Meet.jit.si in-browser video breaks (no display) if Firefox fingerprint protection (UA spoofing) is ENabled?

I’m setting up for desktop browser usage of “meet.jit.si”.

Currently, browser here is:

	Name 	Firefox
	Version 	67.0.2
	Build ID 	20190607204818
	Update Channel 	release
	OS 	Linux 5.1.10-25.gad24342-default

FF’s fingerprint-resistance is == ON,

As a result, the FF UA is changed from its real/native,

	User Agent 	Mozilla/5.0 (X11; Linux x86_64; rv:67.0) Gecko/20100101 Firefox/67.0

to a spoofed/ESR

	User Agent 	Mozilla/5.0 (Windows NT 6.1; rv:60.0) Gecko/20100101 Firefox/60.0

@ Firefox’s fingerprint-protection-dependent UA logic is,

https://dxr.mozilla.org/mozilla-central/source/dom/base/Navigator.cpp#1668

With this SPOOFED UA, functionality at meet.jit.si is broken.

WebCam video/audio is activated, but there’s NO video shown – either from local cam, or from remote, connected users – in the browser.

DISABLING fingerprinting in FF, which sets UA string back to real/native, gets meet.jit.si working again.

In @mozilla IRC, the comment’s made:

“sites shouldn’t rely on UA strings”

Q: DOES meet.jit.si require a ‘real’ UA string? If so, what are the specifics for that requirement?

There is expectation that is be a valid user agent. Spoofing should be okay, as I spoof sometimes to test something real quick. There isn’t much userAgent searching that jitsi-meet does on its own. Most of what is parsed from the user agent is the browser type so different experiences can be shown based on that.


That’s unfortunately inconsistent with what I’m experiencing at the moment.

WITH the UA spoofed – turned ‘on’ by FF’s ‘fingerprint-resistance’, using a ‘valid’ UA string – meet.jit.si simply works not at all. No camera activation, and of course, no video display.

With UA spoofing DISabled, the camera’s activated, video’s visible in the ‘Settings’ pane, but in the main chat window, still no video display whatsoever.

The identical USER environment, connecting via other vidconf sites/apps (zoom, duo, skype) has no problems.

Also, Chrome/linux connection to meet.jit.si seems to work as well.

This appears to be a problem unique to the combination of FF/linux + jit.si.

‘What’ the problem is …