/**
 * Copyright (c) 1996-2005 Cafesoft, LLC. All Rights Reserved.
 *
 * This software is the confidential and proprietary information of
 * Cafesoft, LLC. ("Confidential Information"). You shall not disclose
 * such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Cafesoft.
 *
 * CAFESOFT MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY
 * OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. CAFESOFT SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 */
package com.cafesoft.security.engine.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;

import java.io.IOException;

/**
 * CallBack interface for JAAS LoginModules that must prompt for input. Provides
 * the specified username and password when prompted by the Callback.
 *
 * @version  $Revision: 1.2 $ $Date: 2005/04/28 23:29:18 $ $Author: gary $
 * @since    11/8/01
 * @author   Norbert K. Kuhnert
 * @author   Derek G. Stainer
 * @author   Kelly Ray Jensen
 */
public class NamePasswordCallbackHandler implements CallbackHandler
{
	/**
	 * The username to be provided when prompted.
	 */
	private String username;

	/**
	 * The password to be provided when prompted.
	 */
	private String password;

	/**
	 * Create a new NamePasswordCallbackHandler.
	 */
	public NamePasswordCallbackHandler()
	{
		this.username = null;
		this.password = null;
	}

	/**
	 * Create a new NamePasswordCallbackHandler.
	 *
	 * @param username the username to provide when prompted.
	 * @param password the password to provide when prompted.
	 */
	public NamePasswordCallbackHandler(String username, String password)
	{
		setUsername(username);
		setPassword(password);
	}

	/**
	 * Set the username.
	 *
	 * @param username the username to be provided to a NameCallback.
	 */
	public void setUsername(String username)
	{
		if (username == null)
		{
			this.username = "";
			return;
		}

		this.username = username;
	}

	/**
	 * Set the password.
	 *
	 * @param password the password to be provided to a PasswordCallback.
	 */
	public void setPassword(String password)
	{
		if (password == null)
		{
			this.password = "";
			return;
		}

		this.password = password;
	}

	/**
	 * Handle Callbacks.
	 *
	 * @param callbacks an array of Callbacks to be handled.
	 */
	public void handle(Callback[] callbacks)
		throws IOException, UnsupportedCallbackException
	{
		// Loop over all Callbacks.
		for (int i = 0; i < callbacks.length; i++)
		{
			Callback cb = callbacks[i];

			if (cb instanceof NameCallback)
			{
				handleNameCallback((NameCallback)cb);
			}
			else if (cb instanceof PasswordCallback)
			{
				handlePasswordCallback((PasswordCallback)cb);
			}
			else
			{
				throw new UnsupportedCallbackException(
					cb, "Unrecognized Callback");
			}
		}
	}

	/**
	 * Handle a NameCallback.
	 *
	 * @param  nc  the NameCallback.
	 */
	 private void handleNameCallback(NameCallback nc)
	 {
		nc.setName(username);
	 }

	/**
	 * Handle a PasswordCallback.
	 *
	 * @param  pc  the PasswordCallback.
	 */
	 private void handlePasswordCallback(PasswordCallback pc)
	 {
		// JAAS specifies that the password is a char[] rather than a String.
		int length = password.length();
		char[] password_chars = new char[length];

		for (int i = 0; i < length; i++)
		{
			password_chars[i] = password.charAt(i);
		}

	 	pc.setPassword(password_chars);
	 }

}  // End of class: NamePasswordCallbackHandler