1# Rustls 2 3[Rustls is a TLS backend written in Rust.](https://docs.rs/rustls/). Curl can 4be built to use it as an alternative to OpenSSL or other TLS backends. We use 5the [rustls-ffi C bindings](https://github.com/rustls/rustls-ffi/). This 6version of curl depends on version v0.7.0 of rustls-ffi. 7 8# Building with rustls 9 10First, [install Rust](https://rustup.rs/). 11 12Next, check out, build, and install the appropriate version of rustls-ffi: 13 14 % cargo install cbindgen 15 % git clone https://github.com/rustls/rustls-ffi -b v0.7.0 16 % cd rustls-ffi 17 % make 18 % make DESTDIR=${HOME}/rustls-ffi-built/ install 19 20Now configure and build curl with rustls: 21 22 % git clone https://github.com/curl/curl 23 % cd curl 24 % ./buildconf 25 % ./configure --with-rustls=${HOME}/rustls-ffi-built 26 % make 27