using System;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

​

namespace ConsoleApp1

{

    public class Sha512Adapter

    {

        public string Hash(string input)

        {

            var hash = SHA512.Create().ComputeHash(Encoding.UTF8.GetBytes(input));

            var result = new StringBuilder(hash.Length * 2);

            foreach (var b in hash)

            {

                result.Append(b.ToString("X2"));

            }

​

            return result.ToString();

        }

    }

​

    public class Program

    {

        public static void Main()

        {

            var hashCode = RandomString(8);

            var requestTimeStamp = new DateTimeOffset(DateTime.UtcNow).ToUnixTimeSeconds();

            var merchantCode = "CRIC69";

            var fattyPayApiKey = "CRIC69-A11E89CF-5458-491A-B9FB-BAD2281B59BE";

            var signature = ( merchantCode + "&" + requestTimeStamp + "&" + fattyPayApiKey).ToSha512Hash();

            var requestUrl = "https://" + $"api.fatty168.xyz/api/v1/query/paymentMethod?Signature={signature}&MerchantCode={merchantCode}&Timestamp={requestTimeStamp}";

            Console.WriteLine(requestUrl);

        }

​

        public static string RandomString(int length)

        {

            var random = new Random(Guid.NewGuid().GetHashCode());

            const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";

            return new string (Enumerable.Repeat(chars, length).Select(s => s[random.Next(s.Length)]).ToArray());

        }

    }

​

    public static class StringExtensions

    {

        public static string ToSha512Hash(this string text)

        {

            return new Sha512Adapter().Hash(text);

        }

    }

}