Creating google oauth X.509 certificate in PEM format within Mac OS X

I am currently in the process of setting up the Google oauth for my site and I was wondering if it is possible to generate a X.509 certificate in PEM format withi开发者_运维知识库n MAC OS X via terminal?

Google provides this page as reference:

http://code.google.com/apis/gdata/docs/auth/authsub.html#Registered

but I was hoping it could be done within the Mac OS instead.

You can use OpenSSL for that, it should be installed by default on OS X. This tutorial shows you how you may create your own self-signed certificate.

You can also use OpenSSL for something more sophisticated, e.g. a root CA that would issue either further sub-CAs or end-entity certificates directly.