Here is a question regarding some details how SiteMinder secures access to the SharePoint 2007. I've read a bunch of materials regarding this and have some picture for SharePoint 2010 FBA claims-based + SiteMinder security (can be wrong here, of course): SiteMinder is registered as a trusted identity provider for the SharePoint; It means (to my mind) that SharePoint has no need to go into all those user directories like AD, RDBMS or whatever to create a record for user being granted access to SharePoint - instead it consumes a claims-based id supplied by SiteMinder SiteMinder checks all requests to SharePoint resources and starts login sequence via SiteMinder if does not find required headers in the request (SMSESSION, etc.) SiteMinder creates a GenericIdentity with the user login name if headers are OK, so SharePoint recognizes the user as authenticated But in the case of SharePoint 2007 with FBA + SiteMinder, I cannot find an answer for questions like: Does SharePoint need to go to all those user directories like AD to know something about users (as SiteMinder is not in charge of providing user info like claims-based ids)? So, SharePoint admin should configure SharePoint FBA to talk to these sources? Let's say I'm talking to a Web Service of SharePoint protected by SiteMinder. Shall I make a Authentication.asmx-Login call to create a authentication ticket or this schema is somehow changed by the SiteMinder? If such call is needed, do I also need a SiteMinder authentication sequence? What prevents me from rewriting request headers (say, manually in Fiddler) before posting request to the SharePoint protected by SiteMinder to override its defence? Pity, but I do not have access to deployed SiteMinder + SharePoint, so need to investigate some question blindly. Thanks.