Need to mirror encryption written in Java into C#

Question

Basically, I have an encryption method written in Java (Actually it's a 3rd party one I need to use, it came with the provided key), it works fine and dandy, but trying to implement the same thing thing in C# I have run into a major issue, I can't figure out how to provide a key length larger then 8 characters to DESCryptoServiceProvider.

Here's my java code:

public static String EncryptUrl(String parameters){

    try{
        String encodedStr = "";
        Cipher cipher;
        DESKeySpec keySpec = new DESKeySpec(key.getBytes("UTF8"));
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("DES");
        cipher = Cipher.getInstance("DES");
        cipher.init(Cipher.ENCRYPT_MODE, keyFactory.generateSecret(keySpec));

        encodedStr = Base64.encodeBase64String(cipher.doFinal(parameters.getBytes("UTF8")));

        try{
            encodedStr = URLEncoder.encode(encodedStr, "UTF-8");
        } catch (UnsupportedEncodingException e) {

            throw new AssertionError("UTF-8 is unknown");
        }

        return encodedStr;
    }
    catch(Exception ex){
        return null;
    }
}

And here's my attempt so far at a C# implementation:

    public static string EncryptUrl(string originalString)
    {
        if (String.IsNullOrEmpty(originalString))
        {
            throw new ArgumentNullException
                   ("The string which needs to be encrypted can not be null.");
        }

        byte[] tempKeyBytes = Encoding.ASCII.GetBytes("^op!l#ahD");
        byte[] keyBytes = new byte[16];

        Array.Copy(tempKeyBytes, keyBytes, tempKeyBytes.Length);

        DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider()
        {
            Padding = PaddingMode.None,
            KeySize = 128,
            BlockSize = 128
        };
        MemoryStream memoryStream = new MemoryStream();

        ICryptoTransform encryptor =    cryptoProvider.CreateWeakEncryptor(tempKeyBytes, tempKeyBytes);


        CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write);
        StreamWriter writer = new StreamWriter(cryptoStream);
        writer.Write(originalString);
        cryptoStream.FlushFinalBlock();
        writer.Flush();
        string encryptedUrl =  Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);

        return Uri.EscapeDataString(encryptedUrl);
    }

So long story short The key I was provided is 9 characters long (I HAVE to use this key and i HAVE to use DES and i HAVE to implement in C#), DESCryptoServiceProvider has an issue when using anything above 8 characters as a key, because of the fact the DES implementation in .NET only accepts a 64-bit key, so i'm wondering if there is a way to use a 9 character key for a DES encryption implementation

Answer 1

Here's what ended up working for me i.e what directly replicates the java class functionality in C#.

Points I had wrong initially:

• Java uses ECB cipher mode by default, C# uses CBC by default so I needed to explicitly tell C# to use ECB
• Java's DESKeySpec only uses the first 8 bytes of the given key, so in C# you need to only take the first 8 bytes of the given key
• How I was writing to the memory stream was also wrong, turns out I HAD to use CryptoStream.FlushFinalBlock to get the desired output

Here's the final code in C#:

public static string EncripytParameters(string prameters)
{
    if (String.IsNullOrEmpty(prameters))
    {
        throw new ArgumentNullException
               ("The string which needs to be encrypted can not be null.");
    }

    byte[] keyBytes = Encoding.UTF8.GetBytes(Key).Take(8).ToArray();

    DES cryptoProvider = new DESCryptoServiceProvider()
    {
        Mode = CipherMode.ECB,
        Key = keyBytes
    };
    var cryptoObject = cryptoProvider.CreateEncryptor();

    MemoryStream memoryStream = new MemoryStream();

    CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoObject, CryptoStreamMode.Write);

    byte[] tempArray = Encoding.UTF8.GetBytes(prameters);

    cryptoStream.Write(tempArray, 0, prameters.Length);

    cryptoStream.FlushFinalBlock();

    var outputData = memoryStream.ToArray();

    string encryptedParameters = Convert.ToBase64String(outputData);

    return Uri.EscapeDataString(encryptedParameters);
}