using System;

using System.Linq;

using System.Text;

using System.Security.Cryptography;

public class Program

{

    public static string Sha1Hex(byte[] data, string key) {

        HMAC hmac = HMAC.Create("hmacsha1");

        hmac.Key = Encoding.UTF8.GetBytes(key);

        var code = hmac.ComputeHash(data);

        return BitConverter.ToString(code).Replace("-", string.Empty);

    }

    public static void Main()

    {

        var data = Encoding.UTF8.GetBytes("hello world");

        Console.WriteLine(Sha1Hex(data, "password"));

    }

}