1 /* $OpenBSD: x509_purp.c,v 1.18 2022/11/26 16:08:55 tb Exp $ */ 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 59 #include <stdio.h> 60 #include <string.h> 61 62 #include <openssl/opensslconf.h> 63 64 #include <openssl/err.h> 65 #include <openssl/x509v3.h> 66 #include <openssl/x509_vfy.h> 67 68 #include "x509_internal.h" 69 #include "x509_local.h" 70 71 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS) 72 #define ku_reject(x, usage) \ 73 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage))) 74 #define xku_reject(x, usage) \ 75 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage))) 76 #define ns_reject(x, usage) \ 77 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage))) 78 79 void x509v3_cache_extensions(X509 *x); 80 81 static int check_ssl_ca(const X509 *x); 82 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, 83 int ca); 84 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, 85 int ca); 86 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, 87 int ca); 88 static int purpose_smime(const X509 *x, int ca); 89 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, 90 int ca); 91 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, 92 int ca); 93 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, 94 int ca); 95 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, 96 int ca); 97 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); 98 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); 99 100 static int xp_cmp(const X509_PURPOSE * const *a, const X509_PURPOSE * const *b); 101 static void xptable_free(X509_PURPOSE *p); 102 103 static X509_PURPOSE xstandard[] = { 104 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL}, 105 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL}, 106 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL}, 107 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL}, 108 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL}, 109 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL}, 110 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL}, 111 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL}, 112 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", NULL}, 113 }; 114 115 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE)) 116 117 static STACK_OF(X509_PURPOSE) *xptable = NULL; 118 119 static int 120 xp_cmp(const X509_PURPOSE * const *a, const X509_PURPOSE * const *b) 121 { 122 return (*a)->purpose - (*b)->purpose; 123 } 124 125 /* As much as I'd like to make X509_check_purpose use a "const" X509* 126 * I really can't because it does recalculate hashes and do other non-const 127 * things. */ 128 int 129 X509_check_purpose(X509 *x, int id, int ca) 130 { 131 int idx; 132 const X509_PURPOSE *pt; 133 134 if (!(x->ex_flags & EXFLAG_SET)) { 135 CRYPTO_w_lock(CRYPTO_LOCK_X509); 136 x509v3_cache_extensions(x); 137 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 138 if (x->ex_flags & EXFLAG_INVALID) 139 return -1; 140 } 141 if (id == -1) 142 return 1; 143 idx = X509_PURPOSE_get_by_id(id); 144 if (idx == -1) 145 return -1; 146 pt = X509_PURPOSE_get0(idx); 147 return pt->check_purpose(pt, x, ca); 148 } 149 LCRYPTO_ALIAS(X509_check_purpose) 150 151 int 152 X509_PURPOSE_set(int *p, int purpose) 153 { 154 if (X509_PURPOSE_get_by_id(purpose) == -1) { 155 X509V3error(X509V3_R_INVALID_PURPOSE); 156 return 0; 157 } 158 *p = purpose; 159 return 1; 160 } 161 LCRYPTO_ALIAS(X509_PURPOSE_set) 162 163 int 164 X509_PURPOSE_get_count(void) 165 { 166 if (!xptable) 167 return X509_PURPOSE_COUNT; 168 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; 169 } 170 LCRYPTO_ALIAS(X509_PURPOSE_get_count) 171 172 X509_PURPOSE * 173 X509_PURPOSE_get0(int idx) 174 { 175 if (idx < 0) 176 return NULL; 177 if (idx < (int)X509_PURPOSE_COUNT) 178 return xstandard + idx; 179 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); 180 } 181 LCRYPTO_ALIAS(X509_PURPOSE_get0) 182 183 int 184 X509_PURPOSE_get_by_sname(const char *sname) 185 { 186 int i; 187 X509_PURPOSE *xptmp; 188 189 for (i = 0; i < X509_PURPOSE_get_count(); i++) { 190 xptmp = X509_PURPOSE_get0(i); 191 if (!strcmp(xptmp->sname, sname)) 192 return i; 193 } 194 return -1; 195 } 196 LCRYPTO_ALIAS(X509_PURPOSE_get_by_sname) 197 198 int 199 X509_PURPOSE_get_by_id(int purpose) 200 { 201 X509_PURPOSE tmp; 202 int idx; 203 204 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) 205 return purpose - X509_PURPOSE_MIN; 206 tmp.purpose = purpose; 207 if (!xptable) 208 return -1; 209 idx = sk_X509_PURPOSE_find(xptable, &tmp); 210 if (idx == -1) 211 return -1; 212 return idx + X509_PURPOSE_COUNT; 213 } 214 LCRYPTO_ALIAS(X509_PURPOSE_get_by_id) 215 216 int 217 X509_PURPOSE_add(int id, int trust, int flags, 218 int (*ck)(const X509_PURPOSE *, const X509 *, int), const char *name, 219 const char *sname, void *arg) 220 { 221 int idx; 222 X509_PURPOSE *ptmp; 223 char *name_dup, *sname_dup; 224 225 name_dup = sname_dup = NULL; 226 227 if (name == NULL || sname == NULL) { 228 X509V3error(X509V3_R_INVALID_NULL_ARGUMENT); 229 return 0; 230 } 231 232 /* This is set according to what we change: application can't set it */ 233 flags &= ~X509_PURPOSE_DYNAMIC; 234 /* This will always be set for application modified trust entries */ 235 flags |= X509_PURPOSE_DYNAMIC_NAME; 236 /* Get existing entry if any */ 237 idx = X509_PURPOSE_get_by_id(id); 238 /* Need a new entry */ 239 if (idx == -1) { 240 if ((ptmp = malloc(sizeof(X509_PURPOSE))) == NULL) { 241 X509V3error(ERR_R_MALLOC_FAILURE); 242 return 0; 243 } 244 ptmp->flags = X509_PURPOSE_DYNAMIC; 245 } else 246 ptmp = X509_PURPOSE_get0(idx); 247 248 if ((name_dup = strdup(name)) == NULL) 249 goto err; 250 if ((sname_dup = strdup(sname)) == NULL) 251 goto err; 252 253 /* free existing name if dynamic */ 254 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { 255 free(ptmp->name); 256 free(ptmp->sname); 257 } 258 /* dup supplied name */ 259 ptmp->name = name_dup; 260 ptmp->sname = sname_dup; 261 /* Keep the dynamic flag of existing entry */ 262 ptmp->flags &= X509_PURPOSE_DYNAMIC; 263 /* Set all other flags */ 264 ptmp->flags |= flags; 265 266 ptmp->purpose = id; 267 ptmp->trust = trust; 268 ptmp->check_purpose = ck; 269 ptmp->usr_data = arg; 270 271 /* If its a new entry manage the dynamic table */ 272 if (idx == -1) { 273 if (xptable == NULL && 274 (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) 275 goto err; 276 if (sk_X509_PURPOSE_push(xptable, ptmp) == 0) 277 goto err; 278 } 279 return 1; 280 281 err: 282 free(name_dup); 283 free(sname_dup); 284 if (idx == -1) 285 free(ptmp); 286 X509V3error(ERR_R_MALLOC_FAILURE); 287 return 0; 288 } 289 LCRYPTO_ALIAS(X509_PURPOSE_add) 290 291 static void 292 xptable_free(X509_PURPOSE *p) 293 { 294 if (!p) 295 return; 296 if (p->flags & X509_PURPOSE_DYNAMIC) { 297 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { 298 free(p->name); 299 free(p->sname); 300 } 301 free(p); 302 } 303 } 304 305 void 306 X509_PURPOSE_cleanup(void) 307 { 308 sk_X509_PURPOSE_pop_free(xptable, xptable_free); 309 xptable = NULL; 310 } 311 LCRYPTO_ALIAS(X509_PURPOSE_cleanup) 312 313 int 314 X509_PURPOSE_get_id(const X509_PURPOSE *xp) 315 { 316 return xp->purpose; 317 } 318 LCRYPTO_ALIAS(X509_PURPOSE_get_id) 319 320 char * 321 X509_PURPOSE_get0_name(const X509_PURPOSE *xp) 322 { 323 return xp->name; 324 } 325 LCRYPTO_ALIAS(X509_PURPOSE_get0_name) 326 327 char * 328 X509_PURPOSE_get0_sname(const X509_PURPOSE *xp) 329 { 330 return xp->sname; 331 } 332 LCRYPTO_ALIAS(X509_PURPOSE_get0_sname) 333 334 int 335 X509_PURPOSE_get_trust(const X509_PURPOSE *xp) 336 { 337 return xp->trust; 338 } 339 LCRYPTO_ALIAS(X509_PURPOSE_get_trust) 340 341 static int 342 nid_cmp(const int *a, const int *b) 343 { 344 return *a - *b; 345 } 346 347 static int nid_cmp_BSEARCH_CMP_FN(const void *, const void *); 348 static int nid_cmp(int const *, int const *); 349 static int *OBJ_bsearch_nid(int *key, int const *base, int num); 350 351 static int 352 nid_cmp_BSEARCH_CMP_FN(const void *a_, const void *b_) 353 { 354 int const *a = a_; 355 int const *b = b_; 356 return nid_cmp(a, b); 357 } 358 359 static int * 360 OBJ_bsearch_nid(int *key, int const *base, int num) 361 { 362 return (int *)OBJ_bsearch_(key, base, num, sizeof(int), 363 nid_cmp_BSEARCH_CMP_FN); 364 } 365 366 int 367 X509_supported_extension(X509_EXTENSION *ex) 368 { 369 /* This table is a list of the NIDs of supported extensions: 370 * that is those which are used by the verify process. If 371 * an extension is critical and doesn't appear in this list 372 * then the verify process will normally reject the certificate. 373 * The list must be kept in numerical order because it will be 374 * searched using bsearch. 375 */ 376 377 static const int supported_nids[] = { 378 NID_netscape_cert_type, /* 71 */ 379 NID_key_usage, /* 83 */ 380 NID_subject_alt_name, /* 85 */ 381 NID_basic_constraints, /* 87 */ 382 NID_certificate_policies, /* 89 */ 383 NID_ext_key_usage, /* 126 */ 384 #ifndef OPENSSL_NO_RFC3779 385 NID_sbgp_ipAddrBlock, /* 290 */ 386 NID_sbgp_autonomousSysNum, /* 291 */ 387 #endif 388 NID_policy_constraints, /* 401 */ 389 NID_proxyCertInfo, /* 663 */ 390 NID_name_constraints, /* 666 */ 391 NID_policy_mappings, /* 747 */ 392 NID_inhibit_any_policy /* 748 */ 393 }; 394 395 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); 396 397 if (ex_nid == NID_undef) 398 return 0; 399 400 if (OBJ_bsearch_nid(&ex_nid, supported_nids, 401 sizeof(supported_nids) / sizeof(int))) 402 return 1; 403 return 0; 404 } 405 LCRYPTO_ALIAS(X509_supported_extension) 406 407 static void 408 setup_dp(X509 *x, DIST_POINT *dp) 409 { 410 X509_NAME *iname = NULL; 411 int i; 412 413 if (dp->reasons) { 414 if (dp->reasons->length > 0) 415 dp->dp_reasons = dp->reasons->data[0]; 416 if (dp->reasons->length > 1) 417 dp->dp_reasons |= (dp->reasons->data[1] << 8); 418 dp->dp_reasons &= CRLDP_ALL_REASONS; 419 } else 420 dp->dp_reasons = CRLDP_ALL_REASONS; 421 if (!dp->distpoint || (dp->distpoint->type != 1)) 422 return; 423 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { 424 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 425 if (gen->type == GEN_DIRNAME) { 426 iname = gen->d.directoryName; 427 break; 428 } 429 } 430 if (!iname) 431 iname = X509_get_issuer_name(x); 432 433 DIST_POINT_set_dpname(dp->distpoint, iname); 434 435 } 436 437 static void 438 setup_crldp(X509 *x) 439 { 440 int i; 441 442 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL); 443 if (x->crldp == NULL && i != -1) { 444 x->ex_flags |= EXFLAG_INVALID; 445 return; 446 } 447 448 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) 449 setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); 450 } 451 452 void 453 x509v3_cache_extensions(X509 *x) 454 { 455 BASIC_CONSTRAINTS *bs; 456 PROXY_CERT_INFO_EXTENSION *pci; 457 ASN1_BIT_STRING *usage; 458 ASN1_BIT_STRING *ns; 459 EXTENDED_KEY_USAGE *extusage; 460 X509_EXTENSION *ex; 461 int i; 462 463 if (x->ex_flags & EXFLAG_SET) 464 return; 465 466 X509_digest(x, X509_CERT_HASH_EVP, x->hash, NULL); 467 468 /* V1 should mean no extensions ... */ 469 if (!X509_get_version(x)) 470 x->ex_flags |= EXFLAG_V1; 471 472 /* Handle basic constraints */ 473 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) { 474 if (bs->ca) 475 x->ex_flags |= EXFLAG_CA; 476 if (bs->pathlen) { 477 if ((bs->pathlen->type == V_ASN1_NEG_INTEGER) || 478 !bs->ca) { 479 x->ex_flags |= EXFLAG_INVALID; 480 x->ex_pathlen = 0; 481 } else 482 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); 483 } else 484 x->ex_pathlen = -1; 485 BASIC_CONSTRAINTS_free(bs); 486 x->ex_flags |= EXFLAG_BCONS; 487 } else if (i != -1) { 488 x->ex_flags |= EXFLAG_INVALID; 489 } 490 491 /* Handle proxy certificates */ 492 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL))) { 493 if (x->ex_flags & EXFLAG_CA || 494 X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 || 495 X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) { 496 x->ex_flags |= EXFLAG_INVALID; 497 } 498 if (pci->pcPathLengthConstraint) { 499 if (pci->pcPathLengthConstraint->type == 500 V_ASN1_NEG_INTEGER) { 501 x->ex_flags |= EXFLAG_INVALID; 502 x->ex_pcpathlen = 0; 503 } else 504 x->ex_pcpathlen = 505 ASN1_INTEGER_get(pci-> 506 pcPathLengthConstraint); 507 } else 508 x->ex_pcpathlen = -1; 509 PROXY_CERT_INFO_EXTENSION_free(pci); 510 x->ex_flags |= EXFLAG_PROXY; 511 } else if (i != -1) { 512 x->ex_flags |= EXFLAG_INVALID; 513 } 514 515 /* Handle key usage */ 516 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) { 517 if (usage->length > 0) { 518 x->ex_kusage = usage->data[0]; 519 if (usage->length > 1) 520 x->ex_kusage |= usage->data[1] << 8; 521 } else 522 x->ex_kusage = 0; 523 x->ex_flags |= EXFLAG_KUSAGE; 524 ASN1_BIT_STRING_free(usage); 525 } else if (i != -1) { 526 x->ex_flags |= EXFLAG_INVALID; 527 } 528 529 x->ex_xkusage = 0; 530 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) { 531 x->ex_flags |= EXFLAG_XKUSAGE; 532 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { 533 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) { 534 case NID_server_auth: 535 x->ex_xkusage |= XKU_SSL_SERVER; 536 break; 537 538 case NID_client_auth: 539 x->ex_xkusage |= XKU_SSL_CLIENT; 540 break; 541 542 case NID_email_protect: 543 x->ex_xkusage |= XKU_SMIME; 544 break; 545 546 case NID_code_sign: 547 x->ex_xkusage |= XKU_CODE_SIGN; 548 break; 549 550 case NID_ms_sgc: 551 case NID_ns_sgc: 552 x->ex_xkusage |= XKU_SGC; 553 break; 554 555 case NID_OCSP_sign: 556 x->ex_xkusage |= XKU_OCSP_SIGN; 557 break; 558 559 case NID_time_stamp: 560 x->ex_xkusage |= XKU_TIMESTAMP; 561 break; 562 563 case NID_dvcs: 564 x->ex_xkusage |= XKU_DVCS; 565 break; 566 567 case NID_anyExtendedKeyUsage: 568 x->ex_xkusage |= XKU_ANYEKU; 569 break; 570 } 571 } 572 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); 573 } else if (i != -1) { 574 x->ex_flags |= EXFLAG_INVALID; 575 } 576 577 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) { 578 if (ns->length > 0) 579 x->ex_nscert = ns->data[0]; 580 else 581 x->ex_nscert = 0; 582 x->ex_flags |= EXFLAG_NSCERT; 583 ASN1_BIT_STRING_free(ns); 584 } else if (i != -1) { 585 x->ex_flags |= EXFLAG_INVALID; 586 } 587 588 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL); 589 if (x->skid == NULL && i != -1) 590 x->ex_flags |= EXFLAG_INVALID; 591 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL); 592 if (x->akid == NULL && i != -1) 593 x->ex_flags |= EXFLAG_INVALID; 594 595 /* Does subject name match issuer? */ 596 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) { 597 x->ex_flags |= EXFLAG_SI; 598 /* If SKID matches AKID also indicate self signed. */ 599 if (X509_check_akid(x, x->akid) == X509_V_OK && 600 !ku_reject(x, KU_KEY_CERT_SIGN)) 601 x->ex_flags |= EXFLAG_SS; 602 } 603 604 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL); 605 if (x->altname == NULL && i != -1) 606 x->ex_flags |= EXFLAG_INVALID; 607 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL); 608 if (!x->nc && (i != -1)) 609 x->ex_flags |= EXFLAG_INVALID; 610 setup_crldp(x); 611 612 #ifndef OPENSSL_NO_RFC3779 613 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL); 614 if (x->rfc3779_addr == NULL && i != -1) 615 x->ex_flags |= EXFLAG_INVALID; 616 if (!X509v3_addr_is_canonical(x->rfc3779_addr)) 617 x->ex_flags |= EXFLAG_INVALID; 618 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL); 619 if (x->rfc3779_asid == NULL && i != -1) 620 x->ex_flags |= EXFLAG_INVALID; 621 if (!X509v3_asid_is_canonical(x->rfc3779_asid)) 622 x->ex_flags |= EXFLAG_INVALID; 623 #endif 624 625 for (i = 0; i < X509_get_ext_count(x); i++) { 626 ex = X509_get_ext(x, i); 627 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == 628 NID_freshest_crl) 629 x->ex_flags |= EXFLAG_FRESHEST; 630 if (!X509_EXTENSION_get_critical(ex)) 631 continue; 632 if (!X509_supported_extension(ex)) { 633 x->ex_flags |= EXFLAG_CRITICAL; 634 break; 635 } 636 } 637 638 x509_verify_cert_info_populate(x); 639 640 x->ex_flags |= EXFLAG_SET; 641 } 642 643 /* CA checks common to all purposes 644 * return codes: 645 * 0 not a CA 646 * 1 is a CA 647 * 2 basicConstraints absent so "maybe" a CA 648 * 3 basicConstraints absent but self signed V1. 649 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. 650 */ 651 652 static int 653 check_ca(const X509 *x) 654 { 655 /* keyUsage if present should allow cert signing */ 656 if (ku_reject(x, KU_KEY_CERT_SIGN)) 657 return 0; 658 if (x->ex_flags & EXFLAG_BCONS) { 659 if (x->ex_flags & EXFLAG_CA) 660 return 1; 661 /* If basicConstraints says not a CA then say so */ 662 else 663 return 0; 664 } else { 665 /* we support V1 roots for... uh, I don't really know why. */ 666 if ((x->ex_flags & V1_ROOT) == V1_ROOT) 667 return 3; 668 /* If key usage present it must have certSign so tolerate it */ 669 else if (x->ex_flags & EXFLAG_KUSAGE) 670 return 4; 671 /* Older certificates could have Netscape-specific CA types */ 672 else if (x->ex_flags & EXFLAG_NSCERT && 673 x->ex_nscert & NS_ANY_CA) 674 return 5; 675 /* can this still be regarded a CA certificate? I doubt it */ 676 return 0; 677 } 678 } 679 680 int 681 X509_check_ca(X509 *x) 682 { 683 if (!(x->ex_flags & EXFLAG_SET)) { 684 CRYPTO_w_lock(CRYPTO_LOCK_X509); 685 x509v3_cache_extensions(x); 686 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 687 } 688 689 return check_ca(x); 690 } 691 LCRYPTO_ALIAS(X509_check_ca) 692 693 /* Check SSL CA: common checks for SSL client and server */ 694 static int 695 check_ssl_ca(const X509 *x) 696 { 697 int ca_ret; 698 699 ca_ret = check_ca(x); 700 if (!ca_ret) 701 return 0; 702 /* check nsCertType if present */ 703 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA) 704 return ca_ret; 705 else 706 return 0; 707 } 708 709 static int 710 check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca) 711 { 712 if (xku_reject(x, XKU_SSL_CLIENT)) 713 return 0; 714 if (ca) 715 return check_ssl_ca(x); 716 /* We need to do digital signatures with it */ 717 if (ku_reject(x, KU_DIGITAL_SIGNATURE)) 718 return 0; 719 /* nsCertType if present should allow SSL client use */ 720 if (ns_reject(x, NS_SSL_CLIENT)) 721 return 0; 722 return 1; 723 } 724 725 static int 726 check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 727 { 728 if (xku_reject(x, XKU_SSL_SERVER|XKU_SGC)) 729 return 0; 730 if (ca) 731 return check_ssl_ca(x); 732 733 if (ns_reject(x, NS_SSL_SERVER)) 734 return 0; 735 /* Now as for keyUsage: we'll at least need to sign OR encipher */ 736 if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) 737 return 0; 738 739 return 1; 740 } 741 742 static int 743 check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 744 { 745 int ret; 746 747 ret = check_purpose_ssl_server(xp, x, ca); 748 if (!ret || ca) 749 return ret; 750 /* We need to encipher or Netscape complains */ 751 if (ku_reject(x, KU_KEY_ENCIPHERMENT)) 752 return 0; 753 return ret; 754 } 755 756 /* common S/MIME checks */ 757 static int 758 purpose_smime(const X509 *x, int ca) 759 { 760 if (xku_reject(x, XKU_SMIME)) 761 return 0; 762 if (ca) { 763 int ca_ret; 764 ca_ret = check_ca(x); 765 if (!ca_ret) 766 return 0; 767 /* check nsCertType if present */ 768 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) 769 return ca_ret; 770 else 771 return 0; 772 } 773 if (x->ex_flags & EXFLAG_NSCERT) { 774 if (x->ex_nscert & NS_SMIME) 775 return 1; 776 /* Workaround for some buggy certificates */ 777 if (x->ex_nscert & NS_SSL_CLIENT) 778 return 2; 779 return 0; 780 } 781 return 1; 782 } 783 784 static int 785 check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 786 { 787 int ret; 788 789 ret = purpose_smime(x, ca); 790 if (!ret || ca) 791 return ret; 792 if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) 793 return 0; 794 return ret; 795 } 796 797 static int 798 check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca) 799 { 800 int ret; 801 802 ret = purpose_smime(x, ca); 803 if (!ret || ca) 804 return ret; 805 if (ku_reject(x, KU_KEY_ENCIPHERMENT)) 806 return 0; 807 return ret; 808 } 809 810 static int 811 check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 812 { 813 if (ca) { 814 int ca_ret; 815 if ((ca_ret = check_ca(x)) != 2) 816 return ca_ret; 817 else 818 return 0; 819 } 820 if (ku_reject(x, KU_CRL_SIGN)) 821 return 0; 822 return 1; 823 } 824 825 /* OCSP helper: this is *not* a full OCSP check. It just checks that 826 * each CA is valid. Additional checks must be made on the chain. 827 */ 828 static int 829 ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) 830 { 831 /* Must be a valid CA. Should we really support the "I don't know" 832 value (2)? */ 833 if (ca) 834 return check_ca(x); 835 /* leaf certificate is checked in OCSP_verify() */ 836 return 1; 837 } 838 839 static int 840 check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 841 { 842 int i_ext; 843 844 /* If ca is true we must return if this is a valid CA certificate. */ 845 if (ca) 846 return check_ca(x); 847 848 /* 849 * Check the optional key usage field: 850 * if Key Usage is present, it must be one of digitalSignature 851 * and/or nonRepudiation (other values are not consistent and shall 852 * be rejected). 853 */ 854 if ((x->ex_flags & EXFLAG_KUSAGE) && 855 ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || 856 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) 857 return 0; 858 859 /* Only time stamp key usage is permitted and it's required. */ 860 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) 861 return 0; 862 863 /* Extended Key Usage MUST be critical */ 864 i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1); 865 if (i_ext >= 0) { 866 X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext); 867 if (!X509_EXTENSION_get_critical(ext)) 868 return 0; 869 } 870 871 return 1; 872 } 873 874 static int 875 no_check(const X509_PURPOSE *xp, const X509 *x, int ca) 876 { 877 return 1; 878 } 879 880 /* Various checks to see if one certificate issued the second. 881 * This can be used to prune a set of possible issuer certificates 882 * which have been looked up using some simple method such as by 883 * subject name. 884 * These are: 885 * 1. Check issuer_name(subject) == subject_name(issuer) 886 * 2. If akid(subject) exists check it matches issuer 887 * 3. If key_usage(issuer) exists check it supports certificate signing 888 * returns 0 for OK, positive for reason for mismatch, reasons match 889 * codes for X509_verify_cert() 890 */ 891 892 int 893 X509_check_issued(X509 *issuer, X509 *subject) 894 { 895 if (X509_NAME_cmp(X509_get_subject_name(issuer), 896 X509_get_issuer_name(subject))) 897 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; 898 if (!(issuer->ex_flags & EXFLAG_SET)) { 899 CRYPTO_w_lock(CRYPTO_LOCK_X509); 900 x509v3_cache_extensions(issuer); 901 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 902 } 903 if (issuer->ex_flags & EXFLAG_INVALID) 904 return X509_V_ERR_UNSPECIFIED; 905 if (!(subject->ex_flags & EXFLAG_SET)) { 906 CRYPTO_w_lock(CRYPTO_LOCK_X509); 907 x509v3_cache_extensions(subject); 908 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 909 } 910 if (subject->ex_flags & EXFLAG_INVALID) 911 return X509_V_ERR_UNSPECIFIED; 912 913 if (subject->akid) { 914 int ret = X509_check_akid(issuer, subject->akid); 915 if (ret != X509_V_OK) 916 return ret; 917 } 918 919 if (subject->ex_flags & EXFLAG_PROXY) { 920 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE)) 921 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE; 922 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) 923 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; 924 return X509_V_OK; 925 } 926 LCRYPTO_ALIAS(X509_check_issued) 927 928 int 929 X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) 930 { 931 if (!akid) 932 return X509_V_OK; 933 934 /* Check key ids (if present) */ 935 if (akid->keyid && issuer->skid && 936 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) ) 937 return X509_V_ERR_AKID_SKID_MISMATCH; 938 /* Check serial number */ 939 if (akid->serial && 940 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) 941 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 942 /* Check issuer name */ 943 if (akid->issuer) { 944 /* Ugh, for some peculiar reason AKID includes 945 * SEQUENCE OF GeneralName. So look for a DirName. 946 * There may be more than one but we only take any 947 * notice of the first. 948 */ 949 GENERAL_NAMES *gens; 950 GENERAL_NAME *gen; 951 X509_NAME *nm = NULL; 952 int i; 953 gens = akid->issuer; 954 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 955 gen = sk_GENERAL_NAME_value(gens, i); 956 if (gen->type == GEN_DIRNAME) { 957 nm = gen->d.dirn; 958 break; 959 } 960 } 961 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) 962 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 963 } 964 return X509_V_OK; 965 } 966 LCRYPTO_ALIAS(X509_check_akid) 967 968 uint32_t 969 X509_get_extension_flags(X509 *x) 970 { 971 /* Call for side-effect of computing hash and caching extensions */ 972 if (X509_check_purpose(x, -1, -1) != 1) 973 return EXFLAG_INVALID; 974 975 return x->ex_flags; 976 } 977 LCRYPTO_ALIAS(X509_get_extension_flags) 978 979 uint32_t 980 X509_get_key_usage(X509 *x) 981 { 982 /* Call for side-effect of computing hash and caching extensions */ 983 if (X509_check_purpose(x, -1, -1) != 1) 984 return 0; 985 986 if (x->ex_flags & EXFLAG_KUSAGE) 987 return x->ex_kusage; 988 989 return UINT32_MAX; 990 } 991 LCRYPTO_ALIAS(X509_get_key_usage) 992 993 uint32_t 994 X509_get_extended_key_usage(X509 *x) 995 { 996 /* Call for side-effect of computing hash and caching extensions */ 997 if (X509_check_purpose(x, -1, -1) != 1) 998 return 0; 999 1000 if (x->ex_flags & EXFLAG_XKUSAGE) 1001 return x->ex_xkusage; 1002 1003 return UINT32_MAX; 1004 } 1005 LCRYPTO_ALIAS(X509_get_extended_key_usage) 1006