1 /* crypto/ts/ts_resp_verify.c */ 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 "cryptlib.h" 61 #include <openssl/objects.h> 62 #include <openssl/ts.h> 63 #include <openssl/pkcs7.h> 64 65 /* Private function declarations. */ 66 67 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, 68 X509 *signer, STACK_OF(X509) **chain); 69 static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain); 70 static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si); 71 static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert); 72 static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo); 73 static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, 74 PKCS7 *token, TS_TST_INFO *tst_info); 75 static int TS_check_status_info(TS_RESP *response); 76 static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text); 77 static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info); 78 static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, 79 X509_ALGOR **md_alg, 80 unsigned char **imprint, unsigned *imprint_len); 81 static int TS_check_imprints(X509_ALGOR *algor_a, 82 unsigned char *imprint_a, unsigned len_a, 83 TS_TST_INFO *tst_info); 84 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info); 85 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer); 86 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name); 87 88 /* 89 * Local mapping between response codes and descriptions. 90 * Don't forget to change TS_STATUS_BUF_SIZE when modifying 91 * the elements of this array. 92 */ 93 static const char *TS_status_text[] = 94 { "granted", 95 "grantedWithMods", 96 "rejection", 97 "waiting", 98 "revocationWarning", 99 "revocationNotification" }; 100 101 #define TS_STATUS_TEXT_SIZE (sizeof(TS_status_text)/sizeof(*TS_status_text)) 102 103 /* 104 * This must be greater or equal to the sum of the strings in TS_status_text 105 * plus the number of its elements. 106 */ 107 #define TS_STATUS_BUF_SIZE 256 108 109 static struct 110 { 111 int code; 112 const char *text; 113 } TS_failure_info[] = 114 { { TS_INFO_BAD_ALG, "badAlg" }, 115 { TS_INFO_BAD_REQUEST, "badRequest" }, 116 { TS_INFO_BAD_DATA_FORMAT, "badDataFormat" }, 117 { TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable" }, 118 { TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy" }, 119 { TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension" }, 120 { TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable" }, 121 { TS_INFO_SYSTEM_FAILURE, "systemFailure" } }; 122 123 #define TS_FAILURE_INFO_SIZE (sizeof(TS_failure_info) / \ 124 sizeof(*TS_failure_info)) 125 126 /* Functions for verifying a signed TS_TST_INFO structure. */ 127 128 /* 129 * This function carries out the following tasks: 130 * - Checks if there is one and only one signer. 131 * - Search for the signing certificate in 'certs' and in the response. 132 * - Check the extended key usage and key usage fields of the signer 133 * certificate (done by the path validation). 134 * - Build and validate the certificate path. 135 * - Check if the certificate path meets the requirements of the 136 * SigningCertificate ESS signed attribute. 137 * - Verify the signature value. 138 * - Returns the signer certificate in 'signer', if 'signer' is not NULL. 139 */ 140 int TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs, 141 X509_STORE *store, X509 **signer_out) 142 { 143 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL; 144 PKCS7_SIGNER_INFO *si; 145 STACK_OF(X509) *signers = NULL; 146 X509 *signer; 147 STACK_OF(X509) *chain = NULL; 148 char buf[4096]; 149 int i, j = 0, ret = 0; 150 BIO *p7bio = NULL; 151 152 /* Some sanity checks first. */ 153 if (!token) 154 { 155 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_INVALID_NULL_POINTER); 156 goto err; 157 } 158 159 /* Check for the correct content type */ 160 if(!PKCS7_type_is_signed(token)) 161 { 162 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_WRONG_CONTENT_TYPE); 163 goto err; 164 } 165 166 /* Check if there is one and only one signer. */ 167 sinfos = PKCS7_get_signer_info(token); 168 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) 169 { 170 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, 171 TS_R_THERE_MUST_BE_ONE_SIGNER); 172 goto err; 173 } 174 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0); 175 176 /* Check for no content: no data to verify signature. */ 177 if (PKCS7_get_detached(token)) 178 { 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) goto err; 187 signer = sk_X509_value(signers, 0); 188 189 /* Now verify the certificate. */ 190 if (!TS_verify_cert(store, certs, signer, &chain)) goto err; 191 192 /* Check if the signer certificate is consistent with the 193 ESS extension. */ 194 if (!TS_check_signing_certs(si, chain)) goto err; 195 196 /* Creating the message digest. */ 197 p7bio = PKCS7_dataInit(token, NULL); 198 199 /* We now have to 'read' from p7bio to calculate digests etc. */ 200 while ((i = BIO_read(p7bio,buf,sizeof(buf))) > 0); 201 202 /* Verifying the signature. */ 203 j = PKCS7_signatureVerify(p7bio, token, si, signer); 204 if (j <= 0) 205 { 206 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_SIGNATURE_FAILURE); 207 goto err; 208 } 209 210 /* Return the signer certificate if needed. */ 211 if (signer_out) 212 { 213 *signer_out = signer; 214 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509); 215 } 216 217 ret = 1; 218 219 err: 220 BIO_free_all(p7bio); 221 sk_X509_pop_free(chain, X509_free); 222 sk_X509_free(signers); 223 224 return ret; 225 } 226 227 /* 228 * The certificate chain is returned in chain. Caller is responsible for 229 * freeing the vector. 230 */ 231 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, 232 X509 *signer, STACK_OF(X509) **chain) 233 { 234 X509_STORE_CTX cert_ctx; 235 int i; 236 int ret = 1; 237 238 /* chain is an out argument. */ 239 *chain = NULL; 240 X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted); 241 X509_STORE_CTX_set_purpose(&cert_ctx, X509_PURPOSE_TIMESTAMP_SIGN); 242 i = X509_verify_cert(&cert_ctx); 243 if (i <= 0) 244 { 245 int j = X509_STORE_CTX_get_error(&cert_ctx); 246 TSerr(TS_F_TS_VERIFY_CERT, TS_R_CERTIFICATE_VERIFY_ERROR); 247 ERR_add_error_data(2, "Verify error:", 248 X509_verify_cert_error_string(j)); 249 ret = 0; 250 } 251 else 252 { 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 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain) 263 { 264 ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si); 265 STACK_OF(ESS_CERT_ID) *cert_ids = NULL; 266 X509 *cert; 267 int i = 0; 268 int ret = 0; 269 270 if (!ss) goto err; 271 cert_ids = ss->cert_ids; 272 /* The signer certificate must be the first in cert_ids. */ 273 cert = sk_X509_value(chain, 0); 274 if (TS_find_cert(cert_ids, cert) != 0) goto err; 275 276 /* Check the other certificates of the chain if there are more 277 than one certificate ids in cert_ids. */ 278 if (sk_ESS_CERT_ID_num(cert_ids) > 1) 279 { 280 /* All the certificates of the chain must be in cert_ids. */ 281 for (i = 1; i < sk_X509_num(chain); ++i) 282 { 283 cert = sk_X509_value(chain, i); 284 if (TS_find_cert(cert_ids, cert) < 0) goto err; 285 } 286 } 287 ret = 1; 288 err: 289 if (!ret) 290 TSerr(TS_F_TS_CHECK_SIGNING_CERTS, 291 TS_R_ESS_SIGNING_CERTIFICATE_ERROR); 292 ESS_SIGNING_CERT_free(ss); 293 return ret; 294 } 295 296 static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si) 297 { 298 ASN1_TYPE *attr; 299 const unsigned char *p; 300 attr = PKCS7_get_signed_attribute(si, 301 NID_id_smime_aa_signingCertificate); 302 if (!attr) return NULL; 303 p = attr->value.sequence->data; 304 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length); 305 } 306 307 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 308 static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert) 309 { 310 int i; 311 312 if (!cert_ids || !cert) return -1; 313 314 /* Recompute SHA1 hash of certificate if necessary (side effect). */ 315 X509_check_purpose(cert, -1, 0); 316 317 /* Look for cert in the cert_ids vector. */ 318 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) 319 { 320 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i); 321 322 /* Check the SHA-1 hash first. */ 323 if (cid->hash->length == sizeof(cert->sha1_hash) 324 && !memcmp(cid->hash->data, cert->sha1_hash, 325 sizeof(cert->sha1_hash))) 326 { 327 /* Check the issuer/serial as well if specified. */ 328 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 329 if (!is || !TS_issuer_serial_cmp(is, cert->cert_info)) 330 return i; 331 } 332 } 333 334 return -1; 335 } 336 337 static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo) 338 { 339 GENERAL_NAME *issuer; 340 341 if (!is || !cinfo || sk_GENERAL_NAME_num(is->issuer) != 1) return -1; 342 343 /* Check the issuer first. It must be a directory name. */ 344 issuer = sk_GENERAL_NAME_value(is->issuer, 0); 345 if (issuer->type != GEN_DIRNAME 346 || X509_NAME_cmp(issuer->d.dirn, cinfo->issuer)) 347 return -1; 348 349 /* Check the serial number, too. */ 350 if (ASN1_INTEGER_cmp(is->serial, cinfo->serialNumber)) 351 return -1; 352 353 return 0; 354 } 355 356 /* 357 * Verifies whether 'response' contains a valid response with regards 358 * to the settings of the context: 359 * - Gives an error message if the TS_TST_INFO is not present. 360 * - Calls _TS_RESP_verify_token to verify the token content. 361 */ 362 int TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response) 363 { 364 PKCS7 *token = TS_RESP_get_token(response); 365 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response); 366 int ret = 0; 367 368 /* Check if we have a successful TS_TST_INFO object in place. */ 369 if (!TS_check_status_info(response)) goto err; 370 371 /* Check the contents of the time stamp token. */ 372 if (!int_TS_RESP_verify_token(ctx, token, tst_info)) 373 goto err; 374 375 ret = 1; 376 err: 377 return ret; 378 } 379 380 /* 381 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and 382 * calls the internal int_TS_RESP_verify_token function for verifying it. 383 */ 384 int TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token) 385 { 386 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token); 387 int ret = 0; 388 if (tst_info) 389 { 390 ret = int_TS_RESP_verify_token(ctx, token, tst_info); 391 TS_TST_INFO_free(tst_info); 392 } 393 return ret; 394 } 395 396 /* 397 * Verifies whether the 'token' contains a valid time stamp token 398 * with regards to the settings of the context. Only those checks are 399 * carried out that are specified in the context: 400 * - Verifies the signature of the TS_TST_INFO. 401 * - Checks the version number of the response. 402 * - Check if the requested and returned policies math. 403 * - Check if the message imprints are the same. 404 * - Check if the nonces are the same. 405 * - Check if the TSA name matches the signer. 406 * - Check if the TSA name is the expected TSA. 407 */ 408 static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, 409 PKCS7 *token, TS_TST_INFO *tst_info) 410 { 411 X509 *signer = NULL; 412 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info); 413 X509_ALGOR *md_alg = NULL; 414 unsigned char *imprint = NULL; 415 unsigned imprint_len = 0; 416 int ret = 0; 417 418 /* Verify the signature. */ 419 if ((ctx->flags & TS_VFY_SIGNATURE) 420 && !TS_RESP_verify_signature(token, ctx->certs, ctx->store, 421 &signer)) 422 goto err; 423 424 /* Check version number of response. */ 425 if ((ctx->flags & TS_VFY_VERSION) 426 && TS_TST_INFO_get_version(tst_info) != 1) 427 { 428 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_UNSUPPORTED_VERSION); 429 goto err; 430 } 431 432 /* Check policies. */ 433 if ((ctx->flags & TS_VFY_POLICY) 434 && !TS_check_policy(ctx->policy, tst_info)) 435 goto err; 436 437 /* Check message imprints. */ 438 if ((ctx->flags & TS_VFY_IMPRINT) 439 && !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len, 440 tst_info)) 441 goto err; 442 443 /* Compute and check message imprints. */ 444 if ((ctx->flags & TS_VFY_DATA) 445 && (!TS_compute_imprint(ctx->data, tst_info, 446 &md_alg, &imprint, &imprint_len) 447 || !TS_check_imprints(md_alg, imprint, imprint_len, tst_info))) 448 goto err; 449 450 /* Check nonces. */ 451 if ((ctx->flags & TS_VFY_NONCE) 452 && !TS_check_nonces(ctx->nonce, tst_info)) 453 goto err; 454 455 /* Check whether TSA name and signer certificate match. */ 456 if ((ctx->flags & TS_VFY_SIGNER) 457 && tsa_name && !TS_check_signer_name(tsa_name, signer)) 458 { 459 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_NAME_MISMATCH); 460 goto err; 461 } 462 463 /* Check whether the TSA is the expected one. */ 464 if ((ctx->flags & TS_VFY_TSA_NAME) 465 && !TS_check_signer_name(ctx->tsa_name, signer)) 466 { 467 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_UNTRUSTED); 468 goto err; 469 } 470 471 ret = 1; 472 err: 473 X509_free(signer); 474 X509_ALGOR_free(md_alg); 475 OPENSSL_free(imprint); 476 return ret; 477 } 478 479 static int TS_check_status_info(TS_RESP *response) 480 { 481 TS_STATUS_INFO *info = TS_RESP_get_status_info(response); 482 long status = ASN1_INTEGER_get(info->status); 483 const char *status_text = NULL; 484 char *embedded_status_text = NULL; 485 char failure_text[TS_STATUS_BUF_SIZE] = ""; 486 487 /* Check if everything went fine. */ 488 if (status == 0 || status == 1) return 1; 489 490 /* There was an error, get the description in status_text. */ 491 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE) 492 status_text = TS_status_text[status]; 493 else 494 status_text = "unknown code"; 495 496 /* Set the embedded_status_text to the returned description. */ 497 if (sk_ASN1_UTF8STRING_num(info->text) > 0 498 && !(embedded_status_text = TS_get_status_text(info->text))) 499 return 0; 500 501 /* Filling in failure_text with the failure information. */ 502 if (info->failure_info) 503 { 504 int i; 505 int first = 1; 506 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) 507 { 508 if (ASN1_BIT_STRING_get_bit(info->failure_info, 509 TS_failure_info[i].code)) 510 { 511 if (!first) 512 strcpy(failure_text, ","); 513 else 514 first = 0; 515 strcat(failure_text, TS_failure_info[i].text); 516 } 517 } 518 } 519 if (failure_text[0] == '\0') 520 strcpy(failure_text, "unspecified"); 521 522 /* Making up the error string. */ 523 TSerr(TS_F_TS_CHECK_STATUS_INFO, TS_R_NO_TIME_STAMP_TOKEN); 524 ERR_add_error_data(6, 525 "status code: ", status_text, 526 ", status text: ", embedded_status_text ? 527 embedded_status_text : "unspecified", 528 ", failure codes: ", failure_text); 529 OPENSSL_free(embedded_status_text); 530 531 return 0; 532 } 533 534 static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text) 535 { 536 int i; 537 unsigned int length = 0; 538 char *result = NULL; 539 char *p; 540 541 /* Determine length first. */ 542 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) 543 { 544 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 545 length += ASN1_STRING_length(current); 546 length += 1; /* separator character */ 547 } 548 /* Allocate memory (closing '\0' included). */ 549 if (!(result = OPENSSL_malloc(length))) 550 { 551 TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE); 552 return NULL; 553 } 554 /* Concatenate the descriptions. */ 555 for (i = 0, p = result; i < sk_ASN1_UTF8STRING_num(text); ++i) 556 { 557 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 558 length = ASN1_STRING_length(current); 559 if (i > 0) *p++ = '/'; 560 strncpy(p, (const char *)ASN1_STRING_data(current), length); 561 p += length; 562 } 563 /* We do have space for this, too. */ 564 *p = '\0'; 565 566 return result; 567 } 568 569 static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info) 570 { 571 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info); 572 573 if (OBJ_cmp(req_oid, resp_oid) != 0) 574 { 575 TSerr(TS_F_TS_CHECK_POLICY, TS_R_POLICY_MISMATCH); 576 return 0; 577 } 578 579 return 1; 580 } 581 582 static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, 583 X509_ALGOR **md_alg, 584 unsigned char **imprint, unsigned *imprint_len) 585 { 586 TS_MSG_IMPRINT *msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info); 587 X509_ALGOR *md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint); 588 const EVP_MD *md; 589 EVP_MD_CTX md_ctx; 590 unsigned char buffer[4096]; 591 int length; 592 593 *md_alg = NULL; 594 *imprint = NULL; 595 596 /* Return the MD algorithm of the response. */ 597 if (!(*md_alg = X509_ALGOR_dup(md_alg_resp))) goto err; 598 599 /* Getting the MD object. */ 600 if (!(md = EVP_get_digestbyobj((*md_alg)->algorithm))) 601 { 602 TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM); 603 goto err; 604 } 605 606 /* Compute message digest. */ 607 length = EVP_MD_size(md); 608 if (length < 0) 609 goto err; 610 *imprint_len = length; 611 if (!(*imprint = OPENSSL_malloc(*imprint_len))) 612 { 613 TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE); 614 goto err; 615 } 616 617 if (!EVP_DigestInit(&md_ctx, md)) 618 goto err; 619 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) 620 { 621 if (!EVP_DigestUpdate(&md_ctx, buffer, length)) 622 goto err; 623 } 624 if (!EVP_DigestFinal(&md_ctx, *imprint, NULL)) 625 goto err; 626 627 return 1; 628 err: 629 X509_ALGOR_free(*md_alg); 630 OPENSSL_free(*imprint); 631 *imprint_len = 0; 632 return 0; 633 } 634 635 static int TS_check_imprints(X509_ALGOR *algor_a, 636 unsigned char *imprint_a, unsigned len_a, 637 TS_TST_INFO *tst_info) 638 { 639 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info); 640 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b); 641 int ret = 0; 642 643 /* algor_a is optional. */ 644 if (algor_a) 645 { 646 /* Compare algorithm OIDs. */ 647 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) goto err; 648 649 /* The parameter must be NULL in both. */ 650 if ((algor_a->parameter 651 && ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) 652 || (algor_b->parameter 653 && ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL)) 654 goto err; 655 } 656 657 /* Compare octet strings. */ 658 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) && 659 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0; 660 err: 661 if (!ret) 662 TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH); 663 return ret; 664 } 665 666 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info) 667 { 668 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info); 669 670 /* Error if nonce is missing. */ 671 if (!b) 672 { 673 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED); 674 return 0; 675 } 676 677 /* No error if a nonce is returned without being requested. */ 678 if (ASN1_INTEGER_cmp(a, b) != 0) 679 { 680 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH); 681 return 0; 682 } 683 684 return 1; 685 } 686 687 /* Check if the specified TSA name matches either the subject 688 or one of the subject alternative names of the TSA certificate. */ 689 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer) 690 { 691 STACK_OF(GENERAL_NAME) *gen_names = NULL; 692 int idx = -1; 693 int found = 0; 694 695 /* Check the subject name first. */ 696 if (tsa_name->type == GEN_DIRNAME 697 && X509_name_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0) 698 return 1; 699 700 /* Check all the alternative names. */ 701 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 702 NULL, &idx); 703 while (gen_names != NULL 704 && !(found = TS_find_name(gen_names, tsa_name) >= 0)) 705 { 706 /* Get the next subject alternative name, 707 although there should be no more than one. */ 708 GENERAL_NAMES_free(gen_names); 709 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 710 NULL, &idx); 711 } 712 if (gen_names) GENERAL_NAMES_free(gen_names); 713 714 return found; 715 } 716 717 /* Returns 1 if name is in gen_names, 0 otherwise. */ 718 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name) 719 { 720 int i, found; 721 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); 722 ++i) 723 { 724 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i); 725 found = GENERAL_NAME_cmp(current, name) == 0; 726 } 727 return found ? i - 1 : -1; 728 } 729