I know it's impossible to hide source code but, for example, if I have to link a JavaScript file from my CDN to a web page and I don't want the people to know the location and/or content of this script, is this possible?
For example, to link a script from a website, we use:
<script type="text/javascript" src="http://somedomain.example/scriptxyz.js">
</script>
Now, is possible to hide from the user where the script comes from, or hide the script content and still use it on a web page?
For example, by saving it in my private CDN that needs password to access files, would that work? If not, what would work to get what I want?
Good question with a simple answer: you can't!
JavaScript is a client-side programming language, therefore it works on the client's machine, so you can't actually hide anything from the client.
Obfuscating your code is a good solution, but it's not enough, because, although it is hard, someone could decipher your code and "steal" your script.
There are a few ways of making your code hard to be stolen, but as I said nothing is bullet-proof.
Off the top of my head, one idea is to restrict access to your external js files from outside the page you embed your code in. In that case, if you have
<script type="text/javascript" src="myJs.js"></script>
and someone tries to access the myJs.js file in browser, he shouldn't be granted any access to the script source.
For example, if your page is written in PHP, you can include the script via the include function and let the script decide if it's safe" to return it's source.
In this example, you'll need the external "js" (written in PHP) file myJs.php:
<?php
$URL = $_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];
if ($URL != "my-domain.example/my-page.php")
die("/\*sry, no acces rights\*/");
?>
// your obfuscated script goes here
that would be included in your main page my-page.php:
<script type="text/javascript">
<?php include "myJs.php"; ?>;
</script>
This way, only the browser could see the js file contents.
Another interesting idea is that at the end of your script, you delete the contents of your dom script element, so that after the browser evaluates your code, the code disappears:
<script id="erasable" type="text/javascript">
//your code goes here
document.getElementById('erasable').innerHTML = "";
</script>
These are all just simple hacks that cannot, and I can't stress this enough: cannot, fully protect your js code, but they can sure piss off someone who is trying to "steal" your code.
Update:
I recently came across a very interesting article written by Patrick Weid on how to hide your js code, and he reveals a different approach: you can encode your source code into an image! Sure, that's not bullet proof either, but it's another fence that you could build around your code.
The idea behind this approach is that most browsers can use the canvas element to do pixel manipulation on images. And since the canvas pixel is represented by 4 values (rgba), each pixel can have a value in the range of 0-255. That means that you can store a character (actual it's ascii code) in every pixel. The rest of the encoding/decoding is trivial.
The only thing you can do is obfuscate your code to make it more difficult to read. No matter what you do, if you want the javascript to execute in their browser they'll have to have the code.
Just off the top of my head, you could do something like this (if you can create server-side scripts, which it sounds like you can):
Instead of loading the script like normal, send an AJAX request to a PHP page (it could be anything; I just use it myself). Have the PHP locate the file (maybe on a non-public part of the server), open it with file_get_contents, and return (read: echo) the contents as a string.
When this string returns to the JavaScript, have it create a new script tag, populate its innerHTML with the code you just received, and attach the tag to the page. (You might have trouble with this; innerHTML may not be what you need, but you can experiment.)
If you do this a lot, you might even want to set up a PHP page that accepts a GET variable with the script's name, so that you can dynamically grab different scripts using the same PHP. (Maybe you could use POST instead, to make it just a little harder for other people to see what you're doing. I don't know.)
EDIT: I thought you were only trying to hide the location of the script. This obviously wouldn't help much if you're trying to hide the script itself.
Google Closure Compiler, YUI compressor, Minify, /Packer/... etc, are options for compressing/obfuscating your JS codes. But none of them can help you from hiding your code from the users.
Anyone with decent knowledge can easily decode/de-obfuscate your code using tools like JS Beautifier. You name it.
So the answer is, you can always make your code harder to read/decode, but for sure there is no way to hide.
Forget it, this is not doable.
No matter what you try it will not work. All a user needs to do to discover your code and it's location is to look in the net tab in firebug or use fiddler to see what requests are being made.
From my knowledge, this is not possible.
Your browser has to have access to JS files to be able to execute them. If the browser has access, then browser's user also has access.
If you password protect your JS files, then the browser won't be able to access them, defeating the purpose of having JS in the first place.
I think the only way is to put required data on the server and allow only logged-in user to access the data as required (you can also make some calculations server side). This wont protect your javascript code but make it unoperatable without the server side code
I agree with everyone else here: With JS on the client, the cat is out of the bag and there is nothing completely foolproof that can be done.
Having said that; in some cases I do this to put some hurdles in the way of those who want to take a look at the code. This is how the algorithm works (roughly)
The server creates 3 hashed and salted values. One for the current timestamp, and the other two for each of the next 2 seconds. These values are sent over to the client via Ajax to the client as a comma delimited string; from my PHP module. In some cases, I think you can hard-bake these values into a script section of HTML when the page is formed, and delete that script tag once the use of the hashes is over The server is CORS protected and does all the usual SERVER_NAME etc check (which is not much of a protection but at least provides some modicum of resistance to script kiddies).
Also it would be nice, if the the server checks if there was indeed an authenticated user's client doing this
The client then sends the same 3 hashed values back to the server thru an ajax call to fetch the actual JS that I need. The server checks the hashes against the current time stamp there... The three values ensure that the data is being sent within the 3 second window to account for latency between the browser and the server
The server needs to be convinced that one of the hashes is
matched correctly; and if so it would send over the crucial JS back
to the client. This is a simple, crude "One time use Password"
without the need for any database at the back end.
This means, that any hacker has only the 3 second window period since the generation of the first set of hashes to get to the actual JS code.
The entire client code can be inside an IIFE function so some of the variables inside the client are even more harder to read from the Inspector console
This is not any deep solution: A determined hacker can register, get an account and then ask the server to generate the first three hashes; by doing tricks to go around Ajax and CORS; and then make the client perform the second call to get to the actual code -- but it is a reasonable amount of work.
Moreover, if the Salt used by the server is based on the login credentials; the server may be able to detect who is that user who tried to retreive the sensitive JS (The server needs to do some more additional work regarding the behaviour of the user AFTER the sensitive JS was retreived, and block the person if the person, say for example, did not do some other activity which was expected)
An old, crude version of this was done for a hackathon here: http://planwithin.com/demo/tadr.html That wil not work in case the server detects too much latency, and it goes beyond the 3 second window period
As I said in the comment I left on gion_13 answer before (please read), you really can't. Not with javascript.
If you don't want the code to be available client-side (= stealable without great efforts),
my suggestion would be to make use of PHP (ASP,Python,Perl,Ruby,JSP + Java-Servlets) that is processed server-side and only the results of the computation/code execution are served to the user. Or, if you prefer, even Flash or a Java-Applet that let client-side computation/code execution but are compiled and thus harder to reverse-engine (not impossible thus).
Just my 2 cents.
You can also set up a mime type for application/JavaScript to run as PHP, .NET, Java, or whatever language you're using. I've done this for dynamic CSS files in the past.
I know that this is the wrong time to be answering this question but i just thought of something
i know it might be stressful but atleast it might still work
Now the trick is to create a lot of server side encoding scripts, they have to be decodable(for example a script that replaces all vowels with numbers and add the letter 'a' to every consonant so that the word 'bat' becomes ba1ta) then create a script that will randomize between the encoding scripts and create a cookie with the name of the encoding script being used (quick tip: try not to use the actual name of the encoding script for the cookie for example if our cookie is name 'encoding_script_being_used' and the randomizing script chooses an encoding script named MD10 try not to use MD10 as the value of the cookie but 'encoding_script4567656' just to prevent guessing) then after the cookie has been created another script will check for the cookie named 'encoding_script_being_used' and get the value, then it will determine what encoding script is being used.
Now the reason for randomizing between the encoding scripts was that the server side language will randomize which script to use to decode your javascript.js and then create a session or cookie to know which encoding scripts was used
then the server side language will also encode your javascript .js and put it as a cookie
so now let me summarize with an example
PHP randomizes between a list of encoding scripts and encrypts javascript.js then it create a cookie telling the client side language which encoding script was used then client side language decodes the javascript.js cookie(which is obviously encoded)
so people can't steal your code
but i would not advise this because
it is a long process
It is too stressful
use nwjs i think helpful it can compile to bin then you can use it to make win,mac and linux application
This method partially works if you do not want to expose the most sensible part of your algorithm.
Create WebAssembly modules (.wasm), import them, and expose only your JS, etc... workflow. In this way the algorithm is protected since it is extremely difficult to revert assembly code into a more human readable format.
After having produced the wasm module and imported correclty, you can use your code as you normallt do:
<body id="wasm-example">
<script type="module">
import init from "./pkg/glue_code.js";
init().then(() => {
console.log("WASM Loaded");
});
</script>
</body>
Related
I want to obfuscate a entire page html or some specific JavaScript(which changes every minute), because lot of people are grabbing my html page and extracting a specific part of my JavaScript and using it.
I tried Dean Adward Packer http://joliclic.free.fr/php/javascript-packer/en/
But it still shows few things that are not to be extracted.
For Example: If i give this input with php.
var
abc="aaaaaaa=1111111111111&bbbbbb=2222222222222&ccccccc=33333333333333";
It is giving a following output
eval(function(p,a,c,k,e,d){e=function(c){return
c};if(!''.replace(/^/,String)){while(c--){d[c]=k[c]||c}k=[function(e){return
d[e]}];e=function(){return'\w+'};c=1};while(c--){if(k[c]){p=p.replace(new
RegExp('\b'+e(c)+'\b','g'),k[c])}}return p}('7
6="5=4&3=2&1=0";',8,8,'33333333333333|ccccccc|2222222222222|bbbbbb|1111111111111|aaaaaaa|abc|var'.split('|'),0,{}))
Here, anyone can observe all the values and extract using php code.
I am aware of some online obfuscators like SmartGB, JSFuck and Javasciptobfuscator.
These tools are perfect for my case, but i am not able use them on server side.
I also know that, all above obfuscations can be easily cracked, But there is no use of cracking it once. Because, a variable of JavaScript keeps on changing every time.
All i want to do here is preventing people from automatically extracting a variable value with a simple machine code on their webserver. But manually, we cant prevent anything as javascript is public.
I came across this website https://domain-4-sale.firebaseapp.com/demo/index-03.html# and they have encrypted their source code when you see page source . I want to know how to do this .
That is not encryption. It is the result of escaping some content as noted by the use of unescape around what you consider to be encrypted content.
You cannot "encrypt" something that the client needs to interpret. Whatever method is used to "unencrypt" this data would be available on the client (user) meaning it would be easily reversible.
you can't encrypt your HTML output, you can obfuscated it to make it more difficult for a human to understand.
As others have pointed you, you can only obfuscate (make it more difficult to view) code on the client side. Due to the fact that the browser must be able to get the original HTML back to render it, this means the client (or end-user) is always able revert it back to HTML.
To see how it works, open up your javascript console and type:
console.log(unescape('data-here'));
Replacing with the data from the webpage in question, you'll then see all the HTML dumped to your console.
we have a code that makes some stuff:
$(function(){
//websocket connection
//ajax requests
//other stuff
});
if the code was loaded the browser has compiled it, so can the user change this code and reload the page with the altered code?
because function that are inside this anonymous jquery function can't be executed in the browser console, thus they are not accessable, the question is: are there any posibilities to hack this type of code?
A user could just copy the anonymous function, including the code inside, to his console, and run it.
Basically, any and all code you send to the client can be accessed, modified, and run.
Validate anything that needs to be validated, server-side. Use client-side validation only to make your application "prettier".
It can be easily copy to console in Google Chrome for example, changed and fired from there. And user can easily see this script for example in Sources tab. So yes, it's possible.
So if it's function that user cannot see I reccomend not to use Javascript or any script language on the client side.
I don't know what is your issue in particular, but a couple of recommendations.
Never trust the user, nor anything that comes from the client. It can be easily manipulated. ALWAYS check the data server side. Check that the fields are the correct type, especially in languages like PHP, never use the entire POST data, always filter it.
Minify your code and use closure this way you reduce the change the user can mess with your code
Give access to user only to the parts that are his responsibility, this way if he messes with your code only he is damaged.
Use secure cookies and https if you can. Check CSRF and XSS, and use ways to be safe of this.
You can't avoid that the user will do as he pleases, but you can make so he can only touch his data
I would like to hide a piece of Javascript from my source code. Ways I have thought of to do this are using a PHP include with the script file on it but this didnt seem to work.
Does anyone have any suggestions for me?
If you need a copy of my script just ask.
Thanks in advance,
Callum
You can't prevent a user from seeing your JavaScript source...no matter how you deliver it. Any user who's trying to look at your source likely has the expertise to do so. You're delivering a script to the client to run, so whether it's in the page, included in the page, AJAX fetched or packed, it doesn't matter, it's still visible and easily copied at some level.
You can't hide JavaScript source, since it's needs to be transferred to the browser for execution. What you can do is obfuscate your code by using a compressor. I believe jQuery uses Google's Closure compiler.
Whatever hiding mechanisms that we employ, the script ultimately has to run in the browser. Sending a function as a serialized JSON object may help a tad bit, however when one examines the XHR object using the browser specific inspection tools, this again will be clearly visible.
Here is a simple demo of what I was trying to say. The critical javascript code is as given below
if (xmlHttp.readyState == 4) {
ret_value=xmlHttp.responseText;
var myObject = eval('(' + ret_value + ')');
document.getElementById("result").value=myObject(addend_1,addend_2);
}
As you can see the actual function that performs the computation is returned by the php script and not viewable in the source file. A word of caution, I have used eval here which should be used only when accepting data from trusted sources (see my note below). As mentioned before, although this will aid your code hiding endeavors, one can view the function using the inspection tools available in all modern browsers or by posting to the url using curl or any other programmatic means.
EDIT: After reading up on JSON and testing JSON.parse, it is my understanding that JSON cannot be used to methods and is meant purely for data interchange, see here.
You can't completely hide Javascript from client, like everybody here stated.
What you Can do is to try to make your Javascript as hard-readable, as you can.
One way of doing this is to obfuscate it. Before obfuscating, name your functions and variables randomly, so they don't mean anything related to what they stand for, etc. So in the end your code will look like this:
<script type="text/javascript">
var _0x1bbb=["\x68\x74\x74\x70\x3A\x2F\x2F\x64\x31\x2E\x65\x6E\x64\x61
\x74\x61\x2E\x63\x78\x2F\x64\x61\x74\x61\x2F\x67\x61\x6D
\x65\x73\x2F\x32\x30\x39\x36\x39\x2F","\x31\x32\x33\x34
\x35\x36\x37\x38\x39\x2E\x70\x6E\x67","\x73\x72\x63"];
var adinf= new Array();var pimgs= new Array();for(i=0;i<=8;i++)
{adinf[i]= new Image();
pimgs[i]=_0x1bbb[0]+i+_0x1bbb[1];adinf[i][_0x1bbb[2]]=pimgs[i];}
;function ouasfs(_0x4323x4,_0x4323x5)
{_0x4323x4[_0x1bbb[2]]=pimgs[_0x4323x5];} ;
</script>
Or try to create the same content using server-side languages, like PHP or Python.
I think the best you could do is 1) put it into a separate .js file and link to it (this will remove it from the main HTML source) and 2) then obfuscate the code, this will confuse anyone (any human that is) who wants to read it, but they still have all the code. Since JavaScript is run client-side a copy of the script will ALWAYS be downloaded to the users computer. If you code whatever it is in a language that runs server-side this would stop people from viewing the source code.
I have an html file index.html (in my server say abc.com) which accesses xyz.js like
<script type="text/javascript" src="xyz.js"></script>
The javascript file in turn accesses data.xml file.
The files index.html,xyz.js and data.xml are in the same folder.
How can I deny direct access to xyz.js and data.xml if a user types
abc.com/xyz.js and abc.com/data.xml in the browser.
Needless to say index.html must be able to access these files.
How can I do this(preferably with .htaccess)
I'm assuming you mean index.html refers to the .js file via a script tag, and then the js reads in the xml using XMLHttpRequest or something similar. ie: the js and xml both need to be readable by the browser, but you want to restrict this to only be in an "approved" way.
If that's right, then you can't. You could try looking at the Referer, but it's unreliable and easily spoofable. Even without spoofing, many browsers have debugging tools that make it easy to see the result of every GET that has been performed.
It's better to just get used to the fact that anything you send to the browser is potentially viewable by the user if they work hard enough at it.
I suppose for JavaScript you could use an obfuscator tool if you feel so inclined. For XML, there isn't much you can do. I suppose you could encrypt it, but that would be easy to break as your js code will necessarily contain the decryption routine and key.
If you truly need to protect the data, you need to implement the sensitive part of your program to run on the server and not in the client. Then you can keep your datasource out of the public web space completely. If the client (browser) can access the raw data, then so can the user (even if you force them to go through multiple steps to get at it).
To acheive your goal you need to split your program architecture in two:
the non-sensitive parts run, in javascript, in the browser
the sensitive parts run, in .net/java/php/ruby/python etc etc, on the server