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  • Committer: Teddy Hogeborn
  • Date: 2008-08-11 08:04:35 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080811080435-7qfkwv5g43ww5h9x
* plugins.d/password-request.c (main): Bug fix: Bring up network
                                       interface *before* dropping
                                       privileges.

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Lines of Context:
mandos
11
11
# and some lines in "main".
12
12
# 
13
13
# Everything else is
14
 
# Copyright © 2008 Teddy Hogeborn & Björn Påhlsson
 
14
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
15
15
# 
16
16
# This program is free software: you can redistribute it and/or modify
17
17
# it under the terms of the GNU General Public License as published by
24
24
#     GNU General Public License for more details.
25
25
# 
26
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/>.
 
27
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
29
28
# 
30
29
# Contact the authors at <mandos@fukt.bsnet.se>.
31
30
# 
32
31
 
33
 
from __future__ import division, with_statement, absolute_import
 
32
from __future__ import division
34
33
 
35
34
import SocketServer
36
35
import socket
 
36
import select
37
37
from optparse import OptionParser
38
38
import datetime
39
39
import errno
54
54
import stat
55
55
import logging
56
56
import logging.handlers
57
 
import pwd
58
 
from contextlib import closing
59
57
 
60
58
import dbus
61
59
import gobject
62
60
import avahi
63
61
from dbus.mainloop.glib import DBusGMainLoop
64
62
import ctypes
65
 
import ctypes.util
66
63
 
67
 
version = "1.0.2"
 
64
version = "1.0"
68
65
 
69
66
logger = logging.Logger('mandos')
70
67
syslogger = logging.handlers.SysLogHandler\
82
79
class AvahiError(Exception):
83
80
    def __init__(self, value):
84
81
        self.value = value
85
 
        super(AvahiError, self).__init__()
86
82
    def __str__(self):
87
83
        return repr(self.value)
88
84
 
110
106
                  a sensible number of times
111
107
    """
112
108
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
113
 
                 servicetype = None, port = None, TXT = None, domain = "",
 
109
                 type = None, port = None, TXT = None, domain = "",
114
110
                 host = "", max_renames = 32768):
115
111
        self.interface = interface
116
112
        self.name = name
117
 
        self.type = servicetype
 
113
        self.type = type
118
114
        self.port = port
119
115
        if TXT is None:
120
116
            self.TXT = []
123
119
        self.domain = domain
124
120
        self.host = host
125
121
        self.rename_count = 0
126
 
        self.max_renames = max_renames
127
122
    def rename(self):
128
123
        """Derived from the Avahi example code"""
129
124
        if self.rename_count >= self.max_renames:
130
 
            logger.critical(u"No suitable Zeroconf service name found"
131
 
                            u" after %i retries, exiting.",
132
 
                            self.rename_count)
 
125
            logger.critical(u"No suitable service name found after %i"
 
126
                            u" retries, exiting.", rename_count)
133
127
            raise AvahiServiceError("Too many renames")
134
 
        self.name = server.GetAlternativeServiceName(self.name)
135
 
        logger.info(u"Changing Zeroconf service name to %r ...",
136
 
                    str(self.name))
 
128
        name = server.GetAlternativeServiceName(name)
 
129
        logger.error(u"Changing name to %r ...", name)
137
130
        syslogger.setFormatter(logging.Formatter\
138
131
                               ('Mandos (%s): %%(levelname)s:'
139
 
                               ' %%(message)s' % self.name))
 
132
                               ' %%(message)s' % name))
140
133
        self.remove()
141
134
        self.add()
142
135
        self.rename_count += 1
154
147
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
155
148
            group.connect_to_signal('StateChanged',
156
149
                                    entry_group_state_changed)
157
 
        logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
 
150
        logger.debug(u"Adding service '%s' of type '%s' ...",
158
151
                     service.name, service.type)
159
152
        group.AddService(
160
153
                self.interface,         # interface
224
217
    interval = property(lambda self: self._interval,
225
218
                        _set_interval)
226
219
    del _set_interval
227
 
    def __init__(self, name = None, stop_hook=None, config=None):
 
220
    def __init__(self, name = None, stop_hook=None, config={}):
228
221
        """Note: the 'checker' key in 'config' sets the
229
222
        'checker_command' attribute and *not* the 'checker'
230
223
        attribute."""
231
 
        if config is None:
232
 
            config = {}
233
224
        self.name = name
234
225
        logger.debug(u"Creating client %r", self.name)
235
226
        # Uppercase and remove spaces from fingerprint for later
241
232
        if "secret" in config:
242
233
            self.secret = config["secret"].decode(u"base64")
243
234
        elif "secfile" in config:
244
 
            with closing(open(os.path.expanduser
245
 
                              (os.path.expandvars
246
 
                               (config["secfile"])))) \
247
 
                               as secfile:
248
 
                self.secret = secfile.read()
 
235
            sf = open(config["secfile"])
 
236
            self.secret = sf.read()
 
237
            sf.close()
249
238
        else:
250
239
            raise TypeError(u"No secret or secfile for client %s"
251
240
                            % self.name)
299
288
        self.stop()
300
289
    def checker_callback(self, pid, condition):
301
290
        """The checker has completed, so take appropriate actions."""
 
291
        now = datetime.datetime.now()
302
292
        self.checker_callback_tag = None
303
293
        self.checker = None
304
294
        if os.WIFEXITED(condition) \
305
295
               and (os.WEXITSTATUS(condition) == 0):
306
296
            logger.info(u"Checker for %(name)s succeeded",
307
297
                        vars(self))
308
 
            self.bump_timeout()
 
298
            self.last_checked_ok = now
 
299
            gobject.source_remove(self.stop_initiator_tag)
 
300
            self.stop_initiator_tag = gobject.timeout_add\
 
301
                                      (self._timeout_milliseconds,
 
302
                                       self.stop)
309
303
        elif not os.WIFEXITED(condition):
310
304
            logger.warning(u"Checker for %(name)s crashed?",
311
305
                           vars(self))
312
306
        else:
313
307
            logger.info(u"Checker for %(name)s failed",
314
308
                        vars(self))
315
 
    def bump_timeout(self):
316
 
        """Bump up the timeout for this client.
317
 
        This should only be called when the client has been seen,
318
 
        alive and well.
319
 
        """
320
 
        self.last_checked_ok = datetime.datetime.now()
321
 
        gobject.source_remove(self.stop_initiator_tag)
322
 
        self.stop_initiator_tag = gobject.timeout_add\
323
 
            (self._timeout_milliseconds, self.stop)
324
309
    def start_checker(self):
325
310
        """Start a new checker subprocess if one is not running.
326
311
        If a checker already exists, leave it running and do
351
336
            try:
352
337
                logger.info(u"Starting checker %r for %s",
353
338
                            command, self.name)
354
 
                # We don't need to redirect stdout and stderr, since
355
 
                # in normal mode, that is already done by daemon(),
356
 
                # and in debug mode we don't want to.  (Stdin is
357
 
                # always replaced by /dev/null.)
358
339
                self.checker = subprocess.Popen(command,
359
340
                                                close_fds=True,
360
341
                                                shell=True, cwd="/")
361
342
                self.checker_callback_tag = gobject.child_watch_add\
362
343
                                            (self.checker.pid,
363
344
                                             self.checker_callback)
364
 
            except OSError, error:
 
345
            except subprocess.OSError, error:
365
346
                logger.error(u"Failed to start subprocess: %s",
366
347
                             error)
367
348
        # Re-run this periodically if run by gobject.timeout_add
424
405
    gnutls.library.functions.gnutls_openpgp_crt_import\
425
406
                    (crt, ctypes.byref(datum),
426
407
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
427
 
    # Verify the self signature in the key
428
 
    crtverify = ctypes.c_uint()
429
 
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
430
 
        (crt, 0, ctypes.byref(crtverify))
431
 
    if crtverify.value != 0:
432
 
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
433
 
        raise gnutls.errors.CertificateSecurityError("Verify failed")
434
408
    # New buffer for the fingerprint
435
 
    buf = ctypes.create_string_buffer(20)
436
 
    buf_len = ctypes.c_size_t()
 
409
    buffer = ctypes.create_string_buffer(20)
 
410
    buffer_length = ctypes.c_size_t()
437
411
    # Get the fingerprint from the certificate into the buffer
438
412
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
439
 
        (crt, ctypes.byref(buf), ctypes.byref(buf_len))
 
413
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
440
414
    # Deinit the certificate
441
415
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
442
416
    # Convert the buffer to a Python bytestring
443
 
    fpr = ctypes.string_at(buf, buf_len.value)
 
417
    fpr = ctypes.string_at(buffer, buffer_length.value)
444
418
    # Convert the bytestring to hexadecimal notation
445
419
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
446
420
    return hex_fpr
447
421
 
448
422
 
449
 
class TCP_handler(SocketServer.BaseRequestHandler, object):
 
423
class tcp_handler(SocketServer.BaseRequestHandler, object):
450
424
    """A TCP request handler class.
451
425
    Instantiated by IPv6_TCPServer for each request to handle it.
452
426
    Note: This will run in its own forked process."""
453
427
    
454
428
    def handle(self):
455
429
        logger.info(u"TCP connection from: %s",
456
 
                    unicode(self.client_address))
 
430
                     unicode(self.client_address))
457
431
        session = gnutls.connection.ClientSession\
458
432
                  (self.request, gnutls.connection.X509Credentials())
459
433
        
474
448
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
475
449
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
476
450
        #                "+DHE-DSS"))
477
 
        # Use a fallback default, since this MUST be set.
478
 
        priority = self.server.settings.get("priority", "NORMAL")
 
451
        priority = "NORMAL"             # Fallback default, since this
 
452
                                        # MUST be set.
 
453
        if self.server.settings["priority"]:
 
454
            priority = self.server.settings["priority"]
479
455
        gnutls.library.functions.gnutls_priority_set_direct\
480
 
            (session._c_object, priority, None)
 
456
            (session._c_object, priority, None);
481
457
        
482
458
        try:
483
459
            session.handshake()
511
487
                           vars(client))
512
488
            session.bye()
513
489
            return
514
 
        ## This won't work here, since we're in a fork.
515
 
        # client.bump_timeout()
516
490
        sent_size = 0
517
491
        while sent_size < len(client.secret):
518
492
            sent = session.send(client.secret[sent_size:])
523
497
        session.bye()
524
498
 
525
499
 
526
 
class IPv6_TCPServer(SocketServer.ForkingMixIn,
527
 
                     SocketServer.TCPServer, object):
 
500
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
528
501
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
529
502
    Attributes:
530
503
        settings:       Server settings
531
504
        clients:        Set() of Client objects
532
 
        enabled:        Boolean; whether this server is activated yet
533
505
    """
534
506
    address_family = socket.AF_INET6
535
507
    def __init__(self, *args, **kwargs):
539
511
        if "clients" in kwargs:
540
512
            self.clients = kwargs["clients"]
541
513
            del kwargs["clients"]
542
 
        self.enabled = False
543
 
        super(IPv6_TCPServer, self).__init__(*args, **kwargs)
 
514
        return super(type(self), self).__init__(*args, **kwargs)
544
515
    def server_bind(self):
545
516
        """This overrides the normal server_bind() function
546
517
        to bind to an interface if one was specified, and also NOT to
575
546
#                                            if_nametoindex
576
547
#                                            (self.settings
577
548
#                                             ["interface"]))
578
 
            return super(IPv6_TCPServer, self).server_bind()
579
 
    def server_activate(self):
580
 
        if self.enabled:
581
 
            return super(IPv6_TCPServer, self).server_activate()
582
 
    def enable(self):
583
 
        self.enabled = True
 
549
            return super(type(self), self).server_bind()
584
550
 
585
551
 
586
552
def string_to_delta(interval):
596
562
    datetime.timedelta(1)
597
563
    >>> string_to_delta(u'1w')
598
564
    datetime.timedelta(7)
599
 
    >>> string_to_delta('5m 30s')
600
 
    datetime.timedelta(0, 330)
601
565
    """
602
 
    timevalue = datetime.timedelta(0)
603
 
    for s in interval.split():
604
 
        try:
605
 
            suffix = unicode(s[-1])
606
 
            value = int(s[:-1])
607
 
            if suffix == u"d":
608
 
                delta = datetime.timedelta(value)
609
 
            elif suffix == u"s":
610
 
                delta = datetime.timedelta(0, value)
611
 
            elif suffix == u"m":
612
 
                delta = datetime.timedelta(0, 0, 0, 0, value)
613
 
            elif suffix == u"h":
614
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
615
 
            elif suffix == u"w":
616
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
617
 
            else:
618
 
                raise ValueError
619
 
        except (ValueError, IndexError):
 
566
    try:
 
567
        suffix=unicode(interval[-1])
 
568
        value=int(interval[:-1])
 
569
        if suffix == u"d":
 
570
            delta = datetime.timedelta(value)
 
571
        elif suffix == u"s":
 
572
            delta = datetime.timedelta(0, value)
 
573
        elif suffix == u"m":
 
574
            delta = datetime.timedelta(0, 0, 0, 0, value)
 
575
        elif suffix == u"h":
 
576
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
577
        elif suffix == u"w":
 
578
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
579
        else:
620
580
            raise ValueError
621
 
        timevalue += delta
622
 
    return timevalue
 
581
    except (ValueError, IndexError):
 
582
        raise ValueError
 
583
    return delta
623
584
 
624
585
 
625
586
def server_state_changed(state):
626
587
    """Derived from the Avahi example code"""
627
588
    if state == avahi.SERVER_COLLISION:
628
 
        logger.error(u"Zeroconf server name collision")
 
589
        logger.error(u"Server name collision")
629
590
        service.remove()
630
591
    elif state == avahi.SERVER_RUNNING:
631
592
        service.add()
633
594
 
634
595
def entry_group_state_changed(state, error):
635
596
    """Derived from the Avahi example code"""
636
 
    logger.debug(u"Avahi state change: %i", state)
 
597
    logger.debug(u"state change: %i", state)
637
598
    
638
599
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
639
 
        logger.debug(u"Zeroconf service established.")
 
600
        logger.debug(u"Service established.")
640
601
    elif state == avahi.ENTRY_GROUP_COLLISION:
641
 
        logger.warning(u"Zeroconf service name collision.")
 
602
        logger.warning(u"Service name collision.")
642
603
        service.rename()
643
604
    elif state == avahi.ENTRY_GROUP_FAILURE:
644
 
        logger.critical(u"Avahi: Error in group state changed %s",
 
605
        logger.critical(u"Error in group state changed %s",
645
606
                        unicode(error))
646
607
        raise AvahiGroupError("State changed: %s", str(error))
647
608
 
649
610
    """Call the C function if_nametoindex(), or equivalent"""
650
611
    global if_nametoindex
651
612
    try:
 
613
        if "ctypes.util" not in sys.modules:
 
614
            import ctypes.util
652
615
        if_nametoindex = ctypes.cdll.LoadLibrary\
653
616
            (ctypes.util.find_library("c")).if_nametoindex
654
617
    except (OSError, AttributeError):
659
622
        def if_nametoindex(interface):
660
623
            "Get an interface index the hard way, i.e. using fcntl()"
661
624
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
662
 
            with closing(socket.socket()) as s:
663
 
                ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
664
 
                                    struct.pack("16s16x", interface))
 
625
            s = socket.socket()
 
626
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
627
                                struct.pack("16s16x", interface))
 
628
            s.close()
665
629
            interface_index = struct.unpack("I", ifreq[16:20])[0]
666
630
            return interface_index
667
631
    return if_nametoindex(interface)
691
655
 
692
656
 
693
657
def main():
 
658
    global main_loop_started
 
659
    main_loop_started = False
 
660
    
694
661
    parser = OptionParser(version = "%%prog %s" % version)
695
662
    parser.add_option("-i", "--interface", type="string",
696
663
                      metavar="IF", help="Bind to interface IF")
711
678
                      default="/etc/mandos", metavar="DIR",
712
679
                      help="Directory to search for configuration"
713
680
                      " files")
714
 
    options = parser.parse_args()[0]
 
681
    (options, args) = parser.parse_args()
715
682
    
716
683
    if options.check:
717
684
        import doctest
732
699
    server_config = ConfigParser.SafeConfigParser(server_defaults)
733
700
    del server_defaults
734
701
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
702
    server_section = "server"
735
703
    # Convert the SafeConfigParser object to a dict
736
 
    server_settings = server_config.defaults()
 
704
    server_settings = dict(server_config.items(server_section))
737
705
    # Use getboolean on the boolean config option
738
706
    server_settings["debug"] = server_config.getboolean\
739
 
                               ("DEFAULT", "debug")
 
707
                               (server_section, "debug")
740
708
    del server_config
741
709
    
742
710
    # Override the settings from the config file with command line
764
732
    # Parse config file with clients
765
733
    client_defaults = { "timeout": "1h",
766
734
                        "interval": "5m",
767
 
                        "checker": "fping -q -- %(host)s",
768
 
                        "host": "",
 
735
                        "checker": "fping -q -- %%(host)s",
769
736
                        }
770
737
    client_config = ConfigParser.SafeConfigParser(client_defaults)
771
738
    client_config.read(os.path.join(server_settings["configdir"],
772
739
                                    "clients.conf"))
773
740
    
774
 
    clients = Set()
775
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
776
 
                                 server_settings["port"]),
777
 
                                TCP_handler,
778
 
                                settings=server_settings,
779
 
                                clients=clients)
780
 
    pidfilename = "/var/run/mandos.pid"
781
 
    try:
782
 
        pidfile = open(pidfilename, "w")
783
 
    except IOError, error:
784
 
        logger.error("Could not open file %r", pidfilename)
785
 
    
786
 
    uid = 65534
787
 
    gid = 65534
788
 
    try:
789
 
        uid = pwd.getpwnam("mandos").pw_uid
790
 
    except KeyError:
791
 
        try:
792
 
            uid = pwd.getpwnam("nobody").pw_uid
793
 
        except KeyError:
794
 
            pass
795
 
    try:
796
 
        gid = pwd.getpwnam("mandos").pw_gid
797
 
    except KeyError:
798
 
        try:
799
 
            gid = pwd.getpwnam("nogroup").pw_gid
800
 
        except KeyError:
801
 
            pass
802
 
    try:
803
 
        os.setuid(uid)
804
 
        os.setgid(gid)
805
 
    except OSError, error:
806
 
        if error[0] != errno.EPERM:
807
 
            raise error
808
 
    
809
741
    global service
810
742
    service = AvahiService(name = server_settings["servicename"],
811
 
                           servicetype = "_mandos._tcp", )
 
743
                           type = "_mandos._tcp", );
812
744
    if server_settings["interface"]:
813
 
        service.interface = if_nametoindex\
814
 
                            (server_settings["interface"])
 
745
        service.interface = if_nametoindex(server_settings["interface"])
815
746
    
816
747
    global main_loop
817
748
    global bus
820
751
    DBusGMainLoop(set_as_default=True )
821
752
    main_loop = gobject.MainLoop()
822
753
    bus = dbus.SystemBus()
823
 
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
824
 
                                           avahi.DBUS_PATH_SERVER),
825
 
                            avahi.DBUS_INTERFACE_SERVER)
 
754
    server = dbus.Interface(
 
755
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
 
756
            avahi.DBUS_INTERFACE_SERVER )
826
757
    # End of Avahi example code
827
758
    
 
759
    clients = Set()
828
760
    def remove_from_clients(client):
829
761
        clients.remove(client)
830
762
        if not clients:
840
772
        logger.critical(u"No clients defined")
841
773
        sys.exit(1)
842
774
    
843
 
    if debug:
844
 
        # Redirect stdin so all checkers get /dev/null
845
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
846
 
        os.dup2(null, sys.stdin.fileno())
847
 
        if null > 2:
848
 
            os.close(null)
849
 
    else:
850
 
        # No console logging
 
775
    if not debug:
851
776
        logger.removeHandler(console)
852
 
        # Close all input and output, do double fork, etc.
853
777
        daemon()
854
778
    
 
779
    pidfilename = "/var/run/mandos/mandos.pid"
 
780
    pid = os.getpid()
855
781
    try:
856
 
        pid = os.getpid()
 
782
        pidfile = open(pidfilename, "w")
857
783
        pidfile.write(str(pid) + "\n")
858
784
        pidfile.close()
859
785
        del pidfile
860
 
    except IOError:
861
 
        logger.error(u"Could not write to file %r with PID %d",
862
 
                     pidfilename, pid)
863
 
    except NameError:
864
 
        # "pidfile" was never created
865
 
        pass
866
 
    del pidfilename
 
786
    except IOError, err:
 
787
        logger.error(u"Could not write %s file with PID %d",
 
788
                     pidfilename, os.getpid())
867
789
    
868
790
    def cleanup():
869
791
        "Cleanup function; run on exit"
889
811
    for client in clients:
890
812
        client.start()
891
813
    
892
 
    tcp_server.enable()
893
 
    tcp_server.server_activate()
894
 
    
 
814
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
815
                                 server_settings["port"]),
 
816
                                tcp_handler,
 
817
                                settings=server_settings,
 
818
                                clients=clients)
895
819
    # Find out what port we got
896
820
    service.port = tcp_server.socket.getsockname()[1]
897
821
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
915
839
                             (*args[2:], **kwargs) or True)
916
840
        
917
841
        logger.debug(u"Starting main loop")
 
842
        main_loop_started = True
918
843
        main_loop.run()
919
844
    except AvahiError, error:
920
845
        logger.critical(u"AvahiError: %s" + unicode(error))