Launch app into Winlogon desktop when LogonUI.exe or consent.exe is present in the target session.

Author: jared-at-immy

Agent/Services/Windows/AppLauncherWin.cs

@@ -49,8 +49,6 @@ public async Task<int> LaunchChatService(string pipeName, string userConnectionI
                         $" --org-name \"{orgName}\"" +
                         $" --org-id \"{orgId}\"",
                     targetSessionId: -1,
-                    forceConsoleSession: false,
-                    desktopName: "default",
                     hiddenWindow: false,
                     out var procInfo);
                 if (!result)
@@ -122,8 +120,6 @@ await hubConnection.SendAsync("DisplayMessage",
                         $" --session-id \"{sessionId}\"" +
                         $" --access-key \"{accessKey}\"",
                     targetSessionId: targetSessionId,
-                    forceConsoleSession: Shlwapi.IsOS(OsType.OS_ANYSERVER) && targetSessionId == -1,
-                    desktopName: "default",
                     hiddenWindow: false,
                     out _);
                 if (!result)
@@ -180,8 +176,6 @@ public async Task RestartScreenCaster(string[] viewerIds, string sessionId, stri
                         $" --viewers {string.Join(",", viewerIds)}",
 
                     targetSessionId: targetSessionID,
-                    forceConsoleSession: Shlwapi.IsOS(OsType.OS_ANYSERVER) && targetSessionID == -1,
-                    desktopName: "default",
                     hiddenWindow: false,
                     out _);
 

Desktop.Native/Windows/Win32Interop.cs

@@ -104,11 +104,9 @@ public static nint OpenInputDesktop()
 
     public static bool CreateInteractiveSystemProcess(
         string commandLine,
-         int targetSessionId,
-         bool forceConsoleSession,
-         string desktopName,
-         bool hiddenWindow,
-         out PROCESS_INFORMATION procInfo)
+        int targetSessionId,
+        bool hiddenWindow,
+        out PROCESS_INFORMATION procInfo)
     {
         uint winlogonPid = 0;
         var hUserTokenDup = nint.Zero;
@@ -117,21 +115,7 @@ public static bool CreateInteractiveSystemProcess(
 
         procInfo = new PROCESS_INFORMATION();
 
-        // If not force console, find target session.  If not present,
-        // use last active session.
-        var dwSessionId = Kernel32.WTSGetActiveConsoleSessionId();
-        if (!forceConsoleSession)
-        {
-            var activeSessions = GetActiveSessions();
-            if (activeSessions.Any(x => x.Id == targetSessionId))
-            {
-                dwSessionId = (uint)targetSessionId;
-            }
-            else
-            {
-                dwSessionId = activeSessions.Last().Id;
-            }
-        }
+        var dwSessionId = ResolveWindowsSession(targetSessionId);
 
         // Obtain the process ID of the winlogon process that is running within the currently active session.
         var processes = Process.GetProcessesByName("winlogon");
@@ -171,7 +155,7 @@ public static bool CreateInteractiveSystemProcess(
         // interaction with the new process.
         var si = new STARTUPINFO();
         si.cb = Marshal.SizeOf(si);
-        si.lpDesktop = @"winsta0\" + desktopName;
+        si.lpDesktop = @"winsta0\" + ResolveDesktopName(dwSessionId);
 
         // Flags that specify the priority and creation method of the process.
         uint dwCreationFlags;
@@ -208,6 +192,53 @@ public static bool CreateInteractiveSystemProcess(
         return result;
     }
 
+    public static string ResolveDesktopName(uint targetSessionId)
+    {
+        var winDir = Environment.GetFolderPath(Environment.SpecialFolder.Windows);
+        var logonUiPath = Path.Combine(winDir, "System32", "LogonUI.exe");
+        var consentPath = Path.Combine(winDir, "System32", "consent.exe");
+
+        var isLogonScreenVisible = Process
+            .GetProcessesByName("LogonUI")
+            .Any(x => x.SessionId == targetSessionId && x.MainModule?.FileName.Equals(logonUiPath, StringComparison.OrdinalIgnoreCase) == true);
+
+        var isSecureDesktopVisible = Process
+            .GetProcessesByName("consent")
+            .Any(x => x.SessionId == targetSessionId && x.MainModule?.FileName.Equals(consentPath, StringComparison.OrdinalIgnoreCase) == true);
+
+        if (isLogonScreenVisible || isSecureDesktopVisible)
+        {
+            return "Winlogon";
+        }
+
+        return "Default";
+    }
+
+    public static uint ResolveWindowsSession(int targetSessionId)
+    {
+        var activeSessions = GetActiveSessions();
+        if (activeSessions.Any(x => x.Id == targetSessionId))
+        {
+            // If exact match is found, return that session.
+            return (uint)targetSessionId;
+        }
+        
+        if (Shlwapi.IsOS(OsType.OS_ANYSERVER))
+        {
+            // If Windows Server, default to console session.
+            return Kernel32.WTSGetActiveConsoleSessionId();
+        }
+
+        // If consumer version and there's an RDP session active, return that.
+        if (activeSessions.Find(x => x.Type == WindowsSessionType.RDP) is { } rdSession)
+        {
+            return rdSession.Id;
+        }
+
+        // Otherwise, return the console session.
+        return Kernel32.WTSGetActiveConsoleSessionId();
+    }
+
     public static void SetMonitorState(MonitorState state)
     {
         SendMessage(0xFFFF, 0x112, 0xF170, (int)state);

Desktop.Shared/Startup/IServiceProviderExtensions.cs

@@ -154,8 +154,6 @@ private static void RelaunchElevated()
             commandLine,
             -1,
             false,
-            "default",
-            true,
             out var procInfo);
         Console.WriteLine($"Elevate result: {result}. Process ID: {procInfo.dwProcessId}.");
         Environment.Exit(0);