1 /* 2 * Copyright 1999-2023 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <stdio.h> 11 #include "internal/cryptlib.h" 12 #include "internal/numbers.h" 13 #include <openssl/x509v3.h> 14 #include <openssl/x509_vfy.h> 15 #include "crypto/x509.h" 16 #include "internal/tsan_assist.h" 17 #include "x509_local.h" 18 19 static int check_ssl_ca(const X509 *x); 20 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, 21 int require_ca); 22 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, 23 int require_ca); 24 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, 25 int require_ca); 26 static int purpose_smime(const X509 *x, int require_ca); 27 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, 28 int require_ca); 29 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, 30 int require_ca); 31 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, 32 int require_ca); 33 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, 34 int require_ca); 35 static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x, 36 int require_ca); 37 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x, 38 int require_ca); 39 40 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b); 41 static void xptable_free(X509_PURPOSE *p); 42 43 static X509_PURPOSE xstandard[] = { 44 {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, 45 check_purpose_ssl_client, "SSL client", "sslclient", NULL}, 46 {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, 47 check_purpose_ssl_server, "SSL server", "sslserver", NULL}, 48 {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, 49 check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL}, 50 {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, 51 "S/MIME signing", "smimesign", NULL}, 52 {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, 53 check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL}, 54 {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, 55 "CRL signing", "crlsign", NULL}, 56 {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check_purpose, 57 "Any Purpose", "any", 58 NULL}, 59 {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, check_purpose_ocsp_helper, 60 "OCSP helper", "ocsphelper", NULL}, 61 {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, 62 check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", 63 NULL}, 64 }; 65 66 #define X509_PURPOSE_COUNT OSSL_NELEM(xstandard) 67 68 static STACK_OF(X509_PURPOSE) *xptable = NULL; 69 70 static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b) 71 { 72 return (*a)->purpose - (*b)->purpose; 73 } 74 75 /* 76 * As much as I'd like to make X509_check_purpose use a "const" X509* I really 77 * can't because it does recalculate hashes and do other non-const things. 78 * If id == -1 it just calls x509v3_cache_extensions() for its side-effect. 79 * Returns 1 on success, 0 if x does not allow purpose, -1 on (internal) error. 80 */ 81 int X509_check_purpose(X509 *x, int id, int require_ca) 82 { 83 int idx; 84 const X509_PURPOSE *pt; 85 86 if (!ossl_x509v3_cache_extensions(x)) 87 return -1; 88 if (id == -1) 89 return 1; 90 91 idx = X509_PURPOSE_get_by_id(id); 92 if (idx == -1) 93 return -1; 94 pt = X509_PURPOSE_get0(idx); 95 return pt->check_purpose(pt, x, require_ca); 96 } 97 98 int X509_PURPOSE_set(int *p, int purpose) 99 { 100 if (X509_PURPOSE_get_by_id(purpose) == -1) { 101 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_PURPOSE); 102 return 0; 103 } 104 *p = purpose; 105 return 1; 106 } 107 108 int X509_PURPOSE_get_count(void) 109 { 110 if (!xptable) 111 return X509_PURPOSE_COUNT; 112 return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT; 113 } 114 115 X509_PURPOSE *X509_PURPOSE_get0(int idx) 116 { 117 if (idx < 0) 118 return NULL; 119 if (idx < (int)X509_PURPOSE_COUNT) 120 return xstandard + idx; 121 return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT); 122 } 123 124 int X509_PURPOSE_get_by_sname(const char *sname) 125 { 126 int i; 127 X509_PURPOSE *xptmp; 128 for (i = 0; i < X509_PURPOSE_get_count(); i++) { 129 xptmp = X509_PURPOSE_get0(i); 130 if (strcmp(xptmp->sname, sname) == 0) 131 return i; 132 } 133 return -1; 134 } 135 136 /* Returns -1 on error, else an index => 0 in standard/extended purpose table */ 137 int X509_PURPOSE_get_by_id(int purpose) 138 { 139 X509_PURPOSE tmp; 140 int idx; 141 142 if (purpose >= X509_PURPOSE_MIN && purpose <= X509_PURPOSE_MAX) 143 return purpose - X509_PURPOSE_MIN; 144 if (xptable == NULL) 145 return -1; 146 tmp.purpose = purpose; 147 idx = sk_X509_PURPOSE_find(xptable, &tmp); 148 if (idx < 0) 149 return -1; 150 return idx + X509_PURPOSE_COUNT; 151 } 152 153 int X509_PURPOSE_add(int id, int trust, int flags, 154 int (*ck) (const X509_PURPOSE *, const X509 *, int), 155 const char *name, const char *sname, void *arg) 156 { 157 int idx; 158 X509_PURPOSE *ptmp; 159 160 /* This is set according to what we change: application can't set it */ 161 flags &= ~X509_PURPOSE_DYNAMIC; 162 /* This will always be set for application modified trust entries */ 163 flags |= X509_PURPOSE_DYNAMIC_NAME; 164 /* Get existing entry if any */ 165 idx = X509_PURPOSE_get_by_id(id); 166 /* Need a new entry */ 167 if (idx == -1) { 168 if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) { 169 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE); 170 return 0; 171 } 172 ptmp->flags = X509_PURPOSE_DYNAMIC; 173 } else 174 ptmp = X509_PURPOSE_get0(idx); 175 176 /* OPENSSL_free existing name if dynamic */ 177 if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) { 178 OPENSSL_free(ptmp->name); 179 OPENSSL_free(ptmp->sname); 180 } 181 /* Dup supplied name */ 182 ptmp->name = OPENSSL_strdup(name); 183 ptmp->sname = OPENSSL_strdup(sname); 184 if (ptmp->name == NULL|| ptmp->sname == NULL) { 185 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE); 186 goto err; 187 } 188 /* Keep the dynamic flag of existing entry */ 189 ptmp->flags &= X509_PURPOSE_DYNAMIC; 190 /* Set all other flags */ 191 ptmp->flags |= flags; 192 193 ptmp->purpose = id; 194 ptmp->trust = trust; 195 ptmp->check_purpose = ck; 196 ptmp->usr_data = arg; 197 198 /* If its a new entry manage the dynamic table */ 199 if (idx == -1) { 200 if (xptable == NULL 201 && (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) { 202 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE); 203 goto err; 204 } 205 if (!sk_X509_PURPOSE_push(xptable, ptmp)) { 206 ERR_raise(ERR_LIB_X509V3, ERR_R_MALLOC_FAILURE); 207 goto err; 208 } 209 } 210 return 1; 211 err: 212 if (idx == -1) { 213 OPENSSL_free(ptmp->name); 214 OPENSSL_free(ptmp->sname); 215 OPENSSL_free(ptmp); 216 } 217 return 0; 218 } 219 220 static void xptable_free(X509_PURPOSE *p) 221 { 222 if (p == NULL) 223 return; 224 if (p->flags & X509_PURPOSE_DYNAMIC) { 225 if (p->flags & X509_PURPOSE_DYNAMIC_NAME) { 226 OPENSSL_free(p->name); 227 OPENSSL_free(p->sname); 228 } 229 OPENSSL_free(p); 230 } 231 } 232 233 void X509_PURPOSE_cleanup(void) 234 { 235 sk_X509_PURPOSE_pop_free(xptable, xptable_free); 236 xptable = NULL; 237 } 238 239 int X509_PURPOSE_get_id(const X509_PURPOSE *xp) 240 { 241 return xp->purpose; 242 } 243 244 char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp) 245 { 246 return xp->name; 247 } 248 249 char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp) 250 { 251 return xp->sname; 252 } 253 254 int X509_PURPOSE_get_trust(const X509_PURPOSE *xp) 255 { 256 return xp->trust; 257 } 258 259 static int nid_cmp(const int *a, const int *b) 260 { 261 return *a - *b; 262 } 263 264 DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid); 265 IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid); 266 267 int X509_supported_extension(X509_EXTENSION *ex) 268 { 269 /* 270 * This table is a list of the NIDs of supported extensions: that is 271 * those which are used by the verify process. If an extension is 272 * critical and doesn't appear in this list then the verify process will 273 * normally reject the certificate. The list must be kept in numerical 274 * order because it will be searched using bsearch. 275 */ 276 static const int supported_nids[] = { 277 NID_netscape_cert_type, /* 71 */ 278 NID_key_usage, /* 83 */ 279 NID_subject_alt_name, /* 85 */ 280 NID_basic_constraints, /* 87 */ 281 NID_certificate_policies, /* 89 */ 282 NID_crl_distribution_points, /* 103 */ 283 NID_ext_key_usage, /* 126 */ 284 #ifndef OPENSSL_NO_RFC3779 285 NID_sbgp_ipAddrBlock, /* 290 */ 286 NID_sbgp_autonomousSysNum, /* 291 */ 287 #endif 288 NID_id_pkix_OCSP_noCheck, /* 369 */ 289 NID_policy_constraints, /* 401 */ 290 NID_proxyCertInfo, /* 663 */ 291 NID_name_constraints, /* 666 */ 292 NID_policy_mappings, /* 747 */ 293 NID_inhibit_any_policy /* 748 */ 294 }; 295 296 int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); 297 298 if (ex_nid == NID_undef) 299 return 0; 300 301 if (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids))) 302 return 1; 303 return 0; 304 } 305 306 /* Returns 1 on success, 0 if x is invalid, -1 on (internal) error. */ 307 static int setup_dp(const X509 *x, DIST_POINT *dp) 308 { 309 const X509_NAME *iname = NULL; 310 int i; 311 312 if (dp->distpoint == NULL && sk_GENERAL_NAME_num(dp->CRLissuer) <= 0) { 313 ERR_raise(ERR_LIB_X509, X509_R_INVALID_DISTPOINT); 314 return 0; 315 } 316 if (dp->reasons != NULL) { 317 if (dp->reasons->length > 0) 318 dp->dp_reasons = dp->reasons->data[0]; 319 if (dp->reasons->length > 1) 320 dp->dp_reasons |= (dp->reasons->data[1] << 8); 321 dp->dp_reasons &= CRLDP_ALL_REASONS; 322 } else { 323 dp->dp_reasons = CRLDP_ALL_REASONS; 324 } 325 if (dp->distpoint == NULL || dp->distpoint->type != 1) 326 return 1; 327 328 /* Handle name fragment given by nameRelativeToCRLIssuer */ 329 /* 330 * Note that the below way of determining iname is not really compliant 331 * with https://tools.ietf.org/html/rfc5280#section-4.2.1.13 332 * According to it, sk_GENERAL_NAME_num(dp->CRLissuer) MUST be <= 1 333 * and any CRLissuer could be of type different to GEN_DIRNAME. 334 */ 335 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { 336 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 337 338 if (gen->type == GEN_DIRNAME) { 339 iname = gen->d.directoryName; 340 break; 341 } 342 } 343 if (iname == NULL) 344 iname = X509_get_issuer_name(x); 345 return DIST_POINT_set_dpname(dp->distpoint, iname) ? 1 : -1; 346 } 347 348 /* Return 1 on success, 0 if x is invalid, -1 on (internal) error. */ 349 static int setup_crldp(X509 *x) 350 { 351 int i; 352 353 x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &i, NULL); 354 if (x->crldp == NULL && i != -1) 355 return 0; 356 357 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) { 358 int res = setup_dp(x, sk_DIST_POINT_value(x->crldp, i)); 359 360 if (res < 1) 361 return res; 362 } 363 return 1; 364 } 365 366 /* Check that issuer public key algorithm matches subject signature algorithm */ 367 static int check_sig_alg_match(const EVP_PKEY *issuer_key, const X509 *subject) 368 { 369 int subj_sig_nid; 370 371 if (issuer_key == NULL) 372 return X509_V_ERR_NO_ISSUER_PUBLIC_KEY; 373 if (OBJ_find_sigid_algs(OBJ_obj2nid(subject->cert_info.signature.algorithm), 374 NULL, &subj_sig_nid) == 0) 375 return X509_V_ERR_UNSUPPORTED_SIGNATURE_ALGORITHM; 376 if (EVP_PKEY_is_a(issuer_key, OBJ_nid2sn(subj_sig_nid)) 377 || (EVP_PKEY_is_a(issuer_key, "RSA") && subj_sig_nid == NID_rsassaPss)) 378 return X509_V_OK; 379 return X509_V_ERR_SIGNATURE_ALGORITHM_MISMATCH; 380 } 381 382 #define V1_ROOT (EXFLAG_V1|EXFLAG_SS) 383 #define ku_reject(x, usage) \ 384 (((x)->ex_flags & EXFLAG_KUSAGE) != 0 && ((x)->ex_kusage & (usage)) == 0) 385 #define xku_reject(x, usage) \ 386 (((x)->ex_flags & EXFLAG_XKUSAGE) != 0 && ((x)->ex_xkusage & (usage)) == 0) 387 #define ns_reject(x, usage) \ 388 (((x)->ex_flags & EXFLAG_NSCERT) != 0 && ((x)->ex_nscert & (usage)) == 0) 389 390 /* 391 * Cache info on various X.509v3 extensions and further derived information, 392 * e.g., if cert 'x' is self-issued, in x->ex_flags and other internal fields. 393 * x->sha1_hash is filled in, or else EXFLAG_NO_FINGERPRINT is set in x->flags. 394 * X509_SIG_INFO_VALID is set in x->flags if x->siginf was filled successfully. 395 * Set EXFLAG_INVALID and return 0 in case the certificate is invalid. 396 */ 397 int ossl_x509v3_cache_extensions(X509 *x) 398 { 399 BASIC_CONSTRAINTS *bs; 400 PROXY_CERT_INFO_EXTENSION *pci; 401 ASN1_BIT_STRING *usage; 402 ASN1_BIT_STRING *ns; 403 EXTENDED_KEY_USAGE *extusage; 404 int i; 405 int res; 406 407 #ifdef tsan_ld_acq 408 /* Fast lock-free check, see end of the function for details. */ 409 if (tsan_ld_acq((TSAN_QUALIFIER int *)&x->ex_cached)) 410 return (x->ex_flags & EXFLAG_INVALID) == 0; 411 #endif 412 413 if (!CRYPTO_THREAD_write_lock(x->lock)) 414 return 0; 415 if (x->ex_flags & EXFLAG_SET) { /* Cert has already been processed */ 416 CRYPTO_THREAD_unlock(x->lock); 417 return (x->ex_flags & EXFLAG_INVALID) == 0; 418 } 419 420 /* Cache the SHA1 digest of the cert */ 421 if (!X509_digest(x, EVP_sha1(), x->sha1_hash, NULL)) 422 x->ex_flags |= EXFLAG_NO_FINGERPRINT; 423 424 ERR_set_mark(); 425 426 /* V1 should mean no extensions ... */ 427 if (X509_get_version(x) == X509_VERSION_1) 428 x->ex_flags |= EXFLAG_V1; 429 430 /* Handle basic constraints */ 431 x->ex_pathlen = -1; 432 if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, NULL)) != NULL) { 433 if (bs->ca) 434 x->ex_flags |= EXFLAG_CA; 435 if (bs->pathlen != NULL) { 436 /* 437 * The error case !bs->ca is checked by check_chain() 438 * in case ctx->param->flags & X509_V_FLAG_X509_STRICT 439 */ 440 if (bs->pathlen->type == V_ASN1_NEG_INTEGER) { 441 ERR_raise(ERR_LIB_X509V3, X509V3_R_NEGATIVE_PATHLEN); 442 x->ex_flags |= EXFLAG_INVALID; 443 } else { 444 x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen); 445 } 446 } 447 BASIC_CONSTRAINTS_free(bs); 448 x->ex_flags |= EXFLAG_BCONS; 449 } else if (i != -1) { 450 x->ex_flags |= EXFLAG_INVALID; 451 } 452 453 /* Handle proxy certificates */ 454 if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, &i, NULL)) != NULL) { 455 if (x->ex_flags & EXFLAG_CA 456 || X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0 457 || X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) { 458 x->ex_flags |= EXFLAG_INVALID; 459 } 460 if (pci->pcPathLengthConstraint != NULL) 461 x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint); 462 else 463 x->ex_pcpathlen = -1; 464 PROXY_CERT_INFO_EXTENSION_free(pci); 465 x->ex_flags |= EXFLAG_PROXY; 466 } else if (i != -1) { 467 x->ex_flags |= EXFLAG_INVALID; 468 } 469 470 /* Handle (basic) key usage */ 471 if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, NULL)) != NULL) { 472 x->ex_kusage = 0; 473 if (usage->length > 0) { 474 x->ex_kusage = usage->data[0]; 475 if (usage->length > 1) 476 x->ex_kusage |= usage->data[1] << 8; 477 } 478 x->ex_flags |= EXFLAG_KUSAGE; 479 ASN1_BIT_STRING_free(usage); 480 /* Check for empty key usage according to RFC 5280 section 4.2.1.3 */ 481 if (x->ex_kusage == 0) { 482 ERR_raise(ERR_LIB_X509V3, X509V3_R_EMPTY_KEY_USAGE); 483 x->ex_flags |= EXFLAG_INVALID; 484 } 485 } else if (i != -1) { 486 x->ex_flags |= EXFLAG_INVALID; 487 } 488 489 /* Handle extended key usage */ 490 x->ex_xkusage = 0; 491 if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, NULL)) != NULL) { 492 x->ex_flags |= EXFLAG_XKUSAGE; 493 for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) { 494 switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) { 495 case NID_server_auth: 496 x->ex_xkusage |= XKU_SSL_SERVER; 497 break; 498 case NID_client_auth: 499 x->ex_xkusage |= XKU_SSL_CLIENT; 500 break; 501 case NID_email_protect: 502 x->ex_xkusage |= XKU_SMIME; 503 break; 504 case NID_code_sign: 505 x->ex_xkusage |= XKU_CODE_SIGN; 506 break; 507 case NID_ms_sgc: 508 case NID_ns_sgc: 509 x->ex_xkusage |= XKU_SGC; 510 break; 511 case NID_OCSP_sign: 512 x->ex_xkusage |= XKU_OCSP_SIGN; 513 break; 514 case NID_time_stamp: 515 x->ex_xkusage |= XKU_TIMESTAMP; 516 break; 517 case NID_dvcs: 518 x->ex_xkusage |= XKU_DVCS; 519 break; 520 case NID_anyExtendedKeyUsage: 521 x->ex_xkusage |= XKU_ANYEKU; 522 break; 523 default: 524 /* Ignore unknown extended key usage */ 525 break; 526 } 527 } 528 sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free); 529 } else if (i != -1) { 530 x->ex_flags |= EXFLAG_INVALID; 531 } 532 533 /* Handle legacy Netscape extension */ 534 if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, NULL)) != NULL) { 535 if (ns->length > 0) 536 x->ex_nscert = ns->data[0]; 537 else 538 x->ex_nscert = 0; 539 x->ex_flags |= EXFLAG_NSCERT; 540 ASN1_BIT_STRING_free(ns); 541 } else if (i != -1) { 542 x->ex_flags |= EXFLAG_INVALID; 543 } 544 545 /* Handle subject key identifier and issuer/authority key identifier */ 546 x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL); 547 if (x->skid == NULL && i != -1) 548 x->ex_flags |= EXFLAG_INVALID; 549 550 x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL); 551 if (x->akid == NULL && i != -1) 552 x->ex_flags |= EXFLAG_INVALID; 553 554 /* Check if subject name matches issuer */ 555 if (X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)) == 0) { 556 x->ex_flags |= EXFLAG_SI; /* Cert is self-issued */ 557 if (X509_check_akid(x, x->akid) == X509_V_OK /* SKID matches AKID */ 558 /* .. and the signature alg matches the PUBKEY alg: */ 559 && check_sig_alg_match(X509_get0_pubkey(x), x) == X509_V_OK) 560 x->ex_flags |= EXFLAG_SS; /* indicate self-signed */ 561 /* This is very related to ossl_x509_likely_issued(x, x) == X509_V_OK */ 562 } 563 564 /* Handle subject alternative names and various other extensions */ 565 x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &i, NULL); 566 if (x->altname == NULL && i != -1) 567 x->ex_flags |= EXFLAG_INVALID; 568 x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL); 569 if (x->nc == NULL && i != -1) 570 x->ex_flags |= EXFLAG_INVALID; 571 572 /* Handle CRL distribution point entries */ 573 res = setup_crldp(x); 574 if (res == 0) 575 x->ex_flags |= EXFLAG_INVALID; 576 else if (res < 0) 577 goto err; 578 579 #ifndef OPENSSL_NO_RFC3779 580 x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, &i, NULL); 581 if (x->rfc3779_addr == NULL && i != -1) 582 x->ex_flags |= EXFLAG_INVALID; 583 x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL); 584 if (x->rfc3779_asid == NULL && i != -1) 585 x->ex_flags |= EXFLAG_INVALID; 586 #endif 587 for (i = 0; i < X509_get_ext_count(x); i++) { 588 X509_EXTENSION *ex = X509_get_ext(x, i); 589 int nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex)); 590 591 if (nid == NID_freshest_crl) 592 x->ex_flags |= EXFLAG_FRESHEST; 593 if (!X509_EXTENSION_get_critical(ex)) 594 continue; 595 if (!X509_supported_extension(ex)) { 596 x->ex_flags |= EXFLAG_CRITICAL; 597 break; 598 } 599 switch (nid) { 600 case NID_basic_constraints: 601 x->ex_flags |= EXFLAG_BCONS_CRITICAL; 602 break; 603 case NID_authority_key_identifier: 604 x->ex_flags |= EXFLAG_AKID_CRITICAL; 605 break; 606 case NID_subject_key_identifier: 607 x->ex_flags |= EXFLAG_SKID_CRITICAL; 608 break; 609 case NID_subject_alt_name: 610 x->ex_flags |= EXFLAG_SAN_CRITICAL; 611 break; 612 default: 613 break; 614 } 615 } 616 617 /* Set x->siginf, ignoring errors due to unsupported algos */ 618 (void)ossl_x509_init_sig_info(x); 619 620 x->ex_flags |= EXFLAG_SET; /* Indicate that cert has been processed */ 621 #ifdef tsan_st_rel 622 tsan_st_rel((TSAN_QUALIFIER int *)&x->ex_cached, 1); 623 /* 624 * Above store triggers fast lock-free check in the beginning of the 625 * function. But one has to ensure that the structure is "stable", i.e. 626 * all stores are visible on all processors. Hence the release fence. 627 */ 628 #endif 629 ERR_pop_to_mark(); 630 if ((x->ex_flags & (EXFLAG_INVALID | EXFLAG_NO_FINGERPRINT)) == 0) { 631 CRYPTO_THREAD_unlock(x->lock); 632 return 1; 633 } 634 if ((x->ex_flags & EXFLAG_INVALID) != 0) 635 ERR_raise(ERR_LIB_X509V3, X509V3_R_INVALID_CERTIFICATE); 636 /* If computing sha1_hash failed the error queue already reflects this. */ 637 638 err: 639 x->ex_flags |= EXFLAG_SET; /* indicate that cert has been processed */ 640 CRYPTO_THREAD_unlock(x->lock); 641 return 0; 642 } 643 644 /*- 645 * CA checks common to all purposes 646 * return codes: 647 * 0 not a CA 648 * 1 is a CA 649 * 2 Only possible in older versions of openSSL when basicConstraints are absent 650 * new versions will not return this value. May be a CA 651 * 3 basicConstraints absent but self-signed V1. 652 * 4 basicConstraints absent but keyUsage present and keyCertSign asserted. 653 * 5 Netscape specific CA Flags present 654 */ 655 656 static int check_ca(const X509 *x) 657 { 658 /* keyUsage if present should allow cert signing */ 659 if (ku_reject(x, KU_KEY_CERT_SIGN)) 660 return 0; 661 if ((x->ex_flags & EXFLAG_BCONS) != 0) { 662 /* If basicConstraints says not a CA then say so */ 663 return (x->ex_flags & EXFLAG_CA) != 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 /* 669 * If key usage present it must have certSign so tolerate it 670 */ 671 else if (x->ex_flags & EXFLAG_KUSAGE) 672 return 4; 673 /* Older certificates could have Netscape-specific CA types */ 674 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA) 675 return 5; 676 /* Can this still be regarded a CA certificate? I doubt it. */ 677 return 0; 678 } 679 } 680 681 void X509_set_proxy_flag(X509 *x) 682 { 683 if (CRYPTO_THREAD_write_lock(x->lock)) { 684 x->ex_flags |= EXFLAG_PROXY; 685 CRYPTO_THREAD_unlock(x->lock); 686 } 687 } 688 689 void X509_set_proxy_pathlen(X509 *x, long l) 690 { 691 x->ex_pcpathlen = l; 692 } 693 694 int X509_check_ca(X509 *x) 695 { 696 /* Note 0 normally means "not a CA" - but in this case means error. */ 697 if (!ossl_x509v3_cache_extensions(x)) 698 return 0; 699 700 return check_ca(x); 701 } 702 703 /* Check SSL CA: common checks for SSL client and server. */ 704 static int check_ssl_ca(const X509 *x) 705 { 706 int ca_ret = check_ca(x); 707 708 if (ca_ret == 0) 709 return 0; 710 /* Check nsCertType if present */ 711 return ca_ret != 5 || (x->ex_nscert & NS_SSL_CA) != 0; 712 } 713 714 static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, 715 int require_ca) 716 { 717 if (xku_reject(x, XKU_SSL_CLIENT)) 718 return 0; 719 if (require_ca) 720 return check_ssl_ca(x); 721 /* We need to do digital signatures or key agreement */ 722 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT)) 723 return 0; 724 /* nsCertType if present should allow SSL client use */ 725 if (ns_reject(x, NS_SSL_CLIENT)) 726 return 0; 727 return 1; 728 } 729 730 /* 731 * Key usage needed for TLS/SSL server: digital signature, encipherment or 732 * key agreement. The ssl code can check this more thoroughly for individual 733 * key types. 734 */ 735 #define KU_TLS \ 736 KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT|KU_KEY_AGREEMENT 737 738 static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, 739 int require_ca) 740 { 741 if (xku_reject(x, XKU_SSL_SERVER | XKU_SGC)) 742 return 0; 743 if (require_ca) 744 return check_ssl_ca(x); 745 746 if (ns_reject(x, NS_SSL_SERVER)) 747 return 0; 748 if (ku_reject(x, KU_TLS)) 749 return 0; 750 751 return 1; 752 753 } 754 755 static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, 756 int require_ca) 757 { 758 int ret; 759 ret = check_purpose_ssl_server(xp, x, require_ca); 760 if (!ret || require_ca) 761 return ret; 762 /* We need to encipher or Netscape complains */ 763 if (ku_reject(x, KU_KEY_ENCIPHERMENT)) 764 return 0; 765 return ret; 766 } 767 768 /* common S/MIME checks */ 769 static int purpose_smime(const X509 *x, int require_ca) 770 { 771 if (xku_reject(x, XKU_SMIME)) 772 return 0; 773 if (require_ca) { 774 int ca_ret; 775 ca_ret = check_ca(x); 776 if (ca_ret == 0) 777 return 0; 778 /* Check nsCertType if present */ 779 if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) 780 return ca_ret; 781 else 782 return 0; 783 } 784 if (x->ex_flags & EXFLAG_NSCERT) { 785 if (x->ex_nscert & NS_SMIME) 786 return 1; 787 /* Workaround for some buggy certificates */ 788 if (x->ex_nscert & NS_SSL_CLIENT) 789 return 2; 790 return 0; 791 } 792 return 1; 793 } 794 795 static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, 796 int require_ca) 797 { 798 int ret; 799 ret = purpose_smime(x, require_ca); 800 if (!ret || require_ca) 801 return ret; 802 if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION)) 803 return 0; 804 return ret; 805 } 806 807 static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, 808 int require_ca) 809 { 810 int ret; 811 ret = purpose_smime(x, require_ca); 812 if (!ret || require_ca) 813 return ret; 814 if (ku_reject(x, KU_KEY_ENCIPHERMENT)) 815 return 0; 816 return ret; 817 } 818 819 static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, 820 int require_ca) 821 { 822 if (require_ca) { 823 int ca_ret; 824 if ((ca_ret = check_ca(x)) != 2) 825 return ca_ret; 826 else 827 return 0; 828 } 829 if (ku_reject(x, KU_CRL_SIGN)) 830 return 0; 831 return 1; 832 } 833 834 /* 835 * OCSP helper: this is *not* a full OCSP check. It just checks that each CA 836 * is valid. Additional checks must be made on the chain. 837 */ 838 static int check_purpose_ocsp_helper(const X509_PURPOSE *xp, const X509 *x, 839 int require_ca) 840 { 841 /* 842 * Must be a valid CA. Should we really support the "I don't know" value 843 * (2)? 844 */ 845 if (require_ca) 846 return check_ca(x); 847 /* Leaf certificate is checked in OCSP_verify() */ 848 return 1; 849 } 850 851 static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x, 852 int require_ca) 853 { 854 int i_ext; 855 856 /* If ca is true we must return if this is a valid CA certificate. */ 857 if (require_ca) 858 return check_ca(x); 859 860 /* 861 * Check the optional key usage field: 862 * if Key Usage is present, it must be one of digitalSignature 863 * and/or nonRepudiation (other values are not consistent and shall 864 * be rejected). 865 */ 866 if ((x->ex_flags & EXFLAG_KUSAGE) 867 && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) || 868 !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) 869 return 0; 870 871 /* Only time stamp key usage is permitted and it's required. */ 872 if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) 873 return 0; 874 875 /* Extended Key Usage MUST be critical */ 876 i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1); 877 if (i_ext >= 0) { 878 X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext); 879 if (!X509_EXTENSION_get_critical(ext)) 880 return 0; 881 } 882 883 return 1; 884 } 885 886 static int no_check_purpose(const X509_PURPOSE *xp, const X509 *x, 887 int require_ca) 888 { 889 return 1; 890 } 891 892 /*- 893 * Various checks to see if one certificate potentially issued the second. 894 * This can be used to prune a set of possible issuer certificates which 895 * have been looked up using some simple method such as by subject name. 896 * These are: 897 * 1. issuer_name(subject) == subject_name(issuer) 898 * 2. If akid(subject) exists, it matches the respective issuer fields. 899 * 3. subject signature algorithm == issuer public key algorithm 900 * 4. If key_usage(issuer) exists, it allows for signing subject. 901 * Note that this does not include actually checking the signature. 902 * Returns 0 for OK, or positive for reason for mismatch 903 * where reason codes match those for X509_verify_cert(). 904 */ 905 int X509_check_issued(X509 *issuer, X509 *subject) 906 { 907 int ret; 908 909 if ((ret = ossl_x509_likely_issued(issuer, subject)) != X509_V_OK) 910 return ret; 911 return ossl_x509_signing_allowed(issuer, subject); 912 } 913 914 /* do the checks 1., 2., and 3. as described above for X509_check_issued() */ 915 int ossl_x509_likely_issued(X509 *issuer, X509 *subject) 916 { 917 int ret; 918 919 if (X509_NAME_cmp(X509_get_subject_name(issuer), 920 X509_get_issuer_name(subject)) != 0) 921 return X509_V_ERR_SUBJECT_ISSUER_MISMATCH; 922 923 /* set issuer->skid and subject->akid */ 924 if (!ossl_x509v3_cache_extensions(issuer) 925 || !ossl_x509v3_cache_extensions(subject)) 926 return X509_V_ERR_UNSPECIFIED; 927 928 ret = X509_check_akid(issuer, subject->akid); 929 if (ret != X509_V_OK) 930 return ret; 931 932 /* Check if the subject signature alg matches the issuer's PUBKEY alg */ 933 return check_sig_alg_match(X509_get0_pubkey(issuer), subject); 934 } 935 936 /*- 937 * Check if certificate I<issuer> is allowed to issue certificate I<subject> 938 * according to the B<keyUsage> field of I<issuer> if present 939 * depending on any proxyCertInfo extension of I<subject>. 940 * Returns 0 for OK, or positive for reason for rejection 941 * where reason codes match those for X509_verify_cert(). 942 */ 943 int ossl_x509_signing_allowed(const X509 *issuer, const X509 *subject) 944 { 945 if (subject->ex_flags & EXFLAG_PROXY) { 946 if (ku_reject(issuer, KU_DIGITAL_SIGNATURE)) 947 return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE; 948 } else if (ku_reject(issuer, KU_KEY_CERT_SIGN)) 949 return X509_V_ERR_KEYUSAGE_NO_CERTSIGN; 950 return X509_V_OK; 951 } 952 953 int X509_check_akid(const X509 *issuer, const AUTHORITY_KEYID *akid) 954 { 955 if (akid == NULL) 956 return X509_V_OK; 957 958 /* Check key ids (if present) */ 959 if (akid->keyid && issuer->skid && 960 ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid)) 961 return X509_V_ERR_AKID_SKID_MISMATCH; 962 /* Check serial number */ 963 if (akid->serial && 964 ASN1_INTEGER_cmp(X509_get0_serialNumber(issuer), akid->serial)) 965 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 966 /* Check issuer name */ 967 if (akid->issuer) { 968 /* 969 * Ugh, for some peculiar reason AKID includes SEQUENCE OF 970 * GeneralName. So look for a DirName. There may be more than one but 971 * we only take any notice of the first. 972 */ 973 GENERAL_NAMES *gens; 974 GENERAL_NAME *gen; 975 X509_NAME *nm = NULL; 976 int i; 977 gens = akid->issuer; 978 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 979 gen = sk_GENERAL_NAME_value(gens, i); 980 if (gen->type == GEN_DIRNAME) { 981 nm = gen->d.dirn; 982 break; 983 } 984 } 985 if (nm != NULL && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)) != 0) 986 return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH; 987 } 988 return X509_V_OK; 989 } 990 991 uint32_t X509_get_extension_flags(X509 *x) 992 { 993 /* Call for side-effect of computing hash and caching extensions */ 994 X509_check_purpose(x, -1, 0); 995 return x->ex_flags; 996 } 997 998 uint32_t X509_get_key_usage(X509 *x) 999 { 1000 /* Call for side-effect of computing hash and caching extensions */ 1001 if (X509_check_purpose(x, -1, 0) != 1) 1002 return 0; 1003 if (x->ex_flags & EXFLAG_KUSAGE) 1004 return x->ex_kusage; 1005 return UINT32_MAX; 1006 } 1007 1008 uint32_t X509_get_extended_key_usage(X509 *x) 1009 { 1010 /* Call for side-effect of computing hash and caching extensions */ 1011 if (X509_check_purpose(x, -1, 0) != 1) 1012 return 0; 1013 if (x->ex_flags & EXFLAG_XKUSAGE) 1014 return x->ex_xkusage; 1015 return UINT32_MAX; 1016 } 1017 1018 const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x) 1019 { 1020 /* Call for side-effect of computing hash and caching extensions */ 1021 if (X509_check_purpose(x, -1, 0) != 1) 1022 return NULL; 1023 return x->skid; 1024 } 1025 1026 const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x) 1027 { 1028 /* Call for side-effect of computing hash and caching extensions */ 1029 if (X509_check_purpose(x, -1, 0) != 1) 1030 return NULL; 1031 return (x->akid != NULL ? x->akid->keyid : NULL); 1032 } 1033 1034 const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x) 1035 { 1036 /* Call for side-effect of computing hash and caching extensions */ 1037 if (X509_check_purpose(x, -1, 0) != 1) 1038 return NULL; 1039 return (x->akid != NULL ? x->akid->issuer : NULL); 1040 } 1041 1042 const ASN1_INTEGER *X509_get0_authority_serial(X509 *x) 1043 { 1044 /* Call for side-effect of computing hash and caching extensions */ 1045 if (X509_check_purpose(x, -1, 0) != 1) 1046 return NULL; 1047 return (x->akid != NULL ? x->akid->serial : NULL); 1048 } 1049 1050 long X509_get_pathlen(X509 *x) 1051 { 1052 /* Called for side effect of caching extensions */ 1053 if (X509_check_purpose(x, -1, 0) != 1 1054 || (x->ex_flags & EXFLAG_BCONS) == 0) 1055 return -1; 1056 return x->ex_pathlen; 1057 } 1058 1059 long X509_get_proxy_pathlen(X509 *x) 1060 { 1061 /* Called for side effect of caching extensions */ 1062 if (X509_check_purpose(x, -1, 0) != 1 1063 || (x->ex_flags & EXFLAG_PROXY) == 0) 1064 return -1; 1065 return x->ex_pcpathlen; 1066 } 1067