2 * Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 #include "internal/cryptlib.h"
12 #include <openssl/objects.h>
13 #include <openssl/ts.h>
14 #include <openssl/pkcs7.h>
17 static int ts_verify_cert(X509_STORE
*store
, STACK_OF(X509
) *untrusted
,
18 X509
*signer
, STACK_OF(X509
) **chain
);
19 static int ts_check_signing_certs(PKCS7_SIGNER_INFO
*si
,
20 STACK_OF(X509
) *chain
);
21 static ESS_SIGNING_CERT
*ess_get_signing_cert(PKCS7_SIGNER_INFO
*si
);
22 static int ts_find_cert(STACK_OF(ESS_CERT_ID
) *cert_ids
, X509
*cert
);
23 static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL
*is
, X509
*cert
);
24 static int int_ts_RESP_verify_token(TS_VERIFY_CTX
*ctx
,
25 PKCS7
*token
, TS_TST_INFO
*tst_info
);
26 static int ts_check_status_info(TS_RESP
*response
);
27 static char *ts_get_status_text(STACK_OF(ASN1_UTF8STRING
) *text
);
28 static int ts_check_policy(const ASN1_OBJECT
*req_oid
,
29 const TS_TST_INFO
*tst_info
);
30 static int ts_compute_imprint(BIO
*data
, TS_TST_INFO
*tst_info
,
32 unsigned char **imprint
, unsigned *imprint_len
);
33 static int ts_check_imprints(X509_ALGOR
*algor_a
,
34 const unsigned char *imprint_a
, unsigned len_a
,
35 TS_TST_INFO
*tst_info
);
36 static int ts_check_nonces(const ASN1_INTEGER
*a
, TS_TST_INFO
*tst_info
);
37 static int ts_check_signer_name(GENERAL_NAME
*tsa_name
, X509
*signer
);
38 static int ts_find_name(STACK_OF(GENERAL_NAME
) *gen_names
,
42 * This must be large enough to hold all values in ts_status_text (with
43 * comma separator) or all text fields in ts_failure_info (also with comma).
45 #define TS_STATUS_BUF_SIZE 256
48 * Local mapping between response codes and descriptions.
50 static const char *ts_status_text
[] = {
56 "revocationNotification"
59 #define TS_STATUS_TEXT_SIZE OSSL_NELEM(ts_status_text)
64 } ts_failure_info
[] = {
65 {TS_INFO_BAD_ALG
, "badAlg"},
66 {TS_INFO_BAD_REQUEST
, "badRequest"},
67 {TS_INFO_BAD_DATA_FORMAT
, "badDataFormat"},
68 {TS_INFO_TIME_NOT_AVAILABLE
, "timeNotAvailable"},
69 {TS_INFO_UNACCEPTED_POLICY
, "unacceptedPolicy"},
70 {TS_INFO_UNACCEPTED_EXTENSION
, "unacceptedExtension"},
71 {TS_INFO_ADD_INFO_NOT_AVAILABLE
, "addInfoNotAvailable"},
72 {TS_INFO_SYSTEM_FAILURE
, "systemFailure"}
77 * This function carries out the following tasks:
78 * - Checks if there is one and only one signer.
79 * - Search for the signing certificate in 'certs' and in the response.
80 * - Check the extended key usage and key usage fields of the signer
81 * certificate (done by the path validation).
82 * - Build and validate the certificate path.
83 * - Check if the certificate path meets the requirements of the
84 * SigningCertificate ESS signed attribute.
85 * - Verify the signature value.
86 * - Returns the signer certificate in 'signer', if 'signer' is not NULL.
88 int TS_RESP_verify_signature(PKCS7
*token
, STACK_OF(X509
) *certs
,
89 X509_STORE
*store
, X509
**signer_out
)
91 STACK_OF(PKCS7_SIGNER_INFO
) *sinfos
= NULL
;
92 PKCS7_SIGNER_INFO
*si
;
93 STACK_OF(X509
) *signers
= NULL
;
95 STACK_OF(X509
) *chain
= NULL
;
97 int i
, j
= 0, ret
= 0;
100 /* Some sanity checks first. */
102 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_INVALID_NULL_POINTER
);
105 if (!PKCS7_type_is_signed(token
)) {
106 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_WRONG_CONTENT_TYPE
);
109 sinfos
= PKCS7_get_signer_info(token
);
110 if (!sinfos
|| sk_PKCS7_SIGNER_INFO_num(sinfos
) != 1) {
111 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_THERE_MUST_BE_ONE_SIGNER
);
114 si
= sk_PKCS7_SIGNER_INFO_value(sinfos
, 0);
115 if (PKCS7_get_detached(token
)) {
116 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_NO_CONTENT
);
121 * Get hold of the signer certificate, search only internal certificates
122 * if it was requested.
124 signers
= PKCS7_get0_signers(token
, certs
, 0);
125 if (!signers
|| sk_X509_num(signers
) != 1)
127 signer
= sk_X509_value(signers
, 0);
129 if (!ts_verify_cert(store
, certs
, signer
, &chain
))
131 if (!ts_check_signing_certs(si
, chain
))
133 p7bio
= PKCS7_dataInit(token
, NULL
);
135 /* We now have to 'read' from p7bio to calculate digests etc. */
136 while ((i
= BIO_read(p7bio
, buf
, sizeof(buf
))) > 0)
139 j
= PKCS7_signatureVerify(p7bio
, token
, si
, signer
);
141 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_SIGNATURE_FAILURE
);
146 *signer_out
= signer
;
153 sk_X509_pop_free(chain
, X509_free
);
154 sk_X509_free(signers
);
160 * The certificate chain is returned in chain. Caller is responsible for
161 * freeing the vector.
163 static int ts_verify_cert(X509_STORE
*store
, STACK_OF(X509
) *untrusted
,
164 X509
*signer
, STACK_OF(X509
) **chain
)
166 X509_STORE_CTX
*cert_ctx
= NULL
;
171 cert_ctx
= X509_STORE_CTX_new();
172 if (cert_ctx
== NULL
) {
173 TSerr(TS_F_TS_VERIFY_CERT
, ERR_R_MALLOC_FAILURE
);
176 if (!X509_STORE_CTX_init(cert_ctx
, store
, signer
, untrusted
))
178 X509_STORE_CTX_set_purpose(cert_ctx
, X509_PURPOSE_TIMESTAMP_SIGN
);
179 i
= X509_verify_cert(cert_ctx
);
181 int j
= X509_STORE_CTX_get_error(cert_ctx
);
182 TSerr(TS_F_TS_VERIFY_CERT
, TS_R_CERTIFICATE_VERIFY_ERROR
);
183 ERR_add_error_data(2, "Verify error:",
184 X509_verify_cert_error_string(j
));
187 *chain
= X509_STORE_CTX_get1_chain(cert_ctx
);
195 X509_STORE_CTX_free(cert_ctx
);
199 static int ts_check_signing_certs(PKCS7_SIGNER_INFO
*si
,
200 STACK_OF(X509
) *chain
)
202 ESS_SIGNING_CERT
*ss
= ess_get_signing_cert(si
);
203 STACK_OF(ESS_CERT_ID
) *cert_ids
= NULL
;
210 cert_ids
= ss
->cert_ids
;
211 cert
= sk_X509_value(chain
, 0);
212 if (ts_find_cert(cert_ids
, cert
) != 0)
216 * Check the other certificates of the chain if there are more than one
217 * certificate ids in cert_ids.
219 if (sk_ESS_CERT_ID_num(cert_ids
) > 1) {
220 for (i
= 1; i
< sk_X509_num(chain
); ++i
) {
221 cert
= sk_X509_value(chain
, i
);
222 if (ts_find_cert(cert_ids
, cert
) < 0)
229 TSerr(TS_F_TS_CHECK_SIGNING_CERTS
,
230 TS_R_ESS_SIGNING_CERTIFICATE_ERROR
);
231 ESS_SIGNING_CERT_free(ss
);
235 static ESS_SIGNING_CERT
*ess_get_signing_cert(PKCS7_SIGNER_INFO
*si
)
238 const unsigned char *p
;
239 attr
= PKCS7_get_signed_attribute(si
, NID_id_smime_aa_signingCertificate
);
242 p
= attr
->value
.sequence
->data
;
243 return d2i_ESS_SIGNING_CERT(NULL
, &p
, attr
->value
.sequence
->length
);
246 /* Returns < 0 if certificate is not found, certificate index otherwise. */
247 static int ts_find_cert(STACK_OF(ESS_CERT_ID
) *cert_ids
, X509
*cert
)
250 unsigned char cert_sha1
[SHA_DIGEST_LENGTH
];
252 if (!cert_ids
|| !cert
)
255 X509_digest(cert
, EVP_sha1(), cert_sha1
, NULL
);
257 /* Recompute SHA1 hash of certificate if necessary (side effect). */
258 X509_check_purpose(cert
, -1, 0);
260 /* Look for cert in the cert_ids vector. */
261 for (i
= 0; i
< sk_ESS_CERT_ID_num(cert_ids
); ++i
) {
262 ESS_CERT_ID
*cid
= sk_ESS_CERT_ID_value(cert_ids
, i
);
264 if (cid
->hash
->length
== SHA_DIGEST_LENGTH
265 && memcmp(cid
->hash
->data
, cert_sha1
, SHA_DIGEST_LENGTH
) == 0) {
266 ESS_ISSUER_SERIAL
*is
= cid
->issuer_serial
;
267 if (!is
|| !ts_issuer_serial_cmp(is
, cert
))
275 static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL
*is
, X509
*cert
)
277 GENERAL_NAME
*issuer
;
279 if (!is
|| !cert
|| sk_GENERAL_NAME_num(is
->issuer
) != 1)
282 issuer
= sk_GENERAL_NAME_value(is
->issuer
, 0);
283 if (issuer
->type
!= GEN_DIRNAME
284 || X509_NAME_cmp(issuer
->d
.dirn
, X509_get_issuer_name(cert
)))
287 if (ASN1_INTEGER_cmp(is
->serial
, X509_get_serialNumber(cert
)))
294 * Verifies whether 'response' contains a valid response with regards
295 * to the settings of the context:
296 * - Gives an error message if the TS_TST_INFO is not present.
297 * - Calls _TS_RESP_verify_token to verify the token content.
299 int TS_RESP_verify_response(TS_VERIFY_CTX
*ctx
, TS_RESP
*response
)
301 PKCS7
*token
= response
->token
;
302 TS_TST_INFO
*tst_info
= response
->tst_info
;
305 if (!ts_check_status_info(response
))
307 if (!int_ts_RESP_verify_token(ctx
, token
, tst_info
))
316 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and
317 * calls the internal int_TS_RESP_verify_token function for verifying it.
319 int TS_RESP_verify_token(TS_VERIFY_CTX
*ctx
, PKCS7
*token
)
321 TS_TST_INFO
*tst_info
= PKCS7_to_TS_TST_INFO(token
);
324 ret
= int_ts_RESP_verify_token(ctx
, token
, tst_info
);
325 TS_TST_INFO_free(tst_info
);
331 * Verifies whether the 'token' contains a valid time stamp token
332 * with regards to the settings of the context. Only those checks are
333 * carried out that are specified in the context:
334 * - Verifies the signature of the TS_TST_INFO.
335 * - Checks the version number of the response.
336 * - Check if the requested and returned policies math.
337 * - Check if the message imprints are the same.
338 * - Check if the nonces are the same.
339 * - Check if the TSA name matches the signer.
340 * - Check if the TSA name is the expected TSA.
342 static int int_ts_RESP_verify_token(TS_VERIFY_CTX
*ctx
,
343 PKCS7
*token
, TS_TST_INFO
*tst_info
)
346 GENERAL_NAME
*tsa_name
= tst_info
->tsa
;
347 X509_ALGOR
*md_alg
= NULL
;
348 unsigned char *imprint
= NULL
;
349 unsigned imprint_len
= 0;
351 int flags
= ctx
->flags
;
353 /* Some options require us to also check the signature */
354 if (((flags
& TS_VFY_SIGNER
) && tsa_name
!= NULL
)
355 || (flags
& TS_VFY_TSA_NAME
)) {
356 flags
|= TS_VFY_SIGNATURE
;
359 if ((flags
& TS_VFY_SIGNATURE
)
360 && !TS_RESP_verify_signature(token
, ctx
->certs
, ctx
->store
, &signer
))
362 if ((flags
& TS_VFY_VERSION
)
363 && TS_TST_INFO_get_version(tst_info
) != 1) {
364 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN
, TS_R_UNSUPPORTED_VERSION
);
367 if ((flags
& TS_VFY_POLICY
)
368 && !ts_check_policy(ctx
->policy
, tst_info
))
370 if ((flags
& TS_VFY_IMPRINT
)
371 && !ts_check_imprints(ctx
->md_alg
, ctx
->imprint
, ctx
->imprint_len
,
374 if ((flags
& TS_VFY_DATA
)
375 && (!ts_compute_imprint(ctx
->data
, tst_info
,
376 &md_alg
, &imprint
, &imprint_len
)
377 || !ts_check_imprints(md_alg
, imprint
, imprint_len
, tst_info
)))
379 if ((flags
& TS_VFY_NONCE
)
380 && !ts_check_nonces(ctx
->nonce
, tst_info
))
382 if ((flags
& TS_VFY_SIGNER
)
383 && tsa_name
&& !ts_check_signer_name(tsa_name
, signer
)) {
384 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN
, TS_R_TSA_NAME_MISMATCH
);
387 if ((flags
& TS_VFY_TSA_NAME
)
388 && !ts_check_signer_name(ctx
->tsa_name
, signer
)) {
389 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN
, TS_R_TSA_UNTRUSTED
);
396 X509_ALGOR_free(md_alg
);
397 OPENSSL_free(imprint
);
401 static int ts_check_status_info(TS_RESP
*response
)
403 TS_STATUS_INFO
*info
= response
->status_info
;
404 long status
= ASN1_INTEGER_get(info
->status
);
405 const char *status_text
= NULL
;
406 char *embedded_status_text
= NULL
;
407 char failure_text
[TS_STATUS_BUF_SIZE
] = "";
409 if (status
== 0 || status
== 1)
412 /* There was an error, get the description in status_text. */
413 if (0 <= status
&& status
< (long) OSSL_NELEM(ts_status_text
))
414 status_text
= ts_status_text
[status
];
416 status_text
= "unknown code";
418 if (sk_ASN1_UTF8STRING_num(info
->text
) > 0
419 && (embedded_status_text
= ts_get_status_text(info
->text
)) == NULL
)
422 /* Fill in failure_text with the failure information. */
423 if (info
->failure_info
) {
426 for (i
= 0; i
< (int)OSSL_NELEM(ts_failure_info
); ++i
) {
427 if (ASN1_BIT_STRING_get_bit(info
->failure_info
,
428 ts_failure_info
[i
].code
)) {
430 strcat(failure_text
, ",");
433 strcat(failure_text
, ts_failure_info
[i
].text
);
437 if (failure_text
[0] == '\0')
438 strcpy(failure_text
, "unspecified");
440 TSerr(TS_F_TS_CHECK_STATUS_INFO
, TS_R_NO_TIME_STAMP_TOKEN
);
441 ERR_add_error_data(6,
442 "status code: ", status_text
,
443 ", status text: ", embedded_status_text
?
444 embedded_status_text
: "unspecified",
445 ", failure codes: ", failure_text
);
446 OPENSSL_free(embedded_status_text
);
451 static char *ts_get_status_text(STACK_OF(ASN1_UTF8STRING
) *text
)
458 for (i
= 0; i
< sk_ASN1_UTF8STRING_num(text
); ++i
) {
459 ASN1_UTF8STRING
*current
= sk_ASN1_UTF8STRING_value(text
, i
);
460 if (ASN1_STRING_length(current
) > TS_MAX_STATUS_LENGTH
- length
- 1)
462 length
+= ASN1_STRING_length(current
);
463 length
+= 1; /* separator character */
465 if ((result
= OPENSSL_malloc(length
)) == NULL
) {
466 TSerr(TS_F_TS_GET_STATUS_TEXT
, ERR_R_MALLOC_FAILURE
);
470 for (i
= 0, p
= result
; i
< sk_ASN1_UTF8STRING_num(text
); ++i
) {
471 ASN1_UTF8STRING
*current
= sk_ASN1_UTF8STRING_value(text
, i
);
472 length
= ASN1_STRING_length(current
);
475 strncpy(p
, (const char *)ASN1_STRING_data(current
), length
);
483 static int ts_check_policy(const ASN1_OBJECT
*req_oid
,
484 const TS_TST_INFO
*tst_info
)
486 const ASN1_OBJECT
*resp_oid
= tst_info
->policy_id
;
488 if (OBJ_cmp(req_oid
, resp_oid
) != 0) {
489 TSerr(TS_F_TS_CHECK_POLICY
, TS_R_POLICY_MISMATCH
);
496 static int ts_compute_imprint(BIO
*data
, TS_TST_INFO
*tst_info
,
498 unsigned char **imprint
, unsigned *imprint_len
)
500 TS_MSG_IMPRINT
*msg_imprint
= tst_info
->msg_imprint
;
501 X509_ALGOR
*md_alg_resp
= msg_imprint
->hash_algo
;
503 EVP_MD_CTX
*md_ctx
= NULL
;
504 unsigned char buffer
[4096];
510 if ((*md_alg
= X509_ALGOR_dup(md_alg_resp
)) == NULL
)
512 if ((md
= EVP_get_digestbyobj((*md_alg
)->algorithm
)) == NULL
) {
513 TSerr(TS_F_TS_COMPUTE_IMPRINT
, TS_R_UNSUPPORTED_MD_ALGORITHM
);
516 length
= EVP_MD_size(md
);
519 *imprint_len
= length
;
520 if ((*imprint
= OPENSSL_malloc(*imprint_len
)) == NULL
) {
521 TSerr(TS_F_TS_COMPUTE_IMPRINT
, ERR_R_MALLOC_FAILURE
);
525 md_ctx
= EVP_MD_CTX_new();
526 if (md_ctx
== NULL
) {
527 TSerr(TS_F_TS_COMPUTE_IMPRINT
, ERR_R_MALLOC_FAILURE
);
530 if (!EVP_DigestInit(md_ctx
, md
))
532 while ((length
= BIO_read(data
, buffer
, sizeof(buffer
))) > 0) {
533 if (!EVP_DigestUpdate(md_ctx
, buffer
, length
))
536 if (!EVP_DigestFinal(md_ctx
, *imprint
, NULL
))
538 EVP_MD_CTX_free(md_ctx
);
542 EVP_MD_CTX_free(md_ctx
);
543 X509_ALGOR_free(*md_alg
);
544 OPENSSL_free(*imprint
);
550 static int ts_check_imprints(X509_ALGOR
*algor_a
,
551 const unsigned char *imprint_a
, unsigned len_a
,
552 TS_TST_INFO
*tst_info
)
554 TS_MSG_IMPRINT
*b
= tst_info
->msg_imprint
;
555 X509_ALGOR
*algor_b
= b
->hash_algo
;
559 if (OBJ_cmp(algor_a
->algorithm
, algor_b
->algorithm
))
562 /* The parameter must be NULL in both. */
563 if ((algor_a
->parameter
564 && ASN1_TYPE_get(algor_a
->parameter
) != V_ASN1_NULL
)
565 || (algor_b
->parameter
566 && ASN1_TYPE_get(algor_b
->parameter
) != V_ASN1_NULL
))
570 ret
= len_a
== (unsigned)ASN1_STRING_length(b
->hashed_msg
) &&
571 memcmp(imprint_a
, ASN1_STRING_data(b
->hashed_msg
), len_a
) == 0;
574 TSerr(TS_F_TS_CHECK_IMPRINTS
, TS_R_MESSAGE_IMPRINT_MISMATCH
);
578 static int ts_check_nonces(const ASN1_INTEGER
*a
, TS_TST_INFO
*tst_info
)
580 const ASN1_INTEGER
*b
= tst_info
->nonce
;
583 TSerr(TS_F_TS_CHECK_NONCES
, TS_R_NONCE_NOT_RETURNED
);
587 /* No error if a nonce is returned without being requested. */
588 if (ASN1_INTEGER_cmp(a
, b
) != 0) {
589 TSerr(TS_F_TS_CHECK_NONCES
, TS_R_NONCE_MISMATCH
);
597 * Check if the specified TSA name matches either the subject or one of the
598 * subject alternative names of the TSA certificate.
600 static int ts_check_signer_name(GENERAL_NAME
*tsa_name
, X509
*signer
)
602 STACK_OF(GENERAL_NAME
) *gen_names
= NULL
;
606 if (tsa_name
->type
== GEN_DIRNAME
607 && X509_name_cmp(tsa_name
->d
.dirn
, X509_get_subject_name(signer
)) == 0)
609 gen_names
= X509_get_ext_d2i(signer
, NID_subject_alt_name
, NULL
, &idx
);
610 while (gen_names
!= NULL
) {
611 found
= ts_find_name(gen_names
, tsa_name
) >= 0;
615 * Get the next subject alternative name, although there should be no
618 GENERAL_NAMES_free(gen_names
);
619 gen_names
= X509_get_ext_d2i(signer
, NID_subject_alt_name
, NULL
, &idx
);
621 GENERAL_NAMES_free(gen_names
);
626 /* Returns 1 if name is in gen_names, 0 otherwise. */
627 static int ts_find_name(STACK_OF(GENERAL_NAME
) *gen_names
, GENERAL_NAME
*name
)
630 for (i
= 0, found
= 0; !found
&& i
< sk_GENERAL_NAME_num(gen_names
); ++i
) {
631 GENERAL_NAME
*current
= sk_GENERAL_NAME_value(gen_names
, i
);
632 found
= GENERAL_NAME_cmp(current
, name
) == 0;
634 return found
? i
- 1 : -1;