Spring Security SAML: support setting AssertingPartyDetails from IdP metadata located on file/classpath/InputStream

Expected Behavior

Defining the AssertingPartyDetails should support reading IdP metadata from a file/classpath resource/InputStream.

Current Behavior

There is also no mechanism at all for populating AssertingPartyDetails from IdP metadata located on a file/classpath resource/InputStream.

Context

It is common to configure the IdP an SP is talking to by loading the IdP metadata. Currently, users are required to parse the IdP metadata with OpenSAML and set the AssertingPartyDetails manually.

Comment From: jzheaux

Thanks for the report, @handcraftedbits.

I believe this is already possible with RelyingPartyRegistrations:

RelyingPartyRegistration.Builder registration = RelyingPartyRegistrations.fromMetadataLocation("classpath:metadata.xml");

It looks like the documentation needs updating since this wasn't clear. Would you be able to provide a PR that updates the linked section of the documentation to indicate other protocols that fromMetadataLocation supports?

Comment From: handcraftedbits

Ah, thanks. I was using 5.4.2, which seems to make a REST call, and since then this has been fixed. Thanks!