Restore SEBPatch

SafeExamBrowser.Service/CompositionRoot.cs

@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2024 ETH Zürich, IT Services
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Security.AccessControl;
+using System.Security.Principal;
+using System.Threading;
+using SafeExamBrowser.Communication.Hosts;
+using SafeExamBrowser.Communication.Proxies;
+using SafeExamBrowser.Configuration.Contracts;
+using SafeExamBrowser.Core.Contracts.OperationModel;
+using SafeExamBrowser.Core.OperationModel;
+using SafeExamBrowser.Core.Operations;
+using SafeExamBrowser.Lockdown;
+using SafeExamBrowser.Logging;
+using SafeExamBrowser.Logging.Contracts;
+using SafeExamBrowser.Service.Communication;
+using SafeExamBrowser.Service.Operations;
+using SafeExamBrowser.Settings.Logging;
+
+namespace SafeExamBrowser.Service
+{
+	internal class CompositionRoot
+	{
+		private ILogger logger;
+
+		internal ServiceController ServiceController { get; private set; }
+
+		internal void BuildObjectGraph()
+		{
+			const int ONE_SECOND = 1000;
+			const int FIVE_SECONDS = 5000;
+			const int FIFTEEN_SECONDS = 15000;
+
+			var backupFilePath = BuildBackupFilePath();
+
+			InitializeLogging();
+
+			var featureBackup = new FeatureConfigurationBackup(backupFilePath, new ModuleLogger(logger, nameof(FeatureConfigurationBackup)));
+			var featureFactory = new FeatureConfigurationFactory(new ModuleLogger(logger, nameof(FeatureConfigurationFactory)));
+			var featureMonitor = new FeatureConfigurationMonitor(new ModuleLogger(logger, nameof(FeatureConfigurationMonitor)), ONE_SECOND);
+			var proxyFactory = new ProxyFactory(new ProxyObjectFactory(), new ModuleLogger(logger, nameof(ProxyFactory)));
+			var serviceHost = new ServiceHost(AppConfig.SERVICE_ADDRESS, new HostObjectFactory(), new ModuleLogger(logger, nameof(ServiceHost)), FIFTEEN_SECONDS);
+			var sessionContext = new SessionContext();
+			var systemConfigurationUpdate = new SystemConfigurationUpdate(new ModuleLogger(logger, nameof(SystemConfigurationUpdate)));
+
+			var bootstrapOperations = new Queue<IOperation>();
+			var sessionOperations = new Queue<IOperation>();
+
+			sessionContext.AutoRestoreMechanism = new AutoRestoreMechanism(featureBackup, new ModuleLogger(logger, nameof(AutoRestoreMechanism)), systemConfigurationUpdate, FIVE_SECONDS);
+
+			bootstrapOperations.Enqueue(new RestoreOperation(featureBackup, logger, sessionContext));
+			bootstrapOperations.Enqueue(new CommunicationHostOperation(serviceHost, logger));
+			bootstrapOperations.Enqueue(new ServiceEventCleanupOperation(logger, sessionContext));
+
+			sessionOperations.Enqueue(new SessionInitializationOperation(logger, ServiceEventFactory, sessionContext));
+			sessionOperations.Enqueue(new LockdownOperation(featureBackup, featureFactory, featureMonitor, logger, sessionContext));
+			sessionOperations.Enqueue(new SessionActivationOperation(logger, sessionContext));
+
+			var bootstrapSequence = new OperationSequence(logger, bootstrapOperations);
+			var sessionSequence = new OperationSequence(logger, sessionOperations);
+
+			ServiceController = new ServiceController(logger, LogWriterFactory, bootstrapSequence, sessionSequence, serviceHost, sessionContext, systemConfigurationUpdate);
+		}
+
+		private string BuildBackupFilePath()
+		{
+			var appDataFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), nameof(SafeExamBrowser));
+			var filePath = Path.Combine(appDataFolder, AppConfig.BACKUP_FILE_NAME);
+
+			return filePath;
+		}
+
+		internal void LogStartupInformation()
+		{
+			logger.Log($"# Service started at {DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff")}");
+			logger.Log(string.Empty);
+		}
+
+		internal void LogShutdownInformation()
+		{
+			logger?.Log($"# Service terminated at {DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff")}");
+		}
+
+		private void InitializeLogging()
+		{
+			var appDataFolder = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), nameof(SafeExamBrowser));
+			var logFolder = Path.Combine(appDataFolder, "Logs");
+			var logFilePrefix = DateTime.Now.ToString("yyyy-MM-dd\\_HH\\hmm\\mss\\s");
+			var logFilePath = Path.Combine(logFolder, $"{logFilePrefix}_Service.log");
+			var logFileWriter = new LogFileWriter(new DefaultLogFormatter(), logFilePath);
+
+			logger = new Logger();
+			logger.LogLevel = LogLevel.Debug;
+			logger.Subscribe(logFileWriter);
+			logFileWriter.Initialize();
+		}
+
+		private ILogObserver LogWriterFactory(string filePath)
+		{
+			var writer = new LogFileWriter(new DefaultLogFormatter(), filePath);
+
+			writer.Initialize();
+
+			return writer;
+		}
+
+		private EventWaitHandle ServiceEventFactory(string eventName)
+		{
+			var securityIdentifier = new SecurityIdentifier(WellKnownSidType.BuiltinUsersSid, null);
+			var accessRule = new EventWaitHandleAccessRule(securityIdentifier, EventWaitHandleRights.Synchronize, AccessControlType.Allow);
+			var security = new EventWaitHandleSecurity();
+
+			security.AddAccessRule(accessRule);
+
+			return new EventWaitHandle(false, EventResetMode.AutoReset, eventName, out _, security);
+		}
+	}
+}