMIME))
747 return 0;
748 if (ca) {
749 int ca_ret;
750 ca_ret = check_ca(x);
751 if (!ca_ret)
752 return 0;
753 /* check nsCertType if present */
754 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
755 return ca_ret;
756 else
757 return 0;
758 }
759 if (x->ex_flags & EXFLAG_NSCERT) {
760 if (x->ex_nscert & NS_SMIME)
761 return 1;
762 /* Workaround for some buggy certificates */
763 if (x->ex_nscert & NS_SSL_CLIENT)
764 return 2;
765 return 0;
766 }
767 return 1;
768 }
769
770 static int
check_purpose_smime_sign(const X509_PURPOSE * xp,const X509 * x,int ca)771 check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
772 {
773 int ret;
774
775 ret = purpose_smime(x, ca);
776 if (!ret || ca)
777 return ret;
778 if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION))
779 return 0;
780 return ret;
781 }
782
783 static int
check_purpose_smime_encrypt(const X509_PURPOSE * xp,const X509 * x,int ca)784 check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
785 {
786 int ret;
787
788 ret = purpose_smime(x, ca);
789 if (!ret || ca)
790 return ret;
791 if (ku_reject(x, KU_KEY_ENCIPHERMENT))
792 return 0;
793 return ret;
794 }
795
796 static int
check_purpose_crl_sign(const X509_PURPOSE * xp,const X509 * x,int ca)797 check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
798 {
799 if (ca) {
800 int ca_ret;
801 if ((ca_ret = check_ca(x)) != 2)
802 return ca_ret;
803 else
804 return 0;
805 }
806 if (ku_reject(x, KU_CRL_SIGN))
807 return 0;
808 return 1;
809 }
810
811 /* OCSP helper: this is *not* a full OCSP check. It just checks that
812 * each CA is valid. Additional checks must be made on the chain.
813 */
814 static int
ocsp_helper(const X509_PURPOSE * xp,const X509 * x,int ca)815 ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
816 {
817 /* Must be a valid CA. Should we really support the "I don't know"
818 value (2)? */
819 if (ca)
820 return check_ca(x);
821 /* leaf certificate is checked in OCSP_verify() */
822 return 1;
823 }
824
825 static int
check_purpose_timestamp_sign(const X509_PURPOSE * xp,const X509 * x,int ca)826 check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
827 {
828 int i_ext;
829
830 /* If ca is true we must return if this is a valid CA certificate. */
831 if (ca)
832 return check_ca(x);
833
834 /*
835 * Check the optional key usage field:
836 * if Key Usage is present, it must be one of digitalSignature
837 * and/or nonRepudiation (other values are not consistent and shall
838 * be rejected).
839 */
840 if ((x->ex_flags & EXFLAG_KUSAGE) &&
841 ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
842 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
843 return 0;
844
845 /* Only time stamp key usage is permitted and it's required. */
846 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
847 return 0;
848
849 /* Extended Key Usage MUST be critical */
850 i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1);
851 if (i_ext >= 0) {
852 X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext);
853 if (!X509_EXTENSION_get_critical(ext))
854 return 0;
855 }
856
857 return 1;
858 }
859
860 static int
no_check(const X509_PURPOSE * xp,const X509 * x,int ca)861 no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
862 {
863 return 1;
864 }
865
866 /* Various checks to see if one certificate issued the second.
867 * This can be used to prune a set of possible issuer certificates
868 * which have been looked up using some simple method such as by
869 * subject name.
870 * These are:
871 * 1. Check issuer_name(subject) == subject_name(issuer)
872 * 2. If akid(subject) exists check it matches issuer
873 * 3. If key_usage(issuer) exists check it supports certificate signing
874 * returns 0 for OK, positive for reason for mismatch, reasons match
875 * codes for X509_verify_cert()
876 */
877
878 int
X509_check_issued(X509 * issuer,X509 * subject)879 X509_check_issued(X509 *issuer, X509 *subject)
880 {
881 if (X509_NAME_cmp(X509_get_subject_name(issuer),
882 X509_get_issuer_name(subject)))
883 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
884 if (!(issuer->ex_flags & EXFLAG_SET)) {
885 CRYPTO_w_lock(CRYPTO_LOCK_X509);
886 x509v3_cache_extensions(issuer);
887 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
888 }
889 if (issuer->ex_flags & EXFLAG_INVALID)
890 return X509_V_ERR_UNSPECIFIED;
891 if (!(subject->ex_flags & EXFLAG_SET)) {
892 CRYPTO_w_lock(CRYPTO_LOCK_X509);
893 x509v3_cache_extensions(subject);
894 CRYPTO_w_unlock(CRYPTO_LOCK_X509);
895 }
896 if (subject->ex_flags & EXFLAG_INVALID)
897 return X509_V_ERR_UNSPECIFIED;
898
899 if (subject->akid) {
900 int ret = X509_check_akid(issuer, subject->akid);
901 if (ret != X509_V_OK)
902 return ret;
903 }
904
905 if (subject->ex_flags & EXFLAG_PROXY) {
906 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
907 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
908 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN))
909 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
910 return X509_V_OK;
911 }
912
913 int
X509_check_akid(X509 * issuer,AUTHORITY_KEYID * akid)914 X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
915 {
916 if (!akid)
917 return X509_V_OK;
918
919 /* Check key ids (if present) */
920 if (akid->keyid && issuer->skid &&
921 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) )
922 return X509_V_ERR_AKID_SKID_MISMATCH;
923 /* Check serial number */
924 if (akid->serial &&
925 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
926 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
927 /* Check issuer name */
928 if (akid->issuer) {
929 /* Ugh, for some peculiar reason AKID includes
930 * SEQUENCE OF GeneralName. So look for a DirName.
931 * There may be more than one but we only take any
932 * notice of the first.
933 */
934 GENERAL_NAMES *gens;
935 GENERAL_NAME *gen;
936 X509_NAME *nm = NULL;
937 int i;
938 gens = akid->issuer;
939 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
940 gen = sk_GENERAL_NAME_value(gens, i);
941 if (gen->type == GEN_DIRNAME) {
942 nm = gen->d.dirn;
943 break;
944 }
945 }
946 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
947 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
948 }
949 return X509_V_OK;
950 }
951
952 uint32_t
X509_get_extension_flags(X509 * x)953 X509_get_extension_flags(X509 *x)
954 {
955 /* Call for side-effect of computing hash and caching extensions */
956 if (X509_check_purpose(x, -1, -1) != 1)
957 return EXFLAG_INVALID;
958
959 return x->ex_flags;
960 }
961
962 uint32_t
X509_get_key_usage(X509 * x)963 X509_get_key_usage(X509 *x)
964 {
965 /* Call for side-effect of computing hash and caching extensions */
966 if (X509_check_purpose(x, -1, -1) != 1)
967 return 0;
968
969 if (x->ex_flags & EXFLAG_KUSAGE)
970 return x->ex_kusage;
971
972 return UINT32_MAX;
973 }
974
975 uint32_t
X509_get_extended_key_usage(X509 * x)976 X509_get_extended_key_usage(X509 *x)
977 {
978 /* Call for side-effect of computing hash and caching extensions */
979 if (X509_check_purpose(x, -1, -1) != 1)
980 return 0;
981
982 if (x->ex_flags & EXFLAG_XKUSAGE)
983 return x->ex_xkusage;
984
985 return UINT32_MAX;
986 }
987