异常 java.security.InvalidKeyException：无效的密钥长度：使用 DESede 的 24 字节

Exception java.security.InvalidKeyException: Invalid key length: 24 bytes using DESede

提问by nitinkt

I know that this question is often asked but I have checked everything I found in Stack Overflow and did not find the solution to my problem.
i am using DESede for encryption and decryption and taking external 24 byte key input. but getting exception.

我知道这个问题经常被问到，但我已经检查了我在 Stack Overflow 中找到的所有内容，但没有找到我的问题的解决方案。
我正在使用 DESede 进行加密和解密，并采用外部 24 字节密钥输入。但得到例外。

here is my code:

这是我的代码：

    import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    import java.security.spec.InvalidKeySpecException;

    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.SecretKeyFactory;
    import javax.crypto.NoSuchPaddingException;
    import javax.crypto.SecretKey;
    import javax.crypto.spec.DESedeKeySpec;
    import javax.xml.bind.DatatypeConverter;

    public class DESede {

     private static Cipher encryptCipher;
     private static Cipher decryptCipher;

     public static void main(String[] args) throws InvalidKeySpecException {
      try {


       String desKey = "0123456789abcdef0123456789abcdef0123456789abcdef"; // value from user
       byte[] keyBytes = DatatypeConverter.parseHexBinary(desKey);
       System.out.println((int)keyBytes.length);

       SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");
       SecretKey key = factory.generateSecret(new DESedeKeySpec(keyBytes));

       encryptCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
       encryptCipher.init(Cipher.ENCRYPT_MODE, key); //throwing Exception
       byte[] encryptedData = encryptData("Confidential data");

       decryptCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
       decryptCipher.init(Cipher.DECRYPT_MODE, key);
       decryptData(encryptedData);

      } catch (NoSuchAlgorithmException e) {
       e.printStackTrace();
      } catch (NoSuchPaddingException e) {
       e.printStackTrace();
      } catch (InvalidKeyException e) {
       e.printStackTrace();
      } catch (IllegalBlockSizeException e) {
       e.printStackTrace();
      } catch (BadPaddingException e) {
       e.printStackTrace();
      }

     }

//method for encryption

//加密方法

     private static byte[] encryptData(String data)
       throws IllegalBlockSizeException, BadPaddingException {
      System.out.println("Data Before Encryption :" + data);
      byte[] dataToEncrypt = data.getBytes();
      byte[] encryptedData = encryptCipher.doFinal(dataToEncrypt);
      System.out.println("Encryted Data: " + encryptedData);

      return encryptedData;
     }

//method for decryption

//解密方法

     private static void decryptData(byte[] data)
       throws IllegalBlockSizeException, BadPaddingException {
      byte[] textDecrypted = decryptCipher.doFinal(data);
      System.out.println("Decryted Data: " + new String(textDecrypted));
     }
    }

i am getting exception at the line: java.security.InvalidKeyException: Invalid key length: 24 bytes

我在该行遇到异常：java.security.InvalidKeyException：无效的密钥长度：24 字节

encryptCipher.init(Cipher.ENCRYPT_MODE, key);

any one have any idea why this is happening?

有人知道为什么会这样吗？

采纳答案by lakshman

There is two mistakes you have done in your code

您在代码中犯了两个错误

you use DESedeto create the secret key factory in this line

您用于DESede在此行中创建密钥工厂

 SecretKeyFactory factory = SecretKeyFactory.getInstance("DESede");

but you use the DESto get the Cipherobject. you have to use DESedeinstead

但是您使用DES来获取Cipher对象。你必须DESede改用

so use this line

所以使用这条线

encryptCipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");

encryptCipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");

instead of this line

而不是这条线

encryptCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

encryptCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

use the same algorithm to get decripting cipher

使用相同的算法来获得解密密码

and another one is use a AlgorithmParameterSpecto init the decrypting cipher.

另一个是使用 aAlgorithmParameterSpec来初始化解密密码。

byte iv[] = encryptCipher.getIV(); 
IvParameterSpec dps = new IvParameterSpec(iv);
decryptCipher.init(Cipher.DECRYPT_MODE, key, dps);

you can use above code to apply the AlgorithmParameterSpecto the initialization of cipher

您可以使用上面的代码将 应用于AlgorithmParameterSpec密码的初始化