According to the WS-Trust specification, a service consumer has a way to negotiate or ask for specific claims to the STS. Those claims (or some of them) will be generally used by the service implementation running on the relying party. They are negotiated through an "claims" element in the RST message...

The other day and friend of mine asked me about portable STS implementations, if I knew about any available solution that he could use on his company. That reminded me of a conversation I had like two years ago with another developer working on custom .NET CLR framework version for portable devices ...

Geneva framework supports today the two WS-Trust profiles, Active and Passive. The active profile deals specially with applications that are able to make soap request to any WS-Trust endpoint. On other hand, the passive profile is for clients that are unable to emit proper SOAP (a web browser for instance...

I have been thinking for a while about what could be a good way to support brokered authentication for active REST clients. Something I did not want to do was to force the use of WS-Trust Active profile, which is in essence SOAP based. Some of the qualities attributes that are easy to reach with REST...