fzddecyauti.java

对一个字符串通过UDP进行加密解密

import java.security.*;
import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.net.*;

public class FZDDecyAuti {
	private static String Algorithm="DES"; 
	public FZDDecyAuti(){}
	
	public static byte[] decryp(byte[] keybyte, byte[] src)
	{      
		try
		{
            //生成密钥
            SecretKey deskey = new SecretKeySpec(keybyte, Algorithm);

            //解密
            Cipher c1 = Cipher.getInstance(Algorithm);
            c1.init(Cipher.DECRYPT_MODE, deskey);
            return c1.doFinal(src);
        }
        catch (Exception e){e.printStackTrace();}
        return null;
    }
	public static void main(String[] args) throws Exception
	{
		// TODO: Add your code here
		Security.addProvider(new com.sun.crypto.provider.SunJCE());
        final byte[] keyBytes = {0x11, 0x22, 0x4F, 0x58, (byte)0x88, 0x10, 0x40, 0x38
                               , 0x28, 0x25, 0x79, 0x51, (byte)0xCB, (byte)0xDD, 0x55, 0x66
                               , 0x77, 0x29, 0x74, (byte)0x98, 0x30, 0x40, 0x36, (byte)0xE2};
                               //24字节的密钥
        DatagramSocket ds=new DatagramSocket(3000);
        byte [] buf=new byte[1024];
        DatagramPacket dp=new DatagramPacket(buf,1024);
        ds.receive(dp);
        String str=new String(dp.getData(),0,dp.getLength());
        System.out.println("解密前的字符串:" + str);
        byte[] srcBytes = decryp(keyBytes,dp.getData());
        System.out.println("解密后的字符串:" + (new String(dp.getData())));
        
	}	
}