func registerSTSRouter(router *mux.Router) {
	// Initialize STS.
	sts := &stsAPIHandlers{}

	// STS Router
	stsRouter := router.NewRoute().PathPrefix(SlashSeparator).Subrouter()

	// Assume roles with no JWT, handles AssumeRole.
	stsRouter.Methods(http.MethodPost).MatcherFunc(func(r *http.Request, rm *mux.RouteMatch) bool {
		ctypeOk := wildcard.MatchSimple("application/x-www-form-urlencoded*", r.Header.Get(xhttp.ContentType))

#                                                 Permission
#                                                     ------
authentication.admin.users=admin
authentication.admin.roles=admin

role.search.default.permissions=
role.search.default.display.permissions={role}guest
role.search.guest.permissions={role}guest

role.search.user.prefix=1
role.search.group.prefix=2

			version:  "v1",
			resource: "customresourcedefinitions",
		},
		{
			namespace: istioNamespace,
			group:     "rbac.authorization.k8s.io",
			version:   "v1",
			resource:  "roles",
		},
		{
			namespace: istioNamespace,
			version:   "v1",
			resource:  "serviceaccounts",
		},
		{
			namespace: istioNamespace,
			version:   "v1",
			resource:  "services",
		},