ACME Java Client

This is a Java client for the Automatic Certificate Management Environment (ACME) protocol as specified in RFC 8555.

ACME is a protocol that a certificate authority (CA) and an applicant can use to automate the process of verification and certificate issuance.

This Java client helps connecting to an ACME server, and performing all necessary steps to manage certificates.

It is an independent open source implementation that is not affiliated with or endorsed by Let's Encrypt.

Note: Make sure to use acme4j 2.5 or higher, before November 1st 2019. Due to a change in the ACME protocol, acme4j < 2.5 will fail to connect to servers after that date. acme4j v1 is not affected. See here for details.

Features

• Fully RFC 8555 compliant
• Supports the http-01, dns-01 and tls-alpn-01 challenges
• Supports the acme-ip draft
• Supports the acme-star draft for short-term automatic certificate renewal (experimental)
• Easy to use Java API
• Requires JRE 8 (update 101) or higher
• Built with maven, packages available at Maven Central
• Small, only requires jose4j and slf4j as dependencies
• Extensive unit and integration tests

Usage

• See the online documentation about how to use acme4j.
• For a quick start, have a look at the source code of an example.
• The previous ACME v1 protocol is still supported by acme4j version 1.

Contribute

• Fork the Source code at GitHub. Feel free to send pull requests.
• Found a bug? File a bug report!

License

acme4j is open source software. The source code is distributed under the terms of Apache License 2.0.

Acknowledgements

• I would like to thank Brian Campbell and all the other jose4j developers. acme4j would not exist without your excellent work.
• Thanks to Daniel McCarney for his help with the ACME protocol, Pebble, and Boulder.
• Ulrich Krause for his help to make acme4j run on IBM Java VMs.
• I also like to thank everyone who contributed to acme4j.