IETF Logo Mail Archive

Re: [TLS] Industry Concerns about TLS 1.3

Thijs van Dijk <schnabbel@inurbanus.nl> Fri, 23 September 2016 07:35 UTC

Return-Path: <schnabbel@inurbanus.nl>
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 5605912BEDF for <tls@ietfa.amsl.com>; Fri, 23 Sep 2016 00:35:31 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.334
X-Spam-Level:
X-Spam-Status: No, score=-1.334 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, SPF_SOFTFAIL=0.665] autolearn=no autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=inurbanus.nl
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 5hf_EgZp-1yD for <tls@ietfa.amsl.com>; Fri, 23 Sep 2016 00:35:29 -0700 (PDT)
Received: from mail-ua0-x229.google.com (mail-ua0-x229.google.com [IPv6:2607:f8b0:400c:c08::229]) (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 C22EA12BE04 for <tls@ietf.org>; Fri, 23 Sep 2016 00:35:29 -0700 (PDT)
Received: by mail-ua0-x229.google.com with SMTP id 107so27713386uah.2 for <tls@ietf.org>; Fri, 23 Sep 2016 00:35:29 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=inurbanus.nl; s=google-inurb; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=COUGLY5fkgameQZCVpyi/+fTPun45Umk88kSiffBhmI=; b=NXs942iTSpnxW0+TVECObJGuK9wLauMXRzs389B9IpU/AoAaB7qm7xuj807d/fYk1z U5EXjte0N5obAG6Bl3cBADUuoBrpOyg4u3OFUsd/LxckjJ5lI1YDABLobpI2cM2APN89 Cx7WK55l5mNWgX81BNJv/AzUPj1gr+BCh4qSM=
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=COUGLY5fkgameQZCVpyi/+fTPun45Umk88kSiffBhmI=; b=dU/JaM/HxIdeMb2YDKThN/SKdHiWNagUC71Z4a2tSybxAN3CvzU7VOFCp1mxF/GWt5 e/4KCIjo4Ig60ZSQDOV22L16DR1zZtj6z7EWhPwjuxzb73WzVGL7PEQLdVEPAHyAZpNn /ZQc4BE4c+nOW8FaVVagAPqRv+WHnRSm7x/Xmus89nKP1PLmuN+AZBwCu8Xk5TUVkYkP s/S6Q+pxGOGYsP2kGs1Au2uDJgcuh8nzgienGe74wHSiYqCU2HTnTFkdKABPS70ITYY4 NVgzqOH9yhyvZ5195uUXFyUEdoMLjnezTNp7GxDCRsdvTHJejNFgtl3tyquw25+Xres+ 965w==
X-Gm-Message-State: AE9vXwMdF/n1mJ62mQuow0yfLu1sQvrC2k025EA0PUYJ1ldi/8jcip8vcpYCdME2if7I0j3MdLqeTXcId5Y22A==
X-Received: by 10.159.33.184 with SMTP id 53mr3344941uac.88.1474616128665; Fri, 23 Sep 2016 00:35:28 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.103.0.71 with HTTP; Fri, 23 Sep 2016 00:35:27 -0700 (PDT)
In-Reply-To: <CAAF6GDdyQkVeMoCWkMx0LBBO60aD55zsybCmK1Z8VMUtum4KWw@mail.gmail.com>
References: <DM5PR11MB1419B782D2BEF0E0A35E420DF4C90@DM5PR11MB1419.namprd11.prod.outlook.com> <CADi0yUPZzLrPize4eKpASdM=2nm1h1T2UXs7_sdk2eDv=ku_2w@mail.gmail.com> <CAAF6GDfTCgaxvgb8cRu9iA3SoK208SKjJcC_DM_skWA93bG1xg@mail.gmail.com> <CADi0yUO_3foUHakahionFMbU25o3t1d4-XwjquA55XAoCq8dMg@mail.gmail.com> <CAAF6GDdyQkVeMoCWkMx0LBBO60aD55zsybCmK1Z8VMUtum4KWw@mail.gmail.com>
From: Thijs van Dijk <schnabbel@inurbanus.nl>
Date: Fri, 23 Sep 2016 09:35:27 +0200
Message-ID: <CADGaDpEfypv+0mMQGsYGhGUJH28+hb7exGqyzJy90cQ87q8yJA@mail.gmail.com>
To: Colm MacCárthaigh <colm@allcosts.net>
Content-Type: multipart/alternative; boundary="001a113ac906879838053d27d26b"
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/hTKJDmL1gy-bCpD2lavZB1fVWT4>
Cc: "tls@ietf.org" <tls@ietf.org>
Subject: Re: [TLS] Industry Concerns about TLS 1.3
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: Fri, 23 Sep 2016 07:35:31 -0000

On 23 September 2016 at 04:04, Colm MacCárthaigh <colm@allcosts.net> wrote:

> If the problem is the use of forward secrecy then there is a simple
>>>> solution, don't use it.
>>>> That is, you can, as a server, have a fixed key_share for which the
>>>> secret exponent becomes the private key exactly as in the RSA case. It does
>>>> require some careful analysis, though.
>>>>
>>>
>> The key_share contributed by the client is indeed ephemeral and it
>> replaces the random key chosen by the client in the RSA-based scheme.
>>
>
> Yep, you're right, now I get it. I also now wonder if clients should make
> a best effort of detecting duplicate parameters and rejecting them.
>

Regular clients, no.
But this would be a useful addition to debugging / scanning suites (e.g.
Qualys), or browser extensions for the security conscious (e.g. CertPatrol).

-Thijs

v2.23.0 | Report a Bug | By Email