Hello. I am facing a redirect loop between my SF app and the external STS I have configured the app with. I configured the STS to WS-Federate with an Identity Provider which authenticates the user and returns claims. The STS generates the security token and sends it to the SF app. However the app sends another request to the STS instead of logging in the user.
The STS code is based on this code so I know it should be generating a token compatible with Sitefinity: https://github.com/svetlay/Sitefinity-STS-Modification/tree/master/SitefinityStsWebApp