001/**
002 * Copyright 2015 DuraSpace, Inc.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016package org.fcrepo.auth.webac;
017
018import static java.util.Collections.unmodifiableMap;
019import static org.fcrepo.auth.webac.URIConstants.FOAF_AGENT_VALUE;
020import static org.fcrepo.auth.webac.URIConstants.WEBAC_MODE_CONTROL_VALUE;
021import static org.fcrepo.auth.webac.URIConstants.WEBAC_MODE_READ_VALUE;
022import static org.fcrepo.auth.webac.URIConstants.WEBAC_MODE_WRITE_VALUE;
023import static org.modeshape.jcr.ModeShapePermissions.ADD_NODE;
024import static org.modeshape.jcr.ModeShapePermissions.MODIFY_ACCESS_CONTROL;
025import static org.modeshape.jcr.ModeShapePermissions.READ;
026import static org.modeshape.jcr.ModeShapePermissions.READ_ACCESS_CONTROL;
027import static org.modeshape.jcr.ModeShapePermissions.REGISTER_NAMESPACE;
028import static org.modeshape.jcr.ModeShapePermissions.REMOVE;
029import static org.modeshape.jcr.ModeShapePermissions.REMOVE_CHILD_NODES;
030import static org.modeshape.jcr.ModeShapePermissions.SET_PROPERTY;
031
032import java.security.Principal;
033import java.util.Arrays;
034import java.util.HashMap;
035import java.util.Map;
036import java.util.Set;
037
038import javax.jcr.Session;
039
040import org.fcrepo.auth.roles.common.AbstractRolesAuthorizationDelegate;
041
042import org.slf4j.Logger;
043import org.slf4j.LoggerFactory;
044
045/**
046 * Authorization Delegate responsible for resolving Fedora's permissions using Web Access Control (WebAC) access
047 * control lists.
048 *
049 * @author Peter Eichman
050 * @since Aug 24, 2015
051 */
052public class WebACAuthorizationDelegate extends AbstractRolesAuthorizationDelegate {
053
054    /**
055     * Class-level logger.
056     */
057    private static final Logger LOGGER = LoggerFactory.getLogger(WebACAuthorizationDelegate.class);
058
059    private static final Map<String, String> actionMap;
060
061    static {
062        final Map<String, String> map = new HashMap<>();
063        // WEBAC_MODE_READ Permissions
064        map.put(READ, WEBAC_MODE_READ_VALUE);
065        // WEBAC_MODE_WRITE Permissions
066        map.put(ADD_NODE, WEBAC_MODE_WRITE_VALUE);
067        map.put(REGISTER_NAMESPACE, WEBAC_MODE_WRITE_VALUE);
068        map.put(REMOVE, WEBAC_MODE_WRITE_VALUE);
069        map.put(REMOVE_CHILD_NODES, WEBAC_MODE_WRITE_VALUE);
070        map.put(SET_PROPERTY, WEBAC_MODE_WRITE_VALUE);
071        // WEBAC_MODE_CONTROL Permissions
072        map.put(MODIFY_ACCESS_CONTROL, WEBAC_MODE_CONTROL_VALUE);
073        map.put(READ_ACCESS_CONTROL, WEBAC_MODE_CONTROL_VALUE);
074        actionMap = unmodifiableMap(map);
075    }
076
077    /**
078     * The security principal for every request, that represents the foaf:Agent agent class that is used to designate
079     * "everyone".
080     */
081    private static final Principal EVERYONE = new Principal() {
082
083        @Override
084        public String getName() {
085            return FOAF_AGENT_VALUE;
086        }
087
088        @Override
089        public String toString() {
090            return getName();
091        }
092
093    };
094
095    @Override
096    public boolean rolesHavePermission(final Session userSession, final String absPath,
097            final String[] actions, final Set<String> roles) {
098
099        /*
100         * If any value in the actions Array is NOT also in the roles Set, the request should be denied.
101         * Otherwise, e.g. all of the actions values are contained in the roles set, the request is approved.
102         * 
103         * The logic here may not be immediately obvious. The process is thus:
104         *   map: map the modeshape action to a webac action
105         *   filter: ALL of these actions MUST exist in the roles Set, so if any action
106         *      value does NOT exist in the roles Set, we want to know about that
107         *   findFirst: If any value makes it through that filter, it is enough to invalidate
108         *      the request. This is evaluated lazily, so the first item encountered will
109         *      short-circut the processing of the rest of the stream.
110         *   isPresent: this returns true if any value passed through the filter, but we
111         *      actually want to invert that logic, hence the ! at the beginning of the expression.
112         */
113        final boolean permit = !Arrays.asList(actions).stream()
114                 .map(actionMap::get)
115                 .filter(x -> !roles.contains(x))
116                 .findFirst()
117                 .isPresent();
118
119        LOGGER.debug("Request for actions: {}, on path: {}, with roles: {}. Permission={}",
120                actions,
121                absPath,
122                roles,
123                permit);
124
125        return permit;
126    }
127
128    @Override
129    public Principal getEveryonePrincipal() {
130        return EVERYONE;
131    }
132
133}