#26 Screenshots Not Blocked in Lion

v1.0 (example)
closed
nobody
None
5
2015-01-26
2012-03-13
Doug Loomer
No

Upgraded to Lion so we could test screenshot blocking. SEB is not stopping screenshotting under Lion. Running on a 64bit Macbook. Am I missing something?

Discussion

  • Sorry, we found out last week that apparently in OS X 10.7.3 Apple again allows screen shots in its screen shot tool regardless of the parameter in windows (setSharingType: NSWindowSharingNone). I'm sure it was working before I updated to 10.7.3 and I got another feedback from an user confirming this. I will file a bug report to Apple (but maybe they consider this a feature and not bug...).

    If Apple doesn't change this, we have to find another solution. As mentioned there is a way to stop the systems screenshots, but this requires administrator rights (elevating the applications rights to root) and Apple doesn't allow this in the Mac App Store. But we probably will implement this anyways for the version downloaded directly from our website.

    In case you want to stop screen shots completely on your exam machines and if you know what you're doing, you can run the following command in terminal:

    sudo mv /usr/sbin/screencapture /usr/sbin/screencapture.old
    (you need to be admin and re-enter your admin password)

    To switch screen shots on again:
    sudo mv /usr/sbin/screencapture.old /usr/sbin/screencapture

    Hope we will find a solution in SEB soon.

     
  • Doug Loomer
    Doug Loomer
    2012-03-13

    Wow! Thanks for your unbelievably fast and helpful reply. I tried disabling screenshots from the command line, but there was no file named screencapture in the /usr/bin/ directory. Any chance it has a different name? I see a file named screen located there.

    In any case, why not wrap the SEB in script(s) that disables screenshots at launch and restore it at exit? For better or worse, our students all have sudo access rights to their macs via an admin rights install account on their computer. Wouldn't they just need to be prompted to enter their admin password at launch and exit?

    Thanks for your wonderful program, and all your help. I know that we can't eliminate camera capture of screen information, but we can't eliminate that risk with paper tests either. As it stands, the mac is a screencapturing machine, and changing that would really help encourage teachers to get onboard with Moodle testing.

    Again, thanks!

     
  • Doug Loomer
    Doug Loomer
    2012-03-13

    Ooops...I see it is /usr/sbin, not /usr/bin. So sorry. The birthdays are catching up with me.

     
  • I will take a shot at adding a method to a custom version of the SEB code that will rename the screencapture file on program launch and restore it on program close. I'm a java programmer, not an Objective-C programmer, but will give it a shot and will forward a copy of the modified code to you when I'm finished.

     
  • I do understand now that for many of you stopping screen shots is quite important.

    But what we need is a proper solution, a helper tool/daemon, which will only need to enter admin credentials once, when installing it. This still won't be accepted by Apple for the Mac App Store, so it will be included only in the SEB version downloaded from our website and maybe available here also as an additional installer for people which still want to install SEB itself from the App Store.

    I will try to fit this in my schedule, but I guess I will need a couple of months to implement this.

     
  • Thanks. We will very much look forward to the SEB with helper tool/daemon. I understand busy schedules, and appreciate that you are willing to slot this work in at all. In the mean time, for our internal use only of course, I will put together a hack that lets us disable screencapture so we can use SEB with a test group of students this spring (in anticipation of putting a proper version of SEB on every student's mac next fall when we reimage to Lion).

    Thank you again for making SEB available. It is an absolutely essential tool for those of us who are delivering exams via Moodle. All the best.

     
  • I started to actually working now on the SEB helper tool/daemon blocking screen shots. It should be included in the final release of SEB 2.0 for Mac OS X and be released in Q1/2013.

     
    • status: open --> closed
    • Group: --> v1.0 (example)
     
  • SEB 2.0 for Mac OS X (final release version) blocks the OS X screenshot functionality.