Files
l2j_mobius/trunk/java/com/l2jmobius/util/crypt/LoginCrypt.java
2016-03-19 08:47:52 +00:00

127 lines
3.5 KiB
Java

/*
* This file is part of the L2J Mobius project.
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
package com.l2jmobius.util.crypt;
import java.io.IOException;
import com.l2jmobius.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 static final NewCrypt _STATIC_CRYPT = new NewCrypt(STATIC_BLOWFISH_KEY);
private NewCrypt _crypt = null;
private boolean _static = true;
/**
* Method to initialize the the blowfish cipher with dynamic key.
* @param key the blowfish key to initialize the dynamic blowfish cipher with
*/
public void setKey(byte[] key)
{
_crypt = new NewCrypt(key);
}
/**
* Method to decrypt an incoming login client packet.
* @param raw array with encrypted data
* @param offset offset where the encrypted data is located
* @param size number of bytes of encrypted data
* @return true when checksum could be verified, false otherwise
* @throws IOException the size is not multiple of blowfishs block size or the raw array can't hold size bytes starting at offset due to it's size
*/
public boolean decrypt(byte[] raw, int offset, int size) throws IOException
{
if ((size % 8) != 0)
{
throw new IOException("size have to be multiple of 8");
}
if ((offset + size) > raw.length)
{
throw new IOException("raw array too short for size starting from offset");
}
_crypt.decrypt(raw, offset, size);
return NewCrypt.verifyChecksum(raw, offset, size);
}
/**
* Method to encrypt an outgoing packet to login client.<br>
* Performs padding and resizing of data array.
* @param raw array with plain data
* @param offset offset where the plain data is located
* @param size number of bytes of plain data
* @return the new array size
* @throws IOException packet is too long to make padding and add verification data
*/
public int encrypt(byte[] raw, int offset, int size) throws IOException
{
// reserve checksum
size += 4;
if (_static)
{
// reserve for XOR "key"
size += 4;
// padding
size += 8 - (size % 8);
if ((offset + size) > raw.length)
{
throw new IOException("packet too long");
}
NewCrypt.encXORPass(raw, offset, size, Rnd.nextInt());
_STATIC_CRYPT.crypt(raw, offset, size);
_static = false;
}
else
{
// padding
size += 8 - (size % 8);
if ((offset + size) > raw.length)
{
throw new IOException("packet too long");
}
NewCrypt.appendChecksum(raw, offset, size);
_crypt.crypt(raw, offset, size);
}
return size;
}
}