1 /* $OpenBSD: ts_rsp_verify.c,v 1.28 2022/07/24 08:16:47 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 "ts_local.h"
69 #include "x509_lcl.h"
70
71 /* Private function declarations. */
72
73 static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted,
74 X509 *signer, STACK_OF(X509) **chain);
75 static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain);
76 static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si);
77 static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert);
78 static ESS_SIGNING_CERT_V2 *ESS_get_signing_cert_v2(PKCS7_SIGNER_INFO *si);
79 static int TS_find_cert_v2(STACK_OF(ESS_CERT_ID_V2) *cert_ids, X509 *cert);
80 static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert);
81 static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx,
82 PKCS7 *token, TS_TST_INFO *tst_info);
83 static int TS_check_status_info(TS_RESP *response);
84 static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text);
85 static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info);
86 static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info,
87 X509_ALGOR **md_alg,
88 unsigned char **imprint, unsigned *imprint_len);
89 static int TS_check_imprints(X509_ALGOR *algor_a,
90 unsigned char *imprint_a, unsigned len_a,
91 TS_TST_INFO *tst_info);
92 static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info);
93 static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer);
94 static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name);
95
96 /*
97 * Local mapping between response codes and descriptions.
98 * Don't forget to change TS_STATUS_BUF_SIZE when modifying
99 * the elements of this array.
100 */
101 static const char *TS_status_text[] = {
102 "granted",
103 "grantedWithMods",
104 "rejection",
105 "waiting",
106 "revocationWarning",
107 "revocationNotification"
108 };
109
110 #define TS_STATUS_TEXT_SIZE (sizeof(TS_status_text)/sizeof(*TS_status_text))
111
112 /*
113 * This must be greater or equal to the sum of the strings in TS_status_text
114 * plus the number of its elements.
115 */
116 #define TS_STATUS_BUF_SIZE 256
117
118 static struct {
119 int code;
120 const char *text;
121 } TS_failure_info[] = {
122 { TS_INFO_BAD_ALG, "badAlg" },
123 { TS_INFO_BAD_REQUEST, "badRequest" },
124 { TS_INFO_BAD_DATA_FORMAT, "badDataFormat" },
125 { TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable" },
126 { TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy" },
127 { TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension" },
128 { TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable" },
129 { TS_INFO_SYSTEM_FAILURE, "systemFailure" }
130 };
131
132 #define TS_FAILURE_INFO_SIZE (sizeof(TS_failure_info) / \
133 sizeof(*TS_failure_info))
134
135 /* Functions for verifying a signed TS_TST_INFO structure. */
136
137 /*
138 * This function carries out the following tasks:
139 * - Checks if there is one and only one signer.
140 * - Search for the signing certificate in 'certs' and in the response.
141 * - Check the extended key usage and key usage fields of the signer
142 * certificate (done by the path validation).
143 * - Build and validate the certificate path.
144 * - Check if the certificate path meets the requirements of the
145 * SigningCertificate ESS signed attribute.
146 * - Verify the signature value.
147 * - Returns the signer certificate in 'signer', if 'signer' is not NULL.
148 */
149 int
TS_RESP_verify_signature(PKCS7 * token,STACK_OF (X509)* certs,X509_STORE * store,X509 ** signer_out)150 TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs,
151 X509_STORE *store, X509 **signer_out)
152 {
153 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL;
154 PKCS7_SIGNER_INFO *si;
155 STACK_OF(X509) *signers = NULL;
156 X509 *signer;
157 STACK_OF(X509) *chain = NULL;
158 char buf[4096];
159 int i, j = 0, ret = 0;
160 BIO *p7bio = NULL;
161
162 /* Some sanity checks first. */
163 if (!token) {
164 TSerror(TS_R_INVALID_NULL_POINTER);
165 goto err;
166 }
167
168 /* Check for the correct content type */
169 if (!PKCS7_type_is_signed(token)) {
170 TSerror(TS_R_WRONG_CONTENT_TYPE);
171 goto err;
172 }
173
174 /* Check if there is one and only one signer. */
175 sinfos = PKCS7_get_signer_info(token);
176 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) {
177 TSerror(TS_R_THERE_MUST_BE_ONE_SIGNER);
178 goto err;
179 }
180 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0);
181
182 /* Check for no content: no data to verify signature. */
183 if (PKCS7_get_detached(token)) {
184 TSerror(TS_R_NO_CONTENT);
185 goto err;
186 }
187
188 /* Get hold of the signer certificate, search only internal
189 certificates if it was requested. */
190 signers = PKCS7_get0_signers(token, certs, 0);
191 if (!signers || sk_X509_num(signers) != 1)
192 goto err;
193 signer = sk_X509_value(signers, 0);
194
195 /* Now verify the certificate. */
196 if (!TS_verify_cert(store, certs, signer, &chain))
197 goto err;
198
199 /* Check if the signer certificate is consistent with the
200 ESS extension. */
201 if (!TS_check_signing_certs(si, chain))
202 goto err;
203
204 /* Creating the message digest. */
205 p7bio = PKCS7_dataInit(token, NULL);
206
207 /* We now have to 'read' from p7bio to calculate digests etc. */
208 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0)
209 ;
210
211 /* Verifying the signature. */
212 j = PKCS7_signatureVerify(p7bio, token, si, signer);
213 if (j <= 0) {
214 TSerror(TS_R_SIGNATURE_FAILURE);
215 goto err;
216 }
217
218 /* Return the signer certificate if needed. */
219 if (signer_out) {
220 *signer_out = signer;
221 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509);
222 }
223
224 ret = 1;
225
226 err:
227 BIO_free_all(p7bio);
228 sk_X509_pop_free(chain, X509_free);
229 sk_X509_free(signers);
230
231 return ret;
232 }
233
234 /*
235 * The certificate chain is returned in chain. Caller is responsible for
236 * freeing the vector.
237 */
238 static int
TS_verify_cert(X509_STORE * store,STACK_OF (X509)* untrusted,X509 * signer,STACK_OF (X509)** chain)239 TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, X509 *signer,
240 STACK_OF(X509) **chain)
241 {
242 X509_STORE_CTX cert_ctx;
243 int i;
244 int ret = 0;
245
246 /* chain is an out argument. */
247 *chain = NULL;
248 if (X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted) == 0) {
249 TSerror(ERR_R_X509_LIB);
250 goto err;
251 }
252 if (X509_STORE_CTX_set_purpose(&cert_ctx,
253 X509_PURPOSE_TIMESTAMP_SIGN) == 0)
254 goto err;
255 i = X509_verify_cert(&cert_ctx);
256 if (i <= 0) {
257 int j = X509_STORE_CTX_get_error(&cert_ctx);
258
259 TSerror(TS_R_CERTIFICATE_VERIFY_ERROR);
260 ERR_asprintf_error_data("Verify error:%s",
261 X509_verify_cert_error_string(j));
262 goto err;
263 } else {
264 /* Get a copy of the certificate chain. */
265 *chain = X509_STORE_CTX_get1_chain(&cert_ctx);
266 ret = 1;
267 }
268
269 err:
270 X509_STORE_CTX_cleanup(&cert_ctx);
271
272 return ret;
273 }
274
275 static int
TS_check_signing_certs(PKCS7_SIGNER_INFO * si,STACK_OF (X509)* chain)276 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain)
277 {
278 ESS_SIGNING_CERT *ss = NULL;
279 STACK_OF(ESS_CERT_ID) *cert_ids;
280 ESS_SIGNING_CERT_V2 *ssv2 = NULL;
281 STACK_OF(ESS_CERT_ID_V2) *cert_ids_v2;
282 X509 *cert;
283 int i = 0;
284 int ret = 0;
285
286 if ((ss = ESS_get_signing_cert(si)) != NULL) {
287 cert_ids = ss->cert_ids;
288 /* The signer certificate must be the first in cert_ids. */
289 cert = sk_X509_value(chain, 0);
290
291 if (TS_find_cert(cert_ids, cert) != 0)
292 goto err;
293
294 /*
295 * Check the other certificates of the chain if there are more
296 * than one certificate ids in cert_ids.
297 */
298 if (sk_ESS_CERT_ID_num(cert_ids) > 1) {
299 /* All the certificates of the chain must be in cert_ids. */
300 for (i = 1; i < sk_X509_num(chain); i++) {
301 cert = sk_X509_value(chain, i);
302
303 if (TS_find_cert(cert_ids, cert) < 0)
304 goto err;
305 }
306 }
307 }
308
309 if ((ssv2 = ESS_get_signing_cert_v2(si)) != NULL) {
310 cert_ids_v2 = ssv2->cert_ids;
311 /* The signer certificate must be the first in cert_ids_v2. */
312 cert = sk_X509_value(chain, 0);
313
314 if (TS_find_cert_v2(cert_ids_v2, cert) != 0)
315 goto err;
316
317 /*
318 * Check the other certificates of the chain if there are more
319 * than one certificate ids in cert_ids_v2.
320 */
321 if (sk_ESS_CERT_ID_V2_num(cert_ids_v2) > 1) {
322 /* All the certificates of the chain must be in cert_ids_v2. */
323 for (i = 1; i < sk_X509_num(chain); i++) {
324 cert = sk_X509_value(chain, i);
325
326 if (TS_find_cert_v2(cert_ids_v2, cert) < 0)
327 goto err;
328 }
329 }
330 }
331
332 ret = 1;
333
334 err:
335 if (!ret)
336 TSerror(TS_R_ESS_SIGNING_CERTIFICATE_ERROR);
337 ESS_SIGNING_CERT_free(ss);
338 ESS_SIGNING_CERT_V2_free(ssv2);
339 return ret;
340 }
341
342 static ESS_SIGNING_CERT *
ESS_get_signing_cert(PKCS7_SIGNER_INFO * si)343 ESS_get_signing_cert(PKCS7_SIGNER_INFO *si)
344 {
345 ASN1_TYPE *attr;
346 const unsigned char *p;
347
348 attr = PKCS7_get_signed_attribute(si,
349 NID_id_smime_aa_signingCertificate);
350 if (!attr)
351 return NULL;
352 if (attr->type != V_ASN1_SEQUENCE)
353 return NULL;
354 p = attr->value.sequence->data;
355 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length);
356 }
357
358 static ESS_SIGNING_CERT_V2 *
ESS_get_signing_cert_v2(PKCS7_SIGNER_INFO * si)359 ESS_get_signing_cert_v2(PKCS7_SIGNER_INFO *si)
360 {
361 ASN1_TYPE *attr;
362 const unsigned char *p;
363
364 attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificateV2);
365 if (attr == NULL)
366 return NULL;
367 p = attr->value.sequence->data;
368 return d2i_ESS_SIGNING_CERT_V2(NULL, &p, attr->value.sequence->length);
369 }
370
371 /* Returns < 0 if certificate is not found, certificate index otherwise. */
372 static int
TS_find_cert(STACK_OF (ESS_CERT_ID)* cert_ids,X509 * cert)373 TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert)
374 {
375 int i;
376 unsigned char cert_hash[TS_HASH_LEN];
377
378 if (!cert_ids || !cert)
379 return -1;
380
381 if (!X509_digest(cert, TS_HASH_EVP, cert_hash, NULL))
382 return -1;
383
384 /* Recompute SHA1 hash of certificate if necessary (side effect). */
385 if (X509_check_purpose(cert, -1, 0) == -1)
386 return -1;
387
388 /* Look for cert in the cert_ids vector. */
389 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) {
390 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i);
391
392 /* Check the SHA-1 hash first. */
393 if (cid->hash->length == TS_HASH_LEN && !memcmp(cid->hash->data,
394 cert_hash, TS_HASH_LEN)) {
395 /* Check the issuer/serial as well if specified. */
396 ESS_ISSUER_SERIAL *is = cid->issuer_serial;
397
398 if (is == NULL || TS_issuer_serial_cmp(is, cert) == 0)
399 return i;
400 }
401 }
402
403 return -1;
404 }
405
406 /* Returns < 0 if certificate is not found, certificate index otherwise. */
407 static int
TS_find_cert_v2(STACK_OF (ESS_CERT_ID_V2)* cert_ids,X509 * cert)408 TS_find_cert_v2(STACK_OF(ESS_CERT_ID_V2) *cert_ids, X509 *cert)
409 {
410 int i;
411 unsigned char cert_digest[EVP_MAX_MD_SIZE];
412 unsigned int len;
413
414 /* Look for cert in the cert_ids vector. */
415 for (i = 0; i < sk_ESS_CERT_ID_V2_num(cert_ids); ++i) {
416 ESS_CERT_ID_V2 *cid = sk_ESS_CERT_ID_V2_value(cert_ids, i);
417 const EVP_MD *md = EVP_sha256();
418
419 if (cid->hash_alg != NULL)
420 md = EVP_get_digestbyobj(cid->hash_alg->algorithm);
421 if (md == NULL)
422 return -1;
423
424 if (!X509_digest(cert, md, cert_digest, &len))
425 return -1;
426
427 if ((unsigned int)cid->hash->length != len)
428 return -1;
429
430 if (memcmp(cid->hash->data, cert_digest, cid->hash->length) == 0) {
431 ESS_ISSUER_SERIAL *is = cid->issuer_serial;
432
433 if (is == NULL || TS_issuer_serial_cmp(is, cert) == 0)
434 return i;
435 }
436 }
437
438 return -1;
439 }
440
441 static int
TS_issuer_serial_cmp(ESS_ISSUER_SERIAL * is,X509 * cert)442 TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert)
443 {
444 GENERAL_NAME *issuer;
445
446 if (is == NULL || cert == NULL || sk_GENERAL_NAME_num(is->issuer) != 1)
447 return -1;
448
449 /* Check the issuer first. It must be a directory name. */
450 issuer = sk_GENERAL_NAME_value(is->issuer, 0);
451 if (issuer->type != GEN_DIRNAME ||
452 X509_NAME_cmp(issuer->d.dirn, X509_get_issuer_name(cert)))
453 return -1;
454
455 /* Check the serial number, too. */
456 if (ASN1_INTEGER_cmp(is->serial, X509_get_serialNumber(cert)))
457 return -1;
458
459 return 0;
460 }
461
462 /*
463 * Verifies whether 'response' contains a valid response with regards
464 * to the settings of the context:
465 * - Gives an error message if the TS_TST_INFO is not present.
466 * - Calls _TS_RESP_verify_token to verify the token content.
467 */
468 int
TS_RESP_verify_response(TS_VERIFY_CTX * ctx,TS_RESP * response)469 TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response)
470 {
471 PKCS7 *token = TS_RESP_get_token(response);
472 TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response);
473 int ret = 0;
474
475 /* Check if we have a successful TS_TST_INFO object in place. */
476 if (!TS_check_status_info(response))
477 goto err;
478
479 /* Check the contents of the time stamp token. */
480 if (!int_TS_RESP_verify_token(ctx, token, tst_info))
481 goto err;
482
483 ret = 1;
484
485 err:
486 return ret;
487 }
488
489 /*
490 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and
491 * calls the internal int_TS_RESP_verify_token function for verifying it.
492 */
493 int
TS_RESP_verify_token(TS_VERIFY_CTX * ctx,PKCS7 * token)494 TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token)
495 {
496 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token);
497 int ret = 0;
498
499 if (tst_info) {
500 ret = int_TS_RESP_verify_token(ctx, token, tst_info);
501 TS_TST_INFO_free(tst_info);
502 }
503 return ret;
504 }
505
506 /*
507 * Verifies whether the 'token' contains a valid time stamp token
508 * with regards to the settings of the context. Only those checks are
509 * carried out that are specified in the context:
510 * - Verifies the signature of the TS_TST_INFO.
511 * - Checks the version number of the response.
512 * - Check if the requested and returned policies math.
513 * - Check if the message imprints are the same.
514 * - Check if the nonces are the same.
515 * - Check if the TSA name matches the signer.
516 * - Check if the TSA name is the expected TSA.
517 */
518 static int
int_TS_RESP_verify_token(TS_VERIFY_CTX * ctx,PKCS7 * token,TS_TST_INFO * tst_info)519 int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token,
520 TS_TST_INFO *tst_info)
521 {
522 X509 *signer = NULL;
523 GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info);
524 X509_ALGOR *md_alg = NULL;
525 unsigned char *imprint = NULL;
526 unsigned imprint_len = 0;
527 int ret = 0;
528
529 /* Verify the signature. */
530 if ((ctx->flags & TS_VFY_SIGNATURE) &&
531 !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer))
532 goto err;
533
534 /* Check version number of response. */
535 if ((ctx->flags & TS_VFY_VERSION) &&
536 TS_TST_INFO_get_version(tst_info) != 1) {
537 TSerror(TS_R_UNSUPPORTED_VERSION);
538 goto err;
539 }
540
541 /* Check policies. */
542 if ((ctx->flags & TS_VFY_POLICY) &&
543 !TS_check_policy(ctx->policy, tst_info))
544 goto err;
545
546 /* Check message imprints. */
547 if ((ctx->flags & TS_VFY_IMPRINT) &&
548 !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len,
549 tst_info))
550 goto err;
551
552 /* Compute and check message imprints. */
553 if ((ctx->flags & TS_VFY_DATA) &&
554 (!TS_compute_imprint(ctx->data, tst_info,
555 &md_alg, &imprint, &imprint_len) ||
556 !TS_check_imprints(md_alg, imprint, imprint_len, tst_info)))
557 goto err;
558
559 /* Check nonces. */
560 if ((ctx->flags & TS_VFY_NONCE) &&
561 !TS_check_nonces(ctx->nonce, tst_info))
562 goto err;
563
564 /* Check whether TSA name and signer certificate match. */
565 if ((ctx->flags & TS_VFY_SIGNER) &&
566 tsa_name && !TS_check_signer_name(tsa_name, signer)) {
567 TSerror(TS_R_TSA_NAME_MISMATCH);
568 goto err;
569 }
570
571 /* Check whether the TSA is the expected one. */
572 if ((ctx->flags & TS_VFY_TSA_NAME) &&
573 !TS_check_signer_name(ctx->tsa_name, signer)) {
574 TSerror(TS_R_TSA_UNTRUSTED);
575 goto err;
576 }
577
578 ret = 1;
579
580 err:
581 X509_free(signer);
582 X509_ALGOR_free(md_alg);
583 free(imprint);
584 return ret;
585 }
586
587 static int
TS_check_status_info(TS_RESP * response)588 TS_check_status_info(TS_RESP *response)
589 {
590 TS_STATUS_INFO *info = TS_RESP_get_status_info(response);
591 long status = ASN1_INTEGER_get(info->status);
592 const char *status_text = NULL;
593 char *embedded_status_text = NULL;
594 char failure_text[TS_STATUS_BUF_SIZE] = "";
595
596 /* Check if everything went fine. */
597 if (status == 0 || status == 1)
598 return 1;
599
600 /* There was an error, get the description in status_text. */
601 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE)
602 status_text = TS_status_text[status];
603 else
604 status_text = "unknown code";
605
606 /* Set the embedded_status_text to the returned description. */
607 if (sk_ASN1_UTF8STRING_num(info->text) > 0 &&
608 !(embedded_status_text = TS_get_status_text(info->text)))
609 return 0;
610
611 /* Filling in failure_text with the failure information. */
612 if (info->failure_info) {
613 int i;
614 int first = 1;
615 for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i) {
616 if (ASN1_BIT_STRING_get_bit(info->failure_info,
617 TS_failure_info[i].code)) {
618 if (!first)
619 strlcat(failure_text, ",",
620 TS_STATUS_BUF_SIZE);
621 else
622 first = 0;
623 strlcat(failure_text, TS_failure_info[i].text,
624 TS_STATUS_BUF_SIZE);
625 }
626 }
627 }
628 if (failure_text[0] == '\0')
629 strlcpy(failure_text, "unspecified", TS_STATUS_BUF_SIZE);
630
631 /* Making up the error string. */
632 TSerror(TS_R_NO_TIME_STAMP_TOKEN);
633 ERR_asprintf_error_data
634 ("status code: %s, status text: %s, failure codes: %s",
635 status_text,
636 embedded_status_text ? embedded_status_text : "unspecified",
637 failure_text);
638 free(embedded_status_text);
639
640 return 0;
641 }
642
643 static char *
TS_get_status_text(STACK_OF (ASN1_UTF8STRING)* text)644 TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text)
645 {
646 int i;
647 unsigned int length = 0;
648 char *result = NULL;
649
650 /* Determine length first. */
651 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) {
652 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
653 length += ASN1_STRING_length(current);
654 length += 1; /* separator character */
655 }
656 /* Allocate memory (closing '\0' included). */
657 if (!(result = malloc(length))) {
658 TSerror(ERR_R_MALLOC_FAILURE);
659 return NULL;
660 }
661 /* Concatenate the descriptions. */
662 result[0] = '\0';
663 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) {
664 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
665 if (i > 0)
666 strlcat(result, "/", length);
667 strlcat(result, (const char *)ASN1_STRING_data(current), length);
668 }
669 return result;
670 }
671
672 static int
TS_check_policy(ASN1_OBJECT * req_oid,TS_TST_INFO * tst_info)673 TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info)
674 {
675 ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info);
676
677 if (OBJ_cmp(req_oid, resp_oid) != 0) {
678 TSerror(TS_R_POLICY_MISMATCH);
679 return 0;
680 }
681
682 return 1;
683 }
684
685 static int
TS_compute_imprint(BIO * data,TS_TST_INFO * tst_info,X509_ALGOR ** out_md_alg,unsigned char ** out_imprint,unsigned int * out_imprint_len)686 TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **out_md_alg,
687 unsigned char **out_imprint, unsigned int *out_imprint_len)
688 {
689 TS_MSG_IMPRINT *msg_imprint;
690 X509_ALGOR *md_alg_resp;
691 X509_ALGOR *md_alg = NULL;
692 unsigned char *imprint = NULL;
693 unsigned int imprint_len = 0;
694 const EVP_MD *md;
695 EVP_MD_CTX md_ctx;
696 unsigned char buffer[4096];
697 int length;
698
699 *out_md_alg = NULL;
700 *out_imprint = NULL;
701 *out_imprint_len = 0;
702
703 /* Retrieve the MD algorithm of the response. */
704 msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info);
705 md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint);
706 if ((md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL)
707 goto err;
708
709 /* Getting the MD object. */
710 if ((md = EVP_get_digestbyobj((md_alg)->algorithm)) == NULL) {
711 TSerror(TS_R_UNSUPPORTED_MD_ALGORITHM);
712 goto err;
713 }
714
715 /* Compute message digest. */
716 if ((length = EVP_MD_size(md)) < 0)
717 goto err;
718 imprint_len = length;
719 if ((imprint = malloc(imprint_len)) == NULL) {
720 TSerror(ERR_R_MALLOC_FAILURE);
721 goto err;
722 }
723
724 if (!EVP_DigestInit(&md_ctx, md))
725 goto err;
726 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) {
727 if (!EVP_DigestUpdate(&md_ctx, buffer, length))
728 goto err;
729 }
730 if (!EVP_DigestFinal(&md_ctx, imprint, NULL))
731 goto err;
732
733 *out_md_alg = md_alg;
734 md_alg = NULL;
735 *out_imprint = imprint;
736 imprint = NULL;
737 *out_imprint_len = imprint_len;
738
739 return 1;
740
741 err:
742 X509_ALGOR_free(md_alg);
743 free(imprint);
744 return 0;
745 }
746
747 static int
TS_check_imprints(X509_ALGOR * algor_a,unsigned char * imprint_a,unsigned len_a,TS_TST_INFO * tst_info)748 TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a,
749 TS_TST_INFO *tst_info)
750 {
751 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info);
752 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b);
753 int ret = 0;
754
755 /* algor_a is optional. */
756 if (algor_a) {
757 /* Compare algorithm OIDs. */
758 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm))
759 goto err;
760
761 /* The parameter must be NULL in both. */
762 if ((algor_a->parameter &&
763 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) ||
764 (algor_b->parameter &&
765 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL))
766 goto err;
767 }
768
769 /* Compare octet strings. */
770 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) &&
771 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0;
772
773 err:
774 if (!ret)
775 TSerror(TS_R_MESSAGE_IMPRINT_MISMATCH);
776 return ret;
777 }
778
779 static int
TS_check_nonces(const ASN1_INTEGER * a,TS_TST_INFO * tst_info)780 TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info)
781 {
782 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info);
783
784 /* Error if nonce is missing. */
785 if (!b) {
786 TSerror(TS_R_NONCE_NOT_RETURNED);
787 return 0;
788 }
789
790 /* No error if a nonce is returned without being requested. */
791 if (ASN1_INTEGER_cmp(a, b) != 0) {
792 TSerror(TS_R_NONCE_MISMATCH);
793 return 0;
794 }
795
796 return 1;
797 }
798
799 /* Check if the specified TSA name matches either the subject
800 or one of the subject alternative names of the TSA certificate. */
801 static int
TS_check_signer_name(GENERAL_NAME * tsa_name,X509 * signer)802 TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer)
803 {
804 STACK_OF(GENERAL_NAME) *gen_names = NULL;
805 int idx = -1;
806 int found = 0;
807
808 if (signer == NULL)
809 return 0;
810
811 /* Check the subject name first. */
812 if (tsa_name->type == GEN_DIRNAME &&
813 X509_name_cmp(tsa_name->d.dirn, X509_get_subject_name(signer)) == 0)
814 return 1;
815
816 /* Check all the alternative names. */
817 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
818 NULL, &idx);
819 while (gen_names != NULL &&
820 !(found = (TS_find_name(gen_names, tsa_name) >= 0))) {
821 /* Get the next subject alternative name,
822 although there should be no more than one. */
823 GENERAL_NAMES_free(gen_names);
824 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
825 NULL, &idx);
826 }
827 if (gen_names)
828 GENERAL_NAMES_free(gen_names);
829
830 return found;
831 }
832
833 /* Returns 1 if name is in gen_names, 0 otherwise. */
834 static int
TS_find_name(STACK_OF (GENERAL_NAME)* gen_names,GENERAL_NAME * name)835 TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name)
836 {
837 int i, found;
838 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names);
839 ++i) {
840 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i);
841 found = GENERAL_NAME_cmp(current, name) == 0;
842 }
843 return found ? i - 1 : -1;
844 }
845