1 /* 2 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <stdio.h> 11 #include <time.h> 12 #include <errno.h> 13 #include <limits.h> 14 15 #include "crypto/ctype.h" 16 #include "internal/cryptlib.h" 17 #include <openssl/crypto.h> 18 #include <openssl/buffer.h> 19 #include <openssl/evp.h> 20 #include <openssl/asn1.h> 21 #include <openssl/x509.h> 22 #include <openssl/x509v3.h> 23 #include <openssl/objects.h> 24 #include "internal/dane.h" 25 #include "crypto/x509.h" 26 #include "x509_local.h" 27 28 /* CRL score values */ 29 30 /* No unhandled critical extensions */ 31 32 #define CRL_SCORE_NOCRITICAL 0x100 33 34 /* certificate is within CRL scope */ 35 36 #define CRL_SCORE_SCOPE 0x080 37 38 /* CRL times valid */ 39 40 #define CRL_SCORE_TIME 0x040 41 42 /* Issuer name matches certificate */ 43 44 #define CRL_SCORE_ISSUER_NAME 0x020 45 46 /* If this score or above CRL is probably valid */ 47 48 #define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE) 49 50 /* CRL issuer is certificate issuer */ 51 52 #define CRL_SCORE_ISSUER_CERT 0x018 53 54 /* CRL issuer is on certificate path */ 55 56 #define CRL_SCORE_SAME_PATH 0x008 57 58 /* CRL issuer matches CRL AKID */ 59 60 #define CRL_SCORE_AKID 0x004 61 62 /* Have a delta CRL with valid times */ 63 64 #define CRL_SCORE_TIME_DELTA 0x002 65 66 static int build_chain(X509_STORE_CTX *ctx); 67 static int verify_chain(X509_STORE_CTX *ctx); 68 static int dane_verify(X509_STORE_CTX *ctx); 69 static int null_callback(int ok, X509_STORE_CTX *e); 70 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer); 71 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x); 72 static int check_chain_extensions(X509_STORE_CTX *ctx); 73 static int check_name_constraints(X509_STORE_CTX *ctx); 74 static int check_id(X509_STORE_CTX *ctx); 75 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted); 76 static int check_revocation(X509_STORE_CTX *ctx); 77 static int check_cert(X509_STORE_CTX *ctx); 78 static int check_policy(X509_STORE_CTX *ctx); 79 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x); 80 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth); 81 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert); 82 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert); 83 84 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 85 unsigned int *preasons, X509_CRL *crl, X509 *x); 86 static int get_crl_delta(X509_STORE_CTX *ctx, 87 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x); 88 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, 89 int *pcrl_score, X509_CRL *base, 90 STACK_OF(X509_CRL) *crls); 91 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer, 92 int *pcrl_score); 93 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 94 unsigned int *preasons); 95 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x); 96 static int check_crl_chain(X509_STORE_CTX *ctx, 97 STACK_OF(X509) *cert_path, 98 STACK_OF(X509) *crl_path); 99 100 static int internal_verify(X509_STORE_CTX *ctx); 101 102 static int null_callback(int ok, X509_STORE_CTX *e) 103 { 104 return ok; 105 } 106 107 /* Return 1 is a certificate is self signed */ 108 static int cert_self_signed(X509 *x) 109 { 110 if (X509_check_purpose(x, -1, 0) != 1) 111 return 0; 112 if (x->ex_flags & EXFLAG_SS) 113 return 1; 114 else 115 return 0; 116 } 117 118 /* Given a certificate try and find an exact match in the store */ 119 120 static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x) 121 { 122 STACK_OF(X509) *certs; 123 X509 *xtmp = NULL; 124 int i; 125 /* Lookup all certs with matching subject name */ 126 certs = ctx->lookup_certs(ctx, X509_get_subject_name(x)); 127 if (certs == NULL) 128 return NULL; 129 /* Look for exact match */ 130 for (i = 0; i < sk_X509_num(certs); i++) { 131 xtmp = sk_X509_value(certs, i); 132 if (!X509_cmp(xtmp, x)) 133 break; 134 } 135 if (i < sk_X509_num(certs)) 136 X509_up_ref(xtmp); 137 else 138 xtmp = NULL; 139 sk_X509_pop_free(certs, X509_free); 140 return xtmp; 141 } 142 143 /*- 144 * Inform the verify callback of an error. 145 * If B<x> is not NULL it is the error cert, otherwise use the chain cert at 146 * B<depth>. 147 * If B<err> is not X509_V_OK, that's the error value, otherwise leave 148 * unchanged (presumably set by the caller). 149 * 150 * Returns 0 to abort verification with an error, non-zero to continue. 151 */ 152 static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err) 153 { 154 ctx->error_depth = depth; 155 ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth); 156 if (err != X509_V_OK) 157 ctx->error = err; 158 return ctx->verify_cb(0, ctx); 159 } 160 161 /*- 162 * Inform the verify callback of an error, CRL-specific variant. Here, the 163 * error depth and certificate are already set, we just specify the error 164 * number. 165 * 166 * Returns 0 to abort verification with an error, non-zero to continue. 167 */ 168 static int verify_cb_crl(X509_STORE_CTX *ctx, int err) 169 { 170 ctx->error = err; 171 return ctx->verify_cb(0, ctx); 172 } 173 174 static int check_auth_level(X509_STORE_CTX *ctx) 175 { 176 int i; 177 int num = sk_X509_num(ctx->chain); 178 179 if (ctx->param->auth_level <= 0) 180 return 1; 181 182 for (i = 0; i < num; ++i) { 183 X509 *cert = sk_X509_value(ctx->chain, i); 184 185 /* 186 * We've already checked the security of the leaf key, so here we only 187 * check the security of issuer keys. 188 */ 189 if (i > 0 && !check_key_level(ctx, cert) && 190 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL) == 0) 191 return 0; 192 /* 193 * We also check the signature algorithm security of all certificates 194 * except those of the trust anchor at index num-1. 195 */ 196 if (i < num - 1 && !check_sig_level(ctx, cert) && 197 verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK) == 0) 198 return 0; 199 } 200 return 1; 201 } 202 203 static int verify_chain(X509_STORE_CTX *ctx) 204 { 205 int err; 206 int ok; 207 208 /* 209 * Before either returning with an error, or continuing with CRL checks, 210 * instantiate chain public key parameters. 211 */ 212 if ((ok = build_chain(ctx)) == 0 || 213 (ok = check_chain_extensions(ctx)) == 0 || 214 (ok = check_auth_level(ctx)) == 0 || 215 (ok = check_id(ctx)) == 0 || 1) 216 X509_get_pubkey_parameters(NULL, ctx->chain); 217 if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0) 218 return ok; 219 220 err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain, 221 ctx->param->flags); 222 if (err != X509_V_OK) { 223 if ((ok = verify_cb_cert(ctx, NULL, ctx->error_depth, err)) == 0) 224 return ok; 225 } 226 227 /* Verify chain signatures and expiration times */ 228 ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx); 229 if (!ok) 230 return ok; 231 232 if ((ok = check_name_constraints(ctx)) == 0) 233 return ok; 234 235 #ifndef OPENSSL_NO_RFC3779 236 /* RFC 3779 path validation, now that CRL check has been done */ 237 if ((ok = X509v3_asid_validate_path(ctx)) == 0) 238 return ok; 239 if ((ok = X509v3_addr_validate_path(ctx)) == 0) 240 return ok; 241 #endif 242 243 /* If we get this far evaluate policies */ 244 if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK) 245 ok = ctx->check_policy(ctx); 246 return ok; 247 } 248 249 int X509_verify_cert(X509_STORE_CTX *ctx) 250 { 251 SSL_DANE *dane = ctx->dane; 252 int ret; 253 254 if (ctx->cert == NULL) { 255 X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY); 256 ctx->error = X509_V_ERR_INVALID_CALL; 257 return -1; 258 } 259 260 if (ctx->chain != NULL) { 261 /* 262 * This X509_STORE_CTX has already been used to verify a cert. We 263 * cannot do another one. 264 */ 265 X509err(X509_F_X509_VERIFY_CERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 266 ctx->error = X509_V_ERR_INVALID_CALL; 267 return -1; 268 } 269 270 /* 271 * first we make sure the chain we are going to build is present and that 272 * the first entry is in place 273 */ 274 if (((ctx->chain = sk_X509_new_null()) == NULL) || 275 (!sk_X509_push(ctx->chain, ctx->cert))) { 276 X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE); 277 ctx->error = X509_V_ERR_OUT_OF_MEM; 278 return -1; 279 } 280 X509_up_ref(ctx->cert); 281 ctx->num_untrusted = 1; 282 283 /* If the peer's public key is too weak, we can stop early. */ 284 if (!check_key_level(ctx, ctx->cert) && 285 !verify_cb_cert(ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL)) 286 return 0; 287 288 if (DANETLS_ENABLED(dane)) 289 ret = dane_verify(ctx); 290 else 291 ret = verify_chain(ctx); 292 293 /* 294 * Safety-net. If we are returning an error, we must also set ctx->error, 295 * so that the chain is not considered verified should the error be ignored 296 * (e.g. TLS with SSL_VERIFY_NONE). 297 */ 298 if (ret <= 0 && ctx->error == X509_V_OK) 299 ctx->error = X509_V_ERR_UNSPECIFIED; 300 return ret; 301 } 302 303 /* 304 * Given a STACK_OF(X509) find the issuer of cert (if any) 305 */ 306 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x) 307 { 308 int i; 309 X509 *issuer, *rv = NULL; 310 311 for (i = 0; i < sk_X509_num(sk); i++) { 312 issuer = sk_X509_value(sk, i); 313 if (ctx->check_issued(ctx, x, issuer)) { 314 rv = issuer; 315 if (x509_check_cert_time(ctx, rv, -1)) 316 break; 317 } 318 } 319 return rv; 320 } 321 322 /* Given a possible certificate and issuer check them */ 323 324 static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer) 325 { 326 int ret; 327 if (x == issuer) 328 return cert_self_signed(x); 329 ret = X509_check_issued(issuer, x); 330 if (ret == X509_V_OK) { 331 int i; 332 X509 *ch; 333 /* Special case: single self signed certificate */ 334 if (cert_self_signed(x) && sk_X509_num(ctx->chain) == 1) 335 return 1; 336 for (i = 0; i < sk_X509_num(ctx->chain); i++) { 337 ch = sk_X509_value(ctx->chain, i); 338 if (ch == issuer || !X509_cmp(ch, issuer)) { 339 ret = X509_V_ERR_PATH_LOOP; 340 break; 341 } 342 } 343 } 344 345 return (ret == X509_V_OK); 346 } 347 348 /* Alternative lookup method: look from a STACK stored in other_ctx */ 349 350 static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x) 351 { 352 *issuer = find_issuer(ctx, ctx->other_ctx, x); 353 if (*issuer) { 354 X509_up_ref(*issuer); 355 return 1; 356 } else 357 return 0; 358 } 359 360 static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, X509_NAME *nm) 361 { 362 STACK_OF(X509) *sk = NULL; 363 X509 *x; 364 int i; 365 366 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) { 367 x = sk_X509_value(ctx->other_ctx, i); 368 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) { 369 if (sk == NULL) 370 sk = sk_X509_new_null(); 371 if (sk == NULL || sk_X509_push(sk, x) == 0) { 372 sk_X509_pop_free(sk, X509_free); 373 X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_MALLOC_FAILURE); 374 ctx->error = X509_V_ERR_OUT_OF_MEM; 375 return NULL; 376 } 377 X509_up_ref(x); 378 } 379 } 380 return sk; 381 } 382 383 /* 384 * Check EE or CA certificate purpose. For trusted certificates explicit local 385 * auxiliary trust can be used to override EKU-restrictions. 386 */ 387 static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth, 388 int must_be_ca) 389 { 390 int tr_ok = X509_TRUST_UNTRUSTED; 391 392 /* 393 * For trusted certificates we want to see whether any auxiliary trust 394 * settings trump the purpose constraints. 395 * 396 * This is complicated by the fact that the trust ordinals in 397 * ctx->param->trust are entirely independent of the purpose ordinals in 398 * ctx->param->purpose! 399 * 400 * What connects them is their mutual initialization via calls from 401 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets 402 * related values of both param->trust and param->purpose. It is however 403 * typically possible to infer associated trust values from a purpose value 404 * via the X509_PURPOSE API. 405 * 406 * Therefore, we can only check for trust overrides when the purpose we're 407 * checking is the same as ctx->param->purpose and ctx->param->trust is 408 * also set. 409 */ 410 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose) 411 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT); 412 413 switch (tr_ok) { 414 case X509_TRUST_TRUSTED: 415 return 1; 416 case X509_TRUST_REJECTED: 417 break; 418 default: 419 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) { 420 case 1: 421 return 1; 422 case 0: 423 break; 424 default: 425 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0) 426 return 1; 427 } 428 break; 429 } 430 431 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE); 432 } 433 434 /* 435 * Check a certificate chains extensions for consistency with the supplied 436 * purpose 437 */ 438 439 static int check_chain_extensions(X509_STORE_CTX *ctx) 440 { 441 int i, must_be_ca, plen = 0; 442 X509 *x; 443 int proxy_path_length = 0; 444 int purpose; 445 int allow_proxy_certs; 446 int num = sk_X509_num(ctx->chain); 447 448 /*- 449 * must_be_ca can have 1 of 3 values: 450 * -1: we accept both CA and non-CA certificates, to allow direct 451 * use of self-signed certificates (which are marked as CA). 452 * 0: we only accept non-CA certificates. This is currently not 453 * used, but the possibility is present for future extensions. 454 * 1: we only accept CA certificates. This is currently used for 455 * all certificates in the chain except the leaf certificate. 456 */ 457 must_be_ca = -1; 458 459 /* CRL path validation */ 460 if (ctx->parent) { 461 allow_proxy_certs = 0; 462 purpose = X509_PURPOSE_CRL_SIGN; 463 } else { 464 allow_proxy_certs = 465 ! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS); 466 purpose = ctx->param->purpose; 467 } 468 469 for (i = 0; i < num; i++) { 470 int ret; 471 x = sk_X509_value(ctx->chain, i); 472 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) 473 && (x->ex_flags & EXFLAG_CRITICAL)) { 474 if (!verify_cb_cert(ctx, x, i, 475 X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION)) 476 return 0; 477 } 478 if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) { 479 if (!verify_cb_cert(ctx, x, i, 480 X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED)) 481 return 0; 482 } 483 ret = X509_check_ca(x); 484 switch (must_be_ca) { 485 case -1: 486 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) 487 && (ret != 1) && (ret != 0)) { 488 ret = 0; 489 ctx->error = X509_V_ERR_INVALID_CA; 490 } else 491 ret = 1; 492 break; 493 case 0: 494 if (ret != 0) { 495 ret = 0; 496 ctx->error = X509_V_ERR_INVALID_NON_CA; 497 } else 498 ret = 1; 499 break; 500 default: 501 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */ 502 if ((ret == 0) 503 || ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT) 504 && (ret != 1))) { 505 ret = 0; 506 ctx->error = X509_V_ERR_INVALID_CA; 507 } else 508 ret = 1; 509 break; 510 } 511 if ((x->ex_flags & EXFLAG_CA) == 0 512 && x->ex_pathlen != -1 513 && (ctx->param->flags & X509_V_FLAG_X509_STRICT)) { 514 ctx->error = X509_V_ERR_INVALID_EXTENSION; 515 ret = 0; 516 } 517 if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK)) 518 return 0; 519 /* check_purpose() makes the callback as needed */ 520 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca)) 521 return 0; 522 /* Check pathlen */ 523 if ((i > 1) && (x->ex_pathlen != -1) 524 && (plen > (x->ex_pathlen + proxy_path_length))) { 525 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED)) 526 return 0; 527 } 528 /* Increment path length if not a self issued intermediate CA */ 529 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0) 530 plen++; 531 /* 532 * If this certificate is a proxy certificate, the next certificate 533 * must be another proxy certificate or a EE certificate. If not, 534 * the next certificate must be a CA certificate. 535 */ 536 if (x->ex_flags & EXFLAG_PROXY) { 537 /* 538 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint 539 * is less than max_path_length, the former should be copied to 540 * the latter, and 4.1.4 (a) stipulates that max_path_length 541 * should be verified to be larger than zero and decrement it. 542 * 543 * Because we're checking the certs in the reverse order, we start 544 * with verifying that proxy_path_length isn't larger than pcPLC, 545 * and copy the latter to the former if it is, and finally, 546 * increment proxy_path_length. 547 */ 548 if (x->ex_pcpathlen != -1) { 549 if (proxy_path_length > x->ex_pcpathlen) { 550 if (!verify_cb_cert(ctx, x, i, 551 X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED)) 552 return 0; 553 } 554 proxy_path_length = x->ex_pcpathlen; 555 } 556 proxy_path_length++; 557 must_be_ca = 0; 558 } else 559 must_be_ca = 1; 560 } 561 return 1; 562 } 563 564 static int has_san_id(X509 *x, int gtype) 565 { 566 int i; 567 int ret = 0; 568 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); 569 570 if (gs == NULL) 571 return 0; 572 573 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) { 574 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i); 575 576 if (g->type == gtype) { 577 ret = 1; 578 break; 579 } 580 } 581 GENERAL_NAMES_free(gs); 582 return ret; 583 } 584 585 static int check_name_constraints(X509_STORE_CTX *ctx) 586 { 587 int i; 588 589 /* Check name constraints for all certificates */ 590 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) { 591 X509 *x = sk_X509_value(ctx->chain, i); 592 int j; 593 594 /* Ignore self issued certs unless last in chain */ 595 if (i && (x->ex_flags & EXFLAG_SI)) 596 continue; 597 598 /* 599 * Proxy certificates policy has an extra constraint, where the 600 * certificate subject MUST be the issuer with a single CN entry 601 * added. 602 * (RFC 3820: 3.4, 4.1.3 (a)(4)) 603 */ 604 if (x->ex_flags & EXFLAG_PROXY) { 605 X509_NAME *tmpsubject = X509_get_subject_name(x); 606 X509_NAME *tmpissuer = X509_get_issuer_name(x); 607 X509_NAME_ENTRY *tmpentry = NULL; 608 int last_object_nid = 0; 609 int err = X509_V_OK; 610 int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1; 611 612 /* Check that there are at least two RDNs */ 613 if (last_object_loc < 1) { 614 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 615 goto proxy_name_done; 616 } 617 618 /* 619 * Check that there is exactly one more RDN in subject as 620 * there is in issuer. 621 */ 622 if (X509_NAME_entry_count(tmpsubject) 623 != X509_NAME_entry_count(tmpissuer) + 1) { 624 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 625 goto proxy_name_done; 626 } 627 628 /* 629 * Check that the last subject component isn't part of a 630 * multivalued RDN 631 */ 632 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, 633 last_object_loc)) 634 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, 635 last_object_loc - 1))) { 636 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 637 goto proxy_name_done; 638 } 639 640 /* 641 * Check that the last subject RDN is a commonName, and that 642 * all the previous RDNs match the issuer exactly 643 */ 644 tmpsubject = X509_NAME_dup(tmpsubject); 645 if (tmpsubject == NULL) { 646 X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE); 647 ctx->error = X509_V_ERR_OUT_OF_MEM; 648 return 0; 649 } 650 651 tmpentry = 652 X509_NAME_delete_entry(tmpsubject, last_object_loc); 653 last_object_nid = 654 OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry)); 655 656 if (last_object_nid != NID_commonName 657 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) { 658 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 659 } 660 661 X509_NAME_ENTRY_free(tmpentry); 662 X509_NAME_free(tmpsubject); 663 664 proxy_name_done: 665 if (err != X509_V_OK 666 && !verify_cb_cert(ctx, x, i, err)) 667 return 0; 668 } 669 670 /* 671 * Check against constraints for all certificates higher in chain 672 * including trust anchor. Trust anchor not strictly speaking needed 673 * but if it includes constraints it is to be assumed it expects them 674 * to be obeyed. 675 */ 676 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) { 677 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc; 678 679 if (nc) { 680 int rv = NAME_CONSTRAINTS_check(x, nc); 681 682 /* If EE certificate check commonName too */ 683 if (rv == X509_V_OK && i == 0 684 && (ctx->param->hostflags 685 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0 686 && ((ctx->param->hostflags 687 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0 688 || !has_san_id(x, GEN_DNS))) 689 rv = NAME_CONSTRAINTS_check_CN(x, nc); 690 691 switch (rv) { 692 case X509_V_OK: 693 break; 694 case X509_V_ERR_OUT_OF_MEM: 695 return 0; 696 default: 697 if (!verify_cb_cert(ctx, x, i, rv)) 698 return 0; 699 break; 700 } 701 } 702 } 703 } 704 return 1; 705 } 706 707 static int check_id_error(X509_STORE_CTX *ctx, int errcode) 708 { 709 return verify_cb_cert(ctx, ctx->cert, 0, errcode); 710 } 711 712 static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm) 713 { 714 int i; 715 int n = sk_OPENSSL_STRING_num(vpm->hosts); 716 char *name; 717 718 if (vpm->peername != NULL) { 719 OPENSSL_free(vpm->peername); 720 vpm->peername = NULL; 721 } 722 for (i = 0; i < n; ++i) { 723 name = sk_OPENSSL_STRING_value(vpm->hosts, i); 724 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0) 725 return 1; 726 } 727 return n == 0; 728 } 729 730 static int check_id(X509_STORE_CTX *ctx) 731 { 732 X509_VERIFY_PARAM *vpm = ctx->param; 733 X509 *x = ctx->cert; 734 if (vpm->hosts && check_hosts(x, vpm) <= 0) { 735 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH)) 736 return 0; 737 } 738 if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) { 739 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH)) 740 return 0; 741 } 742 if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) { 743 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH)) 744 return 0; 745 } 746 return 1; 747 } 748 749 static int check_trust(X509_STORE_CTX *ctx, int num_untrusted) 750 { 751 int i; 752 X509 *x = NULL; 753 X509 *mx; 754 SSL_DANE *dane = ctx->dane; 755 int num = sk_X509_num(ctx->chain); 756 int trust; 757 758 /* 759 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2) 760 * match, we're done, otherwise we'll merely record the match depth. 761 */ 762 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) { 763 switch (trust = check_dane_issuer(ctx, num_untrusted)) { 764 case X509_TRUST_TRUSTED: 765 case X509_TRUST_REJECTED: 766 return trust; 767 } 768 } 769 770 /* 771 * Check trusted certificates in chain at depth num_untrusted and up. 772 * Note, that depths 0..num_untrusted-1 may also contain trusted 773 * certificates, but the caller is expected to have already checked those, 774 * and wants to incrementally check just any added since. 775 */ 776 for (i = num_untrusted; i < num; i++) { 777 x = sk_X509_value(ctx->chain, i); 778 trust = X509_check_trust(x, ctx->param->trust, 0); 779 /* If explicitly trusted return trusted */ 780 if (trust == X509_TRUST_TRUSTED) 781 goto trusted; 782 if (trust == X509_TRUST_REJECTED) 783 goto rejected; 784 } 785 786 /* 787 * If we are looking at a trusted certificate, and accept partial chains, 788 * the chain is PKIX trusted. 789 */ 790 if (num_untrusted < num) { 791 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) 792 goto trusted; 793 return X509_TRUST_UNTRUSTED; 794 } 795 796 if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) { 797 /* 798 * Last-resort call with no new trusted certificates, check the leaf 799 * for a direct trust store match. 800 */ 801 i = 0; 802 x = sk_X509_value(ctx->chain, i); 803 mx = lookup_cert_match(ctx, x); 804 if (!mx) 805 return X509_TRUST_UNTRUSTED; 806 807 /* 808 * Check explicit auxiliary trust/reject settings. If none are set, 809 * we'll accept X509_TRUST_UNTRUSTED when not self-signed. 810 */ 811 trust = X509_check_trust(mx, ctx->param->trust, 0); 812 if (trust == X509_TRUST_REJECTED) { 813 X509_free(mx); 814 goto rejected; 815 } 816 817 /* Replace leaf with trusted match */ 818 (void) sk_X509_set(ctx->chain, 0, mx); 819 X509_free(x); 820 ctx->num_untrusted = 0; 821 goto trusted; 822 } 823 824 /* 825 * If no trusted certs in chain at all return untrusted and allow 826 * standard (no issuer cert) etc errors to be indicated. 827 */ 828 return X509_TRUST_UNTRUSTED; 829 830 rejected: 831 if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED)) 832 return X509_TRUST_REJECTED; 833 return X509_TRUST_UNTRUSTED; 834 835 trusted: 836 if (!DANETLS_ENABLED(dane)) 837 return X509_TRUST_TRUSTED; 838 if (dane->pdpth < 0) 839 dane->pdpth = num_untrusted; 840 /* With DANE, PKIX alone is not trusted until we have both */ 841 if (dane->mdpth >= 0) 842 return X509_TRUST_TRUSTED; 843 return X509_TRUST_UNTRUSTED; 844 } 845 846 static int check_revocation(X509_STORE_CTX *ctx) 847 { 848 int i = 0, last = 0, ok = 0; 849 if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK)) 850 return 1; 851 if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL) 852 last = sk_X509_num(ctx->chain) - 1; 853 else { 854 /* If checking CRL paths this isn't the EE certificate */ 855 if (ctx->parent) 856 return 1; 857 last = 0; 858 } 859 for (i = 0; i <= last; i++) { 860 ctx->error_depth = i; 861 ok = check_cert(ctx); 862 if (!ok) 863 return ok; 864 } 865 return 1; 866 } 867 868 static int check_cert(X509_STORE_CTX *ctx) 869 { 870 X509_CRL *crl = NULL, *dcrl = NULL; 871 int ok = 0; 872 int cnum = ctx->error_depth; 873 X509 *x = sk_X509_value(ctx->chain, cnum); 874 875 ctx->current_cert = x; 876 ctx->current_issuer = NULL; 877 ctx->current_crl_score = 0; 878 ctx->current_reasons = 0; 879 880 if (x->ex_flags & EXFLAG_PROXY) 881 return 1; 882 883 while (ctx->current_reasons != CRLDP_ALL_REASONS) { 884 unsigned int last_reasons = ctx->current_reasons; 885 886 /* Try to retrieve relevant CRL */ 887 if (ctx->get_crl) 888 ok = ctx->get_crl(ctx, &crl, x); 889 else 890 ok = get_crl_delta(ctx, &crl, &dcrl, x); 891 /* 892 * If error looking up CRL, nothing we can do except notify callback 893 */ 894 if (!ok) { 895 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 896 goto done; 897 } 898 ctx->current_crl = crl; 899 ok = ctx->check_crl(ctx, crl); 900 if (!ok) 901 goto done; 902 903 if (dcrl) { 904 ok = ctx->check_crl(ctx, dcrl); 905 if (!ok) 906 goto done; 907 ok = ctx->cert_crl(ctx, dcrl, x); 908 if (!ok) 909 goto done; 910 } else 911 ok = 1; 912 913 /* Don't look in full CRL if delta reason is removefromCRL */ 914 if (ok != 2) { 915 ok = ctx->cert_crl(ctx, crl, x); 916 if (!ok) 917 goto done; 918 } 919 920 X509_CRL_free(crl); 921 X509_CRL_free(dcrl); 922 crl = NULL; 923 dcrl = NULL; 924 /* 925 * If reasons not updated we won't get anywhere by another iteration, 926 * so exit loop. 927 */ 928 if (last_reasons == ctx->current_reasons) { 929 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 930 goto done; 931 } 932 } 933 done: 934 X509_CRL_free(crl); 935 X509_CRL_free(dcrl); 936 937 ctx->current_crl = NULL; 938 return ok; 939 } 940 941 /* Check CRL times against values in X509_STORE_CTX */ 942 943 static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify) 944 { 945 time_t *ptime; 946 int i; 947 948 if (notify) 949 ctx->current_crl = crl; 950 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) 951 ptime = &ctx->param->check_time; 952 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) 953 return 1; 954 else 955 ptime = NULL; 956 957 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime); 958 if (i == 0) { 959 if (!notify) 960 return 0; 961 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD)) 962 return 0; 963 } 964 965 if (i > 0) { 966 if (!notify) 967 return 0; 968 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID)) 969 return 0; 970 } 971 972 if (X509_CRL_get0_nextUpdate(crl)) { 973 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime); 974 975 if (i == 0) { 976 if (!notify) 977 return 0; 978 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD)) 979 return 0; 980 } 981 /* Ignore expiry of base CRL is delta is valid */ 982 if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) { 983 if (!notify) 984 return 0; 985 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED)) 986 return 0; 987 } 988 } 989 990 if (notify) 991 ctx->current_crl = NULL; 992 993 return 1; 994 } 995 996 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, 997 X509 **pissuer, int *pscore, unsigned int *preasons, 998 STACK_OF(X509_CRL) *crls) 999 { 1000 int i, crl_score, best_score = *pscore; 1001 unsigned int reasons, best_reasons = 0; 1002 X509 *x = ctx->current_cert; 1003 X509_CRL *crl, *best_crl = NULL; 1004 X509 *crl_issuer = NULL, *best_crl_issuer = NULL; 1005 1006 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1007 crl = sk_X509_CRL_value(crls, i); 1008 reasons = *preasons; 1009 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x); 1010 if (crl_score < best_score || crl_score == 0) 1011 continue; 1012 /* If current CRL is equivalent use it if it is newer */ 1013 if (crl_score == best_score && best_crl != NULL) { 1014 int day, sec; 1015 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl), 1016 X509_CRL_get0_lastUpdate(crl)) == 0) 1017 continue; 1018 /* 1019 * ASN1_TIME_diff never returns inconsistent signs for |day| 1020 * and |sec|. 1021 */ 1022 if (day <= 0 && sec <= 0) 1023 continue; 1024 } 1025 best_crl = crl; 1026 best_crl_issuer = crl_issuer; 1027 best_score = crl_score; 1028 best_reasons = reasons; 1029 } 1030 1031 if (best_crl) { 1032 X509_CRL_free(*pcrl); 1033 *pcrl = best_crl; 1034 *pissuer = best_crl_issuer; 1035 *pscore = best_score; 1036 *preasons = best_reasons; 1037 X509_CRL_up_ref(best_crl); 1038 X509_CRL_free(*pdcrl); 1039 *pdcrl = NULL; 1040 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls); 1041 } 1042 1043 if (best_score >= CRL_SCORE_VALID) 1044 return 1; 1045 1046 return 0; 1047 } 1048 1049 /* 1050 * Compare two CRL extensions for delta checking purposes. They should be 1051 * both present or both absent. If both present all fields must be identical. 1052 */ 1053 1054 static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid) 1055 { 1056 ASN1_OCTET_STRING *exta, *extb; 1057 int i; 1058 i = X509_CRL_get_ext_by_NID(a, nid, -1); 1059 if (i >= 0) { 1060 /* Can't have multiple occurrences */ 1061 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1) 1062 return 0; 1063 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i)); 1064 } else 1065 exta = NULL; 1066 1067 i = X509_CRL_get_ext_by_NID(b, nid, -1); 1068 1069 if (i >= 0) { 1070 1071 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1) 1072 return 0; 1073 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i)); 1074 } else 1075 extb = NULL; 1076 1077 if (!exta && !extb) 1078 return 1; 1079 1080 if (!exta || !extb) 1081 return 0; 1082 1083 if (ASN1_OCTET_STRING_cmp(exta, extb)) 1084 return 0; 1085 1086 return 1; 1087 } 1088 1089 /* See if a base and delta are compatible */ 1090 1091 static int check_delta_base(X509_CRL *delta, X509_CRL *base) 1092 { 1093 /* Delta CRL must be a delta */ 1094 if (!delta->base_crl_number) 1095 return 0; 1096 /* Base must have a CRL number */ 1097 if (!base->crl_number) 1098 return 0; 1099 /* Issuer names must match */ 1100 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta))) 1101 return 0; 1102 /* AKID and IDP must match */ 1103 if (!crl_extension_match(delta, base, NID_authority_key_identifier)) 1104 return 0; 1105 if (!crl_extension_match(delta, base, NID_issuing_distribution_point)) 1106 return 0; 1107 /* Delta CRL base number must not exceed Full CRL number. */ 1108 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0) 1109 return 0; 1110 /* Delta CRL number must exceed full CRL number */ 1111 if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0) 1112 return 1; 1113 return 0; 1114 } 1115 1116 /* 1117 * For a given base CRL find a delta... maybe extend to delta scoring or 1118 * retrieve a chain of deltas... 1119 */ 1120 1121 static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore, 1122 X509_CRL *base, STACK_OF(X509_CRL) *crls) 1123 { 1124 X509_CRL *delta; 1125 int i; 1126 if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS)) 1127 return; 1128 if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST)) 1129 return; 1130 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1131 delta = sk_X509_CRL_value(crls, i); 1132 if (check_delta_base(delta, base)) { 1133 if (check_crl_time(ctx, delta, 0)) 1134 *pscore |= CRL_SCORE_TIME_DELTA; 1135 X509_CRL_up_ref(delta); 1136 *dcrl = delta; 1137 return; 1138 } 1139 } 1140 *dcrl = NULL; 1141 } 1142 1143 /* 1144 * For a given CRL return how suitable it is for the supplied certificate 1145 * 'x'. The return value is a mask of several criteria. If the issuer is not 1146 * the certificate issuer this is returned in *pissuer. The reasons mask is 1147 * also used to determine if the CRL is suitable: if no new reasons the CRL 1148 * is rejected, otherwise reasons is updated. 1149 */ 1150 1151 static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 1152 unsigned int *preasons, X509_CRL *crl, X509 *x) 1153 { 1154 1155 int crl_score = 0; 1156 unsigned int tmp_reasons = *preasons, crl_reasons; 1157 1158 /* First see if we can reject CRL straight away */ 1159 1160 /* Invalid IDP cannot be processed */ 1161 if (crl->idp_flags & IDP_INVALID) 1162 return 0; 1163 /* Reason codes or indirect CRLs need extended CRL support */ 1164 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) { 1165 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS)) 1166 return 0; 1167 } else if (crl->idp_flags & IDP_REASONS) { 1168 /* If no new reasons reject */ 1169 if (!(crl->idp_reasons & ~tmp_reasons)) 1170 return 0; 1171 } 1172 /* Don't process deltas at this stage */ 1173 else if (crl->base_crl_number) 1174 return 0; 1175 /* If issuer name doesn't match certificate need indirect CRL */ 1176 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) { 1177 if (!(crl->idp_flags & IDP_INDIRECT)) 1178 return 0; 1179 } else 1180 crl_score |= CRL_SCORE_ISSUER_NAME; 1181 1182 if (!(crl->flags & EXFLAG_CRITICAL)) 1183 crl_score |= CRL_SCORE_NOCRITICAL; 1184 1185 /* Check expiry */ 1186 if (check_crl_time(ctx, crl, 0)) 1187 crl_score |= CRL_SCORE_TIME; 1188 1189 /* Check authority key ID and locate certificate issuer */ 1190 crl_akid_check(ctx, crl, pissuer, &crl_score); 1191 1192 /* If we can't locate certificate issuer at this point forget it */ 1193 1194 if (!(crl_score & CRL_SCORE_AKID)) 1195 return 0; 1196 1197 /* Check cert for matching CRL distribution points */ 1198 1199 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) { 1200 /* If no new reasons reject */ 1201 if (!(crl_reasons & ~tmp_reasons)) 1202 return 0; 1203 tmp_reasons |= crl_reasons; 1204 crl_score |= CRL_SCORE_SCOPE; 1205 } 1206 1207 *preasons = tmp_reasons; 1208 1209 return crl_score; 1210 1211 } 1212 1213 static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, 1214 X509 **pissuer, int *pcrl_score) 1215 { 1216 X509 *crl_issuer = NULL; 1217 X509_NAME *cnm = X509_CRL_get_issuer(crl); 1218 int cidx = ctx->error_depth; 1219 int i; 1220 1221 if (cidx != sk_X509_num(ctx->chain) - 1) 1222 cidx++; 1223 1224 crl_issuer = sk_X509_value(ctx->chain, cidx); 1225 1226 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1227 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) { 1228 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT; 1229 *pissuer = crl_issuer; 1230 return; 1231 } 1232 } 1233 1234 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) { 1235 crl_issuer = sk_X509_value(ctx->chain, cidx); 1236 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) 1237 continue; 1238 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1239 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH; 1240 *pissuer = crl_issuer; 1241 return; 1242 } 1243 } 1244 1245 /* Anything else needs extended CRL support */ 1246 1247 if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) 1248 return; 1249 1250 /* 1251 * Otherwise the CRL issuer is not on the path. Look for it in the set of 1252 * untrusted certificates. 1253 */ 1254 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) { 1255 crl_issuer = sk_X509_value(ctx->untrusted, i); 1256 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) 1257 continue; 1258 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1259 *pissuer = crl_issuer; 1260 *pcrl_score |= CRL_SCORE_AKID; 1261 return; 1262 } 1263 } 1264 } 1265 1266 /* 1267 * Check the path of a CRL issuer certificate. This creates a new 1268 * X509_STORE_CTX and populates it with most of the parameters from the 1269 * parent. This could be optimised somewhat since a lot of path checking will 1270 * be duplicated by the parent, but this will rarely be used in practice. 1271 */ 1272 1273 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x) 1274 { 1275 X509_STORE_CTX crl_ctx; 1276 int ret; 1277 1278 /* Don't allow recursive CRL path validation */ 1279 if (ctx->parent) 1280 return 0; 1281 if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted)) 1282 return -1; 1283 1284 crl_ctx.crls = ctx->crls; 1285 /* Copy verify params across */ 1286 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param); 1287 1288 crl_ctx.parent = ctx; 1289 crl_ctx.verify_cb = ctx->verify_cb; 1290 1291 /* Verify CRL issuer */ 1292 ret = X509_verify_cert(&crl_ctx); 1293 if (ret <= 0) 1294 goto err; 1295 1296 /* Check chain is acceptable */ 1297 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain); 1298 err: 1299 X509_STORE_CTX_cleanup(&crl_ctx); 1300 return ret; 1301 } 1302 1303 /* 1304 * RFC3280 says nothing about the relationship between CRL path and 1305 * certificate path, which could lead to situations where a certificate could 1306 * be revoked or validated by a CA not authorised to do so. RFC5280 is more 1307 * strict and states that the two paths must end in the same trust anchor, 1308 * though some discussions remain... until this is resolved we use the 1309 * RFC5280 version 1310 */ 1311 1312 static int check_crl_chain(X509_STORE_CTX *ctx, 1313 STACK_OF(X509) *cert_path, 1314 STACK_OF(X509) *crl_path) 1315 { 1316 X509 *cert_ta, *crl_ta; 1317 cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1); 1318 crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1); 1319 if (!X509_cmp(cert_ta, crl_ta)) 1320 return 1; 1321 return 0; 1322 } 1323 1324 /*- 1325 * Check for match between two dist point names: three separate cases. 1326 * 1. Both are relative names and compare X509_NAME types. 1327 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES. 1328 * 3. Both are full names and compare two GENERAL_NAMES. 1329 * 4. One is NULL: automatic match. 1330 */ 1331 1332 static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b) 1333 { 1334 X509_NAME *nm = NULL; 1335 GENERAL_NAMES *gens = NULL; 1336 GENERAL_NAME *gena, *genb; 1337 int i, j; 1338 if (!a || !b) 1339 return 1; 1340 if (a->type == 1) { 1341 if (!a->dpname) 1342 return 0; 1343 /* Case 1: two X509_NAME */ 1344 if (b->type == 1) { 1345 if (!b->dpname) 1346 return 0; 1347 if (!X509_NAME_cmp(a->dpname, b->dpname)) 1348 return 1; 1349 else 1350 return 0; 1351 } 1352 /* Case 2: set name and GENERAL_NAMES appropriately */ 1353 nm = a->dpname; 1354 gens = b->name.fullname; 1355 } else if (b->type == 1) { 1356 if (!b->dpname) 1357 return 0; 1358 /* Case 2: set name and GENERAL_NAMES appropriately */ 1359 gens = a->name.fullname; 1360 nm = b->dpname; 1361 } 1362 1363 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */ 1364 if (nm) { 1365 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 1366 gena = sk_GENERAL_NAME_value(gens, i); 1367 if (gena->type != GEN_DIRNAME) 1368 continue; 1369 if (!X509_NAME_cmp(nm, gena->d.directoryName)) 1370 return 1; 1371 } 1372 return 0; 1373 } 1374 1375 /* Else case 3: two GENERAL_NAMES */ 1376 1377 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) { 1378 gena = sk_GENERAL_NAME_value(a->name.fullname, i); 1379 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) { 1380 genb = sk_GENERAL_NAME_value(b->name.fullname, j); 1381 if (!GENERAL_NAME_cmp(gena, genb)) 1382 return 1; 1383 } 1384 } 1385 1386 return 0; 1387 1388 } 1389 1390 static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score) 1391 { 1392 int i; 1393 X509_NAME *nm = X509_CRL_get_issuer(crl); 1394 /* If no CRLissuer return is successful iff don't need a match */ 1395 if (!dp->CRLissuer) 1396 return ! !(crl_score & CRL_SCORE_ISSUER_NAME); 1397 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { 1398 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 1399 if (gen->type != GEN_DIRNAME) 1400 continue; 1401 if (!X509_NAME_cmp(gen->d.directoryName, nm)) 1402 return 1; 1403 } 1404 return 0; 1405 } 1406 1407 /* Check CRLDP and IDP */ 1408 1409 static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 1410 unsigned int *preasons) 1411 { 1412 int i; 1413 if (crl->idp_flags & IDP_ONLYATTR) 1414 return 0; 1415 if (x->ex_flags & EXFLAG_CA) { 1416 if (crl->idp_flags & IDP_ONLYUSER) 1417 return 0; 1418 } else { 1419 if (crl->idp_flags & IDP_ONLYCA) 1420 return 0; 1421 } 1422 *preasons = crl->idp_reasons; 1423 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) { 1424 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i); 1425 if (crldp_check_crlissuer(dp, crl, crl_score)) { 1426 if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) { 1427 *preasons &= dp->dp_reasons; 1428 return 1; 1429 } 1430 } 1431 } 1432 if ((!crl->idp || !crl->idp->distpoint) 1433 && (crl_score & CRL_SCORE_ISSUER_NAME)) 1434 return 1; 1435 return 0; 1436 } 1437 1438 /* 1439 * Retrieve CRL corresponding to current certificate. If deltas enabled try 1440 * to find a delta CRL too 1441 */ 1442 1443 static int get_crl_delta(X509_STORE_CTX *ctx, 1444 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x) 1445 { 1446 int ok; 1447 X509 *issuer = NULL; 1448 int crl_score = 0; 1449 unsigned int reasons; 1450 X509_CRL *crl = NULL, *dcrl = NULL; 1451 STACK_OF(X509_CRL) *skcrl; 1452 X509_NAME *nm = X509_get_issuer_name(x); 1453 1454 reasons = ctx->current_reasons; 1455 ok = get_crl_sk(ctx, &crl, &dcrl, 1456 &issuer, &crl_score, &reasons, ctx->crls); 1457 if (ok) 1458 goto done; 1459 1460 /* Lookup CRLs from store */ 1461 1462 skcrl = ctx->lookup_crls(ctx, nm); 1463 1464 /* If no CRLs found and a near match from get_crl_sk use that */ 1465 if (!skcrl && crl) 1466 goto done; 1467 1468 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl); 1469 1470 sk_X509_CRL_pop_free(skcrl, X509_CRL_free); 1471 1472 done: 1473 /* If we got any kind of CRL use it and return success */ 1474 if (crl) { 1475 ctx->current_issuer = issuer; 1476 ctx->current_crl_score = crl_score; 1477 ctx->current_reasons = reasons; 1478 *pcrl = crl; 1479 *pdcrl = dcrl; 1480 return 1; 1481 } 1482 return 0; 1483 } 1484 1485 /* Check CRL validity */ 1486 static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl) 1487 { 1488 X509 *issuer = NULL; 1489 EVP_PKEY *ikey = NULL; 1490 int cnum = ctx->error_depth; 1491 int chnum = sk_X509_num(ctx->chain) - 1; 1492 1493 /* if we have an alternative CRL issuer cert use that */ 1494 if (ctx->current_issuer) 1495 issuer = ctx->current_issuer; 1496 /* 1497 * Else find CRL issuer: if not last certificate then issuer is next 1498 * certificate in chain. 1499 */ 1500 else if (cnum < chnum) 1501 issuer = sk_X509_value(ctx->chain, cnum + 1); 1502 else { 1503 issuer = sk_X509_value(ctx->chain, chnum); 1504 /* If not self signed, can't check signature */ 1505 if (!ctx->check_issued(ctx, issuer, issuer) && 1506 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER)) 1507 return 0; 1508 } 1509 1510 if (issuer == NULL) 1511 return 1; 1512 1513 /* 1514 * Skip most tests for deltas because they have already been done 1515 */ 1516 if (!crl->base_crl_number) { 1517 /* Check for cRLSign bit if keyUsage present */ 1518 if ((issuer->ex_flags & EXFLAG_KUSAGE) && 1519 !(issuer->ex_kusage & KU_CRL_SIGN) && 1520 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN)) 1521 return 0; 1522 1523 if (!(ctx->current_crl_score & CRL_SCORE_SCOPE) && 1524 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE)) 1525 return 0; 1526 1527 if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH) && 1528 check_crl_path(ctx, ctx->current_issuer) <= 0 && 1529 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR)) 1530 return 0; 1531 1532 if ((crl->idp_flags & IDP_INVALID) && 1533 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION)) 1534 return 0; 1535 } 1536 1537 if (!(ctx->current_crl_score & CRL_SCORE_TIME) && 1538 !check_crl_time(ctx, crl, 1)) 1539 return 0; 1540 1541 /* Attempt to get issuer certificate public key */ 1542 ikey = X509_get0_pubkey(issuer); 1543 1544 if (!ikey && 1545 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY)) 1546 return 0; 1547 1548 if (ikey) { 1549 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags); 1550 1551 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv)) 1552 return 0; 1553 /* Verify CRL signature */ 1554 if (X509_CRL_verify(crl, ikey) <= 0 && 1555 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE)) 1556 return 0; 1557 } 1558 return 1; 1559 } 1560 1561 /* Check certificate against CRL */ 1562 static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x) 1563 { 1564 X509_REVOKED *rev; 1565 1566 /* 1567 * The rules changed for this... previously if a CRL contained unhandled 1568 * critical extensions it could still be used to indicate a certificate 1569 * was revoked. This has since been changed since critical extensions can 1570 * change the meaning of CRL entries. 1571 */ 1572 if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) 1573 && (crl->flags & EXFLAG_CRITICAL) && 1574 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION)) 1575 return 0; 1576 /* 1577 * Look for serial number of certificate in CRL. If found, make sure 1578 * reason is not removeFromCRL. 1579 */ 1580 if (X509_CRL_get0_by_cert(crl, &rev, x)) { 1581 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL) 1582 return 2; 1583 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED)) 1584 return 0; 1585 } 1586 1587 return 1; 1588 } 1589 1590 static int check_policy(X509_STORE_CTX *ctx) 1591 { 1592 int ret; 1593 1594 if (ctx->parent) 1595 return 1; 1596 /* 1597 * With DANE, the trust anchor might be a bare public key, not a 1598 * certificate! In that case our chain does not have the trust anchor 1599 * certificate as a top-most element. This comports well with RFC5280 1600 * chain verification, since there too, the trust anchor is not part of the 1601 * chain to be verified. In particular, X509_policy_check() does not look 1602 * at the TA cert, but assumes that it is present as the top-most chain 1603 * element. We therefore temporarily push a NULL cert onto the chain if it 1604 * was verified via a bare public key, and pop it off right after the 1605 * X509_policy_check() call. 1606 */ 1607 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) { 1608 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE); 1609 ctx->error = X509_V_ERR_OUT_OF_MEM; 1610 return 0; 1611 } 1612 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain, 1613 ctx->param->policies, ctx->param->flags); 1614 if (ctx->bare_ta_signed) 1615 sk_X509_pop(ctx->chain); 1616 1617 if (ret == X509_PCY_TREE_INTERNAL) { 1618 X509err(X509_F_CHECK_POLICY, ERR_R_MALLOC_FAILURE); 1619 ctx->error = X509_V_ERR_OUT_OF_MEM; 1620 return 0; 1621 } 1622 /* Invalid or inconsistent extensions */ 1623 if (ret == X509_PCY_TREE_INVALID) { 1624 int i; 1625 1626 /* Locate certificates with bad extensions and notify callback. */ 1627 for (i = 1; i < sk_X509_num(ctx->chain); i++) { 1628 X509 *x = sk_X509_value(ctx->chain, i); 1629 1630 if (!(x->ex_flags & EXFLAG_INVALID_POLICY)) 1631 continue; 1632 if (!verify_cb_cert(ctx, x, i, 1633 X509_V_ERR_INVALID_POLICY_EXTENSION)) 1634 return 0; 1635 } 1636 return 1; 1637 } 1638 if (ret == X509_PCY_TREE_FAILURE) { 1639 ctx->current_cert = NULL; 1640 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY; 1641 return ctx->verify_cb(0, ctx); 1642 } 1643 if (ret != X509_PCY_TREE_VALID) { 1644 X509err(X509_F_CHECK_POLICY, ERR_R_INTERNAL_ERROR); 1645 return 0; 1646 } 1647 1648 if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) { 1649 ctx->current_cert = NULL; 1650 /* 1651 * Verification errors need to be "sticky", a callback may have allowed 1652 * an SSL handshake to continue despite an error, and we must then 1653 * remain in an error state. Therefore, we MUST NOT clear earlier 1654 * verification errors by setting the error to X509_V_OK. 1655 */ 1656 if (!ctx->verify_cb(2, ctx)) 1657 return 0; 1658 } 1659 1660 return 1; 1661 } 1662 1663 /*- 1664 * Check certificate validity times. 1665 * If depth >= 0, invoke verification callbacks on error, otherwise just return 1666 * the validation status. 1667 * 1668 * Return 1 on success, 0 otherwise. 1669 */ 1670 int x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth) 1671 { 1672 time_t *ptime; 1673 int i; 1674 1675 if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) 1676 ptime = &ctx->param->check_time; 1677 else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) 1678 return 1; 1679 else 1680 ptime = NULL; 1681 1682 i = X509_cmp_time(X509_get0_notBefore(x), ptime); 1683 if (i >= 0 && depth < 0) 1684 return 0; 1685 if (i == 0 && !verify_cb_cert(ctx, x, depth, 1686 X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD)) 1687 return 0; 1688 if (i > 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID)) 1689 return 0; 1690 1691 i = X509_cmp_time(X509_get0_notAfter(x), ptime); 1692 if (i <= 0 && depth < 0) 1693 return 0; 1694 if (i == 0 && !verify_cb_cert(ctx, x, depth, 1695 X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD)) 1696 return 0; 1697 if (i < 0 && !verify_cb_cert(ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED)) 1698 return 0; 1699 return 1; 1700 } 1701 1702 static int internal_verify(X509_STORE_CTX *ctx) 1703 { 1704 int n = sk_X509_num(ctx->chain) - 1; 1705 X509 *xi = sk_X509_value(ctx->chain, n); 1706 X509 *xs; 1707 1708 /* 1709 * With DANE-verified bare public key TA signatures, it remains only to 1710 * check the timestamps of the top certificate. We report the issuer as 1711 * NULL, since all we have is a bare key. 1712 */ 1713 if (ctx->bare_ta_signed) { 1714 xs = xi; 1715 xi = NULL; 1716 goto check_cert; 1717 } 1718 1719 if (ctx->check_issued(ctx, xi, xi)) 1720 xs = xi; 1721 else { 1722 if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) { 1723 xs = xi; 1724 goto check_cert; 1725 } 1726 if (n <= 0) 1727 return verify_cb_cert(ctx, xi, 0, 1728 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE); 1729 n--; 1730 ctx->error_depth = n; 1731 xs = sk_X509_value(ctx->chain, n); 1732 } 1733 1734 /* 1735 * Do not clear ctx->error=0, it must be "sticky", only the user's callback 1736 * is allowed to reset errors (at its own peril). 1737 */ 1738 while (n >= 0) { 1739 EVP_PKEY *pkey; 1740 1741 /* 1742 * Skip signature check for self signed certificates unless explicitly 1743 * asked for. It doesn't add any security and just wastes time. If 1744 * the issuer's public key is unusable, report the issuer certificate 1745 * and its depth (rather than the depth of the subject). 1746 */ 1747 if (xs != xi || (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)) { 1748 if ((pkey = X509_get0_pubkey(xi)) == NULL) { 1749 if (!verify_cb_cert(ctx, xi, xi != xs ? n+1 : n, 1750 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY)) 1751 return 0; 1752 } else if (X509_verify(xs, pkey) <= 0) { 1753 if (!verify_cb_cert(ctx, xs, n, 1754 X509_V_ERR_CERT_SIGNATURE_FAILURE)) 1755 return 0; 1756 } 1757 } 1758 1759 check_cert: 1760 /* Calls verify callback as needed */ 1761 if (!x509_check_cert_time(ctx, xs, n)) 1762 return 0; 1763 1764 /* 1765 * Signal success at this depth. However, the previous error (if any) 1766 * is retained. 1767 */ 1768 ctx->current_issuer = xi; 1769 ctx->current_cert = xs; 1770 ctx->error_depth = n; 1771 if (!ctx->verify_cb(1, ctx)) 1772 return 0; 1773 1774 if (--n >= 0) { 1775 xi = xs; 1776 xs = sk_X509_value(ctx->chain, n); 1777 } 1778 } 1779 return 1; 1780 } 1781 1782 int X509_cmp_current_time(const ASN1_TIME *ctm) 1783 { 1784 return X509_cmp_time(ctm, NULL); 1785 } 1786 1787 int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time) 1788 { 1789 static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1; 1790 static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1; 1791 ASN1_TIME *asn1_cmp_time = NULL; 1792 int i, day, sec, ret = 0; 1793 #ifdef CHARSET_EBCDIC 1794 const char upper_z = 0x5A; 1795 #else 1796 const char upper_z = 'Z'; 1797 #endif 1798 /* 1799 * Note that ASN.1 allows much more slack in the time format than RFC5280. 1800 * In RFC5280, the representation is fixed: 1801 * UTCTime: YYMMDDHHMMSSZ 1802 * GeneralizedTime: YYYYMMDDHHMMSSZ 1803 * 1804 * We do NOT currently enforce the following RFC 5280 requirement: 1805 * "CAs conforming to this profile MUST always encode certificate 1806 * validity dates through the year 2049 as UTCTime; certificate validity 1807 * dates in 2050 or later MUST be encoded as GeneralizedTime." 1808 */ 1809 switch (ctm->type) { 1810 case V_ASN1_UTCTIME: 1811 if (ctm->length != (int)(utctime_length)) 1812 return 0; 1813 break; 1814 case V_ASN1_GENERALIZEDTIME: 1815 if (ctm->length != (int)(generalizedtime_length)) 1816 return 0; 1817 break; 1818 default: 1819 return 0; 1820 } 1821 1822 /** 1823 * Verify the format: the ASN.1 functions we use below allow a more 1824 * flexible format than what's mandated by RFC 5280. 1825 * Digit and date ranges will be verified in the conversion methods. 1826 */ 1827 for (i = 0; i < ctm->length - 1; i++) { 1828 if (!ascii_isdigit(ctm->data[i])) 1829 return 0; 1830 } 1831 if (ctm->data[ctm->length - 1] != upper_z) 1832 return 0; 1833 1834 /* 1835 * There is ASN1_UTCTIME_cmp_time_t but no 1836 * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t, 1837 * so we go through ASN.1 1838 */ 1839 asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time); 1840 if (asn1_cmp_time == NULL) 1841 goto err; 1842 if (!ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time)) 1843 goto err; 1844 1845 /* 1846 * X509_cmp_time comparison is <=. 1847 * The return value 0 is reserved for errors. 1848 */ 1849 ret = (day >= 0 && sec >= 0) ? -1 : 1; 1850 1851 err: 1852 ASN1_TIME_free(asn1_cmp_time); 1853 return ret; 1854 } 1855 1856 ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj) 1857 { 1858 return X509_time_adj(s, adj, NULL); 1859 } 1860 1861 ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm) 1862 { 1863 return X509_time_adj_ex(s, 0, offset_sec, in_tm); 1864 } 1865 1866 ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s, 1867 int offset_day, long offset_sec, time_t *in_tm) 1868 { 1869 time_t t; 1870 1871 if (in_tm) 1872 t = *in_tm; 1873 else 1874 time(&t); 1875 1876 if (s && !(s->flags & ASN1_STRING_FLAG_MSTRING)) { 1877 if (s->type == V_ASN1_UTCTIME) 1878 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec); 1879 if (s->type == V_ASN1_GENERALIZEDTIME) 1880 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec); 1881 } 1882 return ASN1_TIME_adj(s, t, offset_day, offset_sec); 1883 } 1884 1885 int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain) 1886 { 1887 EVP_PKEY *ktmp = NULL, *ktmp2; 1888 int i, j; 1889 1890 if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey)) 1891 return 1; 1892 1893 for (i = 0; i < sk_X509_num(chain); i++) { 1894 ktmp = X509_get0_pubkey(sk_X509_value(chain, i)); 1895 if (ktmp == NULL) { 1896 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS, 1897 X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY); 1898 return 0; 1899 } 1900 if (!EVP_PKEY_missing_parameters(ktmp)) 1901 break; 1902 } 1903 if (ktmp == NULL) { 1904 X509err(X509_F_X509_GET_PUBKEY_PARAMETERS, 1905 X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN); 1906 return 0; 1907 } 1908 1909 /* first, populate the other certs */ 1910 for (j = i - 1; j >= 0; j--) { 1911 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j)); 1912 EVP_PKEY_copy_parameters(ktmp2, ktmp); 1913 } 1914 1915 if (pkey != NULL) 1916 EVP_PKEY_copy_parameters(pkey, ktmp); 1917 return 1; 1918 } 1919 1920 /* Make a delta CRL as the diff between two full CRLs */ 1921 1922 X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer, 1923 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags) 1924 { 1925 X509_CRL *crl = NULL; 1926 int i; 1927 STACK_OF(X509_REVOKED) *revs = NULL; 1928 /* CRLs can't be delta already */ 1929 if (base->base_crl_number || newer->base_crl_number) { 1930 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA); 1931 return NULL; 1932 } 1933 /* Base and new CRL must have a CRL number */ 1934 if (!base->crl_number || !newer->crl_number) { 1935 X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER); 1936 return NULL; 1937 } 1938 /* Issuer names must match */ 1939 if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) { 1940 X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH); 1941 return NULL; 1942 } 1943 /* AKID and IDP must match */ 1944 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) { 1945 X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH); 1946 return NULL; 1947 } 1948 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) { 1949 X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH); 1950 return NULL; 1951 } 1952 /* Newer CRL number must exceed full CRL number */ 1953 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) { 1954 X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER); 1955 return NULL; 1956 } 1957 /* CRLs must verify */ 1958 if (skey && (X509_CRL_verify(base, skey) <= 0 || 1959 X509_CRL_verify(newer, skey) <= 0)) { 1960 X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE); 1961 return NULL; 1962 } 1963 /* Create new CRL */ 1964 crl = X509_CRL_new(); 1965 if (crl == NULL || !X509_CRL_set_version(crl, 1)) 1966 goto memerr; 1967 /* Set issuer name */ 1968 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer))) 1969 goto memerr; 1970 1971 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer))) 1972 goto memerr; 1973 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer))) 1974 goto memerr; 1975 1976 /* Set base CRL number: must be critical */ 1977 1978 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0)) 1979 goto memerr; 1980 1981 /* 1982 * Copy extensions across from newest CRL to delta: this will set CRL 1983 * number to correct value too. 1984 */ 1985 1986 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) { 1987 X509_EXTENSION *ext; 1988 ext = X509_CRL_get_ext(newer, i); 1989 if (!X509_CRL_add_ext(crl, ext, -1)) 1990 goto memerr; 1991 } 1992 1993 /* Go through revoked entries, copying as needed */ 1994 1995 revs = X509_CRL_get_REVOKED(newer); 1996 1997 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) { 1998 X509_REVOKED *rvn, *rvtmp; 1999 rvn = sk_X509_REVOKED_value(revs, i); 2000 /* 2001 * Add only if not also in base. TODO: need something cleverer here 2002 * for some more complex CRLs covering multiple CAs. 2003 */ 2004 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) { 2005 rvtmp = X509_REVOKED_dup(rvn); 2006 if (!rvtmp) 2007 goto memerr; 2008 if (!X509_CRL_add0_revoked(crl, rvtmp)) { 2009 X509_REVOKED_free(rvtmp); 2010 goto memerr; 2011 } 2012 } 2013 } 2014 /* TODO: optionally prune deleted entries */ 2015 2016 if (skey && md && !X509_CRL_sign(crl, skey, md)) 2017 goto memerr; 2018 2019 return crl; 2020 2021 memerr: 2022 X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE); 2023 X509_CRL_free(crl); 2024 return NULL; 2025 } 2026 2027 int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data) 2028 { 2029 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data); 2030 } 2031 2032 void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx) 2033 { 2034 return CRYPTO_get_ex_data(&ctx->ex_data, idx); 2035 } 2036 2037 int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx) 2038 { 2039 return ctx->error; 2040 } 2041 2042 void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err) 2043 { 2044 ctx->error = err; 2045 } 2046 2047 int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx) 2048 { 2049 return ctx->error_depth; 2050 } 2051 2052 void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth) 2053 { 2054 ctx->error_depth = depth; 2055 } 2056 2057 X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx) 2058 { 2059 return ctx->current_cert; 2060 } 2061 2062 void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x) 2063 { 2064 ctx->current_cert = x; 2065 } 2066 2067 STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx) 2068 { 2069 return ctx->chain; 2070 } 2071 2072 STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx) 2073 { 2074 if (!ctx->chain) 2075 return NULL; 2076 return X509_chain_up_ref(ctx->chain); 2077 } 2078 2079 X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx) 2080 { 2081 return ctx->current_issuer; 2082 } 2083 2084 X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx) 2085 { 2086 return ctx->current_crl; 2087 } 2088 2089 X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx) 2090 { 2091 return ctx->parent; 2092 } 2093 2094 void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x) 2095 { 2096 ctx->cert = x; 2097 } 2098 2099 void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk) 2100 { 2101 ctx->crls = sk; 2102 } 2103 2104 int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose) 2105 { 2106 /* 2107 * XXX: Why isn't this function always used to set the associated trust? 2108 * Should there even be a VPM->trust field at all? Or should the trust 2109 * always be inferred from the purpose by X509_STORE_CTX_init(). 2110 */ 2111 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0); 2112 } 2113 2114 int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust) 2115 { 2116 /* 2117 * XXX: See above, this function would only be needed when the default 2118 * trust for the purpose needs an override in a corner case. 2119 */ 2120 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust); 2121 } 2122 2123 /* 2124 * This function is used to set the X509_STORE_CTX purpose and trust values. 2125 * This is intended to be used when another structure has its own trust and 2126 * purpose values which (if set) will be inherited by the ctx. If they aren't 2127 * set then we will usually have a default purpose in mind which should then 2128 * be used to set the trust value. An example of this is SSL use: an SSL 2129 * structure will have its own purpose and trust settings which the 2130 * application can set: if they aren't set then we use the default of SSL 2131 * client/server. 2132 */ 2133 2134 int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose, 2135 int purpose, int trust) 2136 { 2137 int idx; 2138 /* If purpose not set use default */ 2139 if (!purpose) 2140 purpose = def_purpose; 2141 /* If we have a purpose then check it is valid */ 2142 if (purpose) { 2143 X509_PURPOSE *ptmp; 2144 idx = X509_PURPOSE_get_by_id(purpose); 2145 if (idx == -1) { 2146 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2147 X509_R_UNKNOWN_PURPOSE_ID); 2148 return 0; 2149 } 2150 ptmp = X509_PURPOSE_get0(idx); 2151 if (ptmp->trust == X509_TRUST_DEFAULT) { 2152 idx = X509_PURPOSE_get_by_id(def_purpose); 2153 /* 2154 * XXX: In the two callers above def_purpose is always 0, which is 2155 * not a known value, so idx will always be -1. How is the 2156 * X509_TRUST_DEFAULT case actually supposed to be handled? 2157 */ 2158 if (idx == -1) { 2159 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2160 X509_R_UNKNOWN_PURPOSE_ID); 2161 return 0; 2162 } 2163 ptmp = X509_PURPOSE_get0(idx); 2164 } 2165 /* If trust not set then get from purpose default */ 2166 if (!trust) 2167 trust = ptmp->trust; 2168 } 2169 if (trust) { 2170 idx = X509_TRUST_get_by_id(trust); 2171 if (idx == -1) { 2172 X509err(X509_F_X509_STORE_CTX_PURPOSE_INHERIT, 2173 X509_R_UNKNOWN_TRUST_ID); 2174 return 0; 2175 } 2176 } 2177 2178 if (purpose && !ctx->param->purpose) 2179 ctx->param->purpose = purpose; 2180 if (trust && !ctx->param->trust) 2181 ctx->param->trust = trust; 2182 return 1; 2183 } 2184 2185 X509_STORE_CTX *X509_STORE_CTX_new(void) 2186 { 2187 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx)); 2188 2189 if (ctx == NULL) { 2190 X509err(X509_F_X509_STORE_CTX_NEW, ERR_R_MALLOC_FAILURE); 2191 return NULL; 2192 } 2193 return ctx; 2194 } 2195 2196 void X509_STORE_CTX_free(X509_STORE_CTX *ctx) 2197 { 2198 if (ctx == NULL) 2199 return; 2200 2201 X509_STORE_CTX_cleanup(ctx); 2202 OPENSSL_free(ctx); 2203 } 2204 2205 int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509, 2206 STACK_OF(X509) *chain) 2207 { 2208 int ret = 1; 2209 2210 ctx->ctx = store; 2211 ctx->cert = x509; 2212 ctx->untrusted = chain; 2213 ctx->crls = NULL; 2214 ctx->num_untrusted = 0; 2215 ctx->other_ctx = NULL; 2216 ctx->valid = 0; 2217 ctx->chain = NULL; 2218 ctx->error = 0; 2219 ctx->explicit_policy = 0; 2220 ctx->error_depth = 0; 2221 ctx->current_cert = NULL; 2222 ctx->current_issuer = NULL; 2223 ctx->current_crl = NULL; 2224 ctx->current_crl_score = 0; 2225 ctx->current_reasons = 0; 2226 ctx->tree = NULL; 2227 ctx->parent = NULL; 2228 ctx->dane = NULL; 2229 ctx->bare_ta_signed = 0; 2230 /* Zero ex_data to make sure we're cleanup-safe */ 2231 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2232 2233 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */ 2234 if (store) 2235 ctx->cleanup = store->cleanup; 2236 else 2237 ctx->cleanup = 0; 2238 2239 if (store && store->check_issued) 2240 ctx->check_issued = store->check_issued; 2241 else 2242 ctx->check_issued = check_issued; 2243 2244 if (store && store->get_issuer) 2245 ctx->get_issuer = store->get_issuer; 2246 else 2247 ctx->get_issuer = X509_STORE_CTX_get1_issuer; 2248 2249 if (store && store->verify_cb) 2250 ctx->verify_cb = store->verify_cb; 2251 else 2252 ctx->verify_cb = null_callback; 2253 2254 if (store && store->verify) 2255 ctx->verify = store->verify; 2256 else 2257 ctx->verify = internal_verify; 2258 2259 if (store && store->check_revocation) 2260 ctx->check_revocation = store->check_revocation; 2261 else 2262 ctx->check_revocation = check_revocation; 2263 2264 if (store && store->get_crl) 2265 ctx->get_crl = store->get_crl; 2266 else 2267 ctx->get_crl = NULL; 2268 2269 if (store && store->check_crl) 2270 ctx->check_crl = store->check_crl; 2271 else 2272 ctx->check_crl = check_crl; 2273 2274 if (store && store->cert_crl) 2275 ctx->cert_crl = store->cert_crl; 2276 else 2277 ctx->cert_crl = cert_crl; 2278 2279 if (store && store->check_policy) 2280 ctx->check_policy = store->check_policy; 2281 else 2282 ctx->check_policy = check_policy; 2283 2284 if (store && store->lookup_certs) 2285 ctx->lookup_certs = store->lookup_certs; 2286 else 2287 ctx->lookup_certs = X509_STORE_CTX_get1_certs; 2288 2289 if (store && store->lookup_crls) 2290 ctx->lookup_crls = store->lookup_crls; 2291 else 2292 ctx->lookup_crls = X509_STORE_CTX_get1_crls; 2293 2294 ctx->param = X509_VERIFY_PARAM_new(); 2295 if (ctx->param == NULL) { 2296 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2297 goto err; 2298 } 2299 2300 /* 2301 * Inherit callbacks and flags from X509_STORE if not set use defaults. 2302 */ 2303 if (store) 2304 ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param); 2305 else 2306 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE; 2307 2308 if (ret) 2309 ret = X509_VERIFY_PARAM_inherit(ctx->param, 2310 X509_VERIFY_PARAM_lookup("default")); 2311 2312 if (ret == 0) { 2313 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2314 goto err; 2315 } 2316 2317 /* 2318 * XXX: For now, continue to inherit trust from VPM, but infer from the 2319 * purpose if this still yields the default value. 2320 */ 2321 if (ctx->param->trust == X509_TRUST_DEFAULT) { 2322 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose); 2323 X509_PURPOSE *xp = X509_PURPOSE_get0(idx); 2324 2325 if (xp != NULL) 2326 ctx->param->trust = X509_PURPOSE_get_trust(xp); 2327 } 2328 2329 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, 2330 &ctx->ex_data)) 2331 return 1; 2332 X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE); 2333 2334 err: 2335 /* 2336 * On error clean up allocated storage, if the store context was not 2337 * allocated with X509_STORE_CTX_new() this is our last chance to do so. 2338 */ 2339 X509_STORE_CTX_cleanup(ctx); 2340 return 0; 2341 } 2342 2343 /* 2344 * Set alternative lookup method: just a STACK of trusted certificates. This 2345 * avoids X509_STORE nastiness where it isn't needed. 2346 */ 2347 void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2348 { 2349 ctx->other_ctx = sk; 2350 ctx->get_issuer = get_issuer_sk; 2351 ctx->lookup_certs = lookup_certs_sk; 2352 } 2353 2354 void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx) 2355 { 2356 /* 2357 * We need to be idempotent because, unfortunately, free() also calls 2358 * cleanup(), so the natural call sequence new(), init(), cleanup(), free() 2359 * calls cleanup() for the same object twice! Thus we must zero the 2360 * pointers below after they're freed! 2361 */ 2362 /* Seems to always be 0 in OpenSSL, do this at most once. */ 2363 if (ctx->cleanup != NULL) { 2364 ctx->cleanup(ctx); 2365 ctx->cleanup = NULL; 2366 } 2367 if (ctx->param != NULL) { 2368 if (ctx->parent == NULL) 2369 X509_VERIFY_PARAM_free(ctx->param); 2370 ctx->param = NULL; 2371 } 2372 X509_policy_tree_free(ctx->tree); 2373 ctx->tree = NULL; 2374 sk_X509_pop_free(ctx->chain, X509_free); 2375 ctx->chain = NULL; 2376 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data)); 2377 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2378 } 2379 2380 void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth) 2381 { 2382 X509_VERIFY_PARAM_set_depth(ctx->param, depth); 2383 } 2384 2385 void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags) 2386 { 2387 X509_VERIFY_PARAM_set_flags(ctx->param, flags); 2388 } 2389 2390 void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, 2391 time_t t) 2392 { 2393 X509_VERIFY_PARAM_set_time(ctx->param, t); 2394 } 2395 2396 X509 *X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx) 2397 { 2398 return ctx->cert; 2399 } 2400 2401 STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx) 2402 { 2403 return ctx->untrusted; 2404 } 2405 2406 void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2407 { 2408 ctx->untrusted = sk; 2409 } 2410 2411 void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2412 { 2413 sk_X509_pop_free(ctx->chain, X509_free); 2414 ctx->chain = sk; 2415 } 2416 2417 void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx, 2418 X509_STORE_CTX_verify_cb verify_cb) 2419 { 2420 ctx->verify_cb = verify_cb; 2421 } 2422 2423 X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(X509_STORE_CTX *ctx) 2424 { 2425 return ctx->verify_cb; 2426 } 2427 2428 void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx, 2429 X509_STORE_CTX_verify_fn verify) 2430 { 2431 ctx->verify = verify; 2432 } 2433 2434 X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(X509_STORE_CTX *ctx) 2435 { 2436 return ctx->verify; 2437 } 2438 2439 X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(X509_STORE_CTX *ctx) 2440 { 2441 return ctx->get_issuer; 2442 } 2443 2444 X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(X509_STORE_CTX *ctx) 2445 { 2446 return ctx->check_issued; 2447 } 2448 2449 X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(X509_STORE_CTX *ctx) 2450 { 2451 return ctx->check_revocation; 2452 } 2453 2454 X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(X509_STORE_CTX *ctx) 2455 { 2456 return ctx->get_crl; 2457 } 2458 2459 X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(X509_STORE_CTX *ctx) 2460 { 2461 return ctx->check_crl; 2462 } 2463 2464 X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(X509_STORE_CTX *ctx) 2465 { 2466 return ctx->cert_crl; 2467 } 2468 2469 X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(X509_STORE_CTX *ctx) 2470 { 2471 return ctx->check_policy; 2472 } 2473 2474 X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(X509_STORE_CTX *ctx) 2475 { 2476 return ctx->lookup_certs; 2477 } 2478 2479 X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(X509_STORE_CTX *ctx) 2480 { 2481 return ctx->lookup_crls; 2482 } 2483 2484 X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(X509_STORE_CTX *ctx) 2485 { 2486 return ctx->cleanup; 2487 } 2488 2489 X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(X509_STORE_CTX *ctx) 2490 { 2491 return ctx->tree; 2492 } 2493 2494 int X509_STORE_CTX_get_explicit_policy(X509_STORE_CTX *ctx) 2495 { 2496 return ctx->explicit_policy; 2497 } 2498 2499 int X509_STORE_CTX_get_num_untrusted(X509_STORE_CTX *ctx) 2500 { 2501 return ctx->num_untrusted; 2502 } 2503 2504 int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name) 2505 { 2506 const X509_VERIFY_PARAM *param; 2507 param = X509_VERIFY_PARAM_lookup(name); 2508 if (!param) 2509 return 0; 2510 return X509_VERIFY_PARAM_inherit(ctx->param, param); 2511 } 2512 2513 X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx) 2514 { 2515 return ctx->param; 2516 } 2517 2518 void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param) 2519 { 2520 X509_VERIFY_PARAM_free(ctx->param); 2521 ctx->param = param; 2522 } 2523 2524 void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane) 2525 { 2526 ctx->dane = dane; 2527 } 2528 2529 static unsigned char *dane_i2d( 2530 X509 *cert, 2531 uint8_t selector, 2532 unsigned int *i2dlen) 2533 { 2534 unsigned char *buf = NULL; 2535 int len; 2536 2537 /* 2538 * Extract ASN.1 DER form of certificate or public key. 2539 */ 2540 switch (selector) { 2541 case DANETLS_SELECTOR_CERT: 2542 len = i2d_X509(cert, &buf); 2543 break; 2544 case DANETLS_SELECTOR_SPKI: 2545 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf); 2546 break; 2547 default: 2548 X509err(X509_F_DANE_I2D, X509_R_BAD_SELECTOR); 2549 return NULL; 2550 } 2551 2552 if (len < 0 || buf == NULL) { 2553 X509err(X509_F_DANE_I2D, ERR_R_MALLOC_FAILURE); 2554 return NULL; 2555 } 2556 2557 *i2dlen = (unsigned int)len; 2558 return buf; 2559 } 2560 2561 #define DANETLS_NONE 256 /* impossible uint8_t */ 2562 2563 static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth) 2564 { 2565 SSL_DANE *dane = ctx->dane; 2566 unsigned usage = DANETLS_NONE; 2567 unsigned selector = DANETLS_NONE; 2568 unsigned ordinal = DANETLS_NONE; 2569 unsigned mtype = DANETLS_NONE; 2570 unsigned char *i2dbuf = NULL; 2571 unsigned int i2dlen = 0; 2572 unsigned char mdbuf[EVP_MAX_MD_SIZE]; 2573 unsigned char *cmpbuf = NULL; 2574 unsigned int cmplen = 0; 2575 int i; 2576 int recnum; 2577 int matched = 0; 2578 danetls_record *t = NULL; 2579 uint32_t mask; 2580 2581 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK; 2582 2583 /* 2584 * The trust store is not applicable with DANE-TA(2) 2585 */ 2586 if (depth >= ctx->num_untrusted) 2587 mask &= DANETLS_PKIX_MASK; 2588 2589 /* 2590 * If we've previously matched a PKIX-?? record, no need to test any 2591 * further PKIX-?? records, it remains to just build the PKIX chain. 2592 * Had the match been a DANE-?? record, we'd be done already. 2593 */ 2594 if (dane->mdpth >= 0) 2595 mask &= ~DANETLS_PKIX_MASK; 2596 2597 /*- 2598 * https://tools.ietf.org/html/rfc7671#section-5.1 2599 * https://tools.ietf.org/html/rfc7671#section-5.2 2600 * https://tools.ietf.org/html/rfc7671#section-5.3 2601 * https://tools.ietf.org/html/rfc7671#section-5.4 2602 * 2603 * We handle DANE-EE(3) records first as they require no chain building 2604 * and no expiration or hostname checks. We also process digests with 2605 * higher ordinals first and ignore lower priorities except Full(0) which 2606 * is always processed (last). If none match, we then process PKIX-EE(1). 2607 * 2608 * NOTE: This relies on DANE usages sorting before the corresponding PKIX 2609 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest 2610 * priorities. See twin comment in ssl/ssl_lib.c. 2611 * 2612 * We expect that most TLSA RRsets will have just a single usage, so we 2613 * don't go out of our way to cache multiple selector-specific i2d buffers 2614 * across usages, but if the selector happens to remain the same as switch 2615 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1", 2616 * records would result in us generating each of the certificate and public 2617 * key DER forms twice, but more typically we'd just see multiple "3 1 1" 2618 * or multiple "3 0 1" records. 2619 * 2620 * As soon as we find a match at any given depth, we stop, because either 2621 * we've matched a DANE-?? record and the peer is authenticated, or, after 2622 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is 2623 * sufficient for DANE, and what remains to do is ordinary PKIX validation. 2624 */ 2625 recnum = (dane->umask & mask) ? sk_danetls_record_num(dane->trecs) : 0; 2626 for (i = 0; matched == 0 && i < recnum; ++i) { 2627 t = sk_danetls_record_value(dane->trecs, i); 2628 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0) 2629 continue; 2630 if (t->usage != usage) { 2631 usage = t->usage; 2632 2633 /* Reset digest agility for each usage/selector pair */ 2634 mtype = DANETLS_NONE; 2635 ordinal = dane->dctx->mdord[t->mtype]; 2636 } 2637 if (t->selector != selector) { 2638 selector = t->selector; 2639 2640 /* Update per-selector state */ 2641 OPENSSL_free(i2dbuf); 2642 i2dbuf = dane_i2d(cert, selector, &i2dlen); 2643 if (i2dbuf == NULL) 2644 return -1; 2645 2646 /* Reset digest agility for each usage/selector pair */ 2647 mtype = DANETLS_NONE; 2648 ordinal = dane->dctx->mdord[t->mtype]; 2649 } else if (t->mtype != DANETLS_MATCHING_FULL) { 2650 /*- 2651 * Digest agility: 2652 * 2653 * <https://tools.ietf.org/html/rfc7671#section-9> 2654 * 2655 * For a fixed selector, after processing all records with the 2656 * highest mtype ordinal, ignore all mtypes with lower ordinals 2657 * other than "Full". 2658 */ 2659 if (dane->dctx->mdord[t->mtype] < ordinal) 2660 continue; 2661 } 2662 2663 /* 2664 * Each time we hit a (new selector or) mtype, re-compute the relevant 2665 * digest, more complex caching is not worth the code space. 2666 */ 2667 if (t->mtype != mtype) { 2668 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype]; 2669 cmpbuf = i2dbuf; 2670 cmplen = i2dlen; 2671 2672 if (md != NULL) { 2673 cmpbuf = mdbuf; 2674 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) { 2675 matched = -1; 2676 break; 2677 } 2678 } 2679 } 2680 2681 /* 2682 * Squirrel away the certificate and depth if we have a match. Any 2683 * DANE match is dispositive, but with PKIX we still need to build a 2684 * full chain. 2685 */ 2686 if (cmplen == t->dlen && 2687 memcmp(cmpbuf, t->data, cmplen) == 0) { 2688 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK) 2689 matched = 1; 2690 if (matched || dane->mdpth < 0) { 2691 dane->mdpth = depth; 2692 dane->mtlsa = t; 2693 OPENSSL_free(dane->mcert); 2694 dane->mcert = cert; 2695 X509_up_ref(cert); 2696 } 2697 break; 2698 } 2699 } 2700 2701 /* Clear the one-element DER cache */ 2702 OPENSSL_free(i2dbuf); 2703 return matched; 2704 } 2705 2706 static int check_dane_issuer(X509_STORE_CTX *ctx, int depth) 2707 { 2708 SSL_DANE *dane = ctx->dane; 2709 int matched = 0; 2710 X509 *cert; 2711 2712 if (!DANETLS_HAS_TA(dane) || depth == 0) 2713 return X509_TRUST_UNTRUSTED; 2714 2715 /* 2716 * Record any DANE trust-anchor matches, for the first depth to test, if 2717 * there's one at that depth. (This'll be false for length 1 chains looking 2718 * for an exact match for the leaf certificate). 2719 */ 2720 cert = sk_X509_value(ctx->chain, depth); 2721 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0) 2722 return X509_TRUST_REJECTED; 2723 if (matched > 0) { 2724 ctx->num_untrusted = depth - 1; 2725 return X509_TRUST_TRUSTED; 2726 } 2727 2728 return X509_TRUST_UNTRUSTED; 2729 } 2730 2731 static int check_dane_pkeys(X509_STORE_CTX *ctx) 2732 { 2733 SSL_DANE *dane = ctx->dane; 2734 danetls_record *t; 2735 int num = ctx->num_untrusted; 2736 X509 *cert = sk_X509_value(ctx->chain, num - 1); 2737 int recnum = sk_danetls_record_num(dane->trecs); 2738 int i; 2739 2740 for (i = 0; i < recnum; ++i) { 2741 t = sk_danetls_record_value(dane->trecs, i); 2742 if (t->usage != DANETLS_USAGE_DANE_TA || 2743 t->selector != DANETLS_SELECTOR_SPKI || 2744 t->mtype != DANETLS_MATCHING_FULL || 2745 X509_verify(cert, t->spki) <= 0) 2746 continue; 2747 2748 /* Clear any PKIX-?? matches that failed to extend to a full chain */ 2749 X509_free(dane->mcert); 2750 dane->mcert = NULL; 2751 2752 /* Record match via a bare TA public key */ 2753 ctx->bare_ta_signed = 1; 2754 dane->mdpth = num - 1; 2755 dane->mtlsa = t; 2756 2757 /* Prune any excess chain certificates */ 2758 num = sk_X509_num(ctx->chain); 2759 for (; num > ctx->num_untrusted; --num) 2760 X509_free(sk_X509_pop(ctx->chain)); 2761 2762 return X509_TRUST_TRUSTED; 2763 } 2764 2765 return X509_TRUST_UNTRUSTED; 2766 } 2767 2768 static void dane_reset(SSL_DANE *dane) 2769 { 2770 /* 2771 * Reset state to verify another chain, or clear after failure. 2772 */ 2773 X509_free(dane->mcert); 2774 dane->mcert = NULL; 2775 dane->mtlsa = NULL; 2776 dane->mdpth = -1; 2777 dane->pdpth = -1; 2778 } 2779 2780 static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert) 2781 { 2782 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags); 2783 2784 if (err == X509_V_OK) 2785 return 1; 2786 return verify_cb_cert(ctx, cert, 0, err); 2787 } 2788 2789 static int dane_verify(X509_STORE_CTX *ctx) 2790 { 2791 X509 *cert = ctx->cert; 2792 SSL_DANE *dane = ctx->dane; 2793 int matched; 2794 int done; 2795 2796 dane_reset(dane); 2797 2798 /*- 2799 * When testing the leaf certificate, if we match a DANE-EE(3) record, 2800 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1) 2801 * record, the match depth and matching TLSA record are recorded, but the 2802 * return value is 0, because we still need to find a PKIX trust-anchor. 2803 * Therefore, when DANE authentication is enabled (required), we're done 2804 * if: 2805 * + matched < 0, internal error. 2806 * + matched == 1, we matched a DANE-EE(3) record 2807 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no 2808 * DANE-TA(2) or PKIX-TA(0) to test. 2809 */ 2810 matched = dane_match(ctx, ctx->cert, 0); 2811 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0); 2812 2813 if (done) 2814 X509_get_pubkey_parameters(NULL, ctx->chain); 2815 2816 if (matched > 0) { 2817 /* Callback invoked as needed */ 2818 if (!check_leaf_suiteb(ctx, cert)) 2819 return 0; 2820 /* Callback invoked as needed */ 2821 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 && 2822 !check_id(ctx)) 2823 return 0; 2824 /* Bypass internal_verify(), issue depth 0 success callback */ 2825 ctx->error_depth = 0; 2826 ctx->current_cert = cert; 2827 return ctx->verify_cb(1, ctx); 2828 } 2829 2830 if (matched < 0) { 2831 ctx->error_depth = 0; 2832 ctx->current_cert = cert; 2833 ctx->error = X509_V_ERR_OUT_OF_MEM; 2834 return -1; 2835 } 2836 2837 if (done) { 2838 /* Fail early, TA-based success is not possible */ 2839 if (!check_leaf_suiteb(ctx, cert)) 2840 return 0; 2841 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH); 2842 } 2843 2844 /* 2845 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0 2846 * certificates happens in-line with building the rest of the chain. 2847 */ 2848 return verify_chain(ctx); 2849 } 2850 2851 /* Get issuer, without duplicate suppression */ 2852 static int get_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert) 2853 { 2854 STACK_OF(X509) *saved_chain = ctx->chain; 2855 int ok; 2856 2857 ctx->chain = NULL; 2858 ok = ctx->get_issuer(issuer, ctx, cert); 2859 ctx->chain = saved_chain; 2860 2861 return ok; 2862 } 2863 2864 static int build_chain(X509_STORE_CTX *ctx) 2865 { 2866 SSL_DANE *dane = ctx->dane; 2867 int num = sk_X509_num(ctx->chain); 2868 X509 *cert = sk_X509_value(ctx->chain, num - 1); 2869 int ss = cert_self_signed(cert); 2870 STACK_OF(X509) *sktmp = NULL; 2871 unsigned int search; 2872 int may_trusted = 0; 2873 int may_alternate = 0; 2874 int trust = X509_TRUST_UNTRUSTED; 2875 int alt_untrusted = 0; 2876 int depth; 2877 int ok = 0; 2878 int i; 2879 2880 /* Our chain starts with a single untrusted element. */ 2881 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) { 2882 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 2883 ctx->error = X509_V_ERR_UNSPECIFIED; 2884 return 0; 2885 } 2886 2887 #define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */ 2888 #define S_DOTRUSTED (1 << 1) /* Search trusted store */ 2889 #define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */ 2890 /* 2891 * Set up search policy, untrusted if possible, trusted-first if enabled. 2892 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the 2893 * trust_store, otherwise we might look there first. If not trusted-first, 2894 * and alternate chains are not disabled, try building an alternate chain 2895 * if no luck with untrusted first. 2896 */ 2897 search = (ctx->untrusted != NULL) ? S_DOUNTRUSTED : 0; 2898 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) { 2899 if (search == 0 || ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) 2900 search |= S_DOTRUSTED; 2901 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) 2902 may_alternate = 1; 2903 may_trusted = 1; 2904 } 2905 2906 /* 2907 * Shallow-copy the stack of untrusted certificates (with TLS, this is 2908 * typically the content of the peer's certificate message) so can make 2909 * multiple passes over it, while free to remove elements as we go. 2910 */ 2911 if (ctx->untrusted && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) { 2912 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2913 ctx->error = X509_V_ERR_OUT_OF_MEM; 2914 return 0; 2915 } 2916 2917 /* 2918 * If we got any "DANE-TA(2) Cert(0) Full(0)" trust-anchors from DNS, add 2919 * them to our working copy of the untrusted certificate stack. Since the 2920 * caller of X509_STORE_CTX_init() may have provided only a leaf cert with 2921 * no corresponding stack of untrusted certificates, we may need to create 2922 * an empty stack first. [ At present only the ssl library provides DANE 2923 * support, and ssl_verify_cert_chain() always provides a non-null stack 2924 * containing at least the leaf certificate, but we must be prepared for 2925 * this to change. ] 2926 */ 2927 if (DANETLS_ENABLED(dane) && dane->certs != NULL) { 2928 if (sktmp == NULL && (sktmp = sk_X509_new_null()) == NULL) { 2929 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2930 ctx->error = X509_V_ERR_OUT_OF_MEM; 2931 return 0; 2932 } 2933 for (i = 0; i < sk_X509_num(dane->certs); ++i) { 2934 if (!sk_X509_push(sktmp, sk_X509_value(dane->certs, i))) { 2935 sk_X509_free(sktmp); 2936 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 2937 ctx->error = X509_V_ERR_OUT_OF_MEM; 2938 return 0; 2939 } 2940 } 2941 } 2942 2943 /* 2944 * Still absurdly large, but arithmetically safe, a lower hard upper bound 2945 * might be reasonable. 2946 */ 2947 if (ctx->param->depth > INT_MAX/2) 2948 ctx->param->depth = INT_MAX/2; 2949 2950 /* 2951 * Try to Extend the chain until we reach an ultimately trusted issuer. 2952 * Build chains up to one longer the limit, later fail if we hit the limit, 2953 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code. 2954 */ 2955 depth = ctx->param->depth + 1; 2956 2957 while (search != 0) { 2958 X509 *x; 2959 X509 *xtmp = NULL; 2960 2961 /* 2962 * Look in the trust store if enabled for first lookup, or we've run 2963 * out of untrusted issuers and search here is not disabled. When we 2964 * reach the depth limit, we stop extending the chain, if by that point 2965 * we've not found a trust-anchor, any trusted chain would be too long. 2966 * 2967 * The error reported to the application verify callback is at the 2968 * maximal valid depth with the current certificate equal to the last 2969 * not ultimately-trusted issuer. For example, with verify_depth = 0, 2970 * the callback will report errors at depth=1 when the immediate issuer 2971 * of the leaf certificate is not a trust anchor. No attempt will be 2972 * made to locate an issuer for that certificate, since such a chain 2973 * would be a-priori too long. 2974 */ 2975 if ((search & S_DOTRUSTED) != 0) { 2976 i = num = sk_X509_num(ctx->chain); 2977 if ((search & S_DOALTERNATE) != 0) { 2978 /* 2979 * As high up the chain as we can, look for an alternative 2980 * trusted issuer of an untrusted certificate that currently 2981 * has an untrusted issuer. We use the alt_untrusted variable 2982 * to track how far up the chain we find the first match. It 2983 * is only if and when we find a match, that we prune the chain 2984 * and reset ctx->num_untrusted to the reduced count of 2985 * untrusted certificates. While we're searching for such a 2986 * match (which may never be found), it is neither safe nor 2987 * wise to preemptively modify either the chain or 2988 * ctx->num_untrusted. 2989 * 2990 * Note, like ctx->num_untrusted, alt_untrusted is a count of 2991 * untrusted certificates, not a "depth". 2992 */ 2993 i = alt_untrusted; 2994 } 2995 x = sk_X509_value(ctx->chain, i-1); 2996 2997 ok = (depth < num) ? 0 : get_issuer(&xtmp, ctx, x); 2998 2999 if (ok < 0) { 3000 trust = X509_TRUST_REJECTED; 3001 ctx->error = X509_V_ERR_STORE_LOOKUP; 3002 search = 0; 3003 continue; 3004 } 3005 3006 if (ok > 0) { 3007 /* 3008 * Alternative trusted issuer for a mid-chain untrusted cert? 3009 * Pop the untrusted cert's successors and retry. We might now 3010 * be able to complete a valid chain via the trust store. Note 3011 * that despite the current trust-store match we might still 3012 * fail complete the chain to a suitable trust-anchor, in which 3013 * case we may prune some more untrusted certificates and try 3014 * again. Thus the S_DOALTERNATE bit may yet be turned on 3015 * again with an even shorter untrusted chain! 3016 * 3017 * If in the process we threw away our matching PKIX-TA trust 3018 * anchor, reset DANE trust. We might find a suitable trusted 3019 * certificate among the ones from the trust store. 3020 */ 3021 if ((search & S_DOALTERNATE) != 0) { 3022 if (!ossl_assert(num > i && i > 0 && ss == 0)) { 3023 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3024 X509_free(xtmp); 3025 trust = X509_TRUST_REJECTED; 3026 ctx->error = X509_V_ERR_UNSPECIFIED; 3027 search = 0; 3028 continue; 3029 } 3030 search &= ~S_DOALTERNATE; 3031 for (; num > i; --num) 3032 X509_free(sk_X509_pop(ctx->chain)); 3033 ctx->num_untrusted = num; 3034 3035 if (DANETLS_ENABLED(dane) && 3036 dane->mdpth >= ctx->num_untrusted) { 3037 dane->mdpth = -1; 3038 X509_free(dane->mcert); 3039 dane->mcert = NULL; 3040 } 3041 if (DANETLS_ENABLED(dane) && 3042 dane->pdpth >= ctx->num_untrusted) 3043 dane->pdpth = -1; 3044 } 3045 3046 /* 3047 * Self-signed untrusted certificates get replaced by their 3048 * trusted matching issuer. Otherwise, grow the chain. 3049 */ 3050 if (ss == 0) { 3051 if (!sk_X509_push(ctx->chain, x = xtmp)) { 3052 X509_free(xtmp); 3053 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 3054 trust = X509_TRUST_REJECTED; 3055 ctx->error = X509_V_ERR_OUT_OF_MEM; 3056 search = 0; 3057 continue; 3058 } 3059 ss = cert_self_signed(x); 3060 } else if (num == ctx->num_untrusted) { 3061 /* 3062 * We have a self-signed certificate that has the same 3063 * subject name (and perhaps keyid and/or serial number) as 3064 * a trust-anchor. We must have an exact match to avoid 3065 * possible impersonation via key substitution etc. 3066 */ 3067 if (X509_cmp(x, xtmp) != 0) { 3068 /* Self-signed untrusted mimic. */ 3069 X509_free(xtmp); 3070 ok = 0; 3071 } else { 3072 X509_free(x); 3073 ctx->num_untrusted = --num; 3074 (void) sk_X509_set(ctx->chain, num, x = xtmp); 3075 } 3076 } 3077 3078 /* 3079 * We've added a new trusted certificate to the chain, recheck 3080 * trust. If not done, and not self-signed look deeper. 3081 * Whether or not we're doing "trusted first", we no longer 3082 * look for untrusted certificates from the peer's chain. 3083 * 3084 * At this point ctx->num_trusted and num must reflect the 3085 * correct number of untrusted certificates, since the DANE 3086 * logic in check_trust() depends on distinguishing CAs from 3087 * "the wire" from CAs from the trust store. In particular, the 3088 * certificate at depth "num" should be the new trusted 3089 * certificate with ctx->num_untrusted <= num. 3090 */ 3091 if (ok) { 3092 if (!ossl_assert(ctx->num_untrusted <= num)) { 3093 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3094 trust = X509_TRUST_REJECTED; 3095 ctx->error = X509_V_ERR_UNSPECIFIED; 3096 search = 0; 3097 continue; 3098 } 3099 search &= ~S_DOUNTRUSTED; 3100 switch (trust = check_trust(ctx, num)) { 3101 case X509_TRUST_TRUSTED: 3102 case X509_TRUST_REJECTED: 3103 search = 0; 3104 continue; 3105 } 3106 if (ss == 0) 3107 continue; 3108 } 3109 } 3110 3111 /* 3112 * No dispositive decision, and either self-signed or no match, if 3113 * we were doing untrusted-first, and alt-chains are not disabled, 3114 * do that, by repeatedly losing one untrusted element at a time, 3115 * and trying to extend the shorted chain. 3116 */ 3117 if ((search & S_DOUNTRUSTED) == 0) { 3118 /* Continue search for a trusted issuer of a shorter chain? */ 3119 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0) 3120 continue; 3121 /* Still no luck and no fallbacks left? */ 3122 if (!may_alternate || (search & S_DOALTERNATE) != 0 || 3123 ctx->num_untrusted < 2) 3124 break; 3125 /* Search for a trusted issuer of a shorter chain */ 3126 search |= S_DOALTERNATE; 3127 alt_untrusted = ctx->num_untrusted - 1; 3128 ss = 0; 3129 } 3130 } 3131 3132 /* 3133 * Extend chain with peer-provided certificates 3134 */ 3135 if ((search & S_DOUNTRUSTED) != 0) { 3136 num = sk_X509_num(ctx->chain); 3137 if (!ossl_assert(num == ctx->num_untrusted)) { 3138 X509err(X509_F_BUILD_CHAIN, ERR_R_INTERNAL_ERROR); 3139 trust = X509_TRUST_REJECTED; 3140 ctx->error = X509_V_ERR_UNSPECIFIED; 3141 search = 0; 3142 continue; 3143 } 3144 x = sk_X509_value(ctx->chain, num-1); 3145 3146 /* 3147 * Once we run out of untrusted issuers, we stop looking for more 3148 * and start looking only in the trust store if enabled. 3149 */ 3150 xtmp = (ss || depth < num) ? NULL : find_issuer(ctx, sktmp, x); 3151 if (xtmp == NULL) { 3152 search &= ~S_DOUNTRUSTED; 3153 if (may_trusted) 3154 search |= S_DOTRUSTED; 3155 continue; 3156 } 3157 3158 /* Drop this issuer from future consideration */ 3159 (void) sk_X509_delete_ptr(sktmp, xtmp); 3160 3161 if (!sk_X509_push(ctx->chain, xtmp)) { 3162 X509err(X509_F_BUILD_CHAIN, ERR_R_MALLOC_FAILURE); 3163 trust = X509_TRUST_REJECTED; 3164 ctx->error = X509_V_ERR_OUT_OF_MEM; 3165 search = 0; 3166 continue; 3167 } 3168 3169 X509_up_ref(x = xtmp); 3170 ++ctx->num_untrusted; 3171 ss = cert_self_signed(xtmp); 3172 3173 /* 3174 * Check for DANE-TA trust of the topmost untrusted certificate. 3175 */ 3176 switch (trust = check_dane_issuer(ctx, ctx->num_untrusted - 1)) { 3177 case X509_TRUST_TRUSTED: 3178 case X509_TRUST_REJECTED: 3179 search = 0; 3180 continue; 3181 } 3182 } 3183 } 3184 sk_X509_free(sktmp); 3185 3186 /* 3187 * Last chance to make a trusted chain, either bare DANE-TA public-key 3188 * signers, or else direct leaf PKIX trust. 3189 */ 3190 num = sk_X509_num(ctx->chain); 3191 if (num <= depth) { 3192 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane)) 3193 trust = check_dane_pkeys(ctx); 3194 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted) 3195 trust = check_trust(ctx, num); 3196 } 3197 3198 switch (trust) { 3199 case X509_TRUST_TRUSTED: 3200 return 1; 3201 case X509_TRUST_REJECTED: 3202 /* Callback already issued */ 3203 return 0; 3204 case X509_TRUST_UNTRUSTED: 3205 default: 3206 num = sk_X509_num(ctx->chain); 3207 if (num > depth) 3208 return verify_cb_cert(ctx, NULL, num-1, 3209 X509_V_ERR_CERT_CHAIN_TOO_LONG); 3210 if (DANETLS_ENABLED(dane) && 3211 (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0)) 3212 return verify_cb_cert(ctx, NULL, num-1, X509_V_ERR_DANE_NO_MATCH); 3213 if (ss && sk_X509_num(ctx->chain) == 1) 3214 return verify_cb_cert(ctx, NULL, num-1, 3215 X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT); 3216 if (ss) 3217 return verify_cb_cert(ctx, NULL, num-1, 3218 X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN); 3219 if (ctx->num_untrusted < num) 3220 return verify_cb_cert(ctx, NULL, num-1, 3221 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT); 3222 return verify_cb_cert(ctx, NULL, num-1, 3223 X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY); 3224 } 3225 } 3226 3227 static const int minbits_table[] = { 80, 112, 128, 192, 256 }; 3228 static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table); 3229 3230 /* 3231 * Check whether the public key of ``cert`` meets the security level of 3232 * ``ctx``. 3233 * 3234 * Returns 1 on success, 0 otherwise. 3235 */ 3236 static int check_key_level(X509_STORE_CTX *ctx, X509 *cert) 3237 { 3238 EVP_PKEY *pkey = X509_get0_pubkey(cert); 3239 int level = ctx->param->auth_level; 3240 3241 /* 3242 * At security level zero, return without checking for a supported public 3243 * key type. Some engines support key types not understood outside the 3244 * engine, and we only need to understand the key when enforcing a security 3245 * floor. 3246 */ 3247 if (level <= 0) 3248 return 1; 3249 3250 /* Unsupported or malformed keys are not secure */ 3251 if (pkey == NULL) 3252 return 0; 3253 3254 if (level > NUM_AUTH_LEVELS) 3255 level = NUM_AUTH_LEVELS; 3256 3257 return EVP_PKEY_security_bits(pkey) >= minbits_table[level - 1]; 3258 } 3259 3260 /* 3261 * Check whether the signature digest algorithm of ``cert`` meets the security 3262 * level of ``ctx``. Should not be checked for trust anchors (whether 3263 * self-signed or otherwise). 3264 * 3265 * Returns 1 on success, 0 otherwise. 3266 */ 3267 static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert) 3268 { 3269 int secbits = -1; 3270 int level = ctx->param->auth_level; 3271 3272 if (level <= 0) 3273 return 1; 3274 if (level > NUM_AUTH_LEVELS) 3275 level = NUM_AUTH_LEVELS; 3276 3277 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL)) 3278 return 0; 3279 3280 return secbits >= minbits_table[level - 1]; 3281 } 3282