001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *  
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *  
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License. 
018 *  
019 */
020package org.apache.directory.server.ldap.handlers.sasl.external.certificate;
021
022
023import org.apache.commons.lang3.exception.ExceptionUtils;
024import org.apache.directory.api.ldap.model.constants.AuthenticationLevel;
025import org.apache.directory.api.ldap.model.constants.SchemaConstants;
026import org.apache.directory.api.ldap.model.constants.SupportedSaslMechanisms;
027import org.apache.directory.api.ldap.model.entry.Entry;
028import org.apache.directory.api.ldap.model.entry.Value;
029import org.apache.directory.api.ldap.model.exception.LdapAuthenticationException;
030import org.apache.directory.api.ldap.model.filter.EqualityNode;
031import org.apache.directory.api.ldap.model.message.BindRequest;
032import org.apache.directory.api.ldap.model.message.SearchScope;
033import org.apache.directory.api.util.Strings;
034import org.apache.directory.server.core.api.CoreSession;
035import org.apache.directory.server.core.api.DirectoryService;
036import org.apache.directory.server.core.api.LdapPrincipal;
037import org.apache.directory.server.core.api.OperationEnum;
038import org.apache.directory.server.core.api.OperationManager;
039import org.apache.directory.server.core.api.filtering.EntryFilteringCursor;
040import org.apache.directory.server.core.api.interceptor.context.BindOperationContext;
041import org.apache.directory.server.core.api.interceptor.context.SearchOperationContext;
042import org.apache.directory.server.ldap.LdapServer;
043import org.apache.directory.server.ldap.LdapSession;
044import org.apache.directory.server.ldap.handlers.sasl.AbstractSaslServer;
045import org.apache.directory.server.ldap.handlers.sasl.SaslConstants;
046import org.apache.mina.filter.ssl.SslFilter;
047
048import javax.naming.Context;
049import javax.net.ssl.SSLSession;
050import javax.security.sasl.SaslException;
051import java.security.cert.Certificate;
052
053
054/**
055 * A SaslServer implementation for certificate based SASL EXTERNAL mechanism.
056 *
057 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
058 */
059public final class ExternalSaslServer extends AbstractSaslServer
060{
061    /**
062     * The possible states for the negotiation of a EXTERNAL mechanism.
063     */
064    private enum NegotiationState
065    {
066        INITIALIZED, // Negotiation has just started
067        COMPLETED // The user/password have been received
068    }
069
070    /** The current negotiation state */
071    private NegotiationState state;
072
073    /**
074     *
075     * Creates a new instance of ExternalSaslServer.
076     *
077     * @param ldapSession The associated LdapSession instance
078     * @param adminSession The Administrator session
079     * @param bindRequest The associated BindRequest object
080     */
081    ExternalSaslServer( LdapSession ldapSession, CoreSession adminSession, BindRequest bindRequest )
082    {
083        super( ldapSession, adminSession, bindRequest );
084        state = NegotiationState.INITIALIZED;
085    }
086
087
088    /**
089     * {@inheritDoc}
090     */
091    public String getMechanismName()
092    {
093        return SupportedSaslMechanisms.EXTERNAL;
094    }
095
096
097    /**
098     * {@inheritDoc}
099     */
100    public byte[] evaluateResponse( byte[] initialResponse ) throws SaslException
101    {
102        try
103        {
104            SSLSession sslSession = ( SSLSession ) getLdapSession().getIoSession().getAttribute( SslFilter.SSL_SESSION );
105            Certificate[] peerCertificates = sslSession.getPeerCertificates();
106
107            if ( null == peerCertificates || 1 > peerCertificates.length )
108            {
109                throw new SaslException( "No peer certificate provided - cancel bind." );
110            }
111
112            getLdapSession().setCoreSession( authenticate( peerCertificates[0] ) );
113            state = NegotiationState.COMPLETED;
114        }
115        catch ( Exception e )
116        {
117            throw new SaslException( "Error authentication using client certificate: " + ExceptionUtils.getStackTrace( e ), e );
118        }
119        
120        return Strings.EMPTY_BYTES;
121    }
122
123
124    /**
125     * Provides {@code true} if negationstate is {@link NegotiationState#COMPLETED}
126     *
127     * @return {@code true} if completed, otherwise {@code false}
128     */
129    public boolean isComplete()
130    {
131        return state == NegotiationState.COMPLETED;
132    }
133
134
135    /**
136     * Try to authenticate the user against the underlying LDAP server.
137     * We identify the user using the provided peercertificate.
138     */
139    private CoreSession authenticate( Certificate peerCertificate ) throws Exception
140    {
141        LdapSession ldapSession = getLdapSession();
142        CoreSession adminSession = getAdminSession();
143        DirectoryService directoryService = adminSession.getDirectoryService();
144        LdapServer ldapServer = ldapSession.getLdapServer();
145        OperationManager operationManager = directoryService.getOperationManager();
146
147        // find user by userCertificate
148        EqualityNode<String> filter = new EqualityNode<>(
149                directoryService.getSchemaManager().getAttributeType( SchemaConstants.USER_CERTIFICATE_AT ),
150                new Value( peerCertificate.getEncoded() ) );
151
152        SearchOperationContext searchContext = new SearchOperationContext( directoryService.getAdminSession() );
153        searchContext.setDn( directoryService.getDnFactory().create( ldapServer.getSearchBaseDn() ) );
154        searchContext.setScope( SearchScope.SUBTREE );
155        searchContext.setFilter( filter );
156        searchContext.setSizeLimit( 1 );
157        searchContext.setNoAttributes( true );
158
159        try ( EntryFilteringCursor cursor = operationManager.search( searchContext ) )
160        {
161            if ( cursor.next() )
162            {
163                Entry entry = cursor.get();
164
165                BindOperationContext bindContext = new BindOperationContext( ldapSession.getCoreSession() );
166                bindContext.setDn( entry.getDn() );
167                bindContext.setSaslMechanism( getMechanismName() );
168                bindContext.setSaslAuthId( getBindRequest().getName() );
169                bindContext.setIoSession( ldapSession.getIoSession() );
170                bindContext.setInterceptors( directoryService.getInterceptors( OperationEnum.BIND ) );
171
172                operationManager.bind( bindContext );
173
174                ldapSession.putSaslProperty( SaslConstants.SASL_AUTHENT_USER, new LdapPrincipal( directoryService.getSchemaManager(),
175                        entry.getDn(), AuthenticationLevel.STRONG ) );
176                getLdapSession().putSaslProperty( Context.SECURITY_PRINCIPAL, getBindRequest().getName() );
177
178                return bindContext.getSession();
179            }
180
181            throw new LdapAuthenticationException( "Cannot authenticate user cert=" + peerCertificate );
182        }
183    }
184}