1 /* $OpenBSD: ts_rsp_verify.c,v 1.15 2015/07/19 05:42:55 miod 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 = 0; 240 241 /* chain is an out argument. */ 242 *chain = NULL; 243 if (X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted) == 0) { 244 TSerr(TS_F_TS_VERIFY_CERT, ERR_R_X509_LIB); 245 goto err; 246 } 247 X509_STORE_CTX_set_purpose(&cert_ctx, X509_PURPOSE_TIMESTAMP_SIGN); 248 i = X509_verify_cert(&cert_ctx); 249 if (i <= 0) { 250 int j = X509_STORE_CTX_get_error(&cert_ctx); 251 252 TSerr(TS_F_TS_VERIFY_CERT, TS_R_CERTIFICATE_VERIFY_ERROR); 253 ERR_asprintf_error_data("Verify error:%s", 254 X509_verify_cert_error_string(j)); 255 goto err; 256 } else { 257 /* Get a copy of the certificate chain. */ 258 *chain = X509_STORE_CTX_get1_chain(&cert_ctx); 259 ret = 1; 260 } 261 262 err: 263 X509_STORE_CTX_cleanup(&cert_ctx); 264 265 return ret; 266 } 267 268 static int 269 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain) 270 { 271 ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si); 272 STACK_OF(ESS_CERT_ID) *cert_ids = NULL; 273 X509 *cert; 274 int i = 0; 275 int ret = 0; 276 277 if (!ss) 278 goto err; 279 cert_ids = ss->cert_ids; 280 /* The signer certificate must be the first in cert_ids. */ 281 cert = sk_X509_value(chain, 0); 282 if (TS_find_cert(cert_ids, cert) != 0) 283 goto err; 284 285 /* Check the other certificates of the chain if there are more 286 than one certificate ids in cert_ids. */ 287 if (sk_ESS_CERT_ID_num(cert_ids) > 1) { 288 /* All the certificates of the chain must be in cert_ids. */ 289 for (i = 1; i < sk_X509_num(chain); ++i) { 290 cert = sk_X509_value(chain, i); 291 if (TS_find_cert(cert_ids, cert) < 0) 292 goto err; 293 } 294 } 295 ret = 1; 296 297 err: 298 if (!ret) 299 TSerr(TS_F_TS_CHECK_SIGNING_CERTS, 300 TS_R_ESS_SIGNING_CERTIFICATE_ERROR); 301 ESS_SIGNING_CERT_free(ss); 302 return ret; 303 } 304 305 static ESS_SIGNING_CERT * 306 ESS_get_signing_cert(PKCS7_SIGNER_INFO *si) 307 { 308 ASN1_TYPE *attr; 309 const unsigned char *p; 310 311 attr = PKCS7_get_signed_attribute(si, 312 NID_id_smime_aa_signingCertificate); 313 if (!attr) 314 return NULL; 315 if (attr->type != V_ASN1_SEQUENCE) 316 return NULL; 317 p = attr->value.sequence->data; 318 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length); 319 } 320 321 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 322 static int 323 TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert) 324 { 325 int i; 326 327 if (!cert_ids || !cert) 328 return -1; 329 330 /* Recompute SHA1 hash of certificate if necessary (side effect). */ 331 X509_check_purpose(cert, -1, 0); 332 333 /* Look for cert in the cert_ids vector. */ 334 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) { 335 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i); 336 337 /* Check the SHA-1 hash first. */ 338 if (cid->hash->length == sizeof(cert->sha1_hash) && 339 !memcmp(cid->hash->data, cert->sha1_hash, 340 sizeof(cert->sha1_hash))) { 341 /* Check the issuer/serial as well if specified. */ 342 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 343 if (!is || !TS_issuer_serial_cmp(is, cert->cert_info)) 344 return i; 345 } 346 } 347 348 return -1; 349 } 350 351 static int 352 TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo) 353 { 354 GENERAL_NAME *issuer; 355 356 if (!is || !cinfo || sk_GENERAL_NAME_num(is->issuer) != 1) 357 return -1; 358 359 /* Check the issuer first. It must be a directory name. */ 360 issuer = sk_GENERAL_NAME_value(is->issuer, 0); 361 if (issuer->type != GEN_DIRNAME || 362 X509_NAME_cmp(issuer->d.dirn, cinfo->issuer)) 363 return -1; 364 365 /* Check the serial number, too. */ 366 if (ASN1_INTEGER_cmp(is->serial, cinfo->serialNumber)) 367 return -1; 368 369 return 0; 370 } 371 372 /* 373 * Verifies whether 'response' contains a valid response with regards 374 * to the settings of the context: 375 * - Gives an error message if the TS_TST_INFO is not present. 376 * - Calls _TS_RESP_verify_token to verify the token content. 377 */ 378 int 379 TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response) 380 { 381 PKCS7 *token = TS_RESP_get_token(response); 382 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response); 383 int ret = 0; 384 385 /* Check if we have a successful TS_TST_INFO object in place. */ 386 if (!TS_check_status_info(response)) 387 goto err; 388 389 /* Check the contents of the time stamp token. */ 390 if (!int_TS_RESP_verify_token(ctx, token, tst_info)) 391 goto err; 392 393 ret = 1; 394 395 err: 396 return ret; 397 } 398 399 /* 400 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and 401 * calls the internal int_TS_RESP_verify_token function for verifying it. 402 */ 403 int 404 TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token) 405 { 406 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token); 407 int ret = 0; 408 409 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 429 int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token, 430 TS_TST_INFO *tst_info) 431 { 432 X509 *signer = NULL; 433 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info); 434 X509_ALGOR *md_alg = NULL; 435 unsigned char *imprint = NULL; 436 unsigned imprint_len = 0; 437 int ret = 0; 438 439 /* Verify the signature. */ 440 if ((ctx->flags & TS_VFY_SIGNATURE) && 441 !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer)) 442 goto err; 443 444 /* Check version number of response. */ 445 if ((ctx->flags & TS_VFY_VERSION) && 446 TS_TST_INFO_get_version(tst_info) != 1) { 447 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_UNSUPPORTED_VERSION); 448 goto err; 449 } 450 451 /* Check policies. */ 452 if ((ctx->flags & TS_VFY_POLICY) && 453 !TS_check_policy(ctx->policy, tst_info)) 454 goto err; 455 456 /* Check message imprints. */ 457 if ((ctx->flags & TS_VFY_IMPRINT) && 458 !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len, 459 tst_info)) 460 goto err; 461 462 /* Compute and check message imprints. */ 463 if ((ctx->flags & TS_VFY_DATA) && 464 (!TS_compute_imprint(ctx->data, tst_info, 465 &md_alg, &imprint, &imprint_len) || 466 !TS_check_imprints(md_alg, imprint, imprint_len, tst_info))) 467 goto err; 468 469 /* Check nonces. */ 470 if ((ctx->flags & TS_VFY_NONCE) && 471 !TS_check_nonces(ctx->nonce, tst_info)) 472 goto err; 473 474 /* Check whether TSA name and signer certificate match. */ 475 if ((ctx->flags & TS_VFY_SIGNER) && 476 tsa_name && !TS_check_signer_name(tsa_name, signer)) { 477 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_NAME_MISMATCH); 478 goto err; 479 } 480 481 /* Check whether the TSA is the expected one. */ 482 if ((ctx->flags & TS_VFY_TSA_NAME) && 483 !TS_check_signer_name(ctx->tsa_name, signer)) { 484 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_UNTRUSTED); 485 goto err; 486 } 487 488 ret = 1; 489 490 err: 491 X509_free(signer); 492 X509_ALGOR_free(md_alg); 493 free(imprint); 494 return ret; 495 } 496 497 static int 498 TS_check_status_info(TS_RESP *response) 499 { 500 TS_STATUS_INFO *info = TS_RESP_get_status_info(response); 501 long status = ASN1_INTEGER_get(info->status); 502 const char *status_text = NULL; 503 char *embedded_status_text = NULL; 504 char failure_text[TS_STATUS_BUF_SIZE] = ""; 505 506 /* Check if everything went fine. */ 507 if (status == 0 || status == 1) 508 return 1; 509 510 /* There was an error, get the description in status_text. */ 511 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE) 512 status_text = TS_status_text[status]; 513 else 514 status_text = "unknown code"; 515 516 /* Set the embedded_status_text to the returned description. */ 517 if (sk_ASN1_UTF8STRING_num(info->text) > 0 && 518 !(embedded_status_text = TS_get_status_text(info->text))) 519 return 0; 520 521 /* Filling in failure_text with the failure information. */ 522 if (info->failure_info) { 523 int i; 524 int first = 1; 525 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) { 526 if (ASN1_BIT_STRING_get_bit(info->failure_info, 527 TS_failure_info[i].code)) { 528 if (!first) 529 strlcat(failure_text, ",", 530 TS_STATUS_BUF_SIZE); 531 else 532 first = 0; 533 strlcat(failure_text, TS_failure_info[i].text, 534 TS_STATUS_BUF_SIZE); 535 } 536 } 537 } 538 if (failure_text[0] == '\0') 539 strlcpy(failure_text, "unspecified", TS_STATUS_BUF_SIZE); 540 541 /* Making up the error string. */ 542 TSerr(TS_F_TS_CHECK_STATUS_INFO, TS_R_NO_TIME_STAMP_TOKEN); 543 ERR_asprintf_error_data 544 ("status code: %s, status text: %s, failure codes: %s", 545 status_text, 546 embedded_status_text ? embedded_status_text : "unspecified", 547 failure_text); 548 free(embedded_status_text); 549 550 return 0; 551 } 552 553 static char * 554 TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text) 555 { 556 int i; 557 unsigned int length = 0; 558 char *result = NULL; 559 560 /* Determine length first. */ 561 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 562 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 563 length += ASN1_STRING_length(current); 564 length += 1; /* separator character */ 565 } 566 /* Allocate memory (closing '\0' included). */ 567 if (!(result = malloc(length))) { 568 TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE); 569 return NULL; 570 } 571 /* Concatenate the descriptions. */ 572 result[0] = '\0'; 573 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 574 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 575 if (i > 0) 576 strlcat(result, "/", length); 577 strlcat(result, (const char *)ASN1_STRING_data(current), length); 578 } 579 return result; 580 } 581 582 static int 583 TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info) 584 { 585 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info); 586 587 if (OBJ_cmp(req_oid, resp_oid) != 0) { 588 TSerr(TS_F_TS_CHECK_POLICY, TS_R_POLICY_MISMATCH); 589 return 0; 590 } 591 592 return 1; 593 } 594 595 static int 596 TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **md_alg, 597 unsigned char **imprint, unsigned *imprint_len) 598 { 599 TS_MSG_IMPRINT *msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info); 600 X509_ALGOR *md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint); 601 const EVP_MD *md; 602 EVP_MD_CTX md_ctx; 603 unsigned char buffer[4096]; 604 int length; 605 606 *md_alg = NULL; 607 *imprint = NULL; 608 609 /* Return the MD algorithm of the response. */ 610 if (!(*md_alg = X509_ALGOR_dup(md_alg_resp))) 611 goto err; 612 613 /* Getting the MD object. */ 614 if (!(md = EVP_get_digestbyobj((*md_alg)->algorithm))) { 615 TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM); 616 goto err; 617 } 618 619 /* Compute message digest. */ 620 length = EVP_MD_size(md); 621 if (length < 0) 622 goto err; 623 *imprint_len = length; 624 if (!(*imprint = malloc(*imprint_len))) { 625 TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE); 626 goto err; 627 } 628 629 if (!EVP_DigestInit(&md_ctx, md)) 630 goto err; 631 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) { 632 if (!EVP_DigestUpdate(&md_ctx, buffer, length)) 633 goto err; 634 } 635 if (!EVP_DigestFinal(&md_ctx, *imprint, NULL)) 636 goto err; 637 638 return 1; 639 640 err: 641 X509_ALGOR_free(*md_alg); 642 free(*imprint); 643 *imprint = NULL; 644 *imprint_len = 0; 645 return 0; 646 } 647 648 static int 649 TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a, 650 TS_TST_INFO *tst_info) 651 { 652 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info); 653 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b); 654 int ret = 0; 655 656 /* algor_a is optional. */ 657 if (algor_a) { 658 /* Compare algorithm OIDs. */ 659 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) 660 goto err; 661 662 /* The parameter must be NULL in both. */ 663 if ((algor_a->parameter && 664 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) || 665 (algor_b->parameter && 666 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL)) 667 goto err; 668 } 669 670 /* Compare octet strings. */ 671 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) && 672 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0; 673 674 err: 675 if (!ret) 676 TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH); 677 return ret; 678 } 679 680 static int 681 TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info) 682 { 683 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info); 684 685 /* Error if nonce is missing. */ 686 if (!b) { 687 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED); 688 return 0; 689 } 690 691 /* No error if a nonce is returned without being requested. */ 692 if (ASN1_INTEGER_cmp(a, b) != 0) { 693 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH); 694 return 0; 695 } 696 697 return 1; 698 } 699 700 /* Check if the specified TSA name matches either the subject 701 or one of the subject alternative names of the TSA certificate. */ 702 static int 703 TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer) 704 { 705 STACK_OF(GENERAL_NAME) *gen_names = NULL; 706 int idx = -1; 707 int found = 0; 708 709 if (signer == NULL) 710 return 0; 711 712 /* Check the subject name first. */ 713 if (tsa_name->type == GEN_DIRNAME && 714 X509_name_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0) 715 return 1; 716 717 /* Check all the alternative names. */ 718 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 719 NULL, &idx); 720 while (gen_names != NULL && 721 !(found = (TS_find_name(gen_names, tsa_name) >= 0))) { 722 /* Get the next subject alternative name, 723 although there should be no more than one. */ 724 GENERAL_NAMES_free(gen_names); 725 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 726 NULL, &idx); 727 } 728 if (gen_names) 729 GENERAL_NAMES_free(gen_names); 730 731 return found; 732 } 733 734 /* Returns 1 if name is in gen_names, 0 otherwise. */ 735 static int 736 TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name) 737 { 738 int i, found; 739 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); 740 ++i) { 741 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i); 742 found = GENERAL_NAME_cmp(current, name) == 0; 743 } 744 return found ? i - 1 : -1; 745 } 746