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Re: [rtcweb] AVPF [was: Encryption mandate (and offer/answer)]

Matthew Kaufman <matthew.kaufman@skype.net> Fri, 09 September 2011 18:10 UTC

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Date: Fri, 09 Sep 2011 11:11:32 -0700
From: Matthew Kaufman <matthew.kaufman@skype.net>
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To: Alan Johnston <alan.b.johnston@gmail.com>
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Cc: Randell Jesup <randell-ietf@jesup.org>, Jonathan Lennox <jonathan@vidyo.com>, "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] AVPF [was: Encryption mandate (and offer/answer)]
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On 9/9/11 10:47 AM, Alan Johnston wrote:
>    The default will be SRTP - this can be
> expressed in SDP without CapNeg.  Should the RTCWEB clients choose to
> instead negotiate RTP, then this could be done with a second SDP
> Offer/Answer exchange.

I believe you've just designed a downgrade vulnerability.

Matthew Kaufman

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