Re: [TLS] tls-flags: abort on malformed extension

Hubert Kario <hkario@redhat.com> Mon, 11 October 2021 11:12 UTC

Return-Path: <hkario@redhat.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 22AA53A0DFC for <tls@ietfa.amsl.com>; Mon, 11 Oct 2021 04:12:21 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.553
X-Spam-Level:
X-Spam-Status: No, score=-2.553 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.452, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=redhat.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 MQDFPfGxSZ4b for <tls@ietfa.amsl.com>; Mon, 11 Oct 2021 04:12:19 -0700 (PDT)
Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 5D4F43A0DD6 for <tls@ietf.org>; Mon, 11 Oct 2021 04:12:19 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633950738; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=34lnfQgdTONCITYcyvmKu+yR42OseiAq8gqFEZKz00g=; b=jPCntmZeP6PjcaviQtWlr+moUQ+Jd7kWN2704I2YThcqiJ+Gunc0Y39YFHkXoIMsSwIpnA 4GCZdQV9AdN1hX+8fe1+ywM8GKsPqKTtDjUSl2PZkEw0NKbu80mW5m26+IJAqHnO/ku7d3 u6PcmPqsmQxE765bxXpoPpjia+7C47g=
Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-217-kgvWXVyUMHi91vdE_7IOww-1; Mon, 11 Oct 2021 07:12:17 -0400
X-MC-Unique: kgvWXVyUMHi91vdE_7IOww-1
Received: by mail-ed1-f72.google.com with SMTP id 14-20020a508e4e000000b003d84544f33eso15599847edx.2 for <tls@ietf.org>; Mon, 11 Oct 2021 04:12:17 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:mime-version:message-id :in-reply-to:references:organization:user-agent :content-transfer-encoding; bh=34lnfQgdTONCITYcyvmKu+yR42OseiAq8gqFEZKz00g=; b=1P3sFK3VCTom7CL0A/IAGh0vtX696w3vtxWvN3fzFwUYBeNMRjCOWL9Aw8laj7ZHMq je9vtOYtF5clGFLHs+3m6aYgmsLY+EB35J7FrlvBCaWcOYoshG7V2QAXwvO9gV/WBpuB Z3hqaDuIhwsf7ERTZHeoAqG81pPzBY0R/skuzPkeW8UwXdzb0KHMNuiGRGCQEHfk72WO 90s0NN3ZUAVr7GhkaU1Kw/uM0D1rJEYvRKkRQL7cDnjZeYamr4P3yK05XY47Jsk81qos YYhYO8CWIp4df64nS7xdGQGVBZ+XKZXb4Um7OsgBJiIoSceiFgJZ6pyanSJ03HdcqSvu xd/g==
X-Gm-Message-State: AOAM531e0XGIZXJlFhF1EaUU3dCiYwrpZDSSgmwdZJgyBJ2R1DiJe3Sg 2KonokGS4+PhsF+/8Bsjn7Qyf5X5lqcE1KVfy6+6rGKKbdYt0jKHjDpRuXinj6ulJ1MlFY4CPZi K9pc=
X-Received: by 2002:a17:906:314e:: with SMTP id e14mr24112419eje.165.1633950736117; Mon, 11 Oct 2021 04:12:16 -0700 (PDT)
X-Google-Smtp-Source: ABdhPJwb06ee3+llI7GVL2fOJQGwaS01ZCdON2qLHJ8fuwO/wHRPV+xZu9+YgCn3VL9rLbPaGAMh9A==
X-Received: by 2002:a17:906:314e:: with SMTP id e14mr24112392eje.165.1633950735893; Mon, 11 Oct 2021 04:12:15 -0700 (PDT)
Received: from localhost (ip-94-112-13-200.net.upcbroadband.cz. [94.112.13.200]) by smtp.gmail.com with ESMTPSA id p5sm3314228eju.30.2021.10.11.04.12.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Oct 2021 04:12:15 -0700 (PDT)
From: Hubert Kario <hkario@redhat.com>
To: Yoav Nir <ynir.ietf@gmail.com>
Cc: "<tls@ietf.org>" <tls@ietf.org>
Date: Mon, 11 Oct 2021 13:12:14 +0200
MIME-Version: 1.0
Message-ID: <2fa1d7c1-41b7-4fc0-8775-a3deba54c3a9@redhat.com>
In-Reply-To: <E37094D9-A40B-4E7B-BE6B-0AE16F0E0C64@gmail.com>
References: <5BFCE990-52C0-4C0C-BD8A-AC3DB0A48084@gmail.com> <E37094D9-A40B-4E7B-BE6B-0AE16F0E0C64@gmail.com>
Organization: Red Hat
User-Agent: Trojita/0.7-git; Qt/5.15.2; xcb; Linux; Fedora release 33 (Thirty Three)
Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hkario@redhat.com
X-Mimecast-Spam-Score: 0
X-Mimecast-Originator: redhat.com
Content-Type: text/plain; charset="utf-8"; format="flowed"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://mailarchive.ietf.org/arch/msg/tls/0zAG3_PD6K-SRkIXW0DIFWm4myA>
Subject: Re: [TLS] tls-flags: abort on malformed extension
X-BeenThere: tls@ietf.org
X-Mailman-Version: 2.1.29
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: Mon, 11 Oct 2021 11:12:28 -0000

On Thursday, 7 October 2021 20:37:22 CEST, Yoav Nir wrote:
>
> OK, so now my response:
>
> I agree with the first and second comments. About the third, 
> what I meant was that a supported flag that is supposed to 
> appear only in CH appears instead and CR, or more likely, a flag 
> that should appear in EE apears in SH instead.
>
> But I think the best way to resolve the issue is to remove the 
> bullet point list and the last sentence before them, IOW: remove 
> the examples.

Clients aborting on unrecognised flags in SH or EE is expected, that's what
already happens for normal extensions, but yes, it's too strong for CH. 
Maybe
also NST.


-- 
Regards,
Hubert Kario
Senior Quality Engineer, QE BaseOS Security team
Web: www.cz.redhat.com
Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic