Re: (short version) Re: Last Call: <draft-faltstrom-uri-10.txt> (The Uniform Resource Identifier (URI) DNS Resource Record) to Proposed Standard
Eliot Lear <lear@cisco.com> Fri, 27 February 2015 16:11 UTC
Return-Path: <lear@cisco.com>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id A6A401ACD84 for <ietf@ietfa.amsl.com>; Fri, 27 Feb 2015 08:11:52 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -14.511
X-Spam-Level:
X-Spam-Status: No, score=-14.511 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_PASS=-0.001, T_RP_MATCHES_RCVD=-0.01, USER_IN_DEF_DKIM_WL=-7.5] 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 e8I8kQMngXej for <ietf@ietfa.amsl.com>; Fri, 27 Feb 2015 08:11:51 -0800 (PST)
Received: from aer-iport-4.cisco.com (aer-iport-4.cisco.com [173.38.203.54]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 373341ACD7E for <ietf@ietf.org>; Fri, 27 Feb 2015 08:11:49 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=4264; q=dns/txt; s=iport; t=1425053509; x=1426263109; h=message-id:date:from:mime-version:to:cc:subject: references:in-reply-to; bh=YnVm7G87+OWAbd2/OxI3oVR+4aiM2ajoykl5MsFlh6k=; b=Ij3ZlnEurs/4/bECsPZrMQANog+xylkPAaoJBqxRh3NChJWhwN3osI9y HQVRfTMJxVvq5bNXjFi4gGl0PlZWdP+4wJqw/DnT46ZUmPQpr5bpnJxYZ S7mmjNpdm5TOLvmaYvE/8un0V6IVTUkcIM+zbuuSTdOwaP/dfSfOFL8xs 0=;
X-Files: signature.asc : 486
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: A0AbBgD4lfBU/xbLJq1bDoNGWoMKvxCFdAKBcQEBAQEBAXyEEAEBBCNVARALGAkMAwcEBwICCQMCAQIBRQYNAQUCAQGIK71KmhQBAQEBAQEBAQEBAQEBAQEBAQEBGYsShG4HCQEOglCBQwWRVoEuUYVmgRo5hRaJLYM+I4Iyfz49MYEEJIEbAQEB
X-IronPort-AV: E=Sophos;i="5.09,660,1418083200"; d="asc'?scan'208";a="358405867"
Received: from aer-iport-nat.cisco.com (HELO aer-core-2.cisco.com) ([173.38.203.22]) by aer-iport-4.cisco.com with ESMTP; 27 Feb 2015 16:11:46 +0000
Received: from [10.61.169.189] ([10.61.169.189]) by aer-core-2.cisco.com (8.14.5/8.14.5) with ESMTP id t1RGBkeZ012481; Fri, 27 Feb 2015 16:11:46 GMT
Message-ID: <54F09740.4030502@cisco.com>
Date: Fri, 27 Feb 2015 17:11:44 +0100
From: Eliot Lear <lear@cisco.com>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.5.0
MIME-Version: 1.0
To: Sam Hartman <hartmans-ietf@mit.edu>
Subject: Re: (short version) Re: Last Call: <draft-faltstrom-uri-10.txt> (The Uniform Resource Identifier (URI) DNS Resource Record) to Proposed Standard
References: <20150127223859.28024.43756.idtracker@ietfa.amsl.com> <4257D8A3-0EFE-40E3-B0AD-8E23772B7693@mnot.net> <6F9BB11D-C224-4D7B-A06C-41EACBAAB4B2@netnod.se> <54C9DA42.5040901@cisco.com> <9EB44D8A-278B-42FC-A542-1C182AD43128@netnod.se> <A74A30F4D1214630918FD4CA@JcK-HP8200.jck.com> <20150223153757.GI1260@mournblade.imrryr.org> <20150223155241.GJ1260@mournblade.imrryr.org> <tsl8ufoh9ko.fsf@mit.edu> <20150224170209.GV1260@mournblade.imrryr.org> <54F03F38.9090601@cisco.com> <1ED9F633-40B1-4A90-85FE-14526C27A485@frobbit.se> <54F043F8.6090409@cisco.com> <tsl7fv35sez.fsf@mit.edu> <54F0832A.4000409@cisco.com> <tslzj7z4c3d.fsf@mit.edu>
In-Reply-To: <tslzj7z4c3d.fsf@mit.edu>
Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="kw6Xfwwxo83T0dL8bbcnsS2J2ueCceKJk"
Archived-At: <http://mailarchive.ietf.org/arch/msg/ietf/NR0YfkWx8Jp91dSv5Ez4xj4AiSk>
Cc: ietf@ietf.org, Patrik Fältström <paf@frobbit.se>
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 27 Feb 2015 16:11:52 -0000
Ok, I understand what you are saying. The changing of the origin that gets validated is the fundamental no no. Eliot On 2/27/15 4:18 PM, Sam Hartman wrote: >>>>>> "Eliot" == Eliot Lear <lear@cisco.com> writes: > > I don't understand your statement. What's a decision process? > > Your DNS libraries definitely have a different trust validation process > than your application TLS libraries. > Your application is probably not entirely aware of its use of DNS; > that's how we write apps today. > > Let's take a concrete example. > I felt greate unease when I heard Patrik talk about getting support for > the URI record added to libcurl. > > Imagine that's done, and by default libcurl will follow a URI RR > redirection if it's DNSSec validated. > > I am using libcurl to talk to some cloud service. > I've carefully configured libcurl's TLS parameters because I know > exactly what I'm expecting. > Let's say that I've done so in a way that's site specific. > If libcurl is fetching the URI https://cloud.example.com/ then my > validation rules apply. > (I believe that libcurl has sufficiently rich callback interfaces to > support this, but I get the various HTTP library capabilities confused) > > > I have a fairly strict set of trust anchors for that URI because I know > exactly what to expect. > > however, an attacker has managed to steal example.com's DNS registry > account password and has compromised their zone. > With a version of libcurl that does not support the URI rr, my > application is vulnerable to a denial of service attack if they mess up > the DNS zone, but I am not vulnerable to an attack on integrity of my > interactions with the cloud services. > > However, now that libcurl follows the URI RR, since the attacker has > compromised example.com's DNS zone, they can now redirect me elsewhere. > And since the URI RR draft specifies we're going to do our TLS > validation based on the target of the redirection rather than the > source, my validation rules for cloud.example.com no longer apply, and > so my security is likely weak enough to attack if the attacker can get a > cert for a domain controlled by the attacker. > > OK, so perhaps libcurl should not default to following URI RR redirects. > Fine. But we as standards authors need to help application authors > understand the implications of turning on the URI RR. You probably > don't want to follow URI RR if you're supplying a non-default TLS trust > anchor set, pinning to a specific certificate or the like unless you're > somehow supplying specific acceptable DNSSec trust anchors for the zones > in question and not trusting the root trust anchor. Note, however that > application TLS libraries ar much more customizable in their validation > than application-layer DNSSec libraries. In practice TLS allows > application security policy to be specified, but DNSSec seems to use one > global security policy. I understand that's not inherent in the > standards, although the way the two standards are written does > contribute to it. It does seem true in the code for TLS and DNSSec I'm > aware of, and it is to the best of my understanding a practical reality > for authors of applications. > >
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Mark Nottingham
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Patrik Fältström
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Mark Nottingham
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Eliot Lear
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Patrik Fältström
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Patrik Fältström
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Eliot Lear
- (short version) Re: Last Call: <draft-faltstrom-u… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Dirk-Willem van Gulik
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… Paul Hoffman
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Mark Andrews
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… Pete Resnick
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Andrew Newton
- Re: (short version) Re: Last Call: <draft-faltstr… Nico Williams
- Re: (short version) Re: Last Call: <draft-faltstr… Nico Williams
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Nico Williams
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Mark Nottingham
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Eliot Lear
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Eliot Lear
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Andrew Newton
- Re: (short version) Re: Last Call: <draft-faltstr… Phillip Hallam-Baker
- Re: (short version) Re: Last Call: <draft-faltstr… Eliot Lear
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Andrew Newton
- Re: (short version) Re: Last Call: <draft-faltstr… Eliot Lear
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Pete Resnick
- Re: (short version) Re: Last Call: <draft-faltstr… Nico Williams
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Nico Williams
- draft-newton-link-rr (was Re: Last Call: <draft-f… Nico Williams
- Re: draft-newton-link-rr (was Re: Last Call: <dra… Nico Williams
- Re: (short version) Re: Last Call: <draft-faltstr… Mark Andrews
- Re: (short version) Re: Last Call: <draft-faltstr… Phillip Hallam-Baker
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Mark Andrews
- Re: (short version) Re: Last Call: <draft-faltstr… Phillip Hallam-Baker
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Patrik Fältström
- Re: draft-newton-link-rr (was Re: Last Call: <dra… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: draft-newton-link-rr (was Re: Last Call: <dra… Andrew Newton
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: draft-newton-link-rr (was Re: Last Call: <dra… Patrik Fältström
- Re: Last Call: <draft-faltstrom-uri-10.txt> (The … Mark Andrews
- Re: (short version) Re: Last Call: <draft-faltstr… Mark Nottingham
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Mark Nottingham
- Re: (short version) Re: Last Call: <draft-faltstr… Pete Resnick
- Re: (short version) Re: Last Call: <draft-faltstr… Pete Resnick
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Eliot Lear
- Re: (short version) Re: Last Call: <draft-faltstr… Pete Resnick
- Re: (short version) Re: Last Call: <draft-faltstr… Viktor Dukhovni
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… Sam Hartman
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… John C Klensin
- Re: (short version) Re: Last Call: <draft-faltstr… Eliot Lear
- Re: (short version) Re: Last Call: <draft-faltstr… Eliot Lear
- Re: (short version) Re: Last Call: <draft-faltstr… Nico Williams
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström
- Re: (short version) Re: Last Call: <draft-faltstr… Pete Resnick
- Re: (short version) Re: Last Call: <draft-faltstr… Pete Resnick
- Where to do the work was Re: (short version) Re: … t.p.
- Re: (short version) Re: Last Call: <draft-faltstr… Patrik Fältström