web: Spoof prototypes to prevent false positive bot detections

[lihe07]

Some bot detection libraries will detect the prototypes for navigator.plugins.

Current extension will cause false positives in such detections. (for example: by BotD)

This PR includes code that spoofs prototypes of related objects.

[Dinnerbone]

Thank you for this! Unfortunately it seems to break things, al of the tests are now failing with:

Uncaught TypeError: navigator.plugins.install is not a function

[lihe07]

Thank you for this! Unfortunately it seems to break things, al of the tests are now failing with:

Uncaught TypeError: navigator.plugins.install is not a function

Thank you!

Now things should work, and navigator.plugins instanceof PluginArray should be true.

[evilpie]

I want to look into this next week.

[evilpie]

I don't understand this?

[evilpie]

Okay, I guess this wouldn't be Firefox specific. By changing the prototype of the RufflePluginArray all methods that we add to the prototype of course become inaccessible. If we want to go with this approach we should probably remove the RufflePluginArray class altogether, it's going to be more confusing than useful.

I have an alternative solution that still bypasses the somewhat weak BotD check using instanceof PluginArray. We can simply add the original prototype to the prototype chain of our new object.

evilpie@3462ae2

[evilpie]

Ah sorry. This doesn't actually work for the MimeTypeArray. I think because the plugins that we "install" aren't an instance of MimeType.

[lihe07]

I guess this wouldn't be Firefox specific.

Yeah that's the case.

We can simply add the original prototype to the prototype chain of our new object.

I tried that initially, but constructing the object seems to always give this error: typeerror: Illegal constructor.

[lihe07]

Using a lot Object.defineProperty is indeed confusing. I can use this instead:

        // bypass TypeError
        for (const method of ["namedItem", "refresh", "item"]) {
            // @ts-expect-error: We're adding a method to the object
            navigator.plugins[method] = proto[method];
        }