Showing CAS username in ZK

After authenticating, CAS saves the username in a session variable as documented on the jasig site.

ZK has good offline documentation on how implicit objects session and sessionScope can be used but I needed to access Sun's Java EE tutorial's unified EL page because of my rusty EL.

Here's how I did it in a ZK label.

<label value="Welcome ${sessionScope['edu.yale.its.tp.cas.client.filter.user']}"/>

Setting up CAS Java client

I started my journey by creating a new web project in eclipse and configured the web xml according to the CAS Java Client procedure. I basically pointed to an apache2 load balancer for a tomcat cluster where the CAS deployment was running.

I immediately ran into problems with the following error:

sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

This error occured because the certificate being referenced was not in my JRE's keystore. I was able to resolve following the procedure at dreamingthings blog.

I was not thru yet. I then got this error:

javax.net.ssl.SSLHandshakeException: java.security.cert.CertificateException: No subject alternative names present

This error arose since I was using the IP address of the server in the CAS authentication URL. While I had used the IP for the Common Name (CN) entry while generating the certificate, this sun forum answer by user ejp discourages that.

I finally regenerated the self signed certificate, making sure that I used the hostname for the CN entry. There were no more errors after that :)

My next post should be on getting ZK to show the CAS username saved in the session.