Cloud computing provides on-demand access to IT resources via the Internet. Permissions for these resources are defined by expressive access control policies. This paper presents a formalization of the Amazon Web Services (AWS) policy language and a corresponding analysis tool, called ZELKOVA, for verifying policy properties. ZELKOVA encodes the semantics of policies into SMT, compares behaviors, and verifies properties. It provides users a sound mechanism to detect misconfigurations of their policies. ZELKOVA solves a PSPACE-complete problem and is invoked many millions of times daily.

No abstract

International audienceHypervisors must isolate memories of guest operating systems. This paper is concerned with proving memory isolation properties about the virtualization of the memory management unit provided by a hypervisor through shadow page tables. We conduct the proofs using abstraction techniques between high-level and low-level descriptions of the system, based on techniques from previous work on formally proving memory isolation in micro-kernels. The present paper shows how a hypervisor developed by Technische Universität Berlin has been formalized and presents the isolation properties we have proved on the targeted abstract model. In particular, we provide details about how the management of page tables has been formally modeled

No abstract

No abstract