WORKERS AHEAD!
You are viewing the development documentation for the Apereo CAS server. The functionality presented here is not officially released yet. This is a work in progress and will be continually updated as development moves forward. You are most encouraged to test the changes presented.
Apache Tomcat - Embedded Servlet Container SSL Valve
The Apache Tomcat SSLValve
is a way to get a client certificate from an SSL proxy (e.g. HAProxy or BigIP F5)
running in front of Tomcat via an HTTP header. If you enable this, make sure your proxy is ensuring
that this header does not originate with the client (e.g. the browser).
The following settings and properties are available from the CAS configuration catalog:
cas.server.tomcat.ssl-valve.enabled=false
Enable the SSL valve for apache tomcat.
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cas.server.tomcat.ssl-valve.ssl-cipher-header=ssl_cipher
Allows setting a custom name for the ssl_cipher header. If not specified, the default of ssl_cipher is used.
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cas.server.tomcat.ssl-valve.ssl-cipher-user-key-size-header=ssl_cipher_usekeysize
Allows setting a custom name for the ssl_cipher_usekeysize header. If not specified, the default of ssl_cipher_usekeysize is used.
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cas.server.tomcat.ssl-valve.ssl-client-cert-header=ssl_client_cert
Allows setting a custom name for the ssl_client_cert header. If not specified, the default of ssl_client_cert is used.
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cas.server.tomcat.ssl-valve.ssl-session-id-header=ssl_session_id
Allows setting a custom name for the ssl_session_id header. If not specified, the default of ssl_session_id is used.
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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.
Example HAProxy Configuration (snippet): Configure SSL frontend with cert optional, redirect to cas, if cert provided, put it on header.
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frontend web-vip
bind 192.168.2.10:443 ssl crt /var/lib/haproxy/certs/www.example.com.pem ca-file /var/lib/haproxy/certs/ca.pem verify optional
mode http
acl www-cert ssl_fc_sni if { www.example.com }
acl empty-path path /
http-request redirect location /cas/ if empty-path www-cert
http-request del-header ssl_client_cert unless { ssl_fc_has_crt }
http-request set-header ssl_client_cert -----BEGIN\ CERTIFICATE-----\ %[ssl_c_der,base64]\ -----END\ CERTIFICATE-----\ if { ssl_fc_has_crt }
acl cas-path path_beg -i /cas
reqadd X-Forwarded-Proto:\ https
use_backend cas-pool if cas-path
backend cas-pool
option httpclose
option forwardfor
cookie SERVERID-cas insert indirect nocache
server cas-1 192.168.2.10:8080 check cookie cas-1