Spring security Oauth2 client modify authorization request going to Oauth server - spring-security

Question

I have use case where I need to add additional parameter(login hint)
to the authorize request. On researching I found that we can do this
by OAuth2AuthorizationRequestResolver. The problem I am facing is
that the HttpServeletRequest object present in this class is not the
instance of original HttpServletRequest initiated by client. So, I can
not fetch the query param or path param send by client and append them
to to the authorization URI as extra parameter(e.g. User name).
public class CustomAuthorizationRequestResolver implements OAuth2AuthorizationRequestResolver {
private OAuth2AuthorizationRequestResolver defaultResolver;
public CustomAuthorizationRequestResolver(ClientRegistrationRepository repo, String authorizationRequestBaseUri) {
defaultResolver = new DefaultOAuth2AuthorizationRequestResolver(repo, authorizationRequestBaseUri);
}
#Override
public OAuth2AuthorizationRequest resolve(HttpServletRequest request) {
defaultResolver.resolve(request);
OAuth2AuthorizationRequest req = defaultResolver.resolve(request);
if (req != null) {
req = customizeAuthorizationRequest(req, request);
}
return req;
}
#Override
public OAuth2AuthorizationRequest resolve(HttpServletRequest request, String clientRegistrationId) {
OAuth2AuthorizationRequest req = defaultResolver.resolve(request, clientRegistrationId);
if (req != null) {
req = customizeAuthorizationRequest(req, request);
}
return req;
}
private OAuth2AuthorizationRequest customizeAuthorizationRequest(OAuth2AuthorizationRequest req,
HttpServletRequest request) {
Map<String, Object> extraParams = new HashMap<String, Object>();
extraParams.putAll(req.getAdditionalParameters());
String userName = request.getParameter("userName");
extraParams.put("login_hint", userName);
return OAuth2AuthorizationRequest.from(req).additionalParameters(extraParams).build();
}
}
Any help would be appreciated.