How can I fool a site that looks at the JavaScript object 'navigator' to see that I'm not on Windows?

Question

I am trying to a website, however, it only works under Windows and Mac because they use the use navigator.platform from JavaScript to find out the architecture I run on. Of course, they also use the browser's user agent, but that was easy to spoof.

Here is the .js in question: http://pastebin.com/f56fd608d. The code responsible for browser detection is at the top. Is there any way of changing the .js file before the site runs, or something similar, so I can eliminate the check?

Using the JavaScript console yields:

>navigator.platform
Linux i686

Evidently I changed the browser's user agent, but navigator.platform does not seem to take it's value from the user agent.

Maybe someone knows how to change the value returned by navigator.platform, because I hate running Windows under VirtualBox to use this site.

EDIT: This could be of interest because Linux users might be artificially denied access to websites, and can do nothing about it.

Answer 1

Attempting to change this property (at any time) in Firefox yields:

Error: setting a property that has only a getter

Source File: index.html

Line: 1

So I think you will have a hard time.

I'd try to contact the author about obtaining a fix.

Answer 2

For a Mozilla-based browser, GreaseSpot / Code Snippets # Hijacking browser properties demonstrates how it may be done. This code may be injected from a GreaseMonkey script.

Answer 3

Since you can't directly set navigator.platform, you will have to be sneaky - create an object that behaves like navigator, replace its platform, then set navigator to it.

var fake_navigator = {};

for (var i in navigator) {
  fake_navigator[i] =  navigator[i];
}

fake_navigator.platform = 'MyOS';

navigator = fake_navigator;

If you execute this code before the document loads (using GreaseMonkey, an addon or a Chrome extension), then the page will see navigator.platform as "MyOS".

Note: tested only in Chrome.

Answer 4

var fakePlatformGetter = function () {
  return "your fake platform";
};
if (Object.defineProperty) {
  Object.defineProperty(navigator, "platform", {
    get: fakePlatformGetter
  });
} else if (Object.prototype.__defineGetter__) {
  navigator.__defineGetter__("platform", fakePlatformGetter);
}

Answer 5

about:config - > general.platform.override