jaas/src/main/java/org/apache/felix/jaas/internal/BundleLoginModuleCreator.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.felix.jaas.internal;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import javax.security.auth.spi.LoginModule;

import org.apache.sling.commons.osgi.ManifestHeader;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleEvent;
import org.osgi.service.log.LogService;
import org.osgi.util.tracker.BundleTracker;

class BundleLoginModuleCreator extends BundleTracker implements LoginModuleCreator
{

    private static final String JAAS_MODULE_CLASS = "Jaas-ModuleClass";

    private final Map<String, LoginModuleInfo> loginModuleInfo = new ConcurrentHashMap<String, LoginModuleInfo>();

    private final Logger log;

    public BundleLoginModuleCreator(BundleContext context, Logger log)
    {
        super(context, Bundle.ACTIVE, null /* customizer */);
        this.log = log;
    }

    public LoginModule newInstance(String className)
    {
        LoginModuleInfo lmInfo = loginModuleInfo.get(className);

        //TODO Rethink about exception handling. Probably introduce custom exception classes
        if (lmInfo == null)
        {
            throw new AssertionError("No bundle exists to create LoginModule from "
                + className);
        }

        try
        {
            return lmInfo.newInstance();
        }
        catch (IllegalAccessException e)
        {
            throw new RuntimeException("Error occurred while creating LoginModule for "
                + className, e);
        }
        catch (InstantiationException e)
        {
            throw new RuntimeException("Error occurred while creating LoginModule for "
                + className, e);
        }
    }

    public Map<Bundle, Set<String>> getBundleToLoginModuleMapping()
    {
        //With R5 we could have used Map<Bundle, T> BundleTracker.getTracked()
        //Determine the bundle -> login module classes map
        Map<Bundle, Set<String>> bundleMap = new HashMap<Bundle, Set<String>>();
        for (LoginModuleInfo e : loginModuleInfo.values())
        {
            Bundle b = e.getBundle();
            @SuppressWarnings("unchecked")
            Set<String> classNames = (Set<String>) getObject(b);

            if (classNames == null)
            {
                continue;
            }
            bundleMap.put(b, classNames);
        }
        return bundleMap;
    }

    // ---------- BundleTracker integration ----------------------------------------------

    @Override
    public Object addingBundle(Bundle bundle, BundleEvent event)
    {
        if (providesLoginModule(bundle))
        {
            return registerBundle(bundle);
        }
        return null;
    }

    @Override
    public void removedBundle(Bundle bundle, BundleEvent event, Object object)
    {
        @SuppressWarnings("unchecked")
        Set<String> classNames = (Set<String>) object;

        for (String className : classNames)
        {
            loginModuleInfo.remove(className);
        }
    }

    private boolean providesLoginModule(Bundle bundle)
    {
        return bundle.getHeaders().get(JAAS_MODULE_CLASS) != null;
    }

    private Set<String> registerBundle(Bundle bundle)
    {
        Set<String> classNames = parseHeader((String) bundle.getHeaders().get(
            JAAS_MODULE_CLASS));
        for (String className : classNames)
        {
            LoginModuleInfo bi = new LoginModuleInfo(className, bundle, log);
            if (bi.isValid())
            {

                //Duplicate registration check
                if (loginModuleInfo.containsKey(className))
                {
                    LoginModuleInfo existingInfo = loginModuleInfo.get(className);
                    String msg = String.format(
                        "LoginModule class %s is already registered with Bundle %s. Entry "
                            + "from bundle %s would be ignored", className,
                        existingInfo.getBundle(), bundle);
                    log.log(LogService.LOG_WARNING, msg);
                    continue;
                }

                loginModuleInfo.put(className, bi);
                log.log(LogService.LOG_INFO, "Registering LoginModule class ["
                    + className + "] from Bundle" + bundle);
            }
            else
            {
                log.log(LogService.LOG_WARNING,
                    "Could not load LoginModule class " + bi.getClassName()
                        + " from bundle " + bundle);
            }
        }
        return classNames;
    }

    static final class LoginModuleInfo
    {
        private final String className;
        private final Bundle bundle;
        private final Class<LoginModule> clazz;

        @SuppressWarnings("unchecked")
        public LoginModuleInfo(String className, Bundle bundle, Logger log)
        {
            this.className = className;
            this.bundle = bundle;

            Class<LoginModule> clazz = null;
            try
            {
                clazz = bundle.loadClass(className);
            }
            catch (ClassNotFoundException e)
            {
                log.log(LogService.LOG_WARNING, "Error loading class [" + className
                    + "] from bundle " + bundle, e);
            }
            this.clazz = clazz;
        }

        public LoginModule newInstance() throws IllegalAccessException,
            InstantiationException
        {
            if (clazz == null)
            {
                throw new IllegalStateException("LoginModule class not initialized");
            }
            return clazz.newInstance();
        }

        public boolean isValid()
        {
            return clazz != null;
        }

        public String getClassName()
        {
            return className;
        }

        public Bundle getBundle()
        {
            return bundle;
        }
    }

    private static Set<String> parseHeader(String header)
    {
        Set<String> values = new HashSet<String>();
        ManifestHeader mh = ManifestHeader.parse(header);
        for(ManifestHeader.Entry e : mh.getEntries())
        {
            values.add(e.getValue());
        }
        return values;
    }

}