1/* 2 * Copyright 1995-2021 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 66static int build_chain(X509_STORE_CTX *ctx); 67static int verify_chain(X509_STORE_CTX *ctx); 68static int dane_verify(X509_STORE_CTX *ctx); 69static int null_callback(int ok, X509_STORE_CTX *e); 70static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer); 71static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x); 72static int check_chain_extensions(X509_STORE_CTX *ctx); 73static int check_name_constraints(X509_STORE_CTX *ctx); 74static int check_id(X509_STORE_CTX *ctx); 75static int check_trust(X509_STORE_CTX *ctx, int num_untrusted); 76static int check_revocation(X509_STORE_CTX *ctx); 77static int check_cert(X509_STORE_CTX *ctx); 78static int check_policy(X509_STORE_CTX *ctx); 79static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x); 80static int check_dane_issuer(X509_STORE_CTX *ctx, int depth); 81static int check_key_level(X509_STORE_CTX *ctx, X509 *cert); 82static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert); 83static int check_curve(X509 *cert); 84 85static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 86 unsigned int *preasons, X509_CRL *crl, X509 *x); 87static int get_crl_delta(X509_STORE_CTX *ctx, 88 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x); 89static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, 90 int *pcrl_score, X509_CRL *base, 91 STACK_OF(X509_CRL) *crls); 92static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer, 93 int *pcrl_score); 94static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 95 unsigned int *preasons); 96static int check_crl_path(X509_STORE_CTX *ctx, X509 *x); 97static int check_crl_chain(X509_STORE_CTX *ctx, 98 STACK_OF(X509) *cert_path, 99 STACK_OF(X509) *crl_path); 100 101static int internal_verify(X509_STORE_CTX *ctx); 102 103static 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 */ 114static 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 126static 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 */ 157static 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 */ 173static int verify_cb_crl(X509_STORE_CTX *ctx, int err) 174{ 175 ctx->error = err; 176 return ctx->verify_cb(0, ctx); 177} 178 179static 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 208static 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 254int 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 315static int sk_X509_contains(STACK_OF(X509) *sk, X509 *cert) 316{ 317 int i, n = sk_X509_num(sk); 318 319 for (i = 0; i < n; i++) 320 if (X509_cmp(sk_X509_value(sk, i), cert) == 0) 321 return 1; 322 return 0; 323} 324 325/* 326 * Find in given STACK_OF(X509) sk an issuer cert of given cert x. 327 * The issuer must not yet be in ctx->chain, where the exceptional case 328 * that x is self-issued and ctx->chain has just one element is allowed. 329 * Prefer the first one that is not expired, else take the last expired one. 330 */ 331static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x) 332{ 333 int i; 334 X509 *issuer, *rv = NULL; 335 336 for (i = 0; i < sk_X509_num(sk); i++) { 337 issuer = sk_X509_value(sk, i); 338 if (ctx->check_issued(ctx, x, issuer) 339 && (((x->ex_flags & EXFLAG_SI) != 0 && sk_X509_num(ctx->chain) == 1) 340 || !sk_X509_contains(ctx->chain, issuer))) { 341 rv = issuer; 342 if (x509_check_cert_time(ctx, rv, -1)) 343 break; 344 } 345 } 346 return rv; 347} 348 349/* Check that the given certificate 'x' is issued by the certificate 'issuer' */ 350static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer) 351{ 352 return x509_likely_issued(issuer, x) == X509_V_OK; 353} 354 355/* Alternative lookup method: look from a STACK stored in other_ctx */ 356static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x) 357{ 358 *issuer = find_issuer(ctx, ctx->other_ctx, x); 359 360 if (*issuer == NULL || !X509_up_ref(*issuer)) 361 goto err; 362 363 return 1; 364 365 err: 366 *issuer = NULL; 367 return 0; 368} 369 370static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, X509_NAME *nm) 371{ 372 STACK_OF(X509) *sk = NULL; 373 X509 *x; 374 int i; 375 376 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) { 377 x = sk_X509_value(ctx->other_ctx, i); 378 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) { 379 if (!X509_up_ref(x)) { 380 sk_X509_pop_free(sk, X509_free); 381 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_INTERNAL_ERROR); 382 ctx->error = X509_V_ERR_UNSPECIFIED; 383 return NULL; 384 } 385 if (sk == NULL) 386 sk = sk_X509_new_null(); 387 if (sk == NULL || !sk_X509_push(sk, x)) { 388 X509_free(x); 389 sk_X509_pop_free(sk, X509_free); 390 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_MALLOC_FAILURE); 391 ctx->error = X509_V_ERR_OUT_OF_MEM; 392 return NULL; 393 } 394 } 395 } 396 return sk; 397} 398 399/* 400 * Check EE or CA certificate purpose. For trusted certificates explicit local 401 * auxiliary trust can be used to override EKU-restrictions. 402 */ 403static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth, 404 int must_be_ca) 405{ 406 int tr_ok = X509_TRUST_UNTRUSTED; 407 408 /* 409 * For trusted certificates we want to see whether any auxiliary trust 410 * settings trump the purpose constraints. 411 * 412 * This is complicated by the fact that the trust ordinals in 413 * ctx->param->trust are entirely independent of the purpose ordinals in 414 * ctx->param->purpose! 415 * 416 * What connects them is their mutual initialization via calls from 417 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets 418 * related values of both param->trust and param->purpose. It is however 419 * typically possible to infer associated trust values from a purpose value 420 * via the X509_PURPOSE API. 421 * 422 * Therefore, we can only check for trust overrides when the purpose we're 423 * checking is the same as ctx->param->purpose and ctx->param->trust is 424 * also set. 425 */ 426 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose) 427 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT); 428 429 switch (tr_ok) { 430 case X509_TRUST_TRUSTED: 431 return 1; 432 case X509_TRUST_REJECTED: 433 break; 434 default: 435 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) { 436 case 1: 437 return 1; 438 case 0: 439 break; 440 default: 441 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0) 442 return 1; 443 } 444 break; 445 } 446 447 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE); 448} 449 450/* 451 * Check a certificate chains extensions for consistency with the supplied 452 * purpose 453 */ 454 455static int check_chain_extensions(X509_STORE_CTX *ctx) 456{ 457 int i, must_be_ca, plen = 0; 458 X509 *x; 459 int proxy_path_length = 0; 460 int purpose; 461 int allow_proxy_certs; 462 int num = sk_X509_num(ctx->chain); 463 464 /*- 465 * must_be_ca can have 1 of 3 values: 466 * -1: we accept both CA and non-CA certificates, to allow direct 467 * use of self-signed certificates (which are marked as CA). 468 * 0: we only accept non-CA certificates. This is currently not 469 * used, but the possibility is present for future extensions. 470 * 1: we only accept CA certificates. This is currently used for 471 * all certificates in the chain except the leaf certificate. 472 */ 473 must_be_ca = -1; 474 475 /* CRL path validation */ 476 if (ctx->parent) { 477 allow_proxy_certs = 0; 478 purpose = X509_PURPOSE_CRL_SIGN; 479 } else { 480 allow_proxy_certs = 481 ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS); 482 purpose = ctx->param->purpose; 483 } 484 485 for (i = 0; i < num; i++) { 486 int ret; 487 x = sk_X509_value(ctx->chain, i); 488 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) 489 && (x->ex_flags & EXFLAG_CRITICAL)) { 490 if (!verify_cb_cert(ctx, x, i, 491 X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION)) 492 return 0; 493 } 494 if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) { 495 if (!verify_cb_cert(ctx, x, i, 496 X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED)) 497 return 0; 498 } 499 ret = X509_check_ca(x); 500 switch (must_be_ca) { 501 case -1: 502 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) 503 && (ret != 1) && (ret != 0)) { 504 ret = 0; 505 ctx->error = X509_V_ERR_INVALID_CA; 506 } else 507 ret = 1; 508 break; 509 case 0: 510 if (ret != 0) { 511 ret = 0; 512 ctx->error = X509_V_ERR_INVALID_NON_CA; 513 } else 514 ret = 1; 515 break; 516 default: 517 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */ 518 if ((ret == 0) 519 || ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT) 520 && (ret != 1))) { 521 ret = 0; 522 ctx->error = X509_V_ERR_INVALID_CA; 523 } else 524 ret = 1; 525 break; 526 } 527 if (ret > 0 528 && (ctx->param->flags & X509_V_FLAG_X509_STRICT) && num > 1) { 529 /* Check for presence of explicit elliptic curve parameters */ 530 ret = check_curve(x); 531 if (ret < 0) { 532 ctx->error = X509_V_ERR_UNSPECIFIED; 533 ret = 0; 534 } else if (ret == 0) { 535 ctx->error = X509_V_ERR_EC_KEY_EXPLICIT_PARAMS; 536 } 537 } 538 if (ret > 0 539 && (x->ex_flags & EXFLAG_CA) == 0 540 && x->ex_pathlen != -1 541 && (ctx->param->flags & X509_V_FLAG_X509_STRICT)) { 542 ctx->error = X509_V_ERR_INVALID_EXTENSION; 543 ret = 0; 544 } 545 if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK)) 546 return 0; 547 /* check_purpose() makes the callback as needed */ 548 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca)) 549 return 0; 550 /* Check pathlen */ 551 if ((i > 1) && (x->ex_pathlen != -1) 552 && (plen > (x->ex_pathlen + proxy_path_length))) { 553 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED)) 554 return 0; 555 } 556 /* Increment path length if not a self issued intermediate CA */ 557 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0) 558 plen++; 559 /* 560 * If this certificate is a proxy certificate, the next certificate 561 * must be another proxy certificate or a EE certificate. If not, 562 * the next certificate must be a CA certificate. 563 */ 564 if (x->ex_flags & EXFLAG_PROXY) { 565 /* 566 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint 567 * is less than max_path_length, the former should be copied to 568 * the latter, and 4.1.4 (a) stipulates that max_path_length 569 * should be verified to be larger than zero and decrement it. 570 * 571 * Because we're checking the certs in the reverse order, we start 572 * with verifying that proxy_path_length isn't larger than pcPLC, 573 * and copy the latter to the former if it is, and finally, 574 * increment proxy_path_length. 575 */ 576 if (x->ex_pcpathlen != -1) { 577 if (proxy_path_length > x->ex_pcpathlen) { 578 if (!verify_cb_cert(ctx, x, i, 579 X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED)) 580 return 0; 581 } 582 proxy_path_length = x->ex_pcpathlen; 583 } 584 proxy_path_length++; 585 must_be_ca = 0; 586 } else 587 must_be_ca = 1; 588 } 589 return 1; 590} 591 592static int has_san_id(X509 *x, int gtype) 593{ 594 int i; 595 int ret = 0; 596 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); 597 598 if (gs == NULL) 599 return 0; 600 601 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) { 602 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i); 603 604 if (g->type == gtype) { 605 ret = 1; 606 break; 607 } 608 } 609 GENERAL_NAMES_free(gs); 610 return ret; 611} 612 613static int check_name_constraints(X509_STORE_CTX *ctx) 614{ 615 int i; 616 617 /* Check name constraints for all certificates */ 618 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) { 619 X509 *x = sk_X509_value(ctx->chain, i); 620 int j; 621 622 /* Ignore self issued certs unless last in chain */ 623 if (i && (x->ex_flags & EXFLAG_SI)) 624 continue; 625 626 /* 627 * Proxy certificates policy has an extra constraint, where the 628 * certificate subject MUST be the issuer with a single CN entry 629 * added. 630 * (RFC 3820: 3.4, 4.1.3 (a)(4)) 631 */ 632 if (x->ex_flags & EXFLAG_PROXY) { 633 X509_NAME *tmpsubject = X509_get_subject_name(x); 634 X509_NAME *tmpissuer = X509_get_issuer_name(x); 635 X509_NAME_ENTRY *tmpentry = NULL; 636 int last_object_nid = 0; 637 int err = X509_V_OK; 638 int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1; 639 640 /* Check that there are at least two RDNs */ 641 if (last_object_loc < 1) { 642 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 643 goto proxy_name_done; 644 } 645 646 /* 647 * Check that there is exactly one more RDN in subject as 648 * there is in issuer. 649 */ 650 if (X509_NAME_entry_count(tmpsubject) 651 != X509_NAME_entry_count(tmpissuer) + 1) { 652 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 653 goto proxy_name_done; 654 } 655 656 /* 657 * Check that the last subject component isn't part of a 658 * multivalued RDN 659 */ 660 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, 661 last_object_loc)) 662 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, 663 last_object_loc - 1))) { 664 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 665 goto proxy_name_done; 666 } 667 668 /* 669 * Check that the last subject RDN is a commonName, and that 670 * all the previous RDNs match the issuer exactly 671 */ 672 tmpsubject = X509_NAME_dup(tmpsubject); 673 if (tmpsubject == NULL) { 674 X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE); 675 ctx->error = X509_V_ERR_OUT_OF_MEM; 676 return 0; 677 } 678 679 tmpentry = 680 X509_NAME_delete_entry(tmpsubject, last_object_loc); 681 last_object_nid = 682 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry)); 683 684 if (last_object_nid != NID_commonName 685 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) { 686 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 687 } 688 689 X509_NAME_ENTRY_free(tmpentry); 690 X509_NAME_free(tmpsubject); 691 692 proxy_name_done: 693 if (err != X509_V_OK 694 && !verify_cb_cert(ctx, x, i, err)) 695 return 0; 696 } 697 698 /* 699 * Check against constraints for all certificates higher in chain 700 * including trust anchor. Trust anchor not strictly speaking needed 701 * but if it includes constraints it is to be assumed it expects them 702 * to be obeyed. 703 */ 704 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) { 705 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc; 706 707 if (nc) { 708 int rv = NAME_CONSTRAINTS_check(x, nc); 709 710 /* If EE certificate check commonName too */ 711 if (rv == X509_V_OK && i == 0 712 && (ctx->param->hostflags 713 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0 714 && ((ctx->param->hostflags 715 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0 716 || !has_san_id(x, GEN_DNS))) 717 rv = NAME_CONSTRAINTS_check_CN(x, nc); 718 719 switch (rv) { 720 case X509_V_OK: 721 break; 722 case X509_V_ERR_OUT_OF_MEM: 723 return 0; 724 default: 725 if (!verify_cb_cert(ctx, x, i, rv)) 726 return 0; 727 break; 728 } 729 } 730 } 731 } 732 return 1; 733} 734 735static int check_id_error(X509_STORE_CTX *ctx, int errcode) 736{ 737 return verify_cb_cert(ctx, ctx->cert, 0, errcode); 738} 739 740static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm) 741{ 742 int i; 743 int n = sk_OPENSSL_STRING_num(vpm->hosts); 744 char *name; 745 746 if (vpm->peername != NULL) { 747 OPENSSL_free(vpm->peername); 748 vpm->peername = NULL; 749 } 750 for (i = 0; i < n; ++i) { 751 name = sk_OPENSSL_STRING_value(vpm->hosts, i); 752 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0) 753 return 1; 754 } 755 return n == 0; 756} 757 758static int check_id(X509_STORE_CTX *ctx) 759{ 760 X509_VERIFY_PARAM *vpm = ctx->param; 761 X509 *x = ctx->cert; 762 if (vpm->hosts && check_hosts(x, vpm) <= 0) { 763 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH)) 764 return 0; 765 } 766 if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) { 767 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH)) 768 return 0; 769 } 770 if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) { 771 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH)) 772 return 0; 773 } 774 return 1; 775} 776 777static int check_trust(X509_STORE_CTX *ctx, int num_untrusted) 778{ 779 int i; 780 X509 *x = NULL; 781 X509 *mx; 782 SSL_DANE *dane = ctx->dane; 783 int num = sk_X509_num(ctx->chain); 784 int trust; 785 786 /* 787 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2) 788 * match, we're done, otherwise we'll merely record the match depth. 789 */ 790 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) { 791 switch (trust = check_dane_issuer(ctx, num_untrusted)) { 792 case X509_TRUST_TRUSTED: 793 case X509_TRUST_REJECTED: 794 return trust; 795 } 796 } 797 798 /* 799 * Check trusted certificates in chain at depth num_untrusted and up. 800 * Note, that depths 0..num_untrusted-1 may also contain trusted 801 * certificates, but the caller is expected to have already checked those, 802 * and wants to incrementally check just any added since. 803 */ 804 for (i = num_untrusted; i < num; i++) { 805 x = sk_X509_value(ctx->chain, i); 806 trust = X509_check_trust(x, ctx->param->trust, 0); 807 /* If explicitly trusted return trusted */ 808 if (trust == X509_TRUST_TRUSTED) 809 goto trusted; 810 if (trust == X509_TRUST_REJECTED) 811 goto rejected; 812 } 813 814 /* 815 * If we are looking at a trusted certificate, and accept partial chains, 816 * the chain is PKIX trusted. 817 */ 818 if (num_untrusted < num) { 819 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) 820 goto trusted; 821 return X509_TRUST_UNTRUSTED; 822 } 823 824 if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) { 825 /* 826 * Last-resort call with no new trusted certificates, check the leaf 827 * for a direct trust store match. 828 */ 829 i = 0; 830 x = sk_X509_value(ctx->chain, i); 831 mx = lookup_cert_match(ctx, x); 832 if (!mx) 833 return X509_TRUST_UNTRUSTED; 834 835 /* 836 * Check explicit auxiliary trust/reject settings. If none are set, 837 * we'll accept X509_TRUST_UNTRUSTED when not self-signed. 838 */ 839 trust = X509_check_trust(mx, ctx->param->trust, 0); 840 if (trust == X509_TRUST_REJECTED) { 841 X509_free(mx); 842 goto rejected; 843 } 844 845 /* Replace leaf with trusted match */ 846 (void) sk_X509_set(ctx->chain, 0, mx); 847 X509_free(x); 848 ctx->num_untrusted = 0; 849 goto trusted; 850 } 851 852 /* 853 * If no trusted certs in chain at all return untrusted and allow 854 * standard (no issuer cert) etc errors to be indicated. 855 */ 856 return X509_TRUST_UNTRUSTED; 857 858 rejected: 859 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED)) 860 return X509_TRUST_REJECTED; 861 return X509_TRUST_UNTRUSTED; 862 863 trusted: 864 if (!DANETLS_ENABLED(dane)) 865 return X509_TRUST_TRUSTED; 866 if (dane->pdpth < 0) 867 dane->pdpth = num_untrusted; 868 /* With DANE, PKIX alone is not trusted until we have both */ 869 if (dane->mdpth >= 0) 870 return X509_TRUST_TRUSTED; 871 return X509_TRUST_UNTRUSTED; 872} 873 874static int check_revocation(X509_STORE_CTX *ctx) 875{ 876 int i = 0, last = 0, ok = 0; 877 if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK)) 878 return 1; 879 if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL) 880 last = sk_X509_num(ctx->chain) - 1; 881 else { 882 /* If checking CRL paths this isn't the EE certificate */ 883 if (ctx->parent) 884 return 1; 885 last = 0; 886 } 887 for (i = 0; i <= last; i++) { 888 ctx->error_depth = i; 889 ok = check_cert(ctx); 890 if (!ok) 891 return ok; 892 } 893 return 1; 894} 895 896static int check_cert(X509_STORE_CTX *ctx) 897{ 898 X509_CRL *crl = NULL, *dcrl = NULL; 899 int ok = 0; 900 int cnum = ctx->error_depth; 901 X509 *x = sk_X509_value(ctx->chain, cnum); 902 903 ctx->current_cert = x; 904 ctx->current_issuer = NULL; 905 ctx->current_crl_score = 0; 906 ctx->current_reasons = 0; 907 908 if (x->ex_flags & EXFLAG_PROXY) 909 return 1; 910 911 while (ctx->current_reasons != CRLDP_ALL_REASONS) { 912 unsigned int last_reasons = ctx->current_reasons; 913 914 /* Try to retrieve relevant CRL */ 915 if (ctx->get_crl) 916 ok = ctx->get_crl(ctx, &crl, x); 917 else 918 ok = get_crl_delta(ctx, &crl, &dcrl, x); 919 /* 920 * If error looking up CRL, nothing we can do except notify callback 921 */ 922 if (!ok) { 923 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 924 goto done; 925 } 926 ctx->current_crl = crl; 927 ok = ctx->check_crl(ctx, crl); 928 if (!ok) 929 goto done; 930 931 if (dcrl) { 932 ok = ctx->check_crl(ctx, dcrl); 933 if (!ok) 934 goto done; 935 ok = ctx->cert_crl(ctx, dcrl, x); 936 if (!ok) 937 goto done; 938 } else 939 ok = 1; 940 941 /* Don't look in full CRL if delta reason is removefromCRL */ 942 if (ok != 2) { 943 ok = ctx->cert_crl(ctx, crl, x); 944 if (!ok) 945 goto done; 946 } 947 948 X509_CRL_free(crl); 949 X509_CRL_free(dcrl); 950 crl = NULL; 951 dcrl = NULL; 952 /* 953 * If reasons not updated we won't get anywhere by another iteration, 954 * so exit loop. 955 */ 956 if (last_reasons == ctx->current_reasons) { 957 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 958 goto done; 959 } 960 } 961 done: 962 X509_CRL_free(crl); 963 X509_CRL_free(dcrl); 964 965 ctx->current_crl = NULL; 966 return ok; 967} 968 969/* Check CRL times against values in X509_STORE_CTX */ 970 971static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify) 972{ 973 time_t *ptime; 974 int i; 975 976 if (notify) 977 ctx->current_crl = crl; 978 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) 979 ptime = &ctx->param->check_time; 980 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) 981 return 1; 982 else 983 ptime = NULL; 984 985 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime); 986 if (i == 0) { 987 if (!notify) 988 return 0; 989 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD)) 990 return 0; 991 } 992 993 if (i > 0) { 994 if (!notify) 995 return 0; 996 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID)) 997 return 0; 998 } 999 1000 if (X509_CRL_get0_nextUpdate(crl)) { 1001 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime); 1002 1003 if (i == 0) { 1004 if (!notify) 1005 return 0; 1006 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD)) 1007 return 0; 1008 } 1009 /* Ignore expiry of base CRL is delta is valid */ 1010 if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) { 1011 if (!notify) 1012 return 0; 1013 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED)) 1014 return 0; 1015 } 1016 } 1017 1018 if (notify) 1019 ctx->current_crl = NULL; 1020 1021 return 1; 1022} 1023 1024static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, 1025 X509 **pissuer, int *pscore, unsigned int *preasons, 1026 STACK_OF(X509_CRL) *crls) 1027{ 1028 int i, crl_score, best_score = *pscore; 1029 unsigned int reasons, best_reasons = 0; 1030 X509 *x = ctx->current_cert; 1031 X509_CRL *crl, *best_crl = NULL; 1032 X509 *crl_issuer = NULL, *best_crl_issuer = NULL; 1033 1034 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1035 crl = sk_X509_CRL_value(crls, i); 1036 reasons = *preasons; 1037 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x); 1038 if (crl_score < best_score || crl_score == 0) 1039 continue; 1040 /* If current CRL is equivalent use it if it is newer */ 1041 if (crl_score == best_score && best_crl != NULL) { 1042 int day, sec; 1043 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl), 1044 X509_CRL_get0_lastUpdate(crl)) == 0) 1045 continue; 1046 /* 1047 * ASN1_TIME_diff never returns inconsistent signs for |day| 1048 * and |sec|. 1049 */ 1050 if (day <= 0 && sec <= 0) 1051 continue; 1052 } 1053 best_crl = crl; 1054 best_crl_issuer = crl_issuer; 1055 best_score = crl_score; 1056 best_reasons = reasons; 1057 } 1058 1059 if (best_crl) { 1060 X509_CRL_free(*pcrl); 1061 *pcrl = best_crl; 1062 *pissuer = best_crl_issuer; 1063 *pscore = best_score; 1064 *preasons = best_reasons; 1065 X509_CRL_up_ref(best_crl); 1066 X509_CRL_free(*pdcrl); 1067 *pdcrl = NULL; 1068 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls); 1069 } 1070 1071 if (best_score >= CRL_SCORE_VALID) 1072 return 1; 1073 1074 return 0; 1075} 1076 1077/* 1078 * Compare two CRL extensions for delta checking purposes. They should be 1079 * both present or both absent. If both present all fields must be identical. 1080 */ 1081 1082static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid) 1083{ 1084 ASN1_OCTET_STRING *exta, *extb; 1085 int i; 1086 i = X509_CRL_get_ext_by_NID(a, nid, -1); 1087 if (i >= 0) { 1088 /* Can't have multiple occurrences */ 1089 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1) 1090 return 0; 1091 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i)); 1092 } else 1093 exta = NULL; 1094 1095 i = X509_CRL_get_ext_by_NID(b, nid, -1); 1096 1097 if (i >= 0) { 1098 1099 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1) 1100 return 0; 1101 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i)); 1102 } else 1103 extb = NULL; 1104 1105 if (!exta && !extb) 1106 return 1; 1107 1108 if (!exta || !extb) 1109 return 0; 1110 1111 if (ASN1_OCTET_STRING_cmp(exta, extb)) 1112 return 0; 1113 1114 return 1; 1115} 1116 1117/* See if a base and delta are compatible */ 1118 1119static int check_delta_base(X509_CRL *delta, X509_CRL *base) 1120{ 1121 /* Delta CRL must be a delta */ 1122 if (!delta->base_crl_number) 1123 return 0; 1124 /* Base must have a CRL number */ 1125 if (!base->crl_number) 1126 return 0; 1127 /* Issuer names must match */ 1128 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta))) 1129 return 0; 1130 /* AKID and IDP must match */ 1131 if (!crl_extension_match(delta, base, NID_authority_key_identifier)) 1132 return 0; 1133 if (!crl_extension_match(delta, base, NID_issuing_distribution_point)) 1134 return 0; 1135 /* Delta CRL base number must not exceed Full CRL number. */ 1136 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0) 1137 return 0; 1138 /* Delta CRL number must exceed full CRL number */ 1139 if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0) 1140 return 1; 1141 return 0; 1142} 1143 1144/* 1145 * For a given base CRL find a delta... maybe extend to delta scoring or 1146 * retrieve a chain of deltas... 1147 */ 1148 1149static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore, 1150 X509_CRL *base, STACK_OF(X509_CRL) *crls) 1151{ 1152 X509_CRL *delta; 1153 int i; 1154 if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS)) 1155 return; 1156 if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST)) 1157 return; 1158 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1159 delta = sk_X509_CRL_value(crls, i); 1160 if (check_delta_base(delta, base)) { 1161 if (check_crl_time(ctx, delta, 0)) 1162 *pscore |= CRL_SCORE_TIME_DELTA; 1163 X509_CRL_up_ref(delta); 1164 *dcrl = delta; 1165 return; 1166 } 1167 } 1168 *dcrl = NULL; 1169} 1170 1171/* 1172 * For a given CRL return how suitable it is for the supplied certificate 1173 * 'x'. The return value is a mask of several criteria. If the issuer is not 1174 * the certificate issuer this is returned in *pissuer. The reasons mask is 1175 * also used to determine if the CRL is suitable: if no new reasons the CRL 1176 * is rejected, otherwise reasons is updated. 1177 */ 1178 1179static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 1180 unsigned int *preasons, X509_CRL *crl, X509 *x) 1181{ 1182 1183 int crl_score = 0; 1184 unsigned int tmp_reasons = *preasons, crl_reasons; 1185 1186 /* First see if we can reject CRL straight away */ 1187 1188 /* Invalid IDP cannot be processed */ 1189 if (crl->idp_flags & IDP_INVALID) 1190 return 0; 1191 /* Reason codes or indirect CRLs need extended CRL support */ 1192 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) { 1193 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS)) 1194 return 0; 1195 } else if (crl->idp_flags & IDP_REASONS) { 1196 /* If no new reasons reject */ 1197 if (!(crl->idp_reasons & ~tmp_reasons)) 1198 return 0; 1199 } 1200 /* Don't process deltas at this stage */ 1201 else if (crl->base_crl_number) 1202 return 0; 1203 /* If issuer name doesn't match certificate need indirect CRL */ 1204 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) { 1205 if (!(crl->idp_flags & IDP_INDIRECT)) 1206 return 0; 1207 } else 1208 crl_score |= CRL_SCORE_ISSUER_NAME; 1209 1210 if (!(crl->flags & EXFLAG_CRITICAL)) 1211 crl_score |= CRL_SCORE_NOCRITICAL; 1212 1213 /* Check expiry */ 1214 if (check_crl_time(ctx, crl, 0)) 1215 crl_score |= CRL_SCORE_TIME; 1216 1217 /* Check authority key ID and locate certificate issuer */ 1218 crl_akid_check(ctx, crl, pissuer, &crl_score); 1219 1220 /* If we can't locate certificate issuer at this point forget it */ 1221 1222 if (!(crl_score & CRL_SCORE_AKID)) 1223 return 0; 1224 1225 /* Check cert for matching CRL distribution points */ 1226 1227 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) { 1228 /* If no new reasons reject */ 1229 if (!(crl_reasons & ~tmp_reasons)) 1230 return 0; 1231 tmp_reasons |= crl_reasons; 1232 crl_score |= CRL_SCORE_SCOPE; 1233 } 1234 1235 *preasons = tmp_reasons; 1236 1237 return crl_score; 1238 1239} 1240 1241static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, 1242 X509 **pissuer, int *pcrl_score) 1243{ 1244 X509 *crl_issuer = NULL; 1245 X509_NAME *cnm = X509_CRL_get_issuer(crl); 1246 int cidx = ctx->error_depth; 1247 int i; 1248 1249 if (cidx != sk_X509_num(ctx->chain) - 1) 1250 cidx++; 1251 1252 crl_issuer = sk_X509_value(ctx->chain, cidx); 1253 1254 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1255 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) { 1256 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT; 1257 *pissuer = crl_issuer; 1258 return; 1259 } 1260 } 1261 1262 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) { 1263 crl_issuer = sk_X509_value(ctx->chain, cidx); 1264 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) 1265 continue; 1266 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1267 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH; 1268 *pissuer = crl_issuer; 1269 return; 1270 } 1271 } 1272 1273 /* Anything else needs extended CRL support */ 1274 1275 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) 1276 return; 1277 1278 /* 1279 * Otherwise the CRL issuer is not on the path. Look for it in the set of 1280 * untrusted certificates. 1281 */ 1282 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) { 1283 crl_issuer = sk_X509_value(ctx->untrusted, i); 1284 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) 1285 continue; 1286 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1287 *pissuer = crl_issuer; 1288 *pcrl_score |= CRL_SCORE_AKID; 1289 return; 1290 } 1291 } 1292} 1293 1294/* 1295 * Check the path of a CRL issuer certificate. This creates a new 1296 * X509_STORE_CTX and populates it with most of the parameters from the 1297 * parent. This could be optimised somewhat since a lot of path checking will 1298 * be duplicated by the parent, but this will rarely be used in practice. 1299 */ 1300 1301static int check_crl_path(X509_STORE_CTX *ctx, X509 *x) 1302{ 1303 X509_STORE_CTX crl_ctx; 1304 int ret; 1305 1306 /* Don't allow recursive CRL path validation */ 1307 if (ctx->parent) 1308 return 0; 1309 if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted)) 1310 return -1; 1311 1312 crl_ctx.crls = ctx->crls; 1313 /* Copy verify params across */ 1314 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param); 1315 1316 crl_ctx.parent = ctx; 1317 crl_ctx.verify_cb = ctx->verify_cb; 1318 1319 /* Verify CRL issuer */ 1320 ret = X509_verify_cert(&crl_ctx); 1321 if (ret <= 0) 1322 goto err; 1323 1324 /* Check chain is acceptable */ 1325 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain); 1326 err: 1327 X509_STORE_CTX_cleanup(&crl_ctx); 1328 return ret; 1329} 1330 1331/* 1332 * RFC3280 says nothing about the relationship between CRL path and 1333 * certificate path, which could lead to situations where a certificate could 1334 * be revoked or validated by a CA not authorised to do so. RFC5280 is more 1335 * strict and states that the two paths must end in the same trust anchor, 1336 * though some discussions remain... until this is resolved we use the 1337 * RFC5280 version 1338 */ 1339 1340static int check_crl_chain(X509_STORE_CTX *ctx, 1341 STACK_OF(X509) *cert_path, 1342 STACK_OF(X509) *crl_path) 1343{ 1344 X509 *cert_ta, *crl_ta; 1345 cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1); 1346 crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1); 1347 if (!X509_cmp(cert_ta, crl_ta)) 1348 return 1; 1349 return 0; 1350} 1351 1352/*- 1353 * Check for match between two dist point names: three separate cases. 1354 * 1. Both are relative names and compare X509_NAME types. 1355 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES. 1356 * 3. Both are full names and compare two GENERAL_NAMES. 1357 * 4. One is NULL: automatic match. 1358 */ 1359 1360static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b) 1361{ 1362 X509_NAME *nm = NULL; 1363 GENERAL_NAMES *gens = NULL; 1364 GENERAL_NAME *gena, *genb; 1365 int i, j; 1366 if (!a || !b) 1367 return 1; 1368 if (a->type == 1) { 1369 if (!a->dpname) 1370 return 0; 1371 /* Case 1: two X509_NAME */ 1372 if (b->type == 1) { 1373 if (!b->dpname) 1374 return 0; 1375 if (!X509_NAME_cmp(a->dpname, b->dpname)) 1376 return 1; 1377 else 1378 return 0; 1379 } 1380 /* Case 2: set name and GENERAL_NAMES appropriately */ 1381 nm = a->dpname; 1382 gens = b->name.fullname; 1383 } else if (b->type == 1) { 1384 if (!b->dpname) 1385 return 0; 1386 /* Case 2: set name and GENERAL_NAMES appropriately */ 1387 gens = a->name.fullname; 1388 nm = b->dpname; 1389 } 1390 1391 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */ 1392 if (nm) { 1393 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 1394 gena = sk_GENERAL_NAME_value(gens, i); 1395 if (gena->type != GEN_DIRNAME) 1396 continue; 1397 if (!X509_NAME_cmp(nm, gena->d.directoryName)) 1398 return 1; 1399 } 1400 return 0; 1401 } 1402 1403 /* Else case 3: two GENERAL_NAMES */ 1404 1405 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) { 1406 gena = sk_GENERAL_NAME_value(a->name.fullname, i); 1407 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) { 1408 genb = sk_GENERAL_NAME_value(b->name.fullname, j); 1409 if (!GENERAL_NAME_cmp(gena, genb)) 1410 return 1; 1411 } 1412 } 1413 1414 return 0; 1415 1416} 1417 1418static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score) 1419{ 1420 int i; 1421 X509_NAME *nm = X509_CRL_get_issuer(crl); 1422 /* If no CRLissuer return is successful iff don't need a match */ 1423 if (!dp->CRLissuer) 1424 return ! !(crl_score & CRL_SCORE_ISSUER_NAME); 1425 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { 1426 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 1427 if (gen->type != GEN_DIRNAME) 1428 continue; 1429 if (!X509_NAME_cmp(gen->d.directoryName, nm)) 1430 return 1; 1431 } 1432 return 0; 1433} 1434 1435/* Check CRLDP and IDP */ 1436 1437static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 1438 unsigned int *preasons) 1439{ 1440 int i; 1441 if (crl->idp_flags & IDP_ONLYATTR) 1442 return 0; 1443 if (x->ex_flags & EXFLAG_CA) { 1444 if (crl->idp_flags & IDP_ONLYUSER) 1445 return 0; 1446 } else { 1447 if (crl->idp_flags & IDP_ONLYCA) 1448 return 0; 1449 } 1450 *preasons = crl->idp_reasons; 1451 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) { 1452 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i); 1453 if (crldp_check_crlissuer(dp, crl, crl_score)) { 1454 if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) { 1455 *preasons &= dp->dp_reasons; 1456 return 1; 1457 } 1458 } 1459 } 1460 if ((!crl->idp || !crl->idp->distpoint) 1461 && (crl_score & CRL_SCORE_ISSUER_NAME)) 1462 return 1; 1463 return 0; 1464} 1465 1466/* 1467 * Retrieve CRL corresponding to current certificate. If deltas enabled try 1468 * to find a delta CRL too 1469 */ 1470 1471static int get_crl_delta(X509_STORE_CTX *ctx, 1472 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x) 1473{ 1474 int ok; 1475 X509 *issuer = NULL; 1476 int crl_score = 0; 1477 unsigned int reasons; 1478 X509_CRL *crl = NULL, *dcrl = NULL; 1479 STACK_OF(X509_CRL) *skcrl; 1480 X509_NAME *nm = X509_get_issuer_name(x); 1481 1482 reasons = ctx->current_reasons; 1483 ok = get_crl_sk(ctx, &crl, &dcrl, 1484 &issuer, &crl_score, &reasons, ctx->crls); 1485 if (ok) 1486 goto done; 1487 1488 /* Lookup CRLs from store */ 1489 1490 skcrl = ctx->lookup_crls(ctx, nm); 1491 1492 /* If no CRLs found and a near match from get_crl_sk use that */ 1493 if (!skcrl && crl) 1494 goto done; 1495 1496 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl); 1497 1498 sk_X509_CRL_pop_free(skcrl, X509_CRL_free); 1499 1500 done: 1501 /* If we got any kind of CRL use it and return success */ 1502 if (crl) { 1503 ctx->current_issuer = issuer; 1504 ctx->current_crl_score = crl_score; 1505 ctx->current_reasons = reasons; 1506 *pcrl = crl; 1507 *pdcrl = dcrl; 1508 return 1; 1509 } 1510 return 0; 1511} 1512 1513/* Check CRL validity */ 1514static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl) 1515{ 1516 X509 *issuer = NULL; 1517 EVP_PKEY *ikey = NULL; 1518 int cnum = ctx->error_depth; 1519 int chnum = sk_X509_num(ctx->chain) - 1; 1520 1521 /* if we have an alternative CRL issuer cert use that */ 1522 if (ctx->current_issuer) 1523 issuer = ctx->current_issuer; 1524 /* 1525 * Else find CRL issuer: if not last certificate then issuer is next 1526 * certificate in chain. 1527 */ 1528 else if (cnum < chnum) 1529 issuer = sk_X509_value(ctx->chain, cnum + 1); 1530 else { 1531 issuer = sk_X509_value(ctx->chain, chnum); 1532 /* If not self signed, can't check signature */ 1533 if (!ctx->check_issued(ctx, issuer, issuer) && 1534 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER)) 1535 return 0; 1536 } 1537 1538 if (issuer == NULL) 1539 return 1; 1540 1541 /* 1542 * Skip most tests for deltas because they have already been done 1543 */ 1544 if (!crl->base_crl_number) { 1545 /* Check for cRLSign bit if keyUsage present */ 1546 if ((issuer->ex_flags & EXFLAG_KUSAGE) && 1547 !(issuer->ex_kusage & KU_CRL_SIGN) && 1548 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN)) 1549 return 0; 1550 1551 if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) && 1552 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE)) 1553 return 0; 1554 1555 if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) && 1556 check_crl_path(ctx, ctx->current_issuer) <= 0 && 1557 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR)) 1558 return 0; 1559 1560 if ((crl->idp_flags & IDP_INVALID) && 1561 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION)) 1562 return 0; 1563 } 1564 1565 if (!(ctx->current_crl_score & CRL_SCORE_TIME) && 1566 !check_crl_time(ctx, crl, 1)) 1567 return 0; 1568 1569 /* Attempt to get issuer certificate public key */ 1570 ikey = X509_get0_pubkey(issuer); 1571 1572 if (!ikey && 1573 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY)) 1574 return 0; 1575 1576 if (ikey) { 1577 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags); 1578 1579 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv)) 1580 return 0; 1581 /* Verify CRL signature */ 1582 if (X509_CRL_verify(crl, ikey) <= 0 && 1583 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE)) 1584 return 0; 1585 } 1586 return 1; 1587} 1588 1589/* Check certificate against CRL */ 1590static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x) 1591{ 1592 X509_REVOKED *rev; 1593 1594 /* 1595 * The rules changed for this... previously if a CRL contained unhandled 1596 * critical extensions it could still be used to indicate a certificate 1597 * was revoked. This has since been changed since critical extensions can 1598 * change the meaning of CRL entries. 1599 */ 1600 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) 1601 && (crl->flags & EXFLAG_CRITICAL) && 1602 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION)) 1603 return 0; 1604 /* 1605 * Look for serial number of certificate in CRL. If found, make sure 1606 * reason is not removeFromCRL. 1607 */ 1608 if (X509_CRL_get0_by_cert(crl, &rev, x)) { 1609 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL) 1610 return 2; 1611 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED)) 1612 return 0; 1613 } 1614 1615 return 1; 1616} 1617 1618static int check_policy(X509_STORE_CTX *ctx) 1619{ 1620 int ret; 1621 1622 if (ctx->parent) 1623 return 1; 1624 /* 1625 * With DANE, the trust anchor might be a bare public key, not a 1626 * certificate! In that case our chain does not have the trust anchor 1627 * certificate as a top-most element. This comports well with RFC5280 1628 * chain verification, since there too, the trust anchor is not part of the 1629 * chain to be verified. In particular, X509_policy_check() does not look 1630 * at the TA cert, but assumes that it is present as the top-most chain 1631 * element. We therefore temporarily push a NULL cert onto the chain if it 1632 * was verified via a bare public key, and pop it off right after the 1633 * X509_policy_check() call. 1634 */ 1635 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) { 1636 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE); 1637 ctx->error = X509_V_ERR_OUT_OF_MEM; 1638 return 0; 1639 } 1640 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain, 1641 ctx->param->policies, ctx->param->flags); 1642 if (ctx->bare_ta_signed) 1643 sk_X509_pop(ctx->chain); 1644 1645 if (ret == X509_PCY_TREE_INTERNAL) { 1646 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE); 1647 ctx->error = X509_V_ERR_OUT_OF_MEM; 1648 return 0; 1649 } 1650 /* Invalid or inconsistent extensions */ 1651 if (ret == X509_PCY_TREE_INVALID) { 1652 int i; 1653 1654 /* Locate certificates with bad extensions and notify callback. */ 1655 for (i = 1; i < sk_X509_num(ctx->chain); i++) { 1656 X509 *x = sk_X509_value(ctx->chain, i); 1657 1658 if (!(x->ex_flags & EXFLAG_INVALID_POLICY)) 1659 continue; 1660 if (!verify_cb_cert(ctx, x, i, 1661 X509_V_ERR_INVALID_POLICY_EXTENSION)) 1662 return 0; 1663 } 1664 return 1; 1665 } 1666 if (ret == X509_PCY_TREE_FAILURE) { 1667 ctx->current_cert = NULL; 1668 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY; 1669 return ctx->verify_cb(0, ctx); 1670 } 1671 if (ret != X509_PCY_TREE_VALID) { 1672 X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR); 1673 return 0; 1674 } 1675 1676 if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) { 1677 ctx->current_cert = NULL; 1678 /* 1679 * Verification errors need to be "sticky", a callback may have allowed 1680 * an SSL handshake to continue despite an error, and we must then 1681 * remain in an error state. Therefore, we MUST NOT clear earlier 1682 * verification errors by setting the error to X509_V_OK. 1683 */ 1684 if (!ctx->verify_cb(2, ctx)) 1685 return 0; 1686 } 1687 1688 return 1; 1689} 1690 1691/*- 1692 * Check certificate validity times. 1693 * If depth >= 0, invoke verification callbacks on error, otherwise just return 1694 * the validation status. 1695 * 1696 * Return 1 on success, 0 otherwise. 1697 */ 1698int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth) 1699{ 1700 time_t *ptime; 1701 int i; 1702 1703 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) 1704 ptime = &ctx->param->check_time; 1705 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) 1706 return 1; 1707 else 1708 ptime = NULL; 1709 1710 i = X509_cmp_time(X509_get0_notBefore(x), ptime); 1711 if (i >= 0 && depth < 0) 1712 return 0; 1713 if (i == 0 && !verify_cb_cert(ctx, x, depth, 1714 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD)) 1715 return 0; 1716 if (i > 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID)) 1717 return 0; 1718 1719 i = X509_cmp_time(X509_get0_notAfter(x), ptime); 1720 if (i <= 0 && depth < 0) 1721 return 0; 1722 if (i == 0 && !verify_cb_cert(ctx, x, depth, 1723 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD)) 1724 return 0; 1725 if (i < 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED)) 1726 return 0; 1727 return 1; 1728} 1729 1730/* verify the issuer signatures and cert times of ctx->chain */ 1731static int internal_verify(X509_STORE_CTX *ctx) 1732{ 1733 int n = sk_X509_num(ctx->chain) - 1; 1734 X509 *xi = sk_X509_value(ctx->chain, n); 1735 X509 *xs; 1736 1737 /* 1738 * With DANE-verified bare public key TA signatures, it remains only to 1739 * check the timestamps of the top certificate. We report the issuer as 1740 * NULL, since all we have is a bare key. 1741 */ 1742 if (ctx->bare_ta_signed) { 1743 xs = xi; 1744 xi = NULL; 1745 goto check_cert_time; 1746 } 1747 1748 if (ctx->check_issued(ctx, xi, xi)) 1749 xs = xi; /* the typical case: last cert in the chain is self-issued */ 1750 else { 1751 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) { 1752 xs = xi; 1753 goto check_cert_time; 1754 } 1755 if (n <= 0) { 1756 if (!verify_cb_cert(ctx, xi, 0, 1757 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE)) 1758 return 0; 1759 1760 xs = xi; 1761 goto check_cert_time; 1762 } 1763 1764 n--; 1765 ctx->error_depth = n; 1766 xs = sk_X509_value(ctx->chain, n); 1767 } 1768 1769 /* 1770 * Do not clear ctx->error=0, it must be "sticky", only the user's callback 1771 * is allowed to reset errors (at its own peril). 1772 */ 1773 while (n >= 0) { 1774 /* 1775 * For each iteration of this loop: 1776 * n is the subject depth 1777 * xs is the subject cert, for which the signature is to be checked 1778 * xi is the supposed issuer cert containing the public key to use 1779 * Initially xs == xi if the last cert in the chain is self-issued. 1780 * 1781 * Skip signature check for self-signed certificates unless explicitly 1782 * asked for because it does not add any security and just wastes time. 1783 */ 1784 if (xs != xi || ((ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE) 1785 && (xi->ex_flags & EXFLAG_SS) != 0)) { 1786 EVP_PKEY *pkey; 1787 /* 1788 * If the issuer's public key is not available or its key usage 1789 * does not support issuing the subject cert, report the issuer 1790 * cert and its depth (rather than n, the depth of the subject). 1791 */ 1792 int issuer_depth = n + (xs == xi ? 0 : 1); 1793 /* 1794 * According to https://tools.ietf.org/html/rfc5280#section-6.1.4 1795 * step (n) we must check any given key usage extension in a CA cert 1796 * when preparing the verification of a certificate issued by it. 1797 * According to https://tools.ietf.org/html/rfc5280#section-4.2.1.3 1798 * we must not verify a certifiate signature if the key usage of the 1799 * CA certificate that issued the certificate prohibits signing. 1800 * In case the 'issuing' certificate is the last in the chain and is 1801 * not a CA certificate but a 'self-issued' end-entity cert (i.e., 1802 * xs == xi && !(xi->ex_flags & EXFLAG_CA)) RFC 5280 does not apply 1803 * (see https://tools.ietf.org/html/rfc6818#section-2) and thus 1804 * we are free to ignore any key usage restrictions on such certs. 1805 */ 1806 int ret = xs == xi && (xi->ex_flags & EXFLAG_CA) == 0 1807 ? X509_V_OK : x509_signing_allowed(xi, xs); 1808 1809 if (ret != X509_V_OK && !verify_cb_cert(ctx, xi, issuer_depth, ret)) 1810 return 0; 1811 if ((pkey = X509_get0_pubkey(xi)) == NULL) { 1812 ret = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY; 1813 if (!verify_cb_cert(ctx, xi, issuer_depth, ret)) 1814 return 0; 1815 } else if (X509_verify(xs, pkey) <= 0) { 1816 ret = X509_V_ERR_CERT_SIGNATURE_FAILURE; 1817 if (!verify_cb_cert(ctx, xs, n, ret)) 1818 return 0; 1819 } 1820 } 1821 1822 check_cert_time: /* in addition to RFC 5280, do also for trusted (root) cert */ 1823 /* Calls verify callback as needed */ 1824 if (!x509_check_cert_time(ctx, xs, n)) 1825 return 0; 1826 1827 /* 1828 * Signal success at this depth. However, the previous error (if any) 1829 * is retained. 1830 */ 1831 ctx->current_issuer = xi; 1832 ctx->current_cert = xs; 1833 ctx->error_depth = n; 1834 if (!ctx->verify_cb(1, ctx)) 1835 return 0; 1836 1837 if (--n >= 0) { 1838 xi = xs; 1839 xs = sk_X509_value(ctx->chain, n); 1840 } 1841 } 1842 return 1; 1843} 1844 1845int X509_cmp_current_time(const ASN1_TIME *ctm) 1846{ 1847 return X509_cmp_time(ctm, NULL); 1848} 1849 1850int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time) 1851{ 1852 static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1; 1853 static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1; 1854 ASN1_TIME *asn1_cmp_time = NULL; 1855 int i, day, sec, ret = 0; 1856#ifdef CHARSET_EBCDIC 1857 const char upper_z = 0x5A; 1858#else 1859 const char upper_z = 'Z'; 1860#endif 1861 /* 1862 * Note that ASN.1 allows much more slack in the time format than RFC5280. 1863 * In RFC5280, the representation is fixed: 1864 * UTCTime: YYMMDDHHMMSSZ 1865 * GeneralizedTime: YYYYMMDDHHMMSSZ 1866 * 1867 * We do NOT currently enforce the following RFC 5280 requirement: 1868 * "CAs conforming to this profile MUST always encode certificate 1869 * validity dates through the year 2049 as UTCTime; certificate validity 1870 * dates in 2050 or later MUST be encoded as GeneralizedTime." 1871 */ 1872 switch (ctm->type) { 1873 case V_ASN1_UTCTIME: 1874 if (ctm->length != (int)(utctime_length)) 1875 return 0; 1876 break; 1877 case V_ASN1_GENERALIZEDTIME: 1878 if (ctm->length != (int)(generalizedtime_length)) 1879 return 0; 1880 break; 1881 default: 1882 return 0; 1883 } 1884 1885 /** 1886 * Verify the format: the ASN.1 functions we use below allow a more 1887 * flexible format than what's mandated by RFC 5280. 1888 * Digit and date ranges will be verified in the conversion methods. 1889 */ 1890 for (i = 0; i < ctm->length - 1; i++) { 1891 if (!ascii_isdigit(ctm->data[i])) 1892 return 0; 1893 } 1894 if (ctm->data[ctm->length - 1] != upper_z) 1895 return 0; 1896 1897 /* 1898 * There is ASN1_UTCTIME_cmp_time_t but no 1899 * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t, 1900 * so we go through ASN.1 1901 */ 1902 asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time); 1903 if (asn1_cmp_time == NULL) 1904 goto err; 1905 if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time)) 1906 goto err; 1907 1908 /* 1909 * X509_cmp_time comparison is <=. 1910 * The return value 0 is reserved for errors. 1911 */ 1912 ret = (day >= 0 && sec >= 0) ? -1 : 1; 1913 1914 err: 1915 ASN1_TIME_free(asn1_cmp_time); 1916 return ret; 1917} 1918 1919ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj) 1920{ 1921 return X509_time_adj(s, adj, NULL); 1922} 1923 1924ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm) 1925{ 1926 return X509_time_adj_ex(s, 0, offset_sec, in_tm); 1927} 1928 1929ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s, 1930 int offset_day, long offset_sec, time_t *in_tm) 1931{ 1932 time_t t; 1933 1934 if (in_tm) 1935 t = *in_tm; 1936 else 1937 time(&t); 1938 1939 if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) { 1940 if (s->type == V_ASN1_UTCTIME) 1941 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec); 1942 if (s->type == V_ASN1_GENERALIZEDTIME) 1943 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec); 1944 } 1945 return ASN1_TIME_adj(s, t, offset_day, offset_sec); 1946} 1947 1948int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain) 1949{ 1950 EVP_PKEY *ktmp = NULL, *ktmp2; 1951 int i, j; 1952 1953 if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey)) 1954 return 1; 1955 1956 for (i = 0; i < sk_X509_num(chain); i++) { 1957 ktmp = X509_get0_pubkey(sk_X509_value(chain, i)); 1958 if (ktmp == NULL) { 1959 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS, 1960 X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY); 1961 return 0; 1962 } 1963 if (!EVP_PKEY_missing_parameters(ktmp)) 1964 break; 1965 } 1966 if (ktmp == NULL) { 1967 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS, 1968 X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN); 1969 return 0; 1970 } 1971 1972 /* first, populate the other certs */ 1973 for (j = i - 1; j >= 0; j--) { 1974 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j)); 1975 EVP_PKEY_copy_parameters(ktmp2, ktmp); 1976 } 1977 1978 if (pkey != NULL) 1979 EVP_PKEY_copy_parameters(pkey, ktmp); 1980 return 1; 1981} 1982 1983/* Make a delta CRL as the diff between two full CRLs */ 1984 1985X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer, 1986 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags) 1987{ 1988 X509_CRL *crl = NULL; 1989 int i; 1990 STACK_OF(X509_REVOKED) *revs = NULL; 1991 /* CRLs can't be delta already */ 1992 if (base->base_crl_number || newer->base_crl_number) { 1993 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA); 1994 return NULL; 1995 } 1996 /* Base and new CRL must have a CRL number */ 1997 if (!base->crl_number || !newer->crl_number) { 1998 X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER); 1999 return NULL; 2000 } 2001 /* Issuer names must match */ 2002 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) { 2003 X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH); 2004 return NULL; 2005 } 2006 /* AKID and IDP must match */ 2007 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) { 2008 X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH); 2009 return NULL; 2010 } 2011 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) { 2012 X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH); 2013 return NULL; 2014 } 2015 /* Newer CRL number must exceed full CRL number */ 2016 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) { 2017 X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER); 2018 return NULL; 2019 } 2020 /* CRLs must verify */ 2021 if (skey && (X509_CRL_verify(base, skey) <= 0 || 2022 X509_CRL_verify(newer, skey) <= 0)) { 2023 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE); 2024 return NULL; 2025 } 2026 /* Create new CRL */ 2027 crl = X509_CRL_new(); 2028 if (crl == NULL || !X509_CRL_set_version(crl, 1)) 2029 goto memerr; 2030 /* Set issuer name */ 2031 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer))) 2032 goto memerr; 2033 2034 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer))) 2035 goto memerr; 2036 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer))) 2037 goto memerr; 2038 2039 /* Set base CRL number: must be critical */ 2040 2041 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0)) 2042 goto memerr; 2043 2044 /* 2045 * Copy extensions across from newest CRL to delta: this will set CRL 2046 * number to correct value too. 2047 */ 2048 2049 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) { 2050 X509_EXTENSION *ext; 2051 ext = X509_CRL_get_ext(newer, i); 2052 if (!X509_CRL_add_ext(crl, ext, -1)) 2053 goto memerr; 2054 } 2055 2056 /* Go through revoked entries, copying as needed */ 2057 2058 revs = X509_CRL_get_REVOKED(newer); 2059 2060 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) { 2061 X509_REVOKED *rvn, *rvtmp; 2062 rvn = sk_X509_REVOKED_value(revs, i); 2063 /* 2064 * Add only if not also in base. TODO: need something cleverer here 2065 * for some more complex CRLs covering multiple CAs. 2066 */ 2067 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) { 2068 rvtmp = X509_REVOKED_dup(rvn); 2069 if (!rvtmp) 2070 goto memerr; 2071 if (!X509_CRL_add0_revoked(crl, rvtmp)) { 2072 X509_REVOKED_free(rvtmp); 2073 goto memerr; 2074 } 2075 } 2076 } 2077 /* TODO: optionally prune deleted entries */ 2078 2079 if (skey && md && !X509_CRL_sign(crl, skey, md)) 2080 goto memerr; 2081 2082 return crl; 2083 2084 memerr: 2085 X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE); 2086 X509_CRL_free(crl); 2087 return NULL; 2088} 2089 2090int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data) 2091{ 2092 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data); 2093} 2094 2095void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx) 2096{ 2097 return CRYPTO_get_ex_data(&ctx->ex_data, idx); 2098} 2099 2100int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx) 2101{ 2102 return ctx->error; 2103} 2104 2105void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err) 2106{ 2107 ctx->error = err; 2108} 2109 2110int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx) 2111{ 2112 return ctx->error_depth; 2113} 2114 2115void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth) 2116{ 2117 ctx->error_depth = depth; 2118} 2119 2120X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx) 2121{ 2122 return ctx->current_cert; 2123} 2124 2125void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x) 2126{ 2127 ctx->current_cert = x; 2128} 2129 2130STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx) 2131{ 2132 return ctx->chain; 2133} 2134 2135STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx) 2136{ 2137 if (!ctx->chain) 2138 return NULL; 2139 return X509_chain_up_ref(ctx->chain); 2140} 2141 2142X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx) 2143{ 2144 return ctx->current_issuer; 2145} 2146 2147X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx) 2148{ 2149 return ctx->current_crl; 2150} 2151 2152X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx) 2153{ 2154 return ctx->parent; 2155} 2156 2157void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x) 2158{ 2159 ctx->cert = x; 2160} 2161 2162void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk) 2163{ 2164 ctx->crls = sk; 2165} 2166 2167int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose) 2168{ 2169 /* 2170 * XXX: Why isn't this function always used to set the associated trust? 2171 * Should there even be a VPM->trust field at all? Or should the trust 2172 * always be inferred from the purpose by X509_STORE_CTX_init(). 2173 */ 2174 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0); 2175} 2176 2177int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust) 2178{ 2179 /* 2180 * XXX: See above, this function would only be needed when the default 2181 * trust for the purpose needs an override in a corner case. 2182 */ 2183 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust); 2184} 2185 2186/* 2187 * This function is used to set the X509_STORE_CTX purpose and trust values. 2188 * This is intended to be used when another structure has its own trust and 2189 * purpose values which (if set) will be inherited by the ctx. If they aren't 2190 * set then we will usually have a default purpose in mind which should then 2191 * be used to set the trust value. An example of this is SSL use: an SSL 2192 * structure will have its own purpose and trust settings which the 2193 * application can set: if they aren't set then we use the default of SSL 2194 * client/server. 2195 */ 2196 2197int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose, 2198 int purpose, int trust) 2199{ 2200 int idx; 2201 /* If purpose not set use default */ 2202 if (!purpose) 2203 purpose = def_purpose; 2204 /* If we have a purpose then check it is valid */ 2205 if (purpose) { 2206 X509_PURPOSE *ptmp; 2207 idx = X509_PURPOSE_get_by_id(purpose); 2208 if (idx == -1) { 2209 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2210 X509_R_UNKNOWN_PURPOSE_ID); 2211 return 0; 2212 } 2213 ptmp = X509_PURPOSE_get0(idx); 2214 if (ptmp->trust == X509_TRUST_DEFAULT) { 2215 idx = X509_PURPOSE_get_by_id(def_purpose); 2216 /* 2217 * XXX: In the two callers above def_purpose is always 0, which is 2218 * not a known value, so idx will always be -1. How is the 2219 * X509_TRUST_DEFAULT case actually supposed to be handled? 2220 */ 2221 if (idx == -1) { 2222 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2223 X509_R_UNKNOWN_PURPOSE_ID); 2224 return 0; 2225 } 2226 ptmp = X509_PURPOSE_get0(idx); 2227 } 2228 /* If trust not set then get from purpose default */ 2229 if (!trust) 2230 trust = ptmp->trust; 2231 } 2232 if (trust) { 2233 idx = X509_TRUST_get_by_id(trust); 2234 if (idx == -1) { 2235 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2236 X509_R_UNKNOWN_TRUST_ID); 2237 return 0; 2238 } 2239 } 2240 2241 if (purpose && !ctx->param->purpose) 2242 ctx->param->purpose = purpose; 2243 if (trust && !ctx->param->trust) 2244 ctx->param->trust = trust; 2245 return 1; 2246} 2247 2248X509_STORE_CTX *X509_STORE_CTX_new(void) 2249{ 2250 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx)); 2251 2252 if (ctx == NULL) { 2253 X509err(X509_F_X509_STORE_CTX_NEW, ERR_R_MALLOC_FAILURE); 2254 return NULL; 2255 } 2256 return ctx; 2257} 2258 2259void X509_STORE_CTX_free(X509_STORE_CTX *ctx) 2260{ 2261 if (ctx == NULL) 2262 return; 2263 2264 X509_STORE_CTX_cleanup(ctx); 2265 OPENSSL_free(ctx); 2266} 2267 2268int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509, 2269 STACK_OF(X509) *chain) 2270{ 2271 int ret = 1; 2272 2273 ctx->ctx = store; 2274 ctx->cert = x509; 2275 ctx->untrusted = chain; 2276 ctx->crls = NULL; 2277 ctx->num_untrusted = 0; 2278 ctx->other_ctx = NULL; 2279 ctx->valid = 0; 2280 ctx->chain = NULL; 2281 ctx->error = 0; 2282 ctx->explicit_policy = 0; 2283 ctx->error_depth = 0; 2284 ctx->current_cert = NULL; 2285 ctx->current_issuer = NULL; 2286 ctx->current_crl = NULL; 2287 ctx->current_crl_score = 0; 2288 ctx->current_reasons = 0; 2289 ctx->tree = NULL; 2290 ctx->parent = NULL; 2291 ctx->dane = NULL; 2292 ctx->bare_ta_signed = 0; 2293 /* Zero ex_data to make sure we're cleanup-safe */ 2294 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2295 2296 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */ 2297 if (store) 2298 ctx->cleanup = store->cleanup; 2299 else 2300 ctx->cleanup = 0; 2301 2302 if (store && store->check_issued) 2303 ctx->check_issued = store->check_issued; 2304 else 2305 ctx->check_issued = check_issued; 2306 2307 if (store && store->get_issuer) 2308 ctx->get_issuer = store->get_issuer; 2309 else 2310 ctx->get_issuer = X509_STORE_CTX_get1_issuer; 2311 2312 if (store && store->verify_cb) 2313 ctx->verify_cb = store->verify_cb; 2314 else 2315 ctx->verify_cb = null_callback; 2316 2317 if (store && store->verify) 2318 ctx->verify = store->verify; 2319 else 2320 ctx->verify = internal_verify; 2321 2322 if (store && store->check_revocation) 2323 ctx->check_revocation = store->check_revocation; 2324 else 2325 ctx->check_revocation = check_revocation; 2326 2327 if (store && store->get_crl) 2328 ctx->get_crl = store->get_crl; 2329 else 2330 ctx->get_crl = NULL; 2331 2332 if (store && store->check_crl) 2333 ctx->check_crl = store->check_crl; 2334 else 2335 ctx->check_crl = check_crl; 2336 2337 if (store && store->cert_crl) 2338 ctx->cert_crl = store->cert_crl; 2339 else 2340 ctx->cert_crl = cert_crl; 2341 2342 if (store && store->check_policy) 2343 ctx->check_policy = store->check_policy; 2344 else 2345 ctx->check_policy = check_policy; 2346 2347 if (store && store->lookup_certs) 2348 ctx->lookup_certs = store->lookup_certs; 2349 else 2350 ctx->lookup_certs = X509_STORE_CTX_get1_certs; 2351 2352 if (store && store->lookup_crls) 2353 ctx->lookup_crls = store->lookup_crls; 2354 else 2355 ctx->lookup_crls = X509_STORE_CTX_get1_crls; 2356 2357 ctx->param = X509_VERIFY_PARAM_new(); 2358 if (ctx->param == NULL) { 2359 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2360 goto err; 2361 } 2362 2363 /* 2364 * Inherit callbacks and flags from X509_STORE if not set use defaults. 2365 */ 2366 if (store) 2367 ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param); 2368 else 2369 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE; 2370 2371 if (ret) 2372 ret = X509_VERIFY_PARAM_inherit(ctx->param, 2373 X509_VERIFY_PARAM_lookup("default")); 2374 2375 if (ret == 0) { 2376 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2377 goto err; 2378 } 2379 2380 /* 2381 * XXX: For now, continue to inherit trust from VPM, but infer from the 2382 * purpose if this still yields the default value. 2383 */ 2384 if (ctx->param->trust == X509_TRUST_DEFAULT) { 2385 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose); 2386 X509_PURPOSE *xp = X509_PURPOSE_get0(idx); 2387 2388 if (xp != NULL) 2389 ctx->param->trust = X509_PURPOSE_get_trust(xp); 2390 } 2391 2392 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, 2393 &ctx->ex_data)) 2394 return 1; 2395 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2396 2397 err: 2398 /* 2399 * On error clean up allocated storage, if the store context was not 2400 * allocated with X509_STORE_CTX_new() this is our last chance to do so. 2401 */ 2402 X509_STORE_CTX_cleanup(ctx); 2403 return 0; 2404} 2405 2406/* 2407 * Set alternative lookup method: just a STACK of trusted certificates. This 2408 * avoids X509_STORE nastiness where it isn't needed. 2409 */ 2410void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2411{ 2412 ctx->other_ctx = sk; 2413 ctx->get_issuer = get_issuer_sk; 2414 ctx->lookup_certs = lookup_certs_sk; 2415} 2416 2417void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx) 2418{ 2419 /* 2420 * We need to be idempotent because, unfortunately, free() also calls 2421 * cleanup(), so the natural call sequence new(), init(), cleanup(), free() 2422 * calls cleanup() for the same object twice! Thus we must zero the 2423 * pointers below after they're freed! 2424 */ 2425 /* Seems to always be 0 in OpenSSL, do this at most once. */ 2426 if (ctx->cleanup != NULL) { 2427 ctx->cleanup(ctx); 2428 ctx->cleanup = NULL; 2429 } 2430 if (ctx->param != NULL) { 2431 if (ctx->parent == NULL) 2432 X509_VERIFY_PARAM_free(ctx->param); 2433 ctx->param = NULL; 2434 } 2435 X509_policy_tree_free(ctx->tree); 2436 ctx->tree = NULL; 2437 sk_X509_pop_free(ctx->chain, X509_free); 2438 ctx->chain = NULL; 2439 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data)); 2440 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2441} 2442 2443void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth) 2444{ 2445 X509_VERIFY_PARAM_set_depth(ctx->param, depth); 2446} 2447 2448void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags) 2449{ 2450 X509_VERIFY_PARAM_set_flags(ctx->param, flags); 2451} 2452 2453void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, 2454 time_t t) 2455{ 2456 X509_VERIFY_PARAM_set_time(ctx->param, t); 2457} 2458 2459X509 *X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx) 2460{ 2461 return ctx->cert; 2462} 2463 2464STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx) 2465{ 2466 return ctx->untrusted; 2467} 2468 2469void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2470{ 2471 ctx->untrusted = sk; 2472} 2473 2474void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2475{ 2476 sk_X509_pop_free(ctx->chain, X509_free); 2477 ctx->chain = sk; 2478} 2479 2480void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx, 2481 X509_STORE_CTX_verify_cb verify_cb) 2482{ 2483 ctx->verify_cb = verify_cb; 2484} 2485 2486X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx) 2487{ 2488 return ctx->verify_cb; 2489} 2490 2491void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx, 2492 X509_STORE_CTX_verify_fn verify) 2493{ 2494 ctx->verify = verify; 2495} 2496 2497X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(X509_STORE_CTX *ctx) 2498{ 2499 return ctx->verify; 2500} 2501 2502X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx) 2503{ 2504 return ctx->get_issuer; 2505} 2506 2507X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx) 2508{ 2509 return ctx->check_issued; 2510} 2511 2512X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx) 2513{ 2514 return ctx->check_revocation; 2515} 2516 2517X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx) 2518{ 2519 return ctx->get_crl; 2520} 2521 2522X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx) 2523{ 2524 return ctx->check_crl; 2525} 2526 2527X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx) 2528{ 2529 return ctx->cert_crl; 2530} 2531 2532X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx) 2533{ 2534 return ctx->check_policy; 2535} 2536 2537X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx) 2538{ 2539 return ctx->lookup_certs; 2540} 2541 2542X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx) 2543{ 2544 return ctx->lookup_crls; 2545} 2546 2547X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx) 2548{ 2549 return ctx->cleanup; 2550} 2551 2552X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx) 2553{ 2554 return ctx->tree; 2555} 2556 2557int X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx) 2558{ 2559 return ctx->explicit_policy; 2560} 2561 2562int X509_STORE_CTX_get_num_untrusted(X509_STORE_CTX *ctx) 2563{ 2564 return ctx->num_untrusted; 2565} 2566 2567int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name) 2568{ 2569 const X509_VERIFY_PARAM *param; 2570 param = X509_VERIFY_PARAM_lookup(name); 2571 if (!param) 2572 return 0; 2573 return X509_VERIFY_PARAM_inherit(ctx->param, param); 2574} 2575 2576X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx) 2577{ 2578 return ctx->param; 2579} 2580 2581void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param) 2582{ 2583 X509_VERIFY_PARAM_free(ctx->param); 2584 ctx->param = param; 2585} 2586 2587void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane) 2588{ 2589 ctx->dane = dane; 2590} 2591 2592static unsigned char *dane_i2d( 2593 X509 *cert, 2594 uint8_t selector, 2595 unsigned int *i2dlen) 2596{ 2597 unsigned char *buf = NULL; 2598 int len; 2599 2600 /* 2601 * Extract ASN.1 DER form of certificate or public key. 2602 */ 2603 switch (selector) { 2604 case DANETLS_SELECTOR_CERT: 2605 len = i2d_X509(cert, &buf); 2606 break; 2607 case DANETLS_SELECTOR_SPKI: 2608 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf); 2609 break; 2610 default: 2611 X509err(X509_F_DANE_I2D, X509_R_BAD_SELECTOR); 2612 return NULL; 2613 } 2614 2615 if (len < 0 || buf == NULL) { 2616 X509err(X509_F_DANE_I2D, ERR_R_MALLOC_FAILURE); 2617 return NULL; 2618 } 2619 2620 *i2dlen = (unsigned int)len; 2621 return buf; 2622} 2623 2624#define DANETLS_NONE 256 /* impossible uint8_t */ 2625 2626static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth) 2627{ 2628 SSL_DANE *dane = ctx->dane; 2629 unsigned usage = DANETLS_NONE; 2630 unsigned selector = DANETLS_NONE; 2631 unsigned ordinal = DANETLS_NONE; 2632 unsigned mtype = DANETLS_NONE; 2633 unsigned char *i2dbuf = NULL; 2634 unsigned int i2dlen = 0; 2635 unsigned char mdbuf[EVP_MAX_MD_SIZE]; 2636 unsigned char *cmpbuf = NULL; 2637 unsigned int cmplen = 0; 2638 int i; 2639 int recnum; 2640 int matched = 0; 2641 danetls_record *t = NULL; 2642 uint32_t mask; 2643 2644 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK; 2645 2646 /* 2647 * The trust store is not applicable with DANE-TA(2) 2648 */ 2649 if (depth >= ctx->num_untrusted) 2650 mask &= DANETLS_PKIX_MASK; 2651 2652 /* 2653 * If we've previously matched a PKIX-?? record, no need to test any 2654 * further PKIX-?? records, it remains to just build the PKIX chain. 2655 * Had the match been a DANE-?? record, we'd be done already. 2656 */ 2657 if (dane->mdpth >= 0) 2658 mask &= ~DANETLS_PKIX_MASK; 2659 2660 /*- 2661 * https://tools.ietf.org/html/rfc7671#section-5.1 2662 * https://tools.ietf.org/html/rfc7671#section-5.2 2663 * https://tools.ietf.org/html/rfc7671#section-5.3 2664 * https://tools.ietf.org/html/rfc7671#section-5.4 2665 * 2666 * We handle DANE-EE(3) records first as they require no chain building 2667 * and no expiration or hostname checks. We also process digests with 2668 * higher ordinals first and ignore lower priorities except Full(0) which 2669 * is always processed (last). If none match, we then process PKIX-EE(1). 2670 * 2671 * NOTE: This relies on DANE usages sorting before the corresponding PKIX 2672 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest 2673 * priorities. See twin comment in ssl/ssl_lib.c. 2674 * 2675 * We expect that most TLSA RRsets will have just a single usage, so we 2676 * don't go out of our way to cache multiple selector-specific i2d buffers 2677 * across usages, but if the selector happens to remain the same as switch 2678 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1", 2679 * records would result in us generating each of the certificate and public 2680 * key DER forms twice, but more typically we'd just see multiple "3 1 1" 2681 * or multiple "3 0 1" records. 2682 * 2683 * As soon as we find a match at any given depth, we stop, because either 2684 * we've matched a DANE-?? record and the peer is authenticated, or, after 2685 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is 2686 * sufficient for DANE, and what remains to do is ordinary PKIX validation. 2687 */ 2688 recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0; 2689 for (i = 0; matched == 0 && i < recnum; ++i) { 2690 t = sk_danetls_record_value(dane->trecs, i); 2691 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0) 2692 continue; 2693 if (t->usage != usage) { 2694 usage = t->usage; 2695 2696 /* Reset digest agility for each usage/selector pair */ 2697 mtype = DANETLS_NONE; 2698 ordinal = dane->dctx->mdord[t->mtype]; 2699 } 2700 if (t->selector != selector) { 2701 selector = t->selector; 2702 2703 /* Update per-selector state */ 2704 OPENSSL_free(i2dbuf); 2705 i2dbuf = dane_i2d(cert, selector, &i2dlen); 2706 if (i2dbuf == NULL) 2707 return -1; 2708 2709 /* Reset digest agility for each usage/selector pair */ 2710 mtype = DANETLS_NONE; 2711 ordinal = dane->dctx->mdord[t->mtype]; 2712 } else if (t->mtype != DANETLS_MATCHING_FULL) { 2713 /*- 2714 * Digest agility: 2715 * 2716 * <https://tools.ietf.org/html/rfc7671#section-9> 2717 * 2718 * For a fixed selector, after processing all records with the 2719 * highest mtype ordinal, ignore all mtypes with lower ordinals 2720 * other than "Full". 2721 */ 2722 if (dane->dctx->mdord[t->mtype] < ordinal) 2723 continue; 2724 } 2725 2726 /* 2727 * Each time we hit a (new selector or) mtype, re-compute the relevant 2728 * digest, more complex caching is not worth the code space. 2729 */ 2730 if (t->mtype != mtype) { 2731 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype]; 2732 cmpbuf = i2dbuf; 2733 cmplen = i2dlen; 2734 2735 if (md != NULL) { 2736 cmpbuf = mdbuf; 2737 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) { 2738 matched = -1; 2739 break; 2740 } 2741 } 2742 } 2743 2744 /* 2745 * Squirrel away the certificate and depth if we have a match. Any 2746 * DANE match is dispositive, but with PKIX we still need to build a 2747 * full chain. 2748 */ 2749 if (cmplen == t->dlen && 2750 memcmp(cmpbuf, t->data, cmplen) == 0) { 2751 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK) 2752 matched = 1; 2753 if (matched || dane->mdpth < 0) { 2754 dane->mdpth = depth; 2755 dane->mtlsa = t; 2756 OPENSSL_free(dane->mcert); 2757 dane->mcert = cert; 2758 X509_up_ref(cert); 2759 } 2760 break; 2761 } 2762 } 2763 2764 /* Clear the one-element DER cache */ 2765 OPENSSL_free(i2dbuf); 2766 return matched; 2767} 2768 2769static int check_dane_issuer(X509_STORE_CTX *ctx, int depth) 2770{ 2771 SSL_DANE *dane = ctx->dane; 2772 int matched = 0; 2773 X509 *cert; 2774 2775 if (!DANETLS_HAS_TA(dane) || depth == 0) 2776 return X509_TRUST_UNTRUSTED; 2777 2778 /* 2779 * Record any DANE trust-anchor matches, for the first depth to test, if 2780 * there's one at that depth. (This'll be false for length 1 chains looking 2781 * for an exact match for the leaf certificate). 2782 */ 2783 cert = sk_X509_value(ctx->chain, depth); 2784 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0) 2785 return X509_TRUST_REJECTED; 2786 if (matched > 0) { 2787 ctx->num_untrusted = depth - 1; 2788 return X509_TRUST_TRUSTED; 2789 } 2790 2791 return X509_TRUST_UNTRUSTED; 2792} 2793 2794static int check_dane_pkeys(X509_STORE_CTX *ctx) 2795{ 2796 SSL_DANE *dane = ctx->dane; 2797 danetls_record *t; 2798 int num = ctx->num_untrusted; 2799 X509 *cert = sk_X509_value(ctx->chain, num - 1); 2800 int recnum = sk_danetls_record_num(dane->trecs); 2801 int i; 2802 2803 for (i = 0; i < recnum; ++i) { 2804 t = sk_danetls_record_value(dane->trecs, i); 2805 if (t->usage != DANETLS_USAGE_DANE_TA || 2806 t->selector != DANETLS_SELECTOR_SPKI || 2807 t->mtype != DANETLS_MATCHING_FULL || 2808 X509_verify(cert, t->spki) <= 0) 2809 continue; 2810 2811 /* Clear any PKIX-?? matches that failed to extend to a full chain */ 2812 X509_free(dane->mcert); 2813 dane->mcert = NULL; 2814 2815 /* Record match via a bare TA public key */ 2816 ctx->bare_ta_signed = 1; 2817 dane->mdpth = num - 1; 2818 dane->mtlsa = t; 2819 2820 /* Prune any excess chain certificates */ 2821 num = sk_X509_num(ctx->chain); 2822 for (; num > ctx->num_untrusted; --num) 2823 X509_free(sk_X509_pop(ctx->chain)); 2824 2825 return X509_TRUST_TRUSTED; 2826 } 2827 2828 return X509_TRUST_UNTRUSTED; 2829} 2830 2831static void dane_reset(SSL_DANE *dane) 2832{ 2833 /* 2834 * Reset state to verify another chain, or clear after failure. 2835 */ 2836 X509_free(dane->mcert); 2837 dane->mcert = NULL; 2838 dane->mtlsa = NULL; 2839 dane->mdpth = -1; 2840 dane->pdpth = -1; 2841} 2842 2843static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert) 2844{ 2845 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags); 2846 2847 if (err == X509_V_OK) 2848 return 1; 2849 return verify_cb_cert(ctx, cert, 0, err); 2850} 2851 2852static int dane_verify(X509_STORE_CTX *ctx) 2853{ 2854 X509 *cert = ctx->cert; 2855 SSL_DANE *dane = ctx->dane; 2856 int matched; 2857 int done; 2858 2859 dane_reset(dane); 2860 2861 /*- 2862 * When testing the leaf certificate, if we match a DANE-EE(3) record, 2863 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1) 2864 * record, the match depth and matching TLSA record are recorded, but the 2865 * return value is 0, because we still need to find a PKIX trust-anchor. 2866 * Therefore, when DANE authentication is enabled (required), we're done 2867 * if: 2868 * + matched < 0, internal error. 2869 * + matched == 1, we matched a DANE-EE(3) record 2870 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no 2871 * DANE-TA(2) or PKIX-TA(0) to test. 2872 */ 2873 matched = dane_match(ctx, ctx->cert, 0); 2874 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0); 2875 2876 if (done) 2877 X509_get_pubkey_parameters(NULL, ctx->chain); 2878 2879 if (matched > 0) { 2880 /* Callback invoked as needed */ 2881 if (!check_leaf_suiteb(ctx, cert)) 2882 return 0; 2883 /* Callback invoked as needed */ 2884 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 && 2885 !check_id(ctx)) 2886 return 0; 2887 /* Bypass internal_verify(), issue depth 0 success callback */ 2888 ctx->error_depth = 0; 2889 ctx->current_cert = cert; 2890 return ctx->verify_cb(1, ctx); 2891 } 2892 2893 if (matched < 0) { 2894 ctx->error_depth = 0; 2895 ctx->current_cert = cert; 2896 ctx->error = X509_V_ERR_OUT_OF_MEM; 2897 return -1; 2898 } 2899 2900 if (done) { 2901 /* Fail early, TA-based success is not possible */ 2902 if (!check_leaf_suiteb(ctx, cert)) 2903 return 0; 2904 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH); 2905 } 2906 2907 /* 2908 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0 2909 * certificates happens in-line with building the rest of the chain. 2910 */ 2911 return verify_chain(ctx); 2912} 2913 2914/* Get issuer, without duplicate suppression */ 2915static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert) 2916{ 2917 STACK_OF(X509) *saved_chain = ctx->chain; 2918 int ok; 2919 2920 ctx->chain = NULL; 2921 ok = ctx->get_issuer(issuer, ctx, cert); 2922 ctx->chain = saved_chain; 2923 2924 return ok; 2925} 2926 2927static int build_chain(X509_STORE_CTX *ctx) 2928{ 2929 SSL_DANE *dane = ctx->dane; 2930 int num = sk_X509_num(ctx->chain); 2931 X509 *cert = sk_X509_value(ctx->chain, num - 1); 2932 int ss = cert_self_signed(cert); 2933 STACK_OF(X509) *sktmp = NULL; 2934 unsigned int search; 2935 int may_trusted = 0; 2936 int may_alternate = 0; 2937 int trust = X509_TRUST_UNTRUSTED; 2938 int alt_untrusted = 0; 2939 int depth; 2940 int ok = 0; 2941 int i; 2942 2943 /* Our chain starts with a single untrusted element. */ 2944 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) { 2945 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 2946 ctx->error = X509_V_ERR_UNSPECIFIED; 2947 return 0; 2948 } 2949 2950#define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */ 2951#define S_DOTRUSTED (1 << 1) /* Search trusted store */ 2952#define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */ 2953 /* 2954 * Set up search policy, untrusted if possible, trusted-first if enabled. 2955 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the 2956 * trust_store, otherwise we might look there first. If not trusted-first, 2957 * and alternate chains are not disabled, try building an alternate chain 2958 * if no luck with untrusted first. 2959 */ 2960 search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0; 2961 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) { 2962 if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) 2963 search |= S_DOTRUSTED; 2964 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) 2965 may_alternate = 1; 2966 may_trusted = 1; 2967 } 2968 2969 /* 2970 * Shallow-copy the stack of untrusted certificates (with TLS, this is 2971 * typically the content of the peer's certificate message) so can make 2972 * multiple passes over it, while free to remove elements as we go. 2973 */ 2974 if (ctx->untrusted && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) { 2975 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2976 ctx->error = X509_V_ERR_OUT_OF_MEM; 2977 return 0; 2978 } 2979 2980 /* 2981 * If we got any "DANE-TA(2) Cert(0) Full(0)" trust-anchors from DNS, add 2982 * them to our working copy of the untrusted certificate stack. Since the 2983 * caller of X509_STORE_CTX_init() may have provided only a leaf cert with 2984 * no corresponding stack of untrusted certificates, we may need to create 2985 * an empty stack first. [ At present only the ssl library provides DANE 2986 * support, and ssl_verify_cert_chain() always provides a non-null stack 2987 * containing at least the leaf certificate, but we must be prepared for 2988 * this to change. ] 2989 */ 2990 if (DANETLS_ENABLED(dane) && dane->certs != NULL) { 2991 if (sktmp == NULL && (sktmp = sk_X509_new_null()) == NULL) { 2992 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2993 ctx->error = X509_V_ERR_OUT_OF_MEM; 2994 return 0; 2995 } 2996 for (i = 0; i < sk_X509_num(dane->certs); ++i) { 2997 if (!sk_X509_push(sktmp, sk_X509_value(dane->certs, i))) { 2998 sk_X509_free(sktmp); 2999 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 3000 ctx->error = X509_V_ERR_OUT_OF_MEM; 3001 return 0; 3002 } 3003 } 3004 } 3005 3006 /* 3007 * Still absurdly large, but arithmetically safe, a lower hard upper bound 3008 * might be reasonable. 3009 */ 3010 if (ctx->param->depth > INT_MAX/2) 3011 ctx->param->depth = INT_MAX/2; 3012 3013 /* 3014 * Try to Extend the chain until we reach an ultimately trusted issuer. 3015 * Build chains up to one longer the limit, later fail if we hit the limit, 3016 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code. 3017 */ 3018 depth = ctx->param->depth + 1; 3019 3020 while (search != 0) { 3021 X509 *x; 3022 X509 *xtmp = NULL; 3023 3024 /* 3025 * Look in the trust store if enabled for first lookup, or we've run 3026 * out of untrusted issuers and search here is not disabled. When we 3027 * reach the depth limit, we stop extending the chain, if by that point 3028 * we've not found a trust-anchor, any trusted chain would be too long. 3029 * 3030 * The error reported to the application verify callback is at the 3031 * maximal valid depth with the current certificate equal to the last 3032 * not ultimately-trusted issuer. For example, with verify_depth = 0, 3033 * the callback will report errors at depth=1 when the immediate issuer 3034 * of the leaf certificate is not a trust anchor. No attempt will be 3035 * made to locate an issuer for that certificate, since such a chain 3036 * would be a-priori too long. 3037 */ 3038 if ((search & S_DOTRUSTED) != 0) { 3039 i = num = sk_X509_num(ctx->chain); 3040 if ((search & S_DOALTERNATE) != 0) { 3041 /* 3042 * As high up the chain as we can, look for an alternative 3043 * trusted issuer of an untrusted certificate that currently 3044 * has an untrusted issuer. We use the alt_untrusted variable 3045 * to track how far up the chain we find the first match. It 3046 * is only if and when we find a match, that we prune the chain 3047 * and reset ctx->num_untrusted to the reduced count of 3048 * untrusted certificates. While we're searching for such a 3049 * match (which may never be found), it is neither safe nor 3050 * wise to preemptively modify either the chain or 3051 * ctx->num_untrusted. 3052 * 3053 * Note, like ctx->num_untrusted, alt_untrusted is a count of 3054 * untrusted certificates, not a "depth". 3055 */ 3056 i = alt_untrusted; 3057 } 3058 x = sk_X509_value(ctx->chain, i-1); 3059 3060 ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x); 3061 3062 if (ok < 0) { 3063 trust = X509_TRUST_REJECTED; 3064 ctx->error = X509_V_ERR_STORE_LOOKUP; 3065 search = 0; 3066 continue; 3067 } 3068 3069 if (ok > 0) { 3070 /* 3071 * Alternative trusted issuer for a mid-chain untrusted cert? 3072 * Pop the untrusted cert's successors and retry. We might now 3073 * be able to complete a valid chain via the trust store. Note 3074 * that despite the current trust-store match we might still 3075 * fail complete the chain to a suitable trust-anchor, in which 3076 * case we may prune some more untrusted certificates and try 3077 * again. Thus the S_DOALTERNATE bit may yet be turned on 3078 * again with an even shorter untrusted chain! 3079 * 3080 * If in the process we threw away our matching PKIX-TA trust 3081 * anchor, reset DANE trust. We might find a suitable trusted 3082 * certificate among the ones from the trust store. 3083 */ 3084 if ((search & S_DOALTERNATE) != 0) { 3085 if (!ossl_assert(num > i && i > 0 && ss == 0)) { 3086 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3087 X509_free(xtmp); 3088 trust = X509_TRUST_REJECTED; 3089 ctx->error = X509_V_ERR_UNSPECIFIED; 3090 search = 0; 3091 continue; 3092 } 3093 search &= ~S_DOALTERNATE; 3094 for (; num > i; --num) 3095 X509_free(sk_X509_pop(ctx->chain)); 3096 ctx->num_untrusted = num; 3097 3098 if (DANETLS_ENABLED(dane) && 3099 dane->mdpth >= ctx->num_untrusted) { 3100 dane->mdpth = -1; 3101 X509_free(dane->mcert); 3102 dane->mcert = NULL; 3103 } 3104 if (DANETLS_ENABLED(dane) && 3105 dane->pdpth >= ctx->num_untrusted) 3106 dane->pdpth = -1; 3107 } 3108 3109 /* 3110 * Self-signed untrusted certificates get replaced by their 3111 * trusted matching issuer. Otherwise, grow the chain. 3112 */ 3113 if (ss == 0) { 3114 if (!sk_X509_push(ctx->chain, x = xtmp)) { 3115 X509_free(xtmp); 3116 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 3117 trust = X509_TRUST_REJECTED; 3118 ctx->error = X509_V_ERR_OUT_OF_MEM; 3119 search = 0; 3120 continue; 3121 } 3122 ss = cert_self_signed(x); 3123 } else if (num == ctx->num_untrusted) { 3124 /* 3125 * We have a self-signed certificate that has the same 3126 * subject name (and perhaps keyid and/or serial number) as 3127 * a trust-anchor. We must have an exact match to avoid 3128 * possible impersonation via key substitution etc. 3129 */ 3130 if (X509_cmp(x, xtmp) != 0) { 3131 /* Self-signed untrusted mimic. */ 3132 X509_free(xtmp); 3133 ok = 0; 3134 } else { 3135 X509_free(x); 3136 ctx->num_untrusted = --num; 3137 (void) sk_X509_set(ctx->chain, num, x = xtmp); 3138 } 3139 } 3140 3141 /* 3142 * We've added a new trusted certificate to the chain, recheck 3143 * trust. If not done, and not self-signed look deeper. 3144 * Whether or not we're doing "trusted first", we no longer 3145 * look for untrusted certificates from the peer's chain. 3146 * 3147 * At this point ctx->num_trusted and num must reflect the 3148 * correct number of untrusted certificates, since the DANE 3149 * logic in check_trust() depends on distinguishing CAs from 3150 * "the wire" from CAs from the trust store. In particular, the 3151 * certificate at depth "num" should be the new trusted 3152 * certificate with ctx->num_untrusted <= num. 3153 */ 3154 if (ok) { 3155 if (!ossl_assert(ctx->num_untrusted <= num)) { 3156 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3157 trust = X509_TRUST_REJECTED; 3158 ctx->error = X509_V_ERR_UNSPECIFIED; 3159 search = 0; 3160 continue; 3161 } 3162 search &= ~S_DOUNTRUSTED; 3163 switch (trust = check_trust(ctx, num)) { 3164 case X509_TRUST_TRUSTED: 3165 case X509_TRUST_REJECTED: 3166 search = 0; 3167 continue; 3168 } 3169 if (ss == 0) 3170 continue; 3171 } 3172 } 3173 3174 /* 3175 * No dispositive decision, and either self-signed or no match, if 3176 * we were doing untrusted-first, and alt-chains are not disabled, 3177 * do that, by repeatedly losing one untrusted element at a time, 3178 * and trying to extend the shorted chain. 3179 */ 3180 if ((search & S_DOUNTRUSTED) == 0) { 3181 /* Continue search for a trusted issuer of a shorter chain? */ 3182 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0) 3183 continue; 3184 /* Still no luck and no fallbacks left? */ 3185 if (!may_alternate || (search & S_DOALTERNATE) != 0 || 3186 ctx->num_untrusted < 2) 3187 break; 3188 /* Search for a trusted issuer of a shorter chain */ 3189 search |= S_DOALTERNATE; 3190 alt_untrusted = ctx->num_untrusted - 1; 3191 ss = 0; 3192 } 3193 } 3194 3195 /* 3196 * Extend chain with peer-provided certificates 3197 */ 3198 if ((search & S_DOUNTRUSTED) != 0) { 3199 num = sk_X509_num(ctx->chain); 3200 if (!ossl_assert(num == ctx->num_untrusted)) { 3201 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3202 trust = X509_TRUST_REJECTED; 3203 ctx->error = X509_V_ERR_UNSPECIFIED; 3204 search = 0; 3205 continue; 3206 } 3207 x = sk_X509_value(ctx->chain, num-1); 3208 3209 /* 3210 * Once we run out of untrusted issuers, we stop looking for more 3211 * and start looking only in the trust store if enabled. 3212 */ 3213 xtmp = (ss || depth < num) ? NULL : find_issuer(ctx, sktmp, x); 3214 if (xtmp == NULL) { 3215 search &= ~S_DOUNTRUSTED; 3216 if (may_trusted) 3217 search |= S_DOTRUSTED; 3218 continue; 3219 } 3220 3221 /* Drop this issuer from future consideration */ 3222 (void) sk_X509_delete_ptr(sktmp, xtmp); 3223 3224 if (!X509_up_ref(xtmp)) { 3225 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3226 trust = X509_TRUST_REJECTED; 3227 ctx->error = X509_V_ERR_UNSPECIFIED; 3228 search = 0; 3229 continue; 3230 } 3231 3232 if (!sk_X509_push(ctx->chain, xtmp)) { 3233 X509_free(xtmp); 3234 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 3235 trust = X509_TRUST_REJECTED; 3236 ctx->error = X509_V_ERR_OUT_OF_MEM; 3237 search = 0; 3238 continue; 3239 } 3240 3241 x = xtmp; 3242 ++ctx->num_untrusted; 3243 ss = cert_self_signed(xtmp); 3244 3245 /* 3246 * Check for DANE-TA trust of the topmost untrusted certificate. 3247 */ 3248 switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) { 3249 case X509_TRUST_TRUSTED: 3250 case X509_TRUST_REJECTED: 3251 search = 0; 3252 continue; 3253 } 3254 } 3255 } 3256 sk_X509_free(sktmp); 3257 3258 /* 3259 * Last chance to make a trusted chain, either bare DANE-TA public-key 3260 * signers, or else direct leaf PKIX trust. 3261 */ 3262 num = sk_X509_num(ctx->chain); 3263 if (num <= depth) { 3264 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane)) 3265 trust = check_dane_pkeys(ctx); 3266 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted) 3267 trust = check_trust(ctx, num); 3268 } 3269 3270 switch (trust) { 3271 case X509_TRUST_TRUSTED: 3272 return 1; 3273 case X509_TRUST_REJECTED: 3274 /* Callback already issued */ 3275 return 0; 3276 case X509_TRUST_UNTRUSTED: 3277 default: 3278 num = sk_X509_num(ctx->chain); 3279 if (num > depth) 3280 return verify_cb_cert(ctx, NULL, num-1, 3281 X509_V_ERR_CERT_CHAIN_TOO_LONG); 3282 if (DANETLS_ENABLED(dane) && 3283 (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0)) 3284 return verify_cb_cert(ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH); 3285 if (ss && sk_X509_num(ctx->chain) == 1) 3286 return verify_cb_cert(ctx, NULL, num-1, 3287 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT); 3288 if (ss) 3289 return verify_cb_cert(ctx, NULL, num-1, 3290 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN); 3291 if (ctx->num_untrusted < num) 3292 return verify_cb_cert(ctx, NULL, num-1, 3293 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT); 3294 return verify_cb_cert(ctx, NULL, num-1, 3295 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY); 3296 } 3297} 3298 3299static const int minbits_table[] = { 80, 112, 128, 192, 256 }; 3300static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table); 3301 3302/* 3303 * Check whether the public key of ``cert`` meets the security level of 3304 * ``ctx``. 3305 * 3306 * Returns 1 on success, 0 otherwise. 3307 */ 3308static int check_key_level(X509_STORE_CTX *ctx, X509 *cert) 3309{ 3310 EVP_PKEY *pkey = X509_get0_pubkey(cert); 3311 int level = ctx->param->auth_level; 3312 3313 /* 3314 * At security level zero, return without checking for a supported public 3315 * key type. Some engines support key types not understood outside the 3316 * engine, and we only need to understand the key when enforcing a security 3317 * floor. 3318 */ 3319 if (level <= 0) 3320 return 1; 3321 3322 /* Unsupported or malformed keys are not secure */ 3323 if (pkey == NULL) 3324 return 0; 3325 3326 if (level > NUM_AUTH_LEVELS) 3327 level = NUM_AUTH_LEVELS; 3328 3329 return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1]; 3330} 3331 3332/* 3333 * Check whether the public key of ``cert`` does not use explicit params 3334 * for an elliptic curve. 3335 * 3336 * Returns 1 on success, 0 if check fails, -1 for other errors. 3337 */ 3338static int check_curve(X509 *cert) 3339{ 3340#ifndef OPENSSL_NO_EC 3341 EVP_PKEY *pkey = X509_get0_pubkey(cert); 3342 3343 /* Unsupported or malformed key */ 3344 if (pkey == NULL) 3345 return -1; 3346 3347 if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) { 3348 int ret; 3349 3350 ret = EC_KEY_decoded_from_explicit_params(EVP_PKEY_get0_EC_KEY(pkey)); 3351 return ret < 0 ? ret : !ret; 3352 } 3353#endif 3354 3355 return 1; 3356} 3357 3358/* 3359 * Check whether the signature digest algorithm of ``cert`` meets the security 3360 * level of ``ctx``. Should not be checked for trust anchors (whether 3361 * self-signed or otherwise). 3362 * 3363 * Returns 1 on success, 0 otherwise. 3364 */ 3365static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert) 3366{ 3367 int secbits = -1; 3368 int level = ctx->param->auth_level; 3369 3370 if (level <= 0) 3371 return 1; 3372 if (level > NUM_AUTH_LEVELS) 3373 level = NUM_AUTH_LEVELS; 3374 3375 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL)) 3376 return 0; 3377 3378 return secbits >= minbits_table[level - 1]; 3379} 3380