using System;

using System.Collections.Generic;

using System.Security.Cryptography;

using System.Text;

public class Program

{

    public static void Main()

    {

        string interfaceKey = "BdDoqYjSVgc", QueryString = "";

        byte[] SHA512Bytes = null;      

        Dictionary<string, string> dict1 = new Dictionary<string, string>(); 

        dict1.Add("documentingUser", Base64Encode("Admin"));

        dict1.Add("Mcg-Partner-ID", Base64Encode("220f6d5b-7631-4e3e-9cdc-033b157ca5e7|AaNeel_Infotech"));

        dict1.Add("Mcg-Solution-ID", Base64Encode("AaNeelCare"));

        dict1.Add("Mcg-Solution-Version", Base64Encode("10.0.1"));

        dict1.Add("requestType", Base64Encode("documentation"));

        foreach(KeyValuePair<string, string> ele in dict1)

        {

            QueryString = QueryString + string.Concat("&",ele.Key,"=",ele.Value);           

        }   

        QueryString = QueryString.Substring(1);     

        string requestedSHAText = string.Concat(QueryString,interfaceKey);

        SHA512Bytes = SHA512Encode(requestedSHAText);       

        string HashValue = Convert.ToBase64String(SHA512Bytes,0,SHA512Bytes.Length);

        string GetQueryString = string.Concat(QueryString,"&messageHash=",HashValue);

        Console.WriteLine(GetQueryString);

    }

    public static string Base64Encode(string plainText) 

    {

        var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);

        return System.Convert.ToBase64String(plainTextBytes);

    }

    public static byte[] SHA512Encode(string source) 

    {

        //string hash = "";

        byte[] hashBytes = null;

        using (SHA512 sha512Hash = SHA512.Create())

        {        

            byte[] sourceBytes = Encoding.UTF8.GetBytes(source);

            hashBytes = sha512Hash.ComputeHash(sourceBytes);

            //hash = BitConverter.ToString(hashBytes).Replace("-", String.Empty);

        }

        //return hash;

        return hashBytes;

    }

}