DigestAuthenticationEntryPoint::start()

Returns a response that directs the user to authenticate.

This is called when an anonymous request accesses a resource that requires authentication. The job of this method is to return some response that "helps" the user start into the authentication process.

Examples: A) For a form login, you might redirect to the login page return new Response('/login'); B) For an API token authentication system, you return a 401 response return new Response('Auth header required', 401);