[horde] WebDAV remote access and IMP authentication

[Thibault Le Meur]

Hi,

Context:
* 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,
* most of my users are defined in an LDAP server used by the email 
servers, but some specific users are directly defined in the email server
* Thus I am using IMP as the Horde authentication application, and I 
display the list of available web servers to users

Because IMP authentication requires login/password _and_ a server name, 
it is not possible for end-users to reach their remote calendar. Indeed, 
when using Sunbird to access the remote calendar (for instance), the 
HTTP based authentication provides a user and a password but no server 
name, and thus the first server defined in imp/config/servers.php is 
used. This seems quite understandable so far.

I searched for possible solutions in the list and finally I decided to 
to implement a _horde_hook_preauthenticate function that automatically 
sets the server from an external database into the $_SESSION['imp'] 
variable. Then, I've set up IMP>Server with the 'show servers' option 
set to 'None' (or 'Hidden'). This works as expected on the login page: 
now users can authenticate to horde using a simple user/password.

However, when using the WebDAV authentication, the first server defined 
in imp/config/servers.php is still used, regardless of the server 
auto-selection I've implemented. In fact I've found out that the 
_horde_hook_preauthenticate is not called by the Horde/WebDAV 
authentication.

Is it normal? Is the setup I'm trying to use is supported by Horde?
If yes, what am I missing?
If No, what would be the good setup?

I've got another problem related to the userList capability of the 
authentication driver used, because the list of users proposed when 
trying to set permissions on a shared object is empty, ... but I think 
I'll start another thread with this issue once I've found a solution for 
the first one ;-)

Many thanks in advance for any tip, idea, advice that you could give me.

Best regards,
Thibault Le Meur