org.apache.jxtadoop.security.authorize.ServiceAuthorizationManager.java Source code

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Here is the source code for org.apache.jxtadoop.security.authorize.ServiceAuthorizationManager.java

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/**
 * 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.jxtadoop.security.authorize;

import java.security.AccessControlException;
import java.security.AccessController;
import java.security.Permission;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import javax.security.auth.Subject;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.jxtadoop.security.UserGroupInformation;

/**
 * An authorization manager which handles service-level authorization
 * for incoming service requests.
 */
public class ServiceAuthorizationManager {

    private static final Log LOG = LogFactory.getLog(ServiceAuthorizationManager.class);

    /**
     * Configuration key for controlling service-level authorization for Hadoop.
     */
    public static final String SERVICE_AUTHORIZATION_CONFIG = "hadoop.security.authorization";

    private static Map<Class<?>, Permission> protocolToPermissionMap = Collections
            .synchronizedMap(new HashMap<Class<?>, Permission>());

    /**
     * Authorize the user to access the protocol being used.
     * 
     * @param user user accessing the service 
     * @param protocol service being accessed
     * @throws AuthorizationException on authorization failure
     */
    public static void authorize(Subject user, Class<?> protocol) throws AuthorizationException {
        Permission permission = protocolToPermissionMap.get(protocol);
        if (permission == null) {
            permission = new ConnectionPermission(protocol);
            protocolToPermissionMap.put(protocol, permission);
        }

        checkPermission(user, permission);
    }

    /**
     * Check if the given {@link Subject} has all of necessary {@link Permission} 
     * set.
     * 
     * @param user <code>Subject</code> to be authorized
     * @param permissions <code>Permission</code> set
     * @throws AuthorizationException if the authorization failed
     */
    private static void checkPermission(final Subject user, final Permission... permissions)
            throws AuthorizationException {
        try {
            Subject.doAs(user, new PrivilegedExceptionAction<Void>() {
                public Void run() throws Exception {
                    try {
                        for (Permission permission : permissions) {
                            AccessController.checkPermission(permission);
                        }
                    } catch (AccessControlException ace) {
                        LOG.info("Authorization failed for " + UserGroupInformation.getCurrentUGI(), ace);
                        throw new AuthorizationException(ace);
                    }
                    return null;
                }
            });
        } catch (PrivilegedActionException e) {
            throw new AuthorizationException(e.getException());
        }
    }

}