Formal Verification of a Modern Boot Loader

We introduce the Syracuse Assured Boot Loader Executive (SABLE), a trustworthy secure loader. A trusted boot loader performs a cryptographic measurement (hash) of program code and executes it unconditionally, allowing later-stage software to verify the integrity of the system through local or remote attestation. A secure loader differs from a trusted loader in that it executes subsequent code only if measurements of that code match known-good values. We have applied a rigorous formal verification technique recently demonstrated in practice by NICTA in their verification of the seL4 microkernel. We summarize our design philosophy from a high level and present our formal verification strategy