using System;

using System.Security.Cryptography;

using System.Text;

​

public class SignatureVerification

{

    public static void Main()

    {

        // For CO Form and Pay with iyzico

        string secretKey = "sandbox-UuLnD7wZa0a3DmytfIrwHQqAMfqCNJrs";

        string iyziEventType = "CHECKOUT_FORM_AUTH";

        string iyziPaymentId = "22502046";

        string token = "67921f98-792a-400a-a7b0-1a553d7e6297";

        string paymentConversationId = "conversationId";

        string status = "SUCCESS";

​

        string key = secretKey + iyziEventType + iyziPaymentId + token + paymentConversationId + status;

        string hmac256Signature = CalculateHMACSHA256(key, secretKey);

​

        string signature_v3 = "67712f0a5918839d9032e5560e1678324d045f66e33bef934e013faf504f9c58";

​

        if (hmac256Signature == signature_v3)

        {

            Console.WriteLine("HMAC-SHA256 Signature Verified: " + hmac256Signature);

            Console.WriteLine("Enjoy your code...");

        }

        else

        {

            Console.WriteLine("Signature verification failed.");

        }

    }

​

    private static string CalculateHMACSHA256(string data, string key)

    {

        byte[] keyBytes = Encoding.UTF8.GetBytes(key);

        byte[] dataBytes = Encoding.UTF8.GetBytes(data);

​

        using (var hmac = new HMACSHA256(keyBytes))

        {

            byte[] hmacBytes = hmac.ComputeHash(dataBytes);

            return BitConverter.ToString(hmacBytes).Replace("-", "").ToLower();

        }

    }

}

​