Biblio

The area of secure compilation aims to design compilers which produce hardened code that can withstand attacks from low-level co-linked components. So far, there is no formal correctness criterion for secure compilers that comes with a clear understanding of what security properties the criterion actually provides. Ideally, we would like a criterion that, if fulfilled by a compiler, guarantees that large classes of security properties of source language programs continue to hold in the compiled program, even as the compiled program is run against adversaries with low-level attack capabilities. This paper provides such a novel correctness criterion for secure compilers, called trace-preserving compilation (TPC). We show that TPC preserves a large class of security properties, namely all safety hyperproperties. Further, we show that TPC preserves more properties than full abstraction, the de-facto criterion used for secure compilation. Then, we show that several fully abstract compilers described in literature satisfy an additional, common property, which implies that they also satisfy TPC. As an illustration, we prove that a fully abstract compiler from a typed source language to an untyped target language satisfies TPC.

Interface-confinement is a common mechanism that secures untrusted code by executing it inside a sandbox. The sandbox limits (confines) the code's interaction with key system resources to a restricted set of interfaces. This practice is seen in web browsers, hypervisors, and other security-critical systems. Motivated by these systems, we present a program logic, called System M, for modeling and proving safety properties of systems that execute adversary-supplied code via interface-confinement. In addition to using computation types to specify effects of computations, System M includes a novel invariant type to specify the properties of interface-confined code. The interpretation of invariant type includes terms whose effects satisfy an invariant. We construct a step-indexed model built over traces and prove the soundness of System M relative to the model. System M is the first program logic that allows proofs of safety for programs that execute adversary-supplied code without forcing the adversarial code to be available for deep static analysis. System M can be used to model and verify protocols as well as system designs. We demonstrate the reasoning principles of System M by verifying the state integrity property of the design of Memoir, a previously proposed trusted computing system.