Triple DES Encryption implementation compatible between Java and .NET!

One problem that I have had to solve in the past was making encryption between Java and .NET possible.  Specifically, I was charged to read an encrypted query string parameter from a Java system in my ASP.NET application.  After a few iterations of incompatible implementations, I created an implementation in both .NET (c#) and Java to ensure compatibility.

Since this caused me so much pain, I thought I would share my implementation with you in hopes that it will work for you as well.

Let me know if you have any questions or want to provide a decrypt implementation for the java class.

DOWNLOAD C# CLASS FILE

DOWNLOAD JAVA CLASS FILE

 

.NET (C#) Implementation

/// <summary>
/// Encryption utility class that implements Triple DES algorithm
/// </summary>
public class TripleDESImplementation
{
    //Encryption Key
    private byte[] EncryptionKey { get; set; }
    // The Initialization Vector for the DES encryption routine
    private byte[] IV { get; set; }

    /// <summary>
    /// Constructor for TripleDESImplementation class
    /// </summary>
    /// <param name="encryptionKey">The 24-byte encryption key (24 character ASCII)</param>
    /// <param name="IV">The 8-byte DES encryption initialization vector (8 characters ASCII)</param>
    public TripleDESImplementation(string encryptionKey, string IV)
    {
        if (string.IsNullOrEmpty(encryptionKey))
        {
            throw new ArgumentNullException("'encryptionKey' parameter cannot be null.", "encryptionKey");
        }
        if (string.IsNullOrEmpty(IV))
        {
            throw new ArgumentException("'IV' parameter cannot be null or empty.", "IV");
        }

        EncryptionKey = Encoding.ASCII.GetBytes(encryptionKey);
        // Ensures length of 24 for encryption key
        Trace.Assert(EncryptionKey.Length == 24, "Encryption key must be exactly 24 characters of ASCII text (24 bytes)");

        this.IV = Encoding.ASCII.GetBytes(IV);
        // Ensures length of 8 for init. vector
        Trace.Assert(IV.Length == 8, "Init. vector must be exactly 8 characters of ASCII text (8 bytes)");
    }

    /// <summary>
    /// Encrypts a text block
    /// </summary>
    public string Encrypt(string textToEncrypt)
    {
        TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
        tdes.Key = EncryptionKey;
        tdes.IV = IV;

        byte[] buffer = Encoding.ASCII.GetBytes(textToEncrypt);
        return Convert.ToBase64String(tdes.CreateEncryptor().TransformFinalBlock(buffer, 0, buffer.Length));
    }

    /// <summary>
    /// Decrypts an encrypted text block
    /// </summary>
    public string Decrypt(string textToDecrypt)
    {
        byte[] buffer = Convert.FromBase64String(textToDecrypt);

        TripleDESCryptoServiceProvider des = new TripleDESCryptoServiceProvider();
        des.Key = EncryptionKey;
        des.IV = IV;

        return Encoding.ASCII.GetString(des.CreateDecryptor().TransformFinalBlock(buffer, 0, buffer.Length));
    }
}

Java Implementation

public class TripleDesImplementation {
    private String key;
    private String initializationVector;
    public TripleDesImplementation(String key, String initializationVector)
    {
        this.key = key;
        this.initializationVector = initializationVector;
    }

    public String encryptText(String plainText) throws Exception{
    //----  Use specified 3DES key and IV from other source --------------
      byte[] plaintext = plainText.getBytes();
      byte[] tdesKeyData = key.getBytes();

      byte[] myIV = initializationVector.getBytes();

      Cipher c3des = Cipher.getInstance("DESede/CBC/PKCS5Padding");
      SecretKeySpec    myKey = new SecretKeySpec(tdesKeyData, "DESede");
      IvParameterSpec ivspec = new IvParameterSpec(myIV);

      c3des.init(Cipher.ENCRYPT_MODE, myKey, ivspec);
      byte[] cipherText = c3des.doFinal(plaintext);

      return Base64Coder.encodeString(new String(cipherText));
    }
}