mirror of
git://git.gnupg.org/gnupg.git
synced 2024-12-22 10:19:57 +01:00
gpgsm: Create binary detached sigs with definite form length octets.
* sm/sign.c: Include tlv.h. (write_detached_signature): New, (gpgsm_sign): Fixup binary detached signatures. -- This helps some other software to verify detached signatures. (cherry picked from commit 8996b0b655952fa6b5bb678a92d3106f72f80f2a)
This commit is contained in:
Werner Koch
parent
6bdf11f671
commit
3d3b941ce9
7
NEWS
7
NEWS
@ -31,6 +31,13 @@ Noteworthy changes in version 2.2.42 (unreleased)
|
||||
|
||||
* gpgsm: Major rewrite of the PKCS#12 parser. [T6536]
|
||||
|
||||
* gpgsm: Non-armored detached signature are now created without
|
||||
using indefinite form length octets. This improves compatibility
|
||||
with some PDF signature verification software.
|
||||
|
||||
* gpgsm: Verification of detached signatures does now strip trailing
|
||||
zeroes from the input if --assume-binary is used. [rG6bdf11f671]
|
||||
|
||||
* dirmngr: New option --ignore-crl-extensions. [T6545]
|
||||
|
||||
* dirmngr: Backport of the AD_QUERY command. [rG2a3bad5985]
|
||||
|
||||
254
sm/sign.c
254
sm/sign.c
@ -1,6 +1,8 @@
|
||||
/* sign.c - Sign a message
|
||||
* Copyright (C) 2001, 2002, 2003, 2008,
|
||||
* 2010 Free Software Foundation, Inc.
|
||||
* Copyright (C) 2003-2012, 2016-2017, 2019,
|
||||
* 2020, 2022-2023 g10 Code GmbH
|
||||
*
|
||||
* This file is part of GnuPG.
|
||||
*
|
||||
@ -16,6 +18,7 @@
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, see <https://www.gnu.org/licenses/>.
|
||||
* SPDX-License-Identifier: GPL-3.0-or-later
|
||||
*/
|
||||
|
||||
#include <config.h>
|
||||
@ -33,6 +36,7 @@
|
||||
|
||||
#include "keydb.h"
|
||||
#include "../common/i18n.h"
|
||||
#include "../common/tlv.h"
|
||||
|
||||
|
||||
/* Hash the data and return if something was hashed. Return -1 on error. */
|
||||
@ -303,6 +307,215 @@ add_certificate_list (ctrl_t ctrl, ksba_cms_t cms, ksba_cert_t cert)
|
||||
|
||||
|
||||
|
||||
|
||||
/* This function takes a binary detached signature in (BLOB,BLOBLEN)
|
||||
* and writes it to OUT_FP. The core of the function is to replace
|
||||
* NDEF length sequences in the input to those with fixed inputs.
|
||||
* This helps certain other implementations to properly verify
|
||||
* detached signature. Moreover, it allows our own trailing zero
|
||||
* stripping code - which we need for PDF signatures - to work
|
||||
* correctly.
|
||||
*
|
||||
* Example start of a detached signature as created by us:
|
||||
* 0 NDEF: SEQUENCE { -- 1st sequence
|
||||
* 2 9: OBJECT IDENTIFIER signedData (1 2 840 113549 1 7 2)
|
||||
* 13 NDEF: [0] { -- 2nd sequence
|
||||
* 15 NDEF: SEQUENCE { -- 3rd sequence
|
||||
* 17 1: INTEGER 1 -- version
|
||||
* 20 15: SET { -- set of algorithms
|
||||
* 22 13: SEQUENCE {
|
||||
* 24 9: OBJECT IDENTIFIER sha-256 (2 16 840 1 101 3 4 2 1)
|
||||
* 35 0: NULL
|
||||
* : }
|
||||
* : }
|
||||
* 37 NDEF: SEQUENCE { -- 4th pretty short sequence
|
||||
* 39 9: OBJECT IDENTIFIER data (1 2 840 113549 1 7 1)
|
||||
* : }
|
||||
* 52 869: [0] {
|
||||
* Our goal is to replace the NDEF by fixed length tags.
|
||||
*/
|
||||
static gpg_error_t
|
||||
write_detached_signature (const void *blob, size_t bloblen, estream_t out_fp)
|
||||
{
|
||||
gpg_error_t err;
|
||||
const unsigned char *p;
|
||||
size_t n, objlen, hdrlen;
|
||||
int class, tag, cons, ndef;
|
||||
const unsigned char *p_ctoid, *p_version, *p_algoset, *p_dataoid;
|
||||
size_t n_ctoid, n_version, n_algoset, n_dataoid;
|
||||
const unsigned char *p_certset, *p_signerinfos;
|
||||
size_t n_certset, n_signerinfos;
|
||||
int i;
|
||||
ksba_der_t dbld;
|
||||
unsigned char *finalder = NULL;
|
||||
size_t finalderlen;
|
||||
|
||||
p = blob;
|
||||
n = bloblen;
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_SEQUENCE && cons))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No 1st sequence. */
|
||||
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_OBJECT_ID && !cons))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No signedData OID. */
|
||||
if (objlen > n)
|
||||
return gpg_error (GPG_ERR_BAD_BER); /* Object larger than data. */
|
||||
p_ctoid = p;
|
||||
n_ctoid = objlen;
|
||||
p += objlen;
|
||||
n -= objlen;
|
||||
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_CONTEXT && tag == 0 && cons))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No 2nd sequence. */
|
||||
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_SEQUENCE && cons))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No 3rd sequence. */
|
||||
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_INTEGER))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No version. */
|
||||
if (objlen > n)
|
||||
return gpg_error (GPG_ERR_BAD_BER); /* Object larger than data. */
|
||||
p_version = p;
|
||||
n_version = objlen;
|
||||
p += objlen;
|
||||
n -= objlen;
|
||||
|
||||
p_algoset = p;
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_SET && cons && !ndef))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No set of algorithms. */
|
||||
if (objlen > n)
|
||||
return gpg_error (GPG_ERR_BAD_BER); /* Object larger than data. */
|
||||
n_algoset = hdrlen + objlen;
|
||||
p += objlen;
|
||||
n -= objlen;
|
||||
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_SEQUENCE && cons))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No 4th sequence. */
|
||||
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_OBJECT_ID && !cons))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No data OID. */
|
||||
if (objlen > n)
|
||||
return gpg_error (GPG_ERR_BAD_BER); /* Object larger than data. */
|
||||
p_dataoid = p;
|
||||
n_dataoid = objlen;
|
||||
p += objlen;
|
||||
n -= objlen;
|
||||
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_NONE && !cons && !objlen))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No End tag. */
|
||||
|
||||
/* certificates [0] IMPLICIT CertificateSet OPTIONAL,
|
||||
* Note: We ignore the following
|
||||
* crls [1] IMPLICIT CertificateRevocationLists OPTIONAL
|
||||
* because gpgsm does not create them. */
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (class == CLASS_CONTEXT && tag == 0 && cons)
|
||||
{
|
||||
if (objlen > n)
|
||||
return gpg_error (GPG_ERR_BAD_BER); /* Object larger than data. */
|
||||
p_certset = p;
|
||||
n_certset = objlen;
|
||||
p += objlen;
|
||||
n -= objlen;
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,
|
||||
&objlen,&hdrlen)))
|
||||
return err;
|
||||
}
|
||||
else
|
||||
{
|
||||
p_certset = NULL;
|
||||
n_certset = 0;
|
||||
}
|
||||
|
||||
/* SignerInfos ::= SET OF SignerInfo */
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_SET && cons && !ndef))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No set of signerInfos. */
|
||||
if (objlen > n)
|
||||
return gpg_error (GPG_ERR_BAD_BER); /* Object larger than data. */
|
||||
p_signerinfos = p;
|
||||
n_signerinfos = objlen;
|
||||
p += objlen;
|
||||
n -= objlen;
|
||||
|
||||
/* For the fun of it check the 3 end tags. */
|
||||
for (i=0; i < 3; i++)
|
||||
{
|
||||
if ((err=parse_ber_header (&p,&n,&class,&tag,&cons,&ndef,
|
||||
&objlen,&hdrlen)))
|
||||
return err;
|
||||
if (!(class == CLASS_UNIVERSAL && tag == TAG_NONE && !cons && !objlen))
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* No End tag. */
|
||||
}
|
||||
if (n)
|
||||
return gpg_error (GPG_ERR_INV_CMS_OBJ); /* Garbage */
|
||||
|
||||
/*---- From here on we jump to leave on error. ----*/
|
||||
|
||||
/* Now create a new object from the collected data. */
|
||||
dbld = ksba_der_builder_new (16); /* (pre-allocate 16 items) */
|
||||
if (!dbld)
|
||||
{
|
||||
err = gpg_error_from_syserror ();
|
||||
goto leave;
|
||||
}
|
||||
ksba_der_add_tag (dbld, 0, KSBA_TYPE_SEQUENCE);
|
||||
ksba_der_add_val ( dbld, 0, KSBA_TYPE_OBJECT_ID, p_ctoid, n_ctoid);
|
||||
ksba_der_add_tag ( dbld, KSBA_CLASS_CONTEXT, 0);
|
||||
ksba_der_add_tag ( dbld, 0, KSBA_TYPE_SEQUENCE);
|
||||
ksba_der_add_val ( dbld, 0, KSBA_TYPE_INTEGER, p_version, n_version);
|
||||
ksba_der_add_der ( dbld, p_algoset, n_algoset);
|
||||
ksba_der_add_tag ( dbld, 0, KSBA_TYPE_SEQUENCE);
|
||||
ksba_der_add_val ( dbld, 0, KSBA_TYPE_OBJECT_ID, p_dataoid, n_dataoid);
|
||||
ksba_der_add_end ( dbld);
|
||||
if (p_certset)
|
||||
{
|
||||
ksba_der_add_tag ( dbld, KSBA_CLASS_CONTEXT, 0);
|
||||
ksba_der_add_der ( dbld, p_certset, n_certset);
|
||||
ksba_der_add_end ( dbld);
|
||||
}
|
||||
ksba_der_add_tag ( dbld, 0, KSBA_TYPE_SET);
|
||||
ksba_der_add_der ( dbld, p_signerinfos, n_signerinfos);
|
||||
ksba_der_add_end ( dbld);
|
||||
ksba_der_add_end ( dbld);
|
||||
ksba_der_add_end ( dbld);
|
||||
ksba_der_add_end (dbld);
|
||||
|
||||
err = ksba_der_builder_get (dbld, &finalder, &finalderlen);
|
||||
if (err)
|
||||
goto leave;
|
||||
|
||||
if (es_fwrite (finalder, finalderlen, 1, out_fp) != 1)
|
||||
{
|
||||
err = gpg_error_from_syserror ();
|
||||
goto leave;
|
||||
}
|
||||
|
||||
|
||||
leave:
|
||||
ksba_der_release (dbld);
|
||||
ksba_free (finalder);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
||||
|
||||
/* Perform a sign operation.
|
||||
|
||||
@ -318,6 +531,7 @@ gpgsm_sign (ctrl_t ctrl, certlist_t signerlist,
|
||||
gpg_error_t err;
|
||||
gnupg_ksba_io_t b64writer = NULL;
|
||||
ksba_writer_t writer;
|
||||
estream_t sig_fp = NULL; /* Used for detached signatures. */
|
||||
ksba_cms_t cms = NULL;
|
||||
ksba_stop_reason_t stopreason;
|
||||
KEYDB_HANDLE kh = NULL;
|
||||
@ -328,6 +542,7 @@ gpgsm_sign (ctrl_t ctrl, certlist_t signerlist,
|
||||
ksba_isotime_t signed_at;
|
||||
certlist_t cl;
|
||||
int release_signerlist = 0;
|
||||
int binary_detached = detached && !ctrl->create_pem && !ctrl->create_base64;
|
||||
|
||||
audit_set_type (ctrl->audit, AUDIT_TYPE_SIGN);
|
||||
|
||||
@ -350,11 +565,25 @@ gpgsm_sign (ctrl_t ctrl, certlist_t signerlist,
|
||||
goto leave;
|
||||
}
|
||||
|
||||
/* Note that in detached mode the b64 write is actually a binary
|
||||
* writer because we need to fixup the created signature later.
|
||||
* Note that we do this only for binary output because we have no
|
||||
* PEM writer interface outside of the ksba create writer code. */
|
||||
ctrl->pem_name = "SIGNED MESSAGE";
|
||||
rc = gnupg_ksba_create_writer
|
||||
(&b64writer, ((ctrl->create_pem? GNUPG_KSBA_IO_PEM : 0)
|
||||
| (ctrl->create_base64? GNUPG_KSBA_IO_BASE64 : 0)),
|
||||
ctrl->pem_name, out_fp, &writer);
|
||||
if (binary_detached)
|
||||
{
|
||||
sig_fp = es_fopenmem (0, "w+");
|
||||
rc = sig_fp? 0 : gpg_error_from_syserror ();
|
||||
if (!rc)
|
||||
rc = gnupg_ksba_create_writer (&b64writer, 0, NULL, sig_fp, &writer);
|
||||
}
|
||||
else
|
||||
{
|
||||
rc = gnupg_ksba_create_writer
|
||||
(&b64writer, ((ctrl->create_pem? GNUPG_KSBA_IO_PEM : 0)
|
||||
| (ctrl->create_base64? GNUPG_KSBA_IO_BASE64 : 0)),
|
||||
ctrl->pem_name, out_fp, &writer);
|
||||
}
|
||||
if (rc)
|
||||
{
|
||||
log_error ("can't create writer: %s\n", gpg_strerror (rc));
|
||||
@ -838,6 +1067,22 @@ gpgsm_sign (ctrl_t ctrl, certlist_t signerlist,
|
||||
goto leave;
|
||||
}
|
||||
|
||||
if (binary_detached)
|
||||
{
|
||||
void *blob = NULL;
|
||||
size_t bloblen;
|
||||
|
||||
rc = es_fclose_snatch (sig_fp, &blob, &bloblen);
|
||||
sig_fp = NULL;
|
||||
if (rc)
|
||||
goto leave;
|
||||
rc = write_detached_signature (blob, bloblen, out_fp);
|
||||
xfree (blob);
|
||||
if (rc)
|
||||
goto leave;
|
||||
}
|
||||
|
||||
|
||||
audit_log (ctrl->audit, AUDIT_SIGNING_DONE);
|
||||
log_info ("signature created\n");
|
||||
|
||||
@ -851,5 +1096,6 @@ gpgsm_sign (ctrl_t ctrl, certlist_t signerlist,
|
||||
gnupg_ksba_destroy_writer (b64writer);
|
||||
keydb_release (kh);
|
||||
gcry_md_close (data_md);
|
||||
es_fclose (sig_fp);
|
||||
return rc;
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user