/* 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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your option) any later version.

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WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
USA

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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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.AuthenticationException;
import javax.security.sasl.SaslClient;
import javax.security.sasl.SaslException;

/**
 * The ANONYMOUS client-side mechanism.
 */
public class AnonymousClient
    extends ClientMechanism
    implements SaslClient
{
  public AnonymousClient()
  {
    super(Registry.SASL_ANONYMOUS_MECHANISM);
  }

  protected void initMechanism() throws SaslException
  {
  }

  protected void resetMechanism() throws SaslException
  {
  }

  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;
    final byte[] result;
    try
      {
        result = authorizationID.getBytes("UTF-8");
      }
    catch (UnsupportedEncodingException x)
      {
        throw new AuthenticationException("response()", x);
      }
    return result;
  }
}