secretwriting.java

一个java语言的des的加密和解密的程序

import java.io.*;
import java.security.*;
import javax.crypto.*;
import sun.misc.*;
public class Secretwriting
{
    public static void main(String[] args) throws Exception
    {
        if(args.length<2)
        {
            System.out.println("usage:Secretwriting -e|-d text");
            return;
        }
        Key key;
        try
        {
            ObjectInputStream in=new ObjectInputStream(new FileInputStream("secretkey.ser"));
            key=(Key)in.readObject();
            in.close();
        }
        catch(FileNotFoundException fnfe)
        {
            KeyGenerator generator=KeyGenerator.getInstance("des");
            generator.init(new SecureRandom());
            key=generator.generateKey();
            ObjectOutputStream out=new ObjectOutputStream(new FileOutputStream("secretkey.ser"));
            out.writeObject(key);
            out.close();
         }
        Cipher cipher = Cipher.getInstance("des");
        if (args[0].indexOf("e")!=-1)
        {
            cipher.init(Cipher.ENCRYPT_MODE,key);
            String amalgam=args[1];
            for(int i=2;i<args.length;i++)
            amalgam+=""+args[i];
            byte[] stringBytes=amalgam.getBytes("UTF8");
            byte[] raw=cipher.doFinal(stringBytes);
            BASE64Encoder encoder=new BASE64Encoder();
            String base64=encoder.encode(raw);
            System.out.println(base64);
         }
         else if (args[0].indexOf("d")!=-1)
         {
             cipher.init(Cipher.DECRYPT_MODE,key);
             BASE64Decoder decoder=new BASE64Decoder();
             byte[] raw=decoder.decodeBuffer(args[1]);
             byte[] stringBytes=cipher.doFinal(raw);
             String result=new String(stringBytes,"UTf8");
             System.out.println(result);
         }
     }  
}