mirror of
git://git.gnupg.org/gnupg.git
synced 2024-11-10 21:38:50 +01:00
313 lines
8.7 KiB
C
313 lines
8.7 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"
|
|
|
|
|
|
static int
|
|
do_check( PKT_secret_cert *cert )
|
|
{
|
|
byte *buffer;
|
|
u16 csum=0;
|
|
int res;
|
|
unsigned nbytes;
|
|
|
|
if( cert->is_protected ) { /* remove the protection */
|
|
DEK *dek = NULL;
|
|
u32 keyid[2];
|
|
CIPHER_HANDLE cipher_hd=NULL;
|
|
PKT_secret_cert *save_cert;
|
|
char save_iv[8];
|
|
|
|
switch( cert->protect.algo ) {
|
|
case CIPHER_ALGO_NONE: BUG(); break;
|
|
case CIPHER_ALGO_BLOWFISH:
|
|
case CIPHER_ALGO_CAST:
|
|
keyid_from_skc( cert, keyid );
|
|
if( cert->protect.s2k == 1 || cert->protect.s2k == 3 )
|
|
dek = get_passphrase_hash( keyid, NULL,
|
|
cert->protect.salt );
|
|
else
|
|
dek = get_passphrase_hash( keyid, NULL, NULL );
|
|
|
|
cipher_hd = cipher_open( cert->protect.algo,
|
|
CIPHER_MODE_AUTO_CFB, 1);
|
|
cipher_setkey( cipher_hd, dek->key, dek->keylen );
|
|
cipher_setiv( cipher_hd, NULL );
|
|
m_free(dek); /* pw is in secure memory, so m_free() burns it */
|
|
save_cert = copy_secret_cert( NULL, cert );
|
|
memcpy(save_iv, cert->protect.iv, 8 );
|
|
cipher_decrypt( cipher_hd, cert->protect.iv, cert->protect.iv, 8 );
|
|
switch( cert->pubkey_algo ) {
|
|
case PUBKEY_ALGO_ELGAMAL:
|
|
buffer = mpi_get_secure_buffer( cert->d.elg.x, &nbytes, NULL );
|
|
cipher_decrypt( cipher_hd, buffer, buffer, nbytes );
|
|
mpi_set_buffer( cert->d.elg.x, buffer, nbytes, 0 );
|
|
csum = checksum_mpi( cert->d.elg.x );
|
|
m_free( buffer );
|
|
break;
|
|
case PUBKEY_ALGO_DSA:
|
|
buffer = mpi_get_secure_buffer( cert->d.dsa.x, &nbytes, NULL );
|
|
cipher_decrypt( cipher_hd, buffer, buffer, nbytes );
|
|
mpi_set_buffer( cert->d.dsa.x, buffer, nbytes, 0 );
|
|
csum = checksum_mpi( cert->d.dsa.x );
|
|
m_free( buffer );
|
|
break;
|
|
#ifdef HAVE_RSA_CIPHER
|
|
case PUBKEY_ALGO_RSA:
|
|
csum = 0;
|
|
#define X(a) do { \
|
|
buffer = mpi_get_secure_buffer( cert->d.rsa.##a, \
|
|
&nbytes, NULL ); \
|
|
csum += checksum_u16( nbytes*8 ); \
|
|
cipher_decrypt( cipher_hd, buffer, buffer, nbytes ); \
|
|
csum += checksum( buffer, nbytes ); \
|
|
mpi_set_buffer(cert->d.rsa.##a, buffer, nbytes, 0 ); \
|
|
m_free( buffer ); \
|
|
} while(0)
|
|
X(d);
|
|
X(p);
|
|
X(q);
|
|
X(u);
|
|
#undef X
|
|
break;
|
|
#endif /* HAVE_RSA_CIPHER */
|
|
|
|
default: BUG();
|
|
}
|
|
cipher_close( cipher_hd );
|
|
/* now let's see whether we have used the right passphrase */
|
|
if( csum != cert->csum ) {
|
|
if( cert->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
|
|
/* very bad kludge to work around an early bug */
|
|
csum -= checksum_u16( mpi_get_nbits(cert->d.elg.x) );
|
|
nbytes = mpi_get_nlimbs(cert->d.elg.x) * 4;
|
|
csum += checksum_u16( nbytes*8 );
|
|
if( !opt.batch && csum == cert->csum )
|
|
log_info("Probably you have an old key - use "
|
|
"\"--change-passphrase\" to convert.\n");
|
|
}
|
|
if( csum != cert->csum ) {
|
|
copy_secret_cert( cert, save_cert );
|
|
free_secret_cert( save_cert );
|
|
memcpy( cert->protect.iv, save_iv, 8 );
|
|
return G10ERR_BAD_PASS;
|
|
}
|
|
}
|
|
|
|
switch( cert->pubkey_algo ) {
|
|
case PUBKEY_ALGO_ELGAMAL:
|
|
res = elg_check_secret_key( &cert->d.elg );
|
|
break;
|
|
case PUBKEY_ALGO_DSA:
|
|
res = dsa_check_secret_key( &cert->d.dsa );
|
|
break;
|
|
#ifdef HAVE_RSA_CIPHER
|
|
case PUBKEY_ALGO_RSA:
|
|
res = rsa_check_secret_key( &cert->d.rsa );
|
|
break;
|
|
#endif
|
|
default: BUG();
|
|
}
|
|
if( !res ) {
|
|
copy_secret_cert( cert, save_cert );
|
|
free_secret_cert( save_cert );
|
|
memcpy( cert->protect.iv, save_iv, 8 );
|
|
return G10ERR_BAD_PASS;
|
|
}
|
|
free_secret_cert( save_cert );
|
|
cert->is_protected = 0;
|
|
break;
|
|
|
|
default:
|
|
return G10ERR_CIPHER_ALGO; /* unsupported protection algorithm */
|
|
}
|
|
}
|
|
else { /* not protected */
|
|
switch( cert->pubkey_algo ) {
|
|
case PUBKEY_ALGO_ELGAMAL:
|
|
csum = checksum_mpi( cert->d.elg.x );
|
|
break;
|
|
case PUBKEY_ALGO_DSA:
|
|
csum = checksum_mpi( cert->d.dsa.x );
|
|
break;
|
|
#ifdef HAVE_RSA_CIPHER
|
|
case PUBKEY_ALGO_RSA:
|
|
csum =0;
|
|
buffer = mpi_get_buffer( cert->d.rsa.rsa_d, &nbytes, NULL );
|
|
csum += checksum_u16( nbytes*8 );
|
|
csum += checksum( buffer, nbytes );
|
|
m_free( buffer );
|
|
buffer = mpi_get_buffer( cert->d.rsa.rsa_p, &nbytes, NULL );
|
|
csum += checksum_u16( nbytes*8 );
|
|
csum += checksum( buffer, nbytes );
|
|
m_free( buffer );
|
|
buffer = mpi_get_buffer( cert->d.rsa.rsa_q, &nbytes, NULL );
|
|
csum += checksum_u16( nbytes*8 );
|
|
csum += checksum( buffer, nbytes );
|
|
m_free( buffer );
|
|
buffer = mpi_get_buffer( cert->d.rsa.rsa_u, &nbytes, NULL );
|
|
csum += checksum_u16( nbytes*8 );
|
|
csum += checksum( buffer, nbytes );
|
|
m_free( buffer );
|
|
break;
|
|
#endif
|
|
default: BUG();
|
|
}
|
|
if( csum != cert->csum ) {
|
|
if( cert->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) {
|
|
/* very bad kludge to work around an early bug */
|
|
csum -= checksum_u16( mpi_get_nbits(cert->d.elg.x) );
|
|
nbytes = mpi_get_nlimbs(cert->d.elg.x) * 4;
|
|
csum += checksum_u16( nbytes*8 );
|
|
if( !opt.batch && csum == cert->csum )
|
|
log_info("Probably you have an old key - use "
|
|
"\"--change-passphrase\" to convert.\n");
|
|
}
|
|
if( csum != cert->csum )
|
|
return G10ERR_CHECKSUM;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
/****************
|
|
* Check the secret key certificate
|
|
* Ask up to 3 times for a correct passphrase
|
|
*/
|
|
int
|
|
check_secret_key( PKT_secret_cert *cert )
|
|
{
|
|
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");
|
|
switch( cert->pubkey_algo ) {
|
|
case PUBKEY_ALGO_ELGAMAL:
|
|
case PUBKEY_ALGO_DSA:
|
|
rc = do_check( cert );
|
|
break;
|
|
default: rc = G10ERR_PUBKEY_ALGO;
|
|
}
|
|
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_cert *cert )
|
|
{
|
|
return cert->is_protected? cert->protect.algo : 0;
|
|
}
|
|
|
|
|
|
static int
|
|
do_protect( void (*fnc)(CIPHER_HANDLE, byte *, byte *, unsigned),
|
|
CIPHER_HANDLE fnc_hd, PKT_secret_cert *cert )
|
|
{
|
|
byte *buffer;
|
|
unsigned nbytes;
|
|
|
|
switch( cert->pubkey_algo ) {
|
|
case PUBKEY_ALGO_ELGAMAL:
|
|
/* recalculate the checksum, so that --change-passphrase
|
|
* can be used to convert from the faulty to the correct one
|
|
* wk 06.04.98:
|
|
* fixme: remove this some time in the future.
|
|
*/
|
|
cert->csum = checksum_mpi( cert->d.elg.x );
|
|
buffer = mpi_get_buffer( cert->d.elg.x, &nbytes, NULL );
|
|
(*fnc)( fnc_hd, buffer, buffer, nbytes );
|
|
mpi_set_buffer( cert->d.elg.x, buffer, nbytes, 0 );
|
|
m_free( buffer );
|
|
break;
|
|
|
|
case PUBKEY_ALGO_DSA:
|
|
buffer = mpi_get_buffer( cert->d.dsa.x, &nbytes, NULL );
|
|
(*fnc)( fnc_hd, buffer, buffer, nbytes );
|
|
mpi_set_buffer( cert->d.dsa.x, buffer, nbytes, 0 );
|
|
m_free( buffer );
|
|
break;
|
|
|
|
default: return G10ERR_PUBKEY_ALGO;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/****************
|
|
* Protect the secret key certificate with the passphrase from DEK
|
|
*/
|
|
int
|
|
protect_secret_key( PKT_secret_cert *cert, DEK *dek )
|
|
{
|
|
int rc=0;
|
|
|
|
if( !dek )
|
|
return 0;
|
|
|
|
if( !cert->is_protected ) { /* okay, apply the protection */
|
|
CIPHER_HANDLE cipher_hd=NULL;
|
|
|
|
switch( cert->protect.algo ) {
|
|
case CIPHER_ALGO_NONE: BUG(); break;
|
|
case CIPHER_ALGO_BLOWFISH:
|
|
case CIPHER_ALGO_CAST:
|
|
cipher_hd = cipher_open( cert->protect.algo,
|
|
CIPHER_MODE_AUTO_CFB, 1 );
|
|
cipher_setkey( cipher_hd, dek->key, dek->keylen );
|
|
cipher_setiv( cipher_hd, NULL );
|
|
cipher_encrypt( cipher_hd, cert->protect.iv, cert->protect.iv, 8 );
|
|
if( !do_protect( &cipher_encrypt, cipher_hd, cert ) )
|
|
cert->is_protected = 1;
|
|
cipher_close( cipher_hd );
|
|
break;
|
|
|
|
default:
|
|
rc = G10ERR_CIPHER_ALGO; /* unsupport protection algorithm */
|
|
break;
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|