package com.house365.web.util;

import java.security.NoSuchAlgorithmException;  
import javax.crypto.Cipher;  
import javax.crypto.NoSuchPaddingException;  
import javax.crypto.spec.IvParameterSpec;  
import javax.crypto.spec.SecretKeySpec;  
  
public class MCrypt{  
  
    private String iv = "fedcba9876543210"; //Dummy iv (CHANGE IT!)  
    private IvParameterSpec ivspec;  
    private SecretKeySpec keyspec;  
    private Cipher cipher;  
  
    private String SecretKey = "0123456789abcdef"; //Dummy secretKey (CHANGE IT!)  
  
    public MCrypt()  
    {  
        ivspec = new IvParameterSpec(iv.getBytes());  
        keyspec = new SecretKeySpec(SecretKey.getBytes(), "AES");  
  
        try {  
            cipher = Cipher.getInstance("AES/CBC/NoPadding");  
        }   
        catch (NoSuchAlgorithmException e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        }   
        catch (NoSuchPaddingException e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        }  
    }  
  
    public byte[] encrypt(String text) throws Exception  
    {  
        if(text == null || text.length() == 0)  
            throw new Exception("Empty string");  
  
        byte[] encrypted = null;  
  
        try {  
            cipher.init(Cipher.ENCRYPT_MODE, keyspec, ivspec);  
  
            encrypted = cipher.doFinal(padString(text).getBytes());  
        }   
        catch (Exception e)  
        {             
            throw new Exception("[encrypt] " + e.getMessage());  
        }  
  
        return encrypted;  
    }  
  
    public byte[] decrypt(String code) throws Exception  
    {  
        if(code == null || code.length() == 0)  
                throw new Exception("Empty string");  
  
        byte[] decrypted = null;  
  
        try {  
            cipher.init(Cipher.DECRYPT_MODE, keyspec, ivspec);  
  
            decrypted = cipher.doFinal(hexToBytes(code));  
        }   
        catch (Exception e)  
        {  
            throw new Exception("[decrypt] " + e.getMessage());  
        }  
        return decrypted;  
    }  
  
    public static String bytesToHex(byte[] data)  
    {  
        if (data==null) return null;  
  
        int len = data.length;  
        String str = "";  
        for (int i=0; i<len; i++) {  
                if ((data[i]&0xFF)<16)  
                    str = str + "0" + java.lang.Integer.toHexString(data[i]&0xFF);  
                else  
                    str = str + java.lang.Integer.toHexString(data[i]&0xFF);  
        }  
        return str;  
    }  
  
    public static byte[] hexToBytes(String str)   
    {  
        if (str==null) {  
            return null;  
        }   
        else if (str.length() < 2) {  
            return null;  
        }   
        else {  
            int len = str.length() / 2;  
            byte[] buffer = new byte[len];  
            for (int i=0; i<len; i++) {  
                    buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16);  
            }  
            return buffer;  
        }  
    }  
  
    private static String padString(String source)  
    {  
      char paddingChar = ' ';  
      int size = 16;  
      int x = source.length() % size;  
      int padLength = size - x;  
  
      for (int i = 0; i < padLength; i++)  
      {  
        source += paddingChar;  
      }  
  
      return source;  
    }  
}  