return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if origin := w.Header().Get("Access-Control-Allow-Origin"); origin == "null" {
			// This is a workaround change to ensure that "Origin: null"
			// incoming request to a response back as "*" instead of "null"
			w.Header().Set("Access-Control-Allow-Origin", "*")
		}
		if globalDNSConfig == nil || !globalBucketFederation ||