Shibboleth restricted authentication to Box.

[ShibFan]

Hello,

We are in the process of adding Box to our Shibboleth implementation. We 
managed to get the SSO working.

We would like to also limit the authentication to Box for certain users 
within our domain via Shibboleth using Active directory multi value 
attributes such as (otherIpPhone attribute).

How can we achieve this from the IDP side ?  Has anyone done similar 
configuration in their environment ? Any help is greatly appreciated.

Best Regards.