1/* v3_purp.c */ 2/* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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 "cryptlib.h" 61#include <openssl/x509v3.h> 62#include <openssl/x509_vfy.h> 63 64static void x509v3_cache_extensions(X509 *x); 65 66static int check_ssl_ca(const X509 *x); 67static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca); 68static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); 69static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca); 70static int purpose_smime(const X509 *x, int ca); 71static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 72static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca); 73static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca); 74static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca); 75static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca); 76 77static int xp_cmp(const X509_PURPOSE * const *a, 78 const X509_PURPOSE * const *b); 79static void xptable_free(X509_PURPOSE *p); 80 81static X509_PURPOSE xstandard[] = { 82 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL}, 83 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL}, 84 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL}, 85 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL}, 86 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL}, 87 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL}, 88 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL}, 89 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL}, 90}; 91 92#define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE)) 93 94IMPLEMENT_STACK_OF(X509_PURPOSE) 95 96static STACK_OF(X509_PURPOSE) *xptable = NULL; 97 98static int xp_cmp(const X509_PURPOSE * const *a, 99 const X509_PURPOSE * const *b) 100{ 101 return (*a)->purpose - (*b)->purpose; 102} 103 104/* As much as I'd like to make X509_check_purpose use a "const" X509* 105 * I really can't because it does recalculate hashes and do other non-const 106 * things. */ 107int X509_check_purpose(X509 *x, int id, int ca) 108{ 109 int idx; 110 const X509_PURPOSE *pt; 111 if(!(x->ex_flags & EXFLAG_SET)) { 112 CRYPTO_w_lock(CRYPTO_LOCK_X509); 113 x509v3_cache_extensions(x); 114 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 115 } 116 if(id == -1) return 1; 117 idx = X509_PURPOSE_get_by_id(id); 118 if(idx == -1) return -1; 119 pt = X509_PURPOSE_get0(idx); 120 return pt->check_purpose(pt, x, ca); 121} 122 123int X509_PURPOSE_set(int *p, int purpose) 124{ 125 if(X509_PURPOSE_get_by_id(purpose) == -1) { 126 X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE); 127 return 0; 128 } 129 *p = purpose; 130 return 1; 131} 132 133int X509_PURPOSE_get_count(void) 134{ 135 if(!xptable) return X509_PURPOSE_COUNT; 136 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; 137} 138 139X509_PURPOSE * X509_PURPOSE_get0(int idx) 140{ 141 if(idx < 0) return NULL; 142 if(idx < X509_PURPOSE_COUNT) return xstandard + idx; 143 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); 144} 145 146int X509_PURPOSE_get_by_sname(char *sname) 147{ 148 int i; 149 X509_PURPOSE *xptmp; 150 for(i = 0; i < X509_PURPOSE_get_count(); i++) { 151 xptmp = X509_PURPOSE_get0(i); 152 if(!strcmp(xptmp->sname, sname)) return i; 153 } 154 return -1; 155} 156 157int X509_PURPOSE_get_by_id(int purpose) 158{ 159 X509_PURPOSE tmp; 160 int idx; 161 if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) 162 return purpose - X509_PURPOSE_MIN; 163 tmp.purpose = purpose; 164 if(!xptable) return -1; 165 idx = sk_X509_PURPOSE_find(xptable, &tmp); 166 if(idx == -1) return -1; 167 return idx + X509_PURPOSE_COUNT; 168} 169 170int X509_PURPOSE_add(int id, int trust, int flags, 171 int (*ck)(const X509_PURPOSE *, const X509 *, int), 172 char *name, char *sname, void *arg) 173{ 174 int idx; 175 X509_PURPOSE *ptmp; 176 /* This is set according to what we change: application can't set it */ 177 flags &= ~X509_PURPOSE_DYNAMIC; 178 /* This will always be set for application modified trust entries */ 179 flags |= X509_PURPOSE_DYNAMIC_NAME; 180 /* Get existing entry if any */ 181 idx = X509_PURPOSE_get_by_id(id); 182 /* Need a new entry */ 183 if(idx == -1) { 184 if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) { 185 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 186 return 0; 187 } 188 ptmp->flags = X509_PURPOSE_DYNAMIC; 189 } else ptmp = X509_PURPOSE_get0(idx); 190 191 /* OPENSSL_free existing name if dynamic */ 192 if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { 193 OPENSSL_free(ptmp->name); 194 OPENSSL_free(ptmp->sname); 195 } 196 /* dup supplied name */ 197 ptmp->name = BUF_strdup(name); 198 ptmp->sname = BUF_strdup(sname); 199 if(!ptmp->name || !ptmp->sname) { 200 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 201 return 0; 202 } 203 /* Keep the dynamic flag of existing entry */ 204 ptmp->flags &= X509_PURPOSE_DYNAMIC; 205 /* Set all other flags */ 206 ptmp->flags |= flags; 207 208 ptmp->purpose = id; 209 ptmp->trust = trust; 210 ptmp->check_purpose = ck; 211 ptmp->usr_data = arg; 212 213 /* If its a new entry manage the dynamic table */ 214 if(idx == -1) { 215 if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) { 216 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 217 return 0; 218 } 219 if (!sk_X509_PURPOSE_push(xptable, ptmp)) { 220 X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE); 221 return 0; 222 } 223 } 224 return 1; 225} 226 227static void xptable_free(X509_PURPOSE *p) 228 { 229 if(!p) return; 230 if (p->flags & X509_PURPOSE_DYNAMIC) 231 { 232 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { 233 OPENSSL_free(p->name); 234 OPENSSL_free(p->sname); 235 } 236 OPENSSL_free(p); 237 } 238 } 239 240void X509_PURPOSE_cleanup(void) 241{ 242 int i; 243 sk_X509_PURPOSE_pop_free(xptable, xptable_free); 244 for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i); 245 xptable = NULL; 246} 247 248int X509_PURPOSE_get_id(X509_PURPOSE *xp) 249{ 250 return xp->purpose; 251} 252 253char *X509_PURPOSE_get0_name(X509_PURPOSE *xp) 254{ 255 return xp->name; 256} 257 258char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp) 259{ 260 return xp->sname; 261} 262 263int X509_PURPOSE_get_trust(X509_PURPOSE *xp) 264{ 265 return xp->trust; 266} 267 268static int nid_cmp(int *a, int *b) 269 { 270 return *a - *b; 271 } 272 273int X509_supported_extension(X509_EXTENSION *ex) 274 { 275 /* This table is a list of the NIDs of supported extensions: 276 * that is those which are used by the verify process. If 277 * an extension is critical and doesn't appear in this list 278 * then the verify process will normally reject the certificate. 279 * The list must be kept in numerical order because it will be 280 * searched using bsearch. 281 */ 282 283 static int supported_nids[] = { 284 NID_netscape_cert_type, /* 71 */ 285 NID_key_usage, /* 83 */ 286 NID_subject_alt_name, /* 85 */ 287 NID_basic_constraints, /* 87 */ 288 NID_ext_key_usage /* 126 */ 289 }; 290 291 int ex_nid; 292 293 ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); 294 295 if (ex_nid == NID_undef) 296 return 0; 297 298 if (OBJ_bsearch((char *)&ex_nid, (char *)supported_nids, 299 sizeof(supported_nids)/sizeof(int), sizeof(int), 300 (int (*)(const void *, const void *))nid_cmp)) 301 return 1; 302 return 0; 303 } 304 305 306static void x509v3_cache_extensions(X509 *x) 307{ 308 BASIC_CONSTRAINTS *bs; 309 ASN1_BIT_STRING *usage; 310 ASN1_BIT_STRING *ns; 311 EXTENDED_KEY_USAGE *extusage; 312 X509_EXTENSION *ex; 313 314 int i; 315 if(x->ex_flags & EXFLAG_SET) return; 316#ifndef OPENSSL_NO_SHA 317 X509_digest(x, EVP_sha1(), x->sha1_hash, NULL); 318#endif 319 /* Does subject name match issuer ? */ 320 if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) 321 x->ex_flags |= EXFLAG_SS; 322 /* V1 should mean no extensions ... */ 323 if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1; 324 /* Handle basic constraints */ 325 if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) { 326 if(bs->ca) x->ex_flags |= EXFLAG_CA; 327 if(bs->pathlen) { 328 if((bs->pathlen->type == V_ASN1_NEG_INTEGER) 329 || !bs->ca) { 330 x->ex_flags |= EXFLAG_INVALID; 331 x->ex_pathlen = 0; 332 } else x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); 333 } else x->ex_pathlen = -1; 334 BASIC_CONSTRAINTS_free(bs); 335 x->ex_flags |= EXFLAG_BCONS; 336 } 337 /* Handle key usage */ 338 if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) { 339 if(usage->length > 0) { 340 x->ex_kusage = usage->data[0]; 341 if(usage->length > 1) 342 x->ex_kusage |= usage->data[1] << 8; 343 } else x->ex_kusage = 0; 344 x->ex_flags |= EXFLAG_KUSAGE; 345 ASN1_BIT_STRING_free(usage); 346 } 347 x->ex_xkusage = 0; 348 if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) { 349 x->ex_flags |= EXFLAG_XKUSAGE; 350 for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { 351 switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) { 352 case NID_server_auth: 353 x->ex_xkusage |= XKU_SSL_SERVER; 354 break; 355 356 case NID_client_auth: 357 x->ex_xkusage |= XKU_SSL_CLIENT; 358 break; 359 360 case NID_email_protect: 361 x->ex_xkusage |= XKU_SMIME; 362 break; 363 364 case NID_code_sign: 365 x->ex_xkusage |= XKU_CODE_SIGN; 366 break; 367 368 case NID_ms_sgc: 369 case NID_ns_sgc: 370 x->ex_xkusage |= XKU_SGC; 371 break; 372 373 case NID_OCSP_sign: 374 x->ex_xkusage |= XKU_OCSP_SIGN; 375 break; 376 377 case NID_time_stamp: 378 x->ex_xkusage |= XKU_TIMESTAMP; 379 break; 380 381 case NID_dvcs: 382 x->ex_xkusage |= XKU_DVCS; 383 break; 384 } 385 } 386 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); 387 } 388 389 if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) { 390 if(ns->length > 0) x->ex_nscert = ns->data[0]; 391 else x->ex_nscert = 0; 392 x->ex_flags |= EXFLAG_NSCERT; 393 ASN1_BIT_STRING_free(ns); 394 } 395 x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL); 396 x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL); 397 for (i = 0; i < X509_get_ext_count(x); i++) 398 { 399 ex = X509_get_ext(x, i); 400 if (!X509_EXTENSION_get_critical(ex)) 401 continue; 402 if (!X509_supported_extension(ex)) 403 { 404 x->ex_flags |= EXFLAG_CRITICAL; 405 break; 406 } 407 } 408 x->ex_flags |= EXFLAG_SET; 409} 410 411/* CA checks common to all purposes 412 * return codes: 413 * 0 not a CA 414 * 1 is a CA 415 * 2 basicConstraints absent so "maybe" a CA 416 * 3 basicConstraints absent but self signed V1. 417 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. 418 */ 419 420#define V1_ROOT (EXFLAG_V1|EXFLAG_SS) 421#define ku_reject(x, usage) \ 422 (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage))) 423#define xku_reject(x, usage) \ 424 (((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage))) 425#define ns_reject(x, usage) \ 426 (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage))) 427 428static int check_ca(const X509 *x) 429{ 430 /* keyUsage if present should allow cert signing */ 431 if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0; 432 if(x->ex_flags & EXFLAG_BCONS) { 433 if(x->ex_flags & EXFLAG_CA) return 1; 434 /* If basicConstraints says not a CA then say so */ 435 else return 0; 436 } else { 437 /* we support V1 roots for... uh, I don't really know why. */ 438 if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3; 439 /* If key usage present it must have certSign so tolerate it */ 440 else if (x->ex_flags & EXFLAG_KUSAGE) return 4; 441 /* Older certificates could have Netscape-specific CA types */ 442 else if (x->ex_flags & EXFLAG_NSCERT 443 && x->ex_nscert & NS_ANY_CA) return 5; 444 /* can this still be regarded a CA certificate? I doubt it */ 445 return 0; 446 } 447} 448 449int X509_check_ca(X509 *x) 450{ 451 if(!(x->ex_flags & EXFLAG_SET)) { 452 CRYPTO_w_lock(CRYPTO_LOCK_X509); 453 x509v3_cache_extensions(x); 454 CRYPTO_w_unlock(CRYPTO_LOCK_X509); 455 } 456 457 return check_ca(x); 458} 459 460/* Check SSL CA: common checks for SSL client and server */ 461static int check_ssl_ca(const X509 *x) 462{ 463 int ca_ret; 464 ca_ret = check_ca(x); 465 if(!ca_ret) return 0; 466 /* check nsCertType if present */ 467 if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret; 468 else return 0; 469} 470 471 472static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca) 473{ 474 if(xku_reject(x,XKU_SSL_CLIENT)) return 0; 475 if(ca) return check_ssl_ca(x); 476 /* We need to do digital signatures with it */ 477 if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0; 478 /* nsCertType if present should allow SSL client use */ 479 if(ns_reject(x, NS_SSL_CLIENT)) return 0; 480 return 1; 481} 482 483static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 484{ 485 if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0; 486 if(ca) return check_ssl_ca(x); 487 488 if(ns_reject(x, NS_SSL_SERVER)) return 0; 489 /* Now as for keyUsage: we'll at least need to sign OR encipher */ 490 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT)) return 0; 491 492 return 1; 493 494} 495 496static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca) 497{ 498 int ret; 499 ret = check_purpose_ssl_server(xp, x, ca); 500 if(!ret || ca) return ret; 501 /* We need to encipher or Netscape complains */ 502 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; 503 return ret; 504} 505 506/* common S/MIME checks */ 507static int purpose_smime(const X509 *x, int ca) 508{ 509 if(xku_reject(x,XKU_SMIME)) return 0; 510 if(ca) { 511 int ca_ret; 512 ca_ret = check_ca(x); 513 if(!ca_ret) return 0; 514 /* check nsCertType if present */ 515 if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret; 516 else return 0; 517 } 518 if(x->ex_flags & EXFLAG_NSCERT) { 519 if(x->ex_nscert & NS_SMIME) return 1; 520 /* Workaround for some buggy certificates */ 521 if(x->ex_nscert & NS_SSL_CLIENT) return 2; 522 return 0; 523 } 524 return 1; 525} 526 527static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 528{ 529 int ret; 530 ret = purpose_smime(x, ca); 531 if(!ret || ca) return ret; 532 if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0; 533 return ret; 534} 535 536static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca) 537{ 538 int ret; 539 ret = purpose_smime(x, ca); 540 if(!ret || ca) return ret; 541 if(ku_reject(x, KU_KEY_ENCIPHERMENT)) return 0; 542 return ret; 543} 544 545static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca) 546{ 547 if(ca) { 548 int ca_ret; 549 if((ca_ret = check_ca(x)) != 2) return ca_ret; 550 else return 0; 551 } 552 if(ku_reject(x, KU_CRL_SIGN)) return 0; 553 return 1; 554} 555 556/* OCSP helper: this is *not* a full OCSP check. It just checks that 557 * each CA is valid. Additional checks must be made on the chain. 558 */ 559 560static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) 561{ 562 /* Must be a valid CA. Should we really support the "I don't know" 563 value (2)? */ 564 if(ca) return check_ca(x); 565 /* leaf certificate is checked in OCSP_verify() */ 566 return 1; 567} 568 569static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca) 570{ 571 return 1; 572} 573 574/* Various checks to see if one certificate issued the second. 575 * This can be used to prune a set of possible issuer certificates 576 * which have been looked up using some simple method such as by 577 * subject name. 578 * These are: 579 * 1. Check issuer_name(subject) == subject_name(issuer) 580 * 2. If akid(subject) exists check it matches issuer 581 * 3. If key_usage(issuer) exists check it supports certificate signing 582 * returns 0 for OK, positive for reason for mismatch, reasons match 583 * codes for X509_verify_cert() 584 */ 585 586int X509_check_issued(X509 *issuer, X509 *subject) 587{ 588 if(X509_NAME_cmp(X509_get_subject_name(issuer), 589 X509_get_issuer_name(subject))) 590 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; 591 x509v3_cache_extensions(issuer); 592 x509v3_cache_extensions(subject); 593 if(subject->akid) { 594 /* Check key ids (if present) */ 595 if(subject->akid->keyid && issuer->skid && 596 ASN1_OCTET_STRING_cmp(subject->akid->keyid, issuer->skid) ) 597 return X509_V_ERR_AKID_SKID_MISMATCH; 598 /* Check serial number */ 599 if(subject->akid->serial && 600 ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), 601 subject->akid->serial)) 602 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 603 /* Check issuer name */ 604 if(subject->akid->issuer) { 605 /* Ugh, for some peculiar reason AKID includes 606 * SEQUENCE OF GeneralName. So look for a DirName. 607 * There may be more than one but we only take any 608 * notice of the first. 609 */ 610 GENERAL_NAMES *gens; 611 GENERAL_NAME *gen; 612 X509_NAME *nm = NULL; 613 int i; 614 gens = subject->akid->issuer; 615 for(i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 616 gen = sk_GENERAL_NAME_value(gens, i); 617 if(gen->type == GEN_DIRNAME) { 618 nm = gen->d.dirn; 619 break; 620 } 621 } 622 if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) 623 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 624 } 625 } 626 if(ku_reject(issuer, KU_KEY_CERT_SIGN)) return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; 627 return X509_V_OK; 628} 629 630