mirror of
git://git.gnupg.org/gnupg.git
synced 2025-07-03 22:56:33 +02:00
Base code for gpgsm --verify does work
This commit is contained in:
Werner Koch
parent
90d060c199
commit
0f26760d9f
13 changed files with 562 additions and 88 deletions
374
sm/verify.c
Normal file
374
sm/verify.c
Normal file
|
|
@ -0,0 +1,374 @@
|
|||
/* verify.c - Verify a messages signature
|
||||
* Copyright (C) 2001 Free Software Foundation, Inc.
|
||||
*
|
||||
* This file is part of GnuPG.
|
||||
*
|
||||
* GnuPG is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* GnuPG is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
|
||||
*/
|
||||
|
||||
#include <config.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
#include <errno.h>
|
||||
#include <unistd.h>
|
||||
#include <time.h>
|
||||
#include <assert.h>
|
||||
|
||||
#include <gcrypt.h>
|
||||
#include <ksba.h>
|
||||
|
||||
#include "gpgsm.h"
|
||||
#include "keydb.h"
|
||||
#include "i18n.h"
|
||||
|
||||
struct reader_cb_parm_s {
|
||||
FILE *fp;
|
||||
};
|
||||
|
||||
/* FIXME: We need to write a generic reader callback which should be able
|
||||
to detect and convert base-64 */
|
||||
static int
|
||||
reader_cb (void *cb_value, char *buffer, size_t count, size_t *nread)
|
||||
{
|
||||
struct reader_cb_parm_s *parm = cb_value;
|
||||
size_t n;
|
||||
int c = 0;
|
||||
|
||||
*nread = 0;
|
||||
if (!buffer)
|
||||
return -1; /* not supported */
|
||||
|
||||
for (n=0; n < count; n++)
|
||||
{
|
||||
c = getc (parm->fp);
|
||||
if (c == EOF)
|
||||
{
|
||||
if ( ferror (parm->fp) )
|
||||
return -1;
|
||||
if (n)
|
||||
break; /* return what we have before an EOF */
|
||||
return -1;
|
||||
}
|
||||
*(byte *)buffer++ = c;
|
||||
}
|
||||
|
||||
*nread = n;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* fixme: duplicated from import.c */
|
||||
static void
|
||||
store_cert (KsbaCert cert)
|
||||
{
|
||||
KEYDB_HANDLE kh;
|
||||
int rc;
|
||||
|
||||
kh = keydb_new (0);
|
||||
if (!kh)
|
||||
{
|
||||
log_error (_("failed to allocated keyDB handle\n"));
|
||||
return;
|
||||
}
|
||||
rc = keydb_locate_writable (kh, 0);
|
||||
if (rc)
|
||||
log_error (_("error finding writable keyDB: %s\n"), gpgsm_strerror (rc));
|
||||
|
||||
rc = keydb_insert_cert (kh, cert);
|
||||
if (rc)
|
||||
{
|
||||
log_error (_("error storing certificate: %s\n"), gpgsm_strerror (rc));
|
||||
}
|
||||
keydb_release (kh);
|
||||
}
|
||||
|
||||
|
||||
|
||||
static void
|
||||
print_integer (unsigned char *p)
|
||||
{
|
||||
unsigned long len;
|
||||
|
||||
if (!p)
|
||||
printf ("none");
|
||||
else
|
||||
{
|
||||
len = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
|
||||
for (p+=4; len; len--, p++)
|
||||
printf ("%02X", *p);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
int
|
||||
gpgsm_verify (int in_fd)
|
||||
{
|
||||
int i, rc;
|
||||
KsbaError err;
|
||||
KsbaReader reader = NULL;
|
||||
KsbaWriter writer = NULL;
|
||||
KsbaCMS cms = NULL;
|
||||
KsbaStopReason stopreason;
|
||||
KsbaCert cert;
|
||||
KEYDB_HANDLE kh;
|
||||
GCRY_MD_HD data_md = NULL;
|
||||
struct reader_cb_parm_s rparm;
|
||||
int signer;
|
||||
int algo;
|
||||
int is_detached;
|
||||
|
||||
memset (&rparm, 0, sizeof rparm);
|
||||
|
||||
kh = keydb_new (0);
|
||||
if (!kh)
|
||||
{
|
||||
log_error (_("failed to allocated keyDB handle\n"));
|
||||
rc = GPGSM_General_Error;
|
||||
goto leave;
|
||||
}
|
||||
|
||||
|
||||
rparm.fp = fdopen ( dup (in_fd), "rb");
|
||||
if (!rparm.fp)
|
||||
{
|
||||
log_error ("fdopen() failed: %s\n", strerror (errno));
|
||||
rc = seterr (IO_Error);
|
||||
goto leave;
|
||||
}
|
||||
|
||||
/* setup a skaba reader which uses a callback function so that we can
|
||||
strip off a base64 encoding when necessary */
|
||||
reader = ksba_reader_new ();
|
||||
writer = ksba_writer_new ();
|
||||
if (!reader || !writer)
|
||||
{
|
||||
rc = seterr (Out_Of_Core);
|
||||
goto leave;
|
||||
}
|
||||
|
||||
rc = ksba_reader_set_cb (reader, reader_cb, &rparm );
|
||||
if (rc)
|
||||
{
|
||||
ksba_reader_release (reader);
|
||||
rc = map_ksba_err (rc);
|
||||
goto leave;
|
||||
}
|
||||
|
||||
cms = ksba_cms_new ();
|
||||
if (!cms)
|
||||
{
|
||||
rc = seterr (Out_Of_Core);
|
||||
goto leave;
|
||||
}
|
||||
|
||||
err = ksba_cms_set_reader_writer (cms, reader, writer);
|
||||
if (err)
|
||||
{
|
||||
log_debug ("ksba_cms_set_reader_writer failed: %s\n",
|
||||
ksba_strerror (err));
|
||||
rc = map_ksba_err (err);
|
||||
goto leave;
|
||||
}
|
||||
|
||||
data_md = gcry_md_open (0, 0);
|
||||
if (!data_md)
|
||||
{
|
||||
rc = map_gcry_err (gcry_errno());
|
||||
log_error ("md_open failed: %s\n", gcry_strerror (-1));
|
||||
goto leave;
|
||||
}
|
||||
|
||||
is_detached = 0;
|
||||
do
|
||||
{
|
||||
err = ksba_cms_parse (cms, &stopreason);
|
||||
if (err)
|
||||
{
|
||||
log_debug ("ksba_cms_parse failed: %s\n", ksba_strerror (err));
|
||||
rc = map_ksba_err (err);
|
||||
goto leave;
|
||||
}
|
||||
log_debug ("ksba_cms_parse - stop reason %d\n", stopreason);
|
||||
if (stopreason == KSBA_SR_NEED_HASH)
|
||||
{
|
||||
is_detached = 1;
|
||||
log_debug ("Detached signature\n");
|
||||
}
|
||||
if (stopreason == KSBA_SR_BEGIN_DATA)
|
||||
log_error ("error: only detached signatuires are supportted\n");
|
||||
|
||||
if (stopreason == KSBA_SR_NEED_HASH
|
||||
|| stopreason == KSBA_SR_BEGIN_DATA)
|
||||
{ /* We are now able to enable the hash algorithms */
|
||||
for (i=0; (algo = ksba_cms_get_digest_algo_list (cms, i)) >= 0; i++)
|
||||
{
|
||||
if (algo)
|
||||
gcry_md_enable (data_md, algo);
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
while (stopreason != KSBA_SR_READY);
|
||||
|
||||
for (i=0; (cert=ksba_cms_get_cert (cms, i)); i++)
|
||||
{
|
||||
log_debug ("storing certifcate %d\n", i);
|
||||
/* Fixme: we should mark the stored certificates as temporary
|
||||
and put them in a cache first */
|
||||
store_cert (cert);
|
||||
ksba_cert_release (cert);
|
||||
}
|
||||
|
||||
cert = NULL;
|
||||
err = 0;
|
||||
for (signer=0; signer < 1; signer++)
|
||||
{
|
||||
char *issuer = NULL;
|
||||
char *sigval = NULL;
|
||||
unsigned char *serial;
|
||||
char *msgdigest = NULL;
|
||||
size_t msgdigestlen;
|
||||
|
||||
err = ksba_cms_get_issuer_serial (cms, signer, &issuer, &serial);
|
||||
if (err)
|
||||
break;
|
||||
printf ("signer %d - issuer: `%s'\n", signer, issuer? issuer:"[NONE]");
|
||||
printf ("signer %d - serial: ", signer);
|
||||
print_integer (serial);
|
||||
putchar ('\n');
|
||||
|
||||
err = ksba_cms_get_message_digest (cms, signer,
|
||||
&msgdigest, &msgdigestlen);
|
||||
if (err)
|
||||
break;
|
||||
|
||||
algo = ksba_cms_get_digest_algo (cms, signer);
|
||||
printf ("signer %d - digest algo: %d\n", signer, algo);
|
||||
if ( !gcry_md_info (data_md, GCRYCTL_IS_ALGO_ENABLED, &algo, NULL) )
|
||||
{
|
||||
log_debug ("digest algo %d has not been enabled\n", algo);
|
||||
goto next_signer;
|
||||
}
|
||||
|
||||
sigval = ksba_cms_get_sig_val (cms, signer);
|
||||
printf ("signer %d - signature: `%s'\n",
|
||||
signer, sigval? sigval: "[ERROR]");
|
||||
|
||||
/* Find the certificate of the signer */
|
||||
keydb_search_reset (kh);
|
||||
rc = keydb_search_issuer_sn (kh, issuer, serial);
|
||||
if (rc)
|
||||
{
|
||||
log_debug ("failed to find the certificate: %s\n",
|
||||
gpgsm_strerror(rc));
|
||||
goto next_signer;
|
||||
}
|
||||
|
||||
rc = keydb_get_cert (kh, &cert);
|
||||
if (rc)
|
||||
{
|
||||
log_debug ("failed to get cert: %s\n", gpgsm_strerror (rc));
|
||||
goto next_signer;
|
||||
}
|
||||
|
||||
if (msgdigest)
|
||||
{ /* Signed attributes are available. */
|
||||
GCRY_MD_HD md;
|
||||
unsigned char *s;
|
||||
|
||||
/* check that the message digest in the signed attributes
|
||||
matches the one we calculated on the data */
|
||||
s = gcry_md_read (data_md, algo);
|
||||
if ( !s || !msgdigestlen
|
||||
|| gcry_md_get_algo_dlen (algo) != msgdigestlen
|
||||
|| !s || memcmp (s, msgdigest, msgdigestlen) )
|
||||
{
|
||||
log_error ("message digest attribute does not "
|
||||
"match calculated one\n");
|
||||
/*goto next_signer; FIXME: only for debugging commented*/
|
||||
}
|
||||
|
||||
md = gcry_md_open (algo, 0);
|
||||
if (!md)
|
||||
{
|
||||
log_error ("md_open failed: %s\n", gcry_strerror (-1));
|
||||
goto next_signer;
|
||||
}
|
||||
ksba_cms_set_hash_function (cms, HASH_FNC, md);
|
||||
rc = ksba_cms_hash_signed_attrs (cms, signer);
|
||||
if (rc)
|
||||
{
|
||||
log_debug ("hashing signed attrs failed: %s\n",
|
||||
ksba_strerror (rc));
|
||||
gcry_md_close (md);
|
||||
goto next_signer;
|
||||
}
|
||||
rc = gpgsm_check_cms_signature (cert, sigval, md, algo);
|
||||
gcry_md_close (md);
|
||||
}
|
||||
else
|
||||
{
|
||||
rc = gpgsm_check_cms_signature (cert, sigval, data_md, algo);
|
||||
}
|
||||
|
||||
if (rc)
|
||||
{
|
||||
log_error ("invalid signature: %s\n", gpgsm_strerror (rc));
|
||||
goto next_signer;
|
||||
}
|
||||
log_debug ("signature is good - checking certs\n");
|
||||
/* FIXME: validate_path */
|
||||
rc = gpgsm_validate_path (cert);
|
||||
if (rc)
|
||||
{
|
||||
log_error ("invalid certification path: %s\n", gpgsm_strerror (rc));
|
||||
goto next_signer;
|
||||
}
|
||||
log_info ("signature is good\n");
|
||||
|
||||
|
||||
next_signer:
|
||||
rc = 0;
|
||||
xfree (issuer);
|
||||
xfree (serial);
|
||||
xfree (sigval);
|
||||
xfree (msgdigest);
|
||||
ksba_cert_release (cert);
|
||||
cert = NULL;
|
||||
}
|
||||
rc = 0;
|
||||
if (err)
|
||||
{
|
||||
log_debug ("ksba error: %s\n", ksba_strerror (err));
|
||||
rc = map_ksba_err (rc);
|
||||
}
|
||||
|
||||
|
||||
|
||||
leave:
|
||||
ksba_cms_release (cms);
|
||||
ksba_reader_release (reader);
|
||||
keydb_release (kh);
|
||||
gcry_md_close (data_md);
|
||||
if (rparm.fp)
|
||||
fclose (rparm.fp);
|
||||
return rc;
|
||||
}
|
||||
|
||||
|
||||
Loading…
Add table
Add a link
Reference in a new issue