The steps below outline how to set up SSL on a server running CentOS 6.4 and Apache by generating a Certificate Request file, generating an RSA key, and installing a CA Root Certificate.

First, install the apache SSL module

yum install mod_ssl  

Then go to the certs directory

cd /etc/ssl/certs/  

Generate a Certificate Request file and an RSA key file

openssl req -nodes -newkey rsa:2048 -keyout mysite.key -out mysite.csr  

Get a CA Root Certificate from Verisign, Thawte, Globalsign, Comodo, etc. They'll request the contents of mysite.csr and mysite.key.

Once you have the CA Root Certificate, save it to the server in the /etc/ssl/certs/ directory. We'll just call it mysite.crt for this example.

Open the SSL configuration file

vi /etc/httpd/conf.d/ssl.conf  

Now edit the following lines

SSLEngine on  
SSLCertificateFile /etc/ssl/certs/mysite.crt  
SSLCertificateKeyFile /etc/ssl/certs/mysite.key  

Now restart the https service

service httpd restart