Attribute to show authentication method

Is there an easy well to determin in post-auth which authentication method was used to authenticate a user? We have a fairly complex setup where a user can be "authenticated" by MAC address in the Authorize section or via EAP-TLS or EAP-PEAP, both with their own virtual servers. In the outer post-auth I want to call a logging module that explicitly says how the user was authenticated but I can't find an attribute which I can reliably check. Thanks, Jonathan -- Jonathan Gazeley Senior Systems Administrator IT Services University of Bristol