.. _authentication_pam:

Pluggable Authentication Modules
--------------------------------

Authentication of users in ThinLinc is performed using the *Pluggable
Authentication Modules* (PAM). This means ThinLinc can authenticate
users using any system for which there is a PAM module. Examples of PAM
modules are **pam_ldap** for accessing LDAP directories (including
Novell NDS/eDirectory) and **pam_winbind** for authenticating against a
Windows Domain. Of course, authentication using the standard plaintext
password files of Linux is also possible using the PAM module
**pam_unix**.

.. _authentication_pam-files:

Configuration files for PAM
~~~~~~~~~~~~~~~~~~~~~~~~~~~

PAM is configured by editing the files located in the directory
:file:`/etc/pam.d/`.

Different Linux distributions have slightly different ways of
configuring PAM. The ThinLinc installation program will setup ThinLinc
to authenticate using the same PAM setup as the Secure Shell Daemon, by
creating a symbolic link from :file:`/etc/pam.d/thinlinc` to either
:file:`/etc/pam.d/sshd` or :file:`/etc/pam.d/ssh`, depending on which of
the latter files that exists at installation. This seems to work on most
distributions. Be aware that the PAM settings for the Secure Shell
Daemon might really be somewhere else. For example, on Red Hat
distributions, the file :file:`/etc/pam.d/system-auth` is included by
all other pam-files, so in most cases, that is the file that should be
modified instead of the file used by sshd.