== link:index.html[Index] -> link:modules.html[Modules] -> link:modules_validators.html[Validators]

Validator: PAM
~~~~~~~~~~~~~~

The pam validator uses the *Pluggable Authentication Module* to validate the
username/password combination.

[[parameters]]
Parameters
^^^^^^^^^^

Users: You can restrict to some local system users

[[compatibility]]
Compatibility
^^^^^^^^^^^^^

This validator is compatible with the **basic** scheme.

[[example]]
Example
^^^^^^^

image::media/images/admin_validators_pam.png[Validator PAM]

Requires a valid user and password system pair to access the protected
directory. It will be available for all local users, unless a
restriction list is provided.

[[notes]]
Notes
^^^^^

The PAM approach ensures a dynamic configuration for how the
authentication is performed. This dynamic configuration must be
specified. This means that a /etc/pam.d/cherokee file must define the
connection between Cherokee and the pluggable authentication modules
that perform the actual authentication tasks.

Cherokee's installation procedure already takes care of the creation
of such file (under /etc or whatever system configuration directory is
used in your platform of choice). If you consistently fail to use the
PAM validator, make sure that such configuration definitions are set.

.Sample: /etc/pam.d/cherokee
----
#
# The PAM configuration file for Cherokee
#

account    required   pam_unix.so
auth       required   pam_unix.so nullok
auth       required   pam_env.so
session    required   pam_unix.so
----

Bare in mind that Cherokee needs to be able to read `/etc/shadow` in
order to perform PAM authentication. If you are not successful setting
up this validator, check your logs for clarification about the
authentication failures you might be experiencing. The solution to
this particular problem is adding the user under which Cherokee is
running to the shadow-group and restarting cherokee. This is easily
achievable. For instance, assuming Cherokee is running as `www-data`
on a Debian based Linux distribution, this can be done with the
following command.

.Adding Cherokee user to shadow group on Debian
----
sudo adduser www-data shadow
----