Re: [TLS] draft-jay-tls-psk-identity-extension-01
Eric Rescorla <ekr@rtfm.com> Wed, 21 September 2016 20:37 UTC
Return-Path: <ekr@rtfm.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A866412BFBD for <tls@ietfa.amsl.com>; Wed, 21 Sep 2016 13:37:12 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=rtfm-com.20150623.gappssmtp.com
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 j0suEdngZ1XR for <tls@ietfa.amsl.com>; Wed, 21 Sep 2016 13:37:10 -0700 (PDT)
Received: from mail-yw0-x22f.google.com (mail-yw0-x22f.google.com [IPv6:2607:f8b0:4002:c05::22f]) (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 A9EE312BFBF for <tls@ietf.org>; Wed, 21 Sep 2016 13:37:10 -0700 (PDT)
Received: by mail-yw0-x22f.google.com with SMTP id i129so74528234ywb.0 for <tls@ietf.org>; Wed, 21 Sep 2016 13:37:10 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rtfm-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=a9kMBSh4zlEVuJBlfzp9F3rSzlWhzb3Ujbc7swdePFI=; b=Cw2p4XCTkz2NOdSKVvddw3cI5+0BfDmA4yezE6qSqueIfkgGa+lWF4lxFY0/orznUh bbAVsK16DaPEIeyjGzMl3KC0gAsYS2qDmmphC0IycLjo1RaWNzFpOG/ifK1E4hKlygcW 5ZseyQomX9ni51mOLpCThfwNft2nAZHaLe3sANwUCvGqVpqcRp2+w/h0uPlZhQoYupMX 1vfir7JwMfJR44gwC/+D5zgdqIMp5SQGHdc85eU9a+M3cpXt4CNdEUFLrgDnka8tLYFE M4ed7MAQYUqNZplOwiIOsHXBSr8RThgLrVl+yHqKmXKY1LiPMQMJT5GOajK7I6a/QfOC tu8A==
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; bh=a9kMBSh4zlEVuJBlfzp9F3rSzlWhzb3Ujbc7swdePFI=; b=bK6oXQusIt9ylKSbdSOC1E2pqnLR5H4x2Wx5RTz9KRbYT3nQjGtQf/kr78O37SrAMh zcT82N+dTzdtYg/q/xP0sl69LUzCVAPL4MES7rOFpGRjC3UtwUh1+3PyfWbZ4hqQ1pQ3 VZQ82+JrCgDCXH0M0qSWniRLFZ0OPQa2bm/n3+m1lhPfLalMKD+D/Ui8N2q4iLyYfWXO pjMJDTzXiIfchm3twvK74c4s6EEKT4V9fzgLteHKMXu7/Kgu0SscjgqPMmNAQPnV9kzY SBcvAIqWOxsBXSP4GTvOK0ET2SoKazuR2F/wzd/vC++C7xbxz5WqMzGUg2EpejEBidI3 HHiA==
X-Gm-Message-State: AE9vXwOC94J+J61MaQb/NiPYNjhoUKehpUdoR9DXIQEwrNU2VDb+6ehowZuMZ+zbljkcNAjJxTRpk37q2iUH4Q==
X-Received: by 10.129.125.69 with SMTP id y66mr23937874ywc.234.1474490229913; Wed, 21 Sep 2016 13:37:09 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.129.160.10 with HTTP; Wed, 21 Sep 2016 13:36:29 -0700 (PDT)
In-Reply-To: <1474489991.30494.5.camel@infradead.org>
References: <1474098807.2070.10.camel@gmail.com> <1474270465.144982.206.camel@infradead.org> <FDFEA8C9B9B6BD4685DCC959079C81F5E18F6DA9@BLREML509-MBX.china.huawei.com> <1474485375.24595.250.camel@infradead.org> <20160921200022.GA14520@LK-Perkele-V2.elisa-laajakaista.fi> <1474489991.30494.5.camel@infradead.org>
From: Eric Rescorla <ekr@rtfm.com>
Date: Wed, 21 Sep 2016 13:36:29 -0700
Message-ID: <CABcZeBMM0cjfLTtCe5akd1Ya+Fu1tDG6raJAxDC5NVT878LeLA@mail.gmail.com>
To: David Woodhouse <dwmw2@infradead.org>
Content-Type: multipart/alternative; boundary="001a1149417e61657c053d0a823b"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/IuL0myeiZTrl1lY8xWXfaWFnLlc>
Cc: "jayaraghavendran@gmail.com" <jayaraghavendran@gmail.com>, "tls@ietf.org" <tls@ietf.org>, Nikos Mavrogiannopoulos <n.mavrogiannopoulos@gmail.com>
Subject: Re: [TLS] draft-jay-tls-psk-identity-extension-01
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: "This is the mailing list for the Transport Layer Security working group of the IETF." <tls.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tls>, <mailto:tls-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tls/>
List-Post: <mailto:tls@ietf.org>
List-Help: <mailto:tls-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tls>, <mailto:tls-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 21 Sep 2016 20:37:13 -0000
On Wed, Sep 21, 2016 at 1:33 PM, David Woodhouse <dwmw2@infradead.org> wrote: > On Wed, 2016-09-21 at 23:00 +0300, Ilari Liusvaara wrote: > > On Wed, Sep 21, 2016 at 08:16:15PM +0100, David Woodhouse wrote: > > > > > > On Wed, 2016-09-21 at 17:46 +0000, Raja ashok wrote: > > > > > > > > > > > [ashok] : I feel sending the selected ID is better, otherwise while > > > > process "server hello" msg, client has to maintain the PSK ID list in > > > > the same order in which it sent. Already there was a discussion in > > > > TLS1.3 group for sending selected ID instead of index. > > > There is also discussion of supporting only a *single* PSK identity in > > > TLSv1.3. If that happens, is there a real need for the extension to > > > permit more than one identity in TLS <= 1.2. > > Is the intended usecase some "IoT"/"embedded" devices? If so, I think > > this is *extremely* bad idea. > > > > Those things tend to have very long lifespans, so one shouldn't put > > one out except with cutting-edge stuff. Anything less, and there is > > substantial risk of it going bad during lifetime. > > > > It would be possible to retrofit an extension to do multiple identites > > at once into TLS 1.3 even if baseline TLS 1.3 allows only one, altough > > implementing it probably will not be pleasant.[1] > > Typically I would expect that a given IoT client would still support > only one form of PSK, and offer one identifier. The update model would > be that the server accepts *either* the old or the new keys, and > clients are slowly upgraded to offer the latter. But still only one at > a time? > > > [1] E.g. altering hello_finished to be a list, one entry for each > > identity, or omitting it entierely for "implicit finished with the > > used 0-RTT key before ServerHello" trick I outlined earlier. > > > > (Neither is probably pleasant to implement... The latter is probably > > easier if the library architecture is suitable). > > I had also suggested including a hello_finished only for the first > (preferred) PSK identity. If the server doesn't want that one, it can > send a HelloRetryRequest with a PreSharedKeyExtension indicating which > PSK identity it *does* want. > I don't see how this is appreciably easier than just having the client offer one and then the server HRR. -Ekr > > Or did I miss a reason why that wasn't sufficient and *each* > ClientHello needed to be validated? I confess I've only been looking at > this for the last day or so. > > -- > dwmw2 > > > > _______________________________________________ > TLS mailing list > TLS@ietf.org > https://www.ietf.org/mailman/listinfo/tls > >
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 Raja ashok
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 David Woodhouse
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 Ilari Liusvaara
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 David Woodhouse
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 Eric Rescorla
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 Ilari Liusvaara
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 David Woodhouse
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 Eric Rescorla
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 David Woodhouse
- Re: [TLS] draft-jay-tls-psk-identity-extension-01 Raja ashok