java文本文件加密解密類

123bt 9年前發布 | 6K 次閱讀 Java 加密
import java.awt.;
import java.awt.event.;
import javax.swing.;
import java.io.;
import java.security.;
import javax.crypto.;
import javax.crypto.spec.*;
/**

文本文件加密解密類
*
文件名：FileEncrypter.java JDK：1.40以上 說明：文件加密 加密方法：三重DES加密
加密過程：對選中的文件加密后在同文件夾下生成一個增加了".tdes" 擴展名的加密文件
*
解密過程：對選中的加密文件（必須有".tdes"擴展名）進行解密
*/
public class Test extends JFrame
{
 public static final int WIDTH = 550;
 public static final int HEIGHT = 200;
public static void main ( String args[] )
 {

 Test fe = new Test();
 fe.show();

}
Test()
 {

 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 ( "文件選擇" );
 c.add ( fp );

 final KeyPanel pp = new KeyPanel ( "密碼" );
 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, "請選擇文件！", "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, "請選擇文件！", "提示",
                                             JOptionPane.OK_OPTION );
     }
 } );

}
/**

加密函數 輸入： 要加密的文件，密碼（由0-F組成，共48個字符，表示3個8位的密碼）如：
AD67EA2F3BE6E5ADD368DFE03120B5DF92A8FD8FEC2F0746 其中： AD67EA2F3BE6E5AD
DES密碼一 D368DFE03120B5DF DES密碼二 92A8FD8FEC2F0746 DES密碼三 輸出：
對輸入的文件加密后，保存到同一文件夾下增加了".tdes"擴展名的文件中。
*/
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, "密碼長度必須等于48！", "錯誤信息",
                                     JOptionPane.ERROR_MESSAGE );

}
 catch ( Exception e )
 {

 e.printStackTrace();

}
}
/**

解密函數 輸入： 要解密的文件，密碼（由0-F組成，共48個字符，表示3個8位的密碼）如：
AD67EA2F3BE6E5ADD368DFE03120B5DF92A8FD8FEC2F0746 其中： AD67EA2F3BE6E5AD
DES密碼一 D368DFE03120B5DF DES密碼二 92A8FD8FEC2F0746 DES密碼三 輸出：
對輸入的文件解密后，保存到用戶指定的文件中。
*/
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 ) );
     // 用戶指定要保存的文件
     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, "密碼長度必須等于48！", "錯誤信息",
                                     JOptionPane.ERROR_MESSAGE );

}
 catch ( Exception e )
 {

 JOptionPane.showMessageDialog ( this, "解密失敗，請核對密碼！", "提示",
                                 JOptionPane.OK_OPTION );

}
}
/**

用DES方法加密輸入的字節 bytKey需為8字節長，是加密的密碼
*/
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方法解密輸入的字節 bytKey需為8字節長，是解密的密碼
*/
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 );
}
/**

輸入密碼的字符形式，返回字節數組形式。 如輸入字符串：AD67EA2F3BE6E5AD 返回字節數組：{
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;
}
/**

計算一個16進制字符的10進制值 輸入：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;
}
}



/**

文件選擇組件。
*/
class FilePanel extends JPanel
{
 FilePanel ( String str )
 {

 JLabel label = new JLabel ( str );
 JTextField fileText = new JTextField ( 35 );
 JButton chooseButton = new JButton ( "瀏覽..." );
 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;

}
}


/**

密碼生成組件。
*/
class KeyPanel extends JPanel
{
 KeyPanel ( String str )
 {

 JLabel label = new JLabel ( str );
 JTextField fileText = new JTextField ( 35 );
 JButton chooseButton = new JButton ( "隨機產生" );
 this.add ( label );
 this.add ( fileText );
 this.add ( chooseButton );
 clickAction ca = new clickAction ( this );
 chooseButton.addActionListener ( ca );


}
// 返回生成的密碼（48個字符長度）
 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;

}
}</pre>
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Java 加密
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