/*
 * $Header: /home/harald/repos/remotetea.sf.net/remotetea/src/org/acplt/oncrpc/OncRpcClientAuthNone.java,v 1.1 2003/08/13 12:03:40 haraldalbrecht Exp $
 *
 * Copyright (c) 1999, 2000
 * Lehrstuhl fuer Prozessleittechnik (PLT), RWTH Aachen
 * D-52064 Aachen, Germany.
 * All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this program (see the file LICENSE.txt for more
 * details); if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

package org.acplt.oncrpc;

import java.io.IOException;

/**
 * The <code>OncRpcClientAuthNone</code> class handles protocol issues of
 * ONC/RPC <code>AUTH_NONE</code> authentication.
 *
 * @version $Revision: 1.1 $ $Date: 2003/08/13 12:03:40 $ $State: Exp $ $Locker:  $
 * @author Harald Albrecht
 */
public class OncRpcClientAuthNone extends OncRpcClientAuth {

    /**
     * Encodes ONC/RPC authentication information in form of a credential
     * and a verifier when sending an ONC/RPC call message.
     *
     * @param xdr XDR stream where to encode the credential and the verifier
     *   to.
     *
     * @throws OncRpcException if an ONC/RPC error occurs.
     * @throws IOException if an I/O error occurs.
     */
    protected void xdrEncodeCredVerf(XdrEncodingStream xdr)
              throws OncRpcException, IOException {
        //
        // The credential only consists of the indication of AUTH_NONE with
        // no opaque authentication data following.
        //
        xdr.xdrEncodeInt(OncRpcAuthType.ONCRPC_AUTH_NONE);
        xdr.xdrEncodeInt(0);
        //
        // But we also need to encode the verifier. This is always of type
        // AUTH_NONE too. For some obscure historical reasons, we have to
        // deal with credentials and verifiers, although they belong together,
        // according to Sun's specification.
        //
        xdr.xdrEncodeInt(OncRpcAuthType.ONCRPC_AUTH_NONE);
        xdr.xdrEncodeInt(0);
    }

    /**
     * Decodes ONC/RPC authentication information in form of a verifier
     * when receiving an ONC/RPC reply message. 
     *
     * @param xdr XDR stream from which to receive the verifier sent together
     *   with an ONC/RPC reply message.
     *
     * @throws OncRpcAuthenticationException if the received verifier is
     *   not kosher.
     * @throws OncRpcException if an ONC/RPC error occurs.
     * @throws IOException if an I/O error occurs.
     */
    protected void xdrDecodeVerf(XdrDecodingStream xdr)
              throws OncRpcException, IOException {
        //
        // Make sure that we received a AUTH_NONE verifier and that it
        // does not contain any opaque data. Anything different from this
        // is not kosher and an authentication exception will be thrown.
        //
        if ( (xdr.xdrDecodeInt() != OncRpcAuthType.ONCRPC_AUTH_NONE) ||
             (xdr.xdrDecodeInt() != 0) ) {
            throw(new OncRpcAuthenticationException(
                OncRpcAuthStatus.ONCRPC_AUTH_FAILED));
        }
    }

    /**
     * Indicates whether the ONC/RPC authentication credential can be
     * refreshed.
     *
     * @return true, if the credential can be refreshed
     */
    protected boolean canRefreshCred() {
        //
        // Nothing to do here, as AUTH_NONE doesn't know anything of
        // credential refreshing. How refreshing...
        //
        return false;
    }

    /**
     * Contains a singleton which comes in handy if you just need an
     * AUTH_NONE authentification for an ONC/RPC client.
     */
    public static final OncRpcClientAuthNone AUTH_NONE = new OncRpcClientAuthNone();

}

// End of OncRpcClientAuthNone.java
