Zimbra mail SSO using a proxy on another VM

[initt]

I'm trying to create a system of two virtual machines. One for zimbra mail and another for zimbra proxy (or just nginx). The goal is to make this work with single sign-on using cards, as in: I connect with my favorite browser to zimbra proxy, enter the card pin code and get sent directly to my zimbra mail without having to enter an accountname or a password. Here's a couple of questions:

- Is this even possible?
- When installing zimbra, what are the packages that the zimbra mail and zimbra proxy should contain, and is it mandatory that the VM's are connected to the internet during the installation?
- What are the specific configurations i need to do in order to make SSO work?
- Is there a step-by-step guide out there for creating such a system?

I'm using centos 7 VM's in a hyper-v environment.

Thanks in advance!