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v3_purp.c 23 KB

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  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. */
  58. #include <stdio.h>
  59. #include "cryptlib.h"
  60. #include <openssl/x509v3.h>
  61. #include <openssl/x509_vfy.h>
  62. static void x509v3_cache_extensions(X509 *x);
  63. static int check_ssl_ca(const X509 *x);
  64. static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca);
  65. static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
  66. static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
  67. static int purpose_smime(const X509 *x, int ca);
  68. static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
  69. static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca);
  70. static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
  71. static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
  72. static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
  73. static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
  74. static int xp_cmp(const X509_PURPOSE * const *a,
  75. const X509_PURPOSE * const *b);
  76. static void xptable_free(X509_PURPOSE *p);
  77. static X509_PURPOSE xstandard[] = {
  78. {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
  79. {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
  80. {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
  81. {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
  82. {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
  83. {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
  84. {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL},
  85. {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL},
  86. {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", NULL},
  87. };
  88. #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
  89. IMPLEMENT_STACK_OF(X509_PURPOSE)
  90. static STACK_OF(X509_PURPOSE) *xptable = NULL;
  91. static int xp_cmp(const X509_PURPOSE * const *a,
  92. const X509_PURPOSE * const *b)
  93. {
  94. return (*a)->purpose - (*b)->purpose;
  95. }
  96. /* As much as I'd like to make X509_check_purpose use a "const" X509*
  97. * I really can't because it does recalculate hashes and do other non-const
  98. * things. */
  99. int X509_check_purpose(X509 *x, int id, int ca)
  100. {
  101. int idx;
  102. const X509_PURPOSE *pt;
  103. if(!(x->ex_flags & EXFLAG_SET)) {
  104. CRYPTO_w_lock(CRYPTO_LOCK_X509);
  105. x509v3_cache_extensions(x);
  106. CRYPTO_w_unlock(CRYPTO_LOCK_X509);
  107. }
  108. if(id == -1) return 1;
  109. idx = X509_PURPOSE_get_by_id(id);
  110. if(idx == -1) return -1;
  111. pt = X509_PURPOSE_get0(idx);
  112. return pt->check_purpose(pt, x, ca);
  113. }
  114. int X509_PURPOSE_set(int *p, int purpose)
  115. {
  116. if(X509_PURPOSE_get_by_id(purpose) == -1) {
  117. X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
  118. return 0;
  119. }
  120. *p = purpose;
  121. return 1;
  122. }
  123. int X509_PURPOSE_get_count(void)
  124. {
  125. if(!xptable) return X509_PURPOSE_COUNT;
  126. return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
  127. }
  128. X509_PURPOSE * X509_PURPOSE_get0(int idx)
  129. {
  130. if(idx < 0) return NULL;
  131. if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx;
  132. return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
  133. }
  134. int X509_PURPOSE_get_by_sname(char *sname)
  135. {
  136. int i;
  137. X509_PURPOSE *xptmp;
  138. for(i = 0; i < X509_PURPOSE_get_count(); i++) {
  139. xptmp = X509_PURPOSE_get0(i);
  140. if(!strcmp(xptmp->sname, sname)) return i;
  141. }
  142. return -1;
  143. }
  144. int X509_PURPOSE_get_by_id(int purpose)
  145. {
  146. X509_PURPOSE tmp;
  147. int idx;
  148. if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
  149. return purpose - X509_PURPOSE_MIN;
  150. tmp.purpose = purpose;
  151. if(!xptable) return -1;
  152. idx = sk_X509_PURPOSE_find(xptable, &tmp);
  153. if(idx == -1) return -1;
  154. return idx + X509_PURPOSE_COUNT;
  155. }
  156. int X509_PURPOSE_add(int id, int trust, int flags,
  157. int (*ck)(const X509_PURPOSE *, const X509 *, int),
  158. char *name, char *sname, void *arg)
  159. {
  160. int idx;
  161. X509_PURPOSE *ptmp;
  162. /* This is set according to what we change: application can't set it */
  163. flags &= ~X509_PURPOSE_DYNAMIC;
  164. /* This will always be set for application modified trust entries */
  165. flags |= X509_PURPOSE_DYNAMIC_NAME;
  166. /* Get existing entry if any */
  167. idx = X509_PURPOSE_get_by_id(id);
  168. /* Need a new entry */
  169. if(idx == -1) {
  170. if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
  171. X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
  172. return 0;
  173. }
  174. ptmp->flags = X509_PURPOSE_DYNAMIC;
  175. } else ptmp = X509_PURPOSE_get0(idx);
  176. /* OPENSSL_free existing name if dynamic */
  177. if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
  178. OPENSSL_free(ptmp->name);
  179. OPENSSL_free(ptmp->sname);
  180. }
  181. /* dup supplied name */
  182. ptmp->name = BUF_strdup(name);
  183. ptmp->sname = BUF_strdup(sname);
  184. if(!ptmp->name || !ptmp->sname) {
  185. X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
  186. return 0;
  187. }
  188. /* Keep the dynamic flag of existing entry */
  189. ptmp->flags &= X509_PURPOSE_DYNAMIC;
  190. /* Set all other flags */
  191. ptmp->flags |= flags;
  192. ptmp->purpose = id;
  193. ptmp->trust = trust;
  194. ptmp->check_purpose = ck;
  195. ptmp->usr_data = arg;
  196. /* If its a new entry manage the dynamic table */
  197. if(idx == -1) {
  198. if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
  199. X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
  200. return 0;
  201. }
  202. if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
  203. X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
  204. return 0;
  205. }
  206. }
  207. return 1;
  208. }
  209. static void xptable_free(X509_PURPOSE *p)
  210. {
  211. if(!p) return;
  212. if (p->flags & X509_PURPOSE_DYNAMIC)
  213. {
  214. if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
  215. OPENSSL_free(p->name);
  216. OPENSSL_free(p->sname);
  217. }
  218. OPENSSL_free(p);
  219. }
  220. }
  221. void X509_PURPOSE_cleanup(void)
  222. {
  223. unsigned int i;
  224. sk_X509_PURPOSE_pop_free(xptable, xptable_free);
  225. for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
  226. xptable = NULL;
  227. }
  228. int X509_PURPOSE_get_id(X509_PURPOSE *xp)
  229. {
  230. return xp->purpose;
  231. }
  232. char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
  233. {
  234. return xp->name;
  235. }
  236. char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
  237. {
  238. return xp->sname;
  239. }
  240. int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
  241. {
  242. return xp->trust;
  243. }
  244. static int nid_cmp(const int *a, const int *b)
  245. {
  246. return *a - *b;
  247. }
  248. DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
  249. IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
  250. int X509_supported_extension(X509_EXTENSION *ex)
  251. {
  252. /* This table is a list of the NIDs of supported extensions:
  253. * that is those which are used by the verify process. If
  254. * an extension is critical and doesn't appear in this list
  255. * then the verify process will normally reject the certificate.
  256. * The list must be kept in numerical order because it will be
  257. * searched using bsearch.
  258. */
  259. static const int supported_nids[] = {
  260. NID_netscape_cert_type, /* 71 */
  261. NID_key_usage, /* 83 */
  262. NID_subject_alt_name, /* 85 */
  263. NID_basic_constraints, /* 87 */
  264. NID_certificate_policies, /* 89 */
  265. NID_ext_key_usage, /* 126 */
  266. #ifndef OPENSSL_NO_RFC3779
  267. NID_sbgp_ipAddrBlock, /* 290 */
  268. NID_sbgp_autonomousSysNum, /* 291 */
  269. #endif
  270. NID_policy_constraints, /* 401 */
  271. NID_proxyCertInfo, /* 663 */
  272. NID_name_constraints, /* 666 */
  273. NID_policy_mappings, /* 747 */
  274. NID_inhibit_any_policy /* 748 */
  275. };
  276. int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
  277. if (ex_nid == NID_undef)
  278. return 0;
  279. if (OBJ_bsearch_nid(&ex_nid, supported_nids,
  280. sizeof(supported_nids)/sizeof(int)))
  281. return 1;
  282. return 0;
  283. }
  284. static void setup_dp(X509 *x, DIST_POINT *dp)
  285. {
  286. X509_NAME *iname = NULL;
  287. int i;
  288. if (dp->reasons)
  289. {
  290. if (dp->reasons->length > 0)
  291. dp->dp_reasons = dp->reasons->data[0];
  292. if (dp->reasons->length > 1)
  293. dp->dp_reasons |= (dp->reasons->data[1] << 8);
  294. dp->dp_reasons &= CRLDP_ALL_REASONS;
  295. }
  296. else
  297. dp->dp_reasons = CRLDP_ALL_REASONS;
  298. if (!dp->distpoint || (dp->distpoint->type != 1))
  299. return;
  300. for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++)
  301. {
  302. GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
  303. if (gen->type == GEN_DIRNAME)
  304. {
  305. iname = gen->d.directoryName;
  306. break;
  307. }
  308. }
  309. if (!iname)
  310. iname = X509_get_issuer_name(x);
  311. DIST_POINT_set_dpname(dp->distpoint, iname);
  312. }
  313. static void setup_crldp(X509 *x)
  314. {
  315. int i;
  316. x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
  317. for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
  318. setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
  319. }
  320. static void x509v3_cache_extensions(X509 *x)
  321. {
  322. BASIC_CONSTRAINTS *bs;
  323. PROXY_CERT_INFO_EXTENSION *pci;
  324. ASN1_BIT_STRING *usage;
  325. ASN1_BIT_STRING *ns;
  326. EXTENDED_KEY_USAGE *extusage;
  327. X509_EXTENSION *ex;
  328. int i;
  329. if(x->ex_flags & EXFLAG_SET) return;
  330. #ifndef OPENSSL_NO_SHA
  331. X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
  332. #endif
  333. /* V1 should mean no extensions ... */
  334. if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
  335. /* Handle basic constraints */
  336. if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
  337. if(bs->ca) x->ex_flags |= EXFLAG_CA;
  338. if(bs->pathlen) {
  339. if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
  340. || !bs->ca) {
  341. x->ex_flags |= EXFLAG_INVALID;
  342. x->ex_pathlen = 0;
  343. } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
  344. } else x->ex_pathlen = -1;
  345. BASIC_CONSTRAINTS_free(bs);
  346. x->ex_flags |= EXFLAG_BCONS;
  347. }
  348. /* Handle proxy certificates */
  349. if((pci=X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
  350. if (x->ex_flags & EXFLAG_CA
  351. || X509_get_ext_by_NID(x, NID_subject_alt_name, 0) >= 0
  352. || X509_get_ext_by_NID(x, NID_issuer_alt_name, 0) >= 0) {
  353. x->ex_flags |= EXFLAG_INVALID;
  354. }
  355. if (pci->pcPathLengthConstraint) {
  356. x->ex_pcpathlen =
  357. ASN1_INTEGER_get(pci->pcPathLengthConstraint);
  358. } else x->ex_pcpathlen = -1;
  359. PROXY_CERT_INFO_EXTENSION_free(pci);
  360. x->ex_flags |= EXFLAG_PROXY;
  361. }
  362. /* Handle key usage */
  363. if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
  364. if(usage->length > 0) {
  365. x->ex_kusage = usage->data[0];
  366. if(usage->length > 1)
  367. x->ex_kusage |= usage->data[1] << 8;
  368. } else x->ex_kusage = 0;
  369. x->ex_flags |= EXFLAG_KUSAGE;
  370. ASN1_BIT_STRING_free(usage);
  371. }
  372. x->ex_xkusage = 0;
  373. if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
  374. x->ex_flags |= EXFLAG_XKUSAGE;
  375. for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
  376. switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
  377. case NID_server_auth:
  378. x->ex_xkusage |= XKU_SSL_SERVER;
  379. break;
  380. case NID_client_auth:
  381. x->ex_xkusage |= XKU_SSL_CLIENT;
  382. break;
  383. case NID_email_protect:
  384. x->ex_xkusage |= XKU_SMIME;
  385. break;
  386. case NID_code_sign:
  387. x->ex_xkusage |= XKU_CODE_SIGN;
  388. break;
  389. case NID_ms_sgc:
  390. case NID_ns_sgc:
  391. x->ex_xkusage |= XKU_SGC;
  392. break;
  393. case NID_OCSP_sign:
  394. x->ex_xkusage |= XKU_OCSP_SIGN;
  395. break;
  396. case NID_time_stamp:
  397. x->ex_xkusage |= XKU_TIMESTAMP;
  398. break;
  399. case NID_dvcs:
  400. x->ex_xkusage |= XKU_DVCS;
  401. break;
  402. case NID_anyExtendedKeyUsage:
  403. x->ex_xkusage |= XKU_ANYEKU;
  404. break;
  405. }
  406. }
  407. sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
  408. }
  409. if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
  410. if(ns->length > 0) x->ex_nscert = ns->data[0];
  411. else x->ex_nscert = 0;
  412. x->ex_flags |= EXFLAG_NSCERT;
  413. ASN1_BIT_STRING_free(ns);
  414. }
  415. x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
  416. x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
  417. /* Does subject name match issuer ? */
  418. if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
  419. {
  420. x->ex_flags |= EXFLAG_SI;
  421. /* If SKID matches AKID also indicate self signed */
  422. if (X509_check_akid(x, x->akid) == X509_V_OK)
  423. x->ex_flags |= EXFLAG_SS;
  424. }
  425. x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
  426. x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
  427. if (!x->nc && (i != -1))
  428. x->ex_flags |= EXFLAG_INVALID;
  429. setup_crldp(x);
  430. #ifndef OPENSSL_NO_RFC3779
  431. x->rfc3779_addr =X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL);
  432. x->rfc3779_asid =X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum,
  433. NULL, NULL);
  434. #endif
  435. for (i = 0; i < X509_get_ext_count(x); i++)
  436. {
  437. ex = X509_get_ext(x, i);
  438. if (!X509_EXTENSION_get_critical(ex))
  439. continue;
  440. if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
  441. == NID_freshest_crl)
  442. x->ex_flags |= EXFLAG_FRESHEST;
  443. if (!X509_supported_extension(ex))
  444. {
  445. x->ex_flags |= EXFLAG_CRITICAL;
  446. break;
  447. }
  448. }
  449. x->ex_flags |= EXFLAG_SET;
  450. }
  451. /* CA checks common to all purposes
  452. * return codes:
  453. * 0 not a CA
  454. * 1 is a CA
  455. * 2 basicConstraints absent so "maybe" a CA
  456. * 3 basicConstraints absent but self signed V1.
  457. * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
  458. */
  459. #define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
  460. #define ku_reject(x, usage) \
  461. (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
  462. #define xku_reject(x, usage) \
  463. (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
  464. #define ns_reject(x, usage) \
  465. (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
  466. static int check_ca(const X509 *x)
  467. {
  468. /* keyUsage if present should allow cert signing */
  469. if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
  470. if(x->ex_flags & EXFLAG_BCONS) {
  471. if(x->ex_flags & EXFLAG_CA) return 1;
  472. /* If basicConstraints says not a CA then say so */
  473. else return 0;
  474. } else {
  475. /* we support V1 roots for... uh, I don't really know why. */
  476. if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
  477. /* If key usage present it must have certSign so tolerate it */
  478. else if (x->ex_flags & EXFLAG_KUSAGE) return 4;
  479. /* Older certificates could have Netscape-specific CA types */
  480. else if (x->ex_flags & EXFLAG_NSCERT
  481. && x->ex_nscert & NS_ANY_CA) return 5;
  482. /* can this still be regarded a CA certificate? I doubt it */
  483. return 0;
  484. }
  485. }
  486. int X509_check_ca(X509 *x)
  487. {
  488. if(!(x->ex_flags & EXFLAG_SET)) {
  489. CRYPTO_w_lock(CRYPTO_LOCK_X509);
  490. x509v3_cache_extensions(x);
  491. CRYPTO_w_unlock(CRYPTO_LOCK_X509);
  492. }
  493. return check_ca(x);
  494. }
  495. /* Check SSL CA: common checks for SSL client and server */
  496. static int check_ssl_ca(const X509 *x)
  497. {
  498. int ca_ret;
  499. ca_ret = check_ca(x);
  500. if(!ca_ret) return 0;
  501. /* check nsCertType if present */
  502. if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret;
  503. else return 0;
  504. }
  505. static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
  506. {
  507. if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
  508. if(ca) return check_ssl_ca(x);
  509. /* We need to do digital signatures with it */
  510. if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
  511. /* nsCertType if present should allow SSL client use */
  512. if(ns_reject(x, NS_SSL_CLIENT)) return 0;
  513. return 1;
  514. }
  515. static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
  516. {
  517. if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
  518. if(ca) return check_ssl_ca(x);
  519. if(ns_reject(x, NS_SSL_SERVER)) return 0;
  520. /* Now as for keyUsage: we'll at least need to sign OR encipher */
  521. if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0;
  522. return 1;
  523. }
  524. static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
  525. {
  526. int ret;
  527. ret = check_purpose_ssl_server(xp, x, ca);
  528. if(!ret || ca) return ret;
  529. /* We need to encipher or Netscape complains */
  530. if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
  531. return ret;
  532. }
  533. /* common S/MIME checks */
  534. static int purpose_smime(const X509 *x, int ca)
  535. {
  536. if(xku_reject(x,XKU_SMIME)) return 0;
  537. if(ca) {
  538. int ca_ret;
  539. ca_ret = check_ca(x);
  540. if(!ca_ret) return 0;
  541. /* check nsCertType if present */
  542. if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret;
  543. else return 0;
  544. }
  545. if(x->ex_flags & EXFLAG_NSCERT) {
  546. if(x->ex_nscert & NS_SMIME) return 1;
  547. /* Workaround for some buggy certificates */
  548. if(x->ex_nscert & NS_SSL_CLIENT) return 2;
  549. return 0;
  550. }
  551. return 1;
  552. }
  553. static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
  554. {
  555. int ret;
  556. ret = purpose_smime(x, ca);
  557. if(!ret || ca) return ret;
  558. if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0;
  559. return ret;
  560. }
  561. static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
  562. {
  563. int ret;
  564. ret = purpose_smime(x, ca);
  565. if(!ret || ca) return ret;
  566. if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0;
  567. return ret;
  568. }
  569. static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
  570. {
  571. if(ca) {
  572. int ca_ret;
  573. if((ca_ret = check_ca(x)) != 2) return ca_ret;
  574. else return 0;
  575. }
  576. if(ku_reject(x, KU_CRL_SIGN)) return 0;
  577. return 1;
  578. }
  579. /* OCSP helper: this is *not* a full OCSP check. It just checks that
  580. * each CA is valid. Additional checks must be made on the chain.
  581. */
  582. static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
  583. {
  584. /* Must be a valid CA. Should we really support the "I don't know"
  585. value (2)? */
  586. if(ca) return check_ca(x);
  587. /* leaf certificate is checked in OCSP_verify() */
  588. return 1;
  589. }
  590. static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
  591. int ca)
  592. {
  593. int i_ext;
  594. /* If ca is true we must return if this is a valid CA certificate. */
  595. if (ca) return check_ca(x);
  596. /*
  597. * Check the optional key usage field:
  598. * if Key Usage is present, it must be one of digitalSignature
  599. * and/or nonRepudiation (other values are not consistent and shall
  600. * be rejected).
  601. */
  602. if ((x->ex_flags & EXFLAG_KUSAGE)
  603. && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
  604. !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
  605. return 0;
  606. /* Only time stamp key usage is permitted and it's required. */
  607. if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
  608. return 0;
  609. /* Extended Key Usage MUST be critical */
  610. i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, 0);
  611. if (i_ext >= 0)
  612. {
  613. X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext);
  614. if (!X509_EXTENSION_get_critical(ext))
  615. return 0;
  616. }
  617. return 1;
  618. }
  619. static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
  620. {
  621. return 1;
  622. }
  623. /* Various checks to see if one certificate issued the second.
  624. * This can be used to prune a set of possible issuer certificates
  625. * which have been looked up using some simple method such as by
  626. * subject name.
  627. * These are:
  628. * 1. Check issuer_name(subject) == subject_name(issuer)
  629. * 2. If akid(subject) exists check it matches issuer
  630. * 3. If key_usage(issuer) exists check it supports certificate signing
  631. * returns 0 for OK, positive for reason for mismatch, reasons match
  632. * codes for X509_verify_cert()
  633. */
  634. int X509_check_issued(X509 *issuer, X509 *subject)
  635. {
  636. if(X509_NAME_cmp(X509_get_subject_name(issuer),
  637. X509_get_issuer_name(subject)))
  638. return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
  639. x509v3_cache_extensions(issuer);
  640. x509v3_cache_extensions(subject);
  641. if(subject->akid)
  642. {
  643. int ret = X509_check_akid(issuer, subject->akid);
  644. if (ret != X509_V_OK)
  645. return ret;
  646. }
  647. if(subject->ex_flags & EXFLAG_PROXY)
  648. {
  649. if(ku_reject(issuer, KU_DIGITAL_SIGNATURE))
  650. return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
  651. }
  652. else if(ku_reject(issuer, KU_KEY_CERT_SIGN))
  653. return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
  654. return X509_V_OK;
  655. }
  656. int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
  657. {
  658. if(!akid)
  659. return X509_V_OK;
  660. /* Check key ids (if present) */
  661. if(akid->keyid && issuer->skid &&
  662. ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) )
  663. return X509_V_ERR_AKID_SKID_MISMATCH;
  664. /* Check serial number */
  665. if(akid->serial &&
  666. ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial))
  667. return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
  668. /* Check issuer name */
  669. if(akid->issuer)
  670. {
  671. /* Ugh, for some peculiar reason AKID includes
  672. * SEQUENCE OF GeneralName. So look for a DirName.
  673. * There may be more than one but we only take any
  674. * notice of the first.
  675. */
  676. GENERAL_NAMES *gens;
  677. GENERAL_NAME *gen;
  678. X509_NAME *nm = NULL;
  679. int i;
  680. gens = akid->issuer;
  681. for(i = 0; i < sk_GENERAL_NAME_num(gens); i++)
  682. {
  683. gen = sk_GENERAL_NAME_value(gens, i);
  684. if(gen->type == GEN_DIRNAME)
  685. {
  686. nm = gen->d.dirn;
  687. break;
  688. }
  689. }
  690. if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
  691. return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
  692. }
  693. return X509_V_OK;
  694. }