/*
 * $Header: /home/cvs/jakarta-tomcat-catalina/catalina/src/share/org/apache/catalina/authenticator/SSLAuthenticator.java,v 1.11 2004/01/27 12:29:35 remm Exp $
 * $Revision: 1.11 $
 * $Date: 2004/01/27 12:29:35 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * ====================================================================
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 * This software consists of voluntary contributions made by many
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 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
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 */


package org.apache.catalina.authenticator;


import java.io.IOException;
import java.security.Principal;
import java.security.cert.X509Certificate;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.catalina.Globals;
import org.apache.catalina.HttpRequest;
import org.apache.catalina.HttpResponse;
import org.apache.catalina.LifecycleException;
import org.apache.catalina.deploy.LoginConfig;



/**
 * An <b>Authenticator</b> and <b>Valve</b> implementation of authentication
 * that utilizes SSL certificates to identify client users.
 *
 * @author Craig R. McClanahan
 * @version $Revision: 1.11 $ $Date: 2004/01/27 12:29:35 $
 */

public class SSLAuthenticator
    extends AuthenticatorBase {


    // ------------------------------------------------------------- Properties


    /**
     * Descriptive information about this implementation.
     */
    protected static final String info =
        "org.apache.catalina.authenticator.SSLAuthenticator/1.0";


    /**
     * Return descriptive information about this Valve implementation.
     */
    public String getInfo() {

        return (info);

    }


    // --------------------------------------------------------- Public Methods


    /**
     * Authenticate the user by checking for the existence of a certificate
     * chain, and optionally asking a trust manager to validate that we trust
     * this user.
     *
     * @param request Request we are processing
     * @param response Response we are creating
     * @param config    Login configuration describing how authentication
     *              should be performed
     *
     * @exception IOException if an input/output error occurs
     */
    public boolean authenticate(HttpRequest request,
                                HttpResponse response,
                                LoginConfig config)
        throws IOException {

        // Have we already authenticated someone?
        Principal principal =
            ((HttpServletRequest) request.getRequest()).getUserPrincipal();
        //String ssoId = (String) request.getNote(Constants.REQ_SSOID_NOTE);
        if (principal != null) {
            if (debug >= 1)
                log("Already authenticated '" + principal.getName() + "'");
            // Associate the session with any existing SSO session in order
            // to get coordinated session invalidation at logout
            String ssoId = (String) request.getNote(Constants.REQ_SSOID_NOTE);
            if (ssoId != null)
                associate(ssoId, getSession(request, true));
            return (true);
        }

        // NOTE: We don't try to reauthenticate using any existing SSO session,
        // because that will only work if the original authentication was
        // BASIC or FORM, which are less secure than the CLIENT-CERT auth-type
        // specified for this webapp
        //
        // Uncomment below to allow previous FORM or BASIC authentications
        // to authenticate users for this webapp
        // TODO make this a configurable attribute (in SingleSignOn??)
        /*
        // Is there an SSO session against which we can try to reauthenticate?
        if (ssoId != null) {
            if (log.isDebugEnabled())
                log.debug("SSO Id " + ssoId + " set; attempting " +
                          "reauthentication");
            // Try to reauthenticate using data cached by SSO.  If this fails,
            // either the original SSO logon was of DIGEST or SSL (which
            // we can't reauthenticate ourselves because there is no
            // cached username and password), or the realm denied
            // the user's reauthentication for some reason.
            // In either case we have to prompt the user for a logon
            if (reauthenticateFromSSO(ssoId, request))
                return true;
        }
        */

        // Retrieve the certificate chain for this client
        HttpServletResponse hres =
            (HttpServletResponse) response.getResponse();
        if (debug >= 1)
            log(" Looking up certificates");

        X509Certificate certs[] = (X509Certificate[])
            request.getRequest().getAttribute(Globals.CERTIFICATES_ATTR);
        if ((certs == null) || (certs.length < 1)) {
            certs = (X509Certificate[])
                request.getRequest().getAttribute(Globals.SSL_CERTIFICATE_ATTR);
        }
        if ((certs == null) || (certs.length < 1)) {
            if (debug >= 1)
                log("  No certificates included with this request");
            hres.sendError(HttpServletResponse.SC_BAD_REQUEST,
                           sm.getString("authenticator.certificates"));
            return (false);
        }

        // Authenticate the specified certificate chain
        principal = context.getRealm().authenticate(certs);
        if (principal == null) {
            if (debug >= 1)
                log("  Realm.authenticate() returned false");
            hres.sendError(HttpServletResponse.SC_UNAUTHORIZED,
                           sm.getString("authenticator.unauthorized"));
            return (false);
        }

        // Cache the principal (if requested) and record this authentication
        register(request, response, principal, Constants.CERT_METHOD,
                 null, null);
        return (true);

    }


    // ------------------------------------------------------ Lifecycle Methods


    /**
     * Initialize the database we will be using for client verification
     * and certificate validation (if any).
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that prevents this component from being used
     */
    public void start() throws LifecycleException {

        super.start();

    }


    /**
     * Finalize the database we used for client verification and
     * certificate validation (if any).
     *
     * @exception LifecycleException if this component detects a fatal error
     *  that prevents this component from being used
     */
    public void stop() throws LifecycleException {

        super.stop();

    }


}
