/mandos/trunk : revision 504

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#!/usr/bin/python

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# -*- mode: python; coding: utf-8 -*-

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#

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# Mandos server - give out binary blobs to connecting clients.

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#

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# This program is partly derived from an example program for an Avahi

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# service publisher, downloaded from

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# <http://avahi.org/wiki/PythonPublishExample>. This includes the

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# methods "add", "remove", "server_state_changed",

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# "entry_group_state_changed", "cleanup", and "activate" in the

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# "AvahiService" class, and some lines in "main".

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#

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# Everything else is

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#

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# This program is free software: you can redistribute it and/or modify

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# it under the terms of the GNU General Public License as published by

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# the Free Software Foundation, either version 3 of the License, or

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# (at your option) any later version.

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#

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# This program is distributed in the hope that it will be useful,

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# but WITHOUT ANY WARRANTY; without even the implied warranty of

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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

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# GNU General Public License for more details.

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#

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# You should have received a copy of the GNU General Public License

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# along with this program. If not, see

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# <http://www.gnu.org/licenses/>.

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#

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# Contact the authors at <mandos@fukt.bsnet.se>.

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#

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from __future__ import (division, absolute_import, print_function,

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unicode_literals)

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import SocketServer as socketserver

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import socket

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import argparse

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import datetime

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import errno

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import gnutls.crypto

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import gnutls.connection

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import gnutls.errors

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import gnutls.library.functions

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import gnutls.library.constants

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import gnutls.library.types

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import ConfigParser as configparser

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import sys

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import re

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import os

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import signal

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import subprocess

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import atexit

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import stat

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import logging

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import logging.handlers

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import pwd

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import contextlib

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import struct

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import fcntl

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import functools

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import cPickle as pickle

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import multiprocessing

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import dbus

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import dbus.service

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import gobject

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import avahi

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from dbus.mainloop.glib import DBusGMainLoop

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import ctypes

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import ctypes.util

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import xml.dom.minidom

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import inspect

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try:

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SO_BINDTODEVICE = socket.SO_BINDTODEVICE

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except AttributeError:

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try:

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from IN import SO_BINDTODEVICE

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except ImportError:

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SO_BINDTODEVICE = None

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version = "1.3.1"

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#logger = logging.getLogger('mandos')

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logger = logging.Logger('mandos')

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syslogger = (logging.handlers.SysLogHandler

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(facility = logging.handlers.SysLogHandler.LOG_DAEMON,

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address = str("/dev/log")))

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syslogger.setFormatter(logging.Formatter

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('Mandos [%(process)d]: %(levelname)s:'

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' %(message)s'))

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logger.addHandler(syslogger)

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console = logging.StreamHandler()

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console.setFormatter(logging.Formatter('%(name)s [%(process)d]:'

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' %(levelname)s:'

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' %(message)s'))

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logger.addHandler(console)

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class AvahiError(Exception):

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def __init__(self, value, *args, **kwargs):

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self.value = value

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super(AvahiError, self).__init__(value, *args, **kwargs)

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def __unicode__(self):

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return unicode(repr(self.value))

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class AvahiServiceError(AvahiError):

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pass

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class AvahiGroupError(AvahiError):

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pass

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class AvahiService(object):

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"""An Avahi (Zeroconf) service.

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Attributes:

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interface: integer; avahi.IF_UNSPEC or an interface index.

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Used to optionally bind to the specified interface.

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name: string; Example: 'Mandos'

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type: string; Example: '_mandos._tcp'.

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See <http://www.dns-sd.org/ServiceTypes.html>

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port: integer; what port to announce

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TXT: list of strings; TXT record for the service

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domain: string; Domain to publish on, default to .local if empty.

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host: string; Host to publish records for, default is localhost

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max_renames: integer; maximum number of renames

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rename_count: integer; counter so we only rename after collisions

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a sensible number of times

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group: D-Bus Entry Group

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server: D-Bus Server

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bus: dbus.SystemBus()

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"""

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def __init__(self, interface = avahi.IF_UNSPEC, name = None,

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servicetype = None, port = None, TXT = None,

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domain = "", host = "", max_renames = 32768,

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protocol = avahi.PROTO_UNSPEC, bus = None):

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self.interface = interface

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self.name = name

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self.type = servicetype

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self.port = port

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self.TXT = TXT if TXT is not None else []

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self.domain = domain

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self.host = host

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self.rename_count = 0

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self.max_renames = max_renames

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self.protocol = protocol

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self.group = None # our entry group

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self.server = None

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self.bus = bus

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self.entry_group_state_changed_match = None

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def rename(self):

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"""Derived from the Avahi example code"""

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if self.rename_count >= self.max_renames:

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logger.critical("No suitable Zeroconf service name found"

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" after %i retries, exiting.",

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self.rename_count)

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raise AvahiServiceError("Too many renames")

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self.name = unicode(self.server.GetAlternativeServiceName(self.name))

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logger.info("Changing Zeroconf service name to %r ...",

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self.name)

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syslogger.setFormatter(logging.Formatter

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('Mandos (%s) [%%(process)d]:'

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' %%(levelname)s: %%(message)s'

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% self.name))

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self.remove()

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try:

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self.add()

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except dbus.exceptions.DBusException as error:

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logger.critical("DBusException: %s", error)

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self.cleanup()

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os._exit(1)

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self.rename_count += 1

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def remove(self):

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"""Derived from the Avahi example code"""

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if self.entry_group_state_changed_match is not None:

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self.entry_group_state_changed_match.remove()

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self.entry_group_state_changed_match = None

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if self.group is not None:

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self.group.Reset()

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def add(self):

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"""Derived from the Avahi example code"""

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self.remove()

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if self.group is None:

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self.group = dbus.Interface(

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self.bus.get_object(avahi.DBUS_NAME,

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self.server.EntryGroupNew()),

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avahi.DBUS_INTERFACE_ENTRY_GROUP)

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self.entry_group_state_changed_match = (

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self.group.connect_to_signal(

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'StateChanged', self .entry_group_state_changed))

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logger.debug("Adding Zeroconf service '%s' of type '%s' ...",

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self.name, self.type)

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self.group.AddService(

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self.interface,

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self.protocol,

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dbus.UInt32(0), # flags

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self.name, self.type,

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self.domain, self.host,

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dbus.UInt16(self.port),

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avahi.string_array_to_txt_array(self.TXT))

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self.group.Commit()

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def entry_group_state_changed(self, state, error):

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"""Derived from the Avahi example code"""

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logger.debug("Avahi entry group state change: %i", state)

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if state == avahi.ENTRY_GROUP_ESTABLISHED:

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logger.debug("Zeroconf service established.")

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elif state == avahi.ENTRY_GROUP_COLLISION:

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logger.info("Zeroconf service name collision.")

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self.rename()

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elif state == avahi.ENTRY_GROUP_FAILURE:

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logger.critical("Avahi: Error in group state changed %s",

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unicode(error))

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raise AvahiGroupError("State changed: %s"

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% unicode(error))

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def cleanup(self):

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"""Derived from the Avahi example code"""

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if self.group is not None:

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try:

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self.group.Free()

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except (dbus.exceptions.UnknownMethodException,

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dbus.exceptions.DBusException) as e:

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pass

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self.group = None

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self.remove()

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def server_state_changed(self, state, error=None):

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"""Derived from the Avahi example code"""

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logger.debug("Avahi server state change: %i", state)

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bad_states = { avahi.SERVER_INVALID:

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"Zeroconf server invalid",

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avahi.SERVER_REGISTERING: None,

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avahi.SERVER_COLLISION:

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"Zeroconf server name collision",

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avahi.SERVER_FAILURE:

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"Zeroconf server failure" }

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if state in bad_states:

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if bad_states[state] is not None:

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if error is None:

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logger.error(bad_states[state])

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else:

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logger.error(bad_states[state] + ": %r", error)

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self.cleanup()

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elif state == avahi.SERVER_RUNNING:

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self.add()

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else:

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if error is None:

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logger.debug("Unknown state: %r", state)

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else:

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logger.debug("Unknown state: %r: %r", state, error)

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def activate(self):

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"""Derived from the Avahi example code"""

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if self.server is None:

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self.server = dbus.Interface(

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self.bus.get_object(avahi.DBUS_NAME,

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avahi.DBUS_PATH_SERVER,

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follow_name_owner_changes=True),

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avahi.DBUS_INTERFACE_SERVER)

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self.server.connect_to_signal("StateChanged",

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self.server_state_changed)

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self.server_state_changed(self.server.GetState())

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def _timedelta_to_milliseconds(td):

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"Convert a datetime.timedelta() to milliseconds"

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return ((td.days * 24 * 60 * 60 * 1000)

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+ (td.seconds * 1000)

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+ (td.microseconds // 1000))

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class Client(object):

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"""A representation of a client host served by this server.

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Attributes:

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_approved: bool(); 'None' if not yet approved/disapproved

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approval_delay: datetime.timedelta(); Time to wait for approval

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approval_duration: datetime.timedelta(); Duration of one approval

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checker: subprocess.Popen(); a running checker process used

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to see if the client lives.

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'None' if no process is running.

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checker_callback_tag: a gobject event source tag, or None

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checker_command: string; External command which is run to check

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if client lives. %() expansions are done at

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runtime with vars(self) as dict, so that for

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instance %(name)s can be used in the command.

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checker_initiator_tag: a gobject event source tag, or None

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created: datetime.datetime(); (UTC) object creation

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current_checker_command: string; current running checker_command

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disable_hook: If set, called by disable() as disable_hook(self)

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disable_initiator_tag: a gobject event source tag, or None

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enabled: bool()

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fingerprint: string (40 or 32 hexadecimal digits); used to

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uniquely identify the client

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host: string; available for use by the checker command

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interval: datetime.timedelta(); How often to start a new checker

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last_approval_request: datetime.datetime(); (UTC) or None

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last_checked_ok: datetime.datetime(); (UTC) or None

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last_enabled: datetime.datetime(); (UTC)

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name: string; from the config file, used in log messages and

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D-Bus identifiers

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secret: bytestring; sent verbatim (over TLS) to client

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timeout: datetime.timedelta(); How long from last_checked_ok

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until this client is disabled

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extended_timeout: extra long timeout when password has been sent

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runtime_expansions: Allowed attributes for runtime expansion.

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expires: datetime.datetime(); time (UTC) when a client will be

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disabled, or None

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"""

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runtime_expansions = ("approval_delay", "approval_duration",

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"created", "enabled", "fingerprint",

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"host", "interval", "last_checked_ok",

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"last_enabled", "name", "timeout")

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def timeout_milliseconds(self):

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"Return the 'timeout' attribute in milliseconds"

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return _timedelta_to_milliseconds(self.timeout)

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def extended_timeout_milliseconds(self):

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"Return the 'extended_timeout' attribute in milliseconds"

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return _timedelta_to_milliseconds(self.extended_timeout)

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def interval_milliseconds(self):

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"Return the 'interval' attribute in milliseconds"

327

return _timedelta_to_milliseconds(self.interval)

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def approval_delay_milliseconds(self):

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return _timedelta_to_milliseconds(self.approval_delay)

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def __init__(self, name = None, disable_hook=None, config=None):

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"""Note: the 'checker' key in 'config' sets the

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'checker_command' attribute and *not* the 'checker'

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attribute."""

336

self.name = name

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if config is None:

338

config = {}

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logger.debug("Creating client %r", self.name)

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# Uppercase and remove spaces from fingerprint for later

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# comparison purposes with return value from the fingerprint()

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# function

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self.fingerprint = (config["fingerprint"].upper()

344

.replace(" ", ""))

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logger.debug(" Fingerprint: %s", self.fingerprint)

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if "secret" in config:

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self.secret = config["secret"].decode("base64")

348

elif "secfile" in config:

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with open(os.path.expanduser(os.path.expandvars

350

(config["secfile"])),

351

"rb") as secfile:

352

self.secret = secfile.read()

353

else:

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raise TypeError("No secret or secfile for client %s"

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% self.name)

356

self.host = config.get("host", "")

357

self.created = datetime.datetime.utcnow()

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self.enabled = False

359

self.last_approval_request = None

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self.last_enabled = None

361

self.last_checked_ok = None

362

self.timeout = string_to_delta(config["timeout"])

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self.extended_timeout = string_to_delta(config["extended_timeout"])

364

self.interval = string_to_delta(config["interval"])

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self.disable_hook = disable_hook

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self.checker = None

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self.checker_initiator_tag = None

368

self.disable_initiator_tag = None

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self.expires = None

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self.checker_callback_tag = None

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self.checker_command = config["checker"]

372

self.current_checker_command = None

373

self.last_connect = None

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self._approved = None

375

self.approved_by_default = config.get("approved_by_default",

376

True)

377

self.approvals_pending = 0

378

self.approval_delay = string_to_delta(

379

config["approval_delay"])

380

self.approval_duration = string_to_delta(

381

config["approval_duration"])

382

self.changedstate = multiprocessing_manager.Condition(multiprocessing_manager.Lock())

383

384

def send_changedstate(self):

385

self.changedstate.acquire()

386

self.changedstate.notify_all()

387

self.changedstate.release()

388

389

def enable(self):

390

"""Start this client's checker and timeout hooks"""

391

if getattr(self, "enabled", False):

392

# Already enabled

393

return

394

self.send_changedstate()

395

# Schedule a new checker to be started an 'interval' from now,

396

# and every interval from then on.

397

self.checker_initiator_tag = (gobject.timeout_add

398

(self.interval_milliseconds(),

399

self.start_checker))

400

# Schedule a disable() when 'timeout' has passed

401

self.expires = datetime.datetime.utcnow() + self.timeout

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self.disable_initiator_tag = (gobject.timeout_add

403

(self.timeout_milliseconds(),

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self.disable))

405

self.enabled = True

406

self.last_enabled = datetime.datetime.utcnow()

407

# Also start a new checker *right now*.

408

self.start_checker()

409

410

def disable(self, quiet=True):

411

"""Disable this client."""

412

if not getattr(self, "enabled", False):

413

return False

414

if not quiet:

415

self.send_changedstate()

416

if not quiet:

417

logger.info("Disabling client %s", self.name)

418

if getattr(self, "disable_initiator_tag", False):

419

gobject.source_remove(self.disable_initiator_tag)

420

self.disable_initiator_tag = None

421

self.expires = None

422

if getattr(self, "checker_initiator_tag", False):

423

gobject.source_remove(self.checker_initiator_tag)

424

self.checker_initiator_tag = None

425

self.stop_checker()

426

if self.disable_hook:

427

self.disable_hook(self)

428

self.enabled = False

429

# Do not run this again if called by a gobject.timeout_add

430

return False

431

432

def __del__(self):

433

self.disable_hook = None

434

self.disable()

435

436

def checker_callback(self, pid, condition, command):

437

"""The checker has completed, so take appropriate actions."""

438

self.checker_callback_tag = None

439

self.checker = None

440

if os.WIFEXITED(condition):

441

exitstatus = os.WEXITSTATUS(condition)

442

if exitstatus == 0:

443

logger.info("Checker for %(name)s succeeded",

444

vars(self))

445

self.checked_ok()

446

else:

447

logger.info("Checker for %(name)s failed",

448

vars(self))

449

else:

450

logger.warning("Checker for %(name)s crashed?",

451

vars(self))

452

453

def checked_ok(self, timeout=None):

454

"""Bump up the timeout for this client.

455

456

This should only be called when the client has been seen,

457

alive and well.

458

"""

459

if timeout is None:

460

timeout = self.timeout

461

self.last_checked_ok = datetime.datetime.utcnow()

462

gobject.source_remove(self.disable_initiator_tag)

463

self.expires = datetime.datetime.utcnow() + timeout

464

self.disable_initiator_tag = (gobject.timeout_add

465

(_timedelta_to_milliseconds(timeout),

466

self.disable))

467

468

def need_approval(self):

469

self.last_approval_request = datetime.datetime.utcnow()

470

471

def start_checker(self):

472

"""Start a new checker subprocess if one is not running.

473

474

If a checker already exists, leave it running and do

475

nothing."""

476

# The reason for not killing a running checker is that if we

477

# did that, then if a checker (for some reason) started

478

# running slowly and taking more than 'interval' time, the

479

# client would inevitably timeout, since no checker would get

480

# a chance to run to completion. If we instead leave running

481

# checkers alone, the checker would have to take more time

482

# than 'timeout' for the client to be disabled, which is as it

483

# should be.

484

485

# If a checker exists, make sure it is not a zombie

486

try:

487

pid, status = os.waitpid(self.checker.pid, os.WNOHANG)

488

except (AttributeError, OSError) as error:

489

if (isinstance(error, OSError)

490

and error.errno != errno.ECHILD):

491

raise error

492

else:

493

if pid:

494

logger.warning("Checker was a zombie")

495

gobject.source_remove(self.checker_callback_tag)

496

self.checker_callback(pid, status,

497

self.current_checker_command)

498

# Start a new checker if needed

499

if self.checker is None:

500

try:

501

# In case checker_command has exactly one % operator

502

command = self.checker_command % self.host

503

except TypeError:

504

# Escape attributes for the shell

505

escaped_attrs = dict(

506

(attr,

507

re.escape(unicode(str(getattr(self, attr, "")),

508

errors=

509

'replace')))

510

for attr in

511

self.runtime_expansions)

512

513

try:

514

command = self.checker_command % escaped_attrs

515

except TypeError as error:

516

logger.error('Could not format string "%s":'

517

' %s', self.checker_command, error)

518

return True # Try again later

519

self.current_checker_command = command

520

try:

521

logger.info("Starting checker %r for %s",

522

command, self.name)

523

# We don't need to redirect stdout and stderr, since

524

# in normal mode, that is already done by daemon(),

525

# and in debug mode we don't want to. (Stdin is

526

# always replaced by /dev/null.)

527

self.checker = subprocess.Popen(command,

528

close_fds=True,

529

shell=True, cwd="/")

530

self.checker_callback_tag = (gobject.child_watch_add

531

(self.checker.pid,

532

self.checker_callback,

533

data=command))

534

# The checker may have completed before the gobject

535

# watch was added. Check for this.

536

pid, status = os.waitpid(self.checker.pid, os.WNOHANG)

537

if pid:

538

gobject.source_remove(self.checker_callback_tag)

539

self.checker_callback(pid, status, command)

540

except OSError as error:

541

logger.error("Failed to start subprocess: %s",

542

error)

543

# Re-run this periodically if run by gobject.timeout_add

544

return True

545

546

def stop_checker(self):

547

"""Force the checker process, if any, to stop."""

548

if self.checker_callback_tag:

549

gobject.source_remove(self.checker_callback_tag)

550

self.checker_callback_tag = None

551

if getattr(self, "checker", None) is None:

552

return

553

logger.debug("Stopping checker for %(name)s", vars(self))

554

try:

555

os.kill(self.checker.pid, signal.SIGTERM)

556

#time.sleep(0.5)

557

#if self.checker.poll() is None:

558

# os.kill(self.checker.pid, signal.SIGKILL)

559

except OSError as error:

560

if error.errno != errno.ESRCH: # No such process

561

raise

562

self.checker = None

563

564

565

def dbus_service_property(dbus_interface, signature="v",

566

access="readwrite", byte_arrays=False):

567

"""Decorators for marking methods of a DBusObjectWithProperties to

568

become properties on the D-Bus.

569

570

The decorated method will be called with no arguments by "Get"

571

and with one argument by "Set".

572

573

The parameters, where they are supported, are the same as

574

dbus.service.method, except there is only "signature", since the

575

type from Get() and the type sent to Set() is the same.

576

"""

577

# Encoding deeply encoded byte arrays is not supported yet by the

578

# "Set" method, so we fail early here:

579

if byte_arrays and signature != "ay":

580

raise ValueError("Byte arrays not supported for non-'ay'"

581

" signature %r" % signature)

582

def decorator(func):

583

func._dbus_is_property = True

584

func._dbus_interface = dbus_interface

585

func._dbus_signature = signature

586

func._dbus_access = access

587

func._dbus_name = func.__name__

588

if func._dbus_name.endswith("_dbus_property"):

589

func._dbus_name = func._dbus_name[:-14]

590

func._dbus_get_args_options = {'byte_arrays': byte_arrays }

591

return func

592

return decorator

593

594

595

class DBusPropertyException(dbus.exceptions.DBusException):

596

"""A base class for D-Bus property-related exceptions

597

"""

598

def __unicode__(self):

599

return unicode(str(self))

600

601

602

class DBusPropertyAccessException(DBusPropertyException):

603

"""A property's access permissions disallows an operation.

604

"""

605

pass

606

607

608

class DBusPropertyNotFound(DBusPropertyException):

609

"""An attempt was made to access a non-existing property.

610

"""

611

pass

612

613

614

class DBusObjectWithProperties(dbus.service.Object):

615

"""A D-Bus object with properties.

616

617

Classes inheriting from this can use the dbus_service_property

618

decorator to expose methods as D-Bus properties. It exposes the

619

standard Get(), Set(), and GetAll() methods on the D-Bus.

620

"""

621

622

@staticmethod

623

def _is_dbus_property(obj):

624

return getattr(obj, "_dbus_is_property", False)

625

626

def _get_all_dbus_properties(self):

627

"""Returns a generator of (name, attribute) pairs

628

"""

629

return ((prop._dbus_name, prop)

630

for name, prop in

631

inspect.getmembers(self, self._is_dbus_property))

632

633

def _get_dbus_property(self, interface_name, property_name):

634

"""Returns a bound method if one exists which is a D-Bus

635

property with the specified name and interface.

636

"""

637

for name in (property_name,

638

property_name + "_dbus_property"):

639

prop = getattr(self, name, None)

640

if (prop is None

641

or not self._is_dbus_property(prop)

642

or prop._dbus_name != property_name

643

or (interface_name and prop._dbus_interface

644

and interface_name != prop._dbus_interface)):

645

continue

646

return prop

647

# No such property

648

raise DBusPropertyNotFound(self.dbus_object_path + ":"

649

+ interface_name + "."

650

+ property_name)

651

652

@dbus.service.method(dbus.PROPERTIES_IFACE, in_signature="ss",

653

out_signature="v")

654

def Get(self, interface_name, property_name):

655

"""Standard D-Bus property Get() method, see D-Bus standard.

656

"""

657

prop = self._get_dbus_property(interface_name, property_name)

658

if prop._dbus_access == "write":

659

raise DBusPropertyAccessException(property_name)

660

value = prop()

661

if not hasattr(value, "variant_level"):

662

return value

663

return type(value)(value, variant_level=value.variant_level+1)

664

665

@dbus.service.method(dbus.PROPERTIES_IFACE, in_signature="ssv")

666

def Set(self, interface_name, property_name, value):

667

"""Standard D-Bus property Set() method, see D-Bus standard.

668

"""

669

prop = self._get_dbus_property(interface_name, property_name)

670

if prop._dbus_access == "read":

671

raise DBusPropertyAccessException(property_name)

672

if prop._dbus_get_args_options["byte_arrays"]:

673

# The byte_arrays option is not supported yet on

674

# signatures other than "ay".

675

if prop._dbus_signature != "ay":

676

raise ValueError

677

value = dbus.ByteArray(''.join(unichr(byte)

678

for byte in value))

679

prop(value)

680

681

@dbus.service.method(dbus.PROPERTIES_IFACE, in_signature="s",

682

out_signature="a{sv}")

683

def GetAll(self, interface_name):

684

"""Standard D-Bus property GetAll() method, see D-Bus

685

standard.

686

687

Note: Will not include properties with access="write".

688

"""

689

all = {}

690

for name, prop in self._get_all_dbus_properties():

691

if (interface_name

692

and interface_name != prop._dbus_interface):

693

# Interface non-empty but did not match

694

continue

695

# Ignore write-only properties

696

if prop._dbus_access == "write":

697

continue

698

value = prop()

699

if not hasattr(value, "variant_level"):

700

all[name] = value

701

continue

702

all[name] = type(value)(value, variant_level=

703

value.variant_level+1)

704

return dbus.Dictionary(all, signature="sv")

705

706

@dbus.service.method(dbus.INTROSPECTABLE_IFACE,

707

out_signature="s",

708

path_keyword='object_path',

709

connection_keyword='connection')

710

def Introspect(self, object_path, connection):

711

"""Standard D-Bus method, overloaded to insert property tags.

712

"""

713

xmlstring = dbus.service.Object.Introspect(self, object_path,

714

connection)

715

try:

716

document = xml.dom.minidom.parseString(xmlstring)

717

def make_tag(document, name, prop):

718

e = document.createElement("property")

719

e.setAttribute("name", name)

720

e.setAttribute("type", prop._dbus_signature)

721

e.setAttribute("access", prop._dbus_access)

722

return e

723

for if_tag in document.getElementsByTagName("interface"):

724

for tag in (make_tag(document, name, prop)

725

for name, prop

726

in self._get_all_dbus_properties()

727

if prop._dbus_interface

728

== if_tag.getAttribute("name")):

729

if_tag.appendChild(tag)

730

# Add the names to the return values for the

731

# "org.freedesktop.DBus.Properties" methods

732

if (if_tag.getAttribute("name")

733

== "org.freedesktop.DBus.Properties"):

734

for cn in if_tag.getElementsByTagName("method"):

735

if cn.getAttribute("name") == "Get":

736

for arg in cn.getElementsByTagName("arg"):

737

if (arg.getAttribute("direction")

738

== "out"):

739

arg.setAttribute("name", "value")

740

elif cn.getAttribute("name") == "GetAll":

741

for arg in cn.getElementsByTagName("arg"):

742

if (arg.getAttribute("direction")

743

== "out"):

744

arg.setAttribute("name", "props")

745

xmlstring = document.toxml("utf-8")

746

document.unlink()

747

except (AttributeError, xml.dom.DOMException,

748

xml.parsers.expat.ExpatError) as error:

749

logger.error("Failed to override Introspection method",

750

error)

751

return xmlstring

752

753

754

def datetime_to_dbus (dt, variant_level=0):

755

"""Convert a UTC datetime.datetime() to a D-Bus type."""

756

if dt is None:

757

return dbus.String("", variant_level = variant_level)

758

return dbus.String(dt.isoformat(),

759

variant_level=variant_level)

760

761

762

class ClientDBus(Client, DBusObjectWithProperties):

763

"""A Client class using D-Bus

764

765

Attributes:

766

dbus_object_path: dbus.ObjectPath

767

bus: dbus.SystemBus()

768

"""

769

770

runtime_expansions = (Client.runtime_expansions

771

+ ("dbus_object_path",))

772

773

# dbus.service.Object doesn't use super(), so we can't either.

774

775

def __init__(self, bus = None, *args, **kwargs):

776

self._approvals_pending = 0

777

self.bus = bus

778

Client.__init__(self, *args, **kwargs)

779

# Only now, when this client is initialized, can it show up on

780

# the D-Bus

781

client_object_name = unicode(self.name).translate(

782

{ord("."): ord("_"),

783

ord("-"): ord("_")})

784

self.dbus_object_path = (dbus.ObjectPath

785

("/clients/" + client_object_name))

786

DBusObjectWithProperties.__init__(self, self.bus,

787

self.dbus_object_path)

788

789

def notifychangeproperty(transform_func,

790

dbus_name, type_func=lambda x: x,

791

variant_level=1):

792

""" Modify a variable so that its a property that announce its

793

changes to DBus.

794

transform_fun: Function that takes a value and transform it to

795

DBus type.

796

dbus_name: DBus name of the variable

797

type_func: Function that transform the value before sending it

798

to DBus

799

variant_level: DBus variant level. default: 1

800

"""

801

real_value = [None,]

802

def setter(self, value):

803

old_value = real_value[0]

804

real_value[0] = value

805

if hasattr(self, "dbus_object_path"):

806

if type_func(old_value) != type_func(real_value[0]):

807

dbus_value = transform_func(type_func(real_value[0]),

808

variant_level)

809

self.PropertyChanged(dbus.String(dbus_name),

810

dbus_value)

811

812

return property(lambda self: real_value[0], setter)

813

814

815

expires = notifychangeproperty(datetime_to_dbus, "Expires")

816

approvals_pending = notifychangeproperty(dbus.Boolean,

817

"ApprovalPending",

818

type_func = bool)

819

enabled = notifychangeproperty(dbus.Boolean, "Enabled")

820

last_enabled = notifychangeproperty(datetime_to_dbus,

821

"LastEnabled")

822

checker = notifychangeproperty(dbus.Boolean, "CheckerRunning",

823

type_func = lambda checker: checker is not None)

824

last_checked_ok = notifychangeproperty(datetime_to_dbus,

825

"LastCheckedOK")

826

last_approval_request = notifychangeproperty(datetime_to_dbus,

827

"LastApprovalRequest")

828

approved_by_default = notifychangeproperty(dbus.Boolean,

829

"ApprovedByDefault")

830

approval_delay = notifychangeproperty(dbus.UInt16, "ApprovalDelay",

831

type_func = _timedelta_to_milliseconds)

832

approval_duration = notifychangeproperty(dbus.UInt16, "ApprovalDuration",

833

type_func = _timedelta_to_milliseconds)

834

host = notifychangeproperty(dbus.String, "Host")

835

timeout = notifychangeproperty(dbus.UInt16, "Timeout",

836

type_func = _timedelta_to_milliseconds)

837

extended_timeout = notifychangeproperty(dbus.UInt16, "ExtendedTimeout",

838

type_func = _timedelta_to_milliseconds)

839

interval = notifychangeproperty(dbus.UInt16, "Interval",

840

type_func = _timedelta_to_milliseconds)

841

checker_command = notifychangeproperty(dbus.String, "Checker")

842

843

del notifychangeproperty

844

845

def __del__(self, *args, **kwargs):

846

try:

847

self.remove_from_connection()

848

except LookupError:

849

pass

850

if hasattr(DBusObjectWithProperties, "__del__"):

851

DBusObjectWithProperties.__del__(self, *args, **kwargs)

852

Client.__del__(self, *args, **kwargs)

853

854

def checker_callback(self, pid, condition, command,

855

*args, **kwargs):

856

self.checker_callback_tag = None

857

self.checker = None

858

if os.WIFEXITED(condition):

859

exitstatus = os.WEXITSTATUS(condition)

860

# Emit D-Bus signal

861

self.CheckerCompleted(dbus.Int16(exitstatus),

862

dbus.Int64(condition),

863

dbus.String(command))

864

else:

865

# Emit D-Bus signal

866

self.CheckerCompleted(dbus.Int16(-1),

867

dbus.Int64(condition),

868

dbus.String(command))

869

870

return Client.checker_callback(self, pid, condition, command,

871

*args, **kwargs)

872

873

def start_checker(self, *args, **kwargs):

874

old_checker = self.checker

875

if self.checker is not None:

876

old_checker_pid = self.checker.pid

877

else:

878

old_checker_pid = None

879

r = Client.start_checker(self, *args, **kwargs)

880

# Only if new checker process was started

881

if (self.checker is not None

882

and old_checker_pid != self.checker.pid):

883

# Emit D-Bus signal

884

self.CheckerStarted(self.current_checker_command)

885

return r

886

887

def _reset_approved(self):

888

self._approved = None

889

return False

890

891

def approve(self, value=True):

892

self.send_changedstate()

893

self._approved = value

894

gobject.timeout_add(_timedelta_to_milliseconds

895

(self.approval_duration),

896

self._reset_approved)

897

898

899

## D-Bus methods, signals & properties

900

_interface = "se.bsnet.fukt.Mandos.Client"

901

902

## Signals

903

904

# CheckerCompleted - signal

905

@dbus.service.signal(_interface, signature="nxs")

906

def CheckerCompleted(self, exitcode, waitstatus, command):

907

"D-Bus signal"

908

pass

909

910

# CheckerStarted - signal

911

@dbus.service.signal(_interface, signature="s")

912

def CheckerStarted(self, command):

913

"D-Bus signal"

914

pass

915

916

# PropertyChanged - signal

917

@dbus.service.signal(_interface, signature="sv")

918

def PropertyChanged(self, property, value):

919

"D-Bus signal"

920

pass

921

922

# GotSecret - signal

923

@dbus.service.signal(_interface)

924

def GotSecret(self):

925

"""D-Bus signal

926

Is sent after a successful transfer of secret from the Mandos

927

server to mandos-client

928

"""

929

pass

930

931

# Rejected - signal

932

@dbus.service.signal(_interface, signature="s")

933

def Rejected(self, reason):

934

"D-Bus signal"

935

pass

936

937

# NeedApproval - signal

938

@dbus.service.signal(_interface, signature="tb")

939

def NeedApproval(self, timeout, default):

940

"D-Bus signal"

941

return self.need_approval()

942

943

## Methods

944

945

# Approve - method

946

@dbus.service.method(_interface, in_signature="b")

947

def Approve(self, value):

948

self.approve(value)

949

950

# CheckedOK - method

951

@dbus.service.method(_interface)

952

def CheckedOK(self):

953

self.checked_ok()

954

955

# Enable - method

956

@dbus.service.method(_interface)

957

def Enable(self):

958

"D-Bus method"

959

self.enable()

960

961

# StartChecker - method

962

@dbus.service.method(_interface)

963

def StartChecker(self):

964

"D-Bus method"

965

self.start_checker()

966

967

# Disable - method

968

@dbus.service.method(_interface)

969

def Disable(self):

970

"D-Bus method"

971

self.disable()

972

973

# StopChecker - method

974

@dbus.service.method(_interface)

975

def StopChecker(self):

976

self.stop_checker()

977

978

## Properties

979

980

# ApprovalPending - property

981

@dbus_service_property(_interface, signature="b", access="read")

982

def ApprovalPending_dbus_property(self):

983

return dbus.Boolean(bool(self.approvals_pending))

984

985

# ApprovedByDefault - property

986

@dbus_service_property(_interface, signature="b",

987

access="readwrite")

988

def ApprovedByDefault_dbus_property(self, value=None):

989

if value is None: # get

990

return dbus.Boolean(self.approved_by_default)

991

self.approved_by_default = bool(value)

992

993

# ApprovalDelay - property

994

@dbus_service_property(_interface, signature="t",

995

access="readwrite")

996

def ApprovalDelay_dbus_property(self, value=None):

997

if value is None: # get

998

return dbus.UInt64(self.approval_delay_milliseconds())

999

self.approval_delay = datetime.timedelta(0, 0, 0, value)

1000

1001

# ApprovalDuration - property

1002

@dbus_service_property(_interface, signature="t",

1003

access="readwrite")

1004

def ApprovalDuration_dbus_property(self, value=None):

1005

if value is None: # get

1006

return dbus.UInt64(_timedelta_to_milliseconds(

1007

self.approval_duration))

1008

self.approval_duration = datetime.timedelta(0, 0, 0, value)

1009

1010

# Name - property

1011

@dbus_service_property(_interface, signature="s", access="read")

1012

def Name_dbus_property(self):

1013

return dbus.String(self.name)

1014

1015

# Fingerprint - property

1016

@dbus_service_property(_interface, signature="s", access="read")

1017

def Fingerprint_dbus_property(self):

1018

return dbus.String(self.fingerprint)

1019

1020

# Host - property

1021

@dbus_service_property(_interface, signature="s",

1022

access="readwrite")

1023

def Host_dbus_property(self, value=None):

1024

if value is None: # get

1025

return dbus.String(self.host)

1026

self.host = value

1027

1028

# Created - property

1029

@dbus_service_property(_interface, signature="s", access="read")

1030

def Created_dbus_property(self):

1031

return dbus.String(datetime_to_dbus(self.created))

1032

1033

# LastEnabled - property

1034

@dbus_service_property(_interface, signature="s", access="read")

1035

def LastEnabled_dbus_property(self):

1036

return datetime_to_dbus(self.last_enabled)

1037

1038

# Enabled - property

1039

@dbus_service_property(_interface, signature="b",

1040

access="readwrite")

1041

def Enabled_dbus_property(self, value=None):

1042

if value is None: # get

1043

return dbus.Boolean(self.enabled)

1044

if value:

1045

self.enable()

1046

else:

1047

self.disable()

1048

1049

# LastCheckedOK - property

1050

@dbus_service_property(_interface, signature="s",

1051

access="readwrite")

1052

def LastCheckedOK_dbus_property(self, value=None):

1053

if value is not None:

1054

self.checked_ok()

1055

return

1056

return datetime_to_dbus(self.last_checked_ok)

1057

1058

# Expires - property

1059

@dbus_service_property(_interface, signature="s", access="read")

1060

def Expires_dbus_property(self):

1061

return datetime_to_dbus(self.expires)

1062

1063

# LastApprovalRequest - property

1064

@dbus_service_property(_interface, signature="s", access="read")

1065

def LastApprovalRequest_dbus_property(self):

1066

return datetime_to_dbus(self.last_approval_request)

1067

1068

# Timeout - property

1069

@dbus_service_property(_interface, signature="t",

1070

access="readwrite")

1071

def Timeout_dbus_property(self, value=None):

1072

if value is None: # get

1073

return dbus.UInt64(self.timeout_milliseconds())

1074

self.timeout = datetime.timedelta(0, 0, 0, value)

1075

if getattr(self, "disable_initiator_tag", None) is None:

1076

return

1077

# Reschedule timeout

1078

gobject.source_remove(self.disable_initiator_tag)

1079

self.disable_initiator_tag = None

1080

self.expires = None

1081

time_to_die = (self.

1082

_timedelta_to_milliseconds((self

1083

.last_checked_ok

1084

+ self.timeout)

1085

- datetime.datetime

1086

.utcnow()))

1087

if time_to_die <= 0:

1088

# The timeout has passed

1089

self.disable()

1090

else:

1091

self.expires = (datetime.datetime.utcnow()

1092

+ datetime.timedelta(milliseconds = time_to_die))

1093

self.disable_initiator_tag = (gobject.timeout_add

1094

(time_to_die, self.disable))

1095

1096

# ExtendedTimeout - property

1097

@dbus_service_property(_interface, signature="t",

1098

access="readwrite")

1099

def ExtendedTimeout_dbus_property(self, value=None):

1100

if value is None: # get

1101

return dbus.UInt64(self.extended_timeout_milliseconds())

1102

self.extended_timeout = datetime.timedelta(0, 0, 0, value)

1103

1104

# Interval - property

1105

@dbus_service_property(_interface, signature="t",

1106

access="readwrite")

1107

def Interval_dbus_property(self, value=None):

1108

if value is None: # get

1109

return dbus.UInt64(self.interval_milliseconds())

1110

self.interval = datetime.timedelta(0, 0, 0, value)

1111

if getattr(self, "checker_initiator_tag", None) is None:

1112

return

1113

# Reschedule checker run

1114

gobject.source_remove(self.checker_initiator_tag)

1115

self.checker_initiator_tag = (gobject.timeout_add

1116

(value, self.start_checker))

1117

self.start_checker() # Start one now, too

1118

1119

# Checker - property

1120

@dbus_service_property(_interface, signature="s",

1121

access="readwrite")

1122

def Checker_dbus_property(self, value=None):

1123

if value is None: # get

1124

return dbus.String(self.checker_command)

1125

self.checker_command = value

1126

1127

# CheckerRunning - property

1128

@dbus_service_property(_interface, signature="b",

1129

access="readwrite")

1130

def CheckerRunning_dbus_property(self, value=None):

1131

if value is None: # get

1132

return dbus.Boolean(self.checker is not None)

1133

if value:

1134

self.start_checker()

1135

else:

1136

self.stop_checker()

1137

1138

# ObjectPath - property

1139

@dbus_service_property(_interface, signature="o", access="read")

1140

def ObjectPath_dbus_property(self):

1141

return self.dbus_object_path # is already a dbus.ObjectPath

1142

1143

# Secret = property

1144

@dbus_service_property(_interface, signature="ay",

1145

access="write", byte_arrays=True)

1146

def Secret_dbus_property(self, value):

1147

self.secret = str(value)

1148

1149

del _interface

1150

1151

1152

class ProxyClient(object):

1153

def __init__(self, child_pipe, fpr, address):

1154

self._pipe = child_pipe

1155

self._pipe.send(('init', fpr, address))

1156

if not self._pipe.recv():

1157

raise KeyError()

1158

1159

def __getattribute__(self, name):

1160

if(name == '_pipe'):

1161

return super(ProxyClient, self).__getattribute__(name)

1162

self._pipe.send(('getattr', name))

1163

data = self._pipe.recv()

1164

if data[0] == 'data':

1165

return data[1]

1166

if data[0] == 'function':

1167

def func(*args, **kwargs):

1168

self._pipe.send(('funcall', name, args, kwargs))

1169

return self._pipe.recv()[1]

1170

return func

1171

1172

def __setattr__(self, name, value):

1173

if(name == '_pipe'):

1174

return super(ProxyClient, self).__setattr__(name, value)

1175

self._pipe.send(('setattr', name, value))

1176

1177

1178

class ClientHandler(socketserver.BaseRequestHandler, object):

1179

"""A class to handle client connections.

1180

1181

Instantiated once for each connection to handle it.

1182

Note: This will run in its own forked process."""

1183

1184

def handle(self):

1185

with contextlib.closing(self.server.child_pipe) as child_pipe:

1186

logger.info("TCP connection from: %s",

1187

unicode(self.client_address))

1188

logger.debug("Pipe FD: %d",

1189

self.server.child_pipe.fileno())

1190

1191

session = (gnutls.connection

1192

.ClientSession(self.request,

1193

gnutls.connection

1194

.X509Credentials()))

1195

1196

# Note: gnutls.connection.X509Credentials is really a

1197

# generic GnuTLS certificate credentials object so long as

1198

# no X.509 keys are added to it. Therefore, we can use it

1199

# here despite using OpenPGP certificates.

1200

1201

#priority = ':'.join(("NONE", "+VERS-TLS1.1",

1202

# "+AES-256-CBC", "+SHA1",

1203

# "+COMP-NULL", "+CTYPE-OPENPGP",

1204

# "+DHE-DSS"))

1205

# Use a fallback default, since this MUST be set.

1206

priority = self.server.gnutls_priority

1207

if priority is None:

1208

priority = "NORMAL"

1209

(gnutls.library.functions

1210

.gnutls_priority_set_direct(session._c_object,

1211

priority, None))

1212

1213

# Start communication using the Mandos protocol

1214

# Get protocol number

1215

line = self.request.makefile().readline()

1216

logger.debug("Protocol version: %r", line)

1217

try:

1218

if int(line.strip().split()[0]) > 1:

1219

raise RuntimeError

1220

except (ValueError, IndexError, RuntimeError) as error:

1221

logger.error("Unknown protocol version: %s", error)

1222

return

1223

1224

# Start GnuTLS connection

1225

try:

1226

session.handshake()

1227

except gnutls.errors.GNUTLSError as error:

1228

logger.warning("Handshake failed: %s", error)

1229

# Do not run session.bye() here: the session is not

1230

# established. Just abandon the request.

1231

return

1232

logger.debug("Handshake succeeded")

1233

1234

approval_required = False

1235

try:

1236

try:

1237

fpr = self.fingerprint(self.peer_certificate

1238

(session))

1239

except (TypeError,

1240

gnutls.errors.GNUTLSError) as error:

1241

logger.warning("Bad certificate: %s", error)

1242

return

1243

logger.debug("Fingerprint: %s", fpr)

1244

1245

try:

1246

client = ProxyClient(child_pipe, fpr,

1247

self.client_address)

1248

except KeyError:

1249

return

1250

1251

if client.approval_delay:

1252

delay = client.approval_delay

1253

client.approvals_pending += 1

1254

approval_required = True

1255

1256

while True:

1257

if not client.enabled:

1258

logger.info("Client %s is disabled",

1259

client.name)

1260

if self.server.use_dbus:

1261

# Emit D-Bus signal

1262

client.Rejected("Disabled")

1263

return

1264

1265

if client._approved or not client.approval_delay:

1266

#We are approved or approval is disabled

1267

break

1268

elif client._approved is None:

1269

logger.info("Client %s needs approval",

1270

client.name)

1271

if self.server.use_dbus:

1272

# Emit D-Bus signal

1273

client.NeedApproval(

1274

client.approval_delay_milliseconds(),

1275

client.approved_by_default)

1276

else:

1277

logger.warning("Client %s was not approved",

1278

client.name)

1279

if self.server.use_dbus:

1280

# Emit D-Bus signal

1281

client.Rejected("Denied")

1282

return

1283

1284

#wait until timeout or approved

1285

#x = float(client._timedelta_to_milliseconds(delay))

1286

time = datetime.datetime.now()

1287

client.changedstate.acquire()

1288

client.changedstate.wait(float(client._timedelta_to_milliseconds(delay) / 1000))

1289

client.changedstate.release()

1290

time2 = datetime.datetime.now()

1291

if (time2 - time) >= delay:

1292

if not client.approved_by_default:

1293

logger.warning("Client %s timed out while"

1294

" waiting for approval",

1295

client.name)

1296

if self.server.use_dbus:

1297

# Emit D-Bus signal

1298

client.Rejected("Approval timed out")

1299

return

1300

else:

1301

break

1302

else:

1303

delay -= time2 - time

1304

1305

sent_size = 0

1306

while sent_size < len(client.secret):

1307

try:

1308

sent = session.send(client.secret[sent_size:])

1309

except gnutls.errors.GNUTLSError as error:

1310

logger.warning("gnutls send failed")

1311

return

1312

logger.debug("Sent: %d, remaining: %d",

1313

sent, len(client.secret)

1314

- (sent_size + sent))

1315

sent_size += sent

1316

1317

logger.info("Sending secret to %s", client.name)

1318

# bump the timeout as if seen

1319

client.checked_ok(client.extended_timeout)

1320

if self.server.use_dbus:

1321

# Emit D-Bus signal

1322

client.GotSecret()

1323

1324

finally:

1325

if approval_required:

1326

client.approvals_pending -= 1

1327

try:

1328

session.bye()

1329

except gnutls.errors.GNUTLSError as error:

1330

logger.warning("GnuTLS bye failed")

1331

1332

@staticmethod

1333

def peer_certificate(session):

1334

"Return the peer's OpenPGP certificate as a bytestring"

1335

# If not an OpenPGP certificate...

1336

if (gnutls.library.functions

1337

.gnutls_certificate_type_get(session._c_object)

1338

!= gnutls.library.constants.GNUTLS_CRT_OPENPGP):

1339

# ...do the normal thing

1340

return session.peer_certificate

1341

list_size = ctypes.c_uint(1)

1342

cert_list = (gnutls.library.functions

1343

.gnutls_certificate_get_peers

1344

(session._c_object, ctypes.byref(list_size)))

1345

if not bool(cert_list) and list_size.value != 0:

1346

raise gnutls.errors.GNUTLSError("error getting peer"

1347

" certificate")

1348

if list_size.value == 0:

1349

return None

1350

cert = cert_list[0]

1351

return ctypes.string_at(cert.data, cert.size)

1352

1353

@staticmethod

1354

def fingerprint(openpgp):

1355

"Convert an OpenPGP bytestring to a hexdigit fingerprint"

1356

# New GnuTLS "datum" with the OpenPGP public key

1357

datum = (gnutls.library.types

1358

.gnutls_datum_t(ctypes.cast(ctypes.c_char_p(openpgp),

1359

ctypes.POINTER

1360

(ctypes.c_ubyte)),

1361

ctypes.c_uint(len(openpgp))))

1362

# New empty GnuTLS certificate

1363

crt = gnutls.library.types.gnutls_openpgp_crt_t()

1364

(gnutls.library.functions

1365

.gnutls_openpgp_crt_init(ctypes.byref(crt)))

1366

# Import the OpenPGP public key into the certificate

1367

(gnutls.library.functions

1368

.gnutls_openpgp_crt_import(crt, ctypes.byref(datum),

1369

gnutls.library.constants

1370

.GNUTLS_OPENPGP_FMT_RAW))

1371

# Verify the self signature in the key

1372

crtverify = ctypes.c_uint()

1373

(gnutls.library.functions

1374

.gnutls_openpgp_crt_verify_self(crt, 0,

1375

ctypes.byref(crtverify)))

1376

if crtverify.value != 0:

1377

gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)

1378

raise (gnutls.errors.CertificateSecurityError

1379

("Verify failed"))

1380

# New buffer for the fingerprint

1381

buf = ctypes.create_string_buffer(20)

1382

buf_len = ctypes.c_size_t()

1383

# Get the fingerprint from the certificate into the buffer

1384

(gnutls.library.functions

1385

.gnutls_openpgp_crt_get_fingerprint(crt, ctypes.byref(buf),

1386

ctypes.byref(buf_len)))

1387

# Deinit the certificate

1388

gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)

1389

# Convert the buffer to a Python bytestring

1390

fpr = ctypes.string_at(buf, buf_len.value)

1391

# Convert the bytestring to hexadecimal notation

1392

hex_fpr = ''.join("%02X" % ord(char) for char in fpr)

1393

return hex_fpr

1394

1395

1396

class MultiprocessingMixIn(object):

1397

"""Like socketserver.ThreadingMixIn, but with multiprocessing"""

1398

def sub_process_main(self, request, address):

1399

try:

1400

self.finish_request(request, address)

1401

except:

1402

self.handle_error(request, address)

1403

self.close_request(request)

1404

1405

def process_request(self, request, address):

1406

"""Start a new process to process the request."""

1407

multiprocessing.Process(target = self.sub_process_main,

1408

args = (request, address)).start()

1409

1410

1411

class MultiprocessingMixInWithPipe(MultiprocessingMixIn, object):

1412

""" adds a pipe to the MixIn """

1413

def process_request(self, request, client_address):

1414

"""Overrides and wraps the original process_request().

1415

1416

This function creates a new pipe in self.pipe

1417

"""

1418

parent_pipe, self.child_pipe = multiprocessing.Pipe()

1419

1420

super(MultiprocessingMixInWithPipe,

1421

self).process_request(request, client_address)

1422

self.child_pipe.close()

1423

self.add_pipe(parent_pipe)

1424

1425

def add_pipe(self, parent_pipe):

1426

"""Dummy function; override as necessary"""

1427

raise NotImplementedError

1428

1429

1430

class IPv6_TCPServer(MultiprocessingMixInWithPipe,

1431

socketserver.TCPServer, object):

1432

"""IPv6-capable TCP server. Accepts 'None' as address and/or port

1433

1434

Attributes:

1435

enabled: Boolean; whether this server is activated yet

1436

interface: None or a network interface name (string)

1437

use_ipv6: Boolean; to use IPv6 or not

1438

"""

1439

def __init__(self, server_address, RequestHandlerClass,

1440

interface=None, use_ipv6=True):

1441

self.interface = interface

1442

if use_ipv6:

1443

self.address_family = socket.AF_INET6

1444

socketserver.TCPServer.__init__(self, server_address,

1445

RequestHandlerClass)

1446

def server_bind(self):

1447

"""This overrides the normal server_bind() function

1448

to bind to an interface if one was specified, and also NOT to

1449

bind to an address or port if they were not specified."""

1450

if self.interface is not None:

1451

if SO_BINDTODEVICE is None:

1452

logger.error("SO_BINDTODEVICE does not exist;"

1453

" cannot bind to interface %s",

1454

self.interface)

1455

else:

1456

try:

1457

self.socket.setsockopt(socket.SOL_SOCKET,

1458

SO_BINDTODEVICE,

1459

str(self.interface

1460

+ '\0'))

1461

except socket.error as error:

1462

if error[0] == errno.EPERM:

1463

logger.error("No permission to"

1464

" bind to interface %s",

1465

self.interface)

1466

elif error[0] == errno.ENOPROTOOPT:

1467

logger.error("SO_BINDTODEVICE not available;"

1468

" cannot bind to interface %s",

1469

self.interface)

1470

else:

1471

raise

1472

# Only bind(2) the socket if we really need to.

1473

if self.server_address[0] or self.server_address[1]:

1474

if not self.server_address[0]:

1475

if self.address_family == socket.AF_INET6:

1476

any_address = "::" # in6addr_any

1477

else:

1478

any_address = socket.INADDR_ANY

1479

self.server_address = (any_address,

1480

self.server_address[1])

1481

elif not self.server_address[1]:

1482

self.server_address = (self.server_address[0],

1483

0)

1484

# if self.interface:

1485

# self.server_address = (self.server_address[0],

1486

# 0, # port

1487

# 0, # flowinfo

1488

# if_nametoindex

1489

# (self.interface))

1490

return socketserver.TCPServer.server_bind(self)

1491

1492

1493

class MandosServer(IPv6_TCPServer):

1494

"""Mandos server.

1495

1496

Attributes:

1497

clients: set of Client objects

1498

gnutls_priority GnuTLS priority string

1499

use_dbus: Boolean; to emit D-Bus signals or not

1500

1501

Assumes a gobject.MainLoop event loop.

1502

"""

1503

def __init__(self, server_address, RequestHandlerClass,

1504

interface=None, use_ipv6=True, clients=None,

1505

gnutls_priority=None, use_dbus=True):

1506

self.enabled = False

1507

self.clients = clients

1508

if self.clients is None:

1509

self.clients = set()

1510

self.use_dbus = use_dbus

1511

self.gnutls_priority = gnutls_priority

1512

IPv6_TCPServer.__init__(self, server_address,

1513

RequestHandlerClass,

1514

interface = interface,

1515

use_ipv6 = use_ipv6)

1516

def server_activate(self):

1517

if self.enabled:

1518

return socketserver.TCPServer.server_activate(self)

1519

def enable(self):

1520

self.enabled = True

1521

def add_pipe(self, parent_pipe):

1522

# Call "handle_ipc" for both data and EOF events

1523

gobject.io_add_watch(parent_pipe.fileno(),

1524

gobject.IO_IN | gobject.IO_HUP,

1525

functools.partial(self.handle_ipc,

1526

parent_pipe = parent_pipe))

1527

1528

def handle_ipc(self, source, condition, parent_pipe=None,

1529

client_object=None):

1530

condition_names = {

1531

gobject.IO_IN: "IN", # There is data to read.

1532

gobject.IO_OUT: "OUT", # Data can be written (without

1533

# blocking).

1534

gobject.IO_PRI: "PRI", # There is urgent data to read.

1535

gobject.IO_ERR: "ERR", # Error condition.

1536

gobject.IO_HUP: "HUP" # Hung up (the connection has been

1537

# broken, usually for pipes and

1538

# sockets).

1539

}

1540

conditions_string = ' | '.join(name

1541

for cond, name in

1542

condition_names.iteritems()

1543

if cond & condition)

1544

# error or the other end of multiprocessing.Pipe has closed

1545

if condition & (gobject.IO_ERR | condition & gobject.IO_HUP):

1546

return False

1547

1548

# Read a request from the child

1549

request = parent_pipe.recv()

1550

command = request[0]

1551

1552

if command == 'init':

1553

fpr = request[1]

1554

address = request[2]

1555

1556

for c in self.clients:

1557

if c.fingerprint == fpr:

1558

client = c

1559

break

1560

else:

1561

logger.info("Client not found for fingerprint: %s, ad"

1562

"dress: %s", fpr, address)

1563

if self.use_dbus:

1564

# Emit D-Bus signal

1565

mandos_dbus_service.ClientNotFound(fpr, address[0])

1566

parent_pipe.send(False)

1567

return False

1568

1569

gobject.io_add_watch(parent_pipe.fileno(),

1570

gobject.IO_IN | gobject.IO_HUP,

1571

functools.partial(self.handle_ipc,

1572

parent_pipe = parent_pipe,

1573

client_object = client))

1574

parent_pipe.send(True)

1575

# remove the old hook in favor of the new above hook on same fileno

1576

return False

1577

if command == 'funcall':

1578

funcname = request[1]

1579

args = request[2]

1580

kwargs = request[3]

1581

1582

parent_pipe.send(('data', getattr(client_object, funcname)(*args, **kwargs)))

1583

1584

if command == 'getattr':

1585

attrname = request[1]

1586

if callable(client_object.__getattribute__(attrname)):

1587

parent_pipe.send(('function',))

1588

else:

1589

parent_pipe.send(('data', client_object.__getattribute__(attrname)))

1590

1591

if command == 'setattr':

1592

attrname = request[1]

1593

value = request[2]

1594

setattr(client_object, attrname, value)

1595

1596

return True

1597

1598

1599

def string_to_delta(interval):

1600

"""Parse a string and return a datetime.timedelta

1601

1602

>>> string_to_delta('7d')

1603

datetime.timedelta(7)

1604

>>> string_to_delta('60s')

1605

datetime.timedelta(0, 60)

1606

>>> string_to_delta('60m')

1607

datetime.timedelta(0, 3600)

1608

>>> string_to_delta('24h')

1609

datetime.timedelta(1)

1610

>>> string_to_delta('1w')

1611

datetime.timedelta(7)

1612

>>> string_to_delta('5m 30s')

1613

datetime.timedelta(0, 330)

1614

"""

1615

timevalue = datetime.timedelta(0)

1616

for s in interval.split():

1617

try:

1618

suffix = unicode(s[-1])

1619

value = int(s[:-1])

1620

if suffix == "d":

1621

delta = datetime.timedelta(value)

1622

elif suffix == "s":

1623

delta = datetime.timedelta(0, value)

1624

elif suffix == "m":

1625

delta = datetime.timedelta(0, 0, 0, 0, value)

1626

elif suffix == "h":

1627

delta = datetime.timedelta(0, 0, 0, 0, 0, value)

1628

elif suffix == "w":

1629

delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)

1630

else:

1631

raise ValueError("Unknown suffix %r" % suffix)

1632

except (ValueError, IndexError) as e:

1633

raise ValueError(*(e.args))

1634

timevalue += delta

1635

return timevalue

1636

1637

1638

def if_nametoindex(interface):

1639

"""Call the C function if_nametoindex(), or equivalent

1640

1641

Note: This function cannot accept a unicode string."""

1642

global if_nametoindex

1643

try:

1644

if_nametoindex = (ctypes.cdll.LoadLibrary

1645

(ctypes.util.find_library("c"))

1646

.if_nametoindex)

1647

except (OSError, AttributeError):

1648

logger.warning("Doing if_nametoindex the hard way")

1649

def if_nametoindex(interface):

1650

"Get an interface index the hard way, i.e. using fcntl()"

1651

SIOCGIFINDEX = 0x8933 # From /usr/include/linux/sockios.h

1652

with contextlib.closing(socket.socket()) as s:

1653

ifreq = fcntl.ioctl(s, SIOCGIFINDEX,

1654

struct.pack(str("16s16x"),

1655

interface))

1656

interface_index = struct.unpack(str("I"),

1657

ifreq[16:20])[0]

1658

return interface_index

1659

return if_nametoindex(interface)

1660

1661

1662

def daemon(nochdir = False, noclose = False):

1663

"""See daemon(3). Standard BSD Unix function.

1664

1665

This should really exist as os.daemon, but it doesn't (yet)."""

1666

if os.fork():

1667

sys.exit()

1668

os.setsid()

1669

if not nochdir:

1670

os.chdir("/")

1671

if os.fork():

1672

sys.exit()

1673

if not noclose:

1674

# Close all standard open file descriptors

1675

null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)

1676

if not stat.S_ISCHR(os.fstat(null).st_mode):

1677

raise OSError(errno.ENODEV,

1678

"%s not a character device"

1679

% os.path.devnull)

1680

os.dup2(null, sys.stdin.fileno())

1681

os.dup2(null, sys.stdout.fileno())

1682

os.dup2(null, sys.stderr.fileno())

1683

if null > 2:

1684

os.close(null)

1685

1686

1687

def main():

1688

1689

##################################################################

1690

# Parsing of options, both command line and config file

1691

1692

parser = argparse.ArgumentParser()

1693

parser.add_argument("-v", "--version", action="version",

1694

version = "%%(prog)s %s" % version,

1695

help="show version number and exit")

1696

parser.add_argument("-i", "--interface", metavar="IF",

1697

help="Bind to interface IF")

1698

parser.add_argument("-a", "--address",

1699

help="Address to listen for requests on")

1700

parser.add_argument("-p", "--port", type=int,

1701

help="Port number to receive requests on")

1702

parser.add_argument("--check", action="store_true",

1703

help="Run self-test")

1704

parser.add_argument("--debug", action="store_true",

1705

help="Debug mode; run in foreground and log"

1706

" to terminal")

1707

parser.add_argument("--debuglevel", metavar="LEVEL",

1708

help="Debug level for stdout output")

1709

parser.add_argument("--priority", help="GnuTLS"

1710

" priority string (see GnuTLS documentation)")

1711

parser.add_argument("--servicename",

1712

metavar="NAME", help="Zeroconf service name")

1713

parser.add_argument("--configdir",

1714

default="/etc/mandos", metavar="DIR",

1715

help="Directory to search for configuration"

1716

" files")

1717

parser.add_argument("--no-dbus", action="store_false",

1718

dest="use_dbus", help="Do not provide D-Bus"

1719

" system bus interface")

1720

parser.add_argument("--no-ipv6", action="store_false",

1721

dest="use_ipv6", help="Do not use IPv6")

1722

options = parser.parse_args()

1723

1724

if options.check:

1725

import doctest

1726

doctest.testmod()

1727

sys.exit()

1728

1729

# Default values for config file for server-global settings

1730

server_defaults = { "interface": "",

1731

"address": "",

1732

"port": "",

1733

"debug": "False",

1734

"priority":

1735

"SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",

1736

"servicename": "Mandos",

1737

"use_dbus": "True",

1738

"use_ipv6": "True",

1739

"debuglevel": "",

1740

}

1741

1742

# Parse config file for server-global settings

1743

server_config = configparser.SafeConfigParser(server_defaults)

1744

del server_defaults

1745

server_config.read(os.path.join(options.configdir,

1746

"mandos.conf"))

1747

# Convert the SafeConfigParser object to a dict

1748

server_settings = server_config.defaults()

1749

# Use the appropriate methods on the non-string config options

1750

for option in ("debug", "use_dbus", "use_ipv6"):

1751

server_settings[option] = server_config.getboolean("DEFAULT",

1752

option)

1753

if server_settings["port"]:

1754

server_settings["port"] = server_config.getint("DEFAULT",

1755

"port")

1756

del server_config

1757

1758

# Override the settings from the config file with command line

1759

# options, if set.

1760

for option in ("interface", "address", "port", "debug",

1761

"priority", "servicename", "configdir",

1762

"use_dbus", "use_ipv6", "debuglevel"):

1763

value = getattr(options, option)

1764

if value is not None:

1765

server_settings[option] = value

1766

del options

1767

# Force all strings to be unicode

1768

for option in server_settings.keys():

1769

if type(server_settings[option]) is str:

1770

server_settings[option] = unicode(server_settings[option])

1771

# Now we have our good server settings in "server_settings"

1772

1773

##################################################################

1774

1775

# For convenience

1776

debug = server_settings["debug"]

1777

debuglevel = server_settings["debuglevel"]

1778

use_dbus = server_settings["use_dbus"]

1779

use_ipv6 = server_settings["use_ipv6"]

1780

1781

if server_settings["servicename"] != "Mandos":

1782

syslogger.setFormatter(logging.Formatter

1783

('Mandos (%s) [%%(process)d]:'

1784

' %%(levelname)s: %%(message)s'

1785

% server_settings["servicename"]))

1786

1787

# Parse config file with clients

1788

client_defaults = { "timeout": "5m",

1789

"extended_timeout": "15m",

1790

"interval": "2m",

1791

"checker": "fping -q -- %%(host)s",

1792

"host": "",

1793

"approval_delay": "0s",

1794

"approval_duration": "1s",

1795

}

1796

client_config = configparser.SafeConfigParser(client_defaults)

1797

client_config.read(os.path.join(server_settings["configdir"],

1798

"clients.conf"))

1799

1800

global mandos_dbus_service

1801

mandos_dbus_service = None

1802

1803

tcp_server = MandosServer((server_settings["address"],

1804

server_settings["port"]),

1805

ClientHandler,

1806

interface=(server_settings["interface"]

1807

or None),

1808

use_ipv6=use_ipv6,

1809

gnutls_priority=

1810

server_settings["priority"],

1811

use_dbus=use_dbus)

1812

if not debug:

1813

pidfilename = "/var/run/mandos.pid"

1814

try:

1815

pidfile = open(pidfilename, "w")

1816

except IOError:

1817

logger.error("Could not open file %r", pidfilename)

1818

1819

try:

1820

uid = pwd.getpwnam("_mandos").pw_uid

1821

gid = pwd.getpwnam("_mandos").pw_gid

1822

except KeyError:

1823

try:

1824

uid = pwd.getpwnam("mandos").pw_uid

1825

gid = pwd.getpwnam("mandos").pw_gid

1826

except KeyError:

1827

try:

1828

uid = pwd.getpwnam("nobody").pw_uid

1829

gid = pwd.getpwnam("nobody").pw_gid

1830

except KeyError:

1831

uid = 65534

1832

gid = 65534

1833

try:

1834

os.setgid(gid)

1835

os.setuid(uid)

1836

except OSError as error:

1837

if error[0] != errno.EPERM:

1838

raise error

1839

1840

if not debug and not debuglevel:

1841

syslogger.setLevel(logging.WARNING)

1842

console.setLevel(logging.WARNING)

1843

if debuglevel:

1844

level = getattr(logging, debuglevel.upper())

1845

syslogger.setLevel(level)

1846

console.setLevel(level)

1847

1848

if debug:

1849

# Enable all possible GnuTLS debugging

1850

1851

# "Use a log level over 10 to enable all debugging options."

1852

# - GnuTLS manual

1853

gnutls.library.functions.gnutls_global_set_log_level(11)

1854

1855

@gnutls.library.types.gnutls_log_func

1856

def debug_gnutls(level, string):

1857

logger.debug("GnuTLS: %s", string[:-1])

1858

1859

(gnutls.library.functions

1860

.gnutls_global_set_log_function(debug_gnutls))

1861

1862

# Redirect stdin so all checkers get /dev/null

1863

null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)

1864

os.dup2(null, sys.stdin.fileno())

1865

if null > 2:

1866

os.close(null)

1867

else:

1868

# No console logging

1869

logger.removeHandler(console)

1870

1871

# Need to fork before connecting to D-Bus

1872

if not debug:

1873

# Close all input and output, do double fork, etc.

1874

daemon()

1875

1876

global main_loop

1877

# From the Avahi example code

1878

DBusGMainLoop(set_as_default=True )

1879

main_loop = gobject.MainLoop()

1880

bus = dbus.SystemBus()

1881

# End of Avahi example code

1882

if use_dbus:

1883

try:

1884

bus_name = dbus.service.BusName("se.bsnet.fukt.Mandos",

1885

bus, do_not_queue=True)

1886

except dbus.exceptions.NameExistsException as e:

1887

logger.error(unicode(e) + ", disabling D-Bus")

1888

use_dbus = False

1889

server_settings["use_dbus"] = False

1890

tcp_server.use_dbus = False

1891

protocol = avahi.PROTO_INET6 if use_ipv6 else avahi.PROTO_INET

1892

service = AvahiService(name = server_settings["servicename"],

1893

servicetype = "_mandos._tcp",

1894

protocol = protocol, bus = bus)

1895

if server_settings["interface"]:

1896

service.interface = (if_nametoindex

1897

(str(server_settings["interface"])))

1898

1899

global multiprocessing_manager

1900

multiprocessing_manager = multiprocessing.Manager()

1901

1902

client_class = Client

1903

if use_dbus:

1904

client_class = functools.partial(ClientDBus, bus = bus)

1905

def client_config_items(config, section):

1906

special_settings = {

1907

"approved_by_default":

1908

lambda: config.getboolean(section,

1909

"approved_by_default"),

1910

}

1911

for name, value in config.items(section):

1912

try:

1913

yield (name, special_settings[name]())

1914

except KeyError:

1915

yield (name, value)

1916

1917

tcp_server.clients.update(set(

1918

client_class(name = section,

1919

config= dict(client_config_items(

1920

client_config, section)))

1921

for section in client_config.sections()))

1922

if not tcp_server.clients:

1923

logger.warning("No clients defined")

1924

1925

if not debug:

1926

try:

1927

with pidfile:

1928

pid = os.getpid()

1929

pidfile.write(str(pid) + "\n".encode("utf-8"))

1930

del pidfile

1931

except IOError:

1932

logger.error("Could not write to file %r with PID %d",

1933

pidfilename, pid)

1934

except NameError:

1935

# "pidfile" was never created

1936

pass

1937

del pidfilename

1938

1939

signal.signal(signal.SIGINT, signal.SIG_IGN)

1940

1941

signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())

1942

signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())

1943

1944

if use_dbus:

1945

class MandosDBusService(dbus.service.Object):

1946

"""A D-Bus proxy object"""

1947

def __init__(self):

1948

dbus.service.Object.__init__(self, bus, "/")

1949

_interface = "se.bsnet.fukt.Mandos"

1950

1951

@dbus.service.signal(_interface, signature="o")

1952

def ClientAdded(self, objpath):

1953

"D-Bus signal"

1954

pass

1955

1956

@dbus.service.signal(_interface, signature="ss")

1957

def ClientNotFound(self, fingerprint, address):

1958

"D-Bus signal"

1959

pass

1960

1961

@dbus.service.signal(_interface, signature="os")

1962

def ClientRemoved(self, objpath, name):

1963

"D-Bus signal"

1964

pass

1965

1966

@dbus.service.method(_interface, out_signature="ao")

1967

def GetAllClients(self):

1968

"D-Bus method"

1969

return dbus.Array(c.dbus_object_path

1970

for c in tcp_server.clients)

1971

1972

@dbus.service.method(_interface,

1973

out_signature="a{oa{sv}}")

1974

def GetAllClientsWithProperties(self):

1975

"D-Bus method"

1976

return dbus.Dictionary(

1977

((c.dbus_object_path, c.GetAll(""))

1978

for c in tcp_server.clients),

1979

signature="oa{sv}")

1980

1981

@dbus.service.method(_interface, in_signature="o")

1982

def RemoveClient(self, object_path):

1983

"D-Bus method"

1984

for c in tcp_server.clients:

1985

if c.dbus_object_path == object_path:

1986

tcp_server.clients.remove(c)

1987

c.remove_from_connection()

1988

# Don't signal anything except ClientRemoved

1989

c.disable(quiet=True)

1990

# Emit D-Bus signal

1991

self.ClientRemoved(object_path, c.name)

1992

return

1993

raise KeyError(object_path)

1994

1995

del _interface

1996

1997

mandos_dbus_service = MandosDBusService()

1998

1999

def cleanup():

2000

"Cleanup function; run on exit"

2001

service.cleanup()

2002

2003

while tcp_server.clients:

2004

client = tcp_server.clients.pop()

2005

if use_dbus:

2006

client.remove_from_connection()

2007

client.disable_hook = None

2008

# Don't signal anything except ClientRemoved

2009

client.disable(quiet=True)

2010

if use_dbus:

2011

# Emit D-Bus signal

2012

mandos_dbus_service.ClientRemoved(client.dbus_object_path,

2013

client.name)

2014

2015

atexit.register(cleanup)

2016

2017

for client in tcp_server.clients:

2018

if use_dbus:

2019

# Emit D-Bus signal

2020

mandos_dbus_service.ClientAdded(client.dbus_object_path)

2021

client.enable()

2022

2023

tcp_server.enable()

2024

tcp_server.server_activate()

2025

2026

# Find out what port we got

2027

service.port = tcp_server.socket.getsockname()[1]

2028

if use_ipv6:

2029

logger.info("Now listening on address %r, port %d,"

2030

" flowinfo %d, scope_id %d"

2031

% tcp_server.socket.getsockname())

2032

else: # IPv4

2033

logger.info("Now listening on address %r, port %d"

2034

% tcp_server.socket.getsockname())

2035

2036

#service.interface = tcp_server.socket.getsockname()[3]

2037

2038

try:

2039

# From the Avahi example code

2040

try:

2041

service.activate()

2042

except dbus.exceptions.DBusException as error:

2043

logger.critical("DBusException: %s", error)

2044

cleanup()

2045

sys.exit(1)

2046

# End of Avahi example code

2047

2048

gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,

2049

lambda *args, **kwargs:

2050

(tcp_server.handle_request

2051

(*args[2:], **kwargs) or True))

2052

2053

logger.debug("Starting main loop")

2054

main_loop.run()

2055

except AvahiError as error:

2056

logger.critical("AvahiError: %s", error)

2057

cleanup()

2058

sys.exit(1)

2059

except KeyboardInterrupt:

2060

if debug:

2061

print("", file=sys.stderr)

2062

logger.debug("Server received KeyboardInterrupt")

2063

logger.debug("Server exiting")

2064

# Must run before the D-Bus bus name gets deregistered

2065

cleanup()

2066

2067

2068

if __name__ == '__main__':

2069

main()