How to protect Javascript code from copying by Ajax method

How to protect Javascript code from copying by Ajax method
by Janeth Kent Date: 24-06-2013 javascript ajax jquery websecurity script tutorial

Today, in this mini tutorial we will introduce a simple method to protect javascript code from copying.

IMPORTANT: We are not sure this method will protect javascript 100% but it will be better than do nothing ;-D

As we said, this method is very simple: basically we have to combine AJAX method with little server-side script to prevent visitors access javascript file directly.

Let's explain our method:

		
 	<!DOCTYPE html>
 
 	<html>
 
 	<head>
 
 	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 
 	<title>Protecting Javascript Code From Copying</title>
 
 	 
 
 	<!-- jQuery Library 1.8.3 -->
 
 	<script type="text/javascript" src="js/jquery/jquery.min.183.js"></script>
 
 	 
 
 	<script type="text/javascript">
 
 	 
 
 	$(document).ready(function(e) {   
 
 	  function MyJSFunction() {
 
 	    alert("This is my script, you can not copy this!");
 
 	  }
 
 	  // Show Alert
 
 	  MyJSFunction();  
 
 	});
 
 	</script>
 
 	</head>
 
 	 
 
 	<body>
 
 	  Protecting Javascript Code From Copying.
 
 	</body>
 
 	</html>
						
					
	

 

So, we have a javascript function called MyJSFucntion that we don't want users view it.

When users access the page they will see an alert message. Then users want to see the javascript code that is used to trigger the alert message so they will use “view page source” or “inspect element” or “firebug”.

But the question is we don't want anyone see our javascript code so we'll put the javascript code into a php file ( js-protect.php ).

Then we use an AJAX method to load the php file.

js-protect.php content:

		
 	<script type="text/javascript">
 
 	function MyJSFunction() {
 
 	  alert("This is my script, you can not copy this!");
 
 	}  
 
 	// Show Alert
 
 	MyJSFunction();
 
 	</script>
						
					
	

The AJAX code to load js-protect.php file in “js/” folder ( we use jQuery ):

		
 	<script type="text/javascript">
 
 	$(window).load(function() {
 
 	  $.ajax({
 
 	    url: 'js/js-protect.php',
 
 	    type:'POST',
 
 	    cache: false,
 
 	    success: function(data){
 
 	      if(data){
 
 	        $('body').append(data);
 
 	      }
 
 	    }
 
 	  });
 
 	})
 
 	</script>
						
					
	

 

Now, when users view source code of the page they will not see the javascript we wrote.

But, some experient user may be know the link of js.php file by which they can access the file directly.

To protect javascript from this "intrusion" we will use a simple validating method to check referer link. If the referer link is the index page we will allow them to access the javascript code otherwise we will show them another content.

Changing the js-protect.php file:

		
 	<?php
 
 	  $referer = $_SERVER['HTTP_REFERER'];
 
 	  // Check URL
 
 	  if ( $referer=='http://ma-no.org/free/demo/demo-protect.php' ) {
 
 	?>
 
 	 
 
 	<script type="text/javascript">
 
 	function MyJSFunction() {
 
 	  alert("This is my script, you can not copy this!");
 
 	}  
 
 	// Show Alert
 
 	MyJSFunction();
 
 	</script>
 
 	 
 
 	<?php }
 
 	// If strange url
 
 	else { ?>
 
 	    Sorry! You can not see this content. Please go to <a href="http://ma-no.org">MA_NO.ORG</a><br />
 
 	<?php } ?>
						
				

The index page ( demo.php ):

		
 	<!DOCTYPE html>
 
 	<html>
 
 	<head>
 
 	<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 
 	<title>Protecting Javascript Code From Copying</title>
 
 	 
 
 	<!-- jQuery Library 1.8.3 -->
 
 	<script type="text/javascript" src="js/jquery/jquery.min.183.js"></script>
 
 	 
 
 	<script type="text/javascript">
 
 	$(window).load(function() {
 
 	  $.ajax({
 
 	    url: 'js/js-protect.php',
 
 	    type:'POST',
 
 	    cache: false,
 
 	    success: function(data){
 
 	      if(data){
 
 	        $('body').append(data);
 
 	      }
 
 	    }
 
 	  });
 
 	})
 
 	</script>
 
 	</head>
 
 	 
 
 	<body>
 
 	  Protecting Javascript Code From Copying.
 
 	</body>
 
 	</html>
						
					
	

 

Our work is completed!

 
by Janeth Kent Date: 24-06-2013 javascript ajax jquery websecurity script tutorial hits : 11224  
 
Janeth Kent

Janeth Kent

Licenciada en Bellas Artes y programadora por pasión. Cuando tengo un rato retoco fotos, edito vídeos y diseño cosas. El resto del tiempo escribo en MA-NO WEB DESIGN AND DEVELOPMENT.

 
 
 

Related Posts

How to upload files to the server using JavaScript

In this tutorial we are going to see how you can upload files to a server using Node.js using JavaScript, which is very common. For example, you might want to…

How to combine multiple objects in JavaScript

In JavaScript you can merge multiple objects in a variety of ways. The most commonly used methods are the spread operator ... and the Object.assign() function.   How to copy objects with…

The Payment Request API: Revolutionizing Online Payments (Part 2)

In the first part of this series, we explored the fundamentals of the Payment Request API and how it simplifies the payment experience. Now, let's delve deeper into advanced features…

The Payment Request API: Revolutionizing Online Payments (Part 1)

The Payment Request API has emerged as the new standard for online payments, transforming the way transactions are conducted on the internet. In this two-part series, we will delve into…

Let's create a Color Picker from scratch with HTML5 Canvas, Javascript and CSS3

HTML5 Canvas is a technology that allows developers to generate real-time graphics and animations using JavaScript. It provides a blank canvas on which graphical elements, such as lines, shapes, images…

How do you stop JavaScript execution for a while: sleep()

A sleep()function is a function that allows you to stop the execution of code for a certain amount of time. Using a function similar to this can be interesting for…

Mastering array sorting in JavaScript: a guide to the sort() function

In this article, I will explain the usage and potential of the sort() function in JavaScript.   What does the sort() function do?   The sort() function allows you to sort the elements of…

Infinite scrolling with native JavaScript using the Fetch API

I have long wanted to talk about how infinite scroll functionality can be implemented in a list of items that might be on any Web page. Infinite scroll is a technique…

Sorting elements with SortableJS and storing them in localStorage

SortableJS is a JavaScript extension that you will be able to use in your developments to offer your users the possibility to drag and drop elements in order to change…

What is a JWT token and how does it work?

JWT tokens are a standard used to create application access tokens, enabling user authentication in web applications. Specifically, it follows the RFC 7519 standard. What is a JWT token A JWT token…

Template Literals in JavaScript

Template literals, also known as template literals, appeared in JavaScript in its ES6 version, providing a new method of declaring strings using inverted quotes, offering several new and improved possibilities. About…

How to use the endsWith method in JavaScript

In this short tutorial, we are going to see what the endsWith method, introduced in JavaScript ES6, is and how it is used with strings in JavaScript. The endsWith method is…

Clicky