rustle

Rust crates for building OpenSSL 3.4+ loadable providers — dynamically loaded modules that supply cryptographic algorithm implementations to libcrypto.

The workspace splits the problem in two, so that speaking the provider ABI and implementing cryptography never live in the same crate:

Crate	Role
crates/rustle	Safe abstraction over the provider FFI — contains every unsafe block in the workspace, behind safe APIs
crates/rustle-macros	Host-side method-presence macro for optional provider callbacks
crates/bc-rust-provider	The loadable provider module (cdylib) — #![forbid(unsafe_code)], crypto from bc-rust

Quick start

Needs a Rust toolchain with edition 2024 and OpenSSL 3.4 or newer. Cargo fetches bc-rust automatically from Git.

cargo build -p bc-rust-provider

printf abc | openssl dgst -sha256 -provider-path target/debug -provider libbc_rust

make test

Documentation

The book covers the design, the algorithm tables, and the build invariants:

mdbook serve docs

License

Apache License 2.0, the same terms as OpenSSL itself — see LICENSE.txt.