PoliSeer: A Tool for Managing Complex Security Policies

Abstract

Complex software-security policies are difficult to specify, understand, and update. The same is true for complex software in general, but while many tools and techniques exist for decomposing complex general software into simpler reusable modules (packages, classes, functions, aspects, etc.), few tools exist for decomposing complex security policies into simpler reusable modules. The tools that do exist for modularizing policies either encapsulate entire policies as atomic modules that cannot be decomposed or allow fine-grained policy modularization but require expertise to use correctly. This paper presents PoliSeer, a GUI-based tool designed to enable users who are not expert policy engineers to flexibly specify, visualize, modify, and enforce complex runtime policies on untrusted software. PoliSeer users rely on expert policy engineers to specify universally composable policy modules; PoliSeer users then build complex policies by composing those expert-written modules. This paper describes the design and implementation of PoliSeer and a case study in which we have used PoliSeer to specify and enforce a policy on PoliSeer itself.