2 * Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL project
5 /* ====================================================================
6 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
34 * 6. Redistributions of any form whatsoever must retain the following
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 * ====================================================================
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).
60 #include "internal/cryptlib.h"
61 #include <openssl/objects.h>
62 #include <openssl/ts.h>
63 #include <openssl/pkcs7.h>
66 static int ts_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted,
67 X509 *signer, STACK_OF(X509) **chain);
68 static int ts_check_signing_certs(PKCS7_SIGNER_INFO *si,
69 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 *cert);
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,
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,
90 * This must be large enough to hold all values in ts_status_text (with
91 * comma separator) or all text fields in ts_failure_info (also with comma).
93 #define TS_STATUS_BUF_SIZE 256
96 * Local mapping between response codes and descriptions.
98 static const char *ts_status_text[] = {
104 "revocationNotification"
107 #define TS_STATUS_TEXT_SIZE OSSL_NELEM(ts_status_text)
112 } ts_failure_info[] = {
113 {TS_INFO_BAD_ALG, "badAlg"},
114 {TS_INFO_BAD_REQUEST, "badRequest"},
115 {TS_INFO_BAD_DATA_FORMAT, "badDataFormat"},
116 {TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable"},
117 {TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy"},
118 {TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension"},
119 {TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable"},
120 {TS_INFO_SYSTEM_FAILURE, "systemFailure"}
125 * This function carries out the following tasks:
126 * - Checks if there is one and only one signer.
127 * - Search for the signing certificate in 'certs' and in the response.
128 * - Check the extended key usage and key usage fields of the signer
129 * certificate (done by the path validation).
130 * - Build and validate the certificate path.
131 * - Check if the certificate path meets the requirements of the
132 * SigningCertificate ESS signed attribute.
133 * - Verify the signature value.
134 * - Returns the signer certificate in 'signer', if 'signer' is not NULL.
136 int TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs,
137 X509_STORE *store, X509 **signer_out)
139 STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL;
140 PKCS7_SIGNER_INFO *si;
141 STACK_OF(X509) *signers = NULL;
143 STACK_OF(X509) *chain = NULL;
145 int i, j = 0, ret = 0;
148 /* Some sanity checks first. */
150 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_INVALID_NULL_POINTER);
153 if (!PKCS7_type_is_signed(token)) {
154 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_WRONG_CONTENT_TYPE);
157 sinfos = PKCS7_get_signer_info(token);
158 if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1) {
159 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_THERE_MUST_BE_ONE_SIGNER);
162 si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0);
163 if (PKCS7_get_detached(token)) {
164 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_NO_CONTENT);
169 * Get hold of the signer certificate, search only internal certificates
170 * if it was requested.
172 signers = PKCS7_get0_signers(token, certs, 0);
173 if (!signers || sk_X509_num(signers) != 1)
175 signer = sk_X509_value(signers, 0);
177 if (!ts_verify_cert(store, certs, signer, &chain))
179 if (!ts_check_signing_certs(si, chain))
181 p7bio = PKCS7_dataInit(token, NULL);
183 /* We now have to 'read' from p7bio to calculate digests etc. */
184 while ((i = BIO_read(p7bio, buf, sizeof(buf))) > 0)
187 j = PKCS7_signatureVerify(p7bio, token, si, signer);
189 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_SIGNATURE_FAILURE);
194 *signer_out = signer;
201 sk_X509_pop_free(chain, X509_free);
202 sk_X509_free(signers);
208 * The certificate chain is returned in chain. Caller is responsible for
209 * freeing the vector.
211 static int ts_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted,
212 X509 *signer, STACK_OF(X509) **chain)
214 X509_STORE_CTX cert_ctx;
219 if (!X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted))
221 X509_STORE_CTX_set_purpose(&cert_ctx, X509_PURPOSE_TIMESTAMP_SIGN);
222 i = X509_verify_cert(&cert_ctx);
224 int j = X509_STORE_CTX_get_error(&cert_ctx);
225 TSerr(TS_F_TS_VERIFY_CERT, TS_R_CERTIFICATE_VERIFY_ERROR);
226 ERR_add_error_data(2, "Verify error:",
227 X509_verify_cert_error_string(j));
230 *chain = X509_STORE_CTX_get1_chain(&cert_ctx);
233 X509_STORE_CTX_cleanup(&cert_ctx);
238 static int ts_check_signing_certs(PKCS7_SIGNER_INFO *si,
239 STACK_OF(X509) *chain)
241 ESS_SIGNING_CERT *ss = ess_get_signing_cert(si);
242 STACK_OF(ESS_CERT_ID) *cert_ids = NULL;
249 cert_ids = ss->cert_ids;
250 cert = sk_X509_value(chain, 0);
251 if (ts_find_cert(cert_ids, cert) != 0)
255 * Check the other certificates of the chain if there are more than one
256 * certificate ids in cert_ids.
258 if (sk_ESS_CERT_ID_num(cert_ids) > 1) {
259 for (i = 1; i < sk_X509_num(chain); ++i) {
260 cert = sk_X509_value(chain, i);
261 if (ts_find_cert(cert_ids, cert) < 0)
268 TSerr(TS_F_TS_CHECK_SIGNING_CERTS,
269 TS_R_ESS_SIGNING_CERTIFICATE_ERROR);
270 ESS_SIGNING_CERT_free(ss);
274 static ESS_SIGNING_CERT *ess_get_signing_cert(PKCS7_SIGNER_INFO *si)
277 const unsigned char *p;
278 attr = PKCS7_get_signed_attribute(si, NID_id_smime_aa_signingCertificate);
281 p = attr->value.sequence->data;
282 return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length);
285 /* Returns < 0 if certificate is not found, certificate index otherwise. */
286 static int ts_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert)
289 unsigned char cert_sha1[SHA_DIGEST_LENGTH];
291 if (!cert_ids || !cert)
294 X509_digest(cert, EVP_sha1(), cert_sha1, NULL);
296 /* Recompute SHA1 hash of certificate if necessary (side effect). */
297 X509_check_purpose(cert, -1, 0);
299 /* Look for cert in the cert_ids vector. */
300 for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i) {
301 ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i);
303 if (cid->hash->length == SHA_DIGEST_LENGTH
304 && memcmp(cid->hash->data, cert_sha1, SHA_DIGEST_LENGTH) == 0) {
305 ESS_ISSUER_SERIAL *is = cid->issuer_serial;
306 if (!is || !ts_issuer_serial_cmp(is, cert))
314 static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert)
316 GENERAL_NAME *issuer;
318 if (!is || !cert || sk_GENERAL_NAME_num(is->issuer) != 1)
321 issuer = sk_GENERAL_NAME_value(is->issuer, 0);
322 if (issuer->type != GEN_DIRNAME
323 || X509_NAME_cmp(issuer->d.dirn, X509_get_issuer_name(cert)))
326 if (ASN1_INTEGER_cmp(is->serial, X509_get_serialNumber(cert)))
333 * Verifies whether 'response' contains a valid response with regards
334 * to the settings of the context:
335 * - Gives an error message if the TS_TST_INFO is not present.
336 * - Calls _TS_RESP_verify_token to verify the token content.
338 int TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response)
340 PKCS7 *token = response->token;
341 TS_TST_INFO *tst_info = response->tst_info;
344 if (!ts_check_status_info(response))
346 if (!int_ts_RESP_verify_token(ctx, token, tst_info))
355 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and
356 * calls the internal int_TS_RESP_verify_token function for verifying it.
358 int TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token)
360 TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token);
363 ret = int_ts_RESP_verify_token(ctx, token, tst_info);
364 TS_TST_INFO_free(tst_info);
370 * Verifies whether the 'token' contains a valid time stamp token
371 * with regards to the settings of the context. Only those checks are
372 * carried out that are specified in the context:
373 * - Verifies the signature of the TS_TST_INFO.
374 * - Checks the version number of the response.
375 * - Check if the requested and returned policies math.
376 * - Check if the message imprints are the same.
377 * - Check if the nonces are the same.
378 * - Check if the TSA name matches the signer.
379 * - Check if the TSA name is the expected TSA.
381 static int int_ts_RESP_verify_token(TS_VERIFY_CTX *ctx,
382 PKCS7 *token, TS_TST_INFO *tst_info)
385 GENERAL_NAME *tsa_name = tst_info->tsa;
386 X509_ALGOR *md_alg = NULL;
387 unsigned char *imprint = NULL;
388 unsigned imprint_len = 0;
391 if ((ctx->flags & TS_VFY_SIGNATURE)
392 && !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer))
394 if ((ctx->flags & TS_VFY_VERSION)
395 && TS_TST_INFO_get_version(tst_info) != 1) {
396 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_UNSUPPORTED_VERSION);
399 if ((ctx->flags & TS_VFY_POLICY)
400 && !ts_check_policy(ctx->policy, tst_info))
402 if ((ctx->flags & TS_VFY_IMPRINT)
403 && !ts_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len,
406 if ((ctx->flags & TS_VFY_DATA)
407 && (!ts_compute_imprint(ctx->data, tst_info,
408 &md_alg, &imprint, &imprint_len)
409 || !ts_check_imprints(md_alg, imprint, imprint_len, tst_info)))
411 if ((ctx->flags & TS_VFY_NONCE)
412 && !ts_check_nonces(ctx->nonce, tst_info))
414 if ((ctx->flags & TS_VFY_SIGNER)
415 && tsa_name && !ts_check_signer_name(tsa_name, signer)) {
416 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_NAME_MISMATCH);
419 if ((ctx->flags & TS_VFY_TSA_NAME)
420 && !ts_check_signer_name(ctx->tsa_name, signer)) {
421 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_UNTRUSTED);
428 X509_ALGOR_free(md_alg);
429 OPENSSL_free(imprint);
433 static int ts_check_status_info(TS_RESP *response)
435 TS_STATUS_INFO *info = response->status_info;
436 long status = ASN1_INTEGER_get(info->status);
437 const char *status_text = NULL;
438 char *embedded_status_text = NULL;
439 char failure_text[TS_STATUS_BUF_SIZE] = "";
441 if (status == 0 || status == 1)
444 /* There was an error, get the description in status_text. */
445 if (0 <= status && status < (long) OSSL_NELEM(ts_status_text))
446 status_text = ts_status_text[status];
448 status_text = "unknown code";
450 if (sk_ASN1_UTF8STRING_num(info->text) > 0
451 && (embedded_status_text = ts_get_status_text(info->text)) == NULL)
454 /* Fill in failure_text with the failure information. */
455 if (info->failure_info) {
458 for (i = 0; i < (int)OSSL_NELEM(ts_failure_info); ++i) {
459 if (ASN1_BIT_STRING_get_bit(info->failure_info,
460 ts_failure_info[i].code)) {
462 strcat(failure_text, ",");
465 strcat(failure_text, ts_failure_info[i].text);
469 if (failure_text[0] == '\0')
470 strcpy(failure_text, "unspecified");
472 TSerr(TS_F_TS_CHECK_STATUS_INFO, TS_R_NO_TIME_STAMP_TOKEN);
473 ERR_add_error_data(6,
474 "status code: ", status_text,
475 ", status text: ", embedded_status_text ?
476 embedded_status_text : "unspecified",
477 ", failure codes: ", failure_text);
478 OPENSSL_free(embedded_status_text);
483 static char *ts_get_status_text(STACK_OF(ASN1_UTF8STRING) *text)
486 unsigned int length = 0;
490 for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) {
491 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
492 length += ASN1_STRING_length(current);
493 length += 1; /* separator character */
495 if ((result = OPENSSL_malloc(length)) == NULL) {
496 TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE);
500 for (i = 0, p = result; i < sk_ASN1_UTF8STRING_num(text); ++i) {
501 ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
502 length = ASN1_STRING_length(current);
505 strncpy(p, (const char *)ASN1_STRING_data(current), length);
513 static int ts_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info)
515 ASN1_OBJECT *resp_oid = tst_info->policy_id;
517 if (OBJ_cmp(req_oid, resp_oid) != 0) {
518 TSerr(TS_F_TS_CHECK_POLICY, TS_R_POLICY_MISMATCH);
525 static int ts_compute_imprint(BIO *data, TS_TST_INFO *tst_info,
527 unsigned char **imprint, unsigned *imprint_len)
529 TS_MSG_IMPRINT *msg_imprint = tst_info->msg_imprint;
530 X509_ALGOR *md_alg_resp = msg_imprint->hash_algo;
532 EVP_MD_CTX *md_ctx = NULL;
533 unsigned char buffer[4096];
539 if ((*md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL)
541 if ((md = EVP_get_digestbyobj((*md_alg)->algorithm)) == NULL) {
542 TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM);
545 length = EVP_MD_size(md);
548 *imprint_len = length;
549 if ((*imprint = OPENSSL_malloc(*imprint_len)) == NULL) {
550 TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE);
554 md_ctx = EVP_MD_CTX_new();
555 if (md_ctx == NULL) {
556 TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE);
559 if (!EVP_DigestInit(md_ctx, md))
561 while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) {
562 if (!EVP_DigestUpdate(md_ctx, buffer, length))
565 if (!EVP_DigestFinal(md_ctx, *imprint, NULL))
567 EVP_MD_CTX_free(md_ctx);
571 EVP_MD_CTX_free(md_ctx);
572 X509_ALGOR_free(*md_alg);
573 OPENSSL_free(*imprint);
579 static int ts_check_imprints(X509_ALGOR *algor_a,
580 unsigned char *imprint_a, unsigned len_a,
581 TS_TST_INFO *tst_info)
583 TS_MSG_IMPRINT *b = tst_info->msg_imprint;
584 X509_ALGOR *algor_b = b->hash_algo;
588 if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm))
591 /* The parameter must be NULL in both. */
592 if ((algor_a->parameter
593 && ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL)
594 || (algor_b->parameter
595 && ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL))
599 ret = len_a == (unsigned)ASN1_STRING_length(b->hashed_msg) &&
600 memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0;
603 TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH);
607 static int ts_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info)
609 const ASN1_INTEGER *b = tst_info->nonce;
612 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED);
616 /* No error if a nonce is returned without being requested. */
617 if (ASN1_INTEGER_cmp(a, b) != 0) {
618 TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH);
626 * Check if the specified TSA name matches either the subject or one of the
627 * subject alternative names of the TSA certificate.
629 static int ts_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer)
631 STACK_OF(GENERAL_NAME) *gen_names = NULL;
635 if (tsa_name->type == GEN_DIRNAME
636 && X509_name_cmp(tsa_name->d.dirn, X509_get_subject_name(signer)) == 0)
638 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, NULL, &idx);
639 while (gen_names != NULL) {
640 found = ts_find_name(gen_names, tsa_name) >= 0;
644 * Get the next subject alternative name, although there should be no
647 GENERAL_NAMES_free(gen_names);
648 gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name, NULL, &idx);
650 GENERAL_NAMES_free(gen_names);
655 /* Returns 1 if name is in gen_names, 0 otherwise. */
656 static int ts_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name)
659 for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names); ++i) {
660 GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i);
661 found = GENERAL_NAME_cmp(current, name) == 0;
663 return found ? i - 1 : -1;