using System;

using System.Collections.Generic;

using System.Security.Cryptography;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        NavigatedPage();

    }

​

    public static void NavigatedPage()

    {

        string bytes = "<?xml version=\"1.0\" encoding=\"utf-8\" ?><Command>  <LMI_PAYMENT_NO>1000</LMI_PAYMENT_NO><LMI_MERCHANT_ID>2096</LMI_MERCHANT_ID>  <LMI_HASH></LMI_HASH>  <LMI_PAYMENT_SYSTEM>18</LMI_PAYMENT_SYSTEM>  <LMI_PAYMENT_AMOUNT>1001</LMI_PAYMENT_AMOUNT>  <LMI_PAYMENT_DESC>Оплата договора</LMI_PAYMENT_DESC></Command>";

        string key = "14653285";

        string message = bytes; //xml document in a string

        byte[] keyByte = Encoding.UTF8.GetBytes(key);

        HMACSHA256 hmacsha256 = new HMACSHA256(keyByte);

        byte[] messageBytes = Encoding.UTF8.GetBytes(message);

        byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);

        var tempHash = ByteToString(hashmessage);

        Console.WriteLine(tempHash);

    }

​

    public static string ByteToString(byte[] buff)

    {

        string sbinary = "";

        for (int i = 0; i < buff.Length; i++)

        {

            sbinary += buff[i].ToString("X2"); // hex format

        }

​

        return (sbinary);

    }

}