ACME
MTG Certificate Lifecycle Manager Server includes an implementation of the ACME protocol according to RFC 8555 [RFC8555].
Usage
ACME can be used by all clients that are compliant to the RFC 8555 [RFC8555] protocol. For using the ACME service, an ACME client needs the URL of the ACME directory endpoint, where it can obtain all ACME endpoints specified by the RFC. The URL follows the following pattern:
https://[ACME_URL_PREFIX]/[API_VERSION]/directory
- ACME_URL_PREFIX
-
This part specifies the location of the application. It consists of the domain the ACME server is hosted and a URL prefix which offsets the root of the server application. For example, the URL prefix could be "example.com/acme".
- API_VERSION
-
The API version the ACME endpoint has to use. Since currently only the latest version 2 is supported, the value of API_VERSION has to be "v2".
Listing 1 shows a certificate application using the Certbot [certbot] ACME client. The first command shows the creation of an ACME account which authenticates the subsequent communication with the ACME server and the second command executes the actual certificate application for the example domain mydomain.example.com.
certbot --server https://example.com/acme/v2/directory register \
--no-eff-email -m test@example.com --agree-tos
certbot --server https://example.com/acme/v2/directory certonly \
-d mydomain.example.com --standalone
Endpoints for other policies
By default, the ACME server provides the following endpoint:
https://[ACME_URL_PREFIX]/[API_VERSION]/directory
Client requests to this endpoint use the default policy.
The ACME server provides additional endpoints to support requests that require a different policy. Requests to these endpoints specify a different policy, instead of the default policy of the associated API client. These are the endpoints for the different policy endpoints:
https://[ACME_URL_PREFIX]/[API_VERSION]/[POLICY_ID]/directory
The POLICY_ID
must be replaced with a valid policy ID.
For example, to create a certificate under the policy
2ef92632-aaff-4d13-b3cb-6b27f2dac399
, use the following URL:
https://[ACME_URL_PREFIX]/[API_VERSION]/2ef92632-aaff-4d13-b3cb-6b27f2dac399/directory
.