1 /* $OpenBSD: x509_purp.c,v 1.19 2023/01/20 22:00:47 job 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 static int check_ssl_ca(const X509 *x); 80 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, 81 int ca); 82 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, 83 int ca); 84 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, 85 int ca); 86 static int purpose_smime(const X509 *x, int ca); 87 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, 88 int ca); 89 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, 90 int ca); 91 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, 92 int ca); 93 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, 94 int ca); 95 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); 96 static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); 97 98 static int xp_cmp(const X509_PURPOSE * const *a, const X509_PURPOSE * const *b); 99 static void xptable_free(X509_PURPOSE *p); 100 101 static X509_PURPOSE xstandard[] = { 102 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL}, 103 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL}, 104 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL}, 105 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL}, 106 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL}, 107 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL}, 108 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL}, 109 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL}, 110 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", NULL}, 111 }; 112 113 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE)) 114 115 static STACK_OF(X509_PURPOSE) *xptable = NULL; 116 117 static int 118 xp_cmp(const X509_PURPOSE * const *a, const X509_PURPOSE * const *b) 119 { 120 return (*a)->purpose - (*b)->purpose; 121 } 122 123 /* As much as I'd like to make X509_check_purpose use a "const" X509* 124 * I really can't because it does recalculate hashes and do other non-const 125 * things. */ 126 int 127 X509_check_purpose(X509 *x, int id, int ca) 128 { 129 int idx; 130 const X509_PURPOSE *pt; 131 132 if (!x509v3_cache_extensions(x)) 133 return -1; 134 135 if (id == -1) 136 return 1; 137 idx = X509_PURPOSE_get_by_id(id); 138 if (idx == -1) 139 return -1; 140 pt = X509_PURPOSE_get0(idx); 141 return pt->check_purpose(pt, x, ca); 142 } 143 LCRYPTO_ALIAS(X509_check_purpose) 144 145 int 146 X509_PURPOSE_set(int *p, int purpose) 147 { 148 if (X509_PURPOSE_get_by_id(purpose) == -1) { 149 X509V3error(X509V3_R_INVALID_PURPOSE); 150 return 0; 151 } 152 *p = purpose; 153 return 1; 154 } 155 LCRYPTO_ALIAS(X509_PURPOSE_set) 156 157 int 158 X509_PURPOSE_get_count(void) 159 { 160 if (!xptable) 161 return X509_PURPOSE_COUNT; 162 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; 163 } 164 LCRYPTO_ALIAS(X509_PURPOSE_get_count) 165 166 X509_PURPOSE * 167 X509_PURPOSE_get0(int idx) 168 { 169 if (idx < 0) 170 return NULL; 171 if (idx < (int)X509_PURPOSE_COUNT) 172 return xstandard + idx; 173 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); 174 } 175 LCRYPTO_ALIAS(X509_PURPOSE_get0) 176 177 int 178 X509_PURPOSE_get_by_sname(const char *sname) 179 { 180 int i; 181 X509_PURPOSE *xptmp; 182 183 for (i = 0; i < X509_PURPOSE_get_count(); i++) { 184 xptmp = X509_PURPOSE_get0(i); 185 if (!strcmp(xptmp->sname, sname)) 186 return i; 187 } 188 return -1; 189 } 190 LCRYPTO_ALIAS(X509_PURPOSE_get_by_sname) 191 192 int 193 X509_PURPOSE_get_by_id(int purpose) 194 { 195 X509_PURPOSE tmp; 196 int idx; 197 198 if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) 199 return purpose - X509_PURPOSE_MIN; 200 tmp.purpose = purpose; 201 if (!xptable) 202 return -1; 203 idx = sk_X509_PURPOSE_find(xptable, &tmp); 204 if (idx == -1) 205 return -1; 206 return idx + X509_PURPOSE_COUNT; 207 } 208 LCRYPTO_ALIAS(X509_PURPOSE_get_by_id) 209 210 int 211 X509_PURPOSE_add(int id, int trust, int flags, 212 int (*ck)(const X509_PURPOSE *, const X509 *, int), const char *name, 213 const char *sname, void *arg) 214 { 215 int idx; 216 X509_PURPOSE *ptmp; 217 char *name_dup, *sname_dup; 218 219 name_dup = sname_dup = NULL; 220 221 if (name == NULL || sname == NULL) { 222 X509V3error(X509V3_R_INVALID_NULL_ARGUMENT); 223 return 0; 224 } 225 226 /* This is set according to what we change: application can't set it */ 227 flags &= ~X509_PURPOSE_DYNAMIC; 228 /* This will always be set for application modified trust entries */ 229 flags |= X509_PURPOSE_DYNAMIC_NAME; 230 /* Get existing entry if any */ 231 idx = X509_PURPOSE_get_by_id(id); 232 /* Need a new entry */ 233 if (idx == -1) { 234 if ((ptmp = malloc(sizeof(X509_PURPOSE))) == NULL) { 235 X509V3error(ERR_R_MALLOC_FAILURE); 236 return 0; 237 } 238 ptmp->flags = X509_PURPOSE_DYNAMIC; 239 } else 240 ptmp = X509_PURPOSE_get0(idx); 241 242 if ((name_dup = strdup(name)) == NULL) 243 goto err; 244 if ((sname_dup = strdup(sname)) == NULL) 245 goto err; 246 247 /* free existing name if dynamic */ 248 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { 249 free(ptmp->name); 250 free(ptmp->sname); 251 } 252 /* dup supplied name */ 253 ptmp->name = name_dup; 254 ptmp->sname = sname_dup; 255 /* Keep the dynamic flag of existing entry */ 256 ptmp->flags &= X509_PURPOSE_DYNAMIC; 257 /* Set all other flags */ 258 ptmp->flags |= flags; 259 260 ptmp->purpose = id; 261 ptmp->trust = trust; 262 ptmp->check_purpose = ck; 263 ptmp->usr_data = arg; 264 265 /* If its a new entry manage the dynamic table */ 266 if (idx == -1) { 267 if (xptable == NULL && 268 (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) 269 goto err; 270 if (sk_X509_PURPOSE_push(xptable, ptmp) == 0) 271 goto err; 272 } 273 return 1; 274 275 err: 276 free(name_dup); 277 free(sname_dup); 278 if (idx == -1) 279 free(ptmp); 280 X509V3error(ERR_R_MALLOC_FAILURE); 281 return 0; 282 } 283 LCRYPTO_ALIAS(X509_PURPOSE_add) 284 285 static void 286 xptable_free(X509_PURPOSE *p) 287 { 288 if (!p) 289 return; 290 if (p->flags & X509_PURPOSE_DYNAMIC) { 291 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { 292 free(p->name); 293 free(p->sname); 294 } 295 free(p); 296 } 297 } 298 299 void 300 X509_PURPOSE_cleanup(void) 301 { 302 sk_X509_PURPOSE_pop_free(xptable, xptable_free); 303 xptable = NULL; 304 } 305 LCRYPTO_ALIAS(X509_PURPOSE_cleanup) 306 307 int 308 X509_PURPOSE_get_id(const X509_PURPOSE *xp) 309 { 310 return xp->purpose; 311 } 312 LCRYPTO_ALIAS(X509_PURPOSE_get_id) 313 314 char * 315 X509_PURPOSE_get0_name(const X509_PURPOSE *xp) 316 { 317 return xp->name; 318 } 319 LCRYPTO_ALIAS(X509_PURPOSE_get0_name) 320 321 char * 322 X509_PURPOSE_get0_sname(const X509_PURPOSE *xp) 323 { 324 return xp->sname; 325 } 326 LCRYPTO_ALIAS(X509_PURPOSE_get0_sname) 327 328 int 329 X509_PURPOSE_get_trust(const X509_PURPOSE *xp) 330 { 331 return xp->trust; 332 } 333 LCRYPTO_ALIAS(X509_PURPOSE_get_trust) 334 335 static int 336 nid_cmp(const int *a, const int *b) 337 { 338 return *a - *b; 339 } 340 341 static int nid_cmp_BSEARCH_CMP_FN(const void *, const void *); 342 static int nid_cmp(int const *, int const *); 343 static int *OBJ_bsearch_nid(int *key, int const *base, int num); 344 345 static int 346 nid_cmp_BSEARCH_CMP_FN(const void *a_, const void *b_) 347 { 348 int const *a = a_; 349 int const *b = b_; 350 return nid_cmp(a, b); 351 } 352 353 static int * 354 OBJ_bsearch_nid(int *key, int const *base, int num) 355 { 356 return (int *)OBJ_bsearch_(key, base, num, sizeof(int), 357 nid_cmp_BSEARCH_CMP_FN); 358 } 359 360 int 361 X509_supported_extension(X509_EXTENSION *ex) 362 { 363 /* This table is a list of the NIDs of supported extensions: 364 * that is those which are used by the verify process. If 365 * an extension is critical and doesn't appear in this list 366 * then the verify process will normally reject the certificate. 367 * The list must be kept in numerical order because it will be 368 * searched using bsearch. 369 */ 370 371 static const int supported_nids[] = { 372 NID_netscape_cert_type, /* 71 */ 373 NID_key_usage, /* 83 */ 374 NID_subject_alt_name, /* 85 */ 375 NID_basic_constraints, /* 87 */ 376 NID_certificate_policies, /* 89 */ 377 NID_ext_key_usage, /* 126 */ 378 #ifndef OPENSSL_NO_RFC3779 379 NID_sbgp_ipAddrBlock, /* 290 */ 380 NID_sbgp_autonomousSysNum, /* 291 */ 381 #endif 382 NID_policy_constraints, /* 401 */ 383 NID_proxyCertInfo, /* 663 */ 384 NID_name_constraints, /* 666 */ 385 NID_policy_mappings, /* 747 */ 386 NID_inhibit_any_policy /* 748 */ 387 }; 388 389 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); 390 391 if (ex_nid == NID_undef) 392 return 0; 393 394 if (OBJ_bsearch_nid(&ex_nid, supported_nids, 395 sizeof(supported_nids) / sizeof(int))) 396 return 1; 397 return 0; 398 } 399 LCRYPTO_ALIAS(X509_supported_extension) 400 401 static void 402 setup_dp(X509 *x, DIST_POINT *dp) 403 { 404 X509_NAME *iname = NULL; 405 int i; 406 407 if (dp->reasons) { 408 if (dp->reasons->length > 0) 409 dp->dp_reasons = dp->reasons->data[0]; 410 if (dp->reasons->length > 1) 411 dp->dp_reasons |= (dp->reasons->data[1] << 8); 412 dp->dp_reasons &= CRLDP_ALL_REASONS; 413 } else 414 dp->dp_reasons = CRLDP_ALL_REASONS; 415 if (!dp->distpoint || (dp->distpoint->type != 1)) 416 return; 417 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { 418 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 419 if (gen->type == GEN_DIRNAME) { 420 iname = gen->d.directoryName; 421 break; 422 } 423 } 424 if (!iname) 425 iname = X509_get_issuer_name(x); 426 427 DIST_POINT_set_dpname(dp->distpoint, iname); 428 429 } 430 431 static void 432 setup_crldp(X509 *x) 433 { 434 int i; 435 436 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL); 437 if (x->crldp == NULL && i != -1) { 438 x->ex_flags |= EXFLAG_INVALID; 439 return; 440 } 441 442 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) 443 setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); 444 } 445 446 static void 447 x509v3_cache_extensions_internal(X509 *x) 448 { 449 BASIC_CONSTRAINTS *bs; 450 PROXY_CERT_INFO_EXTENSION *pci; 451 ASN1_BIT_STRING *usage; 452 ASN1_BIT_STRING *ns; 453 EXTENDED_KEY_USAGE *extusage; 454 X509_EXTENSION *ex; 455 int i; 456 457 if (x->ex_flags & EXFLAG_SET) 458 return; 459 460 X509_digest(x, X509_CERT_HASH_EVP, x->hash, NULL); 461 462 /* V1 should mean no extensions ... */ 463 if (!X509_get_version(x)) 464 x->ex_flags |= EXFLAG_V1; 465 466 /* Handle basic constraints */ 467 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL))) { 468 if (bs->ca) 469 x->ex_flags |= EXFLAG_CA; 470 if (bs->pathlen) { 471 if ((bs->pathlen->type == V_ASN1_NEG_INTEGER) || 472 !bs->ca) { 473 x->ex_flags |= EXFLAG_INVALID; 474 x->ex_pathlen = 0; 475 } else 476 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); 477 } else 478 x->ex_pathlen = -1; 479 BASIC_CONSTRAINTS_free(bs); 480 x->ex_flags |= EXFLAG_BCONS; 481 } else if (i != -1) { 482 x->ex_flags |= EXFLAG_INVALID; 483 } 484 485 /* Handle proxy certificates */ 486 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL))) { 487 if (x->ex_flags & EXFLAG_CA || 488 X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 || 489 X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) { 490 x->ex_flags |= EXFLAG_INVALID; 491 } 492 if (pci->pcPathLengthConstraint) { 493 if (pci->pcPathLengthConstraint->type == 494 V_ASN1_NEG_INTEGER) { 495 x->ex_flags |= EXFLAG_INVALID; 496 x->ex_pcpathlen = 0; 497 } else 498 x->ex_pcpathlen = 499 ASN1_INTEGER_get(pci-> 500 pcPathLengthConstraint); 501 } else 502 x->ex_pcpathlen = -1; 503 PROXY_CERT_INFO_EXTENSION_free(pci); 504 x->ex_flags |= EXFLAG_PROXY; 505 } else if (i != -1) { 506 x->ex_flags |= EXFLAG_INVALID; 507 } 508 509 /* Handle key usage */ 510 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL))) { 511 if (usage->length > 0) { 512 x->ex_kusage = usage->data[0]; 513 if (usage->length > 1) 514 x->ex_kusage |= usage->data[1] << 8; 515 } else 516 x->ex_kusage = 0; 517 x->ex_flags |= EXFLAG_KUSAGE; 518 ASN1_BIT_STRING_free(usage); 519 } else if (i != -1) { 520 x->ex_flags |= EXFLAG_INVALID; 521 } 522 523 x->ex_xkusage = 0; 524 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL))) { 525 x->ex_flags |= EXFLAG_XKUSAGE; 526 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { 527 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) { 528 case NID_server_auth: 529 x->ex_xkusage |= XKU_SSL_SERVER; 530 break; 531 532 case NID_client_auth: 533 x->ex_xkusage |= XKU_SSL_CLIENT; 534 break; 535 536 case NID_email_protect: 537 x->ex_xkusage |= XKU_SMIME; 538 break; 539 540 case NID_code_sign: 541 x->ex_xkusage |= XKU_CODE_SIGN; 542 break; 543 544 case NID_ms_sgc: 545 case NID_ns_sgc: 546 x->ex_xkusage |= XKU_SGC; 547 break; 548 549 case NID_OCSP_sign: 550 x->ex_xkusage |= XKU_OCSP_SIGN; 551 break; 552 553 case NID_time_stamp: 554 x->ex_xkusage |= XKU_TIMESTAMP; 555 break; 556 557 case NID_dvcs: 558 x->ex_xkusage |= XKU_DVCS; 559 break; 560 561 case NID_anyExtendedKeyUsage: 562 x->ex_xkusage |= XKU_ANYEKU; 563 break; 564 } 565 } 566 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); 567 } else if (i != -1) { 568 x->ex_flags |= EXFLAG_INVALID; 569 } 570 571 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL))) { 572 if (ns->length > 0) 573 x->ex_nscert = ns->data[0]; 574 else 575 x->ex_nscert = 0; 576 x->ex_flags |= EXFLAG_NSCERT; 577 ASN1_BIT_STRING_free(ns); 578 } else if (i != -1) { 579 x->ex_flags |= EXFLAG_INVALID; 580 } 581 582 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL); 583 if (x->skid == NULL && i != -1) 584 x->ex_flags |= EXFLAG_INVALID; 585 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL); 586 if (x->akid == NULL && i != -1) 587 x->ex_flags |= EXFLAG_INVALID; 588 589 /* Does subject name match issuer? */ 590 if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) { 591 x->ex_flags |= EXFLAG_SI; 592 /* If SKID matches AKID also indicate self signed. */ 593 if (X509_check_akid(x, x->akid) == X509_V_OK && 594 !ku_reject(x, KU_KEY_CERT_SIGN)) 595 x->ex_flags |= EXFLAG_SS; 596 } 597 598 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL); 599 if (x->altname == NULL && i != -1) 600 x->ex_flags |= EXFLAG_INVALID; 601 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL); 602 if (!x->nc && (i != -1)) 603 x->ex_flags |= EXFLAG_INVALID; 604 setup_crldp(x); 605 606 #ifndef OPENSSL_NO_RFC3779 607 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL); 608 if (x->rfc3779_addr == NULL && i != -1) 609 x->ex_flags |= EXFLAG_INVALID; 610 if (!X509v3_addr_is_canonical(x->rfc3779_addr)) 611 x->ex_flags |= EXFLAG_INVALID; 612 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL); 613 if (x->rfc3779_asid == NULL && i != -1) 614 x->ex_flags |= EXFLAG_INVALID; 615 if (!X509v3_asid_is_canonical(x->rfc3779_asid)) 616 x->ex_flags |= EXFLAG_INVALID; 617 #endif 618 619 for (i = 0; i < X509_get_ext_count(x); i++) { 620 ex = X509_get_ext(x, i); 621 if (OBJ_obj2nid(X509_EXTENSION_get_object(ex)) == 622 NID_freshest_crl) 623 x->ex_flags |= EXFLAG_FRESHEST; 624 if (!X509_EXTENSION_get_critical(ex)) 625 continue; 626 if (!X509_supported_extension(ex)) { 627 x->ex_flags |= EXFLAG_CRITICAL; 628 break; 629 } 630 } 631 632 x509_verify_cert_info_populate(x); 633 634 x->ex_flags |= EXFLAG_SET; 635 } 636 637 int 638 x509v3_cache_extensions(X509 *x) 639 { 640 if ((x->ex_flags & EXFLAG_SET) == 0) { 641 CRYPTO_w_lock(CRYPTO_LOCK_X509); 642 x509v3_cache_extensions_internal(x); 643 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 644 } 645 646 return (x->ex_flags & EXFLAG_INVALID) == 0; 647 } 648 649 /* CA checks common to all purposes 650 * return codes: 651 * 0 not a CA 652 * 1 is a CA 653 * 2 basicConstraints absent so "maybe" a CA 654 * 3 basicConstraints absent but self signed V1. 655 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. 656 */ 657 658 static int 659 check_ca(const X509 *x) 660 { 661 /* keyUsage if present should allow cert signing */ 662 if (ku_reject(x, KU_KEY_CERT_SIGN)) 663 return 0; 664 if (x->ex_flags & EXFLAG_BCONS) { 665 if (x->ex_flags & EXFLAG_CA) 666 return 1; 667 /* If basicConstraints says not a CA then say so */ 668 else 669 return 0; 670 } else { 671 /* we support V1 roots for... uh, I don't really know why. */ 672 if ((x->ex_flags & V1_ROOT) == V1_ROOT) 673 return 3; 674 /* If key usage present it must have certSign so tolerate it */ 675 else if (x->ex_flags & EXFLAG_KUSAGE) 676 return 4; 677 /* Older certificates could have Netscape-specific CA types */ 678 else if (x->ex_flags & EXFLAG_NSCERT && 679 x->ex_nscert & NS_ANY_CA) 680 return 5; 681 /* can this still be regarded a CA certificate? I doubt it */ 682 return 0; 683 } 684 } 685 686 int 687 X509_check_ca(X509 *x) 688 { 689 x509v3_cache_extensions(x); 690 691 return check_ca(x); 692 } 693 LCRYPTO_ALIAS(X509_check_ca) 694 695 /* Check SSL CA: common checks for SSL client and server */ 696 static int 697 check_ssl_ca(const X509 *x) 698 { 699 int ca_ret; 700 701 ca_ret = check_ca(x); 702 if (!ca_ret) 703 return 0; 704 /* check nsCertType if present */ 705 if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA) 706 return ca_ret; 707 else 708 return 0; 709 } 710 711 static int 712 check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca) 713 { 714 if (xku_reject(x, XKU_SSL_CLIENT)) 715 return 0; 716 if (ca) 717 return check_ssl_ca(x); 718 /* We need to do digital signatures with it */ 719 if (ku_reject(x, KU_DIGITAL_SIGNATURE)) 720 return 0; 721 /* nsCertType if present should allow SSL client use */ 722 if (ns_reject(x, NS_SSL_CLIENT)) 723 return 0; 724 return 1; 725 } 726 727 static int 728 check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 729 { 730 if (xku_reject(x, XKU_SSL_SERVER|XKU_SGC)) 731 return 0; 732 if (ca) 733 return check_ssl_ca(x); 734 735 if (ns_reject(x, NS_SSL_SERVER)) 736 return 0; 737 /* Now as for keyUsage: we'll at least need to sign OR encipher */ 738 if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) 739 return 0; 740 741 return 1; 742 } 743 744 static int 745 check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 746 { 747 int ret; 748 749 ret = check_purpose_ssl_server(xp, x, ca); 750 if (!ret || ca) 751 return ret; 752 /* We need to encipher or Netscape complains */ 753 if (ku_reject(x, KU_KEY_ENCIPHERMENT)) 754 return 0; 755 return ret; 756 } 757 758 /* common S/MIME checks */ 759 static int 760 purpose_smime(const X509 *x, int ca) 761 { 762 if (xku_reject(x, XKU_SMIME)) 763 return 0; 764 if (ca) { 765 int ca_ret; 766 ca_ret = check_ca(x); 767 if (!ca_ret) 768 return 0; 769 /* check nsCertType if present */ 770 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) 771 return ca_ret; 772 else 773 return 0; 774 } 775 if (x->ex_flags & EXFLAG_NSCERT) { 776 if (x->ex_nscert & NS_SMIME) 777 return 1; 778 /* Workaround for some buggy certificates */ 779 if (x->ex_nscert & NS_SSL_CLIENT) 780 return 2; 781 return 0; 782 } 783 return 1; 784 } 785 786 static int 787 check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 788 { 789 int ret; 790 791 ret = purpose_smime(x, ca); 792 if (!ret || ca) 793 return ret; 794 if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) 795 return 0; 796 return ret; 797 } 798 799 static int 800 check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca) 801 { 802 int ret; 803 804 ret = purpose_smime(x, ca); 805 if (!ret || ca) 806 return ret; 807 if (ku_reject(x, KU_KEY_ENCIPHERMENT)) 808 return 0; 809 return ret; 810 } 811 812 static int 813 check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 814 { 815 if (ca) { 816 int ca_ret; 817 if ((ca_ret = check_ca(x)) != 2) 818 return ca_ret; 819 else 820 return 0; 821 } 822 if (ku_reject(x, KU_CRL_SIGN)) 823 return 0; 824 return 1; 825 } 826 827 /* OCSP helper: this is *not* a full OCSP check. It just checks that 828 * each CA is valid. Additional checks must be made on the chain. 829 */ 830 static int 831 ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) 832 { 833 /* Must be a valid CA. Should we really support the "I don't know" 834 value (2)? */ 835 if (ca) 836 return check_ca(x); 837 /* leaf certificate is checked in OCSP_verify() */ 838 return 1; 839 } 840 841 static int 842 check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 843 { 844 int i_ext; 845 846 /* If ca is true we must return if this is a valid CA certificate. */ 847 if (ca) 848 return check_ca(x); 849 850 /* 851 * Check the optional key usage field: 852 * if Key Usage is present, it must be one of digitalSignature 853 * and/or nonRepudiation (other values are not consistent and shall 854 * be rejected). 855 */ 856 if ((x->ex_flags & EXFLAG_KUSAGE) && 857 ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || 858 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) 859 return 0; 860 861 /* Only time stamp key usage is permitted and it's required. */ 862 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) 863 return 0; 864 865 /* Extended Key Usage MUST be critical */ 866 i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, -1); 867 if (i_ext >= 0) { 868 X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext); 869 if (!X509_EXTENSION_get_critical(ext)) 870 return 0; 871 } 872 873 return 1; 874 } 875 876 static int 877 no_check(const X509_PURPOSE *xp, const X509 *x, int ca) 878 { 879 return 1; 880 } 881 882 /* Various checks to see if one certificate issued the second. 883 * This can be used to prune a set of possible issuer certificates 884 * which have been looked up using some simple method such as by 885 * subject name. 886 * These are: 887 * 1. Check issuer_name(subject) == subject_name(issuer) 888 * 2. If akid(subject) exists check it matches issuer 889 * 3. If key_usage(issuer) exists check it supports certificate signing 890 * returns 0 for OK, positive for reason for mismatch, reasons match 891 * codes for X509_verify_cert() 892 */ 893 894 int 895 X509_check_issued(X509 *issuer, X509 *subject) 896 { 897 if (X509_NAME_cmp(X509_get_subject_name(issuer), 898 X509_get_issuer_name(subject))) 899 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; 900 901 if (!x509v3_cache_extensions(issuer)) 902 return X509_V_ERR_UNSPECIFIED; 903 if (!x509v3_cache_extensions(subject)) 904 return X509_V_ERR_UNSPECIFIED; 905 906 if (subject->akid) { 907 int ret = X509_check_akid(issuer, subject->akid); 908 if (ret != X509_V_OK) 909 return ret; 910 } 911 912 if (subject->ex_flags & EXFLAG_PROXY) { 913 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE)) 914 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE; 915 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) 916 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; 917 return X509_V_OK; 918 } 919 LCRYPTO_ALIAS(X509_check_issued) 920 921 int 922 X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) 923 { 924 if (!akid) 925 return X509_V_OK; 926 927 /* Check key ids (if present) */ 928 if (akid->keyid && issuer->skid && 929 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid) ) 930 return X509_V_ERR_AKID_SKID_MISMATCH; 931 /* Check serial number */ 932 if (akid->serial && 933 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) 934 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 935 /* Check issuer name */ 936 if (akid->issuer) { 937 /* Ugh, for some peculiar reason AKID includes 938 * SEQUENCE OF GeneralName. So look for a DirName. 939 * There may be more than one but we only take any 940 * notice of the first. 941 */ 942 GENERAL_NAMES *gens; 943 GENERAL_NAME *gen; 944 X509_NAME *nm = NULL; 945 int i; 946 gens = akid->issuer; 947 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 948 gen = sk_GENERAL_NAME_value(gens, i); 949 if (gen->type == GEN_DIRNAME) { 950 nm = gen->d.dirn; 951 break; 952 } 953 } 954 if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) 955 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 956 } 957 return X509_V_OK; 958 } 959 LCRYPTO_ALIAS(X509_check_akid) 960 961 uint32_t 962 X509_get_extension_flags(X509 *x) 963 { 964 /* Call for side-effect of computing hash and caching extensions */ 965 if (X509_check_purpose(x, -1, -1) != 1) 966 return EXFLAG_INVALID; 967 968 return x->ex_flags; 969 } 970 LCRYPTO_ALIAS(X509_get_extension_flags) 971 972 uint32_t 973 X509_get_key_usage(X509 *x) 974 { 975 /* Call for side-effect of computing hash and caching extensions */ 976 if (X509_check_purpose(x, -1, -1) != 1) 977 return 0; 978 979 if (x->ex_flags & EXFLAG_KUSAGE) 980 return x->ex_kusage; 981 982 return UINT32_MAX; 983 } 984 LCRYPTO_ALIAS(X509_get_key_usage) 985 986 uint32_t 987 X509_get_extended_key_usage(X509 *x) 988 { 989 /* Call for side-effect of computing hash and caching extensions */ 990 if (X509_check_purpose(x, -1, -1) != 1) 991 return 0; 992 993 if (x->ex_flags & EXFLAG_XKUSAGE) 994 return x->ex_xkusage; 995 996 return UINT32_MAX; 997 } 998 LCRYPTO_ALIAS(X509_get_extended_key_usage) 999