$res1 = hash_hmac("sha1","signatureString", "secret");
        echo $res1."\n";
        //ee1b654aa861c41fd5813dc365ef106c9801f8f6
        echo base64_encode($res1)."\n";
        //ZWUxYjY1NGFhODYxYzQxZmQ1ODEzZGMzNjVlZjEwNmM5ODAxZjhmNg==

        $res2 = hash_hmac("sha1","signatureString", "secret", true);
        //echo "$res2\n";//binary byte[]
        $data = unpack('C*', $res2);
        print_r($data);
        /*
        Array
        (
            [1] => 238
            [2] => 27
            [3] => 101
            [4] => 74
            [5] => 168
            [6] => 97
            [7] => 196
            [8] => 31
            [9] => 213
            [10] => 129
            [11] => 61
            [12] => 195
            [13] => 101
            [14] => 239
            [15] => 16
            [16] => 108
            [17] => 152
            [18] => 1
            [19] => 248
            [20] => 246
        )

        */

        echo base64_encode("$res2\n");
        //7htlSqhhxB/VgT3DZe8QbJgB+PYK
?>

using System.IO;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

namespace ConsoleApplication1
{
    class Program
    {
        private Object hash_hmac(string signatureString, string secretKey, bool raw_output = false)
        {
            var enc = Encoding.UTF8;
            HMACSHA1 hmac = new HMACSHA1(enc.GetBytes(secretKey));
            hmac.Initialize();

            byte[] buffer = enc.GetBytes(signatureString);
            if (raw_output)
            {
                return hmac.ComputeHash(buffer);
            }
            else
            {
                return BitConverter.ToString(hmac.ComputeHash(buffer)).Replace("-", "").ToLower();
            }
        }

        static void Main(string[] args)
        {
            Program p = new Program();
            String res1 = (String)p.hash_hmac("signatureString", "secret");
            Console.WriteLine(res1);
            //ee1b654aa861c41fd5813dc365ef106c9801f8f6
            Console.WriteLine(Convert.ToBase64String(Encoding.UTF8.GetBytes(res1)));
            //ZWUxYjY1NGFhODYxYzQxZmQ1ODEzZGMzNjVlZjEwNmM5ODAxZjhmNg==

            byte[] ret = (byte[])p.hash_hmac("signatureString", "secret", true);
            for (int i = 0; i < ret.Length; i++) {
                Console.Write(ret[i] + " ");
            }
            //238 27 101 74 168 97 196 31 213 129 61 195 101 239 16 108 152 1 248 246
            Console.WriteLine();

            Console.WriteLine(Convert.ToBase64String(ret));
            //7htlSqhhxB/VgT3DZe8QbJgB+PY=
        }
    }
}