using Microsoft.Owin.Security.DataHandler.Encoder;

using System;

using System.Security.Cryptography;

​

public class Program

{

    public static void Main()

    {

        int size = 32;

        var base64Secret = CreateBase64Secret(size);

        Console.WriteLine(base64Secret);

    }

​

    private static string CreateBase64Secret(int size)

    {

        var key = new byte[size];

        RNGCryptoServiceProvider.Create().GetBytes(key);

        var secret = TextEncodings.Base64Url.Encode(key);

        return secret;

    }

    private static string CreateBase64SecretWithNoDependencies(int size)

    {

        var key = new byte[size];

        RandomNumberGenerator.Create().GetBytes(key);

        var secret = Convert.ToBase64String(key);

        return secret;

    }   

}