From: DeskNow Knowledge Base
http://www.desknow.com/kb/

Custom authentication
http://www.desknow.com/kb/idx/5/002/article/
DeskNow version: 2.4 and later 

This article describes how to use a custom mechanism to authenticate DeskNow users.

By default DeskNow manages its users and domains internally.

It is possible to use an external mechanism to authenticate DeskNow users. For instance, by looking up an LDAP server, or retrieving account information from an external database, etc.

DeskNow can also automatically generate user accounts if they exist in the external user repository.

Active Directory: DeskNow already provides a custom authentication plugin for ActiveDirectory. DeskNow supports also some advanced security mechanisms associated with AD, like Kerberos authentication.

LDAP: DeskNow already provides a custom authentication plugin for LDAP.

Please see the DeskNow - Administration and Configuration manual at the section 'External Authentication' for more information on how to use these plugins.

Custom authentication: every custom written plugin consists of a Java class that implements at least one of the following interface (possibly more than one, or all): AuthenticationProvider, PasswordInfoProvider, AccountInfoProvider.

For more details and full API reference, see docs/control/api/index.html in the DeskNow distribution (C:Program FilesDeskNow or /var/desknow). The Java library that defines this API is desknow_server_x_y_z.jar, and is contained in webapps/desknow/WEB-INF/lib