.NET TripleDESCryptoServiceProvider equivalent in Java

Question

Please, just don\'t ask me why. I just have this code in .NET that encrypt/decrypt strings of data. I need now to make \'exactly\' the same funcionality in java. I have trie

Answer 1

Code follows, but first a few notes.

1. A different initialization vector must be chosen for every message. Hard-coding the initialization vector does not make sense. The IV should be sent along with the cipher text to the message recipient (it's not secret).
2. I used my own utility class for base-64 encoding. You can use sun.misc.BASE64Encoder and sun.misc.BASE64Decoder instead, use a third-party library like BouncyCastle, or write your own.
3. You are using 2-key triple DES, where the first key and the third key is the same. I modified sharedkey to reflect this, since the Java DESede cipher always requires a 192-bit key; it's up to the key generator to handle the keying option.
4. A CBC IV is only 64 bits. I've used only the first 64 bits of sharedvector.

This class should inter-operate with the C# version.

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class Encryption
{

  private static byte[] sharedkey = {
    0x01, 0x02, 0x03, 0x05, 0x07, 0x0B, 0x0D, 0x11, 
    0x12, 0x11, 0x0D, 0x0B, 0x07, 0x02, 0x04, 0x08, 
    0x01, 0x02, 0x03, 0x05, 0x07, 0x0B, 0x0D, 0x11
  };

  private static byte[] sharedvector = {
    0x01, 0x02, 0x03, 0x05, 0x07, 0x0B, 0x0D, 0x11
  };

  public static void main(String... argv)
    throws Exception
  {
    String plaintext = "userNameHere:passwordHere";
    String ciphertext = encrypt(plaintext);
    System.out.println(ciphertext);
    System.out.println(decrypt(ciphertext));
  }

  public static String encrypt(String plaintext)
    throws Exception
  {
    Cipher c = Cipher.getInstance("DESede/CBC/PKCS5Padding");
    c.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(sharedkey, "DESede"), new IvParameterSpec(sharedvector));
    byte[] encrypted = c.doFinal(plaintext.getBytes("UTF-8"));
    return Base64.encode(encrypted);
  }

  public static String decrypt(String ciphertext)
    throws Exception
  {
    Cipher c = Cipher.getInstance("DESede/CBC/PKCS5Padding");
    c.init(Cipher.DECRYPT_MODE, new SecretKeySpec(sharedkey, "DESede"), new IvParameterSpec(sharedvector));
    byte[] decrypted = c.doFinal(Base64.decode(ciphertext));
    return new String(decrypted, "UTF-8");
  }

}

Output:

zQPZgQHpjxR+41Bc6+2Bvqo7+pQAxBBVN+0V1tRXcOc=

userNameHere:passwordHere