Make client registration more flexible and provide parameter reference

[kuschzzp]

As you can see in the figure above, the clientId and clientSecret that the registration endpoint cannot customize, along with some other information.

spring-authorization-server/oauth2-authorization-server/src/main/java/org/springframework/security/oauth2/server/authorization/oidc/authentication/OidcClientRegistrationAuthenticationProvider.java

Lines 391 to 393 in f06ed40

	ClientSettings.Builder clientSettingsBuilder = ClientSettings.builder()
	.requireProofKey(true)
	.requireAuthorizationConsent(true);

Also, if I don't use breakpoints, I don't know the 13 parameters that the /connect/register endpoint can receive. I think we should add a corresponding parameter documentation.

[jgrandja]

@kuschzzp

the clientId and clientSecret that the registration endpoint cannot customize

The client metadata can be customized. The extension point for customizing client metadata before it's saved to RegisteredClientRepository is OidcClientRegistrationAuthenticationProvider.setRegisteredClientConverter().

This is currently not documented in the reference manual so I logged a new issue gh-1044. I'll close this as a duplicate.

I don't know the 13 parameters that the /connect/register endpoint can receive. I think we should add a corresponding parameter documentation.

The spec defines all available Client metadata and the supported metadata is documented in OidcClientRegistration and it's implementation of OidcClientMetadataClaimAccessor.