1904304 - Firefox 127 WebRTC Audio-Video Sharing & Receiving is Not Working on web.nynja.net

Status: REOPENED

(Web Compatibility :: Site Reports, defect, P3)

Description

[ayan.karmakar]

Attachment: firefox_webrtc_log.txt

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Steps to reproduce:

Open https://web.nynja.net/, from Normal tab and Incognito tab.
Create 2 accounts.
Send Invite from one user to the other.
Accept Invite.
Click on New Meeting >> Choose the other User >> Start Meeting
Give Mic Permission
Accept Call At other Users end

Note:

• It was working on earlier versions of Firefox(< v127)
• Chrome to Chrome Everything works fine
• P2P call works with Firefox
• Issue with conference call
• Attached about:webrtc log

Actual results:

Call is getting established, ICE state is connected but
Firefox User is not able to send/receive audio, video, screen share to/from Remote(Chrome/Firefox) User.

Expected results:

Firefox User should be able to send/receive audio, video, screen share to/from Remote User.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::WebRTC' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Andreas Pehrson [:pehrsons]]

I don't think there were many changes in 127 for webrtc networking, but one thing is that we enabled the use of DTLS 1.3 by default.
Could you on about:config set the pref media.peerconnection.dtls.version.min to 771, restart Firefox, and test again, please? That effectively reverts to only support DTLS 1.2. Don't forget to reset it once you're done testing.

Comment 3

[ayan.karmakar]

Hi Andreas,

Thanks for the response.
I've checked about:config of firefox 127, and I see media.peerconnection.dtls.version.min is already set to 771.
I changed media.peerconnection.dtls.version.max from 772 to 771, and then every thing(audio, video, screen share send-recv) works perfectly fine.
Since media.peerconnection.dtls.version.min is already 771, is Firefox allowing DTLS 1.2, but for some reason it choosing DTLS 1.3?

Regards,
Ayan

Comment 4

[Andreas Pehrson [:pehrsons]]

Thanks for confirming.

Firefox 126 allowed only DTLS 1.2, while Firefox 127 allows both DTLS 1.2 and 1.3.
Which DTLS version to use is negotiated with the remote side during the DTLS handshake. See RFC 9147 on the DTLS 1.3 spec's mention of backwards compatibility and RFC 8446 Appendix D for more details from the TLS 1.3 spec.

This seems to be an issue on nynja's end.

Comment 5

[ayan.karmakar]

Hi Andreas,

I've checked the wireshark packet capture logs for both Firefox 126 and Firefox 127, in both the cases I see DTLSv1.2

I've attached Firefox 127 network trace(no change in media.peerconnection.dtls.version), please check.

Comment 6

[ayan.karmakar]

Attachment: Firefox-127.pcapng

Firefox v127 packet capture

Comment 7

[Andreas Pehrson [:pehrsons]]

Could you upload the 126 pcap also? Thanks

Comment 8

[ayan.karmakar]

Attachment: Firefox-126.pcapng

Attached the Firefox-126 network logs, Please check.
Thanks

Comment 9

[Anna Weine]

The behaviour seems to resemble (IIRC) the behaviour here: https://bugzilla.mozilla.org/show_bug.cgi?id=1875686.

More specifically what we observed was the following:

But the response we receive is dramatically different. If in one case (DTLS1.2) we receive all the messages, in DTLS1.3 we receive only ServerHello/Certificate (of the server)/Server key Exchange message.

That's what I see in 127 cap.

Reminder:
they used their implementation, and it was crashing (or something like this) when they saw DTLS1.3. It's to say that they didnot try to use DTLS1.3, but due to a wrong code, having DTLS1.3 in the ClientHello was causing the crash.

Comment 10

[Anna Weine]

Upd: it does not seem to play a role.

The bug in Bouncy Castle: https://github.com/bcgit/bc-java/issues/1487

Still not resolved.

Comment 11

[ayan.karmakar]

Thanks for looking into it, @Anna.

Comment 12

[Andreas Pehrson [:pehrsons]]

With 126 after the server sends a Server Key Exchange it also sends a Certificate Request and Server Hello Done. With 127 the latter two are missing, suggesting it's a server issue.

Comment 13

[Andreas Pehrson [:pehrsons]]

Since nynja is indeed broken in Firefox but works in Chrome, let's keep the bug for webcompat.