Step One: Copy your certificate to a file on your apache server
You will receive an email from Comodo with the certificate in the email. The certificate will be called 'yourDOMAINNAME.crt' and will be within a *.zip file you have received as an email from us. When viewed in a text editor, your certificate will look something like this:
Copy your Certificate into the same directory as your Private Key. In this example we will use '/etc/ssl/crt/'. The private key used in the example will be labeled 'private.key' and the public key will be 'yourDOMAINNAME.crt'.
Note: It is recommended that you make the directory that contains the private key file only readable by root.
Step Two: Install the Root and Intermediate Certificates
You will need to install the Root and Intermediate CA certificates in order for browsers and devices to trust your certificate. The Root and Intermediate CA certificates are contained within the 'ca-bundle' file that was attached to your email in the *.zip file we sent you (this should be named 'yourSERVERNAME.ca-bundle'). In the relevant 'Virtual Host' section for your site, you will need to do the following to get this file correctly referenced:
a. First, copy the 'yourSERVERNAME.ca-bundle' file to the same directory as the certificate and key files. As a reminder, in this example we called the directory '/etc/ssl/crt/'.
b. Next, add the following line to the SSL section of the 'httpd.conf' file. Again we assume that '/etc/ssl/crt/' is the directory to where you have copied the intermediate CA file. If the line already exists amend it to read the following:
c. If you are using a different location and different certificate file names, you will need to change the path and filename to reflect the path and filename that you are using. The SSL section of the updated config file should now read:
SSLCertificateChainFile /etc/ssl/crt/yourSERVERNAME.ca-bundle ***
d. Save your 'config' file and restart Apache.
*** For Apache 1.x: Please use: SSLCACertificateFile /etc/ssl/crt/yourSERVERNAME.ca-bundle
Note: The SSL configuration file will always be referenced in the apache config file if the configuration is not included in it. Look for the lines starting 'include', which is the directive for including other files etc. For example, depending on the distribution, it might be called ssl.conf, httpd-ssl.conf etc