<?php
   $secret = ""; // Get your secret key from Revlum
 
   $subId = isset($_REQUEST['subId']) ? $_REQUEST['subId'] : null;
   $transId = isset($_REQUEST['transId']) ? $_REQUEST['transId'] : null;
   $reward = isset($_REQUEST['reward']) ? $_REQUEST['reward'] : null;
   $signature = isset($_REQUEST['signature']) ? $_REQUEST['signature'] : null;
 
   // Validate Signature
   if(md5($subId.$transId.$reward.$secret) != $signature)
   {
    echo "ERROR: Signature doesn't match";
    return;
   }
 ?>

const express = require('express');
const crypto = require('crypto');

const app = express();
const secret = "";  // Get your secret key from Revlum

app.get('/your-endpoint', (req, res) => {
  const { subId, transId, reward, signature } = req.query;

  // Validate Signature
  const hash = crypto.createHash('md5').update(subId + transId + reward + secret).digest('hex');
  if (hash !== signature) {
    res.send("ERROR: Signature doesn't match");
    return;
  }
  res.send("Signature is valid");
});

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

@SpringBootApplication
@RestController
public class Application {

    private static final String secret = "";  // Get your secret key from Revlum

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

    @GetMapping("/your-endpoint")
    public String validateSignature(@RequestParam String subId,
                                    @RequestParam String transId,
                                    @RequestParam String reward,
                                    @RequestParam String signature) throws NoSuchAlgorithmException {
        MessageDigest md = MessageDigest.getInstance("MD5");
        byte[] hashBytes = md.digest((subId + transId + reward + secret).getBytes());
        StringBuilder sb = new StringBuilder();
        for (byte b : hashBytes) {
            sb.append(String.format("%02x", b));
        }
        if (!sb.toString().equals(signature)) {
            return "ERROR: Signature doesn't match";
        }
        return "Signature is valid";
    }
}

const express = require('express');
const crypto = require('crypto');

const app = express();
const secret = "";  // Get your secret key from Revlum

app.get('/api/validate', (req, res) => {
  const { subId, transId, reward, signature } = req.query;

  // Validate Signature
  const hash = crypto.createHash('md5').update(subId + transId + reward + secret).digest('hex');
  if (hash !== signature) {
    res.send("ERROR: Signature doesn't match");
    return;
  }
  res.send("Signature is valid");
});

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

using System;
using System.Security.Cryptography;
using System.Text;

public class SignatureValidation
{
    private string secret = ""; // Get your secret key from Revlum

    public void ValidateSignature(string subId, string transId, string reward, string signature)
    {
        string dataToValidate = subId + transId + reward + secret;
        string calculatedSignature = CalculateMD5Hash(dataToValidate);

        if (calculatedSignature != signature)
        {
            Console.WriteLine("ERROR: Signature doesn't match");
            return;
        }

        // Continue processing as signature is valid
    }

    private string CalculateMD5Hash(string input)
    {
        using (MD5 md5 = MD5.Create())
        {
            byte[] inputBytes = Encoding.ASCII.GetBytes(input);
            byte[] hashBytes = md5.ComputeHash(inputBytes);

            StringBuilder sb = new StringBuilder();
            foreach (byte b in hashBytes)
            {
                sb.Append(b.ToString("X2"));
            }
            return sb.ToString().ToLower();
        }
    }
}

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class SignatureValidationController extends Controller
{
    private $secret = ''; // Get your secret key from Revlum

    public function validateSignature(Request $request)
    {
        $subId = $request->input('subId');
        $transId = $request->input('transId');
        $reward = $request->input('reward');
        $signature = $request->input('signature');

        if (md5($subId . $transId . $reward . $this->secret) != $signature) {
            return response()->json(['error' => "Signature doesn't match"], 400);
        }

        // Continue processing as signature is valid
    }
}