[10723] in bugtraq
Re: weaknesses in dns label encoding
daemon@ATHENA.MIT.EDU (Walter Misar)
Fri Jun 4 16:51:33 1999
Message-Id: <199906042033.WAA13919@hp91.rbg.informatik.tu-darmstadt.de>
Date: Fri, 4 Jun 1999 22:33:47 +0200
Reply-To: Walter Misar <misar@RBG.INFORMATIK.TU-DARMSTADT.DE>
From: Walter Misar <misar@RBG.INFORMATIK.TU-DARMSTADT.DE>
To: BUGTRAQ@NETSPACE.ORG
Kragen Sitaker <kragen@POBOX.COM> wrote:
> Are there other RFCs that describe allowed syntax for domain names?
Yes, probably most important 1123 (host requirements):
|> The syntax of a legal Internet host name was specified in RFC-952
|> [DNS:4]. One aspect of host name syntax is hereby changed: the
|> restriction on the first character is relaxed to allow either a
|> letter or a digit. Host software MUST support this more liberal
|> syntax.
Rfc 952 specifies:
|> <hname> ::= <name>*["."<name>]
|> <name> ::= <let>[*[<let-or-digit-or-hyphen>]<let-or-digit>]
All digit names are allowed, underscore is not, two letter names are ok.
Walter
