Adding external authentication support to a web project

The aim of this thesis is to extend Drupal such that it will support optional external authentication, in particular using mod_auth_gssapi and mod_intercept_form_submit, as well as retrieving additional information about the user from an external identity provider using mod_lookup_identity. Moreover, this functionality will be implemented on the basis of an established mechanism of passing the authentication results to web applications, so there is a viable possibility that it will be usable by multiple external authentication mechanisms. The thesis also provides a description and explanation of the related issues, relevant technologies and their use and configuration, Drupal, as well as the state before the extension, the extension itself, and the resultant state and its implications.