1 /* crypto/ts/ts_resp_verify.c */
3 * Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL project
6 /* ====================================================================
7 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * licensing@OpenSSL.org.
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
61 #include "internal/cryptlib.h"
62 #include <openssl/objects.h>
63 #include <openssl/ts.h>
64 #include <openssl/pkcs7.h>
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,
70 STACK_OF(X509) *chain);
71 static ESS_SIGNING_CERT *ess_get_signing_cert(PKCS7_SIGNER_INFO *si);
72 static int ts_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert);
73 static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert);
74 static int int_ts_RESP_verify_token(TS_VERIFY_CTX *ctx,
75 PKCS7 *token, TS_TST_INFO *tst_info);
76 static int ts_check_status_info(TS_RESP *response);
77 static char *ts_get_status_text(STACK_OF(ASN1_UTF8STRING) *text);
78 static int ts_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info);
79 static int ts_compute_imprint(BIO *data, TS_TST_INFO *tst_info,
81 unsigned char **imprint, unsigned *imprint_len);
82 static int ts_check_imprints(X509_ALGOR *algor_a,
83 unsigned char *imprint_a, unsigned len_a,
84 TS_TST_INFO *tst_info);
85 static int ts_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info);
86 static int ts_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer);
87 static int ts_find_name(STACK_OF(GENERAL_NAME) *gen_names,
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.
95 static const char *ts_status_text[] = { "granted",
100 "revocationNotification"
103 #define TS_STATUS_TEXT_SIZE OSSL_NELEM(ts_status_text)
106 * This must be greater or equal to the sum of the strings in TS_status_text
107 * plus the number of its elements.
109 #define TS_STATUS_BUF_SIZE 256
114 } ts_failure_info[] = {
115 {TS_INFO_BAD_ALG, "badAlg"},
116 {TS_INFO_BAD_REQUEST, "badRequest"},
117 {TS_INFO_BAD_DATA_FORMAT, "badDataFormat"},
118 {TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable"},
119 {TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy"},
120 {TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension"},
121 {TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable"},
122 {TS_INFO_SYSTEM_FAILURE, "systemFailure"}
125 #define TS_FAILURE_INFO_SIZE OSSL_NELEM(ts_failure_info)
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.
140 int TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs,
141 X509_STORE *store, X509 **signer_out)
143 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL;
144 PKCS7_SIGNER_INFO *si;
145 STACK_OF(X509) *signers = NULL;
147 STACK_OF(X509) *chain = NULL;
149 int i, j = 0, ret = 0;
152 /* Some sanity checks first. */
154 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_INVALID_NULL_POINTER);
157 if (!PKCS7_type_is_signed(token)) {
158 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_WRONG_CONTENT_TYPE);
161 sinfos = PKCS7_get_signer_info(token);
162 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) {
163 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_THERE_MUST_BE_ONE_SIGNER);
166 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0);
167 if (PKCS7_get_detached(token)) {
168 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_NO_CONTENT);
173 * Get hold of the signer certificate, search only internal certificates
174 * if it was requested.
176 signers = PKCS7_get0_signers(token, certs, 0);
177 if (!signers || sk_X509_num(signers) != 1)
179 signer = sk_X509_value(signers, 0);
181 if (!ts_verify_cert(store, certs, signer, &chain))
183 if (!ts_check_signing_certs(si, chain))
185 p7bio = PKCS7_dataInit(token, NULL);
187 /* We now have to 'read' from p7bio to calculate digests etc. */
188 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0)
191 j = PKCS7_signatureVerify(p7bio, token, si, signer);
193 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_SIGNATURE_FAILURE);
198 *signer_out = signer;
205 sk_X509_pop_free(chain, X509_free);
206 sk_X509_free(signers);
212 * The certificate chain is returned in chain. Caller is responsible for
213 * freeing the vector.
215 static int ts_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted,
216 X509 *signer, STACK_OF(X509) **chain)
218 X509_STORE_CTX cert_ctx;
223 X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted);
224 X509_STORE_CTX_set_purpose(&cert_ctx, X509_PURPOSE_TIMESTAMP_SIGN);
225 i = X509_verify_cert(&cert_ctx);
227 int j = X509_STORE_CTX_get_error(&cert_ctx);
228 TSerr(TS_F_TS_VERIFY_CERT, TS_R_CERTIFICATE_VERIFY_ERROR);
229 ERR_add_error_data(2, "Verify error:",
230 X509_verify_cert_error_string(j));
233 *chain = X509_STORE_CTX_get1_chain(&cert_ctx);
236 X509_STORE_CTX_cleanup(&cert_ctx);
241 static int ts_check_signing_certs(PKCS7_SIGNER_INFO *si,
242 STACK_OF(X509) *chain)
244 ESS_SIGNING_CERT *ss = ess_get_signing_cert(si);
245 STACK_OF(ESS_CERT_ID) *cert_ids = NULL;
252 cert_ids = ss->cert_ids;
253 cert = sk_X509_value(chain, 0);
254 if (ts_find_cert(cert_ids, cert) != 0)
258 * Check the other certificates of the chain if there are more than one
259 * certificate ids in cert_ids.
261 if (sk_ESS_CERT_ID_num(cert_ids) > 1) {
262 for (i = 1; i < sk_X509_num(chain); ++i) {
263 cert = sk_X509_value(chain, i);
264 if (ts_find_cert(cert_ids, cert) < 0)
271 TSerr(TS_F_TS_CHECK_SIGNING_CERTS,
272 TS_R_ESS_SIGNING_CERTIFICATE_ERROR);
273 ESS_SIGNING_CERT_free(ss);
277 static ESS_SIGNING_CERT *ess_get_signing_cert(PKCS7_SIGNER_INFO *si)
280 const unsigned char *p;
281 attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificate);
284 p = attr->value.sequence->data;
285 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length);
288 /* Returns < 0 if certificate is not found, certificate index otherwise. */
289 static int ts_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert)
292 unsigned char cert_sha1[SHA_DIGEST_LENGTH];
294 if (!cert_ids || !cert)
297 X509_digest(cert, EVP_sha1(), cert_sha1, NULL);
299 /* Recompute SHA1 hash of certificate if necessary (side effect). */
300 X509_check_purpose(cert, -1, 0);
302 /* Look for cert in the cert_ids vector. */
303 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) {
304 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i);
306 if (cid->hash->length == SHA_DIGEST_LENGTH
307 && memcmp(cid->hash->data, cert_sha1, SHA_DIGEST_LENGTH) == 0) {
308 ESS_ISSUER_SERIAL *is = cid->issuer_serial;
309 if (!is || !ts_issuer_serial_cmp(is, cert))
317 static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert)
319 GENERAL_NAME *issuer;
321 if (!is || !cert || sk_GENERAL_NAME_num(is->issuer) != 1)
324 issuer = sk_GENERAL_NAME_value(is->issuer, 0);
325 if (issuer->type != GEN_DIRNAME
326 || X509_NAME_cmp(issuer->d.dirn, X509_get_issuer_name(cert)))
329 if (ASN1_INTEGER_cmp(is->serial, X509_get_serialNumber(cert)))
336 * Verifies whether 'response' contains a valid response with regards
337 * to the settings of the context:
338 * - Gives an error message if the TS_TST_INFO is not present.
339 * - Calls _TS_RESP_verify_token to verify the token content.
341 int TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response)
343 PKCS7 *token = response->token;
344 TS_TST_INFO *tst_info = response->tst_info;
347 if (!ts_check_status_info(response))
349 if (!int_ts_RESP_verify_token(ctx, token, tst_info))
358 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and
359 * calls the internal int_TS_RESP_verify_token function for verifying it.
361 int TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token)
363 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token);
366 ret = int_ts_RESP_verify_token(ctx, token, tst_info);
367 TS_TST_INFO_free(tst_info);
373 * Verifies whether the 'token' contains a valid time stamp token
374 * with regards to the settings of the context. Only those checks are
375 * carried out that are specified in the context:
376 * - Verifies the signature of the TS_TST_INFO.
377 * - Checks the version number of the response.
378 * - Check if the requested and returned policies math.
379 * - Check if the message imprints are the same.
380 * - Check if the nonces are the same.
381 * - Check if the TSA name matches the signer.
382 * - Check if the TSA name is the expected TSA.
384 static int int_ts_RESP_verify_token(TS_VERIFY_CTX *ctx,
385 PKCS7 *token, TS_TST_INFO *tst_info)
388 GENERAL_NAME *tsa_name = tst_info->tsa;
389 X509_ALGOR *md_alg = NULL;
390 unsigned char *imprint = NULL;
391 unsigned imprint_len = 0;
394 if ((ctx->flags & TS_VFY_SIGNATURE)
395 && !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer))
397 if ((ctx->flags & TS_VFY_VERSION)
398 && TS_TST_INFO_get_version(tst_info) != 1) {
399 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_UNSUPPORTED_VERSION);
402 if ((ctx->flags & TS_VFY_POLICY)
403 && !ts_check_policy(ctx->policy, tst_info))
405 if ((ctx->flags & TS_VFY_IMPRINT)
406 && !ts_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len,
409 if ((ctx->flags & TS_VFY_DATA)
410 && (!ts_compute_imprint(ctx->data, tst_info,
411 &md_alg, &imprint, &imprint_len)
412 || !ts_check_imprints(md_alg, imprint, imprint_len, tst_info)))
414 if ((ctx->flags & TS_VFY_NONCE)
415 && !ts_check_nonces(ctx->nonce, tst_info))
417 if ((ctx->flags & TS_VFY_SIGNER)
418 && tsa_name && !ts_check_signer_name(tsa_name, signer)) {
419 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_NAME_MISMATCH);
422 if ((ctx->flags & TS_VFY_TSA_NAME)
423 && !ts_check_signer_name(ctx->tsa_name, signer)) {
424 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_UNTRUSTED);
431 X509_ALGOR_free(md_alg);
432 OPENSSL_free(imprint);
436 static int ts_check_status_info(TS_RESP *response)
438 TS_STATUS_INFO *info = response->status_info;
439 long status = ASN1_INTEGER_get(info->status);
440 const char *status_text = NULL;
441 char *embedded_status_text = NULL;
442 char failure_text[TS_STATUS_BUF_SIZE] = "";
444 if (status == 0 || status == 1)
447 /* There was an error, get the description in status_text. */
448 if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE)
449 status_text = ts_status_text[status];
451 status_text = "unknown code";
453 if (sk_ASN1_UTF8STRING_num(info->text) > 0
454 && (embedded_status_text = ts_get_status_text(info->text)) == NULL)
457 /* Fill in failure_text with the failure information. */
458 if (info->failure_info) {
461 for (i = 0; i < (int)OSSL_NELEM(ts_failure_info); ++i) {
462 if (ASN1_BIT_STRING_get_bit(info->failure_info,
463 ts_failure_info[i].code)) {
465 strcpy(failure_text, ",");
468 strcat(failure_text, ts_failure_info[i].text);
472 if (failure_text[0] == '\0')
473 strcpy(failure_text, "unspecified");
475 TSerr(TS_F_TS_CHECK_STATUS_INFO, TS_R_NO_TIME_STAMP_TOKEN);
476 ERR_add_error_data(6,
477 "status code: ", status_text,
478 ", status text: ", embedded_status_text ?
479 embedded_status_text : "unspecified",
480 ", failure codes: ", failure_text);
481 OPENSSL_free(embedded_status_text);
486 static char *ts_get_status_text(STACK_OF(ASN1_UTF8STRING) *text)
489 unsigned int length = 0;
493 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) {
494 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
495 length += ASN1_STRING_length(current);
496 length += 1; /* separator character */
498 if ((result = OPENSSL_malloc(length)) == NULL) {
499 TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE);
503 for (i = 0, p = result; i < sk_ASN1_UTF8STRING_num(text); ++i) {
504 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
505 length = ASN1_STRING_length(current);
508 strncpy(p, (const char *)ASN1_STRING_data(current), length);
516 static int ts_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info)
518 ASN1_OBJECT *resp_oid = tst_info->policy_id;
520 if (OBJ_cmp(req_oid, resp_oid) != 0) {
521 TSerr(TS_F_TS_CHECK_POLICY, TS_R_POLICY_MISMATCH);
528 static int ts_compute_imprint(BIO *data, TS_TST_INFO *tst_info,
530 unsigned char **imprint, unsigned *imprint_len)
532 TS_MSG_IMPRINT *msg_imprint = tst_info->msg_imprint;
533 X509_ALGOR *md_alg_resp = msg_imprint->hash_algo;
536 unsigned char buffer[4096];
542 if ((*md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL)
544 if ((md = EVP_get_digestbyobj((*md_alg)->algorithm)) == NULL) {
545 TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM);
548 length = EVP_MD_size(md);
551 *imprint_len = length;
552 if ((*imprint = OPENSSL_malloc(*imprint_len)) == NULL) {
553 TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE);
557 if (!EVP_DigestInit(&md_ctx, md))
559 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) {
560 if (!EVP_DigestUpdate(&md_ctx, buffer, length))
563 if (!EVP_DigestFinal(&md_ctx, *imprint, NULL))
568 X509_ALGOR_free(*md_alg);
569 OPENSSL_free(*imprint);
575 static int ts_check_imprints(X509_ALGOR *algor_a,
576 unsigned char *imprint_a, unsigned len_a,
577 TS_TST_INFO *tst_info)
579 TS_MSG_IMPRINT *b = tst_info->msg_imprint;
580 X509_ALGOR *algor_b = b->hash_algo;
584 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm))
587 /* The parameter must be NULL in both. */
588 if ((algor_a->parameter
589 && ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL)
590 || (algor_b->parameter
591 && ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL))
595 ret = len_a == (unsigned)ASN1_STRING_length(b->hashed_msg) &&
596 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0;
599 TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH);
603 static int ts_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info)
605 const ASN1_INTEGER *b = tst_info->nonce;
608 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED);
612 /* No error if a nonce is returned without being requested. */
613 if (ASN1_INTEGER_cmp(a, b) != 0) {
614 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH);
622 * Check if the specified TSA name matches either the subject or one of the
623 * subject alternative names of the TSA certificate.
625 static int ts_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer)
627 STACK_OF(GENERAL_NAME) *gen_names = NULL;
631 if (tsa_name->type == GEN_DIRNAME
632 && X509_name_cmp(tsa_name->d.dirn, X509_get_subject_name(signer)) == 0)
634 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, NULL, &idx);
635 while (gen_names != NULL) {
636 found = ts_find_name(gen_names, tsa_name) >= 0;
640 * Get the next subject alternative name, although there should be no
643 GENERAL_NAMES_free(gen_names);
644 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, NULL, &idx);
646 GENERAL_NAMES_free(gen_names);
651 /* Returns 1 if name is in gen_names, 0 otherwise. */
652 static int ts_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name)
655 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); ++i) {
656 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i);
657 found = GENERAL_NAME_cmp(current, name) == 0;
659 return found ? i - 1 : -1;