Secure Sockets Layer (SSL) is critical as a first step in security on any operating system, including Linux. What follows is how to create SSL certificates for running on Linux and supporting Webmin. Webmin is a terrific tool for maintaining and managing your Ubuntu server.
One the main elements in Webmin is ssl.combined certificates. To create the ssl.combined file, you must first have the Certificate Authority certs, followed by your SSL key file. As an example of building an ssl.combined file, run the following command:
cat /root/certs/intecore.com.crt /root/certs/gd_bundle-g2-g1.crt > ssl.combined
This builds a properly formatted ssl.combined certificate file for Webmin and Virtualmin