1 /* 2 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (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 <time.h> 12 #include <errno.h> 13 #include <limits.h> 14 15 #include "crypto/ctype.h" 16 #include "internal/cryptlib.h" 17 #include <openssl/crypto.h> 18 #include <openssl/buffer.h> 19 #include <openssl/evp.h> 20 #include <openssl/asn1.h> 21 #include <openssl/x509.h> 22 #include <openssl/x509v3.h> 23 #include <openssl/objects.h> 24 #include "internal/dane.h" 25 #include "crypto/x509.h" 26 #include "x509_local.h" 27 28 /* CRL score values */ 29 30 /* No unhandled critical extensions */ 31 32 #define CRL_SCORE_NOCRITICAL 0x100 33 34 /* certificate is within CRL scope */ 35 36 #define CRL_SCORE_SCOPE 0x080 37 38 /* CRL times valid */ 39 40 #define CRL_SCORE_TIME 0x040 41 42 /* Issuer name matches certificate */ 43 44 #define CRL_SCORE_ISSUER_NAME 0x020 45 46 /* If this score or above CRL is probably valid */ 47 48 #define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE) 49 50 /* CRL issuer is certificate issuer */ 51 52 #define CRL_SCORE_ISSUER_CERT 0x018 53 54 /* CRL issuer is on certificate path */ 55 56 #define CRL_SCORE_SAME_PATH 0x008 57 58 /* CRL issuer matches CRL AKID */ 59 60 #define CRL_SCORE_AKID 0x004 61 62 /* Have a delta CRL with valid times */ 63 64 #define CRL_SCORE_TIME_DELTA 0x002 65 66 static int build_chain(X509_STORE_CTX *ctx); 67 static int verify_chain(X509_STORE_CTX *ctx); 68 static int dane_verify(X509_STORE_CTX *ctx); 69 static int null_callback(int ok, X509_STORE_CTX *e); 70 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer); 71 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x); 72 static int check_chain_extensions(X509_STORE_CTX *ctx); 73 static int check_name_constraints(X509_STORE_CTX *ctx); 74 static int check_id(X509_STORE_CTX *ctx); 75 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted); 76 static int check_revocation(X509_STORE_CTX *ctx); 77 static int check_cert(X509_STORE_CTX *ctx); 78 static int check_policy(X509_STORE_CTX *ctx); 79 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x); 80 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth); 81 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert); 82 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert); 83 static int check_curve(X509 *cert); 84 85 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 86 unsigned int *preasons, X509_CRL *crl, X509 *x); 87 static int get_crl_delta(X509_STORE_CTX *ctx, 88 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x); 89 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, 90 int *pcrl_score, X509_CRL *base, 91 STACK_OF(X509_CRL) *crls); 92 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer, 93 int *pcrl_score); 94 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 95 unsigned int *preasons); 96 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x); 97 static int check_crl_chain(X509_STORE_CTX *ctx, 98 STACK_OF(X509) *cert_path, 99 STACK_OF(X509) *crl_path); 100 101 static int internal_verify(X509_STORE_CTX *ctx); 102 103 static int null_callback(int ok, X509_STORE_CTX *e) 104 { 105 return ok; 106 } 107 108 /* 109 * Return 1 if given cert is considered self-signed, 0 if not or on error. 110 * This does not verify self-signedness but relies on x509v3_cache_extensions() 111 * matching issuer and subject names (i.e., the cert being self-issued) and any 112 * present authority key identifier matching the subject key identifier, etc. 113 */ 114 static int cert_self_signed(X509 *x) 115 { 116 if (X509_check_purpose(x, -1, 0) != 1) 117 return 0; 118 if (x->ex_flags & EXFLAG_SS) 119 return 1; 120 else 121 return 0; 122 } 123 124 /* Given a certificate try and find an exact match in the store */ 125 126 static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x) 127 { 128 STACK_OF(X509) *certs; 129 X509 *xtmp = NULL; 130 int i; 131 /* Lookup all certs with matching subject name */ 132 certs = ctx->lookup_certs(ctx, X509_get_subject_name(x)); 133 if (certs == NULL) 134 return NULL; 135 /* Look for exact match */ 136 for (i = 0; i < sk_X509_num(certs); i++) { 137 xtmp = sk_X509_value(certs, i); 138 if (!X509_cmp(xtmp, x)) 139 break; 140 xtmp = NULL; 141 } 142 if (xtmp != NULL && !X509_up_ref(xtmp)) 143 xtmp = NULL; 144 sk_X509_pop_free(certs, X509_free); 145 return xtmp; 146 } 147 148 /*- 149 * Inform the verify callback of an error. 150 * If B<x> is not NULL it is the error cert, otherwise use the chain cert at 151 * B<depth>. 152 * If B<err> is not X509_V_OK, that's the error value, otherwise leave 153 * unchanged (presumably set by the caller). 154 * 155 * Returns 0 to abort verification with an error, non-zero to continue. 156 */ 157 static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err) 158 { 159 ctx->error_depth = depth; 160 ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth); 161 if (err != X509_V_OK) 162 ctx->error = err; 163 return ctx->verify_cb(0, ctx); 164 } 165 166 /*- 167 * Inform the verify callback of an error, CRL-specific variant. Here, the 168 * error depth and certificate are already set, we just specify the error 169 * number. 170 * 171 * Returns 0 to abort verification with an error, non-zero to continue. 172 */ 173 static int verify_cb_crl(X509_STORE_CTX *ctx, int err) 174 { 175 ctx->error = err; 176 return ctx->verify_cb(0, ctx); 177 } 178 179 static int check_auth_level(X509_STORE_CTX *ctx) 180 { 181 int i; 182 int num = sk_X509_num(ctx->chain); 183 184 if (ctx->param->auth_level <= 0) 185 return 1; 186 187 for (i = 0; i < num; ++i) { 188 X509 *cert = sk_X509_value(ctx->chain, i); 189 190 /* 191 * We've already checked the security of the leaf key, so here we only 192 * check the security of issuer keys. 193 */ 194 if (i > 0 && !check_key_level(ctx, cert) && 195 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL) == 0) 196 return 0; 197 /* 198 * We also check the signature algorithm security of all certificates 199 * except those of the trust anchor at index num-1. 200 */ 201 if (i < num - 1 && !check_sig_level(ctx, cert) && 202 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK) == 0) 203 return 0; 204 } 205 return 1; 206 } 207 208 static int verify_chain(X509_STORE_CTX *ctx) 209 { 210 int err; 211 int ok; 212 213 /* 214 * Before either returning with an error, or continuing with CRL checks, 215 * instantiate chain public key parameters. 216 */ 217 if ((ok = build_chain(ctx)) == 0 || 218 (ok = check_chain_extensions(ctx)) == 0 || 219 (ok = check_auth_level(ctx)) == 0 || 220 (ok = check_id(ctx)) == 0 || 1) 221 X509_get_pubkey_parameters(NULL, ctx->chain); 222 if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0) 223 return ok; 224 225 err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain, 226 ctx->param->flags); 227 if (err != X509_V_OK) { 228 if ((ok = verify_cb_cert(ctx, NULL, ctx->error_depth, err)) == 0) 229 return ok; 230 } 231 232 /* Verify chain signatures and expiration times */ 233 ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx); 234 if (!ok) 235 return ok; 236 237 if ((ok = check_name_constraints(ctx)) == 0) 238 return ok; 239 240 #ifndef OPENSSL_NO_RFC3779 241 /* RFC 3779 path validation, now that CRL check has been done */ 242 if ((ok = X509v3_asid_validate_path(ctx)) == 0) 243 return ok; 244 if ((ok = X509v3_addr_validate_path(ctx)) == 0) 245 return ok; 246 #endif 247 248 /* If we get this far evaluate policies */ 249 if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK) 250 ok = ctx->check_policy(ctx); 251 return ok; 252 } 253 254 int X509_verify_cert(X509_STORE_CTX *ctx) 255 { 256 SSL_DANE *dane = ctx->dane; 257 int ret; 258 259 if (ctx->cert == NULL) { 260 X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY); 261 ctx->error = X509_V_ERR_INVALID_CALL; 262 return -1; 263 } 264 265 if (ctx->chain != NULL) { 266 /* 267 * This X509_STORE_CTX has already been used to verify a cert. We 268 * cannot do another one. 269 */ 270 X509err(X509_F_X509_VERIFY_CERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 271 ctx->error = X509_V_ERR_INVALID_CALL; 272 return -1; 273 } 274 275 if (!X509_up_ref(ctx->cert)) { 276 X509err(X509_F_X509_VERIFY_CERT, ERR_R_INTERNAL_ERROR); 277 ctx->error = X509_V_ERR_UNSPECIFIED; 278 return -1; 279 } 280 281 /* 282 * first we make sure the chain we are going to build is present and that 283 * the first entry is in place 284 */ 285 if ((ctx->chain = sk_X509_new_null()) == NULL 286 || !sk_X509_push(ctx->chain, ctx->cert)) { 287 X509_free(ctx->cert); 288 X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE); 289 ctx->error = X509_V_ERR_OUT_OF_MEM; 290 return -1; 291 } 292 293 ctx->num_untrusted = 1; 294 295 /* If the peer's public key is too weak, we can stop early. */ 296 if (!check_key_level(ctx, ctx->cert) && 297 !verify_cb_cert(ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL)) 298 return 0; 299 300 if (DANETLS_ENABLED(dane)) 301 ret = dane_verify(ctx); 302 else 303 ret = verify_chain(ctx); 304 305 /* 306 * Safety-net. If we are returning an error, we must also set ctx->error, 307 * so that the chain is not considered verified should the error be ignored 308 * (e.g. TLS with SSL_VERIFY_NONE). 309 */ 310 if (ret <= 0 && ctx->error == X509_V_OK) 311 ctx->error = X509_V_ERR_UNSPECIFIED; 312 return ret; 313 } 314 315 /* 316 * Given a STACK_OF(X509) find the issuer of cert (if any) 317 */ 318 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x) 319 { 320 int i; 321 X509 *issuer, *rv = NULL; 322 323 for (i = 0; i < sk_X509_num(sk); i++) { 324 issuer = sk_X509_value(sk, i); 325 if (ctx->check_issued(ctx, x, issuer)) { 326 rv = issuer; 327 if (x509_check_cert_time(ctx, rv, -1)) 328 break; 329 } 330 } 331 return rv; 332 } 333 334 /* 335 * Check that the given certificate 'x' is issued by the certificate 'issuer' 336 * and the issuer is not yet in ctx->chain, where the exceptional case 337 * that 'x' is self-issued and ctx->chain has just one element is allowed. 338 */ 339 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer) 340 { 341 if (x509_likely_issued(issuer, x) != X509_V_OK) 342 return 0; 343 if ((x->ex_flags & EXFLAG_SI) == 0 || sk_X509_num(ctx->chain) != 1) { 344 int i; 345 X509 *ch; 346 347 for (i = 0; i < sk_X509_num(ctx->chain); i++) { 348 ch = sk_X509_value(ctx->chain, i); 349 if (ch == issuer || X509_cmp(ch, issuer) == 0) 350 return 0; 351 } 352 } 353 return 1; 354 } 355 356 /* Alternative lookup method: look from a STACK stored in other_ctx */ 357 358 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x) 359 { 360 *issuer = find_issuer(ctx, ctx->other_ctx, x); 361 362 if (*issuer == NULL || !X509_up_ref(*issuer)) 363 goto err; 364 365 return 1; 366 367 err: 368 *issuer = NULL; 369 return 0; 370 } 371 372 static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, X509_NAME *nm) 373 { 374 STACK_OF(X509) *sk = NULL; 375 X509 *x; 376 int i; 377 378 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) { 379 x = sk_X509_value(ctx->other_ctx, i); 380 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) { 381 if (!X509_up_ref(x)) { 382 sk_X509_pop_free(sk, X509_free); 383 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_INTERNAL_ERROR); 384 ctx->error = X509_V_ERR_UNSPECIFIED; 385 return NULL; 386 } 387 if (sk == NULL) 388 sk = sk_X509_new_null(); 389 if (sk == NULL || !sk_X509_push(sk, x)) { 390 X509_free(x); 391 sk_X509_pop_free(sk, X509_free); 392 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_MALLOC_FAILURE); 393 ctx->error = X509_V_ERR_OUT_OF_MEM; 394 return NULL; 395 } 396 } 397 } 398 return sk; 399 } 400 401 /* 402 * Check EE or CA certificate purpose. For trusted certificates explicit local 403 * auxiliary trust can be used to override EKU-restrictions. 404 */ 405 static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth, 406 int must_be_ca) 407 { 408 int tr_ok = X509_TRUST_UNTRUSTED; 409 410 /* 411 * For trusted certificates we want to see whether any auxiliary trust 412 * settings trump the purpose constraints. 413 * 414 * This is complicated by the fact that the trust ordinals in 415 * ctx->param->trust are entirely independent of the purpose ordinals in 416 * ctx->param->purpose! 417 * 418 * What connects them is their mutual initialization via calls from 419 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets 420 * related values of both param->trust and param->purpose. It is however 421 * typically possible to infer associated trust values from a purpose value 422 * via the X509_PURPOSE API. 423 * 424 * Therefore, we can only check for trust overrides when the purpose we're 425 * checking is the same as ctx->param->purpose and ctx->param->trust is 426 * also set. 427 */ 428 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose) 429 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT); 430 431 switch (tr_ok) { 432 case X509_TRUST_TRUSTED: 433 return 1; 434 case X509_TRUST_REJECTED: 435 break; 436 default: 437 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) { 438 case 1: 439 return 1; 440 case 0: 441 break; 442 default: 443 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0) 444 return 1; 445 } 446 break; 447 } 448 449 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE); 450 } 451 452 /* 453 * Check a certificate chains extensions for consistency with the supplied 454 * purpose 455 */ 456 457 static int check_chain_extensions(X509_STORE_CTX *ctx) 458 { 459 int i, must_be_ca, plen = 0; 460 X509 *x; 461 int proxy_path_length = 0; 462 int purpose; 463 int allow_proxy_certs; 464 int num = sk_X509_num(ctx->chain); 465 466 /*- 467 * must_be_ca can have 1 of 3 values: 468 * -1: we accept both CA and non-CA certificates, to allow direct 469 * use of self-signed certificates (which are marked as CA). 470 * 0: we only accept non-CA certificates. This is currently not 471 * used, but the possibility is present for future extensions. 472 * 1: we only accept CA certificates. This is currently used for 473 * all certificates in the chain except the leaf certificate. 474 */ 475 must_be_ca = -1; 476 477 /* CRL path validation */ 478 if (ctx->parent) { 479 allow_proxy_certs = 0; 480 purpose = X509_PURPOSE_CRL_SIGN; 481 } else { 482 allow_proxy_certs = 483 ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS); 484 purpose = ctx->param->purpose; 485 } 486 487 for (i = 0; i < num; i++) { 488 int ret; 489 x = sk_X509_value(ctx->chain, i); 490 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) 491 && (x->ex_flags & EXFLAG_CRITICAL)) { 492 if (!verify_cb_cert(ctx, x, i, 493 X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION)) 494 return 0; 495 } 496 if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) { 497 if (!verify_cb_cert(ctx, x, i, 498 X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED)) 499 return 0; 500 } 501 ret = X509_check_ca(x); 502 switch (must_be_ca) { 503 case -1: 504 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) 505 && (ret != 1) && (ret != 0)) { 506 ret = 0; 507 ctx->error = X509_V_ERR_INVALID_CA; 508 } else 509 ret = 1; 510 break; 511 case 0: 512 if (ret != 0) { 513 ret = 0; 514 ctx->error = X509_V_ERR_INVALID_NON_CA; 515 } else 516 ret = 1; 517 break; 518 default: 519 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */ 520 if ((ret == 0) 521 || ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT) 522 && (ret != 1))) { 523 ret = 0; 524 ctx->error = X509_V_ERR_INVALID_CA; 525 } else 526 ret = 1; 527 break; 528 } 529 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) && num > 1) { 530 /* Check for presence of explicit elliptic curve parameters */ 531 ret = check_curve(x); 532 if (ret < 0) 533 ctx->error = X509_V_ERR_UNSPECIFIED; 534 else if (ret == 0) 535 ctx->error = X509_V_ERR_EC_KEY_EXPLICIT_PARAMS; 536 } 537 if ((x->ex_flags & EXFLAG_CA) == 0 538 && x->ex_pathlen != -1 539 && (ctx->param->flags & X509_V_FLAG_X509_STRICT)) { 540 ctx->error = X509_V_ERR_INVALID_EXTENSION; 541 ret = 0; 542 } 543 if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK)) 544 return 0; 545 /* check_purpose() makes the callback as needed */ 546 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca)) 547 return 0; 548 /* Check pathlen */ 549 if ((i > 1) && (x->ex_pathlen != -1) 550 && (plen > (x->ex_pathlen + proxy_path_length))) { 551 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED)) 552 return 0; 553 } 554 /* Increment path length if not a self issued intermediate CA */ 555 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0) 556 plen++; 557 /* 558 * If this certificate is a proxy certificate, the next certificate 559 * must be another proxy certificate or a EE certificate. If not, 560 * the next certificate must be a CA certificate. 561 */ 562 if (x->ex_flags & EXFLAG_PROXY) { 563 /* 564 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint 565 * is less than max_path_length, the former should be copied to 566 * the latter, and 4.1.4 (a) stipulates that max_path_length 567 * should be verified to be larger than zero and decrement it. 568 * 569 * Because we're checking the certs in the reverse order, we start 570 * with verifying that proxy_path_length isn't larger than pcPLC, 571 * and copy the latter to the former if it is, and finally, 572 * increment proxy_path_length. 573 */ 574 if (x->ex_pcpathlen != -1) { 575 if (proxy_path_length > x->ex_pcpathlen) { 576 if (!verify_cb_cert(ctx, x, i, 577 X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED)) 578 return 0; 579 } 580 proxy_path_length = x->ex_pcpathlen; 581 } 582 proxy_path_length++; 583 must_be_ca = 0; 584 } else 585 must_be_ca = 1; 586 } 587 return 1; 588 } 589 590 static int has_san_id(X509 *x, int gtype) 591 { 592 int i; 593 int ret = 0; 594 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); 595 596 if (gs == NULL) 597 return 0; 598 599 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) { 600 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i); 601 602 if (g->type == gtype) { 603 ret = 1; 604 break; 605 } 606 } 607 GENERAL_NAMES_free(gs); 608 return ret; 609 } 610 611 static int check_name_constraints(X509_STORE_CTX *ctx) 612 { 613 int i; 614 615 /* Check name constraints for all certificates */ 616 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) { 617 X509 *x = sk_X509_value(ctx->chain, i); 618 int j; 619 620 /* Ignore self issued certs unless last in chain */ 621 if (i && (x->ex_flags & EXFLAG_SI)) 622 continue; 623 624 /* 625 * Proxy certificates policy has an extra constraint, where the 626 * certificate subject MUST be the issuer with a single CN entry 627 * added. 628 * (RFC 3820: 3.4, 4.1.3 (a)(4)) 629 */ 630 if (x->ex_flags & EXFLAG_PROXY) { 631 X509_NAME *tmpsubject = X509_get_subject_name(x); 632 X509_NAME *tmpissuer = X509_get_issuer_name(x); 633 X509_NAME_ENTRY *tmpentry = NULL; 634 int last_object_nid = 0; 635 int err = X509_V_OK; 636 int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1; 637 638 /* Check that there are at least two RDNs */ 639 if (last_object_loc < 1) { 640 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 641 goto proxy_name_done; 642 } 643 644 /* 645 * Check that there is exactly one more RDN in subject as 646 * there is in issuer. 647 */ 648 if (X509_NAME_entry_count(tmpsubject) 649 != X509_NAME_entry_count(tmpissuer) + 1) { 650 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 651 goto proxy_name_done; 652 } 653 654 /* 655 * Check that the last subject component isn't part of a 656 * multivalued RDN 657 */ 658 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, 659 last_object_loc)) 660 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, 661 last_object_loc - 1))) { 662 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 663 goto proxy_name_done; 664 } 665 666 /* 667 * Check that the last subject RDN is a commonName, and that 668 * all the previous RDNs match the issuer exactly 669 */ 670 tmpsubject = X509_NAME_dup(tmpsubject); 671 if (tmpsubject == NULL) { 672 X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE); 673 ctx->error = X509_V_ERR_OUT_OF_MEM; 674 return 0; 675 } 676 677 tmpentry = 678 X509_NAME_delete_entry(tmpsubject, last_object_loc); 679 last_object_nid = 680 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry)); 681 682 if (last_object_nid != NID_commonName 683 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) { 684 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 685 } 686 687 X509_NAME_ENTRY_free(tmpentry); 688 X509_NAME_free(tmpsubject); 689 690 proxy_name_done: 691 if (err != X509_V_OK 692 && !verify_cb_cert(ctx, x, i, err)) 693 return 0; 694 } 695 696 /* 697 * Check against constraints for all certificates higher in chain 698 * including trust anchor. Trust anchor not strictly speaking needed 699 * but if it includes constraints it is to be assumed it expects them 700 * to be obeyed. 701 */ 702 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) { 703 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc; 704 705 if (nc) { 706 int rv = NAME_CONSTRAINTS_check(x, nc); 707 708 /* If EE certificate check commonName too */ 709 if (rv == X509_V_OK && i == 0 710 && (ctx->param->hostflags 711 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0 712 && ((ctx->param->hostflags 713 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0 714 || !has_san_id(x, GEN_DNS))) 715 rv = NAME_CONSTRAINTS_check_CN(x, nc); 716 717 switch (rv) { 718 case X509_V_OK: 719 break; 720 case X509_V_ERR_OUT_OF_MEM: 721 return 0; 722 default: 723 if (!verify_cb_cert(ctx, x, i, rv)) 724 return 0; 725 break; 726 } 727 } 728 } 729 } 730 return 1; 731 } 732 733 static int check_id_error(X509_STORE_CTX *ctx, int errcode) 734 { 735 return verify_cb_cert(ctx, ctx->cert, 0, errcode); 736 } 737 738 static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm) 739 { 740 int i; 741 int n = sk_OPENSSL_STRING_num(vpm->hosts); 742 char *name; 743 744 if (vpm->peername != NULL) { 745 OPENSSL_free(vpm->peername); 746 vpm->peername = NULL; 747 } 748 for (i = 0; i < n; ++i) { 749 name = sk_OPENSSL_STRING_value(vpm->hosts, i); 750 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0) 751 return 1; 752 } 753 return n == 0; 754 } 755 756 static int check_id(X509_STORE_CTX *ctx) 757 { 758 X509_VERIFY_PARAM *vpm = ctx->param; 759 X509 *x = ctx->cert; 760 if (vpm->hosts && check_hosts(x, vpm) <= 0) { 761 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH)) 762 return 0; 763 } 764 if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) { 765 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH)) 766 return 0; 767 } 768 if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) { 769 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH)) 770 return 0; 771 } 772 return 1; 773 } 774 775 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted) 776 { 777 int i; 778 X509 *x = NULL; 779 X509 *mx; 780 SSL_DANE *dane = ctx->dane; 781 int num = sk_X509_num(ctx->chain); 782 int trust; 783 784 /* 785 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2) 786 * match, we're done, otherwise we'll merely record the match depth. 787 */ 788 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) { 789 switch (trust = check_dane_issuer(ctx, num_untrusted)) { 790 case X509_TRUST_TRUSTED: 791 case X509_TRUST_REJECTED: 792 return trust; 793 } 794 } 795 796 /* 797 * Check trusted certificates in chain at depth num_untrusted and up. 798 * Note, that depths 0..num_untrusted-1 may also contain trusted 799 * certificates, but the caller is expected to have already checked those, 800 * and wants to incrementally check just any added since. 801 */ 802 for (i = num_untrusted; i < num; i++) { 803 x = sk_X509_value(ctx->chain, i); 804 trust = X509_check_trust(x, ctx->param->trust, 0); 805 /* If explicitly trusted return trusted */ 806 if (trust == X509_TRUST_TRUSTED) 807 goto trusted; 808 if (trust == X509_TRUST_REJECTED) 809 goto rejected; 810 } 811 812 /* 813 * If we are looking at a trusted certificate, and accept partial chains, 814 * the chain is PKIX trusted. 815 */ 816 if (num_untrusted < num) { 817 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) 818 goto trusted; 819 return X509_TRUST_UNTRUSTED; 820 } 821 822 if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) { 823 /* 824 * Last-resort call with no new trusted certificates, check the leaf 825 * for a direct trust store match. 826 */ 827 i = 0; 828 x = sk_X509_value(ctx->chain, i); 829 mx = lookup_cert_match(ctx, x); 830 if (!mx) 831 return X509_TRUST_UNTRUSTED; 832 833 /* 834 * Check explicit auxiliary trust/reject settings. If none are set, 835 * we'll accept X509_TRUST_UNTRUSTED when not self-signed. 836 */ 837 trust = X509_check_trust(mx, ctx->param->trust, 0); 838 if (trust == X509_TRUST_REJECTED) { 839 X509_free(mx); 840 goto rejected; 841 } 842 843 /* Replace leaf with trusted match */ 844 (void) sk_X509_set(ctx->chain, 0, mx); 845 X509_free(x); 846 ctx->num_untrusted = 0; 847 goto trusted; 848 } 849 850 /* 851 * If no trusted certs in chain at all return untrusted and allow 852 * standard (no issuer cert) etc errors to be indicated. 853 */ 854 return X509_TRUST_UNTRUSTED; 855 856 rejected: 857 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED)) 858 return X509_TRUST_REJECTED; 859 return X509_TRUST_UNTRUSTED; 860 861 trusted: 862 if (!DANETLS_ENABLED(dane)) 863 return X509_TRUST_TRUSTED; 864 if (dane->pdpth < 0) 865 dane->pdpth = num_untrusted; 866 /* With DANE, PKIX alone is not trusted until we have both */ 867 if (dane->mdpth >= 0) 868 return X509_TRUST_TRUSTED; 869 return X509_TRUST_UNTRUSTED; 870 } 871 872 static int check_revocation(X509_STORE_CTX *ctx) 873 { 874 int i = 0, last = 0, ok = 0; 875 if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK)) 876 return 1; 877 if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL) 878 last = sk_X509_num(ctx->chain) - 1; 879 else { 880 /* If checking CRL paths this isn't the EE certificate */ 881 if (ctx->parent) 882 return 1; 883 last = 0; 884 } 885 for (i = 0; i <= last; i++) { 886 ctx->error_depth = i; 887 ok = check_cert(ctx); 888 if (!ok) 889 return ok; 890 } 891 return 1; 892 } 893 894 static int check_cert(X509_STORE_CTX *ctx) 895 { 896 X509_CRL *crl = NULL, *dcrl = NULL; 897 int ok = 0; 898 int cnum = ctx->error_depth; 899 X509 *x = sk_X509_value(ctx->chain, cnum); 900 901 ctx->current_cert = x; 902 ctx->current_issuer = NULL; 903 ctx->current_crl_score = 0; 904 ctx->current_reasons = 0; 905 906 if (x->ex_flags & EXFLAG_PROXY) 907 return 1; 908 909 while (ctx->current_reasons != CRLDP_ALL_REASONS) { 910 unsigned int last_reasons = ctx->current_reasons; 911 912 /* Try to retrieve relevant CRL */ 913 if (ctx->get_crl) 914 ok = ctx->get_crl(ctx, &crl, x); 915 else 916 ok = get_crl_delta(ctx, &crl, &dcrl, x); 917 /* 918 * If error looking up CRL, nothing we can do except notify callback 919 */ 920 if (!ok) { 921 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 922 goto done; 923 } 924 ctx->current_crl = crl; 925 ok = ctx->check_crl(ctx, crl); 926 if (!ok) 927 goto done; 928 929 if (dcrl) { 930 ok = ctx->check_crl(ctx, dcrl); 931 if (!ok) 932 goto done; 933 ok = ctx->cert_crl(ctx, dcrl, x); 934 if (!ok) 935 goto done; 936 } else 937 ok = 1; 938 939 /* Don't look in full CRL if delta reason is removefromCRL */ 940 if (ok != 2) { 941 ok = ctx->cert_crl(ctx, crl, x); 942 if (!ok) 943 goto done; 944 } 945 946 X509_CRL_free(crl); 947 X509_CRL_free(dcrl); 948 crl = NULL; 949 dcrl = NULL; 950 /* 951 * If reasons not updated we won't get anywhere by another iteration, 952 * so exit loop. 953 */ 954 if (last_reasons == ctx->current_reasons) { 955 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 956 goto done; 957 } 958 } 959 done: 960 X509_CRL_free(crl); 961 X509_CRL_free(dcrl); 962 963 ctx->current_crl = NULL; 964 return ok; 965 } 966 967 /* Check CRL times against values in X509_STORE_CTX */ 968 969 static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify) 970 { 971 time_t *ptime; 972 int i; 973 974 if (notify) 975 ctx->current_crl = crl; 976 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) 977 ptime = &ctx->param->check_time; 978 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) 979 return 1; 980 else 981 ptime = NULL; 982 983 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime); 984 if (i == 0) { 985 if (!notify) 986 return 0; 987 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD)) 988 return 0; 989 } 990 991 if (i > 0) { 992 if (!notify) 993 return 0; 994 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID)) 995 return 0; 996 } 997 998 if (X509_CRL_get0_nextUpdate(crl)) { 999 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime); 1000 1001 if (i == 0) { 1002 if (!notify) 1003 return 0; 1004 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD)) 1005 return 0; 1006 } 1007 /* Ignore expiry of base CRL is delta is valid */ 1008 if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) { 1009 if (!notify) 1010 return 0; 1011 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED)) 1012 return 0; 1013 } 1014 } 1015 1016 if (notify) 1017 ctx->current_crl = NULL; 1018 1019 return 1; 1020 } 1021 1022 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, 1023 X509 **pissuer, int *pscore, unsigned int *preasons, 1024 STACK_OF(X509_CRL) *crls) 1025 { 1026 int i, crl_score, best_score = *pscore; 1027 unsigned int reasons, best_reasons = 0; 1028 X509 *x = ctx->current_cert; 1029 X509_CRL *crl, *best_crl = NULL; 1030 X509 *crl_issuer = NULL, *best_crl_issuer = NULL; 1031 1032 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1033 crl = sk_X509_CRL_value(crls, i); 1034 reasons = *preasons; 1035 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x); 1036 if (crl_score < best_score || crl_score == 0) 1037 continue; 1038 /* If current CRL is equivalent use it if it is newer */ 1039 if (crl_score == best_score && best_crl != NULL) { 1040 int day, sec; 1041 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl), 1042 X509_CRL_get0_lastUpdate(crl)) == 0) 1043 continue; 1044 /* 1045 * ASN1_TIME_diff never returns inconsistent signs for |day| 1046 * and |sec|. 1047 */ 1048 if (day <= 0 && sec <= 0) 1049 continue; 1050 } 1051 best_crl = crl; 1052 best_crl_issuer = crl_issuer; 1053 best_score = crl_score; 1054 best_reasons = reasons; 1055 } 1056 1057 if (best_crl) { 1058 X509_CRL_free(*pcrl); 1059 *pcrl = best_crl; 1060 *pissuer = best_crl_issuer; 1061 *pscore = best_score; 1062 *preasons = best_reasons; 1063 X509_CRL_up_ref(best_crl); 1064 X509_CRL_free(*pdcrl); 1065 *pdcrl = NULL; 1066 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls); 1067 } 1068 1069 if (best_score >= CRL_SCORE_VALID) 1070 return 1; 1071 1072 return 0; 1073 } 1074 1075 /* 1076 * Compare two CRL extensions for delta checking purposes. They should be 1077 * both present or both absent. If both present all fields must be identical. 1078 */ 1079 1080 static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid) 1081 { 1082 ASN1_OCTET_STRING *exta, *extb; 1083 int i; 1084 i = X509_CRL_get_ext_by_NID(a, nid, -1); 1085 if (i >= 0) { 1086 /* Can't have multiple occurrences */ 1087 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1) 1088 return 0; 1089 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i)); 1090 } else 1091 exta = NULL; 1092 1093 i = X509_CRL_get_ext_by_NID(b, nid, -1); 1094 1095 if (i >= 0) { 1096 1097 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1) 1098 return 0; 1099 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i)); 1100 } else 1101 extb = NULL; 1102 1103 if (!exta && !extb) 1104 return 1; 1105 1106 if (!exta || !extb) 1107 return 0; 1108 1109 if (ASN1_OCTET_STRING_cmp(exta, extb)) 1110 return 0; 1111 1112 return 1; 1113 } 1114 1115 /* See if a base and delta are compatible */ 1116 1117 static int check_delta_base(X509_CRL *delta, X509_CRL *base) 1118 { 1119 /* Delta CRL must be a delta */ 1120 if (!delta->base_crl_number) 1121 return 0; 1122 /* Base must have a CRL number */ 1123 if (!base->crl_number) 1124 return 0; 1125 /* Issuer names must match */ 1126 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta))) 1127 return 0; 1128 /* AKID and IDP must match */ 1129 if (!crl_extension_match(delta, base, NID_authority_key_identifier)) 1130 return 0; 1131 if (!crl_extension_match(delta, base, NID_issuing_distribution_point)) 1132 return 0; 1133 /* Delta CRL base number must not exceed Full CRL number. */ 1134 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0) 1135 return 0; 1136 /* Delta CRL number must exceed full CRL number */ 1137 if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0) 1138 return 1; 1139 return 0; 1140 } 1141 1142 /* 1143 * For a given base CRL find a delta... maybe extend to delta scoring or 1144 * retrieve a chain of deltas... 1145 */ 1146 1147 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore, 1148 X509_CRL *base, STACK_OF(X509_CRL) *crls) 1149 { 1150 X509_CRL *delta; 1151 int i; 1152 if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS)) 1153 return; 1154 if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST)) 1155 return; 1156 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1157 delta = sk_X509_CRL_value(crls, i); 1158 if (check_delta_base(delta, base)) { 1159 if (check_crl_time(ctx, delta, 0)) 1160 *pscore |= CRL_SCORE_TIME_DELTA; 1161 X509_CRL_up_ref(delta); 1162 *dcrl = delta; 1163 return; 1164 } 1165 } 1166 *dcrl = NULL; 1167 } 1168 1169 /* 1170 * For a given CRL return how suitable it is for the supplied certificate 1171 * 'x'. The return value is a mask of several criteria. If the issuer is not 1172 * the certificate issuer this is returned in *pissuer. The reasons mask is 1173 * also used to determine if the CRL is suitable: if no new reasons the CRL 1174 * is rejected, otherwise reasons is updated. 1175 */ 1176 1177 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 1178 unsigned int *preasons, X509_CRL *crl, X509 *x) 1179 { 1180 1181 int crl_score = 0; 1182 unsigned int tmp_reasons = *preasons, crl_reasons; 1183 1184 /* First see if we can reject CRL straight away */ 1185 1186 /* Invalid IDP cannot be processed */ 1187 if (crl->idp_flags & IDP_INVALID) 1188 return 0; 1189 /* Reason codes or indirect CRLs need extended CRL support */ 1190 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) { 1191 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS)) 1192 return 0; 1193 } else if (crl->idp_flags & IDP_REASONS) { 1194 /* If no new reasons reject */ 1195 if (!(crl->idp_reasons & ~tmp_reasons)) 1196 return 0; 1197 } 1198 /* Don't process deltas at this stage */ 1199 else if (crl->base_crl_number) 1200 return 0; 1201 /* If issuer name doesn't match certificate need indirect CRL */ 1202 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) { 1203 if (!(crl->idp_flags & IDP_INDIRECT)) 1204 return 0; 1205 } else 1206 crl_score |= CRL_SCORE_ISSUER_NAME; 1207 1208 if (!(crl->flags & EXFLAG_CRITICAL)) 1209 crl_score |= CRL_SCORE_NOCRITICAL; 1210 1211 /* Check expiry */ 1212 if (check_crl_time(ctx, crl, 0)) 1213 crl_score |= CRL_SCORE_TIME; 1214 1215 /* Check authority key ID and locate certificate issuer */ 1216 crl_akid_check(ctx, crl, pissuer, &crl_score); 1217 1218 /* If we can't locate certificate issuer at this point forget it */ 1219 1220 if (!(crl_score & CRL_SCORE_AKID)) 1221 return 0; 1222 1223 /* Check cert for matching CRL distribution points */ 1224 1225 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) { 1226 /* If no new reasons reject */ 1227 if (!(crl_reasons & ~tmp_reasons)) 1228 return 0; 1229 tmp_reasons |= crl_reasons; 1230 crl_score |= CRL_SCORE_SCOPE; 1231 } 1232 1233 *preasons = tmp_reasons; 1234 1235 return crl_score; 1236 1237 } 1238 1239 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, 1240 X509 **pissuer, int *pcrl_score) 1241 { 1242 X509 *crl_issuer = NULL; 1243 X509_NAME *cnm = X509_CRL_get_issuer(crl); 1244 int cidx = ctx->error_depth; 1245 int i; 1246 1247 if (cidx != sk_X509_num(ctx->chain) - 1) 1248 cidx++; 1249 1250 crl_issuer = sk_X509_value(ctx->chain, cidx); 1251 1252 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1253 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) { 1254 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT; 1255 *pissuer = crl_issuer; 1256 return; 1257 } 1258 } 1259 1260 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) { 1261 crl_issuer = sk_X509_value(ctx->chain, cidx); 1262 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) 1263 continue; 1264 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1265 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH; 1266 *pissuer = crl_issuer; 1267 return; 1268 } 1269 } 1270 1271 /* Anything else needs extended CRL support */ 1272 1273 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) 1274 return; 1275 1276 /* 1277 * Otherwise the CRL issuer is not on the path. Look for it in the set of 1278 * untrusted certificates. 1279 */ 1280 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) { 1281 crl_issuer = sk_X509_value(ctx->untrusted, i); 1282 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) 1283 continue; 1284 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1285 *pissuer = crl_issuer; 1286 *pcrl_score |= CRL_SCORE_AKID; 1287 return; 1288 } 1289 } 1290 } 1291 1292 /* 1293 * Check the path of a CRL issuer certificate. This creates a new 1294 * X509_STORE_CTX and populates it with most of the parameters from the 1295 * parent. This could be optimised somewhat since a lot of path checking will 1296 * be duplicated by the parent, but this will rarely be used in practice. 1297 */ 1298 1299 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x) 1300 { 1301 X509_STORE_CTX crl_ctx; 1302 int ret; 1303 1304 /* Don't allow recursive CRL path validation */ 1305 if (ctx->parent) 1306 return 0; 1307 if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted)) 1308 return -1; 1309 1310 crl_ctx.crls = ctx->crls; 1311 /* Copy verify params across */ 1312 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param); 1313 1314 crl_ctx.parent = ctx; 1315 crl_ctx.verify_cb = ctx->verify_cb; 1316 1317 /* Verify CRL issuer */ 1318 ret = X509_verify_cert(&crl_ctx); 1319 if (ret <= 0) 1320 goto err; 1321 1322 /* Check chain is acceptable */ 1323 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain); 1324 err: 1325 X509_STORE_CTX_cleanup(&crl_ctx); 1326 return ret; 1327 } 1328 1329 /* 1330 * RFC3280 says nothing about the relationship between CRL path and 1331 * certificate path, which could lead to situations where a certificate could 1332 * be revoked or validated by a CA not authorised to do so. RFC5280 is more 1333 * strict and states that the two paths must end in the same trust anchor, 1334 * though some discussions remain... until this is resolved we use the 1335 * RFC5280 version 1336 */ 1337 1338 static int check_crl_chain(X509_STORE_CTX *ctx, 1339 STACK_OF(X509) *cert_path, 1340 STACK_OF(X509) *crl_path) 1341 { 1342 X509 *cert_ta, *crl_ta; 1343 cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1); 1344 crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1); 1345 if (!X509_cmp(cert_ta, crl_ta)) 1346 return 1; 1347 return 0; 1348 } 1349 1350 /*- 1351 * Check for match between two dist point names: three separate cases. 1352 * 1. Both are relative names and compare X509_NAME types. 1353 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES. 1354 * 3. Both are full names and compare two GENERAL_NAMES. 1355 * 4. One is NULL: automatic match. 1356 */ 1357 1358 static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b) 1359 { 1360 X509_NAME *nm = NULL; 1361 GENERAL_NAMES *gens = NULL; 1362 GENERAL_NAME *gena, *genb; 1363 int i, j; 1364 if (!a || !b) 1365 return 1; 1366 if (a->type == 1) { 1367 if (!a->dpname) 1368 return 0; 1369 /* Case 1: two X509_NAME */ 1370 if (b->type == 1) { 1371 if (!b->dpname) 1372 return 0; 1373 if (!X509_NAME_cmp(a->dpname, b->dpname)) 1374 return 1; 1375 else 1376 return 0; 1377 } 1378 /* Case 2: set name and GENERAL_NAMES appropriately */ 1379 nm = a->dpname; 1380 gens = b->name.fullname; 1381 } else if (b->type == 1) { 1382 if (!b->dpname) 1383 return 0; 1384 /* Case 2: set name and GENERAL_NAMES appropriately */ 1385 gens = a->name.fullname; 1386 nm = b->dpname; 1387 } 1388 1389 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */ 1390 if (nm) { 1391 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 1392 gena = sk_GENERAL_NAME_value(gens, i); 1393 if (gena->type != GEN_DIRNAME) 1394 continue; 1395 if (!X509_NAME_cmp(nm, gena->d.directoryName)) 1396 return 1; 1397 } 1398 return 0; 1399 } 1400 1401 /* Else case 3: two GENERAL_NAMES */ 1402 1403 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) { 1404 gena = sk_GENERAL_NAME_value(a->name.fullname, i); 1405 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) { 1406 genb = sk_GENERAL_NAME_value(b->name.fullname, j); 1407 if (!GENERAL_NAME_cmp(gena, genb)) 1408 return 1; 1409 } 1410 } 1411 1412 return 0; 1413 1414 } 1415 1416 static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score) 1417 { 1418 int i; 1419 X509_NAME *nm = X509_CRL_get_issuer(crl); 1420 /* If no CRLissuer return is successful iff don't need a match */ 1421 if (!dp->CRLissuer) 1422 return ! !(crl_score & CRL_SCORE_ISSUER_NAME); 1423 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { 1424 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 1425 if (gen->type != GEN_DIRNAME) 1426 continue; 1427 if (!X509_NAME_cmp(gen->d.directoryName, nm)) 1428 return 1; 1429 } 1430 return 0; 1431 } 1432 1433 /* Check CRLDP and IDP */ 1434 1435 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 1436 unsigned int *preasons) 1437 { 1438 int i; 1439 if (crl->idp_flags & IDP_ONLYATTR) 1440 return 0; 1441 if (x->ex_flags & EXFLAG_CA) { 1442 if (crl->idp_flags & IDP_ONLYUSER) 1443 return 0; 1444 } else { 1445 if (crl->idp_flags & IDP_ONLYCA) 1446 return 0; 1447 } 1448 *preasons = crl->idp_reasons; 1449 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) { 1450 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i); 1451 if (crldp_check_crlissuer(dp, crl, crl_score)) { 1452 if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) { 1453 *preasons &= dp->dp_reasons; 1454 return 1; 1455 } 1456 } 1457 } 1458 if ((!crl->idp || !crl->idp->distpoint) 1459 && (crl_score & CRL_SCORE_ISSUER_NAME)) 1460 return 1; 1461 return 0; 1462 } 1463 1464 /* 1465 * Retrieve CRL corresponding to current certificate. If deltas enabled try 1466 * to find a delta CRL too 1467 */ 1468 1469 static int get_crl_delta(X509_STORE_CTX *ctx, 1470 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x) 1471 { 1472 int ok; 1473 X509 *issuer = NULL; 1474 int crl_score = 0; 1475 unsigned int reasons; 1476 X509_CRL *crl = NULL, *dcrl = NULL; 1477 STACK_OF(X509_CRL) *skcrl; 1478 X509_NAME *nm = X509_get_issuer_name(x); 1479 1480 reasons = ctx->current_reasons; 1481 ok = get_crl_sk(ctx, &crl, &dcrl, 1482 &issuer, &crl_score, &reasons, ctx->crls); 1483 if (ok) 1484 goto done; 1485 1486 /* Lookup CRLs from store */ 1487 1488 skcrl = ctx->lookup_crls(ctx, nm); 1489 1490 /* If no CRLs found and a near match from get_crl_sk use that */ 1491 if (!skcrl && crl) 1492 goto done; 1493 1494 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl); 1495 1496 sk_X509_CRL_pop_free(skcrl, X509_CRL_free); 1497 1498 done: 1499 /* If we got any kind of CRL use it and return success */ 1500 if (crl) { 1501 ctx->current_issuer = issuer; 1502 ctx->current_crl_score = crl_score; 1503 ctx->current_reasons = reasons; 1504 *pcrl = crl; 1505 *pdcrl = dcrl; 1506 return 1; 1507 } 1508 return 0; 1509 } 1510 1511 /* Check CRL validity */ 1512 static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl) 1513 { 1514 X509 *issuer = NULL; 1515 EVP_PKEY *ikey = NULL; 1516 int cnum = ctx->error_depth; 1517 int chnum = sk_X509_num(ctx->chain) - 1; 1518 1519 /* if we have an alternative CRL issuer cert use that */ 1520 if (ctx->current_issuer) 1521 issuer = ctx->current_issuer; 1522 /* 1523 * Else find CRL issuer: if not last certificate then issuer is next 1524 * certificate in chain. 1525 */ 1526 else if (cnum < chnum) 1527 issuer = sk_X509_value(ctx->chain, cnum + 1); 1528 else { 1529 issuer = sk_X509_value(ctx->chain, chnum); 1530 /* If not self signed, can't check signature */ 1531 if (!ctx->check_issued(ctx, issuer, issuer) && 1532 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER)) 1533 return 0; 1534 } 1535 1536 if (issuer == NULL) 1537 return 1; 1538 1539 /* 1540 * Skip most tests for deltas because they have already been done 1541 */ 1542 if (!crl->base_crl_number) { 1543 /* Check for cRLSign bit if keyUsage present */ 1544 if ((issuer->ex_flags & EXFLAG_KUSAGE) && 1545 !(issuer->ex_kusage & KU_CRL_SIGN) && 1546 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN)) 1547 return 0; 1548 1549 if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) && 1550 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE)) 1551 return 0; 1552 1553 if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) && 1554 check_crl_path(ctx, ctx->current_issuer) <= 0 && 1555 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR)) 1556 return 0; 1557 1558 if ((crl->idp_flags & IDP_INVALID) && 1559 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION)) 1560 return 0; 1561 } 1562 1563 if (!(ctx->current_crl_score & CRL_SCORE_TIME) && 1564 !check_crl_time(ctx, crl, 1)) 1565 return 0; 1566 1567 /* Attempt to get issuer certificate public key */ 1568 ikey = X509_get0_pubkey(issuer); 1569 1570 if (!ikey && 1571 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY)) 1572 return 0; 1573 1574 if (ikey) { 1575 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags); 1576 1577 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv)) 1578 return 0; 1579 /* Verify CRL signature */ 1580 if (X509_CRL_verify(crl, ikey) <= 0 && 1581 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE)) 1582 return 0; 1583 } 1584 return 1; 1585 } 1586 1587 /* Check certificate against CRL */ 1588 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x) 1589 { 1590 X509_REVOKED *rev; 1591 1592 /* 1593 * The rules changed for this... previously if a CRL contained unhandled 1594 * critical extensions it could still be used to indicate a certificate 1595 * was revoked. This has since been changed since critical extensions can 1596 * change the meaning of CRL entries. 1597 */ 1598 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) 1599 && (crl->flags & EXFLAG_CRITICAL) && 1600 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION)) 1601 return 0; 1602 /* 1603 * Look for serial number of certificate in CRL. If found, make sure 1604 * reason is not removeFromCRL. 1605 */ 1606 if (X509_CRL_get0_by_cert(crl, &rev, x)) { 1607 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL) 1608 return 2; 1609 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED)) 1610 return 0; 1611 } 1612 1613 return 1; 1614 } 1615 1616 static int check_policy(X509_STORE_CTX *ctx) 1617 { 1618 int ret; 1619 1620 if (ctx->parent) 1621 return 1; 1622 /* 1623 * With DANE, the trust anchor might be a bare public key, not a 1624 * certificate! In that case our chain does not have the trust anchor 1625 * certificate as a top-most element. This comports well with RFC5280 1626 * chain verification, since there too, the trust anchor is not part of the 1627 * chain to be verified. In particular, X509_policy_check() does not look 1628 * at the TA cert, but assumes that it is present as the top-most chain 1629 * element. We therefore temporarily push a NULL cert onto the chain if it 1630 * was verified via a bare public key, and pop it off right after the 1631 * X509_policy_check() call. 1632 */ 1633 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) { 1634 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE); 1635 ctx->error = X509_V_ERR_OUT_OF_MEM; 1636 return 0; 1637 } 1638 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain, 1639 ctx->param->policies, ctx->param->flags); 1640 if (ctx->bare_ta_signed) 1641 sk_X509_pop(ctx->chain); 1642 1643 if (ret == X509_PCY_TREE_INTERNAL) { 1644 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE); 1645 ctx->error = X509_V_ERR_OUT_OF_MEM; 1646 return 0; 1647 } 1648 /* Invalid or inconsistent extensions */ 1649 if (ret == X509_PCY_TREE_INVALID) { 1650 int i; 1651 1652 /* Locate certificates with bad extensions and notify callback. */ 1653 for (i = 1; i < sk_X509_num(ctx->chain); i++) { 1654 X509 *x = sk_X509_value(ctx->chain, i); 1655 1656 if (!(x->ex_flags & EXFLAG_INVALID_POLICY)) 1657 continue; 1658 if (!verify_cb_cert(ctx, x, i, 1659 X509_V_ERR_INVALID_POLICY_EXTENSION)) 1660 return 0; 1661 } 1662 return 1; 1663 } 1664 if (ret == X509_PCY_TREE_FAILURE) { 1665 ctx->current_cert = NULL; 1666 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY; 1667 return ctx->verify_cb(0, ctx); 1668 } 1669 if (ret != X509_PCY_TREE_VALID) { 1670 X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR); 1671 return 0; 1672 } 1673 1674 if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) { 1675 ctx->current_cert = NULL; 1676 /* 1677 * Verification errors need to be "sticky", a callback may have allowed 1678 * an SSL handshake to continue despite an error, and we must then 1679 * remain in an error state. Therefore, we MUST NOT clear earlier 1680 * verification errors by setting the error to X509_V_OK. 1681 */ 1682 if (!ctx->verify_cb(2, ctx)) 1683 return 0; 1684 } 1685 1686 return 1; 1687 } 1688 1689 /*- 1690 * Check certificate validity times. 1691 * If depth >= 0, invoke verification callbacks on error, otherwise just return 1692 * the validation status. 1693 * 1694 * Return 1 on success, 0 otherwise. 1695 */ 1696 int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth) 1697 { 1698 time_t *ptime; 1699 int i; 1700 1701 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) 1702 ptime = &ctx->param->check_time; 1703 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) 1704 return 1; 1705 else 1706 ptime = NULL; 1707 1708 i = X509_cmp_time(X509_get0_notBefore(x), ptime); 1709 if (i >= 0 && depth < 0) 1710 return 0; 1711 if (i == 0 && !verify_cb_cert(ctx, x, depth, 1712 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD)) 1713 return 0; 1714 if (i > 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID)) 1715 return 0; 1716 1717 i = X509_cmp_time(X509_get0_notAfter(x), ptime); 1718 if (i <= 0 && depth < 0) 1719 return 0; 1720 if (i == 0 && !verify_cb_cert(ctx, x, depth, 1721 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD)) 1722 return 0; 1723 if (i < 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED)) 1724 return 0; 1725 return 1; 1726 } 1727 1728 /* verify the issuer signatures and cert times of ctx->chain */ 1729 static int internal_verify(X509_STORE_CTX *ctx) 1730 { 1731 int n = sk_X509_num(ctx->chain) - 1; 1732 X509 *xi = sk_X509_value(ctx->chain, n); 1733 X509 *xs; 1734 1735 /* 1736 * With DANE-verified bare public key TA signatures, it remains only to 1737 * check the timestamps of the top certificate. We report the issuer as 1738 * NULL, since all we have is a bare key. 1739 */ 1740 if (ctx->bare_ta_signed) { 1741 xs = xi; 1742 xi = NULL; 1743 goto check_cert; 1744 } 1745 1746 if (ctx->check_issued(ctx, xi, xi)) 1747 xs = xi; /* the typical case: last cert in the chain is self-issued */ 1748 else { 1749 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) { 1750 xs = xi; 1751 goto check_cert; 1752 } 1753 if (n <= 0) 1754 return verify_cb_cert(ctx, xi, 0, 1755 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE); 1756 n--; 1757 ctx->error_depth = n; 1758 xs = sk_X509_value(ctx->chain, n); 1759 } 1760 1761 /* 1762 * Do not clear ctx->error=0, it must be "sticky", only the user's callback 1763 * is allowed to reset errors (at its own peril). 1764 */ 1765 while (n >= 0) { 1766 /* 1767 * For each iteration of this loop: 1768 * n is the subject depth 1769 * xs is the subject cert, for which the signature is to be checked 1770 * xi is the supposed issuer cert containing the public key to use 1771 * Initially xs == xi if the last cert in the chain is self-issued. 1772 * 1773 * Skip signature check for self-signed certificates unless explicitly 1774 * asked for because it does not add any security and just wastes time. 1775 */ 1776 if (xs != xi || ((ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE) 1777 && (xi->ex_flags & EXFLAG_SS) != 0)) { 1778 EVP_PKEY *pkey; 1779 /* 1780 * If the issuer's public key is not available or its key usage 1781 * does not support issuing the subject cert, report the issuer 1782 * cert and its depth (rather than n, the depth of the subject). 1783 */ 1784 int issuer_depth = n + (xs == xi ? 0 : 1); 1785 /* 1786 * According to https://tools.ietf.org/html/rfc5280#section-6.1.4 1787 * step (n) we must check any given key usage extension in a CA cert 1788 * when preparing the verification of a certificate issued by it. 1789 * According to https://tools.ietf.org/html/rfc5280#section-4.2.1.3 1790 * we must not verify a certifiate signature if the key usage of the 1791 * CA certificate that issued the certificate prohibits signing. 1792 * In case the 'issuing' certificate is the last in the chain and is 1793 * not a CA certificate but a 'self-issued' end-entity cert (i.e., 1794 * xs == xi && !(xi->ex_flags & EXFLAG_CA)) RFC 5280 does not apply 1795 * (see https://tools.ietf.org/html/rfc6818#section-2) and thus 1796 * we are free to ignore any key usage restrictions on such certs. 1797 */ 1798 int ret = xs == xi && (xi->ex_flags & EXFLAG_CA) == 0 1799 ? X509_V_OK : x509_signing_allowed(xi, xs); 1800 1801 if (ret != X509_V_OK && !verify_cb_cert(ctx, xi, issuer_depth, ret)) 1802 return 0; 1803 if ((pkey = X509_get0_pubkey(xi)) == NULL) { 1804 ret = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY; 1805 if (!verify_cb_cert(ctx, xi, issuer_depth, ret)) 1806 return 0; 1807 } else if (X509_verify(xs, pkey) <= 0) { 1808 ret = X509_V_ERR_CERT_SIGNATURE_FAILURE; 1809 if (!verify_cb_cert(ctx, xs, n, ret)) 1810 return 0; 1811 } 1812 } 1813 1814 check_cert: 1815 /* Calls verify callback as needed */ 1816 if (!x509_check_cert_time(ctx, xs, n)) 1817 return 0; 1818 1819 /* 1820 * Signal success at this depth. However, the previous error (if any) 1821 * is retained. 1822 */ 1823 ctx->current_issuer = xi; 1824 ctx->current_cert = xs; 1825 ctx->error_depth = n; 1826 if (!ctx->verify_cb(1, ctx)) 1827 return 0; 1828 1829 if (--n >= 0) { 1830 xi = xs; 1831 xs = sk_X509_value(ctx->chain, n); 1832 } 1833 } 1834 return 1; 1835 } 1836 1837 int X509_cmp_current_time(const ASN1_TIME *ctm) 1838 { 1839 return X509_cmp_time(ctm, NULL); 1840 } 1841 1842 int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time) 1843 { 1844 static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1; 1845 static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1; 1846 ASN1_TIME *asn1_cmp_time = NULL; 1847 int i, day, sec, ret = 0; 1848 #ifdef CHARSET_EBCDIC 1849 const char upper_z = 0x5A; 1850 #else 1851 const char upper_z = 'Z'; 1852 #endif 1853 /* 1854 * Note that ASN.1 allows much more slack in the time format than RFC5280. 1855 * In RFC5280, the representation is fixed: 1856 * UTCTime: YYMMDDHHMMSSZ 1857 * GeneralizedTime: YYYYMMDDHHMMSSZ 1858 * 1859 * We do NOT currently enforce the following RFC 5280 requirement: 1860 * "CAs conforming to this profile MUST always encode certificate 1861 * validity dates through the year 2049 as UTCTime; certificate validity 1862 * dates in 2050 or later MUST be encoded as GeneralizedTime." 1863 */ 1864 switch (ctm->type) { 1865 case V_ASN1_UTCTIME: 1866 if (ctm->length != (int)(utctime_length)) 1867 return 0; 1868 break; 1869 case V_ASN1_GENERALIZEDTIME: 1870 if (ctm->length != (int)(generalizedtime_length)) 1871 return 0; 1872 break; 1873 default: 1874 return 0; 1875 } 1876 1877 /** 1878 * Verify the format: the ASN.1 functions we use below allow a more 1879 * flexible format than what's mandated by RFC 5280. 1880 * Digit and date ranges will be verified in the conversion methods. 1881 */ 1882 for (i = 0; i < ctm->length - 1; i++) { 1883 if (!ascii_isdigit(ctm->data[i])) 1884 return 0; 1885 } 1886 if (ctm->data[ctm->length - 1] != upper_z) 1887 return 0; 1888 1889 /* 1890 * There is ASN1_UTCTIME_cmp_time_t but no 1891 * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t, 1892 * so we go through ASN.1 1893 */ 1894 asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time); 1895 if (asn1_cmp_time == NULL) 1896 goto err; 1897 if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time)) 1898 goto err; 1899 1900 /* 1901 * X509_cmp_time comparison is <=. 1902 * The return value 0 is reserved for errors. 1903 */ 1904 ret = (day >= 0 && sec >= 0) ? -1 : 1; 1905 1906 err: 1907 ASN1_TIME_free(asn1_cmp_time); 1908 return ret; 1909 } 1910 1911 ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj) 1912 { 1913 return X509_time_adj(s, adj, NULL); 1914 } 1915 1916 ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm) 1917 { 1918 return X509_time_adj_ex(s, 0, offset_sec, in_tm); 1919 } 1920 1921 ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s, 1922 int offset_day, long offset_sec, time_t *in_tm) 1923 { 1924 time_t t; 1925 1926 if (in_tm) 1927 t = *in_tm; 1928 else 1929 time(&t); 1930 1931 if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) { 1932 if (s->type == V_ASN1_UTCTIME) 1933 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec); 1934 if (s->type == V_ASN1_GENERALIZEDTIME) 1935 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec); 1936 } 1937 return ASN1_TIME_adj(s, t, offset_day, offset_sec); 1938 } 1939 1940 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain) 1941 { 1942 EVP_PKEY *ktmp = NULL, *ktmp2; 1943 int i, j; 1944 1945 if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey)) 1946 return 1; 1947 1948 for (i = 0; i < sk_X509_num(chain); i++) { 1949 ktmp = X509_get0_pubkey(sk_X509_value(chain, i)); 1950 if (ktmp == NULL) { 1951 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS, 1952 X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY); 1953 return 0; 1954 } 1955 if (!EVP_PKEY_missing_parameters(ktmp)) 1956 break; 1957 } 1958 if (ktmp == NULL) { 1959 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS, 1960 X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN); 1961 return 0; 1962 } 1963 1964 /* first, populate the other certs */ 1965 for (j = i - 1; j >= 0; j--) { 1966 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j)); 1967 EVP_PKEY_copy_parameters(ktmp2, ktmp); 1968 } 1969 1970 if (pkey != NULL) 1971 EVP_PKEY_copy_parameters(pkey, ktmp); 1972 return 1; 1973 } 1974 1975 /* Make a delta CRL as the diff between two full CRLs */ 1976 1977 X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer, 1978 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags) 1979 { 1980 X509_CRL *crl = NULL; 1981 int i; 1982 STACK_OF(X509_REVOKED) *revs = NULL; 1983 /* CRLs can't be delta already */ 1984 if (base->base_crl_number || newer->base_crl_number) { 1985 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA); 1986 return NULL; 1987 } 1988 /* Base and new CRL must have a CRL number */ 1989 if (!base->crl_number || !newer->crl_number) { 1990 X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER); 1991 return NULL; 1992 } 1993 /* Issuer names must match */ 1994 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) { 1995 X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH); 1996 return NULL; 1997 } 1998 /* AKID and IDP must match */ 1999 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) { 2000 X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH); 2001 return NULL; 2002 } 2003 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) { 2004 X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH); 2005 return NULL; 2006 } 2007 /* Newer CRL number must exceed full CRL number */ 2008 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) { 2009 X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER); 2010 return NULL; 2011 } 2012 /* CRLs must verify */ 2013 if (skey && (X509_CRL_verify(base, skey) <= 0 || 2014 X509_CRL_verify(newer, skey) <= 0)) { 2015 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE); 2016 return NULL; 2017 } 2018 /* Create new CRL */ 2019 crl = X509_CRL_new(); 2020 if (crl == NULL || !X509_CRL_set_version(crl, 1)) 2021 goto memerr; 2022 /* Set issuer name */ 2023 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer))) 2024 goto memerr; 2025 2026 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer))) 2027 goto memerr; 2028 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer))) 2029 goto memerr; 2030 2031 /* Set base CRL number: must be critical */ 2032 2033 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0)) 2034 goto memerr; 2035 2036 /* 2037 * Copy extensions across from newest CRL to delta: this will set CRL 2038 * number to correct value too. 2039 */ 2040 2041 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) { 2042 X509_EXTENSION *ext; 2043 ext = X509_CRL_get_ext(newer, i); 2044 if (!X509_CRL_add_ext(crl, ext, -1)) 2045 goto memerr; 2046 } 2047 2048 /* Go through revoked entries, copying as needed */ 2049 2050 revs = X509_CRL_get_REVOKED(newer); 2051 2052 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) { 2053 X509_REVOKED *rvn, *rvtmp; 2054 rvn = sk_X509_REVOKED_value(revs, i); 2055 /* 2056 * Add only if not also in base. TODO: need something cleverer here 2057 * for some more complex CRLs covering multiple CAs. 2058 */ 2059 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) { 2060 rvtmp = X509_REVOKED_dup(rvn); 2061 if (!rvtmp) 2062 goto memerr; 2063 if (!X509_CRL_add0_revoked(crl, rvtmp)) { 2064 X509_REVOKED_free(rvtmp); 2065 goto memerr; 2066 } 2067 } 2068 } 2069 /* TODO: optionally prune deleted entries */ 2070 2071 if (skey && md && !X509_CRL_sign(crl, skey, md)) 2072 goto memerr; 2073 2074 return crl; 2075 2076 memerr: 2077 X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE); 2078 X509_CRL_free(crl); 2079 return NULL; 2080 } 2081 2082 int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data) 2083 { 2084 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data); 2085 } 2086 2087 void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx) 2088 { 2089 return CRYPTO_get_ex_data(&ctx->ex_data, idx); 2090 } 2091 2092 int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx) 2093 { 2094 return ctx->error; 2095 } 2096 2097 void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err) 2098 { 2099 ctx->error = err; 2100 } 2101 2102 int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx) 2103 { 2104 return ctx->error_depth; 2105 } 2106 2107 void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth) 2108 { 2109 ctx->error_depth = depth; 2110 } 2111 2112 X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx) 2113 { 2114 return ctx->current_cert; 2115 } 2116 2117 void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x) 2118 { 2119 ctx->current_cert = x; 2120 } 2121 2122 STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx) 2123 { 2124 return ctx->chain; 2125 } 2126 2127 STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx) 2128 { 2129 if (!ctx->chain) 2130 return NULL; 2131 return X509_chain_up_ref(ctx->chain); 2132 } 2133 2134 X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx) 2135 { 2136 return ctx->current_issuer; 2137 } 2138 2139 X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx) 2140 { 2141 return ctx->current_crl; 2142 } 2143 2144 X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx) 2145 { 2146 return ctx->parent; 2147 } 2148 2149 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x) 2150 { 2151 ctx->cert = x; 2152 } 2153 2154 void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk) 2155 { 2156 ctx->crls = sk; 2157 } 2158 2159 int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose) 2160 { 2161 /* 2162 * XXX: Why isn't this function always used to set the associated trust? 2163 * Should there even be a VPM->trust field at all? Or should the trust 2164 * always be inferred from the purpose by X509_STORE_CTX_init(). 2165 */ 2166 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0); 2167 } 2168 2169 int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust) 2170 { 2171 /* 2172 * XXX: See above, this function would only be needed when the default 2173 * trust for the purpose needs an override in a corner case. 2174 */ 2175 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust); 2176 } 2177 2178 /* 2179 * This function is used to set the X509_STORE_CTX purpose and trust values. 2180 * This is intended to be used when another structure has its own trust and 2181 * purpose values which (if set) will be inherited by the ctx. If they aren't 2182 * set then we will usually have a default purpose in mind which should then 2183 * be used to set the trust value. An example of this is SSL use: an SSL 2184 * structure will have its own purpose and trust settings which the 2185 * application can set: if they aren't set then we use the default of SSL 2186 * client/server. 2187 */ 2188 2189 int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose, 2190 int purpose, int trust) 2191 { 2192 int idx; 2193 /* If purpose not set use default */ 2194 if (!purpose) 2195 purpose = def_purpose; 2196 /* If we have a purpose then check it is valid */ 2197 if (purpose) { 2198 X509_PURPOSE *ptmp; 2199 idx = X509_PURPOSE_get_by_id(purpose); 2200 if (idx == -1) { 2201 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2202 X509_R_UNKNOWN_PURPOSE_ID); 2203 return 0; 2204 } 2205 ptmp = X509_PURPOSE_get0(idx); 2206 if (ptmp->trust == X509_TRUST_DEFAULT) { 2207 idx = X509_PURPOSE_get_by_id(def_purpose); 2208 /* 2209 * XXX: In the two callers above def_purpose is always 0, which is 2210 * not a known value, so idx will always be -1. How is the 2211 * X509_TRUST_DEFAULT case actually supposed to be handled? 2212 */ 2213 if (idx == -1) { 2214 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2215 X509_R_UNKNOWN_PURPOSE_ID); 2216 return 0; 2217 } 2218 ptmp = X509_PURPOSE_get0(idx); 2219 } 2220 /* If trust not set then get from purpose default */ 2221 if (!trust) 2222 trust = ptmp->trust; 2223 } 2224 if (trust) { 2225 idx = X509_TRUST_get_by_id(trust); 2226 if (idx == -1) { 2227 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2228 X509_R_UNKNOWN_TRUST_ID); 2229 return 0; 2230 } 2231 } 2232 2233 if (purpose && !ctx->param->purpose) 2234 ctx->param->purpose = purpose; 2235 if (trust && !ctx->param->trust) 2236 ctx->param->trust = trust; 2237 return 1; 2238 } 2239 2240 X509_STORE_CTX *X509_STORE_CTX_new(void) 2241 { 2242 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx)); 2243 2244 if (ctx == NULL) { 2245 X509err(X509_F_X509_STORE_CTX_NEW, ERR_R_MALLOC_FAILURE); 2246 return NULL; 2247 } 2248 return ctx; 2249 } 2250 2251 void X509_STORE_CTX_free(X509_STORE_CTX *ctx) 2252 { 2253 if (ctx == NULL) 2254 return; 2255 2256 X509_STORE_CTX_cleanup(ctx); 2257 OPENSSL_free(ctx); 2258 } 2259 2260 int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509, 2261 STACK_OF(X509) *chain) 2262 { 2263 int ret = 1; 2264 2265 ctx->ctx = store; 2266 ctx->cert = x509; 2267 ctx->untrusted = chain; 2268 ctx->crls = NULL; 2269 ctx->num_untrusted = 0; 2270 ctx->other_ctx = NULL; 2271 ctx->valid = 0; 2272 ctx->chain = NULL; 2273 ctx->error = 0; 2274 ctx->explicit_policy = 0; 2275 ctx->error_depth = 0; 2276 ctx->current_cert = NULL; 2277 ctx->current_issuer = NULL; 2278 ctx->current_crl = NULL; 2279 ctx->current_crl_score = 0; 2280 ctx->current_reasons = 0; 2281 ctx->tree = NULL; 2282 ctx->parent = NULL; 2283 ctx->dane = NULL; 2284 ctx->bare_ta_signed = 0; 2285 /* Zero ex_data to make sure we're cleanup-safe */ 2286 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2287 2288 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */ 2289 if (store) 2290 ctx->cleanup = store->cleanup; 2291 else 2292 ctx->cleanup = 0; 2293 2294 if (store && store->check_issued) 2295 ctx->check_issued = store->check_issued; 2296 else 2297 ctx->check_issued = check_issued; 2298 2299 if (store && store->get_issuer) 2300 ctx->get_issuer = store->get_issuer; 2301 else 2302 ctx->get_issuer = X509_STORE_CTX_get1_issuer; 2303 2304 if (store && store->verify_cb) 2305 ctx->verify_cb = store->verify_cb; 2306 else 2307 ctx->verify_cb = null_callback; 2308 2309 if (store && store->verify) 2310 ctx->verify = store->verify; 2311 else 2312 ctx->verify = internal_verify; 2313 2314 if (store && store->check_revocation) 2315 ctx->check_revocation = store->check_revocation; 2316 else 2317 ctx->check_revocation = check_revocation; 2318 2319 if (store && store->get_crl) 2320 ctx->get_crl = store->get_crl; 2321 else 2322 ctx->get_crl = NULL; 2323 2324 if (store && store->check_crl) 2325 ctx->check_crl = store->check_crl; 2326 else 2327 ctx->check_crl = check_crl; 2328 2329 if (store && store->cert_crl) 2330 ctx->cert_crl = store->cert_crl; 2331 else 2332 ctx->cert_crl = cert_crl; 2333 2334 if (store && store->check_policy) 2335 ctx->check_policy = store->check_policy; 2336 else 2337 ctx->check_policy = check_policy; 2338 2339 if (store && store->lookup_certs) 2340 ctx->lookup_certs = store->lookup_certs; 2341 else 2342 ctx->lookup_certs = X509_STORE_CTX_get1_certs; 2343 2344 if (store && store->lookup_crls) 2345 ctx->lookup_crls = store->lookup_crls; 2346 else 2347 ctx->lookup_crls = X509_STORE_CTX_get1_crls; 2348 2349 ctx->param = X509_VERIFY_PARAM_new(); 2350 if (ctx->param == NULL) { 2351 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2352 goto err; 2353 } 2354 2355 /* 2356 * Inherit callbacks and flags from X509_STORE if not set use defaults. 2357 */ 2358 if (store) 2359 ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param); 2360 else 2361 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE; 2362 2363 if (ret) 2364 ret = X509_VERIFY_PARAM_inherit(ctx->param, 2365 X509_VERIFY_PARAM_lookup("default")); 2366 2367 if (ret == 0) { 2368 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2369 goto err; 2370 } 2371 2372 /* 2373 * XXX: For now, continue to inherit trust from VPM, but infer from the 2374 * purpose if this still yields the default value. 2375 */ 2376 if (ctx->param->trust == X509_TRUST_DEFAULT) { 2377 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose); 2378 X509_PURPOSE *xp = X509_PURPOSE_get0(idx); 2379 2380 if (xp != NULL) 2381 ctx->param->trust = X509_PURPOSE_get_trust(xp); 2382 } 2383 2384 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, 2385 &ctx->ex_data)) 2386 return 1; 2387 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2388 2389 err: 2390 /* 2391 * On error clean up allocated storage, if the store context was not 2392 * allocated with X509_STORE_CTX_new() this is our last chance to do so. 2393 */ 2394 X509_STORE_CTX_cleanup(ctx); 2395 return 0; 2396 } 2397 2398 /* 2399 * Set alternative lookup method: just a STACK of trusted certificates. This 2400 * avoids X509_STORE nastiness where it isn't needed. 2401 */ 2402 void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2403 { 2404 ctx->other_ctx = sk; 2405 ctx->get_issuer = get_issuer_sk; 2406 ctx->lookup_certs = lookup_certs_sk; 2407 } 2408 2409 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx) 2410 { 2411 /* 2412 * We need to be idempotent because, unfortunately, free() also calls 2413 * cleanup(), so the natural call sequence new(), init(), cleanup(), free() 2414 * calls cleanup() for the same object twice! Thus we must zero the 2415 * pointers below after they're freed! 2416 */ 2417 /* Seems to always be 0 in OpenSSL, do this at most once. */ 2418 if (ctx->cleanup != NULL) { 2419 ctx->cleanup(ctx); 2420 ctx->cleanup = NULL; 2421 } 2422 if (ctx->param != NULL) { 2423 if (ctx->parent == NULL) 2424 X509_VERIFY_PARAM_free(ctx->param); 2425 ctx->param = NULL; 2426 } 2427 X509_policy_tree_free(ctx->tree); 2428 ctx->tree = NULL; 2429 sk_X509_pop_free(ctx->chain, X509_free); 2430 ctx->chain = NULL; 2431 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data)); 2432 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2433 } 2434 2435 void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth) 2436 { 2437 X509_VERIFY_PARAM_set_depth(ctx->param, depth); 2438 } 2439 2440 void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags) 2441 { 2442 X509_VERIFY_PARAM_set_flags(ctx->param, flags); 2443 } 2444 2445 void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, 2446 time_t t) 2447 { 2448 X509_VERIFY_PARAM_set_time(ctx->param, t); 2449 } 2450 2451 X509 *X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx) 2452 { 2453 return ctx->cert; 2454 } 2455 2456 STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx) 2457 { 2458 return ctx->untrusted; 2459 } 2460 2461 void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2462 { 2463 ctx->untrusted = sk; 2464 } 2465 2466 void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2467 { 2468 sk_X509_pop_free(ctx->chain, X509_free); 2469 ctx->chain = sk; 2470 } 2471 2472 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx, 2473 X509_STORE_CTX_verify_cb verify_cb) 2474 { 2475 ctx->verify_cb = verify_cb; 2476 } 2477 2478 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx) 2479 { 2480 return ctx->verify_cb; 2481 } 2482 2483 void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx, 2484 X509_STORE_CTX_verify_fn verify) 2485 { 2486 ctx->verify = verify; 2487 } 2488 2489 X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(X509_STORE_CTX *ctx) 2490 { 2491 return ctx->verify; 2492 } 2493 2494 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx) 2495 { 2496 return ctx->get_issuer; 2497 } 2498 2499 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx) 2500 { 2501 return ctx->check_issued; 2502 } 2503 2504 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx) 2505 { 2506 return ctx->check_revocation; 2507 } 2508 2509 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx) 2510 { 2511 return ctx->get_crl; 2512 } 2513 2514 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx) 2515 { 2516 return ctx->check_crl; 2517 } 2518 2519 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx) 2520 { 2521 return ctx->cert_crl; 2522 } 2523 2524 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx) 2525 { 2526 return ctx->check_policy; 2527 } 2528 2529 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx) 2530 { 2531 return ctx->lookup_certs; 2532 } 2533 2534 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx) 2535 { 2536 return ctx->lookup_crls; 2537 } 2538 2539 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx) 2540 { 2541 return ctx->cleanup; 2542 } 2543 2544 X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx) 2545 { 2546 return ctx->tree; 2547 } 2548 2549 int X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx) 2550 { 2551 return ctx->explicit_policy; 2552 } 2553 2554 int X509_STORE_CTX_get_num_untrusted(X509_STORE_CTX *ctx) 2555 { 2556 return ctx->num_untrusted; 2557 } 2558 2559 int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name) 2560 { 2561 const X509_VERIFY_PARAM *param; 2562 param = X509_VERIFY_PARAM_lookup(name); 2563 if (!param) 2564 return 0; 2565 return X509_VERIFY_PARAM_inherit(ctx->param, param); 2566 } 2567 2568 X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx) 2569 { 2570 return ctx->param; 2571 } 2572 2573 void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param) 2574 { 2575 X509_VERIFY_PARAM_free(ctx->param); 2576 ctx->param = param; 2577 } 2578 2579 void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane) 2580 { 2581 ctx->dane = dane; 2582 } 2583 2584 static unsigned char *dane_i2d( 2585 X509 *cert, 2586 uint8_t selector, 2587 unsigned int *i2dlen) 2588 { 2589 unsigned char *buf = NULL; 2590 int len; 2591 2592 /* 2593 * Extract ASN.1 DER form of certificate or public key. 2594 */ 2595 switch (selector) { 2596 case DANETLS_SELECTOR_CERT: 2597 len = i2d_X509(cert, &buf); 2598 break; 2599 case DANETLS_SELECTOR_SPKI: 2600 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf); 2601 break; 2602 default: 2603 X509err(X509_F_DANE_I2D, X509_R_BAD_SELECTOR); 2604 return NULL; 2605 } 2606 2607 if (len < 0 || buf == NULL) { 2608 X509err(X509_F_DANE_I2D, ERR_R_MALLOC_FAILURE); 2609 return NULL; 2610 } 2611 2612 *i2dlen = (unsigned int)len; 2613 return buf; 2614 } 2615 2616 #define DANETLS_NONE 256 /* impossible uint8_t */ 2617 2618 static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth) 2619 { 2620 SSL_DANE *dane = ctx->dane; 2621 unsigned usage = DANETLS_NONE; 2622 unsigned selector = DANETLS_NONE; 2623 unsigned ordinal = DANETLS_NONE; 2624 unsigned mtype = DANETLS_NONE; 2625 unsigned char *i2dbuf = NULL; 2626 unsigned int i2dlen = 0; 2627 unsigned char mdbuf[EVP_MAX_MD_SIZE]; 2628 unsigned char *cmpbuf = NULL; 2629 unsigned int cmplen = 0; 2630 int i; 2631 int recnum; 2632 int matched = 0; 2633 danetls_record *t = NULL; 2634 uint32_t mask; 2635 2636 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK; 2637 2638 /* 2639 * The trust store is not applicable with DANE-TA(2) 2640 */ 2641 if (depth >= ctx->num_untrusted) 2642 mask &= DANETLS_PKIX_MASK; 2643 2644 /* 2645 * If we've previously matched a PKIX-?? record, no need to test any 2646 * further PKIX-?? records, it remains to just build the PKIX chain. 2647 * Had the match been a DANE-?? record, we'd be done already. 2648 */ 2649 if (dane->mdpth >= 0) 2650 mask &= ~DANETLS_PKIX_MASK; 2651 2652 /*- 2653 * https://tools.ietf.org/html/rfc7671#section-5.1 2654 * https://tools.ietf.org/html/rfc7671#section-5.2 2655 * https://tools.ietf.org/html/rfc7671#section-5.3 2656 * https://tools.ietf.org/html/rfc7671#section-5.4 2657 * 2658 * We handle DANE-EE(3) records first as they require no chain building 2659 * and no expiration or hostname checks. We also process digests with 2660 * higher ordinals first and ignore lower priorities except Full(0) which 2661 * is always processed (last). If none match, we then process PKIX-EE(1). 2662 * 2663 * NOTE: This relies on DANE usages sorting before the corresponding PKIX 2664 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest 2665 * priorities. See twin comment in ssl/ssl_lib.c. 2666 * 2667 * We expect that most TLSA RRsets will have just a single usage, so we 2668 * don't go out of our way to cache multiple selector-specific i2d buffers 2669 * across usages, but if the selector happens to remain the same as switch 2670 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1", 2671 * records would result in us generating each of the certificate and public 2672 * key DER forms twice, but more typically we'd just see multiple "3 1 1" 2673 * or multiple "3 0 1" records. 2674 * 2675 * As soon as we find a match at any given depth, we stop, because either 2676 * we've matched a DANE-?? record and the peer is authenticated, or, after 2677 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is 2678 * sufficient for DANE, and what remains to do is ordinary PKIX validation. 2679 */ 2680 recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0; 2681 for (i = 0; matched == 0 && i < recnum; ++i) { 2682 t = sk_danetls_record_value(dane->trecs, i); 2683 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0) 2684 continue; 2685 if (t->usage != usage) { 2686 usage = t->usage; 2687 2688 /* Reset digest agility for each usage/selector pair */ 2689 mtype = DANETLS_NONE; 2690 ordinal = dane->dctx->mdord[t->mtype]; 2691 } 2692 if (t->selector != selector) { 2693 selector = t->selector; 2694 2695 /* Update per-selector state */ 2696 OPENSSL_free(i2dbuf); 2697 i2dbuf = dane_i2d(cert, selector, &i2dlen); 2698 if (i2dbuf == NULL) 2699 return -1; 2700 2701 /* Reset digest agility for each usage/selector pair */ 2702 mtype = DANETLS_NONE; 2703 ordinal = dane->dctx->mdord[t->mtype]; 2704 } else if (t->mtype != DANETLS_MATCHING_FULL) { 2705 /*- 2706 * Digest agility: 2707 * 2708 * <https://tools.ietf.org/html/rfc7671#section-9> 2709 * 2710 * For a fixed selector, after processing all records with the 2711 * highest mtype ordinal, ignore all mtypes with lower ordinals 2712 * other than "Full". 2713 */ 2714 if (dane->dctx->mdord[t->mtype] < ordinal) 2715 continue; 2716 } 2717 2718 /* 2719 * Each time we hit a (new selector or) mtype, re-compute the relevant 2720 * digest, more complex caching is not worth the code space. 2721 */ 2722 if (t->mtype != mtype) { 2723 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype]; 2724 cmpbuf = i2dbuf; 2725 cmplen = i2dlen; 2726 2727 if (md != NULL) { 2728 cmpbuf = mdbuf; 2729 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) { 2730 matched = -1; 2731 break; 2732 } 2733 } 2734 } 2735 2736 /* 2737 * Squirrel away the certificate and depth if we have a match. Any 2738 * DANE match is dispositive, but with PKIX we still need to build a 2739 * full chain. 2740 */ 2741 if (cmplen == t->dlen && 2742 memcmp(cmpbuf, t->data, cmplen) == 0) { 2743 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK) 2744 matched = 1; 2745 if (matched || dane->mdpth < 0) { 2746 dane->mdpth = depth; 2747 dane->mtlsa = t; 2748 OPENSSL_free(dane->mcert); 2749 dane->mcert = cert; 2750 X509_up_ref(cert); 2751 } 2752 break; 2753 } 2754 } 2755 2756 /* Clear the one-element DER cache */ 2757 OPENSSL_free(i2dbuf); 2758 return matched; 2759 } 2760 2761 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth) 2762 { 2763 SSL_DANE *dane = ctx->dane; 2764 int matched = 0; 2765 X509 *cert; 2766 2767 if (!DANETLS_HAS_TA(dane) || depth == 0) 2768 return X509_TRUST_UNTRUSTED; 2769 2770 /* 2771 * Record any DANE trust-anchor matches, for the first depth to test, if 2772 * there's one at that depth. (This'll be false for length 1 chains looking 2773 * for an exact match for the leaf certificate). 2774 */ 2775 cert = sk_X509_value(ctx->chain, depth); 2776 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0) 2777 return X509_TRUST_REJECTED; 2778 if (matched > 0) { 2779 ctx->num_untrusted = depth - 1; 2780 return X509_TRUST_TRUSTED; 2781 } 2782 2783 return X509_TRUST_UNTRUSTED; 2784 } 2785 2786 static int check_dane_pkeys(X509_STORE_CTX *ctx) 2787 { 2788 SSL_DANE *dane = ctx->dane; 2789 danetls_record *t; 2790 int num = ctx->num_untrusted; 2791 X509 *cert = sk_X509_value(ctx->chain, num - 1); 2792 int recnum = sk_danetls_record_num(dane->trecs); 2793 int i; 2794 2795 for (i = 0; i < recnum; ++i) { 2796 t = sk_danetls_record_value(dane->trecs, i); 2797 if (t->usage != DANETLS_USAGE_DANE_TA || 2798 t->selector != DANETLS_SELECTOR_SPKI || 2799 t->mtype != DANETLS_MATCHING_FULL || 2800 X509_verify(cert, t->spki) <= 0) 2801 continue; 2802 2803 /* Clear any PKIX-?? matches that failed to extend to a full chain */ 2804 X509_free(dane->mcert); 2805 dane->mcert = NULL; 2806 2807 /* Record match via a bare TA public key */ 2808 ctx->bare_ta_signed = 1; 2809 dane->mdpth = num - 1; 2810 dane->mtlsa = t; 2811 2812 /* Prune any excess chain certificates */ 2813 num = sk_X509_num(ctx->chain); 2814 for (; num > ctx->num_untrusted; --num) 2815 X509_free(sk_X509_pop(ctx->chain)); 2816 2817 return X509_TRUST_TRUSTED; 2818 } 2819 2820 return X509_TRUST_UNTRUSTED; 2821 } 2822 2823 static void dane_reset(SSL_DANE *dane) 2824 { 2825 /* 2826 * Reset state to verify another chain, or clear after failure. 2827 */ 2828 X509_free(dane->mcert); 2829 dane->mcert = NULL; 2830 dane->mtlsa = NULL; 2831 dane->mdpth = -1; 2832 dane->pdpth = -1; 2833 } 2834 2835 static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert) 2836 { 2837 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags); 2838 2839 if (err == X509_V_OK) 2840 return 1; 2841 return verify_cb_cert(ctx, cert, 0, err); 2842 } 2843 2844 static int dane_verify(X509_STORE_CTX *ctx) 2845 { 2846 X509 *cert = ctx->cert; 2847 SSL_DANE *dane = ctx->dane; 2848 int matched; 2849 int done; 2850 2851 dane_reset(dane); 2852 2853 /*- 2854 * When testing the leaf certificate, if we match a DANE-EE(3) record, 2855 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1) 2856 * record, the match depth and matching TLSA record are recorded, but the 2857 * return value is 0, because we still need to find a PKIX trust-anchor. 2858 * Therefore, when DANE authentication is enabled (required), we're done 2859 * if: 2860 * + matched < 0, internal error. 2861 * + matched == 1, we matched a DANE-EE(3) record 2862 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no 2863 * DANE-TA(2) or PKIX-TA(0) to test. 2864 */ 2865 matched = dane_match(ctx, ctx->cert, 0); 2866 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0); 2867 2868 if (done) 2869 X509_get_pubkey_parameters(NULL, ctx->chain); 2870 2871 if (matched > 0) { 2872 /* Callback invoked as needed */ 2873 if (!check_leaf_suiteb(ctx, cert)) 2874 return 0; 2875 /* Callback invoked as needed */ 2876 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 && 2877 !check_id(ctx)) 2878 return 0; 2879 /* Bypass internal_verify(), issue depth 0 success callback */ 2880 ctx->error_depth = 0; 2881 ctx->current_cert = cert; 2882 return ctx->verify_cb(1, ctx); 2883 } 2884 2885 if (matched < 0) { 2886 ctx->error_depth = 0; 2887 ctx->current_cert = cert; 2888 ctx->error = X509_V_ERR_OUT_OF_MEM; 2889 return -1; 2890 } 2891 2892 if (done) { 2893 /* Fail early, TA-based success is not possible */ 2894 if (!check_leaf_suiteb(ctx, cert)) 2895 return 0; 2896 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH); 2897 } 2898 2899 /* 2900 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0 2901 * certificates happens in-line with building the rest of the chain. 2902 */ 2903 return verify_chain(ctx); 2904 } 2905 2906 /* Get issuer, without duplicate suppression */ 2907 static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert) 2908 { 2909 STACK_OF(X509) *saved_chain = ctx->chain; 2910 int ok; 2911 2912 ctx->chain = NULL; 2913 ok = ctx->get_issuer(issuer, ctx, cert); 2914 ctx->chain = saved_chain; 2915 2916 return ok; 2917 } 2918 2919 static int build_chain(X509_STORE_CTX *ctx) 2920 { 2921 SSL_DANE *dane = ctx->dane; 2922 int num = sk_X509_num(ctx->chain); 2923 X509 *cert = sk_X509_value(ctx->chain, num - 1); 2924 int ss = cert_self_signed(cert); 2925 STACK_OF(X509) *sktmp = NULL; 2926 unsigned int search; 2927 int may_trusted = 0; 2928 int may_alternate = 0; 2929 int trust = X509_TRUST_UNTRUSTED; 2930 int alt_untrusted = 0; 2931 int depth; 2932 int ok = 0; 2933 int i; 2934 2935 /* Our chain starts with a single untrusted element. */ 2936 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) { 2937 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 2938 ctx->error = X509_V_ERR_UNSPECIFIED; 2939 return 0; 2940 } 2941 2942 #define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */ 2943 #define S_DOTRUSTED (1 << 1) /* Search trusted store */ 2944 #define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */ 2945 /* 2946 * Set up search policy, untrusted if possible, trusted-first if enabled. 2947 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the 2948 * trust_store, otherwise we might look there first. If not trusted-first, 2949 * and alternate chains are not disabled, try building an alternate chain 2950 * if no luck with untrusted first. 2951 */ 2952 search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0; 2953 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) { 2954 if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) 2955 search |= S_DOTRUSTED; 2956 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) 2957 may_alternate = 1; 2958 may_trusted = 1; 2959 } 2960 2961 /* 2962 * Shallow-copy the stack of untrusted certificates (with TLS, this is 2963 * typically the content of the peer's certificate message) so can make 2964 * multiple passes over it, while free to remove elements as we go. 2965 */ 2966 if (ctx->untrusted && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) { 2967 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2968 ctx->error = X509_V_ERR_OUT_OF_MEM; 2969 return 0; 2970 } 2971 2972 /* 2973 * If we got any "DANE-TA(2) Cert(0) Full(0)" trust-anchors from DNS, add 2974 * them to our working copy of the untrusted certificate stack. Since the 2975 * caller of X509_STORE_CTX_init() may have provided only a leaf cert with 2976 * no corresponding stack of untrusted certificates, we may need to create 2977 * an empty stack first. [ At present only the ssl library provides DANE 2978 * support, and ssl_verify_cert_chain() always provides a non-null stack 2979 * containing at least the leaf certificate, but we must be prepared for 2980 * this to change. ] 2981 */ 2982 if (DANETLS_ENABLED(dane) && dane->certs != NULL) { 2983 if (sktmp == NULL && (sktmp = sk_X509_new_null()) == NULL) { 2984 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2985 ctx->error = X509_V_ERR_OUT_OF_MEM; 2986 return 0; 2987 } 2988 for (i = 0; i < sk_X509_num(dane->certs); ++i) { 2989 if (!sk_X509_push(sktmp, sk_X509_value(dane->certs, i))) { 2990 sk_X509_free(sktmp); 2991 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2992 ctx->error = X509_V_ERR_OUT_OF_MEM; 2993 return 0; 2994 } 2995 } 2996 } 2997 2998 /* 2999 * Still absurdly large, but arithmetically safe, a lower hard upper bound 3000 * might be reasonable. 3001 */ 3002 if (ctx->param->depth > INT_MAX/2) 3003 ctx->param->depth = INT_MAX/2; 3004 3005 /* 3006 * Try to Extend the chain until we reach an ultimately trusted issuer. 3007 * Build chains up to one longer the limit, later fail if we hit the limit, 3008 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code. 3009 */ 3010 depth = ctx->param->depth + 1; 3011 3012 while (search != 0) { 3013 X509 *x; 3014 X509 *xtmp = NULL; 3015 3016 /* 3017 * Look in the trust store if enabled for first lookup, or we've run 3018 * out of untrusted issuers and search here is not disabled. When we 3019 * reach the depth limit, we stop extending the chain, if by that point 3020 * we've not found a trust-anchor, any trusted chain would be too long. 3021 * 3022 * The error reported to the application verify callback is at the 3023 * maximal valid depth with the current certificate equal to the last 3024 * not ultimately-trusted issuer. For example, with verify_depth = 0, 3025 * the callback will report errors at depth=1 when the immediate issuer 3026 * of the leaf certificate is not a trust anchor. No attempt will be 3027 * made to locate an issuer for that certificate, since such a chain 3028 * would be a-priori too long. 3029 */ 3030 if ((search & S_DOTRUSTED) != 0) { 3031 i = num = sk_X509_num(ctx->chain); 3032 if ((search & S_DOALTERNATE) != 0) { 3033 /* 3034 * As high up the chain as we can, look for an alternative 3035 * trusted issuer of an untrusted certificate that currently 3036 * has an untrusted issuer. We use the alt_untrusted variable 3037 * to track how far up the chain we find the first match. It 3038 * is only if and when we find a match, that we prune the chain 3039 * and reset ctx->num_untrusted to the reduced count of 3040 * untrusted certificates. While we're searching for such a 3041 * match (which may never be found), it is neither safe nor 3042 * wise to preemptively modify either the chain or 3043 * ctx->num_untrusted. 3044 * 3045 * Note, like ctx->num_untrusted, alt_untrusted is a count of 3046 * untrusted certificates, not a "depth". 3047 */ 3048 i = alt_untrusted; 3049 } 3050 x = sk_X509_value(ctx->chain, i-1); 3051 3052 ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x); 3053 3054 if (ok < 0) { 3055 trust = X509_TRUST_REJECTED; 3056 ctx->error = X509_V_ERR_STORE_LOOKUP; 3057 search = 0; 3058 continue; 3059 } 3060 3061 if (ok > 0) { 3062 /* 3063 * Alternative trusted issuer for a mid-chain untrusted cert? 3064 * Pop the untrusted cert's successors and retry. We might now 3065 * be able to complete a valid chain via the trust store. Note 3066 * that despite the current trust-store match we might still 3067 * fail complete the chain to a suitable trust-anchor, in which 3068 * case we may prune some more untrusted certificates and try 3069 * again. Thus the S_DOALTERNATE bit may yet be turned on 3070 * again with an even shorter untrusted chain! 3071 * 3072 * If in the process we threw away our matching PKIX-TA trust 3073 * anchor, reset DANE trust. We might find a suitable trusted 3074 * certificate among the ones from the trust store. 3075 */ 3076 if ((search & S_DOALTERNATE) != 0) { 3077 if (!ossl_assert(num > i && i > 0 && ss == 0)) { 3078 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3079 X509_free(xtmp); 3080 trust = X509_TRUST_REJECTED; 3081 ctx->error = X509_V_ERR_UNSPECIFIED; 3082 search = 0; 3083 continue; 3084 } 3085 search &= ~S_DOALTERNATE; 3086 for (; num > i; --num) 3087 X509_free(sk_X509_pop(ctx->chain)); 3088 ctx->num_untrusted = num; 3089 3090 if (DANETLS_ENABLED(dane) && 3091 dane->mdpth >= ctx->num_untrusted) { 3092 dane->mdpth = -1; 3093 X509_free(dane->mcert); 3094 dane->mcert = NULL; 3095 } 3096 if (DANETLS_ENABLED(dane) && 3097 dane->pdpth >= ctx->num_untrusted) 3098 dane->pdpth = -1; 3099 } 3100 3101 /* 3102 * Self-signed untrusted certificates get replaced by their 3103 * trusted matching issuer. Otherwise, grow the chain. 3104 */ 3105 if (ss == 0) { 3106 if (!sk_X509_push(ctx->chain, x = xtmp)) { 3107 X509_free(xtmp); 3108 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 3109 trust = X509_TRUST_REJECTED; 3110 ctx->error = X509_V_ERR_OUT_OF_MEM; 3111 search = 0; 3112 continue; 3113 } 3114 ss = cert_self_signed(x); 3115 } else if (num == ctx->num_untrusted) { 3116 /* 3117 * We have a self-signed certificate that has the same 3118 * subject name (and perhaps keyid and/or serial number) as 3119 * a trust-anchor. We must have an exact match to avoid 3120 * possible impersonation via key substitution etc. 3121 */ 3122 if (X509_cmp(x, xtmp) != 0) { 3123 /* Self-signed untrusted mimic. */ 3124 X509_free(xtmp); 3125 ok = 0; 3126 } else { 3127 X509_free(x); 3128 ctx->num_untrusted = --num; 3129 (void) sk_X509_set(ctx->chain, num, x = xtmp); 3130 } 3131 } 3132 3133 /* 3134 * We've added a new trusted certificate to the chain, recheck 3135 * trust. If not done, and not self-signed look deeper. 3136 * Whether or not we're doing "trusted first", we no longer 3137 * look for untrusted certificates from the peer's chain. 3138 * 3139 * At this point ctx->num_trusted and num must reflect the 3140 * correct number of untrusted certificates, since the DANE 3141 * logic in check_trust() depends on distinguishing CAs from 3142 * "the wire" from CAs from the trust store. In particular, the 3143 * certificate at depth "num" should be the new trusted 3144 * certificate with ctx->num_untrusted <= num. 3145 */ 3146 if (ok) { 3147 if (!ossl_assert(ctx->num_untrusted <= num)) { 3148 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3149 trust = X509_TRUST_REJECTED; 3150 ctx->error = X509_V_ERR_UNSPECIFIED; 3151 search = 0; 3152 continue; 3153 } 3154 search &= ~S_DOUNTRUSTED; 3155 switch (trust = check_trust(ctx, num)) { 3156 case X509_TRUST_TRUSTED: 3157 case X509_TRUST_REJECTED: 3158 search = 0; 3159 continue; 3160 } 3161 if (ss == 0) 3162 continue; 3163 } 3164 } 3165 3166 /* 3167 * No dispositive decision, and either self-signed or no match, if 3168 * we were doing untrusted-first, and alt-chains are not disabled, 3169 * do that, by repeatedly losing one untrusted element at a time, 3170 * and trying to extend the shorted chain. 3171 */ 3172 if ((search & S_DOUNTRUSTED) == 0) { 3173 /* Continue search for a trusted issuer of a shorter chain? */ 3174 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0) 3175 continue; 3176 /* Still no luck and no fallbacks left? */ 3177 if (!may_alternate || (search & S_DOALTERNATE) != 0 || 3178 ctx->num_untrusted < 2) 3179 break; 3180 /* Search for a trusted issuer of a shorter chain */ 3181 search |= S_DOALTERNATE; 3182 alt_untrusted = ctx->num_untrusted - 1; 3183 ss = 0; 3184 } 3185 } 3186 3187 /* 3188 * Extend chain with peer-provided certificates 3189 */ 3190 if ((search & S_DOUNTRUSTED) != 0) { 3191 num = sk_X509_num(ctx->chain); 3192 if (!ossl_assert(num == ctx->num_untrusted)) { 3193 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3194 trust = X509_TRUST_REJECTED; 3195 ctx->error = X509_V_ERR_UNSPECIFIED; 3196 search = 0; 3197 continue; 3198 } 3199 x = sk_X509_value(ctx->chain, num-1); 3200 3201 /* 3202 * Once we run out of untrusted issuers, we stop looking for more 3203 * and start looking only in the trust store if enabled. 3204 */ 3205 xtmp = (ss || depth < num) ? NULL : find_issuer(ctx, sktmp, x); 3206 if (xtmp == NULL) { 3207 search &= ~S_DOUNTRUSTED; 3208 if (may_trusted) 3209 search |= S_DOTRUSTED; 3210 continue; 3211 } 3212 3213 /* Drop this issuer from future consideration */ 3214 (void) sk_X509_delete_ptr(sktmp, xtmp); 3215 3216 if (!X509_up_ref(xtmp)) { 3217 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3218 trust = X509_TRUST_REJECTED; 3219 ctx->error = X509_V_ERR_UNSPECIFIED; 3220 search = 0; 3221 continue; 3222 } 3223 3224 if (!sk_X509_push(ctx->chain, xtmp)) { 3225 X509_free(xtmp); 3226 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 3227 trust = X509_TRUST_REJECTED; 3228 ctx->error = X509_V_ERR_OUT_OF_MEM; 3229 search = 0; 3230 continue; 3231 } 3232 3233 x = xtmp; 3234 ++ctx->num_untrusted; 3235 ss = cert_self_signed(xtmp); 3236 3237 /* 3238 * Check for DANE-TA trust of the topmost untrusted certificate. 3239 */ 3240 switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) { 3241 case X509_TRUST_TRUSTED: 3242 case X509_TRUST_REJECTED: 3243 search = 0; 3244 continue; 3245 } 3246 } 3247 } 3248 sk_X509_free(sktmp); 3249 3250 /* 3251 * Last chance to make a trusted chain, either bare DANE-TA public-key 3252 * signers, or else direct leaf PKIX trust. 3253 */ 3254 num = sk_X509_num(ctx->chain); 3255 if (num <= depth) { 3256 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane)) 3257 trust = check_dane_pkeys(ctx); 3258 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted) 3259 trust = check_trust(ctx, num); 3260 } 3261 3262 switch (trust) { 3263 case X509_TRUST_TRUSTED: 3264 return 1; 3265 case X509_TRUST_REJECTED: 3266 /* Callback already issued */ 3267 return 0; 3268 case X509_TRUST_UNTRUSTED: 3269 default: 3270 num = sk_X509_num(ctx->chain); 3271 if (num > depth) 3272 return verify_cb_cert(ctx, NULL, num-1, 3273 X509_V_ERR_CERT_CHAIN_TOO_LONG); 3274 if (DANETLS_ENABLED(dane) && 3275 (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0)) 3276 return verify_cb_cert(ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH); 3277 if (ss && sk_X509_num(ctx->chain) == 1) 3278 return verify_cb_cert(ctx, NULL, num-1, 3279 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT); 3280 if (ss) 3281 return verify_cb_cert(ctx, NULL, num-1, 3282 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN); 3283 if (ctx->num_untrusted < num) 3284 return verify_cb_cert(ctx, NULL, num-1, 3285 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT); 3286 return verify_cb_cert(ctx, NULL, num-1, 3287 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY); 3288 } 3289 } 3290 3291 static const int minbits_table[] = { 80, 112, 128, 192, 256 }; 3292 static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table); 3293 3294 /* 3295 * Check whether the public key of ``cert`` meets the security level of 3296 * ``ctx``. 3297 * 3298 * Returns 1 on success, 0 otherwise. 3299 */ 3300 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert) 3301 { 3302 EVP_PKEY *pkey = X509_get0_pubkey(cert); 3303 int level = ctx->param->auth_level; 3304 3305 /* 3306 * At security level zero, return without checking for a supported public 3307 * key type. Some engines support key types not understood outside the 3308 * engine, and we only need to understand the key when enforcing a security 3309 * floor. 3310 */ 3311 if (level <= 0) 3312 return 1; 3313 3314 /* Unsupported or malformed keys are not secure */ 3315 if (pkey == NULL) 3316 return 0; 3317 3318 if (level > NUM_AUTH_LEVELS) 3319 level = NUM_AUTH_LEVELS; 3320 3321 return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1]; 3322 } 3323 3324 /* 3325 * Check whether the public key of ``cert`` does not use explicit params 3326 * for an elliptic curve. 3327 * 3328 * Returns 1 on success, 0 if check fails, -1 for other errors. 3329 */ 3330 static int check_curve(X509 *cert) 3331 { 3332 #ifndef OPENSSL_NO_EC 3333 EVP_PKEY *pkey = X509_get0_pubkey(cert); 3334 3335 /* Unsupported or malformed key */ 3336 if (pkey == NULL) 3337 return -1; 3338 3339 if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) { 3340 int ret; 3341 3342 ret = EC_KEY_decoded_from_explicit_params(EVP_PKEY_get0_EC_KEY(pkey)); 3343 return ret < 0 ? ret : !ret; 3344 } 3345 #endif 3346 3347 return 1; 3348 } 3349 3350 /* 3351 * Check whether the signature digest algorithm of ``cert`` meets the security 3352 * level of ``ctx``. Should not be checked for trust anchors (whether 3353 * self-signed or otherwise). 3354 * 3355 * Returns 1 on success, 0 otherwise. 3356 */ 3357 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert) 3358 { 3359 int secbits = -1; 3360 int level = ctx->param->auth_level; 3361 3362 if (level <= 0) 3363 return 1; 3364 if (level > NUM_AUTH_LEVELS) 3365 level = NUM_AUTH_LEVELS; 3366 3367 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL)) 3368 return 0; 3369 3370 return secbits >= minbits_table[level - 1]; 3371 } 3372