Vale (Verified Assembly Language for Everest)

Vale is a tool for constructing formally verified high-performance assembly language code, with an emphasis on cryptographic code. It uses existing verification frameworks, such as Dafny and F*, for formal verification. It supports multiple architectures, such as x86, x64, and ARM, and multiple platforms, such as Windows, Mac, and Linux. Additional architectures and platforms can be supported with no changes to the Vale tool.

Vale is part of the Everest project, which aims to build and deploy a verified HTTPS stack.

Installation

See the INSTALL file for installing Vale and its dependencies.

Code Organization

See the CODE file for more details on the various files in the repository.

Documentation

See the Vale documentation for a description of the Vale language and Vale tool.

You can also see our academic papers describing Vale:

• Vale: Verifying High-Performance Cryptographic Assembly Code
  Barry Bond, Chris Hawblitzel, Manos Kapritsos, K. Rustan M. Leino, Jacob R. Lorch, Bryan Parno, Ashay Rane, Srinath Setty, Laure Thompson. In Proceedings of the USENIX Security Symposium, 2017. Distinguished Paper Award.
• A Verified, Efficient Embedding of a Verifiable Assembly Language
  Aymeric Fromherz, Nick Giannarakis, Chris Hawblitzel, Bryan Parno, Aseem Rastogi, Nikhil Swamy. In Proceedings of the Symposium on Principles of Programming Languages (POPL), 2019.
• Verified Transformations and Hoare Logic: Beautiful Proofs for Ugly Assembly Language
  Jay Bosamiya, Sydney Gibson, Yao Li, Bryan Parno, Chris Hawblitzel. In Proceedings of the Conference on Verified Software: Theories, Tools, and Experiments (VSTTE) 2020.

Projects using Vale

For cryptography implementations verified with Vale/F*, see HACL*.
For cryptography implementations verified with Vale/Dafny, see the Dafny legacy branch.
For the Komodo secure enclave reference monitor, see here and here.
For developing verified low-level cryptography on heterogeneous hardware, see the Galápagos project repository.

License

Vale is licensed under the Apache license in the LICENSE file.

Version History

• v0.1: Initial code release, containing code written by: Andrew Baumann, Barry Bond, Andrew Ferraiuolo, Chris Hawblitzel, Jon Howell, Manos Kapritsos, K. Rustan M. Leino, Jacob R. Lorch, Bryan Parno, Ashay Rane, Srinath Setty, and Laure Thompson.