package org.wowemu.realm.network.crypt;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.log4j.Logger;


public class Crypt {
	private static final Logger log = Logger
			.getLogger(Crypt.class);
	byte[] ServerEncryptionKey = { (byte) 0xCC,  (byte)0x98,  (byte)0xAE, 0x04,
			(byte)0xE8,  (byte)0x97, (byte)0xEA,  (byte)0xCA, 0x12,
			(byte)0xDD,  (byte)0xC0,  (byte)0x93, 0x42,  (byte)0x91, 0x53,
			0x57 };
	byte[] ServerDecryptionKey = { (byte) 0xC2, (byte) 0xB3, 0x72, 0x3C, (byte) 0xC6, (byte) 0xAE, (byte) 0xD9,
			(byte) 0xB5, 0x34, 0x3C, 0x53, (byte) 0xEE, 0x2F, 0x43, 0x67, (byte) 0xCE };

	private boolean isEnabled = false;

	private SARC4 _clientDecrypt = new SARC4(); 
	private SARC4 _serverEncrypt = new SARC4(); 

	public Crypt() { 
	}

	public byte[] decrypt(byte[] data) {
		if (!isEnabled)
			return data;
		return _clientDecrypt.Update(data);
	}

	public byte[] encrypt(byte[] data) {
		if (!isEnabled)
			return data; 
		return _serverEncrypt.Update(data);

	}
	public void init(byte[] key){
		byte[] encryptHash = getKey(ServerEncryptionKey,key);
		_clientDecrypt.init(encryptHash);
		byte[] decryptHash = getKey(ServerDecryptionKey,key);
		_serverEncrypt.init(decryptHash);
		byte[] tar = new byte[1024];
		for(int i = 0; i < tar.length; i++)
		 {
			tar[i] = 0;
		 }
		_serverEncrypt.Update(tar);
		for(int i = 0; i < tar.length; i++)
		 {
			tar[i] = 0;
		 }
		 _clientDecrypt.Update(tar);
		this.isEnabled = true;
	}
	private byte[] getKey(byte[] EncryptionKey,byte[] key) {
		SecretKeySpec ds = new SecretKeySpec(EncryptionKey, "HmacSHA1");
		Mac m;
		try {
			m = Mac.getInstance("HmacSHA1");
			m.init(ds);
			return  m.doFinal(key);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;		
	}

}

package org.wowemu.realm.network.crypt;

public class SARC4 {
	private byte state[] = new byte[256];
    private int x;
    private int y;
	
	public boolean init(byte[] key) {

        for (int i=0; i < 256; i++) {
            state[i] = (byte)i;
        }
        
        x = 0;
        y = 0;
        
        int index1 = 0;
        int index2 = 0;
        
        byte tmp;
        
        if (key == null || key.length == 0) {
            throw new NullPointerException();
        }
        
        for (int i=0; i < 256; i++) {

            index2 = ((key[index1] & 0xff) + (state[i] & 0xff) + index2) & 0xff;

            tmp = state[i];
            state[i] = state[index2];
            state[index2] = tmp;
            
            index1 = (index1 + 1) % key.length;
        }
		return true;
		
	}
	public byte[] Update(byte[] buf){

	        int xorIndex;
	        byte tmp;
	        
	        if (buf == null) {
	            return null;
	        }
	        
	        byte[] result = new byte[buf.length];
	        
	        for (int i=0; i < buf.length; i++) {

	            x = (x + 1) & 0xff;
	            y = ((state[x] & 0xff) + y) & 0xff;

	            tmp = state[x];
	            state[x] = state[y];
	            state[y] = tmp;
	            
	            xorIndex = ((state[x] &0xff) + (state[y] & 0xff)) & 0xff;
	            result[i] = (byte)(buf[i] ^ state[xorIndex]);
	        }
	        
	        return result;
	    }
	}