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  • Committer: Teddy Hogeborn
  • Date: 2008-07-19 18:43:24 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080719184324-iwhoa5in75xa0u2u
* mandos-clients.conf ([foo]/dn, [foo]/password, [braxen_client]/dn,
                       [braxen_client]/password): Removed.
  ([foo]/fingerprint, [braxen_client]/fingerprint): New.
  ([foo]/checker): New.
  ([foo]/secfile): New.
  ([braxen_client]/secret): New.

* server.py: New "--debug" option to set debug flag.  Removed "cert",
             "key", "ca", "crl", and "cred" variables.  Added default
             value for "checker" config file setting.  Do not pass
             credentials to IPv6_TCPServer constructor.
  (debug): New global debug flag.  Used by most debugging output code.
  (Client.__init__): Keyword argument "dn" replaced by "fingerprint",
                     "password" renamed to "secret", and "passfile"
                     renamed to "secfile".  New keyword argument
                     "checker". All callers changed.
  (Client.dn): Removed.
  (Client.fingerprint): New.
  (Client.password): Renamed to "secret"; all users changed.
  (Client.passfile): Renamed to "secfile"; all users changed.
  (Client.timeout, Client.interval): Changed to be properties; now
                                     automatically updates the
                                     "_timeout_milliseconds" and
                                     "_interval_milliseconds" values.
  (Client.timeout_milliseconds): Renamed to "_timeout_milliseconds".
  (Client.interval_milliseconds): Renamed to "_interval_milliseconds".
  (Client.check_command): New.
  (Client.start_checker): Use the new "check_command" attribute.
  (peer_certificate, fingerprint): New functions.

  (tcp_handler.handle): Use ClientSession with empty credentials
                        object instead of ServerSession.  Set gnutls
                        priority string.  Do not verify peer.  Use
                        fingerprint instead of DN when searching for
                        clients.  Bug fix: Loop sending data so even large
                        secret data strings are sent.
  (IPv6_TCPServer.credentials): Removed.
  (if_nametoindex): Do not import ctypes since that is now imported
                    globally.

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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
 
 
65
 
logger = logging.Logger('mandos')
66
 
syslogger = logging.handlers.SysLogHandler\
67
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
68
 
             address = "/dev/log")
69
 
syslogger.setFormatter(logging.Formatter\
70
 
                        ('Mandos: %(levelname)s: %(message)s'))
71
 
logger.addHandler(syslogger)
72
 
 
73
 
 
74
 
class AvahiError(Exception):
75
 
    def __init__(self, value):
76
 
        self.value = value
77
 
    def __str__(self):
78
 
        return repr(self.value)
79
 
 
80
 
class AvahiServiceError(AvahiError):
81
 
    pass
82
 
 
83
 
class AvahiGroupError(AvahiError):
84
 
    pass
85
 
 
86
 
 
87
 
class AvahiService(object):
88
 
    """An Avahi (Zeroconf) service.
89
 
    Attributes:
90
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
91
 
               Used to optionally bind to the specified interface.
92
 
    name: string; Example: 'Mandos'
93
 
    type: string; Example: '_mandos._tcp'.
94
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
95
 
    port: integer; what port to announce
96
 
    TXT: list of strings; TXT record for the service
97
 
    domain: string; Domain to publish on, default to .local if empty.
98
 
    host: string; Host to publish records for, default is localhost
99
 
    max_renames: integer; maximum number of renames
100
 
    rename_count: integer; counter so we only rename after collisions
101
 
                  a sensible number of times
102
 
    """
103
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
104
 
                 type = None, port = None, TXT = None, domain = "",
105
 
                 host = "", max_renames = 32768):
106
 
        self.interface = interface
107
 
        self.name = name
108
 
        self.type = type
109
 
        self.port = port
110
 
        if TXT is None:
111
 
            self.TXT = []
112
 
        else:
113
 
            self.TXT = TXT
114
 
        self.domain = domain
115
 
        self.host = host
116
 
        self.rename_count = 0
117
 
    def rename(self):
118
 
        """Derived from the Avahi example code"""
119
 
        if self.rename_count >= self.max_renames:
120
 
            logger.critical(u"No suitable service name found after %i"
121
 
                            u" retries, exiting.", rename_count)
122
 
            raise AvahiServiceError("Too many renames")
123
 
        name = server.GetAlternativeServiceName(name)
124
 
        logger.error(u"Changing name to %r ...", name)
125
 
        syslogger.setFormatter(logging.Formatter\
126
 
                               ('Mandos (%s): %%(levelname)s:'
127
 
                               ' %%(message)s' % name))
128
 
        self.remove()
129
 
        self.add()
130
 
        self.rename_count += 1
131
 
    def remove(self):
132
 
        """Derived from the Avahi example code"""
133
 
        if group is not None:
134
 
            group.Reset()
135
 
    def add(self):
136
 
        """Derived from the Avahi example code"""
137
 
        global group
138
 
        if group is None:
139
 
            group = dbus.Interface\
140
 
                    (bus.get_object(avahi.DBUS_NAME,
141
 
                                    server.EntryGroupNew()),
142
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
143
 
            group.connect_to_signal('StateChanged',
144
 
                                    entry_group_state_changed)
145
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
146
 
                     service.name, service.type)
147
 
        group.AddService(
148
 
                self.interface,         # interface
149
 
                avahi.PROTO_INET6,      # protocol
150
 
                dbus.UInt32(0),         # flags
151
 
                self.name, self.type,
152
 
                self.domain, self.host,
153
 
                dbus.UInt16(self.port),
154
 
                avahi.string_array_to_txt_array(self.TXT))
155
 
        group.Commit()
156
 
 
157
 
# From the Avahi example code:
158
 
group = None                            # our entry group
 
31
# This variable is used to optionally bind to a specified interface.
 
32
# It is a global variable to fit in with the other variables from the
 
33
# Avahi server example code.
 
34
serviceInterface = avahi.IF_UNSPEC
 
35
# From the Avahi server example code:
 
36
serviceName = "Mandos"
 
37
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
 
38
servicePort = None                      # Not known at startup
 
39
serviceTXT = []                         # TXT record for the service
 
40
domain = ""                  # Domain to publish on, default to .local
 
41
host = ""          # Host to publish records for, default to localhost
 
42
group = None #our entry group
 
43
rename_count = 12       # Counter so we only rename after collisions a
 
44
                        # sensible number of times
159
45
# End of Avahi example code
160
46
 
161
47
 
166
52
    fingerprint: string (40 or 32 hexadecimal digits); used to
167
53
                 uniquely identify the client
168
54
    secret:    bytestring; sent verbatim (over TLS) to client
169
 
    host:      string; available for use by the checker command
170
 
    created:   datetime.datetime(); object creation, not client host
171
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
172
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
173
 
                                     until this client is invalid
 
55
    fqdn:      string (FQDN); available for use by the checker command
 
56
    created:   datetime.datetime()
 
57
    last_seen: datetime.datetime() or None if not yet seen
 
58
    timeout:   datetime.timedelta(); How long from last_seen until
 
59
                                     this client is invalid
174
60
    interval:  datetime.timedelta(); How often to start a new checker
175
61
    stop_hook: If set, called by stop() as stop_hook(self)
176
62
    checker:   subprocess.Popen(); a running checker process used
177
63
                                   to see if the client lives.
178
 
                                   'None' if no process is running.
 
64
                                   Is None if no process is running.
179
65
    checker_initiator_tag: a gobject event source tag, or None
180
66
    stop_initiator_tag:    - '' -
181
67
    checker_callback_tag:  - '' -
182
68
    checker_command: string; External command which is run to check if
183
 
                     client lives.  %() expansions are done at
 
69
                     client lives.  %()s expansions are done at
184
70
                     runtime with vars(self) as dict, so that for
185
71
                     instance %(name)s can be used in the command.
186
72
    Private attibutes:
187
73
    _timeout: Real variable for 'timeout'
188
74
    _interval: Real variable for 'interval'
189
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
75
    _timeout_milliseconds: Used by gobject.timeout_add()
190
76
    _interval_milliseconds: - '' -
191
77
    """
192
78
    def _set_timeout(self, timeout):
212
98
    interval = property(lambda self: self._interval,
213
99
                        _set_interval)
214
100
    del _set_interval
215
 
    def __init__(self, name = None, stop_hook=None, config={}):
216
 
        """Note: the 'checker' key in 'config' sets the
217
 
        'checker_command' attribute and *not* the 'checker'
218
 
        attribute."""
 
101
    def __init__(self, name=None, options=None, stop_hook=None,
 
102
                 fingerprint=None, secret=None, secfile=None, fqdn=None,
 
103
                 timeout=None, interval=-1, checker=None):
219
104
        self.name = name
220
 
        logger.debug(u"Creating client %r", self.name)
221
 
        # Uppercase and remove spaces from fingerprint for later
222
 
        # comparison purposes with return value from the fingerprint()
223
 
        # function
224
 
        self.fingerprint = config["fingerprint"].upper()\
225
 
                           .replace(u" ", u"")
226
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
227
 
        if "secret" in config:
228
 
            self.secret = config["secret"].decode(u"base64")
229
 
        elif "secfile" in config:
230
 
            sf = open(config["secfile"])
 
105
        # Uppercase and remove spaces from fingerprint
 
106
        # for later comparison purposes with return value of
 
107
        # the fingerprint() function
 
108
        self.fingerprint = fingerprint.upper().replace(u" ", u"")
 
109
        if secret:
 
110
            self.secret = secret.decode(u"base64")
 
111
        elif secfile:
 
112
            sf = open(secfile)
231
113
            self.secret = sf.read()
232
114
            sf.close()
233
115
        else:
234
 
            raise TypeError(u"No secret or secfile for client %s"
235
 
                            % self.name)
236
 
        self.host = config.get("host", "")
 
116
            raise RuntimeError(u"No secret or secfile for client %s"
 
117
                               % self.name)
 
118
        self.fqdn = fqdn                # string
237
119
        self.created = datetime.datetime.now()
238
 
        self.last_checked_ok = None
239
 
        self.timeout = string_to_delta(config["timeout"])
240
 
        self.interval = string_to_delta(config["interval"])
 
120
        self.last_seen = None
 
121
        if timeout is None:
 
122
            timeout = options.timeout
 
123
        self.timeout = timeout
 
124
        if interval == -1:
 
125
            interval = options.interval
 
126
        else:
 
127
            interval = string_to_delta(interval)
 
128
        self.interval = interval
241
129
        self.stop_hook = stop_hook
242
130
        self.checker = None
243
131
        self.checker_initiator_tag = None
244
132
        self.stop_initiator_tag = None
245
133
        self.checker_callback_tag = None
246
 
        self.check_command = config["checker"]
 
134
        self.check_command = checker
247
135
    def start(self):
248
 
        """Start this client's checker and timeout hooks"""
 
136
        """Start this clients checker and timeout hooks"""
249
137
        # Schedule a new checker to be started an 'interval' from now,
250
138
        # and every interval from then on.
251
139
        self.checker_initiator_tag = gobject.timeout_add\
259
147
                                   self.stop)
260
148
    def stop(self):
261
149
        """Stop this client.
262
 
        The possibility that a client might be restarted is left open,
263
 
        but not currently used."""
264
 
        # If this client doesn't have a secret, it is already stopped.
265
 
        if hasattr(self, "secret") and self.secret:
266
 
            logger.info(u"Stopping client %s", self.name)
267
 
            self.secret = None
268
 
        else:
269
 
            return False
270
 
        if getattr(self, "stop_initiator_tag", False):
 
150
        The possibility that this client might be restarted is left
 
151
        open, but not currently used."""
 
152
        if debug:
 
153
            sys.stderr.write(u"Stopping client %s\n" % self.name)
 
154
        self.secret = None
 
155
        if self.stop_initiator_tag:
271
156
            gobject.source_remove(self.stop_initiator_tag)
272
157
            self.stop_initiator_tag = None
273
 
        if getattr(self, "checker_initiator_tag", False):
 
158
        if self.checker_initiator_tag:
274
159
            gobject.source_remove(self.checker_initiator_tag)
275
160
            self.checker_initiator_tag = None
276
161
        self.stop_checker()
279
164
        # Do not run this again if called by a gobject.timeout_add
280
165
        return False
281
166
    def __del__(self):
282
 
        self.stop_hook = None
283
 
        self.stop()
 
167
        # Some code duplication here and in stop()
 
168
        if hasattr(self, "stop_initiator_tag") \
 
169
               and self.stop_initiator_tag:
 
170
            gobject.source_remove(self.stop_initiator_tag)
 
171
            self.stop_initiator_tag = None
 
172
        if hasattr(self, "checker_initiator_tag") \
 
173
               and self.checker_initiator_tag:
 
174
            gobject.source_remove(self.checker_initiator_tag)
 
175
            self.checker_initiator_tag = None
 
176
        self.stop_checker()
284
177
    def checker_callback(self, pid, condition):
285
178
        """The checker has completed, so take appropriate actions."""
286
179
        now = datetime.datetime.now()
287
 
        self.checker_callback_tag = None
288
 
        self.checker = None
289
180
        if os.WIFEXITED(condition) \
290
181
               and (os.WEXITSTATUS(condition) == 0):
291
 
            logger.info(u"Checker for %(name)s succeeded",
292
 
                        vars(self))
293
 
            self.last_checked_ok = now
 
182
            if debug:
 
183
                sys.stderr.write(u"Checker for %(name)s succeeded\n"
 
184
                                 % vars(self))
 
185
            self.last_seen = now
294
186
            gobject.source_remove(self.stop_initiator_tag)
295
187
            self.stop_initiator_tag = gobject.timeout_add\
296
188
                                      (self._timeout_milliseconds,
297
189
                                       self.stop)
298
 
        elif not os.WIFEXITED(condition):
299
 
            logger.warning(u"Checker for %(name)s crashed?",
300
 
                           vars(self))
301
 
        else:
302
 
            logger.info(u"Checker for %(name)s failed",
303
 
                        vars(self))
 
190
        elif debug:
 
191
            if not os.WIFEXITED(condition):
 
192
                sys.stderr.write(u"Checker for %(name)s crashed?\n"
 
193
                                 % vars(self))
 
194
            else:
 
195
                sys.stderr.write(u"Checker for %(name)s failed\n"
 
196
                                 % vars(self))
 
197
        self.checker = None
 
198
        self.checker_callback_tag = None
304
199
    def start_checker(self):
305
200
        """Start a new checker subprocess if one is not running.
306
201
        If a checker already exists, leave it running and do
307
202
        nothing."""
308
 
        # The reason for not killing a running checker is that if we
309
 
        # did that, then if a checker (for some reason) started
310
 
        # running slowly and taking more than 'interval' time, the
311
 
        # client would inevitably timeout, since no checker would get
312
 
        # a chance to run to completion.  If we instead leave running
313
 
        # checkers alone, the checker would have to take more time
314
 
        # than 'timeout' for the client to be declared invalid, which
315
 
        # is as it should be.
316
203
        if self.checker is None:
 
204
            if debug:
 
205
                sys.stderr.write(u"Starting checker for %s\n"
 
206
                                 % self.name)
317
207
            try:
318
 
                # In case check_command has exactly one % operator
319
 
                command = self.check_command % self.host
 
208
                command = self.check_command % self.fqdn
320
209
            except TypeError:
321
 
                # Escape attributes for the shell
322
210
                escaped_attrs = dict((key, re.escape(str(val)))
323
211
                                     for key, val in
324
212
                                     vars(self).iteritems())
325
 
                try:
326
 
                    command = self.check_command % escaped_attrs
327
 
                except TypeError, error:
328
 
                    logger.error(u'Could not format string "%s":'
329
 
                                 u' %s', self.check_command, error)
330
 
                    return True # Try again later
 
213
                command = self.check_command % escaped_attrs
331
214
            try:
332
 
                logger.info(u"Starting checker %r for %s",
333
 
                            command, self.name)
334
 
                self.checker = subprocess.Popen(command,
335
 
                                                close_fds=True,
336
 
                                                shell=True, cwd="/")
337
 
                self.checker_callback_tag = gobject.child_watch_add\
338
 
                                            (self.checker.pid,
339
 
                                             self.checker_callback)
 
215
                self.checker = subprocess.\
 
216
                               Popen(command,
 
217
                                     stdout=subprocess.PIPE,
 
218
                                     close_fds=True, shell=True,
 
219
                                     cwd="/")
 
220
                self.checker_callback_tag = gobject.\
 
221
                                            child_watch_add(self.checker.pid,
 
222
                                                            self.\
 
223
                                                            checker_callback)
340
224
            except subprocess.OSError, error:
341
 
                logger.error(u"Failed to start subprocess: %s",
342
 
                             error)
 
225
                sys.stderr.write(u"Failed to start subprocess: %s\n"
 
226
                                 % error)
343
227
        # Re-run this periodically if run by gobject.timeout_add
344
228
        return True
345
229
    def stop_checker(self):
346
230
        """Force the checker process, if any, to stop."""
347
 
        if self.checker_callback_tag:
348
 
            gobject.source_remove(self.checker_callback_tag)
349
 
            self.checker_callback_tag = None
350
 
        if getattr(self, "checker", None) is None:
 
231
        if not hasattr(self, "checker") or self.checker is None:
351
232
            return
352
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
353
 
        try:
354
 
            os.kill(self.checker.pid, signal.SIGTERM)
355
 
            #os.sleep(0.5)
356
 
            #if self.checker.poll() is None:
357
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
358
 
        except OSError, error:
359
 
            if error.errno != errno.ESRCH: # No such process
360
 
                raise
 
233
        gobject.source_remove(self.checker_callback_tag)
 
234
        self.checker_callback_tag = None
 
235
        os.kill(self.checker.pid, signal.SIGTERM)
 
236
        if self.checker.poll() is None:
 
237
            os.kill(self.checker.pid, signal.SIGKILL)
361
238
        self.checker = None
362
 
    def still_valid(self):
 
239
    def still_valid(self, now=None):
363
240
        """Has the timeout not yet passed for this client?"""
364
 
        now = datetime.datetime.now()
365
 
        if self.last_checked_ok is None:
 
241
        if now is None:
 
242
            now = datetime.datetime.now()
 
243
        if self.last_seen is None:
366
244
            return now < (self.created + self.timeout)
367
245
        else:
368
 
            return now < (self.last_checked_ok + self.timeout)
 
246
            return now < (self.last_seen + self.timeout)
369
247
 
370
248
 
371
249
def peer_certificate(session):
372
 
    "Return the peer's OpenPGP certificate as a bytestring"
373
250
    # If not an OpenPGP certificate...
374
251
    if gnutls.library.functions.gnutls_certificate_type_get\
375
252
            (session._c_object) \
386
263
 
387
264
 
388
265
def fingerprint(openpgp):
389
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
266
    # New empty GnuTLS certificate
 
267
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
268
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
269
        (ctypes.byref(crt))
390
270
    # New GnuTLS "datum" with the OpenPGP public key
391
271
    datum = gnutls.library.types.gnutls_datum_t\
392
272
        (ctypes.cast(ctypes.c_char_p(openpgp),
393
273
                     ctypes.POINTER(ctypes.c_ubyte)),
394
274
         ctypes.c_uint(len(openpgp)))
395
 
    # New empty GnuTLS certificate
396
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
397
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
398
 
        (ctypes.byref(crt))
399
275
    # Import the OpenPGP public key into the certificate
400
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
401
 
                    (crt, ctypes.byref(datum),
402
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
276
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
 
277
        (crt,
 
278
         ctypes.byref(datum),
 
279
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
403
280
    # New buffer for the fingerprint
404
281
    buffer = ctypes.create_string_buffer(20)
405
282
    buffer_length = ctypes.c_size_t()
421
298
    Note: This will run in its own forked process."""
422
299
    
423
300
    def handle(self):
424
 
        logger.info(u"TCP connection from: %s",
425
 
                     unicode(self.client_address))
426
 
        session = gnutls.connection.ClientSession\
427
 
                  (self.request, gnutls.connection.X509Credentials())
428
 
        
429
 
        line = self.request.makefile().readline()
430
 
        logger.debug(u"Protocol version: %r", line)
431
 
        try:
432
 
            if int(line.strip().split()[0]) > 1:
433
 
                raise RuntimeError
434
 
        except (ValueError, IndexError, RuntimeError), error:
435
 
            logger.error(u"Unknown protocol version: %s", error)
436
 
            return
437
 
        
438
 
        # Note: gnutls.connection.X509Credentials is really a generic
439
 
        # GnuTLS certificate credentials object so long as no X.509
440
 
        # keys are added to it.  Therefore, we can use it here despite
441
 
        # using OpenPGP certificates.
 
301
        if debug:
 
302
            sys.stderr.write(u"TCP request came\n")
 
303
            sys.stderr.write(u"Request: %s\n" % self.request)
 
304
            sys.stderr.write(u"Client Address: %s\n"
 
305
                             % unicode(self.client_address))
 
306
            sys.stderr.write(u"Server: %s\n" % self.server)
 
307
        session = gnutls.connection.ClientSession(self.request,
 
308
                                                  gnutls.connection.\
 
309
                                                  X509Credentials())
442
310
        
443
311
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
444
312
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
445
313
        #                "+DHE-DSS"))
446
 
        priority = "NORMAL"             # Fallback default, since this
447
 
                                        # MUST be set.
448
 
        if self.server.settings["priority"]:
449
 
            priority = self.server.settings["priority"]
 
314
        priority = "SECURE256"
 
315
        
450
316
        gnutls.library.functions.gnutls_priority_set_direct\
451
317
            (session._c_object, priority, None);
452
318
        
453
319
        try:
454
320
            session.handshake()
455
321
        except gnutls.errors.GNUTLSError, error:
456
 
            logger.warning(u"Handshake failed: %s", error)
 
322
            if debug:
 
323
                sys.stderr.write(u"Handshake failed: %s\n" % error)
457
324
            # Do not run session.bye() here: the session is not
458
325
            # established.  Just abandon the request.
459
326
            return
460
327
        try:
461
328
            fpr = fingerprint(peer_certificate(session))
462
329
        except (TypeError, gnutls.errors.GNUTLSError), error:
463
 
            logger.warning(u"Bad certificate: %s", error)
 
330
            if debug:
 
331
                sys.stderr.write(u"Bad certificate: %s\n" % error)
464
332
            session.bye()
465
333
            return
466
 
        logger.debug(u"Fingerprint: %s", fpr)
 
334
        if debug:
 
335
            sys.stderr.write(u"Fingerprint: %s\n" % fpr)
467
336
        client = None
468
 
        for c in self.server.clients:
 
337
        for c in clients:
469
338
            if c.fingerprint == fpr:
470
339
                client = c
471
340
                break
472
 
        if not client:
473
 
            logger.warning(u"Client not found for fingerprint: %s",
474
 
                           fpr)
475
 
            session.bye()
476
 
            return
477
341
        # Have to check if client.still_valid(), since it is possible
478
342
        # that the client timed out while establishing the GnuTLS
479
343
        # session.
480
 
        if not client.still_valid():
481
 
            logger.warning(u"Client %(name)s is invalid",
482
 
                           vars(client))
 
344
        if (not client) or (not client.still_valid()):
 
345
            if debug:
 
346
                if client:
 
347
                    sys.stderr.write(u"Client %(name)s is invalid\n"
 
348
                                     % vars(client))
 
349
                else:
 
350
                    sys.stderr.write(u"Client not found for "
 
351
                                     u"fingerprint: %s\n" % fpr)
483
352
            session.bye()
484
353
            return
485
354
        sent_size = 0
486
355
        while sent_size < len(client.secret):
487
356
            sent = session.send(client.secret[sent_size:])
488
 
            logger.debug(u"Sent: %d, remaining: %d",
489
 
                         sent, len(client.secret)
490
 
                         - (sent_size + sent))
 
357
            if debug:
 
358
                sys.stderr.write(u"Sent: %d, remaining: %d\n"
 
359
                                 % (sent, len(client.secret)
 
360
                                    - (sent_size + sent)))
491
361
            sent_size += sent
492
362
        session.bye()
493
363
 
495
365
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
496
366
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
497
367
    Attributes:
498
 
        settings:       Server settings
 
368
        options:        Command line options
499
369
        clients:        Set() of Client objects
500
370
    """
501
371
    address_family = socket.AF_INET6
502
372
    def __init__(self, *args, **kwargs):
503
 
        if "settings" in kwargs:
504
 
            self.settings = kwargs["settings"]
505
 
            del kwargs["settings"]
 
373
        if "options" in kwargs:
 
374
            self.options = kwargs["options"]
 
375
            del kwargs["options"]
506
376
        if "clients" in kwargs:
507
377
            self.clients = kwargs["clients"]
508
378
            del kwargs["clients"]
511
381
        """This overrides the normal server_bind() function
512
382
        to bind to an interface if one was specified, and also NOT to
513
383
        bind to an address or port if they were not specified."""
514
 
        if self.settings["interface"]:
515
 
            # 25 is from /usr/include/asm-i486/socket.h
516
 
            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
517
388
            try:
518
389
                self.socket.setsockopt(socket.SOL_SOCKET,
519
 
                                       SO_BINDTODEVICE,
520
 
                                       self.settings["interface"])
 
390
                                       socket.SO_BINDTODEVICE,
 
391
                                       self.options.interface)
521
392
            except socket.error, error:
522
393
                if error[0] == errno.EPERM:
523
 
                    logger.error(u"No permission to"
524
 
                                 u" bind to interface %s",
525
 
                                 self.settings["interface"])
 
394
                    sys.stderr.write(u"Warning: No permission to" \
 
395
                                     u" bind to interface %s\n"
 
396
                                     % self.options.interface)
526
397
                else:
527
398
                    raise error
528
399
        # Only bind(2) the socket if we really need to.
531
402
                in6addr_any = "::"
532
403
                self.server_address = (in6addr_any,
533
404
                                       self.server_address[1])
534
 
            elif not self.server_address[1]:
 
405
            elif self.server_address[1] is None:
535
406
                self.server_address = (self.server_address[0],
536
407
                                       0)
537
 
#                 if self.settings["interface"]:
538
 
#                     self.server_address = (self.server_address[0],
539
 
#                                            0, # port
540
 
#                                            0, # flowinfo
541
 
#                                            if_nametoindex
542
 
#                                            (self.settings
543
 
#                                             ["interface"]))
544
408
            return super(type(self), self).server_bind()
545
409
 
546
410
 
578
442
    return delta
579
443
 
580
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
    if debug:
 
457
        sys.stderr.write(u"Adding service '%s' of type '%s' ...\n"
 
458
                         % (serviceName, serviceType))
 
459
    
 
460
    group.AddService(
 
461
            serviceInterface,           # interface
 
462
            avahi.PROTO_INET6,          # protocol
 
463
            dbus.UInt32(0),             # flags
 
464
            serviceName, serviceType,
 
465
            domain, host,
 
466
            dbus.UInt16(servicePort),
 
467
            avahi.string_array_to_txt_array(serviceTXT))
 
468
    group.Commit()
 
469
 
 
470
 
 
471
def remove_service():
 
472
    """From the Avahi server example code"""
 
473
    global group
 
474
    
 
475
    if not group is None:
 
476
        group.Reset()
 
477
 
 
478
 
581
479
def server_state_changed(state):
582
 
    """Derived from the Avahi example code"""
 
480
    """From the Avahi server example code"""
583
481
    if state == avahi.SERVER_COLLISION:
584
 
        logger.error(u"Server name collision")
585
 
        service.remove()
 
482
        sys.stderr.write(u"WARNING: Server name collision\n")
 
483
        remove_service()
586
484
    elif state == avahi.SERVER_RUNNING:
587
 
        service.add()
 
485
        add_service()
588
486
 
589
487
 
590
488
def entry_group_state_changed(state, error):
591
 
    """Derived from the Avahi example code"""
592
 
    logger.debug(u"state change: %i", state)
 
489
    """From the Avahi server example code"""
 
490
    global serviceName, server, rename_count
 
491
    
 
492
    if debug:
 
493
        sys.stderr.write(u"state change: %i\n" % state)
593
494
    
594
495
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
595
 
        logger.debug(u"Service established.")
 
496
        if debug:
 
497
            sys.stderr.write(u"Service established.\n")
596
498
    elif state == avahi.ENTRY_GROUP_COLLISION:
597
 
        logger.warning(u"Service name collision.")
598
 
        service.rename()
 
499
        
 
500
        rename_count = rename_count - 1
 
501
        if rename_count > 0:
 
502
            name = server.GetAlternativeServiceName(name)
 
503
            sys.stderr.write(u"WARNING: Service name collision, "
 
504
                             u"changing name to '%s' ...\n" % name)
 
505
            remove_service()
 
506
            add_service()
 
507
            
 
508
        else:
 
509
            sys.stderr.write(u"ERROR: No suitable service name found "
 
510
                             u"after %i retries, exiting.\n"
 
511
                             % n_rename)
 
512
            main_loop.quit()
599
513
    elif state == avahi.ENTRY_GROUP_FAILURE:
600
 
        logger.critical(u"Error in group state changed %s",
601
 
                        unicode(error))
602
 
        raise AvahiGroupError("State changed: %s", str(error))
 
514
        sys.stderr.write(u"Error in group state changed %s\n"
 
515
                         % unicode(error))
 
516
        main_loop.quit()
 
517
        return
 
518
 
603
519
 
604
520
def if_nametoindex(interface):
605
 
    """Call the C function if_nametoindex(), or equivalent"""
606
 
    global if_nametoindex
 
521
    """Call the C function if_nametoindex()"""
607
522
    try:
608
 
        if "ctypes.util" not in sys.modules:
609
 
            import ctypes.util
610
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
611
 
            (ctypes.util.find_library("c")).if_nametoindex
 
523
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
524
        return libc.if_nametoindex(interface)
612
525
    except (OSError, AttributeError):
613
526
        if "struct" not in sys.modules:
614
527
            import struct
615
528
        if "fcntl" not in sys.modules:
616
529
            import fcntl
617
 
        def if_nametoindex(interface):
618
 
            "Get an interface index the hard way, i.e. using fcntl()"
619
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
620
 
            s = socket.socket()
621
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
622
 
                                struct.pack("16s16x", interface))
623
 
            s.close()
624
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
625
 
            return interface_index
626
 
    return if_nametoindex(interface)
627
 
 
628
 
 
629
 
def daemon(nochdir = False, noclose = False):
630
 
    """See daemon(3).  Standard BSD Unix function.
631
 
    This should really exist as os.daemon, but it doesn't (yet)."""
632
 
    if os.fork():
633
 
        sys.exit()
634
 
    os.setsid()
635
 
    if not nochdir:
636
 
        os.chdir("/")
637
 
    if os.fork():
638
 
        sys.exit()
639
 
    if not noclose:
640
 
        # Close all standard open file descriptors
641
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
642
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
643
 
            raise OSError(errno.ENODEV,
644
 
                          "/dev/null not a character device")
645
 
        os.dup2(null, sys.stdin.fileno())
646
 
        os.dup2(null, sys.stdout.fileno())
647
 
        os.dup2(null, sys.stderr.fileno())
648
 
        if null > 2:
649
 
            os.close(null)
650
 
 
651
 
 
652
 
def main():
653
 
    global main_loop_started
654
 
    main_loop_started = False
655
 
    
 
530
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
 
531
        s = socket.socket()
 
532
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
533
                            struct.pack("16s16x", interface))
 
534
        s.close()
 
535
        interface_index = struct.unpack("I", ifreq[16:20])[0]
 
536
        return interface_index
 
537
 
 
538
 
 
539
if __name__ == '__main__':
656
540
    parser = OptionParser()
657
541
    parser.add_option("-i", "--interface", type="string",
658
 
                      metavar="IF", help="Bind to interface IF")
659
 
    parser.add_option("-a", "--address", type="string",
660
 
                      help="Address to listen for requests on")
661
 
    parser.add_option("-p", "--port", type="int",
 
542
                      default=None, metavar="IF",
 
543
                      help="Bind to interface IF")
 
544
    parser.add_option("--cert", type="string", default="cert.pem",
 
545
                      metavar="FILE",
 
546
                      help="Public key certificate PEM file to use")
 
547
    parser.add_option("--key", type="string", default="key.pem",
 
548
                      metavar="FILE",
 
549
                      help="Private key PEM file to use")
 
550
    parser.add_option("--ca", type="string", default="ca.pem",
 
551
                      metavar="FILE",
 
552
                      help="Certificate Authority certificate PEM file to use")
 
553
    parser.add_option("--crl", type="string", default="crl.pem",
 
554
                      metavar="FILE",
 
555
                      help="Certificate Revokation List PEM file to use")
 
556
    parser.add_option("-p", "--port", type="int", default=None,
662
557
                      help="Port number to receive requests on")
 
558
    parser.add_option("--timeout", type="string", # Parsed later
 
559
                      default="1h",
 
560
                      help="Amount of downtime allowed for clients")
 
561
    parser.add_option("--interval", type="string", # Parsed later
 
562
                      default="5m",
 
563
                      help="How often to check that a client is up")
663
564
    parser.add_option("--check", action="store_true", default=False,
664
565
                      help="Run self-test")
665
 
    parser.add_option("--debug", action="store_true",
666
 
                      help="Debug mode; run in foreground and log to"
667
 
                      " terminal")
668
 
    parser.add_option("--priority", type="string", help="GnuTLS"
669
 
                      " priority string (see GnuTLS documentation)")
670
 
    parser.add_option("--servicename", type="string", metavar="NAME",
671
 
                      help="Zeroconf service name")
672
 
    parser.add_option("--configdir", type="string",
673
 
                      default="/etc/mandos", metavar="DIR",
674
 
                      help="Directory to search for configuration"
675
 
                      " files")
 
566
    parser.add_option("--debug", action="store_true", default=False,
 
567
                      help="Debug mode")
676
568
    (options, args) = parser.parse_args()
677
569
    
678
570
    if options.check:
680
572
        doctest.testmod()
681
573
        sys.exit()
682
574
    
683
 
    # Default values for config file for server-global settings
684
 
    server_defaults = { "interface": "",
685
 
                        "address": "",
686
 
                        "port": "",
687
 
                        "debug": "False",
688
 
                        "priority":
689
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
690
 
                        "servicename": "Mandos",
691
 
                        }
692
 
    
693
 
    # Parse config file for server-global settings
694
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
695
 
    del server_defaults
696
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
697
 
    server_section = "server"
698
 
    # Convert the SafeConfigParser object to a dict
699
 
    server_settings = dict(server_config.items(server_section))
700
 
    # Use getboolean on the boolean config option
701
 
    server_settings["debug"] = server_config.getboolean\
702
 
                               (server_section, "debug")
703
 
    del server_config
704
 
    
705
 
    # Override the settings from the config file with command line
706
 
    # options, if set.
707
 
    for option in ("interface", "address", "port", "debug",
708
 
                   "priority", "servicename", "configdir"):
709
 
        value = getattr(options, option)
710
 
        if value is not None:
711
 
            server_settings[option] = value
712
 
    del options
713
 
    # Now we have our good server settings in "server_settings"
714
 
    
715
 
    debug = server_settings["debug"]
716
 
    
717
 
    if not debug:
718
 
        syslogger.setLevel(logging.WARNING)
719
 
    
720
 
    if server_settings["servicename"] != "Mandos":
721
 
        syslogger.setFormatter(logging.Formatter\
722
 
                               ('Mandos (%s): %%(levelname)s:'
723
 
                                ' %%(message)s'
724
 
                                % server_settings["servicename"]))
725
 
    
726
 
    # Parse config file with clients
727
 
    client_defaults = { "timeout": "1h",
728
 
                        "interval": "5m",
729
 
                        "checker": "fping -q -- %%(host)s",
730
 
                        }
731
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
732
 
    client_config.read(os.path.join(server_settings["configdir"],
733
 
                                    "clients.conf"))
734
 
    
735
 
    global service
736
 
    service = AvahiService(name = server_settings["servicename"],
737
 
                           type = "_mandos._tcp", );
738
 
    if server_settings["interface"]:
739
 
        service.interface = if_nametoindex(server_settings["interface"])
740
 
    
741
 
    global main_loop
742
 
    global bus
743
 
    global server
744
 
    # From the Avahi example code
 
575
    # Parse the time arguments
 
576
    try:
 
577
        options.timeout = string_to_delta(options.timeout)
 
578
    except ValueError:
 
579
        parser.error("option --timeout: Unparseable time")
 
580
    try:
 
581
        options.interval = string_to_delta(options.interval)
 
582
    except ValueError:
 
583
        parser.error("option --interval: Unparseable time")
 
584
    
 
585
    # Parse config file
 
586
    defaults = { "checker": "sleep 1; fping -q -- %%(fqdn)s" }
 
587
    client_config = ConfigParser.SafeConfigParser(defaults)
 
588
    #client_config.readfp(open("secrets.conf"), "secrets.conf")
 
589
    client_config.read("mandos-clients.conf")
 
590
    
 
591
    # From the Avahi server example code
745
592
    DBusGMainLoop(set_as_default=True )
746
593
    main_loop = gobject.MainLoop()
747
594
    bus = dbus.SystemBus()
750
597
            avahi.DBUS_INTERFACE_SERVER )
751
598
    # End of Avahi example code
752
599
    
753
 
    if debug:
754
 
        console = logging.StreamHandler()
755
 
        # console.setLevel(logging.DEBUG)
756
 
        console.setFormatter(logging.Formatter\
757
 
                             ('%(levelname)s: %(message)s'))
758
 
        logger.addHandler(console)
759
 
        del console
 
600
    debug = options.debug
760
601
    
761
602
    clients = Set()
762
603
    def remove_from_clients(client):
763
604
        clients.remove(client)
764
605
        if not clients:
765
 
            logger.critical(u"No clients left, exiting")
766
 
            sys.exit()
 
606
            if debug:
 
607
                sys.stderr.write(u"No clients left, exiting\n")
 
608
            main_loop.quit()
767
609
    
768
 
    clients.update(Set(Client(name = section,
 
610
    clients.update(Set(Client(name=section, options=options,
769
611
                              stop_hook = remove_from_clients,
770
 
                              config
771
 
                              = dict(client_config.items(section)))
 
612
                              **(dict(client_config\
 
613
                                      .items(section))))
772
614
                       for section in client_config.sections()))
773
 
    if not clients:
774
 
        logger.critical(u"No clients defined")
775
 
        sys.exit(1)
776
 
    
777
 
    if not debug:
778
 
        daemon()
779
 
    
780
 
    pidfilename = "/var/run/mandos/mandos.pid"
781
 
    pid = os.getpid()
782
 
    try:
783
 
        pidfile = open(pidfilename, "w")
784
 
        pidfile.write(str(pid) + "\n")
785
 
        pidfile.close()
786
 
        del pidfile
787
 
    except IOError, err:
788
 
        logger.error(u"Could not write %s file with PID %d",
789
 
                     pidfilename, os.getpid())
790
 
    
791
 
    def cleanup():
792
 
        "Cleanup function; run on exit"
793
 
        global group
794
 
        # From the Avahi example code
795
 
        if not group is None:
796
 
            group.Free()
797
 
            group = None
798
 
        # End of Avahi example code
799
 
        
800
 
        while clients:
801
 
            client = clients.pop()
802
 
            client.stop_hook = None
803
 
            client.stop()
804
 
    
805
 
    atexit.register(cleanup)
806
 
    
807
 
    if not debug:
808
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
809
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
810
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
811
 
    
812
615
    for client in clients:
813
616
        client.start()
814
617
    
815
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
816
 
                                 server_settings["port"]),
 
618
    tcp_server = IPv6_TCPServer((None, options.port),
817
619
                                tcp_handler,
818
 
                                settings=server_settings,
 
620
                                options=options,
819
621
                                clients=clients)
820
 
    # Find out what port we got
821
 
    service.port = tcp_server.socket.getsockname()[1]
822
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
823
 
                u" scope_id %d" % tcp_server.socket.getsockname())
824
 
    
825
 
    #service.interface = tcp_server.socket.getsockname()[3]
826
 
    
 
622
    # Find out what random port we got
 
623
    servicePort = tcp_server.socket.getsockname()[1]
 
624
    if debug:
 
625
        sys.stderr.write(u"Now listening on port %d\n" % servicePort)
 
626
    
 
627
    if options.interface is not None:
 
628
        serviceInterface = if_nametoindex(options.interface)
 
629
    
 
630
    # From the Avahi server example code
 
631
    server.connect_to_signal("StateChanged", server_state_changed)
 
632
    server_state_changed(server.GetState())
 
633
    # End of Avahi example code
 
634
    
 
635
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
636
                         lambda *args, **kwargs:
 
637
                         tcp_server.handle_request(*args[2:],
 
638
                                                   **kwargs) or True)
827
639
    try:
828
 
        # From the Avahi example code
829
 
        server.connect_to_signal("StateChanged", server_state_changed)
830
 
        try:
831
 
            server_state_changed(server.GetState())
832
 
        except dbus.exceptions.DBusException, error:
833
 
            logger.critical(u"DBusException: %s", error)
834
 
            sys.exit(1)
835
 
        # End of Avahi example code
836
 
        
837
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
838
 
                             lambda *args, **kwargs:
839
 
                             tcp_server.handle_request\
840
 
                             (*args[2:], **kwargs) or True)
841
 
        
842
 
        logger.debug(u"Starting main loop")
843
 
        main_loop_started = True
844
640
        main_loop.run()
845
 
    except AvahiError, error:
846
 
        logger.critical(u"AvahiError: %s" + unicode(error))
847
 
        sys.exit(1)
848
641
    except KeyboardInterrupt:
849
 
        if debug:
850
 
            print
 
642
        print
 
643
    
 
644
    # Cleanup here
851
645
 
852
 
if __name__ == '__main__':
853
 
    main()
 
646
    # From the Avahi server example code
 
647
    if not group is None:
 
648
        group.Free()
 
649
    # End of Avahi example code
 
650
    
 
651
    for client in clients:
 
652
        client.stop_hook = None
 
653
        client.stop()