/*
* Created on 03-Mar-2005
* Created by Paul Gardner
* Copyright (C) 2004, 2005, 2006 Aelitis, All Rights Reserved.
*
* This program 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.
* This program 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.
*
* AELITIS, SAS au capital de 46,603.30 euros
* 8 Allee Lenotre, La Grille Royale, 78600 Le Mesnil le Roi, France.
*
*/
package org.gudy.azureus2.pluginsimpl.local.ddb;
import java.util.*;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import org.gudy.azureus2.core3.logging.LogAlert;
import org.gudy.azureus2.core3.logging.Logger;
import org.gudy.azureus2.core3.util.*;
import org.gudy.azureus2.plugins.PluginInterface;
import org.gudy.azureus2.plugins.ddb.*;
import org.gudy.azureus2.plugins.download.Download;
import org.gudy.azureus2.plugins.torrent.Torrent;
import org.gudy.azureus2.plugins.torrent.TorrentAttribute;
import org.gudy.azureus2.pluginsimpl.local.PluginInitializer;
import com.aelitis.azureus.plugins.dht.DHTPluginProgressListener;
/**
* @author parg
*
*/
public class
DDBaseTTTorrent
implements DistributedDatabaseTransferType, DistributedDatabaseTransferHandler
{
private static final boolean TRACE = false;
private static final byte CRYPTO_VERSION = 1;
static{
if ( TRACE ){
System.out.println( "**** Torrent xfer tracing on ****" );
}
}
private DDBaseImpl ddb;
private TorrentAttribute ta_sha1;
private boolean crypto_tested;
private boolean crypto_available;
private List external_downloads;
private Map data_cache =
new LinkedHashMap(5,0.75f,true)
{
protected boolean
removeEldestEntry(
Map.Entry eldest)
{
return size() > 5;
}
};
protected
DDBaseTTTorrent(
DDBaseImpl _ddb )
{
ddb = _ddb;
}
public void
addDownload(
Download download )
{
synchronized( this ){
if ( external_downloads == null ){
external_downloads = new ArrayList();
}
external_downloads.add( download );
}
}
public void
removeDownload(
Download download )
{
synchronized( this ){
if ( external_downloads != null ){
external_downloads.remove( download );
}
if ( external_downloads.size() == 0 ){
external_downloads = null;
}
}
}
// server side read
public DistributedDatabaseValue
read(
DistributedDatabaseContact contact,
DistributedDatabaseTransferType type,
DistributedDatabaseKey key )
throws DistributedDatabaseException
{
// We use sha1(hash) as the key for torrent downloads
// and encrypt the torrent content using the hash as the basis for a key. This
// prevents someone without the hash from downloading the torrent
try{
byte[] search_key = ((DDBaseKeyImpl)key).getBytes();
Download download = null;
PluginInterface pi = PluginInitializer.getDefaultInterface();
String search_sha1 = pi.getUtilities().getFormatters().encodeBytesToString( search_key );
if ( ta_sha1 == null ){
ta_sha1 = pi.getTorrentManager().getPluginAttribute( "DDBaseTTTorrent::sha1");
}
// gotta look for the sha1(hash)
Download[] downloads = pi.getDownloadManager().getDownloads();
for (int i=0;i<downloads.length;i++){
Download dl = downloads[i];
if ( dl.getTorrent() == null ){
continue;
}
String sha1 = dl.getAttribute( ta_sha1 );
if ( sha1 == null ){
sha1 = pi.getUtilities().getFormatters().encodeBytesToString(
new SHA1Simple().calculateHash( dl.getTorrent().getHash()));
dl.setAttribute( ta_sha1, sha1 );
}
if ( sha1.equals( search_sha1 )){
download = dl;
break;
}
}
if ( download == null ){
synchronized( this ){
if ( external_downloads != null ){
for (int i=0;i<external_downloads.size();i++){
Download dl = (Download)external_downloads.get(i);
if ( dl.getTorrent() == null ){
continue;
}
String sha1 = dl.getAttribute( ta_sha1 );
if ( sha1 == null ){
sha1 = pi.getUtilities().getFormatters().encodeBytesToString(
new SHA1Simple().calculateHash( dl.getTorrent().getHash()));
dl.setAttribute( ta_sha1, sha1 );
}
if ( sha1.equals( search_sha1 )){
download = dl;
break;
}
}
}
}
}
String originator = contact.getName();
if ( download == null ){
String msg = "TorrentDownload: request from " + originator + " for '" + pi.getUtilities().getFormatters().encodeBytesToString( search_key ) + "' not found";
if ( TRACE ){
System.out.println( msg );
}
ddb.log( msg );
// torrent not found - probably been removed whilst info still published in DHT
return( null );
}
Torrent torrent = download.getTorrent();
if ( torrent.isPrivate()){
Debug.out( "Attempt to download private torrent" );
ddb.log( "TorrentDownload: request from " + originator + " for '" + download.getName() + "' denied as it is private" );
// should never happen as private torrents are not tracked so they can't be found for
// download
return( null );
}
String msg = "TorrentDownload: request from " + originator + " for '" + download.getName() + "' OK";
if ( TRACE ){
System.out.println( msg );
}
ddb.log( msg );
HashWrapper hw = new HashWrapper( torrent.getHash());
synchronized( data_cache ){
Object[] data = (Object[])data_cache.get( hw );
if ( data != null ){
data[1] = new Long( SystemTime.getCurrentTime());
return( ddb.createValue((byte[])data[0]));
}
}
torrent = torrent.removeAdditionalProperties();
// when clients get a torrent from the DHT they take on
// responsibility for tracking it too
torrent.setDecentralisedBackupRequested( true );
byte[] data = torrent.writeToBEncodedData();
data = encrypt( torrent.getHash(), data );
if ( data == null ){
return( null );
}
synchronized( data_cache ){
if ( data_cache.size() == 0 ){
final TimerEventPeriodic[]pe = { null };
pe[0] = SimpleTimer.addPeriodicEvent(
"DDBTorrent:timeout",
30*1000,
new TimerEventPerformer()
{
public void
perform(
TimerEvent event )
{
long now = SystemTime.getCurrentTime();
synchronized( data_cache ){
Iterator it = data_cache.values().iterator();
while( it.hasNext()){
long time = ((Long)((Object[])it.next())[1]).longValue();
if ( now < time || now - time > 120*1000 ){
it.remove();
}
}
if ( data_cache.size() == 0 ){
pe[0].cancel();
}
}
}
});
}
data_cache.put( hw, new Object[]{ data, new Long( SystemTime.getCurrentTime())});
}
return( ddb.createValue( data ));
}catch( Throwable e ){
throw( new DistributedDatabaseException("Torrent write fails", e ));
}
}
// server side write
public void
write(
DistributedDatabaseContact contact,
DistributedDatabaseTransferType type,
DistributedDatabaseKey key,
DistributedDatabaseValue value )
throws DistributedDatabaseException
{
throw( new DistributedDatabaseException( "not supported" ));
}
// client side read
protected DistributedDatabaseValue
read(
DDBaseContactImpl contact,
final DistributedDatabaseProgressListener listener,
DistributedDatabaseTransferType type,
DistributedDatabaseKey key,
long timeout )
throws DistributedDatabaseException
{
byte[] torrent_hash = ((DDBaseKeyImpl)key).getBytes();
byte[] lookup_key = new SHA1Simple().calculateHash( torrent_hash );
if ( TRACE ){
System.out.println( "TorrentXfer: sending via sha1(hash)" );
}
byte[] data = contact.getContact().read(
new DHTPluginProgressListener()
{
public void
reportSize(
long size )
{
listener.reportSize( size );
}
public void
reportActivity(
String str )
{
listener.reportActivity( str );
}
public void
reportCompleteness(
int percent )
{
listener.reportCompleteness( percent );
}
},
DDBaseHelpers.getKey(type.getClass()).getHash(),
lookup_key,
timeout );
if ( data == null ){
return( null );
}
data = decrypt( torrent_hash, data );
if ( data == null ){
return( null );
}
return( new DDBaseValueImpl( contact, data, SystemTime.getCurrentTime(), -1));
}
protected byte[]
encrypt(
byte[] hash,
byte[] data )
{
if ( !testCrypto()){
return( null );
}
byte[] enc = doCrypt( Cipher.ENCRYPT_MODE, hash, data, 0 );
if ( enc == null ){
if ( TRACE ){
System.out.println( "TorrentXfer: encryption failed, using plain" );
}
byte[] res = new byte[data.length+2];
res[0] = CRYPTO_VERSION;
res[1] = 0; // not encrypted
System.arraycopy( data, 0, res, 2, data.length );
return( res );
}else{
if ( TRACE ){
System.out.println( "TorrentXfer: encryption ok" );
}
byte[] res = new byte[enc.length+2];
res[0] = CRYPTO_VERSION;
res[1] = 1; // encrypted
System.arraycopy( enc, 0, res, 2, enc.length );
return( res );
}
}
protected byte[]
decrypt(
byte[] hash,
byte[] data )
{
if ( !testCrypto()){
return( null );
}
if ( data[0] != CRYPTO_VERSION ){
Debug.out( "Invalid crypto version received" );
return( data );
}
if ( data[1] == 0 ){
// encryption failed, in plain
if ( TRACE ){
System.out.println( "TorrentXfer: encryption failed, retrieving plain" );
}
byte[] res = new byte[data.length-2];
System.arraycopy( data, 2, res, 0, res.length );
return( res );
}else{
if ( TRACE ){
System.out.println( "TorrentXfer: encryption ok, decrypting" );
}
byte[] res = doCrypt( Cipher.DECRYPT_MODE, hash, data, 2 );
return( res );
}
}
protected byte[]
doCrypt(
int mode,
byte[] hash,
byte[] data,
int data_offset )
{
try{
byte[] key_data = new byte[24];
// hash is 20 bytes so we've got 4 zeros at the end. tough
System.arraycopy( hash, 0, key_data, 0, hash.length );
SecretKey tdes_key = new SecretKeySpec( key_data, "DESede" );
Cipher cipher = Cipher.getInstance("DESede"); // Triple-DES encryption
cipher.init(mode, tdes_key );
return( cipher.doFinal(data, data_offset, data.length - data_offset ));
}catch( Throwable e ){
Debug.out( e );
return( null );
}
}
protected boolean
testCrypto()
{
if ( !crypto_tested ){
crypto_tested = true;
try{
Cipher.getInstance("DESede"); // Triple-DES encryption
crypto_available = true;
}catch( Throwable e ){
Logger.log(new LogAlert(LogAlert.UNREPEATABLE,
"Unable to initialise cryptographic framework for magnet-based "
+ "torrent downloads, please re-install Java", e));
}
}
return( crypto_available );
}
}