1 | /* |
2 | * Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved. |
3 | * |
4 | * Licensed under the Apache License 2.0 (the "License"). You may not use |
5 | * this file except in compliance with the License. You can obtain a copy |
6 | * in the file LICENSE in the source distribution or at |
7 | * https://www.openssl.org/source/license.html |
8 | */ |
9 | |
10 | #include <stdio.h> |
11 | #include "internal/cryptlib.h" |
12 | #include "internal/numbers.h" |
13 | #include <openssl/x509v3.h> |
14 | #include <openssl/x509_vfy.h> |
15 | #include "crypto/x509.h" |
16 | #include "internal/tsan_assist.h" |
17 | |
18 | static void x509v3_cache_extensions(X509 *x); |
19 | |
20 | static int check_ssl_ca(const X509 *x); |
21 | static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, |
22 | int ca); |
23 | static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
24 | int ca); |
25 | static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
26 | int ca); |
27 | static int purpose_smime(const X509 *x, int ca); |
28 | static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, |
29 | int ca); |
30 | static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, |
31 | int ca); |
32 | static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, |
33 | int ca); |
34 | static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, |
35 | int ca); |
36 | static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); |
37 | static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); |
38 | |
39 | static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b); |
40 | static void xptable_free(X509_PURPOSE *p); |
41 | |
42 | static X509_PURPOSE xstandard[] = { |
43 | {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, |
44 | check_purpose_ssl_client, "SSL client" , "sslclient" , NULL}, |
45 | {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, |
46 | check_purpose_ssl_server, "SSL server" , "sslserver" , NULL}, |
47 | {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, |
48 | check_purpose_ns_ssl_server, "Netscape SSL server" , "nssslserver" , NULL}, |
49 | {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, |
50 | "S/MIME signing" , "smimesign" , NULL}, |
51 | {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, |
52 | check_purpose_smime_encrypt, "S/MIME encryption" , "smimeencrypt" , NULL}, |
53 | {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, |
54 | "CRL signing" , "crlsign" , NULL}, |
55 | {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose" , "any" , |
56 | NULL}, |
57 | {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, |
58 | "OCSP helper" , "ocsphelper" , NULL}, |
59 | {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, |
60 | check_purpose_timestamp_sign, "Time Stamp signing" , "timestampsign" , |
61 | NULL}, |
62 | }; |
63 | |
64 | #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard) |
65 | |
66 | static STACK_OF(X509_PURPOSE) *xptable = NULL; |
67 | |
68 | static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b) |
69 | { |
70 | return (*a)->purpose - (*b)->purpose; |
71 | } |
72 | |
73 | /* |
74 | * As much as I'd like to make X509_check_purpose use a "const" X509* I |
75 | * really can't because it does recalculate hashes and do other non-const |
76 | * things. |
77 | */ |
78 | int X509_check_purpose(X509 *x, int id, int ca) |
79 | { |
80 | int idx; |
81 | const X509_PURPOSE *pt; |
82 | |
83 | x509v3_cache_extensions(x); |
84 | |
85 | /* Return if side-effect only call */ |
86 | if (id == -1) |
87 | return 1; |
88 | idx = X509_PURPOSE_get_by_id(id); |
89 | if (idx == -1) |
90 | return -1; |
91 | pt = X509_PURPOSE_get0(idx); |
92 | return pt->check_purpose(pt, x, ca); |
93 | } |
94 | |
95 | int X509_PURPOSE_set(int *p, int purpose) |
96 | { |
97 | if (X509_PURPOSE_get_by_id(purpose) == -1) { |
98 | X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE); |
99 | return 0; |
100 | } |
101 | *p = purpose; |
102 | return 1; |
103 | } |
104 | |
105 | int X509_PURPOSE_get_count(void) |
106 | { |
107 | if (!xptable) |
108 | return X509_PURPOSE_COUNT; |
109 | return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; |
110 | } |
111 | |
112 | X509_PURPOSE *X509_PURPOSE_get0(int idx) |
113 | { |
114 | if (idx < 0) |
115 | return NULL; |
116 | if (idx < (int)X509_PURPOSE_COUNT) |
117 | return xstandard + idx; |
118 | return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); |
119 | } |
120 | |
121 | int X509_PURPOSE_get_by_sname(const char *sname) |
122 | { |
123 | int i; |
124 | X509_PURPOSE *xptmp; |
125 | for (i = 0; i < X509_PURPOSE_get_count(); i++) { |
126 | xptmp = X509_PURPOSE_get0(i); |
127 | if (strcmp(xptmp->sname, sname) == 0) |
128 | return i; |
129 | } |
130 | return -1; |
131 | } |
132 | |
133 | int X509_PURPOSE_get_by_id(int purpose) |
134 | { |
135 | X509_PURPOSE tmp; |
136 | int idx; |
137 | |
138 | if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) |
139 | return purpose - X509_PURPOSE_MIN; |
140 | if (xptable == NULL) |
141 | return -1; |
142 | tmp.purpose = purpose; |
143 | idx = sk_X509_PURPOSE_find(xptable, &tmp); |
144 | if (idx < 0) |
145 | return -1; |
146 | return idx + X509_PURPOSE_COUNT; |
147 | } |
148 | |
149 | int X509_PURPOSE_add(int id, int trust, int flags, |
150 | int (*ck) (const X509_PURPOSE *, const X509 *, int), |
151 | const char *name, const char *sname, void *arg) |
152 | { |
153 | int idx; |
154 | X509_PURPOSE *ptmp; |
155 | /* |
156 | * This is set according to what we change: application can't set it |
157 | */ |
158 | flags &= ~X509_PURPOSE_DYNAMIC; |
159 | /* This will always be set for application modified trust entries */ |
160 | flags |= X509_PURPOSE_DYNAMIC_NAME; |
161 | /* Get existing entry if any */ |
162 | idx = X509_PURPOSE_get_by_id(id); |
163 | /* Need a new entry */ |
164 | if (idx == -1) { |
165 | if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) { |
166 | X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE); |
167 | return 0; |
168 | } |
169 | ptmp->flags = X509_PURPOSE_DYNAMIC; |
170 | } else |
171 | ptmp = X509_PURPOSE_get0(idx); |
172 | |
173 | /* OPENSSL_free existing name if dynamic */ |
174 | if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { |
175 | OPENSSL_free(ptmp->name); |
176 | OPENSSL_free(ptmp->sname); |
177 | } |
178 | /* dup supplied name */ |
179 | ptmp->name = OPENSSL_strdup(name); |
180 | ptmp->sname = OPENSSL_strdup(sname); |
181 | if (ptmp->name == NULL|| ptmp->sname == NULL) { |
182 | X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE); |
183 | goto err; |
184 | } |
185 | /* Keep the dynamic flag of existing entry */ |
186 | ptmp->flags &= X509_PURPOSE_DYNAMIC; |
187 | /* Set all other flags */ |
188 | ptmp->flags |= flags; |
189 | |
190 | ptmp->purpose = id; |
191 | ptmp->trust = trust; |
192 | ptmp->check_purpose = ck; |
193 | ptmp->usr_data = arg; |
194 | |
195 | /* If its a new entry manage the dynamic table */ |
196 | if (idx == -1) { |
197 | if (xptable == NULL |
198 | && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) { |
199 | X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE); |
200 | goto err; |
201 | } |
202 | if (!sk_X509_PURPOSE_push(xptable, ptmp)) { |
203 | X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE); |
204 | goto err; |
205 | } |
206 | } |
207 | return 1; |
208 | err: |
209 | if (idx == -1) { |
210 | OPENSSL_free(ptmp->name); |
211 | OPENSSL_free(ptmp->sname); |
212 | OPENSSL_free(ptmp); |
213 | } |
214 | return 0; |
215 | } |
216 | |
217 | static void xptable_free(X509_PURPOSE *p) |
218 | { |
219 | if (p == NULL) |
220 | return; |
221 | if (p->flags & X509_PURPOSE_DYNAMIC) { |
222 | if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { |
223 | OPENSSL_free(p->name); |
224 | OPENSSL_free(p->sname); |
225 | } |
226 | OPENSSL_free(p); |
227 | } |
228 | } |
229 | |
230 | void X509_PURPOSE_cleanup(void) |
231 | { |
232 | sk_X509_PURPOSE_pop_free(xptable, xptable_free); |
233 | xptable = NULL; |
234 | } |
235 | |
236 | int X509_PURPOSE_get_id(const X509_PURPOSE *xp) |
237 | { |
238 | return xp->purpose; |
239 | } |
240 | |
241 | char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp) |
242 | { |
243 | return xp->name; |
244 | } |
245 | |
246 | char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp) |
247 | { |
248 | return xp->sname; |
249 | } |
250 | |
251 | int X509_PURPOSE_get_trust(const X509_PURPOSE *xp) |
252 | { |
253 | return xp->trust; |
254 | } |
255 | |
256 | static int nid_cmp(const int *a, const int *b) |
257 | { |
258 | return *a - *b; |
259 | } |
260 | |
261 | DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid); |
262 | IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid); |
263 | |
264 | int X509_supported_extension(X509_EXTENSION *ex) |
265 | { |
266 | /* |
267 | * This table is a list of the NIDs of supported extensions: that is |
268 | * those which are used by the verify process. If an extension is |
269 | * critical and doesn't appear in this list then the verify process will |
270 | * normally reject the certificate. The list must be kept in numerical |
271 | * order because it will be searched using bsearch. |
272 | */ |
273 | |
274 | static const int supported_nids[] = { |
275 | NID_netscape_cert_type, /* 71 */ |
276 | NID_key_usage, /* 83 */ |
277 | NID_subject_alt_name, /* 85 */ |
278 | NID_basic_constraints, /* 87 */ |
279 | NID_certificate_policies, /* 89 */ |
280 | NID_crl_distribution_points, /* 103 */ |
281 | NID_ext_key_usage, /* 126 */ |
282 | #ifndef OPENSSL_NO_RFC3779 |
283 | NID_sbgp_ipAddrBlock, /* 290 */ |
284 | NID_sbgp_autonomousSysNum, /* 291 */ |
285 | #endif |
286 | NID_policy_constraints, /* 401 */ |
287 | NID_proxyCertInfo, /* 663 */ |
288 | NID_name_constraints, /* 666 */ |
289 | NID_policy_mappings, /* 747 */ |
290 | NID_inhibit_any_policy /* 748 */ |
291 | }; |
292 | |
293 | int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); |
294 | |
295 | if (ex_nid == NID_undef) |
296 | return 0; |
297 | |
298 | if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids))) |
299 | return 1; |
300 | return 0; |
301 | } |
302 | |
303 | static void setup_dp(X509 *x, DIST_POINT *dp) |
304 | { |
305 | X509_NAME *iname = NULL; |
306 | int i; |
307 | if (dp->reasons) { |
308 | if (dp->reasons->length > 0) |
309 | dp->dp_reasons = dp->reasons->data[0]; |
310 | if (dp->reasons->length > 1) |
311 | dp->dp_reasons |= (dp->reasons->data[1] << 8); |
312 | dp->dp_reasons &= CRLDP_ALL_REASONS; |
313 | } else |
314 | dp->dp_reasons = CRLDP_ALL_REASONS; |
315 | if (!dp->distpoint || (dp->distpoint->type != 1)) |
316 | return; |
317 | for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { |
318 | GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); |
319 | if (gen->type == GEN_DIRNAME) { |
320 | iname = gen->d.directoryName; |
321 | break; |
322 | } |
323 | } |
324 | if (!iname) |
325 | iname = X509_get_issuer_name(x); |
326 | |
327 | DIST_POINT_set_dpname(dp->distpoint, iname); |
328 | |
329 | } |
330 | |
331 | static void setup_crldp(X509 *x) |
332 | { |
333 | int i; |
334 | x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL); |
335 | for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) |
336 | setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); |
337 | } |
338 | |
339 | #define V1_ROOT (EXFLAG_V1|EXFLAG_SS) |
340 | #define ku_reject(x, usage) \ |
341 | (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage))) |
342 | #define xku_reject(x, usage) \ |
343 | (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage))) |
344 | #define ns_reject(x, usage) \ |
345 | (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage))) |
346 | |
347 | static void x509v3_cache_extensions(X509 *x) |
348 | { |
349 | BASIC_CONSTRAINTS *bs; |
350 | PROXY_CERT_INFO_EXTENSION *pci; |
351 | ASN1_BIT_STRING *usage; |
352 | ASN1_BIT_STRING *ns; |
353 | EXTENDED_KEY_USAGE *extusage; |
354 | X509_EXTENSION *ex; |
355 | int i; |
356 | |
357 | #ifdef tsan_ld_acq |
358 | /* fast lock-free check, see end of the function for details. */ |
359 | if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached)) |
360 | return; |
361 | #endif |
362 | |
363 | CRYPTO_THREAD_write_lock(x->lock); |
364 | if (x->ex_flags & EXFLAG_SET) { |
365 | CRYPTO_THREAD_unlock(x->lock); |
366 | return; |
367 | } |
368 | |
369 | X509_digest(x, EVP_sha1(), x->sha1_hash, NULL); |
370 | /* V1 should mean no extensions ... */ |
371 | if (!X509_get_version(x)) |
372 | x->ex_flags |= EXFLAG_V1; |
373 | /* Handle basic constraints */ |
374 | if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) { |
375 | if (bs->ca) |
376 | x->ex_flags |= EXFLAG_CA; |
377 | if (bs->pathlen) { |
378 | if ((bs->pathlen->type == V_ASN1_NEG_INTEGER) |
379 | || !bs->ca) { |
380 | x->ex_flags |= EXFLAG_INVALID; |
381 | x->ex_pathlen = 0; |
382 | } else |
383 | x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); |
384 | } else |
385 | x->ex_pathlen = -1; |
386 | BASIC_CONSTRAINTS_free(bs); |
387 | x->ex_flags |= EXFLAG_BCONS; |
388 | } |
389 | /* Handle proxy certificates */ |
390 | if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) { |
391 | if (x->ex_flags & EXFLAG_CA |
392 | || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 |
393 | || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) { |
394 | x->ex_flags |= EXFLAG_INVALID; |
395 | } |
396 | if (pci->pcPathLengthConstraint) { |
397 | x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint); |
398 | } else |
399 | x->ex_pcpathlen = -1; |
400 | PROXY_CERT_INFO_EXTENSION_free(pci); |
401 | x->ex_flags |= EXFLAG_PROXY; |
402 | } |
403 | /* Handle key usage */ |
404 | if ((usage = X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) { |
405 | if (usage->length > 0) { |
406 | x->ex_kusage = usage->data[0]; |
407 | if (usage->length > 1) |
408 | x->ex_kusage |= usage->data[1] << 8; |
409 | } else |
410 | x->ex_kusage = 0; |
411 | x->ex_flags |= EXFLAG_KUSAGE; |
412 | ASN1_BIT_STRING_free(usage); |
413 | } |
414 | x->ex_xkusage = 0; |
415 | if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) { |
416 | x->ex_flags |= EXFLAG_XKUSAGE; |
417 | for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { |
418 | switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) { |
419 | case NID_server_auth: |
420 | x->ex_xkusage |= XKU_SSL_SERVER; |
421 | break; |
422 | |
423 | case NID_client_auth: |
424 | x->ex_xkusage |= XKU_SSL_CLIENT; |
425 | break; |
426 | |
427 | case NID_email_protect: |
428 | x->ex_xkusage |= XKU_SMIME; |
429 | break; |
430 | |
431 | case NID_code_sign: |
432 | x->ex_xkusage |= XKU_CODE_SIGN; |
433 | break; |
434 | |
435 | case NID_ms_sgc: |
436 | case NID_ns_sgc: |
437 | x->ex_xkusage |= XKU_SGC; |
438 | break; |
439 | |
440 | case NID_OCSP_sign: |
441 | x->ex_xkusage |= XKU_OCSP_SIGN; |
442 | break; |
443 | |
444 | case NID_time_stamp: |
445 | x->ex_xkusage |= XKU_TIMESTAMP; |
446 | break; |
447 | |
448 | case NID_dvcs: |
449 | x->ex_xkusage |= XKU_DVCS; |
450 | break; |
451 | |
452 | case NID_anyExtendedKeyUsage: |
453 | x->ex_xkusage |= XKU_ANYEKU; |
454 | break; |
455 | } |
456 | } |
457 | sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); |
458 | } |
459 | |
460 | if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) { |
461 | if (ns->length > 0) |
462 | x->ex_nscert = ns->data[0]; |
463 | else |
464 | x->ex_nscert = 0; |
465 | x->ex_flags |= EXFLAG_NSCERT; |
466 | ASN1_BIT_STRING_free(ns); |
467 | } |
468 | x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL); |
469 | x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL); |
470 | /* Does subject name match issuer ? */ |
471 | if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) { |
472 | x->ex_flags |= EXFLAG_SI; |
473 | /* If SKID matches AKID also indicate self signed */ |
474 | if (X509_check_akid(x, x->akid) == X509_V_OK && |
475 | !ku_reject(x, KU_KEY_CERT_SIGN)) |
476 | x->ex_flags |= EXFLAG_SS; |
477 | } |
478 | x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); |
479 | x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL); |
480 | if (!x->nc && (i != -1)) |
481 | x->ex_flags |= EXFLAG_INVALID; |
482 | setup_crldp(x); |
483 | |
484 | #ifndef OPENSSL_NO_RFC3779 |
485 | x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL); |
486 | x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, |
487 | NULL, NULL); |
488 | #endif |
489 | for (i = 0; i < X509_get_ext_count(x); i++) { |
490 | ex = X509_get_ext(x, i); |
491 | if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) |
492 | == NID_freshest_crl) |
493 | x->ex_flags |= EXFLAG_FRESHEST; |
494 | if (!X509_EXTENSION_get_critical(ex)) |
495 | continue; |
496 | if (!X509_supported_extension(ex)) { |
497 | x->ex_flags |= EXFLAG_CRITICAL; |
498 | break; |
499 | } |
500 | } |
501 | x509_init_sig_info(x); |
502 | x->ex_flags |= EXFLAG_SET; |
503 | #ifdef tsan_st_rel |
504 | tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1); |
505 | /* |
506 | * Above store triggers fast lock-free check in the beginning of the |
507 | * function. But one has to ensure that the structure is "stable", i.e. |
508 | * all stores are visible on all processors. Hence the release fence. |
509 | */ |
510 | #endif |
511 | CRYPTO_THREAD_unlock(x->lock); |
512 | } |
513 | |
514 | /*- |
515 | * CA checks common to all purposes |
516 | * return codes: |
517 | * 0 not a CA |
518 | * 1 is a CA |
519 | * 2 basicConstraints absent so "maybe" a CA |
520 | * 3 basicConstraints absent but self signed V1. |
521 | * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. |
522 | */ |
523 | |
524 | static int check_ca(const X509 *x) |
525 | { |
526 | /* keyUsage if present should allow cert signing */ |
527 | if (ku_reject(x, KU_KEY_CERT_SIGN)) |
528 | return 0; |
529 | if (x->ex_flags & EXFLAG_BCONS) { |
530 | if (x->ex_flags & EXFLAG_CA) |
531 | return 1; |
532 | /* If basicConstraints says not a CA then say so */ |
533 | else |
534 | return 0; |
535 | } else { |
536 | /* we support V1 roots for... uh, I don't really know why. */ |
537 | if ((x->ex_flags & V1_ROOT) == V1_ROOT) |
538 | return 3; |
539 | /* |
540 | * If key usage present it must have certSign so tolerate it |
541 | */ |
542 | else if (x->ex_flags & EXFLAG_KUSAGE) |
543 | return 4; |
544 | /* Older certificates could have Netscape-specific CA types */ |
545 | else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA) |
546 | return 5; |
547 | /* can this still be regarded a CA certificate? I doubt it */ |
548 | return 0; |
549 | } |
550 | } |
551 | |
552 | void X509_set_proxy_flag(X509 *x) |
553 | { |
554 | x->ex_flags |= EXFLAG_PROXY; |
555 | } |
556 | |
557 | void X509_set_proxy_pathlen(X509 *x, long l) |
558 | { |
559 | x->ex_pcpathlen = l; |
560 | } |
561 | |
562 | int X509_check_ca(X509 *x) |
563 | { |
564 | x509v3_cache_extensions(x); |
565 | |
566 | return check_ca(x); |
567 | } |
568 | |
569 | /* Check SSL CA: common checks for SSL client and server */ |
570 | static int check_ssl_ca(const X509 *x) |
571 | { |
572 | int ca_ret; |
573 | ca_ret = check_ca(x); |
574 | if (!ca_ret) |
575 | return 0; |
576 | /* check nsCertType if present */ |
577 | if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA) |
578 | return ca_ret; |
579 | else |
580 | return 0; |
581 | } |
582 | |
583 | static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, |
584 | int ca) |
585 | { |
586 | if (xku_reject(x, XKU_SSL_CLIENT)) |
587 | return 0; |
588 | if (ca) |
589 | return check_ssl_ca(x); |
590 | /* We need to do digital signatures or key agreement */ |
591 | if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT)) |
592 | return 0; |
593 | /* nsCertType if present should allow SSL client use */ |
594 | if (ns_reject(x, NS_SSL_CLIENT)) |
595 | return 0; |
596 | return 1; |
597 | } |
598 | |
599 | /* |
600 | * Key usage needed for TLS/SSL server: digital signature, encipherment or |
601 | * key agreement. The ssl code can check this more thoroughly for individual |
602 | * key types. |
603 | */ |
604 | #define KU_TLS \ |
605 | KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT |
606 | |
607 | static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
608 | int ca) |
609 | { |
610 | if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC)) |
611 | return 0; |
612 | if (ca) |
613 | return check_ssl_ca(x); |
614 | |
615 | if (ns_reject(x, NS_SSL_SERVER)) |
616 | return 0; |
617 | if (ku_reject(x, KU_TLS)) |
618 | return 0; |
619 | |
620 | return 1; |
621 | |
622 | } |
623 | |
624 | static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, |
625 | int ca) |
626 | { |
627 | int ret; |
628 | ret = check_purpose_ssl_server(xp, x, ca); |
629 | if (!ret || ca) |
630 | return ret; |
631 | /* We need to encipher or Netscape complains */ |
632 | if (ku_reject(x, KU_KEY_ENCIPHERMENT)) |
633 | return 0; |
634 | return ret; |
635 | } |
636 | |
637 | /* common S/MIME checks */ |
638 | static int purpose_smime(const X509 *x, int ca) |
639 | { |
640 | if (xku_reject(x, XKU_SMIME)) |
641 | return 0; |
642 | if (ca) { |
643 | int ca_ret; |
644 | ca_ret = check_ca(x); |
645 | if (!ca_ret) |
646 | return 0; |
647 | /* check nsCertType if present */ |
648 | if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) |
649 | return ca_ret; |
650 | else |
651 | return 0; |
652 | } |
653 | if (x->ex_flags & EXFLAG_NSCERT) { |
654 | if (x->ex_nscert & NS_SMIME) |
655 | return 1; |
656 | /* Workaround for some buggy certificates */ |
657 | if (x->ex_nscert & NS_SSL_CLIENT) |
658 | return 2; |
659 | return 0; |
660 | } |
661 | return 1; |
662 | } |
663 | |
664 | static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, |
665 | int ca) |
666 | { |
667 | int ret; |
668 | ret = purpose_smime(x, ca); |
669 | if (!ret || ca) |
670 | return ret; |
671 | if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION)) |
672 | return 0; |
673 | return ret; |
674 | } |
675 | |
676 | static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, |
677 | int ca) |
678 | { |
679 | int ret; |
680 | ret = purpose_smime(x, ca); |
681 | if (!ret || ca) |
682 | return ret; |
683 | if (ku_reject(x, KU_KEY_ENCIPHERMENT)) |
684 | return 0; |
685 | return ret; |
686 | } |
687 | |
688 | static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, |
689 | int ca) |
690 | { |
691 | if (ca) { |
692 | int ca_ret; |
693 | if ((ca_ret = check_ca(x)) != 2) |
694 | return ca_ret; |
695 | else |
696 | return 0; |
697 | } |
698 | if (ku_reject(x, KU_CRL_SIGN)) |
699 | return 0; |
700 | return 1; |
701 | } |
702 | |
703 | /* |
704 | * OCSP helper: this is *not* a full OCSP check. It just checks that each CA |
705 | * is valid. Additional checks must be made on the chain. |
706 | */ |
707 | |
708 | static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) |
709 | { |
710 | /* |
711 | * Must be a valid CA. Should we really support the "I don't know" value |
712 | * (2)? |
713 | */ |
714 | if (ca) |
715 | return check_ca(x); |
716 | /* leaf certificate is checked in OCSP_verify() */ |
717 | return 1; |
718 | } |
719 | |
720 | static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, |
721 | int ca) |
722 | { |
723 | int i_ext; |
724 | |
725 | /* If ca is true we must return if this is a valid CA certificate. */ |
726 | if (ca) |
727 | return check_ca(x); |
728 | |
729 | /* |
730 | * Check the optional key usage field: |
731 | * if Key Usage is present, it must be one of digitalSignature |
732 | * and/or nonRepudiation (other values are not consistent and shall |
733 | * be rejected). |
734 | */ |
735 | if ((x->ex_flags & EXFLAG_KUSAGE) |
736 | && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || |
737 | !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) |
738 | return 0; |
739 | |
740 | /* Only time stamp key usage is permitted and it's required. */ |
741 | if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) |
742 | return 0; |
743 | |
744 | /* Extended Key Usage MUST be critical */ |
745 | i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1); |
746 | if (i_ext >= 0) { |
747 | X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext); |
748 | if (!X509_EXTENSION_get_critical(ext)) |
749 | return 0; |
750 | } |
751 | |
752 | return 1; |
753 | } |
754 | |
755 | static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca) |
756 | { |
757 | return 1; |
758 | } |
759 | |
760 | /*- |
761 | * Various checks to see if one certificate issued the second. |
762 | * This can be used to prune a set of possible issuer certificates |
763 | * which have been looked up using some simple method such as by |
764 | * subject name. |
765 | * These are: |
766 | * 1. Check issuer_name(subject) == subject_name(issuer) |
767 | * 2. If akid(subject) exists, check that it matches issuer |
768 | * 3. Check that issuer public key algorithm matches subject signature algorithm |
769 | * 4. If key_usage(issuer) exists, check that it supports certificate signing |
770 | * returns 0 for OK, positive for reason for mismatch, reasons match |
771 | * codes for X509_verify_cert() |
772 | */ |
773 | |
774 | int X509_check_issued(X509 *issuer, X509 *subject) |
775 | { |
776 | if (X509_NAME_cmp(X509_get_subject_name(issuer), |
777 | X509_get_issuer_name(subject))) |
778 | return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; |
779 | |
780 | x509v3_cache_extensions(issuer); |
781 | x509v3_cache_extensions(subject); |
782 | |
783 | if (subject->akid) { |
784 | int ret = X509_check_akid(issuer, subject->akid); |
785 | if (ret != X509_V_OK) |
786 | return ret; |
787 | } |
788 | |
789 | { |
790 | /* |
791 | * Check if the subject signature algorithm matches the issuer's PUBKEY |
792 | * algorithm |
793 | */ |
794 | EVP_PKEY *i_pkey = X509_get0_pubkey(issuer); |
795 | X509_ALGOR *s_algor = &subject->cert_info.signature; |
796 | int s_pknid = NID_undef, s_mdnid = NID_undef; |
797 | |
798 | if (i_pkey == NULL) |
799 | return X509_V_ERR_NO_ISSUER_PUBLIC_KEY; |
800 | |
801 | if (!OBJ_find_sigid_algs(OBJ_obj2nid(s_algor->algorithm), |
802 | &s_mdnid, &s_pknid) |
803 | || EVP_PKEY_type(s_pknid) != EVP_PKEY_base_id(i_pkey)) |
804 | return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH; |
805 | } |
806 | |
807 | if (subject->ex_flags & EXFLAG_PROXY) { |
808 | if (ku_reject(issuer, KU_DIGITAL_SIGNATURE)) |
809 | return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE; |
810 | } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) |
811 | return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; |
812 | return X509_V_OK; |
813 | } |
814 | |
815 | int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) |
816 | { |
817 | |
818 | if (!akid) |
819 | return X509_V_OK; |
820 | |
821 | /* Check key ids (if present) */ |
822 | if (akid->keyid && issuer->skid && |
823 | ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid)) |
824 | return X509_V_ERR_AKID_SKID_MISMATCH; |
825 | /* Check serial number */ |
826 | if (akid->serial && |
827 | ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) |
828 | return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; |
829 | /* Check issuer name */ |
830 | if (akid->issuer) { |
831 | /* |
832 | * Ugh, for some peculiar reason AKID includes SEQUENCE OF |
833 | * GeneralName. So look for a DirName. There may be more than one but |
834 | * we only take any notice of the first. |
835 | */ |
836 | GENERAL_NAMES *gens; |
837 | GENERAL_NAME *gen; |
838 | X509_NAME *nm = NULL; |
839 | int i; |
840 | gens = akid->issuer; |
841 | for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { |
842 | gen = sk_GENERAL_NAME_value(gens, i); |
843 | if (gen->type == GEN_DIRNAME) { |
844 | nm = gen->d.dirn; |
845 | break; |
846 | } |
847 | } |
848 | if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) |
849 | return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; |
850 | } |
851 | return X509_V_OK; |
852 | } |
853 | |
854 | uint32_t X509_get_extension_flags(X509 *x) |
855 | { |
856 | /* Call for side-effect of computing hash and caching extensions */ |
857 | X509_check_purpose(x, -1, -1); |
858 | return x->ex_flags; |
859 | } |
860 | |
861 | uint32_t X509_get_key_usage(X509 *x) |
862 | { |
863 | /* Call for side-effect of computing hash and caching extensions */ |
864 | X509_check_purpose(x, -1, -1); |
865 | if (x->ex_flags & EXFLAG_KUSAGE) |
866 | return x->ex_kusage; |
867 | return UINT32_MAX; |
868 | } |
869 | |
870 | uint32_t X509_get_extended_key_usage(X509 *x) |
871 | { |
872 | /* Call for side-effect of computing hash and caching extensions */ |
873 | X509_check_purpose(x, -1, -1); |
874 | if (x->ex_flags & EXFLAG_XKUSAGE) |
875 | return x->ex_xkusage; |
876 | return UINT32_MAX; |
877 | } |
878 | |
879 | const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x) |
880 | { |
881 | /* Call for side-effect of computing hash and caching extensions */ |
882 | X509_check_purpose(x, -1, -1); |
883 | return x->skid; |
884 | } |
885 | |
886 | const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x) |
887 | { |
888 | /* Call for side-effect of computing hash and caching extensions */ |
889 | X509_check_purpose(x, -1, -1); |
890 | return (x->akid != NULL ? x->akid->keyid : NULL); |
891 | } |
892 | |
893 | const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x) |
894 | { |
895 | /* Call for side-effect of computing hash and caching extensions */ |
896 | X509_check_purpose(x, -1, -1); |
897 | return (x->akid != NULL ? x->akid->issuer : NULL); |
898 | } |
899 | |
900 | const ASN1_INTEGER *X509_get0_authority_serial(X509 *x) |
901 | { |
902 | /* Call for side-effect of computing hash and caching extensions */ |
903 | X509_check_purpose(x, -1, -1); |
904 | return (x->akid != NULL ? x->akid->serial : NULL); |
905 | } |
906 | |
907 | long X509_get_pathlen(X509 *x) |
908 | { |
909 | /* Called for side effect of caching extensions */ |
910 | if (X509_check_purpose(x, -1, -1) != 1 |
911 | || (x->ex_flags & EXFLAG_BCONS) == 0) |
912 | return -1; |
913 | return x->ex_pathlen; |
914 | } |
915 | |
916 | long X509_get_proxy_pathlen(X509 *x) |
917 | { |
918 | /* Called for side effect of caching extensions */ |
919 | if (X509_check_purpose(x, -1, -1) != 1 |
920 | || (x->ex_flags & EXFLAG_PROXY) == 0) |
921 | return -1; |
922 | return x->ex_pcpathlen; |
923 | } |
924 | |