Self-sign (use this to open ports and make sure SSL is correctly configured)
1.) https://www.digitalocean.com/community/tutorials/how-to-create-a-self-signed-ssl-certificate-for-apache-in-ubuntu-16-04
ports.conf
# If you just change the port or add more ports here, you will likely also
# have to change the VirtualHost statement in
# /etc/apache2/sites-enabled/000-default.conf
Listen 80
Listen 443 https
<IfModule ssl_module>
Listen 443
</IfModule>
<IfModule mod_gnutls.c>
Listen 443
</IfModule>
# vim: syntax=apache ts=4 sw=4 sts=4 sr noet
.pfx –> .key & .crt
2.) http://www.entrust.net/knowledge-base/technote.cfm?tn=7924