Re: [DNSOP] ALT-TLD and (insecure) delgations.

Mark Andrews <marka@isc.org> Tue, 07 February 2017 07:27 UTC

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To: Brian Dickson <brian.peter.dickson@gmail.com>
From: Mark Andrews <marka@isc.org>
References: <CAH1iCiqXohb_7LsQ2EMo8ZB-t20mKq_nUDS8vebhtSXoM13DTg@mail.gmail.com> <20170203210922.7286C618213C@rock.dv.isc.org> <CAH1iCipKwcOsMQY3kjvSZ42LMK37GLD6GP2AVtnWK0c83k-RiA@mail.gmail.com> <20170207040552.8BDCC632F192@rock.dv.isc.org> <3581BE55-B178-4298-8EE8-73FD16B4216D@gmail.com> <20170207063146.BC04763357A9@rock.dv.isc.org> <99431A77-7B62-4655-89EF-FAA32F2A82F6@gmail.com>
In-reply-to: Your message of "Mon, 06 Feb 2017 23:08:21 -0800." <99431A77-7B62-4655-89EF-FAA32F2A82F6@gmail.com>
Date: Tue, 07 Feb 2017 18:27:50 +1100
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Subject: Re: [DNSOP] ALT-TLD and (insecure) delgations.
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In message <99431A77-7B62-4655-89EF-FAA32F2A82F6@gmail.com>, Brian Dickson writes:
> The suggestion of DNAME to empty.as112.arpa involves some subtle details,
> which IMHO may in combination be the right mix here.
>
> The DNAME target is an insecure empty zone.
>
> This avoids the validation issue, and facilitates use of local "alt"
> namespaces.

No it doesn't. 

> The default response to queries under alt would be unsigned NXDOMAINs.

No, it would be a secure response saying that foo.alt is covered
by a DNAME.  The names under empty.as112.arpa are unsigned NXDOMAINs.

The difference between the two descriptions is critical to why a
DNAME in the root zone will not work.  You *have* to leak names to
the root to get a DNAME returned by ordinary processing because the
DNAME is signed.

> I am not seeing a problem with this.
>
> Am I missing anything?

Yes.  A solution that *works*.

> Brian
>
> Sent from my iPhone
-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka@isc.org