cryptonas/bin/CryptoBoxSettings.py

483 lines
16 KiB
Python

import logging
try:
import validate
except:
raise CryptoBoxExceptions.CBEnvironmentError("couldn't import 'validate'! Try 'apt-get install python-formencode'.")
import os
import CryptoBoxExceptions
import subprocess
try:
import configobj ## needed for reading and writing of the config file
except:
raise CryptoBoxExceptions.CBEnvironmentError("couldn't import 'configobj'! Try 'apt-get install python-configobj'.")
class CryptoBoxSettings:
CONF_LOCATIONS = [
"./cryptobox.conf",
"~/.cryptobox.conf",
"/etc/cryptobox/cryptobox.conf"]
VOLUMESDB_FILE = "cryptobox_volumes.db"
PLUGINCONF_FILE = "cryptobox_plugins.conf"
USERDB_FILE = "cryptobox_users.db"
def __init__(self, config_file=None):
self.log = logging.getLogger("CryptoBox")
config_file = self.__getConfigFileName(config_file)
self.log.info("loading config file: %s" % config_file)
self.prefs = self.__getPreferences(config_file)
self.__validateConfig()
self.__configureLogHandler()
self.__checkUnknownPreferences()
self.preparePartition()
self.volumesDB = self.__getVolumesDatabase()
self.pluginConf = self.__getPluginConfig()
self.userDB = self.__getUserDB()
self.misc_files = self.__getMiscFiles()
def write(self):
"""
write all local setting files including the content of the "misc" subdirectory
"""
ok = True
try:
self.volumesDB.write()
except IOError:
self.log.warn("could not save the volume database")
ok = False
try:
self.pluginConf.write()
except IOError:
self.log.warn("could not save the plugin configuration")
ok = False
try:
self.userDB.write()
except IOError:
self.log.warn("could not save the user database")
ok = False
for misc_file in self.misc_files:
if not misc_file.save():
self.log.warn("could not save a misc setting file (%s)" % misc_file.filename)
ok = False
return ok
def requiresPartition(self):
return bool(self.prefs["Main"]["UseConfigPartition"])
def getActivePartition(self):
settings_dir = self.prefs["Locations"]["SettingsDir"]
if not os.path.ismount(settings_dir): return None
for line in file("/proc/mounts"):
fields = line.split(" ")
mount_dir = fields[1]
try:
if os.path.samefile(mount_dir, settings_dir): return fields[0]
except OSError:
pass
## no matching entry found
return None
def mountPartition(self):
self.log.debug("trying to mount configuration partition")
if not self.requiresPartition():
self.log.warn("mountConfigPartition: configuration partition is not required - mounting anyway")
if self.getActivePartition():
self.log.warn("mountConfigPartition: configuration partition already mounted - not mounting again")
return False
confPartitions = self.getAvailablePartitions()
if not confPartitions:
self.log.error("no configuration partitions found - you have to create it first")
return False
partition = confPartitions[0]
proc = subprocess.Popen(
shell = False,
stdout = subprocess.PIPE,
stderr = subprocess.PIPE,
args = [
self.prefs["Programs"]["super"],
self.prefs["Programs"]["CryptoBoxRootActions"],
"mount",
partition,
self.prefs["Locations"]["SettingsDir"]])
(stdout, stderr) = proc.communicate()
if proc.returncode != 0:
self.log.error("failed to mount the configuration partition: %s" % partition)
self.log.error("output of mount: %s" % (stderr,))
return False
self.log.info("configuration partition mounted: %s" % partition)
return True
def umountPartition(self):
if not self.getActivePartition():
self.log.warn("umountConfigPartition: no configuration partition mounted")
return False
proc = subprocess.Popen(
shell = False,
stdout = subprocess.PIPE,
stderr = subprocess.PIPE,
args = [
self.prefs["Programs"]["super"],
self.prefs["Programs"]["CryptoBoxRootActions"],
"umount",
self.prefs["Locations"]["SettingsDir"]])
(stdout, stderr) = proc.communicate()
if proc.returncode != 0:
self.log.error("failed to unmount the configuration partition")
self.log.error("output of mount: %s" % (stderr,))
return False
self.log.info("configuration partition unmounted")
return True
def getAvailablePartitions(self):
"""returns a sequence of found config partitions"""
proc = subprocess.Popen(
shell = False,
stdout = subprocess.PIPE,
args = [
self.prefs["Programs"]["blkid"],
"-c", os.path.devnull,
"-t", "LABEL=%s" % self.prefs["Main"]["ConfigVolumeLabel"] ])
(output, error) = proc.communicate()
if output:
return [e.strip().split(":",1)[0] for e in output.splitlines()]
else:
return []
def preparePartition(self):
if self.requiresPartition() and not self.getActivePartition():
self.mountPartition()
def __getitem__(self, key):
"""redirect all requests to the 'prefs' attribute"""
return self.prefs[key]
def __getPreferences(self, config_file):
import StringIO
config_rules = StringIO.StringIO(self.validation_spec)
try:
prefs = configobj.ConfigObj(config_file, configspec=config_rules)
if prefs:
self.log.info("found config: %s" % prefs.items())
else:
raise CryptoBoxExceptions.CBConfigUnavailableError("failed to load the config file: %s" % config_file)
except IOError:
raise CryptoBoxExceptions.CBConfigUnavailableError("unable to open the config file: %s" % config_file)
return prefs
def __validateConfig(self):
result = self.prefs.validate(CryptoBoxSettingsValidator(), preserve_errors=True)
error_list = configobj.flatten_errors(self.prefs, result)
if not error_list: return
errorMsgs = []
for sections, key, text in error_list:
section_name = "->".join(sections)
if not text:
errorMsg = "undefined configuration value (%s) in section '%s'" % (key, section_name)
else:
errorMsg = "invalid configuration value (%s) in section '%s': %s" % (key, section_name, text)
errorMsgs.append(errorMsg)
raise CryptoBoxExceptions.CBConfigError, "\n".join(errorMsgs)
def __checkUnknownPreferences(self):
import StringIO
config_rules = configobj.ConfigObj(StringIO.StringIO(self.validation_spec), list_values=False)
self.__recursiveConfigSectionCheck("", self.prefs, config_rules)
def __recursiveConfigSectionCheck(self, section_path, section_config, section_rules):
"""should be called by '__checkUnknownPreferences' for every section
sends a warning message to the logger for every undefined (see validation_spec)
configuration setting
"""
for e in section_config.keys():
element_path = section_path + e
if e in section_rules.keys():
if isinstance(section_config[e], configobj.Section):
if isinstance(section_rules[e], configobj.Section):
self.__recursiveConfigSectionCheck(element_path + "->", section_config[e], section_rules[e])
else:
self.log.warn("configuration setting should be a value instead of a section name: %s" % element_path)
else:
if not isinstance(section_rules[e], configobj.Section):
pass # good - the setting is valid
else:
self.log.warn("configuration setting should be a section name instead of a value: %s" % element_path)
else:
self.log.warn("unknown configuration setting: %s" % element_path)
def __getPluginConfig(self):
import StringIO
plugin_rules = StringIO.StringIO(self.pluginValidationSpec)
try:
try:
pluginConf_file = os.path.join(self.prefs["Locations"]["SettingsDir"], self.PLUGINCONF_FILE)
except KeyError:
raise CryptoBoxExceptions.CBConfigUndefinedError("Locations", "SettingsDir")
except SyntaxError:
raise CryptoBoxExceptions.CBConfigInvalidValueError("Locations", "SettingsDir", pluginConf_file, "failed to interprete the filename of the plugin config file correctly (%s)" % pluginConf_file)
## create pluginConf_file if necessary
if os.path.exists(pluginConf_file):
pluginConf = configobj.ConfigObj(pluginConf_file, configspec=plugin_rules)
else:
pluginConf = configobj.ConfigObj(pluginConf_file, configspec=plugin_rules, create_empty=True)
## validate and convert values according to the spec
pluginConf.validate(validate.Validator())
## check if pluginConf_file file was created successfully?
if not os.path.exists(pluginConf_file):
raise CryptoBoxExceptions.CBEnvironmentError("failed to create plugin configuration file (%s)" % pluginConf_file)
return pluginConf
def __getVolumesDatabase(self):
try:
try:
conf_file = os.path.join(self.prefs["Locations"]["SettingsDir"], self.VOLUMESDB_FILE)
except KeyError:
raise CryptoBoxExceptions.CBConfigUndefinedError("Locations", "SettingsDir")
except SyntaxError:
raise CryptoBoxExceptions.CBConfigInvalidValueError("Locations", "SettingsDir", conf_file, "failed to interprete the filename of the volume database correctly (%s)" % conf_file)
## create conf_file if necessary
if os.path.exists(conf_file):
conf = configobj.ConfigObj(conf_file)
else:
conf = configobj.ConfigObj(conf_file, create_empty=True)
## check if conf_file file was created successfully?
if not os.path.exists(conf_file):
raise CryptoBoxExceptions.CBEnvironmentError("failed to create volume database file (%s)" % conf_file)
return conf
def __getUserDB(self):
import StringIO, sha
userDB_rules = StringIO.StringIO(self.userDatabaseSpec)
try:
try:
userDB_file = os.path.join(self.prefs["Locations"]["SettingsDir"], self.USERDB_FILE)
except KeyError:
raise CryptoBoxExceptions.CBConfigUndefinedError("Locations", "SettingsDir")
except SyntaxError:
raise CryptoBoxExceptions.CBConfigInvalidValueError("Locations", "SettingsDir", userDB_file, "failed to interprete the filename of the users database file correctly (%s)" % userDB_file)
## create userDB_file if necessary
if os.path.exists(userDB_file):
userDB = configobj.ConfigObj(userDB_file, configspec=userDB_rules)
else:
userDB = configobj.ConfigObj(userDB_file, configspec=userDB_rules, create_empty=True)
## validate and set default value for "admin" user
userDB.validate(validate.Validator())
## check if userDB file was created successfully?
if not os.path.exists(userDB_file):
raise CryptoBoxExceptions.CBEnvironmentError("failed to create user database file (%s)" % userDB_file)
## define password hash function - never use "sha" directly - SPOT
userDB.getDigest = lambda password: sha.new(password).hexdigest()
return userDB
def __getMiscFiles(self):
misc_dir = os.path.join(self.prefs["Locations"]["SettingsDir"], "misc")
if (not os.path.isdir(misc_dir)) or (not os.access(misc_dir, os.X_OK)):
return []
return [MiscConfigFile(os.path.join(misc_dir, f), self.log)
for f in os.listdir(misc_dir)
if os.path.isfile(os.path.join(misc_dir, f))]
def __getConfigFileName(self, config_file):
# search for the configuration file
import types
if config_file is None:
# no config file was specified - we will look for it in the ususal locations
conf_file_list = [os.path.expanduser(f)
for f in self.CONF_LOCATIONS
if os.path.exists(os.path.expanduser(f))]
if not conf_file_list:
# no possible config file found in the usual locations
raise CryptoBoxExceptions.CBConfigUnavailableError()
config_file = conf_file_list[0]
else:
# a config file was specified (e.g. via command line)
if type(config_file) != types.StringType:
raise CryptoBoxExceptions.CBConfigUnavailableError("invalid config file specified: %s" % config_file)
if not os.path.exists(config_file):
raise CryptoBoxExceptions.CBConfigUnavailableError("could not find the specified configuration file (%s)" % config_file)
return config_file
def __configureLogHandler(self):
try:
log_level = self.prefs["Log"]["Level"].upper()
log_level_avail = ["DEBUG", "INFO", "WARN", "ERROR"]
if not log_level in log_level_avail:
raise TypeError
except KeyError:
raise CryptoBoxExceptions.CBConfigUndefinedError("Log", "Level")
except TypeError:
raise CryptoBoxExceptions.CBConfigInvalidValueError("Log", "Level", log_level, "invalid log level: only %s are allowed" % log_level_avail)
try:
try:
log_handler = logging.FileHandler(self.prefs["Log"]["Details"])
except KeyError:
raise CryptoBoxExceptions.CBConfigUndefinedError("Log", "Details")
except IOError:
raise CryptoBoxExceptions.CBEnvironmentError("could not create the log file (%s)" % self.prefs["Log"]["Details"])
log_handler.setFormatter(logging.Formatter('%(asctime)s CryptoBox %(levelname)s: %(message)s'))
cbox_log = logging.getLogger("CryptoBox")
## remove previous handlers
cbox_log.handlers = []
## add new one
cbox_log.addHandler(log_handler)
## do not call parent's handlers
cbox_log.propagate = False
## 'log_level' is a string -> use 'getattr'
cbox_log.setLevel(getattr(logging,log_level))
## the logger named "CryptoBox" is configured now
validation_spec = """
[Main]
AllowedDevices = list(min=1)
DefaultVolumePrefix = string(min=1)
DefaultCipher = string(default="aes-cbc-essiv:sha256")
ConfigVolumeLabel = string(min=1, default="cbox_config")
UseConfigPartition = integer(min=0, max=1, default=0)
DisabledPlugins = list(default=[])
[Locations]
MountParentDir = directoryExists(default="/var/cache/cryptobox/mnt")
SettingsDir = directoryExists(default="/var/cache/cryptobox/settings")
TemplateDir = directoryExists(default="/usr/share/cryptobox/template")
LangDir = directoryExists(default="/usr/share/cryptobox/lang")
DocDir = directoryExists(default="/usr/share/doc/cryptobox/html")
PluginDir = directoryExists(default="/usr/share/cryptobox/plugins")
HookDir = directoryExists(default="/etc/cryptobox/hooks")
[Log]
Level = option("debug", "info", "warn", "error", default="warn")
Destination = option("file", default="file")
Details = string(min=1)
[WebSettings]
Stylesheet = string(min=1)
Language = string(min=1, default="en")
[Programs]
cryptsetup = fileExecutable(default="/sbin/cryptsetup")
mkfs-data = fileExecutable(default="/sbin/mkfs.ext3")
blkid = fileExecutable(default="/sbin/blkid")
blockdev = fileExecutable(default="/sbin/blockdev")
mount = fileExecutable(default="/bin/mount")
umount = fileExecutable(default="/bin/umount")
super = fileExecutable(default="/usr/bin/super")
# this is the "program" name as defined in /etc/super.tab
CryptoBoxRootActions = string(min=1)
"""
pluginValidationSpec = """
[__many__]
visibility = boolean(default=None)
requestAuth = boolean(default=None)
rank = integer(default=None)
"""
userDatabaseSpec = """
[admins]
admin = string(default=d033e22ae348aeb5660fc2140aec35850c4da997)
"""
class CryptoBoxSettingsValidator(validate.Validator):
def __init__(self):
validate.Validator.__init__(self)
self.functions["directoryExists"] = self.check_directoryExists
self.functions["fileExecutable"] = self.check_fileExecutable
self.functions["fileWriteable"] = self.check_fileWriteable
def check_directoryExists(self, value):
dir_path = os.path.abspath(value)
if not os.path.isdir(dir_path):
raise validate.VdtValueError("%s (not found)" % value)
if not os.access(dir_path, os.X_OK):
raise validate.VdtValueError("%s (access denied)" % value)
return dir_path
def check_fileExecutable(self, value):
file_path = os.path.abspath(value)
if not os.path.isfile(file_path):
raise validate.VdtValueError("%s (not found)" % value)
if not os.access(file_path, os.X_OK):
raise validate.VdtValueError("%s (access denied)" % value)
return file_path
def check_fileWriteable(self, value):
file_path = os.path.abspath(value)
if os.path.isfile(file_path):
if not os.access(file_path, os.W_OK):
raise validate.VdtValueError("%s (not found)" % value)
else:
parent_dir = os.path.dirname(file_path)
if os.path.isdir(parent_dir) and os.access(parent_dir, os.W_OK):
return file_path
raise validate.VdtValueError("%s (directory does not exist)" % value)
return file_path
class MiscConfigFile:
maxSize = 20480
def __init__(self, filename, logger):
self.filename = filename
self.log = logger
self.load()
def load(self):
fd = open(self.filename, "rb")
## limit the maximum size
self.content = fd.read(self.maxSize)
if fd.tell() == self.maxSize:
self.log.warn("file in misc settings directory (%s) is bigger than allowed (%s)" % (self.filename, self.maxSize))
fd.close()
def save(self):
save_dir = os.path.dirname(self.filename)
## create the directory, if necessary
if not os.path.isdir(save_dir):
try:
os.mkdir(save_dir)
except IOError:
return False
## save the content of the file
try:
fd = open(self.filename, "wb")
except IOError:
return False
try:
fd.write(self.content)
fd.close()
return True
except IOError:
fd.close()
return False