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#include <stdio.h> 58 59#include <string.h> 60 61#include <openssl/buf.h> 62#include <openssl/err.h> 63#include <openssl/digest.h> 64#include <openssl/mem.h> 65#include <openssl/obj.h> 66#include <openssl/thread.h> 67#include <openssl/x509_vfy.h> 68#include <openssl/x509v3.h> 69 70#include "../internal.h" 71 72 73static void x509v3_cache_extensions(X509 *x); 74 75static int check_ssl_ca(const X509 *x); 76static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca); 77static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); 78static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); 79static int purpose_smime(const X509 *x, int ca); 80static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 81static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca); 82static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 83static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 84static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); 85static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); 86 87static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b); 88static void xptable_free(X509_PURPOSE *p); 89 90static X509_PURPOSE xstandard[] = { 91 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, (char *) "SSL client", (char *) "sslclient", NULL}, 92 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, (char *) "SSL server", (char *) "sslserver", NULL}, 93 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, (char *) "Netscape SSL server", (char *) "nssslserver", NULL}, 94 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, (char *) "S/MIME signing", (char *) "smimesign", NULL}, 95 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, (char *) "S/MIME encryption", (char *) "smimeencrypt", NULL}, 96 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, (char *) "CRL signing", (char *) "crlsign", NULL}, 97 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, (char *) "Any Purpose", (char *) "any", NULL}, 98 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, (char *) "OCSP helper", (char *) "ocsphelper", NULL}, 99 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, (char *) "Time Stamp signing", (char *) "timestampsign", NULL}, 100}; 101 102#define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE)) 103 104static STACK_OF(X509_PURPOSE) *xptable = NULL; 105 106static int xp_cmp(const X509_PURPOSE **a, const X509_PURPOSE **b) 107{ 108 return (*a)->purpose - (*b)->purpose; 109} 110 111/* As much as I'd like to make X509_check_purpose use a "const" X509* 112 * I really can't because it does recalculate hashes and do other non-const 113 * things. */ 114int X509_check_purpose(X509 *x, int id, int ca) 115{ 116 int idx; 117 const X509_PURPOSE *pt; 118 if(!(x->ex_flags & EXFLAG_SET)) { 119 x509v3_cache_extensions(x); 120 } 121 if(id == -1) return 1; 122 idx = X509_PURPOSE_get_by_id(id); 123 if(idx == -1) return -1; 124 pt = X509_PURPOSE_get0(idx); 125 return pt->check_purpose(pt, x, ca); 126} 127 128int X509_PURPOSE_set(int *p, int purpose) 129{ 130 if(X509_PURPOSE_get_by_id(purpose) == -1) { 131 OPENSSL_PUT_ERROR(X509V3, X509_PURPOSE_set, X509V3_R_INVALID_PURPOSE); 132 return 0; 133 } 134 *p = purpose; 135 return 1; 136} 137 138int X509_PURPOSE_get_count(void) 139{ 140 if(!xptable) return X509_PURPOSE_COUNT; 141 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; 142} 143 144X509_PURPOSE * X509_PURPOSE_get0(int idx) 145{ 146 if(idx < 0) return NULL; 147 if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx; 148 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); 149} 150 151int X509_PURPOSE_get_by_sname(char *sname) 152{ 153 int i; 154 X509_PURPOSE *xptmp; 155 for(i = 0; i < X509_PURPOSE_get_count(); i++) { 156 xptmp = X509_PURPOSE_get0(i); 157 if(!strcmp(xptmp->sname, sname)) return i; 158 } 159 return -1; 160} 161 162int X509_PURPOSE_get_by_id(int purpose) 163{ 164 X509_PURPOSE tmp; 165 size_t idx; 166 167 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) 168 return purpose - X509_PURPOSE_MIN; 169 tmp.purpose = purpose; 170 if(!xptable) return -1; 171 172 if (!sk_X509_PURPOSE_find(xptable, &idx, &tmp)) 173 return -1; 174 return idx + X509_PURPOSE_COUNT; 175} 176 177int X509_PURPOSE_add(int id, int trust, int flags, 178 int (*ck)(const X509_PURPOSE *, const X509 *, int), 179 char *name, char *sname, void *arg) 180{ 181 int idx; 182 X509_PURPOSE *ptmp; 183 char *name_dup, *sname_dup; 184 185 /* This is set according to what we change: application can't set it */ 186 flags &= ~X509_PURPOSE_DYNAMIC; 187 /* This will always be set for application modified trust entries */ 188 flags |= X509_PURPOSE_DYNAMIC_NAME; 189 /* Get existing entry if any */ 190 idx = X509_PURPOSE_get_by_id(id); 191 /* Need a new entry */ 192 if(idx == -1) { 193 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) { 194 OPENSSL_PUT_ERROR(X509V3, X509_PURPOSE_add, ERR_R_MALLOC_FAILURE); 195 return 0; 196 } 197 ptmp->flags = X509_PURPOSE_DYNAMIC; 198 } else ptmp = X509_PURPOSE_get0(idx); 199 200 /* Duplicate the supplied names. */ 201 name_dup = BUF_strdup(name); 202 sname_dup = BUF_strdup(sname); 203 if (name_dup == NULL || sname_dup == NULL) { 204 OPENSSL_PUT_ERROR(X509V3, X509_PURPOSE_add, ERR_R_MALLOC_FAILURE); 205 if (name_dup != NULL) 206 OPENSSL_free(name_dup); 207 if (sname_dup != NULL) 208 OPENSSL_free(sname_dup); 209 if (idx == -1) 210 OPENSSL_free(ptmp); 211 return 0; 212 } 213 214 /* OPENSSL_free existing name if dynamic */ 215 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { 216 OPENSSL_free(ptmp->name); 217 OPENSSL_free(ptmp->sname); 218 } 219 /* dup supplied name */ 220 ptmp->name = name_dup; 221 ptmp->sname = sname_dup; 222 /* Keep the dynamic flag of existing entry */ 223 ptmp->flags &= X509_PURPOSE_DYNAMIC; 224 /* Set all other flags */ 225 ptmp->flags |= flags; 226 227 ptmp->purpose = id; 228 ptmp->trust = trust; 229 ptmp->check_purpose = ck; 230 ptmp->usr_data = arg; 231 232 /* If its a new entry manage the dynamic table */ 233 if(idx == -1) { 234 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) { 235 OPENSSL_PUT_ERROR(X509V3, X509_PURPOSE_add, ERR_R_MALLOC_FAILURE); 236 xptable_free(ptmp); 237 return 0; 238 } 239 if (!sk_X509_PURPOSE_push(xptable, ptmp)) { 240 OPENSSL_PUT_ERROR(X509V3, X509_PURPOSE_add, ERR_R_MALLOC_FAILURE); 241 xptable_free(ptmp); 242 return 0; 243 } 244 } 245 return 1; 246} 247 248static void xptable_free(X509_PURPOSE *p) 249 { 250 if(!p) return; 251 if (p->flags & X509_PURPOSE_DYNAMIC) 252 { 253 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { 254 OPENSSL_free(p->name); 255 OPENSSL_free(p->sname); 256 } 257 OPENSSL_free(p); 258 } 259 } 260 261void X509_PURPOSE_cleanup(void) 262{ 263 unsigned int i; 264 sk_X509_PURPOSE_pop_free(xptable, xptable_free); 265 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i); 266 xptable = NULL; 267} 268 269int X509_PURPOSE_get_id(X509_PURPOSE *xp) 270{ 271 return xp->purpose; 272} 273 274char *X509_PURPOSE_get0_name(X509_PURPOSE *xp) 275{ 276 return xp->name; 277} 278 279char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp) 280{ 281 return xp->sname; 282} 283 284int X509_PURPOSE_get_trust(X509_PURPOSE *xp) 285{ 286 return xp->trust; 287} 288 289static int nid_cmp(const void *void_a, const void *void_b) 290 { 291 const int *a = void_a, *b = void_b; 292 293 return *a - *b; 294 } 295 296int X509_supported_extension(X509_EXTENSION *ex) 297 { 298 /* This table is a list of the NIDs of supported extensions: 299 * that is those which are used by the verify process. If 300 * an extension is critical and doesn't appear in this list 301 * then the verify process will normally reject the certificate. 302 * The list must be kept in numerical order because it will be 303 * searched using bsearch. 304 */ 305 306 static const int supported_nids[] = { 307 NID_netscape_cert_type, /* 71 */ 308 NID_key_usage, /* 83 */ 309 NID_subject_alt_name, /* 85 */ 310 NID_basic_constraints, /* 87 */ 311 NID_certificate_policies, /* 89 */ 312 NID_ext_key_usage, /* 126 */ 313 NID_policy_constraints, /* 401 */ 314 NID_proxyCertInfo, /* 663 */ 315 NID_name_constraints, /* 666 */ 316 NID_policy_mappings, /* 747 */ 317 NID_inhibit_any_policy /* 748 */ 318 }; 319 320 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); 321 322 if (ex_nid == NID_undef) 323 return 0; 324 325 if (bsearch(&ex_nid, supported_nids, sizeof(supported_nids)/sizeof(int), sizeof(int), nid_cmp) != NULL) 326 return 1; 327 return 0; 328 } 329 330static void setup_dp(X509 *x, DIST_POINT *dp) 331 { 332 X509_NAME *iname = NULL; 333 size_t i; 334 if (dp->reasons) 335 { 336 if (dp->reasons->length > 0) 337 dp->dp_reasons = dp->reasons->data[0]; 338 if (dp->reasons->length > 1) 339 dp->dp_reasons |= (dp->reasons->data[1] << 8); 340 dp->dp_reasons &= CRLDP_ALL_REASONS; 341 } 342 else 343 dp->dp_reasons = CRLDP_ALL_REASONS; 344 if (!dp->distpoint || (dp->distpoint->type != 1)) 345 return; 346 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) 347 { 348 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 349 if (gen->type == GEN_DIRNAME) 350 { 351 iname = gen->d.directoryName; 352 break; 353 } 354 } 355 if (!iname) 356 iname = X509_get_issuer_name(x); 357 358 DIST_POINT_set_dpname(dp->distpoint, iname); 359 360 } 361 362static void setup_crldp(X509 *x) 363 { 364 size_t i; 365 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL); 366 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) 367 setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); 368 } 369 370/* g_x509_cache_extensions_lock is used to protect against concurrent calls to 371 * |x509v3_cache_extensions|. Ideally this would be done with a |CRYPTO_once_t| 372 * in the |X509| structure, but |CRYPTO_once_t| isn't public. 373 * 374 * Note: it's not entirely clear whether this lock is needed. Not all paths to 375 * this function took a lock in OpenSSL. */ 376static struct CRYPTO_STATIC_MUTEX g_x509_cache_extensions_lock = 377 CRYPTO_STATIC_MUTEX_INIT; 378 379static void x509v3_cache_extensions(X509 *x) 380{ 381 BASIC_CONSTRAINTS *bs; 382 PROXY_CERT_INFO_EXTENSION *pci; 383 ASN1_BIT_STRING *usage; 384 ASN1_BIT_STRING *ns; 385 EXTENDED_KEY_USAGE *extusage; 386 X509_EXTENSION *ex; 387 size_t i; 388 int j; 389 390 CRYPTO_STATIC_MUTEX_lock_write(&g_x509_cache_extensions_lock); 391 392 if(x->ex_flags & EXFLAG_SET) 393 { 394 CRYPTO_STATIC_MUTEX_unlock(&g_x509_cache_extensions_lock); 395 return; 396 } 397 398 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL); 399 /* V1 should mean no extensions ... */ 400 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1; 401 /* Handle basic constraints */ 402 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) { 403 if(bs->ca) x->ex_flags |= EXFLAG_CA; 404 if(bs->pathlen) { 405 if((bs->pathlen->type == V_ASN1_NEG_INTEGER) 406 || !bs->ca) { 407 x->ex_flags |= EXFLAG_INVALID; 408 x->ex_pathlen = 0; 409 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); 410 } else x->ex_pathlen = -1; 411 BASIC_CONSTRAINTS_free(bs); 412 x->ex_flags |= EXFLAG_BCONS; 413 } 414 /* Handle proxy certificates */ 415 if((pci=X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) { 416 if (x->ex_flags & EXFLAG_CA 417 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 418 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) { 419 x->ex_flags |= EXFLAG_INVALID; 420 } 421 if (pci->pcPathLengthConstraint) { 422 x->ex_pcpathlen = 423 ASN1_INTEGER_get(pci->pcPathLengthConstraint); 424 } else x->ex_pcpathlen = -1; 425 PROXY_CERT_INFO_EXTENSION_free(pci); 426 x->ex_flags |= EXFLAG_PROXY; 427 } 428 /* Handle key usage */ 429 if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) { 430 if(usage->length > 0) { 431 x->ex_kusage = usage->data[0]; 432 if(usage->length > 1) 433 x->ex_kusage |= usage->data[1] << 8; 434 } else x->ex_kusage = 0; 435 x->ex_flags |= EXFLAG_KUSAGE; 436 ASN1_BIT_STRING_free(usage); 437 } 438 x->ex_xkusage = 0; 439 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) { 440 x->ex_flags |= EXFLAG_XKUSAGE; 441 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { 442 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) { 443 case NID_server_auth: 444 x->ex_xkusage |= XKU_SSL_SERVER; 445 break; 446 447 case NID_client_auth: 448 x->ex_xkusage |= XKU_SSL_CLIENT; 449 break; 450 451 case NID_email_protect: 452 x->ex_xkusage |= XKU_SMIME; 453 break; 454 455 case NID_code_sign: 456 x->ex_xkusage |= XKU_CODE_SIGN; 457 break; 458 459 case NID_ms_sgc: 460 case NID_ns_sgc: 461 x->ex_xkusage |= XKU_SGC; 462 break; 463 464 case NID_OCSP_sign: 465 x->ex_xkusage |= XKU_OCSP_SIGN; 466 break; 467 468 case NID_time_stamp: 469 x->ex_xkusage |= XKU_TIMESTAMP; 470 break; 471 472 case NID_dvcs: 473 x->ex_xkusage |= XKU_DVCS; 474 break; 475 476 case NID_anyExtendedKeyUsage: 477 x->ex_xkusage |= XKU_ANYEKU; 478 break; 479 } 480 } 481 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); 482 } 483 484 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) { 485 if(ns->length > 0) x->ex_nscert = ns->data[0]; 486 else x->ex_nscert = 0; 487 x->ex_flags |= EXFLAG_NSCERT; 488 ASN1_BIT_STRING_free(ns); 489 } 490 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL); 491 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL); 492 /* Does subject name match issuer ? */ 493 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) 494 { 495 x->ex_flags |= EXFLAG_SI; 496 /* If SKID matches AKID also indicate self signed */ 497 if (X509_check_akid(x, x->akid) == X509_V_OK) 498 x->ex_flags |= EXFLAG_SS; 499 } 500 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); 501 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &j, NULL); 502 if (!x->nc && (j != -1)) 503 x->ex_flags |= EXFLAG_INVALID; 504 setup_crldp(x); 505 506 for (j = 0; j < X509_get_ext_count(x); j++) 507 { 508 ex = X509_get_ext(x, j); 509 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) 510 == NID_freshest_crl) 511 x->ex_flags |= EXFLAG_FRESHEST; 512 if (!X509_EXTENSION_get_critical(ex)) 513 continue; 514 if (!X509_supported_extension(ex)) 515 { 516 x->ex_flags |= EXFLAG_CRITICAL; 517 break; 518 } 519 } 520 x->ex_flags |= EXFLAG_SET; 521 522 CRYPTO_STATIC_MUTEX_unlock(&g_x509_cache_extensions_lock); 523} 524 525/* CA checks common to all purposes 526 * return codes: 527 * 0 not a CA 528 * 1 is a CA 529 * 2 basicConstraints absent so "maybe" a CA 530 * 3 basicConstraints absent but self signed V1. 531 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. 532 */ 533 534#define V1_ROOT (EXFLAG_V1|EXFLAG_SS) 535#define ku_reject(x, usage) \ 536 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage))) 537#define xku_reject(x, usage) \ 538 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage))) 539#define ns_reject(x, usage) \ 540 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage))) 541 542static int check_ca(const X509 *x) 543{ 544 /* keyUsage if present should allow cert signing */ 545 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0; 546 if(x->ex_flags & EXFLAG_BCONS) { 547 if(x->ex_flags & EXFLAG_CA) return 1; 548 /* If basicConstraints says not a CA then say so */ 549 else return 0; 550 } else { 551 /* we support V1 roots for... uh, I don't really know why. */ 552 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3; 553 /* If key usage present it must have certSign so tolerate it */ 554 else if (x->ex_flags & EXFLAG_KUSAGE) return 4; 555 /* Older certificates could have Netscape-specific CA types */ 556 else if (x->ex_flags & EXFLAG_NSCERT 557 && x->ex_nscert & NS_ANY_CA) return 5; 558 /* can this still be regarded a CA certificate? I doubt it */ 559 return 0; 560 } 561} 562 563int X509_check_ca(X509 *x) 564{ 565 if(!(x->ex_flags & EXFLAG_SET)) { 566 x509v3_cache_extensions(x); 567 } 568 569 return check_ca(x); 570} 571 572/* Check SSL CA: common checks for SSL client and server */ 573static int check_ssl_ca(const X509 *x) 574{ 575 int ca_ret; 576 ca_ret = check_ca(x); 577 if(!ca_ret) return 0; 578 /* check nsCertType if present */ 579 if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret; 580 else return 0; 581} 582 583 584static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca) 585{ 586 if(xku_reject(x,XKU_SSL_CLIENT)) return 0; 587 if(ca) return check_ssl_ca(x); 588 /* We need to do digital signatures or key agreement */ 589 if(ku_reject(x,KU_DIGITAL_SIGNATURE|KU_KEY_AGREEMENT)) return 0; 590 /* nsCertType if present should allow SSL client use */ 591 if(ns_reject(x, NS_SSL_CLIENT)) return 0; 592 return 1; 593} 594/* Key usage needed for TLS/SSL server: digital signature, encipherment or 595 * key agreement. The ssl code can check this more thoroughly for individual 596 * key types. 597 */ 598#define KU_TLS \ 599 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT 600 601static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 602{ 603 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0; 604 if(ca) return check_ssl_ca(x); 605 606 if(ns_reject(x, NS_SSL_SERVER)) return 0; 607 if(ku_reject(x, KU_TLS)) return 0; 608 609 return 1; 610 611} 612 613static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 614{ 615 int ret; 616 ret = check_purpose_ssl_server(xp, x, ca); 617 if(!ret || ca) return ret; 618 /* We need to encipher or Netscape complains */ 619 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; 620 return ret; 621} 622 623/* common S/MIME checks */ 624static int purpose_smime(const X509 *x, int ca) 625{ 626 if(xku_reject(x,XKU_SMIME)) return 0; 627 if(ca) { 628 int ca_ret; 629 ca_ret = check_ca(x); 630 if(!ca_ret) return 0; 631 /* check nsCertType if present */ 632 if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret; 633 else return 0; 634 } 635 if(x->ex_flags & EXFLAG_NSCERT) { 636 if(x->ex_nscert & NS_SMIME) return 1; 637 /* Workaround for some buggy certificates */ 638 if(x->ex_nscert & NS_SSL_CLIENT) return 2; 639 return 0; 640 } 641 return 1; 642} 643 644static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 645{ 646 int ret; 647 ret = purpose_smime(x, ca); 648 if(!ret || ca) return ret; 649 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0; 650 return ret; 651} 652 653static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca) 654{ 655 int ret; 656 ret = purpose_smime(x, ca); 657 if(!ret || ca) return ret; 658 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; 659 return ret; 660} 661 662static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 663{ 664 if(ca) { 665 int ca_ret; 666 if((ca_ret = check_ca(x)) != 2) return ca_ret; 667 else return 0; 668 } 669 if(ku_reject(x, KU_CRL_SIGN)) return 0; 670 return 1; 671} 672 673/* OCSP helper: this is *not* a full OCSP check. It just checks that 674 * each CA is valid. Additional checks must be made on the chain. 675 */ 676 677static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) 678{ 679 /* Must be a valid CA. Should we really support the "I don't know" 680 value (2)? */ 681 if(ca) return check_ca(x); 682 /* leaf certificate is checked in OCSP_verify() */ 683 return 1; 684} 685 686static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, 687 int ca) 688{ 689 int i_ext; 690 691 /* If ca is true we must return if this is a valid CA certificate. */ 692 if (ca) return check_ca(x); 693 694 /* 695 * Check the optional key usage field: 696 * if Key Usage is present, it must be one of digitalSignature 697 * and/or nonRepudiation (other values are not consistent and shall 698 * be rejected). 699 */ 700 if ((x->ex_flags & EXFLAG_KUSAGE) 701 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || 702 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) 703 return 0; 704 705 /* Only time stamp key usage is permitted and it's required. */ 706 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) 707 return 0; 708 709 /* Extended Key Usage MUST be critical */ 710 i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1); 711 if (i_ext >= 0) 712 { 713 X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext); 714 if (!X509_EXTENSION_get_critical(ext)) 715 return 0; 716 } 717 718 return 1; 719} 720 721static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca) 722{ 723 return 1; 724} 725 726/* Various checks to see if one certificate issued the second. 727 * This can be used to prune a set of possible issuer certificates 728 * which have been looked up using some simple method such as by 729 * subject name. 730 * These are: 731 * 1. Check issuer_name(subject) == subject_name(issuer) 732 * 2. If akid(subject) exists check it matches issuer 733 * 3. If key_usage(issuer) exists check it supports certificate signing 734 * returns 0 for OK, positive for reason for mismatch, reasons match 735 * codes for X509_verify_cert() 736 */ 737 738int X509_check_issued(X509 *issuer, X509 *subject) 739{ 740 if(X509_NAME_cmp(X509_get_subject_name(issuer), 741 X509_get_issuer_name(subject))) 742 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; 743 x509v3_cache_extensions(issuer); 744 x509v3_cache_extensions(subject); 745 746 if(subject->akid) 747 { 748 int ret = X509_check_akid(issuer, subject->akid); 749 if (ret != X509_V_OK) 750 return ret; 751 } 752 753 if(subject->ex_flags & EXFLAG_PROXY) 754 { 755 if(ku_reject(issuer, KU_DIGITAL_SIGNATURE)) 756 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE; 757 } 758 else if(ku_reject(issuer, KU_KEY_CERT_SIGN)) 759 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; 760 return X509_V_OK; 761} 762 763int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) 764 { 765 766 if(!akid) 767 return X509_V_OK; 768 769 /* Check key ids (if present) */ 770 if(akid->keyid && issuer->skid && 771 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) ) 772 return X509_V_ERR_AKID_SKID_MISMATCH; 773 /* Check serial number */ 774 if(akid->serial && 775 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) 776 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 777 /* Check issuer name */ 778 if(akid->issuer) 779 { 780 /* Ugh, for some peculiar reason AKID includes 781 * SEQUENCE OF GeneralName. So look for a DirName. 782 * There may be more than one but we only take any 783 * notice of the first. 784 */ 785 GENERAL_NAMES *gens; 786 GENERAL_NAME *gen; 787 X509_NAME *nm = NULL; 788 size_t i; 789 gens = akid->issuer; 790 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++) 791 { 792 gen = sk_GENERAL_NAME_value(gens, i); 793 if(gen->type == GEN_DIRNAME) 794 { 795 nm = gen->d.dirn; 796 break; 797 } 798 } 799 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) 800 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 801 } 802 return X509_V_OK; 803 } 804 805