archinstall/archinstall/lib/luks.py

150 lines
5.1 KiB
Python

import os
import shlex
import time
import pathlib
from .exceptions import *
from .general import *
from .disk import Partition
from .output import log, LOG_LEVELS
from .storage import storage
class luks2():
def __init__(self, partition, mountpoint, password, key_file=None, auto_unmount=False, *args, **kwargs):
self.password = password
self.partition = partition
self.mountpoint = mountpoint
self.args = args
self.kwargs = kwargs
self.key_file = key_file
self.auto_unmount = auto_unmount
self.filesystem = 'crypto_LUKS'
self.mapdev = None
def __enter__(self):
#if self.partition.allow_formatting:
# self.key_file = self.encrypt(self.partition, *self.args, **self.kwargs)
#else:
if not self.key_file:
self.key_file = f"/tmp/{os.path.basename(self.partition.path)}.disk_pw" # TODO: Make disk-pw-file randomly unique?
if type(self.password) != bytes:
self.password = bytes(self.password, 'UTF-8')
with open(self.key_file, 'wb') as fh:
fh.write(self.password)
return self.unlock(self.partition, self.mountpoint, self.key_file)
def __exit__(self, *args, **kwargs):
# TODO: https://stackoverflow.com/questions/28157929/how-to-safely-handle-an-exception-inside-a-context-manager
if self.auto_unmount:
self.close()
if len(args) >= 2 and args[1]:
raise args[1]
return True
def encrypt(self, partition, password=None, key_size=512, hash_type='sha512', iter_time=10000, key_file=None):
if not self.partition.allow_formatting:
raise DiskError(f'Could not encrypt volume {self.partition} due to it having a formatting lock.')
log(f'Encrypting {partition} (This might take a while)', level=LOG_LEVELS.Info)
if not key_file:
if self.key_file:
key_file = self.key_file
else:
key_file = f"/tmp/{os.path.basename(self.partition.path)}.disk_pw" # TODO: Make disk-pw-file randomly unique?
if not password:
password = self.password
if type(password) != bytes:
password = bytes(password, 'UTF-8')
with open(key_file, 'wb') as fh:
fh.write(password)
cryptsetup_args = shlex.join([
'/usr/bin/cryptsetup',
'--batch-mode',
'--verbose',
'--type', 'luks2',
'--pbkdf', 'argon2i',
'--hash', hash_type,
'--key-size', str(key_size),
'--iter-time', str(iter_time),
'--key-file', os.path.abspath(key_file),
'--use-urandom',
'luksFormat', partition.path,
])
try:
# Try to setup the crypt-device
cmd_handle = sys_command(cryptsetup_args)
except SysCallError as err:
if err.exit_code == 256:
log(f'{partition} is being used, trying to unmount and crypt-close the device and running one more attempt at encrypting the device.', level=LOG_LEVELS.Debug)
# Partition was in use, unmount it and try again
partition.unmount()
# Get crypt-information about the device by doing a reverse lookup starting with the partition path
# For instance: /dev/sda
devinfo = json.loads(b''.join(sys_command(f"lsblk --fs -J {partition.path}")).decode('UTF-8'))['blockdevices'][0]
# For each child (sub-partition/sub-device)
if len(children := devinfo.get('children', [])):
for child in children:
# Unmount the child location
if child_mountpoint := child.get('mountpoint', None):
log(f'Unmounting {child_mountpoint}', level=LOG_LEVELS.Debug)
sys_command(f"umount -R {child_mountpoint}")
# And close it if possible.
log(f"Closing crypt device {child['name']}", level=LOG_LEVELS.Debug)
sys_command(f"cryptsetup close {child['name']}")
# Then try again to set up the crypt-device
cmd_handle = sys_command(cryptsetup_args)
else:
raise err
if cmd_handle.exit_code != 0:
raise DiskError(f'Could not encrypt volume "{partition.path}": {cmd_output}')
return key_file
def unlock(self, partition, mountpoint, key_file):
"""
Mounts a luks2 compatible partition to a certain mountpoint.
Keyfile must be specified as there's no way to interact with the pw-prompt atm.
:param mountpoint: The name without absolute path, for instance "luksdev" will point to /dev/mapper/luksdev
:type mountpoint: str
"""
from .disk import get_filesystem_type
if '/' in mountpoint:
os.path.basename(mountpoint) # TODO: Raise exception instead?
wait_timer = time.time()
while pathlib.Path(partition.path).exists() is False and time.time() - wait_timer < 10:
time.sleep(0.025)
sys_command(f'/usr/bin/cryptsetup open {partition.path} {mountpoint} --key-file {os.path.abspath(key_file)} --type luks2')
if os.path.islink(f'/dev/mapper/{mountpoint}'):
self.mapdev = f'/dev/mapper/{mountpoint}'
unlocked_partition = Partition(self.mapdev, None, encrypted=True, filesystem=get_filesystem_type(self.mapdev), autodetect_filesystem=False)
unlocked_partition.allow_formatting = self.partition.allow_formatting
return unlocked_partition
def close(self, mountpoint=None):
if not mountpoint:
mountpoint = self.mapdev
sys_command(f'/usr/bin/cryptsetup close {self.mapdev}')
return os.path.islink(self.mapdev) is False
def format(self, path):
if (handle := sys_command(f"/usr/bin/cryptsetup -q -v luksErase {path}")).exit_code != 0:
raise DiskError(f'Could not format {path} with {self.filesystem} because: {b"".join(handle)}')