using System;

using System.Security.Cryptography;     

​

public class Program

{

    public static void Main()

    {

        var timestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds().ToString();

        Console.WriteLine(timestamp);

        Console.WriteLine(GenerateSignature(timestamp));

    }

     public static string GenerateSignature(string message)

        {

            var secret = "xtiaNRuZsSILRWVIHIDe";

            secret = secret ?? "";

            var encoding = new System.Text.UTF8Encoding();

            byte[] keyByte = encoding.GetBytes(secret);

            byte[] messageBytes = encoding.GetBytes(message);

            using (var hmacsha1 = new HMACSHA1(keyByte))

            {

                byte[] hashmessage = hmacsha1.ComputeHash(messageBytes);

                return Convert.ToBase64String(hashmessage);

            }

        }

}