encrypted_zim.py

"""
This script is a wrapper around veracrypt and zim that makes it easy to work
with notebooks that reside inside a veracrypt container.

The script does three things:
    1) Mounts a veracrypt container to a target location.
    2) Runs a zim notebook, intended to be located in the mounted partition.
    3) Unmounts the partition when either Zim or this script exits.
        Note: sudo session from mount might have expired. Be prepared to re-insert
        sudo password.

Author: Jørgen Skancke
"""
import atexit  # calls a teardown function when the script exits
import subprocess


# Filesystem paths and zim notebook name: adapt these to your setup
MOUNT_PATH = '/media/veracrypt_zim2/'
CONTAINER_PATH = '/home/jorgen/encryption_test/veracrypt1'
ENCRYPTED_NOTEBOOK_NAME = 'zim_test'

# Veracrypt options
KEYFILE = ""
PIM = 0
HIDDEN_PARTITION = 'no'


def process_returncode(code, task):
    """
    Return codes on linux: 0 is good, 1 is bad, < 0 is killed.
    """
    if code == 0:
        print(f"Performed {task} successfully")
    else:
        print(f"Performed {task} unsuccessfully with return code {code}")


def unmount_encrypted_container():
    """
    Unmount partition from veracrypt container.
    """
    unmount = f'veracrypt -d {MOUNT_PATH}'
    return_code = subprocess.call(unmount, shell=True)
    task = f"unmounting {MOUNT_PATH}"
    process_returncode(return_code, task)


def mount_encryped_container():
    """
    Mount partition from veracrypt container.
    """
    mount_cmd = f'veracrypt -t -k "{KEYFILE}" --pim={PIM} --protect-hidden={HIDDEN_PARTITION} {CONTAINER_PATH} {MOUNT_PATH}'
    rc_mount = subprocess.call(mount_cmd, shell=True)
    task = f'mounting encrypted filesystem {CONTAINER_PATH} at {MOUNT_PATH}'
    process_returncode(rc_mount, task)


def run_zim():
    """
    Run zim, starting with a specified notebook name.
    """
    zim_cmd = f'zim {ENCRYPTED_NOTEBOOK_NAME}'
    task = 'starting Zim'
    rc_zim = subprocess.call(zim_cmd, shell=True)
    process_returncode(rc_zim, task)


def main():

    # Mount
    mount_encryped_container()

    # Run zim
    run_zim()

    # Unmount happens when zim or script terminates


if __name__ == '__main__':

    atexit.register(unmount_encrypted_container)
    main()