2
# -*- mode: python; coding: utf-8 -*-
 
 
4
# Mandos server - give out binary blobs to connecting clients.
 
 
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".
 
 
14
# Copyright © 2008,2009 Teddy Hogeborn
 
 
15
# Copyright © 2008,2009 Björn Påhlsson
 
 
17
# This program is free software: you can redistribute it and/or modify
 
 
18
# it under the terms of the GNU General Public License as published by
 
 
19
# the Free Software Foundation, either version 3 of the License, or
 
 
20
# (at your option) any later version.
 
 
22
#     This program is distributed in the hope that it will be useful,
 
 
23
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
 
 
24
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
 
25
#     GNU General Public License for more details.
 
 
27
# You should have received a copy of the GNU General Public License
 
 
28
# along with this program.  If not, see
 
 
29
# <http://www.gnu.org/licenses/>.
 
 
31
# Contact the authors at <mandos@fukt.bsnet.se>.
 
 
34
from __future__ import division, with_statement, absolute_import
 
 
42
import gnutls.connection
 
 
44
import gnutls.library.functions
 
 
45
import gnutls.library.constants
 
 
46
import gnutls.library.types
 
 
57
import logging.handlers
 
 
59
from contextlib import closing
 
 
65
from dbus.mainloop.glib import DBusGMainLoop
 
 
71
logger = logging.Logger('mandos')
 
 
72
syslogger = (logging.handlers.SysLogHandler
 
 
73
             (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
 
 
74
              address = "/dev/log"))
 
 
75
syslogger.setFormatter(logging.Formatter
 
 
76
                       ('Mandos: %(levelname)s: %(message)s'))
 
 
77
logger.addHandler(syslogger)
 
 
79
console = logging.StreamHandler()
 
 
80
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
 
 
82
logger.addHandler(console)
 
 
84
class AvahiError(Exception):
 
 
85
    def __init__(self, value, *args, **kwargs):
 
 
87
        super(AvahiError, self).__init__(value, *args, **kwargs)
 
 
88
    def __unicode__(self):
 
 
89
        return unicode(repr(self.value))
 
 
91
class AvahiServiceError(AvahiError):
 
 
94
class AvahiGroupError(AvahiError):
 
 
98
class AvahiService(object):
 
 
99
    """An Avahi (Zeroconf) service.
 
 
101
    interface: integer; avahi.IF_UNSPEC or an interface index.
 
 
102
               Used to optionally bind to the specified interface.
 
 
103
    name: string; Example: 'Mandos'
 
 
104
    type: string; Example: '_mandos._tcp'.
 
 
105
                  See <http://www.dns-sd.org/ServiceTypes.html>
 
 
106
    port: integer; what port to announce
 
 
107
    TXT: list of strings; TXT record for the service
 
 
108
    domain: string; Domain to publish on, default to .local if empty.
 
 
109
    host: string; Host to publish records for, default is localhost
 
 
110
    max_renames: integer; maximum number of renames
 
 
111
    rename_count: integer; counter so we only rename after collisions
 
 
112
                  a sensible number of times
 
 
114
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
 
 
115
                 servicetype = None, port = None, TXT = None,
 
 
116
                 domain = "", host = "", max_renames = 32768):
 
 
117
        self.interface = interface
 
 
119
        self.type = servicetype
 
 
121
        self.TXT = TXT if TXT is not None else []
 
 
124
        self.rename_count = 0
 
 
125
        self.max_renames = max_renames
 
 
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.",
 
 
132
            raise AvahiServiceError(u"Too many renames")
 
 
133
        self.name = server.GetAlternativeServiceName(self.name)
 
 
134
        logger.info(u"Changing Zeroconf service name to %r ...",
 
 
136
        syslogger.setFormatter(logging.Formatter
 
 
137
                               ('Mandos (%s): %%(levelname)s:'
 
 
138
                                ' %%(message)s' % self.name))
 
 
141
        self.rename_count += 1
 
 
143
        """Derived from the Avahi example code"""
 
 
144
        if group is not None:
 
 
147
        """Derived from the Avahi example code"""
 
 
150
            group = dbus.Interface(bus.get_object
 
 
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)
 
 
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))
 
 
168
# From the Avahi example code:
 
 
169
group = None                            # our entry group
 
 
170
# End of Avahi example code
 
 
173
def _datetime_to_dbus(dt, variant_level=0):
 
 
174
    """Convert a UTC datetime.datetime() to a D-Bus type."""
 
 
175
    return dbus.String(dt.isoformat(), variant_level=variant_level)
 
 
178
class Client(dbus.service.Object):
 
 
179
    """A representation of a client host served by this server.
 
 
181
    name:       string; from the config file, used in log messages and
 
 
183
    fingerprint: string (40 or 32 hexadecimal digits); used to
 
 
184
                 uniquely identify the client
 
 
185
    secret:     bytestring; sent verbatim (over TLS) to client
 
 
186
    host:       string; available for use by the checker command
 
 
187
    created:    datetime.datetime(); (UTC) object creation
 
 
188
    last_enabled: datetime.datetime(); (UTC)
 
 
190
    last_checked_ok: datetime.datetime(); (UTC) or None
 
 
191
    timeout:    datetime.timedelta(); How long from last_checked_ok
 
 
192
                                      until this client is invalid
 
 
193
    interval:   datetime.timedelta(); How often to start a new checker
 
 
194
    disable_hook:  If set, called by disable() as disable_hook(self)
 
 
195
    checker:    subprocess.Popen(); a running checker process used
 
 
196
                                    to see if the client lives.
 
 
197
                                    'None' if no process is running.
 
 
198
    checker_initiator_tag: a gobject event source tag, or None
 
 
199
    disable_initiator_tag:    - '' -
 
 
200
    checker_callback_tag:  - '' -
 
 
201
    checker_command: string; External command which is run to check if
 
 
202
                     client lives.  %() expansions are done at
 
 
203
                     runtime with vars(self) as dict, so that for
 
 
204
                     instance %(name)s can be used in the command.
 
 
205
    use_dbus: bool(); Whether to provide D-Bus interface and signals
 
 
206
    dbus_object_path: dbus.ObjectPath ; only set if self.use_dbus
 
 
208
    def timeout_milliseconds(self):
 
 
209
        "Return the 'timeout' attribute in milliseconds"
 
 
210
        return ((self.timeout.days * 24 * 60 * 60 * 1000)
 
 
211
                + (self.timeout.seconds * 1000)
 
 
212
                + (self.timeout.microseconds // 1000))
 
 
214
    def interval_milliseconds(self):
 
 
215
        "Return the 'interval' attribute in milliseconds"
 
 
216
        return ((self.interval.days * 24 * 60 * 60 * 1000)
 
 
217
                + (self.interval.seconds * 1000)
 
 
218
                + (self.interval.microseconds // 1000))
 
 
220
    def __init__(self, name = None, disable_hook=None, config=None,
 
 
222
        """Note: the 'checker' key in 'config' sets the
 
 
223
        'checker_command' attribute and *not* the 'checker'
 
 
228
        logger.debug(u"Creating client %r", self.name)
 
 
229
        self.use_dbus = False   # During __init__
 
 
230
        # Uppercase and remove spaces from fingerprint for later
 
 
231
        # comparison purposes with return value from the fingerprint()
 
 
233
        self.fingerprint = (config["fingerprint"].upper()
 
 
235
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
 
 
236
        if "secret" in config:
 
 
237
            self.secret = config["secret"].decode(u"base64")
 
 
238
        elif "secfile" in config:
 
 
239
            with closing(open(os.path.expanduser
 
 
241
                               (config["secfile"])))) as secfile:
 
 
242
                self.secret = secfile.read()
 
 
244
            raise TypeError(u"No secret or secfile for client %s"
 
 
246
        self.host = config.get("host", "")
 
 
247
        self.created = datetime.datetime.utcnow()
 
 
249
        self.last_enabled = None
 
 
250
        self.last_checked_ok = None
 
 
251
        self.timeout = string_to_delta(config["timeout"])
 
 
252
        self.interval = string_to_delta(config["interval"])
 
 
253
        self.disable_hook = disable_hook
 
 
255
        self.checker_initiator_tag = None
 
 
256
        self.disable_initiator_tag = None
 
 
257
        self.checker_callback_tag = None
 
 
258
        self.checker_command = config["checker"]
 
 
259
        self.last_connect = None
 
 
260
        # Only now, when this client is initialized, can it show up on
 
 
262
        self.use_dbus = use_dbus
 
 
264
            self.dbus_object_path = (dbus.ObjectPath
 
 
266
                                      + self.name.replace(".", "_")))
 
 
267
            dbus.service.Object.__init__(self, bus,
 
 
268
                                         self.dbus_object_path)
 
 
271
        """Start this client's checker and timeout hooks"""
 
 
272
        self.last_enabled = datetime.datetime.utcnow()
 
 
273
        # Schedule a new checker to be started an 'interval' from now,
 
 
274
        # and every interval from then on.
 
 
275
        self.checker_initiator_tag = (gobject.timeout_add
 
 
276
                                      (self.interval_milliseconds(),
 
 
278
        # Also start a new checker *right now*.
 
 
280
        # Schedule a disable() when 'timeout' has passed
 
 
281
        self.disable_initiator_tag = (gobject.timeout_add
 
 
282
                                   (self.timeout_milliseconds(),
 
 
287
            self.PropertyChanged(dbus.String(u"enabled"),
 
 
288
                                 dbus.Boolean(True, variant_level=1))
 
 
289
            self.PropertyChanged(dbus.String(u"last_enabled"),
 
 
290
                                 (_datetime_to_dbus(self.last_enabled,
 
 
294
        """Disable this client."""
 
 
295
        if not getattr(self, "enabled", False):
 
 
297
        logger.info(u"Disabling client %s", self.name)
 
 
298
        if getattr(self, "disable_initiator_tag", False):
 
 
299
            gobject.source_remove(self.disable_initiator_tag)
 
 
300
            self.disable_initiator_tag = None
 
 
301
        if getattr(self, "checker_initiator_tag", False):
 
 
302
            gobject.source_remove(self.checker_initiator_tag)
 
 
303
            self.checker_initiator_tag = None
 
 
305
        if self.disable_hook:
 
 
306
            self.disable_hook(self)
 
 
310
            self.PropertyChanged(dbus.String(u"enabled"),
 
 
311
                                 dbus.Boolean(False, variant_level=1))
 
 
312
        # Do not run this again if called by a gobject.timeout_add
 
 
316
        self.disable_hook = None
 
 
319
    def checker_callback(self, pid, condition, command):
 
 
320
        """The checker has completed, so take appropriate actions."""
 
 
321
        self.checker_callback_tag = None
 
 
325
            self.PropertyChanged(dbus.String(u"checker_running"),
 
 
326
                                 dbus.Boolean(False, variant_level=1))
 
 
327
        if os.WIFEXITED(condition):
 
 
328
            exitstatus = os.WEXITSTATUS(condition)
 
 
330
                logger.info(u"Checker for %(name)s succeeded",
 
 
334
                logger.info(u"Checker for %(name)s failed",
 
 
338
                self.CheckerCompleted(dbus.Int16(exitstatus),
 
 
339
                                      dbus.Int64(condition),
 
 
340
                                      dbus.String(command))
 
 
342
            logger.warning(u"Checker for %(name)s crashed?",
 
 
346
                self.CheckerCompleted(dbus.Int16(-1),
 
 
347
                                      dbus.Int64(condition),
 
 
348
                                      dbus.String(command))
 
 
350
    def checked_ok(self):
 
 
351
        """Bump up the timeout for this client.
 
 
352
        This should only be called when the client has been seen,
 
 
355
        self.last_checked_ok = datetime.datetime.utcnow()
 
 
356
        gobject.source_remove(self.disable_initiator_tag)
 
 
357
        self.disable_initiator_tag = (gobject.timeout_add
 
 
358
                                      (self.timeout_milliseconds(),
 
 
362
            self.PropertyChanged(
 
 
363
                dbus.String(u"last_checked_ok"),
 
 
364
                (_datetime_to_dbus(self.last_checked_ok,
 
 
367
    def start_checker(self):
 
 
368
        """Start a new checker subprocess if one is not running.
 
 
369
        If a checker already exists, leave it running and do
 
 
371
        # The reason for not killing a running checker is that if we
 
 
372
        # did that, then if a checker (for some reason) started
 
 
373
        # running slowly and taking more than 'interval' time, the
 
 
374
        # client would inevitably timeout, since no checker would get
 
 
375
        # a chance to run to completion.  If we instead leave running
 
 
376
        # checkers alone, the checker would have to take more time
 
 
377
        # than 'timeout' for the client to be declared invalid, which
 
 
378
        # is as it should be.
 
 
379
        if self.checker is None:
 
 
381
                # In case checker_command has exactly one % operator
 
 
382
                command = self.checker_command % self.host
 
 
384
                # Escape attributes for the shell
 
 
385
                escaped_attrs = dict((key, re.escape(str(val)))
 
 
387
                                     vars(self).iteritems())
 
 
389
                    command = self.checker_command % escaped_attrs
 
 
390
                except TypeError, error:
 
 
391
                    logger.error(u'Could not format string "%s":'
 
 
392
                                 u' %s', self.checker_command, error)
 
 
393
                    return True # Try again later
 
 
395
                logger.info(u"Starting checker %r for %s",
 
 
397
                # We don't need to redirect stdout and stderr, since
 
 
398
                # in normal mode, that is already done by daemon(),
 
 
399
                # and in debug mode we don't want to.  (Stdin is
 
 
400
                # always replaced by /dev/null.)
 
 
401
                self.checker = subprocess.Popen(command,
 
 
406
                    self.CheckerStarted(command)
 
 
407
                    self.PropertyChanged(
 
 
408
                        dbus.String("checker_running"),
 
 
409
                        dbus.Boolean(True, variant_level=1))
 
 
410
                self.checker_callback_tag = (gobject.child_watch_add
 
 
412
                                              self.checker_callback,
 
 
414
            except OSError, error:
 
 
415
                logger.error(u"Failed to start subprocess: %s",
 
 
417
        # Re-run this periodically if run by gobject.timeout_add
 
 
420
    def stop_checker(self):
 
 
421
        """Force the checker process, if any, to stop."""
 
 
422
        if self.checker_callback_tag:
 
 
423
            gobject.source_remove(self.checker_callback_tag)
 
 
424
            self.checker_callback_tag = None
 
 
425
        if getattr(self, "checker", None) is None:
 
 
427
        logger.debug(u"Stopping checker for %(name)s", vars(self))
 
 
429
            os.kill(self.checker.pid, signal.SIGTERM)
 
 
431
            #if self.checker.poll() is None:
 
 
432
            #    os.kill(self.checker.pid, signal.SIGKILL)
 
 
433
        except OSError, error:
 
 
434
            if error.errno != errno.ESRCH: # No such process
 
 
438
            self.PropertyChanged(dbus.String(u"checker_running"),
 
 
439
                                 dbus.Boolean(False, variant_level=1))
 
 
441
    def still_valid(self):
 
 
442
        """Has the timeout not yet passed for this client?"""
 
 
443
        if not getattr(self, "enabled", False):
 
 
445
        now = datetime.datetime.utcnow()
 
 
446
        if self.last_checked_ok is None:
 
 
447
            return now < (self.created + self.timeout)
 
 
449
            return now < (self.last_checked_ok + self.timeout)
 
 
451
    ## D-Bus methods & signals
 
 
452
    _interface = u"se.bsnet.fukt.Mandos.Client"
 
 
455
    CheckedOK = dbus.service.method(_interface)(checked_ok)
 
 
456
    CheckedOK.__name__ = "CheckedOK"
 
 
458
    # CheckerCompleted - signal
 
 
459
    @dbus.service.signal(_interface, signature="nxs")
 
 
460
    def CheckerCompleted(self, exitcode, waitstatus, command):
 
 
464
    # CheckerStarted - signal
 
 
465
    @dbus.service.signal(_interface, signature="s")
 
 
466
    def CheckerStarted(self, command):
 
 
470
    # GetAllProperties - method
 
 
471
    @dbus.service.method(_interface, out_signature="a{sv}")
 
 
472
    def GetAllProperties(self):
 
 
474
        return dbus.Dictionary({
 
 
476
                    dbus.String(self.name, variant_level=1),
 
 
477
                dbus.String("fingerprint"):
 
 
478
                    dbus.String(self.fingerprint, variant_level=1),
 
 
480
                    dbus.String(self.host, variant_level=1),
 
 
481
                dbus.String("created"):
 
 
482
                    _datetime_to_dbus(self.created, variant_level=1),
 
 
483
                dbus.String("last_enabled"):
 
 
484
                    (_datetime_to_dbus(self.last_enabled,
 
 
486
                     if self.last_enabled is not None
 
 
487
                     else dbus.Boolean(False, variant_level=1)),
 
 
488
                dbus.String("enabled"):
 
 
489
                    dbus.Boolean(self.enabled, variant_level=1),
 
 
490
                dbus.String("last_checked_ok"):
 
 
491
                    (_datetime_to_dbus(self.last_checked_ok,
 
 
493
                     if self.last_checked_ok is not None
 
 
494
                     else dbus.Boolean (False, variant_level=1)),
 
 
495
                dbus.String("timeout"):
 
 
496
                    dbus.UInt64(self.timeout_milliseconds(),
 
 
498
                dbus.String("interval"):
 
 
499
                    dbus.UInt64(self.interval_milliseconds(),
 
 
501
                dbus.String("checker"):
 
 
502
                    dbus.String(self.checker_command,
 
 
504
                dbus.String("checker_running"):
 
 
505
                    dbus.Boolean(self.checker is not None,
 
 
507
                dbus.String("object_path"):
 
 
508
                    dbus.ObjectPath(self.dbus_object_path,
 
 
512
    # IsStillValid - method
 
 
513
    IsStillValid = (dbus.service.method(_interface, out_signature="b")
 
 
515
    IsStillValid.__name__ = "IsStillValid"
 
 
517
    # PropertyChanged - signal
 
 
518
    @dbus.service.signal(_interface, signature="sv")
 
 
519
    def PropertyChanged(self, property, value):
 
 
523
    # SetChecker - method
 
 
524
    @dbus.service.method(_interface, in_signature="s")
 
 
525
    def SetChecker(self, checker):
 
 
526
        "D-Bus setter method"
 
 
527
        self.checker_command = checker
 
 
529
        self.PropertyChanged(dbus.String(u"checker"),
 
 
530
                             dbus.String(self.checker_command,
 
 
534
    @dbus.service.method(_interface, in_signature="s")
 
 
535
    def SetHost(self, host):
 
 
536
        "D-Bus setter method"
 
 
539
        self.PropertyChanged(dbus.String(u"host"),
 
 
540
                             dbus.String(self.host, variant_level=1))
 
 
542
    # SetInterval - method
 
 
543
    @dbus.service.method(_interface, in_signature="t")
 
 
544
    def SetInterval(self, milliseconds):
 
 
545
        self.interval = datetime.timedelta(0, 0, 0, milliseconds)
 
 
547
        self.PropertyChanged(dbus.String(u"interval"),
 
 
548
                             (dbus.UInt64(self.interval_milliseconds(),
 
 
552
    @dbus.service.method(_interface, in_signature="ay",
 
 
554
    def SetSecret(self, secret):
 
 
555
        "D-Bus setter method"
 
 
556
        self.secret = str(secret)
 
 
558
    # SetTimeout - method
 
 
559
    @dbus.service.method(_interface, in_signature="t")
 
 
560
    def SetTimeout(self, milliseconds):
 
 
561
        self.timeout = datetime.timedelta(0, 0, 0, milliseconds)
 
 
563
        self.PropertyChanged(dbus.String(u"timeout"),
 
 
564
                             (dbus.UInt64(self.timeout_milliseconds(),
 
 
568
    Enable = dbus.service.method(_interface)(enable)
 
 
569
    Enable.__name__ = "Enable"
 
 
571
    # StartChecker - method
 
 
572
    @dbus.service.method(_interface)
 
 
573
    def StartChecker(self):
 
 
578
    @dbus.service.method(_interface)
 
 
583
    # StopChecker - method
 
 
584
    StopChecker = dbus.service.method(_interface)(stop_checker)
 
 
585
    StopChecker.__name__ = "StopChecker"
 
 
590
def peer_certificate(session):
 
 
591
    "Return the peer's OpenPGP certificate as a bytestring"
 
 
592
    # If not an OpenPGP certificate...
 
 
593
    if (gnutls.library.functions
 
 
594
        .gnutls_certificate_type_get(session._c_object)
 
 
595
        != gnutls.library.constants.GNUTLS_CRT_OPENPGP):
 
 
596
        # ...do the normal thing
 
 
597
        return session.peer_certificate
 
 
598
    list_size = ctypes.c_uint(1)
 
 
599
    cert_list = (gnutls.library.functions
 
 
600
                 .gnutls_certificate_get_peers
 
 
601
                 (session._c_object, ctypes.byref(list_size)))
 
 
602
    if not bool(cert_list) and list_size.value != 0:
 
 
603
        raise gnutls.errors.GNUTLSError("error getting peer"
 
 
605
    if list_size.value == 0:
 
 
608
    return ctypes.string_at(cert.data, cert.size)
 
 
611
def fingerprint(openpgp):
 
 
612
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
 
613
    # New GnuTLS "datum" with the OpenPGP public key
 
 
614
    datum = (gnutls.library.types
 
 
615
             .gnutls_datum_t(ctypes.cast(ctypes.c_char_p(openpgp),
 
 
618
                             ctypes.c_uint(len(openpgp))))
 
 
619
    # New empty GnuTLS certificate
 
 
620
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
 
621
    (gnutls.library.functions
 
 
622
     .gnutls_openpgp_crt_init(ctypes.byref(crt)))
 
 
623
    # Import the OpenPGP public key into the certificate
 
 
624
    (gnutls.library.functions
 
 
625
     .gnutls_openpgp_crt_import(crt, ctypes.byref(datum),
 
 
626
                                gnutls.library.constants
 
 
627
                                .GNUTLS_OPENPGP_FMT_RAW))
 
 
628
    # Verify the self signature in the key
 
 
629
    crtverify = ctypes.c_uint()
 
 
630
    (gnutls.library.functions
 
 
631
     .gnutls_openpgp_crt_verify_self(crt, 0, ctypes.byref(crtverify)))
 
 
632
    if crtverify.value != 0:
 
 
633
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
 
634
        raise gnutls.errors.CertificateSecurityError("Verify failed")
 
 
635
    # New buffer for the fingerprint
 
 
636
    buf = ctypes.create_string_buffer(20)
 
 
637
    buf_len = ctypes.c_size_t()
 
 
638
    # Get the fingerprint from the certificate into the buffer
 
 
639
    (gnutls.library.functions
 
 
640
     .gnutls_openpgp_crt_get_fingerprint(crt, ctypes.byref(buf),
 
 
641
                                         ctypes.byref(buf_len)))
 
 
642
    # Deinit the certificate
 
 
643
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
 
644
    # Convert the buffer to a Python bytestring
 
 
645
    fpr = ctypes.string_at(buf, buf_len.value)
 
 
646
    # Convert the bytestring to hexadecimal notation
 
 
647
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
 
 
651
class TCP_handler(SocketServer.BaseRequestHandler, object):
 
 
652
    """A TCP request handler class.
 
 
653
    Instantiated by IPv6_TCPServer for each request to handle it.
 
 
654
    Note: This will run in its own forked process."""
 
 
657
        logger.info(u"TCP connection from: %s",
 
 
658
                    unicode(self.client_address))
 
 
659
        session = (gnutls.connection
 
 
660
                   .ClientSession(self.request,
 
 
664
        line = self.request.makefile().readline()
 
 
665
        logger.debug(u"Protocol version: %r", line)
 
 
667
            if int(line.strip().split()[0]) > 1:
 
 
669
        except (ValueError, IndexError, RuntimeError), error:
 
 
670
            logger.error(u"Unknown protocol version: %s", error)
 
 
673
        # Note: gnutls.connection.X509Credentials is really a generic
 
 
674
        # GnuTLS certificate credentials object so long as no X.509
 
 
675
        # keys are added to it.  Therefore, we can use it here despite
 
 
676
        # using OpenPGP certificates.
 
 
678
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
 
 
679
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
 
 
681
        # Use a fallback default, since this MUST be set.
 
 
682
        priority = self.server.settings.get("priority", "NORMAL")
 
 
683
        (gnutls.library.functions
 
 
684
         .gnutls_priority_set_direct(session._c_object,
 
 
689
        except gnutls.errors.GNUTLSError, error:
 
 
690
            logger.warning(u"Handshake failed: %s", error)
 
 
691
            # Do not run session.bye() here: the session is not
 
 
692
            # established.  Just abandon the request.
 
 
694
        logger.debug(u"Handshake succeeded")
 
 
696
            fpr = fingerprint(peer_certificate(session))
 
 
697
        except (TypeError, gnutls.errors.GNUTLSError), error:
 
 
698
            logger.warning(u"Bad certificate: %s", error)
 
 
701
        logger.debug(u"Fingerprint: %s", fpr)
 
 
703
        for c in self.server.clients:
 
 
704
            if c.fingerprint == fpr:
 
 
708
            logger.warning(u"Client not found for fingerprint: %s",
 
 
712
        # Have to check if client.still_valid(), since it is possible
 
 
713
        # that the client timed out while establishing the GnuTLS
 
 
715
        if not client.still_valid():
 
 
716
            logger.warning(u"Client %(name)s is invalid",
 
 
720
        ## This won't work here, since we're in a fork.
 
 
721
        # client.checked_ok()
 
 
723
        while sent_size < len(client.secret):
 
 
724
            sent = session.send(client.secret[sent_size:])
 
 
725
            logger.debug(u"Sent: %d, remaining: %d",
 
 
726
                         sent, len(client.secret)
 
 
727
                         - (sent_size + sent))
 
 
732
class IPv6_TCPServer(SocketServer.ForkingMixIn,
 
 
733
                     SocketServer.TCPServer, object):
 
 
734
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
 
 
736
        settings:       Server settings
 
 
737
        clients:        Set() of Client objects
 
 
738
        enabled:        Boolean; whether this server is activated yet
 
 
740
    address_family = socket.AF_INET6
 
 
741
    def __init__(self, *args, **kwargs):
 
 
742
        if "settings" in kwargs:
 
 
743
            self.settings = kwargs["settings"]
 
 
744
            del kwargs["settings"]
 
 
745
        if "clients" in kwargs:
 
 
746
            self.clients = kwargs["clients"]
 
 
747
            del kwargs["clients"]
 
 
749
        super(IPv6_TCPServer, self).__init__(*args, **kwargs)
 
 
750
    def server_bind(self):
 
 
751
        """This overrides the normal server_bind() function
 
 
752
        to bind to an interface if one was specified, and also NOT to
 
 
753
        bind to an address or port if they were not specified."""
 
 
754
        if self.settings["interface"]:
 
 
755
            # 25 is from /usr/include/asm-i486/socket.h
 
 
756
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
 
758
                self.socket.setsockopt(socket.SOL_SOCKET,
 
 
760
                                       self.settings["interface"])
 
 
761
            except socket.error, error:
 
 
762
                if error[0] == errno.EPERM:
 
 
763
                    logger.error(u"No permission to"
 
 
764
                                 u" bind to interface %s",
 
 
765
                                 self.settings["interface"])
 
 
768
        # Only bind(2) the socket if we really need to.
 
 
769
        if self.server_address[0] or self.server_address[1]:
 
 
770
            if not self.server_address[0]:
 
 
772
                self.server_address = (in6addr_any,
 
 
773
                                       self.server_address[1])
 
 
774
            elif not self.server_address[1]:
 
 
775
                self.server_address = (self.server_address[0],
 
 
777
#                 if self.settings["interface"]:
 
 
778
#                     self.server_address = (self.server_address[0],
 
 
784
            return super(IPv6_TCPServer, self).server_bind()
 
 
785
    def server_activate(self):
 
 
787
            return super(IPv6_TCPServer, self).server_activate()
 
 
792
def string_to_delta(interval):
 
 
793
    """Parse a string and return a datetime.timedelta
 
 
795
    >>> string_to_delta('7d')
 
 
796
    datetime.timedelta(7)
 
 
797
    >>> string_to_delta('60s')
 
 
798
    datetime.timedelta(0, 60)
 
 
799
    >>> string_to_delta('60m')
 
 
800
    datetime.timedelta(0, 3600)
 
 
801
    >>> string_to_delta('24h')
 
 
802
    datetime.timedelta(1)
 
 
803
    >>> string_to_delta(u'1w')
 
 
804
    datetime.timedelta(7)
 
 
805
    >>> string_to_delta('5m 30s')
 
 
806
    datetime.timedelta(0, 330)
 
 
808
    timevalue = datetime.timedelta(0)
 
 
809
    for s in interval.split():
 
 
811
            suffix = unicode(s[-1])
 
 
814
                delta = datetime.timedelta(value)
 
 
816
                delta = datetime.timedelta(0, value)
 
 
818
                delta = datetime.timedelta(0, 0, 0, 0, value)
 
 
820
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
 
822
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
 
825
        except (ValueError, IndexError):
 
 
831
def server_state_changed(state):
 
 
832
    """Derived from the Avahi example code"""
 
 
833
    if state == avahi.SERVER_COLLISION:
 
 
834
        logger.error(u"Zeroconf server name collision")
 
 
836
    elif state == avahi.SERVER_RUNNING:
 
 
840
def entry_group_state_changed(state, error):
 
 
841
    """Derived from the Avahi example code"""
 
 
842
    logger.debug(u"Avahi state change: %i", state)
 
 
844
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
 
 
845
        logger.debug(u"Zeroconf service established.")
 
 
846
    elif state == avahi.ENTRY_GROUP_COLLISION:
 
 
847
        logger.warning(u"Zeroconf service name collision.")
 
 
849
    elif state == avahi.ENTRY_GROUP_FAILURE:
 
 
850
        logger.critical(u"Avahi: Error in group state changed %s",
 
 
852
        raise AvahiGroupError(u"State changed: %s" % unicode(error))
 
 
854
def if_nametoindex(interface):
 
 
855
    """Call the C function if_nametoindex(), or equivalent"""
 
 
856
    global if_nametoindex
 
 
858
        if_nametoindex = (ctypes.cdll.LoadLibrary
 
 
859
                          (ctypes.util.find_library("c"))
 
 
861
    except (OSError, AttributeError):
 
 
862
        if "struct" not in sys.modules:
 
 
864
        if "fcntl" not in sys.modules:
 
 
866
        def if_nametoindex(interface):
 
 
867
            "Get an interface index the hard way, i.e. using fcntl()"
 
 
868
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
 
 
869
            with closing(socket.socket()) as s:
 
 
870
                ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
 
871
                                    struct.pack("16s16x", interface))
 
 
872
            interface_index = struct.unpack("I", ifreq[16:20])[0]
 
 
873
            return interface_index
 
 
874
    return if_nametoindex(interface)
 
 
877
def daemon(nochdir = False, noclose = False):
 
 
878
    """See daemon(3).  Standard BSD Unix function.
 
 
879
    This should really exist as os.daemon, but it doesn't (yet)."""
 
 
888
        # Close all standard open file descriptors
 
 
889
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
 
890
        if not stat.S_ISCHR(os.fstat(null).st_mode):
 
 
891
            raise OSError(errno.ENODEV,
 
 
892
                          "/dev/null not a character device")
 
 
893
        os.dup2(null, sys.stdin.fileno())
 
 
894
        os.dup2(null, sys.stdout.fileno())
 
 
895
        os.dup2(null, sys.stderr.fileno())
 
 
901
    parser = optparse.OptionParser(version = "%%prog %s" % version)
 
 
902
    parser.add_option("-i", "--interface", type="string",
 
 
903
                      metavar="IF", help="Bind to interface IF")
 
 
904
    parser.add_option("-a", "--address", type="string",
 
 
905
                      help="Address to listen for requests on")
 
 
906
    parser.add_option("-p", "--port", type="int",
 
 
907
                      help="Port number to receive requests on")
 
 
908
    parser.add_option("--check", action="store_true",
 
 
909
                      help="Run self-test")
 
 
910
    parser.add_option("--debug", action="store_true",
 
 
911
                      help="Debug mode; run in foreground and log to"
 
 
913
    parser.add_option("--priority", type="string", help="GnuTLS"
 
 
914
                      " priority string (see GnuTLS documentation)")
 
 
915
    parser.add_option("--servicename", type="string", metavar="NAME",
 
 
916
                      help="Zeroconf service name")
 
 
917
    parser.add_option("--configdir", type="string",
 
 
918
                      default="/etc/mandos", metavar="DIR",
 
 
919
                      help="Directory to search for configuration"
 
 
921
    parser.add_option("--no-dbus", action="store_false",
 
 
923
                      help="Do not provide D-Bus system bus"
 
 
925
    options = parser.parse_args()[0]
 
 
932
    # Default values for config file for server-global settings
 
 
933
    server_defaults = { "interface": "",
 
 
938
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
 
 
939
                        "servicename": "Mandos",
 
 
943
    # Parse config file for server-global settings
 
 
944
    server_config = ConfigParser.SafeConfigParser(server_defaults)
 
 
946
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
 
947
    # Convert the SafeConfigParser object to a dict
 
 
948
    server_settings = server_config.defaults()
 
 
949
    # Use the appropriate methods on the non-string config options
 
 
950
    server_settings["debug"] = server_config.getboolean("DEFAULT",
 
 
952
    server_settings["use_dbus"] = server_config.getboolean("DEFAULT",
 
 
954
    if server_settings["port"]:
 
 
955
        server_settings["port"] = server_config.getint("DEFAULT",
 
 
959
    # Override the settings from the config file with command line
 
 
961
    for option in ("interface", "address", "port", "debug",
 
 
962
                   "priority", "servicename", "configdir",
 
 
964
        value = getattr(options, option)
 
 
965
        if value is not None:
 
 
966
            server_settings[option] = value
 
 
968
    # Now we have our good server settings in "server_settings"
 
 
971
    debug = server_settings["debug"]
 
 
972
    use_dbus = server_settings["use_dbus"]
 
 
974
    def sigsegvhandler(signum, frame):
 
 
975
        raise RuntimeError('Segmentation fault')
 
 
978
        syslogger.setLevel(logging.WARNING)
 
 
979
        console.setLevel(logging.WARNING)
 
 
981
        signal.signal(signal.SIGSEGV, sigsegvhandler)
 
 
983
    if server_settings["servicename"] != "Mandos":
 
 
984
        syslogger.setFormatter(logging.Formatter
 
 
985
                               ('Mandos (%s): %%(levelname)s:'
 
 
987
                                % server_settings["servicename"]))
 
 
989
    # Parse config file with clients
 
 
990
    client_defaults = { "timeout": "1h",
 
 
992
                        "checker": "fping -q -- %%(host)s",
 
 
995
    client_config = ConfigParser.SafeConfigParser(client_defaults)
 
 
996
    client_config.read(os.path.join(server_settings["configdir"],
 
 
1000
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
 
1001
                                 server_settings["port"]),
 
 
1003
                                settings=server_settings,
 
 
1005
    pidfilename = "/var/run/mandos.pid"
 
 
1007
        pidfile = open(pidfilename, "w")
 
 
1008
    except IOError, error:
 
 
1009
        logger.error("Could not open file %r", pidfilename)
 
 
1012
        uid = pwd.getpwnam("_mandos").pw_uid
 
 
1013
        gid = pwd.getpwnam("_mandos").pw_gid
 
 
1016
            uid = pwd.getpwnam("mandos").pw_uid
 
 
1017
            gid = pwd.getpwnam("mandos").pw_gid
 
 
1020
                uid = pwd.getpwnam("nobody").pw_uid
 
 
1021
                gid = pwd.getpwnam("nogroup").pw_gid
 
 
1028
    except OSError, error:
 
 
1029
        if error[0] != errno.EPERM:
 
 
1032
    # Enable all possible GnuTLS debugging
 
 
1034
        # "Use a log level over 10 to enable all debugging options."
 
 
1036
        gnutls.library.functions.gnutls_global_set_log_level(11)
 
 
1038
        @gnutls.library.types.gnutls_log_func
 
 
1039
        def debug_gnutls(level, string):
 
 
1040
            logger.debug("GnuTLS: %s", string[:-1])
 
 
1042
        (gnutls.library.functions
 
 
1043
         .gnutls_global_set_log_function(debug_gnutls))
 
 
1046
    service = AvahiService(name = server_settings["servicename"],
 
 
1047
                           servicetype = "_mandos._tcp", )
 
 
1048
    if server_settings["interface"]:
 
 
1049
        service.interface = (if_nametoindex
 
 
1050
                             (server_settings["interface"]))
 
 
1055
    # From the Avahi example code
 
 
1056
    DBusGMainLoop(set_as_default=True )
 
 
1057
    main_loop = gobject.MainLoop()
 
 
1058
    bus = dbus.SystemBus()
 
 
1059
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
 
 
1060
                                           avahi.DBUS_PATH_SERVER),
 
 
1061
                            avahi.DBUS_INTERFACE_SERVER)
 
 
1062
    # End of Avahi example code
 
 
1064
        bus_name = dbus.service.BusName(u"se.bsnet.fukt.Mandos", bus)
 
 
1066
    clients.update(Set(Client(name = section,
 
 
1068
                              = dict(client_config.items(section)),
 
 
1069
                              use_dbus = use_dbus)
 
 
1070
                       for section in client_config.sections()))
 
 
1072
        logger.warning(u"No clients defined")
 
 
1075
        # Redirect stdin so all checkers get /dev/null
 
 
1076
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
 
1077
        os.dup2(null, sys.stdin.fileno())
 
 
1081
        # No console logging
 
 
1082
        logger.removeHandler(console)
 
 
1083
        # Close all input and output, do double fork, etc.
 
 
1088
        pidfile.write(str(pid) + "\n")
 
 
1092
        logger.error(u"Could not write to file %r with PID %d",
 
 
1095
        # "pidfile" was never created
 
 
1100
        "Cleanup function; run on exit"
 
 
1102
        # From the Avahi example code
 
 
1103
        if not group is None:
 
 
1106
        # End of Avahi example code
 
 
1109
            client = clients.pop()
 
 
1110
            client.disable_hook = None
 
 
1113
    atexit.register(cleanup)
 
 
1116
        signal.signal(signal.SIGINT, signal.SIG_IGN)
 
 
1117
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
 
 
1118
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
 
 
1121
        class MandosServer(dbus.service.Object):
 
 
1122
            """A D-Bus proxy object"""
 
 
1124
                dbus.service.Object.__init__(self, bus, "/")
 
 
1125
            _interface = u"se.bsnet.fukt.Mandos"
 
 
1127
            @dbus.service.signal(_interface, signature="oa{sv}")
 
 
1128
            def ClientAdded(self, objpath, properties):
 
 
1132
            @dbus.service.signal(_interface, signature="os")
 
 
1133
            def ClientRemoved(self, objpath, name):
 
 
1137
            @dbus.service.method(_interface, out_signature="ao")
 
 
1138
            def GetAllClients(self):
 
 
1140
                return dbus.Array(c.dbus_object_path for c in clients)
 
 
1142
            @dbus.service.method(_interface, out_signature="a{oa{sv}}")
 
 
1143
            def GetAllClientsWithProperties(self):
 
 
1145
                return dbus.Dictionary(
 
 
1146
                    ((c.dbus_object_path, c.GetAllProperties())
 
 
1150
            @dbus.service.method(_interface, in_signature="o")
 
 
1151
            def RemoveClient(self, object_path):
 
 
1154
                    if c.dbus_object_path == object_path:
 
 
1156
                        # Don't signal anything except ClientRemoved
 
 
1160
                        self.ClientRemoved(object_path, c.name)
 
 
1166
        mandos_server = MandosServer()
 
 
1168
    for client in clients:
 
 
1171
            mandos_server.ClientAdded(client.dbus_object_path,
 
 
1172
                                      client.GetAllProperties())
 
 
1176
    tcp_server.server_activate()
 
 
1178
    # Find out what port we got
 
 
1179
    service.port = tcp_server.socket.getsockname()[1]
 
 
1180
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
 
 
1181
                u" scope_id %d" % tcp_server.socket.getsockname())
 
 
1183
    #service.interface = tcp_server.socket.getsockname()[3]
 
 
1186
        # From the Avahi example code
 
 
1187
        server.connect_to_signal("StateChanged", server_state_changed)
 
 
1189
            server_state_changed(server.GetState())
 
 
1190
        except dbus.exceptions.DBusException, error:
 
 
1191
            logger.critical(u"DBusException: %s", error)
 
 
1193
        # End of Avahi example code
 
 
1195
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
 
1196
                             lambda *args, **kwargs:
 
 
1197
                             (tcp_server.handle_request
 
 
1198
                              (*args[2:], **kwargs) or True))
 
 
1200
        logger.debug(u"Starting main loop")
 
 
1202
    except AvahiError, error:
 
 
1203
        logger.critical(u"AvahiError: %s", error)
 
 
1205
    except KeyboardInterrupt:
 
 
1209
if __name__ == '__main__':