Re: [rtcweb] draft-ietf-rtcweb-rtp-usage-12 Client-to-Mixer Audio Level

tim panton <tim@phonefromhere.com> Wed, 05 March 2014 14:33 UTC

Return-Path: <tim@phonefromhere.com>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 44DF71A065A for <rtcweb@ietfa.amsl.com>; Wed, 5 Mar 2014 06:33:34 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tqOMm_sKxJpW for <rtcweb@ietfa.amsl.com>; Wed, 5 Mar 2014 06:33:33 -0800 (PST)
Received: from smtp001.apm-internet.net (smtp001-out.apm-internet.net [85.119.248.222]) by ietfa.amsl.com (Postfix) with ESMTP id 20AB51A063F for <rtcweb@ietf.org>; Wed, 5 Mar 2014 06:33:29 -0800 (PST)
Received: (qmail 84903 invoked from network); 5 Mar 2014 14:33:25 -0000
X-AV-Scan: clean
X-APM-Authkey: 83769 9517
Received: from unknown (HELO zimbra003.verygoodemail.com) (85.119.248.218) by smtp001.apm-internet.net with SMTP; 5 Mar 2014 14:33:25 -0000
Received: from zimbra003.verygoodemail.com (localhost [127.0.0.1]) by zimbra003.verygoodemail.com (Postfix) with ESMTP id A9CAA18A0116; Wed, 5 Mar 2014 14:33:25 +0000 (GMT)
Received: from dhcp-a471.meeting.ietf.org (dhcp-a471.meeting.ietf.org [31.133.164.113]) by zimbra003.verygoodemail.com (Postfix) with ESMTPSA id 46E4B18A0A60; Wed, 5 Mar 2014 14:33:25 +0000 (GMT)
Content-Type: text/plain; charset=windows-1252
Mime-Version: 1.0 (Mac OS X Mail 7.2 \(1874\))
From: tim panton <tim@phonefromhere.com>
In-Reply-To: <CAOJ7v-3JAKZDHtrx9J2v=hqksQ9xdz7XW_1HbqioEzWMqUrn7A@mail.gmail.com>
Date: Wed, 5 Mar 2014 14:33:24 +0000
Content-Transfer-Encoding: quoted-printable
Message-Id: <32D95060-6273-4804-A398-712311481E73@phonefromhere.com>
References: <1BC59A5D-D1C9-4E3F-ABFB-C1D664CD7ACF@cisco.com> <EEF5B1D0-7782-4EB8-90DF-F1D56B2D2ADC@phonefromhere.com> <0526965B-6AC9-42F4-9E62-CF3BF29872D3@cisco.com> <CAOJ7v-3JAKZDHtrx9J2v=hqksQ9xdz7XW_1HbqioEzWMqUrn7A@mail.gmail.com>
To: Justin Uberti <juberti@google.com>
X-Mailer: Apple Mail (2.1874)
Archived-At: http://mailarchive.ietf.org/arch/msg/rtcweb/6vVIFCb9XDeRH6HGyOwWlVrUzm0
Cc: "Cullen Jennings \(fluffy\)" <fluffy@cisco.com>, "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] draft-ietf-rtcweb-rtp-usage-12 Client-to-Mixer Audio Level
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb/>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 05 Mar 2014 14:33:34 -0000

On 5 Mar 2014, at 14:25, Justin Uberti <juberti@google.com> wrote:

> So there are three things here:
> 1) MUST the implementation offer encrypted header extensions? (i.e. mandatory-to-implement)
> 2) MUST the implementation use encrypted header extensions? (i.e. mandatory-to-use)
> 3) MUST the implementation expose an API to control this? (i.e. no SDP munging needed)
> 
> I think we want yes for #1, no for #2, and #3 is potentially interesting but out of scope for 1.0.
> That gives encrypted headers for audio on by default, but remote parties can negotiate this off using RFC 6904 mechanisms.
> 

In order to agree with that I’d need to be persuaded that there isn’t a known-plaintext attack risk there
(e.g. detecting a muted mic therefore knowing the ulaw content of a packet), since
any weakening  in DTLS also impacts the data channel and video channels - assuming bundle.

Like I say, I’m not enough of a cryptographer to know.

T.