A low-level binding crate for Rust that moves in lockstop with BoringSSL. BoringSSL explicitly does not have a stable ABI, bssl-sys is the solution for preventing subtle-memory corruption bugs due to version skew.
bssl-sys uses bindgen as part of the cmake build process to generate Rust compatibility shims for the targeted platform. It is important to generate it for the correct platform because bindgen uses LLVM information for alignment which varies depending on architecture.
Build boringssl with -DRUST_BINDINGS=<rust-triple> and ensure that you have bindgen installed. The rust-triple option should match the Rust target triple when building bssl-sys.
From there, the bssl-sys crate can be built. By default, it looks for bindgen output and BoringSSL static libraries in the build directory. This can be reconfigured with BORINGSSL_BUILD_DIR environment variable. Note the environment variable is evaluated relative to rust/bssl-sys/src, so using an absolute path may be more convenient.