三重DES加密程序

12/23/2007来源:J2EE/J2ME教程人气:7675

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]); 

} fos.close(); JOptionPane.showMessageDialog(this,"加密成功!","提示",JOptionPane.OK_OPTION); }else JOptionPane.showMessageDialog( this,"密码长度必须等于48!","错误信息",JOptionPane.ERROR_MESSAGE); }catch(Exception e){ e.printStackTrace(); } } /** 解密函数 输入: 要解密的文件,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: 对输入的文件解密后,保存到用户指定的文件中。 */ private void decrypt(File fileIn,String sKey){ try{ if(sKey.length() == 48){ String strPath = fileIn.getPath(); if(strPath.substring(strPath.length()-5).toLowerCase().equals(".tdes")) strPath = strPath.substring(0,strPath.length()-5); else{ JOptionPane.showMessageDialog(this,"不是合法的加密文件!","提示",JOptionPane.OK_OPTION); return; } JFileChooser chooser = new JFileChooser(); chooser.setCurrentDirectory(new File(".")); chooser.setSelectedFile(new File(strPath)); //用户指定要保存的文件 int ret = chooser.showSaveDialog(this); if(ret==JFileChooser.APPROVE_OPTION){ 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(); } //解密 byte[] bytOut = decryptByDES(decryptByDES(decryptByDES(bytIn,bytK3),bytK2),bytK1); File fileOut = chooser.getSelectedFile(); fileOut.createNewFile(); FileOutputStream fos = new FileOutputStream(fileOut); for(int i = 0;i< bytOut.length;i++){ fos.write((int)bytOut[i]); } fos.close(); JOptionPane.showMessageDialog(this,"解密成功!","提示",JOptionPane.OK_OPTION); } }else JOptionPane.showMessageDialog(this,"密码长度必须等于48!","错误信息",JOptionPane.ERROR_MESSAGE); }catch(Exception e){ JOptionPane.showMessageDialog(this,"解密失败,请核对密码!","提示",JOptionPane.OK_OPTION); } } /** 用DES方法加密输入的字节 bytKey需为8字节长,是加密的密码 */ private byte[] encryptByDES(byte[] bytP,byte[] bytKey) throws Exception{ DESKeySpec desKS = new DESKeySpec(bytKey); SecretKeyFactory skf = SecretKeyFactory.getInstance("DES"); SecretKey sk = skf.generateSecret(desKS); Cipher cip = Cipher.getInstance("DES"); cip.init(Cipher.ENCRYPT_MODE,sk); return cip.doFinal(bytP); } /** 用DES方法解密输入的字节 bytKey需为8字节长,是解密的密码 */ private byte[] decryptByDES(byte[] bytE,byte[] bytKey) throws Exception{ DESKeySpec desKS = new DESKeySpec(bytKey); SecretKeyFactory skf = SecretKeyFactory.getInstance("DES"); SecretKey sk = skf.generateSecret(desKS);
Cipher cip = Cipher.getInstance("DES"); cip.init(Cipher.DECRYPT_MODE,sk); return cip.doFinal(bytE); } /** 输入密码的字符形式,返回字节数组形式。 如输入字符串:AD67EA2F3BE6E5AD 返回字节数组:{173,103,234,47,59,230,229,173} */ private byte[] getKeyByStr(String str){ byte[] bRet = new byte[str.length()/2]; for(int i=0;i< str.length()/2;i++){ Integer itg =new Integer(16*getChrInt(str.charAt(2*i)) + getChrInt(str.charAt(2*i+1))); bRet[i] = itg.byteValue(); } return bRet; } /** 计算一个16进制字符的10进制值 输入:0-F */ private int getChrInt(char chr){ int iRet=0; if(chr=="0".charAt(0)) iRet = 0; if(chr=="1".charAt(0)) iRet = 1; if(chr=="2".charAt(0)) iRet = 2; if(chr=="3".charAt(0)) iRet = 3; if(chr=="4".charAt(0)) iRet = 4; if(chr=="5".charAt(0)) iRet = 5; if(chr=="6".charAt(0)) iRet = 6; if(chr=="7".charAt(0)) iRet = 7; if(chr=="8".charAt(0)) iRet = 8; if(chr=="9".charAt(0)) iRet = 9; if(chr=="A".charAt(0)) iRet = 10; if(chr=="B".charAt(0)) iRet = 11; if(chr=="C".charAt(0)) iRet = 12; if(chr=="D".charAt(0)) iRet = 13; if(chr=="E".charAt(0)) iRet = 14; if(chr=="F".charAt(0)) iRet = 15; return iRet; } } /** 文件选择组件。 */ class FilePanel extends JPanel{ FilePanel(String str){ JLabel label = new JLabel(str); JTextField fileText = new JTextField(35); JButton chooseButton = new JButton("浏览..."); this.add(label); this.add(fileText); this.add(chooseButton); clickAction ca = new clickAction(this); chooseButton.addActionListener(ca); } public String getFileName(){ JTextField jtf = (JTextField)this.getComponent(1); return jtf.getText(); } private class clickAction implements ActionListener{ clickAction(Component c){ cmpt = c; } public void actionPerformed(ActionEvent event){ JFileChooser chooser = new JFileChooser(); chooser.setCurrentDirectory(new File(".")); int ret = chooser.showOpenDialog(cmpt); if(ret==JFileChooser.APPROVE_OPTION){ JPanel jp = (JPanel)cmpt; JTextField jtf = (JTextField)jp.getComponent(1); jtf.setText(chooser.getSelectedFile().getPath()); } } private Component cmpt; } } /** 密码生成组件。 */ class KeyPanel extends JPanel{ KeyPanel(String str){ JLabel label = new JLabel(str); JTextField fileText = new JTextField(35); JButton chooseButton = new JButton("随机产生"); this.add(label); this.add(fileText); this.add(chooseButton); clickAction ca = new clickAction(this); chooseButton.addActionListener(ca); } //返回生成的密码(48个字符长度) public String getKey(){ JTextField jtf = (JTextField)this.getComponent(1); return jtf.getText(); } private class clickAction implements ActionListener{ clickAction(Component c){ cmpt = c; } public void actionPerformed(ActionEvent event){
try{ KeyGenerator kg = KeyGenerator.getInstance("DES"); kg.init(56); Key ke = kg.generateKey(); byte[] bytK1 = ke.getEncoded(); ke = kg.generateKey(); byte[] bytK2 = ke.getEncoded(); ke = kg.generateKey(); byte[] bytK3 = ke.getEncoded(); JPanel jp = (JPanel)cmpt; JTextField jtf = (JTextField)jp.getComponent(1); jtf.setText(getByteStr(bytK1)+getByteStr(bytK2)+getByteStr(bytK3)); }catch(Exception e){ e.printStackTrace(); } } private String getByteStr(byte[] byt){ String strRet = ""; for(int i=0;i< byt.length;i++){ //System.out.println(byt[i]); strRet += getHexValue((byt[i]&240)/16); strRet += getHexValue(byt[i]&15); } return strRet; } private String getHexValue(int s){ String sRet=null; switch (s){ case 0: sRet = "0";break; case 1: sRet = "1";break; case 2: sRet = "2";break; case 3: sRet = "3";break; case 4: sRet = "4";break; case 5: sRet = "5";break; case 6: sRet = "6";break; case 7: sRet = "7";break; case 8: sRet = "8";break; case 9: sRet = "9";break; case 10: sRet = "A";break; case 11: sRet = "B";break; case 12: sRet = "C";break; case 13: sRet = "D";break; case 14: sRet = "E";break; case 15: sRet = "F"; } return sRet; } private Component cmpt; } } 程序运行图:
三重DES加密程序

(出处:http://www.knowsky.com)