1 /* $OpenBSD: ts_rsp_verify.c,v 1.28 2022/07/24 08:16:47 tb Exp $ */ 2 /* Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL 3 * project 2002. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2006 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 #include <stdio.h> 60 #include <string.h> 61 62 #include <openssl/err.h> 63 #include <openssl/objects.h> 64 #include <openssl/pkcs7.h> 65 #include <openssl/ts.h> 66 67 #include "evp_locl.h" 68 #include "ts_local.h" 69 #include "x509_lcl.h" 70 71 /* Private function declarations. */ 72 73 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, 74 X509 *signer, STACK_OF(X509) **chain); 75 static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain); 76 static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si); 77 static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert); 78 static ESS_SIGNING_CERT_V2 *ESS_get_signing_cert_v2(PKCS7_SIGNER_INFO *si); 79 static int TS_find_cert_v2(STACK_OF(ESS_CERT_ID_V2) *cert_ids, X509 *cert); 80 static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert); 81 static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, 82 PKCS7 *token, TS_TST_INFO *tst_info); 83 static int TS_check_status_info(TS_RESP *response); 84 static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text); 85 static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info); 86 static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, 87 X509_ALGOR **md_alg, 88 unsigned char **imprint, unsigned *imprint_len); 89 static int TS_check_imprints(X509_ALGOR *algor_a, 90 unsigned char *imprint_a, unsigned len_a, 91 TS_TST_INFO *tst_info); 92 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info); 93 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer); 94 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name); 95 96 /* 97 * Local mapping between response codes and descriptions. 98 * Don't forget to change TS_STATUS_BUF_SIZE when modifying 99 * the elements of this array. 100 */ 101 static const char *TS_status_text[] = { 102 "granted", 103 "grantedWithMods", 104 "rejection", 105 "waiting", 106 "revocationWarning", 107 "revocationNotification" 108 }; 109 110 #define TS_STATUS_TEXT_SIZE (sizeof(TS_status_text)/sizeof(*TS_status_text)) 111 112 /* 113 * This must be greater or equal to the sum of the strings in TS_status_text 114 * plus the number of its elements. 115 */ 116 #define TS_STATUS_BUF_SIZE 256 117 118 static struct { 119 int code; 120 const char *text; 121 } TS_failure_info[] = { 122 { TS_INFO_BAD_ALG, "badAlg" }, 123 { TS_INFO_BAD_REQUEST, "badRequest" }, 124 { TS_INFO_BAD_DATA_FORMAT, "badDataFormat" }, 125 { TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable" }, 126 { TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy" }, 127 { TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension" }, 128 { TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable" }, 129 { TS_INFO_SYSTEM_FAILURE, "systemFailure" } 130 }; 131 132 #define TS_FAILURE_INFO_SIZE (sizeof(TS_failure_info) / \ 133 sizeof(*TS_failure_info)) 134 135 /* Functions for verifying a signed TS_TST_INFO structure. */ 136 137 /* 138 * This function carries out the following tasks: 139 * - Checks if there is one and only one signer. 140 * - Search for the signing certificate in 'certs' and in the response. 141 * - Check the extended key usage and key usage fields of the signer 142 * certificate (done by the path validation). 143 * - Build and validate the certificate path. 144 * - Check if the certificate path meets the requirements of the 145 * SigningCertificate ESS signed attribute. 146 * - Verify the signature value. 147 * - Returns the signer certificate in 'signer', if 'signer' is not NULL. 148 */ 149 int 150 TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs, 151 X509_STORE *store, X509 **signer_out) 152 { 153 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL; 154 PKCS7_SIGNER_INFO *si; 155 STACK_OF(X509) *signers = NULL; 156 X509 *signer; 157 STACK_OF(X509) *chain = NULL; 158 char buf[4096]; 159 int i, j = 0, ret = 0; 160 BIO *p7bio = NULL; 161 162 /* Some sanity checks first. */ 163 if (!token) { 164 TSerror(TS_R_INVALID_NULL_POINTER); 165 goto err; 166 } 167 168 /* Check for the correct content type */ 169 if (!PKCS7_type_is_signed(token)) { 170 TSerror(TS_R_WRONG_CONTENT_TYPE); 171 goto err; 172 } 173 174 /* Check if there is one and only one signer. */ 175 sinfos = PKCS7_get_signer_info(token); 176 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) { 177 TSerror(TS_R_THERE_MUST_BE_ONE_SIGNER); 178 goto err; 179 } 180 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0); 181 182 /* Check for no content: no data to verify signature. */ 183 if (PKCS7_get_detached(token)) { 184 TSerror(TS_R_NO_CONTENT); 185 goto err; 186 } 187 188 /* Get hold of the signer certificate, search only internal 189 certificates if it was requested. */ 190 signers = PKCS7_get0_signers(token, certs, 0); 191 if (!signers || sk_X509_num(signers) != 1) 192 goto err; 193 signer = sk_X509_value(signers, 0); 194 195 /* Now verify the certificate. */ 196 if (!TS_verify_cert(store, certs, signer, &chain)) 197 goto err; 198 199 /* Check if the signer certificate is consistent with the 200 ESS extension. */ 201 if (!TS_check_signing_certs(si, chain)) 202 goto err; 203 204 /* Creating the message digest. */ 205 p7bio = PKCS7_dataInit(token, NULL); 206 207 /* We now have to 'read' from p7bio to calculate digests etc. */ 208 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0) 209 ; 210 211 /* Verifying the signature. */ 212 j = PKCS7_signatureVerify(p7bio, token, si, signer); 213 if (j <= 0) { 214 TSerror(TS_R_SIGNATURE_FAILURE); 215 goto err; 216 } 217 218 /* Return the signer certificate if needed. */ 219 if (signer_out) { 220 *signer_out = signer; 221 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509); 222 } 223 224 ret = 1; 225 226 err: 227 BIO_free_all(p7bio); 228 sk_X509_pop_free(chain, X509_free); 229 sk_X509_free(signers); 230 231 return ret; 232 } 233 234 /* 235 * The certificate chain is returned in chain. Caller is responsible for 236 * freeing the vector. 237 */ 238 static int 239 TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, X509 *signer, 240 STACK_OF(X509) **chain) 241 { 242 X509_STORE_CTX cert_ctx; 243 int i; 244 int ret = 0; 245 246 /* chain is an out argument. */ 247 *chain = NULL; 248 if (X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted) == 0) { 249 TSerror(ERR_R_X509_LIB); 250 goto err; 251 } 252 if (X509_STORE_CTX_set_purpose(&cert_ctx, 253 X509_PURPOSE_TIMESTAMP_SIGN) == 0) 254 goto err; 255 i = X509_verify_cert(&cert_ctx); 256 if (i <= 0) { 257 int j = X509_STORE_CTX_get_error(&cert_ctx); 258 259 TSerror(TS_R_CERTIFICATE_VERIFY_ERROR); 260 ERR_asprintf_error_data("Verify error:%s", 261 X509_verify_cert_error_string(j)); 262 goto err; 263 } else { 264 /* Get a copy of the certificate chain. */ 265 *chain = X509_STORE_CTX_get1_chain(&cert_ctx); 266 ret = 1; 267 } 268 269 err: 270 X509_STORE_CTX_cleanup(&cert_ctx); 271 272 return ret; 273 } 274 275 static int 276 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain) 277 { 278 ESS_SIGNING_CERT *ss = NULL; 279 STACK_OF(ESS_CERT_ID) *cert_ids; 280 ESS_SIGNING_CERT_V2 *ssv2 = NULL; 281 STACK_OF(ESS_CERT_ID_V2) *cert_ids_v2; 282 X509 *cert; 283 int i = 0; 284 int ret = 0; 285 286 if ((ss = ESS_get_signing_cert(si)) != NULL) { 287 cert_ids = ss->cert_ids; 288 /* The signer certificate must be the first in cert_ids. */ 289 cert = sk_X509_value(chain, 0); 290 291 if (TS_find_cert(cert_ids, cert) != 0) 292 goto err; 293 294 /* 295 * Check the other certificates of the chain if there are more 296 * than one certificate ids in cert_ids. 297 */ 298 if (sk_ESS_CERT_ID_num(cert_ids) > 1) { 299 /* All the certificates of the chain must be in cert_ids. */ 300 for (i = 1; i < sk_X509_num(chain); i++) { 301 cert = sk_X509_value(chain, i); 302 303 if (TS_find_cert(cert_ids, cert) < 0) 304 goto err; 305 } 306 } 307 } 308 309 if ((ssv2 = ESS_get_signing_cert_v2(si)) != NULL) { 310 cert_ids_v2 = ssv2->cert_ids; 311 /* The signer certificate must be the first in cert_ids_v2. */ 312 cert = sk_X509_value(chain, 0); 313 314 if (TS_find_cert_v2(cert_ids_v2, cert) != 0) 315 goto err; 316 317 /* 318 * Check the other certificates of the chain if there are more 319 * than one certificate ids in cert_ids_v2. 320 */ 321 if (sk_ESS_CERT_ID_V2_num(cert_ids_v2) > 1) { 322 /* All the certificates of the chain must be in cert_ids_v2. */ 323 for (i = 1; i < sk_X509_num(chain); i++) { 324 cert = sk_X509_value(chain, i); 325 326 if (TS_find_cert_v2(cert_ids_v2, cert) < 0) 327 goto err; 328 } 329 } 330 } 331 332 ret = 1; 333 334 err: 335 if (!ret) 336 TSerror(TS_R_ESS_SIGNING_CERTIFICATE_ERROR); 337 ESS_SIGNING_CERT_free(ss); 338 ESS_SIGNING_CERT_V2_free(ssv2); 339 return ret; 340 } 341 342 static ESS_SIGNING_CERT * 343 ESS_get_signing_cert(PKCS7_SIGNER_INFO *si) 344 { 345 ASN1_TYPE *attr; 346 const unsigned char *p; 347 348 attr = PKCS7_get_signed_attribute(si, 349 NID_id_smime_aa_signingCertificate); 350 if (!attr) 351 return NULL; 352 if (attr->type != V_ASN1_SEQUENCE) 353 return NULL; 354 p = attr->value.sequence->data; 355 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length); 356 } 357 358 static ESS_SIGNING_CERT_V2 * 359 ESS_get_signing_cert_v2(PKCS7_SIGNER_INFO *si) 360 { 361 ASN1_TYPE *attr; 362 const unsigned char *p; 363 364 attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificateV2); 365 if (attr == NULL) 366 return NULL; 367 p = attr->value.sequence->data; 368 return d2i_ESS_SIGNING_CERT_V2(NULL, &p, attr->value.sequence->length); 369 } 370 371 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 372 static int 373 TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert) 374 { 375 int i; 376 unsigned char cert_hash[TS_HASH_LEN]; 377 378 if (!cert_ids || !cert) 379 return -1; 380 381 if (!X509_digest(cert, TS_HASH_EVP, cert_hash, NULL)) 382 return -1; 383 384 /* Recompute SHA1 hash of certificate if necessary (side effect). */ 385 if (X509_check_purpose(cert, -1, 0) == -1) 386 return -1; 387 388 /* Look for cert in the cert_ids vector. */ 389 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) { 390 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i); 391 392 /* Check the SHA-1 hash first. */ 393 if (cid->hash->length == TS_HASH_LEN && !memcmp(cid->hash->data, 394 cert_hash, TS_HASH_LEN)) { 395 /* Check the issuer/serial as well if specified. */ 396 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 397 398 if (is == NULL || TS_issuer_serial_cmp(is, cert) == 0) 399 return i; 400 } 401 } 402 403 return -1; 404 } 405 406 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 407 static int 408 TS_find_cert_v2(STACK_OF(ESS_CERT_ID_V2) *cert_ids, X509 *cert) 409 { 410 int i; 411 unsigned char cert_digest[EVP_MAX_MD_SIZE]; 412 unsigned int len; 413 414 /* Look for cert in the cert_ids vector. */ 415 for (i = 0; i < sk_ESS_CERT_ID_V2_num(cert_ids); ++i) { 416 ESS_CERT_ID_V2 *cid = sk_ESS_CERT_ID_V2_value(cert_ids, i); 417 const EVP_MD *md = EVP_sha256(); 418 419 if (cid->hash_alg != NULL) 420 md = EVP_get_digestbyobj(cid->hash_alg->algorithm); 421 if (md == NULL) 422 return -1; 423 424 if (!X509_digest(cert, md, cert_digest, &len)) 425 return -1; 426 427 if ((unsigned int)cid->hash->length != len) 428 return -1; 429 430 if (memcmp(cid->hash->data, cert_digest, cid->hash->length) == 0) { 431 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 432 433 if (is == NULL || TS_issuer_serial_cmp(is, cert) == 0) 434 return i; 435 } 436 } 437 438 return -1; 439 } 440 441 static int 442 TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert) 443 { 444 GENERAL_NAME *issuer; 445 446 if (is == NULL || cert == NULL || sk_GENERAL_NAME_num(is->issuer) != 1) 447 return -1; 448 449 /* Check the issuer first. It must be a directory name. */ 450 issuer = sk_GENERAL_NAME_value(is->issuer, 0); 451 if (issuer->type != GEN_DIRNAME || 452 X509_NAME_cmp(issuer->d.dirn, X509_get_issuer_name(cert))) 453 return -1; 454 455 /* Check the serial number, too. */ 456 if (ASN1_INTEGER_cmp(is->serial, X509_get_serialNumber(cert))) 457 return -1; 458 459 return 0; 460 } 461 462 /* 463 * Verifies whether 'response' contains a valid response with regards 464 * to the settings of the context: 465 * - Gives an error message if the TS_TST_INFO is not present. 466 * - Calls _TS_RESP_verify_token to verify the token content. 467 */ 468 int 469 TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response) 470 { 471 PKCS7 *token = TS_RESP_get_token(response); 472 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response); 473 int ret = 0; 474 475 /* Check if we have a successful TS_TST_INFO object in place. */ 476 if (!TS_check_status_info(response)) 477 goto err; 478 479 /* Check the contents of the time stamp token. */ 480 if (!int_TS_RESP_verify_token(ctx, token, tst_info)) 481 goto err; 482 483 ret = 1; 484 485 err: 486 return ret; 487 } 488 489 /* 490 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and 491 * calls the internal int_TS_RESP_verify_token function for verifying it. 492 */ 493 int 494 TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token) 495 { 496 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token); 497 int ret = 0; 498 499 if (tst_info) { 500 ret = int_TS_RESP_verify_token(ctx, token, tst_info); 501 TS_TST_INFO_free(tst_info); 502 } 503 return ret; 504 } 505 506 /* 507 * Verifies whether the 'token' contains a valid time stamp token 508 * with regards to the settings of the context. Only those checks are 509 * carried out that are specified in the context: 510 * - Verifies the signature of the TS_TST_INFO. 511 * - Checks the version number of the response. 512 * - Check if the requested and returned policies math. 513 * - Check if the message imprints are the same. 514 * - Check if the nonces are the same. 515 * - Check if the TSA name matches the signer. 516 * - Check if the TSA name is the expected TSA. 517 */ 518 static int 519 int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token, 520 TS_TST_INFO *tst_info) 521 { 522 X509 *signer = NULL; 523 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info); 524 X509_ALGOR *md_alg = NULL; 525 unsigned char *imprint = NULL; 526 unsigned imprint_len = 0; 527 int ret = 0; 528 529 /* Verify the signature. */ 530 if ((ctx->flags & TS_VFY_SIGNATURE) && 531 !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer)) 532 goto err; 533 534 /* Check version number of response. */ 535 if ((ctx->flags & TS_VFY_VERSION) && 536 TS_TST_INFO_get_version(tst_info) != 1) { 537 TSerror(TS_R_UNSUPPORTED_VERSION); 538 goto err; 539 } 540 541 /* Check policies. */ 542 if ((ctx->flags & TS_VFY_POLICY) && 543 !TS_check_policy(ctx->policy, tst_info)) 544 goto err; 545 546 /* Check message imprints. */ 547 if ((ctx->flags & TS_VFY_IMPRINT) && 548 !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len, 549 tst_info)) 550 goto err; 551 552 /* Compute and check message imprints. */ 553 if ((ctx->flags & TS_VFY_DATA) && 554 (!TS_compute_imprint(ctx->data, tst_info, 555 &md_alg, &imprint, &imprint_len) || 556 !TS_check_imprints(md_alg, imprint, imprint_len, tst_info))) 557 goto err; 558 559 /* Check nonces. */ 560 if ((ctx->flags & TS_VFY_NONCE) && 561 !TS_check_nonces(ctx->nonce, tst_info)) 562 goto err; 563 564 /* Check whether TSA name and signer certificate match. */ 565 if ((ctx->flags & TS_VFY_SIGNER) && 566 tsa_name && !TS_check_signer_name(tsa_name, signer)) { 567 TSerror(TS_R_TSA_NAME_MISMATCH); 568 goto err; 569 } 570 571 /* Check whether the TSA is the expected one. */ 572 if ((ctx->flags & TS_VFY_TSA_NAME) && 573 !TS_check_signer_name(ctx->tsa_name, signer)) { 574 TSerror(TS_R_TSA_UNTRUSTED); 575 goto err; 576 } 577 578 ret = 1; 579 580 err: 581 X509_free(signer); 582 X509_ALGOR_free(md_alg); 583 free(imprint); 584 return ret; 585 } 586 587 static int 588 TS_check_status_info(TS_RESP *response) 589 { 590 TS_STATUS_INFO *info = TS_RESP_get_status_info(response); 591 long status = ASN1_INTEGER_get(info->status); 592 const char *status_text = NULL; 593 char *embedded_status_text = NULL; 594 char failure_text[TS_STATUS_BUF_SIZE] = ""; 595 596 /* Check if everything went fine. */ 597 if (status == 0 || status == 1) 598 return 1; 599 600 /* There was an error, get the description in status_text. */ 601 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE) 602 status_text = TS_status_text[status]; 603 else 604 status_text = "unknown code"; 605 606 /* Set the embedded_status_text to the returned description. */ 607 if (sk_ASN1_UTF8STRING_num(info->text) > 0 && 608 !(embedded_status_text = TS_get_status_text(info->text))) 609 return 0; 610 611 /* Filling in failure_text with the failure information. */ 612 if (info->failure_info) { 613 int i; 614 int first = 1; 615 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) { 616 if (ASN1_BIT_STRING_get_bit(info->failure_info, 617 TS_failure_info[i].code)) { 618 if (!first) 619 strlcat(failure_text, ",", 620 TS_STATUS_BUF_SIZE); 621 else 622 first = 0; 623 strlcat(failure_text, TS_failure_info[i].text, 624 TS_STATUS_BUF_SIZE); 625 } 626 } 627 } 628 if (failure_text[0] == '\0') 629 strlcpy(failure_text, "unspecified", TS_STATUS_BUF_SIZE); 630 631 /* Making up the error string. */ 632 TSerror(TS_R_NO_TIME_STAMP_TOKEN); 633 ERR_asprintf_error_data 634 ("status code: %s, status text: %s, failure codes: %s", 635 status_text, 636 embedded_status_text ? embedded_status_text : "unspecified", 637 failure_text); 638 free(embedded_status_text); 639 640 return 0; 641 } 642 643 static char * 644 TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text) 645 { 646 int i; 647 unsigned int length = 0; 648 char *result = NULL; 649 650 /* Determine length first. */ 651 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 652 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 653 length += ASN1_STRING_length(current); 654 length += 1; /* separator character */ 655 } 656 /* Allocate memory (closing '\0' included). */ 657 if (!(result = malloc(length))) { 658 TSerror(ERR_R_MALLOC_FAILURE); 659 return NULL; 660 } 661 /* Concatenate the descriptions. */ 662 result[0] = '\0'; 663 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 664 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 665 if (i > 0) 666 strlcat(result, "/", length); 667 strlcat(result, (const char *)ASN1_STRING_data(current), length); 668 } 669 return result; 670 } 671 672 static int 673 TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info) 674 { 675 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info); 676 677 if (OBJ_cmp(req_oid, resp_oid) != 0) { 678 TSerror(TS_R_POLICY_MISMATCH); 679 return 0; 680 } 681 682 return 1; 683 } 684 685 static int 686 TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **out_md_alg, 687 unsigned char **out_imprint, unsigned int *out_imprint_len) 688 { 689 TS_MSG_IMPRINT *msg_imprint; 690 X509_ALGOR *md_alg_resp; 691 X509_ALGOR *md_alg = NULL; 692 unsigned char *imprint = NULL; 693 unsigned int imprint_len = 0; 694 const EVP_MD *md; 695 EVP_MD_CTX md_ctx; 696 unsigned char buffer[4096]; 697 int length; 698 699 *out_md_alg = NULL; 700 *out_imprint = NULL; 701 *out_imprint_len = 0; 702 703 /* Retrieve the MD algorithm of the response. */ 704 msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info); 705 md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint); 706 if ((md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL) 707 goto err; 708 709 /* Getting the MD object. */ 710 if ((md = EVP_get_digestbyobj((md_alg)->algorithm)) == NULL) { 711 TSerror(TS_R_UNSUPPORTED_MD_ALGORITHM); 712 goto err; 713 } 714 715 /* Compute message digest. */ 716 if ((length = EVP_MD_size(md)) < 0) 717 goto err; 718 imprint_len = length; 719 if ((imprint = malloc(imprint_len)) == NULL) { 720 TSerror(ERR_R_MALLOC_FAILURE); 721 goto err; 722 } 723 724 if (!EVP_DigestInit(&md_ctx, md)) 725 goto err; 726 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) { 727 if (!EVP_DigestUpdate(&md_ctx, buffer, length)) 728 goto err; 729 } 730 if (!EVP_DigestFinal(&md_ctx, imprint, NULL)) 731 goto err; 732 733 *out_md_alg = md_alg; 734 md_alg = NULL; 735 *out_imprint = imprint; 736 imprint = NULL; 737 *out_imprint_len = imprint_len; 738 739 return 1; 740 741 err: 742 X509_ALGOR_free(md_alg); 743 free(imprint); 744 return 0; 745 } 746 747 static int 748 TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a, 749 TS_TST_INFO *tst_info) 750 { 751 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info); 752 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b); 753 int ret = 0; 754 755 /* algor_a is optional. */ 756 if (algor_a) { 757 /* Compare algorithm OIDs. */ 758 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) 759 goto err; 760 761 /* The parameter must be NULL in both. */ 762 if ((algor_a->parameter && 763 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) || 764 (algor_b->parameter && 765 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL)) 766 goto err; 767 } 768 769 /* Compare octet strings. */ 770 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) && 771 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0; 772 773 err: 774 if (!ret) 775 TSerror(TS_R_MESSAGE_IMPRINT_MISMATCH); 776 return ret; 777 } 778 779 static int 780 TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info) 781 { 782 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info); 783 784 /* Error if nonce is missing. */ 785 if (!b) { 786 TSerror(TS_R_NONCE_NOT_RETURNED); 787 return 0; 788 } 789 790 /* No error if a nonce is returned without being requested. */ 791 if (ASN1_INTEGER_cmp(a, b) != 0) { 792 TSerror(TS_R_NONCE_MISMATCH); 793 return 0; 794 } 795 796 return 1; 797 } 798 799 /* Check if the specified TSA name matches either the subject 800 or one of the subject alternative names of the TSA certificate. */ 801 static int 802 TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer) 803 { 804 STACK_OF(GENERAL_NAME) *gen_names = NULL; 805 int idx = -1; 806 int found = 0; 807 808 if (signer == NULL) 809 return 0; 810 811 /* Check the subject name first. */ 812 if (tsa_name->type == GEN_DIRNAME && 813 X509_name_cmp(tsa_name->d.dirn, X509_get_subject_name(signer)) == 0) 814 return 1; 815 816 /* Check all the alternative names. */ 817 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 818 NULL, &idx); 819 while (gen_names != NULL && 820 !(found = (TS_find_name(gen_names, tsa_name) >= 0))) { 821 /* Get the next subject alternative name, 822 although there should be no more than one. */ 823 GENERAL_NAMES_free(gen_names); 824 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 825 NULL, &idx); 826 } 827 if (gen_names) 828 GENERAL_NAMES_free(gen_names); 829 830 return found; 831 } 832 833 /* Returns 1 if name is in gen_names, 0 otherwise. */ 834 static int 835 TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name) 836 { 837 int i, found; 838 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); 839 ++i) { 840 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i); 841 found = GENERAL_NAME_cmp(current, name) == 0; 842 } 843 return found ? i - 1 : -1; 844 } 845