Case-Insensitive Response Compression May Cause Problems With Mixed-Case Data and Non-Conforming Clients

Lars-Johan Liman liman at autonomica.se
Mon Feb 10 08:23:55 UTC 2014


[Using my old e-mail address since I noticed that it's still used for
this list. I need to fix that ...]

marka at isc.org:
> Named is not yet fully case preserving.  Owner names are stored based on
> first use of the name in the database (zone or cache) when the red black
> tree is created.  We need to extend the database to record the case used
> in the owner name.  The are two obvious ways to do this.

> 	1) record the complete owner name with the rdata.
> 	2) record a bit vector that contains the case bit (0x20)
> 	   of each character in the owner name.

Hmm. How correct will 2) be if the byte has the high bit set (i.e., its
value is in the range [128-255])? Will there be "bad" consequences?
I'm sure you've been down that path already. :-)

I'm not sure assuming that the value is in the [0-127] range forever and
all is correct, even if that happens to be the case* this very decade ...

				Cheers,
				  /Liman
* Pun intended. :-)
#----------------------------------------------------------------------
# Lars-Johan Liman, M.Sc.               !  E-mail: liman at netnod.se
# Senior Systems Specialist             !  Tel: +46 8 - 562 860 12
# Netnod Internet Exchange, Stockholm   !  http://www.netnod.se/
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