using System;

using Newtonsoft.Json;

using System.Security.Cryptography;

using System.Text;

public class Program

{

    public static void Main()

    {

        var bankResponseHeader = "{\"header\":{\"requestId\":\"0218a7cc280e412eb4427e678c4521b4\",\"swtId\":\"CC82C381E078482AB328943FCCB7100C\",\"returnCode\":\"00\",\"reasonCode\":\"00\",\"message\":\"Başarılı\",\"timestamp\":\"2021-01-16T07:16:52.224+0000\",\"hashedData\":\"5F3592A0447D80AD89456D89DF84FB5D0278291ED47C1CE6788FDC29869BDFE9\"},\"card\":{\"token\":\"D3EB33875B1A48AD9EE09508CBFA2201\",\"binNumber\":\"537829\",\"bankId\":\"62\",\"maskedNumber\":\"537829******1012\",\"bankName\":\"T. GARANTİ BANKASI A.Ş.\"}}";

        var jsonResult = JsonConvert.DeserializeObject(bankResponseHeader);

        Console.WriteLine(jsonResult);

        string requestId = "0218a7cc280e412eb4427e678c4521b4";

        string swtId = "CC82C381E078482AB328943FCCB7100C";

        string returnCode = "00";

        string reasonCode = "00";

        string message = "Başarılı";

        string timeStamp = "2021-01-16T07:16:52.224+0000";

        string responseHash = "5F3592A0447D80AD89456D89DF84FB5D0278291ED47C1CE6788FDC29869BDFE9";

        Console.WriteLine("");

        string ourCalculatedHash = CalculateHash(requestId + swtId + returnCode + reasonCode + message + timeStamp + "123asdASD@");

        Console.WriteLine(ourCalculatedHash);

        Console.WriteLine(responseHash);

    }

    public static string CalculateHash(string rawData)

    {

        if (string.IsNullOrEmpty(rawData))

            return rawData;

​

        using (SHA256 sha256Hash = SHA256.Create())

        {

            byte[] bytes = sha256Hash.ComputeHash(Encoding.UTF8.GetBytes(rawData));

            return GetHexaDecimal(bytes);

        }

    }

​

    public static string GetHexaDecimal(byte[] bytes)

    {

        StringBuilder builder = new StringBuilder();

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

        {

            builder.Append(bytes[i].ToString("x2"));

        }

        return builder.ToString().ToUpper();

    }

}