Restore SEBPatch

SafeExamBrowser.ResetUtility/Procedure/Initialization.cs

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+/*
+ * 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.Security.Principal;
+using System.Threading;
+using SafeExamBrowser.Configuration.Contracts;
+
+namespace SafeExamBrowser.ResetUtility.Procedure
+{
+	internal class Initialization : ProcedureStep
+	{
+		private static readonly Mutex mutex = new Mutex(true, AppConfig.SERVICE_MUTEX_NAME);
+
+		public Initialization(ProcedureContext context) : base(context)
+		{
+		}
+
+		internal override ProcedureStepResult Execute()
+		{
+			InitializeConsole();
+
+			if (IsSingleInstance() && HasAdminPrivileges() && SebNotRunning())
+			{
+				return ProcedureStepResult.Continue;
+			}
+			else
+			{
+				return ProcedureStepResult.Terminate;
+			}
+		}
+
+		internal override ProcedureStep GetNextStep()
+		{
+			return new MainMenu(Context);
+		}
+
+		private bool IsSingleInstance()
+		{
+			var isSingle = mutex.WaitOne(TimeSpan.Zero, true);
+
+			if (isSingle)
+			{
+				Logger.Info("There is currently no other instance running.");
+			}
+			else
+			{
+				Logger.Error("There is currently another instance running! Terminating...");
+				ShowError("You can only run one instance of the Reset Utility at a time! Press any key to exit...");
+			}
+
+			return isSingle;
+		}
+
+		private bool HasAdminPrivileges()
+		{
+			var identity = WindowsIdentity.GetCurrent();
+			var principal = new WindowsPrincipal(identity);
+			var isAdmin = principal.IsInRole(WindowsBuiltInRole.Administrator);
+
+			if (isAdmin)
+			{
+				Logger.Info($"User '{identity.Name}' is running the application with administrator privileges.");
+			}
+			else
+			{
+				Logger.Error($"User '{identity.Name}' is running the application without administrator privileges! Terminating...");
+				ShowError("This application must be run with administrator privileges! Press any key to exit...");
+			}
+
+			return isAdmin;
+		}
+
+		private bool SebNotRunning()
+		{
+			var isRunning = Mutex.TryOpenExisting(AppConfig.RUNTIME_MUTEX_NAME, out _);
+
+			if (isRunning)
+			{
+				Logger.Error("SEB is currently running! Terminating...");
+				ShowError("This application must not be run while SEB is running! Press any key to exit...");
+			}
+			else
+			{
+				Logger.Info("SEB is currently not running.");
+			}
+
+			return !isRunning;
+		}
+	}
+}