trunk/java/com/l2jserver/util/crypt/LoginCrypt.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2004-2014 L2J Server
+ * 
+ * This file is part of L2J Server.
+ * 
+ * L2J Server 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.
+ * 
+ * L2J Server 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.l2jserver.util.crypt;
+
+import java.io.IOException;
+
+import com.l2jserver.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, final int offset, final 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, final 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;
+	}
+}