Subject: [dnsext] signatures for HINFO RRsets

From: Jelte Jansen <[email-masked]>
Date: Tue, 06 Jan 2009 12:46:11 +0100

Hi guys,

(happy new year, etc.)

we just had a discussion over here about signatures for HINFO RRsets,
where apparently we have different views on what to do with the rdata
section before creating or verifying them.

RFC4034 lists the HINFO record as one that should have its "DNS names"
canonicalized (it even lists HINFO twice, which is already mentioned in
DNSSECbis-updates). However, the rdata fields are <character strings>.
One interpretation is, since those are not "DNS names", nothing should
be done. The opposing view is, since you cannot reliably tell DNS names
within strings from non-DNS names, to just lowercase the complete strings.

And regarding that first view, why even mention the type at all in 4034?

Any thoughts?

Jelte

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From: [email-masked] (Andreas Gustafsson)
Date: Tue, 6 Jan 2009 14:46:59 +0200

> within strings from non-DNS names, to just lowercase the complete strings.

Speaking as the author of RFC3597, which section 6.2.3 of RFC4034 was
based on, my interpretation is that that "nothing should be done".
I assume HINFO is listed (twice) in RFC4034 because it was listed
(twice) in RFC3597, which in turn was a mistake on my part - it should
not have been listed at all.

The reason downcasing is done is that domain names in some RRs can
lose their original character case as a result of domain name
compression.  Since character strings are not subject to compression,
there is no reason to downcase them.
-- 
Andreas Gustafsson, [email-masked]

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From: "W.C.A. Wijngaards" <[email-masked]>
Date: Tue, 06 Jan 2009 14:05:51 +0100

> there is no reason to downcase them.

I assumed that since the HINFO arguments should be in all caps according
to RFC1010, that the lowercasing was because HINFO rdata is case
insensitive.

I think some text should be part of dnssec-updates. Which already says
that (sic) 'such DNS names' should be downcased. This is wrong since
HINFO rdata contains CPU and OS names. As text I suggest to replace
'such DNS names' with 'the HINFO RDATA'.

Best regards,
   Wouter

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From: [email-masked] (Andreas Gustafsson)
Date: Tue, 6 Jan 2009 16:00:19 +0200

> to RFC1010, that the lowercasing was because HINFO rdata is case

You assumed incorrectly - the inclusion of HINFO in the list in
RFC3597 was a mistake, pure and simple.

> I think some text should be part of dnssec-updates.

Yes, but...

> Which already says

No, the paragraph should be replaced with "The same section also
erroneously lists HINFO, and twice at that.  Since HINFO records
contain no domain names, they are not subject to downcasing."
-- 
Andreas Gustafsson, [email-masked]

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From: Mark Andrews <[email-masked]>
Date: Wed, 07 Jan 2009 01:16:12 +1100

In message <[email-masked]>, Andreas Gustafsson write
> contain no domain names, they are not subject to downcasing."

	Concur.

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: [email-masked]

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From: "W.C.A. Wijngaards" <[email-masked]>
Date: Tue, 06 Jan 2009 15:52:56 +0100

Hi,

OK, the original draft author says my reasoning is wrong, and there are
hardly any other DNSSEC implementors. You are right, and I support the
text Andreas suggested.

Best regards,
   Wouter