From 4ff7980cfb876de9662ad1a70fe18783be92f0f1 Mon Sep 17 00:00:00 2001
From: Lev Stipakov <lev@openvpn.net>
Date: Mon, 21 Apr 2025 12:00:25 +0300
Subject: [PATCH] Keep PLAP dialog alive by simulating user activity

Add a timer to periodically simulate mouse movement
using SendInput, preventing the pre-logon UI from being
dismissed due to inactivity during mobile QR code authentication.

Signed-off-by: Lev Stipakov <lev@openvpn.net>
---
 qr.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/qr.c b/qr.c
index c9a1e09..7d0a05b 100644
--- a/qr.c
+++ b/qr.c
@@ -97,6 +97,8 @@ INT_PTR CALLBACK
 QrDialogProc(HWND hwnd, UINT msg, UNUSED WPARAM wp, LPARAM lp)
 {
     static HBITMAP hQRBitmap = NULL;
+    static UINT_PTR timerId = 1;
+    static UINT timerElapse = 20000; /* must be less than 30 sec pre-logon timeout */
 
     switch (msg)
     {
@@ -172,6 +174,8 @@ QrDialogProc(HWND hwnd, UINT msg, UNUSED WPARAM wp, LPARAM lp)
             SetWindowText(hwnd, uc->config_name);
 
             g_hwndQR = hwnd;
+
+            SetTimer(hwnd, timerId, timerElapse, NULL);
         }
             return TRUE;
 
@@ -179,10 +183,25 @@ QrDialogProc(HWND hwnd, UINT msg, UNUSED WPARAM wp, LPARAM lp)
             EndDialog(hwnd, 0);
             return TRUE;
 
+        case WM_TIMER:
+            if (wp == timerId)
+            {
+                /* Simulate mouse movement to keep Winlogon from dismissing the PLAP dialog */
+                INPUT input = { 0 };
+                input.type = INPUT_MOUSE;
+                input.mi.dwFlags = MOUSEEVENTF_MOVE;
+                input.mi.dx = 0;
+                input.mi.dy = 0;
+                SendInput(1, &input, sizeof(INPUT));
+            }
+            return TRUE;
+
         case WM_DESTROY:
             if (hQRBitmap)
                 DeleteObject(hQRBitmap);
             g_hwndQR = NULL;
+
+            KillTimer(hwnd, timerId);
             return TRUE;
     }
     return FALSE;