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  • Committer: Björn Påhlsson
  • Date: 2008-07-20 02:52:20 UTC
  • Revision ID: belorn@braxen-20080720025220-r5u0388uy9iu23h6
Added following support:
Pluginbased client handler
rewritten Mandos client
       Avahi instead of udp server discovery
       openpgp encrypted key support
Passprompt stand alone application for direct console input
Added logging for Mandos server

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server.py
1
1
#!/usr/bin/python
2
 
# -*- mode: python; coding: utf-8 -*-
3
 
# 
4
 
# Mandos server - give out binary blobs to connecting clients.
5
 
# 
6
 
# This program is partly derived from an example program for an Avahi
7
 
# service publisher, downloaded from
8
 
# <http://avahi.org/wiki/PythonPublishExample>.  This includes the
9
 
# methods "add" and "remove" in the "AvahiService" class, the
10
 
# "server_state_changed" and "entry_group_state_changed" functions,
11
 
# and some lines in "main".
12
 
# 
13
 
# Everything else is
14
 
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
15
 
# 
16
 
# This program is free software: you can redistribute it and/or modify
17
 
# it under the terms of the GNU General Public License as published by
18
 
# the Free Software Foundation, either version 3 of the License, or
19
 
# (at your option) any later version.
20
 
#
21
 
#     This program is distributed in the hope that it will be useful,
22
 
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
23
 
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24
 
#     GNU General Public License for more details.
25
 
# 
26
 
# You should have received a copy of the GNU General Public License
27
 
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
28
 
# 
29
 
# Contact the authors at <mandos@fukt.bsnet.se>.
30
 
# 
31
2
 
32
3
from __future__ import division
33
4
 
50
21
import signal
51
22
from sets import Set
52
23
import subprocess
53
 
import atexit
54
 
import stat
55
 
import logging
56
 
import logging.handlers
57
24
 
58
25
import dbus
59
26
import gobject
61
28
from dbus.mainloop.glib import DBusGMainLoop
62
29
import ctypes
63
30
 
64
 
version = "1.0"
 
31
import logging
 
32
import logging.handlers
 
33
 
 
34
# logghandler.setFormatter(logging.Formatter('%(levelname)s %(message)s')
65
35
 
66
36
logger = logging.Logger('mandos')
67
 
syslogger = logging.handlers.SysLogHandler\
68
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
69
 
             address = "/dev/log")
70
 
syslogger.setFormatter(logging.Formatter\
71
 
                        ('Mandos: %(levelname)s: %(message)s'))
72
 
logger.addHandler(syslogger)
73
 
 
74
 
 
75
 
class AvahiError(Exception):
76
 
    def __init__(self, value):
77
 
        self.value = value
78
 
    def __str__(self):
79
 
        return repr(self.value)
80
 
 
81
 
class AvahiServiceError(AvahiError):
82
 
    pass
83
 
 
84
 
class AvahiGroupError(AvahiError):
85
 
    pass
86
 
 
87
 
 
88
 
class AvahiService(object):
89
 
    """An Avahi (Zeroconf) service.
90
 
    Attributes:
91
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
92
 
               Used to optionally bind to the specified interface.
93
 
    name: string; Example: 'Mandos'
94
 
    type: string; Example: '_mandos._tcp'.
95
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
96
 
    port: integer; what port to announce
97
 
    TXT: list of strings; TXT record for the service
98
 
    domain: string; Domain to publish on, default to .local if empty.
99
 
    host: string; Host to publish records for, default is localhost
100
 
    max_renames: integer; maximum number of renames
101
 
    rename_count: integer; counter so we only rename after collisions
102
 
                  a sensible number of times
103
 
    """
104
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
105
 
                 type = None, port = None, TXT = None, domain = "",
106
 
                 host = "", max_renames = 32768):
107
 
        self.interface = interface
108
 
        self.name = name
109
 
        self.type = type
110
 
        self.port = port
111
 
        if TXT is None:
112
 
            self.TXT = []
113
 
        else:
114
 
            self.TXT = TXT
115
 
        self.domain = domain
116
 
        self.host = host
117
 
        self.rename_count = 0
118
 
    def rename(self):
119
 
        """Derived from the Avahi example code"""
120
 
        if self.rename_count >= self.max_renames:
121
 
            logger.critical(u"No suitable service name found after %i"
122
 
                            u" retries, exiting.", rename_count)
123
 
            raise AvahiServiceError("Too many renames")
124
 
        name = server.GetAlternativeServiceName(name)
125
 
        logger.error(u"Changing name to %r ...", name)
126
 
        syslogger.setFormatter(logging.Formatter\
127
 
                               ('Mandos (%s): %%(levelname)s:'
128
 
                               ' %%(message)s' % name))
129
 
        self.remove()
130
 
        self.add()
131
 
        self.rename_count += 1
132
 
    def remove(self):
133
 
        """Derived from the Avahi example code"""
134
 
        if group is not None:
135
 
            group.Reset()
136
 
    def add(self):
137
 
        """Derived from the Avahi example code"""
138
 
        global group
139
 
        if group is None:
140
 
            group = dbus.Interface\
141
 
                    (bus.get_object(avahi.DBUS_NAME,
142
 
                                    server.EntryGroupNew()),
143
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
144
 
            group.connect_to_signal('StateChanged',
145
 
                                    entry_group_state_changed)
146
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
147
 
                     service.name, service.type)
148
 
        group.AddService(
149
 
                self.interface,         # interface
150
 
                avahi.PROTO_INET6,      # protocol
151
 
                dbus.UInt32(0),         # flags
152
 
                self.name, self.type,
153
 
                self.domain, self.host,
154
 
                dbus.UInt16(self.port),
155
 
                avahi.string_array_to_txt_array(self.TXT))
156
 
        group.Commit()
157
 
 
158
 
# From the Avahi example code:
159
 
group = None                            # our entry group
 
37
logger.addHandler(logging.handlers.SysLogHandler(facility = logging.handlers.SysLogHandler.LOG_DAEMON))
 
38
 
 
39
# This variable is used to optionally bind to a specified interface.
 
40
# It is a global variable to fit in with the other variables from the
 
41
# Avahi server example code.
 
42
serviceInterface = avahi.IF_UNSPEC
 
43
# From the Avahi server example code:
 
44
serviceName = "Mandos"
 
45
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
 
46
servicePort = None                      # Not known at startup
 
47
serviceTXT = []                         # TXT record for the service
 
48
domain = ""                  # Domain to publish on, default to .local
 
49
host = ""          # Host to publish records for, default to localhost
 
50
group = None #our entry group
 
51
rename_count = 12       # Counter so we only rename after collisions a
 
52
                        # sensible number of times
160
53
# End of Avahi example code
161
54
 
162
55
 
167
60
    fingerprint: string (40 or 32 hexadecimal digits); used to
168
61
                 uniquely identify the client
169
62
    secret:    bytestring; sent verbatim (over TLS) to client
170
 
    host:      string; available for use by the checker command
171
 
    created:   datetime.datetime(); object creation, not client host
172
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
173
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
174
 
                                     until this client is invalid
 
63
    fqdn:      string (FQDN); available for use by the checker command
 
64
    created:   datetime.datetime()
 
65
    last_seen: datetime.datetime() or None if not yet seen
 
66
    timeout:   datetime.timedelta(); How long from last_seen until
 
67
                                     this client is invalid
175
68
    interval:  datetime.timedelta(); How often to start a new checker
176
69
    stop_hook: If set, called by stop() as stop_hook(self)
177
70
    checker:   subprocess.Popen(); a running checker process used
178
71
                                   to see if the client lives.
179
 
                                   'None' if no process is running.
 
72
                                   Is None if no process is running.
180
73
    checker_initiator_tag: a gobject event source tag, or None
181
74
    stop_initiator_tag:    - '' -
182
75
    checker_callback_tag:  - '' -
183
76
    checker_command: string; External command which is run to check if
184
 
                     client lives.  %() expansions are done at
 
77
                     client lives.  %()s expansions are done at
185
78
                     runtime with vars(self) as dict, so that for
186
79
                     instance %(name)s can be used in the command.
187
80
    Private attibutes:
188
81
    _timeout: Real variable for 'timeout'
189
82
    _interval: Real variable for 'interval'
190
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
83
    _timeout_milliseconds: Used by gobject.timeout_add()
191
84
    _interval_milliseconds: - '' -
192
85
    """
193
86
    def _set_timeout(self, timeout):
213
106
    interval = property(lambda self: self._interval,
214
107
                        _set_interval)
215
108
    del _set_interval
216
 
    def __init__(self, name = None, stop_hook=None, config={}):
217
 
        """Note: the 'checker' key in 'config' sets the
218
 
        'checker_command' attribute and *not* the 'checker'
219
 
        attribute."""
 
109
    def __init__(self, name=None, options=None, stop_hook=None,
 
110
                 fingerprint=None, secret=None, secfile=None, fqdn=None,
 
111
                 timeout=None, interval=-1, checker=None):
220
112
        self.name = name
221
 
        logger.debug(u"Creating client %r", self.name)
222
 
        # Uppercase and remove spaces from fingerprint for later
223
 
        # comparison purposes with return value from the fingerprint()
224
 
        # function
225
 
        self.fingerprint = config["fingerprint"].upper()\
226
 
                           .replace(u" ", u"")
227
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
228
 
        if "secret" in config:
229
 
            self.secret = config["secret"].decode(u"base64")
230
 
        elif "secfile" in config:
231
 
            sf = open(config["secfile"])
 
113
        # Uppercase and remove spaces from fingerprint
 
114
        # for later comparison purposes with return value of
 
115
        # the fingerprint() function
 
116
        self.fingerprint = fingerprint.upper().replace(u" ", u"")
 
117
        if secret:
 
118
            self.secret = secret.decode(u"base64")
 
119
        elif secfile:
 
120
            sf = open(secfile)
232
121
            self.secret = sf.read()
233
122
            sf.close()
234
123
        else:
235
 
            raise TypeError(u"No secret or secfile for client %s"
236
 
                            % self.name)
237
 
        self.host = config.get("host", "")
 
124
            raise RuntimeError(u"No secret or secfile for client %s"
 
125
                               % self.name)
 
126
        self.fqdn = fqdn                # string
238
127
        self.created = datetime.datetime.now()
239
 
        self.last_checked_ok = None
240
 
        self.timeout = string_to_delta(config["timeout"])
241
 
        self.interval = string_to_delta(config["interval"])
 
128
        self.last_seen = None
 
129
        if timeout is None:
 
130
            timeout = options.timeout
 
131
        self.timeout = timeout
 
132
        if interval == -1:
 
133
            interval = options.interval
 
134
        else:
 
135
            interval = string_to_delta(interval)
 
136
        self.interval = interval
242
137
        self.stop_hook = stop_hook
243
138
        self.checker = None
244
139
        self.checker_initiator_tag = None
245
140
        self.stop_initiator_tag = None
246
141
        self.checker_callback_tag = None
247
 
        self.check_command = config["checker"]
 
142
        self.check_command = checker
248
143
    def start(self):
249
 
        """Start this client's checker and timeout hooks"""
 
144
        """Start this clients checker and timeout hooks"""
250
145
        # Schedule a new checker to be started an 'interval' from now,
251
146
        # and every interval from then on.
252
147
        self.checker_initiator_tag = gobject.timeout_add\
260
155
                                   self.stop)
261
156
    def stop(self):
262
157
        """Stop this client.
263
 
        The possibility that a client might be restarted is left open,
264
 
        but not currently used."""
265
 
        # If this client doesn't have a secret, it is already stopped.
266
 
        if hasattr(self, "secret") and self.secret:
267
 
            logger.info(u"Stopping client %s", self.name)
268
 
            self.secret = None
269
 
        else:
270
 
            return False
271
 
        if getattr(self, "stop_initiator_tag", False):
 
158
        The possibility that this client might be restarted is left
 
159
        open, but not currently used."""
 
160
        logger.debug(u"Stopping client %s", self.name)
 
161
        self.secret = None
 
162
        if self.stop_initiator_tag:
272
163
            gobject.source_remove(self.stop_initiator_tag)
273
164
            self.stop_initiator_tag = None
274
 
        if getattr(self, "checker_initiator_tag", False):
 
165
        if self.checker_initiator_tag:
275
166
            gobject.source_remove(self.checker_initiator_tag)
276
167
            self.checker_initiator_tag = None
277
168
        self.stop_checker()
280
171
        # Do not run this again if called by a gobject.timeout_add
281
172
        return False
282
173
    def __del__(self):
283
 
        self.stop_hook = None
284
 
        self.stop()
 
174
        # Some code duplication here and in stop()
 
175
        if hasattr(self, "stop_initiator_tag") \
 
176
               and self.stop_initiator_tag:
 
177
            gobject.source_remove(self.stop_initiator_tag)
 
178
            self.stop_initiator_tag = None
 
179
        if hasattr(self, "checker_initiator_tag") \
 
180
               and self.checker_initiator_tag:
 
181
            gobject.source_remove(self.checker_initiator_tag)
 
182
            self.checker_initiator_tag = None
 
183
        self.stop_checker()
285
184
    def checker_callback(self, pid, condition):
286
185
        """The checker has completed, so take appropriate actions."""
287
186
        now = datetime.datetime.now()
288
 
        self.checker_callback_tag = None
289
 
        self.checker = None
290
187
        if os.WIFEXITED(condition) \
291
188
               and (os.WEXITSTATUS(condition) == 0):
292
 
            logger.info(u"Checker for %(name)s succeeded",
293
 
                        vars(self))
294
 
            self.last_checked_ok = now
 
189
            logger.debug(u"Checker for %(name)s succeeded",
 
190
                         vars(self))
 
191
            self.last_seen = now
295
192
            gobject.source_remove(self.stop_initiator_tag)
296
193
            self.stop_initiator_tag = gobject.timeout_add\
297
194
                                      (self._timeout_milliseconds,
298
195
                                       self.stop)
299
 
        elif not os.WIFEXITED(condition):
 
196
        if not os.WIFEXITED(condition):
300
197
            logger.warning(u"Checker for %(name)s crashed?",
301
198
                           vars(self))
302
199
        else:
303
 
            logger.info(u"Checker for %(name)s failed",
304
 
                        vars(self))
 
200
            logger.debug(u"Checker for %(name)s failed",
 
201
                         vars(self))
 
202
            self.checker = None
 
203
        self.checker_callback_tag = None
305
204
    def start_checker(self):
306
205
        """Start a new checker subprocess if one is not running.
307
206
        If a checker already exists, leave it running and do
308
207
        nothing."""
309
 
        # The reason for not killing a running checker is that if we
310
 
        # did that, then if a checker (for some reason) started
311
 
        # running slowly and taking more than 'interval' time, the
312
 
        # client would inevitably timeout, since no checker would get
313
 
        # a chance to run to completion.  If we instead leave running
314
 
        # checkers alone, the checker would have to take more time
315
 
        # than 'timeout' for the client to be declared invalid, which
316
 
        # is as it should be.
317
208
        if self.checker is None:
 
209
            logger.debug(u"Starting checker for %s",
 
210
                         self.name)
318
211
            try:
319
 
                # In case check_command has exactly one % operator
320
 
                command = self.check_command % self.host
 
212
                command = self.check_command % self.fqdn
321
213
            except TypeError:
322
 
                # Escape attributes for the shell
323
214
                escaped_attrs = dict((key, re.escape(str(val)))
324
215
                                     for key, val in
325
216
                                     vars(self).iteritems())
326
217
                try:
327
218
                    command = self.check_command % escaped_attrs
328
219
                except TypeError, error:
329
 
                    logger.error(u'Could not format string "%s":'
330
 
                                 u' %s', self.check_command, error)
 
220
                    logger.critical(u'Could not format string "%s": %s',
 
221
                                    self.check_command, error)
331
222
                    return True # Try again later
332
223
            try:
333
 
                logger.info(u"Starting checker %r for %s",
334
 
                            command, self.name)
335
 
                self.checker = subprocess.Popen(command,
336
 
                                                close_fds=True,
337
 
                                                shell=True, cwd="/")
338
 
                self.checker_callback_tag = gobject.child_watch_add\
339
 
                                            (self.checker.pid,
340
 
                                             self.checker_callback)
 
224
                self.checker = subprocess.\
 
225
                               Popen(command,
 
226
                                     stdout=subprocess.PIPE,
 
227
                                     close_fds=True, shell=True,
 
228
                                     cwd="/")
 
229
                self.checker_callback_tag = gobject.\
 
230
                                            child_watch_add(self.checker.pid,
 
231
                                                            self.\
 
232
                                                            checker_callback)
341
233
            except subprocess.OSError, error:
342
234
                logger.error(u"Failed to start subprocess: %s",
343
235
                             error)
345
237
        return True
346
238
    def stop_checker(self):
347
239
        """Force the checker process, if any, to stop."""
348
 
        if self.checker_callback_tag:
349
 
            gobject.source_remove(self.checker_callback_tag)
350
 
            self.checker_callback_tag = None
351
 
        if getattr(self, "checker", None) is None:
 
240
        if not hasattr(self, "checker") or self.checker is None:
352
241
            return
353
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
354
 
        try:
355
 
            os.kill(self.checker.pid, signal.SIGTERM)
356
 
            #os.sleep(0.5)
357
 
            #if self.checker.poll() is None:
358
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
359
 
        except OSError, error:
360
 
            if error.errno != errno.ESRCH: # No such process
361
 
                raise
 
242
        gobject.source_remove(self.checker_callback_tag)
 
243
        self.checker_callback_tag = None
 
244
        os.kill(self.checker.pid, signal.SIGTERM)
 
245
        if self.checker.poll() is None:
 
246
            os.kill(self.checker.pid, signal.SIGKILL)
362
247
        self.checker = None
363
 
    def still_valid(self):
 
248
    def still_valid(self, now=None):
364
249
        """Has the timeout not yet passed for this client?"""
365
 
        now = datetime.datetime.now()
366
 
        if self.last_checked_ok is None:
 
250
        if now is None:
 
251
            now = datetime.datetime.now()
 
252
        if self.last_seen is None:
367
253
            return now < (self.created + self.timeout)
368
254
        else:
369
 
            return now < (self.last_checked_ok + self.timeout)
 
255
            return now < (self.last_seen + self.timeout)
370
256
 
371
257
 
372
258
def peer_certificate(session):
373
 
    "Return the peer's OpenPGP certificate as a bytestring"
374
259
    # If not an OpenPGP certificate...
375
260
    if gnutls.library.functions.gnutls_certificate_type_get\
376
261
            (session._c_object) \
387
272
 
388
273
 
389
274
def fingerprint(openpgp):
390
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
275
    # New empty GnuTLS certificate
 
276
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
277
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
278
        (ctypes.byref(crt))
391
279
    # New GnuTLS "datum" with the OpenPGP public key
392
280
    datum = gnutls.library.types.gnutls_datum_t\
393
281
        (ctypes.cast(ctypes.c_char_p(openpgp),
394
282
                     ctypes.POINTER(ctypes.c_ubyte)),
395
283
         ctypes.c_uint(len(openpgp)))
396
 
    # New empty GnuTLS certificate
397
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
398
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
399
 
        (ctypes.byref(crt))
400
284
    # Import the OpenPGP public key into the certificate
401
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
402
 
                    (crt, ctypes.byref(datum),
403
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
285
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
 
286
        (crt,
 
287
         ctypes.byref(datum),
 
288
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
404
289
    # New buffer for the fingerprint
405
290
    buffer = ctypes.create_string_buffer(20)
406
291
    buffer_length = ctypes.c_size_t()
422
307
    Note: This will run in its own forked process."""
423
308
    
424
309
    def handle(self):
425
 
        logger.info(u"TCP connection from: %s",
 
310
        logger.debug(u"TCP connection from: %s",
426
311
                     unicode(self.client_address))
427
 
        session = gnutls.connection.ClientSession\
428
 
                  (self.request, gnutls.connection.X509Credentials())
429
 
        
430
 
        line = self.request.makefile().readline()
431
 
        logger.debug(u"Protocol version: %r", line)
432
 
        try:
433
 
            if int(line.strip().split()[0]) > 1:
434
 
                raise RuntimeError
435
 
        except (ValueError, IndexError, RuntimeError), error:
436
 
            logger.error(u"Unknown protocol version: %s", error)
437
 
            return
438
 
        
439
 
        # Note: gnutls.connection.X509Credentials is really a generic
440
 
        # GnuTLS certificate credentials object so long as no X.509
441
 
        # keys are added to it.  Therefore, we can use it here despite
442
 
        # using OpenPGP certificates.
 
312
        session = gnutls.connection.ClientSession(self.request,
 
313
                                                  gnutls.connection.\
 
314
                                                  X509Credentials())
443
315
        
444
316
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
445
317
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
446
318
        #                "+DHE-DSS"))
447
 
        priority = "NORMAL"             # Fallback default, since this
448
 
                                        # MUST be set.
449
 
        if self.server.settings["priority"]:
450
 
            priority = self.server.settings["priority"]
 
319
        priority = "SECURE256"
 
320
        
451
321
        gnutls.library.functions.gnutls_priority_set_direct\
452
322
            (session._c_object, priority, None);
453
323
        
454
324
        try:
455
325
            session.handshake()
456
326
        except gnutls.errors.GNUTLSError, error:
457
 
            logger.warning(u"Handshake failed: %s", error)
 
327
            logger.debug(u"Handshake failed: %s", error)
458
328
            # Do not run session.bye() here: the session is not
459
329
            # established.  Just abandon the request.
460
330
            return
461
331
        try:
462
332
            fpr = fingerprint(peer_certificate(session))
463
333
        except (TypeError, gnutls.errors.GNUTLSError), error:
464
 
            logger.warning(u"Bad certificate: %s", error)
 
334
            logger.debug(u"Bad certificate: %s", error)
465
335
            session.bye()
466
336
            return
467
337
        logger.debug(u"Fingerprint: %s", fpr)
468
338
        client = None
469
 
        for c in self.server.clients:
 
339
        for c in clients:
470
340
            if c.fingerprint == fpr:
471
341
                client = c
472
342
                break
473
 
        if not client:
474
 
            logger.warning(u"Client not found for fingerprint: %s",
475
 
                           fpr)
476
 
            session.bye()
477
 
            return
478
343
        # Have to check if client.still_valid(), since it is possible
479
344
        # that the client timed out while establishing the GnuTLS
480
345
        # session.
481
 
        if not client.still_valid():
482
 
            logger.warning(u"Client %(name)s is invalid",
483
 
                           vars(client))
 
346
        if (not client) or (not client.still_valid()):
 
347
            if client:
 
348
                logger.debug(u"Client %(name)s is invalid",
 
349
                             vars(client))
 
350
            else:
 
351
                logger.debug(u"Client not found for fingerprint: %s",
 
352
                             fpr)
484
353
            session.bye()
485
354
            return
486
355
        sent_size = 0
496
365
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
497
366
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
498
367
    Attributes:
499
 
        settings:       Server settings
 
368
        options:        Command line options
500
369
        clients:        Set() of Client objects
501
370
    """
502
371
    address_family = socket.AF_INET6
503
372
    def __init__(self, *args, **kwargs):
504
 
        if "settings" in kwargs:
505
 
            self.settings = kwargs["settings"]
506
 
            del kwargs["settings"]
 
373
        if "options" in kwargs:
 
374
            self.options = kwargs["options"]
 
375
            del kwargs["options"]
507
376
        if "clients" in kwargs:
508
377
            self.clients = kwargs["clients"]
509
378
            del kwargs["clients"]
512
381
        """This overrides the normal server_bind() function
513
382
        to bind to an interface if one was specified, and also NOT to
514
383
        bind to an address or port if they were not specified."""
515
 
        if self.settings["interface"]:
516
 
            # 25 is from /usr/include/asm-i486/socket.h
517
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
384
        if self.options.interface:
 
385
            if not hasattr(socket, "SO_BINDTODEVICE"):
 
386
                # From /usr/include/asm-i486/socket.h
 
387
                socket.SO_BINDTODEVICE = 25
518
388
            try:
519
389
                self.socket.setsockopt(socket.SOL_SOCKET,
520
 
                                       SO_BINDTODEVICE,
521
 
                                       self.settings["interface"])
 
390
                                       socket.SO_BINDTODEVICE,
 
391
                                       self.options.interface)
522
392
            except socket.error, error:
523
393
                if error[0] == errno.EPERM:
524
 
                    logger.error(u"No permission to"
525
 
                                 u" bind to interface %s",
526
 
                                 self.settings["interface"])
 
394
                    logger.warning(u"No permission to"
 
395
                                   u" bind to interface %s",
 
396
                                   self.options.interface)
527
397
                else:
528
398
                    raise error
529
399
        # Only bind(2) the socket if we really need to.
532
402
                in6addr_any = "::"
533
403
                self.server_address = (in6addr_any,
534
404
                                       self.server_address[1])
535
 
            elif not self.server_address[1]:
 
405
            elif self.server_address[1] is None:
536
406
                self.server_address = (self.server_address[0],
537
407
                                       0)
538
 
#                 if self.settings["interface"]:
539
 
#                     self.server_address = (self.server_address[0],
540
 
#                                            0, # port
541
 
#                                            0, # flowinfo
542
 
#                                            if_nametoindex
543
 
#                                            (self.settings
544
 
#                                             ["interface"]))
545
408
            return super(type(self), self).server_bind()
546
409
 
547
410
 
579
442
    return delta
580
443
 
581
444
 
 
445
def add_service():
 
446
    """From the Avahi server example code"""
 
447
    global group, serviceName, serviceType, servicePort, serviceTXT, \
 
448
           domain, host
 
449
    if group is None:
 
450
        group = dbus.Interface(
 
451
                bus.get_object( avahi.DBUS_NAME,
 
452
                                server.EntryGroupNew()),
 
453
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
454
        group.connect_to_signal('StateChanged',
 
455
                                entry_group_state_changed)
 
456
    logger.debug(u"Adding service '%s' of type '%s' ...",
 
457
                 serviceName, serviceType)
 
458
    
 
459
    group.AddService(
 
460
            serviceInterface,           # interface
 
461
            avahi.PROTO_INET6,          # protocol
 
462
            dbus.UInt32(0),             # flags
 
463
            serviceName, serviceType,
 
464
            domain, host,
 
465
            dbus.UInt16(servicePort),
 
466
            avahi.string_array_to_txt_array(serviceTXT))
 
467
    group.Commit()
 
468
 
 
469
 
 
470
def remove_service():
 
471
    """From the Avahi server example code"""
 
472
    global group
 
473
    
 
474
    if not group is None:
 
475
        group.Reset()
 
476
 
 
477
 
582
478
def server_state_changed(state):
583
 
    """Derived from the Avahi example code"""
 
479
    """From the Avahi server example code"""
584
480
    if state == avahi.SERVER_COLLISION:
585
 
        logger.error(u"Server name collision")
586
 
        service.remove()
 
481
        logger.warning(u"Server name collision")
 
482
        remove_service()
587
483
    elif state == avahi.SERVER_RUNNING:
588
 
        service.add()
 
484
        add_service()
589
485
 
590
486
 
591
487
def entry_group_state_changed(state, error):
592
 
    """Derived from the Avahi example code"""
 
488
    """From the Avahi server example code"""
 
489
    global serviceName, server, rename_count
 
490
    
593
491
    logger.debug(u"state change: %i", state)
594
492
    
595
493
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
596
494
        logger.debug(u"Service established.")
597
495
    elif state == avahi.ENTRY_GROUP_COLLISION:
598
 
        logger.warning(u"Service name collision.")
599
 
        service.rename()
 
496
        
 
497
        rename_count = rename_count - 1
 
498
        if rename_count > 0:
 
499
            name = server.GetAlternativeServiceName(name)
 
500
            logger.warning(u"Service name collision, "
 
501
                           u"changing name to '%s' ...", name)
 
502
            remove_service()
 
503
            add_service()
 
504
            
 
505
        else:
 
506
            logger.error(u"No suitable service name found "
 
507
                         u"after %i retries, exiting.",
 
508
                         n_rename)
 
509
            main_loop.quit()
600
510
    elif state == avahi.ENTRY_GROUP_FAILURE:
601
 
        logger.critical(u"Error in group state changed %s",
602
 
                        unicode(error))
603
 
        raise AvahiGroupError("State changed: %s", str(error))
 
511
        logger.error(u"Error in group state changed %s",
 
512
                     unicode(error))
 
513
        main_loop.quit()
 
514
        return
 
515
 
604
516
 
605
517
def if_nametoindex(interface):
606
 
    """Call the C function if_nametoindex(), or equivalent"""
607
 
    global if_nametoindex
 
518
    """Call the C function if_nametoindex()"""
608
519
    try:
609
 
        if "ctypes.util" not in sys.modules:
610
 
            import ctypes.util
611
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
612
 
            (ctypes.util.find_library("c")).if_nametoindex
 
520
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
521
        return libc.if_nametoindex(interface)
613
522
    except (OSError, AttributeError):
614
523
        if "struct" not in sys.modules:
615
524
            import struct
616
525
        if "fcntl" not in sys.modules:
617
526
            import fcntl
618
 
        def if_nametoindex(interface):
619
 
            "Get an interface index the hard way, i.e. using fcntl()"
620
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
621
 
            s = socket.socket()
622
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
623
 
                                struct.pack("16s16x", interface))
624
 
            s.close()
625
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
626
 
            return interface_index
627
 
    return if_nametoindex(interface)
628
 
 
629
 
 
630
 
def daemon(nochdir = False, noclose = False):
631
 
    """See daemon(3).  Standard BSD Unix function.
632
 
    This should really exist as os.daemon, but it doesn't (yet)."""
633
 
    if os.fork():
634
 
        sys.exit()
635
 
    os.setsid()
636
 
    if not nochdir:
637
 
        os.chdir("/")
638
 
    if os.fork():
639
 
        sys.exit()
640
 
    if not noclose:
641
 
        # Close all standard open file descriptors
642
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
643
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
644
 
            raise OSError(errno.ENODEV,
645
 
                          "/dev/null not a character device")
646
 
        os.dup2(null, sys.stdin.fileno())
647
 
        os.dup2(null, sys.stdout.fileno())
648
 
        os.dup2(null, sys.stderr.fileno())
649
 
        if null > 2:
650
 
            os.close(null)
651
 
 
652
 
 
653
 
def main():
654
 
    global main_loop_started
655
 
    main_loop_started = False
656
 
    
657
 
    parser = OptionParser(version = "Mandos server %s" % version)
 
527
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
 
528
        s = socket.socket()
 
529
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
530
                            struct.pack("16s16x", interface))
 
531
        s.close()
 
532
        interface_index = struct.unpack("I", ifreq[16:20])[0]
 
533
        return interface_index
 
534
 
 
535
 
 
536
if __name__ == '__main__':
 
537
    parser = OptionParser()
658
538
    parser.add_option("-i", "--interface", type="string",
659
 
                      metavar="IF", help="Bind to interface IF")
660
 
    parser.add_option("-a", "--address", type="string",
661
 
                      help="Address to listen for requests on")
662
 
    parser.add_option("-p", "--port", type="int",
 
539
                      default=None, metavar="IF",
 
540
                      help="Bind to interface IF")
 
541
    parser.add_option("--cert", type="string", default="cert.pem",
 
542
                      metavar="FILE",
 
543
                      help="Public key certificate PEM file to use")
 
544
    parser.add_option("--key", type="string", default="key.pem",
 
545
                      metavar="FILE",
 
546
                      help="Private key PEM file to use")
 
547
    parser.add_option("--ca", type="string", default="ca.pem",
 
548
                      metavar="FILE",
 
549
                      help="Certificate Authority certificate PEM file to use")
 
550
    parser.add_option("--crl", type="string", default="crl.pem",
 
551
                      metavar="FILE",
 
552
                      help="Certificate Revokation List PEM file to use")
 
553
    parser.add_option("-p", "--port", type="int", default=None,
663
554
                      help="Port number to receive requests on")
 
555
    parser.add_option("--timeout", type="string", # Parsed later
 
556
                      default="1h",
 
557
                      help="Amount of downtime allowed for clients")
 
558
    parser.add_option("--interval", type="string", # Parsed later
 
559
                      default="5m",
 
560
                      help="How often to check that a client is up")
664
561
    parser.add_option("--check", action="store_true", default=False,
665
562
                      help="Run self-test")
666
 
    parser.add_option("--debug", action="store_true",
667
 
                      help="Debug mode; run in foreground and log to"
668
 
                      " terminal")
669
 
    parser.add_option("--priority", type="string", help="GnuTLS"
670
 
                      " priority string (see GnuTLS documentation)")
671
 
    parser.add_option("--servicename", type="string", metavar="NAME",
672
 
                      help="Zeroconf service name")
673
 
    parser.add_option("--configdir", type="string",
674
 
                      default="/etc/mandos", metavar="DIR",
675
 
                      help="Directory to search for configuration"
676
 
                      " files")
 
563
    parser.add_option("--debug", action="store_true", default=False,
 
564
                      help="Debug mode")
677
565
    (options, args) = parser.parse_args()
678
566
    
679
567
    if options.check:
681
569
        doctest.testmod()
682
570
        sys.exit()
683
571
    
684
 
    # Default values for config file for server-global settings
685
 
    server_defaults = { "interface": "",
686
 
                        "address": "",
687
 
                        "port": "",
688
 
                        "debug": "False",
689
 
                        "priority":
690
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
691
 
                        "servicename": "Mandos",
692
 
                        }
693
 
    
694
 
    # Parse config file for server-global settings
695
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
696
 
    del server_defaults
697
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
698
 
    server_section = "server"
699
 
    # Convert the SafeConfigParser object to a dict
700
 
    server_settings = dict(server_config.items(server_section))
701
 
    # Use getboolean on the boolean config option
702
 
    server_settings["debug"] = server_config.getboolean\
703
 
                               (server_section, "debug")
704
 
    del server_config
705
 
    
706
 
    # Override the settings from the config file with command line
707
 
    # options, if set.
708
 
    for option in ("interface", "address", "port", "debug",
709
 
                   "priority", "servicename", "configdir"):
710
 
        value = getattr(options, option)
711
 
        if value is not None:
712
 
            server_settings[option] = value
713
 
    del options
714
 
    # Now we have our good server settings in "server_settings"
715
 
    
716
 
    debug = server_settings["debug"]
717
 
    
718
 
    if not debug:
719
 
        syslogger.setLevel(logging.WARNING)
720
 
    
721
 
    if server_settings["servicename"] != "Mandos":
722
 
        syslogger.setFormatter(logging.Formatter\
723
 
                               ('Mandos (%s): %%(levelname)s:'
724
 
                                ' %%(message)s'
725
 
                                % server_settings["servicename"]))
726
 
    
727
 
    # Parse config file with clients
728
 
    client_defaults = { "timeout": "1h",
729
 
                        "interval": "5m",
730
 
                        "checker": "fping -q -- %%(host)s",
731
 
                        }
732
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
733
 
    client_config.read(os.path.join(server_settings["configdir"],
734
 
                                    "clients.conf"))
735
 
    
736
 
    global service
737
 
    service = AvahiService(name = server_settings["servicename"],
738
 
                           type = "_mandos._tcp", );
739
 
    if server_settings["interface"]:
740
 
        service.interface = if_nametoindex(server_settings["interface"])
741
 
    
742
 
    global main_loop
743
 
    global bus
744
 
    global server
745
 
    # From the Avahi example code
 
572
    # Parse the time arguments
 
573
    try:
 
574
        options.timeout = string_to_delta(options.timeout)
 
575
    except ValueError:
 
576
        parser.error("option --timeout: Unparseable time")
 
577
    try:
 
578
        options.interval = string_to_delta(options.interval)
 
579
    except ValueError:
 
580
        parser.error("option --interval: Unparseable time")
 
581
    
 
582
    # Parse config file
 
583
    defaults = { "checker": "sleep 1; fping -q -- %%(fqdn)s" }
 
584
    client_config = ConfigParser.SafeConfigParser(defaults)
 
585
    #client_config.readfp(open("secrets.conf"), "secrets.conf")
 
586
    client_config.read("mandos-clients.conf")
 
587
    
 
588
    # From the Avahi server example code
746
589
    DBusGMainLoop(set_as_default=True )
747
590
    main_loop = gobject.MainLoop()
748
591
    bus = dbus.SystemBus()
751
594
            avahi.DBUS_INTERFACE_SERVER )
752
595
    # End of Avahi example code
753
596
    
754
 
    if debug:
755
 
        console = logging.StreamHandler()
756
 
        # console.setLevel(logging.DEBUG)
757
 
        console.setFormatter(logging.Formatter\
758
 
                             ('%(levelname)s: %(message)s'))
759
 
        logger.addHandler(console)
760
 
        del console
 
597
    debug = options.debug
761
598
    
762
599
    clients = Set()
763
600
    def remove_from_clients(client):
764
601
        clients.remove(client)
765
602
        if not clients:
766
 
            logger.critical(u"No clients left, exiting")
767
 
            sys.exit()
 
603
            logger.debug(u"No clients left, exiting")
 
604
            main_loop.quit()
768
605
    
769
 
    clients.update(Set(Client(name = section,
 
606
    clients.update(Set(Client(name=section, options=options,
770
607
                              stop_hook = remove_from_clients,
771
 
                              config
772
 
                              = dict(client_config.items(section)))
 
608
                              **(dict(client_config\
 
609
                                      .items(section))))
773
610
                       for section in client_config.sections()))
774
 
    if not clients:
775
 
        logger.critical(u"No clients defined")
776
 
        sys.exit(1)
777
 
    
778
 
    if not debug:
779
 
        daemon()
780
 
    
781
 
    pidfilename = "/var/run/mandos/mandos.pid"
782
 
    pid = os.getpid()
783
 
    try:
784
 
        pidfile = open(pidfilename, "w")
785
 
        pidfile.write(str(pid) + "\n")
786
 
        pidfile.close()
787
 
        del pidfile
788
 
    except IOError, err:
789
 
        logger.error(u"Could not write %s file with PID %d",
790
 
                     pidfilename, os.getpid())
791
 
    
792
 
    def cleanup():
793
 
        "Cleanup function; run on exit"
794
 
        global group
795
 
        # From the Avahi example code
796
 
        if not group is None:
797
 
            group.Free()
798
 
            group = None
799
 
        # End of Avahi example code
800
 
        
801
 
        while clients:
802
 
            client = clients.pop()
803
 
            client.stop_hook = None
804
 
            client.stop()
805
 
    
806
 
    atexit.register(cleanup)
807
 
    
808
 
    if not debug:
809
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
810
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
811
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
812
 
    
813
611
    for client in clients:
814
612
        client.start()
815
613
    
816
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
817
 
                                 server_settings["port"]),
 
614
    tcp_server = IPv6_TCPServer((None, options.port),
818
615
                                tcp_handler,
819
 
                                settings=server_settings,
 
616
                                options=options,
820
617
                                clients=clients)
821
 
    # Find out what port we got
822
 
    service.port = tcp_server.socket.getsockname()[1]
823
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
824
 
                u" scope_id %d" % tcp_server.socket.getsockname())
825
 
    
826
 
    #service.interface = tcp_server.socket.getsockname()[3]
827
 
    
 
618
    # Find out what random port we got
 
619
    servicePort = tcp_server.socket.getsockname()[1]
 
620
    logger.debug(u"Now listening on port %d", servicePort)
 
621
    
 
622
    if options.interface is not None:
 
623
        serviceInterface = if_nametoindex(options.interface)
 
624
    
 
625
    # From the Avahi server example code
 
626
    server.connect_to_signal("StateChanged", server_state_changed)
 
627
    server_state_changed(server.GetState())
 
628
    # End of Avahi example code
 
629
    
 
630
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
631
                         lambda *args, **kwargs:
 
632
                         tcp_server.handle_request(*args[2:],
 
633
                                                   **kwargs) or True)
828
634
    try:
829
 
        # From the Avahi example code
830
 
        server.connect_to_signal("StateChanged", server_state_changed)
831
 
        try:
832
 
            server_state_changed(server.GetState())
833
 
        except dbus.exceptions.DBusException, error:
834
 
            logger.critical(u"DBusException: %s", error)
835
 
            sys.exit(1)
836
 
        # End of Avahi example code
837
 
        
838
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
839
 
                             lambda *args, **kwargs:
840
 
                             tcp_server.handle_request\
841
 
                             (*args[2:], **kwargs) or True)
842
 
        
843
 
        logger.debug(u"Starting main loop")
844
 
        main_loop_started = True
845
635
        main_loop.run()
846
 
    except AvahiError, error:
847
 
        logger.critical(u"AvahiError: %s" + unicode(error))
848
 
        sys.exit(1)
849
636
    except KeyboardInterrupt:
850
 
        if debug:
851
 
            print
 
637
        print
 
638
    
 
639
    # Cleanup here
852
640
 
853
 
if __name__ == '__main__':
854
 
    main()
 
641
    # From the Avahi server example code
 
642
    if not group is None:
 
643
        group.Free()
 
644
    # End of Avahi example code
 
645
    
 
646
    for client in clients:
 
647
        client.stop_hook = None
 
648
        client.stop()