Abstract We present PyCaliper : a Python-embedded framework to formulate, verify, and auto-synthesize specifications for hardware designs at the register transfer level (RTL). By being Python-embedded, PyCaliper is easy to use and benefits from object-oriented principles and Python’s rich ecosystem. Further, PyCaliper is a common platform that integrates novel research techniques such as specification synthesis and mature, industry-scale tooling, thus allowing them to benefit from each other. We discuss the system and implementation of PyCaliper and demonstrate its use in two case studies: in the first we compare a custom verification backend with a commercial tool and gain insights about the former, and in the second we demonstrate invariant synthesis for an RTL design.

Abstract We have completed machine-assisted proofs of two highly-optimized cryptographic primitives, AES-256-GCM and SHA-384. We have verified that the implementations of these primitives, written in a mix of C and x86 assembly, are memory safe and functionally correct, by which we mean input-output equivalent to their algorithmic specifications. Our proofs were completed using SAW, a bounded cryptographic verification tool which we have extended to handle embedded x86. The code we have verified comes from AWS LibCrypto. This code is identical to BoringSSL and very similar to OpenSSL, from which it ultimately derives. We believe we are the first to formally verify these implementations, which protect the security of nearly everybody on the internet.

We present techniques for reasoning about constructor classes that (like the monad class) fix polymorphic operations and assert polymorphic axioms. We do not require a logic with first-class type constructors, first-class polymorphism, or type quantification; instead, we rely on a domain-theoretic model of the type system in a universal domain to provide these features. These ideas are implemented in the Tycon library for the Isabelle theorem prover, which builds on the HOLCF library of domain theory. The Tycon library provides various axiomatic type constructor classes, including functors and monads. It also provides automation for instantiating those classes, and for defining further subclasses.