Verified X.509 Certificate Validation

This is the main repo of Verdict, a formally verified X.509 certificate validator. For all evaluations, see https://github.com/secure-foundations/verdict-bench.

Dependencies

Build dependencies in Ubuntu 24.04 (other systems are similar):

• Cargo
• build-essential, git, unzip, curl

Usage

Verify and Build

To build, first run (Bash or Zsh)

. tools/activate.sh

This will first compile a vendored version of Verus and add relevant binaries to PATH.

To verify and build the entire project, run

cargo verus build --release

Then use target/release/verdict to validate certificate chains or run benchmarks. See target/release/verdict --help for details.

By default, we only use verified crypto primitives from libcrux and aws-lc-rs. To use primitives entirely from aws-lc-rs which might have better performance but include unverified signature checking for RSA and ECDSA P-256, compile with

cargo verus build --release --features aws-lc

To run some sanity checks

cargo test --workspace

Build without verification

If your system does not support Verus, or for some reason Verus is not working, an alternative is to just build the project without invoking Verus for formal verification.

To do this, simply run (without running . tools/activate.sh)

git submodule update --init
cargo build --release

which should work like in a normal Rust package, with all verification annotations stripped.

Tracing

Use

cargo verus build [--release] --features trace

to build a version with tracing enabled. This will print out every successfully parsed construct and the result of each predicate in the policy DSL.

Project Structure

If you are considering using Verdict or any of its components, see these crates:

• verdict is the main verified X.509 validation library. It includes implementations of different policies (verdict/src/policy) as well as the policy-independent validation procedure (verdict/src/validator.rs).
• verdict-bin builds an executable front-end of Verdict that can, e.g., validate given certificate chains and run benchmarks against other X.509 validators. This crate is unverified and is used for calling the main validation procedure in verdict.
• verdict-parser contains the verified parsers and serializers of X.509 and various ASN.1 components.

Other crates include supporting tools and macros.