IETF Logo Mail Archive

Re: [rtcweb] DTLS, DTLS-SRTP, and 5-tuples

Iñaki Baz Castillo <ibc@aliax.net> Thu, 05 March 2015 09:53 UTC

Return-Path: <ibc@aliax.net>
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 4F3051A8783 for <rtcweb@ietfa.amsl.com>; Thu, 5 Mar 2015 01:53:07 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.678
X-Spam-Level:
X-Spam-Status: No, score=-1.678 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, FM_FORGED_GMAIL=0.622, MIME_8BIT_HEADER=0.3, RCVD_IN_DNSWL_LOW=-0.7] autolearn=no
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 Y0AIz5pFWRzQ for <rtcweb@ietfa.amsl.com>; Thu, 5 Mar 2015 01:53:05 -0800 (PST)
Received: from mail-qg0-f44.google.com (mail-qg0-f44.google.com [209.85.192.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 9AA621A8776 for <rtcweb@ietf.org>; Thu, 5 Mar 2015 01:53:05 -0800 (PST)
Received: by qgdz60 with SMTP id z60so4264257qgd.1 for <rtcweb@ietf.org>; Thu, 05 Mar 2015 01:53:05 -0800 (PST)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type:content-transfer-encoding; bh=jsHm7LeuiKMD0J8bwWeClwkPgnqUNj36NwdzIeaw1YQ=; b=KxEJ9FHY61E1BMisW3M1/BTtSp+kLtBEDLQVt7sZcwzIgfuWxfQWrDXHBocHFkuoOe 46/+frZJEzxbPYv/ESnFOu8k0pOs+B9k/WVB0N06WAHU8IFOsr5+OJv0JtDOV0zZVBh+ LKkUEmniw8PbAfUNmegD86K4+sMtICEqpIXwvqXSjZeUKfl/QMf/4cihaAG+Vef0Q0OE 2kCQOp1IxHq1nkz73WjjTcYtOtgpfFeQxfRghwKMe4CcSuQUGZg8duHo1kJd2vIUhgMf bNXyD8fG2u0Nz3csmrm5SCS5EQlaWu0lIroNjSqveQxu9AwZj0Hk6qjRCOzmeOshJubg BrGA==
X-Gm-Message-State: ALoCoQkhaYZG1dzqT9ugzHSdgoyNAlTHSPc4GvZaUcSjWwev+hRVhsNujLCHACl0TfmR7AicLltf
X-Received: by 10.229.139.194 with SMTP id f2mr11723371qcu.14.1425549184912; Thu, 05 Mar 2015 01:53:04 -0800 (PST)
MIME-Version: 1.0
Received: by 10.96.200.4 with HTTP; Thu, 5 Mar 2015 01:52:44 -0800 (PST)
In-Reply-To: <7594FB04B1934943A5C02806D1A2204B1D727570@ESESSMB209.ericsson.se>
References: <54F74B02.1070902@jive.com> <CAD5OKxs8JYG3-Vvndi59ZrdPE7UTj22ozD4tcWTHgzWrHv=q7Q@mail.gmail.com> <54F756B2.60408@jive.com> <7594FB04B1934943A5C02806D1A2204B1D726AD8@ESESSMB209.ericsson.se> <CAD5OKxu7py3HbrFjxTDZS5ECFzx7vd=wpjve-gT6gWwksjEu+g@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B1D726B71@ESESSMB209.ericsson.se> <CABcZeBO1O6sA8MqvWkCDu3RPLz5-P2G65Us28i0baOavDnRT7Q@mail.gmail.com> <CAD5OKxuWCdgMR5Kxjv9BSwZ3Jm9kGXx9Pi-9FrfsnuQZ_91jAA@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B1D726DC1@ESESSMB209.ericsson.se> <CALiegfkipJhsy7-40+=d9xMUf4RJGdn3_fABL3NN2KuFNvS2BA@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B1D727570@ESESSMB209.ericsson.se>
From: Iñaki Baz Castillo <ibc@aliax.net>
Date: Thu, 05 Mar 2015 10:52:44 +0100
Message-ID: <CALiegfmfvz3NWSjcovGBytiOTbR6kFfyh0vx5cXoMJtytfGzRA@mail.gmail.com>
To: Christer Holmberg <christer.holmberg@ericsson.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <http://mailarchive.ietf.org/arch/msg/rtcweb/jafiNk_zKStRVkk4jFM-Hg-Iwjo>
Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] DTLS, DTLS-SRTP, and 5-tuples
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: Thu, 05 Mar 2015 09:53:07 -0000

2015-03-05 7:58 GMT+01:00 Christer Holmberg <christer.holmberg@ericsson.com>:
> As far as I understand, sending of multiple ClientHellos, on different
> 5-tuples, would require a change to core DTLS (not only DTLS-SRTP), and who
> knows how long such work would take. Do we really want to add such
> dependency to our deliveries at this point?

Sorry, I think I didn't explain well.

It is not about multiple DTLS connections, but about the fact that
DTLS packets belonging to the *same* DTLS connection/association can
be carried over different 5-tuples. This may happen during agressive
ICE nomination in which media (so the DTLS ClientHello) follows the
USE-CANDIDATE Binding request without even waiting for a response.


> In addition, do we expect existing DTLS implementations to support this?

There is nothing new to implement in DTLS libraries. It is just the
the DTLS user must not assume a single and fixed 5-tuple


> If one doesn't want to re-establish DTLS when jumping between candidates,
> doesn't it work by creating separate DTLS connections for each candidate?

This subject has been heavily discussed time ago:

http://www.ietf.org/mail-archive/web/mmusic/current/msg13637.html

No, there MUST NOT be separate DTLS connection for each candidate-pair.


Regards.



-- 
Iñaki Baz Castillo
<ibc@aliax.net>

v2.23.0 | Report a Bug | By Email