Install libapache2-mod-auth-cas by entering the following commands in the terminal:
sudo apt update sudo apt install libapache2-mod-auth-cas
Description:
CAS authentication module for Apache2
mod_auth_cas is an authentication module for Apache2, that allows the webserver to interact with an authentication server that conforms to the CAS (v1 or v2) protocol defined by Yale/JA-SIG.
Homepage: http://www.ja-sig.org/wiki/display/CASC/mod_auth_cas
Version: 1.1-2.1ubuntu1
Section: universe/web