Re: Trying to track down malformed TXT sources

On Tue, Dec 16, 2008 at 2:46 PM, Thomas Cross <[email protected]> wrote:
> Its also possible that there is a basic problem with
> TinyDNS or the tinydns-data program that is resulting in these malformed
> responses.

There's no inherent problem with tinydns or tinydns-data.  E.g.,
leap.yp.to and mochiads.com are two domain names with TXT records that
are served using tinydns and are encoded correctly.

A bit of relevant technical details: tinydns treats record data as
opaque for most record types (exceptions: SOA, MX, CNAME, PTR, NS;
i.e., record types that allow name compression) and just copies the
record data verbatim from the database file.  E.g., for TXT records,
the string length bytes should already be present in the database.

tinydns-data includes native support for adding TXT records to the
database file and always generates TXT RDATA valid under RFC 1035.
However, it also supports a syntax for generic record types, which can
be used to create TXT records that are not valid under RFC 1035.

That said, I wouldn't be surprised to hear that people have written
scripts to generate SPF records using the generic syntax (or even
building database files directly) and messed up counting the bytes
manually or something.