/*
 * JBoss, the OpenSource WebOS
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */
package org.jboss.security.auth.callback;

import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;

/** A simple implementation of CallbackHandler that sets a username and
password in the handle(Callback[]) method to that passed in to
the constructor. This is suitable for environments that need non-interactive
JAAS logins.

 @see javax.security.auth.callback.CallbackHandler
 @see #handle(Callback[])

 @author  Scott.Stark@jboss.org
 @version $Revision: 1.3.4.1 $
 */
public class UsernamePasswordHandler implements CallbackHandler
{
   private transient String username;
   private transient char[] password;
   private transient Object credential;

   /** Initialize the UsernamePasswordHandler with the usernmae
    and password to use.
    */
   public UsernamePasswordHandler(String username, char[] password)
   {
      this.username = username;
      this.password = password;
      this.credential = password;
   }

   public UsernamePasswordHandler(String username, Object credential)
   {
      this.username = username;
      this.credential = credential;
   }

   /** Sets any NameCallback name property to the instance username,
    sets any PasswordCallback password property to the instance, and any
    password.
    @exception UnsupportedCallbackException, thrown if any callback of
    type other than NameCallback or PasswordCallback are seen.
    */
   public void handle(Callback[] callbacks) throws
         UnsupportedCallbackException
   {
      for (int i = 0; i < callbacks.length; i++)
      {
         Callback c = callbacks[i];
         if (c instanceof NameCallback)
         {
            NameCallback nc = (NameCallback) c;
            nc.setName(username);
         }
         else if (c instanceof PasswordCallback)
         {
            PasswordCallback pc = (PasswordCallback) c;
            if( password == null )
            {
               // We were given an opaque Object credential but a char[] is requested?
               if( credential != null )
               {
                  String tmp = credential.toString();
                  password = tmp.toCharArray();
               }
            }
            pc.setPassword(password);
         }
         else if (c instanceof ObjectCallback)
         {
            ObjectCallback oc = (ObjectCallback) c;
            oc.setCredential(credential);
         }
         else
         {
            throw new UnsupportedCallbackException(callbacks[i], "Unrecognized Callback");
         }
      }
   }
}
