Security Configuration
There are several levels of configuration that control the security configuration of objects that are signed, encrypted, etc. These configurations include things like the keys to use, preferred/default algorithms, and algorithms to allow, enforce or reject.
The configurations are generally determined based on the following order:
- Per-service configuration overrides
- Service provider metadata (i.e. entity attributes, etc)
- Global CAS default settings
- OpenSAML initial defaults
In almost all cases, you should leave the defaults in place.
The following settings and properties are available from the CAS configuration catalog:
cas.authn.saml-idp.algs.override-allowed-algorithms=
The Override white listed algorithms.
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cas.authn.saml-idp.algs.override-allowed-signature-signing-algorithms=
The Override allowed signature signing algorithms.
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cas.authn.saml-idp.algs.override-blocked-encryption-algorithms=
The Override black listed encryption algorithms.
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cas.authn.saml-idp.algs.override-blocked-signature-signing-algorithms=
The Override blocked signature signing algorithms.
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cas.authn.saml-idp.algs.override-data-encryption-algorithms=
The Override data encryption algorithms.
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cas.authn.saml-idp.algs.override-key-encryption-algorithms=
The Override key encryption algorithms.
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cas.authn.saml-idp.algs.override-signature-algorithms=
The Override signature algorithms.
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cas.authn.saml-idp.algs.override-signature-canonicalization-algorithm=
The Override signature canonicalization algorithm.
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cas.authn.saml-idp.algs.override-signature-reference-digest-methods=
The Override signature reference digest methods.
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cas.authn.saml-idp.algs.private-key-alg-name=RSA
Algorithm name to use when generating or locating private key for signing operations..
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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.
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, specially 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.
Encryption
The following examples demonstrate encryption security configuration overrides per service provider.
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The following example demonstrates how to configure CAS to use
CBC
encryption for a particular service provider:1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
{ "@class": "org.apereo.cas.support.saml.services.SamlRegisteredService", "serviceId": "sp.example.org", "name": "SAML", "id": 1, "metadataLocation": "/path/to/sp-metadata.xml", "encryptAssertions" : true, "encryptionDataAlgorithms": [ "java.util.ArrayList", [ "http://www.w3.org/2001/04/xmlenc#aes128-cbc" ] ], "encryptionKeyAlgorithms": [ "java.util.ArrayList", [ "http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p" ] ] }
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The following example demonstrates how to configure CAS to use
GCM
encryption for a particular service provider:1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
{ "@class": "org.apereo.cas.support.saml.services.SamlRegisteredService", "serviceId": "sp.example.org", "name": "SAML", "id": 1, "metadataLocation": "/path/to/sp-metadata.xml", "encryptAssertions" : true, "encryptionDataAlgorithms": [ "java.util.ArrayList", [ "http://www.w3.org/2009/xmlenc11#aes128-gcm" ] ], "encryptionKeyAlgorithms": [ "java.util.ArrayList", [ "http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p" ] ] }
Note that encryption operations may also be activated and controlled using SAML2 metadata entity attributes.
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<Extensions>
<mdattr:EntityAttributes>
<saml:Attribute Name="http://shibboleth.net/ns/profiles/encryptAssertions"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">
<saml:AttributeValue>true</saml:AttributeValue>
</saml:Attribute>
</mdattr:EntityAttributes>
</Extensions>
Signing
The following examples demonstrate signing security configuration overrides per service provider.
-
The following example demonstrates how to configure CAS to use
SHA-1
signing and digest algorithms for a particular service provider:1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
{ "@class": "org.apereo.cas.support.saml.services.SamlRegisteredService", "serviceId": "sp.example.org", "name": "SAML", "id": 1, "metadataLocation": "/path/to/sp-metadata.xml", "signAssertions" : true, "signResponses" : true, "signingSignatureAlgorithms": [ "java.util.ArrayList", [ "http://www.w3.org/2000/09/xmldsig#rsa-sha1", "http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha1" ] ], "signingSignatureReferenceDigestMethods": [ "java.util.ArrayList", [ "http://www.w3.org/2000/09/xmldsig#sha1" ] ] }
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The following example demonstrates how to configure CAS to use
SHA-256
signing and digest algorithms for a particular service provider:1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
{ "@class": "org.apereo.cas.support.saml.services.SamlRegisteredService", "serviceId": "sp.example.org", "name": "SAML", "id": 1, "metadataLocation": "/path/to/sp-metadata.xml", "signAssertions" : true, "signResponses" : true, "signingSignatureAlgorithms": [ "java.util.ArrayList", [ "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256", "http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256" ] ], "signingSignatureReferenceDigestMethods": [ "java.util.ArrayList", [ "http://www.w3.org/2001/04/xmlenc#sha256" ] ] }
Note that signing operations may also be activated and controlled using SAML2 metadata entity attributes.
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<Extensions>
<mdattr:EntityAttributes>
<saml:Attribute Name="http://shibboleth.net/ns/profiles/saml2/sso/browser/signResponses"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">
<saml:AttributeValue>true</saml:AttributeValue>
</saml:Attribute>
<saml:Attribute Name="http://shibboleth.net/ns/profiles/saml2/sso/browser/signAssertions"
NameFormat="urn:oasis:names:tc:SAML:2.0:attrname-format:uri">
<saml:AttributeValue>true</saml:AttributeValue>
</saml:Attribute>
</mdattr:EntityAttributes>
</Extensions>
Troubleshooting
To enable additional logging, modify the logging configuration file to add the following:
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<Logger name="org.opensaml" level="debug" additivity="false">
<AppenderRef ref="casConsole"/>
<AppenderRef ref="casFile"/>
</Logger>
<Logger name="PROTOCOL_MESSAGE" level="debug" additivity="false">
<AppenderRef ref="casConsole"/>
<AppenderRef ref="casFile"/>
</Logger>