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.core.authz.support;
021
022
023import java.util.ArrayList;
024import java.util.Collection;
025
026import org.apache.directory.api.ldap.aci.ACITuple;
027import org.apache.directory.api.ldap.aci.ProtectedItem;
028import org.apache.directory.api.ldap.aci.protectedItem.AllAttributeValuesItem;
029import org.apache.directory.api.ldap.aci.protectedItem.AttributeTypeItem;
030import org.apache.directory.api.ldap.aci.protectedItem.AttributeValueItem;
031import org.apache.directory.api.ldap.aci.protectedItem.RangeOfValuesItem;
032import org.apache.directory.api.ldap.aci.protectedItem.SelfValueItem;
033import org.apache.directory.api.ldap.model.entry.Entry;
034import org.apache.directory.api.ldap.model.exception.LdapException;
035
036
037/**
038 * An {@link ACITupleFilter} that chooses the tuples with the most specific
039 * protected item. (18.8.4.3, X.501)
040 * <p>
041 * If more than one tuple remains, choose the tuples with the most specific
042 * protected item. If the protected item is an attribute and there are tuples 
043 * that specify the attribute type explicitly, discard all other tuples. If
044 * the protected item is an attribute value, and there are tuples that specify
045 * the attribute value explicitly, discard all other tuples. A protected item
046 * which is a rangeOfValues is to be treated as specifying an attribute value
047 * explicitly.
048 * 
049 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
050 */
051public class MostSpecificProtectedItemFilter implements ACITupleFilter
052{
053    /**
054     * {@inheritDoc}
055     */
056    @Override
057    public Collection<ACITuple> filter( AciContext aciContext, OperationScope scope, Entry userEntry )
058        throws LdapException
059    {
060        if ( aciContext.getAciTuples().size() <= 1 )
061        {
062            return aciContext.getAciTuples();
063        }
064
065        Collection<ACITuple> filteredTuples = new ArrayList<>();
066
067        // If the protected item is an attribute and there are tuples that
068        // specify the attribute type explicitly, discard all other tuples.
069        for ( ACITuple tuple : aciContext.getAciTuples() )
070        {
071            for ( ProtectedItem item : tuple.getProtectedItems() )
072            {
073                if ( item instanceof AttributeTypeItem || item instanceof AllAttributeValuesItem
074                    || item instanceof SelfValueItem || item instanceof AttributeValueItem )
075                {
076                    filteredTuples.add( tuple );
077                    break;
078                }
079            }
080        }
081
082        if ( !filteredTuples.isEmpty() )
083        {
084            return filteredTuples;
085        }
086
087        // If the protected item is an attribute value, and there are tuples
088        // that specify the attribute value explicitly, discard all other tuples.
089        // A protected item which is a rangeOfValues is to be treated as
090        // specifying an attribute value explicitly. 
091        for ( ACITuple tuple : aciContext.getAciTuples() )
092        {
093            for ( ProtectedItem item : tuple.getProtectedItems() )
094            {
095                if ( item instanceof RangeOfValuesItem )
096                {
097                    filteredTuples.add( tuple );
098                }
099            }
100        }
101
102        if ( !filteredTuples.isEmpty() )
103        {
104            return filteredTuples;
105        }
106
107        return aciContext.getAciTuples();
108    }
109}