qubes-screenshooter

LeakProof screenshot tool for Qubes OS

Features

• Remove EXIF info from image (OPSEC)
• Automatically strip window borders, to prevent leaking VM name and border color (OPSEC)
• Detect active window VM, and save screenshot on this VM
• Save image into ~/QubesIncomming/dom0/ on target VM
• Copy image into target VM clipboard, so a simple Ctrl+V in rich text editors is enough

Usage

Print shortcut:

Take screenshot of active window

1. Take screenshot of current active window (foreground)
2. Remove EXIF info from image (OPSEC)
3. Strip window border, to prevent leaking VM name and border color (OPSEC)
4. Save it into active window's VM (e.g: if window is from vault VM, screenshot is automatically saved in this VM

Ctrl+Print shortcut:

Take screenshot of selected region

1. Select a region to be captured by clicking a point of the screen
2. Remove EXIF info from image (OPSEC)
3. Prompt user a list of running VMs
4. Save image into chosen VM

Installation:

In a terminal on <src-vm> (any Qube with internet access):

# download qubes-screenshooter as zip
wget github.com/nil0x42/qubes-screenshooter/archive/master.zip -O /tmp/qubes-screenshooter.zip

In a terminal on dom0:

# open root shell, to be able to write to /opt (otherwise, you can copy to another location)
sudo -s
# copy zip file from <src-vm> to dom0's /opt directory
qvm-run --pass-io <src-vm> 'cat /tmp/qubes-screenshooter.zip' > qubes-screenshooter.zip
unzip qubes-screenshooter.zip
mv "qubes-screenshooter-master/" /opt

Open Keyboard Settings (on Qubes OS GUI):

• Click on Main Menu (top-left Qubes OS icon)
  • Select System Tools
    • Select Keyboard
      • Open Application Shortcuts tab

• Add the following shortcuts:
  • Print
    • xfce4-screenshooter -m -w -o /opt/qubes-screenshooter/send-screenshot-to-active-vm
  • Ctrl+Print
    • xfce4-screenshooter -r -o /opt/qubes-screenshooter/send-screenshot-to-chosen-vm

If you are running Qubes 4.2, additional packages are needed in dom0:

sudo qubes-dom0-upgrade xwininfo ImageMagick

Dependencies & Third-party tools

qubes-screenshooter must run on dom0 to be able to take screenshots, because GUI runs on dom0.

qubes-screenshooter is basically a set of 2 perl scripts, making use of many pre-installed tools:

• xfce4-screenshooter is the default xfce screenshot tool. It is the actual tool used to take screenshots, before giving ownership to qubes-screenshooter.
• ImageMagick (provides mogrify), allows stripping EXIF info & window borders from image before sending screenshot.
• zenity is used to display VM choice GTK+ dialog
• notify-send is used to display notification of sent screenshot

**IMPORTANT:

The copy image to cpipboard feature depends on xclip being installed on target VMs. So you should install it on all VMs if you want it working**