prevent running application as admin

Author: LeftofZen

Gui/PlatformSpecific.cs

@@ -7,12 +7,42 @@
 using System.Diagnostics;
 using System.IO;
 using System.Runtime.InteropServices;
+using System.Security.Principal;
 using System.Threading.Tasks;
 
 namespace OpenLoco.Gui
 {
+	// For Unix-like systems (Linux, macOS)
+	static class UnixUserChecker
+	{
+		// Imports the geteuid() function from libc (the standard C library)
+		// geteuid() returns the effective user ID of the calling process.
+		// A value of 0 typically indicates the root user.
+		[DllImport("libc", EntryPoint = "geteuid")]
+		internal static extern uint geteuid();
+
+		public static bool IsRoot()
+			=> geteuid() == 0;
+	}
+
 	public static class PlatformSpecific
 	{
+		public static bool RunningAsAdmin()
+		{
+			if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+			{
+				var identity = WindowsIdentity.GetCurrent();
+				var principal = new WindowsPrincipal(identity);
+				return principal.IsInRole(WindowsBuiltInRole.Administrator);
+			}
+			else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux) || RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
+			{
+				return UnixUserChecker.IsRoot();
+			}
+
+			return false;
+		}
+
 		public static void FolderOpenInDesktop(string directory, ILogger logger)
 		{
 			try

Gui/Program.cs

@@ -11,8 +11,26 @@ class Program
 		// SynchronizationContext-reliant code before AppMain is called: things aren't initialized
 		// yet and stuff might break.
 		[STAThread]
-		public static void Main(string[] args) => BuildAvaloniaApp()
-			.StartWithClassicDesktopLifetime(args);
+		public static void Main(string[] args)
+		{
+			PreventRunningAsAdmin();
+			_ = BuildAvaloniaApp()
+				.StartWithClassicDesktopLifetime(args);
+		}
+
+		static void PreventRunningAsAdmin()
+		{
+			if (PlatformSpecific.RunningAsAdmin())
+			{
+				const string errorMessage = "This application should not be run with elevated privileges. Please run it as a regular user.";
+
+				// show user a message. must be OS-independent
+				Console.Error.WriteLine(errorMessage);
+
+				// terminate current program
+				throw new UnauthorizedAccessException(errorMessage);
+			}
+		}
 
 		// Avalonia configuration, don't remove; also used by visual designer.
 		public static AppBuilder BuildAvaloniaApp()

Gui/app.manifest

@@ -1,15 +1,15 @@
 <?xml version="1.0" encoding="utf-8"?>
 <assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
 	<!-- This manifest is used on Windows only.
-       Don't remove it as it might cause problems with window transparency and embeded controls.
-       For more details visit https://learn.microsoft.com/en-us/windows/win32/sbscs/application-manifests -->
+		Don't remove it as it might cause problems with window transparency and embedded controls.
+		For more details visit https://learn.microsoft.com/en-us/windows/win32/sbscs/application-manifests -->
 	<assemblyIdentity version="1.0.0.0" name="OpenLoco.Gui.Desktop"/>
 
 	<compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
 		<application>
 			<!-- A list of the Windows versions that this application has been tested on
-           and is designed to work with. Uncomment the appropriate elements
-           and Windows will automatically select the most compatible environment. -->
+			and is designed to work with. Uncomment the appropriate elements
+			and Windows will automatically select the most compatible environment. -->
 
 			<!-- Windows 10 -->
 			<supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />