Safely overriding document.cookie in Google Chrome extension

Question

I am trying to override document.cookie in my Chrome extension and I'm having a lot of trouble getting the original document.cookie functionality to work at the same time. Currently I have this:

var _cookie = document.cookie; 
document.__defineSetter__("cookie", function(the_cookie) {_cookie=the_cookie;} );
document.__defineGetter__("cookie", function() {return _cookie;} );

I am injecting the JS from a content script using the technique from here .

The behavior I'm seeing is that my re-defined setter and getter get called, but the original function is no longer working. For example, I can check _cookie and document.cookie using the Developer Tools and see that they have the same, expected value, but no cookies ever appear in Chrome's cookie store.

Can anyone tell me how I am breaking the original document.cookie functionality? Is the problem that document.cookie is a property, so I'm not actually getting a pointer to the original setter?

Answer 1

var _cookie = document.cookie; is not saving the original getter and setter for cookie , it is just calling the getter and saving the result.

This page ( original link , now broken) has an example of how to save the cookie setter and getter:

var cookie_setter = document.__lookupSetter__ ('cookie');
var cookie_getter = document.__lookupGetter__ ('cookie');

Answer 2

您已经重新定义了orignal cookie getter和setter函数，并且您可能有可能忘记了新函数中原始函数的重要部分或实现