/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.acegisecurity.ui.x509;

import org.acegisecurity.AuthenticationException;

import org.acegisecurity.ui.AuthenticationEntryPoint;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;


/**
 * In the X.509 authentication case (unlike CAS, for example) the certificate will already have been extracted from
 * the request and a secure context established by the time the security-enforcement filter is invoked.<p>Therefore
 * this class isn't actually responsible for the commencement of authentication, as it is in the case of other
 * providers. It will be called if the certificate was rejected by Acegi's X509AuthenticationProvider, resulting in a
 * null authentication.</p>
 *  The <code>commence</code> method will always return an <code>HttpServletResponse.SC_FORBIDDEN</code> (403
 * error).
 *
 * @author Luke Taylor
 * @version $Id$
 *
 * @see org.acegisecurity.ui.ExceptionTranslationFilter
 */
public class X509ProcessingFilterEntryPoint implements AuthenticationEntryPoint {
    //~ Static fields/initializers =====================================================================================

    private static final Log logger = LogFactory.getLog(X509ProcessingFilterEntryPoint.class);

    //~ Methods ========================================================================================================

    /**
     * Returns a 403 error code to the client.
     *
     * @param request DOCUMENT ME!
     * @param response DOCUMENT ME!
     * @param authException DOCUMENT ME!
     *
     * @throws IOException DOCUMENT ME!
     * @throws ServletException DOCUMENT ME!
     */
    public void commence(ServletRequest request, ServletResponse response, AuthenticationException authException)
        throws IOException, ServletException {
        if (logger.isDebugEnabled()) {
            logger.debug("X509 entry point called. Rejecting access");
        }

        HttpServletResponse httpResponse = (HttpServletResponse) response;
        httpResponse.sendError(HttpServletResponse.SC_FORBIDDEN, "Access Denied");
    }
}
