Overview
Enable support for the Automatic Certificate Management Environment (ACME) protocol as specified in RFC 8555. ACME is a protocol that a certificate authority (CA) such as Let’s Encrypt and an applicant can use to automate the process of verification and certificate issuance.
Usage
This feature is deprecated and is scheduled to be removed in the future.
Support is enabled by including the following dependency in the overlay:
1
2
3
4
5
<dependency>
<groupId>org.apereo.cas</groupId>
<artifactId>cas-server-support-acme</artifactId>
<version>${cas.version}</version>
</dependency>
1
implementation "org.apereo.cas:cas-server-support-acme:${project.'cas.version'}"
1
2
3
4
5
6
7
8
9
dependencyManagement {
imports {
mavenBom "org.apereo.cas:cas-server-support-bom:${project.'cas.version'}"
}
}
dependencies {
implementation "org.apereo.cas:cas-server-support-acme"
}
1
2
3
4
5
6
7
8
9
10
dependencies {
/*
The following platform references are included automatically and are listed for reference only.
implementation enforcedPlatform("org.apereo.cas:cas-server-support-bom:${project.'cas.version'}")
implementation platform(org.springframework.boot.gradle.plugin.SpringBootPlugin.BOM_COORDINATES)
*/
implementation "org.apereo.cas:cas-server-support-acme"
}
The activation of this module is performed on startup when the CAS server is ready serve http requests. When this module is finished successfully, the domain key pair composed of the key and the certificate (including the full certificate path) will be produced in separate files.
If no account was registered with the CA yet, there will also be a new key as the account key pair.
The CSR file contains the CSR that was used for the certificate order. It is generated for convenience and will not be needed later again. When the certificate is renewed, a new CSR will be generated.
There are two sets of key pairs. One is required for creating and accessing your account and the other is required for encrypting the traffic on your domain(s). It is strongly encouraged to use separate key pairs for account and each of the certificates.
NoteBackup key pairs in a safe place, as you will be locked out from your account if you should ever lose it! There is no way to recover a lost key pair, or regain access to your account when the key is lost.
HTTP Challenge
For the HTTP challenge, CAS server will respond to GET requests at
/.well-known/acme-challenge/{token} path. The request is
always performed against port 80 and at the root of the domain which
means CAS MUST be able to operate at that port and context
path to respond to verification challenges.
Configuration
The following settings and properties are available from the CAS configuration catalog:
cas.acme.domain-chain.locationThe location of the resource.
The location of the resource. Resources can be URLs, or files found either on the classpath or outside somewhere in the file system.
In the event the configured resource is a Groovy script, especially if the script is set to reload on changes, you may need to adjust the total number of inotify instances. On Linux, you may need to add the following line to /etc/sysctl.conf: fs.inotify.max_user_instances = 256.
You can check the current value via cat /proc/sys/fs/inotify/max_user_instances.
In situations and scenarios where CAS is able to automatically watch the underlying resource for changes and detect updates and modifications dynamically, you may be able to specify the following setting as either an environment variable or system property with a value of false to disable the resource watcher: org.apereo.cas.util.io.PathWatcherService.
cas.acme.domain-csr.locationThe location of the resource.
The location of the resource. Resources can be URLs, or files found either on the classpath or outside somewhere in the file system.
In the event the configured resource is a Groovy script, especially if the script is set to reload on changes, you may need to adjust the total number of inotify instances. On Linux, you may need to add the following line to /etc/sysctl.conf: fs.inotify.max_user_instances = 256.
You can check the current value via cat /proc/sys/fs/inotify/max_user_instances.
In situations and scenarios where CAS is able to automatically watch the underlying resource for changes and detect updates and modifications dynamically, you may be able to specify the following setting as either an environment variable or system property with a value of false to disable the resource watcher: org.apereo.cas.util.io.PathWatcherService.
cas.acme.domain-key.locationThe location of the resource.
The location of the resource. Resources can be URLs, or files found either on the classpath or outside somewhere in the file system.
In the event the configured resource is a Groovy script, especially if the script is set to reload on changes, you may need to adjust the total number of inotify instances. On Linux, you may need to add the following line to /etc/sysctl.conf: fs.inotify.max_user_instances = 256.
You can check the current value via cat /proc/sys/fs/inotify/max_user_instances.
In situations and scenarios where CAS is able to automatically watch the underlying resource for changes and detect updates and modifications dynamically, you may be able to specify the following setting as either an environment variable or system property with a value of false to disable the resource watcher: org.apereo.cas.util.io.PathWatcherService.
cas.acme.domainsList of domains or sub domains that are requesting a certificate renewal.
List of domains or sub domains that are requesting a certificate renewal.
cas.acme.server-urlServer url to contact, when requesting certificates.
acme://letsencrypt.org/stagingServer url to contact, when requesting certificates. Use acme://letsencrypt.org for production.
cas.acme.terms-of-use-acceptedFlag that indicates ACME terms of use has been accepted by the user.
falseFlag that indicates ACME terms of use has been accepted by the user.
cas.acme.user-key.locationThe location of the resource.
The location of the resource. Resources can be URLs, or files found either on the classpath or outside somewhere in the file system.
In the event the configured resource is a Groovy script, especially if the script is set to reload on changes, you may need to adjust the total number of inotify instances. On Linux, you may need to add the following line to /etc/sysctl.conf: fs.inotify.max_user_instances = 256.
You can check the current value via cat /proc/sys/fs/inotify/max_user_instances.
In situations and scenarios where CAS is able to automatically watch the underlying resource for changes and detect updates and modifications dynamically, you may be able to specify the following setting as either an environment variable or system property with a value of false to disable the resource watcher: org.apereo.cas.util.io.PathWatcherService.
cas.acme.key-sizeIndicate the key length/size used when requesting/generating keys.
2048Indicate the key length/size used when requesting/generating keys.
cas.acme.retry-attemptsNumber of attempts to retry when executing certificate orders or checking for status of an existing order or challenge acknowledgement.
3Number of attempts to retry when executing certificate orders or checking for status of an existing order or challenge acknowledgement.
cas.acme.retry-internalDelay interval between to retry attempts when executing certificate orders or checking for status of an existing order or challenge acknowledgement.
PT2SDelay interval between to retry attempts when executing certificate orders or checking for status of an existing order or challenge acknowledgement.
Required settings may be needed to activate or affect the feature; review them even when they have a default. Optional settings only need to be set to change a default or to turn on the behavior they control. Third party settings belong to libraries such as Spring Boot that CAS builds on; their own documentation may have more detail.
Notes on configuration
Configuration Metadata
The collection of configuration properties listed in this section are automatically generated from the CAS source and components that contain the actual field definitions, types, descriptions, modules, etc. This metadata may not always be 100% accurate, or could be lacking details and sufficient explanations.
Be Selective
This section is meant as a guide only. Do NOT copy/paste the entire collection of settings into your CAS configuration; rather pick only the properties that you need. Do NOT enable settings unless you are certain of their purpose and do NOT copy settings into your configuration only to keep them as reference. All these ideas lead to upgrade headaches, maintenance nightmares and premature aging.
YAGNI
Note that for nearly ALL use cases, declaring and configuring properties listed here is sufficient. You should NOT have to explicitly massage a CAS XML/Java/etc configuration file to design an authentication handler, create attribute release policies, etc. CAS at runtime will auto-configure all required changes for you. If you are unsure about the meaning of a given CAS setting, do NOT turn it on without hesitation. Review the codebase or better yet, ask questions to clarify the intended behavior.
Naming Convention
Property names can be specified in very relaxed terms. For instance cas.someProperty, cas.some-property, cas.some_property are all valid names. While all
forms are accepted by CAS, there are certain components (in CAS and other frameworks used) whose activation at runtime is conditional on a property value, where
this property is required to have been specified in CAS configuration using kebab case. This is both true for properties that are owned by CAS as well as those
that might be presented to the system via an external library or framework such as Spring Boot, etc.
Note
When possible, properties should be stored in lower-case kebab format, such as cas.property-name=value.
The only possible exception to this rule is when naming actuator endpoints; The name of the
actuator endpoints (i.e. ssoSessions) MUST remain in camelCase mode.
Settings and properties that are controlled by the CAS platform directly always begin with the prefix cas. All other settings are controlled and provided
to CAS via other underlying frameworks and may have their own schemas and syntax. BE CAREFUL with
the distinction. Unrecognized properties are rejected by CAS and/or frameworks upon which CAS depends. This means if you somehow misspell a property definition
or fail to adhere to the dot-notation syntax and such, your setting is entirely refused by CAS and likely the feature it controls will never be activated in the
way you intend.
Validation
Configuration properties are automatically validated on CAS startup to report issues with configuration binding, especially if defined CAS settings cannot be recognized or validated by the configuration schema. Additional validation processes are also handled via Configuration Metadata and property migrations applied automatically on startup by Spring Boot and family.
Indexed Settings
CAS settings able to accept multiple values are typically documented with an index, such as cas.some.setting[0]=value. The index [0] is meant to be
incremented by the adopter to allow for distinct multiple configuration blocks.