Using nscl patchWorkers in Firefox

General discussion on the NoScript Commons Library. For bug reports or RFEs please use the issue tracker at https://github.com/hackademix/nscl
skriptimaahinen
Master Bug Buster
Posts: 244
Joined: Wed Jan 10, 2018 7:37 am

Re: Using nscl patchWorkers in Firefox

Post by skriptimaahinen »

Pardon my absence.

Looking at barbazs problem viewtopic.php?f=27&t=26485#p104794

I see that window.frames is not a list of frame elements but list of content windows, which is NOT patched by modifyWindow!

So adding:

Code: Select all

  function modifyWindowFramesList(win) {
    let descriptor = Object.getOwnPropertyDescriptor(win, "frames");
    let origGetter = descriptor.get;

    function frames() {
      let frames = origGetter.call(this);
      for (let i = 0; i < frames.length; i++) {
        let frameWin = frames[i];
        if (frameWin && frameWin instanceof Window) modifyWindow(frameWin);
      }
      return frames;
    }

    descriptor.get = exportFunction(frames, win, {defineAs: `get frames`});
    Object.defineProperty(win, "frames", descriptor);
  }
and also not forgetting to call it from modifyWindow should do the trick.
Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0
User avatar
Giorgio Maone
Site Admin
Posts: 9454
Joined: Wed Mar 18, 2009 11:22 pm
Location: Palermo - Italy
Contact:

Re: Using nscl patchWorkers in Firefox

Post by Giorgio Maone »

skriptimaahinen wrote: Thu Jan 20, 2022 9:16 am and also not forgetting to call it from modifyWindow should do the trick.
Thanks for trying to help, but unfortunately you can access those windows also by just indexing the window object itself (like window[0]): the frames property is just a reference to the window object.
It's a very hairy issue, but as I said https://github.com/hackademix/nscl/commit/93cf0fc should have done the trick (please let me know if you actually see something off there too).
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:96.0) Gecko/20100101 Firefox/96.0
skriptimaahinen
Master Bug Buster
Posts: 244
Joined: Wed Jan 10, 2018 7:37 am

Re: Using nscl patchWorkers in Firefox

Post by skriptimaahinen »

Dang. Missed that completely. That is quite a furball indeed.

Initial testing shows no problems with your approach.
Mozilla/5.0 (Windows NT 10.0; rv:91.0) Gecko/20100101 Firefox/91.0
barbaz
Senior Member
Posts: 10832
Joined: Sat Aug 03, 2013 5:45 pm

Re: Using nscl patchWorkers in Firefox

Post by barbaz »

barbaz wrote: Mon Jan 17, 2022 6:11 pm Unfortunately there is still another way to bypass patchWorkers, and I have no idea what it is :?

The extension I'm making is a UA spoofer, but according to CreepJS main test viewtopic.php?f=18&t=26434 I'm still leaking the real UA in workers. It only happens on the main test page. On their worker-only test page my extension is working as expected.

How is it getting the real UA? Is the bug in my extension or nscl?

(Testing this does not require allowing the 3rd party sites CreepJS calls. The problem shows up just using the pure JS side of the tests.)
Went to test this again with latest nscl, but some nscl change has resulted in patchWorkers completely breaking CreepJS, with different errors each page?

Tried to go through & find the culprit nscl revision, but got wildly inconsistent results :(
*Always* check the changelogs BEFORE updating that important software!
-
barbaz
Senior Member
Posts: 10832
Joined: Sat Aug 03, 2013 5:45 pm

Re: Using nscl patchWorkers in Firefox

Post by barbaz »

Checked again. CreepJS worker test page is working now. Main test page is still broken though.

This would seem to be a nscl bug, and not a new one. More likely it was just exposed by a CreepJS change. Because now it's definitely there with previously known-working versions of nscl.

I would suspect the bug is in nscl because it can be reproduced with even this minimal extension in Firefox 97 -

manifest.json

Code: Select all

{
  "manifest_version": 2,
  "name": "nscl patchWorker test",
  "version": "1",
  "permissions": [
    "<all_urls>",
    "webRequest",
    "webRequestBlocking",
    "webNavigation",
    "storage",
    "notifications",
    "tabs"
  ],
  "background": {
    "scripts": [
      "nscl/service/patchWorkers.js",
      "bg.js"
    ]
  },
  "applications": {
    "gecko": {
      "strict_min_version": "74.0a1",
      "id": "{4cdd3d04-c968-45cb-b94f-2bbf482ccfdb}"
    }
  }
}
bg.js

Code: Select all

browser.contentScripts.register({
  allFrames: true,
  matchAboutBlank: true,
  matches: ['<all_urls>'],
  runAt: 'document_start',
  js: [{
    file: 'nscl/common/uuid.js',
  }, {
    file: 'nscl/content/patchWindow.js',
  }, {
    file: 'nscl/content/patchWorkers.js',
  }, {
    code: 'patchWorkers(function(){});',
  }],
});
*Always* check the changelogs BEFORE updating that important software!
-
barbaz
Senior Member
Posts: 10832
Joined: Sat Aug 03, 2013 5:45 pm

Re: Using nscl patchWorkers in Firefox

Post by barbaz »

bump

I think this maybe caused by something done on the page side, not the worker side. I added a toggle switch to my extension to disable patching worker scopes. If this functionality is enabled, the CreepJS page is broken. But if I disable the worker patching and reload the page, it works as expected, but the worker is patched!
*Always* check the changelogs BEFORE updating that important software!
-
barbaz
Senior Member
Posts: 10832
Joined: Sat Aug 03, 2013 5:45 pm

Re: Using nscl patchWorkers in Firefox

Post by barbaz »

Most of the issues brought up here seems to be resolved now.

However, current state is back to this -
barbaz wrote: Mon Jan 17, 2022 6:11 pm Unfortunately there is still another way to bypass patchWorkers, and I have no idea what it is :?

The extension I'm making is a UA spoofer, but according to CreepJS main test viewtopic.php?f=18&t=26434 I'm still leaking the real UA in workers. It only happens on the main test page. On their worker-only test page my extension is working as expected.

How is it getting the real UA? Is the bug in my extension or nscl?

(Testing this does not require allowing the 3rd party sites CreepJS calls. The problem shows up just using the pure JS side of the tests.)
Adding a console.log call in the patch code, the log message doesn't happen on the main test page, while it does get logged as expected on the worker test page. It looks as if the worker on the main test page is simply not getting patched Image
*Always* check the changelogs BEFORE updating that important software!
Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/112.0
Post Reply