Using Azure ACS to get access to underlying identity provider's access/refresh token

Hi there,

I couldn't find any clear indication of whether ACS provided this functionality or not.

I would like to leverage ACS to do most of my authentication work, but I would also like access to the identity provider's access/refresh token that was sent to ACS, so that I can make API calls to the identity provider to access the user's data such as calendar or profile information (assuming I've requested this access during the application authorization steps).

Is this possible using ACS? It seems as if ACS abstracts most of the underlying identity provider information out, and only provides an ACS token used purely for authentication purposes, not for use in talking directly to the identity provider.

Thanks!