1/* 2 * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10#include "internal/deprecated.h" 11 12#include <stdio.h> 13#include <time.h> 14#include <errno.h> 15#include <limits.h> 16 17#include "crypto/ctype.h" 18#include "internal/cryptlib.h" 19#include <openssl/crypto.h> 20#include <openssl/buffer.h> 21#include <openssl/evp.h> 22#include <openssl/asn1.h> 23#include <openssl/x509.h> 24#include <openssl/x509v3.h> 25#include <openssl/objects.h> 26#include <openssl/core_names.h> 27#include "internal/dane.h" 28#include "crypto/x509.h" 29#include "x509_local.h" 30 31/* CRL score values */ 32 33#define CRL_SCORE_NOCRITICAL 0x100 /* No unhandled critical extensions */ 34#define CRL_SCORE_SCOPE 0x080 /* certificate is within CRL scope */ 35#define CRL_SCORE_TIME 0x040 /* CRL times valid */ 36#define CRL_SCORE_ISSUER_NAME 0x020 /* Issuer name matches certificate */ 37#define CRL_SCORE_VALID /* If this score or above CRL is probably valid */ \ 38 (CRL_SCORE_NOCRITICAL | CRL_SCORE_TIME | CRL_SCORE_SCOPE) 39#define CRL_SCORE_ISSUER_CERT 0x018 /* CRL issuer is certificate issuer */ 40#define CRL_SCORE_SAME_PATH 0x008 /* CRL issuer is on certificate path */ 41#define CRL_SCORE_AKID 0x004 /* CRL issuer matches CRL AKID */ 42#define CRL_SCORE_TIME_DELTA 0x002 /* Have a delta CRL with valid times */ 43 44static int build_chain(X509_STORE_CTX *ctx); 45static int verify_chain(X509_STORE_CTX *ctx); 46static int dane_verify(X509_STORE_CTX *ctx); 47static int null_callback(int ok, X509_STORE_CTX *e); 48static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer); 49static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x); 50static int check_extensions(X509_STORE_CTX *ctx); 51static int check_name_constraints(X509_STORE_CTX *ctx); 52static int check_id(X509_STORE_CTX *ctx); 53static int check_trust(X509_STORE_CTX *ctx, int num_untrusted); 54static int check_revocation(X509_STORE_CTX *ctx); 55static int check_cert(X509_STORE_CTX *ctx); 56static int check_policy(X509_STORE_CTX *ctx); 57static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x); 58static int check_dane_issuer(X509_STORE_CTX *ctx, int depth); 59static int check_key_level(X509_STORE_CTX *ctx, X509 *cert); 60static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert); 61static int check_curve(X509 *cert); 62 63static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 64 unsigned int *preasons, X509_CRL *crl, X509 *x); 65static int get_crl_delta(X509_STORE_CTX *ctx, 66 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x); 67static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, 68 int *pcrl_score, X509_CRL *base, 69 STACK_OF(X509_CRL) *crls); 70static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer, 71 int *pcrl_score); 72static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 73 unsigned int *preasons); 74static int check_crl_path(X509_STORE_CTX *ctx, X509 *x); 75static int check_crl_chain(X509_STORE_CTX *ctx, 76 STACK_OF(X509) *cert_path, 77 STACK_OF(X509) *crl_path); 78 79static int internal_verify(X509_STORE_CTX *ctx); 80 81static int null_callback(int ok, X509_STORE_CTX *e) 82{ 83 return ok; 84} 85 86/*- 87 * Return 1 if given cert is considered self-signed, 0 if not, or -1 on error. 88 * This actually verifies self-signedness only if requested. 89 * It calls ossl_x509v3_cache_extensions() 90 * to match issuer and subject names (i.e., the cert being self-issued) and any 91 * present authority key identifier to match the subject key identifier, etc. 92 */ 93int X509_self_signed(X509 *cert, int verify_signature) 94{ 95 EVP_PKEY *pkey; 96 97 if ((pkey = X509_get0_pubkey(cert)) == NULL) { /* handles cert == NULL */ 98 ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY); 99 return -1; 100 } 101 if (!ossl_x509v3_cache_extensions(cert)) 102 return -1; 103 if ((cert->ex_flags & EXFLAG_SS) == 0) 104 return 0; 105 if (!verify_signature) 106 return 1; 107 return X509_verify(cert, pkey); 108} 109 110/* 111 * Given a certificate, try and find an exact match in the store. 112 * Returns 1 on success, 0 on not found, -1 on internal error. 113 */ 114static int lookup_cert_match(X509 **result, X509_STORE_CTX *ctx, X509 *x) 115{ 116 STACK_OF(X509) *certs; 117 X509 *xtmp = NULL; 118 int i, ret; 119 120 *result = NULL; 121 /* Lookup all certs with matching subject name */ 122 ERR_set_mark(); 123 certs = ctx->lookup_certs(ctx, X509_get_subject_name(x)); 124 ERR_pop_to_mark(); 125 if (certs == NULL) 126 return -1; 127 /* Look for exact match */ 128 for (i = 0; i < sk_X509_num(certs); i++) { 129 xtmp = sk_X509_value(certs, i); 130 if (X509_cmp(xtmp, x) == 0) 131 break; 132 xtmp = NULL; 133 } 134 ret = xtmp != NULL; 135 if (ret) { 136 if (!X509_up_ref(xtmp)) 137 ret = -1; 138 else 139 *result = xtmp; 140 } 141 sk_X509_pop_free(certs, X509_free); 142 return ret; 143} 144 145/*- 146 * Inform the verify callback of an error. 147 * The error code is set to |err| if |err| is not X509_V_OK, else 148 * |ctx->error| is left unchanged (under the assumption it is set elsewhere). 149 * The error depth is |depth| if >= 0, else it defaults to |ctx->error_depth|. 150 * The error cert is |x| if not NULL, else defaults to the chain cert at depth. 151 * 152 * Returns 0 to abort verification with an error, non-zero to continue. 153 */ 154static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err) 155{ 156 if (depth < 0) 157 depth = ctx->error_depth; 158 else 159 ctx->error_depth = depth; 160 ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth); 161 if (err != X509_V_OK) 162 ctx->error = err; 163 return ctx->verify_cb(0, ctx); 164} 165 166#define CB_FAIL_IF(cond, ctx, cert, depth, err) \ 167 if ((cond) && verify_cb_cert(ctx, cert, depth, err) == 0) \ 168 return 0 169 170/*- 171 * Inform the verify callback of an error, CRL-specific variant. Here, the 172 * error depth and certificate are already set, we just specify the error 173 * number. 174 * 175 * Returns 0 to abort verification with an error, non-zero to continue. 176 */ 177static int verify_cb_crl(X509_STORE_CTX *ctx, int err) 178{ 179 ctx->error = err; 180 return ctx->verify_cb(0, ctx); 181} 182 183static int check_auth_level(X509_STORE_CTX *ctx) 184{ 185 int i; 186 int num = sk_X509_num(ctx->chain); 187 188 if (ctx->param->auth_level <= 0) 189 return 1; 190 191 for (i = 0; i < num; ++i) { 192 X509 *cert = sk_X509_value(ctx->chain, i); 193 194 /* 195 * We've already checked the security of the leaf key, so here we only 196 * check the security of issuer keys. 197 */ 198 CB_FAIL_IF(i > 0 && !check_key_level(ctx, cert), 199 ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL); 200 /* 201 * We also check the signature algorithm security of all certificates 202 * except those of the trust anchor at index num-1. 203 */ 204 CB_FAIL_IF(i < num - 1 && !check_sig_level(ctx, cert), 205 ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK); 206 } 207 return 1; 208} 209 210/* Returns -1 on internal error */ 211static int verify_chain(X509_STORE_CTX *ctx) 212{ 213 int err; 214 int ok; 215 216 if ((ok = build_chain(ctx)) <= 0 217 || (ok = check_extensions(ctx)) <= 0 218 || (ok = check_auth_level(ctx)) <= 0 219 || (ok = check_id(ctx)) <= 0 220 || (ok = X509_get_pubkey_parameters(NULL, ctx->chain) ? 1 : -1) <= 0 221 || (ok = ctx->check_revocation(ctx)) <= 0) 222 return ok; 223 224 err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain, 225 ctx->param->flags); 226 CB_FAIL_IF(err != X509_V_OK, ctx, NULL, ctx->error_depth, err); 227 228 /* Verify chain signatures and expiration times */ 229 ok = ctx->verify != NULL ? ctx->verify(ctx) : internal_verify(ctx); 230 if (ok <= 0) 231 return ok; 232 233 if ((ok = check_name_constraints(ctx)) <= 0) 234 return ok; 235 236#ifndef OPENSSL_NO_RFC3779 237 /* RFC 3779 path validation, now that CRL check has been done */ 238 if ((ok = X509v3_asid_validate_path(ctx)) <= 0) 239 return ok; 240 if ((ok = X509v3_addr_validate_path(ctx)) <= 0) 241 return ok; 242#endif 243 244 /* If we get this far evaluate policies */ 245 if ((ctx->param->flags & X509_V_FLAG_POLICY_CHECK) != 0) 246 ok = ctx->check_policy(ctx); 247 return ok; 248} 249 250int X509_STORE_CTX_verify(X509_STORE_CTX *ctx) 251{ 252 if (ctx == NULL) { 253 ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); 254 return -1; 255 } 256 if (ctx->cert == NULL && sk_X509_num(ctx->untrusted) >= 1) 257 ctx->cert = sk_X509_value(ctx->untrusted, 0); 258 return X509_verify_cert(ctx); 259} 260 261int X509_verify_cert(X509_STORE_CTX *ctx) 262{ 263 int ret; 264 265 if (ctx == NULL) { 266 ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); 267 return -1; 268 } 269 if (ctx->cert == NULL) { 270 ERR_raise(ERR_LIB_X509, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY); 271 ctx->error = X509_V_ERR_INVALID_CALL; 272 return -1; 273 } 274 275 if (ctx->chain != NULL) { 276 /* 277 * This X509_STORE_CTX has already been used to verify a cert. We 278 * cannot do another one. 279 */ 280 ERR_raise(ERR_LIB_X509, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 281 ctx->error = X509_V_ERR_INVALID_CALL; 282 return -1; 283 } 284 285 if (!ossl_x509_add_cert_new(&ctx->chain, ctx->cert, X509_ADD_FLAG_UP_REF)) { 286 ctx->error = X509_V_ERR_OUT_OF_MEM; 287 return -1; 288 } 289 ctx->num_untrusted = 1; 290 291 /* If the peer's public key is too weak, we can stop early. */ 292 CB_FAIL_IF(!check_key_level(ctx, ctx->cert), 293 ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL); 294 295 ret = DANETLS_ENABLED(ctx->dane) ? dane_verify(ctx) : verify_chain(ctx); 296 297 /* 298 * Safety-net. If we are returning an error, we must also set ctx->error, 299 * so that the chain is not considered verified should the error be ignored 300 * (e.g. TLS with SSL_VERIFY_NONE). 301 */ 302 if (ret <= 0 && ctx->error == X509_V_OK) 303 ctx->error = X509_V_ERR_UNSPECIFIED; 304 return ret; 305} 306 307static int sk_X509_contains(STACK_OF(X509) *sk, X509 *cert) 308{ 309 int i, n = sk_X509_num(sk); 310 311 for (i = 0; i < n; i++) 312 if (X509_cmp(sk_X509_value(sk, i), cert) == 0) 313 return 1; 314 return 0; 315} 316 317/* 318 * Find in given STACK_OF(X509) |sk| an issuer cert (if any) of given cert |x|. 319 * The issuer must not yet be in |ctx->chain|, yet allowing the exception that 320 * |x| is self-issued and |ctx->chain| has just one element. 321 * Prefer the first non-expired one, else take the most recently expired one. 322 */ 323static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x) 324{ 325 int i; 326 X509 *issuer, *rv = NULL; 327 328 for (i = 0; i < sk_X509_num(sk); i++) { 329 issuer = sk_X509_value(sk, i); 330 if (ctx->check_issued(ctx, x, issuer) 331 && (((x->ex_flags & EXFLAG_SI) != 0 && sk_X509_num(ctx->chain) == 1) 332 || !sk_X509_contains(ctx->chain, issuer))) { 333 if (ossl_x509_check_cert_time(ctx, issuer, -1)) 334 return issuer; 335 if (rv == NULL || ASN1_TIME_compare(X509_get0_notAfter(issuer), 336 X509_get0_notAfter(rv)) > 0) 337 rv = issuer; 338 } 339 } 340 return rv; 341} 342 343/* Check that the given certificate 'x' is issued by the certificate 'issuer' */ 344static int check_issued(ossl_unused X509_STORE_CTX *ctx, X509 *x, X509 *issuer) 345{ 346 int err = ossl_x509_likely_issued(issuer, x); 347 348 if (err == X509_V_OK) 349 return 1; 350 /* 351 * SUBJECT_ISSUER_MISMATCH just means 'x' is clearly not issued by 'issuer'. 352 * Every other error code likely indicates a real error. 353 */ 354 return 0; 355} 356 357/*- 358 * Alternative get_issuer method: look up from a STACK_OF(X509) in other_ctx. 359 * Returns -1 on internal error. 360 */ 361static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x) 362{ 363 *issuer = find_issuer(ctx, ctx->other_ctx, x); 364 if (*issuer != NULL) 365 return X509_up_ref(*issuer) ? 1 : -1; 366 return 0; 367} 368 369/*- 370 * Alternative lookup method: look from a STACK stored in other_ctx. 371 * Returns NULL on internal error (such as out of memory). 372 */ 373static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, 374 const X509_NAME *nm) 375{ 376 STACK_OF(X509) *sk = sk_X509_new_null(); 377 X509 *x; 378 int i; 379 380 if (sk == NULL) 381 return NULL; 382 for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) { 383 x = sk_X509_value(ctx->other_ctx, i); 384 if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) { 385 if (!X509_add_cert(sk, x, X509_ADD_FLAG_UP_REF)) { 386 sk_X509_pop_free(sk, X509_free); 387 ctx->error = X509_V_ERR_OUT_OF_MEM; 388 return NULL; 389 } 390 } 391 } 392 return sk; 393} 394 395/* 396 * Check EE or CA certificate purpose. For trusted certificates explicit local 397 * auxiliary trust can be used to override EKU-restrictions. 398 * Sadly, returns 0 also on internal error. 399 */ 400static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth, 401 int must_be_ca) 402{ 403 int tr_ok = X509_TRUST_UNTRUSTED; 404 405 /* 406 * For trusted certificates we want to see whether any auxiliary trust 407 * settings trump the purpose constraints. 408 * 409 * This is complicated by the fact that the trust ordinals in 410 * ctx->param->trust are entirely independent of the purpose ordinals in 411 * ctx->param->purpose! 412 * 413 * What connects them is their mutual initialization via calls from 414 * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets 415 * related values of both param->trust and param->purpose. It is however 416 * typically possible to infer associated trust values from a purpose value 417 * via the X509_PURPOSE API. 418 * 419 * Therefore, we can only check for trust overrides when the purpose we're 420 * checking is the same as ctx->param->purpose and ctx->param->trust is 421 * also set. 422 */ 423 if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose) 424 tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT); 425 426 switch (tr_ok) { 427 case X509_TRUST_TRUSTED: 428 return 1; 429 case X509_TRUST_REJECTED: 430 break; 431 default: 432 switch (X509_check_purpose(x, purpose, must_be_ca > 0)) { 433 case 1: 434 return 1; 435 case 0: 436 break; 437 default: 438 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0) 439 return 1; 440 } 441 break; 442 } 443 444 return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE); 445} 446 447/* 448 * Check extensions of a cert chain for consistency with the supplied purpose. 449 * Sadly, returns 0 also on internal error. 450 */ 451static int check_extensions(X509_STORE_CTX *ctx) 452{ 453 int i, must_be_ca, plen = 0; 454 X509 *x; 455 int ret, proxy_path_length = 0; 456 int purpose, allow_proxy_certs, num = sk_X509_num(ctx->chain); 457 458 /*- 459 * must_be_ca can have 1 of 3 values: 460 * -1: we accept both CA and non-CA certificates, to allow direct 461 * use of self-signed certificates (which are marked as CA). 462 * 0: we only accept non-CA certificates. This is currently not 463 * used, but the possibility is present for future extensions. 464 * 1: we only accept CA certificates. This is currently used for 465 * all certificates in the chain except the leaf certificate. 466 */ 467 must_be_ca = -1; 468 469 /* CRL path validation */ 470 if (ctx->parent != NULL) { 471 allow_proxy_certs = 0; 472 purpose = X509_PURPOSE_CRL_SIGN; 473 } else { 474 allow_proxy_certs = 475 (ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS) != 0; 476 purpose = ctx->param->purpose; 477 } 478 479 for (i = 0; i < num; i++) { 480 x = sk_X509_value(ctx->chain, i); 481 CB_FAIL_IF((ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) == 0 482 && (x->ex_flags & EXFLAG_CRITICAL) != 0, 483 ctx, x, i, X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION); 484 CB_FAIL_IF(!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY) != 0, 485 ctx, x, i, X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED); 486 ret = X509_check_ca(x); 487 switch (must_be_ca) { 488 case -1: 489 CB_FAIL_IF((ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0 490 && ret != 1 && ret != 0, 491 ctx, x, i, X509_V_ERR_INVALID_CA); 492 break; 493 case 0: 494 CB_FAIL_IF(ret != 0, ctx, x, i, X509_V_ERR_INVALID_NON_CA); 495 break; 496 default: 497 /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */ 498 CB_FAIL_IF(ret == 0 499 || ((i + 1 < num 500 || (ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0) 501 && ret != 1), ctx, x, i, X509_V_ERR_INVALID_CA); 502 break; 503 } 504 if (num > 1) { 505 /* Check for presence of explicit elliptic curve parameters */ 506 ret = check_curve(x); 507 CB_FAIL_IF(ret < 0, ctx, x, i, X509_V_ERR_UNSPECIFIED); 508 CB_FAIL_IF(ret == 0, ctx, x, i, X509_V_ERR_EC_KEY_EXPLICIT_PARAMS); 509 } 510 /* 511 * Do the following set of checks only if strict checking is requested 512 * and not for self-issued (including self-signed) EE (non-CA) certs 513 * because RFC 5280 does not apply to them according RFC 6818 section 2. 514 */ 515 if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0 516 && num > 1) { /* 517 * this should imply 518 * !(i == 0 && (x->ex_flags & EXFLAG_CA) == 0 519 * && (x->ex_flags & EXFLAG_SI) != 0) 520 */ 521 /* Check Basic Constraints according to RFC 5280 section 4.2.1.9 */ 522 if (x->ex_pathlen != -1) { 523 CB_FAIL_IF((x->ex_flags & EXFLAG_CA) == 0, 524 ctx, x, i, X509_V_ERR_PATHLEN_INVALID_FOR_NON_CA); 525 CB_FAIL_IF((x->ex_kusage & KU_KEY_CERT_SIGN) == 0, ctx, 526 x, i, X509_V_ERR_PATHLEN_WITHOUT_KU_KEY_CERT_SIGN); 527 } 528 CB_FAIL_IF((x->ex_flags & EXFLAG_CA) != 0 529 && (x->ex_flags & EXFLAG_BCONS) != 0 530 && (x->ex_flags & EXFLAG_BCONS_CRITICAL) == 0, 531 ctx, x, i, X509_V_ERR_CA_BCONS_NOT_CRITICAL); 532 /* Check Key Usage according to RFC 5280 section 4.2.1.3 */ 533 if ((x->ex_flags & EXFLAG_CA) != 0) { 534 CB_FAIL_IF((x->ex_flags & EXFLAG_KUSAGE) == 0, 535 ctx, x, i, X509_V_ERR_CA_CERT_MISSING_KEY_USAGE); 536 } else { 537 CB_FAIL_IF((x->ex_kusage & KU_KEY_CERT_SIGN) != 0, ctx, x, i, 538 X509_V_ERR_KU_KEY_CERT_SIGN_INVALID_FOR_NON_CA); 539 } 540 /* Check issuer is non-empty acc. to RFC 5280 section 4.1.2.4 */ 541 CB_FAIL_IF(X509_NAME_entry_count(X509_get_issuer_name(x)) == 0, 542 ctx, x, i, X509_V_ERR_ISSUER_NAME_EMPTY); 543 /* Check subject is non-empty acc. to RFC 5280 section 4.1.2.6 */ 544 CB_FAIL_IF(((x->ex_flags & EXFLAG_CA) != 0 545 || (x->ex_kusage & KU_CRL_SIGN) != 0 546 || x->altname == NULL) 547 && X509_NAME_entry_count(X509_get_subject_name(x)) == 0, 548 ctx, x, i, X509_V_ERR_SUBJECT_NAME_EMPTY); 549 CB_FAIL_IF(X509_NAME_entry_count(X509_get_subject_name(x)) == 0 550 && x->altname != NULL 551 && (x->ex_flags & EXFLAG_SAN_CRITICAL) == 0, 552 ctx, x, i, X509_V_ERR_EMPTY_SUBJECT_SAN_NOT_CRITICAL); 553 /* Check SAN is non-empty according to RFC 5280 section 4.2.1.6 */ 554 CB_FAIL_IF(x->altname != NULL 555 && sk_GENERAL_NAME_num(x->altname) <= 0, 556 ctx, x, i, X509_V_ERR_EMPTY_SUBJECT_ALT_NAME); 557 /* Check sig alg consistency acc. to RFC 5280 section 4.1.1.2 */ 558 CB_FAIL_IF(X509_ALGOR_cmp(&x->sig_alg, &x->cert_info.signature) != 0, 559 ctx, x, i, X509_V_ERR_SIGNATURE_ALGORITHM_INCONSISTENCY); 560 CB_FAIL_IF(x->akid != NULL 561 && (x->ex_flags & EXFLAG_AKID_CRITICAL) != 0, 562 ctx, x, i, X509_V_ERR_AUTHORITY_KEY_IDENTIFIER_CRITICAL); 563 CB_FAIL_IF(x->skid != NULL 564 && (x->ex_flags & EXFLAG_SKID_CRITICAL) != 0, 565 ctx, x, i, X509_V_ERR_SUBJECT_KEY_IDENTIFIER_CRITICAL); 566 if (X509_get_version(x) >= X509_VERSION_3) { 567 /* Check AKID presence acc. to RFC 5280 section 4.2.1.1 */ 568 CB_FAIL_IF(i + 1 < num /* 569 * this means not last cert in chain, 570 * taken as "generated by conforming CAs" 571 */ 572 && (x->akid == NULL || x->akid->keyid == NULL), ctx, 573 x, i, X509_V_ERR_MISSING_AUTHORITY_KEY_IDENTIFIER); 574 /* Check SKID presence acc. to RFC 5280 section 4.2.1.2 */ 575 CB_FAIL_IF((x->ex_flags & EXFLAG_CA) != 0 && x->skid == NULL, 576 ctx, x, i, X509_V_ERR_MISSING_SUBJECT_KEY_IDENTIFIER); 577 } else { 578 CB_FAIL_IF(sk_X509_EXTENSION_num(X509_get0_extensions(x)) > 0, 579 ctx, x, i, X509_V_ERR_EXTENSIONS_REQUIRE_VERSION_3); 580 } 581 } 582 583 /* check_purpose() makes the callback as needed */ 584 if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca)) 585 return 0; 586 /* Check path length */ 587 CB_FAIL_IF(i > 1 && x->ex_pathlen != -1 588 && plen > x->ex_pathlen + proxy_path_length, 589 ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED); 590 /* Increment path length if not a self-issued intermediate CA */ 591 if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0) 592 plen++; 593 /* 594 * If this certificate is a proxy certificate, the next certificate 595 * must be another proxy certificate or a EE certificate. If not, 596 * the next certificate must be a CA certificate. 597 */ 598 if (x->ex_flags & EXFLAG_PROXY) { 599 /* 600 * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint 601 * is less than max_path_length, the former should be copied to 602 * the latter, and 4.1.4 (a) stipulates that max_path_length 603 * should be verified to be larger than zero and decrement it. 604 * 605 * Because we're checking the certs in the reverse order, we start 606 * with verifying that proxy_path_length isn't larger than pcPLC, 607 * and copy the latter to the former if it is, and finally, 608 * increment proxy_path_length. 609 */ 610 if (x->ex_pcpathlen != -1) { 611 CB_FAIL_IF(proxy_path_length > x->ex_pcpathlen, 612 ctx, x, i, X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED); 613 proxy_path_length = x->ex_pcpathlen; 614 } 615 proxy_path_length++; 616 must_be_ca = 0; 617 } else { 618 must_be_ca = 1; 619 } 620 } 621 return 1; 622} 623 624static int has_san_id(X509 *x, int gtype) 625{ 626 int i; 627 int ret = 0; 628 GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); 629 630 if (gs == NULL) 631 return 0; 632 633 for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) { 634 GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i); 635 636 if (g->type == gtype) { 637 ret = 1; 638 break; 639 } 640 } 641 GENERAL_NAMES_free(gs); 642 return ret; 643} 644 645/* Returns -1 on internal error */ 646static int check_name_constraints(X509_STORE_CTX *ctx) 647{ 648 int i; 649 650 /* Check name constraints for all certificates */ 651 for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) { 652 X509 *x = sk_X509_value(ctx->chain, i); 653 int j; 654 655 /* Ignore self-issued certs unless last in chain */ 656 if (i != 0 && (x->ex_flags & EXFLAG_SI) != 0) 657 continue; 658 659 /* 660 * Proxy certificates policy has an extra constraint, where the 661 * certificate subject MUST be the issuer with a single CN entry 662 * added. 663 * (RFC 3820: 3.4, 4.1.3 (a)(4)) 664 */ 665 if ((x->ex_flags & EXFLAG_PROXY) != 0) { 666 X509_NAME *tmpsubject = X509_get_subject_name(x); 667 X509_NAME *tmpissuer = X509_get_issuer_name(x); 668 X509_NAME_ENTRY *tmpentry = NULL; 669 int last_nid = 0; 670 int err = X509_V_OK; 671 int last_loc = X509_NAME_entry_count(tmpsubject) - 1; 672 673 /* Check that there are at least two RDNs */ 674 if (last_loc < 1) { 675 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 676 goto proxy_name_done; 677 } 678 679 /* 680 * Check that there is exactly one more RDN in subject as 681 * there is in issuer. 682 */ 683 if (X509_NAME_entry_count(tmpsubject) 684 != X509_NAME_entry_count(tmpissuer) + 1) { 685 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 686 goto proxy_name_done; 687 } 688 689 /* 690 * Check that the last subject component isn't part of a 691 * multi-valued RDN 692 */ 693 if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, last_loc)) 694 == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, 695 last_loc - 1))) { 696 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 697 goto proxy_name_done; 698 } 699 700 /* 701 * Check that the last subject RDN is a commonName, and that 702 * all the previous RDNs match the issuer exactly 703 */ 704 tmpsubject = X509_NAME_dup(tmpsubject); 705 if (tmpsubject == NULL) { 706 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 707 ctx->error = X509_V_ERR_OUT_OF_MEM; 708 return -1; 709 } 710 711 tmpentry = X509_NAME_delete_entry(tmpsubject, last_loc); 712 last_nid = OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry)); 713 714 if (last_nid != NID_commonName 715 || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) { 716 err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; 717 } 718 719 X509_NAME_ENTRY_free(tmpentry); 720 X509_NAME_free(tmpsubject); 721 722 proxy_name_done: 723 CB_FAIL_IF(err != X509_V_OK, ctx, x, i, err); 724 } 725 726 /* 727 * Check against constraints for all certificates higher in chain 728 * including trust anchor. Trust anchor not strictly speaking needed 729 * but if it includes constraints it is to be assumed it expects them 730 * to be obeyed. 731 */ 732 for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) { 733 NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc; 734 735 if (nc) { 736 int rv = NAME_CONSTRAINTS_check(x, nc); 737 int ret = 1; 738 739 /* If EE certificate check commonName too */ 740 if (rv == X509_V_OK && i == 0 741 && (ctx->param->hostflags 742 & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0 743 && ((ctx->param->hostflags 744 & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0 745 || (ret = has_san_id(x, GEN_DNS)) == 0)) 746 rv = NAME_CONSTRAINTS_check_CN(x, nc); 747 if (ret < 0) 748 return ret; 749 750 switch (rv) { 751 case X509_V_OK: 752 break; 753 case X509_V_ERR_OUT_OF_MEM: 754 return -1; 755 default: 756 CB_FAIL_IF(1, ctx, x, i, rv); 757 break; 758 } 759 } 760 } 761 } 762 return 1; 763} 764 765static int check_id_error(X509_STORE_CTX *ctx, int errcode) 766{ 767 return verify_cb_cert(ctx, ctx->cert, 0, errcode); 768} 769 770static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm) 771{ 772 int i; 773 int n = sk_OPENSSL_STRING_num(vpm->hosts); 774 char *name; 775 776 if (vpm->peername != NULL) { 777 OPENSSL_free(vpm->peername); 778 vpm->peername = NULL; 779 } 780 for (i = 0; i < n; ++i) { 781 name = sk_OPENSSL_STRING_value(vpm->hosts, i); 782 if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0) 783 return 1; 784 } 785 return n == 0; 786} 787 788static int check_id(X509_STORE_CTX *ctx) 789{ 790 X509_VERIFY_PARAM *vpm = ctx->param; 791 X509 *x = ctx->cert; 792 793 if (vpm->hosts != NULL && check_hosts(x, vpm) <= 0) { 794 if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH)) 795 return 0; 796 } 797 if (vpm->email != NULL 798 && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) { 799 if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH)) 800 return 0; 801 } 802 if (vpm->ip != NULL && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) { 803 if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH)) 804 return 0; 805 } 806 return 1; 807} 808 809/* Returns -1 on internal error */ 810static int check_trust(X509_STORE_CTX *ctx, int num_untrusted) 811{ 812 int i, res; 813 X509 *x = NULL; 814 X509 *mx; 815 SSL_DANE *dane = ctx->dane; 816 int num = sk_X509_num(ctx->chain); 817 int trust; 818 819 /* 820 * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2) 821 * match, we're done, otherwise we'll merely record the match depth. 822 */ 823 if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) { 824 trust = check_dane_issuer(ctx, num_untrusted); 825 if (trust != X509_TRUST_UNTRUSTED) 826 return trust; 827 } 828 829 /* 830 * Check trusted certificates in chain at depth num_untrusted and up. 831 * Note, that depths 0..num_untrusted-1 may also contain trusted 832 * certificates, but the caller is expected to have already checked those, 833 * and wants to incrementally check just any added since. 834 */ 835 for (i = num_untrusted; i < num; i++) { 836 x = sk_X509_value(ctx->chain, i); 837 trust = X509_check_trust(x, ctx->param->trust, 0); 838 /* If explicitly trusted (so not neutral nor rejected) return trusted */ 839 if (trust == X509_TRUST_TRUSTED) 840 goto trusted; 841 if (trust == X509_TRUST_REJECTED) 842 goto rejected; 843 } 844 845 /* 846 * If we are looking at a trusted certificate, and accept partial chains, 847 * the chain is PKIX trusted. 848 */ 849 if (num_untrusted < num) { 850 if ((ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) != 0) 851 goto trusted; 852 return X509_TRUST_UNTRUSTED; 853 } 854 855 if (num_untrusted == num 856 && (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) != 0) { 857 /* 858 * Last-resort call with no new trusted certificates, check the leaf 859 * for a direct trust store match. 860 */ 861 i = 0; 862 x = sk_X509_value(ctx->chain, i); 863 res = lookup_cert_match(&mx, ctx, x); 864 if (res < 0) 865 return res; 866 if (mx == NULL) 867 return X509_TRUST_UNTRUSTED; 868 869 /* 870 * Check explicit auxiliary trust/reject settings. If none are set, 871 * we'll accept X509_TRUST_UNTRUSTED when not self-signed. 872 */ 873 trust = X509_check_trust(mx, ctx->param->trust, 0); 874 if (trust == X509_TRUST_REJECTED) { 875 X509_free(mx); 876 goto rejected; 877 } 878 879 /* Replace leaf with trusted match */ 880 (void)sk_X509_set(ctx->chain, 0, mx); 881 X509_free(x); 882 ctx->num_untrusted = 0; 883 goto trusted; 884 } 885 886 /* 887 * If no trusted certs in chain at all return untrusted and allow 888 * standard (no issuer cert) etc errors to be indicated. 889 */ 890 return X509_TRUST_UNTRUSTED; 891 892 rejected: 893 return verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED) == 0 894 ? X509_TRUST_REJECTED : X509_TRUST_UNTRUSTED; 895 896 trusted: 897 if (!DANETLS_ENABLED(dane)) 898 return X509_TRUST_TRUSTED; 899 if (dane->pdpth < 0) 900 dane->pdpth = num_untrusted; 901 /* With DANE, PKIX alone is not trusted until we have both */ 902 if (dane->mdpth >= 0) 903 return X509_TRUST_TRUSTED; 904 return X509_TRUST_UNTRUSTED; 905} 906 907/* Sadly, returns 0 also on internal error. */ 908static int check_revocation(X509_STORE_CTX *ctx) 909{ 910 int i = 0, last = 0, ok = 0; 911 912 if ((ctx->param->flags & X509_V_FLAG_CRL_CHECK) == 0) 913 return 1; 914 if ((ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL) != 0) { 915 last = sk_X509_num(ctx->chain) - 1; 916 } else { 917 /* If checking CRL paths this isn't the EE certificate */ 918 if (ctx->parent) 919 return 1; 920 last = 0; 921 } 922 for (i = 0; i <= last; i++) { 923 ctx->error_depth = i; 924 ok = check_cert(ctx); 925 if (!ok) 926 return ok; 927 } 928 return 1; 929} 930 931/* Sadly, returns 0 also on internal error. */ 932static int check_cert(X509_STORE_CTX *ctx) 933{ 934 X509_CRL *crl = NULL, *dcrl = NULL; 935 int ok = 0; 936 int cnum = ctx->error_depth; 937 X509 *x = sk_X509_value(ctx->chain, cnum); 938 939 ctx->current_cert = x; 940 ctx->current_issuer = NULL; 941 ctx->current_crl_score = 0; 942 ctx->current_reasons = 0; 943 944 if ((x->ex_flags & EXFLAG_PROXY) != 0) 945 return 1; 946 947 while (ctx->current_reasons != CRLDP_ALL_REASONS) { 948 unsigned int last_reasons = ctx->current_reasons; 949 950 /* Try to retrieve relevant CRL */ 951 if (ctx->get_crl != NULL) 952 ok = ctx->get_crl(ctx, &crl, x); 953 else 954 ok = get_crl_delta(ctx, &crl, &dcrl, x); 955 /* If error looking up CRL, nothing we can do except notify callback */ 956 if (!ok) { 957 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 958 goto done; 959 } 960 ctx->current_crl = crl; 961 ok = ctx->check_crl(ctx, crl); 962 if (!ok) 963 goto done; 964 965 if (dcrl != NULL) { 966 ok = ctx->check_crl(ctx, dcrl); 967 if (!ok) 968 goto done; 969 ok = ctx->cert_crl(ctx, dcrl, x); 970 if (!ok) 971 goto done; 972 } else { 973 ok = 1; 974 } 975 976 /* Don't look in full CRL if delta reason is removefromCRL */ 977 if (ok != 2) { 978 ok = ctx->cert_crl(ctx, crl, x); 979 if (!ok) 980 goto done; 981 } 982 983 X509_CRL_free(crl); 984 X509_CRL_free(dcrl); 985 crl = NULL; 986 dcrl = NULL; 987 /* 988 * If reasons not updated we won't get anywhere by another iteration, 989 * so exit loop. 990 */ 991 if (last_reasons == ctx->current_reasons) { 992 ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); 993 goto done; 994 } 995 } 996 done: 997 X509_CRL_free(crl); 998 X509_CRL_free(dcrl); 999 1000 ctx->current_crl = NULL; 1001 return ok; 1002} 1003 1004/* Check CRL times against values in X509_STORE_CTX */ 1005static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify) 1006{ 1007 time_t *ptime; 1008 int i; 1009 1010 if ((ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) != 0) 1011 ptime = &ctx->param->check_time; 1012 else if ((ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) != 0) 1013 return 1; 1014 else 1015 ptime = NULL; 1016 if (notify) 1017 ctx->current_crl = crl; 1018 1019 i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime); 1020 if (i == 0) { 1021 if (!notify) 1022 return 0; 1023 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD)) 1024 return 0; 1025 } 1026 1027 if (i > 0) { 1028 if (!notify) 1029 return 0; 1030 if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID)) 1031 return 0; 1032 } 1033 1034 if (X509_CRL_get0_nextUpdate(crl)) { 1035 i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime); 1036 1037 if (i == 0) { 1038 if (!notify) 1039 return 0; 1040 if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD)) 1041 return 0; 1042 } 1043 /* Ignore expiration of base CRL is delta is valid */ 1044 if (i < 0 && (ctx->current_crl_score & CRL_SCORE_TIME_DELTA) == 0) { 1045 if (!notify || !verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED)) 1046 return 0; 1047 } 1048 } 1049 1050 if (notify) 1051 ctx->current_crl = NULL; 1052 1053 return 1; 1054} 1055 1056static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, 1057 X509 **pissuer, int *pscore, unsigned int *preasons, 1058 STACK_OF(X509_CRL) *crls) 1059{ 1060 int i, crl_score, best_score = *pscore; 1061 unsigned int reasons, best_reasons = 0; 1062 X509 *x = ctx->current_cert; 1063 X509_CRL *crl, *best_crl = NULL; 1064 X509 *crl_issuer = NULL, *best_crl_issuer = NULL; 1065 1066 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1067 crl = sk_X509_CRL_value(crls, i); 1068 reasons = *preasons; 1069 crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x); 1070 if (crl_score < best_score || crl_score == 0) 1071 continue; 1072 /* If current CRL is equivalent use it if it is newer */ 1073 if (crl_score == best_score && best_crl != NULL) { 1074 int day, sec; 1075 1076 if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl), 1077 X509_CRL_get0_lastUpdate(crl)) == 0) 1078 continue; 1079 /* 1080 * ASN1_TIME_diff never returns inconsistent signs for |day| 1081 * and |sec|. 1082 */ 1083 if (day <= 0 && sec <= 0) 1084 continue; 1085 } 1086 best_crl = crl; 1087 best_crl_issuer = crl_issuer; 1088 best_score = crl_score; 1089 best_reasons = reasons; 1090 } 1091 1092 if (best_crl != NULL) { 1093 X509_CRL_free(*pcrl); 1094 *pcrl = best_crl; 1095 *pissuer = best_crl_issuer; 1096 *pscore = best_score; 1097 *preasons = best_reasons; 1098 X509_CRL_up_ref(best_crl); 1099 X509_CRL_free(*pdcrl); 1100 *pdcrl = NULL; 1101 get_delta_sk(ctx, pdcrl, pscore, best_crl, crls); 1102 } 1103 1104 if (best_score >= CRL_SCORE_VALID) 1105 return 1; 1106 1107 return 0; 1108} 1109 1110/* 1111 * Compare two CRL extensions for delta checking purposes. They should be 1112 * both present or both absent. If both present all fields must be identical. 1113 */ 1114static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid) 1115{ 1116 ASN1_OCTET_STRING *exta = NULL, *extb = NULL; 1117 int i = X509_CRL_get_ext_by_NID(a, nid, -1); 1118 1119 if (i >= 0) { 1120 /* Can't have multiple occurrences */ 1121 if (X509_CRL_get_ext_by_NID(a, nid, i) != -1) 1122 return 0; 1123 exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i)); 1124 } 1125 1126 i = X509_CRL_get_ext_by_NID(b, nid, -1); 1127 if (i >= 0) { 1128 if (X509_CRL_get_ext_by_NID(b, nid, i) != -1) 1129 return 0; 1130 extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i)); 1131 } 1132 1133 if (exta == NULL && extb == NULL) 1134 return 1; 1135 1136 if (exta == NULL || extb == NULL) 1137 return 0; 1138 1139 return ASN1_OCTET_STRING_cmp(exta, extb) == 0; 1140} 1141 1142/* See if a base and delta are compatible */ 1143static int check_delta_base(X509_CRL *delta, X509_CRL *base) 1144{ 1145 /* Delta CRL must be a delta */ 1146 if (delta->base_crl_number == NULL) 1147 return 0; 1148 /* Base must have a CRL number */ 1149 if (base->crl_number == NULL) 1150 return 0; 1151 /* Issuer names must match */ 1152 if (X509_NAME_cmp(X509_CRL_get_issuer(base), 1153 X509_CRL_get_issuer(delta)) != 0) 1154 return 0; 1155 /* AKID and IDP must match */ 1156 if (!crl_extension_match(delta, base, NID_authority_key_identifier)) 1157 return 0; 1158 if (!crl_extension_match(delta, base, NID_issuing_distribution_point)) 1159 return 0; 1160 /* Delta CRL base number must not exceed Full CRL number. */ 1161 if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0) 1162 return 0; 1163 /* Delta CRL number must exceed full CRL number */ 1164 return ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0; 1165} 1166 1167/* 1168 * For a given base CRL find a delta... maybe extend to delta scoring or 1169 * retrieve a chain of deltas... 1170 */ 1171static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore, 1172 X509_CRL *base, STACK_OF(X509_CRL) *crls) 1173{ 1174 X509_CRL *delta; 1175 int i; 1176 1177 if ((ctx->param->flags & X509_V_FLAG_USE_DELTAS) == 0) 1178 return; 1179 if (((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST) == 0) 1180 return; 1181 for (i = 0; i < sk_X509_CRL_num(crls); i++) { 1182 delta = sk_X509_CRL_value(crls, i); 1183 if (check_delta_base(delta, base)) { 1184 if (check_crl_time(ctx, delta, 0)) 1185 *pscore |= CRL_SCORE_TIME_DELTA; 1186 X509_CRL_up_ref(delta); 1187 *dcrl = delta; 1188 return; 1189 } 1190 } 1191 *dcrl = NULL; 1192} 1193 1194/* 1195 * For a given CRL return how suitable it is for the supplied certificate 1196 * 'x'. The return value is a mask of several criteria. If the issuer is not 1197 * the certificate issuer this is returned in *pissuer. The reasons mask is 1198 * also used to determine if the CRL is suitable: if no new reasons the CRL 1199 * is rejected, otherwise reasons is updated. 1200 */ 1201static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, 1202 unsigned int *preasons, X509_CRL *crl, X509 *x) 1203{ 1204 int crl_score = 0; 1205 unsigned int tmp_reasons = *preasons, crl_reasons; 1206 1207 /* First see if we can reject CRL straight away */ 1208 1209 /* Invalid IDP cannot be processed */ 1210 if ((crl->idp_flags & IDP_INVALID) != 0) 1211 return 0; 1212 /* Reason codes or indirect CRLs need extended CRL support */ 1213 if ((ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT) == 0) { 1214 if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS)) 1215 return 0; 1216 } else if ((crl->idp_flags & IDP_REASONS) != 0) { 1217 /* If no new reasons reject */ 1218 if ((crl->idp_reasons & ~tmp_reasons) == 0) 1219 return 0; 1220 } 1221 /* Don't process deltas at this stage */ 1222 else if (crl->base_crl_number != NULL) 1223 return 0; 1224 /* If issuer name doesn't match certificate need indirect CRL */ 1225 if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl)) != 0) { 1226 if ((crl->idp_flags & IDP_INDIRECT) == 0) 1227 return 0; 1228 } else { 1229 crl_score |= CRL_SCORE_ISSUER_NAME; 1230 } 1231 1232 if ((crl->flags & EXFLAG_CRITICAL) == 0) 1233 crl_score |= CRL_SCORE_NOCRITICAL; 1234 1235 /* Check expiration */ 1236 if (check_crl_time(ctx, crl, 0)) 1237 crl_score |= CRL_SCORE_TIME; 1238 1239 /* Check authority key ID and locate certificate issuer */ 1240 crl_akid_check(ctx, crl, pissuer, &crl_score); 1241 1242 /* If we can't locate certificate issuer at this point forget it */ 1243 if ((crl_score & CRL_SCORE_AKID) == 0) 1244 return 0; 1245 1246 /* Check cert for matching CRL distribution points */ 1247 if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) { 1248 /* If no new reasons reject */ 1249 if ((crl_reasons & ~tmp_reasons) == 0) 1250 return 0; 1251 tmp_reasons |= crl_reasons; 1252 crl_score |= CRL_SCORE_SCOPE; 1253 } 1254 1255 *preasons = tmp_reasons; 1256 1257 return crl_score; 1258 1259} 1260 1261static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, 1262 X509 **pissuer, int *pcrl_score) 1263{ 1264 X509 *crl_issuer = NULL; 1265 const X509_NAME *cnm = X509_CRL_get_issuer(crl); 1266 int cidx = ctx->error_depth; 1267 int i; 1268 1269 if (cidx != sk_X509_num(ctx->chain) - 1) 1270 cidx++; 1271 1272 crl_issuer = sk_X509_value(ctx->chain, cidx); 1273 1274 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1275 if (*pcrl_score & CRL_SCORE_ISSUER_NAME) { 1276 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT; 1277 *pissuer = crl_issuer; 1278 return; 1279 } 1280 } 1281 1282 for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) { 1283 crl_issuer = sk_X509_value(ctx->chain, cidx); 1284 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) 1285 continue; 1286 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1287 *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH; 1288 *pissuer = crl_issuer; 1289 return; 1290 } 1291 } 1292 1293 /* Anything else needs extended CRL support */ 1294 if ((ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT) == 0) 1295 return; 1296 1297 /* 1298 * Otherwise the CRL issuer is not on the path. Look for it in the set of 1299 * untrusted certificates. 1300 */ 1301 for (i = 0; i < sk_X509_num(ctx->untrusted); i++) { 1302 crl_issuer = sk_X509_value(ctx->untrusted, i); 1303 if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm) != 0) 1304 continue; 1305 if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { 1306 *pissuer = crl_issuer; 1307 *pcrl_score |= CRL_SCORE_AKID; 1308 return; 1309 } 1310 } 1311} 1312 1313/* 1314 * Check the path of a CRL issuer certificate. This creates a new 1315 * X509_STORE_CTX and populates it with most of the parameters from the 1316 * parent. This could be optimised somewhat since a lot of path checking will 1317 * be duplicated by the parent, but this will rarely be used in practice. 1318 */ 1319static int check_crl_path(X509_STORE_CTX *ctx, X509 *x) 1320{ 1321 X509_STORE_CTX crl_ctx = {0}; 1322 int ret; 1323 1324 /* Don't allow recursive CRL path validation */ 1325 if (ctx->parent != NULL) 1326 return 0; 1327 if (!X509_STORE_CTX_init(&crl_ctx, ctx->store, x, ctx->untrusted)) 1328 return -1; 1329 1330 crl_ctx.crls = ctx->crls; 1331 /* Copy verify params across */ 1332 X509_STORE_CTX_set0_param(&crl_ctx, ctx->param); 1333 1334 crl_ctx.parent = ctx; 1335 crl_ctx.verify_cb = ctx->verify_cb; 1336 1337 /* Verify CRL issuer */ 1338 ret = X509_verify_cert(&crl_ctx); 1339 if (ret <= 0) 1340 goto err; 1341 1342 /* Check chain is acceptable */ 1343 ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain); 1344 err: 1345 X509_STORE_CTX_cleanup(&crl_ctx); 1346 return ret; 1347} 1348 1349/* 1350 * RFC3280 says nothing about the relationship between CRL path and 1351 * certificate path, which could lead to situations where a certificate could 1352 * be revoked or validated by a CA not authorized to do so. RFC5280 is more 1353 * strict and states that the two paths must end in the same trust anchor, 1354 * though some discussions remain... until this is resolved we use the 1355 * RFC5280 version 1356 */ 1357static int check_crl_chain(X509_STORE_CTX *ctx, 1358 STACK_OF(X509) *cert_path, 1359 STACK_OF(X509) *crl_path) 1360{ 1361 X509 *cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1); 1362 X509 *crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1); 1363 1364 return X509_cmp(cert_ta, crl_ta) == 0; 1365} 1366 1367/*- 1368 * Check for match between two dist point names: three separate cases. 1369 * 1. Both are relative names and compare X509_NAME types. 1370 * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES. 1371 * 3. Both are full names and compare two GENERAL_NAMES. 1372 * 4. One is NULL: automatic match. 1373 */ 1374static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b) 1375{ 1376 X509_NAME *nm = NULL; 1377 GENERAL_NAMES *gens = NULL; 1378 GENERAL_NAME *gena, *genb; 1379 int i, j; 1380 1381 if (a == NULL || b == NULL) 1382 return 1; 1383 if (a->type == 1) { 1384 if (a->dpname == NULL) 1385 return 0; 1386 /* Case 1: two X509_NAME */ 1387 if (b->type == 1) { 1388 if (b->dpname == NULL) 1389 return 0; 1390 return X509_NAME_cmp(a->dpname, b->dpname) == 0; 1391 } 1392 /* Case 2: set name and GENERAL_NAMES appropriately */ 1393 nm = a->dpname; 1394 gens = b->name.fullname; 1395 } else if (b->type == 1) { 1396 if (b->dpname == NULL) 1397 return 0; 1398 /* Case 2: set name and GENERAL_NAMES appropriately */ 1399 gens = a->name.fullname; 1400 nm = b->dpname; 1401 } 1402 1403 /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */ 1404 if (nm != NULL) { 1405 for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { 1406 gena = sk_GENERAL_NAME_value(gens, i); 1407 if (gena->type != GEN_DIRNAME) 1408 continue; 1409 if (X509_NAME_cmp(nm, gena->d.directoryName) == 0) 1410 return 1; 1411 } 1412 return 0; 1413 } 1414 1415 /* Else case 3: two GENERAL_NAMES */ 1416 1417 for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) { 1418 gena = sk_GENERAL_NAME_value(a->name.fullname, i); 1419 for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) { 1420 genb = sk_GENERAL_NAME_value(b->name.fullname, j); 1421 if (GENERAL_NAME_cmp(gena, genb) == 0) 1422 return 1; 1423 } 1424 } 1425 1426 return 0; 1427 1428} 1429 1430static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score) 1431{ 1432 int i; 1433 const X509_NAME *nm = X509_CRL_get_issuer(crl); 1434 1435 /* If no CRLissuer return is successful iff don't need a match */ 1436 if (dp->CRLissuer == NULL) 1437 return (crl_score & CRL_SCORE_ISSUER_NAME) != 0; 1438 for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { 1439 GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); 1440 1441 if (gen->type != GEN_DIRNAME) 1442 continue; 1443 if (X509_NAME_cmp(gen->d.directoryName, nm) == 0) 1444 return 1; 1445 } 1446 return 0; 1447} 1448 1449/* Check CRLDP and IDP */ 1450static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, 1451 unsigned int *preasons) 1452{ 1453 int i; 1454 1455 if ((crl->idp_flags & IDP_ONLYATTR) != 0) 1456 return 0; 1457 if ((x->ex_flags & EXFLAG_CA) != 0) { 1458 if ((crl->idp_flags & IDP_ONLYUSER) != 0) 1459 return 0; 1460 } else { 1461 if ((crl->idp_flags & IDP_ONLYCA) != 0) 1462 return 0; 1463 } 1464 *preasons = crl->idp_reasons; 1465 for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) { 1466 DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i); 1467 1468 if (crldp_check_crlissuer(dp, crl, crl_score)) { 1469 if (crl->idp == NULL 1470 || idp_check_dp(dp->distpoint, crl->idp->distpoint)) { 1471 *preasons &= dp->dp_reasons; 1472 return 1; 1473 } 1474 } 1475 } 1476 return (crl->idp == NULL || crl->idp->distpoint == NULL) 1477 && (crl_score & CRL_SCORE_ISSUER_NAME) != 0; 1478} 1479 1480/* 1481 * Retrieve CRL corresponding to current certificate. If deltas enabled try 1482 * to find a delta CRL too 1483 */ 1484static int get_crl_delta(X509_STORE_CTX *ctx, 1485 X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x) 1486{ 1487 int ok; 1488 X509 *issuer = NULL; 1489 int crl_score = 0; 1490 unsigned int reasons; 1491 X509_CRL *crl = NULL, *dcrl = NULL; 1492 STACK_OF(X509_CRL) *skcrl; 1493 const X509_NAME *nm = X509_get_issuer_name(x); 1494 1495 reasons = ctx->current_reasons; 1496 ok = get_crl_sk(ctx, &crl, &dcrl, 1497 &issuer, &crl_score, &reasons, ctx->crls); 1498 if (ok) 1499 goto done; 1500 1501 /* Lookup CRLs from store */ 1502 skcrl = ctx->lookup_crls(ctx, nm); 1503 1504 /* If no CRLs found and a near match from get_crl_sk use that */ 1505 if (skcrl == NULL && crl != NULL) 1506 goto done; 1507 1508 get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl); 1509 1510 sk_X509_CRL_pop_free(skcrl, X509_CRL_free); 1511 1512 done: 1513 /* If we got any kind of CRL use it and return success */ 1514 if (crl != NULL) { 1515 ctx->current_issuer = issuer; 1516 ctx->current_crl_score = crl_score; 1517 ctx->current_reasons = reasons; 1518 *pcrl = crl; 1519 *pdcrl = dcrl; 1520 return 1; 1521 } 1522 return 0; 1523} 1524 1525/* Check CRL validity */ 1526static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl) 1527{ 1528 X509 *issuer = NULL; 1529 EVP_PKEY *ikey = NULL; 1530 int cnum = ctx->error_depth; 1531 int chnum = sk_X509_num(ctx->chain) - 1; 1532 1533 /* If we have an alternative CRL issuer cert use that */ 1534 if (ctx->current_issuer != NULL) { 1535 issuer = ctx->current_issuer; 1536 /* 1537 * Else find CRL issuer: if not last certificate then issuer is next 1538 * certificate in chain. 1539 */ 1540 } else if (cnum < chnum) { 1541 issuer = sk_X509_value(ctx->chain, cnum + 1); 1542 } else { 1543 issuer = sk_X509_value(ctx->chain, chnum); 1544 /* If not self-issued, can't check signature */ 1545 if (!ctx->check_issued(ctx, issuer, issuer) && 1546 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER)) 1547 return 0; 1548 } 1549 1550 if (issuer == NULL) 1551 return 1; 1552 1553 /* 1554 * Skip most tests for deltas because they have already been done 1555 */ 1556 if (crl->base_crl_number == NULL) { 1557 /* Check for cRLSign bit if keyUsage present */ 1558 if ((issuer->ex_flags & EXFLAG_KUSAGE) != 0 && 1559 (issuer->ex_kusage & KU_CRL_SIGN) == 0 && 1560 !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN)) 1561 return 0; 1562 1563 if ((ctx->current_crl_score & CRL_SCORE_SCOPE) == 0 && 1564 !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE)) 1565 return 0; 1566 1567 if ((ctx->current_crl_score & CRL_SCORE_SAME_PATH) == 0 && 1568 check_crl_path(ctx, ctx->current_issuer) <= 0 && 1569 !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR)) 1570 return 0; 1571 1572 if ((crl->idp_flags & IDP_INVALID) != 0 && 1573 !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION)) 1574 return 0; 1575 } 1576 1577 if ((ctx->current_crl_score & CRL_SCORE_TIME) == 0 && 1578 !check_crl_time(ctx, crl, 1)) 1579 return 0; 1580 1581 /* Attempt to get issuer certificate public key */ 1582 ikey = X509_get0_pubkey(issuer); 1583 if (ikey == NULL && 1584 !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY)) 1585 return 0; 1586 1587 if (ikey != NULL) { 1588 int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags); 1589 1590 if (rv != X509_V_OK && !verify_cb_crl(ctx, rv)) 1591 return 0; 1592 /* Verify CRL signature */ 1593 if (X509_CRL_verify(crl, ikey) <= 0 && 1594 !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE)) 1595 return 0; 1596 } 1597 return 1; 1598} 1599 1600/* Check certificate against CRL */ 1601static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x) 1602{ 1603 X509_REVOKED *rev; 1604 1605 /* 1606 * The rules changed for this... previously if a CRL contained unhandled 1607 * critical extensions it could still be used to indicate a certificate 1608 * was revoked. This has since been changed since critical extensions can 1609 * change the meaning of CRL entries. 1610 */ 1611 if ((ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) == 0 1612 && (crl->flags & EXFLAG_CRITICAL) != 0 && 1613 !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION)) 1614 return 0; 1615 /* 1616 * Look for serial number of certificate in CRL. If found, make sure 1617 * reason is not removeFromCRL. 1618 */ 1619 if (X509_CRL_get0_by_cert(crl, &rev, x)) { 1620 if (rev->reason == CRL_REASON_REMOVE_FROM_CRL) 1621 return 2; 1622 if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED)) 1623 return 0; 1624 } 1625 1626 return 1; 1627} 1628 1629static int check_policy(X509_STORE_CTX *ctx) 1630{ 1631 int ret; 1632 1633 if (ctx->parent) 1634 return 1; 1635 /* 1636 * With DANE, the trust anchor might be a bare public key, not a 1637 * certificate! In that case our chain does not have the trust anchor 1638 * certificate as a top-most element. This comports well with RFC5280 1639 * chain verification, since there too, the trust anchor is not part of the 1640 * chain to be verified. In particular, X509_policy_check() does not look 1641 * at the TA cert, but assumes that it is present as the top-most chain 1642 * element. We therefore temporarily push a NULL cert onto the chain if it 1643 * was verified via a bare public key, and pop it off right after the 1644 * X509_policy_check() call. 1645 */ 1646 if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) 1647 goto memerr; 1648 ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain, 1649 ctx->param->policies, ctx->param->flags); 1650 if (ctx->bare_ta_signed) 1651 (void)sk_X509_pop(ctx->chain); 1652 1653 if (ret == X509_PCY_TREE_INTERNAL) 1654 goto memerr; 1655 /* Invalid or inconsistent extensions */ 1656 if (ret == X509_PCY_TREE_INVALID) { 1657 int i, cbcalled = 0; 1658 1659 /* Locate certificates with bad extensions and notify callback. */ 1660 for (i = 0; i < sk_X509_num(ctx->chain); i++) { 1661 X509 *x = sk_X509_value(ctx->chain, i); 1662 1663 if ((x->ex_flags & EXFLAG_INVALID_POLICY) != 0) 1664 cbcalled = 1; 1665 CB_FAIL_IF((x->ex_flags & EXFLAG_INVALID_POLICY) != 0, 1666 ctx, x, i, X509_V_ERR_INVALID_POLICY_EXTENSION); 1667 } 1668 if (!cbcalled) { 1669 /* Should not be able to get here */ 1670 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR); 1671 return 0; 1672 } 1673 /* The callback ignored the error so we return success */ 1674 return 1; 1675 } 1676 if (ret == X509_PCY_TREE_FAILURE) { 1677 ctx->current_cert = NULL; 1678 ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY; 1679 return ctx->verify_cb(0, ctx); 1680 } 1681 if (ret != X509_PCY_TREE_VALID) { 1682 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR); 1683 return 0; 1684 } 1685 1686 if ((ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) != 0) { 1687 ctx->current_cert = NULL; 1688 /* 1689 * Verification errors need to be "sticky", a callback may have allowed 1690 * an SSL handshake to continue despite an error, and we must then 1691 * remain in an error state. Therefore, we MUST NOT clear earlier 1692 * verification errors by setting the error to X509_V_OK. 1693 */ 1694 if (!ctx->verify_cb(2, ctx)) 1695 return 0; 1696 } 1697 1698 return 1; 1699 1700 memerr: 1701 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 1702 ctx->error = X509_V_ERR_OUT_OF_MEM; 1703 return -1; 1704} 1705 1706/*- 1707 * Check certificate validity times. 1708 * If depth >= 0, invoke verification callbacks on error, otherwise just return 1709 * the validation status. 1710 * 1711 * Return 1 on success, 0 otherwise. 1712 */ 1713int ossl_x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth) 1714{ 1715 time_t *ptime; 1716 int i; 1717 1718 if ((ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) != 0) 1719 ptime = &ctx->param->check_time; 1720 else if ((ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) != 0) 1721 return 1; 1722 else 1723 ptime = NULL; 1724 1725 i = X509_cmp_time(X509_get0_notBefore(x), ptime); 1726 if (i >= 0 && depth < 0) 1727 return 0; 1728 CB_FAIL_IF(i == 0, ctx, x, depth, X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD); 1729 CB_FAIL_IF(i > 0, ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID); 1730 1731 i = X509_cmp_time(X509_get0_notAfter(x), ptime); 1732 if (i <= 0 && depth < 0) 1733 return 0; 1734 CB_FAIL_IF(i == 0, ctx, x, depth, X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD); 1735 CB_FAIL_IF(i < 0, ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED); 1736 return 1; 1737} 1738 1739/* 1740 * Verify the issuer signatures and cert times of ctx->chain. 1741 * Sadly, returns 0 also on internal error. 1742 */ 1743static int internal_verify(X509_STORE_CTX *ctx) 1744{ 1745 int n = sk_X509_num(ctx->chain) - 1; 1746 X509 *xi = sk_X509_value(ctx->chain, n); 1747 X509 *xs = xi; 1748 1749 ctx->error_depth = n; 1750 if (ctx->bare_ta_signed) { 1751 /* 1752 * With DANE-verified bare public key TA signatures, 1753 * on the top certificate we check only the timestamps. 1754 * We report the issuer as NULL because all we have is a bare key. 1755 */ 1756 xi = NULL; 1757 } else if (ossl_x509_likely_issued(xi, xi) != X509_V_OK 1758 /* exceptional case: last cert in the chain is not self-issued */ 1759 && ((ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) == 0)) { 1760 if (n > 0) { 1761 n--; 1762 ctx->error_depth = n; 1763 xs = sk_X509_value(ctx->chain, n); 1764 } else { 1765 CB_FAIL_IF(1, ctx, xi, 0, 1766 X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE); 1767 } 1768 /* 1769 * The below code will certainly not do a 1770 * self-signature check on xi because it is not self-issued. 1771 */ 1772 } 1773 1774 /* 1775 * Do not clear error (by ctx->error = X509_V_OK), it must be "sticky", 1776 * only the user's callback is allowed to reset errors (at its own peril). 1777 */ 1778 while (n >= 0) { 1779 /*- 1780 * For each iteration of this loop: 1781 * n is the subject depth 1782 * xs is the subject cert, for which the signature is to be checked 1783 * xi is NULL for DANE-verified bare public key TA signatures 1784 * else the supposed issuer cert containing the public key to use 1785 * Initially xs == xi if the last cert in the chain is self-issued. 1786 */ 1787 /* 1788 * Do signature check for self-signed certificates only if explicitly 1789 * asked for because it does not add any security and just wastes time. 1790 */ 1791 if (xi != NULL 1792 && (xs != xi 1793 || ((ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE) != 0 1794 && (xi->ex_flags & EXFLAG_SS) != 0))) { 1795 EVP_PKEY *pkey; 1796 /* 1797 * If the issuer's public key is not available or its key usage 1798 * does not support issuing the subject cert, report the issuer 1799 * cert and its depth (rather than n, the depth of the subject). 1800 */ 1801 int issuer_depth = n + (xs == xi ? 0 : 1); 1802 /* 1803 * According to https://tools.ietf.org/html/rfc5280#section-6.1.4 1804 * step (n) we must check any given key usage extension in a CA cert 1805 * when preparing the verification of a certificate issued by it. 1806 * According to https://tools.ietf.org/html/rfc5280#section-4.2.1.3 1807 * we must not verify a certificate signature if the key usage of 1808 * the CA certificate that issued the certificate prohibits signing. 1809 * In case the 'issuing' certificate is the last in the chain and is 1810 * not a CA certificate but a 'self-issued' end-entity cert (i.e., 1811 * xs == xi && !(xi->ex_flags & EXFLAG_CA)) RFC 5280 does not apply 1812 * (see https://tools.ietf.org/html/rfc6818#section-2) and thus 1813 * we are free to ignore any key usage restrictions on such certs. 1814 */ 1815 int ret = xs == xi && (xi->ex_flags & EXFLAG_CA) == 0 1816 ? X509_V_OK : ossl_x509_signing_allowed(xi, xs); 1817 1818 CB_FAIL_IF(ret != X509_V_OK, ctx, xi, issuer_depth, ret); 1819 if ((pkey = X509_get0_pubkey(xi)) == NULL) { 1820 CB_FAIL_IF(1, ctx, xi, issuer_depth, 1821 X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY); 1822 } else { 1823 CB_FAIL_IF(X509_verify(xs, pkey) <= 0, 1824 ctx, xs, n, X509_V_ERR_CERT_SIGNATURE_FAILURE); 1825 } 1826 } 1827 1828 /* In addition to RFC 5280 requirements do also for trust anchor cert */ 1829 /* Calls verify callback as needed */ 1830 if (!ossl_x509_check_cert_time(ctx, xs, n)) 1831 return 0; 1832 1833 /* 1834 * Signal success at this depth. However, the previous error (if any) 1835 * is retained. 1836 */ 1837 ctx->current_issuer = xi; 1838 ctx->current_cert = xs; 1839 ctx->error_depth = n; 1840 if (!ctx->verify_cb(1, ctx)) 1841 return 0; 1842 1843 if (--n >= 0) { 1844 xi = xs; 1845 xs = sk_X509_value(ctx->chain, n); 1846 } 1847 } 1848 return 1; 1849} 1850 1851int X509_cmp_current_time(const ASN1_TIME *ctm) 1852{ 1853 return X509_cmp_time(ctm, NULL); 1854} 1855 1856int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time) 1857{ 1858 static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1; 1859 static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1; 1860 ASN1_TIME *asn1_cmp_time = NULL; 1861 int i, day, sec, ret = 0; 1862#ifdef CHARSET_EBCDIC 1863 const char upper_z = 0x5A; 1864#else 1865 const char upper_z = 'Z'; 1866#endif 1867 1868 /*- 1869 * Note that ASN.1 allows much more slack in the time format than RFC5280. 1870 * In RFC5280, the representation is fixed: 1871 * UTCTime: YYMMDDHHMMSSZ 1872 * GeneralizedTime: YYYYMMDDHHMMSSZ 1873 * 1874 * We do NOT currently enforce the following RFC 5280 requirement: 1875 * "CAs conforming to this profile MUST always encode certificate 1876 * validity dates through the year 2049 as UTCTime; certificate validity 1877 * dates in 2050 or later MUST be encoded as GeneralizedTime." 1878 */ 1879 switch (ctm->type) { 1880 case V_ASN1_UTCTIME: 1881 if (ctm->length != (int)(utctime_length)) 1882 return 0; 1883 break; 1884 case V_ASN1_GENERALIZEDTIME: 1885 if (ctm->length != (int)(generalizedtime_length)) 1886 return 0; 1887 break; 1888 default: 1889 return 0; 1890 } 1891 1892 /** 1893 * Verify the format: the ASN.1 functions we use below allow a more 1894 * flexible format than what's mandated by RFC 5280. 1895 * Digit and date ranges will be verified in the conversion methods. 1896 */ 1897 for (i = 0; i < ctm->length - 1; i++) { 1898 if (!ossl_ascii_isdigit(ctm->data[i])) 1899 return 0; 1900 } 1901 if (ctm->data[ctm->length - 1] != upper_z) 1902 return 0; 1903 1904 /* 1905 * There is ASN1_UTCTIME_cmp_time_t but no 1906 * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t, 1907 * so we go through ASN.1 1908 */ 1909 asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time); 1910 if (asn1_cmp_time == NULL) 1911 goto err; 1912 if (ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time) == 0) 1913 goto err; 1914 1915 /* 1916 * X509_cmp_time comparison is <=. 1917 * The return value 0 is reserved for errors. 1918 */ 1919 ret = (day >= 0 && sec >= 0) ? -1 : 1; 1920 1921 err: 1922 ASN1_TIME_free(asn1_cmp_time); 1923 return ret; 1924} 1925 1926/* 1927 * Return 0 if time should not be checked or reference time is in range, 1928 * or else 1 if it is past the end, or -1 if it is before the start 1929 */ 1930int X509_cmp_timeframe(const X509_VERIFY_PARAM *vpm, 1931 const ASN1_TIME *start, const ASN1_TIME *end) 1932{ 1933 time_t ref_time; 1934 time_t *time = NULL; 1935 unsigned long flags = vpm == NULL ? 0 : X509_VERIFY_PARAM_get_flags(vpm); 1936 1937 if ((flags & X509_V_FLAG_USE_CHECK_TIME) != 0) { 1938 ref_time = X509_VERIFY_PARAM_get_time(vpm); 1939 time = &ref_time; 1940 } else if ((flags & X509_V_FLAG_NO_CHECK_TIME) != 0) { 1941 return 0; /* this means ok */ 1942 } /* else reference time is the current time */ 1943 1944 if (end != NULL && X509_cmp_time(end, time) < 0) 1945 return 1; 1946 if (start != NULL && X509_cmp_time(start, time) > 0) 1947 return -1; 1948 return 0; 1949} 1950 1951ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj) 1952{ 1953 return X509_time_adj(s, adj, NULL); 1954} 1955 1956ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm) 1957{ 1958 return X509_time_adj_ex(s, 0, offset_sec, in_tm); 1959} 1960 1961ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s, 1962 int offset_day, long offset_sec, time_t *in_tm) 1963{ 1964 time_t t; 1965 1966 if (in_tm) 1967 t = *in_tm; 1968 else 1969 time(&t); 1970 1971 if (s != NULL && (s->flags & ASN1_STRING_FLAG_MSTRING) == 0) { 1972 if (s->type == V_ASN1_UTCTIME) 1973 return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec); 1974 if (s->type == V_ASN1_GENERALIZEDTIME) 1975 return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec); 1976 } 1977 return ASN1_TIME_adj(s, t, offset_day, offset_sec); 1978} 1979 1980/* Copy any missing public key parameters up the chain towards pkey */ 1981int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain) 1982{ 1983 EVP_PKEY *ktmp = NULL, *ktmp2; 1984 int i, j; 1985 1986 if (pkey != NULL && !EVP_PKEY_missing_parameters(pkey)) 1987 return 1; 1988 1989 for (i = 0; i < sk_X509_num(chain); i++) { 1990 ktmp = X509_get0_pubkey(sk_X509_value(chain, i)); 1991 if (ktmp == NULL) { 1992 ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY); 1993 return 0; 1994 } 1995 if (!EVP_PKEY_missing_parameters(ktmp)) 1996 break; 1997 ktmp = NULL; 1998 } 1999 if (ktmp == NULL) { 2000 ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN); 2001 return 0; 2002 } 2003 2004 /* first, populate the other certs */ 2005 for (j = i - 1; j >= 0; j--) { 2006 ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j)); 2007 if (!EVP_PKEY_copy_parameters(ktmp2, ktmp)) 2008 return 0; 2009 } 2010 2011 if (pkey != NULL) 2012 return EVP_PKEY_copy_parameters(pkey, ktmp); 2013 return 1; 2014} 2015 2016/* 2017 * Make a delta CRL as the difference between two full CRLs. 2018 * Sadly, returns NULL also on internal error. 2019 */ 2020X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer, 2021 EVP_PKEY *skey, const EVP_MD *md, unsigned int flags) 2022{ 2023 X509_CRL *crl = NULL; 2024 int i; 2025 2026 STACK_OF(X509_REVOKED) *revs = NULL; 2027 /* CRLs can't be delta already */ 2028 if (base->base_crl_number != NULL || newer->base_crl_number != NULL) { 2029 ERR_raise(ERR_LIB_X509, X509_R_CRL_ALREADY_DELTA); 2030 return NULL; 2031 } 2032 /* Base and new CRL must have a CRL number */ 2033 if (base->crl_number == NULL || newer->crl_number == NULL) { 2034 ERR_raise(ERR_LIB_X509, X509_R_NO_CRL_NUMBER); 2035 return NULL; 2036 } 2037 /* Issuer names must match */ 2038 if (X509_NAME_cmp(X509_CRL_get_issuer(base), 2039 X509_CRL_get_issuer(newer)) != 0) { 2040 ERR_raise(ERR_LIB_X509, X509_R_ISSUER_MISMATCH); 2041 return NULL; 2042 } 2043 /* AKID and IDP must match */ 2044 if (!crl_extension_match(base, newer, NID_authority_key_identifier)) { 2045 ERR_raise(ERR_LIB_X509, X509_R_AKID_MISMATCH); 2046 return NULL; 2047 } 2048 if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) { 2049 ERR_raise(ERR_LIB_X509, X509_R_IDP_MISMATCH); 2050 return NULL; 2051 } 2052 /* Newer CRL number must exceed full CRL number */ 2053 if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) { 2054 ERR_raise(ERR_LIB_X509, X509_R_NEWER_CRL_NOT_NEWER); 2055 return NULL; 2056 } 2057 /* CRLs must verify */ 2058 if (skey != NULL && (X509_CRL_verify(base, skey) <= 0 || 2059 X509_CRL_verify(newer, skey) <= 0)) { 2060 ERR_raise(ERR_LIB_X509, X509_R_CRL_VERIFY_FAILURE); 2061 return NULL; 2062 } 2063 /* Create new CRL */ 2064 crl = X509_CRL_new_ex(base->libctx, base->propq); 2065 if (crl == NULL || !X509_CRL_set_version(crl, X509_CRL_VERSION_2)) 2066 goto memerr; 2067 /* Set issuer name */ 2068 if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer))) 2069 goto memerr; 2070 2071 if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer))) 2072 goto memerr; 2073 if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer))) 2074 goto memerr; 2075 2076 /* Set base CRL number: must be critical */ 2077 if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0)) 2078 goto memerr; 2079 2080 /* 2081 * Copy extensions across from newest CRL to delta: this will set CRL 2082 * number to correct value too. 2083 */ 2084 for (i = 0; i < X509_CRL_get_ext_count(newer); i++) { 2085 X509_EXTENSION *ext = X509_CRL_get_ext(newer, i); 2086 2087 if (!X509_CRL_add_ext(crl, ext, -1)) 2088 goto memerr; 2089 } 2090 2091 /* Go through revoked entries, copying as needed */ 2092 revs = X509_CRL_get_REVOKED(newer); 2093 2094 for (i = 0; i < sk_X509_REVOKED_num(revs); i++) { 2095 X509_REVOKED *rvn, *rvtmp; 2096 2097 rvn = sk_X509_REVOKED_value(revs, i); 2098 /* 2099 * Add only if not also in base. 2100 * Need something cleverer here for some more complex CRLs covering 2101 * multiple CAs. 2102 */ 2103 if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) { 2104 rvtmp = X509_REVOKED_dup(rvn); 2105 if (rvtmp == NULL) 2106 goto memerr; 2107 if (!X509_CRL_add0_revoked(crl, rvtmp)) { 2108 X509_REVOKED_free(rvtmp); 2109 goto memerr; 2110 } 2111 } 2112 } 2113 2114 if (skey != NULL && md != NULL && !X509_CRL_sign(crl, skey, md)) 2115 goto memerr; 2116 2117 return crl; 2118 2119 memerr: 2120 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 2121 X509_CRL_free(crl); 2122 return NULL; 2123} 2124 2125int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data) 2126{ 2127 return CRYPTO_set_ex_data(&ctx->ex_data, idx, data); 2128} 2129 2130void *X509_STORE_CTX_get_ex_data(const X509_STORE_CTX *ctx, int idx) 2131{ 2132 return CRYPTO_get_ex_data(&ctx->ex_data, idx); 2133} 2134 2135int X509_STORE_CTX_get_error(const X509_STORE_CTX *ctx) 2136{ 2137 return ctx->error; 2138} 2139 2140void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err) 2141{ 2142 ctx->error = err; 2143} 2144 2145int X509_STORE_CTX_get_error_depth(const X509_STORE_CTX *ctx) 2146{ 2147 return ctx->error_depth; 2148} 2149 2150void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth) 2151{ 2152 ctx->error_depth = depth; 2153} 2154 2155X509 *X509_STORE_CTX_get_current_cert(const X509_STORE_CTX *ctx) 2156{ 2157 return ctx->current_cert; 2158} 2159 2160void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x) 2161{ 2162 ctx->current_cert = x; 2163} 2164 2165STACK_OF(X509) *X509_STORE_CTX_get0_chain(const X509_STORE_CTX *ctx) 2166{ 2167 return ctx->chain; 2168} 2169 2170STACK_OF(X509) *X509_STORE_CTX_get1_chain(const X509_STORE_CTX *ctx) 2171{ 2172 if (ctx->chain == NULL) 2173 return NULL; 2174 return X509_chain_up_ref(ctx->chain); 2175} 2176 2177X509 *X509_STORE_CTX_get0_current_issuer(const X509_STORE_CTX *ctx) 2178{ 2179 return ctx->current_issuer; 2180} 2181 2182X509_CRL *X509_STORE_CTX_get0_current_crl(const X509_STORE_CTX *ctx) 2183{ 2184 return ctx->current_crl; 2185} 2186 2187X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(const X509_STORE_CTX *ctx) 2188{ 2189 return ctx->parent; 2190} 2191 2192void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x) 2193{ 2194 ctx->cert = x; 2195} 2196 2197void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk) 2198{ 2199 ctx->crls = sk; 2200} 2201 2202int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose) 2203{ 2204 /* 2205 * XXX: Why isn't this function always used to set the associated trust? 2206 * Should there even be a VPM->trust field at all? Or should the trust 2207 * always be inferred from the purpose by X509_STORE_CTX_init(). 2208 */ 2209 return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0); 2210} 2211 2212int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust) 2213{ 2214 /* 2215 * XXX: See above, this function would only be needed when the default 2216 * trust for the purpose needs an override in a corner case. 2217 */ 2218 return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust); 2219} 2220 2221/* 2222 * This function is used to set the X509_STORE_CTX purpose and trust values. 2223 * This is intended to be used when another structure has its own trust and 2224 * purpose values which (if set) will be inherited by the ctx. If they aren't 2225 * set then we will usually have a default purpose in mind which should then 2226 * be used to set the trust value. An example of this is SSL use: an SSL 2227 * structure will have its own purpose and trust settings which the 2228 * application can set: if they aren't set then we use the default of SSL 2229 * client/server. 2230 */ 2231int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose, 2232 int purpose, int trust) 2233{ 2234 int idx; 2235 2236 /* If purpose not set use default */ 2237 if (purpose == 0) 2238 purpose = def_purpose; 2239 /* 2240 * If purpose is set but we don't have a default then set the default to 2241 * the current purpose 2242 */ 2243 else if (def_purpose == 0) 2244 def_purpose = purpose; 2245 /* If we have a purpose then check it is valid */ 2246 if (purpose != 0) { 2247 X509_PURPOSE *ptmp; 2248 2249 idx = X509_PURPOSE_get_by_id(purpose); 2250 if (idx == -1) { 2251 ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID); 2252 return 0; 2253 } 2254 ptmp = X509_PURPOSE_get0(idx); 2255 if (ptmp->trust == X509_TRUST_DEFAULT) { 2256 idx = X509_PURPOSE_get_by_id(def_purpose); 2257 if (idx == -1) { 2258 ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID); 2259 return 0; 2260 } 2261 ptmp = X509_PURPOSE_get0(idx); 2262 } 2263 /* If trust not set then get from purpose default */ 2264 if (trust == 0) 2265 trust = ptmp->trust; 2266 } 2267 if (trust != 0) { 2268 idx = X509_TRUST_get_by_id(trust); 2269 if (idx == -1) { 2270 ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_TRUST_ID); 2271 return 0; 2272 } 2273 } 2274 2275 if (ctx->param->purpose == 0 && purpose != 0) 2276 ctx->param->purpose = purpose; 2277 if (ctx->param->trust == 0 && trust != 0) 2278 ctx->param->trust = trust; 2279 return 1; 2280} 2281 2282X509_STORE_CTX *X509_STORE_CTX_new_ex(OSSL_LIB_CTX *libctx, const char *propq) 2283{ 2284 X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx)); 2285 2286 if (ctx == NULL) { 2287 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 2288 return NULL; 2289 } 2290 2291 ctx->libctx = libctx; 2292 if (propq != NULL) { 2293 ctx->propq = OPENSSL_strdup(propq); 2294 if (ctx->propq == NULL) { 2295 OPENSSL_free(ctx); 2296 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 2297 return NULL; 2298 } 2299 } 2300 2301 return ctx; 2302} 2303 2304X509_STORE_CTX *X509_STORE_CTX_new(void) 2305{ 2306 return X509_STORE_CTX_new_ex(NULL, NULL); 2307} 2308 2309void X509_STORE_CTX_free(X509_STORE_CTX *ctx) 2310{ 2311 if (ctx == NULL) 2312 return; 2313 2314 X509_STORE_CTX_cleanup(ctx); 2315 2316 /* libctx and propq survive X509_STORE_CTX_cleanup() */ 2317 OPENSSL_free(ctx->propq); 2318 OPENSSL_free(ctx); 2319} 2320 2321int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509, 2322 STACK_OF(X509) *chain) 2323{ 2324 if (ctx == NULL) { 2325 ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); 2326 return 0; 2327 } 2328 X509_STORE_CTX_cleanup(ctx); 2329 2330 ctx->store = store; 2331 ctx->cert = x509; 2332 ctx->untrusted = chain; 2333 ctx->crls = NULL; 2334 ctx->num_untrusted = 0; 2335 ctx->other_ctx = NULL; 2336 ctx->valid = 0; 2337 ctx->chain = NULL; 2338 ctx->error = X509_V_OK; 2339 ctx->explicit_policy = 0; 2340 ctx->error_depth = 0; 2341 ctx->current_cert = NULL; 2342 ctx->current_issuer = NULL; 2343 ctx->current_crl = NULL; 2344 ctx->current_crl_score = 0; 2345 ctx->current_reasons = 0; 2346 ctx->tree = NULL; 2347 ctx->parent = NULL; 2348 ctx->dane = NULL; 2349 ctx->bare_ta_signed = 0; 2350 /* Zero ex_data to make sure we're cleanup-safe */ 2351 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2352 2353 /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */ 2354 if (store != NULL) 2355 ctx->cleanup = store->cleanup; 2356 else 2357 ctx->cleanup = NULL; 2358 2359 if (store != NULL && store->check_issued != NULL) 2360 ctx->check_issued = store->check_issued; 2361 else 2362 ctx->check_issued = check_issued; 2363 2364 if (store != NULL && store->get_issuer != NULL) 2365 ctx->get_issuer = store->get_issuer; 2366 else 2367 ctx->get_issuer = X509_STORE_CTX_get1_issuer; 2368 2369 if (store != NULL && store->verify_cb != NULL) 2370 ctx->verify_cb = store->verify_cb; 2371 else 2372 ctx->verify_cb = null_callback; 2373 2374 if (store != NULL && store->verify != NULL) 2375 ctx->verify = store->verify; 2376 else 2377 ctx->verify = internal_verify; 2378 2379 if (store != NULL && store->check_revocation != NULL) 2380 ctx->check_revocation = store->check_revocation; 2381 else 2382 ctx->check_revocation = check_revocation; 2383 2384 if (store != NULL && store->get_crl != NULL) 2385 ctx->get_crl = store->get_crl; 2386 else 2387 ctx->get_crl = NULL; 2388 2389 if (store != NULL && store->check_crl != NULL) 2390 ctx->check_crl = store->check_crl; 2391 else 2392 ctx->check_crl = check_crl; 2393 2394 if (store != NULL && store->cert_crl != NULL) 2395 ctx->cert_crl = store->cert_crl; 2396 else 2397 ctx->cert_crl = cert_crl; 2398 2399 if (store != NULL && store->check_policy != NULL) 2400 ctx->check_policy = store->check_policy; 2401 else 2402 ctx->check_policy = check_policy; 2403 2404 if (store != NULL && store->lookup_certs != NULL) 2405 ctx->lookup_certs = store->lookup_certs; 2406 else 2407 ctx->lookup_certs = X509_STORE_CTX_get1_certs; 2408 2409 if (store != NULL && store->lookup_crls != NULL) 2410 ctx->lookup_crls = store->lookup_crls; 2411 else 2412 ctx->lookup_crls = X509_STORE_CTX_get1_crls; 2413 2414 ctx->param = X509_VERIFY_PARAM_new(); 2415 if (ctx->param == NULL) { 2416 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 2417 goto err; 2418 } 2419 2420 /* Inherit callbacks and flags from X509_STORE if not set use defaults. */ 2421 if (store == NULL) 2422 ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE; 2423 else if (X509_VERIFY_PARAM_inherit(ctx->param, store->param) == 0) 2424 goto err; 2425 2426 if (!X509_STORE_CTX_set_default(ctx, "default")) 2427 goto err; 2428 2429 /* 2430 * XXX: For now, continue to inherit trust from VPM, but infer from the 2431 * purpose if this still yields the default value. 2432 */ 2433 if (ctx->param->trust == X509_TRUST_DEFAULT) { 2434 int idx = X509_PURPOSE_get_by_id(ctx->param->purpose); 2435 X509_PURPOSE *xp = X509_PURPOSE_get0(idx); 2436 2437 if (xp != NULL) 2438 ctx->param->trust = X509_PURPOSE_get_trust(xp); 2439 } 2440 2441 if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, 2442 &ctx->ex_data)) 2443 return 1; 2444 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 2445 2446 err: 2447 /* 2448 * On error clean up allocated storage, if the store context was not 2449 * allocated with X509_STORE_CTX_new() this is our last chance to do so. 2450 */ 2451 X509_STORE_CTX_cleanup(ctx); 2452 return 0; 2453} 2454 2455/* 2456 * Set alternative get_issuer method: just from a STACK of trusted certificates. 2457 * This avoids the complexity of X509_STORE where it is not needed. 2458 */ 2459void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2460{ 2461 ctx->other_ctx = sk; 2462 ctx->get_issuer = get_issuer_sk; 2463 ctx->lookup_certs = lookup_certs_sk; 2464} 2465 2466void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx) 2467{ 2468 /* 2469 * We need to be idempotent because, unfortunately, free() also calls 2470 * cleanup(), so the natural call sequence new(), init(), cleanup(), free() 2471 * calls cleanup() for the same object twice! Thus we must zero the 2472 * pointers below after they're freed! 2473 */ 2474 /* Seems to always be NULL in OpenSSL, do this at most once. */ 2475 if (ctx->cleanup != NULL) { 2476 ctx->cleanup(ctx); 2477 ctx->cleanup = NULL; 2478 } 2479 if (ctx->param != NULL) { 2480 if (ctx->parent == NULL) 2481 X509_VERIFY_PARAM_free(ctx->param); 2482 ctx->param = NULL; 2483 } 2484 X509_policy_tree_free(ctx->tree); 2485 ctx->tree = NULL; 2486 sk_X509_pop_free(ctx->chain, X509_free); 2487 ctx->chain = NULL; 2488 CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data)); 2489 memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); 2490} 2491 2492void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth) 2493{ 2494 X509_VERIFY_PARAM_set_depth(ctx->param, depth); 2495} 2496 2497void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags) 2498{ 2499 X509_VERIFY_PARAM_set_flags(ctx->param, flags); 2500} 2501 2502void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, 2503 time_t t) 2504{ 2505 X509_VERIFY_PARAM_set_time(ctx->param, t); 2506} 2507 2508X509 *X509_STORE_CTX_get0_cert(const X509_STORE_CTX *ctx) 2509{ 2510 return ctx->cert; 2511} 2512 2513STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(const X509_STORE_CTX *ctx) 2514{ 2515 return ctx->untrusted; 2516} 2517 2518void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2519{ 2520 ctx->untrusted = sk; 2521} 2522 2523void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) 2524{ 2525 sk_X509_pop_free(ctx->chain, X509_free); 2526 ctx->chain = sk; 2527} 2528 2529void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx, 2530 X509_STORE_CTX_verify_cb verify_cb) 2531{ 2532 ctx->verify_cb = verify_cb; 2533} 2534 2535X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(const X509_STORE_CTX *ctx) 2536{ 2537 return ctx->verify_cb; 2538} 2539 2540void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx, 2541 X509_STORE_CTX_verify_fn verify) 2542{ 2543 ctx->verify = verify; 2544} 2545 2546X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(const X509_STORE_CTX *ctx) 2547{ 2548 return ctx->verify; 2549} 2550 2551X509_STORE_CTX_get_issuer_fn 2552X509_STORE_CTX_get_get_issuer(const X509_STORE_CTX *ctx) 2553{ 2554 return ctx->get_issuer; 2555} 2556 2557X509_STORE_CTX_check_issued_fn 2558X509_STORE_CTX_get_check_issued(const X509_STORE_CTX *ctx) 2559{ 2560 return ctx->check_issued; 2561} 2562 2563X509_STORE_CTX_check_revocation_fn 2564X509_STORE_CTX_get_check_revocation(const X509_STORE_CTX *ctx) 2565{ 2566 return ctx->check_revocation; 2567} 2568 2569X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(const X509_STORE_CTX *ctx) 2570{ 2571 return ctx->get_crl; 2572} 2573 2574X509_STORE_CTX_check_crl_fn 2575X509_STORE_CTX_get_check_crl(const X509_STORE_CTX *ctx) 2576{ 2577 return ctx->check_crl; 2578} 2579 2580X509_STORE_CTX_cert_crl_fn 2581X509_STORE_CTX_get_cert_crl(const X509_STORE_CTX *ctx) 2582{ 2583 return ctx->cert_crl; 2584} 2585 2586X509_STORE_CTX_check_policy_fn 2587X509_STORE_CTX_get_check_policy(const X509_STORE_CTX *ctx) 2588{ 2589 return ctx->check_policy; 2590} 2591 2592X509_STORE_CTX_lookup_certs_fn 2593X509_STORE_CTX_get_lookup_certs(const X509_STORE_CTX *ctx) 2594{ 2595 return ctx->lookup_certs; 2596} 2597 2598X509_STORE_CTX_lookup_crls_fn 2599X509_STORE_CTX_get_lookup_crls(const X509_STORE_CTX *ctx) 2600{ 2601 return ctx->lookup_crls; 2602} 2603 2604X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(const X509_STORE_CTX *ctx) 2605{ 2606 return ctx->cleanup; 2607} 2608 2609X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(const X509_STORE_CTX *ctx) 2610{ 2611 return ctx->tree; 2612} 2613 2614int X509_STORE_CTX_get_explicit_policy(const X509_STORE_CTX *ctx) 2615{ 2616 return ctx->explicit_policy; 2617} 2618 2619int X509_STORE_CTX_get_num_untrusted(const X509_STORE_CTX *ctx) 2620{ 2621 return ctx->num_untrusted; 2622} 2623 2624int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name) 2625{ 2626 const X509_VERIFY_PARAM *param; 2627 2628 param = X509_VERIFY_PARAM_lookup(name); 2629 if (param == NULL) { 2630 ERR_raise_data(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID, "name=%s", name); 2631 return 0; 2632 } 2633 return X509_VERIFY_PARAM_inherit(ctx->param, param); 2634} 2635 2636X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(const X509_STORE_CTX *ctx) 2637{ 2638 return ctx->param; 2639} 2640 2641void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param) 2642{ 2643 X509_VERIFY_PARAM_free(ctx->param); 2644 ctx->param = param; 2645} 2646 2647void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane) 2648{ 2649 ctx->dane = dane; 2650} 2651 2652static unsigned char *dane_i2d(X509 *cert, uint8_t selector, 2653 unsigned int *i2dlen) 2654{ 2655 unsigned char *buf = NULL; 2656 int len; 2657 2658 /* 2659 * Extract ASN.1 DER form of certificate or public key. 2660 */ 2661 switch (selector) { 2662 case DANETLS_SELECTOR_CERT: 2663 len = i2d_X509(cert, &buf); 2664 break; 2665 case DANETLS_SELECTOR_SPKI: 2666 len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf); 2667 break; 2668 default: 2669 ERR_raise(ERR_LIB_X509, X509_R_BAD_SELECTOR); 2670 return NULL; 2671 } 2672 2673 if (len < 0 || buf == NULL) { 2674 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 2675 return NULL; 2676 } 2677 2678 *i2dlen = (unsigned int)len; 2679 return buf; 2680} 2681 2682#define DANETLS_NONE 256 /* impossible uint8_t */ 2683 2684/* Returns -1 on internal error */ 2685static int dane_match(X509_STORE_CTX *ctx, X509 *cert, int depth) 2686{ 2687 SSL_DANE *dane = ctx->dane; 2688 unsigned usage = DANETLS_NONE; 2689 unsigned selector = DANETLS_NONE; 2690 unsigned ordinal = DANETLS_NONE; 2691 unsigned mtype = DANETLS_NONE; 2692 unsigned char *i2dbuf = NULL; 2693 unsigned int i2dlen = 0; 2694 unsigned char mdbuf[EVP_MAX_MD_SIZE]; 2695 unsigned char *cmpbuf = NULL; 2696 unsigned int cmplen = 0; 2697 int i; 2698 int recnum; 2699 int matched = 0; 2700 danetls_record *t = NULL; 2701 uint32_t mask; 2702 2703 mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK; 2704 2705 /* The trust store is not applicable with DANE-TA(2) */ 2706 if (depth >= ctx->num_untrusted) 2707 mask &= DANETLS_PKIX_MASK; 2708 2709 /* 2710 * If we've previously matched a PKIX-?? record, no need to test any 2711 * further PKIX-?? records, it remains to just build the PKIX chain. 2712 * Had the match been a DANE-?? record, we'd be done already. 2713 */ 2714 if (dane->mdpth >= 0) 2715 mask &= ~DANETLS_PKIX_MASK; 2716 2717 /*- 2718 * https://tools.ietf.org/html/rfc7671#section-5.1 2719 * https://tools.ietf.org/html/rfc7671#section-5.2 2720 * https://tools.ietf.org/html/rfc7671#section-5.3 2721 * https://tools.ietf.org/html/rfc7671#section-5.4 2722 * 2723 * We handle DANE-EE(3) records first as they require no chain building 2724 * and no expiration or hostname checks. We also process digests with 2725 * higher ordinals first and ignore lower priorities except Full(0) which 2726 * is always processed (last). If none match, we then process PKIX-EE(1). 2727 * 2728 * NOTE: This relies on DANE usages sorting before the corresponding PKIX 2729 * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest 2730 * priorities. See twin comment in ssl/ssl_lib.c. 2731 * 2732 * We expect that most TLSA RRsets will have just a single usage, so we 2733 * don't go out of our way to cache multiple selector-specific i2d buffers 2734 * across usages, but if the selector happens to remain the same as switch 2735 * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1", 2736 * records would result in us generating each of the certificate and public 2737 * key DER forms twice, but more typically we'd just see multiple "3 1 1" 2738 * or multiple "3 0 1" records. 2739 * 2740 * As soon as we find a match at any given depth, we stop, because either 2741 * we've matched a DANE-?? record and the peer is authenticated, or, after 2742 * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is 2743 * sufficient for DANE, and what remains to do is ordinary PKIX validation. 2744 */ 2745 recnum = (dane->umask & mask) != 0 ? sk_danetls_record_num(dane->trecs) : 0; 2746 for (i = 0; matched == 0 && i < recnum; ++i) { 2747 t = sk_danetls_record_value(dane->trecs, i); 2748 if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0) 2749 continue; 2750 if (t->usage != usage) { 2751 usage = t->usage; 2752 2753 /* Reset digest agility for each usage/selector pair */ 2754 mtype = DANETLS_NONE; 2755 ordinal = dane->dctx->mdord[t->mtype]; 2756 } 2757 if (t->selector != selector) { 2758 selector = t->selector; 2759 2760 /* Update per-selector state */ 2761 OPENSSL_free(i2dbuf); 2762 i2dbuf = dane_i2d(cert, selector, &i2dlen); 2763 if (i2dbuf == NULL) 2764 return -1; 2765 2766 /* Reset digest agility for each usage/selector pair */ 2767 mtype = DANETLS_NONE; 2768 ordinal = dane->dctx->mdord[t->mtype]; 2769 } else if (t->mtype != DANETLS_MATCHING_FULL) { 2770 /*- 2771 * Digest agility: 2772 * 2773 * <https://tools.ietf.org/html/rfc7671#section-9> 2774 * 2775 * For a fixed selector, after processing all records with the 2776 * highest mtype ordinal, ignore all mtypes with lower ordinals 2777 * other than "Full". 2778 */ 2779 if (dane->dctx->mdord[t->mtype] < ordinal) 2780 continue; 2781 } 2782 2783 /* 2784 * Each time we hit a (new selector or) mtype, re-compute the relevant 2785 * digest, more complex caching is not worth the code space. 2786 */ 2787 if (t->mtype != mtype) { 2788 const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype]; 2789 2790 cmpbuf = i2dbuf; 2791 cmplen = i2dlen; 2792 2793 if (md != NULL) { 2794 cmpbuf = mdbuf; 2795 if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) { 2796 matched = -1; 2797 break; 2798 } 2799 } 2800 } 2801 2802 /* 2803 * Squirrel away the certificate and depth if we have a match. Any 2804 * DANE match is dispositive, but with PKIX we still need to build a 2805 * full chain. 2806 */ 2807 if (cmplen == t->dlen && 2808 memcmp(cmpbuf, t->data, cmplen) == 0) { 2809 if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK) 2810 matched = 1; 2811 if (matched || dane->mdpth < 0) { 2812 dane->mdpth = depth; 2813 dane->mtlsa = t; 2814 OPENSSL_free(dane->mcert); 2815 dane->mcert = cert; 2816 X509_up_ref(cert); 2817 } 2818 break; 2819 } 2820 } 2821 2822 /* Clear the one-element DER cache */ 2823 OPENSSL_free(i2dbuf); 2824 return matched; 2825} 2826 2827/* Returns -1 on internal error */ 2828static int check_dane_issuer(X509_STORE_CTX *ctx, int depth) 2829{ 2830 SSL_DANE *dane = ctx->dane; 2831 int matched = 0; 2832 X509 *cert; 2833 2834 if (!DANETLS_HAS_TA(dane) || depth == 0) 2835 return X509_TRUST_UNTRUSTED; 2836 2837 /* 2838 * Record any DANE trust anchor matches, for the first depth to test, if 2839 * there's one at that depth. (This'll be false for length 1 chains looking 2840 * for an exact match for the leaf certificate). 2841 */ 2842 cert = sk_X509_value(ctx->chain, depth); 2843 if (cert != NULL && (matched = dane_match(ctx, cert, depth)) < 0) 2844 return matched; 2845 if (matched > 0) { 2846 ctx->num_untrusted = depth - 1; 2847 return X509_TRUST_TRUSTED; 2848 } 2849 2850 return X509_TRUST_UNTRUSTED; 2851} 2852 2853static int check_dane_pkeys(X509_STORE_CTX *ctx) 2854{ 2855 SSL_DANE *dane = ctx->dane; 2856 danetls_record *t; 2857 int num = ctx->num_untrusted; 2858 X509 *cert = sk_X509_value(ctx->chain, num - 1); 2859 int recnum = sk_danetls_record_num(dane->trecs); 2860 int i; 2861 2862 for (i = 0; i < recnum; ++i) { 2863 t = sk_danetls_record_value(dane->trecs, i); 2864 if (t->usage != DANETLS_USAGE_DANE_TA || 2865 t->selector != DANETLS_SELECTOR_SPKI || 2866 t->mtype != DANETLS_MATCHING_FULL || 2867 X509_verify(cert, t->spki) <= 0) 2868 continue; 2869 2870 /* Clear any PKIX-?? matches that failed to extend to a full chain */ 2871 X509_free(dane->mcert); 2872 dane->mcert = NULL; 2873 2874 /* Record match via a bare TA public key */ 2875 ctx->bare_ta_signed = 1; 2876 dane->mdpth = num - 1; 2877 dane->mtlsa = t; 2878 2879 /* Prune any excess chain certificates */ 2880 num = sk_X509_num(ctx->chain); 2881 for (; num > ctx->num_untrusted; --num) 2882 X509_free(sk_X509_pop(ctx->chain)); 2883 2884 return X509_TRUST_TRUSTED; 2885 } 2886 2887 return X509_TRUST_UNTRUSTED; 2888} 2889 2890static void dane_reset(SSL_DANE *dane) 2891{ 2892 /* Reset state to verify another chain, or clear after failure. */ 2893 X509_free(dane->mcert); 2894 dane->mcert = NULL; 2895 dane->mtlsa = NULL; 2896 dane->mdpth = -1; 2897 dane->pdpth = -1; 2898} 2899 2900static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert) 2901{ 2902 int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags); 2903 2904 CB_FAIL_IF(err != X509_V_OK, ctx, cert, 0, err); 2905 return 1; 2906} 2907 2908/* Returns -1 on internal error */ 2909static int dane_verify(X509_STORE_CTX *ctx) 2910{ 2911 X509 *cert = ctx->cert; 2912 SSL_DANE *dane = ctx->dane; 2913 int matched; 2914 int done; 2915 2916 dane_reset(dane); 2917 2918 /*- 2919 * When testing the leaf certificate, if we match a DANE-EE(3) record, 2920 * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1) 2921 * record, the match depth and matching TLSA record are recorded, but the 2922 * return value is 0, because we still need to find a PKIX trust anchor. 2923 * Therefore, when DANE authentication is enabled (required), we're done 2924 * if: 2925 * + matched < 0, internal error. 2926 * + matched == 1, we matched a DANE-EE(3) record 2927 * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no 2928 * DANE-TA(2) or PKIX-TA(0) to test. 2929 */ 2930 matched = dane_match(ctx, ctx->cert, 0); 2931 done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0); 2932 2933 if (done && !X509_get_pubkey_parameters(NULL, ctx->chain)) 2934 return -1; 2935 2936 if (matched > 0) { 2937 /* Callback invoked as needed */ 2938 if (!check_leaf_suiteb(ctx, cert)) 2939 return 0; 2940 /* Callback invoked as needed */ 2941 if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 && 2942 !check_id(ctx)) 2943 return 0; 2944 /* Bypass internal_verify(), issue depth 0 success callback */ 2945 ctx->error_depth = 0; 2946 ctx->current_cert = cert; 2947 return ctx->verify_cb(1, ctx); 2948 } 2949 2950 if (matched < 0) { 2951 ctx->error_depth = 0; 2952 ctx->current_cert = cert; 2953 ctx->error = X509_V_ERR_OUT_OF_MEM; 2954 return -1; 2955 } 2956 2957 if (done) { 2958 /* Fail early, TA-based success is not possible */ 2959 if (!check_leaf_suiteb(ctx, cert)) 2960 return 0; 2961 return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH); 2962 } 2963 2964 /* 2965 * Chain verification for usages 0/1/2. TLSA record matching of depth > 0 2966 * certificates happens in-line with building the rest of the chain. 2967 */ 2968 return verify_chain(ctx); 2969} 2970 2971/* 2972 * Get trusted issuer, without duplicate suppression 2973 * Returns -1 on internal error. 2974 */ 2975static int get1_trusted_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert) 2976{ 2977 STACK_OF(X509) *saved_chain = ctx->chain; 2978 int ok; 2979 2980 ctx->chain = NULL; 2981 ok = ctx->get_issuer(issuer, ctx, cert); 2982 ctx->chain = saved_chain; 2983 2984 return ok; 2985} 2986 2987/* Returns -1 on internal error */ 2988static int build_chain(X509_STORE_CTX *ctx) 2989{ 2990 SSL_DANE *dane = ctx->dane; 2991 int num = sk_X509_num(ctx->chain); 2992 STACK_OF(X509) *sk_untrusted = NULL; 2993 unsigned int search; 2994 int may_trusted = 0; 2995 int may_alternate = 0; 2996 int trust = X509_TRUST_UNTRUSTED; 2997 int alt_untrusted = 0; 2998 int max_depth; 2999 int ok = 0; 3000 int i; 3001 3002 /* Our chain starts with a single untrusted element. */ 3003 if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) 3004 goto int_err; 3005 3006#define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */ 3007#define S_DOTRUSTED (1 << 1) /* Search trusted store */ 3008#define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */ 3009 /* 3010 * Set up search policy, untrusted if possible, trusted-first if enabled, 3011 * which is the default. 3012 * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the 3013 * trust_store, otherwise we might look there first. If not trusted-first, 3014 * and alternate chains are not disabled, try building an alternate chain 3015 * if no luck with untrusted first. 3016 */ 3017 search = ctx->untrusted != NULL ? S_DOUNTRUSTED : 0; 3018 if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) { 3019 if (search == 0 || (ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) != 0) 3020 search |= S_DOTRUSTED; 3021 else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) 3022 may_alternate = 1; 3023 may_trusted = 1; 3024 } 3025 3026 /* Initialize empty untrusted stack. */ 3027 if ((sk_untrusted = sk_X509_new_null()) == NULL) 3028 goto memerr; 3029 3030 /* 3031 * If we got any "Cert(0) Full(0)" trust anchors from DNS, *prepend* them 3032 * to our working copy of the untrusted certificate stack. 3033 */ 3034 if (DANETLS_ENABLED(dane) && dane->certs != NULL 3035 && !X509_add_certs(sk_untrusted, dane->certs, X509_ADD_FLAG_DEFAULT)) 3036 goto memerr; 3037 3038 /* 3039 * Shallow-copy the stack of untrusted certificates (with TLS, this is 3040 * typically the content of the peer's certificate message) so we can make 3041 * multiple passes over it, while free to remove elements as we go. 3042 */ 3043 if (!X509_add_certs(sk_untrusted, ctx->untrusted, X509_ADD_FLAG_DEFAULT)) 3044 goto memerr; 3045 3046 /* 3047 * Still absurdly large, but arithmetically safe, a lower hard upper bound 3048 * might be reasonable. 3049 */ 3050 if (ctx->param->depth > INT_MAX / 2) 3051 ctx->param->depth = INT_MAX / 2; 3052 3053 /* 3054 * Try to extend the chain until we reach an ultimately trusted issuer. 3055 * Build chains up to one longer the limit, later fail if we hit the limit, 3056 * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code. 3057 */ 3058 max_depth = ctx->param->depth + 1; 3059 3060 while (search != 0) { 3061 X509 *curr, *issuer = NULL; 3062 3063 num = sk_X509_num(ctx->chain); 3064 ctx->error_depth = num - 1; 3065 /* 3066 * Look in the trust store if enabled for first lookup, or we've run 3067 * out of untrusted issuers and search here is not disabled. When we 3068 * reach the depth limit, we stop extending the chain, if by that point 3069 * we've not found a trust anchor, any trusted chain would be too long. 3070 * 3071 * The error reported to the application verify callback is at the 3072 * maximal valid depth with the current certificate equal to the last 3073 * not ultimately-trusted issuer. For example, with verify_depth = 0, 3074 * the callback will report errors at depth=1 when the immediate issuer 3075 * of the leaf certificate is not a trust anchor. No attempt will be 3076 * made to locate an issuer for that certificate, since such a chain 3077 * would be a-priori too long. 3078 */ 3079 if ((search & S_DOTRUSTED) != 0) { 3080 i = num; 3081 if ((search & S_DOALTERNATE) != 0) { 3082 /* 3083 * As high up the chain as we can, look for an alternative 3084 * trusted issuer of an untrusted certificate that currently 3085 * has an untrusted issuer. We use the alt_untrusted variable 3086 * to track how far up the chain we find the first match. It 3087 * is only if and when we find a match, that we prune the chain 3088 * and reset ctx->num_untrusted to the reduced count of 3089 * untrusted certificates. While we're searching for such a 3090 * match (which may never be found), it is neither safe nor 3091 * wise to preemptively modify either the chain or 3092 * ctx->num_untrusted. 3093 * 3094 * Note, like ctx->num_untrusted, alt_untrusted is a count of 3095 * untrusted certificates, not a "depth". 3096 */ 3097 i = alt_untrusted; 3098 } 3099 curr = sk_X509_value(ctx->chain, i - 1); 3100 3101 /* Note: get1_trusted_issuer() must be used even if self-signed. */ 3102 ok = num > max_depth ? 0 : get1_trusted_issuer(&issuer, ctx, curr); 3103 3104 if (ok < 0) { 3105 trust = -1; 3106 ctx->error = X509_V_ERR_STORE_LOOKUP; 3107 break; 3108 } 3109 3110 if (ok > 0) { 3111 int self_signed = X509_self_signed(curr, 0); 3112 3113 if (self_signed < 0) { 3114 X509_free(issuer); 3115 goto int_err; 3116 } 3117 /* 3118 * Alternative trusted issuer for a mid-chain untrusted cert? 3119 * Pop the untrusted cert's successors and retry. We might now 3120 * be able to complete a valid chain via the trust store. Note 3121 * that despite the current trust store match we might still 3122 * fail complete the chain to a suitable trust anchor, in which 3123 * case we may prune some more untrusted certificates and try 3124 * again. Thus the S_DOALTERNATE bit may yet be turned on 3125 * again with an even shorter untrusted chain! 3126 * 3127 * If in the process we threw away our matching PKIX-TA trust 3128 * anchor, reset DANE trust. We might find a suitable trusted 3129 * certificate among the ones from the trust store. 3130 */ 3131 if ((search & S_DOALTERNATE) != 0) { 3132 if (!ossl_assert(num > i && i > 0 && !self_signed)) { 3133 X509_free(issuer); 3134 goto int_err; 3135 } 3136 search &= ~S_DOALTERNATE; 3137 for (; num > i; --num) 3138 X509_free(sk_X509_pop(ctx->chain)); 3139 ctx->num_untrusted = num; 3140 3141 if (DANETLS_ENABLED(dane) && 3142 dane->mdpth >= ctx->num_untrusted) { 3143 dane->mdpth = -1; 3144 X509_free(dane->mcert); 3145 dane->mcert = NULL; 3146 } 3147 if (DANETLS_ENABLED(dane) && 3148 dane->pdpth >= ctx->num_untrusted) 3149 dane->pdpth = -1; 3150 } 3151 3152 /* 3153 * Self-signed untrusted certificates get replaced by their 3154 * trusted matching issuer. Otherwise, grow the chain. 3155 */ 3156 if (!self_signed) { 3157 if (!sk_X509_push(ctx->chain, issuer)) { 3158 X509_free(issuer); 3159 goto memerr; 3160 } 3161 if ((self_signed = X509_self_signed(issuer, 0)) < 0) 3162 goto int_err; 3163 } else { 3164 /* 3165 * We have a self-signed certificate that has the same 3166 * subject name (and perhaps keyid and/or serial number) as 3167 * a trust anchor. We must have an exact match to avoid 3168 * possible impersonation via key substitution etc. 3169 */ 3170 if (X509_cmp(curr, issuer) != 0) { 3171 /* Self-signed untrusted mimic. */ 3172 X509_free(issuer); 3173 ok = 0; 3174 } else { /* curr "==" issuer */ 3175 X509_free(curr); 3176 ctx->num_untrusted = --num; 3177 (void)sk_X509_set(ctx->chain, num, issuer); 3178 } 3179 } 3180 3181 /* 3182 * We've added a new trusted certificate to the chain, re-check 3183 * trust. If not done, and not self-signed look deeper. 3184 * Whether or not we're doing "trusted first", we no longer 3185 * look for untrusted certificates from the peer's chain. 3186 * 3187 * At this point ctx->num_trusted and num must reflect the 3188 * correct number of untrusted certificates, since the DANE 3189 * logic in check_trust() depends on distinguishing CAs from 3190 * "the wire" from CAs from the trust store. In particular, the 3191 * certificate at depth "num" should be the new trusted 3192 * certificate with ctx->num_untrusted <= num. 3193 */ 3194 if (ok) { 3195 if (!ossl_assert(ctx->num_untrusted <= num)) 3196 goto int_err; 3197 search &= ~S_DOUNTRUSTED; 3198 trust = check_trust(ctx, num); 3199 if (trust != X509_TRUST_UNTRUSTED) 3200 break; 3201 if (!self_signed) 3202 continue; 3203 } 3204 } 3205 3206 /* 3207 * No dispositive decision, and either self-signed or no match, if 3208 * we were doing untrusted-first, and alt-chains are not disabled, 3209 * do that, by repeatedly losing one untrusted element at a time, 3210 * and trying to extend the shorted chain. 3211 */ 3212 if ((search & S_DOUNTRUSTED) == 0) { 3213 /* Continue search for a trusted issuer of a shorter chain? */ 3214 if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0) 3215 continue; 3216 /* Still no luck and no fallbacks left? */ 3217 if (!may_alternate || (search & S_DOALTERNATE) != 0 || 3218 ctx->num_untrusted < 2) 3219 break; 3220 /* Search for a trusted issuer of a shorter chain */ 3221 search |= S_DOALTERNATE; 3222 alt_untrusted = ctx->num_untrusted - 1; 3223 } 3224 } 3225 3226 /* 3227 * Extend chain with peer-provided untrusted certificates 3228 */ 3229 if ((search & S_DOUNTRUSTED) != 0) { 3230 num = sk_X509_num(ctx->chain); 3231 if (!ossl_assert(num == ctx->num_untrusted)) 3232 goto int_err; 3233 curr = sk_X509_value(ctx->chain, num - 1); 3234 issuer = (X509_self_signed(curr, 0) > 0 || num > max_depth) ? 3235 NULL : find_issuer(ctx, sk_untrusted, curr); 3236 if (issuer == NULL) { 3237 /* 3238 * Once we have reached a self-signed cert or num > max_depth 3239 * or can't find an issuer in the untrusted list we stop looking 3240 * there and start looking only in the trust store if enabled. 3241 */ 3242 search &= ~S_DOUNTRUSTED; 3243 if (may_trusted) 3244 search |= S_DOTRUSTED; 3245 continue; 3246 } 3247 3248 /* Drop this issuer from future consideration */ 3249 (void)sk_X509_delete_ptr(sk_untrusted, issuer); 3250 3251 if (!X509_add_cert(ctx->chain, issuer, X509_ADD_FLAG_UP_REF)) 3252 goto int_err; 3253 3254 ++ctx->num_untrusted; 3255 3256 /* Check for DANE-TA trust of the topmost untrusted certificate. */ 3257 trust = check_dane_issuer(ctx, ctx->num_untrusted - 1); 3258 if (trust == X509_TRUST_TRUSTED || trust == X509_TRUST_REJECTED) 3259 break; 3260 } 3261 } 3262 sk_X509_free(sk_untrusted); 3263 3264 if (trust < 0) /* internal error */ 3265 return trust; 3266 3267 /* 3268 * Last chance to make a trusted chain, either bare DANE-TA public-key 3269 * signers, or else direct leaf PKIX trust. 3270 */ 3271 num = sk_X509_num(ctx->chain); 3272 if (num <= max_depth) { 3273 if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane)) 3274 trust = check_dane_pkeys(ctx); 3275 if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted) 3276 trust = check_trust(ctx, num); 3277 } 3278 3279 switch (trust) { 3280 case X509_TRUST_TRUSTED: 3281 return 1; 3282 case X509_TRUST_REJECTED: 3283 /* Callback already issued */ 3284 return 0; 3285 case X509_TRUST_UNTRUSTED: 3286 default: 3287 switch(ctx->error) { 3288 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: 3289 case X509_V_ERR_CERT_NOT_YET_VALID: 3290 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: 3291 case X509_V_ERR_CERT_HAS_EXPIRED: 3292 return 0; /* Callback already issued by ossl_x509_check_cert_time() */ 3293 default: /* A preliminary error has become final */ 3294 return verify_cb_cert(ctx, NULL, num - 1, ctx->error); 3295 case X509_V_OK: 3296 break; 3297 } 3298 CB_FAIL_IF(num > max_depth, 3299 ctx, NULL, num - 1, X509_V_ERR_CERT_CHAIN_TOO_LONG); 3300 CB_FAIL_IF(DANETLS_ENABLED(dane) 3301 && (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0), 3302 ctx, NULL, num - 1, X509_V_ERR_DANE_NO_MATCH); 3303 if (X509_self_signed(sk_X509_value(ctx->chain, num - 1), 0) > 0) 3304 return verify_cb_cert(ctx, NULL, num - 1, 3305 num == 1 3306 ? X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT 3307 : X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN); 3308 return verify_cb_cert(ctx, NULL, num - 1, 3309 ctx->num_untrusted < num 3310 ? X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT 3311 : X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY); 3312 } 3313 3314 int_err: 3315 ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR); 3316 ctx->error = X509_V_ERR_UNSPECIFIED; 3317 sk_X509_free(sk_untrusted); 3318 return -1; 3319 3320 memerr: 3321 ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE); 3322 ctx->error = X509_V_ERR_OUT_OF_MEM; 3323 sk_X509_free(sk_untrusted); 3324 return -1; 3325} 3326 3327STACK_OF(X509) *X509_build_chain(X509 *target, STACK_OF(X509) *certs, 3328 X509_STORE *store, int with_self_signed, 3329 OSSL_LIB_CTX *libctx, const char *propq) 3330{ 3331 int finish_chain = store != NULL; 3332 X509_STORE_CTX *ctx; 3333 int flags = X509_ADD_FLAG_UP_REF; 3334 STACK_OF(X509) *result = NULL; 3335 3336 if (target == NULL) { 3337 ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); 3338 return NULL; 3339 } 3340 3341 if ((ctx = X509_STORE_CTX_new_ex(libctx, propq)) == NULL) 3342 return NULL; 3343 if (!X509_STORE_CTX_init(ctx, store, target, finish_chain ? certs : NULL)) 3344 goto err; 3345 if (!finish_chain) 3346 X509_STORE_CTX_set0_trusted_stack(ctx, certs); 3347 if (!ossl_x509_add_cert_new(&ctx->chain, target, X509_ADD_FLAG_UP_REF)) { 3348 ctx->error = X509_V_ERR_OUT_OF_MEM; 3349 goto err; 3350 } 3351 ctx->num_untrusted = 1; 3352 3353 if (!build_chain(ctx) && finish_chain) 3354 goto err; 3355 3356 /* result list to store the up_ref'ed certificates */ 3357 if (sk_X509_num(ctx->chain) > 1 && !with_self_signed) 3358 flags |= X509_ADD_FLAG_NO_SS; 3359 if (!ossl_x509_add_certs_new(&result, ctx->chain, flags)) { 3360 sk_X509_free(result); 3361 result = NULL; 3362 } 3363 3364 err: 3365 X509_STORE_CTX_free(ctx); 3366 return result; 3367} 3368 3369/* 3370 * note that there's a corresponding minbits_table in ssl/ssl_cert.c 3371 * in ssl_get_security_level_bits that's used for selection of DH parameters 3372 */ 3373static const int minbits_table[] = { 80, 112, 128, 192, 256 }; 3374static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table); 3375 3376/*- 3377 * Check whether the public key of `cert` meets the security level of `ctx`. 3378 * Returns 1 on success, 0 otherwise. 3379 */ 3380static int check_key_level(X509_STORE_CTX *ctx, X509 *cert) 3381{ 3382 EVP_PKEY *pkey = X509_get0_pubkey(cert); 3383 int level = ctx->param->auth_level; 3384 3385 /* 3386 * At security level zero, return without checking for a supported public 3387 * key type. Some engines support key types not understood outside the 3388 * engine, and we only need to understand the key when enforcing a security 3389 * floor. 3390 */ 3391 if (level <= 0) 3392 return 1; 3393 3394 /* Unsupported or malformed keys are not secure */ 3395 if (pkey == NULL) 3396 return 0; 3397 3398 if (level > NUM_AUTH_LEVELS) 3399 level = NUM_AUTH_LEVELS; 3400 3401 return EVP_PKEY_get_security_bits(pkey) >= minbits_table[level - 1]; 3402} 3403 3404/*- 3405 * Check whether the public key of ``cert`` does not use explicit params 3406 * for an elliptic curve. 3407 * 3408 * Returns 1 on success, 0 if check fails, -1 for other errors. 3409 */ 3410static int check_curve(X509 *cert) 3411{ 3412 EVP_PKEY *pkey = X509_get0_pubkey(cert); 3413 3414 /* Unsupported or malformed key */ 3415 if (pkey == NULL) 3416 return -1; 3417 3418 if (EVP_PKEY_get_id(pkey) == EVP_PKEY_EC) { 3419 int ret, val; 3420 3421 ret = EVP_PKEY_get_int_param(pkey, 3422 OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS, 3423 &val); 3424 return ret == 1 ? !val : -1; 3425 } 3426 3427 return 1; 3428} 3429 3430/*- 3431 * Check whether the signature digest algorithm of ``cert`` meets the security 3432 * level of ``ctx``. Should not be checked for trust anchors (whether 3433 * self-signed or otherwise). 3434 * 3435 * Returns 1 on success, 0 otherwise. 3436 */ 3437static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert) 3438{ 3439 int secbits = -1; 3440 int level = ctx->param->auth_level; 3441 3442 if (level <= 0) 3443 return 1; 3444 if (level > NUM_AUTH_LEVELS) 3445 level = NUM_AUTH_LEVELS; 3446 3447 if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL)) 3448 return 0; 3449 3450 return secbits >= minbits_table[level - 1]; 3451} 3452