Re: [secdir] Security review of draft-ietf-pce-questions-06

Ben Laurie <> Wed, 09 July 2014 14:04 UTC

Return-Path: <>
Received: from localhost ( []) by (Postfix) with ESMTP id 831AB1A03A1 for <>; Wed, 9 Jul 2014 07:04:30 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.03
X-Spam-Status: No, score=-2.03 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FM_FORGED_GMAIL=0.622, RP_MATCHES_RCVD=-0.651, SPF_PASS=-0.001] autolearn=unavailable
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id a8tpWiUd6-dh for <>; Wed, 9 Jul 2014 07:04:29 -0700 (PDT)
Received: from ( [IPv6:2607:f8b0:400d:c00::233]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id AA42C1A050E for <>; Wed, 9 Jul 2014 07:04:28 -0700 (PDT)
Received: by with SMTP id j7so6061883qaq.24 for <>; Wed, 09 Jul 2014 07:04:27 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=zsbnmCneC6P+pwY5+AL5vfpB6+cntXX/P8DawNXaDN4=; b=EYmAtKyFf66LxzFnz7g1lQ1350fy04eq4T5nGI+n9WZFn7c6MM7QyPAPjk+Jy7h8Ir NNm7qHZyZtl3H+Xgc1TpInbBOk/VlF7EuSDZKjxEr1Unp/OHAuTGF+aCZ5x1Vpuf0b3E flecxy1a1p7PYeUH+wpwEvQnJgMxvChvaIHzZ8hmEsB8cM4LMbHJvQxfZ/kFOwEyRfN5 4wDEnfjlVqP3PB8mNTJSe+13WYEfhlLdJQbd1oSgHmMGlAuaU7Kg5yNPDBKj+QxnhqVI erSth+lx3uk3ez6wUAAjK/f4QfaQLOTGKpheJtUuCby61VuKr884IzQfs71bxsLGgJAW jq1Q==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=zsbnmCneC6P+pwY5+AL5vfpB6+cntXX/P8DawNXaDN4=; b=F1f3ZdFVzN2T8N7/f8A6q+CxK3zewnoU5vanHW3mjoLEd00v2aIcjdkrnkepIY/n2Q 5Z582NutU/Js1Uxljzxk/BJ8iJmTukUrct8RuVTciWtVFQcWo22AGTWrprKdpiaNkAs0 /Dt6PiuIdCxKb0a1PYw0e9lQJ0AC7MYuPzKZ0AINWO2GinD3+1Hwof260MlvcRLFKg71 UX5lrTzBWkrMEtgWK5BTCwWbHfJMm1tNBwOHTbhATjEK5ttxJPfyg17QFSVnpak4NwNi yH4jenF/msebp9vORPDoTgF3zrsxHT6KEgbjMpN/vrmkGcmQOiL6IsBOTK3Jv3eW6z26 B9sA==
X-Gm-Message-State: ALoCoQk4z62cdjGOkSXlaxLVTWtIrs78IPfmeJgsQt1Ks/Y21zfE+fKneWaDDX9oGYeO56ptQL6m
MIME-Version: 1.0
X-Received: by with SMTP id k9mr71000586qat.59.1404914667797; Wed, 09 Jul 2014 07:04:27 -0700 (PDT)
Received: by with HTTP; Wed, 9 Jul 2014 07:04:27 -0700 (PDT)
In-Reply-To: <068f01cf9b53$7fc60b30$7f522190$>
References: <> <068f01cf9b53$7fc60b30$7f522190$>
Date: Wed, 9 Jul 2014 15:04:27 +0100
Message-ID: <>
From: Ben Laurie <>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Cc: The IESG <>, IETF Discussion List <>, "" <>
Subject: Re: [secdir] Security review of draft-ietf-pce-questions-06
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: Security Area Directorate <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Wed, 09 Jul 2014 14:04:30 -0000

On 9 July 2014 09:55, Adrian Farrel <>; wrote:
> Hi Ben,
> Thanks for taking the time to review this document and for posting your comments to the IETF discussion list so that we can consider them as last call comments.
> [snip]
>> The security considerations section makes this claim:
>> "This informational document does not define any new protocol elements
>> or mechanism.  As such, it does not introduce any new security
>> issues."
>> I agree with the premise, but not the conclusion: just because an RFC
>> does not introduce new security issues, that does not mean that there
>> are no security considerations.
>> Indeed, this RFC discusses many things that have quite serious
>> security considerations, without mentioning any of them. For example,
>> section 4 "How Do I Find My PCE?" (the very first question) advocates
>> a number of potentially completely insecure mechanisms with no mention
>> of their security properties (or otherwise). This is obviously
>> pervasive, given the stance taken in the security considerations.
>> The document does mention that RFC 6952 gives a security analysis for
>> PCEP, and perhaps this is sufficient but it seems to me that a
>> document intended to give useful background information to noobs
>> should include security directly in that information rather than defer
>> to another giant document (which mixes PCEP info with other
>> protocols).
> I don't believe that this document is strong on "advocacy", but discusses which tools are out there and what some people do.
> Previous PCE RFCs have given some attention to security concerns in the use of PCE (RFC 4655), PCE discovery (RFC 4674, RFC 5088. RFC 5089), and the PCEP (RFC 4657 and RFC 5440). As such, "PCE Security" was not deemed by the authors to be a previously "unanswered question" and so did not need attention in this document.
> That said, you are correct that the various sections do not discuss the security implications relating to those sections. I would be pretty loathe to add security text to each section in this document: I think that would make the document heavy and less likely to be read by its intended consumers (it is not targeting "noobs" although they are welcome to read it).

Your position appears to be that they will then go on to read much
heavier documents in order to discover the security properties of the
solutions you suggest, which seems a little unlikely, particularly if
there's no mention of the necessity to do so.

Or perhaps you think security is not important?

> Perhaps a solution to this *is* to treat Security as an unanswered question and add a section "How Secure is my PCE-Enabled System?" I can't think of a lot to add there except for general egg-sucking guidance, but there would be a pointer to the TCP-AO discussions currently going on in the WG. What do you think of that as a way forward?

I have no idea what discussions are going on, but once more, if you
are concerned about "heaviness" of documentation, pointing at ongoing
discussions does not strike me as a route to lightness.