1 /* $OpenBSD: ts_rsp_verify.c,v 1.21 2021/07/02 11:15:08 schwarze 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
TS_RESP_verify_signature(PKCS7 * token,STACK_OF (X509)* certs,X509_STORE * store,X509 ** signer_out)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 TSerror(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 TSerror(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 TSerror(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 TSerror(TS_R_NO_CONTENT);
179 goto err;
180 }
181
182 /* Get hold of the signer certificate, search only internal
183 certificates if it was requested. */
184 signers = PKCS7_get0_signers(token, certs, 0);
185 if (!signers || sk_X509_num(signers) != 1)
186 goto err;
187 signer = sk_X509_value(signers, 0);
188
189 /* Now verify the certificate. */
190 if (!TS_verify_cert(store, certs, signer, &chain))
191 goto err;
192
193 /* Check if the signer certificate is consistent with the
194 ESS extension. */
195 if (!TS_check_signing_certs(si, chain))
196 goto err;
197
198 /* Creating the message digest. */
199 p7bio = PKCS7_dataInit(token, NULL);
200
201 /* We now have to 'read' from p7bio to calculate digests etc. */
202 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0)
203 ;
204
205 /* Verifying the signature. */
206 j = PKCS7_signatureVerify(p7bio, token, si, signer);
207 if (j <= 0) {
208 TSerror(TS_R_SIGNATURE_FAILURE);
209 goto err;
210 }
211
212 /* Return the signer certificate if needed. */
213 if (signer_out) {
214 *signer_out = signer;
215 CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509);
216 }
217
218 ret = 1;
219
220 err:
221 BIO_free_all(p7bio);
222 sk_X509_pop_free(chain, X509_free);
223 sk_X509_free(signers);
224
225 return ret;
226 }
227
228 /*
229 * The certificate chain is returned in chain. Caller is responsible for
230 * freeing the vector.
231 */
232 static int
TS_verify_cert(X509_STORE * store,STACK_OF (X509)* untrusted,X509 * signer,STACK_OF (X509)** chain)233 TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted, X509 *signer,
234 STACK_OF(X509) **chain)
235 {
236 X509_STORE_CTX cert_ctx;
237 int i;
238 int ret = 0;
239
240 /* chain is an out argument. */
241 *chain = NULL;
242 if (X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted) == 0) {
243 TSerror(ERR_R_X509_LIB);
244 goto err;
245 }
246 if (X509_STORE_CTX_set_purpose(&cert_ctx,
247 X509_PURPOSE_TIMESTAMP_SIGN) == 0)
248 goto err;
249 i = X509_verify_cert(&cert_ctx);
250 if (i <= 0) {
251 int j = X509_STORE_CTX_get_error(&cert_ctx);
252
253 TSerror(TS_R_CERTIFICATE_VERIFY_ERROR);
254 ERR_asprintf_error_data("Verify error:%s",
255 X509_verify_cert_error_string(j));
256 goto err;
257 } else {
258 /* Get a copy of the certificate chain. */
259 *chain = X509_STORE_CTX_get1_chain(&cert_ctx);
260 ret = 1;
261 }
262
263 err:
264 X509_STORE_CTX_cleanup(&cert_ctx);
265
266 return ret;
267 }
268
269 static int
TS_check_signing_certs(PKCS7_SIGNER_INFO * si,STACK_OF (X509)* chain)270 TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain)
271 {
272 ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si);
273 STACK_OF(ESS_CERT_ID) *cert_ids = NULL;
274 X509 *cert;
275 int i = 0;
276 int ret = 0;
277
278 if (!ss)
279 goto err;
280 cert_ids = ss->cert_ids;
281 /* The signer certificate must be the first in cert_ids. */
282 cert = sk_X509_value(chain, 0);
283 if (TS_find_cert(cert_ids, cert) != 0)
284 goto err;
285
286 /* Check the other certificates of the chain if there are more
287 than one certificate ids in cert_ids. */
288 if (sk_ESS_CERT_ID_num(cert_ids) > 1) {
289 /* All the certificates of the chain must be in cert_ids. */
290 for (i = 1; i < sk_X509_num(chain); ++i) {
291 cert = sk_X509_value(chain, i);
292 if (TS_find_cert(cert_ids, cert) < 0)
293 goto err;
294 }
295 }
296 ret = 1;
297
298 err:
299 if (!ret)
300 TSerror(TS_R_ESS_SIGNING_CERTIFICATE_ERROR);
301 ESS_SIGNING_CERT_free(ss);
302 return ret;
303 }
304
305 static ESS_SIGNING_CERT *
ESS_get_signing_cert(PKCS7_SIGNER_INFO * si)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
TS_find_cert(STACK_OF (ESS_CERT_ID)* cert_ids,X509 * cert)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
TS_issuer_serial_cmp(ESS_ISSUER_SERIAL * is,X509_CINF * cinfo)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
TS_RESP_verify_response(TS_VERIFY_CTX * ctx,TS_RESP * response)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
TS_RESP_verify_token(TS_VERIFY_CTX * ctx,PKCS7 * token)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
int_TS_RESP_verify_token(TS_VERIFY_CTX * ctx,PKCS7 * token,TS_TST_INFO * tst_info)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 TSerror(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 TSerror(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 TSerror(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
TS_check_status_info(TS_RESP * response)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 TSerror(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 *
TS_get_status_text(STACK_OF (ASN1_UTF8STRING)* text)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 TSerror(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
TS_check_policy(ASN1_OBJECT * req_oid,TS_TST_INFO * tst_info)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 TSerror(TS_R_POLICY_MISMATCH);
589 return 0;
590 }
591
592 return 1;
593 }
594
595 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)596 TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info, X509_ALGOR **out_md_alg,
597 unsigned char **out_imprint, unsigned int *out_imprint_len)
598 {
599 TS_MSG_IMPRINT *msg_imprint;
600 X509_ALGOR *md_alg_resp;
601 X509_ALGOR *md_alg = NULL;
602 unsigned char *imprint = NULL;
603 unsigned int imprint_len = 0;
604 const EVP_MD *md;
605 EVP_MD_CTX md_ctx;
606 unsigned char buffer[4096];
607 int length;
608
609 *out_md_alg = NULL;
610 *out_imprint = NULL;
611 *out_imprint_len = 0;
612
613 /* Retrieve the MD algorithm of the response. */
614 msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info);
615 md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint);
616 if ((md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL)
617 goto err;
618
619 /* Getting the MD object. */
620 if ((md = EVP_get_digestbyobj((md_alg)->algorithm)) == NULL) {
621 TSerror(TS_R_UNSUPPORTED_MD_ALGORITHM);
622 goto err;
623 }
624
625 /* Compute message digest. */
626 if ((length = EVP_MD_size(md)) < 0)
627 goto err;
628 imprint_len = length;
629 if ((imprint = malloc(imprint_len)) == NULL) {
630 TSerror(ERR_R_MALLOC_FAILURE);
631 goto err;
632 }
633
634 if (!EVP_DigestInit(&md_ctx, md))
635 goto err;
636 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) {
637 if (!EVP_DigestUpdate(&md_ctx, buffer, length))
638 goto err;
639 }
640 if (!EVP_DigestFinal(&md_ctx, imprint, NULL))
641 goto err;
642
643 *out_md_alg = md_alg;
644 md_alg = NULL;
645 *out_imprint = imprint;
646 imprint = NULL;
647 *out_imprint_len = imprint_len;
648
649 return 1;
650
651 err:
652 X509_ALGOR_free(md_alg);
653 free(imprint);
654 return 0;
655 }
656
657 static int
TS_check_imprints(X509_ALGOR * algor_a,unsigned char * imprint_a,unsigned len_a,TS_TST_INFO * tst_info)658 TS_check_imprints(X509_ALGOR *algor_a, unsigned char *imprint_a, unsigned len_a,
659 TS_TST_INFO *tst_info)
660 {
661 TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info);
662 X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b);
663 int ret = 0;
664
665 /* algor_a is optional. */
666 if (algor_a) {
667 /* Compare algorithm OIDs. */
668 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm))
669 goto err;
670
671 /* The parameter must be NULL in both. */
672 if ((algor_a->parameter &&
673 ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL) ||
674 (algor_b->parameter &&
675 ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL))
676 goto err;
677 }
678
679 /* Compare octet strings. */
680 ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) &&
681 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0;
682
683 err:
684 if (!ret)
685 TSerror(TS_R_MESSAGE_IMPRINT_MISMATCH);
686 return ret;
687 }
688
689 static int
TS_check_nonces(const ASN1_INTEGER * a,TS_TST_INFO * tst_info)690 TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info)
691 {
692 const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info);
693
694 /* Error if nonce is missing. */
695 if (!b) {
696 TSerror(TS_R_NONCE_NOT_RETURNED);
697 return 0;
698 }
699
700 /* No error if a nonce is returned without being requested. */
701 if (ASN1_INTEGER_cmp(a, b) != 0) {
702 TSerror(TS_R_NONCE_MISMATCH);
703 return 0;
704 }
705
706 return 1;
707 }
708
709 /* Check if the specified TSA name matches either the subject
710 or one of the subject alternative names of the TSA certificate. */
711 static int
TS_check_signer_name(GENERAL_NAME * tsa_name,X509 * signer)712 TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer)
713 {
714 STACK_OF(GENERAL_NAME) *gen_names = NULL;
715 int idx = -1;
716 int found = 0;
717
718 if (signer == NULL)
719 return 0;
720
721 /* Check the subject name first. */
722 if (tsa_name->type == GEN_DIRNAME &&
723 X509_NAME_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0)
724 return 1;
725
726 /* Check all the alternative names. */
727 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
728 NULL, &idx);
729 while (gen_names != NULL &&
730 !(found = (TS_find_name(gen_names, tsa_name) >= 0))) {
731 /* Get the next subject alternative name,
732 although there should be no more than one. */
733 GENERAL_NAMES_free(gen_names);
734 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
735 NULL, &idx);
736 }
737 if (gen_names)
738 GENERAL_NAMES_free(gen_names);
739
740 return found;
741 }
742
743 /* Returns 1 if name is in gen_names, 0 otherwise. */
744 static int
TS_find_name(STACK_OF (GENERAL_NAME)* gen_names,GENERAL_NAME * name)745 TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name)
746 {
747 int i, found;
748 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names);
749 ++i) {
750 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i);
751 found = GENERAL_NAME_cmp(current, name) == 0;
752 }
753 return found ? i - 1 : -1;
754 }
755