Problem statement
We are trying to integrate AWS AppStream with Auth0. I tried https://docs.aws.amazon.com/appstream2/latest/developerguide/external-identity-providers-setting-up-saml.html. AWS AppStream had this in their documentation pages. I configured everything, but the response says 401 unsupported authentication mechanism.
Symptoms
The app is responding that with default Auth0 as IdP setup, this fails with Unsupported Authentication Type errors. This happens after authentication completes and shows a successful Login on the Auth0 side.
Solution
The AWS Appstream has more details steps you need to follow to set up.
I created a rule as mentioned in step 6 - Create Assertions for the SAML Authentication Response and attached it to the AppStream application within Auth0.