// signatures.
	//
	// Validates all incoming requests to have a valid date header.
	setAuthMiddleware,
	// Redirect some pre-defined browser request paths to a static location
	// prefix.
	setBrowserRedirectMiddleware,
	// Adds 'crossdomain.xml' policy middleware to serve legacy flash clients.
	setCrossDomainPolicyMiddleware,
	// Limits all body and header sizes to a maximum fixed limit
	setRequestLimitMiddleware,

func guessIsBrowserReq(r *http.Request) bool {
	aType := getRequestAuthType(r)
	return strings.Contains(r.Header.Get("User-Agent"), "Mozilla") &&
		globalBrowserEnabled && aType == authTypeAnonymous
}

func setBrowserRedirectMiddleware(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		read := r.Method == http.MethodGet || r.Method == http.MethodHead