SEBWIN-322: Implemented service configuration infrastructure and windows update service deactivation.

SafeExamBrowser.Lockdown.UnitTests/AutoRestoreMechanismTests.cs

@@ -145,7 +145,7 @@ namespace SafeExamBrowser.Lockdown.UnitTests
 			Thread.Sleep(25);
 			sut.Stop();
 
-			backup.Verify(b => b.GetAllConfigurations(), Times.Exactly(counter));
+			backup.Verify(b => b.GetAllConfigurations(), Times.Between(counter, counter + 1, Range.Inclusive));
 		}
 
 		[TestMethod]

SafeExamBrowser.Lockdown/FeatureConfigurationFactory.cs

@@ -9,9 +9,9 @@
 using System;
 using SafeExamBrowser.Contracts.Lockdown;
 using SafeExamBrowser.Contracts.Logging;
-using SafeExamBrowser.Lockdown.FeatureConfigurations;
 using SafeExamBrowser.Lockdown.FeatureConfigurations.RegistryConfigurations.MachineHive;
 using SafeExamBrowser.Lockdown.FeatureConfigurations.RegistryConfigurations.UserHive;
+using SafeExamBrowser.Lockdown.FeatureConfigurations.ServiceConfigurations;
 
 namespace SafeExamBrowser.Lockdown
 {

SafeExamBrowser.Lockdown/FeatureConfigurations/ServiceConfigurations/ServiceConfiguration.cs

@@ -0,0 +1,288 @@
+/*
+ * 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.Collections.Generic;
+using System.Linq;
+using System.ServiceProcess;
+using SafeExamBrowser.Contracts.Lockdown;
+using SafeExamBrowser.Contracts.Logging;
+
+namespace SafeExamBrowser.Lockdown.FeatureConfigurations.ServiceConfigurations
+{
+	[Serializable]
+	internal abstract class ServiceConfiguration : FeatureConfiguration
+	{
+		private static readonly TimeSpan FIVE_SECONDS = TimeSpan.FromSeconds(5);
+		private IList<ServiceDataItem> originalItems;
+
+		protected abstract IEnumerable<ServiceConfigurationItem> Items { get; }
+
+		public ServiceConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+			originalItems = new List<ServiceDataItem>();
+		}
+
+		public override bool DisableFeature()
+		{
+			var success = true;
+
+			foreach (var item in Items)
+			{
+				success &= TrySet(new ServiceDataItem { Name = item.Name, Status = item.Disabled });
+			}
+
+			if (success)
+			{
+				logger.Info("Successfully disabled feature.");
+			}
+			else
+			{
+				logger.Warn("Failed to disable feature!");
+			}
+
+			return success;
+		}
+
+		public override bool EnableFeature()
+		{
+			var success = true;
+
+			foreach (var item in Items)
+			{
+				success &= TrySet(new ServiceDataItem { Name = item.Name, Status = item.Enabled });
+			}
+
+			if (success)
+			{
+				logger.Info("Successfully enabled feature.");
+			}
+			else
+			{
+				logger.Warn("Failed to enable feature!");
+			}
+
+			return success;
+		}
+
+		public override FeatureConfigurationStatus GetStatus()
+		{
+			var status = FeatureConfigurationStatus.Undefined;
+
+			foreach (var item in Items)
+			{
+				var current = ReadService(item.Name);
+
+				if (current.Status == item.Disabled && status != FeatureConfigurationStatus.Enabled)
+				{
+					status = FeatureConfigurationStatus.Disabled;
+				}
+				else if (current.Status == item.Enabled && status != FeatureConfigurationStatus.Disabled)
+				{
+					status = FeatureConfigurationStatus.Enabled;
+				}
+				else
+				{
+					status = FeatureConfigurationStatus.Undefined;
+
+					break;
+				}
+			}
+
+			return status;
+		}
+
+		public override void Initialize()
+		{
+			foreach (var item in Items)
+			{
+				var original = ReadService(item.Name);
+
+				if (original.Status != ServiceStatus.NotAvailable)
+				{
+					originalItems.Add(original);
+				}
+			}
+		}
+
+		public override bool Restore()
+		{
+			foreach (var item in new List<ServiceDataItem>(originalItems))
+			{
+				if (TrySet(item))
+				{
+					originalItems.Remove(item);
+				}
+			}
+
+			var success = !originalItems.Any();
+
+			if (success)
+			{
+				logger.Info("Successfully restored feature.");
+			}
+			else
+			{
+				logger.Warn("Failed to restore feature!");
+			}
+
+			return success;
+		}
+
+		private ServiceDataItem ReadService(string name)
+		{
+			var item = new ServiceDataItem { Name = name, Status = ServiceStatus.NotAvailable };
+
+			try
+			{
+				using (var service = new ServiceController(name))
+				{
+					item.Status = ToStatus(service.Status);
+				}
+			}
+			catch (Exception e)
+			{
+				logger.Error($"Failed to retrieve status of service '{name}'!", e);
+			}
+
+			return item;
+		}
+
+		private bool TrySet(ServiceDataItem item)
+		{
+			var success = false;
+
+			try
+			{
+				if (IsAvailable(item))
+				{
+					using (var service = new ServiceController(item.Name))
+					{
+						if (item.Status == ServiceStatus.Running)
+						{
+							success = TryStart(service);
+						}
+						else if (item.Status == ServiceStatus.Stopped)
+						{
+							success = TryStop(service);
+						}
+
+						if (success)
+						{
+							logger.Debug($"Successfully set service {item}.");
+						}
+						else
+						{
+							logger.Warn($"Could not set service {item}! Current status: {service.Status}.");
+						}
+					}
+				}
+				else
+				{
+					logger.Warn($"Cannot set service {item} as it does not exist!");
+				}
+			}
+			catch (Exception e)
+			{
+				logger.Error($"Failed to set service {item}!", e);
+			}
+
+			return success;
+		}
+
+		private bool TryStart(ServiceController service)
+		{
+			var success = true;
+
+			if (service.Status == ServiceControllerStatus.PausePending)
+			{
+				service.WaitForStatus(ServiceControllerStatus.Paused, FIVE_SECONDS);
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.Paused)
+			{
+				service.Continue();
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.Stopped)
+			{
+				service.Start();
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.StartPending || service.Status == ServiceControllerStatus.ContinuePending)
+			{
+				service.WaitForStatus(ServiceControllerStatus.Running, FIVE_SECONDS);
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.Running)
+			{
+				success = true;
+			}
+
+			return success;
+		}
+
+		private bool TryStop(ServiceController service)
+		{
+			var success = false;
+
+			if (service.Status == ServiceControllerStatus.Paused)
+			{
+				service.Continue();
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.StartPending || service.Status == ServiceControllerStatus.ContinuePending)
+			{
+				service.WaitForStatus(ServiceControllerStatus.Running, FIVE_SECONDS);
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.Running)
+			{
+				service.Stop();
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.StopPending)
+			{
+				service.WaitForStatus(ServiceControllerStatus.Stopped, FIVE_SECONDS);
+				service.Refresh();
+			}
+
+			if (service.Status == ServiceControllerStatus.Stopped)
+			{
+				success = true;
+			}
+
+			return success;
+		}
+
+		private bool IsAvailable(ServiceDataItem item)
+		{
+			return ServiceController.GetServices().Any(s => s.ServiceName == item.Name);
+		}
+
+		private ServiceStatus ToStatus(ServiceControllerStatus status)
+		{
+			switch (status)
+			{
+				case ServiceControllerStatus.ContinuePending:
+				case ServiceControllerStatus.Running:
+				case ServiceControllerStatus.StartPending:
+					return ServiceStatus.Running;
+				default:
+					return ServiceStatus.Stopped;
+			}
+		}
+	}
+}

SafeExamBrowser.Lockdown/FeatureConfigurations/ServiceConfigurations/ServiceConfigurationItem.cs

@@ -0,0 +1,24 @@
+/*
+ * 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.Lockdown.FeatureConfigurations.ServiceConfigurations
+{
+	internal class ServiceConfigurationItem
+	{
+		internal ServiceStatus Disabled { get; }
+		internal ServiceStatus Enabled { get; }
+		internal string Name { get; }
+
+		internal ServiceConfigurationItem(string name, ServiceStatus disabled, ServiceStatus enabled)
+		{
+			Disabled = disabled;
+			Enabled = enabled;
+			Name = name;
+		}
+	}
+}

SafeExamBrowser.Lockdown/FeatureConfigurations/ServiceConfigurations/ServiceDataItem.cs

@@ -0,0 +1,24 @@
+/*
+ * 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;
+
+namespace SafeExamBrowser.Lockdown.FeatureConfigurations.ServiceConfigurations
+{
+	[Serializable]
+	internal class ServiceDataItem
+	{
+		internal string Name { get; set; }
+		internal ServiceStatus Status { get; set; }
+
+		public override string ToString()
+		{
+			return $@"'{Name}' => '{(Status == ServiceStatus.Running ? ServiceStatus.Running.ToString().ToLower() : ServiceStatus.Stopped.ToString().ToLower())}'";
+		}
+	}
+}

SafeExamBrowser.Lockdown/FeatureConfigurations/ServiceConfigurations/ServiceStatus.cs

@@ -0,0 +1,17 @@
+/*
+ * 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.Lockdown.FeatureConfigurations.ServiceConfigurations
+{
+	internal enum ServiceStatus
+	{
+		NotAvailable,
+		Running,
+		Stopped
+	}
+}

SafeExamBrowser.Lockdown/FeatureConfigurations/ServiceConfigurations/WindowsUpdateConfiguration.cs

@@ -0,0 +1,27 @@
+/*
+ * 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.Collections.Generic;
+using SafeExamBrowser.Contracts.Logging;
+
+namespace SafeExamBrowser.Lockdown.FeatureConfigurations.ServiceConfigurations
+{
+	[Serializable]
+	internal class WindowsUpdateConfiguration : ServiceConfiguration
+	{
+		protected override IEnumerable<ServiceConfigurationItem> Items => new []
+		{
+			new ServiceConfigurationItem("wuauserv", ServiceStatus.Stopped, ServiceStatus.Running)
+		};
+
+		public WindowsUpdateConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
+		{
+		}
+	}
+}

SafeExamBrowser.Lockdown/FeatureConfigurations/WindowsUpdateConfiguration.cs

@@ -1,47 +0,0 @@
-/*
- * 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 SafeExamBrowser.Contracts.Lockdown;
-using SafeExamBrowser.Contracts.Logging;
-
-namespace SafeExamBrowser.Lockdown.FeatureConfigurations
-{
-	[Serializable]
-	internal class WindowsUpdateConfiguration : FeatureConfiguration
-	{
-		public WindowsUpdateConfiguration(Guid groupId, ILogger logger) : base(groupId, logger)
-		{
-		}
-
-		public override bool DisableFeature()
-		{
-			return true;
-		}
-
-		public override bool EnableFeature()
-		{
-			return true;
-		}
-
-		public override FeatureConfigurationStatus GetStatus()
-		{
-			return FeatureConfigurationStatus.Undefined;
-		}
-
-		public override void Initialize()
-		{
-
-		}
-
-		public override bool Restore()
-		{
-			return true;
-		}
-	}
-}

SafeExamBrowser.Lockdown/SafeExamBrowser.Lockdown.csproj

@@ -51,6 +51,7 @@
   <ItemGroup>
     <Reference Include="System" />
     <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.ServiceProcess" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="AutoRestoreMechanism.cs" />
@@ -74,7 +75,11 @@
     <Compile Include="FeatureConfigurations\RegistryConfigurations\UserHive\LockWorkstationConfiguration.cs" />
     <Compile Include="FeatureConfigurations\RegistryConfigurations\MachineHive\SwitchUserConfiguration.cs" />
     <Compile Include="FeatureConfigurations\RegistryConfigurations\UserHive\VmwareOverlayConfiguration.cs" />
-    <Compile Include="FeatureConfigurations\WindowsUpdateConfiguration.cs" />
+    <Compile Include="FeatureConfigurations\ServiceConfigurations\ServiceConfiguration.cs" />
+    <Compile Include="FeatureConfigurations\ServiceConfigurations\ServiceConfigurationItem.cs" />
+    <Compile Include="FeatureConfigurations\ServiceConfigurations\ServiceDataItem.cs" />
+    <Compile Include="FeatureConfigurations\ServiceConfigurations\ServiceStatus.cs" />
+    <Compile Include="FeatureConfigurations\ServiceConfigurations\WindowsUpdateConfiguration.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="SystemConfigurationUpdate.cs" />
   </ItemGroup>