using System;

using System.Linq;

using System.Text;

using System.Security.Cryptography;

public class Program

{

    public static void Main()

    {

        string publicKey = "PUB";

        string privateKey = "PRV";

        var customerAccountNumber = "R4Svb43ER132";

        var msisdn = "21692012791";

        var operatorCode = "60502";

        var subscriptionPlanId = "76";

        var initialPaymentproductId = "1";

        var initialPaymentDate = "2019-06-20T20:00:56.730Z";

        var executeInitialPaymentNow = "true";

        var recurringPaymentproductId = "1";

        var productCatalogName = "Shofha";

        var executeRecurringPaymentNow = "false";

        var contractStartDate = "2019-06-20T20:00:56.730Z";

        var contractEndDate = "2021-06-20T20:00:56.735Z";

        var autoRenewContract = "true";

        var language = "2";

        var redirectUrl = "http://localhost:8080/VOD/confirmLandingOorredo.do";

        var headerEnrichmentSessionId = string.Empty;

        var signature = string.Empty;

        var plainMessage = customerAccountNumber + msisdn + operatorCode + subscriptionPlanId + initialPaymentproductId +

                       initialPaymentDate + executeInitialPaymentNow.ToString().ToLower() + recurringPaymentproductId +

                       productCatalogName + executeRecurringPaymentNow.ToString().ToLower() + contractStartDate +

                       contractEndDate +

                       autoRenewContract.ToString().ToLower()

                       + language;

        using (var hash = new HMACSHA256(Encoding.UTF8.GetBytes(privateKey)))

        {

            var hashed = string.Join("", hash.ComputeHash(Encoding.UTF8.GetBytes(plainMessage)).Select(b => b.ToString("x2")));

            signature = string.Join(":", publicKey, hashed);

        }

        Console.WriteLine(signature);

    }

}