使用填充密码进行解密时,输入长度必须是8的倍数



我有一个客户端/服务器应用程序,它可以在客户端和服务器端加密或解密消息。然而,在解密时,我不断从StackTrace 中得到以下错误

使用填充密码解密时,输入长度必须是8的倍数

下面是来自Server和Client类的代码。问题是,我尝试过使用("DES/CCB/PKCS5Padding"("UTF-8">,但仍然无法解决上述问题。有什么需要帮忙的吗?谢谢?

public class ServerApp   {
public static byte[] encrypt(String input, Key k) {
try {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, k);
byte[] data = input.getBytes();
byte[] result = cipher.doFinal(data);
return result;
} catch (Exception ex) {
return null;
}
}
public static String decrypt(byte[] cipher, Key k) {
try {
Cipher cipher1 = Cipher.getInstance("DES");
cipher1.init(Cipher.DECRYPT_MODE, k);
byte[] original = cipher1.doFinal(cipher);
return new String(original);
} catch (Exception ex) {
return null;
//Logger.getLogger(DES.class.getName()).log(Level.SEVERE, null, ex);
}
}
public static void main(String[] args) throws NoSuchAlgorithmException {
try {
Key key=KeyGen.getSecretKey();
ServerSocket ser = new ServerSocket(3333);
System.out.println("Server Started");
Socket client = ser.accept();
DataInputStream in = new DataInputStream(client.getInputStream());
DataOutputStream out = new DataOutputStream(client.getOutputStream());
Scanner scan = new Scanner(System.in);
// SecretSocket sc = new SecretSocket(client, KeyGen.getSecretKey());
String serMsg, cliMsg, plain;
// OutputStream sout = sc.getOutputStream();
//  InputStream sin = sc.getInputStream();
do {
System.out.print("You say: ");
serMsg = scan.nextLine();
//   sout.write(serMsg.getBytes());
//    System.out.println("cli server "+sin.read());
byte[] ci = encrypt(serMsg, KeyGen.getSecretKey());
System.out.println("encrypt " +ci.toString());
out.writeUTF(ci.toString());
plain = decrypt(ci, KeyGen.getSecretKey() );
System.out.println("decrypt " + plain);
} while (!serMsg.equals("end"));
client.close();
ser.close();
} catch (IOException ex) {
Logger.getLogger(ServerApp.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
public class ClientApp  {
public static byte[] encrypt(String input, Key k) {
try {
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, k);
byte[] data = input.getBytes();
byte[] result = cipher.doFinal(data);
return result;
} catch (Exception ex) {
return null;
}
}
public static String decrypt(byte[] cipher, Key k) {
try {
Cipher cipher1 = Cipher.getInstance("DES/CBC/PKCS5Padding");
cipher1.init(Cipher.DECRYPT_MODE, k);
byte[] original = cipher1.doFinal(cipher);
return new String(original);
} catch (Exception ex) {
return null;
//Logger.getLogger(DES.class.getName()).log(Level.SEVERE, null, ex);
}
}
public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException {
try {
Socket s = new Socket("localhost", 3333);
DataInputStream in = new DataInputStream(s.getInputStream());
DataOutputStream out = new DataOutputStream(s.getOutputStream());
Scanner scan = new Scanner(System.in);
String serMsg, cliMsg, plain;
do {
System.out.println("server server "+in.readUTF());
serMsg = in.readUTF();
System.out.println("enc: " + serMsg);
plain = decrypt(serMsg.getBytes("UTF-8"), KeyGen.getSecretKey());
System.out.println("Server says: " + plain);
} while (!serMsg.equals("end"));
s.close();
} catch (IOException ex) {
Logger.getLogger(ClientApp.class.getName()).log(Level.SEVERE, null, ex);
}
}
Cipher cipher = Cipher.getInstance("DES");
cipher.init(Cipher.ENCRYPT_MODE, k);
byte[] data = input.getBytes();
byte[] result = cipher.doFinal(data);
  1. 在不使用IV的情况下使用DES,即隐含地使用DES/ECB/PKCS5Padding

  2. 不要直接打印字节数组。Java将只输出可打印的字符打印时始终对字节数组进行编码和解码(十六进制或Base64是最常见的编码(

以下是项目的示例

Base64.getEncoder().encodeToString(byteArray) 
  1. 我希望您知道DES现在被认为是一种弱密码,应该只用于向后兼容性

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