# boring
[](https://crates.io/crates/boring)
BoringSSL bindings for the Rust programming language and TLS adapters for [tokio](https://github.com/tokio-rs/tokio)
and [hyper](https://github.com/hyperium/hyper) built on top of it.
[Documentation](https://docs.rs/boring).
## Release Support
By default, the crate statically links with the latest BoringSSL master branch.
## Support for pre-built binaries
While this crate can build BoringSSL on its own, you may want to provide pre-built binaries instead.
To do so, specify the environment variable `BORING_BSSL_PATH` with the path to the binaries.
You can also provide specific headers by setting `BORING_BSSL_INCLUDE_PATH`.
_Notes_: The crate will look for headers in the `$BORING_BSSL_INCLUDE_PATH/openssl/` folder, make sure to place your headers there.
_Warning_: When providing a different version of BoringSSL make sure to use a compatible one, the crate relies on the presence of certain functions.
## Building with a FIPS-validated module
Only BoringCrypto module version ae223d6138807a13006342edfeef32e813246b39, as
certified with [certificate
3678](https://csrc.nist.gov/projects/cryptographic-module-validation-program/certificate/3678)
is supported by this crate. Support is enabled by this crate's `fips` feature.
`boring-sys` comes with a test that FIPS is enabled/disabled depending on the feature flag. You can run it as follows:
```bash
$ cargo test --features fips fips::is_enabled
```
## Contribution
Unless you explicitly state otherwise, any contribution intentionally
submitted for inclusion in the work by you, as defined in the Apache-2.0
license, shall be dual licensed under the terms of both the Apache License,
Version 2.0 and the MIT license without any additional terms or conditions.
## Accolades
The project is based on a fork of [rust-openssl](https://github.com/sfackler/rust-openssl).