1 /* $OpenBSD: ts_rsp_verify.c,v 1.12 2014/07/11 08:44:49 jsing 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 /* Private function declarations. */ 68 69 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, 70 X509 *signer, STACK_OF(X509) **chain); 71 static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain); 72 static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si); 73 static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert); 74 static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo); 75 static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, 76 PKCS7 *token, TS_TST_INFO *tst_info); 77 static int TS_check_status_info(TS_RESP *response); 78 static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text); 79 static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info); 80 static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, 81 X509_ALGOR **md_alg, 82 unsigned char **imprint, unsigned *imprint_len); 83 static int TS_check_imprints(X509_ALGOR *algor_a, 84 unsigned char *imprint_a, unsigned len_a, 85 TS_TST_INFO *tst_info); 86 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info); 87 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer); 88 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name); 89 90 /* 91 * Local mapping between response codes and descriptions. 92 * Don't forget to change TS_STATUS_BUF_SIZE when modifying 93 * the elements of this array. 94 */ 95 static const char *TS_status_text[] = { 96 "granted", 97 "grantedWithMods", 98 "rejection", 99 "waiting", 100 "revocationWarning", 101 "revocationNotification" 102 }; 103 104 #define TS_STATUS_TEXT_SIZE (sizeof(TS_status_text)/sizeof(*TS_status_text)) 105 106 /* 107 * This must be greater or equal to the sum of the strings in TS_status_text 108 * plus the number of its elements. 109 */ 110 #define TS_STATUS_BUF_SIZE 256 111 112 static struct { 113 int code; 114 const char *text; 115 } TS_failure_info[] = { 116 { TS_INFO_BAD_ALG, "badAlg" }, 117 { TS_INFO_BAD_REQUEST, "badRequest" }, 118 { TS_INFO_BAD_DATA_FORMAT, "badDataFormat" }, 119 { TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable" }, 120 { TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy" }, 121 { TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension" }, 122 { TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable" }, 123 { TS_INFO_SYSTEM_FAILURE, "systemFailure" } 124 }; 125 126 #define TS_FAILURE_INFO_SIZE (sizeof(TS_failure_info) / \ 127 sizeof(*TS_failure_info)) 128 129 /* Functions for verifying a signed TS_TST_INFO structure. */ 130 131 /* 132 * This function carries out the following tasks: 133 * - Checks if there is one and only one signer. 134 * - Search for the signing certificate in 'certs' and in the response. 135 * - Check the extended key usage and key usage fields of the signer 136 * certificate (done by the path validation). 137 * - Build and validate the certificate path. 138 * - Check if the certificate path meets the requirements of the 139 * SigningCertificate ESS signed attribute. 140 * - Verify the signature value. 141 * - Returns the signer certificate in 'signer', if 'signer' is not NULL. 142 */ 143 int 144 TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs, 145 X509_STORE *store, X509 **signer_out) 146 { 147 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL; 148 PKCS7_SIGNER_INFO *si; 149 STACK_OF(X509) *signers = NULL; 150 X509 *signer; 151 STACK_OF(X509) *chain = NULL; 152 char buf[4096]; 153 int i, j = 0, ret = 0; 154 BIO *p7bio = NULL; 155 156 /* Some sanity checks first. */ 157 if (!token) { 158 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_INVALID_NULL_POINTER); 159 goto err; 160 } 161 162 /* Check for the correct content type */ 163 if (!PKCS7_type_is_signed(token)) { 164 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_WRONG_CONTENT_TYPE); 165 goto err; 166 } 167 168 /* Check if there is one and only one signer. */ 169 sinfos = PKCS7_get_signer_info(token); 170 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) { 171 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, 172 TS_R_THERE_MUST_BE_ONE_SIGNER); 173 goto err; 174 } 175 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0); 176 177 /* Check for no content: no data to verify signature. */ 178 if (PKCS7_get_detached(token)) { 179 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_NO_CONTENT); 180 goto err; 181 } 182 183 /* Get hold of the signer certificate, search only internal 184 certificates if it was requested. */ 185 signers = PKCS7_get0_signers(token, certs, 0); 186 if (!signers || sk_X509_num(signers) != 1) 187 goto err; 188 signer = sk_X509_value(signers, 0); 189 190 /* Now verify the certificate. */ 191 if (!TS_verify_cert(store, certs, signer, &chain)) 192 goto err; 193 194 /* Check if the signer certificate is consistent with the 195 ESS extension. */ 196 if (!TS_check_signing_certs(si, chain)) 197 goto err; 198 199 /* Creating the message digest. */ 200 p7bio = PKCS7_dataInit(token, NULL); 201 202 /* We now have to 'read' from p7bio to calculate digests etc. */ 203 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0) 204 ; 205 206 /* Verifying the signature. */ 207 j = PKCS7_signatureVerify(p7bio, token, si, signer); 208 if (j <= 0) { 209 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_SIGNATURE_FAILURE); 210 goto err; 211 } 212 213 /* Return the signer certificate if needed. */ 214 if (signer_out) { 215 *signer_out = signer; 216 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509); 217 } 218 219 ret = 1; 220 221 err: 222 BIO_free_all(p7bio); 223 sk_X509_pop_free(chain, X509_free); 224 sk_X509_free(signers); 225 226 return ret; 227 } 228 229 /* 230 * The certificate chain is returned in chain. Caller is responsible for 231 * freeing the vector. 232 */ 233 static int 234 TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, X509 *signer, 235 STACK_OF(X509) **chain) 236 { 237 X509_STORE_CTX cert_ctx; 238 int i; 239 int ret = 1; 240 241 /* chain is an out argument. */ 242 *chain = NULL; 243 X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted); 244 X509_STORE_CTX_set_purpose(&cert_ctx, X509_PURPOSE_TIMESTAMP_SIGN); 245 i = X509_verify_cert(&cert_ctx); 246 if (i <= 0) { 247 int j = X509_STORE_CTX_get_error(&cert_ctx); 248 TSerr(TS_F_TS_VERIFY_CERT, TS_R_CERTIFICATE_VERIFY_ERROR); 249 ERR_asprintf_error_data("Verify error:%s", 250 X509_verify_cert_error_string(j)); 251 ret = 0; 252 } else { 253 /* Get a copy of the certificate chain. */ 254 *chain = X509_STORE_CTX_get1_chain(&cert_ctx); 255 } 256 257 X509_STORE_CTX_cleanup(&cert_ctx); 258 259 return ret; 260 } 261 262 static int 263 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain) 264 { 265 ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si); 266 STACK_OF(ESS_CERT_ID) *cert_ids = NULL; 267 X509 *cert; 268 int i = 0; 269 int ret = 0; 270 271 if (!ss) 272 goto err; 273 cert_ids = ss->cert_ids; 274 /* The signer certificate must be the first in cert_ids. */ 275 cert = sk_X509_value(chain, 0); 276 if (TS_find_cert(cert_ids, cert) != 0) 277 goto err; 278 279 /* Check the other certificates of the chain if there are more 280 than one certificate ids in cert_ids. */ 281 if (sk_ESS_CERT_ID_num(cert_ids) > 1) { 282 /* All the certificates of the chain must be in cert_ids. */ 283 for (i = 1; i < sk_X509_num(chain); ++i) { 284 cert = sk_X509_value(chain, i); 285 if (TS_find_cert(cert_ids, cert) < 0) 286 goto err; 287 } 288 } 289 ret = 1; 290 291 err: 292 if (!ret) 293 TSerr(TS_F_TS_CHECK_SIGNING_CERTS, 294 TS_R_ESS_SIGNING_CERTIFICATE_ERROR); 295 ESS_SIGNING_CERT_free(ss); 296 return ret; 297 } 298 299 static ESS_SIGNING_CERT * 300 ESS_get_signing_cert(PKCS7_SIGNER_INFO *si) 301 { 302 ASN1_TYPE *attr; 303 const unsigned char *p; 304 305 attr = PKCS7_get_signed_attribute(si, 306 NID_id_smime_aa_signingCertificate); 307 if (!attr) 308 return NULL; 309 p = attr->value.sequence->data; 310 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length); 311 } 312 313 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 314 static int 315 TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert) 316 { 317 int i; 318 319 if (!cert_ids || !cert) 320 return -1; 321 322 /* Recompute SHA1 hash of certificate if necessary (side effect). */ 323 X509_check_purpose(cert, -1, 0); 324 325 /* Look for cert in the cert_ids vector. */ 326 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) { 327 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i); 328 329 /* Check the SHA-1 hash first. */ 330 if (cid->hash->length == sizeof(cert->sha1_hash) && 331 !memcmp(cid->hash->data, cert->sha1_hash, 332 sizeof(cert->sha1_hash))) { 333 /* Check the issuer/serial as well if specified. */ 334 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 335 if (!is || !TS_issuer_serial_cmp(is, cert->cert_info)) 336 return i; 337 } 338 } 339 340 return -1; 341 } 342 343 static int 344 TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo) 345 { 346 GENERAL_NAME *issuer; 347 348 if (!is || !cinfo || sk_GENERAL_NAME_num(is->issuer) != 1) 349 return -1; 350 351 /* Check the issuer first. It must be a directory name. */ 352 issuer = sk_GENERAL_NAME_value(is->issuer, 0); 353 if (issuer->type != GEN_DIRNAME || 354 X509_NAME_cmp(issuer->d.dirn, cinfo->issuer)) 355 return -1; 356 357 /* Check the serial number, too. */ 358 if (ASN1_INTEGER_cmp(is->serial, cinfo->serialNumber)) 359 return -1; 360 361 return 0; 362 } 363 364 /* 365 * Verifies whether 'response' contains a valid response with regards 366 * to the settings of the context: 367 * - Gives an error message if the TS_TST_INFO is not present. 368 * - Calls _TS_RESP_verify_token to verify the token content. 369 */ 370 int 371 TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response) 372 { 373 PKCS7 *token = TS_RESP_get_token(response); 374 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response); 375 int ret = 0; 376 377 /* Check if we have a successful TS_TST_INFO object in place. */ 378 if (!TS_check_status_info(response)) 379 goto err; 380 381 /* Check the contents of the time stamp token. */ 382 if (!int_TS_RESP_verify_token(ctx, token, tst_info)) 383 goto err; 384 385 ret = 1; 386 387 err: 388 return ret; 389 } 390 391 /* 392 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and 393 * calls the internal int_TS_RESP_verify_token function for verifying it. 394 */ 395 int 396 TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token) 397 { 398 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token); 399 int ret = 0; 400 401 if (tst_info) { 402 ret = int_TS_RESP_verify_token(ctx, token, tst_info); 403 TS_TST_INFO_free(tst_info); 404 } 405 return ret; 406 } 407 408 /* 409 * Verifies whether the 'token' contains a valid time stamp token 410 * with regards to the settings of the context. Only those checks are 411 * carried out that are specified in the context: 412 * - Verifies the signature of the TS_TST_INFO. 413 * - Checks the version number of the response. 414 * - Check if the requested and returned policies math. 415 * - Check if the message imprints are the same. 416 * - Check if the nonces are the same. 417 * - Check if the TSA name matches the signer. 418 * - Check if the TSA name is the expected TSA. 419 */ 420 static int 421 int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token, 422 TS_TST_INFO *tst_info) 423 { 424 X509 *signer = NULL; 425 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info); 426 X509_ALGOR *md_alg = NULL; 427 unsigned char *imprint = NULL; 428 unsigned imprint_len = 0; 429 int ret = 0; 430 431 /* Verify the signature. */ 432 if ((ctx->flags & TS_VFY_SIGNATURE) && 433 !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer)) 434 goto err; 435 436 /* Check version number of response. */ 437 if ((ctx->flags & TS_VFY_VERSION) && 438 TS_TST_INFO_get_version(tst_info) != 1) { 439 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_UNSUPPORTED_VERSION); 440 goto err; 441 } 442 443 /* Check policies. */ 444 if ((ctx->flags & TS_VFY_POLICY) && 445 !TS_check_policy(ctx->policy, tst_info)) 446 goto err; 447 448 /* Check message imprints. */ 449 if ((ctx->flags & TS_VFY_IMPRINT) && 450 !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len, 451 tst_info)) 452 goto err; 453 454 /* Compute and check message imprints. */ 455 if ((ctx->flags & TS_VFY_DATA) && 456 (!TS_compute_imprint(ctx->data, tst_info, 457 &md_alg, &imprint, &imprint_len) || 458 !TS_check_imprints(md_alg, imprint, imprint_len, tst_info))) 459 goto err; 460 461 /* Check nonces. */ 462 if ((ctx->flags & TS_VFY_NONCE) && 463 !TS_check_nonces(ctx->nonce, tst_info)) 464 goto err; 465 466 /* Check whether TSA name and signer certificate match. */ 467 if ((ctx->flags & TS_VFY_SIGNER) && 468 tsa_name && !TS_check_signer_name(tsa_name, signer)) { 469 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_NAME_MISMATCH); 470 goto err; 471 } 472 473 /* Check whether the TSA is the expected one. */ 474 if ((ctx->flags & TS_VFY_TSA_NAME) && 475 !TS_check_signer_name(ctx->tsa_name, signer)) { 476 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_UNTRUSTED); 477 goto err; 478 } 479 480 ret = 1; 481 482 err: 483 X509_free(signer); 484 X509_ALGOR_free(md_alg); 485 free(imprint); 486 return ret; 487 } 488 489 static int 490 TS_check_status_info(TS_RESP *response) 491 { 492 TS_STATUS_INFO *info = TS_RESP_get_status_info(response); 493 long status = ASN1_INTEGER_get(info->status); 494 const char *status_text = NULL; 495 char *embedded_status_text = NULL; 496 char failure_text[TS_STATUS_BUF_SIZE] = ""; 497 498 /* Check if everything went fine. */ 499 if (status == 0 || status == 1) 500 return 1; 501 502 /* There was an error, get the description in status_text. */ 503 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE) 504 status_text = TS_status_text[status]; 505 else 506 status_text = "unknown code"; 507 508 /* Set the embedded_status_text to the returned description. */ 509 if (sk_ASN1_UTF8STRING_num(info->text) > 0 && 510 !(embedded_status_text = TS_get_status_text(info->text))) 511 return 0; 512 513 /* Filling in failure_text with the failure information. */ 514 if (info->failure_info) { 515 int i; 516 int first = 1; 517 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) { 518 if (ASN1_BIT_STRING_get_bit(info->failure_info, 519 TS_failure_info[i].code)) { 520 if (!first) 521 strlcat(failure_text, ",", 522 TS_STATUS_BUF_SIZE); 523 else 524 first = 0; 525 strlcat(failure_text, TS_failure_info[i].text, 526 TS_STATUS_BUF_SIZE); 527 } 528 } 529 } 530 if (failure_text[0] == '\0') 531 strlcpy(failure_text, "unspecified", TS_STATUS_BUF_SIZE); 532 533 /* Making up the error string. */ 534 TSerr(TS_F_TS_CHECK_STATUS_INFO, TS_R_NO_TIME_STAMP_TOKEN); 535 ERR_asprintf_error_data 536 ("status code: %s, status text: %s, failure codes: %s", 537 status_text, 538 embedded_status_text ? embedded_status_text : "unspecified", 539 failure_text); 540 free(embedded_status_text); 541 542 return 0; 543 } 544 545 static char * 546 TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text) 547 { 548 int i; 549 unsigned int length = 0; 550 char *result = NULL; 551 552 /* Determine length first. */ 553 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 554 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 555 length += ASN1_STRING_length(current); 556 length += 1; /* separator character */ 557 } 558 /* Allocate memory (closing '\0' included). */ 559 if (!(result = malloc(length))) { 560 TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE); 561 return NULL; 562 } 563 /* Concatenate the descriptions. */ 564 result[0] = '\0'; 565 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 566 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 567 if (i > 0) 568 strlcat(result, "/", length); 569 strlcat(result, (const char *)ASN1_STRING_data(current), length); 570 } 571 return result; 572 } 573 574 static int 575 TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info) 576 { 577 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info); 578 579 if (OBJ_cmp(req_oid, resp_oid) != 0) { 580 TSerr(TS_F_TS_CHECK_POLICY, TS_R_POLICY_MISMATCH); 581 return 0; 582 } 583 584 return 1; 585 } 586 587 static int 588 TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **md_alg, 589 unsigned char **imprint, unsigned *imprint_len) 590 { 591 TS_MSG_IMPRINT *msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info); 592 X509_ALGOR *md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint); 593 const EVP_MD *md; 594 EVP_MD_CTX md_ctx; 595 unsigned char buffer[4096]; 596 int length; 597 598 *md_alg = NULL; 599 *imprint = NULL; 600 601 /* Return the MD algorithm of the response. */ 602 if (!(*md_alg = X509_ALGOR_dup(md_alg_resp))) 603 goto err; 604 605 /* Getting the MD object. */ 606 if (!(md = EVP_get_digestbyobj((*md_alg)->algorithm))) { 607 TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM); 608 goto err; 609 } 610 611 /* Compute message digest. */ 612 length = EVP_MD_size(md); 613 if (length < 0) 614 goto err; 615 *imprint_len = length; 616 if (!(*imprint = malloc(*imprint_len))) { 617 TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE); 618 goto err; 619 } 620 621 if (!EVP_DigestInit(&md_ctx, md)) 622 goto err; 623 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) { 624 if (!EVP_DigestUpdate(&md_ctx, buffer, length)) 625 goto err; 626 } 627 if (!EVP_DigestFinal(&md_ctx, *imprint, NULL)) 628 goto err; 629 630 return 1; 631 632 err: 633 X509_ALGOR_free(*md_alg); 634 free(*imprint); 635 *imprint = NULL; 636 *imprint_len = 0; 637 return 0; 638 } 639 640 static int 641 TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a, 642 TS_TST_INFO *tst_info) 643 { 644 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info); 645 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b); 646 int ret = 0; 647 648 /* algor_a is optional. */ 649 if (algor_a) { 650 /* Compare algorithm OIDs. */ 651 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) 652 goto err; 653 654 /* The parameter must be NULL in both. */ 655 if ((algor_a->parameter && 656 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) || 657 (algor_b->parameter && 658 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL)) 659 goto err; 660 } 661 662 /* Compare octet strings. */ 663 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) && 664 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0; 665 666 err: 667 if (!ret) 668 TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH); 669 return ret; 670 } 671 672 static int 673 TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info) 674 { 675 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info); 676 677 /* Error if nonce is missing. */ 678 if (!b) { 679 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED); 680 return 0; 681 } 682 683 /* No error if a nonce is returned without being requested. */ 684 if (ASN1_INTEGER_cmp(a, b) != 0) { 685 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH); 686 return 0; 687 } 688 689 return 1; 690 } 691 692 /* Check if the specified TSA name matches either the subject 693 or one of the subject alternative names of the TSA certificate. */ 694 static int 695 TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer) 696 { 697 STACK_OF(GENERAL_NAME) *gen_names = NULL; 698 int idx = -1; 699 int found = 0; 700 701 /* Check the subject name first. */ 702 if (tsa_name->type == GEN_DIRNAME && 703 X509_name_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0) 704 return 1; 705 706 /* Check all the alternative names. */ 707 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 708 NULL, &idx); 709 while (gen_names != NULL && 710 !(found = TS_find_name(gen_names, tsa_name) >= 0)) { 711 /* Get the next subject alternative name, 712 although there should be no more than one. */ 713 GENERAL_NAMES_free(gen_names); 714 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 715 NULL, &idx); 716 } 717 if (gen_names) 718 GENERAL_NAMES_free(gen_names); 719 720 return found; 721 } 722 723 /* Returns 1 if name is in gen_names, 0 otherwise. */ 724 static int 725 TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name) 726 { 727 int i, found; 728 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); 729 ++i) { 730 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i); 731 found = GENERAL_NAME_cmp(current, name) == 0; 732 } 733 return found ? i - 1 : -1; 734 } 735