Re: [rtcweb] SRTP for communications consent verification [was: New security draft]

Harald Alvestrand <harald@alvestrand.no> Thu, 08 September 2011 12:04 UTC

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Date: Thu, 08 Sep 2011 14:06:22 +0200
From: Harald Alvestrand <harald@alvestrand.no>
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To: Christer Holmberg <christer.holmberg@ericsson.com>
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Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] SRTP for communications consent verification [was: New security draft]
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On 09/08/11 13:57, Christer Holmberg wrote:
>
> Hi,
>
> One question regarding section 4.2 (Communications Consent Verification).
>
> When SRTP is used, could the security establishment procedure for SRTP also be used for communications consent verification purpose?
>
I don't think so, because if the other party lies about his IP address, 
this does not affect the key negotiation when the key negotiation is 
done out-of-band (with SDES).

If using DTLS-SRTP, the ICE handshake has to complete before the keys 
can be negotiated, so verifying consent to communication comes for free 
with the ICE handshake anyway.