Chapter 3. JBoss Security Model

package org.jboss.book.security.ex1;
                
import java.lang.reflect.Method;
import javax.ejb.EJBContext;
                
import org.apache.log4j.Category;
                
import org.jboss.security.SecurityProxy;
                
/** A simple example of a custom SecurityProxy implementation
 *  that demonstrates method argument based security checks.
 * @author Scott.Stark@jboss.org
 * @version $Revision: 1.4 $
 */
public class EchoSecurityProxy implements SecurityProxy
{
    Category log = Category.getInstance(EchoSecurityProxy.class);
    Method echo;
    
    public void init(Class beanHome, Class beanRemote,
                     Object securityMgr)
        throws InstantiationException
    {
        log.debug("init, beanHome="+beanHome
                  + ", beanRemote="+beanRemote
                  + ", securityMgr="+securityMgr);
        // Get the echo method for equality testing in invoke
        try {
            Class[] params = {String.class};
            echo = beanRemote.getDeclaredMethod("echo", params);
        } catch(Exception e) {
            String msg = "Failed to find an echo(String) method";
            log.error(msg, e);
            throw new InstantiationException(msg);
        }
    }
    
    public void setEJBContext(EJBContext ctx)
    {
        log.debug("setEJBContext, ctx="+ctx);
    }
    
    public void invokeHome(Method m, Object[] args)
        throws SecurityException
    {
        // We don't validate access to home methods
    }

    public void invoke(Method m, Object[] args, Object bean)
        throws SecurityException
    {
        log.debug("invoke, m="+m);
        // Check for the echo method
        if (m.equals(echo)) {
            // Validate that the msg arg is not 4 letter word
            String arg = (String) args[0];
            if (arg == null || arg.length() == 4)
                throw new SecurityException("No 4 letter words");
        }
        // We are not responsible for doing the invoke
    }
}           

<jboss>
    <security-domain>java:/jaas/other</security-domain>
                
    <enterprise-beans>
        <session>
            <ejb-name>EchoBean</ejb-name>
            <security-proxy>org.jboss.book.security.ex1.EchoSecurityProxy</security-proxy>
        </session>
    </enterprise-beans>
</jboss>