Web Skype "Audio and Video calls not supported on your Browser"

[mnd]

I clearly installed ungoogled-chromium version 81.0.4044.92-0.b484ad4 from GNU GUIX repository, checked that voice/video calls works in several web meetings clients like Zoom and MS Teams, then open https://web.skype.com/ and got the message that "Audio and Video calls not supported on your Browser"

To Reproduce Steps to reproduce the behavior:

1. Open https://web.skype.com/
2. Login with skype credentials
3. Try to call to the "Echo / Sound Test Service"
4. Call button is not active and write "Audio and Video calls not supported on your Browser" when your mouse over this button.

Expected behavior Calls should work fine.

Environment (please complete the following information):

• OS/Platform and version: GNU Guix f6145358c7d33e73c0708bbe400e6e8e65512ef3 (April 13 update)
• ungoogled-chromium version: 81.0.4044.92-0.b484ad4

Additional context IceCat with same User Agent string as in ungoogled-chromium is able to make calls.

[wchen342]

GUIX seems to have their own modification of WebRTC: https://git.savannah.gnu.org/cgit/guix.git/tree/gnu/packages/chromium.scm#n524. Does this problem reproduce on the portablelinux version?

[mnd]

@wchen342 I checked with guix version, with version 80.0.3987.163-1.bionic1 from https://launchpad.net/~braewoods/+archive/ubuntu/ungoogled-chromium and with https://ungoogled-software.github.io/ungoogled-chromium-binaries/releases/linux_portable/64bit/80.0.3987.106-1.1 (last version linked against glibc 2.27)

If you have any ideas about any changes that can help I can try them

[wchen342]

@mnd If it doesn't work on all the versions you mentioned then it sounds like a bug. It's probably not WebRTC though because I remember I can use Hangouts normally. Is there any errors in the console?

[Eloston]

It looks like Microsoft is doing more aggressive client detection:

• https://forum.vivaldi.net/topic/35654/skype-web-call-support/10
• https://askubuntu.com/questions/1222316/how-to-have-chromium-appear-as-chrome-to-web-sites
• https://arstechnica.com/gadgets/2019/03/microsofts-new-skype-for-web-client-an-early-taste-of-the-browser-monoculture/ (article is old; user agent switching doesn't work anymore as they suggested)

I couldn't find anything on Brave compatibility, so it's possible it might work there. If it does work, then we should figure out how they did it.

[mnd]

@wchen342 There was no noticeable errors:

1. Warning about cross-site cookie
2. Several 404 errors on request to skype assets

There is a saved log from my run on GUIX build: web.skype.com-1587976686992.log

[mnd]

I made the investigation on this topic: According to "skype for web" code audio and video calls allowed only for "Edge" and "Chrome" browser, but forbidden for "Chromium". The "Chromium" browser distinguished from "Chrome" with something like the following check:

function _chromiumCheck() {
  for (var i in navigator.plugins)
    if (navigator.plugins[i].name && navigator.plugins[i].name.startsWith("Chromium"))
      return true;
  return false;
}

I tried to fake skype with the following plugin https://gist.github.com/mnd/cec409269fb0e50445aa914390195e57 but with this plugin web.skype.com failed to load at all. As a temporary solution I changed "PDF" plugin name in code of the browser itself https://github.com/mnd/guix-mnd-pkgs/blob/master/mnd/packages/chromium.scm#L33

Knowing all this this is not "ungoogled-chromium" issue and you can close it.

But do you have ideas how this check can be faked except the patching of the chromium itself?

[Eloston]

But do you have ideas how this check can be faked except the patching of the chromium itself?

It might be possible to improve upon the extension code you provided, but it's becoming increasingly difficult to do such hacking from within JavaScript. it's easier to just patch Chromium.

The patch in 583b3e4c4b62c6c53b4efba2377c0c1f9845ad7a still needs testing.