2 * Copyright 2006-2019 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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>
16 #include "crypto/ess.h"
18 static int ts_verify_cert(X509_STORE
*store
, STACK_OF(X509
) *untrusted
,
19 X509
*signer
, STACK_OF(X509
) **chain
);
20 static int ts_check_signing_certs(PKCS7_SIGNER_INFO
*si
,
21 STACK_OF(X509
) *chain
);
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
,
40 static int ts_find_cert_v2(STACK_OF(ESS_CERT_ID_V2
) *cert_ids
, X509
*cert
);
43 * This must be large enough to hold all values in ts_status_text (with
44 * comma separator) or all text fields in ts_failure_info (also with comma).
46 #define TS_STATUS_BUF_SIZE 256
49 * Local mapping between response codes and descriptions.
51 static const char *ts_status_text
[] = {
57 "revocationNotification"
60 #define TS_STATUS_TEXT_SIZE OSSL_NELEM(ts_status_text)
65 } ts_failure_info
[] = {
66 {TS_INFO_BAD_ALG
, "badAlg"},
67 {TS_INFO_BAD_REQUEST
, "badRequest"},
68 {TS_INFO_BAD_DATA_FORMAT
, "badDataFormat"},
69 {TS_INFO_TIME_NOT_AVAILABLE
, "timeNotAvailable"},
70 {TS_INFO_UNACCEPTED_POLICY
, "unacceptedPolicy"},
71 {TS_INFO_UNACCEPTED_EXTENSION
, "unacceptedExtension"},
72 {TS_INFO_ADD_INFO_NOT_AVAILABLE
, "addInfoNotAvailable"},
73 {TS_INFO_SYSTEM_FAILURE
, "systemFailure"}
78 * This function carries out the following tasks:
79 * - Checks if there is one and only one signer.
80 * - Search for the signing certificate in 'certs' and in the response.
81 * - Check the extended key usage and key usage fields of the signer
82 * certificate (done by the path validation).
83 * - Build and validate the certificate path.
84 * - Check if the certificate path meets the requirements of the
85 * SigningCertificate ESS signed attribute.
86 * - Verify the signature value.
87 * - Returns the signer certificate in 'signer', if 'signer' is not NULL.
89 int TS_RESP_verify_signature(PKCS7
*token
, STACK_OF(X509
) *certs
,
90 X509_STORE
*store
, X509
**signer_out
)
92 STACK_OF(PKCS7_SIGNER_INFO
) *sinfos
= NULL
;
93 PKCS7_SIGNER_INFO
*si
;
94 STACK_OF(X509
) *signers
= NULL
;
96 STACK_OF(X509
) *chain
= NULL
;
98 int i
, j
= 0, ret
= 0;
101 /* Some sanity checks first. */
103 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_INVALID_NULL_POINTER
);
106 if (!PKCS7_type_is_signed(token
)) {
107 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_WRONG_CONTENT_TYPE
);
110 sinfos
= PKCS7_get_signer_info(token
);
111 if (!sinfos
|| sk_PKCS7_SIGNER_INFO_num(sinfos
) != 1) {
112 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_THERE_MUST_BE_ONE_SIGNER
);
115 si
= sk_PKCS7_SIGNER_INFO_value(sinfos
, 0);
116 if (PKCS7_get_detached(token
)) {
117 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_NO_CONTENT
);
122 * Get hold of the signer certificate, search only internal certificates
123 * if it was requested.
125 signers
= PKCS7_get0_signers(token
, certs
, 0);
126 if (!signers
|| sk_X509_num(signers
) != 1)
128 signer
= sk_X509_value(signers
, 0);
130 if (!ts_verify_cert(store
, certs
, signer
, &chain
))
132 if (!ts_check_signing_certs(si
, chain
))
134 p7bio
= PKCS7_dataInit(token
, NULL
);
136 /* We now have to 'read' from p7bio to calculate digests etc. */
137 while ((i
= BIO_read(p7bio
, buf
, sizeof(buf
))) > 0)
140 j
= PKCS7_signatureVerify(p7bio
, token
, si
, signer
);
142 TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE
, TS_R_SIGNATURE_FAILURE
);
147 *signer_out
= signer
;
154 sk_X509_pop_free(chain
, X509_free
);
155 sk_X509_free(signers
);
161 * The certificate chain is returned in chain. Caller is responsible for
162 * freeing the vector.
164 static int ts_verify_cert(X509_STORE
*store
, STACK_OF(X509
) *untrusted
,
165 X509
*signer
, STACK_OF(X509
) **chain
)
167 X509_STORE_CTX
*cert_ctx
= NULL
;
172 cert_ctx
= X509_STORE_CTX_new();
173 if (cert_ctx
== NULL
) {
174 TSerr(TS_F_TS_VERIFY_CERT
, ERR_R_MALLOC_FAILURE
);
177 if (!X509_STORE_CTX_init(cert_ctx
, store
, signer
, untrusted
))
179 X509_STORE_CTX_set_purpose(cert_ctx
, X509_PURPOSE_TIMESTAMP_SIGN
);
180 i
= X509_verify_cert(cert_ctx
);
182 int j
= X509_STORE_CTX_get_error(cert_ctx
);
183 TSerr(TS_F_TS_VERIFY_CERT
, TS_R_CERTIFICATE_VERIFY_ERROR
);
184 ERR_add_error_data(2, "Verify error:",
185 X509_verify_cert_error_string(j
));
188 *chain
= X509_STORE_CTX_get1_chain(cert_ctx
);
196 X509_STORE_CTX_free(cert_ctx
);
200 static int ts_check_signing_certs(PKCS7_SIGNER_INFO
*si
,
201 STACK_OF(X509
) *chain
)
203 ESS_SIGNING_CERT
*ss
= ESS_SIGNING_CERT_get(si
);
204 STACK_OF(ESS_CERT_ID
) *cert_ids
= NULL
;
205 ESS_SIGNING_CERT_V2
*ssv2
= ESS_SIGNING_CERT_V2_get(si
);
206 STACK_OF(ESS_CERT_ID_V2
) *cert_ids_v2
= NULL
;
212 cert_ids
= ss
->cert_ids
;
213 cert
= sk_X509_value(chain
, 0);
214 if (ts_find_cert(cert_ids
, cert
) != 0)
218 * Check the other certificates of the chain if there are more than one
219 * certificate ids in cert_ids.
221 if (sk_ESS_CERT_ID_num(cert_ids
) > 1) {
222 for (i
= 1; i
< sk_X509_num(chain
); ++i
) {
223 cert
= sk_X509_value(chain
, i
);
224 if (ts_find_cert(cert_ids
, cert
) < 0)
228 } else if (ssv2
!= NULL
) {
229 cert_ids_v2
= ssv2
->cert_ids
;
230 cert
= sk_X509_value(chain
, 0);
231 if (ts_find_cert_v2(cert_ids_v2
, cert
) != 0)
235 * Check the other certificates of the chain if there are more than one
236 * certificate ids in cert_ids.
238 if (sk_ESS_CERT_ID_V2_num(cert_ids_v2
) > 1) {
239 for (i
= 1; i
< sk_X509_num(chain
); ++i
) {
240 cert
= sk_X509_value(chain
, i
);
241 if (ts_find_cert_v2(cert_ids_v2
, cert
) < 0)
252 TSerr(TS_F_TS_CHECK_SIGNING_CERTS
,
253 TS_R_ESS_SIGNING_CERTIFICATE_ERROR
);
254 ESS_SIGNING_CERT_free(ss
);
255 ESS_SIGNING_CERT_V2_free(ssv2
);
259 /* Returns < 0 if certificate is not found, certificate index otherwise. */
260 static int ts_find_cert(STACK_OF(ESS_CERT_ID
) *cert_ids
, X509
*cert
)
263 unsigned char cert_sha1
[SHA_DIGEST_LENGTH
];
265 if (!cert_ids
|| !cert
)
268 X509_digest(cert
, EVP_sha1(), cert_sha1
, NULL
);
270 /* Recompute SHA1 hash of certificate if necessary (side effect). */
271 X509_check_purpose(cert
, -1, 0);
273 /* Look for cert in the cert_ids vector. */
274 for (i
= 0; i
< sk_ESS_CERT_ID_num(cert_ids
); ++i
) {
275 ESS_CERT_ID
*cid
= sk_ESS_CERT_ID_value(cert_ids
, i
);
277 if (cid
->hash
->length
== SHA_DIGEST_LENGTH
278 && memcmp(cid
->hash
->data
, cert_sha1
, SHA_DIGEST_LENGTH
) == 0) {
279 ESS_ISSUER_SERIAL
*is
= cid
->issuer_serial
;
280 if (!is
|| !ts_issuer_serial_cmp(is
, cert
))
288 /* Returns < 0 if certificate is not found, certificate index otherwise. */
289 static int ts_find_cert_v2(STACK_OF(ESS_CERT_ID_V2
) *cert_ids
, X509
*cert
)
292 unsigned char cert_digest
[EVP_MAX_MD_SIZE
];
295 /* Look for cert in the cert_ids vector. */
296 for (i
= 0; i
< sk_ESS_CERT_ID_V2_num(cert_ids
); ++i
) {
297 ESS_CERT_ID_V2
*cid
= sk_ESS_CERT_ID_V2_value(cert_ids
, i
);
300 if (cid
->hash_alg
!= NULL
)
301 md
= EVP_get_digestbyobj(cid
->hash_alg
->algorithm
);
305 X509_digest(cert
, md
, cert_digest
, &len
);
306 if (cid
->hash
->length
!= (int)len
)
309 if (memcmp(cid
->hash
->data
, cert_digest
, cid
->hash
->length
) == 0) {
310 ESS_ISSUER_SERIAL
*is
= cid
->issuer_serial
;
312 if (is
== NULL
|| !ts_issuer_serial_cmp(is
, cert
))
320 static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL
*is
, X509
*cert
)
322 GENERAL_NAME
*issuer
;
324 if (!is
|| !cert
|| sk_GENERAL_NAME_num(is
->issuer
) != 1)
327 issuer
= sk_GENERAL_NAME_value(is
->issuer
, 0);
328 if (issuer
->type
!= GEN_DIRNAME
329 || X509_NAME_cmp(issuer
->d
.dirn
, X509_get_issuer_name(cert
)))
332 if (ASN1_INTEGER_cmp(is
->serial
, X509_get_serialNumber(cert
)))
339 * Verifies whether 'response' contains a valid response with regards
340 * to the settings of the context:
341 * - Gives an error message if the TS_TST_INFO is not present.
342 * - Calls _TS_RESP_verify_token to verify the token content.
344 int TS_RESP_verify_response(TS_VERIFY_CTX
*ctx
, TS_RESP
*response
)
346 PKCS7
*token
= response
->token
;
347 TS_TST_INFO
*tst_info
= response
->tst_info
;
350 if (!ts_check_status_info(response
))
352 if (!int_ts_RESP_verify_token(ctx
, token
, tst_info
))
361 * Tries to extract a TS_TST_INFO structure from the PKCS7 token and
362 * calls the internal int_TS_RESP_verify_token function for verifying it.
364 int TS_RESP_verify_token(TS_VERIFY_CTX
*ctx
, PKCS7
*token
)
366 TS_TST_INFO
*tst_info
= PKCS7_to_TS_TST_INFO(token
);
369 ret
= int_ts_RESP_verify_token(ctx
, token
, tst_info
);
370 TS_TST_INFO_free(tst_info
);
376 * Verifies whether the 'token' contains a valid time stamp token
377 * with regards to the settings of the context. Only those checks are
378 * carried out that are specified in the context:
379 * - Verifies the signature of the TS_TST_INFO.
380 * - Checks the version number of the response.
381 * - Check if the requested and returned policies math.
382 * - Check if the message imprints are the same.
383 * - Check if the nonces are the same.
384 * - Check if the TSA name matches the signer.
385 * - Check if the TSA name is the expected TSA.
387 static int int_ts_RESP_verify_token(TS_VERIFY_CTX
*ctx
,
388 PKCS7
*token
, TS_TST_INFO
*tst_info
)
391 GENERAL_NAME
*tsa_name
= tst_info
->tsa
;
392 X509_ALGOR
*md_alg
= NULL
;
393 unsigned char *imprint
= NULL
;
394 unsigned imprint_len
= 0;
396 int flags
= ctx
->flags
;
398 /* Some options require us to also check the signature */
399 if (((flags
& TS_VFY_SIGNER
) && tsa_name
!= NULL
)
400 || (flags
& TS_VFY_TSA_NAME
)) {
401 flags
|= TS_VFY_SIGNATURE
;
404 if ((flags
& TS_VFY_SIGNATURE
)
405 && !TS_RESP_verify_signature(token
, ctx
->certs
, ctx
->store
, &signer
))
407 if ((flags
& TS_VFY_VERSION
)
408 && TS_TST_INFO_get_version(tst_info
) != 1) {
409 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN
, TS_R_UNSUPPORTED_VERSION
);
412 if ((flags
& TS_VFY_POLICY
)
413 && !ts_check_policy(ctx
->policy
, tst_info
))
415 if ((flags
& TS_VFY_IMPRINT
)
416 && !ts_check_imprints(ctx
->md_alg
, ctx
->imprint
, ctx
->imprint_len
,
419 if ((flags
& TS_VFY_DATA
)
420 && (!ts_compute_imprint(ctx
->data
, tst_info
,
421 &md_alg
, &imprint
, &imprint_len
)
422 || !ts_check_imprints(md_alg
, imprint
, imprint_len
, tst_info
)))
424 if ((flags
& TS_VFY_NONCE
)
425 && !ts_check_nonces(ctx
->nonce
, tst_info
))
427 if ((flags
& TS_VFY_SIGNER
)
428 && tsa_name
&& !ts_check_signer_name(tsa_name
, signer
)) {
429 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN
, TS_R_TSA_NAME_MISMATCH
);
432 if ((flags
& TS_VFY_TSA_NAME
)
433 && !ts_check_signer_name(ctx
->tsa_name
, signer
)) {
434 TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN
, TS_R_TSA_UNTRUSTED
);
441 X509_ALGOR_free(md_alg
);
442 OPENSSL_free(imprint
);
446 static int ts_check_status_info(TS_RESP
*response
)
448 TS_STATUS_INFO
*info
= response
->status_info
;
449 long status
= ASN1_INTEGER_get(info
->status
);
450 const char *status_text
= NULL
;
451 char *embedded_status_text
= NULL
;
452 char failure_text
[TS_STATUS_BUF_SIZE
] = "";
454 if (status
== 0 || status
== 1)
457 /* There was an error, get the description in status_text. */
458 if (0 <= status
&& status
< (long) OSSL_NELEM(ts_status_text
))
459 status_text
= ts_status_text
[status
];
461 status_text
= "unknown code";
463 if (sk_ASN1_UTF8STRING_num(info
->text
) > 0
464 && (embedded_status_text
= ts_get_status_text(info
->text
)) == NULL
)
467 /* Fill in failure_text with the failure information. */
468 if (info
->failure_info
) {
471 for (i
= 0; i
< (int)OSSL_NELEM(ts_failure_info
); ++i
) {
472 if (ASN1_BIT_STRING_get_bit(info
->failure_info
,
473 ts_failure_info
[i
].code
)) {
475 strcat(failure_text
, ",");
478 strcat(failure_text
, ts_failure_info
[i
].text
);
482 if (failure_text
[0] == '\0')
483 strcpy(failure_text
, "unspecified");
485 TSerr(TS_F_TS_CHECK_STATUS_INFO
, TS_R_NO_TIME_STAMP_TOKEN
);
486 ERR_add_error_data(6,
487 "status code: ", status_text
,
488 ", status text: ", embedded_status_text
?
489 embedded_status_text
: "unspecified",
490 ", failure codes: ", failure_text
);
491 OPENSSL_free(embedded_status_text
);
496 static char *ts_get_status_text(STACK_OF(ASN1_UTF8STRING
) *text
)
503 for (i
= 0; i
< sk_ASN1_UTF8STRING_num(text
); ++i
) {
504 ASN1_UTF8STRING
*current
= sk_ASN1_UTF8STRING_value(text
, i
);
505 if (ASN1_STRING_length(current
) > TS_MAX_STATUS_LENGTH
- length
- 1)
507 length
+= ASN1_STRING_length(current
);
508 length
+= 1; /* separator character */
510 if ((result
= OPENSSL_malloc(length
)) == NULL
) {
511 TSerr(TS_F_TS_GET_STATUS_TEXT
, ERR_R_MALLOC_FAILURE
);
515 for (i
= 0, p
= result
; i
< sk_ASN1_UTF8STRING_num(text
); ++i
) {
516 ASN1_UTF8STRING
*current
= sk_ASN1_UTF8STRING_value(text
, i
);
517 length
= ASN1_STRING_length(current
);
520 strncpy(p
, (const char *)ASN1_STRING_get0_data(current
), length
);
528 static int ts_check_policy(const ASN1_OBJECT
*req_oid
,
529 const TS_TST_INFO
*tst_info
)
531 const ASN1_OBJECT
*resp_oid
= tst_info
->policy_id
;
533 if (OBJ_cmp(req_oid
, resp_oid
) != 0) {
534 TSerr(TS_F_TS_CHECK_POLICY
, TS_R_POLICY_MISMATCH
);
541 static int ts_compute_imprint(BIO
*data
, TS_TST_INFO
*tst_info
,
543 unsigned char **imprint
, unsigned *imprint_len
)
545 TS_MSG_IMPRINT
*msg_imprint
= tst_info
->msg_imprint
;
546 X509_ALGOR
*md_alg_resp
= msg_imprint
->hash_algo
;
548 EVP_MD_CTX
*md_ctx
= NULL
;
549 unsigned char buffer
[4096];
555 if ((*md_alg
= X509_ALGOR_dup(md_alg_resp
)) == NULL
)
557 if ((md
= EVP_get_digestbyobj((*md_alg
)->algorithm
)) == NULL
) {
558 TSerr(TS_F_TS_COMPUTE_IMPRINT
, TS_R_UNSUPPORTED_MD_ALGORITHM
);
561 length
= EVP_MD_size(md
);
564 *imprint_len
= length
;
565 if ((*imprint
= OPENSSL_malloc(*imprint_len
)) == NULL
) {
566 TSerr(TS_F_TS_COMPUTE_IMPRINT
, ERR_R_MALLOC_FAILURE
);
570 md_ctx
= EVP_MD_CTX_new();
571 if (md_ctx
== NULL
) {
572 TSerr(TS_F_TS_COMPUTE_IMPRINT
, ERR_R_MALLOC_FAILURE
);
575 if (!EVP_DigestInit(md_ctx
, md
))
577 while ((length
= BIO_read(data
, buffer
, sizeof(buffer
))) > 0) {
578 if (!EVP_DigestUpdate(md_ctx
, buffer
, length
))
581 if (!EVP_DigestFinal(md_ctx
, *imprint
, NULL
))
583 EVP_MD_CTX_free(md_ctx
);
587 EVP_MD_CTX_free(md_ctx
);
588 X509_ALGOR_free(*md_alg
);
589 OPENSSL_free(*imprint
);
595 static int ts_check_imprints(X509_ALGOR
*algor_a
,
596 const unsigned char *imprint_a
, unsigned len_a
,
597 TS_TST_INFO
*tst_info
)
599 TS_MSG_IMPRINT
*b
= tst_info
->msg_imprint
;
600 X509_ALGOR
*algor_b
= b
->hash_algo
;
604 if (OBJ_cmp(algor_a
->algorithm
, algor_b
->algorithm
))
607 /* The parameter must be NULL in both. */
608 if ((algor_a
->parameter
609 && ASN1_TYPE_get(algor_a
->parameter
) != V_ASN1_NULL
)
610 || (algor_b
->parameter
611 && ASN1_TYPE_get(algor_b
->parameter
) != V_ASN1_NULL
))
615 ret
= len_a
== (unsigned)ASN1_STRING_length(b
->hashed_msg
) &&
616 memcmp(imprint_a
, ASN1_STRING_get0_data(b
->hashed_msg
), len_a
) == 0;
619 TSerr(TS_F_TS_CHECK_IMPRINTS
, TS_R_MESSAGE_IMPRINT_MISMATCH
);
623 static int ts_check_nonces(const ASN1_INTEGER
*a
, TS_TST_INFO
*tst_info
)
625 const ASN1_INTEGER
*b
= tst_info
->nonce
;
628 TSerr(TS_F_TS_CHECK_NONCES
, TS_R_NONCE_NOT_RETURNED
);
632 /* No error if a nonce is returned without being requested. */
633 if (ASN1_INTEGER_cmp(a
, b
) != 0) {
634 TSerr(TS_F_TS_CHECK_NONCES
, TS_R_NONCE_MISMATCH
);
642 * Check if the specified TSA name matches either the subject or one of the
643 * subject alternative names of the TSA certificate.
645 static int ts_check_signer_name(GENERAL_NAME
*tsa_name
, X509
*signer
)
647 STACK_OF(GENERAL_NAME
) *gen_names
= NULL
;
651 if (tsa_name
->type
== GEN_DIRNAME
652 && X509_name_cmp(tsa_name
->d
.dirn
, X509_get_subject_name(signer
)) == 0)
654 gen_names
= X509_get_ext_d2i(signer
, NID_subject_alt_name
, NULL
, &idx
);
655 while (gen_names
!= NULL
) {
656 found
= ts_find_name(gen_names
, tsa_name
) >= 0;
660 * Get the next subject alternative name, although there should be no
663 GENERAL_NAMES_free(gen_names
);
664 gen_names
= X509_get_ext_d2i(signer
, NID_subject_alt_name
, NULL
, &idx
);
666 GENERAL_NAMES_free(gen_names
);
671 /* Returns 1 if name is in gen_names, 0 otherwise. */
672 static int ts_find_name(STACK_OF(GENERAL_NAME
) *gen_names
, GENERAL_NAME
*name
)
675 for (i
= 0, found
= 0; !found
&& i
< sk_GENERAL_NAME_num(gen_names
); ++i
) {
676 GENERAL_NAME
*current
= sk_GENERAL_NAME_value(gen_names
, i
);
677 found
= GENERAL_NAME_cmp(current
, name
) == 0;
679 return found
? i
- 1 : -1;