Re: [TLS] prohibit <1.2 support on 1.3+ servers (but allow clients)

Tony Arcieri <bascule@gmail.com> Fri, 22 May 2015 03:49 UTC

Return-Path: <bascule@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 5774F1A90BB for <tls@ietfa.amsl.com>; Thu, 21 May 2015 20:49:38 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.1
X-Spam-Level:
X-Spam-Status: No, score=-0.1 tagged_above=-999 required=5 tests=[BAYES_40=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=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 ESTcVeclpN_m for <tls@ietfa.amsl.com>; Thu, 21 May 2015 20:49:36 -0700 (PDT)
Received: from mail-oi0-x22e.google.com (mail-oi0-x22e.google.com [IPv6:2607:f8b0:4003:c06::22e]) (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 B61BB1A9096 for <tls@ietf.org>; Thu, 21 May 2015 20:49:36 -0700 (PDT)
Received: by oige141 with SMTP id e141so5210915oig.1 for <tls@ietf.org>; Thu, 21 May 2015 20:49:36 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=FRY4NnXJdl7FuCJtuQLzlMjjQ1efUFJ1hANlr7LblOU=; b=qhn5kPIg+XS+BlUo8kNoLahFUi3B4e/z+FJrHkSGORKkMM0/hRjPS0oLyCq7MAdiSS DyW7ndcLRR6zW/wFDEHcFq+KMOoyF8IrN9o9IUDzlfxb0EWks24zxKsl1/fP9Z+u4F9Y Qrw3dYMG0bnECmzeT9pxMaTZWmo7dZUsNRJlb+PmBoDUY1vYPPD3pp+u4m+kbz/qs5YL jl6Wf+rssonSu6zijVrvvr/um/FhEw9Lf5r0dODh5fTz81CI6rE2cMQi4ySleA+LwjB0 T3nLjSCfcFn954aT+5Q6mT3h1ifqaUFmb4iN72O+5/gVqEtQOSPRHhdOqeBYPtFZI+Sa 7xVQ==
X-Received: by 10.60.157.202 with SMTP id wo10mr5075130oeb.20.1432266576217; Thu, 21 May 2015 20:49:36 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.76.25.198 with HTTP; Thu, 21 May 2015 20:49:15 -0700 (PDT)
In-Reply-To: <201505212304.11513.davemgarrett@gmail.com>
References: <201505211210.43060.davemgarrett@gmail.com> <20150522025214.GA21141@typhoon.azet.org> <CAHOTMVJ1i+h3x8UShLhku5VcFiB4RRrUmPZL6cz7LnHMeHzAFA@mail.gmail.com> <201505212304.11513.davemgarrett@gmail.com>
From: Tony Arcieri <bascule@gmail.com>
Date: Thu, 21 May 2015 20:49:15 -0700
Message-ID: <CAHOTMVJSyCAwQ0pPKwzncWqgmtjzHiPJKVER8FsqX2VeYCL3XA@mail.gmail.com>
To: Dave Garrett <davemgarrett@gmail.com>
Content-Type: multipart/alternative; boundary=047d7bd6c5e87fcdd50516a38cfa
Archived-At: <http://mailarchive.ietf.org/arch/msg/tls/p5QoncgKpM5q1kGs8o6V_RHJJcI>
Cc: "<tls@ietf.org>" <tls@ietf.org>
Subject: Re: [TLS] prohibit <1.2 support on 1.3+ servers (but allow clients)
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: Fri, 22 May 2015 03:49:38 -0000

On Thu, May 21, 2015 at 8:04 PM, Dave Garrett <davemgarrett@gmail.com>;
wrote:

> That said, the RC4 diediedie is getting largely ignored. To actually kill
> something like this off, it seems to need to be done as a panic response or
> as a requirement of something new that everyone starts together. (e.g. SSL3
> diediedie or old TLS with HTTP/2) Thus was my reasoning for at least
> attempting to suggest it here. :|
>

I managed to get RC4 shut off at Square. The only real point of contention
was Windows XP, which doesn't run a version of IE we support, so in the end
it wasn't that much of an issue.

SSL Labs overall statistics paint a pretty dismal picture for the Internet
as a whole, but I think a lot of high profile sites have A or A+ ratings
(i.e. they've disabled RC4) these days which is nice

-- 
Tony Arcieri