Add support for Zeros padding

[AArnott]

This must be done for all platforms (iOS, Android, desktop, and WinRT)

The sponsor of this issue has provided this sample code snippet of what is done on Desktop that must be done in equivalence via PCLCrypto:

internal static string EncryptData(string data, string key)
{
    // Reference objects
    ICryptoTransform encryptor = null;
    MemoryStream msEncrypt = null;
    CryptoStream csEncrypt = null;

    try
    {
        // Encrypt the PUK Code
        var rijndael = new RijndaelManaged
        {
            Padding = PaddingMode.Zeros,
            Key = Encoding.ASCII.GetBytes(key),
            Mode = CipherMode.ECB
        };
        encryptor = rijndael.CreateEncryptor();

        //Encrypt the data.
        msEncrypt = new MemoryStream();
        csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write);

        //Convert the data to a byte array.
        var toEncryptPuk = Encoding.ASCII.GetBytes(data);

        //Write all data to the crypt stream and flush it.
        csEncrypt.Write(toEncryptPuk, 0, toEncryptPuk.Length);
        csEncrypt.FlushFinalBlock();

        //Get encrypted array of bytes.
        var encryptedPuk = msEncrypt.ToArray();

        return ToHexString(encryptedPuk);
    }
    catch (Exception ex)
    {
        _logger.Error($"{"Static.EncryptData"}: {ex.Message}", ex);
        throw new InvalidOperationException(ex.Message, ex);
    }
    finally
    {
        csEncrypt?.Close();
        msEncrypt?.Close();
        encryptor?.Dispose();
    }
}

[jacodv]

Great news

[AArnott]

Work is ongoing in the issue43 branch.

[AArnott]

Alright. This is now in master (#48) for Zeros padding support for desktop. It's not on other platforms yet, so I'm keeping this issue open.

[jacodv]

Great, and you were right. BouncyCastle does have it, the implementation is just a little diffferent

[AArnott]

Ongoing status of supporting platforms:

• WinRT
• UWP
• Desktop
• Windows Phone 8.1 (Appx)
• iOS
• Android

🔴 Windows Phone 8.x (Silverlight) -- not supported by platform