1 /* crypto/ts/ts_resp_verify.c */ 2 /* 3 * Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL project 4 * 2002. 5 */ 6 /* ==================================================================== 7 * Copyright (c) 2006 The OpenSSL Project. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in 18 * the documentation and/or other materials provided with the 19 * distribution. 20 * 21 * 3. All advertising materials mentioning features or use of this 22 * software must display the following acknowledgment: 23 * "This product includes software developed by the OpenSSL Project 24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 25 * 26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27 * endorse or promote products derived from this software without 28 * prior written permission. For written permission, please contact 29 * licensing@OpenSSL.org. 30 * 31 * 5. Products derived from this software may not be called "OpenSSL" 32 * nor may "OpenSSL" appear in their names without prior written 33 * permission of the OpenSSL Project. 34 * 35 * 6. Redistributions of any form whatsoever must retain the following 36 * acknowledgment: 37 * "This product includes software developed by the OpenSSL Project 38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 39 * 40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51 * OF THE POSSIBILITY OF SUCH DAMAGE. 52 * ==================================================================== 53 * 54 * This product includes cryptographic software written by Eric Young 55 * (eay@cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh@cryptsoft.com). 57 * 58 */ 59 60 #include <stdio.h> 61 #include "cryptlib.h" 62 #include <openssl/objects.h> 63 #include <openssl/ts.h> 64 #include <openssl/pkcs7.h> 65 66 /* Private function declarations. */ 67 68 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, 69 X509 *signer, STACK_OF(X509) **chain); 70 static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, 71 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, 89 GENERAL_NAME *name); 90 91 /* 92 * Local mapping between response codes and descriptions. 93 * Don't forget to change TS_STATUS_BUF_SIZE when modifying 94 * the elements of this array. 95 */ 96 static const char *TS_status_text[] = { "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 { 117 TS_INFO_BAD_ALG, "badAlg" 118 }, 119 { 120 TS_INFO_BAD_REQUEST, "badRequest" 121 }, 122 { 123 TS_INFO_BAD_DATA_FORMAT, "badDataFormat" 124 }, 125 { 126 TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable" 127 }, 128 { 129 TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy" 130 }, 131 { 132 TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension" 133 }, 134 { 135 TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable" 136 }, 137 { 138 TS_INFO_SYSTEM_FAILURE, "systemFailure" 139 } 140 }; 141 142 #define TS_FAILURE_INFO_SIZE (sizeof(TS_failure_info) / \ 143 sizeof(*TS_failure_info)) 144 145 /* Functions for verifying a signed TS_TST_INFO structure. */ 146 147 /*- 148 * This function carries out the following tasks: 149 * - Checks if there is one and only one signer. 150 * - Search for the signing certificate in 'certs' and in the response. 151 * - Check the extended key usage and key usage fields of the signer 152 * certificate (done by the path validation). 153 * - Build and validate the certificate path. 154 * - Check if the certificate path meets the requirements of the 155 * SigningCertificate ESS signed attribute. 156 * - Verify the signature value. 157 * - Returns the signer certificate in 'signer', if 'signer' is not NULL. 158 */ 159 int TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs, 160 X509_STORE *store, X509 **signer_out) 161 { 162 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL; 163 PKCS7_SIGNER_INFO *si; 164 STACK_OF(X509) *signers = NULL; 165 X509 *signer; 166 STACK_OF(X509) *chain = NULL; 167 char buf[4096]; 168 int i, j = 0, ret = 0; 169 BIO *p7bio = NULL; 170 171 /* Some sanity checks first. */ 172 if (!token) { 173 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_INVALID_NULL_POINTER); 174 goto err; 175 } 176 177 /* Check for the correct content type */ 178 if (!PKCS7_type_is_signed(token)) { 179 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_WRONG_CONTENT_TYPE); 180 goto err; 181 } 182 183 /* Check if there is one and only one signer. */ 184 sinfos = PKCS7_get_signer_info(token); 185 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) { 186 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_THERE_MUST_BE_ONE_SIGNER); 187 goto err; 188 } 189 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0); 190 191 /* Check for no content: no data to verify signature. */ 192 if (PKCS7_get_detached(token)) { 193 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_NO_CONTENT); 194 goto err; 195 } 196 197 /* 198 * Get hold of the signer certificate, search only internal certificates 199 * if it was requested. 200 */ 201 signers = PKCS7_get0_signers(token, certs, 0); 202 if (!signers || sk_X509_num(signers) != 1) 203 goto err; 204 signer = sk_X509_value(signers, 0); 205 206 /* Now verify the certificate. */ 207 if (!TS_verify_cert(store, certs, signer, &chain)) 208 goto err; 209 210 /* 211 * Check if the signer certificate is consistent with the ESS extension. 212 */ 213 if (!TS_check_signing_certs(si, chain)) 214 goto err; 215 216 /* Creating the message digest. */ 217 p7bio = PKCS7_dataInit(token, NULL); 218 219 /* We now have to 'read' from p7bio to calculate digests etc. */ 220 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0) ; 221 222 /* Verifying the signature. */ 223 j = PKCS7_signatureVerify(p7bio, token, si, signer); 224 if (j <= 0) { 225 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_SIGNATURE_FAILURE); 226 goto err; 227 } 228 229 /* Return the signer certificate if needed. */ 230 if (signer_out) { 231 *signer_out = signer; 232 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509); 233 } 234 235 ret = 1; 236 237 err: 238 BIO_free_all(p7bio); 239 sk_X509_pop_free(chain, X509_free); 240 sk_X509_free(signers); 241 242 return ret; 243 } 244 245 /* 246 * The certificate chain is returned in chain. Caller is responsible for 247 * freeing the vector. 248 */ 249 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, 250 X509 *signer, STACK_OF(X509) **chain) 251 { 252 X509_STORE_CTX cert_ctx; 253 int i; 254 int ret = 1; 255 256 /* chain is an out argument. */ 257 *chain = NULL; 258 if (!X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted)) 259 return 0; 260 X509_STORE_CTX_set_purpose(&cert_ctx, X509_PURPOSE_TIMESTAMP_SIGN); 261 i = X509_verify_cert(&cert_ctx); 262 if (i <= 0) { 263 int j = X509_STORE_CTX_get_error(&cert_ctx); 264 TSerr(TS_F_TS_VERIFY_CERT, TS_R_CERTIFICATE_VERIFY_ERROR); 265 ERR_add_error_data(2, "Verify error:", 266 X509_verify_cert_error_string(j)); 267 ret = 0; 268 } else { 269 /* Get a copy of the certificate chain. */ 270 *chain = X509_STORE_CTX_get1_chain(&cert_ctx); 271 } 272 273 X509_STORE_CTX_cleanup(&cert_ctx); 274 275 return ret; 276 } 277 278 static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, 279 STACK_OF(X509) *chain) 280 { 281 ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si); 282 STACK_OF(ESS_CERT_ID) *cert_ids = NULL; 283 X509 *cert; 284 int i = 0; 285 int ret = 0; 286 287 if (!ss) 288 goto err; 289 cert_ids = ss->cert_ids; 290 /* The signer certificate must be the first in cert_ids. */ 291 cert = sk_X509_value(chain, 0); 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 than one 297 * 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 if (TS_find_cert(cert_ids, cert) < 0) 304 goto err; 305 } 306 } 307 ret = 1; 308 err: 309 if (!ret) 310 TSerr(TS_F_TS_CHECK_SIGNING_CERTS, 311 TS_R_ESS_SIGNING_CERTIFICATE_ERROR); 312 ESS_SIGNING_CERT_free(ss); 313 return ret; 314 } 315 316 static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si) 317 { 318 ASN1_TYPE *attr; 319 const unsigned char *p; 320 attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificate); 321 if (!attr) 322 return NULL; 323 p = attr->value.sequence->data; 324 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length); 325 } 326 327 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 328 static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert) 329 { 330 int i; 331 332 if (!cert_ids || !cert) 333 return -1; 334 335 /* Recompute SHA1 hash of certificate if necessary (side effect). */ 336 X509_check_purpose(cert, -1, 0); 337 338 /* Look for cert in the cert_ids vector. */ 339 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) { 340 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i); 341 342 /* Check the SHA-1 hash first. */ 343 if (cid->hash->length == sizeof(cert->sha1_hash) 344 && !memcmp(cid->hash->data, cert->sha1_hash, 345 sizeof(cert->sha1_hash))) { 346 /* Check the issuer/serial as well if specified. */ 347 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 348 if (!is || !TS_issuer_serial_cmp(is, cert->cert_info)) 349 return i; 350 } 351 } 352 353 return -1; 354 } 355 356 static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo) 357 { 358 GENERAL_NAME *issuer; 359 360 if (!is || !cinfo || sk_GENERAL_NAME_num(is->issuer) != 1) 361 return -1; 362 363 /* Check the issuer first. It must be a directory name. */ 364 issuer = sk_GENERAL_NAME_value(is->issuer, 0); 365 if (issuer->type != GEN_DIRNAME 366 || X509_NAME_cmp(issuer->d.dirn, cinfo->issuer)) 367 return -1; 368 369 /* Check the serial number, too. */ 370 if (ASN1_INTEGER_cmp(is->serial, cinfo->serialNumber)) 371 return -1; 372 373 return 0; 374 } 375 376 /*- 377 * Verifies whether 'response' contains a valid response with regards 378 * to the settings of the context: 379 * - Gives an error message if the TS_TST_INFO is not present. 380 * - Calls _TS_RESP_verify_token to verify the token content. 381 */ 382 int TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response) 383 { 384 PKCS7 *token = TS_RESP_get_token(response); 385 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response); 386 int ret = 0; 387 388 /* Check if we have a successful TS_TST_INFO object in place. */ 389 if (!TS_check_status_info(response)) 390 goto err; 391 392 /* Check the contents of the time stamp token. */ 393 if (!int_TS_RESP_verify_token(ctx, token, tst_info)) 394 goto err; 395 396 ret = 1; 397 err: 398 return ret; 399 } 400 401 /* 402 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and 403 * calls the internal int_TS_RESP_verify_token function for verifying it. 404 */ 405 int TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token) 406 { 407 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token); 408 int ret = 0; 409 if (tst_info) { 410 ret = int_TS_RESP_verify_token(ctx, token, tst_info); 411 TS_TST_INFO_free(tst_info); 412 } 413 return ret; 414 } 415 416 /*- 417 * Verifies whether the 'token' contains a valid time stamp token 418 * with regards to the settings of the context. Only those checks are 419 * carried out that are specified in the context: 420 * - Verifies the signature of the TS_TST_INFO. 421 * - Checks the version number of the response. 422 * - Check if the requested and returned policies math. 423 * - Check if the message imprints are the same. 424 * - Check if the nonces are the same. 425 * - Check if the TSA name matches the signer. 426 * - Check if the TSA name is the expected TSA. 427 */ 428 static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, 429 PKCS7 *token, TS_TST_INFO *tst_info) 430 { 431 X509 *signer = NULL; 432 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info); 433 X509_ALGOR *md_alg = NULL; 434 unsigned char *imprint = NULL; 435 unsigned imprint_len = 0; 436 int ret = 0; 437 int flags = ctx->flags; 438 439 /* Some options require us to also check the signature */ 440 if (((flags & TS_VFY_SIGNER) && tsa_name != NULL) 441 || (flags & TS_VFY_TSA_NAME)) { 442 flags |= TS_VFY_SIGNATURE; 443 } 444 445 /* Verify the signature. */ 446 if ((flags & TS_VFY_SIGNATURE) 447 && !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer)) 448 goto err; 449 450 /* Check version number of response. */ 451 if ((flags & TS_VFY_VERSION) 452 && TS_TST_INFO_get_version(tst_info) != 1) { 453 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_UNSUPPORTED_VERSION); 454 goto err; 455 } 456 457 /* Check policies. */ 458 if ((flags & TS_VFY_POLICY) 459 && !TS_check_policy(ctx->policy, tst_info)) 460 goto err; 461 462 /* Check message imprints. */ 463 if ((flags & TS_VFY_IMPRINT) 464 && !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len, 465 tst_info)) 466 goto err; 467 468 /* Compute and check message imprints. */ 469 if ((flags & TS_VFY_DATA) 470 && (!TS_compute_imprint(ctx->data, tst_info, 471 &md_alg, &imprint, &imprint_len) 472 || !TS_check_imprints(md_alg, imprint, imprint_len, tst_info))) 473 goto err; 474 475 /* Check nonces. */ 476 if ((flags & TS_VFY_NONCE) 477 && !TS_check_nonces(ctx->nonce, tst_info)) 478 goto err; 479 480 /* Check whether TSA name and signer certificate match. */ 481 if ((flags & TS_VFY_SIGNER) 482 && tsa_name && !TS_check_signer_name(tsa_name, signer)) { 483 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_NAME_MISMATCH); 484 goto err; 485 } 486 487 /* Check whether the TSA is the expected one. */ 488 if ((flags & TS_VFY_TSA_NAME) 489 && !TS_check_signer_name(ctx->tsa_name, signer)) { 490 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_UNTRUSTED); 491 goto err; 492 } 493 494 ret = 1; 495 err: 496 X509_free(signer); 497 X509_ALGOR_free(md_alg); 498 OPENSSL_free(imprint); 499 return ret; 500 } 501 502 static int TS_check_status_info(TS_RESP *response) 503 { 504 TS_STATUS_INFO *info = TS_RESP_get_status_info(response); 505 long status = ASN1_INTEGER_get(info->status); 506 const char *status_text = NULL; 507 char *embedded_status_text = NULL; 508 char failure_text[TS_STATUS_BUF_SIZE] = ""; 509 510 /* Check if everything went fine. */ 511 if (status == 0 || status == 1) 512 return 1; 513 514 /* There was an error, get the description in status_text. */ 515 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE) 516 status_text = TS_status_text[status]; 517 else 518 status_text = "unknown code"; 519 520 /* Set the embedded_status_text to the returned description. */ 521 if (sk_ASN1_UTF8STRING_num(info->text) > 0 522 && !(embedded_status_text = TS_get_status_text(info->text))) 523 return 0; 524 525 /* Filling in failure_text with the failure information. */ 526 if (info->failure_info) { 527 int i; 528 int first = 1; 529 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) { 530 if (ASN1_BIT_STRING_get_bit(info->failure_info, 531 TS_failure_info[i].code)) { 532 if (!first) 533 strcat(failure_text, ","); 534 else 535 first = 0; 536 strcat(failure_text, TS_failure_info[i].text); 537 } 538 } 539 } 540 if (failure_text[0] == '\0') 541 strcpy(failure_text, "unspecified"); 542 543 /* Making up the error string. */ 544 TSerr(TS_F_TS_CHECK_STATUS_INFO, TS_R_NO_TIME_STAMP_TOKEN); 545 ERR_add_error_data(6, 546 "status code: ", status_text, 547 ", status text: ", embedded_status_text ? 548 embedded_status_text : "unspecified", 549 ", failure codes: ", failure_text); 550 OPENSSL_free(embedded_status_text); 551 552 return 0; 553 } 554 555 static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text) 556 { 557 int i; 558 int length = 0; 559 char *result = NULL; 560 char *p; 561 562 /* Determine length first. */ 563 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 564 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 565 if (ASN1_STRING_length(current) > TS_MAX_STATUS_LENGTH - length - 1) 566 return NULL; 567 length += ASN1_STRING_length(current); 568 length += 1; /* separator character */ 569 } 570 /* Allocate memory (closing '\0' included). */ 571 if (!(result = OPENSSL_malloc(length))) { 572 TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE); 573 return NULL; 574 } 575 /* Concatenate the descriptions. */ 576 for (i = 0, p = result; i < sk_ASN1_UTF8STRING_num(text); ++i) { 577 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 578 length = ASN1_STRING_length(current); 579 if (i > 0) 580 *p++ = '/'; 581 strncpy(p, (const char *)ASN1_STRING_data(current), length); 582 p += length; 583 } 584 /* We do have space for this, too. */ 585 *p = '\0'; 586 587 return result; 588 } 589 590 static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info) 591 { 592 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info); 593 594 if (OBJ_cmp(req_oid, resp_oid) != 0) { 595 TSerr(TS_F_TS_CHECK_POLICY, TS_R_POLICY_MISMATCH); 596 return 0; 597 } 598 599 return 1; 600 } 601 602 static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, 603 X509_ALGOR **md_alg, 604 unsigned char **imprint, unsigned *imprint_len) 605 { 606 TS_MSG_IMPRINT *msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info); 607 X509_ALGOR *md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint); 608 const EVP_MD *md; 609 EVP_MD_CTX md_ctx; 610 unsigned char buffer[4096]; 611 int length; 612 613 *md_alg = NULL; 614 *imprint = NULL; 615 616 /* Return the MD algorithm of the response. */ 617 if (!(*md_alg = X509_ALGOR_dup(md_alg_resp))) 618 goto err; 619 620 /* Getting the MD object. */ 621 if (!(md = EVP_get_digestbyobj((*md_alg)->algorithm))) { 622 TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM); 623 goto err; 624 } 625 626 /* Compute message digest. */ 627 length = EVP_MD_size(md); 628 if (length < 0) 629 goto err; 630 *imprint_len = length; 631 if (!(*imprint = OPENSSL_malloc(*imprint_len))) { 632 TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE); 633 goto err; 634 } 635 636 if (!EVP_DigestInit(&md_ctx, md)) 637 goto err; 638 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) { 639 if (!EVP_DigestUpdate(&md_ctx, buffer, length)) 640 goto err; 641 } 642 if (!EVP_DigestFinal(&md_ctx, *imprint, NULL)) 643 goto err; 644 645 return 1; 646 err: 647 X509_ALGOR_free(*md_alg); 648 OPENSSL_free(*imprint); 649 *imprint_len = 0; 650 *imprint = 0; 651 return 0; 652 } 653 654 static int TS_check_imprints(X509_ALGOR *algor_a, 655 unsigned char *imprint_a, unsigned len_a, 656 TS_TST_INFO *tst_info) 657 { 658 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info); 659 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b); 660 int ret = 0; 661 662 /* algor_a is optional. */ 663 if (algor_a) { 664 /* Compare algorithm OIDs. */ 665 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) 666 goto err; 667 668 /* The parameter must be NULL in both. */ 669 if ((algor_a->parameter 670 && ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) 671 || (algor_b->parameter 672 && ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL)) 673 goto err; 674 } 675 676 /* Compare octet strings. */ 677 ret = len_a == (unsigned)ASN1_STRING_length(b->hashed_msg) && 678 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0; 679 err: 680 if (!ret) 681 TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH); 682 return ret; 683 } 684 685 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info) 686 { 687 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info); 688 689 /* Error if nonce is missing. */ 690 if (!b) { 691 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED); 692 return 0; 693 } 694 695 /* No error if a nonce is returned without being requested. */ 696 if (ASN1_INTEGER_cmp(a, b) != 0) { 697 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH); 698 return 0; 699 } 700 701 return 1; 702 } 703 704 /* 705 * Check if the specified TSA name matches either the subject or one of the 706 * subject alternative names of the TSA certificate. 707 */ 708 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer) 709 { 710 STACK_OF(GENERAL_NAME) *gen_names = NULL; 711 int idx = -1; 712 int found = 0; 713 714 /* Check the subject name first. */ 715 if (tsa_name->type == GEN_DIRNAME 716 && X509_name_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0) 717 return 1; 718 719 /* Check all the alternative names. */ 720 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, NULL, &idx); 721 while (gen_names != NULL 722 && !(found = TS_find_name(gen_names, tsa_name) >= 0)) { 723 /* 724 * Get the next subject alternative name, although there should be no 725 * more than one. 726 */ 727 GENERAL_NAMES_free(gen_names); 728 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 729 NULL, &idx); 730 } 731 if (gen_names) 732 GENERAL_NAMES_free(gen_names); 733 734 return found; 735 } 736 737 /* Returns 1 if name is in gen_names, 0 otherwise. */ 738 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name) 739 { 740 int i, found; 741 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); ++i) { 742 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i); 743 found = GENERAL_NAME_cmp(current, name) == 0; 744 } 745 return found ? i - 1 : -1; 746 } 747