/* AnonymousClient.java -- 
   Copyright (C) 2003, 2006 Free Software Foundation, Inc.

This file is a part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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General Public License for more details.

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USA

Linking this library statically or dynamically with other modules is
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permission to link this library with independent modules to produce an
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package gnu.javax.crypto.sasl.anonymous;

import gnu.java.security.Registry;
import gnu.javax.crypto.sasl.ClientMechanism;
import gnu.javax.crypto.sasl.IllegalMechanismStateException;

import java.io.UnsupportedEncodingException;

import javax.security.sasl.SaslClient;
import javax.security.sasl.SaslException;
import javax.security.sasl.AuthenticationException;

/**
 * <p>The ANONYMOUS client-side mechanism.</p>
 */
public class AnonymousClient extends ClientMechanism implements SaslClient
{

  // Constants and variables
  // -------------------------------------------------------------------------

  // Constructor(s)
  // -------------------------------------------------------------------------

  public AnonymousClient()
  {
    super(Registry.SASL_ANONYMOUS_MECHANISM);
  }

  // Class methods
  // -------------------------------------------------------------------------

  // Instance methods
  // -------------------------------------------------------------------------

  // abstract methods implementation -----------------------------------------

  protected void initMechanism() throws SaslException
  {
  }

  protected void resetMechanism() throws SaslException
  {
  }

  // javax.security.sasl.SaslClient interface implementation -----------------

  public boolean hasInitialResponse()
  {
    return true;
  }

  public byte[] evaluateChallenge(final byte[] challenge) throws SaslException
  {
    if (complete)
      {
        throw new IllegalMechanismStateException("evaluateChallenge()");
      }
    return response();
  }

  private byte[] response() throws SaslException
  {
    if (!AnonymousUtil.isValidTraceInformation(authorizationID))
      {
        throw new AuthenticationException(
                                          "Authorisation ID is not a valid email address");
      }
    complete = true;
    //      return authorizationID.getBytes();
    final byte[] result;
    try
      {
        result = authorizationID.getBytes("UTF-8");
      }
    catch (UnsupportedEncodingException x)
      {
        throw new AuthenticationException("response()", x);
      }
    return result;
  }
}