6
6
# This program is partly derived from an example program for an Avahi
7
7
# service publisher, downloaded from
8
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".
9
# following functions: "AvahiService.add", "AvahiService.remove",
10
# "server_state_changed", "entry_group_state_changed", and some lines
13
13
# Everything else is
14
# Copyright © 2008 Teddy Hogeborn & Björn Påhlsson
14
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
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.
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/>.
30
29
# Contact the authors at <mandos@fukt.bsnet.se>.
56
56
import logging.handlers
62
61
from dbus.mainloop.glib import DBusGMainLoop
64
# Brief description of the operation of this program:
66
# This server announces itself as a Zeroconf service. Connecting
67
# clients use the TLS protocol, with the unusual quirk that this
68
# server program acts as a TLS "client" while a connecting client acts
69
# as a TLS "server". The client (acting as a TLS "server") must
70
# supply an OpenPGP certificate, and the fingerprint of this
71
# certificate is used by this server to look up (in a list read from a
72
# file at start time) which binary blob to give the client. No other
73
# authentication or authorization is done by this server.
68
76
logger = logging.Logger('mandos')
69
77
syslogger = logging.handlers.SysLogHandler\
70
(facility = logging.handlers.SysLogHandler.LOG_DAEMON,
78
(facility = logging.handlers.SysLogHandler.LOG_DAEMON)
72
79
syslogger.setFormatter(logging.Formatter\
73
('Mandos: %(levelname)s: %(message)s'))
80
('%(levelname)s: %(message)s'))
74
81
logger.addHandler(syslogger)
76
console = logging.StreamHandler()
77
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
79
logger.addHandler(console)
81
85
class AvahiError(Exception):
82
86
def __init__(self, value):
84
super(AvahiError, self).__init__()
86
89
return repr(self.value)
109
112
a sensible number of times
111
114
def __init__(self, interface = avahi.IF_UNSPEC, name = None,
112
servicetype = None, port = None, TXT = None, domain = "",
113
host = "", max_renames = 32768):
115
type = None, port = None, TXT = None, domain = "",
116
host = "", max_renames = 12):
114
117
self.interface = interface
116
self.type = servicetype
122
125
self.domain = domain
124
127
self.rename_count = 0
125
self.max_renames = max_renames
126
128
def rename(self):
127
129
"""Derived from the Avahi example code"""
128
130
if self.rename_count >= self.max_renames:
129
logger.critical(u"No suitable Zeroconf service name found"
130
u" after %i retries, exiting.",
131
logger.critical(u"No suitable service name found after %i"
132
u" retries, exiting.", rename_count)
132
133
raise AvahiServiceError("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))
134
name = server.GetAlternativeServiceName(name)
135
logger.error(u"Changing name to %r ...", name)
141
138
self.rename_count += 1
153
150
avahi.DBUS_INTERFACE_ENTRY_GROUP)
154
151
group.connect_to_signal('StateChanged',
155
152
entry_group_state_changed)
156
logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
153
logger.debug(u"Adding service '%s' of type '%s' ...",
157
154
service.name, service.type)
158
155
group.AddService(
159
156
self.interface, # interface
177
174
fingerprint: string (40 or 32 hexadecimal digits); used to
178
175
uniquely identify the client
179
176
secret: bytestring; sent verbatim (over TLS) to client
180
host: string; available for use by the checker command
177
fqdn: string (FQDN); available for use by the checker command
181
178
created: datetime.datetime(); object creation, not client host
182
179
last_checked_ok: datetime.datetime() or None if not yet checked OK
183
180
timeout: datetime.timedelta(); How long from last_checked_ok
223
220
interval = property(lambda self: self._interval,
225
222
del _set_interval
226
def __init__(self, name = None, stop_hook=None, config=None):
223
def __init__(self, name = None, stop_hook=None, config={}):
227
224
"""Note: the 'checker' key in 'config' sets the
228
225
'checker_command' attribute and *not* the 'checker'
233
228
logger.debug(u"Creating client %r", self.name)
234
229
# Uppercase and remove spaces from fingerprint for later
240
235
if "secret" in config:
241
236
self.secret = config["secret"].decode(u"base64")
242
237
elif "secfile" in config:
243
secfile = open(os.path.expanduser(os.path.expandvars
244
(config["secfile"])))
245
self.secret = secfile.read()
238
sf = open(config["secfile"])
239
self.secret = sf.read()
248
242
raise TypeError(u"No secret or secfile for client %s"
250
self.host = config.get("host", "")
244
self.fqdn = config.get("fqdn", "")
251
245
self.created = datetime.datetime.now()
252
246
self.last_checked_ok = None
253
247
self.timeout = string_to_delta(config["timeout"])
276
270
The possibility that a client might be restarted is left open,
277
271
but not currently used."""
278
272
# If this client doesn't have a secret, it is already stopped.
279
if hasattr(self, "secret") and self.secret:
280
274
logger.info(u"Stopping client %s", self.name)
281
275
self.secret = None
330
324
if self.checker is None:
332
326
# In case check_command has exactly one % operator
333
command = self.check_command % self.host
327
command = self.check_command % self.fqdn
334
328
except TypeError:
335
329
# Escape attributes for the shell
336
330
escaped_attrs = dict((key, re.escape(str(val)))
346
340
logger.info(u"Starting checker %r for %s",
347
341
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
342
self.checker = subprocess.Popen(command,
354
344
shell=True, cwd="/")
355
345
self.checker_callback_tag = gobject.child_watch_add\
356
346
(self.checker.pid,
357
347
self.checker_callback)
358
except OSError, error:
348
except subprocess.OSError, error:
359
349
logger.error(u"Failed to start subprocess: %s",
361
351
# Re-run this periodically if run by gobject.timeout_add
367
357
self.checker_callback_tag = None
368
358
if getattr(self, "checker", None) is None:
370
logger.debug(u"Stopping checker for %(name)s", vars(self))
360
logger.debug("Stopping checker for %(name)s", vars(self))
372
362
os.kill(self.checker.pid, signal.SIGTERM)
418
408
gnutls.library.functions.gnutls_openpgp_crt_import\
419
409
(crt, ctypes.byref(datum),
420
410
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
411
# New buffer for the fingerprint
429
buf = ctypes.create_string_buffer(20)
430
buf_len = ctypes.c_size_t()
412
buffer = ctypes.create_string_buffer(20)
413
buffer_length = ctypes.c_size_t()
431
414
# Get the fingerprint from the certificate into the buffer
432
415
gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
433
(crt, ctypes.byref(buf), ctypes.byref(buf_len))
416
(crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
434
417
# Deinit the certificate
435
418
gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
436
419
# Convert the buffer to a Python bytestring
437
fpr = ctypes.string_at(buf, buf_len.value)
420
fpr = ctypes.string_at(buffer, buffer_length.value)
438
421
# Convert the bytestring to hexadecimal notation
439
422
hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
443
class TCP_handler(SocketServer.BaseRequestHandler, object):
426
class tcp_handler(SocketServer.BaseRequestHandler, object):
444
427
"""A TCP request handler class.
445
428
Instantiated by IPv6_TCPServer for each request to handle it.
446
429
Note: This will run in its own forked process."""
473
456
if self.server.settings["priority"]:
474
457
priority = self.server.settings["priority"]
475
458
gnutls.library.functions.gnutls_priority_set_direct\
476
(session._c_object, priority, None)
459
(session._c_object, priority, None);
479
462
session.handshake()
523
506
settings: Server settings
524
507
clients: Set() of Client objects
525
enabled: Boolean; whether this server is activated yet
527
509
address_family = socket.AF_INET6
528
510
def __init__(self, *args, **kwargs):
532
514
if "clients" in kwargs:
533
515
self.clients = kwargs["clients"]
534
516
del kwargs["clients"]
536
super(IPv6_TCPServer, self).__init__(*args, **kwargs)
517
return super(type(self), self).__init__(*args, **kwargs)
537
518
def server_bind(self):
538
519
"""This overrides the normal server_bind() function
539
520
to bind to an interface if one was specified, and also NOT to
558
539
in6addr_any = "::"
559
540
self.server_address = (in6addr_any,
560
541
self.server_address[1])
561
elif not self.server_address[1]:
542
elif self.server_address[1] is None:
562
543
self.server_address = (self.server_address[0],
564
# if self.settings["interface"]:
565
# self.server_address = (self.server_address[0],
571
return super(IPv6_TCPServer, self).server_bind()
572
def server_activate(self):
574
return super(IPv6_TCPServer, self).server_activate()
545
return super(type(self), self).server_bind()
579
548
def string_to_delta(interval):
589
558
datetime.timedelta(1)
590
559
>>> string_to_delta(u'1w')
591
560
datetime.timedelta(7)
592
>>> string_to_delta('5m 30s')
593
datetime.timedelta(0, 330)
595
timevalue = datetime.timedelta(0)
596
for s in interval.split():
598
suffix = unicode(s[-1])
601
delta = datetime.timedelta(value)
603
delta = datetime.timedelta(0, value)
605
delta = datetime.timedelta(0, 0, 0, 0, value)
607
delta = datetime.timedelta(0, 0, 0, 0, 0, value)
609
delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
612
except (ValueError, IndexError):
563
suffix=unicode(interval[-1])
564
value=int(interval[:-1])
566
delta = datetime.timedelta(value)
568
delta = datetime.timedelta(0, value)
570
delta = datetime.timedelta(0, 0, 0, 0, value)
572
delta = datetime.timedelta(0, 0, 0, 0, 0, value)
574
delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
577
except (ValueError, IndexError):
618
582
def server_state_changed(state):
619
583
"""Derived from the Avahi example code"""
620
584
if state == avahi.SERVER_COLLISION:
621
logger.error(u"Zeroconf server name collision")
585
logger.error(u"Server name collision")
623
587
elif state == avahi.SERVER_RUNNING:
627
591
def entry_group_state_changed(state, error):
628
592
"""Derived from the Avahi example code"""
629
logger.debug(u"Avahi state change: %i", state)
593
logger.debug(u"state change: %i", state)
631
595
if state == avahi.ENTRY_GROUP_ESTABLISHED:
632
logger.debug(u"Zeroconf service established.")
596
logger.debug(u"Service established.")
633
597
elif state == avahi.ENTRY_GROUP_COLLISION:
634
logger.warning(u"Zeroconf service name collision.")
598
logger.warning(u"Service name collision.")
636
600
elif state == avahi.ENTRY_GROUP_FAILURE:
637
logger.critical(u"Avahi: Error in group state changed %s",
601
logger.critical(u"Error in group state changed %s",
639
603
raise AvahiGroupError("State changed: %s", str(error))
642
606
"""Call the C function if_nametoindex(), or equivalent"""
643
607
global if_nametoindex
609
if "ctypes.util" not in sys.modules:
645
611
if_nametoindex = ctypes.cdll.LoadLibrary\
646
612
(ctypes.util.find_library("c")).if_nametoindex
647
613
except (OSError, AttributeError):
661
627
return if_nametoindex(interface)
664
def daemon(nochdir = False, noclose = False):
630
def daemon(nochdir, noclose):
665
631
"""See daemon(3). Standard BSD Unix function.
666
632
This should really exist as os.daemon, but it doesn't (yet)."""
688
parser = OptionParser(version = "%%prog %s" % version)
652
global main_loop_started
653
main_loop_started = False
655
parser = OptionParser()
689
656
parser.add_option("-i", "--interface", type="string",
690
657
metavar="IF", help="Bind to interface IF")
691
658
parser.add_option("-a", "--address", type="string",
694
661
help="Port number to receive requests on")
695
662
parser.add_option("--check", action="store_true", default=False,
696
663
help="Run self-test")
697
parser.add_option("--debug", action="store_true",
664
parser.add_option("--debug", action="store_true", default=False,
698
665
help="Debug mode; run in foreground and log to"
700
667
parser.add_option("--priority", type="string", help="GnuTLS"
705
672
default="/etc/mandos", metavar="DIR",
706
673
help="Directory to search for configuration"
708
options = parser.parse_args()[0]
675
(options, args) = parser.parse_args()
710
677
if options.check:
725
692
# Parse config file for server-global settings
726
693
server_config = ConfigParser.SafeConfigParser(server_defaults)
727
694
del server_defaults
728
server_config.read(os.path.join(options.configdir, "mandos.conf"))
695
server_config.read(os.path.join(options.configdir, "server.conf"))
696
server_section = "server"
729
697
# Convert the SafeConfigParser object to a dict
730
server_settings = server_config.defaults()
698
server_settings = dict(server_config.items(server_section))
731
699
# Use getboolean on the boolean config option
732
700
server_settings["debug"] = server_config.getboolean\
701
(server_section, "debug")
734
702
del server_config
736
704
# Override the settings from the config file with command line
744
712
# Now we have our good server settings in "server_settings"
746
debug = server_settings["debug"]
749
syslogger.setLevel(logging.WARNING)
750
console.setLevel(logging.WARNING)
752
if server_settings["servicename"] != "Mandos":
753
syslogger.setFormatter(logging.Formatter\
754
('Mandos (%s): %%(levelname)s:'
756
% server_settings["servicename"]))
758
714
# Parse config file with clients
759
715
client_defaults = { "timeout": "1h",
760
716
"interval": "5m",
761
"checker": "fping -q -- %(host)s",
717
"checker": "fping -q -- %%(fqdn)s",
764
719
client_config = ConfigParser.SafeConfigParser(client_defaults)
765
720
client_config.read(os.path.join(server_settings["configdir"],
769
tcp_server = IPv6_TCPServer((server_settings["address"],
770
server_settings["port"]),
772
settings=server_settings,
774
pidfilename = "/var/run/mandos.pid"
776
pidfile = open(pidfilename, "w")
777
except IOError, error:
778
logger.error("Could not open file %r", pidfilename)
783
uid = pwd.getpwnam("mandos").pw_uid
786
uid = pwd.getpwnam("nobody").pw_uid
790
gid = pwd.getpwnam("mandos").pw_gid
793
gid = pwd.getpwnam("nogroup").pw_gid
799
except OSError, error:
800
if error[0] != errno.EPERM:
804
724
service = AvahiService(name = server_settings["servicename"],
805
servicetype = "_mandos._tcp", )
725
type = "_mandos._tcp", );
806
726
if server_settings["interface"]:
807
service.interface = if_nametoindex\
808
(server_settings["interface"])
727
service.interface = if_nametoindex(server_settings["interface"])
814
733
DBusGMainLoop(set_as_default=True )
815
734
main_loop = gobject.MainLoop()
816
735
bus = dbus.SystemBus()
817
server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
818
avahi.DBUS_PATH_SERVER),
819
avahi.DBUS_INTERFACE_SERVER)
736
server = dbus.Interface(
737
bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
738
avahi.DBUS_INTERFACE_SERVER )
820
739
# End of Avahi example code
741
debug = server_settings["debug"]
744
console = logging.StreamHandler()
745
# console.setLevel(logging.DEBUG)
746
console.setFormatter(logging.Formatter\
747
('%(levelname)s: %(message)s'))
748
logger.addHandler(console)
822
752
def remove_from_clients(client):
823
753
clients.remove(client)
831
761
= dict(client_config.items(section)))
832
762
for section in client_config.sections()))
834
logger.critical(u"No clients defined")
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())
845
logger.removeHandler(console)
846
# Close all input and output, do double fork, etc.
851
pidfile.write(str(pid) + "\n")
855
logger.error(u"Could not write to file %r with PID %d",
858
# "pidfile" was never created
863
768
"Cleanup function; run on exit"
883
788
for client in clients:
887
tcp_server.server_activate()
791
tcp_server = IPv6_TCPServer((server_settings["address"],
792
server_settings["port"]),
794
settings=server_settings,
889
796
# Find out what port we got
890
797
service.port = tcp_server.socket.getsockname()[1]
891
798
logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
908
815
tcp_server.handle_request\
909
816
(*args[2:], **kwargs) or True)
911
logger.debug(u"Starting main loop")
818
logger.debug("Starting main loop")
819
main_loop_started = True
913
821
except AvahiError, error:
914
822
logger.critical(u"AvahiError: %s" + unicode(error))