small-acme: small, pure-Rust ACME client

This is a fork from instant-acme without async or hyper, to provide a slim, rustls based solution.

small-acme is a small, pure-Rust ACME (RFC 8555) client.

small-acme is used in production at my websites to help me provision and renew TLS certificates without any intervention. small-acme relies on ureq and rustls to implement the RFC 8555 specification.

Features

• Store/recover your account credentials by serializing/deserializing
• Simple blocking support (which can be used in tokio)
• Support for processing multiple orders concurrently
• Uses ureq with rustls for HTTP requests
• Uses ring for ECDSA signing
• Minimum supported Rust version: 1.64

Limitations

• Only tested with DNS and HTTP challenges against Let's Encrypt so far (staging and production)
• Only supports ECDSA keys for now

Getting started

See the examples directory for examples of how to use small-acme.