/* 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, 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.
 *
 * http://www.gnu.org/copyleft/gpl.html
 */
package com.l2dot.loginserver.crypt;

import java.io.IOException;

import com.l2dot.util.Rnd;


/**
 *
 * @author  KenM
 */
public class LoginCrypt
{
	private static final byte[] STATIC_BLOWFISH_KEY =
	{
		(byte) 0x6b, (byte) 0x60, (byte) 0xcb, (byte) 0x5b,
		(byte) 0x82, (byte) 0xce, (byte) 0x90, (byte) 0xb1,
		(byte) 0xcc, (byte) 0x2b, (byte) 0x6c, (byte) 0x55,
		(byte) 0x6c, (byte) 0x6c, (byte) 0x6c, (byte) 0x6c
	};

	private NewCrypt _staticCrypt = new NewCrypt(STATIC_BLOWFISH_KEY);
    private NewCrypt _crypt;
    private boolean _static = true;

    public void setKey(byte[] key)
    {
        _crypt = new NewCrypt(key);
    }

    public boolean decrypt(byte[] raw, final int offset, final int size) throws IOException
    {
    	_crypt.decrypt(raw, offset, size);
    	return NewCrypt.verifyChecksum(raw, offset, size);
    }

    public int encrypt(byte[] raw, final int offset, int size) throws IOException
    {
    	// reserve checksum
    	size += 4;


    	if (_static)
    	{
    		// reserve for XOR "key"
    		size += 4;

    		// padding
        	size += 8 - size%8;
    		NewCrypt.encXORPass(raw, offset, size, Rnd.nextInt());
    		_staticCrypt.crypt(raw, offset, size);

    		_static = false;
    	}
    	else
    	{
    		// padding
        	size += 8 - size%8;
    		NewCrypt.appendChecksum(raw, offset, size);
    		_crypt.crypt(raw, offset, size);
    	}
    	return size;
    }
}
