Re: [rtcweb] No Interim on SDES at this juncture

Tim Panton <tim@phonefromhere.com> Fri, 14 June 2013 09:01 UTC

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From: Tim Panton <tim@phonefromhere.com>
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Date: Fri, 14 Jun 2013 10:00:57 +0100
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To: Hadriel Kaplan <hadriel.kaplan@oracle.com>
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Subject: Re: [rtcweb] No Interim on SDES at this juncture
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On 14 Jun 2013, at 04:39, Hadriel Kaplan wrote:

> 
> On Jun 13, 2013, at 8:59 AM, Harald Alvestrand <harald@alvestrand.no> wrote:
> 
>> Agree with Tim about the relative difficulty of adding the needed features.
> 
> Afaict, adding SDES is trivial if you went to the trouble of doing DTLS-SRTP already.  The converse isn't true.

If you add SDES to an existing DTLS-SRTP the key and crypto stuff is (relatively) trivial - 
but you are adding additional valid options and paths to the SDP -
making it even harder to validate and parsers even more entangled than before.

You can see that 2 ways:
	1) "SDP is always going to be a loosely defined option ridden pain to parse, thats what SIPit is for - to knock out the bugs"
	2) "SDP is a mess, we should be doing everything possible to simplify the subset we require in rtcWEB"

- I'm mostly in camp 2. Having spent more time on getting the SDP right than I did on the DTLS itself.

T.