1 /* $OpenBSD: ts_rsp_verify.c,v 1.30 2023/07/07 07:25:21 beck 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_local.h" 68 #include "ts_local.h" 69 #include "x509_local.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 LCRYPTO_ALIAS(TS_RESP_verify_signature); 234 235 /* 236 * The certificate chain is returned in chain. Caller is responsible for 237 * freeing the vector. 238 */ 239 static int 240 TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, X509 *signer, 241 STACK_OF(X509) **chain) 242 { 243 X509_STORE_CTX cert_ctx; 244 int i; 245 int ret = 0; 246 247 /* chain is an out argument. */ 248 *chain = NULL; 249 if (X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted) == 0) { 250 TSerror(ERR_R_X509_LIB); 251 goto err; 252 } 253 if (X509_STORE_CTX_set_purpose(&cert_ctx, 254 X509_PURPOSE_TIMESTAMP_SIGN) == 0) 255 goto err; 256 i = X509_verify_cert(&cert_ctx); 257 if (i <= 0) { 258 int j = X509_STORE_CTX_get_error(&cert_ctx); 259 260 TSerror(TS_R_CERTIFICATE_VERIFY_ERROR); 261 ERR_asprintf_error_data("Verify error:%s", 262 X509_verify_cert_error_string(j)); 263 goto err; 264 } else { 265 /* Get a copy of the certificate chain. */ 266 *chain = X509_STORE_CTX_get1_chain(&cert_ctx); 267 ret = 1; 268 } 269 270 err: 271 X509_STORE_CTX_cleanup(&cert_ctx); 272 273 return ret; 274 } 275 276 static int 277 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain) 278 { 279 ESS_SIGNING_CERT *ss = NULL; 280 STACK_OF(ESS_CERT_ID) *cert_ids; 281 ESS_SIGNING_CERT_V2 *ssv2 = NULL; 282 STACK_OF(ESS_CERT_ID_V2) *cert_ids_v2; 283 X509 *cert; 284 int i = 0; 285 int ret = 0; 286 287 if ((ss = ESS_get_signing_cert(si)) != NULL) { 288 cert_ids = ss->cert_ids; 289 /* The signer certificate must be the first in cert_ids. */ 290 cert = sk_X509_value(chain, 0); 291 292 if (TS_find_cert(cert_ids, cert) != 0) 293 goto err; 294 295 /* 296 * Check the other certificates of the chain if there are more 297 * than one certificate ids in cert_ids. 298 */ 299 if (sk_ESS_CERT_ID_num(cert_ids) > 1) { 300 /* All the certificates of the chain must be in cert_ids. */ 301 for (i = 1; i < sk_X509_num(chain); i++) { 302 cert = sk_X509_value(chain, i); 303 304 if (TS_find_cert(cert_ids, cert) < 0) 305 goto err; 306 } 307 } 308 } 309 310 if ((ssv2 = ESS_get_signing_cert_v2(si)) != NULL) { 311 cert_ids_v2 = ssv2->cert_ids; 312 /* The signer certificate must be the first in cert_ids_v2. */ 313 cert = sk_X509_value(chain, 0); 314 315 if (TS_find_cert_v2(cert_ids_v2, cert) != 0) 316 goto err; 317 318 /* 319 * Check the other certificates of the chain if there are more 320 * than one certificate ids in cert_ids_v2. 321 */ 322 if (sk_ESS_CERT_ID_V2_num(cert_ids_v2) > 1) { 323 /* All the certificates of the chain must be in cert_ids_v2. */ 324 for (i = 1; i < sk_X509_num(chain); i++) { 325 cert = sk_X509_value(chain, i); 326 327 if (TS_find_cert_v2(cert_ids_v2, cert) < 0) 328 goto err; 329 } 330 } 331 } 332 333 ret = 1; 334 335 err: 336 if (!ret) 337 TSerror(TS_R_ESS_SIGNING_CERTIFICATE_ERROR); 338 ESS_SIGNING_CERT_free(ss); 339 ESS_SIGNING_CERT_V2_free(ssv2); 340 return ret; 341 } 342 343 static ESS_SIGNING_CERT * 344 ESS_get_signing_cert(PKCS7_SIGNER_INFO *si) 345 { 346 ASN1_TYPE *attr; 347 const unsigned char *p; 348 349 attr = PKCS7_get_signed_attribute(si, 350 NID_id_smime_aa_signingCertificate); 351 if (!attr) 352 return NULL; 353 if (attr->type != V_ASN1_SEQUENCE) 354 return NULL; 355 p = attr->value.sequence->data; 356 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length); 357 } 358 359 static ESS_SIGNING_CERT_V2 * 360 ESS_get_signing_cert_v2(PKCS7_SIGNER_INFO *si) 361 { 362 ASN1_TYPE *attr; 363 const unsigned char *p; 364 365 attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificateV2); 366 if (attr == NULL) 367 return NULL; 368 p = attr->value.sequence->data; 369 return d2i_ESS_SIGNING_CERT_V2(NULL, &p, attr->value.sequence->length); 370 } 371 372 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 373 static int 374 TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert) 375 { 376 int i; 377 unsigned char cert_hash[TS_HASH_LEN]; 378 379 if (!cert_ids || !cert) 380 return -1; 381 382 if (!X509_digest(cert, TS_HASH_EVP, cert_hash, NULL)) 383 return -1; 384 385 /* Recompute SHA1 hash of certificate if necessary (side effect). */ 386 if (X509_check_purpose(cert, -1, 0) == -1) 387 return -1; 388 389 /* Look for cert in the cert_ids vector. */ 390 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) { 391 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i); 392 393 /* Check the SHA-1 hash first. */ 394 if (cid->hash->length == TS_HASH_LEN && !memcmp(cid->hash->data, 395 cert_hash, TS_HASH_LEN)) { 396 /* Check the issuer/serial as well if specified. */ 397 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 398 399 if (is == NULL || TS_issuer_serial_cmp(is, cert) == 0) 400 return i; 401 } 402 } 403 404 return -1; 405 } 406 407 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 408 static int 409 TS_find_cert_v2(STACK_OF(ESS_CERT_ID_V2) *cert_ids, X509 *cert) 410 { 411 int i; 412 unsigned char cert_digest[EVP_MAX_MD_SIZE]; 413 unsigned int len; 414 415 /* Look for cert in the cert_ids vector. */ 416 for (i = 0; i < sk_ESS_CERT_ID_V2_num(cert_ids); ++i) { 417 ESS_CERT_ID_V2 *cid = sk_ESS_CERT_ID_V2_value(cert_ids, i); 418 const EVP_MD *md = EVP_sha256(); 419 420 if (cid->hash_alg != NULL) 421 md = EVP_get_digestbyobj(cid->hash_alg->algorithm); 422 if (md == NULL) 423 return -1; 424 425 if (!X509_digest(cert, md, cert_digest, &len)) 426 return -1; 427 428 if ((unsigned int)cid->hash->length != len) 429 return -1; 430 431 if (memcmp(cid->hash->data, cert_digest, cid->hash->length) == 0) { 432 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 433 434 if (is == NULL || TS_issuer_serial_cmp(is, cert) == 0) 435 return i; 436 } 437 } 438 439 return -1; 440 } 441 442 static int 443 TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert) 444 { 445 GENERAL_NAME *issuer; 446 447 if (is == NULL || cert == NULL || sk_GENERAL_NAME_num(is->issuer) != 1) 448 return -1; 449 450 /* Check the issuer first. It must be a directory name. */ 451 issuer = sk_GENERAL_NAME_value(is->issuer, 0); 452 if (issuer->type != GEN_DIRNAME || 453 X509_NAME_cmp(issuer->d.dirn, X509_get_issuer_name(cert))) 454 return -1; 455 456 /* Check the serial number, too. */ 457 if (ASN1_INTEGER_cmp(is->serial, X509_get_serialNumber(cert))) 458 return -1; 459 460 return 0; 461 } 462 463 /* 464 * Verifies whether 'response' contains a valid response with regards 465 * to the settings of the context: 466 * - Gives an error message if the TS_TST_INFO is not present. 467 * - Calls _TS_RESP_verify_token to verify the token content. 468 */ 469 int 470 TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response) 471 { 472 PKCS7 *token = TS_RESP_get_token(response); 473 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response); 474 int ret = 0; 475 476 /* Check if we have a successful TS_TST_INFO object in place. */ 477 if (!TS_check_status_info(response)) 478 goto err; 479 480 /* Check the contents of the time stamp token. */ 481 if (!int_TS_RESP_verify_token(ctx, token, tst_info)) 482 goto err; 483 484 ret = 1; 485 486 err: 487 return ret; 488 } 489 LCRYPTO_ALIAS(TS_RESP_verify_response); 490 491 /* 492 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and 493 * calls the internal int_TS_RESP_verify_token function for verifying it. 494 */ 495 int 496 TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token) 497 { 498 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token); 499 int ret = 0; 500 501 if (tst_info) { 502 ret = int_TS_RESP_verify_token(ctx, token, tst_info); 503 TS_TST_INFO_free(tst_info); 504 } 505 return ret; 506 } 507 LCRYPTO_ALIAS(TS_RESP_verify_token); 508 509 /* 510 * Verifies whether the 'token' contains a valid time stamp token 511 * with regards to the settings of the context. Only those checks are 512 * carried out that are specified in the context: 513 * - Verifies the signature of the TS_TST_INFO. 514 * - Checks the version number of the response. 515 * - Check if the requested and returned policies math. 516 * - Check if the message imprints are the same. 517 * - Check if the nonces are the same. 518 * - Check if the TSA name matches the signer. 519 * - Check if the TSA name is the expected TSA. 520 */ 521 static int 522 int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token, 523 TS_TST_INFO *tst_info) 524 { 525 X509 *signer = NULL; 526 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info); 527 X509_ALGOR *md_alg = NULL; 528 unsigned char *imprint = NULL; 529 unsigned imprint_len = 0; 530 int ret = 0; 531 532 /* Verify the signature. */ 533 if ((ctx->flags & TS_VFY_SIGNATURE) && 534 !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer)) 535 goto err; 536 537 /* Check version number of response. */ 538 if ((ctx->flags & TS_VFY_VERSION) && 539 TS_TST_INFO_get_version(tst_info) != 1) { 540 TSerror(TS_R_UNSUPPORTED_VERSION); 541 goto err; 542 } 543 544 /* Check policies. */ 545 if ((ctx->flags & TS_VFY_POLICY) && 546 !TS_check_policy(ctx->policy, tst_info)) 547 goto err; 548 549 /* Check message imprints. */ 550 if ((ctx->flags & TS_VFY_IMPRINT) && 551 !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len, 552 tst_info)) 553 goto err; 554 555 /* Compute and check message imprints. */ 556 if ((ctx->flags & TS_VFY_DATA) && 557 (!TS_compute_imprint(ctx->data, tst_info, 558 &md_alg, &imprint, &imprint_len) || 559 !TS_check_imprints(md_alg, imprint, imprint_len, tst_info))) 560 goto err; 561 562 /* Check nonces. */ 563 if ((ctx->flags & TS_VFY_NONCE) && 564 !TS_check_nonces(ctx->nonce, tst_info)) 565 goto err; 566 567 /* Check whether TSA name and signer certificate match. */ 568 if ((ctx->flags & TS_VFY_SIGNER) && 569 tsa_name && !TS_check_signer_name(tsa_name, signer)) { 570 TSerror(TS_R_TSA_NAME_MISMATCH); 571 goto err; 572 } 573 574 /* Check whether the TSA is the expected one. */ 575 if ((ctx->flags & TS_VFY_TSA_NAME) && 576 !TS_check_signer_name(ctx->tsa_name, signer)) { 577 TSerror(TS_R_TSA_UNTRUSTED); 578 goto err; 579 } 580 581 ret = 1; 582 583 err: 584 X509_free(signer); 585 X509_ALGOR_free(md_alg); 586 free(imprint); 587 return ret; 588 } 589 590 static int 591 TS_check_status_info(TS_RESP *response) 592 { 593 TS_STATUS_INFO *info = TS_RESP_get_status_info(response); 594 long status = ASN1_INTEGER_get(info->status); 595 const char *status_text = NULL; 596 char *embedded_status_text = NULL; 597 char failure_text[TS_STATUS_BUF_SIZE] = ""; 598 599 /* Check if everything went fine. */ 600 if (status == 0 || status == 1) 601 return 1; 602 603 /* There was an error, get the description in status_text. */ 604 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE) 605 status_text = TS_status_text[status]; 606 else 607 status_text = "unknown code"; 608 609 /* Set the embedded_status_text to the returned description. */ 610 if (sk_ASN1_UTF8STRING_num(info->text) > 0 && 611 !(embedded_status_text = TS_get_status_text(info->text))) 612 return 0; 613 614 /* Filling in failure_text with the failure information. */ 615 if (info->failure_info) { 616 int i; 617 int first = 1; 618 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) { 619 if (ASN1_BIT_STRING_get_bit(info->failure_info, 620 TS_failure_info[i].code)) { 621 if (!first) 622 strlcat(failure_text, ",", 623 TS_STATUS_BUF_SIZE); 624 else 625 first = 0; 626 strlcat(failure_text, TS_failure_info[i].text, 627 TS_STATUS_BUF_SIZE); 628 } 629 } 630 } 631 if (failure_text[0] == '\0') 632 strlcpy(failure_text, "unspecified", TS_STATUS_BUF_SIZE); 633 634 /* Making up the error string. */ 635 TSerror(TS_R_NO_TIME_STAMP_TOKEN); 636 ERR_asprintf_error_data 637 ("status code: %s, status text: %s, failure codes: %s", 638 status_text, 639 embedded_status_text ? embedded_status_text : "unspecified", 640 failure_text); 641 free(embedded_status_text); 642 643 return 0; 644 } 645 646 static char * 647 TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text) 648 { 649 int i; 650 unsigned int length = 0; 651 char *result = NULL; 652 653 /* Determine length first. */ 654 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 655 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 656 length += ASN1_STRING_length(current); 657 length += 1; /* separator character */ 658 } 659 /* Allocate memory (closing '\0' included). */ 660 if (!(result = malloc(length))) { 661 TSerror(ERR_R_MALLOC_FAILURE); 662 return NULL; 663 } 664 /* Concatenate the descriptions. */ 665 result[0] = '\0'; 666 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 667 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 668 if (i > 0) 669 strlcat(result, "/", length); 670 strlcat(result, (const char *)ASN1_STRING_data(current), length); 671 } 672 return result; 673 } 674 675 static int 676 TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info) 677 { 678 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info); 679 680 if (OBJ_cmp(req_oid, resp_oid) != 0) { 681 TSerror(TS_R_POLICY_MISMATCH); 682 return 0; 683 } 684 685 return 1; 686 } 687 688 static int 689 TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **out_md_alg, 690 unsigned char **out_imprint, unsigned int *out_imprint_len) 691 { 692 TS_MSG_IMPRINT *msg_imprint; 693 X509_ALGOR *md_alg_resp; 694 X509_ALGOR *md_alg = NULL; 695 unsigned char *imprint = NULL; 696 unsigned int imprint_len = 0; 697 const EVP_MD *md; 698 EVP_MD_CTX md_ctx; 699 unsigned char buffer[4096]; 700 int length; 701 702 *out_md_alg = NULL; 703 *out_imprint = NULL; 704 *out_imprint_len = 0; 705 706 /* Retrieve the MD algorithm of the response. */ 707 msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info); 708 md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint); 709 if ((md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL) 710 goto err; 711 712 /* Getting the MD object. */ 713 if ((md = EVP_get_digestbyobj((md_alg)->algorithm)) == NULL) { 714 TSerror(TS_R_UNSUPPORTED_MD_ALGORITHM); 715 goto err; 716 } 717 718 /* Compute message digest. */ 719 if ((length = EVP_MD_size(md)) < 0) 720 goto err; 721 imprint_len = length; 722 if ((imprint = malloc(imprint_len)) == NULL) { 723 TSerror(ERR_R_MALLOC_FAILURE); 724 goto err; 725 } 726 727 if (!EVP_DigestInit(&md_ctx, md)) 728 goto err; 729 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) { 730 if (!EVP_DigestUpdate(&md_ctx, buffer, length)) 731 goto err; 732 } 733 if (!EVP_DigestFinal(&md_ctx, imprint, NULL)) 734 goto err; 735 736 *out_md_alg = md_alg; 737 md_alg = NULL; 738 *out_imprint = imprint; 739 imprint = NULL; 740 *out_imprint_len = imprint_len; 741 742 return 1; 743 744 err: 745 X509_ALGOR_free(md_alg); 746 free(imprint); 747 return 0; 748 } 749 750 static int 751 TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a, 752 TS_TST_INFO *tst_info) 753 { 754 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info); 755 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b); 756 int ret = 0; 757 758 /* algor_a is optional. */ 759 if (algor_a) { 760 /* Compare algorithm OIDs. */ 761 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) 762 goto err; 763 764 /* The parameter must be NULL in both. */ 765 if ((algor_a->parameter && 766 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) || 767 (algor_b->parameter && 768 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL)) 769 goto err; 770 } 771 772 /* Compare octet strings. */ 773 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) && 774 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0; 775 776 err: 777 if (!ret) 778 TSerror(TS_R_MESSAGE_IMPRINT_MISMATCH); 779 return ret; 780 } 781 782 static int 783 TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info) 784 { 785 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info); 786 787 /* Error if nonce is missing. */ 788 if (!b) { 789 TSerror(TS_R_NONCE_NOT_RETURNED); 790 return 0; 791 } 792 793 /* No error if a nonce is returned without being requested. */ 794 if (ASN1_INTEGER_cmp(a, b) != 0) { 795 TSerror(TS_R_NONCE_MISMATCH); 796 return 0; 797 } 798 799 return 1; 800 } 801 802 /* Check if the specified TSA name matches either the subject 803 or one of the subject alternative names of the TSA certificate. */ 804 static int 805 TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer) 806 { 807 STACK_OF(GENERAL_NAME) *gen_names = NULL; 808 int idx = -1; 809 int found = 0; 810 811 if (signer == NULL) 812 return 0; 813 814 /* Check the subject name first. */ 815 if (tsa_name->type == GEN_DIRNAME && 816 X509_name_cmp(tsa_name->d.dirn, X509_get_subject_name(signer)) == 0) 817 return 1; 818 819 /* Check all the alternative names. */ 820 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 821 NULL, &idx); 822 while (gen_names != NULL && 823 !(found = (TS_find_name(gen_names, tsa_name) >= 0))) { 824 /* Get the next subject alternative name, 825 although there should be no more than one. */ 826 GENERAL_NAMES_free(gen_names); 827 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 828 NULL, &idx); 829 } 830 if (gen_names) 831 GENERAL_NAMES_free(gen_names); 832 833 return found; 834 } 835 836 /* Returns 1 if name is in gen_names, 0 otherwise. */ 837 static int 838 TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name) 839 { 840 int i, found; 841 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); 842 ++i) { 843 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i); 844 found = GENERAL_NAME_cmp(current, name) == 0; 845 } 846 return found ? i - 1 : -1; 847 } 848