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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
 
version = "1.0"
65
 
 
66
 
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
 
console = logging.StreamHandler()
75
 
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
76
 
                                       ' %(message)s'))
77
 
logger.addHandler(console)
78
 
 
79
 
class AvahiError(Exception):
80
 
    def __init__(self, value):
81
 
        self.value = value
82
 
    def __str__(self):
83
 
        return repr(self.value)
84
 
 
85
 
class AvahiServiceError(AvahiError):
86
 
    pass
87
 
 
88
 
class AvahiGroupError(AvahiError):
89
 
    pass
90
 
 
91
 
 
92
 
class AvahiService(object):
93
 
    """An Avahi (Zeroconf) service.
94
 
    Attributes:
95
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
96
 
               Used to optionally bind to the specified interface.
97
 
    name: string; Example: 'Mandos'
98
 
    type: string; Example: '_mandos._tcp'.
99
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
100
 
    port: integer; what port to announce
101
 
    TXT: list of strings; TXT record for the service
102
 
    domain: string; Domain to publish on, default to .local if empty.
103
 
    host: string; Host to publish records for, default is localhost
104
 
    max_renames: integer; maximum number of renames
105
 
    rename_count: integer; counter so we only rename after collisions
106
 
                  a sensible number of times
107
 
    """
108
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
109
 
                 type = None, port = None, TXT = None, domain = "",
110
 
                 host = "", max_renames = 32768):
111
 
        self.interface = interface
112
 
        self.name = name
113
 
        self.type = type
114
 
        self.port = port
115
 
        if TXT is None:
116
 
            self.TXT = []
117
 
        else:
118
 
            self.TXT = TXT
119
 
        self.domain = domain
120
 
        self.host = host
121
 
        self.rename_count = 0
122
 
        self.max_renames = max_renames
123
 
    def rename(self):
124
 
        """Derived from the Avahi example code"""
125
 
        if self.rename_count >= self.max_renames:
126
 
            logger.critical(u"No suitable service name found after %i"
127
 
                            u" retries, exiting.", rename_count)
128
 
            raise AvahiServiceError("Too many renames")
129
 
        self.name = server.GetAlternativeServiceName(self.name)
130
 
        logger.info(u"Changing name to %r ...", str(self.name))
131
 
        syslogger.setFormatter(logging.Formatter\
132
 
                               ('Mandos (%s): %%(levelname)s:'
133
 
                               ' %%(message)s' % self.name))
134
 
        self.remove()
135
 
        self.add()
136
 
        self.rename_count += 1
137
 
    def remove(self):
138
 
        """Derived from the Avahi example code"""
139
 
        if group is not None:
140
 
            group.Reset()
141
 
    def add(self):
142
 
        """Derived from the Avahi example code"""
143
 
        global group
144
 
        if group is None:
145
 
            group = dbus.Interface\
146
 
                    (bus.get_object(avahi.DBUS_NAME,
147
 
                                    server.EntryGroupNew()),
148
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
149
 
            group.connect_to_signal('StateChanged',
150
 
                                    entry_group_state_changed)
151
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
152
 
                     service.name, service.type)
153
 
        group.AddService(
154
 
                self.interface,         # interface
155
 
                avahi.PROTO_INET6,      # protocol
156
 
                dbus.UInt32(0),         # flags
157
 
                self.name, self.type,
158
 
                self.domain, self.host,
159
 
                dbus.UInt16(self.port),
160
 
                avahi.string_array_to_txt_array(self.TXT))
161
 
        group.Commit()
162
 
 
163
 
# From the Avahi example code:
164
 
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
165
45
# End of Avahi example code
166
46
 
167
47
 
172
52
    fingerprint: string (40 or 32 hexadecimal digits); used to
173
53
                 uniquely identify the client
174
54
    secret:    bytestring; sent verbatim (over TLS) to client
175
 
    host:      string; available for use by the checker command
176
 
    created:   datetime.datetime(); object creation, not client host
177
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
178
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
179
 
                                     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
180
60
    interval:  datetime.timedelta(); How often to start a new checker
181
61
    stop_hook: If set, called by stop() as stop_hook(self)
182
62
    checker:   subprocess.Popen(); a running checker process used
183
63
                                   to see if the client lives.
184
 
                                   'None' if no process is running.
 
64
                                   Is None if no process is running.
185
65
    checker_initiator_tag: a gobject event source tag, or None
186
66
    stop_initiator_tag:    - '' -
187
67
    checker_callback_tag:  - '' -
188
68
    checker_command: string; External command which is run to check if
189
 
                     client lives.  %() expansions are done at
 
69
                     client lives.  %()s expansions are done at
190
70
                     runtime with vars(self) as dict, so that for
191
71
                     instance %(name)s can be used in the command.
192
72
    Private attibutes:
193
73
    _timeout: Real variable for 'timeout'
194
74
    _interval: Real variable for 'interval'
195
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
75
    _timeout_milliseconds: Used by gobject.timeout_add()
196
76
    _interval_milliseconds: - '' -
197
77
    """
198
78
    def _set_timeout(self, timeout):
218
98
    interval = property(lambda self: self._interval,
219
99
                        _set_interval)
220
100
    del _set_interval
221
 
    def __init__(self, name = None, stop_hook=None, config={}):
222
 
        """Note: the 'checker' key in 'config' sets the
223
 
        'checker_command' attribute and *not* the 'checker'
224
 
        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):
225
104
        self.name = name
226
 
        logger.debug(u"Creating client %r", self.name)
227
 
        # Uppercase and remove spaces from fingerprint for later
228
 
        # comparison purposes with return value from the fingerprint()
229
 
        # function
230
 
        self.fingerprint = config["fingerprint"].upper()\
231
 
                           .replace(u" ", u"")
232
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
233
 
        if "secret" in config:
234
 
            self.secret = config["secret"].decode(u"base64")
235
 
        elif "secfile" in config:
236
 
            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)
237
113
            self.secret = sf.read()
238
114
            sf.close()
239
115
        else:
240
 
            raise TypeError(u"No secret or secfile for client %s"
241
 
                            % self.name)
242
 
        self.host = config.get("host", "")
 
116
            raise RuntimeError(u"No secret or secfile for client %s"
 
117
                               % self.name)
 
118
        self.fqdn = fqdn                # string
243
119
        self.created = datetime.datetime.now()
244
 
        self.last_checked_ok = None
245
 
        self.timeout = string_to_delta(config["timeout"])
246
 
        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
247
129
        self.stop_hook = stop_hook
248
130
        self.checker = None
249
131
        self.checker_initiator_tag = None
250
132
        self.stop_initiator_tag = None
251
133
        self.checker_callback_tag = None
252
 
        self.check_command = config["checker"]
 
134
        self.check_command = checker
253
135
    def start(self):
254
 
        """Start this client's checker and timeout hooks"""
 
136
        """Start this clients checker and timeout hooks"""
255
137
        # Schedule a new checker to be started an 'interval' from now,
256
138
        # and every interval from then on.
257
139
        self.checker_initiator_tag = gobject.timeout_add\
265
147
                                   self.stop)
266
148
    def stop(self):
267
149
        """Stop this client.
268
 
        The possibility that a client might be restarted is left open,
269
 
        but not currently used."""
270
 
        # If this client doesn't have a secret, it is already stopped.
271
 
        if hasattr(self, "secret") and self.secret:
272
 
            logger.info(u"Stopping client %s", self.name)
273
 
            self.secret = None
274
 
        else:
275
 
            return False
276
 
        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:
277
156
            gobject.source_remove(self.stop_initiator_tag)
278
157
            self.stop_initiator_tag = None
279
 
        if getattr(self, "checker_initiator_tag", False):
 
158
        if self.checker_initiator_tag:
280
159
            gobject.source_remove(self.checker_initiator_tag)
281
160
            self.checker_initiator_tag = None
282
161
        self.stop_checker()
285
164
        # Do not run this again if called by a gobject.timeout_add
286
165
        return False
287
166
    def __del__(self):
288
 
        self.stop_hook = None
289
 
        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()
290
177
    def checker_callback(self, pid, condition):
291
178
        """The checker has completed, so take appropriate actions."""
292
179
        now = datetime.datetime.now()
293
 
        self.checker_callback_tag = None
294
 
        self.checker = None
295
180
        if os.WIFEXITED(condition) \
296
181
               and (os.WEXITSTATUS(condition) == 0):
297
 
            logger.info(u"Checker for %(name)s succeeded",
298
 
                        vars(self))
299
 
            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
300
186
            gobject.source_remove(self.stop_initiator_tag)
301
187
            self.stop_initiator_tag = gobject.timeout_add\
302
188
                                      (self._timeout_milliseconds,
303
189
                                       self.stop)
304
 
        elif not os.WIFEXITED(condition):
305
 
            logger.warning(u"Checker for %(name)s crashed?",
306
 
                           vars(self))
307
 
        else:
308
 
            logger.info(u"Checker for %(name)s failed",
309
 
                        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
310
199
    def start_checker(self):
311
200
        """Start a new checker subprocess if one is not running.
312
201
        If a checker already exists, leave it running and do
313
202
        nothing."""
314
 
        # The reason for not killing a running checker is that if we
315
 
        # did that, then if a checker (for some reason) started
316
 
        # running slowly and taking more than 'interval' time, the
317
 
        # client would inevitably timeout, since no checker would get
318
 
        # a chance to run to completion.  If we instead leave running
319
 
        # checkers alone, the checker would have to take more time
320
 
        # than 'timeout' for the client to be declared invalid, which
321
 
        # is as it should be.
322
203
        if self.checker is None:
 
204
            if debug:
 
205
                sys.stderr.write(u"Starting checker for %s\n"
 
206
                                 % self.name)
323
207
            try:
324
 
                # In case check_command has exactly one % operator
325
 
                command = self.check_command % self.host
 
208
                command = self.check_command % self.fqdn
326
209
            except TypeError:
327
 
                # Escape attributes for the shell
328
210
                escaped_attrs = dict((key, re.escape(str(val)))
329
211
                                     for key, val in
330
212
                                     vars(self).iteritems())
331
 
                try:
332
 
                    command = self.check_command % escaped_attrs
333
 
                except TypeError, error:
334
 
                    logger.error(u'Could not format string "%s":'
335
 
                                 u' %s', self.check_command, error)
336
 
                    return True # Try again later
 
213
                command = self.check_command % escaped_attrs
337
214
            try:
338
 
                logger.info(u"Starting checker %r for %s",
339
 
                            command, self.name)
340
 
                self.checker = subprocess.Popen(command,
341
 
                                                close_fds=True,
342
 
                                                shell=True, cwd="/")
343
 
                self.checker_callback_tag = gobject.child_watch_add\
344
 
                                            (self.checker.pid,
345
 
                                             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)
346
224
            except subprocess.OSError, error:
347
 
                logger.error(u"Failed to start subprocess: %s",
348
 
                             error)
 
225
                sys.stderr.write(u"Failed to start subprocess: %s\n"
 
226
                                 % error)
349
227
        # Re-run this periodically if run by gobject.timeout_add
350
228
        return True
351
229
    def stop_checker(self):
352
230
        """Force the checker process, if any, to stop."""
353
 
        if self.checker_callback_tag:
354
 
            gobject.source_remove(self.checker_callback_tag)
355
 
            self.checker_callback_tag = None
356
 
        if getattr(self, "checker", None) is None:
 
231
        if not hasattr(self, "checker") or self.checker is None:
357
232
            return
358
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
359
 
        try:
360
 
            os.kill(self.checker.pid, signal.SIGTERM)
361
 
            #os.sleep(0.5)
362
 
            #if self.checker.poll() is None:
363
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
364
 
        except OSError, error:
365
 
            if error.errno != errno.ESRCH: # No such process
366
 
                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)
367
238
        self.checker = None
368
 
    def still_valid(self):
 
239
    def still_valid(self, now=None):
369
240
        """Has the timeout not yet passed for this client?"""
370
 
        now = datetime.datetime.now()
371
 
        if self.last_checked_ok is None:
 
241
        if now is None:
 
242
            now = datetime.datetime.now()
 
243
        if self.last_seen is None:
372
244
            return now < (self.created + self.timeout)
373
245
        else:
374
 
            return now < (self.last_checked_ok + self.timeout)
 
246
            return now < (self.last_seen + self.timeout)
375
247
 
376
248
 
377
249
def peer_certificate(session):
378
 
    "Return the peer's OpenPGP certificate as a bytestring"
379
250
    # If not an OpenPGP certificate...
380
251
    if gnutls.library.functions.gnutls_certificate_type_get\
381
252
            (session._c_object) \
392
263
 
393
264
 
394
265
def fingerprint(openpgp):
395
 
    "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))
396
270
    # New GnuTLS "datum" with the OpenPGP public key
397
271
    datum = gnutls.library.types.gnutls_datum_t\
398
272
        (ctypes.cast(ctypes.c_char_p(openpgp),
399
273
                     ctypes.POINTER(ctypes.c_ubyte)),
400
274
         ctypes.c_uint(len(openpgp)))
401
 
    # New empty GnuTLS certificate
402
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
403
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
404
 
        (ctypes.byref(crt))
405
275
    # Import the OpenPGP public key into the certificate
406
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
407
 
                    (crt, ctypes.byref(datum),
408
 
                     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)
409
280
    # New buffer for the fingerprint
410
281
    buffer = ctypes.create_string_buffer(20)
411
282
    buffer_length = ctypes.c_size_t()
427
298
    Note: This will run in its own forked process."""
428
299
    
429
300
    def handle(self):
430
 
        logger.info(u"TCP connection from: %s",
431
 
                     unicode(self.client_address))
432
 
        session = gnutls.connection.ClientSession\
433
 
                  (self.request, gnutls.connection.X509Credentials())
434
 
        
435
 
        line = self.request.makefile().readline()
436
 
        logger.debug(u"Protocol version: %r", line)
437
 
        try:
438
 
            if int(line.strip().split()[0]) > 1:
439
 
                raise RuntimeError
440
 
        except (ValueError, IndexError, RuntimeError), error:
441
 
            logger.error(u"Unknown protocol version: %s", error)
442
 
            return
443
 
        
444
 
        # Note: gnutls.connection.X509Credentials is really a generic
445
 
        # GnuTLS certificate credentials object so long as no X.509
446
 
        # keys are added to it.  Therefore, we can use it here despite
447
 
        # 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())
448
310
        
449
311
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
450
312
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
451
313
        #                "+DHE-DSS"))
452
 
        priority = "NORMAL"             # Fallback default, since this
453
 
                                        # MUST be set.
454
 
        if self.server.settings["priority"]:
455
 
            priority = self.server.settings["priority"]
 
314
        priority = "SECURE256"
 
315
        
456
316
        gnutls.library.functions.gnutls_priority_set_direct\
457
317
            (session._c_object, priority, None);
458
318
        
459
319
        try:
460
320
            session.handshake()
461
321
        except gnutls.errors.GNUTLSError, error:
462
 
            logger.warning(u"Handshake failed: %s", error)
 
322
            if debug:
 
323
                sys.stderr.write(u"Handshake failed: %s\n" % error)
463
324
            # Do not run session.bye() here: the session is not
464
325
            # established.  Just abandon the request.
465
326
            return
466
327
        try:
467
328
            fpr = fingerprint(peer_certificate(session))
468
329
        except (TypeError, gnutls.errors.GNUTLSError), error:
469
 
            logger.warning(u"Bad certificate: %s", error)
 
330
            if debug:
 
331
                sys.stderr.write(u"Bad certificate: %s\n" % error)
470
332
            session.bye()
471
333
            return
472
 
        logger.debug(u"Fingerprint: %s", fpr)
 
334
        if debug:
 
335
            sys.stderr.write(u"Fingerprint: %s\n" % fpr)
473
336
        client = None
474
 
        for c in self.server.clients:
 
337
        for c in clients:
475
338
            if c.fingerprint == fpr:
476
339
                client = c
477
340
                break
478
 
        if not client:
479
 
            logger.warning(u"Client not found for fingerprint: %s",
480
 
                           fpr)
481
 
            session.bye()
482
 
            return
483
341
        # Have to check if client.still_valid(), since it is possible
484
342
        # that the client timed out while establishing the GnuTLS
485
343
        # session.
486
 
        if not client.still_valid():
487
 
            logger.warning(u"Client %(name)s is invalid",
488
 
                           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)
489
352
            session.bye()
490
353
            return
491
354
        sent_size = 0
492
355
        while sent_size < len(client.secret):
493
356
            sent = session.send(client.secret[sent_size:])
494
 
            logger.debug(u"Sent: %d, remaining: %d",
495
 
                         sent, len(client.secret)
496
 
                         - (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)))
497
361
            sent_size += sent
498
362
        session.bye()
499
363
 
501
365
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
502
366
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
503
367
    Attributes:
504
 
        settings:       Server settings
 
368
        options:        Command line options
505
369
        clients:        Set() of Client objects
506
370
    """
507
371
    address_family = socket.AF_INET6
508
372
    def __init__(self, *args, **kwargs):
509
 
        if "settings" in kwargs:
510
 
            self.settings = kwargs["settings"]
511
 
            del kwargs["settings"]
 
373
        if "options" in kwargs:
 
374
            self.options = kwargs["options"]
 
375
            del kwargs["options"]
512
376
        if "clients" in kwargs:
513
377
            self.clients = kwargs["clients"]
514
378
            del kwargs["clients"]
517
381
        """This overrides the normal server_bind() function
518
382
        to bind to an interface if one was specified, and also NOT to
519
383
        bind to an address or port if they were not specified."""
520
 
        if self.settings["interface"]:
521
 
            # 25 is from /usr/include/asm-i486/socket.h
522
 
            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
523
388
            try:
524
389
                self.socket.setsockopt(socket.SOL_SOCKET,
525
 
                                       SO_BINDTODEVICE,
526
 
                                       self.settings["interface"])
 
390
                                       socket.SO_BINDTODEVICE,
 
391
                                       self.options.interface)
527
392
            except socket.error, error:
528
393
                if error[0] == errno.EPERM:
529
 
                    logger.error(u"No permission to"
530
 
                                 u" bind to interface %s",
531
 
                                 self.settings["interface"])
 
394
                    sys.stderr.write(u"Warning: No permission to" \
 
395
                                     u" bind to interface %s\n"
 
396
                                     % self.options.interface)
532
397
                else:
533
398
                    raise error
534
399
        # Only bind(2) the socket if we really need to.
537
402
                in6addr_any = "::"
538
403
                self.server_address = (in6addr_any,
539
404
                                       self.server_address[1])
540
 
            elif not self.server_address[1]:
 
405
            elif self.server_address[1] is None:
541
406
                self.server_address = (self.server_address[0],
542
407
                                       0)
543
 
#                 if self.settings["interface"]:
544
 
#                     self.server_address = (self.server_address[0],
545
 
#                                            0, # port
546
 
#                                            0, # flowinfo
547
 
#                                            if_nametoindex
548
 
#                                            (self.settings
549
 
#                                             ["interface"]))
550
408
            return super(type(self), self).server_bind()
551
409
 
552
410
 
584
442
    return delta
585
443
 
586
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
 
587
479
def server_state_changed(state):
588
 
    """Derived from the Avahi example code"""
 
480
    """From the Avahi server example code"""
589
481
    if state == avahi.SERVER_COLLISION:
590
 
        logger.error(u"Server name collision")
591
 
        service.remove()
 
482
        sys.stderr.write(u"WARNING: Server name collision\n")
 
483
        remove_service()
592
484
    elif state == avahi.SERVER_RUNNING:
593
 
        service.add()
 
485
        add_service()
594
486
 
595
487
 
596
488
def entry_group_state_changed(state, error):
597
 
    """Derived from the Avahi example code"""
598
 
    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)
599
494
    
600
495
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
601
 
        logger.debug(u"Service established.")
 
496
        if debug:
 
497
            sys.stderr.write(u"Service established.\n")
602
498
    elif state == avahi.ENTRY_GROUP_COLLISION:
603
 
        logger.warning(u"Service name collision.")
604
 
        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()
605
513
    elif state == avahi.ENTRY_GROUP_FAILURE:
606
 
        logger.critical(u"Error in group state changed %s",
607
 
                        unicode(error))
608
 
        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
 
609
519
 
610
520
def if_nametoindex(interface):
611
 
    """Call the C function if_nametoindex(), or equivalent"""
612
 
    global if_nametoindex
 
521
    """Call the C function if_nametoindex()"""
613
522
    try:
614
 
        if "ctypes.util" not in sys.modules:
615
 
            import ctypes.util
616
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
617
 
            (ctypes.util.find_library("c")).if_nametoindex
 
523
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
524
        return libc.if_nametoindex(interface)
618
525
    except (OSError, AttributeError):
619
526
        if "struct" not in sys.modules:
620
527
            import struct
621
528
        if "fcntl" not in sys.modules:
622
529
            import fcntl
623
 
        def if_nametoindex(interface):
624
 
            "Get an interface index the hard way, i.e. using fcntl()"
625
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
626
 
            s = socket.socket()
627
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
628
 
                                struct.pack("16s16x", interface))
629
 
            s.close()
630
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
631
 
            return interface_index
632
 
    return if_nametoindex(interface)
633
 
 
634
 
 
635
 
def daemon(nochdir = False, noclose = False):
636
 
    """See daemon(3).  Standard BSD Unix function.
637
 
    This should really exist as os.daemon, but it doesn't (yet)."""
638
 
    if os.fork():
639
 
        sys.exit()
640
 
    os.setsid()
641
 
    if not nochdir:
642
 
        os.chdir("/")
643
 
    if os.fork():
644
 
        sys.exit()
645
 
    if not noclose:
646
 
        # Close all standard open file descriptors
647
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
648
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
649
 
            raise OSError(errno.ENODEV,
650
 
                          "/dev/null not a character device")
651
 
        os.dup2(null, sys.stdin.fileno())
652
 
        os.dup2(null, sys.stdout.fileno())
653
 
        os.dup2(null, sys.stderr.fileno())
654
 
        if null > 2:
655
 
            os.close(null)
656
 
 
657
 
 
658
 
def main():
659
 
    global main_loop_started
660
 
    main_loop_started = False
661
 
    
662
 
    parser = OptionParser(version = "%%prog %s" % version)
 
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__':
 
540
    parser = OptionParser()
663
541
    parser.add_option("-i", "--interface", type="string",
664
 
                      metavar="IF", help="Bind to interface IF")
665
 
    parser.add_option("-a", "--address", type="string",
666
 
                      help="Address to listen for requests on")
667
 
    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,
668
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")
669
564
    parser.add_option("--check", action="store_true", default=False,
670
565
                      help="Run self-test")
671
 
    parser.add_option("--debug", action="store_true",
672
 
                      help="Debug mode; run in foreground and log to"
673
 
                      " terminal")
674
 
    parser.add_option("--priority", type="string", help="GnuTLS"
675
 
                      " priority string (see GnuTLS documentation)")
676
 
    parser.add_option("--servicename", type="string", metavar="NAME",
677
 
                      help="Zeroconf service name")
678
 
    parser.add_option("--configdir", type="string",
679
 
                      default="/etc/mandos", metavar="DIR",
680
 
                      help="Directory to search for configuration"
681
 
                      " files")
 
566
    parser.add_option("--debug", action="store_true", default=False,
 
567
                      help="Debug mode")
682
568
    (options, args) = parser.parse_args()
683
569
    
684
570
    if options.check:
686
572
        doctest.testmod()
687
573
        sys.exit()
688
574
    
689
 
    # Default values for config file for server-global settings
690
 
    server_defaults = { "interface": "",
691
 
                        "address": "",
692
 
                        "port": "",
693
 
                        "debug": "False",
694
 
                        "priority":
695
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
696
 
                        "servicename": "Mandos",
697
 
                        }
698
 
    
699
 
    # Parse config file for server-global settings
700
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
701
 
    del server_defaults
702
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
703
 
    server_section = "server"
704
 
    # Convert the SafeConfigParser object to a dict
705
 
    server_settings = dict(server_config.items(server_section))
706
 
    # Use getboolean on the boolean config option
707
 
    server_settings["debug"] = server_config.getboolean\
708
 
                               (server_section, "debug")
709
 
    del server_config
710
 
    
711
 
    # Override the settings from the config file with command line
712
 
    # options, if set.
713
 
    for option in ("interface", "address", "port", "debug",
714
 
                   "priority", "servicename", "configdir"):
715
 
        value = getattr(options, option)
716
 
        if value is not None:
717
 
            server_settings[option] = value
718
 
    del options
719
 
    # Now we have our good server settings in "server_settings"
720
 
    
721
 
    debug = server_settings["debug"]
722
 
    
723
 
    if not debug:
724
 
        syslogger.setLevel(logging.WARNING)
725
 
        console.setLevel(logging.WARNING)
726
 
    
727
 
    if server_settings["servicename"] != "Mandos":
728
 
        syslogger.setFormatter(logging.Formatter\
729
 
                               ('Mandos (%s): %%(levelname)s:'
730
 
                                ' %%(message)s'
731
 
                                % server_settings["servicename"]))
732
 
    
733
 
    # Parse config file with clients
734
 
    client_defaults = { "timeout": "1h",
735
 
                        "interval": "5m",
736
 
                        "checker": "fping -q -- %%(host)s",
737
 
                        }
738
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
739
 
    client_config.read(os.path.join(server_settings["configdir"],
740
 
                                    "clients.conf"))
741
 
    
742
 
    global service
743
 
    service = AvahiService(name = server_settings["servicename"],
744
 
                           type = "_mandos._tcp", );
745
 
    if server_settings["interface"]:
746
 
        service.interface = if_nametoindex(server_settings["interface"])
747
 
    
748
 
    global main_loop
749
 
    global bus
750
 
    global server
751
 
    # 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
752
592
    DBusGMainLoop(set_as_default=True )
753
593
    main_loop = gobject.MainLoop()
754
594
    bus = dbus.SystemBus()
757
597
            avahi.DBUS_INTERFACE_SERVER )
758
598
    # End of Avahi example code
759
599
    
 
600
    debug = options.debug
 
601
    
760
602
    clients = Set()
761
603
    def remove_from_clients(client):
762
604
        clients.remove(client)
763
605
        if not clients:
764
 
            logger.critical(u"No clients left, exiting")
765
 
            sys.exit()
 
606
            if debug:
 
607
                sys.stderr.write(u"No clients left, exiting\n")
 
608
            main_loop.quit()
766
609
    
767
 
    clients.update(Set(Client(name = section,
 
610
    clients.update(Set(Client(name=section, options=options,
768
611
                              stop_hook = remove_from_clients,
769
 
                              config
770
 
                              = dict(client_config.items(section)))
 
612
                              **(dict(client_config\
 
613
                                      .items(section))))
771
614
                       for section in client_config.sections()))
772
 
    if not clients:
773
 
        logger.critical(u"No clients defined")
774
 
        sys.exit(1)
775
 
    
776
 
    if not debug:
777
 
        logger.removeHandler(console)
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()