protocol-changepw/src/main/java/org/apache/directory/server/changepw/service/ExtractPassword.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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.apache.directory.server.changepw.service;


import java.io.UnsupportedEncodingException;

import org.apache.directory.server.changepw.exceptions.ChangePasswordException;
import org.apache.directory.server.changepw.exceptions.ErrorType;
import org.apache.directory.server.changepw.io.ChangePasswordDataDecoder;
import org.apache.directory.server.changepw.messages.ChangePasswordRequest;
import org.apache.directory.server.changepw.value.ChangePasswordData;
import org.apache.directory.server.changepw.value.ChangePasswordDataModifier;
import org.apache.directory.server.kerberos.shared.crypto.encryption.CipherTextHandler;
import org.apache.directory.server.kerberos.shared.crypto.encryption.KeyUsage;
import org.apache.directory.server.kerberos.shared.exceptions.KerberosException;
import org.apache.directory.server.kerberos.shared.messages.components.Authenticator;
import org.apache.directory.server.kerberos.shared.messages.components.EncKrbPrivPart;
import org.apache.directory.server.kerberos.shared.messages.value.EncryptedData;
import org.apache.directory.server.kerberos.shared.messages.value.EncryptionKey;
import org.apache.mina.common.IoSession;
import org.apache.mina.handler.chain.IoHandlerCommand;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
 * @version $Rev$, $Date$
 */
public class ExtractPassword implements IoHandlerCommand
{
    /** the log for this class */
    private static final Logger log = LoggerFactory.getLogger( ExtractPassword.class );

    private String contextKey = "context";


    public void execute( NextCommand next, IoSession session, Object message ) throws Exception
    {
        ChangePasswordContext changepwContext = ( ChangePasswordContext ) session.getAttribute( getContextKey() );

        ChangePasswordRequest request = ( ChangePasswordRequest ) changepwContext.getRequest();
        Authenticator authenticator = changepwContext.getAuthenticator();
        CipherTextHandler cipherTextHandler = changepwContext.getCipherTextHandler();

        // TODO - check ticket is for service authorized to change passwords
        // ticket.getServerPrincipal().getName().equals(config.getChangepwPrincipal().getName()));

        // TODO - check client principal in ticket is authorized to change password

        // get the subsession key from the Authenticator
        EncryptionKey subSessionKey = authenticator.getSubSessionKey();

        // decrypt the request's private message with the subsession key
        EncryptedData encReqPrivPart = request.getPrivateMessage().getEncryptedPart();

        EncKrbPrivPart privatePart;

        try
        {
            privatePart = ( EncKrbPrivPart ) cipherTextHandler.unseal( EncKrbPrivPart.class, subSessionKey,
                encReqPrivPart, KeyUsage.NUMBER13 );
        }
        catch ( KerberosException ke )
        {
            log.error( ke.getMessage(), ke );
            throw new ChangePasswordException( ErrorType.KRB5_KPASSWD_SOFTERROR );
        }

        ChangePasswordData passwordData = null;

        if ( request.getVersionNumber() == ( short ) 1 )
        {
            // Use protocol version 0x0001, the legacy Kerberos change password protocol
            ChangePasswordDataModifier modifier = new ChangePasswordDataModifier();
            modifier.setNewPassword( privatePart.getUserData() );
            passwordData = modifier.getChangePasswdData();
        }
        else
        {
            // Use protocol version 0xFF80, the backwards-compatible MS protocol
            ChangePasswordDataDecoder passwordDecoder = new ChangePasswordDataDecoder();
            passwordData = passwordDecoder.decodeChangePasswordData( privatePart.getUserData() );
        }

        try
        {
            changepwContext.setPassword( new String( passwordData.getPassword(), "UTF-8" ) );
        }
        catch ( UnsupportedEncodingException uee )
        {
            log.error( uee.getMessage(), uee );
            throw new ChangePasswordException( ErrorType.KRB5_KPASSWD_SOFTERROR );
        }

        next.execute( session, message );
    }


    protected String getContextKey()
    {
        return ( this.contextKey );
    }
}