Customize Spring OAUTH2 authorization request URL

Question

How can I customize the OAUTH2 authorization request URL sent by Spring to my configured Identity provider?

Answer 1

Implement OAuth2AuthorizationRequestResolver

@Component
public class CustomAuthorizationRequestResolver implements OAuth2AuthorizationRequestResolver {

    private final CustomAuthorizationRequestResolver defaultResolver;

    public CustomAuthorizationRequestResolver(OAuth2ClientProperties oauth2ClientProperties){
        ClientRegistration auth0 =
                OAuth2ClientPropertiesRegistrationAdapter.getClientRegistrations(oauth2ClientProperties).get("auth0");
        InMemoryClientRegistrationRepository clientRegistrationRepository =
                new InMemoryClientRegistrationRepository(auth0);
        this.defaultResolver = new DefaultOAuth2AuthorizationRequestResolver(clientRegistrationRepository, "/oauth2/authorization");
    }

    @Override
    public OAuth2AuthorizationRequest resolve(HttpServletRequest request) {
        OAuth2AuthorizationRequest req = defaultResolver.resolve(request);
        if(req != null){
            req = customizeAuthorizationRequest(req);
        }
        return req;
    }

    @Override
    public OAuth2AuthorizationRequest resolve(HttpServletRequest request, String clientRegistrationId) {
        OAuth2AuthorizationRequest req = defaultResolver.resolve(request, clientRegistrationId);
        if(req != null){
            req = customizeAuthorizationRequest(req);
        }
        return req;
    }

    // Customize request here
    private OAuth2AuthorizationRequest customizeAuthorizationRequest(OAuth2AuthorizationRequest req) {
        Map<String,Object> extraParams = new HashMap<>(req.getAdditionalParameters());
        extraParams.put("connection", "my-connection-name");
        return OAuth2AuthorizationRequest.from(req).additionalParameters(extraParams).build();
    }
}

Set authorization request resolver on your Spring security configuration:

 @Override
 public void configure(HttpSecurity http) throws Exception {
     http
     ...
      .oauth2Login()
      .authorizationEndpoint()             
      .authorizationRequestResolver(customAuthorizationRequestResolver)
     ...
}