CAS Authentication for Blackboard Learn 9.1


"cas-blackboard-learn" is a CAS authentication module for Blackboard. It utilizes the CAS 3.1 client library in order to connect to CAS 3.x servers (using the CAS 2.0 protocol).

This project is based on CasAuthenticationModule, developed by the University of Bristol and it is heavily influenced by the blackboard-cas project on Google Code.


See the build.properties file for settings and configuration.

Next, customize the following blackboard files by adding the lines immediately following each filename listed below, (including any leading spaces):


rem # CAS
set THIRD_PARTY_CP=%THIRD_PARTY_CP%;cas-bbauth.jar
set THIRD_PARTY_CP=%THIRD_PARTY_CP%;cas-client-core-3.2.1.jar
set THIRD_PARTY_CP=%THIRD_PARTY_CP%;xmlsec-1.3.0.jar
rem # CAS


rem # CAS
rem # CAS


rem # CAS
set CP=%CP%;%BBLIB%\cas-bbauth.jar
set CP=%CP%;%BBLIB%\cas-client-core-3.2.1.jar
set CP=%CP%;%BBLIB%\xmlsec-1.3.0.jar
rem # CAS


rem # CAS
set CP=%CP%;%BBLIB%\cas-bbauth.jar
set CP=%CP%;%BBLIB%\cas-client-core-3.2.1.jar
set CP=%CP%;%BBLIB%\xmlsec-1.3.0.jar
rem # CAS


You'll need an instance of Blackboard in c:\blackboard in order to build and Apache Ant (1.8.2) to run the build. Once you have configured everything, you can build with ant:

c:\workspace\cas-blackboard-learn\ant init

The init target will compile, package and deploy the CAS custom authentication module. Previous log files are also cleared out.

Next, the build will attempt to stop Blackboard services. The Blackboard Push Config process is then executed to deploy custom changes to Blackboard. Services are automatically restarted once the Push Config step is done.

The Push Config step resets Blackboard property files back to their default state! The build will automatically readjust the property values in files config/bb-config.properties and config/authentication.properties so Blackboard can recognize the new authentication mechanism with CAS.


To log into Blackboard without using CAS SSO, append the parameter disableCAS=1 at the end of the URL specified by the blackboard.url property, i.e. http://blackboard.domain.edu/?disableCAS=1


Inside the logs directory of the Blackboard installation folder, you may analyze the following files to examine and troubleshoot CAS behavior (where xyz indicates the file date):

  • bb-services-log-xyz.txt
  • Tomcat logs inside the tomcat directory (i.e. stdout-stderror-xyz.log)
  • Collab server logs inside the collab-server directory.

Upgrade Notes

If you plan to upgrade Blackboard to the next service pack, etc you'll need to make sure that certain CAS changes are disabled before you run upgrade commands.

  • Make sure config/bb-config.properties and config/authentication.properties are reset to their original version.
  • Remove the cas-common.classpath file from c:\blackboard\config\tomcat\classpath.
  • Execute Push Config to enforce the changes.
  • Upgrade Blackboard and repeat the instructions. (You'll have to make the classpath adjustments above again noted in the Configuration section, as the upgrade completely resets everything)