mirror of git://git.gnupg.org/gnupg.git
249 lines
7.2 KiB
C
249 lines
7.2 KiB
C
/* seckey-cert.c - secret key certifucate packet handling
|
|
* Copyright (C) 1998 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 <assert.h>
|
|
#include "util.h"
|
|
#include "memory.h"
|
|
#include "packet.h"
|
|
#include "mpi.h"
|
|
#include "keydb.h"
|
|
#include "cipher.h"
|
|
#include "main.h"
|
|
#include "options.h"
|
|
#include "i18n.h"
|
|
|
|
|
|
static int
|
|
do_check( PKT_secret_key *sk )
|
|
{
|
|
byte *buffer;
|
|
u16 csum=0;
|
|
int i, res;
|
|
unsigned nbytes;
|
|
|
|
if( sk->is_protected ) { /* remove the protection */
|
|
DEK *dek = NULL;
|
|
u32 keyid[2];
|
|
CIPHER_HANDLE cipher_hd=NULL;
|
|
PKT_secret_key *save_sk;
|
|
char save_iv[8];
|
|
|
|
if( sk->protect.algo == CIPHER_ALGO_NONE )
|
|
BUG();
|
|
if( check_cipher_algo( sk->protect.algo ) )
|
|
return G10ERR_CIPHER_ALGO; /* unsupported protection algorithm */
|
|
if( cipher_get_blocksize( sk->protect.algo ) != 8 )
|
|
return G10ERR_CIPHER_ALGO; /* unsupported protection algorithm */
|
|
keyid_from_sk( sk, keyid );
|
|
dek = passphrase_to_dek( keyid, sk->protect.algo,
|
|
&sk->protect.s2k, 0 );
|
|
cipher_hd = cipher_open( sk->protect.algo,
|
|
CIPHER_MODE_AUTO_CFB, 1);
|
|
cipher_setkey( cipher_hd, dek->key, dek->keylen );
|
|
cipher_setiv( cipher_hd, NULL );
|
|
m_free(dek);
|
|
save_sk = copy_secret_key( NULL, sk );
|
|
memcpy(save_iv, sk->protect.iv, 8 );
|
|
cipher_decrypt( cipher_hd, sk->protect.iv, sk->protect.iv, 8 );
|
|
csum = 0;
|
|
if( sk->version >= 4 && !(opt.emulate_bugs & EMUBUG_ENCR_MPI) ) {
|
|
int ndata;
|
|
byte *p, *data;
|
|
|
|
i = pubkey_get_npkey(sk->pubkey_algo);
|
|
assert( mpi_is_opaque( sk->skey[i] ) );
|
|
p = mpi_get_opaque( sk->skey[i], &ndata );
|
|
data = m_alloc_secure( ndata );
|
|
cipher_decrypt( cipher_hd, data, p, ndata );
|
|
mpi_free( sk->skey[i] ); sk->skey[i] = NULL ;
|
|
p = data;
|
|
csum = checksum( data, ndata);
|
|
if( ndata < 2 )
|
|
log_bug("not enough bytes for checksum\n");
|
|
sk->csum = data[ndata-2] << 8 | data[ndata-1];
|
|
/* must check it here otherwise the mpi_read_xx would fail
|
|
* because the length das an abritary value */
|
|
if( sk->csum == csum ) {
|
|
for( ; i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
|
|
nbytes = ndata;
|
|
sk->skey[i] = mpi_read_from_buffer(p, &nbytes, 1 );
|
|
ndata -= nbytes;
|
|
p += nbytes;
|
|
}
|
|
}
|
|
m_free(data);
|
|
}
|
|
else {
|
|
for(i=pubkey_get_npkey(sk->pubkey_algo);
|
|
i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
|
|
buffer = mpi_get_secure_buffer( sk->skey[i], &nbytes, NULL );
|
|
cipher_sync( cipher_hd );
|
|
assert( mpi_is_protected(sk->skey[i]) );
|
|
cipher_decrypt( cipher_hd, buffer, buffer, nbytes );
|
|
mpi_set_buffer( sk->skey[i], buffer, nbytes, 0 );
|
|
mpi_clear_protect_flag( sk->skey[i] );
|
|
csum += checksum_mpi( sk->skey[i] );
|
|
m_free( buffer );
|
|
}
|
|
if( opt.emulate_bugs & EMUBUG_GPGCHKSUM ) {
|
|
csum = sk->csum;
|
|
}
|
|
}
|
|
cipher_close( cipher_hd );
|
|
/* now let's see whether we have used the right passphrase */
|
|
if( csum != sk->csum ) {
|
|
copy_secret_key( sk, save_sk );
|
|
free_secret_key( save_sk );
|
|
memcpy( sk->protect.iv, save_iv, 8 );
|
|
return G10ERR_BAD_PASS;
|
|
}
|
|
/* the checksum may fail, so we also check the key itself */
|
|
res = pubkey_check_secret_key( sk->pubkey_algo, sk->skey );
|
|
if( res ) {
|
|
copy_secret_key( sk, save_sk );
|
|
free_secret_key( save_sk );
|
|
memcpy( sk->protect.iv, save_iv, 8 );
|
|
return G10ERR_BAD_PASS;
|
|
}
|
|
free_secret_key( save_sk );
|
|
sk->is_protected = 0;
|
|
}
|
|
else { /* not protected, assume it is okay if the checksum is okay */
|
|
csum = 0;
|
|
for(i=pubkey_get_npkey(sk->pubkey_algo);
|
|
i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
|
|
csum += checksum_mpi( sk->skey[i] );
|
|
}
|
|
if( csum != sk->csum )
|
|
return G10ERR_CHECKSUM;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
/****************
|
|
* Check the secret key
|
|
* Ask up to 3 times for a correct passphrase
|
|
*/
|
|
int
|
|
check_secret_key( PKT_secret_key *sk )
|
|
{
|
|
int rc = G10ERR_BAD_PASS;
|
|
int i;
|
|
|
|
for(i=0; i < 3 && rc == G10ERR_BAD_PASS; i++ ) {
|
|
if( i )
|
|
log_error(_("Invalid passphrase; please try again ...\n"));
|
|
rc = do_check( sk );
|
|
#if 0 /* set to 1 to enable the workaround */
|
|
if( rc == G10ERR_BAD_PASS && sk->is_protected
|
|
&& sk->protect.algo == CIPHER_ALGO_BLOWFISH
|
|
&& sk->pubkey_algo != PUBKEY_ALGO_ELGAMAL ) {
|
|
/* Workaround for a bug in 0.2.16 which still used
|
|
* a 160 bit key for BLOWFISH. */
|
|
log_info("trying workaround for 0.2.16 passphrase bug ...\n");
|
|
log_info("If you don't need this, uncomment it in g10/seckey-cert.c\n\n");
|
|
sk->protect.algo = CIPHER_ALGO_BLOWFISH160;
|
|
rc = do_check( sk );
|
|
if( rc )
|
|
rc = G10ERR_BAD_PASS;
|
|
sk->protect.algo = CIPHER_ALGO_BLOWFISH;
|
|
}
|
|
#endif
|
|
if( get_passphrase_fd() != -1 )
|
|
break;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/****************
|
|
* check whether the secret key is protected.
|
|
* Returns: 0 not protected, -1 on error or the protection algorithm
|
|
*/
|
|
int
|
|
is_secret_key_protected( PKT_secret_key *sk )
|
|
{
|
|
return sk->is_protected? sk->protect.algo : 0;
|
|
}
|
|
|
|
|
|
|
|
/****************
|
|
* Protect the secret key with the passphrase from DEK
|
|
*/
|
|
int
|
|
protect_secret_key( PKT_secret_key *sk, DEK *dek )
|
|
{
|
|
int i, rc = 0;
|
|
byte *buffer;
|
|
unsigned nbytes;
|
|
u16 csum;
|
|
|
|
if( !dek )
|
|
return 0;
|
|
|
|
if( !sk->is_protected ) { /* okay, apply the protection */
|
|
CIPHER_HANDLE cipher_hd=NULL;
|
|
|
|
if( check_cipher_algo( sk->protect.algo ) )
|
|
rc = G10ERR_CIPHER_ALGO; /* unsupport protection algorithm */
|
|
else if( cipher_get_blocksize( sk->protect.algo ) != 8 )
|
|
rc = G10ERR_CIPHER_ALGO; /* unsupport protection algorithm */
|
|
else {
|
|
cipher_hd = cipher_open( sk->protect.algo,
|
|
CIPHER_MODE_AUTO_CFB, 1 );
|
|
cipher_setkey( cipher_hd, dek->key, dek->keylen );
|
|
cipher_setiv( cipher_hd, NULL );
|
|
cipher_encrypt( cipher_hd, sk->protect.iv, sk->protect.iv, 8 );
|
|
if( sk->version >= 4 && !(opt.emulate_bugs & EMUBUG_ENCR_MPI) ) {
|
|
BUG();
|
|
}
|
|
else {
|
|
/* NOTE: we always recalculate the checksum because there
|
|
* are some * test releases which calculated it wrong */
|
|
csum = 0;
|
|
for(i=pubkey_get_npkey(sk->pubkey_algo);
|
|
i < pubkey_get_nskey(sk->pubkey_algo); i++ ) {
|
|
csum += checksum_mpi_counted_nbits( sk->skey[i] );
|
|
buffer = mpi_get_buffer( sk->skey[i], &nbytes, NULL );
|
|
cipher_sync( cipher_hd );
|
|
assert( !mpi_is_protected(sk->skey[i]) );
|
|
cipher_encrypt( cipher_hd, buffer, buffer, nbytes );
|
|
mpi_set_buffer( sk->skey[i], buffer, nbytes, 0 );
|
|
mpi_set_protect_flag( sk->skey[i] );
|
|
m_free( buffer );
|
|
}
|
|
sk->csum = csum;
|
|
}
|
|
sk->is_protected = 1;
|
|
cipher_close( cipher_hd );
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|