Re: [TLS] 0-RTT and Anti-Replay

Martin Thomson <martin.thomson@gmail.com> Mon, 23 March 2015 15:18 UTC

Return-Path: <martin.thomson@gmail.com>
X-Original-To: tls@ietfa.amsl.com
Delivered-To: tls@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 1DB371A9030 for <tls@ietfa.amsl.com>; Mon, 23 Mar 2015 08:18:59 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2
X-Spam-Level:
X-Spam-Status: No, score=-2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, SPF_PASS=-0.001] 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 CHRyEA9NZWrJ for <tls@ietfa.amsl.com>; Mon, 23 Mar 2015 08:18:57 -0700 (PDT)
Received: from mail-ob0-x22f.google.com (mail-ob0-x22f.google.com [IPv6:2607:f8b0:4003:c01::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 CAC151A89FF for <tls@ietf.org>; Mon, 23 Mar 2015 08:18:14 -0700 (PDT)
Received: by obdfc2 with SMTP id fc2so125432966obd.3 for <tls@ietf.org>; Mon, 23 Mar 2015 08:18:14 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=FiMswNW5ds79NiyEf4gyuGskkK8svF68G1vFOHKzrN8=; b=p2cCHXaDbovzf/bLPcbXQuFu4tZxEv3kDYK2Lf7/1d3VmF1n2qwDAT7a0lbpNbysCc XHtrEbKYBsMPFas2uTBzsrdZdxG9I/g+tmY/KzurSOw8NTjkJZg1isj8T7G3A8Iv6jnf xgWoplYfMeNPdpUaH/fdA9MXdSgcko3S775ZwBPr4EO+ThiPu216xzmjfYAUd9Roy+ml N19xWrU9CC7NPt20CSRHbnlUXFOJgFD2q6pNKqJJvvsiDlKnLJW8rgwUJnTkCkSc3HqM O6wC+ezIzPaetb+hjESyleiqST57PJsgIUMstVIvkWZ4s8+bnKOcctSF8tJ/l6mih19a LIIA==
MIME-Version: 1.0
X-Received: by 10.182.34.131 with SMTP id z3mr6382302obi.4.1427123894327; Mon, 23 Mar 2015 08:18:14 -0700 (PDT)
Received: by 10.202.48.151 with HTTP; Mon, 23 Mar 2015 08:18:14 -0700 (PDT)
In-Reply-To: <m2bnjjlpwa.fsf@usma1mc-0csx92.kendall.corp.akamai.com>
References: <CABcZeBP9LaGhDVETsJeecnAtSPUj=Kv37rb_2esDi3YaGk9b4w@mail.gmail.com> <55101D8B.7050909@zinks.de> <CABkgnnXm3LMsy7sN--Q35ZxVUXj=hQG0+JJarSF6U=ayZ1NZ4A@mail.gmail.com> <m2bnjjlpwa.fsf@usma1mc-0csx92.kendall.corp.akamai.com>
Date: Mon, 23 Mar 2015 08:18:14 -0700
Message-ID: <CABkgnnVP0wn0tsJ+9uud_PDnKQfKrQ2Chx_nVRwWVjfSeG=u8g@mail.gmail.com>
From: Martin Thomson <martin.thomson@gmail.com>
To: Brian Sniffen <bsniffen@akamai.com>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/Y0T9ALGbheGr0qW4VDzdzdI1AF4>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] 0-RTT and Anti-Replay
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.15
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: <http://www.ietf.org/mail-archive/web/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: Mon, 23 Mar 2015 15:18:59 -0000

On 23 March 2015 at 08:00, Brian Sniffen <bsniffen@akamai.com> wrote:
> APIs offering a socket model and attempting to provide a secure socket
> layer shouldn't use the 0RTT path at all, then?  APIs exposing a record
> or message semantics (either TLS's, or their own) can use 0RTT iff they
> can guarantee idempotency of the messages in the 0RTT fragment

That sounds like a reasonable first approximation.  It might be that a
streamed/socket protocol can intrinsically handle the replay problem
because of the nature of the protocol, but in the generic sense, this
would be correct.