Sample: IBM JGSS JAAS-enabled client program

For more information about using the sample client program, see Downloading and running the IBM^® JGSS samples.

// IBM Java GSS 1.0 sample JAAS-enabled client program

package com.ibm.security.jgss.test;
import com.ibm.security.jgss.Debug;
import com.ibm.security.auth.callback.Krb5CallbackHandler;
import javax.security.auth.Subject;
import javax.security.auth.login.LoginContext;
import java.security.PrivilegedExceptionAction;

/**
 * A Java GSS sample client that uses JAAS.
 * 
 * It does a JAAS login and operates within the JAAS login context so created.
 * 
 * It does not set the JAVA variable 
 * javax.security.auth.useSubjectCredsOnly, leaving
 * the variable to default to true
 * so that Java GSS acquires credentials from the JAAS Subject
 * associated with login context (created by the client).
 * 
 * The JAASClient is equivalent to its superclass {@link Client Client}
 * in all other respects, and it
 * can be run against the non-JAAS sample clients and servers.
 */
 
class JAASClient extends Client
{
    JAASClient(String programName) throws Exception
    {
        // Do not set useSubjectCredsOnly. Set only the program name.
        // useSubjectCredsOnly default to "true" if not set.
        super(programName);
    }
 
    static class JAASClientAction implements PrivilegedExceptionAction
    {
         private JAASClient client;
 
         public JAASClientAction(JAASClient client)
         {
             this.client = client;
         }      
 
         public Object run () throws Exception
         {
             client.initialize();
             client.interactWithAcceptor();
             return null;
         }
    }
 
    public static void main(String args[]) throws Exception
    {
        String programName = "JAASClient";
        JAASClient client = null;
        Debug dbg = new Debug();
 
        System.out.println(dbg.toString()); // XXXXXXX
 
        try {
            client = new JAASClient(programName);//use Subject creds
            client.processArgs(args);
 
            LoginContext loginCtxt = new LoginContext("JAASClient",
                                       new Krb5CallbackHandler());
 
            loginCtxt.login();
 
            dbg.out(Debug.OPTS_CAT_APPLICATION, 
                       programName + ": Kerberos login OK");
 
            Subject subject = loginCtxt.getSubject();
 
            PrivilegedExceptionAction jaasClientAction 
                            = new JAASClientAction(client);
 
            Subject.doAsPrivileged(subject, jaasClientAction, null);
      
        } catch (Exception exc) {
            dbg.out(Debug.OPTS_CAT_APPLICATION, 
                        programName + " Exception: " + exc.toString());
            exc.printStackTrace();
            throw exc;
        } finally {
            try {
                if (client != null)
                    client.dispose();
            } catch (Exception exc) {}
        }
 
        dbg.out(Debug.OPTS_CAT_APPLICATION, 
                       programName + ": Done ...");
    }
}