OmniAuthConfigProvider.java

/*
 * Copyright 2013 OmniFaces.
 *
 * Licensed 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.omnifaces.security.jaspic.factory;

import java.util.Map;

import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.message.AuthException;
import javax.security.auth.message.config.AuthConfigFactory;
import javax.security.auth.message.config.AuthConfigProvider;
import javax.security.auth.message.config.ClientAuthConfig;
import javax.security.auth.message.config.ServerAuthConfig;

import org.omnifaces.security.jaspic.config.AuthStacks;

/**
 * This class is a kind of meta-factory or factory-factory for delegates to a SAM, from which we can obtain factories for the server
 * and the client.
 * <p>
 * This AuthConfigProvider only supports factories for the server.
 * 
 * @author Arjan Tijms
 *
 */
public class OmniAuthConfigProvider implements AuthConfigProvider {

	private static final String CALLBACK_HANDLER_PROPERTY_NAME = "authconfigprovider.client.callbackhandler";

	private Map<String, String> providerProperties;
	private AuthStacks stacks;

	public OmniAuthConfigProvider(AuthStacks stacks) {
		this.stacks = stacks;
	}

	/**
	 * Constructor with signature and implementation that's required by API.
	 *
	 * @param properties
	 * @param factory
	 */
	public OmniAuthConfigProvider(Map<String, String> properties, AuthConfigFactory factory) {
		this.providerProperties = properties;

		// API requires self registration if factory is provided. Not clear
		// where the "layer" (2nd parameter)
		// and especially "appContext" (3rd parameter) values have to come from
		// at this place.
		if (factory != null) {
			factory.registerConfigProvider(this, null, null, "Auto registration");
		}
	}

	/**
	 * The actual factory method that creates the factory used to eventually obtain the delegate for a SAM.
	 */
	@Override
	public ServerAuthConfig getServerAuthConfig(String layer, String appContext, CallbackHandler handler) throws AuthException, SecurityException {
		return new OmniServerAuthConfig(layer, appContext, handler == null ? createDefaultCallbackHandler() : handler, providerProperties, stacks);
	}

	@Override
	public ClientAuthConfig getClientAuthConfig(String layer, String appContext, CallbackHandler handler) throws AuthException, SecurityException {
		return null;
	}

	@Override
	public void refresh() {
	}

	/**
	 * Creates a default callback handler via the system property "authconfigprovider.client.callbackhandler", as seemingly required by the API (API
	 * uses wording "may" create default handler).
	 *
	 * @return an instance of the default call back handler
	 * @throws AuthException
	 */
	private CallbackHandler createDefaultCallbackHandler() throws AuthException {
		String callBackClassName = System.getProperty(CALLBACK_HANDLER_PROPERTY_NAME);

		if (callBackClassName == null) {
			throw new AuthException("No default handler set via system property: " + CALLBACK_HANDLER_PROPERTY_NAME);
		}

		try {
			return (CallbackHandler) Thread.currentThread().getContextClassLoader().loadClass(callBackClassName).newInstance();
		}
		catch (Exception e) {
			throw new AuthException(e.getMessage());
		}
	}

}