qubes-installer-qubes-os/storage/devicelibs/crypto.py
2011-01-18 04:24:57 -05:00

194 lines
6.0 KiB
Python

#
# crypto.py
#
# Copyright (C) 2009 Red Hat, Inc. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty 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, see <http://www.gnu.org/licenses/>.
#
# Author(s): Dave Lehman <dlehman@redhat.com>
# Martin Sivak <msivak@redhat.com>
#
import os
from pycryptsetup import CryptSetup
import iutil
from ..errors import *
import gettext
_ = lambda x: gettext.ldgettext("anaconda", x)
# Keep the character set size a power of two to make sure all characters are
# equally likely
GENERATED_PASSPHRASE_CHARSET = ("0123456789"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"./")
# 20 chars * 6 bits per char = 120 "bits of security"
GENERATED_PASSPHRASE_LENGTH = 20
def generateBackupPassphrase():
rnd = os.urandom(GENERATED_PASSPHRASE_LENGTH)
cs = GENERATED_PASSPHRASE_CHARSET
raw = "".join([cs[ord(c) % len(cs)] for c in rnd])
# Make the result easier to read
parts = []
for i in xrange(0, len(raw), 5):
parts.append(raw[i : i + 5])
return "-".join(parts)
def askyes(question):
return True
def dolog(priority, text):
pass
def is_luks(device):
cs = CryptSetup(yesDialog = askyes, logFunc = dolog)
return cs.isLuks(device)
def luks_uuid(device):
cs = CryptSetup(yesDialog = askyes, logFunc = dolog)
return cs.luksUUID(device).strip()
def luks_status(name):
"""True means active, False means inactive (or non-existent)"""
cs = CryptSetup(yesDialog = askyes, logFunc = dolog)
return cs.luksStatus(name)!=0
def luks_format(device,
passphrase=None, key_file=None,
cipher=None, key_size=None):
cs = CryptSetup(yesDialog = askyes, logFunc = dolog)
key_file_unlink = False
if passphrase:
key_file = cs.prepare_passphrase_file(passphrase)
key_file_unlink = True
elif key_file and os.path.isfile(key_file):
pass
else:
raise ValueError("luks_format requires either a passphrase or a key file")
#None is not considered as default value and pycryptsetup doesn't accept it
#so we need to filter out all Nones
kwargs = {}
kwargs["device"] = device
if cipher: kwargs["cipher"] = cipher
if key_file: kwargs["keyfile"] = key_file
if key_size: kwargs["keysize"] = key_size
rc = cs.luksFormat(**kwargs)
if key_file_unlink: os.unlink(key_file)
if rc:
raise CryptoError("luks_format failed for '%s'" % device)
def luks_open(device, name, passphrase=None, key_file=None):
cs = CryptSetup(yesDialog = askyes, logFunc = dolog)
key_file_unlink = False
if passphrase:
key_file = cs.prepare_passphrase_file(passphrase)
key_file_unlink = True
elif key_file and os.path.isfile(key_file):
pass
else:
raise ValueError("luks_open requires either a passphrase or a key file")
rc = cs.luksOpen(device = device, name = name, keyfile = key_file)
if key_file_unlink: os.unlink(key_file)
if rc:
raise CryptoError("luks_open failed for %s (%s)" % (device, name))
def luks_close(name):
cs = CryptSetup(yesDialog = askyes, logFunc = dolog)
rc = cs.luksClose(name)
if rc:
raise CryptoError("luks_close failed for %s" % name)
def luks_add_key(device,
new_passphrase=None, new_key_file=None,
passphrase=None, key_file=None):
params = ["-q"]
p = os.pipe()
if passphrase:
os.write(p[1], "%s\n" % passphrase)
elif key_file and os.path.isfile(key_file):
params.extend(["--key-file", key_file])
else:
raise CryptoError("luks_add_key requires either a passphrase or a key file")
params.extend(["luksAddKey", device])
if new_passphrase:
os.write(p[1], "%s\n" % new_passphrase)
elif new_key_file and os.path.isfile(new_key_file):
params.append("%s" % new_key_file)
else:
raise CryptoError("luks_add_key requires either a passphrase or a key file to add")
os.close(p[1])
rc = iutil.execWithRedirect("cryptsetup", params,
stdin = p[0],
stdout = "/dev/tty5",
stderr = "/dev/tty5")
os.close(p[0])
if rc:
raise CryptoError("luks add key failed with errcode %d" % (rc,))
def luks_remove_key(device,
del_passphrase=None, del_key_file=None,
passphrase=None, key_file=None):
params = []
p = os.pipe()
if del_passphrase: #the first question is about the key we want to remove
os.write(p[1], "%s\n" % del_passphrase)
if passphrase:
os.write(p[1], "%s\n" % passphrase)
elif key_file and os.path.isfile(key_file):
params.extend(["--key-file", key_file])
else:
raise CryptoError("luks_remove_key requires either a passphrase or a key file")
params.extend(["luksRemoveKey", device])
if del_passphrase:
pass
elif del_key_file and os.path.isfile(del_key_file):
params.append("%s" % del_key_file)
else:
raise CryptoError("luks_remove_key requires either a passphrase or a key file to remove")
os.close(p[1])
rc = iutil.execWithRedirect("cryptsetup", params,
stdin = p[0],
stdout = "/dev/tty5",
stderr = "/dev/tty5")
os.close(p[0])
if rc:
raise CryptoError("luks_remove_key failed with errcode %d" % (rc,))