How to read GET parameters in custom authentication driver script?

I need to read values of some GET parameters in /var/lib/one/remotes/auth/<my_custom_auth_driver>/authenticate script. How to do it?

It will require some development from your part.

A few hints to get you started:

Doc for the existing sunstone authentication options

The session is built in this file:

Off the top of my head, I see two options: