System Preparation

Add the Moonshot libraries.

If you have not already done so, you first need to follow the instructions on how to .

Install some prerequisites

Building the Apache mod_auth_kerb module requires you to have several packages already installed on the machine. To install them:

Build the module

We are now ready to build the Apache module.

1. Get a copy of the code via git:

   bash

2. Enter the directory that just got created:

   bash

3. Run autoreconf:

   bash

4. Build the software:

   bashTip

   This will install the module to /usr/local/etc/apache2/mods-available/auth_gssapi.load. To get the process to put the module somewhere where Apache can find it without any intervention, run the following configure command in step 5:

   bash

Installation Instructions

1. To install the Apache module, issue the following command (or create the appropriate symlinks manually):

   bash

2. This module requires the Apache MPM prefork module to be active.

   bash

3. Ensure that the certificates referenced in /etc/radsec.conf can be read by the Apache user:

   bash

4. Verify that the KeepAlive option is enabled in the Apache configuration file /etc/apache2/apache2.conf:

   bash

5. Restart Apache:

   bash

Configuration Instructions

Protecting a location with Moonshot

To protect a particular location on your Apache server, you must configure it with an AuthType of "Negotiate".

Exporting GSS API attributes as environment variables

The module includes an option called GssapiNameAttributes that allows controlling which GSS API attributes (either SAML or RADIUS) are exported as environment variables. It is used as follows:

This option can be specified multiple times, once for each attribute to expose. The Special value "json" is used to expose all attributes in a json formatted string via the special environment variable GSS_NAME_ATTRS_JSON.

Example:

The special environment variable GSS_NAME_ATTR_ERROR is set with the GSS API returned error string in case the inquire name function fails to retrieve attributes, and with the string "0 attributes found", if no attributes are set.

In addition to this, in the event of an authentication failure, the module exports an environment variable called MAG_ERROR which contains one of the following values:

• "NO_AUTH_DATA" when the client did not send any authentication data (usually because the appropriate libraries are not installed on the browser).
• "UNSUP_AUTH_TYPE" when the client sent authentication data of an invalid type.
• "GSS_MECH_ERROR" when the GSS mechanism failed for some reason (e.g. invalid credentials).

Finally, whenever MAG_ERROR takes a value of "GSS_MECH_ERROR", an additional environment variable named GSS_ERROR_STR is sourced. This variable contains the result of the gss_display_status() call and may help web developers to show a more appropriate error page/string to the user.

Populating REMOTE_USER

Web services often rely on the REMOTE_USER Apache environment variable for user information, such as a local user account or a pseudonymous identifier.

To populate REMOTE_USER, update the reply from the RP Proxy with the User-Name RADIUS attribute in the RP Proxy's post-auth section:

HTTPS Internet Explorer compatibility

For updated best practice with Internet Explorer connections, you should also read Microsoft's HTTPS and Keep-Alive Connections article.