Re: [rtcweb] SDP Security Descriptions (RFC 4568) and RTCWeb

[Matthew Kaufman <[e-mail]>]

On 4/25/2013 4:19 PM, Eric Rescorla wrote:
>
> It's certainly true that the site has access to the media with DTLS if you
> don't use identity assertions/isolated streams. However, what it doesn't
> have is *invisible* access. I.e., it must do something that is user 
> visible,
> which allows for the detection of cheating by the site. By contrast, 
> if SDES is used
> then the site can simply passively monitor all your traffic, or at least
> any that goes through its network and you can't detect it.
>

That really depends on what you mean by "user visible" doesn't it? If 
you mean "the user is watching to see that all their packets go to what 
they know is the verified IP address of their buddy" then sure. But if 
you mean "the user is looking at their web browser user interface" or 
even "the user was worried mid-call so checked to see where the packets 
were going" then I think not, as all that needs to happen is for the 
call to be set up with a middlebox in the path that the site claims is 
necessary for the call to work (meets the UI test), keys set with EKT, 
and then a little ICE renegotiation and the middlebox goes away from the 
path (meets even the second test).

Matthew Kaufman