4 releases (2 breaking)

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0.1.1 Aug 2, 2023
0.1.0 Jul 26, 2023
0.0.0 Mar 31, 2023

#1347 in Network programming

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10K SLoC


A code ACL checker for Rust.

Cackle is a tool to analyse the transitive dependencies of your crate to see what kinds of APIs each crate uses.

The idea is look for crates that are using APIs that you don't think they should be using. For example a crate that from its description should just be doing some data processing, but is actually using network APIs.


Currently Cackle only works on Linux. See PORTING.md for more details.

cargo install --locked cackle

Or if you'd like to install from git:

cargo install --locked --git https://github.com/cackle-rs/cackle.git cackle

Installing bubblewrap is recommended as it allows build scripts (build.rs) and tests to be run inside a sandbox.

On systems with apt, this can be done by running:

sudo apt install bubblewrap


From the root of your project (the directory containing Cargo.toml), run:

cackle ui

This will interactively guide you through creating an initial cackle.toml. Some manual editing of your cackle.toml is recommended. In particular, you should look through your dependency tree and think about which crates export APIs that you'd like to restrict. e.g. if you're using a crate that provides network APIs, you should declare this in your config. See CONFIG.md for more details.

Configuration file format

See CONFIG.md.

Limitations and precautions

  • A proc macro might detect that it's being run under Cackle and emit different code.
  • Even without proc macros, a crate may only use problematic APIs only in certain configurations that don't match the configuration used when you run Cackle.
  • Analyzing a crate could well end up executing arbitrary code provided by that crate. If this is a concern, then running in a sandbox is recommended.
  • This tool is intended to supplement and aid manual review of 3rd party code, not replace it.
  • Your configuration might miss defining an API provided by a crate as falling into a certain category that you care about.
  • There are undoubtedly countless ways that a determined person could circumvent detection that they're using some APIs. With time we may try to prevent such circumventions, but for now, you should definitely assume that circumvention is possible.

With all these limitations, what's the point? The goal really is to just raise the bar for what's required to sneak problematic code unnoticed into some package. Use of Cackle should not replace any manual code reviews of your dependencies that you would otherwise have done.

How it works





Contributions are very welcome. If you'd like to get involved, please reach out either by filing an issue or emailing David Lattimore (email address is in the commit log).


This software is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE for details.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.


~286K SLoC