Re: [rtcweb] STUN for keep-alive - RTCP-less applications

Harald Alvestrand <harald@alvestrand.no> Sat, 24 September 2011 16:53 UTC

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Date: Sat, 24 Sep 2011 18:55:40 +0200
From: Harald Alvestrand <harald@alvestrand.no>
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Cc: rtcweb@ietf.org
Subject: Re: [rtcweb] STUN for keep-alive - RTCP-less applications
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On 09/24/2011 06:24 PM, Iñaki Baz Castillo wrote:
>
>> Does this seem reasonable?
> No, but what are we trying to prevent?
In this case (keepalive using RTCP) we're trying to prevent the 
Javascript running in user A's browser from connecting to user B, having 
user B hang up, and the packets continuing to flow "forever" from A to B.
>   a malicious site could always
> initiate a session with a user in behalf of him best friend. I mean a
> valid audio/video session (with ICE, RTCP, SRTP and so). The the user
> (the WebRTC client) sends RTP there and the malicious site/user
> uploads it to Youtube. How can rtcweb security constrains prevent
> that???
>
> In the other side, if user A establishes an audio session with user B,
> and user B indicates a "malicious" address in the SDP (and does not
> send RTCP reports) then user A would realize in just a few seconds
> that "something is wrong since there is no audio" and would hangup. In
> the meanwhile user A would send a few useless UDP packets to somewhere
> within his LAN network, is that so critic?
If the JS in user A negotiates one connection to user B and another to 
user C, and hears audio from user C, when would he realize that user B 
had dropped off the conference call?
> I really wonder what we are trying to achieve in all these threads
> about security in rtcweb.
>
If you can formulate your wondering in terms of 
"draft-ietf-rtcweb-security should be changed to say *this* to make it 
clear", that would be most helpful.

I think I'll take my own advice and shut up on this thread...