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 *imprint = NULL;
633 return 0;
634 }
635
636 static int TS_check_imprints(X509_ALGOR *algor_a,
637 unsigned char *imprint_a, unsigned len_a,
638 TS_TST_INFO *tst_info)
639 {
640 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info);
641 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b);
642 int ret = 0;
643
644 /* algor_a is optional. */
645 if (algor_a)
646 {
647 /* Compare algorithm OIDs. */
648 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) goto err;
649
650 /* The parameter must be NULL in both. */
651 if ((algor_a->parameter
652 && ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL)
653 || (algor_b->parameter
654 && ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL))
655 goto err;
656 }
657
658 /* Compare octet strings. */
659 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) &&
660 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0;
661 err:
662 if (!ret)
663 TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH);
664 return ret;
665 }
666
667 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info)
668 {
669 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info);
670
671 /* Error if nonce is missing. */
672 if (!b)
673 {
674 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED);
675 return 0;
676 }
677
678 /* No error if a nonce is returned without being requested. */
679 if (ASN1_INTEGER_cmp(a, b) != 0)
680 {
681 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH);
682 return 0;
683 }
684
685 return 1;
686 }
687
688 /* Check if the specified TSA name matches either the subject
689 or one of the subject alternative names of the TSA certificate. */
690 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer)
691 {
692 STACK_OF(GENERAL_NAME) *gen_names = NULL;
693 int idx = -1;
694 int found = 0;
695
696 /* Check the subject name first. */
697 if (tsa_name->type == GEN_DIRNAME
698 && X509_name_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0)
699 return 1;
700
701 /* Check all the alternative names. */
702 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
703 NULL, &idx);
704 while (gen_names != NULL
705 && !(found = TS_find_name(gen_names, tsa_name) >= 0))
706 {
707 /* Get the next subject alternative name,
708 although there should be no more than one. */
709 GENERAL_NAMES_free(gen_names);
710 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
711 NULL, &idx);
712 }
713 if (gen_names) GENERAL_NAMES_free(gen_names);
714
715 return found;
716 }
717
718 /* Returns 1 if name is in gen_names, 0 otherwise. */
719 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name)
720 {
721 int i, found;
722 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names);
723 ++i)
724 {
725 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i);
726 found = GENERAL_NAME_cmp(current, name) == 0;
727 }
728 return found ? i - 1 : -1;
729 }