Central Authentication Server

Prerequisties :

Java (JDK) is installed

Apache Tomcat is installed and running with SSL enabled.

ApacheDS is installed

Download CAS server in /tmp folder and unzip.

$ wget -O cas-server-4.0.0.zip http://github.com/Jasig/cas/releases/download/v4.0.0/cas-server-4.0.0-release.zip

Stop the Tomcat server.
$ sudo /opt/apache-tomcat/bin/shutdown.sh

Copy CAS war file to $TOMCAT_HOME/webapps

$ sudo cp /tmp/cas-server-4.0.0/modules/cas-server-webapp-4.0.0.war /opt/apache-tomcat/webapps

Start the Tomcat Server.
$ sudo /opt/apache-tomcat/bin/startup.sh

It will extract the war file  into cas-server-webapp-4.0.0 directory.

Stop the Tomcat server.
$ sudo /opt/apache-tomcat/bin/shutdown.sh

Add cas-server-support-ldap and ldaptive dependencies to /opt/apache-tomcat/webapps/cas-server-webapp-4.0.0/META-INF/maven/org.jasig.cas/cas-server-webapp/pom.xml

      <dependency>
            <groupId>org.jasig.cas</groupId>
            <artifactId>cas-server-support-ldap</artifactId>
            <version>${cas.version}</version>
       </dependency>

       <dependency>
             <groupId>org.ldaptive</groupId>
             <artifactId>ldaptive</artifactId>
             <version>1.1.0</version>
       </dependency>

Copy cas-server-support-ldap-4.0.0.jar and ldaptive-1.1.0.jar to $TOMCAT_HOME\webapps\cas-server-webapp-4.0.0\WEB-INF\lib

$ sudo cp /tmp/cas-server-4.0.0/modules/cas-server-support-ldap-4.0.0.jar /opt/apache-tomcat/webapps/cas-server-webapp-4.0.0/WEB-INF/lib

$ wget http://central.maven.org/maven2/org/ldaptive/ldaptive/1.1.0/ldaptive-1.1.0.jar
$ sudo cp /tmp/ldaptive-1.1.0.jar /opt/apache-tomcat/webapps/cas-server-webapp-4.0.0/WEB-INF/lib

Modify $TOMCAT_HOME\webapps\cas-server-webapp-4.0.0\WEB-INF\deployerConfigContext.xml as follows:

<?xml version="1.0" encoding="UTF-8"?>
<!--

    Licensed to Jasig under one or more contributor license
    agreements. See the NOTICE file distributed with this work
    for additional information regarding copyright ownership.
    Jasig licenses this file to you under the Apache License,
    Version 2.0 (the "License"); you may not use this file
    except in compliance with the License.  You may obtain a
    copy of the License at the following location:

      http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing,
    software distributed under the License is distributed on an
    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    KIND, either express or implied.  See the License for the
    specific language governing permissions and limitations
    under the License.

-->
<!--
| deployerConfigContext.xml centralizes into one file some of the declarative configuration that
| all CAS deployers will need to modify.
|
| This file declares some of the Spring-managed JavaBeans that make up a CAS deployment.
| The beans declared in this file are instantiated at context initialization time by the Spring
| ContextLoaderListener declared in web.xml.  It finds this file because this
| file is among those declared in the context parameter "contextConfigLocation".
|
| By far the most common change you will need to make in this file is to change the last bean
| declaration to replace the default authentication handler with
| one implementing your approach for authenticating usernames and passwords.
+-->

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:c="http://www.springframework.org/schema/c"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:util="http://www.springframework.org/schema/util"
       xmlns:sec="http://www.springframework.org/schema/security"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
       http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.2.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">

    <!--
       | The authentication manager defines security policy for authentication by specifying at a minimum
       | the authentication handlers that will be used to authenticate credential. While the AuthenticationManager
       | interface supports plugging in another implementation, the default PolicyBasedAuthenticationManager should
       | be sufficient in most cases.
       +-->
    <bean id="authenticationManager" class="org.jasig.cas.authentication.PolicyBasedAuthenticationManager">
        <constructor-arg>
            <map>
                <!--
                   | IMPORTANT
                   | Every handler requires a unique name.
                   | If more than one instance of the same handler class is configured, you must explicitly
                   | set its name to something other than its default name (typically the simple class name).
                   -->
               <!--
                <entry key-ref="proxyAuthenticationHandler" value-ref="proxyPrincipalResolver" />
                <entry key-ref="primaryAuthenticationHandler" value-ref="primaryPrincipalResolver" />
               -->
                <entry key-ref="ldapAuthenticationHandler" value-ref="primaryPrincipalResolver" />
            </map>
        </constructor-arg>

        <!-- Uncomment the metadata populator to allow clearpass to capture and cache the password
             This switch effectively will turn on clearpass.
        <property name="authenticationMetaDataPopulators">
           <util:list>
              <bean class="org.jasig.cas.extension.clearpass.CacheCredentialsMetaDataPopulator"
                    c:credentialCache-ref="encryptedMap" />
           </util:list>
        </property>
        -->

        <!--
           | Defines the security policy around authentication. Some alternative policies that ship with CAS:
           |
           | * NotPreventedAuthenticationPolicy - all credential must either pass or fail authentication
           | * AllAuthenticationPolicy - all presented credential must be authenticated successfully
           | * RequiredHandlerAuthenticationPolicy - specifies a handler that must authenticate its credential to pass
           -->
        <property name="authenticationPolicy">
            <bean class="org.jasig.cas.authentication.AnyAuthenticationPolicy" />
        </property>
    </bean>

    <!-- Required for proxy ticket mechanism. -->
    <bean id="proxyAuthenticationHandler"
          class="org.jasig.cas.authentication.handler.support.HttpBasedServiceCredentialsAuthenticationHandler"
          p:httpClient-ref="httpClient" />

    <!--
       | TODO: Replace this component with one suitable for your enviroment.
       |
       | This component provides authentication for the kind of credential used in your environment. In most cases
       | credential is a username/password pair that lives in a system of record like an LDAP directory.
       | The most common authentication handler beans:
       |
       | * org.jasig.cas.authentication.LdapAuthenticationHandler
       | * org.jasig.cas.adaptors.jdbc.QueryDatabaseAuthenticationHandler
       | * org.jasig.cas.adaptors.x509.authentication.handler.support.X509CredentialsAuthenticationHandler
       | * org.jasig.cas.support.spnego.authentication.handler.support.JCIFSSpnegoAuthenticationHandler
       -->
    <!--
    <bean id="primaryAuthenticationHandler"
          class="org.jasig.cas.authentication.AcceptUsersAuthenticationHandler">
        <property name="users">
            <map>
                <entry key="casuser" value="Mellon"/>
            </map>
        </property>
    </bean>
    -->
    <bean id="ldapAuthenticationHandler"
      class="org.jasig.cas.authentication.LdapAuthenticationHandler"
      p:principalIdAttribute="uid"
      c:authenticator-ref="authenticator">
    <property name="principalAttributeMap">
        <map>
            <!--
               | This map provides a simple attribute resolution mechanism.
               | Keys are LDAP attribute names, values are CAS attribute names.
               | Use this facility instead of a PrincipalResolver if LDAP is
               | the only attribute source.
               -->
            <entry key="member" value="member" />
            <entry key="mail" value="mail" />
            <entry key="cn" value="cn" />
        </map>
    </property>
    </bean>

    <!-- Required for proxy ticket mechanism -->
    <bean id="proxyPrincipalResolver"
          class="org.jasig.cas.authentication.principal.BasicPrincipalResolver" />

    <!--
       | Resolves a principal from a credential using an attribute repository that is configured to resolve
       | against a deployer-specific store (e.g. LDAP).
       -->
    <bean id="primaryPrincipalResolver"
          class="org.jasig.cas.authentication.principal.PersonDirectoryPrincipalResolver" >
        <property name="attributeRepository" ref="attributeRepository" />
    </bean>

    <!--
    Bean that defines the attributes that a service may return.  This example uses the Stub/Mock version.  A real implementation
    may go against a database or LDAP server.  The id should remain "attributeRepository" though.
    +-->
    <bean id="attributeRepository" class="org.jasig.services.persondir.support.StubPersonAttributeDao"
            p:backingMap-ref="attrRepoBackingMap" />

    <util:map id="attrRepoBackingMap">
        <entry key="uid" value="uid" />
        <entry key="eduPersonAffiliation" value="eduPersonAffiliation" />
        <entry key="groupMembership" value="groupMembership" />
    </util:map>

    <!--
    Sample, in-memory data store for the ServiceRegistry. A real implementation
    would probably want to replace this with the JPA-backed ServiceRegistry DAO
    The name of this bean should remain "serviceRegistryDao".
    +-->
    <bean id="serviceRegistryDao" class="org.jasig.cas.services.InMemoryServiceRegistryDaoImpl"
            p:registeredServices-ref="registeredServicesList" />

    <util:list id="registeredServicesList">
        <bean class="org.jasig.cas.services.RegexRegisteredService"
              p:id="0" p:name="HTTP and IMAP" p:description="Allows HTTP(S) and IMAP(S) protocols"
              p:serviceId="^(https?|imaps?)://.*" p:evaluationOrder="10000001" />
        <!--
        Use the following definition instead of the above to further restrict access
        to services within your domain (including sub domains).
        Note that example.com must be replaced with the domain you wish to permit.
        This example also demonstrates the configuration of an attribute filter
        that only allows for attributes whose length is 3.
        -->
        <!--
        <bean class="org.jasig.cas.services.RegexRegisteredService">
            <property name="id" value="1" />
            <property name="name" value="HTTP and IMAP on example.com" />
            <property name="description" value="Allows HTTP(S) and IMAP(S) protocols on example.com" />
            <property name="serviceId" value="^(https?|imaps?)://([A-Za-z0-9_-]+\.)*example\.com/.*" />
            <property name="evaluationOrder" value="0" />
            <property name="attributeFilter">
              <bean class="org.jasig.cas.services.support.RegisteredServiceRegexAttributeFilter" c:regex="^\w{3}$" />
            </property>
        </bean>
        -->
    </util:list>

    <bean id="auditTrailManager" class="com.github.inspektr.audit.support.Slf4jLoggingAuditTrailManager" />

    <bean id="healthCheckMonitor" class="org.jasig.cas.monitor.HealthCheckMonitor" p:monitors-ref="monitorsList" />

    <util:list id="monitorsList">
      <bean class="org.jasig.cas.monitor.MemoryMonitor" p:freeMemoryWarnThreshold="10" />
      <!--
        NOTE
        The following ticket registries support SessionMonitor:
          * DefaultTicketRegistry
          * JpaTicketRegistry
        Remove this monitor if you use an unsupported registry.
      -->
      <bean class="org.jasig.cas.monitor.SessionMonitor"
          p:ticketRegistry-ref="ticketRegistry"
          p:serviceTicketCountWarnThreshold="5000"
          p:sessionCountWarnThreshold="100000" />
    </util:list>

<bean id="authenticator" class="org.ldaptive.auth.Authenticator"
      c:resolver-ref="dnResolver"
      c:handler-ref="authHandler" />

<!--
   | The following DN format works for many directories, but may need to be
   | customized.
   -->
<bean id="dnResolver"
      class="org.ldaptive.auth.FormatDnResolver"
      c:format="uid=%s,${ldap.authn.baseDn}" />

<bean id="authHandler" class="org.ldaptive.auth.PooledBindAuthenticationHandler"
      p:connectionFactory-ref="pooledLdapConnectionFactory" />

<bean id="pooledLdapConnectionFactory"
      class="org.ldaptive.pool.PooledConnectionFactory"
      p:connectionPool-ref="connectionPool" />

<bean id="connectionPool"
      class="org.ldaptive.pool.BlockingConnectionPool"
      init-method="initialize"
      p:poolConfig-ref="ldapPoolConfig"
      p:blockWaitTime="${ldap.pool.blockWaitTime}"
      p:validator-ref="searchValidator"
      p:pruneStrategy-ref="pruneStrategy"
      p:connectionFactory-ref="connectionFactory" />

<bean id="ldapPoolConfig" class="org.ldaptive.pool.PoolConfig"
      p:minPoolSize="${ldap.pool.minSize}"
      p:maxPoolSize="${ldap.pool.maxSize}"
      p:validateOnCheckOut="${ldap.pool.validateOnCheckout}"
      p:validatePeriodically="${ldap.pool.validatePeriodically}"
      p:validatePeriod="${ldap.pool.validatePeriod}" />

<bean id="connectionFactory" class="org.ldaptive.DefaultConnectionFactory"
      p:connectionConfig-ref="connectionConfig" />

<bean id="connectionConfig" class="org.ldaptive.ConnectionConfig"
      p:ldapUrl="${ldap.url}"
      p:connectTimeout="${ldap.connectTimeout}"
      p:useStartTLS="${ldap.useStartTLS}"
      p:sslConfig-ref="sslConfig" />

<bean id="sslConfig" class="org.ldaptive.ssl.SslConfig">
    <property name="credentialConfig">
        <bean class="org.ldaptive.ssl.X509CredentialConfig"
              p:trustCertificates="${ldap.trustedCert}" />
    </property>
</bean>

<bean id="pruneStrategy" class="org.ldaptive.pool.IdlePruneStrategy"
      p:prunePeriod="${ldap.pool.prunePeriod}"
      p:idleTime="${ldap.pool.idleTime}" />

<bean id="searchValidator" class="org.ldaptive.pool.SearchValidator" />
</beans>

Add LDAP properties in /WEB-INF/ldap.properties as follows.

#========================================
# General properties
#========================================
ldap.url=ldap://localhost:10389

# LDAP connection timeout in milliseconds
ldap.connectTimeout=3000

# Whether to use StartTLS (probably needed if not SSL connection)
ldap.useStartTLS=false

#========================================
# LDAP connection pool configuration
#========================================
ldap.pool.minSize=3
ldap.pool.maxSize=10
ldap.pool.validateOnCheckout=false
ldap.pool.validatePeriodically=true

# Amount of time in milliseconds to block on pool exhausted condition
# before giving up.
ldap.pool.blockWaitTime=3000

# Frequency of connection validation in seconds
# Only applies if validatePeriodically=true
ldap.pool.validatePeriod=300

# Attempt to prune connections every N seconds
ldap.pool.prunePeriod=300

# Maximum amount of time an idle connection is allowed to be in
# pool before it is liable to be removed/destroyed
ldap.pool.idleTime=600

#========================================
# Authentication
#========================================

# Base DN of users to be authenticated
ldap.authn.baseDn=ou=users,ou=system

# Manager DN for authenticated searches
ldap.authn.managerDN=uid=admin,ou=system,dc=example,dc=com

# Manager password for authenticated searches
ldap.authn.managerPassword=secret

# Search filter used for configurations that require searching for DNs
#ldap.authn.searchFilter=(&(uid={user})(accountState=active))
ldap.authn.searchFilter=(uid={user})

# Search filter used for configurations that require searching for DNs
#ldap.authn.format=uid=%s,ou=users,dc=example,dc=com
ldap.authn.format=%s@example.com

# A path to trusted X.509 certificate for StartTLS
ldap.trustedCert=/path/to/cert.cer

Load into spring application context by modifying  /WEB-INF/spring_configuration/propertyFileConfigurer.xml
    
<context:property-placeholder location="/WEB-INF/cas.properties,/WEB-INF/ldap.properties"/>

Start tomcat and confirm there are no errors in the $TOMCAT_HOME\logs\catalina.out log.

Open a browser to the URL http://localhost:8443/cas-server-webapp-4.0.0 and authenticate with the LDAP credentials.