Timo,
I've written passdb and userdb modules for PostgreSQL. My C skills aren't that great, so I borrowed heavily from the LDAP modules, and I've never developed with automake/autoconf before, so I don't know how acceptable my patch to configure.in is. Anyway, it seems to work ok but I haven't done really heavy testing. If you can get past my poor C skills, I hope you will at least find my work useful as a base to expand from.
The patch supports arbitrary queries which can use the %h/%n/%d macros, so there's no need to have specific table or field names. For example, in the configuration file, you'd specify something like:
password_query = select password from users where userid = '%u'
Like the LDAP module, it supports PLAIN, PLAIN-MD5, DIGEST-MD5, and CRYPT. It also tries to be secure by immediately rejecting any auth attempts that don't fit a very strict format. If the user-provided data contains any non-standard characters, the query returns more than one row, etc., auth will immediately fail.
Are you interested in my patch, and if so, how should I send it? Does the list accept attachments? (The patch is against current CVS, by the way.)
Regards,
-- Alex Howansky Wankwood Associates http://www.wankwood.com/