[sf-lug] DNS & ns1.svlug.org - RNAME squashed to lowercase(!) (interesting, but NOT critical!)

[Rick Moen]

Quoting Michael Paoli (Michael.Paoli at cal.berkeley.edu):

> DNS & ns1.svlug.org - RNAME squashed to lowercase(!) (interesting,
> but NOT critical!)

{shrug}

Something NSD does.

Commented on here:
https://www.nlnetlabs.nl/documentation/nsd/differences.pdf 
 (see item 2.4.16)
https://github.com/NLnetLabs/nsd/blob/master/doc/REQUIREMENTS
 Section C.1.:

   Case of dnames in RDATA will be preserved except for dnames
   for which dname compression in RDATA is allowed, those dname fields
   are converted to lower case. (for that subset of RRs compression
   has preference over case preservation). 

https://nlnetlabs.nl/pipermail/nsd-users/2015-September/002177.html

> Interesting, but NOT critical! 

Not critical, and, IMO, not particularly interesting, either.  But Views
Differ.[tm]  ;->

> Now, per RFC(s), Internet @ type email addresses,
> the localpart (part before @) is recommended, but not required,
> to be treated as case insensitive ... but if I'm not mistaken, it's
> also recommended that case be preserved.

Yeah, they probably shouldn't do that to the LHS, and I'd call it
a (minor) bug.  Might matter in some weird edge-case.  Making the 
somewhat far-fetched assumption that someone is parsing and using e-mail
addresses out of zonefile SOA RRs, _and_ that the destination MTA is
using lettercase-sensitive LHS strings.  Which, thank Gnu, is an
abomination I haven't seen in decades.

> ... I wonder if that DNS server software has a configuration option
> to not squash that data to lowercase.

Can't easily find one.