Installing your Certificate on Apache Mod_SSL / OpenSSL Step one: Copy your certificate to file You will receive an email from Comodo with the certificate in the email (yourdomainname.crt). When viewed in a text editor, your certificate will look something like:

_____BEGIN CERTIFICATE_____
MIAGCSqGSIb3DQEHAqCAMIACAQExADALBgkqhkiG9w0BBwGggDCCAmowggHXAhAF
UbM77e50M63v1Z2A/5O5MA0GCSqGSIb3DQEOBAUAMF8xCzAJBgNVBAYTAlVTMSAw
(.......)
E+cFEpf0WForA+eRP6XraWw8rTN8102zGrcJgg4P6XVS4l39+l5aCEGGbauLP5W6
K99c42ku3QrlX2+KeDi+xBG2cEIsdSiXeQS/16S36ITclu4AADEAAAAAAAAA
_____END CERTIFICATE_____ 

Copy your Certificate into the directory that you will be using to hold your certificates. In this example we will use /etc/ssl/crt/. Both the public and private key files will already be in this directory. The private key used in the example will be labeled private.key and the public key will be yourdomainname.crt.

It is recommended that you make the directory that contains the private key file only readable by root.

Step two: Install the Intermediate Certificate This is the certificate that starts Comodo. You will need to install the Comodo intermediate certificate in order for browsers to trust your certificate. The Comodo intermediate certificate is attached to your email. In the relavant Virtual Host section for your site, you will need to complete the following:

Copy the Comodo intermediate to the same directory as certificate and key files and name it ca.txt

Add the following line to the SSL section of the httpd.conf (assuming /etc/httpd/conf/ is the directory to where you have copied the Comodo intermediate file)

If the line already exists amend it to read the following:

SSLCACertificateFile /etc/httpd/conf/ca.txt 

If you are using a different location and certificate file names you will need to change the path and filename to reflect the path and file name that you are using. The SSL section of the updated config file should now read similar to this example (depending on the file name and directories used):

SSLCertificateFile /etc/ssl/crt/yourdomainname.crt 
SSLCertificateKeyFile /etc/ssl/crt/private.key 
SSLCACertificateFile /etc/ssl/crt/ca.txt 

Save Your config file and restart Apache.