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

Iñaki Baz Castillo <ibc@aliax.net> Sat, 24 September 2011 16:21 UTC

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Date: Sat, 24 Sep 2011 18:24:25 +0200
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From: =?UTF-8?Q?I=C3=B1aki_Baz_Castillo?= <ibc@aliax.net>
To: Harald Alvestrand <harald@alvestrand.no>
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Subject: Re: [rtcweb] STUN for keep-alive - RTCP-less applications
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2011/9/24 Harald Alvestrand <harald@alvestrand.no>no>:
> Are we on the same subject line?
>
> In the context we are talking about here (RTCP-less RTP flows), the prompt
> would have to be:
>
> -----------
> The web site www.domain.org wishes to send media to some other place on the
> Internet, and to set the option that allows it to communicate without using
> congestion control being available. You have no way of figuring out where
> the packets are going, whether this will cause harm to you, your network or
> anything else between here and there.
>
> Do you accept?
>
> [ yes ] [ no ]
> ----------
> (note that if we want to include the place stuff is going to in the prompt,
> the prompt has to pop up AFTER we've established the call, and pop up again
> every time the transport addres is renegotiated.)

Just wondering: is not possible to indicate support for RTCP in the
SDP? Anyhow...


> Does this seem reasonable?

No, but what are we trying to prevent? 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?

I really wonder what we are trying to achieve in all these threads
about security in rtcweb.

-- 
Iñaki Baz Castillo
<ibc@aliax.net>