qubes-installer-qubes-os/anaconda/storage/formats/luks.py
2011-03-31 13:40:54 +02:00

353 lines
13 KiB
Python

# luks.py
# Device format classes for anaconda's storage configuration module.
#
# Copyright (C) 2009 Red Hat, Inc.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# the GNU General Public License v.2, or (at your option) any later version.
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY expressed or implied, including the implied warranties of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
# Public License for more details. You should have received a copy of the
# GNU General Public License along with this program; if not, write to the
# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA. Any Red Hat trademarks that are incorporated in the
# source code or documentation are not subject to the GNU General Public
# License and may only be used or replicated with the express permission of
# Red Hat, Inc.
#
# Red Hat Author(s): Dave Lehman <dlehman@redhat.com>
#
import os
try:
import volume_key
except ImportError:
volume_key = None
from ..storage_log import log_method_call
from ..errors import *
from ..devicelibs import crypto
from . import DeviceFormat, register_device_format
import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)
import logging
log = logging.getLogger("storage")
class LUKS(DeviceFormat):
""" A LUKS device. """
_type = "luks"
_name = "LUKS"
_lockedName = _("Encrypted")
_udevTypes = ["crypto_LUKS"]
_formattable = True # can be formatted
_supported = False # is supported
_linuxNative = True # for clearpart
_packages = ["cryptsetup-luks"] # required packages
def __init__(self, *args, **kwargs):
""" Create a LUKS instance.
Keyword Arguments:
device -- the path to the underlying device
name -- the name of the mapped device
uuid -- this device's UUID
passphrase -- device passphrase (string)
key_file -- path to a file containing a key (string)
cipher -- cipher mode string
key_size -- key size in bits
exists -- indicates whether this is an existing format
escrow_cert -- certificate to use for key escrow
add_backup_passphrase -- generate a backup passphrase?
"""
log_method_call(self, *args, **kwargs)
DeviceFormat.__init__(self, *args, **kwargs)
self.cipher = kwargs.get("cipher")
self.key_size = kwargs.get("key_size")
self.mapName = kwargs.get("name")
if not self.exists and not self.cipher:
self.cipher = "aes-xts-plain"
if not self.key_size:
# default to the max (512 bits) for aes-xts
self.key_size = 512
# FIXME: these should both be lists, but managing them will be a pain
self.__passphrase = kwargs.get("passphrase")
self._key_file = kwargs.get("key_file")
self.escrow_cert = kwargs.get("escrow_cert")
self.add_backup_passphrase = kwargs.get("add_backup_passphrase", False)
if not self.mapName and self.exists and self.uuid:
self.mapName = "luks-%s" % self.uuid
elif not self.mapName and self.device:
self.mapName = "luks-%s" % os.path.basename(self.device)
def __str__(self):
s = DeviceFormat.__str__(self)
if self.__passphrase:
passphrase = "(set)"
else:
passphrase = "(not set)"
s += (" cipher = %(cipher)s keySize = %(keySize)s"
" mapName = %(mapName)s\n"
" keyFile = %(keyFile)s passphrase = %(passphrase)s\n"
" escrowCert = %(escrowCert)s addBackup = %(backup)s" %
{"cipher": self.cipher, "keySize": self.key_size,
"mapName": self.mapName, "keyFile": self._key_file,
"passphrase": passphrase, "escrowCert": self.escrow_cert,
"backup": self.add_backup_passphrase})
return s
@property
def dict(self):
d = super(LUKS, self).dict
d.update({"cipher": self.cipher, "keySize": self.key_size,
"mapName": self.mapName, "hasKey": self.hasKey,
"escrowCert": self.escrow_cert,
"backup": self.add_backup_passphrase})
return d
@property
def name(self):
name = self._name
# for existing locked devices, show "Encrypted" instead of LUKS
if self.hasKey or not self.exists:
name = self._name
else:
name = "%s (%s)" % (self._lockedName, self._name)
return name
def _setPassphrase(self, passphrase):
""" Set the passphrase used to access this device. """
self.__passphrase = passphrase
passphrase = property(fset=_setPassphrase)
@property
def hasKey(self):
return ((self.__passphrase not in ["", None]) or
(self._key_file and os.access(self._key_file, os.R_OK)))
@property
def configured(self):
""" To be ready we need a key or passphrase and a map name. """
return self.hasKey and self.mapName
@property
def status(self):
if not self.exists or not self.mapName:
return False
return os.path.exists("/dev/mapper/%s" % self.mapName)
def probe(self):
""" Probe for any missing information about this format.
cipher mode, key size
"""
raise NotImplementedError("probe method not defined for LUKS")
def setup(self, *args, **kwargs):
""" Open, or set up, the format. """
log_method_call(self, device=self.device, mapName=self.mapName,
type=self.type, status=self.status)
if not self.configured:
raise LUKSError("luks device not configured")
if self.status:
return
DeviceFormat.setup(self, *args, **kwargs)
crypto.luks_open(self.device, self.mapName,
passphrase=self.__passphrase,
key_file=self._key_file)
def teardown(self, *args, **kwargs):
""" Close, or tear down, the format. """
log_method_call(self, device=self.device,
type=self.type, status=self.status)
if not self.exists:
raise LUKSError("format has not been created")
if self.status:
log.debug("unmapping %s" % self.mapName)
crypto.luks_close(self.mapName)
def create(self, *args, **kwargs):
""" Create the format. """
log_method_call(self, device=self.device,
type=self.type, status=self.status)
if not self.hasKey:
raise LUKSError("luks device has no key/passphrase")
intf = kwargs.get("intf")
w = None
if intf:
w = intf.waitWindow(_("Formatting"),
_("Encrypting %s") % kwargs.get("device",
self.device))
try:
DeviceFormat.create(self, *args, **kwargs)
crypto.luks_format(self.device,
passphrase=self.__passphrase,
key_file=self._key_file,
cipher=self.cipher,
key_size=self.key_size)
except Exception:
raise
else:
self.uuid = crypto.luks_uuid(self.device)
self.exists = True
self.mapName = "luks-%s" % self.uuid
self.notifyKernel()
finally:
if w:
w.pop()
def destroy(self, *args, **kwargs):
""" Create the format. """
log_method_call(self, device=self.device,
type=self.type, status=self.status)
self.teardown()
DeviceFormat.destroy(self, *args, **kwargs)
@property
def keyFile(self):
""" Path to key file to be used in /etc/crypttab """
return self._key_file
def addKeyFromFile(self, keyfile):
""" Add a new key from a file.
Add the contents of the specified key file to an available key
slot in the LUKS header.
"""
log_method_call(self, device=self.device,
type=self.type, status=self.status, file=keyfile)
if not self.exists:
raise LUKSError("format has not been created")
crypto.luks_add_key(self.device,
passphrase=self.__passphrase,
key_file=self._key_file,
new_key_file=keyfile)
def addPassphrase(self, passphrase):
""" Add a new passphrase.
Add the specified passphrase to an available key slot in the
LUKS header.
"""
log_method_call(self, device=self.device,
type=self.type, status=self.status)
if not self.exists:
raise LUKSError("format has not been created")
crypto.luks_add_key(self.device,
passphrase=self.__passphrase,
key_file=self._key_file,
new_passphrase=passphrase)
def removeKeyFromFile(self, keyfile):
""" Remove a key contained in a file.
Remove key contained in the specified key file from the LUKS
header.
"""
log_method_call(self, device=self.device,
type=self.type, status=self.status, file=keyfile)
if not self.exists:
raise LUKSError("format has not been created")
crypto.luks_remove_key(self.device,
passphrase=self.__passphrase,
key_file=self._key_file,
del_key_file=keyfile)
def removePassphrase(self, passphrase):
""" Remove the specified passphrase from the LUKS header. """
log_method_call(self, device=self.device,
type=self.type, status=self.status)
if not self.exists:
raise LUKSError("format has not been created")
crypto.luks_remove_key(self.device,
passphrase=self.__passphrase,
key_file=self._key_file,
del_passphrase=passphrase)
def _escrowVolumeIdent(self, vol):
""" Return an escrow packet filename prefix for a volume_key.Volume. """
label = vol.label
if label is not None:
label = label.replace("/", "_")
uuid = vol.uuid
if uuid is not None:
uuid = uuid.replace("/", "_")
# uuid is never None on LUKS volumes
if label is not None and uuid is not None:
volume_ident = "%s-%s" % (label, uuid)
elif uuid is not None:
volume_ident = uuid
elif label is not None:
volume_ident = label
else:
volume_ident = "_unknown"
return volume_ident
def escrow(self, directory, backupPassphrase):
log.debug("escrow: escrowVolume start for %s" % self.device)
if volume_key is None:
raise LUKSError("Missing key escrow support libraries")
vol = volume_key.Volume.open(self.device)
volume_ident = self._escrowVolumeIdent(vol)
ui = volume_key.UI()
# This callback is not expected to be used, let it always fail
ui.generic_cb = lambda unused_prompt, unused_echo: None
def known_passphrase_cb(unused_prompt, failed_attempts):
if failed_attempts == 0:
return self.__passphrase
return None
ui.passphrase_cb = known_passphrase_cb
log.debug("escrow: getting secret")
vol.get_secret(volume_key.SECRET_DEFAULT, ui)
log.debug("escrow: creating packet")
default_packet = vol.create_packet_assymetric_from_cert_data \
(volume_key.SECRET_DEFAULT, self.escrow_cert, ui)
log.debug("escrow: packet created")
with open("%s/%s-escrow" % (directory, volume_ident), "wb") as f:
f.write(default_packet)
log.debug("escrow: packet written")
if self.add_backup_passphrase:
log.debug("escrow: adding backup passphrase")
vol.add_secret(volume_key.SECRET_PASSPHRASE, backupPassphrase)
log.debug("escrow: creating backup packet")
backup_passphrase_packet = \
vol.create_packet_assymetric_from_cert_data \
(volume_key.SECRET_PASSPHRASE, self.escrow_cert, ui)
log.debug("escrow: backup packet created")
with open("%s/%s-escrow-backup-passphrase" %
(directory, volume_ident), "wb") as f:
f.write(backup_passphrase_packet)
log.debug("escrow: backup packet written")
log.debug("escrow: escrowVolume done for %s" % repr(self.device))
register_device_format(LUKS)