Proper remote shutdown of SEB on Windows 10/11 possible?

[cnodegam]

Hi,

I'm the maintainer of a computer pool with 70+ seats at a university. It's a restricted environment with limited and supervised access to students or other users. The seats are all Windows 10 or Windows 11. Upon boot the seats auto login to a restricted user. The pool is being used for different purposes including exams that's where SafeExamBrowser in its current version 3.7.1 comes into play. I can configure the seats remotely for different scenarios, like whether to use and autostart SEB or not, and if SEB is needed I can deploy different versions of SebClientSettings.seb to the folder C:\ProgramData\SafeExamBrowser to accommodate different exam configurations. Our settings have a quit password set that participants of course don't know.

Bad behavior happens when, at the end of the exam or day, we're shutting down the PCs remotely, so if SEB was still running it gets killed. Sometimes but not always upon next boot (with SEB autostart configured) SEB does not start properly but reports with a red screen (translated to English):

"SEB LOCKED - The last session with the currently active configuration or start URL was not properly terminated! Please enter the correct password to unlock SEB"

This had never happened before SEB 3.7.1 but we also introduced quit passwords only recently so it might be related to that too. Right now we go around all seats and unlock the SEB with the quit password, and then SEB shows the proper start screen as configured in the active settings.

My wish: once an SEB powered exam is finished, I want to be able to gracefully shutdown SEB remotely on all seats using some Powershell script or command. For efficiency reasons I do not want me or someone else walk around and manually shut down SEB to avoid the red screen upon next start.

Is it possible to do that, remotely shutting down SEB properly as if someone had clicked the power off button and entered the quit password interactively? Again, we have a restricted environment where only authorized personnel can initiate such commands.

Thanks.

[cnodegam]

Some snippet from the Timestamp_Client.log regarding the shown lock screen:

[..]
2024-08-09 09:16:41.189 [01] - INFO: Application successfully initialized.

2024-08-09 09:16:41.189 [01] - INFO: Attempting to verify session integrity...
2024-08-09 09:16:41.192 [01] - DEBUG: [IntegrityModule] Successfully verified session integrity, session is compromised!
2024-08-09 09:16:41.192 [01] - WARNING: Session integrity is compromised!
2024-08-09 09:16:41.223 [16] - DEBUG: [ClientHost] Received connection request with authentication token '**redacted**'.
2024-08-09 09:16:41.223 [16] - DEBUG: [ClientHost] Accepted connection request.
2024-08-09 09:16:41.239 [30] - DEBUG: [ApplicationMonitor] Window has changed from '' (66314) to 'ActionCenter' (66330).
2024-08-09 09:16:41.239 [25] - DEBUG: [ClientHost] Received message 'SimpleMessage -> Authenticate', sending response 'AuthenticationResponse'.
2024-08-09 09:16:41.351 [45] - DEBUG: [KeyGenerator] Initializing browser exam key...
2024-08-09 09:16:42.201 [40] - INFO: Showing lock screen...
2024-08-09 09:16:42.232 [30] - DEBUG: [ApplicationMonitor] Window has changed from 'ActionCenter' (66330) to '' (66342).
2024-08-09 09:16:42.671 [41] - DEBUG: [ApplicationMonitor] Process 'CefSharp.BrowserSubprocess.exe' (9924) has been started [Original Name: 'CefSharp.BrowserSubprocess.exe', Path: 'C:\Program Files\SafeExamBrowser\Application\CefSharp.BrowserSubprocess.exe', Signature: 2bc82fe8e56a39f96bc6c4b91d6703a0379b76a2].
2024-08-09 09:16:42.672 [41] - DEBUG: [ApplicationMonitor] Process 'CefSharp.BrowserSubprocess.exe' (9884) has been started [Original Name: 'CefSharp.BrowserSubprocess.exe', Path: 'C:\Program Files\SafeExamBrowser\Application\CefSharp.BrowserSubprocess.exe', Signature: 2bc82fe8e56a39f96bc6c4b91d6703a0379b76a2].
2024-08-09 09:16:42.672 [41] - DEBUG: [ApplicationMonitor] Process 'CefSharp.BrowserSubprocess.exe' (10164) has been started [Original Name: 'CefSharp.BrowserSubprocess.exe', Path: 'C:\Program Files\SafeExamBrowser\Application\CefSharp.BrowserSubprocess.exe', Signature: 2bc82fe8e56a39f96bc6c4b91d6703a0379b76a2].
2024-08-09 09:16:42.673 [41] - DEBUG: [ApplicationMonitor] Process 'CefSharp.BrowserSubprocess.exe' (10156) has been started [Original Name: 'CefSharp.BrowserSubprocess.exe', Path: 'C:\Program Files\SafeExamBrowser\Application\CefSharp.BrowserSubprocess.exe', Signature: 2bc82fe8e56a39f96bc6c4b91d6703a0379b76a2].
2024-08-09 09:16:42.673 [41] - DEBUG: [ApplicationMonitor] Process 'CefSharp.BrowserSubprocess.exe' (9732) has been started [Original Name: 'CefSharp.BrowserSubprocess.exe', Path: 'C:\Program Files\SafeExamBrowser\Application\CefSharp.BrowserSubprocess.exe', Signature: 2bc82fe8e56a39f96bc6c4b91d6703a0379b76a2].
2024-08-09 09:16:42.760 [45] - DEBUG: [KeyGenerator] Successfully calculated browser exam key using integrity module.
2024-08-09 09:16:42.811 [38] - INFO: [Browser Window #1] Navigated.
[..]

[danschlet]

Since SEB 3.7, there is a setting to disable this lock screen. Just read the Release Notes: https://safeexambrowser.org/windows/win_release_notes_en.html
There is also a related (closed) issue with more details, which you can search here in this repository.

[dbuechel]

Shutting down remotely (and a lot of other useful functionalities) are available when using SEB Server. The configuration key to disable the lock screen is called enableSessionVerification and may be set to false to disable the lock screen.