.. _rlm_perl_ini:

RADIUS plugin configuration
~~~~~~~~~~~~~~~~~~~~~~~~~~~

The FreeRADIUS plugin is a perl module, that e.g. requires on a Debian system
the following packages to be installed:

* libconfig-inifiles-perl
* libdata-dump-perl
* libtry-tiny-perl
* libjson-perl

The RADIUS plugin configuration is read from the file
``/opt/privacyIDEA/rlm_perl.ini``.

Starting with version 2.7 the plugin first tries to read from the following
locations:

* ``/etc/privacyidea/rlm_perl.ini``
* ``/etc/freeradius/rlm_perl.ini``
* ``/opt/privacyIDEA/rlm_perl.ini``.

If no file exists, the default values are::

   [Default]
   URL = https://localhost/validate/check
   REALM =

But it can also look like this::

   [Default]
   URL = https://your.server/validate/check
   REALM = someRealm
   RESCONF = someResolver
   SSL_CHECK = true
   DEBUG = true

.. note:: The default behaviour is to not check the SSL certificate.
   So in a productive environment where the privacyIDEA system is located on
   another server than the RADIUS server, you should set "SSL_CHECK = true".

.. _radius_and_realms:

Radius and Realms
~~~~~~~~~~~~~~~~~

.. index:: RADIUS, FreeRADIUS, RADIUS Realms, Realms

FreeRADIUS also has a notion of realms. In general the RADIUS realms are not
the same as the privacyIDEA realms, but they can be mapped.

A user can authenticate to the FreeRADIUS either with a simple username
"fred", or a username combined with a RADIUS realm in the format like
"fred@realm1" or "realm1\fred".

.. note:: The format of the realms is defined in
   ``/etc/freeradius/modules/realm`` as "suffix" and "ntdomain". I.e. you could
   also change the delimiter.
   The "suffix" and "ntdomain" is referenced in the ``authorize`` section in
   ``/etc/freeradius/sites-enabled/privacyidea``.

The RADIUS server tries to split the realms according to the definition of
"suffic" or "ntdomain". I.e. a ``User-Name`` "fred@realmRadius" would be
split
into ``Stripped-User-Name`` "fred" and ``Realm`` (RADIUD realm) "realmRadius".
**But only if** FreeRADIUS can identify "realmRadius" as a RADIUS realm. For
FreeRADIUS to identify this as a REALM you need to add this to the file
``/etc/freeradius/proxy.conf``::

   realm realmRadius {
   }

Realm processing in FreeRADIUS
..............................

A ``User-Name`` "fred@realmRadius" or "realmRadius\fred" is sent to the
FreeRADIUS server.

If "realmRadius" can not be identified as RADIUS realm (missing entry in
proxy.conf), then no realm can be split and the complete ``User-Name`` will be
sent to privacyIDEA for validation.
This can work out with "fred@realmRadius", since privacyIDEA
might split the @-sign. But this probably will not work out for
"realmRadius\fred".

If the "realmRadius" can be identified as RADIUS realm (entry in proxy.conf),
then FreeRADIUS will split the ``User-Name`` into the RADIUS attributes
``Stripped-User-Name`` and ``Realm`` and the "fred" will be sent as user and
"realmRadius" as the realm to privacyIDEA.

This way you can directly map RADIUS realms in the RADIUS user name to realm
in privacyIDEA.

.. note:: You can define a realm in ``/opt/privacyIDEA/rlm_perl.ini``. Such a
   realm definition will override a RADIUS realm in the ``User-Name``.

Using the Token serial number
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In case of a successful authentication privacyIDEA returns the serial number
of the token used.

If available (see :ref:`policy_no_detail_on_success` and
:ref:`policy_no_detail_on_fail`) the FreeRADIUS server can receive this
serial number.
The serial number is contained in the response value ``privacyIDEA-Serial``.

To see the ``privacyIDEA-Serial`` in the RADIUS response, you need to include
the ``dictionary.netknights`` in your FreeRADIUS dictionary.

You can get it here [#netknights_dict]_.


Debugging RADIUS
~~~~~~~~~~~~~~~~

If you need to DEBUG the FreeRADIUS go like this.

Add "DEBUG = true" to ``/opt/privacyIDEA/rlm_perl.ini``.
Then stop the FreeRADIUS and run it in debug mode as user root::

   /etc/init.d/freeradius stop; freeradius -X

Now you can send requests to the RADIUS server like this::

   echo 'User-Name=realm3\\cornelius, Password=test' | radclient -s \
      127.0.0.1 auth test

Of course you need to replace the IP of your RADIUS server and the RADIUS
secret "test" with your clients secret.

.. rubric:: Footnotes

.. [#netknights_dict] https://github.com/privacyidea/privacyidea/blob/master/authmodules/FreeRADIUS/dictionary.netknights