1 | /* v3_purp.c */ |
2 | /* |
3 | * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project |
4 | * 2001. |
5 | */ |
6 | /* ==================================================================== |
7 | * Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved. |
8 | * |
9 | * Redistribution and use in source and binary forms, with or without |
10 | * modification, are permitted provided that the following conditions |
11 | * are met: |
12 | * |
13 | * 1. Redistributions of source code must retain the above copyright |
14 | * notice, this list of conditions and the following disclaimer. |
15 | * |
16 | * 2. Redistributions in binary form must reproduce the above copyright |
17 | * notice, this list of conditions and the following disclaimer in |
18 | * the documentation and/or other materials provided with the |
19 | * distribution. |
20 | * |
21 | * 3. All advertising materials mentioning features or use of this |
22 | * software must display the following acknowledgment: |
23 | * "This product includes software developed by the OpenSSL Project |
24 | * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" |
25 | * |
26 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
27 | * endorse or promote products derived from this software without |
28 | * prior written permission. For written permission, please contact |
29 | * licensing@OpenSSL.org. |
30 | * |
31 | * 5. Products derived from this software may not be called "OpenSSL" |
32 | * nor may "OpenSSL" appear in their names without prior written |
33 | * permission of the OpenSSL Project. |
34 | * |
35 | * 6. Redistributions of any form whatsoever must retain the following |
36 | * acknowledgment: |
37 | * "This product includes software developed by the OpenSSL Project |
38 | * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" |
39 | * |
40 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
41 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
43 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
44 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
45 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
46 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
47 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
49 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
50 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
51 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
52 | * ==================================================================== |
53 | * |
54 | * This product includes cryptographic software written by Eric Young |
55 | * (eay@cryptsoft.com). This product includes software written by Tim |
56 | * Hudson (tjh@cryptsoft.com). */ |
57 | |
58 | #include <stdio.h> |
59 | |
60 | #include <string.h> |
61 | |
62 | #include <openssl/buf.h> |
63 | #include <openssl/err.h> |
64 | #include <openssl/digest.h> |
65 | #include <openssl/mem.h> |
66 | #include <openssl/obj.h> |
67 | #include <openssl/thread.h> |
68 | #include <openssl/x509_vfy.h> |
69 | #include <openssl/x509v3.h> |
70 | |
71 | #include "../internal.h" |
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_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, |
84 | int ca); |
85 | static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
86 | int ca); |
87 | static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
88 | int ca); |
89 | static int purpose_smime(const X509 *x, int ca); |
90 | static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, |
91 | int ca); |
92 | static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, |
93 | int ca); |
94 | static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, |
95 | int ca); |
96 | static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, |
97 | int ca); |
98 | static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); |
99 | static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); |
100 | |
101 | static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b); |
102 | static void xptable_free(X509_PURPOSE *p); |
103 | |
104 | static X509_PURPOSE xstandard[] = { |
105 | {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, |
106 | check_purpose_ssl_client, (char *)"SSL client" , (char *)"sslclient" , |
107 | NULL}, |
108 | {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, |
109 | check_purpose_ssl_server, (char *)"SSL server" , (char *)"sslserver" , |
110 | NULL}, |
111 | {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, |
112 | check_purpose_ns_ssl_server, (char *)"Netscape SSL server" , |
113 | (char *)"nssslserver" , NULL}, |
114 | {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, |
115 | (char *)"S/MIME signing" , (char *)"smimesign" , NULL}, |
116 | {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, |
117 | check_purpose_smime_encrypt, (char *)"S/MIME encryption" , |
118 | (char *)"smimeencrypt" , NULL}, |
119 | {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, |
120 | (char *)"CRL signing" , (char *)"crlsign" , NULL}, |
121 | {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, (char *)"Any Purpose" , |
122 | (char *)"any" , NULL}, |
123 | {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, |
124 | (char *)"OCSP helper" , (char *)"ocsphelper" , NULL}, |
125 | {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, |
126 | check_purpose_timestamp_sign, (char *)"Time Stamp signing" , |
127 | (char *)"timestampsign" , NULL}, |
128 | }; |
129 | |
130 | #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE)) |
131 | |
132 | static STACK_OF(X509_PURPOSE) *xptable = NULL; |
133 | |
134 | static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b) |
135 | { |
136 | return (*a)->purpose - (*b)->purpose; |
137 | } |
138 | |
139 | /* |
140 | * As much as I'd like to make X509_check_purpose use a "const" X509* I |
141 | * really can't because it does recalculate hashes and do other non-const |
142 | * things. |
143 | */ |
144 | int X509_check_purpose(X509 *x, int id, int ca) |
145 | { |
146 | int idx; |
147 | const X509_PURPOSE *pt; |
148 | x509v3_cache_extensions(x); |
149 | if (id == -1) |
150 | return 1; |
151 | idx = X509_PURPOSE_get_by_id(id); |
152 | if (idx == -1) |
153 | return -1; |
154 | pt = X509_PURPOSE_get0(idx); |
155 | return pt->check_purpose(pt, x, ca); |
156 | } |
157 | |
158 | int X509_PURPOSE_set(int *p, int purpose) |
159 | { |
160 | if (X509_PURPOSE_get_by_id(purpose) == -1) { |
161 | OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_PURPOSE); |
162 | return 0; |
163 | } |
164 | *p = purpose; |
165 | return 1; |
166 | } |
167 | |
168 | int X509_PURPOSE_get_count(void) |
169 | { |
170 | if (!xptable) |
171 | return X509_PURPOSE_COUNT; |
172 | return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; |
173 | } |
174 | |
175 | X509_PURPOSE *X509_PURPOSE_get0(int idx) |
176 | { |
177 | if (idx < 0) |
178 | return NULL; |
179 | if (idx < (int)X509_PURPOSE_COUNT) |
180 | return xstandard + idx; |
181 | return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); |
182 | } |
183 | |
184 | int X509_PURPOSE_get_by_sname(char *sname) |
185 | { |
186 | int i; |
187 | X509_PURPOSE *xptmp; |
188 | for (i = 0; i < X509_PURPOSE_get_count(); i++) { |
189 | xptmp = X509_PURPOSE_get0(i); |
190 | if (!strcmp(xptmp->sname, sname)) |
191 | return i; |
192 | } |
193 | return -1; |
194 | } |
195 | |
196 | int X509_PURPOSE_get_by_id(int purpose) |
197 | { |
198 | X509_PURPOSE tmp; |
199 | size_t idx; |
200 | |
201 | if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) |
202 | return purpose - X509_PURPOSE_MIN; |
203 | tmp.purpose = purpose; |
204 | if (!xptable) |
205 | return -1; |
206 | |
207 | sk_X509_PURPOSE_sort(xptable); |
208 | if (!sk_X509_PURPOSE_find(xptable, &idx, &tmp)) |
209 | return -1; |
210 | return idx + X509_PURPOSE_COUNT; |
211 | } |
212 | |
213 | int X509_PURPOSE_add(int id, int trust, int flags, |
214 | int (*ck) (const X509_PURPOSE *, const X509 *, int), |
215 | char *name, char *sname, void *arg) |
216 | { |
217 | int idx; |
218 | X509_PURPOSE *ptmp; |
219 | char *name_dup, *sname_dup; |
220 | |
221 | /* |
222 | * This is set according to what we change: application can't set it |
223 | */ |
224 | flags &= ~X509_PURPOSE_DYNAMIC; |
225 | /* This will always be set for application modified trust entries */ |
226 | flags |= X509_PURPOSE_DYNAMIC_NAME; |
227 | /* Get existing entry if any */ |
228 | idx = X509_PURPOSE_get_by_id(id); |
229 | /* Need a new entry */ |
230 | if (idx == -1) { |
231 | if (!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) { |
232 | OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE); |
233 | return 0; |
234 | } |
235 | ptmp->flags = X509_PURPOSE_DYNAMIC; |
236 | } else |
237 | ptmp = X509_PURPOSE_get0(idx); |
238 | |
239 | /* Duplicate the supplied names. */ |
240 | name_dup = BUF_strdup(name); |
241 | sname_dup = BUF_strdup(sname); |
242 | if (name_dup == NULL || sname_dup == NULL) { |
243 | OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE); |
244 | if (name_dup != NULL) |
245 | OPENSSL_free(name_dup); |
246 | if (sname_dup != NULL) |
247 | OPENSSL_free(sname_dup); |
248 | if (idx == -1) |
249 | OPENSSL_free(ptmp); |
250 | return 0; |
251 | } |
252 | |
253 | /* OPENSSL_free existing name if dynamic */ |
254 | if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { |
255 | OPENSSL_free(ptmp->name); |
256 | OPENSSL_free(ptmp->sname); |
257 | } |
258 | /* dup supplied name */ |
259 | ptmp->name = name_dup; |
260 | ptmp->sname = sname_dup; |
261 | /* Keep the dynamic flag of existing entry */ |
262 | ptmp->flags &= X509_PURPOSE_DYNAMIC; |
263 | /* Set all other flags */ |
264 | ptmp->flags |= flags; |
265 | |
266 | ptmp->purpose = id; |
267 | ptmp->trust = trust; |
268 | ptmp->check_purpose = ck; |
269 | ptmp->usr_data = arg; |
270 | |
271 | /* If its a new entry manage the dynamic table */ |
272 | if (idx == -1) { |
273 | if (!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) { |
274 | OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE); |
275 | xptable_free(ptmp); |
276 | return 0; |
277 | } |
278 | if (!sk_X509_PURPOSE_push(xptable, ptmp)) { |
279 | OPENSSL_PUT_ERROR(X509V3, ERR_R_MALLOC_FAILURE); |
280 | xptable_free(ptmp); |
281 | return 0; |
282 | } |
283 | } |
284 | return 1; |
285 | } |
286 | |
287 | static void xptable_free(X509_PURPOSE *p) |
288 | { |
289 | if (!p) |
290 | return; |
291 | if (p->flags & X509_PURPOSE_DYNAMIC) { |
292 | if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { |
293 | OPENSSL_free(p->name); |
294 | OPENSSL_free(p->sname); |
295 | } |
296 | OPENSSL_free(p); |
297 | } |
298 | } |
299 | |
300 | void X509_PURPOSE_cleanup(void) |
301 | { |
302 | unsigned int i; |
303 | sk_X509_PURPOSE_pop_free(xptable, xptable_free); |
304 | for (i = 0; i < X509_PURPOSE_COUNT; i++) |
305 | xptable_free(xstandard + i); |
306 | xptable = NULL; |
307 | } |
308 | |
309 | int X509_PURPOSE_get_id(X509_PURPOSE *xp) |
310 | { |
311 | return xp->purpose; |
312 | } |
313 | |
314 | char *X509_PURPOSE_get0_name(X509_PURPOSE *xp) |
315 | { |
316 | return xp->name; |
317 | } |
318 | |
319 | char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp) |
320 | { |
321 | return xp->sname; |
322 | } |
323 | |
324 | int X509_PURPOSE_get_trust(X509_PURPOSE *xp) |
325 | { |
326 | return xp->trust; |
327 | } |
328 | |
329 | static int nid_cmp(const void *void_a, const void *void_b) |
330 | { |
331 | const int *a = void_a, *b = void_b; |
332 | |
333 | return *a - *b; |
334 | } |
335 | |
336 | int X509_supported_extension(X509_EXTENSION *ex) |
337 | { |
338 | /* |
339 | * This table is a list of the NIDs of supported extensions: that is |
340 | * those which are used by the verify process. If an extension is |
341 | * critical and doesn't appear in this list then the verify process will |
342 | * normally reject the certificate. The list must be kept in numerical |
343 | * order because it will be searched using bsearch. |
344 | */ |
345 | |
346 | static const int supported_nids[] = { |
347 | NID_netscape_cert_type, /* 71 */ |
348 | NID_key_usage, /* 83 */ |
349 | NID_subject_alt_name, /* 85 */ |
350 | NID_basic_constraints, /* 87 */ |
351 | NID_certificate_policies, /* 89 */ |
352 | NID_ext_key_usage, /* 126 */ |
353 | NID_policy_constraints, /* 401 */ |
354 | NID_proxyCertInfo, /* 663 */ |
355 | NID_name_constraints, /* 666 */ |
356 | NID_policy_mappings, /* 747 */ |
357 | NID_inhibit_any_policy /* 748 */ |
358 | }; |
359 | |
360 | int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); |
361 | |
362 | if (ex_nid == NID_undef) |
363 | return 0; |
364 | |
365 | if (bsearch |
366 | (&ex_nid, supported_nids, sizeof(supported_nids) / sizeof(int), |
367 | sizeof(int), nid_cmp) != NULL) |
368 | return 1; |
369 | return 0; |
370 | } |
371 | |
372 | static void setup_dp(X509 *x, DIST_POINT *dp) |
373 | { |
374 | X509_NAME *iname = NULL; |
375 | size_t i; |
376 | if (dp->reasons) { |
377 | if (dp->reasons->length > 0) |
378 | dp->dp_reasons = dp->reasons->data[0]; |
379 | if (dp->reasons->length > 1) |
380 | dp->dp_reasons |= (dp->reasons->data[1] << 8); |
381 | dp->dp_reasons &= CRLDP_ALL_REASONS; |
382 | } else |
383 | dp->dp_reasons = CRLDP_ALL_REASONS; |
384 | if (!dp->distpoint || (dp->distpoint->type != 1)) |
385 | return; |
386 | for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { |
387 | GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); |
388 | if (gen->type == GEN_DIRNAME) { |
389 | iname = gen->d.directoryName; |
390 | break; |
391 | } |
392 | } |
393 | if (!iname) |
394 | iname = X509_get_issuer_name(x); |
395 | |
396 | DIST_POINT_set_dpname(dp->distpoint, iname); |
397 | |
398 | } |
399 | |
400 | static void setup_crldp(X509 *x) |
401 | { |
402 | size_t i; |
403 | x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL); |
404 | for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) |
405 | setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); |
406 | } |
407 | |
408 | static void x509v3_cache_extensions(X509 *x) |
409 | { |
410 | BASIC_CONSTRAINTS *bs; |
411 | PROXY_CERT_INFO_EXTENSION *pci; |
412 | ASN1_BIT_STRING *usage; |
413 | ASN1_BIT_STRING *ns; |
414 | EXTENDED_KEY_USAGE *extusage; |
415 | X509_EXTENSION *ex; |
416 | size_t i; |
417 | int j; |
418 | |
419 | CRYPTO_MUTEX_lock_read(&x->lock); |
420 | const int is_set = x->ex_flags & EXFLAG_SET; |
421 | CRYPTO_MUTEX_unlock_read(&x->lock); |
422 | |
423 | if (is_set) { |
424 | return; |
425 | } |
426 | |
427 | CRYPTO_MUTEX_lock_write(&x->lock); |
428 | if (x->ex_flags & EXFLAG_SET) { |
429 | CRYPTO_MUTEX_unlock_write(&x->lock); |
430 | return; |
431 | } |
432 | |
433 | X509_digest(x, EVP_sha1(), x->sha1_hash, NULL); |
434 | /* V1 should mean no extensions ... */ |
435 | if (!X509_get_version(x)) |
436 | x->ex_flags |= EXFLAG_V1; |
437 | /* Handle basic constraints */ |
438 | if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) { |
439 | if (bs->ca) |
440 | x->ex_flags |= EXFLAG_CA; |
441 | if (bs->pathlen) { |
442 | if ((bs->pathlen->type == V_ASN1_NEG_INTEGER) |
443 | || !bs->ca) { |
444 | x->ex_flags |= EXFLAG_INVALID; |
445 | x->ex_pathlen = 0; |
446 | } else |
447 | x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); |
448 | } else |
449 | x->ex_pathlen = -1; |
450 | BASIC_CONSTRAINTS_free(bs); |
451 | x->ex_flags |= EXFLAG_BCONS; |
452 | } |
453 | /* Handle proxy certificates */ |
454 | if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) { |
455 | if (x->ex_flags & EXFLAG_CA |
456 | || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 |
457 | || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) { |
458 | x->ex_flags |= EXFLAG_INVALID; |
459 | } |
460 | if (pci->pcPathLengthConstraint) { |
461 | x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint); |
462 | } else |
463 | x->ex_pcpathlen = -1; |
464 | PROXY_CERT_INFO_EXTENSION_free(pci); |
465 | x->ex_flags |= EXFLAG_PROXY; |
466 | } |
467 | /* Handle key usage */ |
468 | if ((usage = X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) { |
469 | if (usage->length > 0) { |
470 | x->ex_kusage = usage->data[0]; |
471 | if (usage->length > 1) |
472 | x->ex_kusage |= usage->data[1] << 8; |
473 | } else |
474 | x->ex_kusage = 0; |
475 | x->ex_flags |= EXFLAG_KUSAGE; |
476 | ASN1_BIT_STRING_free(usage); |
477 | } |
478 | x->ex_xkusage = 0; |
479 | if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) { |
480 | x->ex_flags |= EXFLAG_XKUSAGE; |
481 | for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { |
482 | switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) { |
483 | case NID_server_auth: |
484 | x->ex_xkusage |= XKU_SSL_SERVER; |
485 | break; |
486 | |
487 | case NID_client_auth: |
488 | x->ex_xkusage |= XKU_SSL_CLIENT; |
489 | break; |
490 | |
491 | case NID_email_protect: |
492 | x->ex_xkusage |= XKU_SMIME; |
493 | break; |
494 | |
495 | case NID_code_sign: |
496 | x->ex_xkusage |= XKU_CODE_SIGN; |
497 | break; |
498 | |
499 | case NID_ms_sgc: |
500 | case NID_ns_sgc: |
501 | x->ex_xkusage |= XKU_SGC; |
502 | break; |
503 | |
504 | case NID_OCSP_sign: |
505 | x->ex_xkusage |= XKU_OCSP_SIGN; |
506 | break; |
507 | |
508 | case NID_time_stamp: |
509 | x->ex_xkusage |= XKU_TIMESTAMP; |
510 | break; |
511 | |
512 | case NID_dvcs: |
513 | x->ex_xkusage |= XKU_DVCS; |
514 | break; |
515 | |
516 | case NID_anyExtendedKeyUsage: |
517 | x->ex_xkusage |= XKU_ANYEKU; |
518 | break; |
519 | } |
520 | } |
521 | sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); |
522 | } |
523 | |
524 | if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) { |
525 | if (ns->length > 0) |
526 | x->ex_nscert = ns->data[0]; |
527 | else |
528 | x->ex_nscert = 0; |
529 | x->ex_flags |= EXFLAG_NSCERT; |
530 | ASN1_BIT_STRING_free(ns); |
531 | } |
532 | x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL); |
533 | x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL); |
534 | /* Does subject name match issuer ? */ |
535 | if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) { |
536 | x->ex_flags |= EXFLAG_SI; |
537 | /* If SKID matches AKID also indicate self signed */ |
538 | if (X509_check_akid(x, x->akid) == X509_V_OK && |
539 | !ku_reject(x, KU_KEY_CERT_SIGN)) |
540 | x->ex_flags |= EXFLAG_SS; |
541 | } |
542 | x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); |
543 | x->nc = X509_get_ext_d2i(x, NID_name_constraints, &j, NULL); |
544 | if (!x->nc && (j != -1)) |
545 | x->ex_flags |= EXFLAG_INVALID; |
546 | setup_crldp(x); |
547 | |
548 | for (j = 0; j < X509_get_ext_count(x); j++) { |
549 | ex = X509_get_ext(x, j); |
550 | if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) |
551 | == NID_freshest_crl) |
552 | x->ex_flags |= EXFLAG_FRESHEST; |
553 | if (!X509_EXTENSION_get_critical(ex)) |
554 | continue; |
555 | if (!X509_supported_extension(ex)) { |
556 | x->ex_flags |= EXFLAG_CRITICAL; |
557 | break; |
558 | } |
559 | } |
560 | x->ex_flags |= EXFLAG_SET; |
561 | |
562 | CRYPTO_MUTEX_unlock_write(&x->lock); |
563 | } |
564 | |
565 | /* check_ca returns one if |x| should be considered a CA certificate and zero |
566 | * otherwise. */ |
567 | static int check_ca(const X509 *x) |
568 | { |
569 | /* keyUsage if present should allow cert signing */ |
570 | if (ku_reject(x, KU_KEY_CERT_SIGN)) |
571 | return 0; |
572 | /* Version 1 certificates are considered CAs and don't have extensions. */ |
573 | if ((x->ex_flags & V1_ROOT) == V1_ROOT) { |
574 | return 1; |
575 | } |
576 | /* Otherwise, it's only a CA if basicConstraints says so. */ |
577 | return ((x->ex_flags & EXFLAG_BCONS) && |
578 | (x->ex_flags & EXFLAG_CA)); |
579 | } |
580 | |
581 | int X509_check_ca(X509 *x) |
582 | { |
583 | x509v3_cache_extensions(x); |
584 | return check_ca(x); |
585 | } |
586 | |
587 | static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, |
588 | int ca) |
589 | { |
590 | if (xku_reject(x, XKU_SSL_CLIENT)) |
591 | return 0; |
592 | if (ca) |
593 | return check_ca(x); |
594 | /* We need to do digital signatures or key agreement */ |
595 | if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT)) |
596 | return 0; |
597 | /* nsCertType if present should allow SSL client use */ |
598 | if (ns_reject(x, NS_SSL_CLIENT)) |
599 | return 0; |
600 | return 1; |
601 | } |
602 | |
603 | /* |
604 | * Key usage needed for TLS/SSL server: digital signature, encipherment or |
605 | * key agreement. The ssl code can check this more thoroughly for individual |
606 | * key types. |
607 | */ |
608 | #define KU_TLS \ |
609 | (KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT) |
610 | |
611 | static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
612 | int ca) |
613 | { |
614 | if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC)) |
615 | return 0; |
616 | if (ca) |
617 | return check_ca(x); |
618 | |
619 | if (ns_reject(x, NS_SSL_SERVER)) |
620 | return 0; |
621 | if (ku_reject(x, KU_TLS)) |
622 | return 0; |
623 | |
624 | return 1; |
625 | |
626 | } |
627 | |
628 | static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
629 | int ca) |
630 | { |
631 | int ret; |
632 | ret = check_purpose_ssl_server(xp, x, ca); |
633 | if (!ret || ca) |
634 | return ret; |
635 | /* We need to encipher or Netscape complains */ |
636 | if (ku_reject(x, KU_KEY_ENCIPHERMENT)) |
637 | return 0; |
638 | return ret; |
639 | } |
640 | |
641 | /* purpose_smime returns one if |x| is a valid S/MIME leaf (|ca| is zero) or CA |
642 | * (|ca| is one) certificate, and zero otherwise. */ |
643 | static int purpose_smime(const X509 *x, int ca) |
644 | { |
645 | if (xku_reject(x, XKU_SMIME)) |
646 | return 0; |
647 | if (ca) { |
648 | /* check nsCertType if present */ |
649 | if ((x->ex_flags & EXFLAG_NSCERT) && |
650 | (x->ex_nscert & NS_SMIME_CA) == 0) { |
651 | return 0; |
652 | } |
653 | |
654 | return check_ca(x); |
655 | } |
656 | if (x->ex_flags & EXFLAG_NSCERT) { |
657 | return (x->ex_nscert & NS_SMIME) == NS_SMIME; |
658 | } |
659 | return 1; |
660 | } |
661 | |
662 | static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, |
663 | int ca) |
664 | { |
665 | int ret; |
666 | ret = purpose_smime(x, ca); |
667 | if (!ret || ca) |
668 | return ret; |
669 | if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION)) |
670 | return 0; |
671 | return ret; |
672 | } |
673 | |
674 | static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, |
675 | int ca) |
676 | { |
677 | int ret; |
678 | ret = purpose_smime(x, ca); |
679 | if (!ret || ca) |
680 | return ret; |
681 | if (ku_reject(x, KU_KEY_ENCIPHERMENT)) |
682 | return 0; |
683 | return ret; |
684 | } |
685 | |
686 | static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, |
687 | int ca) |
688 | { |
689 | if (ca) { |
690 | return check_ca(x); |
691 | } |
692 | if (ku_reject(x, KU_CRL_SIGN)) |
693 | return 0; |
694 | return 1; |
695 | } |
696 | |
697 | /* |
698 | * OCSP helper: this is *not* a full OCSP check. It just checks that each CA |
699 | * is valid. Additional checks must be made on the chain. |
700 | */ |
701 | |
702 | static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) |
703 | { |
704 | if (ca) |
705 | return check_ca(x); |
706 | /* leaf certificate is checked in OCSP_verify() */ |
707 | return 1; |
708 | } |
709 | |
710 | static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, |
711 | int ca) |
712 | { |
713 | int i_ext; |
714 | |
715 | /* If ca is true we must return if this is a valid CA certificate. */ |
716 | if (ca) |
717 | return check_ca(x); |
718 | |
719 | /* |
720 | * Check the optional key usage field: |
721 | * if Key Usage is present, it must be one of digitalSignature |
722 | * and/or nonRepudiation (other values are not consistent and shall |
723 | * be rejected). |
724 | */ |
725 | if ((x->ex_flags & EXFLAG_KUSAGE) |
726 | && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || |
727 | !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) |
728 | return 0; |
729 | |
730 | /* Only time stamp key usage is permitted and it's required. */ |
731 | if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) |
732 | return 0; |
733 | |
734 | /* Extended Key Usage MUST be critical */ |
735 | i_ext = X509_get_ext_by_NID((X509 *)x, NID_ext_key_usage, -1); |
736 | if (i_ext >= 0) { |
737 | X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext); |
738 | if (!X509_EXTENSION_get_critical(ext)) |
739 | return 0; |
740 | } |
741 | |
742 | return 1; |
743 | } |
744 | |
745 | static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca) |
746 | { |
747 | return 1; |
748 | } |
749 | |
750 | /* |
751 | * Various checks to see if one certificate issued the second. This can be |
752 | * used to prune a set of possible issuer certificates which have been looked |
753 | * up using some simple method such as by subject name. These are: 1. Check |
754 | * issuer_name(subject) == subject_name(issuer) 2. If akid(subject) exists |
755 | * check it matches issuer 3. If key_usage(issuer) exists check it supports |
756 | * certificate signing returns 0 for OK, positive for reason for mismatch, |
757 | * reasons match codes for X509_verify_cert() |
758 | */ |
759 | |
760 | int X509_check_issued(X509 *issuer, X509 *subject) |
761 | { |
762 | if (X509_NAME_cmp(X509_get_subject_name(issuer), |
763 | X509_get_issuer_name(subject))) |
764 | return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; |
765 | x509v3_cache_extensions(issuer); |
766 | x509v3_cache_extensions(subject); |
767 | |
768 | if (subject->akid) { |
769 | int ret = X509_check_akid(issuer, subject->akid); |
770 | if (ret != X509_V_OK) |
771 | return ret; |
772 | } |
773 | |
774 | if (subject->ex_flags & EXFLAG_PROXY) { |
775 | if (ku_reject(issuer, KU_DIGITAL_SIGNATURE)) |
776 | return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE; |
777 | } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) |
778 | return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; |
779 | return X509_V_OK; |
780 | } |
781 | |
782 | int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) |
783 | { |
784 | |
785 | if (!akid) |
786 | return X509_V_OK; |
787 | |
788 | /* Check key ids (if present) */ |
789 | if (akid->keyid && issuer->skid && |
790 | ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid)) |
791 | return X509_V_ERR_AKID_SKID_MISMATCH; |
792 | /* Check serial number */ |
793 | if (akid->serial && |
794 | ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) |
795 | return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; |
796 | /* Check issuer name */ |
797 | if (akid->issuer) { |
798 | /* |
799 | * Ugh, for some peculiar reason AKID includes SEQUENCE OF |
800 | * GeneralName. So look for a DirName. There may be more than one but |
801 | * we only take any notice of the first. |
802 | */ |
803 | GENERAL_NAMES *gens; |
804 | GENERAL_NAME *gen; |
805 | X509_NAME *nm = NULL; |
806 | size_t i; |
807 | gens = akid->issuer; |
808 | for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { |
809 | gen = sk_GENERAL_NAME_value(gens, i); |
810 | if (gen->type == GEN_DIRNAME) { |
811 | nm = gen->d.dirn; |
812 | break; |
813 | } |
814 | } |
815 | if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) |
816 | return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; |
817 | } |
818 | return X509_V_OK; |
819 | } |
820 | |
821 | uint32_t X509_get_extension_flags(X509 *x) |
822 | { |
823 | /* Call for side-effect of computing hash and caching extensions */ |
824 | X509_check_purpose(x, -1, -1); |
825 | return x->ex_flags; |
826 | } |
827 | |
828 | uint32_t X509_get_key_usage(X509 *x) |
829 | { |
830 | /* Call for side-effect of computing hash and caching extensions */ |
831 | X509_check_purpose(x, -1, -1); |
832 | if (x->ex_flags & EXFLAG_KUSAGE) |
833 | return x->ex_kusage; |
834 | return UINT32_MAX; |
835 | } |
836 | |
837 | uint32_t X509_get_extended_key_usage(X509 *x) |
838 | { |
839 | /* Call for side-effect of computing hash and caching extensions */ |
840 | X509_check_purpose(x, -1, -1); |
841 | if (x->ex_flags & EXFLAG_XKUSAGE) |
842 | return x->ex_xkusage; |
843 | return UINT32_MAX; |
844 | } |
845 | |