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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
 
 
75
 
class AvahiError(Exception):
76
 
    def __init__(self, value):
77
 
        self.value = value
78
 
    def __str__(self):
79
 
        return repr(self.value)
80
 
 
81
 
class AvahiServiceError(AvahiError):
82
 
    pass
83
 
 
84
 
class AvahiGroupError(AvahiError):
85
 
    pass
86
 
 
87
 
 
88
 
class AvahiService(object):
89
 
    """An Avahi (Zeroconf) service.
90
 
    Attributes:
91
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
92
 
               Used to optionally bind to the specified interface.
93
 
    name: string; Example: 'Mandos'
94
 
    type: string; Example: '_mandos._tcp'.
95
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
96
 
    port: integer; what port to announce
97
 
    TXT: list of strings; TXT record for the service
98
 
    domain: string; Domain to publish on, default to .local if empty.
99
 
    host: string; Host to publish records for, default is localhost
100
 
    max_renames: integer; maximum number of renames
101
 
    rename_count: integer; counter so we only rename after collisions
102
 
                  a sensible number of times
103
 
    """
104
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
105
 
                 type = None, port = None, TXT = None, domain = "",
106
 
                 host = "", max_renames = 32768):
107
 
        self.interface = interface
108
 
        self.name = name
109
 
        self.type = type
110
 
        self.port = port
111
 
        if TXT is None:
112
 
            self.TXT = []
113
 
        else:
114
 
            self.TXT = TXT
115
 
        self.domain = domain
116
 
        self.host = host
117
 
        self.rename_count = 0
118
 
    def rename(self):
119
 
        """Derived from the Avahi example code"""
120
 
        if self.rename_count >= self.max_renames:
121
 
            logger.critical(u"No suitable service name found after %i"
122
 
                            u" retries, exiting.", rename_count)
123
 
            raise AvahiServiceError("Too many renames")
124
 
        name = server.GetAlternativeServiceName(name)
125
 
        logger.error(u"Changing name to %r ...", name)
126
 
        syslogger.setFormatter(logging.Formatter\
127
 
                               ('Mandos (%s): %%(levelname)s:'
128
 
                               ' %%(message)s' % name))
129
 
        self.remove()
130
 
        self.add()
131
 
        self.rename_count += 1
132
 
    def remove(self):
133
 
        """Derived from the Avahi example code"""
134
 
        if group is not None:
135
 
            group.Reset()
136
 
    def add(self):
137
 
        """Derived from the Avahi example code"""
138
 
        global group
139
 
        if group is None:
140
 
            group = dbus.Interface\
141
 
                    (bus.get_object(avahi.DBUS_NAME,
142
 
                                    server.EntryGroupNew()),
143
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
144
 
            group.connect_to_signal('StateChanged',
145
 
                                    entry_group_state_changed)
146
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
147
 
                     service.name, service.type)
148
 
        group.AddService(
149
 
                self.interface,         # interface
150
 
                avahi.PROTO_INET6,      # protocol
151
 
                dbus.UInt32(0),         # flags
152
 
                self.name, self.type,
153
 
                self.domain, self.host,
154
 
                dbus.UInt16(self.port),
155
 
                avahi.string_array_to_txt_array(self.TXT))
156
 
        group.Commit()
157
 
 
158
 
# From the Avahi example code:
159
 
group = None                            # our entry group
 
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
160
45
# End of Avahi example code
161
46
 
162
47
 
167
52
    fingerprint: string (40 or 32 hexadecimal digits); used to
168
53
                 uniquely identify the client
169
54
    secret:    bytestring; sent verbatim (over TLS) to client
170
 
    host:      string; available for use by the checker command
171
 
    created:   datetime.datetime(); object creation, not client host
172
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
173
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
174
 
                                     until this client is invalid
 
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
175
60
    interval:  datetime.timedelta(); How often to start a new checker
176
61
    stop_hook: If set, called by stop() as stop_hook(self)
177
62
    checker:   subprocess.Popen(); a running checker process used
178
63
                                   to see if the client lives.
179
 
                                   'None' if no process is running.
 
64
                                   Is None if no process is running.
180
65
    checker_initiator_tag: a gobject event source tag, or None
181
66
    stop_initiator_tag:    - '' -
182
67
    checker_callback_tag:  - '' -
183
68
    checker_command: string; External command which is run to check if
184
 
                     client lives.  %() expansions are done at
 
69
                     client lives.  %()s expansions are done at
185
70
                     runtime with vars(self) as dict, so that for
186
71
                     instance %(name)s can be used in the command.
187
72
    Private attibutes:
188
73
    _timeout: Real variable for 'timeout'
189
74
    _interval: Real variable for 'interval'
190
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
75
    _timeout_milliseconds: Used by gobject.timeout_add()
191
76
    _interval_milliseconds: - '' -
192
77
    """
193
78
    def _set_timeout(self, timeout):
213
98
    interval = property(lambda self: self._interval,
214
99
                        _set_interval)
215
100
    del _set_interval
216
 
    def __init__(self, name = None, stop_hook=None, config={}):
217
 
        """Note: the 'checker' key in 'config' sets the
218
 
        'checker_command' attribute and *not* the 'checker'
219
 
        attribute."""
 
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):
220
104
        self.name = name
221
 
        logger.debug(u"Creating client %r", self.name)
222
 
        # Uppercase and remove spaces from fingerprint for later
223
 
        # comparison purposes with return value from the fingerprint()
224
 
        # function
225
 
        self.fingerprint = config["fingerprint"].upper()\
226
 
                           .replace(u" ", u"")
227
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
228
 
        if "secret" in config:
229
 
            self.secret = config["secret"].decode(u"base64")
230
 
        elif "secfile" in config:
231
 
            sf = open(config["secfile"])
 
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)
232
113
            self.secret = sf.read()
233
114
            sf.close()
234
115
        else:
235
 
            raise TypeError(u"No secret or secfile for client %s"
236
 
                            % self.name)
237
 
        self.host = config.get("host", "")
 
116
            raise RuntimeError(u"No secret or secfile for client %s"
 
117
                               % self.name)
 
118
        self.fqdn = fqdn                # string
238
119
        self.created = datetime.datetime.now()
239
 
        self.last_checked_ok = None
240
 
        self.timeout = string_to_delta(config["timeout"])
241
 
        self.interval = string_to_delta(config["interval"])
 
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
242
129
        self.stop_hook = stop_hook
243
130
        self.checker = None
244
131
        self.checker_initiator_tag = None
245
132
        self.stop_initiator_tag = None
246
133
        self.checker_callback_tag = None
247
 
        self.check_command = config["checker"]
 
134
        self.check_command = checker
248
135
    def start(self):
249
 
        """Start this client's checker and timeout hooks"""
 
136
        """Start this clients checker and timeout hooks"""
250
137
        # Schedule a new checker to be started an 'interval' from now,
251
138
        # and every interval from then on.
252
139
        self.checker_initiator_tag = gobject.timeout_add\
260
147
                                   self.stop)
261
148
    def stop(self):
262
149
        """Stop this client.
263
 
        The possibility that a client might be restarted is left open,
264
 
        but not currently used."""
265
 
        # If this client doesn't have a secret, it is already stopped.
266
 
        if hasattr(self, "secret") and self.secret:
267
 
            logger.info(u"Stopping client %s", self.name)
268
 
            self.secret = None
269
 
        else:
270
 
            return False
271
 
        if getattr(self, "stop_initiator_tag", False):
 
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:
272
156
            gobject.source_remove(self.stop_initiator_tag)
273
157
            self.stop_initiator_tag = None
274
 
        if getattr(self, "checker_initiator_tag", False):
 
158
        if self.checker_initiator_tag:
275
159
            gobject.source_remove(self.checker_initiator_tag)
276
160
            self.checker_initiator_tag = None
277
161
        self.stop_checker()
280
164
        # Do not run this again if called by a gobject.timeout_add
281
165
        return False
282
166
    def __del__(self):
283
 
        self.stop_hook = None
284
 
        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()
285
177
    def checker_callback(self, pid, condition):
286
178
        """The checker has completed, so take appropriate actions."""
287
179
        now = datetime.datetime.now()
288
 
        self.checker_callback_tag = None
289
 
        self.checker = None
290
180
        if os.WIFEXITED(condition) \
291
181
               and (os.WEXITSTATUS(condition) == 0):
292
 
            logger.info(u"Checker for %(name)s succeeded",
293
 
                        vars(self))
294
 
            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
295
186
            gobject.source_remove(self.stop_initiator_tag)
296
187
            self.stop_initiator_tag = gobject.timeout_add\
297
188
                                      (self._timeout_milliseconds,
298
189
                                       self.stop)
299
 
        elif not os.WIFEXITED(condition):
300
 
            logger.warning(u"Checker for %(name)s crashed?",
301
 
                           vars(self))
302
 
        else:
303
 
            logger.info(u"Checker for %(name)s failed",
304
 
                        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
305
199
    def start_checker(self):
306
200
        """Start a new checker subprocess if one is not running.
307
201
        If a checker already exists, leave it running and do
308
202
        nothing."""
309
 
        # The reason for not killing a running checker is that if we
310
 
        # did that, then if a checker (for some reason) started
311
 
        # running slowly and taking more than 'interval' time, the
312
 
        # client would inevitably timeout, since no checker would get
313
 
        # a chance to run to completion.  If we instead leave running
314
 
        # checkers alone, the checker would have to take more time
315
 
        # than 'timeout' for the client to be declared invalid, which
316
 
        # is as it should be.
317
203
        if self.checker is None:
 
204
            if debug:
 
205
                sys.stderr.write(u"Starting checker for %s\n"
 
206
                                 % self.name)
318
207
            try:
319
 
                # In case check_command has exactly one % operator
320
 
                command = self.check_command % self.host
 
208
                command = self.check_command % self.fqdn
321
209
            except TypeError:
322
 
                # Escape attributes for the shell
323
210
                escaped_attrs = dict((key, re.escape(str(val)))
324
211
                                     for key, val in
325
212
                                     vars(self).iteritems())
326
 
                try:
327
 
                    command = self.check_command % escaped_attrs
328
 
                except TypeError, error:
329
 
                    logger.error(u'Could not format string "%s":'
330
 
                                 u' %s', self.check_command, error)
331
 
                    return True # Try again later
 
213
                command = self.check_command % escaped_attrs
332
214
            try:
333
 
                logger.info(u"Starting checker %r for %s",
334
 
                            command, self.name)
335
 
                self.checker = subprocess.Popen(command,
336
 
                                                close_fds=True,
337
 
                                                shell=True, cwd="/")
338
 
                self.checker_callback_tag = gobject.child_watch_add\
339
 
                                            (self.checker.pid,
340
 
                                             self.checker_callback)
 
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)
341
224
            except subprocess.OSError, error:
342
 
                logger.error(u"Failed to start subprocess: %s",
343
 
                             error)
 
225
                sys.stderr.write(u"Failed to start subprocess: %s\n"
 
226
                                 % error)
344
227
        # Re-run this periodically if run by gobject.timeout_add
345
228
        return True
346
229
    def stop_checker(self):
347
230
        """Force the checker process, if any, to stop."""
348
 
        if self.checker_callback_tag:
349
 
            gobject.source_remove(self.checker_callback_tag)
350
 
            self.checker_callback_tag = None
351
 
        if getattr(self, "checker", None) is None:
 
231
        if not hasattr(self, "checker") or self.checker is None:
352
232
            return
353
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
354
 
        try:
355
 
            os.kill(self.checker.pid, signal.SIGTERM)
356
 
            #os.sleep(0.5)
357
 
            #if self.checker.poll() is None:
358
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
359
 
        except OSError, error:
360
 
            if error.errno != errno.ESRCH: # No such process
361
 
                raise
 
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)
362
238
        self.checker = None
363
 
    def still_valid(self):
 
239
    def still_valid(self, now=None):
364
240
        """Has the timeout not yet passed for this client?"""
365
 
        now = datetime.datetime.now()
366
 
        if self.last_checked_ok is None:
 
241
        if now is None:
 
242
            now = datetime.datetime.now()
 
243
        if self.last_seen is None:
367
244
            return now < (self.created + self.timeout)
368
245
        else:
369
 
            return now < (self.last_checked_ok + self.timeout)
 
246
            return now < (self.last_seen + self.timeout)
370
247
 
371
248
 
372
249
def peer_certificate(session):
373
 
    "Return the peer's OpenPGP certificate as a bytestring"
374
250
    # If not an OpenPGP certificate...
375
251
    if gnutls.library.functions.gnutls_certificate_type_get\
376
252
            (session._c_object) \
387
263
 
388
264
 
389
265
def fingerprint(openpgp):
390
 
    "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))
391
270
    # New GnuTLS "datum" with the OpenPGP public key
392
271
    datum = gnutls.library.types.gnutls_datum_t\
393
272
        (ctypes.cast(ctypes.c_char_p(openpgp),
394
273
                     ctypes.POINTER(ctypes.c_ubyte)),
395
274
         ctypes.c_uint(len(openpgp)))
396
 
    # New empty GnuTLS certificate
397
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
398
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
399
 
        (ctypes.byref(crt))
400
275
    # Import the OpenPGP public key into the certificate
401
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
402
 
                    (crt, ctypes.byref(datum),
403
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
276
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
 
277
        (crt,
 
278
         ctypes.byref(datum),
 
279
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
404
280
    # New buffer for the fingerprint
405
281
    buffer = ctypes.create_string_buffer(20)
406
282
    buffer_length = ctypes.c_size_t()
422
298
    Note: This will run in its own forked process."""
423
299
    
424
300
    def handle(self):
425
 
        logger.info(u"TCP connection from: %s",
426
 
                     unicode(self.client_address))
427
 
        session = gnutls.connection.ClientSession\
428
 
                  (self.request, gnutls.connection.X509Credentials())
429
 
        
430
 
        line = self.request.makefile().readline()
431
 
        logger.debug(u"Protocol version: %r", line)
432
 
        try:
433
 
            if int(line.strip().split()[0]) > 1:
434
 
                raise RuntimeError
435
 
        except (ValueError, IndexError, RuntimeError), error:
436
 
            logger.error(u"Unknown protocol version: %s", error)
437
 
            return
438
 
        
439
 
        # Note: gnutls.connection.X509Credentials is really a generic
440
 
        # GnuTLS certificate credentials object so long as no X.509
441
 
        # keys are added to it.  Therefore, we can use it here despite
442
 
        # using OpenPGP certificates.
 
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())
443
310
        
444
311
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
445
312
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
446
313
        #                "+DHE-DSS"))
447
 
        priority = "NORMAL"             # Fallback default, since this
448
 
                                        # MUST be set.
449
 
        if self.server.settings["priority"]:
450
 
            priority = self.server.settings["priority"]
 
314
        priority = "SECURE256"
 
315
        
451
316
        gnutls.library.functions.gnutls_priority_set_direct\
452
317
            (session._c_object, priority, None);
453
318
        
454
319
        try:
455
320
            session.handshake()
456
321
        except gnutls.errors.GNUTLSError, error:
457
 
            logger.warning(u"Handshake failed: %s", error)
 
322
            if debug:
 
323
                sys.stderr.write(u"Handshake failed: %s\n" % error)
458
324
            # Do not run session.bye() here: the session is not
459
325
            # established.  Just abandon the request.
460
326
            return
461
327
        try:
462
328
            fpr = fingerprint(peer_certificate(session))
463
329
        except (TypeError, gnutls.errors.GNUTLSError), error:
464
 
            logger.warning(u"Bad certificate: %s", error)
 
330
            if debug:
 
331
                sys.stderr.write(u"Bad certificate: %s\n" % error)
465
332
            session.bye()
466
333
            return
467
 
        logger.debug(u"Fingerprint: %s", fpr)
 
334
        if debug:
 
335
            sys.stderr.write(u"Fingerprint: %s\n" % fpr)
468
336
        client = None
469
 
        for c in self.server.clients:
 
337
        for c in clients:
470
338
            if c.fingerprint == fpr:
471
339
                client = c
472
340
                break
473
 
        if not client:
474
 
            logger.warning(u"Client not found for fingerprint: %s",
475
 
                           fpr)
476
 
            session.bye()
477
 
            return
478
341
        # Have to check if client.still_valid(), since it is possible
479
342
        # that the client timed out while establishing the GnuTLS
480
343
        # session.
481
 
        if not client.still_valid():
482
 
            logger.warning(u"Client %(name)s is invalid",
483
 
                           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)
484
352
            session.bye()
485
353
            return
486
354
        sent_size = 0
487
355
        while sent_size < len(client.secret):
488
356
            sent = session.send(client.secret[sent_size:])
489
 
            logger.debug(u"Sent: %d, remaining: %d",
490
 
                         sent, len(client.secret)
491
 
                         - (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)))
492
361
            sent_size += sent
493
362
        session.bye()
494
363
 
496
365
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
497
366
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
498
367
    Attributes:
499
 
        settings:       Server settings
 
368
        options:        Command line options
500
369
        clients:        Set() of Client objects
501
370
    """
502
371
    address_family = socket.AF_INET6
503
372
    def __init__(self, *args, **kwargs):
504
 
        if "settings" in kwargs:
505
 
            self.settings = kwargs["settings"]
506
 
            del kwargs["settings"]
 
373
        if "options" in kwargs:
 
374
            self.options = kwargs["options"]
 
375
            del kwargs["options"]
507
376
        if "clients" in kwargs:
508
377
            self.clients = kwargs["clients"]
509
378
            del kwargs["clients"]
512
381
        """This overrides the normal server_bind() function
513
382
        to bind to an interface if one was specified, and also NOT to
514
383
        bind to an address or port if they were not specified."""
515
 
        if self.settings["interface"]:
516
 
            # 25 is from /usr/include/asm-i486/socket.h
517
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
384
        if self.options.interface:
 
385
            if not hasattr(socket, "SO_BINDTODEVICE"):
 
386
                # From /usr/include/asm-i486/socket.h
 
387
                socket.SO_BINDTODEVICE = 25
518
388
            try:
519
389
                self.socket.setsockopt(socket.SOL_SOCKET,
520
 
                                       SO_BINDTODEVICE,
521
 
                                       self.settings["interface"])
 
390
                                       socket.SO_BINDTODEVICE,
 
391
                                       self.options.interface)
522
392
            except socket.error, error:
523
393
                if error[0] == errno.EPERM:
524
 
                    logger.error(u"No permission to"
525
 
                                 u" bind to interface %s",
526
 
                                 self.settings["interface"])
 
394
                    sys.stderr.write(u"Warning: No permission to" \
 
395
                                     u" bind to interface %s\n"
 
396
                                     % self.options.interface)
527
397
                else:
528
398
                    raise error
529
399
        # Only bind(2) the socket if we really need to.
532
402
                in6addr_any = "::"
533
403
                self.server_address = (in6addr_any,
534
404
                                       self.server_address[1])
535
 
            elif not self.server_address[1]:
 
405
            elif self.server_address[1] is None:
536
406
                self.server_address = (self.server_address[0],
537
407
                                       0)
538
 
#                 if self.settings["interface"]:
539
 
#                     self.server_address = (self.server_address[0],
540
 
#                                            0, # port
541
 
#                                            0, # flowinfo
542
 
#                                            if_nametoindex
543
 
#                                            (self.settings
544
 
#                                             ["interface"]))
545
408
            return super(type(self), self).server_bind()
546
409
 
547
410
 
579
442
    return delta
580
443
 
581
444
 
 
445
def add_service():
 
446
    """From the Avahi server example code"""
 
447
    global group, serviceName, serviceType, servicePort, serviceTXT, \
 
448
           domain, host
 
449
    if group is None:
 
450
        group = dbus.Interface(
 
451
                bus.get_object( avahi.DBUS_NAME,
 
452
                                server.EntryGroupNew()),
 
453
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
454
        group.connect_to_signal('StateChanged',
 
455
                                entry_group_state_changed)
 
456
    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
 
582
479
def server_state_changed(state):
583
 
    """Derived from the Avahi example code"""
 
480
    """From the Avahi server example code"""
584
481
    if state == avahi.SERVER_COLLISION:
585
 
        logger.error(u"Server name collision")
586
 
        service.remove()
 
482
        sys.stderr.write(u"WARNING: Server name collision\n")
 
483
        remove_service()
587
484
    elif state == avahi.SERVER_RUNNING:
588
 
        service.add()
 
485
        add_service()
589
486
 
590
487
 
591
488
def entry_group_state_changed(state, error):
592
 
    """Derived from the Avahi example code"""
593
 
    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)
594
494
    
595
495
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
596
 
        logger.debug(u"Service established.")
 
496
        if debug:
 
497
            sys.stderr.write(u"Service established.\n")
597
498
    elif state == avahi.ENTRY_GROUP_COLLISION:
598
 
        logger.warning(u"Service name collision.")
599
 
        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()
600
513
    elif state == avahi.ENTRY_GROUP_FAILURE:
601
 
        logger.critical(u"Error in group state changed %s",
602
 
                        unicode(error))
603
 
        raise AvahiGroupError("State changed: %s", str(error))
 
514
        sys.stderr.write(u"Error in group state changed %s\n"
 
515
                         % unicode(error))
 
516
        main_loop.quit()
 
517
        return
 
518
 
604
519
 
605
520
def if_nametoindex(interface):
606
 
    """Call the C function if_nametoindex(), or equivalent"""
607
 
    global if_nametoindex
 
521
    """Call the C function if_nametoindex()"""
608
522
    try:
609
 
        if "ctypes.util" not in sys.modules:
610
 
            import ctypes.util
611
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
612
 
            (ctypes.util.find_library("c")).if_nametoindex
 
523
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
524
        return libc.if_nametoindex(interface)
613
525
    except (OSError, AttributeError):
614
526
        if "struct" not in sys.modules:
615
527
            import struct
616
528
        if "fcntl" not in sys.modules:
617
529
            import fcntl
618
 
        def if_nametoindex(interface):
619
 
            "Get an interface index the hard way, i.e. using fcntl()"
620
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
621
 
            s = socket.socket()
622
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
623
 
                                struct.pack("16s16x", interface))
624
 
            s.close()
625
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
626
 
            return interface_index
627
 
    return if_nametoindex(interface)
628
 
 
629
 
 
630
 
def daemon(nochdir = False, noclose = False):
631
 
    """See daemon(3).  Standard BSD Unix function.
632
 
    This should really exist as os.daemon, but it doesn't (yet)."""
633
 
    if os.fork():
634
 
        sys.exit()
635
 
    os.setsid()
636
 
    if not nochdir:
637
 
        os.chdir("/")
638
 
    if os.fork():
639
 
        sys.exit()
640
 
    if not noclose:
641
 
        # Close all standard open file descriptors
642
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
643
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
644
 
            raise OSError(errno.ENODEV,
645
 
                          "/dev/null not a character device")
646
 
        os.dup2(null, sys.stdin.fileno())
647
 
        os.dup2(null, sys.stdout.fileno())
648
 
        os.dup2(null, sys.stderr.fileno())
649
 
        if null > 2:
650
 
            os.close(null)
651
 
 
652
 
 
653
 
def main():
654
 
    global main_loop_started
655
 
    main_loop_started = False
656
 
    
657
 
    parser = OptionParser(version = "Mandos server %s" % version)
 
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()
658
541
    parser.add_option("-i", "--interface", type="string",
659
 
                      metavar="IF", help="Bind to interface IF")
660
 
    parser.add_option("-a", "--address", type="string",
661
 
                      help="Address to listen for requests on")
662
 
    parser.add_option("-p", "--port", type="int",
 
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,
663
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")
664
564
    parser.add_option("--check", action="store_true", default=False,
665
565
                      help="Run self-test")
666
 
    parser.add_option("--debug", action="store_true",
667
 
                      help="Debug mode; run in foreground and log to"
668
 
                      " terminal")
669
 
    parser.add_option("--priority", type="string", help="GnuTLS"
670
 
                      " priority string (see GnuTLS documentation)")
671
 
    parser.add_option("--servicename", type="string", metavar="NAME",
672
 
                      help="Zeroconf service name")
673
 
    parser.add_option("--configdir", type="string",
674
 
                      default="/etc/mandos", metavar="DIR",
675
 
                      help="Directory to search for configuration"
676
 
                      " files")
 
566
    parser.add_option("--debug", action="store_true", default=False,
 
567
                      help="Debug mode")
677
568
    (options, args) = parser.parse_args()
678
569
    
679
570
    if options.check:
681
572
        doctest.testmod()
682
573
        sys.exit()
683
574
    
684
 
    # Default values for config file for server-global settings
685
 
    server_defaults = { "interface": "",
686
 
                        "address": "",
687
 
                        "port": "",
688
 
                        "debug": "False",
689
 
                        "priority":
690
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
691
 
                        "servicename": "Mandos",
692
 
                        }
693
 
    
694
 
    # Parse config file for server-global settings
695
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
696
 
    del server_defaults
697
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
698
 
    server_section = "server"
699
 
    # Convert the SafeConfigParser object to a dict
700
 
    server_settings = dict(server_config.items(server_section))
701
 
    # Use getboolean on the boolean config option
702
 
    server_settings["debug"] = server_config.getboolean\
703
 
                               (server_section, "debug")
704
 
    del server_config
705
 
    
706
 
    # Override the settings from the config file with command line
707
 
    # options, if set.
708
 
    for option in ("interface", "address", "port", "debug",
709
 
                   "priority", "servicename", "configdir"):
710
 
        value = getattr(options, option)
711
 
        if value is not None:
712
 
            server_settings[option] = value
713
 
    del options
714
 
    # Now we have our good server settings in "server_settings"
715
 
    
716
 
    debug = server_settings["debug"]
717
 
    
718
 
    if not debug:
719
 
        syslogger.setLevel(logging.WARNING)
720
 
    
721
 
    if server_settings["servicename"] != "Mandos":
722
 
        syslogger.setFormatter(logging.Formatter\
723
 
                               ('Mandos (%s): %%(levelname)s:'
724
 
                                ' %%(message)s'
725
 
                                % server_settings["servicename"]))
726
 
    
727
 
    # Parse config file with clients
728
 
    client_defaults = { "timeout": "1h",
729
 
                        "interval": "5m",
730
 
                        "checker": "fping -q -- %%(host)s",
731
 
                        }
732
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
733
 
    client_config.read(os.path.join(server_settings["configdir"],
734
 
                                    "clients.conf"))
735
 
    
736
 
    global service
737
 
    service = AvahiService(name = server_settings["servicename"],
738
 
                           type = "_mandos._tcp", );
739
 
    if server_settings["interface"]:
740
 
        service.interface = if_nametoindex(server_settings["interface"])
741
 
    
742
 
    global main_loop
743
 
    global bus
744
 
    global server
745
 
    # From the Avahi example code
 
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
746
592
    DBusGMainLoop(set_as_default=True )
747
593
    main_loop = gobject.MainLoop()
748
594
    bus = dbus.SystemBus()
751
597
            avahi.DBUS_INTERFACE_SERVER )
752
598
    # End of Avahi example code
753
599
    
754
 
    if debug:
755
 
        console = logging.StreamHandler()
756
 
        # console.setLevel(logging.DEBUG)
757
 
        console.setFormatter(logging.Formatter\
758
 
                             ('%(levelname)s: %(message)s'))
759
 
        logger.addHandler(console)
760
 
        del console
 
600
    debug = options.debug
761
601
    
762
602
    clients = Set()
763
603
    def remove_from_clients(client):
764
604
        clients.remove(client)
765
605
        if not clients:
766
 
            logger.critical(u"No clients left, exiting")
767
 
            sys.exit()
 
606
            if debug:
 
607
                sys.stderr.write(u"No clients left, exiting\n")
 
608
            main_loop.quit()
768
609
    
769
 
    clients.update(Set(Client(name = section,
 
610
    clients.update(Set(Client(name=section, options=options,
770
611
                              stop_hook = remove_from_clients,
771
 
                              config
772
 
                              = dict(client_config.items(section)))
 
612
                              **(dict(client_config\
 
613
                                      .items(section))))
773
614
                       for section in client_config.sections()))
774
 
    if not clients:
775
 
        logger.critical(u"No clients defined")
776
 
        sys.exit(1)
777
 
    
778
 
    if not debug:
779
 
        daemon()
780
 
    
781
 
    pidfilename = "/var/run/mandos/mandos.pid"
782
 
    pid = os.getpid()
783
 
    try:
784
 
        pidfile = open(pidfilename, "w")
785
 
        pidfile.write(str(pid) + "\n")
786
 
        pidfile.close()
787
 
        del pidfile
788
 
    except IOError, err:
789
 
        logger.error(u"Could not write %s file with PID %d",
790
 
                     pidfilename, os.getpid())
791
 
    
792
 
    def cleanup():
793
 
        "Cleanup function; run on exit"
794
 
        global group
795
 
        # From the Avahi example code
796
 
        if not group is None:
797
 
            group.Free()
798
 
            group = None
799
 
        # End of Avahi example code
800
 
        
801
 
        while clients:
802
 
            client = clients.pop()
803
 
            client.stop_hook = None
804
 
            client.stop()
805
 
    
806
 
    atexit.register(cleanup)
807
 
    
808
 
    if not debug:
809
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
810
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
811
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
812
 
    
813
615
    for client in clients:
814
616
        client.start()
815
617
    
816
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
817
 
                                 server_settings["port"]),
 
618
    tcp_server = IPv6_TCPServer((None, options.port),
818
619
                                tcp_handler,
819
 
                                settings=server_settings,
 
620
                                options=options,
820
621
                                clients=clients)
821
 
    # Find out what port we got
822
 
    service.port = tcp_server.socket.getsockname()[1]
823
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
824
 
                u" scope_id %d" % tcp_server.socket.getsockname())
825
 
    
826
 
    #service.interface = tcp_server.socket.getsockname()[3]
827
 
    
 
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)
828
639
    try:
829
 
        # From the Avahi example code
830
 
        server.connect_to_signal("StateChanged", server_state_changed)
831
 
        try:
832
 
            server_state_changed(server.GetState())
833
 
        except dbus.exceptions.DBusException, error:
834
 
            logger.critical(u"DBusException: %s", error)
835
 
            sys.exit(1)
836
 
        # End of Avahi example code
837
 
        
838
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
839
 
                             lambda *args, **kwargs:
840
 
                             tcp_server.handle_request\
841
 
                             (*args[2:], **kwargs) or True)
842
 
        
843
 
        logger.debug(u"Starting main loop")
844
 
        main_loop_started = True
845
640
        main_loop.run()
846
 
    except AvahiError, error:
847
 
        logger.critical(u"AvahiError: %s" + unicode(error))
848
 
        sys.exit(1)
849
641
    except KeyboardInterrupt:
850
 
        if debug:
851
 
            print
 
642
        print
 
643
    
 
644
    # Cleanup here
852
645
 
853
 
if __name__ == '__main__':
854
 
    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()