Security and Screen Savers

ID: Q96780

3.50 3.51 4.00 WINDOWS NT kbprg

The information in this article applies to:

• Microsoft Win32 Application Programming Interface (API) included with:

      - Microsoft Windows NT versions 3.5, 3.51, 4.0
  

SUMMARY

Screen savers are user-mode applications that execute in a different desktop (see the note at the end of the article). Therefore, a screen saver cannot enumerate windows of user-mode applications. This design prevents unauthorized users from viewing the contents of applications displayed on the screen. For secure screen savers (those that ask for a password), this adds a further layer of protection.

Screen savers also execute in the security context of the logged-on user. A screen saver may call ExitWindowsEx(), to log off from or shut down the system, or any other application programming interface (API) that the logged-on user has permission to perform.

MORE INFORMATION

A sample screen saver SCRNSAVE is distributed on the Win32 SDK CD.

NOTE: A desktop is a virtual screen. Windows NT 3.5 and earlier have three desktops--the main desktop, the WinLogon desktop, and a desktop for screen savers. Windows NT 3.51 and later support and document creating multiple desktops.

KBCategory: kbprg KBSubcategory: BseSecurity Additional reference words: 3.50 3.51 4.00 Scrnsave Screen Saver Desktop

Keywords          : kbAPI kbKernBase kbGrpKernBase 
Version           : 3.50 3.51 4.00
Platform          : NT WINDOWS

Last Reviewed: January 18, 1997