WSS 3 and external web site authorization : How to know if user is logged in

Question

I am not common with ISS and SharePoint technologies ... I'll try to explain what I need to do.

There is a web site (call it Site A) running under ISS 6.0 and SharePoint in a Window Server 2003 with NTLM authentication.

There is another web site (call it Site B), on the same subnetwork, but java based. Hyperlinks pointing to Site B are published on site A.

For some security resaons, when a user clicks on an hyperlink to acces to Site B, Site B must know if the user is already logged in on Site A.

Is there a service with SharePoint that can be called from Site B to check if the user is connected or not using some coockies or some key propagated in the HTTP request when the user click on the link?

Thanks Pat

Answer 1

I think the question your posing is that you'd like SSO between 2 site collections? Generally if the user has already authenticated against the IIS server once and its NTLM authentication we're talking about then a user clicking a link to go to site collection B from site collection A would not prompt for authentication again. Generally you'd want to run TMG server to publish these sites and then you can guarantee that the user will be authenticated for the sessions on both sites, regardless of if they are hosted on different servers within the same subnet externally.