169
170
# End of Avahi example code
 
172
 
class Client(object):
 
 
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):
 
173
179
    """A representation of a client host served by this server.
 
175
 
    name:      string; from the config file, used in log messages
 
 
181
    name:       string; from the config file, used in log messages
 
176
182
    fingerprint: string (40 or 32 hexadecimal digits); used to
 
177
183
                 uniquely identify the client
 
178
 
    secret:    bytestring; sent verbatim (over TLS) to client
 
179
 
    host:      string; available for use by the checker command
 
180
 
    created:   datetime.datetime(); object creation, not client host
 
181
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
 
182
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
 
183
 
                                     until this client is invalid
 
184
 
    interval:  datetime.timedelta(); How often to start a new checker
 
185
 
    stop_hook: If set, called by stop() as stop_hook(self)
 
186
 
    checker:   subprocess.Popen(); a running checker process used
 
187
 
                                   to see if the client lives.
 
188
 
                                   'None' if no process is running.
 
 
184
    secret:     bytestring; sent verbatim (over TLS) to client
 
 
185
    host:       string; available for use by the checker command
 
 
186
    created:    datetime.datetime(); (UTC) object creation
 
 
187
    last_enabled: datetime.datetime(); (UTC)
 
 
189
    last_checked_ok: datetime.datetime(); (UTC) or None
 
 
190
    timeout:    datetime.timedelta(); How long from last_checked_ok
 
 
191
                                      until this client is invalid
 
 
192
    interval:   datetime.timedelta(); How often to start a new checker
 
 
193
    disable_hook:  If set, called by disable() as disable_hook(self)
 
 
194
    checker:    subprocess.Popen(); a running checker process used
 
 
195
                                    to see if the client lives.
 
 
196
                                    'None' if no process is running.
 
189
197
    checker_initiator_tag: a gobject event source tag, or None
 
190
 
    stop_initiator_tag:    - '' -
 
 
198
    disable_initiator_tag:    - '' -
 
191
199
    checker_callback_tag:  - '' -
 
192
200
    checker_command: string; External command which is run to check if
 
193
201
                     client lives.  %() expansions are done at
 
194
202
                     runtime with vars(self) as dict, so that for
 
195
203
                     instance %(name)s can be used in the command.
 
197
 
    _timeout: Real variable for 'timeout'
 
198
 
    _interval: Real variable for 'interval'
 
199
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
200
 
    _interval_milliseconds: - '' -
 
 
204
    use_dbus: bool(); Whether to provide D-Bus interface and signals
 
 
205
    dbus_object_path: dbus.ObjectPath ; only set if self.use_dbus
 
202
 
    def _set_timeout(self, timeout):
 
203
 
        "Setter function for 'timeout' attribute"
 
204
 
        self._timeout = timeout
 
205
 
        self._timeout_milliseconds = ((self.timeout.days
 
206
 
                                       * 24 * 60 * 60 * 1000)
 
207
 
                                      + (self.timeout.seconds * 1000)
 
208
 
                                      + (self.timeout.microseconds
 
210
 
    timeout = property(lambda self: self._timeout,
 
213
 
    def _set_interval(self, interval):
 
214
 
        "Setter function for 'interval' attribute"
 
215
 
        self._interval = interval
 
216
 
        self._interval_milliseconds = ((self.interval.days
 
217
 
                                        * 24 * 60 * 60 * 1000)
 
218
 
                                       + (self.interval.seconds
 
220
 
                                       + (self.interval.microseconds
 
222
 
    interval = property(lambda self: self._interval,
 
225
 
    def __init__(self, name = None, stop_hook=None, config={}):
 
 
207
    def timeout_milliseconds(self):
 
 
208
        "Return the 'timeout' attribute in milliseconds"
 
 
209
        return ((self.timeout.days * 24 * 60 * 60 * 1000)
 
 
210
                + (self.timeout.seconds * 1000)
 
 
211
                + (self.timeout.microseconds // 1000))
 
 
213
    def interval_milliseconds(self):
 
 
214
        "Return the 'interval' attribute in milliseconds"
 
 
215
        return ((self.interval.days * 24 * 60 * 60 * 1000)
 
 
216
                + (self.interval.seconds * 1000)
 
 
217
                + (self.interval.microseconds // 1000))
 
 
219
    def __init__(self, name = None, disable_hook=None, config=None,
 
226
221
        """Note: the 'checker' key in 'config' sets the
 
227
222
        'checker_command' attribute and *not* the 'checker'
 
230
227
        logger.debug(u"Creating client %r", self.name)
 
 
228
        self.use_dbus = use_dbus
 
 
230
            self.dbus_object_path = (dbus.ObjectPath
 
 
232
                                      + self.name.replace(".", "_")))
 
 
233
            dbus.service.Object.__init__(self, bus,
 
 
234
                                         self.dbus_object_path)
 
231
235
        # Uppercase and remove spaces from fingerprint for later
 
232
236
        # comparison purposes with return value from the fingerprint()
 
234
 
        self.fingerprint = config["fingerprint"].upper()\
 
 
238
        self.fingerprint = (config["fingerprint"].upper()
 
236
240
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
 
237
241
        if "secret" in config:
 
238
242
            self.secret = config["secret"].decode(u"base64")
 
239
243
        elif "secfile" in config:
 
240
 
            sf = open(config["secfile"])
 
241
 
            self.secret = sf.read()
 
 
244
            with closing(open(os.path.expanduser
 
 
246
                               (config["secfile"])))) as secfile:
 
 
247
                self.secret = secfile.read()
 
244
249
            raise TypeError(u"No secret or secfile for client %s"
 
246
251
        self.host = config.get("host", "")
 
247
 
        self.created = datetime.datetime.now()
 
 
252
        self.created = datetime.datetime.utcnow()
 
 
254
        self.last_enabled = None
 
248
255
        self.last_checked_ok = None
 
249
256
        self.timeout = string_to_delta(config["timeout"])
 
250
257
        self.interval = string_to_delta(config["interval"])
 
251
 
        self.stop_hook = stop_hook
 
 
258
        self.disable_hook = disable_hook
 
252
259
        self.checker = None
 
253
260
        self.checker_initiator_tag = None
 
254
 
        self.stop_initiator_tag = None
 
 
261
        self.disable_initiator_tag = None
 
255
262
        self.checker_callback_tag = None
 
256
 
        self.check_command = config["checker"]
 
 
263
        self.checker_command = config["checker"]
 
258
266
        """Start this client's checker and timeout hooks"""
 
 
267
        self.last_enabled = datetime.datetime.utcnow()
 
259
268
        # Schedule a new checker to be started an 'interval' from now,
 
260
269
        # and every interval from then on.
 
261
 
        self.checker_initiator_tag = gobject.timeout_add\
 
262
 
                                     (self._interval_milliseconds,
 
 
270
        self.checker_initiator_tag = (gobject.timeout_add
 
 
271
                                      (self.interval_milliseconds(),
 
264
273
        # Also start a new checker *right now*.
 
265
274
        self.start_checker()
 
266
 
        # Schedule a stop() when 'timeout' has passed
 
267
 
        self.stop_initiator_tag = gobject.timeout_add\
 
268
 
                                  (self._timeout_milliseconds,
 
272
 
        The possibility that a client might be restarted is left open,
 
273
 
        but not currently used."""
 
274
 
        # If this client doesn't have a secret, it is already stopped.
 
275
 
        if hasattr(self, "secret") and self.secret:
 
276
 
            logger.info(u"Stopping client %s", self.name)
 
 
275
        # Schedule a disable() when 'timeout' has passed
 
 
276
        self.disable_initiator_tag = (gobject.timeout_add
 
 
277
                                   (self.timeout_milliseconds(),
 
 
282
            self.PropertyChanged(dbus.String(u"enabled"),
 
 
283
                                 dbus.Boolean(True, variant_level=1))
 
 
284
            self.PropertyChanged(dbus.String(u"last_enabled"),
 
 
285
                                 (_datetime_to_dbus(self.last_enabled,
 
 
289
        """Disable this client."""
 
 
290
        if not getattr(self, "enabled", False):
 
280
 
        if getattr(self, "stop_initiator_tag", False):
 
281
 
            gobject.source_remove(self.stop_initiator_tag)
 
282
 
            self.stop_initiator_tag = None
 
 
292
        logger.info(u"Disabling client %s", self.name)
 
 
293
        if getattr(self, "disable_initiator_tag", False):
 
 
294
            gobject.source_remove(self.disable_initiator_tag)
 
 
295
            self.disable_initiator_tag = None
 
283
296
        if getattr(self, "checker_initiator_tag", False):
 
284
297
            gobject.source_remove(self.checker_initiator_tag)
 
285
298
            self.checker_initiator_tag = None
 
286
299
        self.stop_checker()
 
 
300
        if self.disable_hook:
 
 
301
            self.disable_hook(self)
 
 
305
            self.PropertyChanged(dbus.String(u"enabled"),
 
 
306
                                 dbus.Boolean(False, variant_level=1))
 
289
307
        # Do not run this again if called by a gobject.timeout_add
 
291
310
    def __del__(self):
 
292
 
        self.stop_hook = None
 
294
 
    def checker_callback(self, pid, condition):
 
 
311
        self.disable_hook = None
 
 
314
    def checker_callback(self, pid, condition, command):
 
295
315
        """The checker has completed, so take appropriate actions."""
 
296
 
        now = datetime.datetime.now()
 
297
316
        self.checker_callback_tag = None
 
298
317
        self.checker = None
 
299
 
        if os.WIFEXITED(condition) \
 
300
 
               and (os.WEXITSTATUS(condition) == 0):
 
 
320
            self.PropertyChanged(dbus.String(u"checker_running"),
 
 
321
                                 dbus.Boolean(False, variant_level=1))
 
 
322
        if (os.WIFEXITED(condition)
 
 
323
            and (os.WEXITSTATUS(condition) == 0)):
 
301
324
            logger.info(u"Checker for %(name)s succeeded",
 
303
 
            self.last_checked_ok = now
 
304
 
            gobject.source_remove(self.stop_initiator_tag)
 
305
 
            self.stop_initiator_tag = gobject.timeout_add\
 
306
 
                                      (self._timeout_milliseconds,
 
 
328
                self.CheckerCompleted(dbus.Boolean(True),
 
 
329
                                      dbus.UInt16(condition),
 
 
330
                                      dbus.String(command))
 
308
332
        elif not os.WIFEXITED(condition):
 
309
333
            logger.warning(u"Checker for %(name)s crashed?",
 
 
337
                self.CheckerCompleted(dbus.Boolean(False),
 
 
338
                                      dbus.UInt16(condition),
 
 
339
                                      dbus.String(command))
 
312
341
            logger.info(u"Checker for %(name)s failed",
 
 
345
                self.CheckerCompleted(dbus.Boolean(False),
 
 
346
                                      dbus.UInt16(condition),
 
 
347
                                      dbus.String(command))
 
 
349
    def bump_timeout(self):
 
 
350
        """Bump up the timeout for this client.
 
 
351
        This should only be called when the client has been seen,
 
 
354
        self.last_checked_ok = datetime.datetime.utcnow()
 
 
355
        gobject.source_remove(self.disable_initiator_tag)
 
 
356
        self.disable_initiator_tag = (gobject.timeout_add
 
 
357
                                      (self.timeout_milliseconds(),
 
 
361
            self.PropertyChanged(
 
 
362
                dbus.String(u"last_checked_ok"),
 
 
363
                (_datetime_to_dbus(self.last_checked_ok,
 
314
366
    def start_checker(self):
 
315
367
        """Start a new checker subprocess if one is not running.
 
316
368
        If a checker already exists, leave it running and do
 
 
373
433
            if error.errno != errno.ESRCH: # No such process
 
375
435
        self.checker = None
 
 
437
            self.PropertyChanged(dbus.String(u"checker_running"),
 
 
438
                                 dbus.Boolean(False, variant_level=1))
 
376
440
    def still_valid(self):
 
377
441
        """Has the timeout not yet passed for this client?"""
 
378
 
        now = datetime.datetime.now()
 
 
442
        if not getattr(self, "enabled", False):
 
 
444
        now = datetime.datetime.utcnow()
 
379
445
        if self.last_checked_ok is None:
 
380
446
            return now < (self.created + self.timeout)
 
382
448
            return now < (self.last_checked_ok + self.timeout)
 
 
450
    ## D-Bus methods & signals
 
 
451
    _interface = u"org.mandos_system.Mandos.Client"
 
 
453
    # BumpTimeout - method
 
 
454
    BumpTimeout = dbus.service.method(_interface)(bump_timeout)
 
 
455
    BumpTimeout.__name__ = "BumpTimeout"
 
 
457
    # CheckerCompleted - signal
 
 
458
    @dbus.service.signal(_interface, signature="bqs")
 
 
459
    def CheckerCompleted(self, success, condition, command):
 
 
463
    # CheckerStarted - signal
 
 
464
    @dbus.service.signal(_interface, signature="s")
 
 
465
    def CheckerStarted(self, command):
 
 
469
    # GetAllProperties - method
 
 
470
    @dbus.service.method(_interface, out_signature="a{sv}")
 
 
471
    def GetAllProperties(self):
 
 
473
        return dbus.Dictionary({
 
 
475
                    dbus.String(self.name, variant_level=1),
 
 
476
                dbus.String("fingerprint"):
 
 
477
                    dbus.String(self.fingerprint, variant_level=1),
 
 
479
                    dbus.String(self.host, variant_level=1),
 
 
480
                dbus.String("created"):
 
 
481
                    _datetime_to_dbus(self.created, variant_level=1),
 
 
482
                dbus.String("last_enabled"):
 
 
483
                    (_datetime_to_dbus(self.last_enabled,
 
 
485
                     if self.last_enabled is not None
 
 
486
                     else dbus.Boolean(False, variant_level=1)),
 
 
487
                dbus.String("enabled"):
 
 
488
                    dbus.Boolean(self.enabled, variant_level=1),
 
 
489
                dbus.String("last_checked_ok"):
 
 
490
                    (_datetime_to_dbus(self.last_checked_ok,
 
 
492
                     if self.last_checked_ok is not None
 
 
493
                     else dbus.Boolean (False, variant_level=1)),
 
 
494
                dbus.String("timeout"):
 
 
495
                    dbus.UInt64(self.timeout_milliseconds(),
 
 
497
                dbus.String("interval"):
 
 
498
                    dbus.UInt64(self.interval_milliseconds(),
 
 
500
                dbus.String("checker"):
 
 
501
                    dbus.String(self.checker_command,
 
 
503
                dbus.String("checker_running"):
 
 
504
                    dbus.Boolean(self.checker is not None,
 
 
508
    # IsStillValid - method
 
 
509
    IsStillValid = (dbus.service.method(_interface, out_signature="b")
 
 
511
    IsStillValid.__name__ = "IsStillValid"
 
 
513
    # PropertyChanged - signal
 
 
514
    @dbus.service.signal(_interface, signature="sv")
 
 
515
    def PropertyChanged(self, property, value):
 
 
519
    # SetChecker - method
 
 
520
    @dbus.service.method(_interface, in_signature="s")
 
 
521
    def SetChecker(self, checker):
 
 
522
        "D-Bus setter method"
 
 
523
        self.checker_command = checker
 
 
525
        self.PropertyChanged(dbus.String(u"checker"),
 
 
526
                             dbus.String(self.checker_command,
 
 
530
    @dbus.service.method(_interface, in_signature="s")
 
 
531
    def SetHost(self, host):
 
 
532
        "D-Bus setter method"
 
 
535
        self.PropertyChanged(dbus.String(u"host"),
 
 
536
                             dbus.String(self.host, variant_level=1))
 
 
538
    # SetInterval - method
 
 
539
    @dbus.service.method(_interface, in_signature="t")
 
 
540
    def SetInterval(self, milliseconds):
 
 
541
        self.interval = datetime.timedelta(0, 0, 0, milliseconds)
 
 
543
        self.PropertyChanged(dbus.String(u"interval"),
 
 
544
                             (dbus.UInt64(self.interval_milliseconds(),
 
 
548
    @dbus.service.method(_interface, in_signature="ay",
 
 
550
    def SetSecret(self, secret):
 
 
551
        "D-Bus setter method"
 
 
552
        self.secret = str(secret)
 
 
554
    # SetTimeout - method
 
 
555
    @dbus.service.method(_interface, in_signature="t")
 
 
556
    def SetTimeout(self, milliseconds):
 
 
557
        self.timeout = datetime.timedelta(0, 0, 0, milliseconds)
 
 
559
        self.PropertyChanged(dbus.String(u"timeout"),
 
 
560
                             (dbus.UInt64(self.timeout_milliseconds(),
 
 
564
    Enable = dbus.service.method(_interface)(enable)
 
 
565
    Enable.__name__ = "Enable"
 
 
567
    # StartChecker - method
 
 
568
    @dbus.service.method(_interface)
 
 
569
    def StartChecker(self):
 
 
574
    @dbus.service.method(_interface)
 
 
579
    # StopChecker - method
 
 
580
    StopChecker = dbus.service.method(_interface)(stop_checker)
 
 
581
    StopChecker.__name__ = "StopChecker"
 
385
586
def peer_certificate(session):
 
386
587
    "Return the peer's OpenPGP certificate as a bytestring"
 
387
588
    # If not an OpenPGP certificate...
 
388
 
    if gnutls.library.functions.gnutls_certificate_type_get\
 
389
 
            (session._c_object) \
 
390
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
 
 
589
    if (gnutls.library.functions
 
 
590
        .gnutls_certificate_type_get(session._c_object)
 
 
591
        != gnutls.library.constants.GNUTLS_CRT_OPENPGP):
 
391
592
        # ...do the normal thing
 
392
593
        return session.peer_certificate
 
393
594
    list_size = ctypes.c_uint()
 
394
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
 
395
 
        (session._c_object, ctypes.byref(list_size))
 
 
595
    cert_list = (gnutls.library.functions
 
 
596
                 .gnutls_certificate_get_peers
 
 
597
                 (session._c_object, ctypes.byref(list_size)))
 
396
598
    if list_size.value == 0:
 
398
600
    cert = cert_list[0]
 
 
402
604
def fingerprint(openpgp):
 
403
605
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
404
606
    # New GnuTLS "datum" with the OpenPGP public key
 
405
 
    datum = gnutls.library.types.gnutls_datum_t\
 
406
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
 
407
 
                     ctypes.POINTER(ctypes.c_ubyte)),
 
408
 
         ctypes.c_uint(len(openpgp)))
 
 
607
    datum = (gnutls.library.types
 
 
608
             .gnutls_datum_t(ctypes.cast(ctypes.c_char_p(openpgp),
 
 
611
                             ctypes.c_uint(len(openpgp))))
 
409
612
    # New empty GnuTLS certificate
 
410
613
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
411
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
 
614
    (gnutls.library.functions
 
 
615
     .gnutls_openpgp_crt_init(ctypes.byref(crt)))
 
413
616
    # Import the OpenPGP public key into the certificate
 
414
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
 
415
 
                    (crt, ctypes.byref(datum),
 
416
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
 
617
    (gnutls.library.functions
 
 
618
     .gnutls_openpgp_crt_import(crt, ctypes.byref(datum),
 
 
619
                                gnutls.library.constants
 
 
620
                                .GNUTLS_OPENPGP_FMT_RAW))
 
417
621
    # Verify the self signature in the key
 
418
 
    crtverify = ctypes.c_uint();
 
419
 
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
 
420
 
        (crt, 0, ctypes.byref(crtverify))
 
 
622
    crtverify = ctypes.c_uint()
 
 
623
    (gnutls.library.functions
 
 
624
     .gnutls_openpgp_crt_verify_self(crt, 0, ctypes.byref(crtverify)))
 
421
625
    if crtverify.value != 0:
 
422
626
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
423
627
        raise gnutls.errors.CertificateSecurityError("Verify failed")
 
424
628
    # New buffer for the fingerprint
 
425
 
    buffer = ctypes.create_string_buffer(20)
 
426
 
    buffer_length = ctypes.c_size_t()
 
 
629
    buf = ctypes.create_string_buffer(20)
 
 
630
    buf_len = ctypes.c_size_t()
 
427
631
    # Get the fingerprint from the certificate into the buffer
 
428
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
 
429
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
 
 
632
    (gnutls.library.functions
 
 
633
     .gnutls_openpgp_crt_get_fingerprint(crt, ctypes.byref(buf),
 
 
634
                                         ctypes.byref(buf_len)))
 
430
635
    # Deinit the certificate
 
431
636
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
432
637
    # Convert the buffer to a Python bytestring
 
433
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
 
 
638
    fpr = ctypes.string_at(buf, buf_len.value)
 
434
639
    # Convert the bytestring to hexadecimal notation
 
435
640
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
 
439
 
class tcp_handler(SocketServer.BaseRequestHandler, object):
 
 
644
class TCP_handler(SocketServer.BaseRequestHandler, object):
 
440
645
    """A TCP request handler class.
 
441
646
    Instantiated by IPv6_TCPServer for each request to handle it.
 
442
647
    Note: This will run in its own forked process."""
 
444
649
    def handle(self):
 
445
650
        logger.info(u"TCP connection from: %s",
 
446
 
                     unicode(self.client_address))
 
447
 
        session = gnutls.connection.ClientSession\
 
448
 
                  (self.request, gnutls.connection.X509Credentials())
 
 
651
                    unicode(self.client_address))
 
 
652
        session = (gnutls.connection
 
 
653
                   .ClientSession(self.request,
 
450
657
        line = self.request.makefile().readline()
 
451
658
        logger.debug(u"Protocol version: %r", line)