1 /* v3_purp.c */ 2 /* Written by Dr Stephen N Henson (steve (at) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh (at) cryptsoft.com). 56 * 57 */ 58 59 #include <stdio.h> 60 #include "cryptlib.h" 61 #include <openssl/x509v3.h> 62 #include <openssl/x509_vfy.h> 63 64 static void x509v3_cache_extensions(X509 *x); 65 66 static int check_ssl_ca(const X509 *x); 67 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca); 68 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); 69 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); 70 static int purpose_smime(const X509 *x, int ca); 71 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 72 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca); 73 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 74 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 75 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); 76 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); 77 78 static int xp_cmp(const X509_PURPOSE * const *a, 79 const X509_PURPOSE * const *b); 80 static void xptable_free(X509_PURPOSE *p); 81 82 static X509_PURPOSE xstandard[] = { 83 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL}, 84 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL}, 85 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL}, 86 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL}, 87 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL}, 88 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL}, 89 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL}, 90 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL}, 91 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", NULL}, 92 }; 93 94 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE)) 95 96 IMPLEMENT_STACK_OF(X509_PURPOSE) 97 98 static STACK_OF(X509_PURPOSE) *xptable = NULL; 99 100 static int xp_cmp(const X509_PURPOSE * const *a, 101 const X509_PURPOSE * const *b) 102 { 103 return (*a)->purpose - (*b)->purpose; 104 } 105 106 /* As much as I'd like to make X509_check_purpose use a "const" X509* 107 * I really can't because it does recalculate hashes and do other non-const 108 * things. */ 109 int X509_check_purpose(X509 *x, int id, int ca) 110 { 111 int idx; 112 const X509_PURPOSE *pt; 113 if(!(x->ex_flags & EXFLAG_SET)) { 114 CRYPTO_w_lock(CRYPTO_LOCK_X509); 115 x509v3_cache_extensions(x); 116 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 117 } 118 if(id == -1) return 1; 119 idx = X509_PURPOSE_get_by_id(id); 120 if(idx == -1) return -1; 121 pt = X509_PURPOSE_get0(idx); 122 return pt->check_purpose(pt, x, ca); 123 } 124 125 int X509_PURPOSE_set(int *p, int purpose) 126 { 127 if(X509_PURPOSE_get_by_id(purpose) == -1) { 128 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE); 129 return 0; 130 } 131 *p = purpose; 132 return 1; 133 } 134 135 int X509_PURPOSE_get_count(void) 136 { 137 if(!xptable) return X509_PURPOSE_COUNT; 138 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; 139 } 140 141 X509_PURPOSE * X509_PURPOSE_get0(int idx) 142 { 143 if(idx < 0) return NULL; 144 if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx; 145 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); 146 } 147 148 int X509_PURPOSE_get_by_sname(char *sname) 149 { 150 int i; 151 X509_PURPOSE *xptmp; 152 for(i = 0; i < X509_PURPOSE_get_count(); i++) { 153 xptmp = X509_PURPOSE_get0(i); 154 if(!strcmp(xptmp->sname, sname)) return i; 155 } 156 return -1; 157 } 158 159 int X509_PURPOSE_get_by_id(int purpose) 160 { 161 X509_PURPOSE tmp; 162 int idx; 163 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) 164 return purpose - X509_PURPOSE_MIN; 165 tmp.purpose = purpose; 166 if(!xptable) return -1; 167 idx = sk_X509_PURPOSE_find(xptable, &tmp); 168 if(idx == -1) return -1; 169 return idx + X509_PURPOSE_COUNT; 170 } 171 172 int X509_PURPOSE_add(int id, int trust, int flags, 173 int (*ck)(const X509_PURPOSE *, const X509 *, int), 174 char *name, char *sname, void *arg) 175 { 176 int idx; 177 X509_PURPOSE *ptmp; 178 /* This is set according to what we change: application can't set it */ 179 flags &= ~X509_PURPOSE_DYNAMIC; 180 /* This will always be set for application modified trust entries */ 181 flags |= X509_PURPOSE_DYNAMIC_NAME; 182 /* Get existing entry if any */ 183 idx = X509_PURPOSE_get_by_id(id); 184 /* Need a new entry */ 185 if(idx == -1) { 186 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) { 187 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 188 return 0; 189 } 190 ptmp->flags = X509_PURPOSE_DYNAMIC; 191 } else ptmp = X509_PURPOSE_get0(idx); 192 193 /* OPENSSL_free existing name if dynamic */ 194 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { 195 OPENSSL_free(ptmp->name); 196 OPENSSL_free(ptmp->sname); 197 } 198 /* dup supplied name */ 199 ptmp->name = BUF_strdup(name); 200 ptmp->sname = BUF_strdup(sname); 201 if(!ptmp->name || !ptmp->sname) { 202 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 203 return 0; 204 } 205 /* Keep the dynamic flag of existing entry */ 206 ptmp->flags &= X509_PURPOSE_DYNAMIC; 207 /* Set all other flags */ 208 ptmp->flags |= flags; 209 210 ptmp->purpose = id; 211 ptmp->trust = trust; 212 ptmp->check_purpose = ck; 213 ptmp->usr_data = arg; 214 215 /* If its a new entry manage the dynamic table */ 216 if(idx == -1) { 217 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) { 218 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 219 return 0; 220 } 221 if (!sk_X509_PURPOSE_push(xptable, ptmp)) { 222 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 223 return 0; 224 } 225 } 226 return 1; 227 } 228 229 static void xptable_free(X509_PURPOSE *p) 230 { 231 if(!p) return; 232 if (p->flags & X509_PURPOSE_DYNAMIC) 233 { 234 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { 235 OPENSSL_free(p->name); 236 OPENSSL_free(p->sname); 237 } 238 OPENSSL_free(p); 239 } 240 } 241 242 void X509_PURPOSE_cleanup(void) 243 { 244 unsigned int i; 245 sk_X509_PURPOSE_pop_free(xptable, xptable_free); 246 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i); 247 xptable = NULL; 248 } 249 250 int X509_PURPOSE_get_id(X509_PURPOSE *xp) 251 { 252 return xp->purpose; 253 } 254 255 char *X509_PURPOSE_get0_name(X509_PURPOSE *xp) 256 { 257 return xp->name; 258 } 259 260 char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp) 261 { 262 return xp->sname; 263 } 264 265 int X509_PURPOSE_get_trust(X509_PURPOSE *xp) 266 { 267 return xp->trust; 268 } 269 270 static int nid_cmp(const int *a, const int *b) 271 { 272 return *a - *b; 273 } 274 275 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid); 276 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid); 277 278 int X509_supported_extension(X509_EXTENSION *ex) 279 { 280 /* This table is a list of the NIDs of supported extensions: 281 * that is those which are used by the verify process. If 282 * an extension is critical and doesn't appear in this list 283 * then the verify process will normally reject the certificate. 284 * The list must be kept in numerical order because it will be 285 * searched using bsearch. 286 */ 287 288 static const int supported_nids[] = { 289 NID_netscape_cert_type, /* 71 */ 290 NID_key_usage, /* 83 */ 291 NID_subject_alt_name, /* 85 */ 292 NID_basic_constraints, /* 87 */ 293 NID_certificate_policies, /* 89 */ 294 NID_ext_key_usage, /* 126 */ 295 #ifndef OPENSSL_NO_RFC3779 296 NID_sbgp_ipAddrBlock, /* 290 */ 297 NID_sbgp_autonomousSysNum, /* 291 */ 298 #endif 299 NID_policy_constraints, /* 401 */ 300 NID_proxyCertInfo, /* 663 */ 301 NID_name_constraints, /* 666 */ 302 NID_policy_mappings, /* 747 */ 303 NID_inhibit_any_policy /* 748 */ 304 }; 305 306 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); 307 308 if (ex_nid == NID_undef) 309 return 0; 310 311 if (OBJ_bsearch_nid(&ex_nid, supported_nids, 312 sizeof(supported_nids)/sizeof(int))) 313 return 1; 314 return 0; 315 } 316 317 static void setup_dp(X509 *x, DIST_POINT *dp) 318 { 319 X509_NAME *iname = NULL; 320 int i; 321 if (dp->reasons) 322 { 323 if (dp->reasons->length > 0) 324 dp->dp_reasons = dp->reasons->data[0]; 325 if (dp->reasons->length > 1) 326 dp->dp_reasons |= (dp->reasons->data[1] << 8); 327 dp->dp_reasons &= CRLDP_ALL_REASONS; 328 } 329 else 330 dp->dp_reasons = CRLDP_ALL_REASONS; 331 if (!dp->distpoint || (dp->distpoint->type != 1)) 332 return; 333 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) 334 { 335 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 336 if (gen->type == GEN_DIRNAME) 337 { 338 iname = gen->d.directoryName; 339 break; 340 } 341 } 342 if (!iname) 343 iname = X509_get_issuer_name(x); 344 345 DIST_POINT_set_dpname(dp->distpoint, iname); 346 347 } 348 349 static void setup_crldp(X509 *x) 350 { 351 int i; 352 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL); 353 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) 354 setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); 355 } 356 357 static void x509v3_cache_extensions(X509 *x) 358 { 359 BASIC_CONSTRAINTS *bs; 360 PROXY_CERT_INFO_EXTENSION *pci; 361 ASN1_BIT_STRING *usage; 362 ASN1_BIT_STRING *ns; 363 EXTENDED_KEY_USAGE *extusage; 364 X509_EXTENSION *ex; 365 366 int i; 367 if(x->ex_flags & EXFLAG_SET) return; 368 #ifndef OPENSSL_NO_SHA 369 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL); 370 #endif 371 /* Does subject name match issuer ? */ 372 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) 373 x->ex_flags |= EXFLAG_SI; 374 /* V1 should mean no extensions ... */ 375 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1; 376 /* Handle basic constraints */ 377 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) { 378 if(bs->ca) x->ex_flags |= EXFLAG_CA; 379 if(bs->pathlen) { 380 if((bs->pathlen->type == V_ASN1_NEG_INTEGER) 381 || !bs->ca) { 382 x->ex_flags |= EXFLAG_INVALID; 383 x->ex_pathlen = 0; 384 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); 385 } else 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 = 398 ASN1_INTEGER_get(pci->pcPathLengthConstraint); 399 } else 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 x->ex_kusage = 0; 410 x->ex_flags |= EXFLAG_KUSAGE; 411 ASN1_BIT_STRING_free(usage); 412 } 413 x->ex_xkusage = 0; 414 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) { 415 x->ex_flags |= EXFLAG_XKUSAGE; 416 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { 417 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) { 418 case NID_server_auth: 419 x->ex_xkusage |= XKU_SSL_SERVER; 420 break; 421 422 case NID_client_auth: 423 x->ex_xkusage |= XKU_SSL_CLIENT; 424 break; 425 426 case NID_email_protect: 427 x->ex_xkusage |= XKU_SMIME; 428 break; 429 430 case NID_code_sign: 431 x->ex_xkusage |= XKU_CODE_SIGN; 432 break; 433 434 case NID_ms_sgc: 435 case NID_ns_sgc: 436 x->ex_xkusage |= XKU_SGC; 437 break; 438 439 case NID_OCSP_sign: 440 x->ex_xkusage |= XKU_OCSP_SIGN; 441 break; 442 443 case NID_time_stamp: 444 x->ex_xkusage |= XKU_TIMESTAMP; 445 break; 446 447 case NID_dvcs: 448 x->ex_xkusage |= XKU_DVCS; 449 break; 450 } 451 } 452 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); 453 } 454 455 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) { 456 if(ns->length > 0) x->ex_nscert = ns->data[0]; 457 else x->ex_nscert = 0; 458 x->ex_flags |= EXFLAG_NSCERT; 459 ASN1_BIT_STRING_free(ns); 460 } 461 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL); 462 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL); 463 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); 464 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL); 465 if (!x->nc && (i != -1)) 466 x->ex_flags |= EXFLAG_INVALID; 467 setup_crldp(x); 468 469 #ifndef OPENSSL_NO_RFC3779 470 x->rfc3779_addr =X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL); 471 x->rfc3779_asid =X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, 472 NULL, NULL); 473 #endif 474 for (i = 0; i < X509_get_ext_count(x); i++) 475 { 476 ex = X509_get_ext(x, i); 477 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) 478 == NID_freshest_crl) 479 x->ex_flags |= EXFLAG_FRESHEST; 480 if (!X509_EXTENSION_get_critical(ex)) 481 continue; 482 if (!X509_supported_extension(ex)) 483 { 484 x->ex_flags |= EXFLAG_CRITICAL; 485 break; 486 } 487 } 488 x->ex_flags |= EXFLAG_SET; 489 } 490 491 /* CA checks common to all purposes 492 * return codes: 493 * 0 not a CA 494 * 1 is a CA 495 * 2 basicConstraints absent so "maybe" a CA 496 * 3 basicConstraints absent but self signed V1. 497 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. 498 */ 499 500 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS) 501 #define ku_reject(x, usage) \ 502 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage))) 503 #define xku_reject(x, usage) \ 504 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage))) 505 #define ns_reject(x, usage) \ 506 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage))) 507 508 static int check_ca(const X509 *x) 509 { 510 /* keyUsage if present should allow cert signing */ 511 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0; 512 if(x->ex_flags & EXFLAG_BCONS) { 513 if(x->ex_flags & EXFLAG_CA) return 1; 514 /* If basicConstraints says not a CA then say so */ 515 else return 0; 516 } else { 517 /* we support V1 roots for... uh, I don't really know why. */ 518 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3; 519 /* If key usage present it must have certSign so tolerate it */ 520 else if (x->ex_flags & EXFLAG_KUSAGE) return 4; 521 /* Older certificates could have Netscape-specific CA types */ 522 else if (x->ex_flags & EXFLAG_NSCERT 523 && x->ex_nscert & NS_ANY_CA) return 5; 524 /* can this still be regarded a CA certificate? I doubt it */ 525 return 0; 526 } 527 } 528 529 int X509_check_ca(X509 *x) 530 { 531 if(!(x->ex_flags & EXFLAG_SET)) { 532 CRYPTO_w_lock(CRYPTO_LOCK_X509); 533 x509v3_cache_extensions(x); 534 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 535 } 536 537 return check_ca(x); 538 } 539 540 /* Check SSL CA: common checks for SSL client and server */ 541 static int check_ssl_ca(const X509 *x) 542 { 543 int ca_ret; 544 ca_ret = check_ca(x); 545 if(!ca_ret) return 0; 546 /* check nsCertType if present */ 547 if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret; 548 else return 0; 549 } 550 551 552 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca) 553 { 554 if(xku_reject(x,XKU_SSL_CLIENT)) return 0; 555 if(ca) return check_ssl_ca(x); 556 /* We need to do digital signatures with it */ 557 if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0; 558 /* nsCertType if present should allow SSL client use */ 559 if(ns_reject(x, NS_SSL_CLIENT)) return 0; 560 return 1; 561 } 562 563 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 564 { 565 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0; 566 if(ca) return check_ssl_ca(x); 567 568 if(ns_reject(x, NS_SSL_SERVER)) return 0; 569 /* Now as for keyUsage: we'll at least need to sign OR encipher */ 570 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0; 571 572 return 1; 573 574 } 575 576 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 577 { 578 int ret; 579 ret = check_purpose_ssl_server(xp, x, ca); 580 if(!ret || ca) return ret; 581 /* We need to encipher or Netscape complains */ 582 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; 583 return ret; 584 } 585 586 /* common S/MIME checks */ 587 static int purpose_smime(const X509 *x, int ca) 588 { 589 if(xku_reject(x,XKU_SMIME)) return 0; 590 if(ca) { 591 int ca_ret; 592 ca_ret = check_ca(x); 593 if(!ca_ret) return 0; 594 /* check nsCertType if present */ 595 if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret; 596 else return 0; 597 } 598 if(x->ex_flags & EXFLAG_NSCERT) { 599 if(x->ex_nscert & NS_SMIME) return 1; 600 /* Workaround for some buggy certificates */ 601 if(x->ex_nscert & NS_SSL_CLIENT) return 2; 602 return 0; 603 } 604 return 1; 605 } 606 607 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 608 { 609 int ret; 610 ret = purpose_smime(x, ca); 611 if(!ret || ca) return ret; 612 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0; 613 return ret; 614 } 615 616 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca) 617 { 618 int ret; 619 ret = purpose_smime(x, ca); 620 if(!ret || ca) return ret; 621 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; 622 return ret; 623 } 624 625 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 626 { 627 if(ca) { 628 int ca_ret; 629 if((ca_ret = check_ca(x)) != 2) return ca_ret; 630 else return 0; 631 } 632 if(ku_reject(x, KU_CRL_SIGN)) return 0; 633 return 1; 634 } 635 636 /* OCSP helper: this is *not* a full OCSP check. It just checks that 637 * each CA is valid. Additional checks must be made on the chain. 638 */ 639 640 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) 641 { 642 /* Must be a valid CA. Should we really support the "I don't know" 643 value (2)? */ 644 if(ca) return check_ca(x); 645 /* leaf certificate is checked in OCSP_verify() */ 646 return 1; 647 } 648 649 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, 650 int ca) 651 { 652 int i_ext; 653 654 /* If ca is true we must return if this is a valid CA certificate. */ 655 if (ca) return check_ca(x); 656 657 /* 658 * Check the optional key usage field: 659 * if Key Usage is present, it must be one of digitalSignature 660 * and/or nonRepudiation (other values are not consistent and shall 661 * be rejected). 662 */ 663 if ((x->ex_flags & EXFLAG_KUSAGE) 664 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || 665 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) 666 return 0; 667 668 /* Only time stamp key usage is permitted and it's required. */ 669 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) 670 return 0; 671 672 /* Extended Key Usage MUST be critical */ 673 i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1); 674 if (i_ext >= 0) 675 { 676 X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext); 677 if (!X509_EXTENSION_get_critical(ext)) 678 return 0; 679 } 680 681 return 1; 682 } 683 684 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca) 685 { 686 return 1; 687 } 688 689 /* Various checks to see if one certificate issued the second. 690 * This can be used to prune a set of possible issuer certificates 691 * which have been looked up using some simple method such as by 692 * subject name. 693 * These are: 694 * 1. Check issuer_name(subject) == subject_name(issuer) 695 * 2. If akid(subject) exists check it matches issuer 696 * 3. If key_usage(issuer) exists check it supports certificate signing 697 * returns 0 for OK, positive for reason for mismatch, reasons match 698 * codes for X509_verify_cert() 699 */ 700 701 int X509_check_issued(X509 *issuer, X509 *subject) 702 { 703 if(X509_NAME_cmp(X509_get_subject_name(issuer), 704 X509_get_issuer_name(subject))) 705 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; 706 x509v3_cache_extensions(issuer); 707 x509v3_cache_extensions(subject); 708 709 if(subject->akid) 710 { 711 int ret = X509_check_akid(issuer, subject->akid); 712 if (ret != X509_V_OK) 713 return ret; 714 } 715 716 if(subject->ex_flags & EXFLAG_PROXY) 717 { 718 if(ku_reject(issuer, KU_DIGITAL_SIGNATURE)) 719 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE; 720 } 721 else if(ku_reject(issuer, KU_KEY_CERT_SIGN)) 722 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; 723 return X509_V_OK; 724 } 725 726 int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) 727 { 728 729 if(!akid) 730 return X509_V_OK; 731 732 /* Check key ids (if present) */ 733 if(akid->keyid && issuer->skid && 734 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) ) 735 return X509_V_ERR_AKID_SKID_MISMATCH; 736 /* Check serial number */ 737 if(akid->serial && 738 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) 739 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 740 /* Check issuer name */ 741 if(akid->issuer) 742 { 743 /* Ugh, for some peculiar reason AKID includes 744 * SEQUENCE OF GeneralName. So look for a DirName. 745 * There may be more than one but we only take any 746 * notice of the first. 747 */ 748 GENERAL_NAMES *gens; 749 GENERAL_NAME *gen; 750 X509_NAME *nm = NULL; 751 int i; 752 gens = akid->issuer; 753 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++) 754 { 755 gen = sk_GENERAL_NAME_value(gens, i); 756 if(gen->type == GEN_DIRNAME) 757 { 758 nm = gen->d.dirn; 759 break; 760 } 761 } 762 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) 763 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 764 } 765 return X509_V_OK; 766 } 767 768
