使用 AES 加密的 Java GUI 程序

Question

我正在开发 Java 测试应用程序。Java 应用程序使用 AES 加密。我在明文 Pane 中输入明文并单击加密按钮。明文是加密密文，密文是设置密文 Pane 。我单击解密按钮，但密文无法解密明文。这是我的代码和结果。我应该做什么？

-文件加密.java-

import java.io.ByteArrayInputStream;    
import java.io.ByteArrayOutputStream;    
import javax.crypto.Cipher;    
import javax.crypto.CipherInputStream;    
import javax.crypto.CipherOutputStream;    
import javax.crypto.spec.IvParameterSpec;    
import javax.crypto.spec.SecretKeySpec;    

public class FileEncryption {

    //Initial Vector
    public static final byte[] iv = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };      

    //EncryptAndDecrypt String -> Input : PlainText + Return : CipherText+DecipherText
    public static String encryptString(String src) throws Exception
    {
        String dst="";
        //Not Input!
        if(src == null || src.length()==0)
            return "";

        //Encryption Setting
        byte[] k="Multimediaproces".getBytes();
        SecretKeySpec Key = new SecretKeySpec(k,"AES");
        IvParameterSpec ivspec = new IvParameterSpec(iv);
        Cipher encryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        encryptCipher.init(Cipher.ENCRYPT_MODE,Key,ivspec);

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        CipherOutputStream cout = new CipherOutputStream(baos,encryptCipher);
        cout.write(src.getBytes());
        cout.flush();               //ByteOutputStream -> Write Encryption Text
        cout.close();           
        dst = new String(baos.toByteArray());   
        return dst;
    }   

    //String src -> EncryptedData
    public static String decryptString(String src) throws Exception 
    {
        //src value is Encrypted Value!
        //So, src value -> Not Byte!
        String dst="";
        byte[] encryptedBytes = src.getBytes();         
        //Not Input!
        if(src == null || src.length()==0)
            return "";          
        //Decryption Setting
        IvParameterSpec ivspec = new IvParameterSpec(iv);
        byte[] k="Multimediaproces".getBytes();
        SecretKeySpec Key = new SecretKeySpec(k,"AES");
        Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        decryptCipher.init(Cipher.DECRYPT_MODE,Key,ivspec); 

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ByteArrayInputStream bais = new ByteArrayInputStream(encryptedBytes);
        CipherInputStream cin = new CipherInputStream(bais,decryptCipher);
        byte[] buf = new byte[1024];
        int read;
        while((read=cin.read(buf))>=0)  //reading encrypted data!
        {
            baos.write(buf,0,read);     //writing decrypted data!
        }

        // closing streams
        cin.close();
        dst = new String(baos.toByteArray());
        return dst;
    }
}

-MyFrame.java-

import java.awt.event.ActionEvent;    
import java.awt.event.ActionListener;
import javax.swing.JButton;    
import javax.swing.JFrame;    
import javax.swing.JLabel;    
import javax.swing.JPanel;    
import javax.swing.JTextPane;    
public class MyFrame extends JFrame
{

    public MyFrame()
    {
        super("Encrypt_Testing");
        setBounds(100, 100, 600, 900);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        getContentPane().setLayout(null);    
        // PlainText Panel
        JPanel plainPanel = new JPanel();
        plainPanel.setBounds(0, 0, 584, 287);
        getContentPane().add(plainPanel);
        plainPanel.setLayout(null);                 
        //PlainPane -> data setting -> final!
        final JTextPane PlainPane = new JTextPane();
        PlainPane.setBounds(12, 29, 560, 205);
        plainPanel.add(PlainPane);
        // PlainText Label
        JLabel PlaintextLabel = new JLabel("PlainText");
        PlaintextLabel.setBounds(12, 10, 57, 15);
        plainPanel.add(PlaintextLabel);         
        // CipherText Panel
        JPanel cipherPanel = new JPanel();
        cipherPanel.setBounds(0, 284, 584, 287);
        getContentPane().add(cipherPanel);
        cipherPanel.setLayout(null);    
        // CipherText Label
        JLabel CipherLabel = new JLabel("CipherText");
        CipherLabel.setBounds(12, 10, 70, 15);
        cipherPanel.add(CipherLabel);           
        //CipherPane -> data setting -> final!
        final JTextPane CipherPane = new JTextPane();
        CipherPane.setBounds(12, 27, 560, 224);
        cipherPanel.add(CipherPane);            
        //Decipher Panel
        JPanel decipherPanel = new JPanel();
        decipherPanel.setBounds(0, 570, 584, 292);
        getContentPane().add(decipherPanel);
        decipherPanel.setLayout(null);                  
        //Decipher Label
        JLabel DecipherLabel = new JLabel("DecipherText");
        DecipherLabel.setBounds(12, 10, 81, 24);
        decipherPanel.add(DecipherLabel);                   
        //Decipher TextPane
        final JTextPane DecipherPane = new JTextPane();
        DecipherPane.setBounds(12, 36, 560, 234);
        decipherPanel.add(DecipherPane);   

        //Decryption Button
        JButton DecryptedButton = new JButton("Decryption");
        DecryptedButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                String cipher,result_de;
                try{
                    cipher = CipherPane.getText();
                    result_de = FileEncryption.decryptString(cipher);
                    DecipherPane.setText(result_de);
                }catch (Exception e)
                {
                    e.printStackTrace();
                }
            }
        });
        DecryptedButton.setBounds(448, 254, 124, 23);
        cipherPanel.add(DecryptedButton);           setVisible(true);                                   
        // Encryption Button
        JButton EncryptedButton = new JButton("Encryption");
        EncryptedButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) 
        {
            //PlainArea -> GetText! -> Plain
            //call encryptString(plain)
            //result <- FileEncryption.encryptString(plain)
            //CipherPane.setText(result)-> Show!
            String plain,result_en;
            try {
                plain = PlainPane.getText();
                result_en = FileEncryption.encryptString(plain);
                CipherPane.setText(result_en);
                } catch (Exception e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }   
            }
        });
        EncryptedButton.setBounds(445, 244, 127, 23);
        plainPanel.add(EncryptedButton);            

    }

    public static void main(String args[])
    {
        new MyFrame();
    }
}

Answer 1

您的主要问题是由加密方法中的这一行引起的:

dst = new String(baos.toByteArray());
return dst;

您无法以这种方式将密文(随机字节)转换为字符串而不丢失信息。尝试转换为十六进制，例如

// in encrypt method
dst = DatatypeConverter.printHexBinary(baos.toByteArray());
return dst;

// in decrypt method
byte[] encryptedBytes = DatatypeConverter.parseHexBinary(src);

需要考虑的其他不相关点:

• 您的 AES key 非常较弱。如果您想使用密码来派生 key ，请使用 key 派生方法，例如 PBKDF2。

• 固定 IV 为零也很弱。每次创建一个随机 IV 并将其附加到您的密文中。

• 我认为您的示例中使用 ByteArrayOutputStream 和 CipherOutputStream 没有任何优势。考虑简单地使用encryptCipher.doFinal(plaintext)。

• 您可以将输入字符串转换为字节数组，而无需指定字符集。这将是依赖于平台的行为，我怀疑您想要这种行为。考虑使用 getBytes("UTF-8") 代替。