1 /* $OpenBSD: ts_rsp_verify.c,v 1.24 2021/12/12 21:30:14 tb Exp $ */ 2 /* Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL 3 * project 2002. 4 */ 5 /* ==================================================================== 6 * Copyright (c) 2006 The OpenSSL Project. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in 17 * the documentation and/or other materials provided with the 18 * distribution. 19 * 20 * 3. All advertising materials mentioning features or use of this 21 * software must display the following acknowledgment: 22 * "This product includes software developed by the OpenSSL Project 23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 24 * 25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26 * endorse or promote products derived from this software without 27 * prior written permission. For written permission, please contact 28 * licensing@OpenSSL.org. 29 * 30 * 5. Products derived from this software may not be called "OpenSSL" 31 * nor may "OpenSSL" appear in their names without prior written 32 * permission of the OpenSSL Project. 33 * 34 * 6. Redistributions of any form whatsoever must retain the following 35 * acknowledgment: 36 * "This product includes software developed by the OpenSSL Project 37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 38 * 39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50 * OF THE POSSIBILITY OF SUCH DAMAGE. 51 * ==================================================================== 52 * 53 * This product includes cryptographic software written by Eric Young 54 * (eay@cryptsoft.com). This product includes software written by Tim 55 * Hudson (tjh@cryptsoft.com). 56 * 57 */ 58 59 #include <stdio.h> 60 #include <string.h> 61 62 #include <openssl/err.h> 63 #include <openssl/objects.h> 64 #include <openssl/pkcs7.h> 65 #include <openssl/ts.h> 66 67 #include "evp_locl.h" 68 #include "x509_lcl.h" 69 70 /* Private function declarations. */ 71 72 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, 73 X509 *signer, STACK_OF(X509) **chain); 74 static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain); 75 static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si); 76 static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert); 77 static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo); 78 static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, 79 PKCS7 *token, TS_TST_INFO *tst_info); 80 static int TS_check_status_info(TS_RESP *response); 81 static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text); 82 static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info); 83 static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, 84 X509_ALGOR **md_alg, 85 unsigned char **imprint, unsigned *imprint_len); 86 static int TS_check_imprints(X509_ALGOR *algor_a, 87 unsigned char *imprint_a, unsigned len_a, 88 TS_TST_INFO *tst_info); 89 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info); 90 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer); 91 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name); 92 93 /* 94 * Local mapping between response codes and descriptions. 95 * Don't forget to change TS_STATUS_BUF_SIZE when modifying 96 * the elements of this array. 97 */ 98 static const char *TS_status_text[] = { 99 "granted", 100 "grantedWithMods", 101 "rejection", 102 "waiting", 103 "revocationWarning", 104 "revocationNotification" 105 }; 106 107 #define TS_STATUS_TEXT_SIZE (sizeof(TS_status_text)/sizeof(*TS_status_text)) 108 109 /* 110 * This must be greater or equal to the sum of the strings in TS_status_text 111 * plus the number of its elements. 112 */ 113 #define TS_STATUS_BUF_SIZE 256 114 115 static struct { 116 int code; 117 const char *text; 118 } TS_failure_info[] = { 119 { TS_INFO_BAD_ALG, "badAlg" }, 120 { TS_INFO_BAD_REQUEST, "badRequest" }, 121 { TS_INFO_BAD_DATA_FORMAT, "badDataFormat" }, 122 { TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable" }, 123 { TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy" }, 124 { TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension" }, 125 { TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable" }, 126 { TS_INFO_SYSTEM_FAILURE, "systemFailure" } 127 }; 128 129 #define TS_FAILURE_INFO_SIZE (sizeof(TS_failure_info) / \ 130 sizeof(*TS_failure_info)) 131 132 /* Functions for verifying a signed TS_TST_INFO structure. */ 133 134 /* 135 * This function carries out the following tasks: 136 * - Checks if there is one and only one signer. 137 * - Search for the signing certificate in 'certs' and in the response. 138 * - Check the extended key usage and key usage fields of the signer 139 * certificate (done by the path validation). 140 * - Build and validate the certificate path. 141 * - Check if the certificate path meets the requirements of the 142 * SigningCertificate ESS signed attribute. 143 * - Verify the signature value. 144 * - Returns the signer certificate in 'signer', if 'signer' is not NULL. 145 */ 146 int 147 TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs, 148 X509_STORE *store, X509 **signer_out) 149 { 150 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL; 151 PKCS7_SIGNER_INFO *si; 152 STACK_OF(X509) *signers = NULL; 153 X509 *signer; 154 STACK_OF(X509) *chain = NULL; 155 char buf[4096]; 156 int i, j = 0, ret = 0; 157 BIO *p7bio = NULL; 158 159 /* Some sanity checks first. */ 160 if (!token) { 161 TSerror(TS_R_INVALID_NULL_POINTER); 162 goto err; 163 } 164 165 /* Check for the correct content type */ 166 if (!PKCS7_type_is_signed(token)) { 167 TSerror(TS_R_WRONG_CONTENT_TYPE); 168 goto err; 169 } 170 171 /* Check if there is one and only one signer. */ 172 sinfos = PKCS7_get_signer_info(token); 173 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) { 174 TSerror(TS_R_THERE_MUST_BE_ONE_SIGNER); 175 goto err; 176 } 177 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0); 178 179 /* Check for no content: no data to verify signature. */ 180 if (PKCS7_get_detached(token)) { 181 TSerror(TS_R_NO_CONTENT); 182 goto err; 183 } 184 185 /* Get hold of the signer certificate, search only internal 186 certificates if it was requested. */ 187 signers = PKCS7_get0_signers(token, certs, 0); 188 if (!signers || sk_X509_num(signers) != 1) 189 goto err; 190 signer = sk_X509_value(signers, 0); 191 192 /* Now verify the certificate. */ 193 if (!TS_verify_cert(store, certs, signer, &chain)) 194 goto err; 195 196 /* Check if the signer certificate is consistent with the 197 ESS extension. */ 198 if (!TS_check_signing_certs(si, chain)) 199 goto err; 200 201 /* Creating the message digest. */ 202 p7bio = PKCS7_dataInit(token, NULL); 203 204 /* We now have to 'read' from p7bio to calculate digests etc. */ 205 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0) 206 ; 207 208 /* Verifying the signature. */ 209 j = PKCS7_signatureVerify(p7bio, token, si, signer); 210 if (j <= 0) { 211 TSerror(TS_R_SIGNATURE_FAILURE); 212 goto err; 213 } 214 215 /* Return the signer certificate if needed. */ 216 if (signer_out) { 217 *signer_out = signer; 218 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509); 219 } 220 221 ret = 1; 222 223 err: 224 BIO_free_all(p7bio); 225 sk_X509_pop_free(chain, X509_free); 226 sk_X509_free(signers); 227 228 return ret; 229 } 230 231 /* 232 * The certificate chain is returned in chain. Caller is responsible for 233 * freeing the vector. 234 */ 235 static int 236 TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, X509 *signer, 237 STACK_OF(X509) **chain) 238 { 239 X509_STORE_CTX cert_ctx; 240 int i; 241 int ret = 0; 242 243 /* chain is an out argument. */ 244 *chain = NULL; 245 if (X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted) == 0) { 246 TSerror(ERR_R_X509_LIB); 247 goto err; 248 } 249 if (X509_STORE_CTX_set_purpose(&cert_ctx, 250 X509_PURPOSE_TIMESTAMP_SIGN) == 0) 251 goto err; 252 i = X509_verify_cert(&cert_ctx); 253 if (i <= 0) { 254 int j = X509_STORE_CTX_get_error(&cert_ctx); 255 256 TSerror(TS_R_CERTIFICATE_VERIFY_ERROR); 257 ERR_asprintf_error_data("Verify error:%s", 258 X509_verify_cert_error_string(j)); 259 goto err; 260 } else { 261 /* Get a copy of the certificate chain. */ 262 *chain = X509_STORE_CTX_get1_chain(&cert_ctx); 263 ret = 1; 264 } 265 266 err: 267 X509_STORE_CTX_cleanup(&cert_ctx); 268 269 return ret; 270 } 271 272 static int 273 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain) 274 { 275 ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si); 276 STACK_OF(ESS_CERT_ID) *cert_ids = NULL; 277 X509 *cert; 278 int i = 0; 279 int ret = 0; 280 281 if (!ss) 282 goto err; 283 cert_ids = ss->cert_ids; 284 /* The signer certificate must be the first in cert_ids. */ 285 cert = sk_X509_value(chain, 0); 286 if (TS_find_cert(cert_ids, cert) != 0) 287 goto err; 288 289 /* Check the other certificates of the chain if there are more 290 than one certificate ids in cert_ids. */ 291 if (sk_ESS_CERT_ID_num(cert_ids) > 1) { 292 /* All the certificates of the chain must be in cert_ids. */ 293 for (i = 1; i < sk_X509_num(chain); ++i) { 294 cert = sk_X509_value(chain, i); 295 if (TS_find_cert(cert_ids, cert) < 0) 296 goto err; 297 } 298 } 299 ret = 1; 300 301 err: 302 if (!ret) 303 TSerror(TS_R_ESS_SIGNING_CERTIFICATE_ERROR); 304 ESS_SIGNING_CERT_free(ss); 305 return ret; 306 } 307 308 static ESS_SIGNING_CERT * 309 ESS_get_signing_cert(PKCS7_SIGNER_INFO *si) 310 { 311 ASN1_TYPE *attr; 312 const unsigned char *p; 313 314 attr = PKCS7_get_signed_attribute(si, 315 NID_id_smime_aa_signingCertificate); 316 if (!attr) 317 return NULL; 318 if (attr->type != V_ASN1_SEQUENCE) 319 return NULL; 320 p = attr->value.sequence->data; 321 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length); 322 } 323 324 /* Returns < 0 if certificate is not found, certificate index otherwise. */ 325 static int 326 TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert) 327 { 328 int i; 329 unsigned char cert_hash[TS_HASH_LEN]; 330 331 if (!cert_ids || !cert) 332 return -1; 333 334 if (!X509_digest(cert, TS_HASH_EVP, cert_hash, NULL)) 335 return -1; 336 337 /* Recompute SHA1 hash of certificate if necessary (side effect). */ 338 X509_check_purpose(cert, -1, 0); 339 340 /* Look for cert in the cert_ids vector. */ 341 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) { 342 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i); 343 344 /* Check the SHA-1 hash first. */ 345 if (cid->hash->length == TS_HASH_LEN && !memcmp(cid->hash->data, 346 cert_hash, TS_HASH_LEN)) { 347 /* Check the issuer/serial as well if specified. */ 348 ESS_ISSUER_SERIAL *is = cid->issuer_serial; 349 if (!is || !TS_issuer_serial_cmp(is, cert->cert_info)) 350 return i; 351 } 352 } 353 354 return -1; 355 } 356 357 static int 358 TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo) 359 { 360 GENERAL_NAME *issuer; 361 362 if (!is || !cinfo || sk_GENERAL_NAME_num(is->issuer) != 1) 363 return -1; 364 365 /* Check the issuer first. It must be a directory name. */ 366 issuer = sk_GENERAL_NAME_value(is->issuer, 0); 367 if (issuer->type != GEN_DIRNAME || 368 X509_NAME_cmp(issuer->d.dirn, cinfo->issuer)) 369 return -1; 370 371 /* Check the serial number, too. */ 372 if (ASN1_INTEGER_cmp(is->serial, cinfo->serialNumber)) 373 return -1; 374 375 return 0; 376 } 377 378 /* 379 * Verifies whether 'response' contains a valid response with regards 380 * to the settings of the context: 381 * - Gives an error message if the TS_TST_INFO is not present. 382 * - Calls _TS_RESP_verify_token to verify the token content. 383 */ 384 int 385 TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response) 386 { 387 PKCS7 *token = TS_RESP_get_token(response); 388 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response); 389 int ret = 0; 390 391 /* Check if we have a successful TS_TST_INFO object in place. */ 392 if (!TS_check_status_info(response)) 393 goto err; 394 395 /* Check the contents of the time stamp token. */ 396 if (!int_TS_RESP_verify_token(ctx, token, tst_info)) 397 goto err; 398 399 ret = 1; 400 401 err: 402 return ret; 403 } 404 405 /* 406 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and 407 * calls the internal int_TS_RESP_verify_token function for verifying it. 408 */ 409 int 410 TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token) 411 { 412 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token); 413 int ret = 0; 414 415 if (tst_info) { 416 ret = int_TS_RESP_verify_token(ctx, token, tst_info); 417 TS_TST_INFO_free(tst_info); 418 } 419 return ret; 420 } 421 422 /* 423 * Verifies whether the 'token' contains a valid time stamp token 424 * with regards to the settings of the context. Only those checks are 425 * carried out that are specified in the context: 426 * - Verifies the signature of the TS_TST_INFO. 427 * - Checks the version number of the response. 428 * - Check if the requested and returned policies math. 429 * - Check if the message imprints are the same. 430 * - Check if the nonces are the same. 431 * - Check if the TSA name matches the signer. 432 * - Check if the TSA name is the expected TSA. 433 */ 434 static int 435 int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token, 436 TS_TST_INFO *tst_info) 437 { 438 X509 *signer = NULL; 439 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info); 440 X509_ALGOR *md_alg = NULL; 441 unsigned char *imprint = NULL; 442 unsigned imprint_len = 0; 443 int ret = 0; 444 445 /* Verify the signature. */ 446 if ((ctx->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 ((ctx->flags & TS_VFY_VERSION) && 452 TS_TST_INFO_get_version(tst_info) != 1) { 453 TSerror(TS_R_UNSUPPORTED_VERSION); 454 goto err; 455 } 456 457 /* Check policies. */ 458 if ((ctx->flags & TS_VFY_POLICY) && 459 !TS_check_policy(ctx->policy, tst_info)) 460 goto err; 461 462 /* Check message imprints. */ 463 if ((ctx->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 ((ctx->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 ((ctx->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 ((ctx->flags & TS_VFY_SIGNER) && 482 tsa_name && !TS_check_signer_name(tsa_name, signer)) { 483 TSerror(TS_R_TSA_NAME_MISMATCH); 484 goto err; 485 } 486 487 /* Check whether the TSA is the expected one. */ 488 if ((ctx->flags & TS_VFY_TSA_NAME) && 489 !TS_check_signer_name(ctx->tsa_name, signer)) { 490 TSerror(TS_R_TSA_UNTRUSTED); 491 goto err; 492 } 493 494 ret = 1; 495 496 err: 497 X509_free(signer); 498 X509_ALGOR_free(md_alg); 499 free(imprint); 500 return ret; 501 } 502 503 static int 504 TS_check_status_info(TS_RESP *response) 505 { 506 TS_STATUS_INFO *info = TS_RESP_get_status_info(response); 507 long status = ASN1_INTEGER_get(info->status); 508 const char *status_text = NULL; 509 char *embedded_status_text = NULL; 510 char failure_text[TS_STATUS_BUF_SIZE] = ""; 511 512 /* Check if everything went fine. */ 513 if (status == 0 || status == 1) 514 return 1; 515 516 /* There was an error, get the description in status_text. */ 517 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE) 518 status_text = TS_status_text[status]; 519 else 520 status_text = "unknown code"; 521 522 /* Set the embedded_status_text to the returned description. */ 523 if (sk_ASN1_UTF8STRING_num(info->text) > 0 && 524 !(embedded_status_text = TS_get_status_text(info->text))) 525 return 0; 526 527 /* Filling in failure_text with the failure information. */ 528 if (info->failure_info) { 529 int i; 530 int first = 1; 531 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) { 532 if (ASN1_BIT_STRING_get_bit(info->failure_info, 533 TS_failure_info[i].code)) { 534 if (!first) 535 strlcat(failure_text, ",", 536 TS_STATUS_BUF_SIZE); 537 else 538 first = 0; 539 strlcat(failure_text, TS_failure_info[i].text, 540 TS_STATUS_BUF_SIZE); 541 } 542 } 543 } 544 if (failure_text[0] == '\0') 545 strlcpy(failure_text, "unspecified", TS_STATUS_BUF_SIZE); 546 547 /* Making up the error string. */ 548 TSerror(TS_R_NO_TIME_STAMP_TOKEN); 549 ERR_asprintf_error_data 550 ("status code: %s, status text: %s, failure codes: %s", 551 status_text, 552 embedded_status_text ? embedded_status_text : "unspecified", 553 failure_text); 554 free(embedded_status_text); 555 556 return 0; 557 } 558 559 static char * 560 TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text) 561 { 562 int i; 563 unsigned int length = 0; 564 char *result = NULL; 565 566 /* Determine length first. */ 567 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 568 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 569 length += ASN1_STRING_length(current); 570 length += 1; /* separator character */ 571 } 572 /* Allocate memory (closing '\0' included). */ 573 if (!(result = malloc(length))) { 574 TSerror(ERR_R_MALLOC_FAILURE); 575 return NULL; 576 } 577 /* Concatenate the descriptions. */ 578 result[0] = '\0'; 579 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { 580 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); 581 if (i > 0) 582 strlcat(result, "/", length); 583 strlcat(result, (const char *)ASN1_STRING_data(current), length); 584 } 585 return result; 586 } 587 588 static int 589 TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info) 590 { 591 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info); 592 593 if (OBJ_cmp(req_oid, resp_oid) != 0) { 594 TSerror(TS_R_POLICY_MISMATCH); 595 return 0; 596 } 597 598 return 1; 599 } 600 601 static int 602 TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **out_md_alg, 603 unsigned char **out_imprint, unsigned int *out_imprint_len) 604 { 605 TS_MSG_IMPRINT *msg_imprint; 606 X509_ALGOR *md_alg_resp; 607 X509_ALGOR *md_alg = NULL; 608 unsigned char *imprint = NULL; 609 unsigned int imprint_len = 0; 610 const EVP_MD *md; 611 EVP_MD_CTX md_ctx; 612 unsigned char buffer[4096]; 613 int length; 614 615 *out_md_alg = NULL; 616 *out_imprint = NULL; 617 *out_imprint_len = 0; 618 619 /* Retrieve the MD algorithm of the response. */ 620 msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info); 621 md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint); 622 if ((md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL) 623 goto err; 624 625 /* Getting the MD object. */ 626 if ((md = EVP_get_digestbyobj((md_alg)->algorithm)) == NULL) { 627 TSerror(TS_R_UNSUPPORTED_MD_ALGORITHM); 628 goto err; 629 } 630 631 /* Compute message digest. */ 632 if ((length = EVP_MD_size(md)) < 0) 633 goto err; 634 imprint_len = length; 635 if ((imprint = malloc(imprint_len)) == NULL) { 636 TSerror(ERR_R_MALLOC_FAILURE); 637 goto err; 638 } 639 640 if (!EVP_DigestInit(&md_ctx, md)) 641 goto err; 642 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) { 643 if (!EVP_DigestUpdate(&md_ctx, buffer, length)) 644 goto err; 645 } 646 if (!EVP_DigestFinal(&md_ctx, imprint, NULL)) 647 goto err; 648 649 *out_md_alg = md_alg; 650 md_alg = NULL; 651 *out_imprint = imprint; 652 imprint = NULL; 653 *out_imprint_len = imprint_len; 654 655 return 1; 656 657 err: 658 X509_ALGOR_free(md_alg); 659 free(imprint); 660 return 0; 661 } 662 663 static int 664 TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a, 665 TS_TST_INFO *tst_info) 666 { 667 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info); 668 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b); 669 int ret = 0; 670 671 /* algor_a is optional. */ 672 if (algor_a) { 673 /* Compare algorithm OIDs. */ 674 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) 675 goto err; 676 677 /* The parameter must be NULL in both. */ 678 if ((algor_a->parameter && 679 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) || 680 (algor_b->parameter && 681 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL)) 682 goto err; 683 } 684 685 /* Compare octet strings. */ 686 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) && 687 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0; 688 689 err: 690 if (!ret) 691 TSerror(TS_R_MESSAGE_IMPRINT_MISMATCH); 692 return ret; 693 } 694 695 static int 696 TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info) 697 { 698 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info); 699 700 /* Error if nonce is missing. */ 701 if (!b) { 702 TSerror(TS_R_NONCE_NOT_RETURNED); 703 return 0; 704 } 705 706 /* No error if a nonce is returned without being requested. */ 707 if (ASN1_INTEGER_cmp(a, b) != 0) { 708 TSerror(TS_R_NONCE_MISMATCH); 709 return 0; 710 } 711 712 return 1; 713 } 714 715 /* Check if the specified TSA name matches either the subject 716 or one of the subject alternative names of the TSA certificate. */ 717 static int 718 TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer) 719 { 720 STACK_OF(GENERAL_NAME) *gen_names = NULL; 721 int idx = -1; 722 int found = 0; 723 724 if (signer == NULL) 725 return 0; 726 727 /* Check the subject name first. */ 728 if (tsa_name->type == GEN_DIRNAME && 729 X509_NAME_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0) 730 return 1; 731 732 /* Check all the alternative names. */ 733 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 734 NULL, &idx); 735 while (gen_names != NULL && 736 !(found = (TS_find_name(gen_names, tsa_name) >= 0))) { 737 /* Get the next subject alternative name, 738 although there should be no more than one. */ 739 GENERAL_NAMES_free(gen_names); 740 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, 741 NULL, &idx); 742 } 743 if (gen_names) 744 GENERAL_NAMES_free(gen_names); 745 746 return found; 747 } 748 749 /* Returns 1 if name is in gen_names, 0 otherwise. */ 750 static int 751 TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name) 752 { 753 int i, found; 754 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); 755 ++i) { 756 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i); 757 found = GENERAL_NAME_cmp(current, name) == 0; 758 } 759 return found ? i - 1 : -1; 760 } 761