Spring Security authentication/authorization via REST endpoint

In my Spring Boot application with RESTful webservices I have configured Spring Security together with Spring Social and SpringSocialConfigurer.

Right now I have two ways of authentication/authorization - via username/password and via social networks for example like Twitter.

In order to implement authentication/authorization via my own RESTful endpoint in my Spring MVC REST controller I have added following method:

@RequestMapping(value = "/login", method = RequestMethod.POST)
public Authentication login(@RequestBody LoginUserRequest userRequest) {
    Authentication authentication = authenticationManager.authenticate(new UsernamePasswordAuthenticationToken(userRequest.getUsername(), userRequest.getPassword()));
    boolean isAuthenticated = isAuthenticated(authentication);
    if (isAuthenticated) {
        SecurityContextHolder.getContext().setAuthentication(authentication);
    }
    return authentication;
}

private boolean isAuthenticated(Authentication authentication) {
    return authentication != null && !(authentication instanceof AnonymousAuthenticationToken) && authentication.isAuthenticated();
}

but I'm not sure what exactly must be returned to client after successfull /login endpoint call. I think returning of full authentication object is redundant.

What should be returned to client in case of successfull authentication ?

Could you please tell me how to correctly implement this login method ?

Also, in case of RESTfull login I'll have UsernamePasswordAuthenticationToken and in case of login through Twitter I'll have SocialAuthenticationToken Is it okay to have different tokens in a same application ?

You can configure what to return on successful authentication by overriding methods in SimpleUrlAuthenticationSuccessHandler

public class CustomAuthenticationSuccessHandler extends SimpleUrlAuthenticationSuccessHandler {

    public CustomAuthenticationSuccessHandler() {
        super();
        setRedirectStrategy(new NoRedirectStrategy());
    }

    @Override
    public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response,
            Authentication authentication) throws IOException, ServletException {

        super.onAuthenticationSuccess(request, response, authentication);
        ObjectMapper mapper = new ObjectMapper();

        response.setContentType("application/json;charset=UTF-8");
        response.getWriter().print(mapper.writeValueAsString(objectToBereturned);
        response.getWriter().flush();
    }

    protected class NoRedirectStrategy implements RedirectStrategy {

        @Override
        public void sendRedirect(HttpServletRequest request, HttpServletResponse response, String url)
                throws IOException {
            // any redirect if required. leave the implementation black if not needed
        }

    }
}

Additionally you can also handle the failure response:

public class CustomAuthenticationFailureHandler extends SimpleUrlAuthenticationFailureHandler {
    @Override
    public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response,
            AuthenticationException exception) throws IOException, ServletException {
        response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
    }
}