[horde] Extending userList capabilities when using IMP authentication

[Thibault Le Meur]

Hi again,

Now here's the second part of my problem.


* I've got a working Horde(3.2.1)/Imp(4.2) server and I recently 
extended it with Kronolith(2.2).
* I've got several internal email servers and am using IMP as the Horde 
authentication application.
* I've implemented a _horde_hook_preauthenticate function that 
automatically sets the server name from an external database. Then, I've 
set up IMP>Server with the 'show servers' option set to 'None' (or 
'Hidden').

So far everything works as expected:
* the user can log in to Horde with a simple username/password and the 
email server is automatically selected by the hook
* the user can remotely access his Kronolith Calendar with WebDAV access 
(with a simple username/password)

However I encounter a  problem when trying to set permissions to a 
Calendar:  I can't define individual user's permissions because the 
select box that should list users is empty. Note that, before the 
_horde_hook_preauthenticate was implemented, I was able to list the 
users defined on the same IMAP server (which was not optimal, but was at 
least working).

I think this is a limitation of the Authentication backend I'm using: 
IMP + _horde_hook_preauthenticate

I've searched the list and found this thread:
http://marc.info/?l=horde&m=112211750913271&w=2

The answer Jan gave at that time was:
<quote>
You don't need a hook. This is one of the purposes of the composite
driver. See http://wiki.horde.org/AuthCompositeHowTo
</quote>

Can anyone elaborate a little more ?
I understand that I should define 2 possible authentication backends,
and then switch from one or another with the composite backend.

How would I use my second auth backend with userList capabilities in the
'Share permissions' context ?

The composite authentication setup has an example with an 'admin' module 
that uses another backend:
$conf['auth']['params']['admin_driver'] = 'corporate_sql';

Is there another configuration parameter such as 
"$conf['auth']['params']['XXX']" that could be used to bind a new auth 
driver for Share/Permissions ?

Thanks in advance for any tip or comment.

Best regards,
Thibault