My company is researching implementing an identity server. Essentially we need to act primarily as a service provider, but need to accept claims via either SAML, OpenId and OAuth (I realize this is an authorization protocol) - and then reroute to the appropriate application server using tokens. It's possible that we would act as an identity provider too and make assertions to outside service providers.
So far the servers we are looking into are WSO2 and OpenAM, but are curious as whether there are any other servers that are being widely used.
We'd also like to be able to use something that's written in .NET. The above mentioned servers are both Java.
Any available resources with regards to this question would be greatly appreciated as well as any feedback on whether you've used either of the above servers and what your experiences were.
Thanks!
Thinktecture IdentityServer v3 together with the Kentor.AuthServices Owin middleware to handle SAML2P authentication against external Idps fulfills most of your requirements. What's missing with that setup is the ability to act as a SAML2P identity provider (but it's open source, so you can always add it yourself).