Keyboard and Mouse simulation are not working in macOS pre-login window

I'm a newbie to Launch agent and daemons. Now I'm currently developing the remote desktop (like VNC) application for macOS with Objective-C and my application supported macOS versions are 10.6 and later. I have created a pre-login agent and it will launch my application when login window open.

I am using CGEventPost to simulate keyboard and mouse events in user logged-in sessions. But it's not working in pre-login window (global login window)

Citrix, LogMeIn are providing the remote controls in Pre-login window too. How are they doing it?

Any help will be highly appreciated.

Please refer the code

//For Keyboard

CGEventRef keyEvent = CGEventCreateKeyboardEvent( NULL, keyCode, down ) ;

CGEventPost( kCGHIDEventTap, keyEvent ) ;

CFRelease( keyEvent ) ;

//For Mouse

CGEventRef event = CGEventCreateMouseEvent(eventSource, eventType, mouseLocation, mouseButton ); CGEventPost(kCGHIDEventTap, event);

CFRelease(event);

//Pre-login launch agent

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>Label</key>

<string>my app label</string>

<key>LimitLoadToSessionType</key>

<string>LoginWindow</string>

<key>RunAtLoad</key>

<true/>

<key>WorkingDirectory</key>

<string>My app directory</string>

<key>ProgramArguments</key>

<array>

<string>app absolute path</string>

<string>service</string>

<string>myservice</string>

</array>

<key>KeepAlive</key>

<true/>

</dict>

</plist>