#certificate-transparency #certificate-validation #signed-certificate-timestamp #ct #client-certificate #logging #sct #gossiping #log-parser #ct-logging

ctclient-async

Certificate Transparency Log client suitable for monitoring, quick SCT validation, gossiping, etc

3 releases

Uses new Rust 2024

0.5.2 Oct 10, 2025
0.5.1 Oct 9, 2025
0.5.0 Oct 6, 2025

#3 in #ct

MIT license

5MB
2.5K SLoC

🔒 Certificate Transparency Log client library

live stream domain video demo

Crates.io Crates.io doc link

Certificate Transparency Log client suitable for monitoring, quick SCT validation, gossiping, etc.

Build requirement

OpenSSL >= 1.1.0

Features

TODOs

  • Implement gossiping protocols
  • A helper to monitor multiple logs simultaneously
  • Certificate submission
  • More test coverage

Examples & DEMOs

Note that you can run those by cargo run --example name

  • examples/parse_sct_list_from_cert.rs: Parse a certificate with a "CT Precertificate SCTs" extension and print out the SCTs. Also check that the logs can provide an inclusion proof for those leafs based on the latest tree head.

    screenshot

  • examples/live_stream_domains.rs: Read out certificates as they are published by a log and print out the CA and domain names.

    DEMO at the top of this README.

  • examples/simple_client/simple_client.rs: A simple SQLite-backed CT log client monitoring a single log.

    • Check that the tree is consistent (extend-only) each time a new tree head is received.
    • Download and inspect all certificates searching for a hard-coded domain name.
    • Store tree heads and matched certificates in SQLite database.
    • Intended to be a base on which more sophisticated clients can be built.

    screenshot

Dependencies

~6–22MB
~256K SLoC