using System;

using System.Security.Cryptography;

using System.Text;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var customerAccountNumber = "8401e447-c4de-4b95-9e77-1b5fce4123ce";

        var msisdn = "";

        var operatorCode = "42403";

        var subscriptionPlanId = 48;

        var initialPaymentproductId = "dv-008";

        var initialPaymentDate = "2020-01-22 09:30:00Z"; //DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ssZ");

        var recurringPaymentproductId = "dv-008";

        var productCatalogName = "DV-Catalog";

        var contractStartDate = "2020-01-22 09:30:00Z"; //DateTime.UtcNow.ToString("yyyy-MM-dd HH:mm:ssZ");

        var contractEndDate = "2021-01-22 09:30:00Z"; //DateTime.UtcNow.AddYears(2).ToString("yyyy-MM-dd HH:mm:ssZ");

        var autoRenewContract = true;

        var sendVerificationSMS = true;

        var executeInitialPaymentNow = false;

        var executeRecurringPaymentNow = false;

        var language = 2; // Auto = 0, English = 1, Arabic = 2, French = 3       

        const string PublicKey = "whpnsHMgiNioDB76MXXw";

        const string PrivateKey = "F1ihKTGCrPL4UVvSnMBR";

        var message = customerAccountNumber + msisdn + operatorCode + subscriptionPlanId.ToString() + initialPaymentproductId + initialPaymentDate + executeInitialPaymentNow.ToString().ToLower() + recurringPaymentproductId + productCatalogName + executeRecurringPaymentNow.ToString().ToLower() + contractStartDate + contractEndDate + autoRenewContract.ToString().ToLower() + (int)language;

        var theDigest = CalculateDigest(PublicKey, PrivateKey, message);

        var url = "https://live.tpay.me/op/42403/sub/new/customerAccountNumber="+customerAccountNumber+"&msisdn=&operatorCode="+operatorCode+"&subscriptionPlanId="+subscriptionPlanId.ToString()+"&initialPaymentproductId="

        +"&initialPaymentDate="+initialPaymentDate +"&executeInitialPaymentNow="+executeInitialPaymentNow+"&recurringPaymentproductId="+recurringPaymentproductId+"&productCatalogName="+productCatalogName

            +"&executeRecurringPaymentNow="+executeRecurringPaymentNow+"&contractStartDate="+contractStartDate+"&contractEndDate="+contractEndDate

            +"&autoRenewContract="+autoRenewContract+"&language="+language+"&signature="+theDigest+"&redirectURL=http://billing.virgopass.com/tpay/du/callback.php";

        Console.WriteLine(url);

    }

​

    public static string CalculateDigest(string publicKey, string privateKey, string message)

    {

        var digest = "";

        var hash = new System.Security.Cryptography.HMACSHA256(System.Text.Encoding.UTF8.GetBytes(privateKey));

        var correctHash = string.Join(string.Empty, hash.ComputeHash(System.Text.Encoding.UTF8.GetBytes(message)).Select(b => b.ToString("x2")));

        digest = publicKey + ":" + correctHash;

​

        return digest;

    }

}

​