Portable Class Library (PCL) Contrib - Cryptography

Question

I want to use the cryptography in the Portable Class Library Contrib project on codeplex but have not found any documentation on how I can use it.

I want to create a wra

Answer 1

It turns out that my generic wrapper for the cryptography algorithms was causing a problem. PCL Contrib contains a class called SymmetricAlgorithm which is itself a wrapper for the real SymmetricAlgorithm. If I make my wrapper class non-generic it works like this:

public sealed class AesManagedSymmetricCryptography : SymmetricCryptography<AesManaged>
{
    #region Constructors

    public AesManagedSymmetricCryptography()
    {
    }

    public AesManagedSymmetricCryptography(byte[] key, byte[] iv)
        : base(key, iv)
    {
    }

    public AesManagedSymmetricCryptography(string password, string salt)
        : base(password, salt)
    {
    }

    public AesManagedSymmetricCryptography(string password, string salt, int iterations)
        : base(password, salt, iterations)
    {
    }

    #endregion
}

Answer 2

The docs are a little lacking, but I call this out in the FAQ:

Can I share the types from PclContrib with my platform-specific projects? No, not currently. While the types in PclContrib look and feel like their platform-specific counterparts, the runtime and compiler will see them as completely different types. While we have some ideas on how to make this work, this is a feature that we won't be looking at for the short term.

Answer 3

The following .net code works on Desktop implementation. First add references to Portable.Desktop and Portable.Security.Cryptography.ProtectedData

   private void button2_Click(object sender, EventArgs e)
    {
        String encrypted = PCL.CentralClass.Encrypt("yo");
        String decreypted = PCL.CentralClass.Decrypt(encrypted);
        //PCL.CentralClass.
    }
    //https://pclcontrib.codeplex.com/documentation?FocusElement=Comment
    //\Source\Portable.Security.Cryptography.ProtectedData\Security\Cryptography\ProtectedData.cs

    static byte[] GetBytes(string str)
    {
        byte[] bytes = new byte[str.Length * sizeof(char)];
        System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
        return bytes;
    }

    static string GetString(byte[] bytes)
    {
        char[] chars = new char[bytes.Length / sizeof(char)];
        System.Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
        return new string(chars);
    }

    public static String Encrypt(String strEncrypt)
    {
        byte[] userData = GetBytes(strEncrypt);
        byte[] optionalEntropy = null;
        byte[] x = System.Security.Cryptography.ProtectedData.Protect(userData, optionalEntropy);
        return GetString(x);
    }
    public static String Decrypt(String strDecrypt)
    {
        byte[] encryptedData = GetBytes(strDecrypt);
        byte[] optionalEntropy = null;
        byte[] x = System.Security.Cryptography.ProtectedData.Unprotect(encryptedData, optionalEntropy);
        return GetString(x); ;
    }