SAML2 Metadata Management
The following CAS endpoints handle the generation of SAML2 metadata:
/idp/metadata/idp/metadata/signingCertificate/idp/metadata/encryptionCertificate
This endpoint will display the CAS IdP SAML2 metadata upon receiving a GET request. If metadata is already available and generated, it will be displayed. If metadata is absent, one will be generated automatically. CAS configuration below dictates where metadata files/keys will be generated and stored.
Note that the endpoint can accept a service parameter either by entity id or numeric identifier. This parameter
is matched against the CAS service registry allowing the endpoint to calculate and combine any identity provider
metadata overrides that may have been specified.
The following settings and properties are available from the CAS configuration catalog:
cas.authn.saml-idp.metadata.core.cache-expirationHow long should metadata be cached.
PT24HHow long should metadata be cached.
cas.authn.saml-idp.metadata.core.cache-maximum-sizeSpecifies the maximum number of entries the cache may contain.
10000Specifies the maximum number of entries the cache may contain. Note that the cache may evict an entry before this limit is exceeded or temporarily exceed the threshold while evicting. As the cache size grows close to the maximum, the cache evicts entries that are less likely to be used again. For example, the cache may evict an entry because it hasn't been used recently or very often.
cas.authn.saml-idp.metadata.core.certificate-algorithmThe algorithm type/name that is used when generating certificates for the SAML2 identity provider.
SHA512withRSAThe algorithm type/name that is used when generating certificates for the SAML2 identity provider. This setting is only relevant when artifacts needs to be generated.
cas.authn.saml-idp.metadata.core.fail-fastWhether invalid metadata should eagerly fail quickly on startup once the resource is parsed.
trueWhether invalid metadata should eagerly fail quickly on startup once the resource is parsed.
cas.authn.saml-idp.metadata.core.key-sizeThis is the key size that is used when generating the initial keypair that would hold the private/public key for the SAML2 metadata.
4096This is the key size that is used when generating the initial keypair that would hold the private/public key for the SAML2 metadata. This setting is only relevant when artifacts needs to be generated.
cas.authn.saml-idp.metadata.core.maximum-retry-attemptsWhen attempting to resolve metadata from sources, particularly URLs, this setting controls the number of retry attempts that CAS should execute when metadata resolution fails.
3When attempting to resolve metadata from sources, particularly URLs, this setting controls the number of retry attempts that CAS should execute when metadata resolution fails. Setting this value to a zero or negative value will disable the retry policy.
cas.authn.saml-idp.metadata.core.require-valid-metadataWhether valid metadata is required.
trueWhether valid metadata is required.
cas.authn.saml-idp.metadata.core.slo-service-post-binding-enabledWhether metadata generation process should support SLO service POST binding.
trueWhether metadata generation process should support SLO service POST binding.
cas.authn.saml-idp.metadata.core.slo-service-redirect-binding-enabledWhether metadata generation process should support SLO service REDIRECT binding.
trueWhether metadata generation process should support SLO service REDIRECT binding.
cas.authn.saml-idp.metadata.core.sso-service-post-binding-enabledWhether metadata generation process should support SSO service POST binding.
trueWhether metadata generation process should support SSO service POST binding.
cas.authn.saml-idp.metadata.core.sso-service-post-simple-sign-binding-enabledWhether metadata generation process should support SSO service POST SimpleSign binding.
trueWhether metadata generation process should support SSO service POST SimpleSign binding.
cas.authn.saml-idp.metadata.core.sso-service-redirect-binding-enabledWhether metadata generation process should support SSO service REDIRECT binding.
trueWhether metadata generation process should support SSO service REDIRECT binding.
cas.authn.saml-idp.metadata.core.sso-service-soap-binding-enabledWhether metadata generation process should support SSO service SOAP binding.
trueWhether metadata generation process should support SSO service SOAP binding.
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.
You may use this service to experiment with the metadata generation process and produce an example metadata for review and study.
Metadata Management
Identity provider metadata can also be managed using the following strategies.
File System
SAML2 identity provider metadata by default is generated on disk. The contents of the generated or found artifacts such as signing and/or encryption keys may be encrypted via CAS configuration security outlined here.
The following settings and properties are available from the CAS configuration catalog:
cas.authn.saml-idp.metadata.file-system.locationDirectory location of SAML metadata and signing/encryption keys.
file:/etc/cas/samlDirectory location of SAML metadata and signing/encryption keys. This directory will be used to hold the configuration files.
cas.authn.saml-idp.metadata.file-system.sign-metadataWhether metadata generated on disk should be digitally signed.
falseWhether metadata generated on disk should be digitally signed. Signing operations use the saml2 identity provider's signing certificate and signing key.
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.
Per Service
Identity provider metadata, certificates and keys can also be defined on a per-service basis to override the global defaults.
Metadata artifacts that would be applicable to a specific service definition and managed via the file system need to be stored
in a directory location named after the service definition’s name and numeric identifier inside the canonical metadata directory. For example,
if global metadata artifacts are managed on disk at /etc/cas/config/saml/metadata, then metadata applicable to a service definition
whose name is configured as SampleService with an id of 1000 are
expected to be found at /etc/cas/config/saml/metadata/SampleService-1000.
Alternatively, a SAML2 service provider can be directly instructed to locate identity provider metadata from a designated location on disk. This can be useful in scenarios where you want to rotate your signing and encryption keys of your SAML2 identity provider metadata and wish to gradually allow service providers to pick up the new metadata:
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{
"@class" : "org.apereo.cas.support.saml.services.SamlRegisteredService",
"serviceId" : "the-entity-id-of-the-sp",
"name" : "SAMLService",
"id" : 1,
"metadataLocation" : "https://url/to/metadata.xml",
"idpMetadataLocation" : "file:/path/to/idp/metadata/directory"
}
Advanced
Service provider or identity provider metadata can also be managed using any one of the following strategies.
| Storage | Description |
|---|---|
| Metadata Query Protocol | See this guide. |
| HTTP/HTTPS | See this guide. |
| REST | See this guide. |
| Git | See this guide. |
| MongoDb | See this guide. |
| Redis | See this guide. |
| JPA | See this guide. |
| Groovy | See this guide. |
| Amazon S3 | See this guide. |
| DynamoDb | See this guide. |
| Google Cloud Storage | See this guide. |
SAML Services
Please see this guide to learn more about how to configure SAML2 service providers.