A high-level implementation of ClienHelloOverride from patched rustls, as well as JA3/JA4 support.

• Allow modifying ClientHello fingerprints of all TLS requests initiated by rustls.
• Import fingerprint from a JA3-full string and check its JA3/JA4 fingerprints.
• Utilities for creating some extensions easily, e.g. grease ECH.

We use the forked version of rustls with necessary modifications. Every rustls version has a corresponding branch in the forked repository. See the next section for more details.

• rustls@0.23.12: 'v0.23.12'

Because this crate relies on the patched rustls, it's impossible to directly use it from crates.io. Instead, you need to use it by adding the following to your Cargo.toml:

ja-tools = { git = "https://github.com/XOR-op/ja-tools.git", branch = "main" }

and add the following to your root Cargo.toml of the workspace (if you have only one Cargo.toml file, add there):

[patch.crates-io]
rustls = { git = "https://github.com/XOR-op/rustls.delta.git", branch = "v0.23.12" }

Adding these will resolve all the same version rustls in the direct or indirect dependencies to the patched crate. If a different version of rustls is used by one dependency, this crate will not work on that particular dependency.

This project is licensed under the MIT License.