From f767de7c83dca11a2c4477c4218cded3f04e08f1 Mon Sep 17 00:00:00 2001
From: Christopher Spinrath <christopher.spinrath@tu-dortmund.de>
Date: Tue, 17 Jul 2018 10:58:05 +0200
Subject: [PATCH] =?UTF-8?q?VeraCrypt:=20F=C3=BCge=20Python-Wrapper=20hinzu?=
 =?UTF-8?q?,=20der=20u.a.=20das=20Passwort=20im=20Keyring=20speichern=20ka?=
 =?UTF-8?q?nn?=
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---
 veracrypt/verausbdrive.py | 153 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100755 veracrypt/verausbdrive.py

diff --git a/veracrypt/verausbdrive.py b/veracrypt/verausbdrive.py
new file mode 100755
index 0000000..cac5224
--- /dev/null
+++ b/veracrypt/verausbdrive.py
@@ -0,0 +1,153 @@
+#!/usr/bin/env python3
+
+import argparse
+import getpass
+import keyring
+import os
+import subprocess
+import sys
+
+DESCRIPTION = "Wrapper for VeraCrypt to assist in working with data on an encrypted usb drive (e.g.\ a GIT repository)."
+KEYRING_SERVICE = "de.tu-dortmund.cs.ls1.veracryptwrapper.hisdnp"
+VERA_CONTAINER_NAME_ENV_VAR = "VERA_CONTAINER_NAME"
+
+DEFAULT_DRIVE_NAME = "KINGSTON"
+DEFAULT_VERA_VOL_NAME = "NO NAME"
+#TODO determine this based on OS
+DEFAULT_MNT_PATH = "/Volumes"
+
+VERA_BINARIES = [
+        'veracrypt',
+        'VeraCrypt',
+        '/Applications/VeraCrypt.app/Contents/MacOS/VeraCrypt', #MacOS
+]
+
+VERA_PARAM_TEXT_MODE = '-t'
+VERA_PARAM_STDIN = '--stdin'
+VERA_PARAM_NON_INTERACTIVE = '--non-interactive'
+
+ARG_CONTAINER_NAME = "arg_container"
+ARG_USB_DRIVE_NAME = "arg_usbstick"
+ARG_VERA_VOL_NAME = "arg_volname"
+ARG_MOUNT_PATH = "arg_mountpath"
+ARG_UNMOUNT_USB_DRIVE = "arg_unmountusbdrive"
+ARG_RESET_PASSWORD = "arg_resetpw"
+ARG_VERA_DISMOUNT = "arg_vera_dismount"
+
+def __vera_binary():
+    binaries = [ b for b in VERA_BINARIES if os.path.exists(b) ]
+    assert binaries, "Unable to find VeraCrypt executable!"
+
+    return binaries[0]
+
+def __sync_io():
+    #Sync all I/O devices (just in case)
+    res = subprocess.run([
+        'sync'
+    ])
+    res.check_returncode()
+    
+def __store_password(pw):
+    username = getpass.getuser()
+    keyring.set_password(KEYRING_SERVICE, username, pw)
+
+def __delete_password():
+    username = getpass.getuser()
+    keyring.delete_password(KEYRING_SERVICE, username)
+
+def __get_password(reset_pw = False):
+    if reset_pw:
+        __delete_password()
+
+    username = getpass.getuser()
+    pw = keyring.get_password(KEYRING_SERVICE, username)
+    if not pw:
+        pw = getpass.getpass()
+    return pw
+
+def __vera_exec(option_list, password = None):
+    args = [ __vera_binary(), VERA_PARAM_TEXT_MODE ]
+
+    if password:
+        args = args + [ VERA_PARAM_STDIN ]
+        password = password.encode()
+
+    return subprocess.run(args + option_list, input = password).returncode
+
+def vera_unmount(volume_path):
+    __sync_io()
+    res = __vera_exec(['-d', volume_path])
+    assert res == 0, \
+            "Failed to dismount VeraCrypt volume! VeraCrypt exited with status {}.".format(res)
+    __sync_io()
+
+#TODO the following function is MacOS specific
+def unmount_usbdrive(usbdrive_mnt_path):
+    __sync_io()
+    res = subprocess.run([
+        'diskutil',
+        'unmount',
+        usbdrive_mnt_path,
+    ])
+
+    res.check_returncode()
+
+def vera_mount(volume_path, container):
+    pw = __get_password()
+
+    res = __vera_exec([
+        VERA_PARAM_NON_INTERACTIVE,
+        '--mount', container,
+    ], pw)
+
+    assert res == 0, \
+            "Failed to mount VeraCrypt volume! VeraCrypt exited with status {}.".format(res)
+    __store_password(pw)
+
+def __parse_cmdline():
+    parser = argparse.ArgumentParser(description = DESCRIPTION)
+
+    container_name_default = os.environ.get(VERA_CONTAINER_NAME_ENV_VAR)
+    if container_name_default:
+        parser.add_argument(ARG_CONTAINER_NAME, default = container_name_default, nargs = '?',
+            help = "Path of the encrypted container file on the usb drive")
+    else:
+        parser.add_argument(ARG_CONTAINER_NAME,
+            help = "Path of the encrypted container file on the usb drive")
+
+    parser.add_argument('--mount-path', '-m', dest = ARG_MOUNT_PATH, default = DEFAULT_MNT_PATH)
+    parser.add_argument('--vera-volume-name', '-v', dest = ARG_VERA_VOL_NAME, default = DEFAULT_VERA_VOL_NAME)
+    parser.add_argument('--usb-drive-part-name', '-n', dest = ARG_USB_DRIVE_NAME, default = DEFAULT_DRIVE_NAME)
+
+    parser.add_argument('--reset-password', '-p', dest = ARG_RESET_PASSWORD, action = 'store_true')
+    parser.add_argument('--dismount', '-d', dest = ARG_VERA_DISMOUNT, action = 'store_true')
+    parser.add_argument('--unmount-usb-drive', '-u', dest = ARG_UNMOUNT_USB_DRIVE, action = 'store_true')
+
+    return vars(parser.parse_args())
+
+def __main():
+    args = __parse_cmdline()
+
+    if args[ARG_RESET_PASSWORD]:
+        __delete_password()
+
+    volume_name = args[ARG_VERA_VOL_NAME]
+    mnt_path = args[ARG_MOUNT_PATH]
+    volume = os.path.join(mnt_path, volume_name)
+
+    usbdrive_name = args[ARG_USB_DRIVE_NAME]
+    usbdrive = os.path.join(mnt_path, usbdrive_name)
+
+    container_name = args[ARG_CONTAINER_NAME]
+    container = os.path.join(usbdrive, container_name)
+
+    if args[ARG_VERA_DISMOUNT]:
+        vera_unmount(volume)
+        if args[ARG_UNMOUNT_USB_DRIVE]:
+            unmount_usbdrive(usbdrive)
+        return
+
+    vera_mount(volume, container)
+
+if __name__ == '__main__':
+    __main()