SEBWIN-301: Finished basic backup mechanism for service.

SafeExamBrowser.Configuration/ConfigurationData/DataValues.cs

@@ -16,8 +16,7 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 {
 	internal class DataValues
 	{
-		private const string BASE_ADDRESS = "net.pipe://localhost/safeexambrowser";
+		private const string DEFAULT_CONFIGURATION_NAME = "SebClientSettings.seb";
-		private const string DEFAULT_FILE_NAME = "SebClientSettings.seb";
 
 		private AppConfig appConfig;
 		private string executablePath;
@@ -48,26 +47,26 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 			var logFilePrefix = startTime.ToString("yyyy-MM-dd\\_HH\\hmm\\mss\\s");
 
 			appConfig = new AppConfig();
-			appConfig.AppDataFilePath = Path.Combine(appDataRoamingFolder, DEFAULT_FILE_NAME);
+			appConfig.AppDataFilePath = Path.Combine(appDataRoamingFolder, DEFAULT_CONFIGURATION_NAME);
 			appConfig.ApplicationStartTime = startTime;
 			appConfig.BrowserCachePath = Path.Combine(appDataLocalFolder, "Cache");
 			appConfig.BrowserLogFilePath = Path.Combine(logFolder, $"{logFilePrefix}_Browser.log");
 			appConfig.ClientId = Guid.NewGuid();
-			appConfig.ClientAddress = $"{BASE_ADDRESS}/client/{Guid.NewGuid()}";
+			appConfig.ClientAddress = $"{AppConfig.BASE_ADDRESS}/client/{Guid.NewGuid()}";
 			appConfig.ClientExecutablePath = Path.Combine(Path.GetDirectoryName(executablePath), $"{nameof(SafeExamBrowser)}.Client.exe");
 			appConfig.ClientLogFilePath = Path.Combine(logFolder, $"{logFilePrefix}_Client.log");
 			appConfig.ConfigurationFileExtension = ".seb";
 			appConfig.DownloadDirectory = Path.Combine(appDataLocalFolder, "Downloads");
 			appConfig.ProgramCopyright = programCopyright;
-			appConfig.ProgramDataFilePath = Path.Combine(programDataFolder, DEFAULT_FILE_NAME);
+			appConfig.ProgramDataFilePath = Path.Combine(programDataFolder, DEFAULT_CONFIGURATION_NAME);
 			appConfig.ProgramTitle = programTitle;
 			appConfig.ProgramVersion = programVersion;
 			appConfig.RuntimeId = Guid.NewGuid();
-			appConfig.RuntimeAddress = $"{BASE_ADDRESS}/runtime/{Guid.NewGuid()}";
+			appConfig.RuntimeAddress = $"{AppConfig.BASE_ADDRESS}/runtime/{Guid.NewGuid()}";
 			appConfig.RuntimeLogFilePath = Path.Combine(logFolder, $"{logFilePrefix}_Runtime.log");
 			appConfig.SebUriScheme = "seb";
 			appConfig.SebUriSchemeSecure = "sebs";
-			appConfig.ServiceAddress = $"{BASE_ADDRESS}/service";
+			appConfig.ServiceAddress = $"{AppConfig.BASE_ADDRESS}/service";
 			appConfig.ServiceEventName = $@"Global\{nameof(SafeExamBrowser)}-{Guid.NewGuid()}";
 			appConfig.ServiceLogFilePath = Path.Combine(logFolder, $"{logFilePrefix}_Service.log");
 
@@ -79,7 +78,7 @@ namespace SafeExamBrowser.Configuration.ConfigurationData
 			var configuration = new SessionConfiguration();
 
 			appConfig.ClientId = Guid.NewGuid();
-			appConfig.ClientAddress = $"{BASE_ADDRESS}/client/{Guid.NewGuid()}";
+			appConfig.ClientAddress = $"{AppConfig.BASE_ADDRESS}/client/{Guid.NewGuid()}";
 			appConfig.ServiceEventName = $@"Global\{nameof(SafeExamBrowser)}-{Guid.NewGuid()}";
 
 			configuration.AppConfig = appConfig.Clone();

SafeExamBrowser.Contracts/Configuration/AppConfig.cs

@@ -16,6 +16,21 @@ namespace SafeExamBrowser.Contracts.Configuration
 	[Serializable]
 	public class AppConfig
 	{
+		/// <summary>
+		/// The name of the backup data file used by the service component.
+		/// </summary>
+		public const string BACKUP_FILE_NAME = "Backup.bin";
+
+		/// <summary>
+		/// The base address for all communication hosts of the application.
+		/// </summary>
+		public const string BASE_ADDRESS = "net.pipe://localhost/safeexambrowser";
+
+		/// <summary>
+		/// The communication address of the service component.
+		/// </summary>
+		public const string SERVICE_ADDRESS = BASE_ADDRESS + "/service";
+
 		/// <summary>
 		/// The file path of the local client configuration for the active user.
 		/// </summary>

SafeExamBrowser.Contracts/Lockdown/IAutoRestoreMechanism.cs

@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ *
+ * 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/.
+ */
+
+namespace SafeExamBrowser.Contracts.Lockdown
+{
+	/// <summary>
+	/// Defines a mechanism which tries to restore all changes saved in a <see cref="IFeatureConfigurationBackup"/>.
+	/// </summary>
+	public interface IAutoRestoreMechanism
+	{
+		/// <summary>
+		/// Starts the procedure.
+		/// </summary>
+		void Start();
+
+		/// <summary>
+		/// Stops the procedure.
+		/// </summary>
+		void Stop();
+	}
+}

SafeExamBrowser.Contracts/Lockdown/IFeatureConfiguration.cs

@@ -6,6 +6,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
+
 namespace SafeExamBrowser.Contracts.Lockdown
 {
 	/// <summary>
@@ -13,6 +15,16 @@ namespace SafeExamBrowser.Contracts.Lockdown
 	/// </summary>
 	public interface IFeatureConfiguration
 	{
+		/// <summary>
+		/// The unique identifier of this feature configuration.
+		/// </summary>
+		Guid Id { get; }
+
+		/// <summary>
+		/// The identifier of the group of changes to which this feature configuration belongs.
+		/// </summary>
+		Guid GroupId { get; }
+
 		/// <summary>
 		/// Disables the feature.
 		/// </summary>
@@ -29,7 +41,7 @@ namespace SafeExamBrowser.Contracts.Lockdown
 		void Monitor();
 
 		/// <summary>
-		/// Restores the feature to its initial configuration.
+		/// Restores the feature to its previous configuration (i.e. before it was enabled or disabled).
 		/// </summary>
 		void Restore();
 	}

SafeExamBrowser.Contracts/Lockdown/IFeatureConfigurationBackup.cs

@@ -6,6 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using System.Collections.Generic;
 
 namespace SafeExamBrowser.Contracts.Lockdown
@@ -15,19 +16,24 @@ namespace SafeExamBrowser.Contracts.Lockdown
 	/// </summary>
 	public interface IFeatureConfigurationBackup
 	{
+		/// <summary>
+		/// Deletes the given <see cref="IFeatureConfiguration"/> from the backup repository.
+		/// </summary>
+		void Delete(IFeatureConfiguration configuration);
+
 		/// <summary>
 		/// Gets all <see cref="IFeatureConfiguration"/> currently saved in the backup repository.
 		/// </summary>
-		IList<IFeatureConfiguration> GetConfigurations();
+		IList<IFeatureConfiguration> GetAllConfigurations();
+
+		/// <summary>
+		/// Gets all <see cref="IFeatureConfiguration"/> which are part of the given group.
+		/// </summary>
+		IList<IFeatureConfiguration> GetBy(Guid groupId);
 
 		/// <summary>
 		/// Saves the given <see cref="IFeatureConfiguration"/> in the backup repository.
 		/// </summary>
 		void Save(IFeatureConfiguration configuration);
-
-		/// <summary>
-		/// Deletes the given <see cref="IFeatureConfiguration"/> from the backup repository.
-		/// </summary>
-		void Delete(IFeatureConfiguration configuration);
 	}
 }

SafeExamBrowser.Contracts/Lockdown/IFeatureConfigurationFactory.cs

@@ -6,6 +6,8 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
+
 namespace SafeExamBrowser.Contracts.Lockdown
 {
 	/// <summary>
@@ -16,61 +18,61 @@ namespace SafeExamBrowser.Contracts.Lockdown
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control notifications of the Google Chrome browser.
 		/// </summary>
-		IFeatureConfiguration CreateChromeNotificationConfiguration();
+		IFeatureConfiguration CreateChromeNotificationConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the ease of access options on the security screen.
 		/// </summary>
-		IFeatureConfiguration CreateEaseOfAccessConfiguration();
+		IFeatureConfiguration CreateEaseOfAccessConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the network options on the security screen.
 		/// </summary>
-		IFeatureConfiguration CreateNetworkOptionsConfiguration();
+		IFeatureConfiguration CreateNetworkOptionsConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the option to change the password of a user account via the security screen.
 		/// </summary>
-		IFeatureConfiguration CreatePasswordChangeConfiguration();
+		IFeatureConfiguration CreatePasswordChangeConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the power options on the security screen.
 		/// </summary>
-		IFeatureConfiguration CreatePowerOptionsConfiguration();
+		IFeatureConfiguration CreatePowerOptionsConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control remote desktop connections.
 		/// </summary>
-		IFeatureConfiguration CreateRemoteConnectionConfiguration();
+		IFeatureConfiguration CreateRemoteConnectionConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the option to sign out out via security screen.
 		/// </summary>
-		IFeatureConfiguration CreateSignoutConfiguration();
+		IFeatureConfiguration CreateSignoutConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the task manager of Windows.
 		/// </summary>
-		IFeatureConfiguration CreateTaskManagerConfiguration();
+		IFeatureConfiguration CreateTaskManagerConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the option to lock the computer via the security screen.
 		/// </summary>
-		IFeatureConfiguration CreateUserLockConfiguration();
+		IFeatureConfiguration CreateUserLockConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the option to switch to another user account via the security screen.
 		/// </summary>
-		IFeatureConfiguration CreateUserSwitchConfiguration();
+		IFeatureConfiguration CreateUserSwitchConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control the user interface overlay for VMware clients.
 		/// </summary>
-		IFeatureConfiguration CreateVmwareOverlayConfiguration();
+		IFeatureConfiguration CreateVmwareOverlayConfiguration(Guid groupId);
 
 		/// <summary>
 		/// Creates an <see cref="IFeatureConfiguration"/> to control Windows Update.
 		/// </summary>
-		IFeatureConfiguration CreateWindowsUpdateConfiguration();
+		IFeatureConfiguration CreateWindowsUpdateConfiguration(Guid groupId);
 	}
 }

SafeExamBrowser.Contracts/SafeExamBrowser.Contracts.csproj

@@ -92,6 +92,7 @@
     <Compile Include="Applications\Events\NameChangedEventHandler.cs" />
     <Compile Include="Applications\IApplicationController.cs" />
     <Compile Include="Applications\InstanceIdentifier.cs" />
+    <Compile Include="Lockdown\IAutoRestoreMechanism.cs" />
     <Compile Include="Lockdown\IFeatureConfiguration.cs" />
     <Compile Include="Lockdown\IFeatureConfigurationBackup.cs" />
     <Compile Include="Lockdown\IFeatureConfigurationFactory.cs" />

SafeExamBrowser.Lockdown/AutoRestoreMechanism.cs

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ *
+ * 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 SafeExamBrowser.Contracts.Lockdown;
+
+namespace SafeExamBrowser.Lockdown
+{
+	public class AutoRestoreMechanism : IAutoRestoreMechanism
+	{
+		private IFeatureConfigurationBackup backup;
+
+		public AutoRestoreMechanism(IFeatureConfigurationBackup backup)
+		{
+			this.backup = backup;
+		}
+
+		public void Start()
+		{
+			
+		}
+
+		public void Stop()
+		{
+			
+		}
+	}
+}

SafeExamBrowser.Lockdown/FeatureConfigurationBackup.cs

@@ -6,7 +6,12 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Runtime.Serialization.Formatters.Binary;
 using SafeExamBrowser.Contracts.Lockdown;
 using SafeExamBrowser.Contracts.Logging;
 
@@ -14,26 +19,114 @@ namespace SafeExamBrowser.Lockdown
 {
 	public class FeatureConfigurationBackup : IFeatureConfigurationBackup
 	{
-		private ILogger logger;
+		private readonly object @lock = new object();
 
-		public FeatureConfigurationBackup(ILogger logger)
+		private string filePath;
+		private IModuleLogger logger;
+
+		public FeatureConfigurationBackup(string filePath, IModuleLogger logger)
 		{
+			this.filePath = filePath;
 			this.logger = logger;
 		}
 
 		public void Delete(IFeatureConfiguration configuration)
 		{
-			
+			lock (@lock)
+			{
+				var configurations = LoadFromFile();
+				var obsolete = configurations.Find(c => c.Id == configuration.Id);
+				
+				if (obsolete != default(IFeatureConfiguration))
+				{
+					configurations.Remove(obsolete);
+					SaveToFile(configurations);
+					logger.Info($"Successfully removed {configuration} from backup.");
+				}
+				else
+				{
+					logger.Warn($"Could not delete {configuration} as it does not exists in backup!");
+				}
+			}
 		}
 
-		public IList<IFeatureConfiguration> GetConfigurations()
+		public IList<IFeatureConfiguration> GetAllConfigurations()
 		{
-			return new List<IFeatureConfiguration>();
+			lock (@lock)
+			{
+				return LoadFromFile();
+			}
+		}
+
+		public IList<IFeatureConfiguration> GetBy(Guid groupId)
+		{
+			lock (@lock)
+			{
+				return LoadFromFile().Where(c => c.GroupId == groupId).ToList();
+			}
 		}
 
 		public void Save(IFeatureConfiguration configuration)
 		{
-			
+			lock (@lock)
+			{
+				var configurations = LoadFromFile();
+
+				configurations.Add(configuration);
+				SaveToFile(configurations);
+				logger.Info($"Successfully added {configuration} to backup.");
+			}
+		}
+
+		private void SaveToFile(List<IFeatureConfiguration> configurations)
+		{
+			try
+			{
+				logger.Debug($"Attempting to save backup data to '{filePath}'...");
+
+				using (var stream = File.Open(filePath, FileMode.Create))
+				{
+					new BinaryFormatter().Serialize(stream, configurations);
+				}
+
+				logger.Debug($"Successfully saved {configurations.Count} items.");
+			}
+			catch (Exception e)
+			{
+				logger.Error($"Failed to save backup data to '{filePath}'!", e);
+			}
+		}
+
+		private List<IFeatureConfiguration> LoadFromFile()
+		{
+			var configurations = new List<IFeatureConfiguration>();
+
+			try
+			{
+				if (File.Exists(filePath))
+				{
+					var context = new StreamingContext(StreamingContextStates.All, logger);
+
+					logger.Debug($"Attempting to load backup data from '{filePath}'...");
+
+					using (var stream = File.Open(filePath, FileMode.Open))
+					{
+						configurations = (List<IFeatureConfiguration>) new BinaryFormatter(null, context).Deserialize(stream);
+					}
+
+					logger.Debug($"Backup data successfully loaded, found {configurations.Count} items.");
+				}
+				else
+				{
+					logger.Debug($"No backup data found under '{filePath}'.");
+				}
+			}
+			catch (Exception e)
+			{
+				logger.Error($"Failed to load backup data from '{filePath}'!", e);
+			}
+
+			return configurations;
 		}
 	}
 }

SafeExamBrowser.Lockdown/FeatureConfigurationFactory.cs

@@ -6,6 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using SafeExamBrowser.Contracts.Lockdown;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Lockdown.FeatureConfigurations;
@@ -21,64 +22,64 @@ namespace SafeExamBrowser.Lockdown
 			this.logger = logger;
 		}
 
-		public IFeatureConfiguration CreateChromeNotificationConfiguration()
+		public IFeatureConfiguration CreateChromeNotificationConfiguration(Guid groupId)
 		{
-			return new ChromeNotificationConfiguration();
+			return new ChromeNotificationConfiguration(groupId, logger.CloneFor(nameof(ChromeNotificationConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateEaseOfAccessConfiguration()
+		public IFeatureConfiguration CreateEaseOfAccessConfiguration(Guid groupId)
 		{
-			return new EaseOfAccessConfiguration();
+			return new EaseOfAccessConfiguration(groupId, logger.CloneFor(nameof(EaseOfAccessConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateNetworkOptionsConfiguration()
+		public IFeatureConfiguration CreateNetworkOptionsConfiguration(Guid groupId)
 		{
-			return new NetworkOptionsConfiguration();
+			return new NetworkOptionsConfiguration(groupId, logger.CloneFor(nameof(NetworkOptionsConfiguration)));
 		}
 
-		public IFeatureConfiguration CreatePasswordChangeConfiguration()
+		public IFeatureConfiguration CreatePasswordChangeConfiguration(Guid groupId)
 		{
-			return new PasswordChangeConfiguration();
+			return new PasswordChangeConfiguration(groupId, logger.CloneFor(nameof(PasswordChangeConfiguration)));
 		}
 
-		public IFeatureConfiguration CreatePowerOptionsConfiguration()
+		public IFeatureConfiguration CreatePowerOptionsConfiguration(Guid groupId)
 		{
-			return new PowerOptionsConfiguration();
+			return new PowerOptionsConfiguration(groupId, logger.CloneFor(nameof(PowerOptionsConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateRemoteConnectionConfiguration()
+		public IFeatureConfiguration CreateRemoteConnectionConfiguration(Guid groupId)
 		{
-			return new RemoteConnectionConfiguration();
+			return new RemoteConnectionConfiguration(groupId, logger.CloneFor(nameof(RemoteConnectionConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateSignoutConfiguration()
+		public IFeatureConfiguration CreateSignoutConfiguration(Guid groupId)
 		{
-			return new SignoutConfiguration();
+			return new SignoutConfiguration(groupId, logger.CloneFor(nameof(SignoutConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateTaskManagerConfiguration()
+		public IFeatureConfiguration CreateTaskManagerConfiguration(Guid groupId)
 		{
-			return new TaskManagerConfiguration();
+			return new TaskManagerConfiguration(groupId, logger.CloneFor(nameof(TaskManagerConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateUserLockConfiguration()
+		public IFeatureConfiguration CreateUserLockConfiguration(Guid groupId)
 		{
-			return new UserLockConfiguration();
+			return new UserLockConfiguration(groupId, logger.CloneFor(nameof(UserLockConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateUserSwitchConfiguration()
+		public IFeatureConfiguration CreateUserSwitchConfiguration(Guid groupId)
 		{
-			return new UserSwitchConfiguration();
+			return new UserSwitchConfiguration(groupId, logger.CloneFor(nameof(UserSwitchConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateVmwareOverlayConfiguration()
+		public IFeatureConfiguration CreateVmwareOverlayConfiguration(Guid groupId)
 		{
-			return new VmwareOverlayConfiguration();
+			return new VmwareOverlayConfiguration(groupId, logger.CloneFor(nameof(VmwareOverlayConfiguration)));
 		}
 
-		public IFeatureConfiguration CreateWindowsUpdateConfiguration()
+		public IFeatureConfiguration CreateWindowsUpdateConfiguration(Guid groupId)
 		{
-			return new WindowsUpdateConfiguration();
+			return new WindowsUpdateConfiguration(groupId, logger.CloneFor(nameof(WindowsUpdateConfiguration)));
 		}
 	}
 }

SafeExamBrowser.Lockdown/FeatureConfigurations/ChromeNotificationConfiguration.cs

@@ -6,30 +6,36 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class ChromeNotificationConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class ChromeNotificationConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public ChromeNotificationConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
 		{
-			
 		}
 
-		public void EnableFeature()
+		public override void DisableFeature()
 		{
-			
+			logger.Info("Disabling...");
 		}
 
-		public void Monitor()
+		public override void EnableFeature()
 		{
-			
+			logger.Info("Enabling...");
 		}
 
-		public void Restore()
+		public override void Monitor()
 		{
-			
+			logger.Info("Monitoring...");
+		}
+
+		public override void Restore()
+		{
+			logger.Info("Restoring...");
 		}
 	}
 }

SafeExamBrowser.Lockdown/FeatureConfigurations/EaseOfAccessConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class EaseOfAccessConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class EaseOfAccessConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public EaseOfAccessConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/FeatureConfiguration.cs

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
+ *
+ * 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.Runtime.Serialization;
+using SafeExamBrowser.Contracts.Lockdown;
+using SafeExamBrowser.Contracts.Logging;
+
+namespace SafeExamBrowser.Lockdown.FeatureConfigurations
+{
+	[Serializable]
+	internal abstract class FeatureConfiguration : IFeatureConfiguration
+	{
+		[NonSerialized]
+		protected ILogger logger;
+
+		public Guid Id { get; }
+		public Guid GroupId { get; }
+
+		public FeatureConfiguration(Guid groupId, ILogger logger)
+		{
+			this.GroupId = groupId;
+			this.Id = Guid.NewGuid();
+			this.logger = logger;
+		}
+
+		public abstract void DisableFeature();
+		public abstract void EnableFeature();
+		public abstract void Monitor();
+		public abstract void Restore();
+
+		public override string ToString()
+		{
+			return $"{GetType().Name} ({Id})";
+		}
+
+		[OnDeserialized]
+		private void OnDeserializedMethod(StreamingContext context)
+		{
+			logger = (context.Context as IModuleLogger).CloneFor(GetType().Name);
+		}
+	}
+}

SafeExamBrowser.Lockdown/FeatureConfigurations/NetworkOptionsConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class NetworkOptionsConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class NetworkOptionsConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public NetworkOptionsConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/PasswordChangeConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class PasswordChangeConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class PasswordChangeConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public PasswordChangeConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/PowerOptionsConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class PowerOptionsConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class PowerOptionsConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public PowerOptionsConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/RemoteConnectionConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class RemoteConnectionConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class RemoteConnectionConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public RemoteConnectionConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/SignoutConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class SignoutConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class SignoutConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public SignoutConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/TaskManagerConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class TaskManagerConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class TaskManagerConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public TaskManagerConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/UserLockConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class UserLockConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class UserLockConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public UserLockConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/UserSwitchConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class UserSwitchConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class UserSwitchConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public UserSwitchConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/VmwareOverlayConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class VmwareOverlayConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class VmwareOverlayConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public VmwareOverlayConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/FeatureConfigurations/WindowsUpdateConfiguration.cs

@@ -6,28 +6,34 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-using SafeExamBrowser.Contracts.Lockdown;
+using System;
+using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Lockdown.FeatureConfigurations
 {
-	internal class WindowsUpdateConfiguration : IFeatureConfiguration
+	[Serializable]
+	internal class WindowsUpdateConfiguration : FeatureConfiguration
 	{
-		public void DisableFeature()
+		public WindowsUpdateConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+
+		public override void DisableFeature()
 		{
 
 		}
 
-		public void EnableFeature()
+		public override void EnableFeature()
 		{
 
 		}
 
-		public void Monitor()
+		public override void Monitor()
 		{
 
 		}
 
-		public void Restore()
+		public override void Restore()
 		{
 
 		}

SafeExamBrowser.Lockdown/SafeExamBrowser.Lockdown.csproj

@@ -53,9 +53,11 @@
     <Reference Include="Microsoft.CSharp" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="AutoRestoreMechanism.cs" />
     <Compile Include="FeatureConfigurationFactory.cs" />
     <Compile Include="FeatureConfigurationBackup.cs" />
     <Compile Include="FeatureConfigurations\ChromeNotificationConfiguration.cs" />
+    <Compile Include="FeatureConfigurations\FeatureConfiguration.cs" />
     <Compile Include="FeatureConfigurations\TaskManagerConfiguration.cs" />
     <Compile Include="FeatureConfigurations\EaseOfAccessConfiguration.cs" />
     <Compile Include="FeatureConfigurations\NetworkOptionsConfiguration.cs" />

SafeExamBrowser.Service.UnitTests/Operations/SessionInitializationOperationTests.cs

@@ -14,6 +14,7 @@ using Moq;
 using SafeExamBrowser.Contracts.Communication.Hosts;
 using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Core.OperationModel;
+using SafeExamBrowser.Contracts.Lockdown;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Service.Operations;
 
@@ -22,6 +23,7 @@ namespace SafeExamBrowser.Service.UnitTests.Operations
 	[TestClass]
 	public class SessionInitializationOperationTests
 	{
+		private Mock<IAutoRestoreMechanism> autoRestoreMechanism;
 		private Mock<ILogger> logger;
 		private Mock<Func<string, ILogObserver>> logWriterFactory;
 		private Mock<IServiceHost> serviceHost;
@@ -32,6 +34,7 @@ namespace SafeExamBrowser.Service.UnitTests.Operations
 		[TestInitialize]
 		public void Initialize()
 		{
+			autoRestoreMechanism = new Mock<IAutoRestoreMechanism>();
 			logger = new Mock<ILogger>();
 			logWriterFactory = new Mock<Func<string, ILogObserver>>();
 			serviceHost = new Mock<IServiceHost>();
@@ -40,6 +43,7 @@ namespace SafeExamBrowser.Service.UnitTests.Operations
 
 			logWriterFactory.Setup(f => f.Invoke(It.IsAny<string>())).Returns(new Mock<ILogObserver>().Object);
 			serviceEventFactory.Setup(f => f.Invoke(It.IsAny<string>())).Returns(new EventStub());
+			sessionContext.AutoRestoreMechanism = autoRestoreMechanism.Object;
 			sessionContext.Configuration = new ServiceConfiguration
 			{
 				AppConfig = new AppConfig { ServiceEventName = $"{nameof(SafeExamBrowser)}-{nameof(SessionInitializationOperationTests)}" }
@@ -74,18 +78,12 @@ namespace SafeExamBrowser.Service.UnitTests.Operations
 		}
 
 		[TestMethod]
-		public void Revert_MustSetServiceEvent()
+		public void Perform_MustStopAutoRestoreMechanism()
 		{
-			sessionContext.ServiceEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
+			var result = sut.Perform();
-
-			var wasSet = false;
-			var task = Task.Run(() => wasSet = sessionContext.ServiceEvent.WaitOne(1000));
-			var result = sut.Revert();
-
-			task.Wait();
 
+			autoRestoreMechanism.Verify(m => m.Stop(), Times.Once);
 			Assert.AreEqual(OperationResult.Success, result);
-			Assert.IsTrue(wasSet);
 		}
 
 		[TestMethod]
@@ -110,5 +108,29 @@ namespace SafeExamBrowser.Service.UnitTests.Operations
 			serviceHost.VerifySet(h => h.AllowConnection = true, Times.Once);
 			Assert.AreEqual(OperationResult.Success, result);
 		}
+
+		[TestMethod]
+		public void Revert_MustSetServiceEvent()
+		{
+			sessionContext.ServiceEvent = new EventWaitHandle(false, EventResetMode.AutoReset);
+
+			var wasSet = false;
+			var task = Task.Run(() => wasSet = sessionContext.ServiceEvent.WaitOne(1000));
+			var result = sut.Revert();
+
+			task.Wait();
+
+			Assert.AreEqual(OperationResult.Success, result);
+			Assert.IsTrue(wasSet);
+		}
+
+		[TestMethod]
+		public void Revert_MustStartAutoRestoreMechanism()
+		{
+			var result = sut.Revert();
+
+			autoRestoreMechanism.Verify(m => m.Start(), Times.Once);
+			Assert.AreEqual(OperationResult.Success, result);
+		}
 	}
 }

SafeExamBrowser.Service/CompositionRoot.cs

@@ -14,6 +14,7 @@ using System.Security.Principal;
 using System.Threading;
 using SafeExamBrowser.Communication.Hosts;
 using SafeExamBrowser.Communication.Proxies;
+using SafeExamBrowser.Contracts.Configuration;
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Contracts.Service;
@@ -34,21 +35,23 @@ namespace SafeExamBrowser.Service
 
 		internal void BuildObjectGraph()
 		{
-			const string SERVICE_ADDRESS = "net.pipe://localhost/safeexambrowser/service";
 			const int FIVE_SECONDS = 5000;
+			var backupFile = BuildBackupFilePath();
 
 			InitializeLogging();
 
-			var featureBackup = new FeatureConfigurationBackup(new ModuleLogger(logger, nameof(FeatureConfigurationBackup)));
+			var featureBackup = new FeatureConfigurationBackup(backupFile, new ModuleLogger(logger, nameof(FeatureConfigurationBackup)));
 			var featureFactory = new FeatureConfigurationFactory(new ModuleLogger(logger, nameof(FeatureConfigurationFactory)));
 			var proxyFactory = new ProxyFactory(new ProxyObjectFactory(), new ModuleLogger(logger, nameof(ProxyFactory)));
-			var serviceHost = new ServiceHost(SERVICE_ADDRESS, new HostObjectFactory(), new ModuleLogger(logger, nameof(ServiceHost)), FIVE_SECONDS);
+			var serviceHost = new ServiceHost(AppConfig.SERVICE_ADDRESS, new HostObjectFactory(), new ModuleLogger(logger, nameof(ServiceHost)), FIVE_SECONDS);
 			var sessionContext = new SessionContext();
 
 			var bootstrapOperations = new Queue<IOperation>();
 			var sessionOperations = new Queue<IOperation>();
 
-			bootstrapOperations.Enqueue(new RestoreOperation(logger));
+			sessionContext.AutoRestoreMechanism = new AutoRestoreMechanism(featureBackup);
+
+			bootstrapOperations.Enqueue(new RestoreOperation(featureBackup, logger, sessionContext));
 			bootstrapOperations.Enqueue(new CommunicationHostOperation(serviceHost, logger));
 			bootstrapOperations.Enqueue(new ServiceEventCleanupOperation(logger, sessionContext));
 
@@ -62,6 +65,14 @@ namespace SafeExamBrowser.Service
 			ServiceController = new ServiceController(logger, bootstrapSequence, sessionSequence, serviceHost, sessionContext);
 		}
 
+		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")}");

SafeExamBrowser.Service/Operations/LockdownOperation.cs

@@ -6,6 +6,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
+using System;
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Lockdown;
 using SafeExamBrowser.Contracts.Logging;
@@ -17,6 +18,7 @@ namespace SafeExamBrowser.Service.Operations
 		private IFeatureConfigurationBackup backup;
 		private IFeatureConfigurationFactory factory;
 		private ILogger logger;
+		private Guid groupId;
 
 		public LockdownOperation(
 			IFeatureConfigurationBackup backup,
@@ -31,18 +33,21 @@ namespace SafeExamBrowser.Service.Operations
 
 		public override OperationResult Perform()
 		{
-			var chromeNotification = factory.CreateChromeNotificationConfiguration();
+			groupId = Guid.NewGuid();
-			var easeOfAccess = factory.CreateEaseOfAccessConfiguration();
+			logger.Info($"Attempting to perform lockdown (feature configuration group: {groupId})...");
-			var networkOptions = factory.CreateNetworkOptionsConfiguration();
+
-			var passwordChange = factory.CreatePasswordChangeConfiguration();
+			var chromeNotification = factory.CreateChromeNotificationConfiguration(groupId);
-			var powerOptions = factory.CreatePowerOptionsConfiguration();
+			var easeOfAccess = factory.CreateEaseOfAccessConfiguration(groupId);
-			var remoteConnection = factory.CreateRemoteConnectionConfiguration();
+			var networkOptions = factory.CreateNetworkOptionsConfiguration(groupId);
-			var signout = factory.CreateSignoutConfiguration();
+			var passwordChange = factory.CreatePasswordChangeConfiguration(groupId);
-			var taskManager = factory.CreateTaskManagerConfiguration();
+			var powerOptions = factory.CreatePowerOptionsConfiguration(groupId);
-			var userLock = factory.CreateUserLockConfiguration();
+			var remoteConnection = factory.CreateRemoteConnectionConfiguration(groupId);
-			var userSwitch = factory.CreateUserSwitchConfiguration();
+			var signout = factory.CreateSignoutConfiguration(groupId);
-			var vmwareOverlay = factory.CreateVmwareOverlayConfiguration();
+			var taskManager = factory.CreateTaskManagerConfiguration(groupId);
-			var windowsUpdate = factory.CreateWindowsUpdateConfiguration();
+			var userLock = factory.CreateUserLockConfiguration(groupId);
+			var userSwitch = factory.CreateUserSwitchConfiguration(groupId);
+			var vmwareOverlay = factory.CreateVmwareOverlayConfiguration(groupId);
+			var windowsUpdate = factory.CreateWindowsUpdateConfiguration(groupId);
 
 			SetConfiguration(chromeNotification, Context.Configuration.Settings.Service.DisableChromeNotifications);
 			SetConfiguration(easeOfAccess, Context.Configuration.Settings.Service.DisableEaseOfAccessOptions);
@@ -57,12 +62,16 @@ namespace SafeExamBrowser.Service.Operations
 			SetConfiguration(vmwareOverlay, Context.Configuration.Settings.Service.DisableVmwareOverlay);
 			SetConfiguration(windowsUpdate, Context.Configuration.Settings.Service.DisableWindowsUpdate);
 
+			logger.Info("Lockdown successful.");
+
 			return OperationResult.Success;
 		}
 
 		public override OperationResult Revert()
 		{
-			var configurations = backup.GetConfigurations();
+			logger.Info($"Attempting to revert lockdown (feature configuration group: {groupId})...");
+
+			var configurations = backup.GetBy(groupId);
 
 			foreach (var configuration in configurations)
 			{
@@ -70,6 +79,8 @@ namespace SafeExamBrowser.Service.Operations
 				backup.Delete(configuration);
 			}
 
+			logger.Info("Lockdown reversion successful.");
+
 			return OperationResult.Success;
 		}
 

SafeExamBrowser.Service/Operations/RestoreOperation.cs

@@ -8,32 +8,40 @@
 
 using SafeExamBrowser.Contracts.Core.OperationModel;
 using SafeExamBrowser.Contracts.Core.OperationModel.Events;
+using SafeExamBrowser.Contracts.Lockdown;
 using SafeExamBrowser.Contracts.Logging;
 
 namespace SafeExamBrowser.Service.Operations
 {
 	internal class RestoreOperation : IOperation
 	{
+		private readonly IFeatureConfigurationBackup backup;
 		private ILogger logger;
+		private readonly SessionContext sessionContext;
 
 		public event ActionRequiredEventHandler ActionRequired { add { } remove { } }
 		public event StatusChangedEventHandler StatusChanged { add { } remove { } }
 
-		public RestoreOperation(ILogger logger)
+		public RestoreOperation(IFeatureConfigurationBackup backup, ILogger logger, SessionContext sessionContext)
 		{
+			this.backup = backup;
 			this.logger = logger;
+			this.sessionContext = sessionContext;
 		}
 
 		public OperationResult Perform()
 		{
-			// TODO: Must not delay startup! If restore does not succeed on first attempt, try again in separate thread!
+			logger.Info("Starting auto-restore mechanism...");
-			//         -> Ensure session cannot be started until values are restored or alike!
+			sessionContext.AutoRestoreMechanism.Start();
 
 			return OperationResult.Success;
 		}
 
 		public OperationResult Revert()
 		{
+			logger.Info("Stopping auto-restore mechanism...");
+			sessionContext.AutoRestoreMechanism.Stop();
+
 			return OperationResult.Success;
 		}
 	}

SafeExamBrowser.Service/Operations/SessionInitializationOperation.cs

@@ -40,12 +40,16 @@ namespace SafeExamBrowser.Service.Operations
 			InitializeSessionWriter();
 
 			logger.Info("Initializing new session...");
-
-			serviceHost.AllowConnection = false;
 			logger.Info($" -> Client-ID: {Context.Configuration.AppConfig.ClientId}");
 			logger.Info($" -> Runtime-ID: {Context.Configuration.AppConfig.RuntimeId}");
 			logger.Info($" -> Session-ID: {Context.Configuration.SessionId}");
 
+			logger.Info("Stopping auto-restore mechanism...");
+			Context.AutoRestoreMechanism.Stop();
+
+			logger.Info("Disabling service host...");
+			serviceHost.AllowConnection = false;
+
 			InitializeServiceEvent();
 
 			return OperationResult.Success;
@@ -71,11 +75,17 @@ namespace SafeExamBrowser.Service.Operations
 				}
 			}
 
-			Context.Configuration = null;
+			logger.Info("Starting auto-restore mechanism...");
-			logger.Unsubscribe(sessionWriter);
+			Context.AutoRestoreMechanism.Start();
-			sessionWriter = null;
+
+			logger.Info("Enabling service host...");
 			serviceHost.AllowConnection = true;
 
+			logger.Info("Clearing session data...");
+			Context.Configuration = null;
+
+			FinalizeSessionWriter();
+
 			return success ? OperationResult.Success : OperationResult.Failed;
 		}
 
@@ -97,6 +107,14 @@ namespace SafeExamBrowser.Service.Operations
 		{
 			sessionWriter = logWriterFactory.Invoke(Context.Configuration.AppConfig.ServiceLogFilePath);
 			logger.Subscribe(sessionWriter);
+			logger.Debug($"Created session log file {Context.Configuration.AppConfig.ServiceLogFilePath}.");
+		}
+
+		private void FinalizeSessionWriter()
+		{
+			logger.Debug("Closed session log file.");
+			logger.Unsubscribe(sessionWriter);
+			sessionWriter = null;
 		}
 	}
 }

SafeExamBrowser.Service/SessionContext.cs

@@ -8,6 +8,7 @@
 
 using System.Threading;
 using SafeExamBrowser.Contracts.Configuration;
+using SafeExamBrowser.Contracts.Lockdown;
 
 namespace SafeExamBrowser.Service
 {
@@ -16,6 +17,11 @@ namespace SafeExamBrowser.Service
 	/// </summary>
 	internal class SessionContext
 	{
+		/// <summary>
+		/// The mechanism trying to restore all changes after an application or system failure.
+		/// </summary>
+		internal IAutoRestoreMechanism AutoRestoreMechanism { get; set; }
+
 		/// <summary>
 		/// The configuration of the currently active session.
 		/// </summary>