#
# cryptodev.py
#
# Copyright (C) 2007 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 .
#
# Author(s): Dave Lehman
#
import os
import iutil
import logging
log = logging.getLogger("anaconda")
def isLuks(device):
if not device.startswith("/"):
device = "/dev/" + device
rc = iutil.execWithRedirect("cryptsetup",
["isLuks", device],
stdout = "/dev/null",
stderr = "/dev/null",
searchPath = 1)
if rc:
return False
else:
return True
def luksUUID(device):
if not device.startswith("/"):
device = "/dev/" + device
if not isLuks(device):
return None
uuid = iutil.execWithCapture("cryptsetup", ["luksUUID", device])
uuid = uuid.strip()
return uuid
class LUKSDevice:
"""LUKSDevice represents an encrypted block device using LUKS/dm-crypt.
It requires an underlying block device and a passphrase to become
functional."""
def __init__(self, device=None, passphrase=None, format=0):
self._device = None
self.passphrase = ""
self.name = ""
self.uuid = None
self.nameLocked = False
self.format = format
self.preexist = not format
self.packages = ["cryptsetup-luks"]
self.scheme = "LUKS"
self.setDevice(device)
self.setPassphrase(passphrase)
if self.getUUID():
name = "%s-%s" % (self.scheme.lower(), self.uuid)
self.setName(name, lock=True)
def getScheme(self):
"""Returns the name of the encryption scheme used by the device."""
return self.scheme
def setDevice(self, device):
if self._device == device:
return
self._device = device
if device is not None:
# this will be temporary, but may be useful for debugging
name = "%s-%s" % (self.scheme.lower(),
os.path.basename(device))
self.setName(name)
def getDevice(self, encrypted=0):
if encrypted:
dev = self._device
else:
dev = "mapper/%s" % (self.name,)
return dev
def getUUID(self):
if self.format:
# self.format means we're going to reformat but haven't yet
# so we shouldn't act like there's anything worth seeing there
return
if not self.uuid:
self.uuid = luksUUID(self.getDevice(encrypted=1))
return self.uuid
def setName(self, name, lock=False):
"""Set the name of the mapped device, eg: 'dmcrypt-sda3'"""
if self.name == name:
return
if self.name and not self.getStatus():
raise RuntimeError, "Cannot rename an active mapping."
if self.nameLocked:
log.debug("Failed to change locked mapping name: %s" %
(self.name,))
return
self.name = name
if lock and name:
# don't allow anyone to lock the name as "" or None
self.nameLocked = True
def setPassphrase(self, passphrase):
"""Set the (plaintext) passphrase used to access the device."""
self.passphrase = passphrase
def crypttab(self):
"""Return a crypttab formatted line describing this mapping."""
format = "%-23s %-15s %s\n"
line = format % (self.name,
"UUID=%s" % (self.getUUID(),),
"none")
return line
def getStatus(self):
"""0 means active, 1 means inactive (or non-existent)"""
if not self.name:
return 1
rc = iutil.execWithRedirect("cryptsetup",
["status", self.name],
stdout = "/dev/null",
stderr = "/dev/null",
searchPath = 1)
return rc
def formatDevice(self):
"""Write a LUKS header onto the device."""
if not self.format:
return
if not self.getStatus():
log.debug("refusing to format active mapping %s" % (self.name,))
return 1
if not self.passphrase:
raise RuntimeError, "Cannot create mapping without a passphrase."
device = self.getDevice(encrypted=1)
if not device:
raise ValueError, "Cannot open mapping without a device."
log.info("formatting %s as %s" % (device, self.getScheme()))
p = os.pipe()
os.write(p[1], "%s\n" % (self.passphrase,))
os.close(p[1])
rc = iutil.execWithRedirect("cryptsetup",
["-q", "luksFormat",
"/dev/%s" % (device,)],
stdin = p[0],
stdout = "/dev/null",
stderr = "/dev/tty5",
searchPath = 1)
self.format = 0
return rc
def openDevice(self):
if not self.getStatus():
# already mapped
return 0
if not self.passphrase:
raise RuntimeError, "Cannot create mapping without a passphrase."
device = self.getDevice(encrypted=1)
if not device:
raise ValueError, "Cannot open mapping without a device."
uuid = self.getUUID()
if not uuid:
raise RuntimeError, "Device has no UUID."
self.setName("%s-%s" % (self.scheme.lower(), uuid), lock=True)
log.info("mapping %s device %s to %s" % (self.getScheme(),
device,
self.name))
p = os.pipe()
os.write(p[1], "%s\n" % (self.passphrase,))
os.close(p[1])
rc = iutil.execWithRedirect("cryptsetup",
["luksOpen",
"/dev/%s" % (device,),
self.name],
stdin = p[0],
stdout = "/dev/null",
stderr = "/dev/tty5",
searchPath = 1)
return rc
def closeDevice(self):
if self.getStatus():
# not mapped
return 0
log.info("unmapping %s device %s" % (self.getScheme(), self.name))
rc = iutil.execWithRedirect("cryptsetup",
["luksClose", self.name],
stdout = "/dev/null",
stderr = "/dev/tty5",
searchPath = 1)
return rc
def addPassphrase(self, newpass):
if not newpass:
return 1
if newpass == self.passphrase:
return 0
p = os.pipe()
os.write(p[1], "%s\n%s" % (self.passphrase, newpass))
os.close(p[1])
device = self.getDevice(encrypted=1)
log.info("adding new passphrase to %s device %s" % (self.getScheme(),
device))
rc = iutil.execWithRedirect("cryptsetup",
["-q",
"luksAddKey",
"/dev/%s" % (device,)],
stdin = p[0],
stdout = "/dev/null",
stderr = "/dev/tty5",
searchPath = 1)
return rc