I have multiple IP based domains and I need to enable more than one certificate. How do I do that?

The configuration information generally resides in a file in your Apache directory structure - probably "httpd.conf". Update that configuration file as follows:

             
   SSLCertificateFile /path/to/server.crt
             
   SSLCertificateKeyFile /path/to/server.key
           

You can have the key and the certificate in a single file if you want by appending the one after the other in the file. However, we recommend separating them for clarity. Sometimes you might have the wrong key in a certificate file, which creates errors that are very hard to debug, so please stick to separate key and certificate files.