content: /*
   * Copyright (c) 2008-2009, Motorola, Inc.
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * - Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above copyright notice,
   * this list of conditions and the following disclaimer in the documentation
   * and/or other materials provided with the distribution.
   *
   * - Neither the name of the Motorola, Inc. nor the names of its contributors
   * may be used to endorse or promote products derived from this software
   * without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   */
  
  package javax.obex;
  
  /**
   * This interface provides a way to respond to authentication challenge and
   * authentication response headers. When a client or server receives an
   * authentication challenge or authentication response header, the
   * <code>onAuthenticationChallenge()</code> or
   * <code>onAuthenticationResponse()</code> will be called, respectively, by the
   * implementation.
   * <P>
   * For more information on how the authentication procedure works in OBEX,
   * please review the IrOBEX specification at <A
   * HREF="http://www.irda.org">http://www.irda.org</A>.
   * <P>
   * <STRONG>Authentication Challenges</STRONG>
   * <P>
   * When a client or server receives an authentication challenge header, the
   * <code>onAuthenticationChallenge()</code> method will be invoked by the OBEX
   * API implementation. The application will then return the user name (if
   * needed) and password via a <code>PasswordAuthentication</code> object. The
   * password in this object is not sent in the authentication response. Instead,
   * the 16-byte challenge received in the authentication challenge is combined
   * with the password returned from the <code>onAuthenticationChallenge()</code>
   * method and passed through the MD5 hash algorithm. The resulting value is sent
   * in the authentication response along with the user name if it was provided.
   * <P>
   * <STRONG>Authentication Responses</STRONG>
   * <P>
   * When a client or server receives an authentication response header, the
   * <code>onAuthenticationResponse()</code> method is invoked by the API
   * implementation with the user name received in the authentication response
   * header. (The user name will be <code>null</code> if no user name was provided
   * in the authentication response header.) The application must determine the
   * correct password. This value should be returned from the
   * <code>onAuthenticationResponse()</code> method. If the authentication request
   * should fail without the implementation checking the password,
   * <code>null</code> should be returned by the application. (This is needed for
   * reasons like not recognizing the user name, etc.) If the returned value is
   * not <code>null</code>, the OBEX API implementation will combine the password
   * returned from the <code>onAuthenticationResponse()</code> method and
   * challenge sent via the authentication challenge, apply the MD5 hash
   * algorithm, and compare the result to the response hash received in the
   * authentication response header. If the values are not equal, an
   * <code>IOException</code> will be thrown if the client requested
   * authentication. If the server requested authentication, the
   * <code>onAuthenticationFailure()</code> method will be called on the
   * <code>ServerRequestHandler</code> that failed authentication. The connection
   * is <B>not</B> closed if authentication failed.
   * @hide
   */
  public interface Authenticator {
  
      /**
       * Called when a client or a server receives an authentication challenge
       * header. It should respond to the challenge with a
       * <code>PasswordAuthentication</code> that contains the correct user name
       * and password for the challenge.
       * @param description the description of which user name and password should
       *        be used; if no description is provided in the authentication
       *        challenge or the description is encoded in an encoding scheme that
       *        is not supported, an empty string will be provided
       * @param isUserIdRequired <code>true</code> if the user ID is required;
       *        <code>false</code> if the user ID is not required
       * @param isFullAccess <code>true</code> if full access to the server will
       *        be granted; <code>false</code> if read only access will be granted
       * @return a <code>PasswordAuthentication</code> object containing the user
       *         name and password used for authentication
       */
      PasswordAuthentication onAuthenticationChallenge(String description, boolean isUserIdRequired,
              boolean isFullAccess);
  
      /**
       * Called when a client or server receives an authentication response
       * header. This method will provide the user name and expect the correct
       * password to be returned.
       * @param userName the user name provided in the authentication response; may
       *        be <code>null</code>
       * @return the correct password for the user name provided; if
       *         <code>null</code> is returned then the authentication request
       *         failed
       */
      byte[] onAuthenticationResponse(byte[] userName);
  }
  