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  • Committer: Teddy Hogeborn
  • Date: 2008-10-04 20:09:53 UTC
  • Revision ID: teddy@fukt.bsnet.se-20081004200953-7j0fjlq6fqsxs9t2
* Makefile (DOCS): Added "plugins.d/askpass-fifo.8mandos".
  (install-client-nokey): Also install
                          "plugins.d/askpass-fifo.8mandos".
  (uninstall-client): Also uninstall "plugins.d/askpass-fifo.8mandos".

* plugins.d/askpass-fifo.xml: New.

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mandos
1
1
#!/usr/bin/python
 
2
# -*- mode: python; coding: utf-8 -*-
 
3
# 
 
4
# Mandos server - give out binary blobs to connecting clients.
 
5
# 
 
6
# This program is partly derived from an example program for an Avahi
 
7
# service publisher, downloaded from
 
8
# <http://avahi.org/wiki/PythonPublishExample>.  This includes the
 
9
# methods "add" and "remove" in the "AvahiService" class, the
 
10
# "server_state_changed" and "entry_group_state_changed" functions,
 
11
# and some lines in "main".
 
12
# 
 
13
# Everything else is
 
14
# Copyright © 2008 Teddy Hogeborn & Björn Påhlsson
 
15
# 
 
16
# This program is free software: you can redistribute it and/or modify
 
17
# it under the terms of the GNU General Public License as published by
 
18
# the Free Software Foundation, either version 3 of the License, or
 
19
# (at your option) any later version.
 
20
#
 
21
#     This program is distributed in the hope that it will be useful,
 
22
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
 
23
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
24
#     GNU General Public License for more details.
 
25
# 
 
26
# You should have received a copy of the GNU General Public License
 
27
# along with this program.  If not, see
 
28
# <http://www.gnu.org/licenses/>.
 
29
# 
 
30
# Contact the authors at <mandos@fukt.bsnet.se>.
 
31
# 
 
32
 
 
33
from __future__ import division
2
34
 
3
35
import SocketServer
4
36
import socket
5
 
import select
6
37
from optparse import OptionParser
7
38
import datetime
8
39
import errno
9
40
import gnutls.crypto
10
41
import gnutls.connection
11
42
import gnutls.errors
 
43
import gnutls.library.functions
 
44
import gnutls.library.constants
 
45
import gnutls.library.types
12
46
import ConfigParser
13
47
import sys
 
48
import re
 
49
import os
 
50
import signal
 
51
from sets import Set
 
52
import subprocess
 
53
import atexit
 
54
import stat
 
55
import logging
 
56
import logging.handlers
 
57
import pwd
 
58
 
 
59
import dbus
 
60
import gobject
 
61
import avahi
 
62
from dbus.mainloop.glib import DBusGMainLoop
 
63
import ctypes
 
64
import ctypes.util
 
65
 
 
66
version = "1.0"
 
67
 
 
68
logger = logging.Logger('mandos')
 
69
syslogger = logging.handlers.SysLogHandler\
 
70
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
 
71
             address = "/dev/log")
 
72
syslogger.setFormatter(logging.Formatter\
 
73
                        ('Mandos: %(levelname)s: %(message)s'))
 
74
logger.addHandler(syslogger)
 
75
 
 
76
console = logging.StreamHandler()
 
77
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
 
78
                                       ' %(message)s'))
 
79
logger.addHandler(console)
 
80
 
 
81
class AvahiError(Exception):
 
82
    def __init__(self, value):
 
83
        self.value = value
 
84
        super(AvahiError, self).__init__()
 
85
    def __str__(self):
 
86
        return repr(self.value)
 
87
 
 
88
class AvahiServiceError(AvahiError):
 
89
    pass
 
90
 
 
91
class AvahiGroupError(AvahiError):
 
92
    pass
 
93
 
 
94
 
 
95
class AvahiService(object):
 
96
    """An Avahi (Zeroconf) service.
 
97
    Attributes:
 
98
    interface: integer; avahi.IF_UNSPEC or an interface index.
 
99
               Used to optionally bind to the specified interface.
 
100
    name: string; Example: 'Mandos'
 
101
    type: string; Example: '_mandos._tcp'.
 
102
                  See <http://www.dns-sd.org/ServiceTypes.html>
 
103
    port: integer; what port to announce
 
104
    TXT: list of strings; TXT record for the service
 
105
    domain: string; Domain to publish on, default to .local if empty.
 
106
    host: string; Host to publish records for, default is localhost
 
107
    max_renames: integer; maximum number of renames
 
108
    rename_count: integer; counter so we only rename after collisions
 
109
                  a sensible number of times
 
110
    """
 
111
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
 
112
                 servicetype = None, port = None, TXT = None, domain = "",
 
113
                 host = "", max_renames = 32768):
 
114
        self.interface = interface
 
115
        self.name = name
 
116
        self.type = servicetype
 
117
        self.port = port
 
118
        if TXT is None:
 
119
            self.TXT = []
 
120
        else:
 
121
            self.TXT = TXT
 
122
        self.domain = domain
 
123
        self.host = host
 
124
        self.rename_count = 0
 
125
        self.max_renames = max_renames
 
126
    def rename(self):
 
127
        """Derived from the Avahi example code"""
 
128
        if self.rename_count >= self.max_renames:
 
129
            logger.critical(u"No suitable Zeroconf service name found"
 
130
                            u" after %i retries, exiting.",
 
131
                            self.rename_count)
 
132
            raise AvahiServiceError("Too many renames")
 
133
        self.name = server.GetAlternativeServiceName(self.name)
 
134
        logger.info(u"Changing Zeroconf service name to %r ...",
 
135
                    str(self.name))
 
136
        syslogger.setFormatter(logging.Formatter\
 
137
                               ('Mandos (%s): %%(levelname)s:'
 
138
                               ' %%(message)s' % self.name))
 
139
        self.remove()
 
140
        self.add()
 
141
        self.rename_count += 1
 
142
    def remove(self):
 
143
        """Derived from the Avahi example code"""
 
144
        if group is not None:
 
145
            group.Reset()
 
146
    def add(self):
 
147
        """Derived from the Avahi example code"""
 
148
        global group
 
149
        if group is None:
 
150
            group = dbus.Interface\
 
151
                    (bus.get_object(avahi.DBUS_NAME,
 
152
                                    server.EntryGroupNew()),
 
153
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
154
            group.connect_to_signal('StateChanged',
 
155
                                    entry_group_state_changed)
 
156
        logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
 
157
                     service.name, service.type)
 
158
        group.AddService(
 
159
                self.interface,         # interface
 
160
                avahi.PROTO_INET6,      # protocol
 
161
                dbus.UInt32(0),         # flags
 
162
                self.name, self.type,
 
163
                self.domain, self.host,
 
164
                dbus.UInt16(self.port),
 
165
                avahi.string_array_to_txt_array(self.TXT))
 
166
        group.Commit()
 
167
 
 
168
# From the Avahi example code:
 
169
group = None                            # our entry group
 
170
# End of Avahi example code
14
171
 
15
172
 
16
173
class Client(object):
17
 
    def __init__(self, name=None, options=None, dn=None,
18
 
                 password=None, passfile=None, fqdn=None,
19
 
                 timeout=None, interval=-1):
 
174
    """A representation of a client host served by this server.
 
175
    Attributes:
 
176
    name:      string; from the config file, used in log messages
 
177
    fingerprint: string (40 or 32 hexadecimal digits); used to
 
178
                 uniquely identify the client
 
179
    secret:    bytestring; sent verbatim (over TLS) to client
 
180
    host:      string; available for use by the checker command
 
181
    created:   datetime.datetime(); object creation, not client host
 
182
    last_checked_ok: datetime.datetime() or None if not yet checked OK
 
183
    timeout:   datetime.timedelta(); How long from last_checked_ok
 
184
                                     until this client is invalid
 
185
    interval:  datetime.timedelta(); How often to start a new checker
 
186
    stop_hook: If set, called by stop() as stop_hook(self)
 
187
    checker:   subprocess.Popen(); a running checker process used
 
188
                                   to see if the client lives.
 
189
                                   'None' if no process is running.
 
190
    checker_initiator_tag: a gobject event source tag, or None
 
191
    stop_initiator_tag:    - '' -
 
192
    checker_callback_tag:  - '' -
 
193
    checker_command: string; External command which is run to check if
 
194
                     client lives.  %() expansions are done at
 
195
                     runtime with vars(self) as dict, so that for
 
196
                     instance %(name)s can be used in the command.
 
197
    Private attibutes:
 
198
    _timeout: Real variable for 'timeout'
 
199
    _interval: Real variable for 'interval'
 
200
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
201
    _interval_milliseconds: - '' -
 
202
    """
 
203
    def _set_timeout(self, timeout):
 
204
        "Setter function for 'timeout' attribute"
 
205
        self._timeout = timeout
 
206
        self._timeout_milliseconds = ((self.timeout.days
 
207
                                       * 24 * 60 * 60 * 1000)
 
208
                                      + (self.timeout.seconds * 1000)
 
209
                                      + (self.timeout.microseconds
 
210
                                         // 1000))
 
211
    timeout = property(lambda self: self._timeout,
 
212
                       _set_timeout)
 
213
    del _set_timeout
 
214
    def _set_interval(self, interval):
 
215
        "Setter function for 'interval' attribute"
 
216
        self._interval = interval
 
217
        self._interval_milliseconds = ((self.interval.days
 
218
                                        * 24 * 60 * 60 * 1000)
 
219
                                       + (self.interval.seconds
 
220
                                          * 1000)
 
221
                                       + (self.interval.microseconds
 
222
                                          // 1000))
 
223
    interval = property(lambda self: self._interval,
 
224
                        _set_interval)
 
225
    del _set_interval
 
226
    def __init__(self, name = None, stop_hook=None, config=None):
 
227
        """Note: the 'checker' key in 'config' sets the
 
228
        'checker_command' attribute and *not* the 'checker'
 
229
        attribute."""
 
230
        if config is None:
 
231
            config = {}
20
232
        self.name = name
21
 
        self.dn = dn
22
 
        if password:
23
 
            self.password = password
24
 
        elif passfile:
25
 
            self.password = open(passfile).readall()
 
233
        logger.debug(u"Creating client %r", self.name)
 
234
        # Uppercase and remove spaces from fingerprint for later
 
235
        # comparison purposes with return value from the fingerprint()
 
236
        # function
 
237
        self.fingerprint = config["fingerprint"].upper()\
 
238
                           .replace(u" ", u"")
 
239
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
 
240
        if "secret" in config:
 
241
            self.secret = config["secret"].decode(u"base64")
 
242
        elif "secfile" in config:
 
243
            secfile = open(os.path.expanduser(os.path.expandvars
 
244
                                              (config["secfile"])))
 
245
            self.secret = secfile.read()
 
246
            secfile.close()
26
247
        else:
27
 
            print "No Password or Passfile in client config file"
28
 
            # raise RuntimeError XXX
29
 
            self.password = "gazonk"
30
 
        self.fqdn = fqdn
 
248
            raise TypeError(u"No secret or secfile for client %s"
 
249
                            % self.name)
 
250
        self.host = config.get("host", "")
31
251
        self.created = datetime.datetime.now()
32
 
        self.last_seen = None
33
 
        if timeout is None:
34
 
            timeout = options.timeout
35
 
        self.timeout = timeout
36
 
        if interval == -1:
37
 
            interval = options.interval
38
 
        self.interval = interval
39
 
        self.next_check = datetime.datetime.now()
40
 
 
41
 
 
42
 
class server_metaclass(type):
43
 
    "Common behavior for the UDP and TCP server classes"
44
 
    def __new__(cls, name, bases, attrs):
45
 
        attrs["address_family"] = socket.AF_INET6
46
 
        attrs["allow_reuse_address"] = True
47
 
        def server_bind(self):
48
 
            if self.options.interface:
49
 
                if not hasattr(socket, "SO_BINDTODEVICE"):
50
 
                    # From /usr/include/asm-i486/socket.h
51
 
                    socket.SO_BINDTODEVICE = 25
 
252
        self.last_checked_ok = None
 
253
        self.timeout = string_to_delta(config["timeout"])
 
254
        self.interval = string_to_delta(config["interval"])
 
255
        self.stop_hook = stop_hook
 
256
        self.checker = None
 
257
        self.checker_initiator_tag = None
 
258
        self.stop_initiator_tag = None
 
259
        self.checker_callback_tag = None
 
260
        self.check_command = config["checker"]
 
261
    def start(self):
 
262
        """Start this client's checker and timeout hooks"""
 
263
        # Schedule a new checker to be started an 'interval' from now,
 
264
        # and every interval from then on.
 
265
        self.checker_initiator_tag = gobject.timeout_add\
 
266
                                     (self._interval_milliseconds,
 
267
                                      self.start_checker)
 
268
        # Also start a new checker *right now*.
 
269
        self.start_checker()
 
270
        # Schedule a stop() when 'timeout' has passed
 
271
        self.stop_initiator_tag = gobject.timeout_add\
 
272
                                  (self._timeout_milliseconds,
 
273
                                   self.stop)
 
274
    def stop(self):
 
275
        """Stop this client.
 
276
        The possibility that a client might be restarted is left open,
 
277
        but not currently used."""
 
278
        # If this client doesn't have a secret, it is already stopped.
 
279
        if hasattr(self, "secret") and self.secret:
 
280
            logger.info(u"Stopping client %s", self.name)
 
281
            self.secret = None
 
282
        else:
 
283
            return False
 
284
        if getattr(self, "stop_initiator_tag", False):
 
285
            gobject.source_remove(self.stop_initiator_tag)
 
286
            self.stop_initiator_tag = None
 
287
        if getattr(self, "checker_initiator_tag", False):
 
288
            gobject.source_remove(self.checker_initiator_tag)
 
289
            self.checker_initiator_tag = None
 
290
        self.stop_checker()
 
291
        if self.stop_hook:
 
292
            self.stop_hook(self)
 
293
        # Do not run this again if called by a gobject.timeout_add
 
294
        return False
 
295
    def __del__(self):
 
296
        self.stop_hook = None
 
297
        self.stop()
 
298
    def checker_callback(self, pid, condition):
 
299
        """The checker has completed, so take appropriate actions."""
 
300
        now = datetime.datetime.now()
 
301
        self.checker_callback_tag = None
 
302
        self.checker = None
 
303
        if os.WIFEXITED(condition) \
 
304
               and (os.WEXITSTATUS(condition) == 0):
 
305
            logger.info(u"Checker for %(name)s succeeded",
 
306
                        vars(self))
 
307
            self.last_checked_ok = now
 
308
            gobject.source_remove(self.stop_initiator_tag)
 
309
            self.stop_initiator_tag = gobject.timeout_add\
 
310
                                      (self._timeout_milliseconds,
 
311
                                       self.stop)
 
312
        elif not os.WIFEXITED(condition):
 
313
            logger.warning(u"Checker for %(name)s crashed?",
 
314
                           vars(self))
 
315
        else:
 
316
            logger.info(u"Checker for %(name)s failed",
 
317
                        vars(self))
 
318
    def start_checker(self):
 
319
        """Start a new checker subprocess if one is not running.
 
320
        If a checker already exists, leave it running and do
 
321
        nothing."""
 
322
        # The reason for not killing a running checker is that if we
 
323
        # did that, then if a checker (for some reason) started
 
324
        # running slowly and taking more than 'interval' time, the
 
325
        # client would inevitably timeout, since no checker would get
 
326
        # a chance to run to completion.  If we instead leave running
 
327
        # checkers alone, the checker would have to take more time
 
328
        # than 'timeout' for the client to be declared invalid, which
 
329
        # is as it should be.
 
330
        if self.checker is None:
 
331
            try:
 
332
                # In case check_command has exactly one % operator
 
333
                command = self.check_command % self.host
 
334
            except TypeError:
 
335
                # Escape attributes for the shell
 
336
                escaped_attrs = dict((key, re.escape(str(val)))
 
337
                                     for key, val in
 
338
                                     vars(self).iteritems())
52
339
                try:
53
 
                    self.socket.setsockopt(socket.SOL_SOCKET,
54
 
                                           socket.SO_BINDTODEVICE,
55
 
                                           self.options.interface)
56
 
                except socket.error, error:
57
 
                    if error[0] == errno.EPERM:
58
 
                        print "Warning: No permission to bind to interface", \
59
 
                              self.options.interface
60
 
                    else:
61
 
                        raise error
62
 
            return super(type(self), self).server_bind()
63
 
        attrs["server_bind"] = server_bind
64
 
        def init(self, *args, **kwargs):
65
 
            if "options" in kwargs:
66
 
                self.options = kwargs["options"]
67
 
                del kwargs["options"]
68
 
            if "clients" in kwargs:
69
 
                self.clients = kwargs["clients"]
70
 
                del kwargs["clients"]
71
 
            if "credentials" in kwargs:
72
 
                self.credentials = kwargs["credentials"]
73
 
                del kwargs["credentials"]
74
 
            return super(type(self), self).__init__(*args, **kwargs)
75
 
        attrs["__init__"] = init
76
 
        return type.__new__(cls, name, bases, attrs)
77
 
 
78
 
 
79
 
class udp_handler(SocketServer.DatagramRequestHandler, object):
80
 
    def handle(self):
81
 
        self.wfile.write("Polo")
82
 
        print "UDP request answered"
83
 
 
84
 
 
85
 
class IPv6_UDPServer(SocketServer.UDPServer, object):
86
 
    __metaclass__ = server_metaclass
87
 
    def verify_request(self, request, client_address):
88
 
        print "UDP request came"
89
 
        return request[0] == "Marco"
90
 
 
91
 
 
92
 
class tcp_handler(SocketServer.BaseRequestHandler, object):
93
 
    def handle(self):
94
 
        print "TCP request came"
95
 
        print "Request:", self.request
96
 
        print "Client Address:", self.client_address
97
 
        print "Server:", self.server
98
 
        session = gnutls.connection.ServerSession(self.request,
99
 
                                                  self.server.credentials)
100
 
        session.handshake()
101
 
        if session.peer_certificate:
102
 
            print "DN:", session.peer_certificate.subject
103
 
        try:
104
 
            session.verify_peer()
105
 
        except gnutls.errors.CertificateError, error:
106
 
            print "Verify failed", error
107
 
            session.bye()
108
 
            return
109
 
        try:
110
 
            session.send(dict((client.dn, client.password)
111
 
                              for client in self.server.clients)
112
 
                         [session.peer_certificate.subject])
113
 
        except KeyError:
114
 
            session.send("gazonk")
115
 
            # Log maybe? XXX
 
340
                    command = self.check_command % escaped_attrs
 
341
                except TypeError, error:
 
342
                    logger.error(u'Could not format string "%s":'
 
343
                                 u' %s', self.check_command, error)
 
344
                    return True # Try again later
 
345
            try:
 
346
                logger.info(u"Starting checker %r for %s",
 
347
                            command, self.name)
 
348
                # We don't need to redirect stdout and stderr, since
 
349
                # in normal mode, that is already done by daemon(),
 
350
                # and in debug mode we don't want to.  (Stdin is
 
351
                # always replaced by /dev/null.)
 
352
                self.checker = subprocess.Popen(command,
 
353
                                                close_fds=True,
 
354
                                                shell=True, cwd="/")
 
355
                self.checker_callback_tag = gobject.child_watch_add\
 
356
                                            (self.checker.pid,
 
357
                                             self.checker_callback)
 
358
            except OSError, error:
 
359
                logger.error(u"Failed to start subprocess: %s",
 
360
                             error)
 
361
        # Re-run this periodically if run by gobject.timeout_add
 
362
        return True
 
363
    def stop_checker(self):
 
364
        """Force the checker process, if any, to stop."""
 
365
        if self.checker_callback_tag:
 
366
            gobject.source_remove(self.checker_callback_tag)
 
367
            self.checker_callback_tag = None
 
368
        if getattr(self, "checker", None) is None:
 
369
            return
 
370
        logger.debug(u"Stopping checker for %(name)s", vars(self))
 
371
        try:
 
372
            os.kill(self.checker.pid, signal.SIGTERM)
 
373
            #os.sleep(0.5)
 
374
            #if self.checker.poll() is None:
 
375
            #    os.kill(self.checker.pid, signal.SIGKILL)
 
376
        except OSError, error:
 
377
            if error.errno != errno.ESRCH: # No such process
 
378
                raise
 
379
        self.checker = None
 
380
    def still_valid(self):
 
381
        """Has the timeout not yet passed for this client?"""
 
382
        now = datetime.datetime.now()
 
383
        if self.last_checked_ok is None:
 
384
            return now < (self.created + self.timeout)
 
385
        else:
 
386
            return now < (self.last_checked_ok + self.timeout)
 
387
 
 
388
 
 
389
def peer_certificate(session):
 
390
    "Return the peer's OpenPGP certificate as a bytestring"
 
391
    # If not an OpenPGP certificate...
 
392
    if gnutls.library.functions.gnutls_certificate_type_get\
 
393
            (session._c_object) \
 
394
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
 
395
        # ...do the normal thing
 
396
        return session.peer_certificate
 
397
    list_size = ctypes.c_uint()
 
398
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
 
399
        (session._c_object, ctypes.byref(list_size))
 
400
    if list_size.value == 0:
 
401
        return None
 
402
    cert = cert_list[0]
 
403
    return ctypes.string_at(cert.data, cert.size)
 
404
 
 
405
 
 
406
def fingerprint(openpgp):
 
407
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
408
    # New GnuTLS "datum" with the OpenPGP public key
 
409
    datum = gnutls.library.types.gnutls_datum_t\
 
410
        (ctypes.cast(ctypes.c_char_p(openpgp),
 
411
                     ctypes.POINTER(ctypes.c_ubyte)),
 
412
         ctypes.c_uint(len(openpgp)))
 
413
    # New empty GnuTLS certificate
 
414
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
415
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
416
        (ctypes.byref(crt))
 
417
    # Import the OpenPGP public key into the certificate
 
418
    gnutls.library.functions.gnutls_openpgp_crt_import\
 
419
                    (crt, ctypes.byref(datum),
 
420
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
421
    # Verify the self signature in the key
 
422
    crtverify = ctypes.c_uint()
 
423
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
 
424
        (crt, 0, ctypes.byref(crtverify))
 
425
    if crtverify.value != 0:
 
426
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
427
        raise gnutls.errors.CertificateSecurityError("Verify failed")
 
428
    # New buffer for the fingerprint
 
429
    buf = ctypes.create_string_buffer(20)
 
430
    buf_len = ctypes.c_size_t()
 
431
    # Get the fingerprint from the certificate into the buffer
 
432
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
 
433
        (crt, ctypes.byref(buf), ctypes.byref(buf_len))
 
434
    # Deinit the certificate
 
435
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
436
    # Convert the buffer to a Python bytestring
 
437
    fpr = ctypes.string_at(buf, buf_len.value)
 
438
    # Convert the bytestring to hexadecimal notation
 
439
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
 
440
    return hex_fpr
 
441
 
 
442
 
 
443
class TCP_handler(SocketServer.BaseRequestHandler, object):
 
444
    """A TCP request handler class.
 
445
    Instantiated by IPv6_TCPServer for each request to handle it.
 
446
    Note: This will run in its own forked process."""
 
447
    
 
448
    def handle(self):
 
449
        logger.info(u"TCP connection from: %s",
 
450
                     unicode(self.client_address))
 
451
        session = gnutls.connection.ClientSession\
 
452
                  (self.request, gnutls.connection.X509Credentials())
 
453
        
 
454
        line = self.request.makefile().readline()
 
455
        logger.debug(u"Protocol version: %r", line)
 
456
        try:
 
457
            if int(line.strip().split()[0]) > 1:
 
458
                raise RuntimeError
 
459
        except (ValueError, IndexError, RuntimeError), error:
 
460
            logger.error(u"Unknown protocol version: %s", error)
 
461
            return
 
462
        
 
463
        # Note: gnutls.connection.X509Credentials is really a generic
 
464
        # GnuTLS certificate credentials object so long as no X.509
 
465
        # keys are added to it.  Therefore, we can use it here despite
 
466
        # using OpenPGP certificates.
 
467
        
 
468
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
 
469
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
 
470
        #                "+DHE-DSS"))
 
471
        priority = "NORMAL"             # Fallback default, since this
 
472
                                        # MUST be set.
 
473
        if self.server.settings["priority"]:
 
474
            priority = self.server.settings["priority"]
 
475
        gnutls.library.functions.gnutls_priority_set_direct\
 
476
            (session._c_object, priority, None)
 
477
        
 
478
        try:
 
479
            session.handshake()
 
480
        except gnutls.errors.GNUTLSError, error:
 
481
            logger.warning(u"Handshake failed: %s", error)
 
482
            # Do not run session.bye() here: the session is not
 
483
            # established.  Just abandon the request.
 
484
            return
 
485
        try:
 
486
            fpr = fingerprint(peer_certificate(session))
 
487
        except (TypeError, gnutls.errors.GNUTLSError), error:
 
488
            logger.warning(u"Bad certificate: %s", error)
 
489
            session.bye()
 
490
            return
 
491
        logger.debug(u"Fingerprint: %s", fpr)
 
492
        client = None
 
493
        for c in self.server.clients:
 
494
            if c.fingerprint == fpr:
 
495
                client = c
 
496
                break
 
497
        if not client:
 
498
            logger.warning(u"Client not found for fingerprint: %s",
 
499
                           fpr)
 
500
            session.bye()
 
501
            return
 
502
        # Have to check if client.still_valid(), since it is possible
 
503
        # that the client timed out while establishing the GnuTLS
 
504
        # session.
 
505
        if not client.still_valid():
 
506
            logger.warning(u"Client %(name)s is invalid",
 
507
                           vars(client))
 
508
            session.bye()
 
509
            return
 
510
        sent_size = 0
 
511
        while sent_size < len(client.secret):
 
512
            sent = session.send(client.secret[sent_size:])
 
513
            logger.debug(u"Sent: %d, remaining: %d",
 
514
                         sent, len(client.secret)
 
515
                         - (sent_size + sent))
 
516
            sent_size += sent
116
517
        session.bye()
117
518
 
118
519
 
119
520
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
120
 
    __metaclass__ = server_metaclass
121
 
    request_queue_size = 1024
122
 
 
123
 
 
124
 
in6addr_any = "::"
125
 
 
126
 
cred = None
 
521
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
 
522
    Attributes:
 
523
        settings:       Server settings
 
524
        clients:        Set() of Client objects
 
525
        enabled:        Boolean; whether this server is activated yet
 
526
    """
 
527
    address_family = socket.AF_INET6
 
528
    def __init__(self, *args, **kwargs):
 
529
        if "settings" in kwargs:
 
530
            self.settings = kwargs["settings"]
 
531
            del kwargs["settings"]
 
532
        if "clients" in kwargs:
 
533
            self.clients = kwargs["clients"]
 
534
            del kwargs["clients"]
 
535
        self.enabled = False
 
536
        super(IPv6_TCPServer, self).__init__(*args, **kwargs)
 
537
    def server_bind(self):
 
538
        """This overrides the normal server_bind() function
 
539
        to bind to an interface if one was specified, and also NOT to
 
540
        bind to an address or port if they were not specified."""
 
541
        if self.settings["interface"]:
 
542
            # 25 is from /usr/include/asm-i486/socket.h
 
543
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
544
            try:
 
545
                self.socket.setsockopt(socket.SOL_SOCKET,
 
546
                                       SO_BINDTODEVICE,
 
547
                                       self.settings["interface"])
 
548
            except socket.error, error:
 
549
                if error[0] == errno.EPERM:
 
550
                    logger.error(u"No permission to"
 
551
                                 u" bind to interface %s",
 
552
                                 self.settings["interface"])
 
553
                else:
 
554
                    raise error
 
555
        # Only bind(2) the socket if we really need to.
 
556
        if self.server_address[0] or self.server_address[1]:
 
557
            if not self.server_address[0]:
 
558
                in6addr_any = "::"
 
559
                self.server_address = (in6addr_any,
 
560
                                       self.server_address[1])
 
561
            elif not self.server_address[1]:
 
562
                self.server_address = (self.server_address[0],
 
563
                                       0)
 
564
#                 if self.settings["interface"]:
 
565
#                     self.server_address = (self.server_address[0],
 
566
#                                            0, # port
 
567
#                                            0, # flowinfo
 
568
#                                            if_nametoindex
 
569
#                                            (self.settings
 
570
#                                             ["interface"]))
 
571
            return super(IPv6_TCPServer, self).server_bind()
 
572
    def server_activate(self):
 
573
        if self.enabled:
 
574
            return super(IPv6_TCPServer, self).server_activate()
 
575
    def enable(self):
 
576
        self.enabled = True
 
577
 
127
578
 
128
579
def string_to_delta(interval):
129
580
    """Parse a string and return a datetime.timedelta
138
589
    datetime.timedelta(1)
139
590
    >>> string_to_delta(u'1w')
140
591
    datetime.timedelta(7)
 
592
    >>> string_to_delta('5m 30s')
 
593
    datetime.timedelta(0, 330)
141
594
    """
142
 
    try:
143
 
        suffix=unicode(interval[-1])
144
 
        value=int(interval[:-1])
145
 
        if suffix == u"d":
146
 
            delta = datetime.timedelta(value)
147
 
        elif suffix == u"s":
148
 
            delta = datetime.timedelta(0, value)
149
 
        elif suffix == u"m":
150
 
            delta = datetime.timedelta(0, 0, 0, 0, value)
151
 
        elif suffix == u"h":
152
 
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
153
 
        elif suffix == u"w":
154
 
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
155
 
        else:
 
595
    timevalue = datetime.timedelta(0)
 
596
    for s in interval.split():
 
597
        try:
 
598
            suffix = unicode(s[-1])
 
599
            value = int(s[:-1])
 
600
            if suffix == u"d":
 
601
                delta = datetime.timedelta(value)
 
602
            elif suffix == u"s":
 
603
                delta = datetime.timedelta(0, value)
 
604
            elif suffix == u"m":
 
605
                delta = datetime.timedelta(0, 0, 0, 0, value)
 
606
            elif suffix == u"h":
 
607
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
608
            elif suffix == u"w":
 
609
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
610
            else:
 
611
                raise ValueError
 
612
        except (ValueError, IndexError):
156
613
            raise ValueError
157
 
    except (ValueError, IndexError):
158
 
        raise ValueError
159
 
    return delta
 
614
        timevalue += delta
 
615
    return timevalue
 
616
 
 
617
 
 
618
def server_state_changed(state):
 
619
    """Derived from the Avahi example code"""
 
620
    if state == avahi.SERVER_COLLISION:
 
621
        logger.error(u"Zeroconf server name collision")
 
622
        service.remove()
 
623
    elif state == avahi.SERVER_RUNNING:
 
624
        service.add()
 
625
 
 
626
 
 
627
def entry_group_state_changed(state, error):
 
628
    """Derived from the Avahi example code"""
 
629
    logger.debug(u"Avahi state change: %i", state)
 
630
    
 
631
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
 
632
        logger.debug(u"Zeroconf service established.")
 
633
    elif state == avahi.ENTRY_GROUP_COLLISION:
 
634
        logger.warning(u"Zeroconf service name collision.")
 
635
        service.rename()
 
636
    elif state == avahi.ENTRY_GROUP_FAILURE:
 
637
        logger.critical(u"Avahi: Error in group state changed %s",
 
638
                        unicode(error))
 
639
        raise AvahiGroupError("State changed: %s", str(error))
 
640
 
 
641
def if_nametoindex(interface):
 
642
    """Call the C function if_nametoindex(), or equivalent"""
 
643
    global if_nametoindex
 
644
    try:
 
645
        if_nametoindex = ctypes.cdll.LoadLibrary\
 
646
            (ctypes.util.find_library("c")).if_nametoindex
 
647
    except (OSError, AttributeError):
 
648
        if "struct" not in sys.modules:
 
649
            import struct
 
650
        if "fcntl" not in sys.modules:
 
651
            import fcntl
 
652
        def if_nametoindex(interface):
 
653
            "Get an interface index the hard way, i.e. using fcntl()"
 
654
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
 
655
            s = socket.socket()
 
656
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
657
                                struct.pack("16s16x", interface))
 
658
            s.close()
 
659
            interface_index = struct.unpack("I", ifreq[16:20])[0]
 
660
            return interface_index
 
661
    return if_nametoindex(interface)
 
662
 
 
663
 
 
664
def daemon(nochdir = False, noclose = False):
 
665
    """See daemon(3).  Standard BSD Unix function.
 
666
    This should really exist as os.daemon, but it doesn't (yet)."""
 
667
    if os.fork():
 
668
        sys.exit()
 
669
    os.setsid()
 
670
    if not nochdir:
 
671
        os.chdir("/")
 
672
    if os.fork():
 
673
        sys.exit()
 
674
    if not noclose:
 
675
        # Close all standard open file descriptors
 
676
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
677
        if not stat.S_ISCHR(os.fstat(null).st_mode):
 
678
            raise OSError(errno.ENODEV,
 
679
                          "/dev/null not a character device")
 
680
        os.dup2(null, sys.stdin.fileno())
 
681
        os.dup2(null, sys.stdout.fileno())
 
682
        os.dup2(null, sys.stderr.fileno())
 
683
        if null > 2:
 
684
            os.close(null)
 
685
 
160
686
 
161
687
def main():
162
 
    parser = OptionParser()
 
688
    parser = OptionParser(version = "%%prog %s" % version)
163
689
    parser.add_option("-i", "--interface", type="string",
164
 
                      default="eth0", metavar="IF",
165
 
                      help="Interface to bind to")
166
 
    parser.add_option("--cert", type="string", default="cert.pem",
167
 
                      metavar="FILE",
168
 
                      help="Public key certificate to use")
169
 
    parser.add_option("--key", type="string", default="key.pem",
170
 
                      metavar="FILE",
171
 
                      help="Private key to use")
172
 
    parser.add_option("--ca", type="string", default="ca.pem",
173
 
                      metavar="FILE",
174
 
                      help="Certificate Authority certificate to use")
175
 
    parser.add_option("--crl", type="string", default="crl.pem",
176
 
                      metavar="FILE",
177
 
                      help="Certificate Revokation List to use")
178
 
    parser.add_option("-p", "--port", type="int", default=49001,
 
690
                      metavar="IF", help="Bind to interface IF")
 
691
    parser.add_option("-a", "--address", type="string",
 
692
                      help="Address to listen for requests on")
 
693
    parser.add_option("-p", "--port", type="int",
179
694
                      help="Port number to receive requests on")
180
 
    parser.add_option("--dh", type="int", metavar="BITS",
181
 
                      help="DH group to use")
182
 
    parser.add_option("-t", "--timeout", type="string", # Parsed later
183
 
                      default="15m",
184
 
                      help="Amount of downtime allowed for clients")
185
 
    parser.add_option("--interval", type="string", # Parsed later
186
 
                      default="5m",
187
 
                      help="How often to check that a client is up")
188
695
    parser.add_option("--check", action="store_true", default=False,
189
696
                      help="Run self-test")
190
 
    (options, args) = parser.parse_args()
191
 
 
 
697
    parser.add_option("--debug", action="store_true",
 
698
                      help="Debug mode; run in foreground and log to"
 
699
                      " terminal")
 
700
    parser.add_option("--priority", type="string", help="GnuTLS"
 
701
                      " priority string (see GnuTLS documentation)")
 
702
    parser.add_option("--servicename", type="string", metavar="NAME",
 
703
                      help="Zeroconf service name")
 
704
    parser.add_option("--configdir", type="string",
 
705
                      default="/etc/mandos", metavar="DIR",
 
706
                      help="Directory to search for configuration"
 
707
                      " files")
 
708
    options = parser.parse_args()[0]
 
709
    
192
710
    if options.check:
193
711
        import doctest
194
712
        doctest.testmod()
195
713
        sys.exit()
196
714
    
197
 
    # Parse the time arguments
198
 
    try:
199
 
        options.timeout = string_to_delta(options.timeout)
200
 
    except ValueError:
201
 
        parser.error("option --timeout: Unparseable time")
202
 
    
203
 
    try:
204
 
        options.interval = string_to_delta(options.interval)
205
 
    except ValueError:
206
 
        parser.error("option --interval: Unparseable time")
207
 
    
208
 
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
209
 
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
210
 
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
211
 
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
212
 
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
213
 
    
214
 
    # Parse config file
215
 
    defaults = {}
216
 
    client_config_object = ConfigParser.SafeConfigParser(defaults)
217
 
    client_config_object.read("mandos-clients.conf")
218
 
    clients = [Client(name=section, options=options,
219
 
                      **(dict(client_config_object.items(section))))
220
 
               for section in client_config_object.sections()]
221
 
    
222
 
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
223
 
                                udp_handler,
224
 
                                options=options)
225
 
    
226
 
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
227
 
                                tcp_handler,
228
 
                                options=options,
229
 
                                clients=clients,
230
 
                                credentials=cred)
231
 
    
232
 
    while True:
233
 
        in_, out, err = select.select((udp_server,
234
 
                                       tcp_server), (), ())
235
 
        for server in in_:
236
 
            server.handle_request()
237
 
 
238
 
 
239
 
if __name__ == "__main__":
 
715
    # Default values for config file for server-global settings
 
716
    server_defaults = { "interface": "",
 
717
                        "address": "",
 
718
                        "port": "",
 
719
                        "debug": "False",
 
720
                        "priority":
 
721
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
 
722
                        "servicename": "Mandos",
 
723
                        }
 
724
    
 
725
    # Parse config file for server-global settings
 
726
    server_config = ConfigParser.SafeConfigParser(server_defaults)
 
727
    del server_defaults
 
728
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
729
    # Convert the SafeConfigParser object to a dict
 
730
    server_settings = server_config.defaults()
 
731
    # Use getboolean on the boolean config option
 
732
    server_settings["debug"] = server_config.getboolean\
 
733
                               ("DEFAULT", "debug")
 
734
    del server_config
 
735
    
 
736
    # Override the settings from the config file with command line
 
737
    # options, if set.
 
738
    for option in ("interface", "address", "port", "debug",
 
739
                   "priority", "servicename", "configdir"):
 
740
        value = getattr(options, option)
 
741
        if value is not None:
 
742
            server_settings[option] = value
 
743
    del options
 
744
    # Now we have our good server settings in "server_settings"
 
745
    
 
746
    debug = server_settings["debug"]
 
747
    
 
748
    if not debug:
 
749
        syslogger.setLevel(logging.WARNING)
 
750
        console.setLevel(logging.WARNING)
 
751
    
 
752
    if server_settings["servicename"] != "Mandos":
 
753
        syslogger.setFormatter(logging.Formatter\
 
754
                               ('Mandos (%s): %%(levelname)s:'
 
755
                                ' %%(message)s'
 
756
                                % server_settings["servicename"]))
 
757
    
 
758
    # Parse config file with clients
 
759
    client_defaults = { "timeout": "1h",
 
760
                        "interval": "5m",
 
761
                        "checker": "fping -q -- %(host)s",
 
762
                        "host": "",
 
763
                        }
 
764
    client_config = ConfigParser.SafeConfigParser(client_defaults)
 
765
    client_config.read(os.path.join(server_settings["configdir"],
 
766
                                    "clients.conf"))
 
767
    
 
768
    clients = Set()
 
769
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
770
                                 server_settings["port"]),
 
771
                                TCP_handler,
 
772
                                settings=server_settings,
 
773
                                clients=clients)
 
774
    pidfilename = "/var/run/mandos.pid"
 
775
    try:
 
776
        pidfile = open(pidfilename, "w")
 
777
    except IOError, error:
 
778
        logger.error("Could not open file %r", pidfilename)
 
779
    
 
780
    uid = 65534
 
781
    gid = 65534
 
782
    try:
 
783
        uid = pwd.getpwnam("mandos").pw_uid
 
784
    except KeyError:
 
785
        try:
 
786
            uid = pwd.getpwnam("nobody").pw_uid
 
787
        except KeyError:
 
788
            pass
 
789
    try:
 
790
        gid = pwd.getpwnam("mandos").pw_gid
 
791
    except KeyError:
 
792
        try:
 
793
            gid = pwd.getpwnam("nogroup").pw_gid
 
794
        except KeyError:
 
795
            pass
 
796
    try:
 
797
        os.setuid(uid)
 
798
        os.setgid(gid)
 
799
    except OSError, error:
 
800
        if error[0] != errno.EPERM:
 
801
            raise error
 
802
    
 
803
    global service
 
804
    service = AvahiService(name = server_settings["servicename"],
 
805
                           servicetype = "_mandos._tcp", )
 
806
    if server_settings["interface"]:
 
807
        service.interface = if_nametoindex\
 
808
                            (server_settings["interface"])
 
809
    
 
810
    global main_loop
 
811
    global bus
 
812
    global server
 
813
    # From the Avahi example code
 
814
    DBusGMainLoop(set_as_default=True )
 
815
    main_loop = gobject.MainLoop()
 
816
    bus = dbus.SystemBus()
 
817
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
 
818
                                           avahi.DBUS_PATH_SERVER),
 
819
                            avahi.DBUS_INTERFACE_SERVER)
 
820
    # End of Avahi example code
 
821
    
 
822
    def remove_from_clients(client):
 
823
        clients.remove(client)
 
824
        if not clients:
 
825
            logger.critical(u"No clients left, exiting")
 
826
            sys.exit()
 
827
    
 
828
    clients.update(Set(Client(name = section,
 
829
                              stop_hook = remove_from_clients,
 
830
                              config
 
831
                              = dict(client_config.items(section)))
 
832
                       for section in client_config.sections()))
 
833
    if not clients:
 
834
        logger.critical(u"No clients defined")
 
835
        sys.exit(1)
 
836
    
 
837
    if debug:
 
838
        # Redirect stdin so all checkers get /dev/null
 
839
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
840
        os.dup2(null, sys.stdin.fileno())
 
841
        if null > 2:
 
842
            os.close(null)
 
843
    else:
 
844
        # No console logging
 
845
        logger.removeHandler(console)
 
846
        # Close all input and output, do double fork, etc.
 
847
        daemon()
 
848
    
 
849
    try:
 
850
        pid = os.getpid()
 
851
        pidfile.write(str(pid) + "\n")
 
852
        pidfile.close()
 
853
        del pidfile
 
854
    except IOError:
 
855
        logger.error(u"Could not write to file %r with PID %d",
 
856
                     pidfilename, pid)
 
857
    except NameError:
 
858
        # "pidfile" was never created
 
859
        pass
 
860
    del pidfilename
 
861
    
 
862
    def cleanup():
 
863
        "Cleanup function; run on exit"
 
864
        global group
 
865
        # From the Avahi example code
 
866
        if not group is None:
 
867
            group.Free()
 
868
            group = None
 
869
        # End of Avahi example code
 
870
        
 
871
        while clients:
 
872
            client = clients.pop()
 
873
            client.stop_hook = None
 
874
            client.stop()
 
875
    
 
876
    atexit.register(cleanup)
 
877
    
 
878
    if not debug:
 
879
        signal.signal(signal.SIGINT, signal.SIG_IGN)
 
880
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
 
881
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
 
882
    
 
883
    for client in clients:
 
884
        client.start()
 
885
    
 
886
    tcp_server.enable()
 
887
    tcp_server.server_activate()
 
888
    
 
889
    # Find out what port we got
 
890
    service.port = tcp_server.socket.getsockname()[1]
 
891
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
 
892
                u" scope_id %d" % tcp_server.socket.getsockname())
 
893
    
 
894
    #service.interface = tcp_server.socket.getsockname()[3]
 
895
    
 
896
    try:
 
897
        # From the Avahi example code
 
898
        server.connect_to_signal("StateChanged", server_state_changed)
 
899
        try:
 
900
            server_state_changed(server.GetState())
 
901
        except dbus.exceptions.DBusException, error:
 
902
            logger.critical(u"DBusException: %s", error)
 
903
            sys.exit(1)
 
904
        # End of Avahi example code
 
905
        
 
906
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
907
                             lambda *args, **kwargs:
 
908
                             tcp_server.handle_request\
 
909
                             (*args[2:], **kwargs) or True)
 
910
        
 
911
        logger.debug(u"Starting main loop")
 
912
        main_loop.run()
 
913
    except AvahiError, error:
 
914
        logger.critical(u"AvahiError: %s" + unicode(error))
 
915
        sys.exit(1)
 
916
    except KeyboardInterrupt:
 
917
        if debug:
 
918
            print
 
919
 
 
920
if __name__ == '__main__':
240
921
    main()
241