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.
/**
 *  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.catalina.authenticator.jaspic;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.security.auth.Subject;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.message.AuthException;
import javax.security.auth.message.MessageInfo;
import javax.security.auth.message.config.ServerAuthConfig;
import javax.security.auth.message.config.ServerAuthContext;
import javax.security.auth.message.module.ServerAuthModule;

import org.apache.tomcat.util.res.StringManager;

Basic implementation primarily intended for use when using third-party ServerAuthModule implementations that only provide the module. This implementation supports configuring the ServerAuthContext with multiple modules. /**
 * Basic implementation primarily intended for use when using third-party
 * {@link ServerAuthModule} implementations that only provide the module. This
 * implementation supports configuring the {@link ServerAuthContext} with
 * multiple modules.
 */
public class SimpleServerAuthConfig implements ServerAuthConfig {

    private static StringManager sm = StringManager.getManager(SimpleServerAuthConfig.class);

    private static final String SERVER_AUTH_MODULE_KEY_PREFIX =
            "org.apache.catalina.authenticator.jaspic.ServerAuthModule.";

    private final String layer;
    private final String appContext;
    private final CallbackHandler handler;
    private final Map<String,String> properties;

    private volatile ServerAuthContext serverAuthContext;

    public SimpleServerAuthConfig(String layer, String appContext, CallbackHandler handler,
            Map<String,String> properties) {
        this.layer = layer;
        this.appContext = appContext;
        this.handler = handler;
        this.properties = properties;
    }


    @Override
    public String getMessageLayer() {
        return layer;
    }


    @Override
    public String getAppContext() {
        return appContext;
    }


    @Override
    public String getAuthContextID(MessageInfo messageInfo) {
        return messageInfo.toString();
    }


    @Override
    public void refresh() {
        serverAuthContext = null;
    }


    @Override
    public boolean isProtected() {
        return false;
    }


    @SuppressWarnings({"rawtypes", "unchecked"}) // JASPIC API uses raw types
    @Override
    public ServerAuthContext getAuthContext(String authContextID, Subject serviceSubject,
            Map properties) throws AuthException {
        ServerAuthContext serverAuthContext = this.serverAuthContext;
        if (serverAuthContext == null) {
            synchronized (this) {
                if (this.serverAuthContext == null) {
                    Map<String,String> mergedProperties = new HashMap<>();
                    if (this.properties != null) {
                        mergedProperties.putAll(this.properties);
                    }
                    if (properties != null) {
                        mergedProperties.putAll(properties);
                    }

                    List<ServerAuthModule> modules = new ArrayList<>();
                    int moduleIndex = 1;
                    String key = SERVER_AUTH_MODULE_KEY_PREFIX + moduleIndex;
                    String moduleClassName = mergedProperties.get(key);
                    while (moduleClassName != null) {
                        try {
                            Class<?> clazz = Class.forName(moduleClassName);
                            ServerAuthModule module =
                                    (ServerAuthModule) clazz.getConstructor().newInstance();
                            module.initialize(null, null, handler, mergedProperties);
                            modules.add(module);
                        } catch (ReflectiveOperationException | IllegalArgumentException |
                                SecurityException e) {
                            AuthException ae = new AuthException();
                            ae.initCause(e);
                            throw ae;
                        }

                        // Look for the next module
                        moduleIndex++;
                        key = SERVER_AUTH_MODULE_KEY_PREFIX + moduleIndex;
                        moduleClassName = mergedProperties.get(key);
                    }

                    if (modules.size() == 0) {
                        throw new AuthException(sm.getString("simpleServerAuthConfig.noModules"));
                    }

                    this.serverAuthContext = createServerAuthContext(modules);
                }
                serverAuthContext = this.serverAuthContext;
            }
        }

        return serverAuthContext;
    }


    protected ServerAuthContext createServerAuthContext(List<ServerAuthModule> modules) {
        return new SimpleServerAuthContext(modules);
    }
}