GSX API SSL Certificate

How do we get a Client certificate as mentioned below;

Security

Client Certificate

Each client should have an individual certificate, and the certificate should be issued/provided by iOS Systems.

Authentication (2-way SSL)

The client shall provide its certificate as part of the SSL handshake for establishing the SSL connection with iOS Systems. This should be the same as is currently required by APNS for sending push notifications, and allows for a "quick disconnect" if the client is unable to provide an appropriate certificate during the SSL handshake.

Thanks!

Ravin