  Automated verification of security protocols based on dynamic root of trust,
typically relying on protected hardware such as TPM, involves several
challenges that we address in this paper. We model the semantics of trusted
computing platforms (including CPU, TPM, OS, and other essential components)
and of associated protocols in a classical process calculus accepted by
ProVerif. As part of the formalization effort, we introduce new equational
theories for representing TPM specific platform states and dynamically loaded
programs. Formal models for such an extensive set of features cannot be readily
handled by ProVerif, due especially to the search space generated by unbounded
extensions of TPM registers. In this context we introduce a transformation of
the TPM process, that simplifies the structure of the search space for
automated verification, while preserving the security properties of interest.
This allows to run ProVerif on our proposed models, so we can derive
automatically security guarantees for protocols running in a dynamic root of
trust context.
