Английская Википедия:Automatic Certificate Management Environment
The Automatic Certificate Management Environment (ACME) protocol is a communications protocol for automating interactions between certificate authorities and their users' servers, allowing the automated deployment of public key infrastructure at very low cost.[1][2] It was designed by the Internet Security Research Group (ISRG) for their Let's Encrypt service.[1]
The protocol, based on passing JSON-formatted messages over HTTPS,[2][3] has been published as an Internet Standard in Шаблон:IETF RFC[4] by its own chartered IETF working group.[5]
Client implementations
The ISRG provides free and open-source reference implementations for ACME: certbot is a Python-based implementation of server certificate management software using the ACME protocol,[6][7][8] and boulder is a certificate authority implementation, written in Go.[9]
Since 2015 a large variety of client options have appeared for all operating systems.[10]
API versions
API version 1
API v1 specification was published on April 12, 2016. It supports issuing certificates for fully-qualified domain names, such as example.com or cluster.example.com, but not wildcards like *.example.com. Let's Encrypt turned off API v1 support on 1 June 2021.[11]
API version 2
API v2 was released March 13, 2018 after being pushed back several times. ACME v2 is not backwards compatible with v1. Version 2 supports wildcard domains, such as *.example.com, allowing for many subdomains to have trusted TLS, e.g. https://cluster01.example.com, https://cluster02.example.com, https://example.com, on private networks under a single domain using a single shared "wildcard" certificate.[12] A major new requirement in v2 is that requests for wildcard certificates require the modification of a Domain Name Service TXT record, verifying control over the domain.
Changes to ACME v2 protocol since v1 include:[13]
- The authorization/issuance flow has changed.
- JWS request authorization has changed.
- The "resource" field of JWS request bodies is replaced by a new JWS header: "url".
- Directory endpoint/resource renaming.
- URI → URL renaming in challenge resources.
- Account creation and ToS agreement are combined into one step. Previously, these were two steps.
- A new challenge type was implemented, TLS-ALPN-01. Two earlier challenge types, TLS-SNI-01 and TLS-SNI-02, were removed because of security issues.[14][15]
See also
- Simple Certificate Enrollment Protocol, a previous attempt at an automated certificate deployment protocol.
References
External links
- Шаблон:Cite web
- List of ACME clients at Let's Encrypt
- List of commonly used ACME clients via acmeclients.com
