高级编程:三重DES加密程序

1/5/2008来源:Java教程人气:6211

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 
import java.io.*; 
import java.security.*; 
import javax.crypto.*; 
import javax.crypto.spec.*; 
/** 
文件名:FileEncrypter.java 
JDK:1.40以上 
说明:文件加密 
加密方法:三重DES加密 
      加密过程:
对选中的文件加密后在同文件夹下生成一个增加了".tdes" 扩展名的加密文件
解密过程:对选中的加密文件(必须有".tdes"扩展名)进行解密 */

public class FileEncrypter extends JFrame{
public static final int WIDTH = 550;
public static final int HEIGHT = 200;
public static void main(String args[]) {
FileEncrypter fe = new FileEncrypter(); fe.show();
}
FileEncrypter(){ 
  this.setSize(WIDTH,HEIGHT); 
  this.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE); 
  this.setResizable(false); 
  Toolkit tk = Toolkit.getDefaultToolkit(); 
  Dimension screenSize = tk.getScreenSize(); 
  this.setLocation((screenSize.width - WIDTH)/2, (screenSize.height - HEIGHT)/2); 
  this.setTitle("文件加密器(TriDES)"); 
  Container c = this.getContentPane(); 
  c.setLayout( new FlowLayout()); 
  final FilePanel fp = new FilePanel("文件选择"); 
  c.add(fp); 
  final KeyPanel pp = new KeyPanel("密码"); 
  c.add(pp); 
  JButton jbE = new JButton("加密"); 
  c.add(jbE); 
  jbE.addActionListener(new ActionListener(){ 
  public void actionPerformed(ActionEvent event){ 
  File file = new File(fp.getFileName()); 
  if (file.exists()) 
    encrypt(file.getAbsoluteFile(),pp.getKey()); 
  else 
    JOptionPane.showMessageDialog( 
  null,"请选择文件!","提示",JOptionPane.OK_OPTION); 
 } 
 }); 
  JButton jbD = new JButton("解密"); 
  c.add(jbD); 
  jbD.addActionListener(new ActionListener(){ 
    public void actionPerformed(ActionEvent event){ 
     File file = new File(fp.getFileName()); 
     if (file.exists()) 
      decrypt(file.getAbsoluteFile(),pp.getKey()); 
     else 
      JOptionPane.showMessageDialog(null,"请选择文件!","提示",JOptionPane.OK_OPTION); 
   } 
  }); 
 } 
/** 
加密函数 
输入: 
要加密的文件,密码(由0-F组成,共48个字符,表示3个8位的密码)如: 
AD67EA2F3BE6E5ADD368DFE03120B5DF92A8FD8FEC2F0746 
其中: 
AD67EA2F3BE6E5AD DES密码一 
D368DFE03120B5DF DES密码二 
92A8FD8FEC2F0746 DES密码三 
输出: 
对输入的文件加密后,保存到同一文件夹下增加了".tdes"扩展名的文件中。 
*/ 
PRivate void encrypt(File fileIn,String sKey){ 
  try{ 
   if(sKey.length() == 48){ 
     byte[] bytK1 = getKeyByStr(sKey.substring(0,16)); 
     byte[] bytK2 = getKeyByStr(sKey.substring(16,32)); 
     byte[] bytK3 = getKeyByStr(sKey.substring(32,48)); 
     FileInputStream fis = new FileInputStream(fileIn); 
     byte[] bytIn = new byte[(int)fileIn.length()]; 
     for(int i = 0;i< fileIn.length();i++){ 
      bytIn[i] = (byte)fis.read(); 
     } 
    //加密 
    byte[] bytOut = encryptByDES(encryptByDES(encryptByDES(bytIn,bytK1),bytK2),bytK3); 
    String fileOut = fileIn.getPath() + ".tdes"; 
    FileOutputStream fos = new FileOutputStream(fileOut); 
    for(int i = 0;i< bytOut.length;i++){ 
      fos.write((int)bytOut[i]);