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  • Committer: Teddy Hogeborn
  • Date: 2008-06-30 01:43:39 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080630014339-rsuztydpl2w5ml83
* server.py: Rewritten to use Zeroconf (mDNS/DNS-SD) in place of the
             old broadcast-UDP-to-port-49001 method.

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#!/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
 
40
11
import gnutls.crypto
41
12
import gnutls.connection
42
13
import gnutls.errors
43
 
import gnutls.library.functions
44
 
import gnutls.library.constants
45
 
import gnutls.library.types
46
14
import ConfigParser
47
15
import sys
48
16
import re
50
18
import signal
51
19
from sets import Set
52
20
import subprocess
53
 
import atexit
54
 
import stat
55
 
import logging
56
 
import logging.handlers
57
21
 
58
22
import dbus
59
23
import gobject
60
24
import avahi
61
25
from dbus.mainloop.glib import DBusGMainLoop
62
 
import ctypes
63
 
 
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
 
26
 
 
27
# This variable is used to optionally bind to a specified
 
28
# interface.
 
29
serviceInterface = avahi.IF_UNSPEC
 
30
# It is a global variable to fit in with the rest of the
 
31
# variables from the Avahi server example code:
 
32
serviceName = "Mandos"
 
33
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
 
34
servicePort = None                      # Not known at startup
 
35
serviceTXT = []                         # TXT record for the service
 
36
domain = ""                  # Domain to publish on, default to .local
 
37
host = ""          # Host to publish records for, default to localhost
 
38
group = None #our entry group
 
39
rename_count = 12       # Counter so we only rename after collisions a
 
40
                        # sensible number of times
165
41
# End of Avahi example code
166
42
 
167
43
 
168
44
class Client(object):
169
45
    """A representation of a client host served by this server.
170
46
    Attributes:
171
 
    name:      string; from the config file, used in log messages
172
 
    fingerprint: string (40 or 32 hexadecimal digits); used to
173
 
                 uniquely identify the client
174
 
    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
 
47
    password:  string
 
48
    fqdn:      string, FQDN (used by the checker)
 
49
    created:   datetime.datetime()
 
50
    last_seen: datetime.datetime() or None if not yet seen
 
51
    timeout:   datetime.timedelta(); How long from last_seen until
 
52
                                     this client is invalid
180
53
    interval:  datetime.timedelta(); How often to start a new checker
 
54
    timeout_milliseconds: Used by gobject.timeout_add()
 
55
    interval_milliseconds: - '' -
181
56
    stop_hook: If set, called by stop() as stop_hook(self)
182
57
    checker:   subprocess.Popen(); a running checker process used
183
58
                                   to see if the client lives.
184
 
                                   'None' if no process is running.
 
59
                                   Is None if no process is running.
185
60
    checker_initiator_tag: a gobject event source tag, or None
186
61
    stop_initiator_tag:    - '' -
187
62
    checker_callback_tag:  - '' -
188
 
    checker_command: string; External command which is run to check if
189
 
                     client lives.  %() expansions are done at
190
 
                     runtime with vars(self) as dict, so that for
191
 
                     instance %(name)s can be used in the command.
192
 
    Private attibutes:
193
 
    _timeout: Real variable for 'timeout'
194
 
    _interval: Real variable for 'interval'
195
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
196
 
    _interval_milliseconds: - '' -
197
63
    """
198
 
    def _set_timeout(self, timeout):
199
 
        "Setter function for 'timeout' attribute"
200
 
        self._timeout = timeout
201
 
        self._timeout_milliseconds = ((self.timeout.days
 
64
    def __init__(self, name=None, options=None, stop_hook=None,
 
65
                 dn=None, password=None, passfile=None, fqdn=None,
 
66
                 timeout=None, interval=-1):
 
67
        self.name = name
 
68
        self.dn = dn
 
69
        if password:
 
70
            self.password = password
 
71
        elif passfile:
 
72
            self.password = open(passfile).readall()
 
73
        else:
 
74
            raise RuntimeError(u"No Password or Passfile for client %s"
 
75
                               % self.name)
 
76
        self.fqdn = fqdn                # string
 
77
        self.created = datetime.datetime.now()
 
78
        self.last_seen = None
 
79
        if timeout is None:
 
80
            timeout = options.timeout
 
81
        self.timeout = timeout
 
82
        self.timeout_milliseconds = ((self.timeout.days
 
83
                                      * 24 * 60 * 60 * 1000)
 
84
                                     + (self.timeout.seconds * 1000)
 
85
                                     + (self.timeout.microseconds
 
86
                                        // 1000))
 
87
        if interval == -1:
 
88
            interval = options.interval
 
89
        else:
 
90
            interval = string_to_delta(interval)
 
91
        self.interval = interval
 
92
        self.interval_milliseconds = ((self.interval.days
202
93
                                       * 24 * 60 * 60 * 1000)
203
 
                                      + (self.timeout.seconds * 1000)
204
 
                                      + (self.timeout.microseconds
 
94
                                      + (self.interval.seconds * 1000)
 
95
                                      + (self.interval.microseconds
205
96
                                         // 1000))
206
 
    timeout = property(lambda self: self._timeout,
207
 
                       _set_timeout)
208
 
    del _set_timeout
209
 
    def _set_interval(self, interval):
210
 
        "Setter function for 'interval' attribute"
211
 
        self._interval = interval
212
 
        self._interval_milliseconds = ((self.interval.days
213
 
                                        * 24 * 60 * 60 * 1000)
214
 
                                       + (self.interval.seconds
215
 
                                          * 1000)
216
 
                                       + (self.interval.microseconds
217
 
                                          // 1000))
218
 
    interval = property(lambda self: self._interval,
219
 
                        _set_interval)
220
 
    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."""
225
 
        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"])
237
 
            self.secret = sf.read()
238
 
            sf.close()
239
 
        else:
240
 
            raise TypeError(u"No secret or secfile for client %s"
241
 
                            % self.name)
242
 
        self.host = config.get("host", "")
243
 
        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"])
247
97
        self.stop_hook = stop_hook
248
98
        self.checker = None
249
99
        self.checker_initiator_tag = None
250
100
        self.stop_initiator_tag = None
251
101
        self.checker_callback_tag = None
252
 
        self.check_command = config["checker"]
253
102
    def start(self):
254
 
        """Start this client's checker and timeout hooks"""
 
103
        """Start this clients checker and timeout hooks"""
255
104
        # Schedule a new checker to be started an 'interval' from now,
256
105
        # and every interval from then on.
257
 
        self.checker_initiator_tag = gobject.timeout_add\
258
 
                                     (self._interval_milliseconds,
259
 
                                      self.start_checker)
 
106
        self.checker_initiator_tag = gobject.\
 
107
                                     timeout_add(self.interval_milliseconds,
 
108
                                                 self.start_checker)
260
109
        # Also start a new checker *right now*.
261
110
        self.start_checker()
262
111
        # Schedule a stop() when 'timeout' has passed
263
 
        self.stop_initiator_tag = gobject.timeout_add\
264
 
                                  (self._timeout_milliseconds,
265
 
                                   self.stop)
 
112
        self.stop_initiator_tag = gobject.\
 
113
                                     timeout_add(self.timeout_milliseconds,
 
114
                                                 self.stop)
266
115
    def stop(self):
267
116
        """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):
 
117
        The possibility that this client might be restarted is left
 
118
        open, but not currently used."""
 
119
        # print "Stopping client", self.name
 
120
        self.password = None
 
121
        if self.stop_initiator_tag:
277
122
            gobject.source_remove(self.stop_initiator_tag)
278
123
            self.stop_initiator_tag = None
279
 
        if getattr(self, "checker_initiator_tag", False):
 
124
        if self.checker_initiator_tag:
280
125
            gobject.source_remove(self.checker_initiator_tag)
281
126
            self.checker_initiator_tag = None
282
127
        self.stop_checker()
285
130
        # Do not run this again if called by a gobject.timeout_add
286
131
        return False
287
132
    def __del__(self):
288
 
        self.stop_hook = None
289
 
        self.stop()
 
133
        # Some code duplication here and in stop()
 
134
        if hasattr(self, "stop_initiator_tag") \
 
135
               and self.stop_initiator_tag:
 
136
            gobject.source_remove(self.stop_initiator_tag)
 
137
            self.stop_initiator_tag = None
 
138
        if hasattr(self, "checker_initiator_tag") \
 
139
               and self.checker_initiator_tag:
 
140
            gobject.source_remove(self.checker_initiator_tag)
 
141
            self.checker_initiator_tag = None
 
142
        self.stop_checker()
290
143
    def checker_callback(self, pid, condition):
291
144
        """The checker has completed, so take appropriate actions."""
292
145
        now = datetime.datetime.now()
293
 
        self.checker_callback_tag = None
294
 
        self.checker = None
295
146
        if os.WIFEXITED(condition) \
296
147
               and (os.WEXITSTATUS(condition) == 0):
297
 
            logger.info(u"Checker for %(name)s succeeded",
298
 
                        vars(self))
299
 
            self.last_checked_ok = now
 
148
            #print "Checker for %(name)s succeeded" % vars(self)
 
149
            self.last_seen = now
300
150
            gobject.source_remove(self.stop_initiator_tag)
301
 
            self.stop_initiator_tag = gobject.timeout_add\
302
 
                                      (self._timeout_milliseconds,
303
 
                                       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))
 
151
            self.stop_initiator_tag = gobject.\
 
152
                                      timeout_add(self.timeout_milliseconds,
 
153
                                                  self.stop)
 
154
        #else:
 
155
        #    if not os.WIFEXITED(condition):
 
156
        #        print "Checker for %(name)s crashed?" % vars(self)
 
157
        #    else:
 
158
        #        print "Checker for %(name)s failed" % vars(self)
 
159
        self.checker = None
 
160
        self.checker_callback_tag = None
310
161
    def start_checker(self):
311
162
        """Start a new checker subprocess if one is not running.
312
163
        If a checker already exists, leave it running and do
313
164
        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
165
        if self.checker is None:
323
 
            try:
324
 
                # In case check_command has exactly one % operator
325
 
                command = self.check_command % self.host
326
 
            except TypeError:
327
 
                # Escape attributes for the shell
328
 
                escaped_attrs = dict((key, re.escape(str(val)))
329
 
                                     for key, val in
330
 
                                     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
337
 
            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)
 
166
            #print "Starting checker for", self.name
 
167
            try:
 
168
                self.checker = subprocess.\
 
169
                               Popen("sleep 1; fping -q -- %s"
 
170
                                     % re.escape(self.fqdn),
 
171
                                     stdout=subprocess.PIPE,
 
172
                                     close_fds=True, shell=True,
 
173
                                     cwd="/")
 
174
                self.checker_callback_tag = gobject.\
 
175
                                            child_watch_add(self.checker.pid,
 
176
                                                            self.\
 
177
                                                            checker_callback)
346
178
            except subprocess.OSError, error:
347
 
                logger.error(u"Failed to start subprocess: %s",
348
 
                             error)
 
179
                sys.stderr.write(u"Failed to start subprocess: %s\n"
 
180
                                 % error)
349
181
        # Re-run this periodically if run by gobject.timeout_add
350
182
        return True
351
183
    def stop_checker(self):
352
184
        """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:
 
185
        if not hasattr(self, "checker") or self.checker is None:
357
186
            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
 
187
        gobject.source_remove(self.checker_callback_tag)
 
188
        self.checker_callback_tag = None
 
189
        os.kill(self.checker.pid, signal.SIGTERM)
 
190
        if self.checker.poll() is None:
 
191
            os.kill(self.checker.pid, signal.SIGKILL)
367
192
        self.checker = None
368
 
    def still_valid(self):
 
193
    def still_valid(self, now=None):
369
194
        """Has the timeout not yet passed for this client?"""
370
 
        now = datetime.datetime.now()
371
 
        if self.last_checked_ok is None:
 
195
        if now is None:
 
196
            now = datetime.datetime.now()
 
197
        if self.last_seen is None:
372
198
            return now < (self.created + self.timeout)
373
199
        else:
374
 
            return now < (self.last_checked_ok + self.timeout)
375
 
 
376
 
 
377
 
def peer_certificate(session):
378
 
    "Return the peer's OpenPGP certificate as a bytestring"
379
 
    # If not an OpenPGP certificate...
380
 
    if gnutls.library.functions.gnutls_certificate_type_get\
381
 
            (session._c_object) \
382
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
383
 
        # ...do the normal thing
384
 
        return session.peer_certificate
385
 
    list_size = ctypes.c_uint()
386
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
387
 
        (session._c_object, ctypes.byref(list_size))
388
 
    if list_size.value == 0:
389
 
        return None
390
 
    cert = cert_list[0]
391
 
    return ctypes.string_at(cert.data, cert.size)
392
 
 
393
 
 
394
 
def fingerprint(openpgp):
395
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
396
 
    # New GnuTLS "datum" with the OpenPGP public key
397
 
    datum = gnutls.library.types.gnutls_datum_t\
398
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
399
 
                     ctypes.POINTER(ctypes.c_ubyte)),
400
 
         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
 
    # 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)
409
 
    # New buffer for the fingerprint
410
 
    buffer = ctypes.create_string_buffer(20)
411
 
    buffer_length = ctypes.c_size_t()
412
 
    # Get the fingerprint from the certificate into the buffer
413
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
414
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
415
 
    # Deinit the certificate
416
 
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
417
 
    # Convert the buffer to a Python bytestring
418
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
419
 
    # Convert the bytestring to hexadecimal notation
420
 
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
421
 
    return hex_fpr
 
200
            return now < (self.last_seen + self.timeout)
422
201
 
423
202
 
424
203
class tcp_handler(SocketServer.BaseRequestHandler, object):
425
204
    """A TCP request handler class.
426
205
    Instantiated by IPv6_TCPServer for each request to handle it.
427
206
    Note: This will run in its own forked process."""
428
 
    
429
207
    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.
448
 
        
449
 
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
450
 
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
451
 
        #                "+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"]
456
 
        gnutls.library.functions.gnutls_priority_set_direct\
457
 
            (session._c_object, priority, None);
458
 
        
 
208
        #print u"TCP request came"
 
209
        #print u"Request:", self.request
 
210
        #print u"Client Address:", self.client_address
 
211
        #print u"Server:", self.server
 
212
        session = gnutls.connection.ServerSession(self.request,
 
213
                                                  self.server\
 
214
                                                  .credentials)
459
215
        try:
460
216
            session.handshake()
461
217
        except gnutls.errors.GNUTLSError, error:
462
 
            logger.warning(u"Handshake failed: %s", error)
 
218
            #sys.stderr.write(u"Handshake failed: %s\n" % error)
463
219
            # Do not run session.bye() here: the session is not
464
220
            # established.  Just abandon the request.
465
221
            return
 
222
        #if session.peer_certificate:
 
223
        #    print "DN:", session.peer_certificate.subject
466
224
        try:
467
 
            fpr = fingerprint(peer_certificate(session))
468
 
        except (TypeError, gnutls.errors.GNUTLSError), error:
469
 
            logger.warning(u"Bad certificate: %s", error)
 
225
            session.verify_peer()
 
226
        except gnutls.errors.CertificateError, error:
 
227
            #sys.stderr.write(u"Verify failed: %s\n" % error)
470
228
            session.bye()
471
229
            return
472
 
        logger.debug(u"Fingerprint: %s", fpr)
473
230
        client = None
474
 
        for c in self.server.clients:
475
 
            if c.fingerprint == fpr:
 
231
        for c in clients:
 
232
            if c.dn == session.peer_certificate.subject:
476
233
                client = c
477
234
                break
478
 
        if not client:
479
 
            logger.warning(u"Client not found for fingerprint: %s",
480
 
                           fpr)
481
 
            session.bye()
482
 
            return
483
235
        # Have to check if client.still_valid(), since it is possible
484
236
        # that the client timed out while establishing the GnuTLS
485
237
        # session.
486
 
        if not client.still_valid():
487
 
            logger.warning(u"Client %(name)s is invalid",
488
 
                           vars(client))
489
 
            session.bye()
490
 
            return
491
 
        sent_size = 0
492
 
        while sent_size < len(client.secret):
493
 
            sent = session.send(client.secret[sent_size:])
494
 
            logger.debug(u"Sent: %d, remaining: %d",
495
 
                         sent, len(client.secret)
496
 
                         - (sent_size + sent))
497
 
            sent_size += sent
 
238
        if client and client.still_valid():
 
239
            session.send(client.password)
 
240
        else:
 
241
            #if client:
 
242
            #    sys.stderr.write(u"Client %(name)s is invalid\n"
 
243
            #                     % vars(client))
 
244
            #else:
 
245
            #    sys.stderr.write(u"Client not found for DN: %s\n"
 
246
            #                     % session.peer_certificate.subject)
 
247
            #session.send("gazonk")
 
248
            pass
498
249
        session.bye()
499
250
 
500
251
 
501
252
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
502
253
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
503
254
    Attributes:
504
 
        settings:       Server settings
 
255
        options:        Command line options
505
256
        clients:        Set() of Client objects
 
257
        credentials:    GnuTLS X.509 credentials
506
258
    """
507
259
    address_family = socket.AF_INET6
508
260
    def __init__(self, *args, **kwargs):
509
 
        if "settings" in kwargs:
510
 
            self.settings = kwargs["settings"]
511
 
            del kwargs["settings"]
 
261
        if "options" in kwargs:
 
262
            self.options = kwargs["options"]
 
263
            del kwargs["options"]
512
264
        if "clients" in kwargs:
513
265
            self.clients = kwargs["clients"]
514
266
            del kwargs["clients"]
 
267
        if "credentials" in kwargs:
 
268
            self.credentials = kwargs["credentials"]
 
269
            del kwargs["credentials"]
515
270
        return super(type(self), self).__init__(*args, **kwargs)
516
271
    def server_bind(self):
517
272
        """This overrides the normal server_bind() function
518
273
        to bind to an interface if one was specified, and also NOT to
519
274
        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)
 
275
        if self.options.interface:
 
276
            if not hasattr(socket, "SO_BINDTODEVICE"):
 
277
                # From /usr/include/asm-i486/socket.h
 
278
                socket.SO_BINDTODEVICE = 25
523
279
            try:
524
280
                self.socket.setsockopt(socket.SOL_SOCKET,
525
 
                                       SO_BINDTODEVICE,
526
 
                                       self.settings["interface"])
 
281
                                       socket.SO_BINDTODEVICE,
 
282
                                       self.options.interface)
527
283
            except socket.error, error:
528
284
                if error[0] == errno.EPERM:
529
 
                    logger.error(u"No permission to"
530
 
                                 u" bind to interface %s",
531
 
                                 self.settings["interface"])
 
285
                    sys.stderr.write(u"Warning: No permission to bind to interface %s\n"
 
286
                                     % self.options.interface)
532
287
                else:
533
288
                    raise error
534
289
        # Only bind(2) the socket if we really need to.
537
292
                in6addr_any = "::"
538
293
                self.server_address = (in6addr_any,
539
294
                                       self.server_address[1])
540
 
            elif not self.server_address[1]:
 
295
            elif self.server_address[1] is None:
541
296
                self.server_address = (self.server_address[0],
542
297
                                       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
298
            return super(type(self), self).server_bind()
551
299
 
552
300
 
584
332
    return delta
585
333
 
586
334
 
 
335
def add_service():
 
336
    """From the Avahi server example code"""
 
337
    global group, serviceName, serviceType, servicePort, serviceTXT, \
 
338
           domain, host
 
339
    if group is None:
 
340
        group = dbus.Interface(
 
341
                bus.get_object( avahi.DBUS_NAME,
 
342
                                server.EntryGroupNew()),
 
343
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
344
        group.connect_to_signal('StateChanged',
 
345
                                entry_group_state_changed)
 
346
    
 
347
    # print "Adding service '%s' of type '%s' ..." % (serviceName,
 
348
    #                                                 serviceType)
 
349
    
 
350
    group.AddService(
 
351
            serviceInterface,           # interface
 
352
            avahi.PROTO_INET6,          # protocol
 
353
            dbus.UInt32(0),             # flags
 
354
            serviceName, serviceType,
 
355
            domain, host,
 
356
            dbus.UInt16(servicePort),
 
357
            avahi.string_array_to_txt_array(serviceTXT))
 
358
    group.Commit()
 
359
 
 
360
 
 
361
def remove_service():
 
362
    """From the Avahi server example code"""
 
363
    global group
 
364
    
 
365
    if not group is None:
 
366
        group.Reset()
 
367
 
 
368
 
587
369
def server_state_changed(state):
588
 
    """Derived from the Avahi example code"""
 
370
    """From the Avahi server example code"""
589
371
    if state == avahi.SERVER_COLLISION:
590
 
        logger.error(u"Server name collision")
591
 
        service.remove()
 
372
        print "WARNING: Server name collision"
 
373
        remove_service()
592
374
    elif state == avahi.SERVER_RUNNING:
593
 
        service.add()
 
375
        add_service()
594
376
 
595
377
 
596
378
def entry_group_state_changed(state, error):
597
 
    """Derived from the Avahi example code"""
598
 
    logger.debug(u"state change: %i", state)
 
379
    """From the Avahi server example code"""
 
380
    global serviceName, server, rename_count
 
381
    
 
382
    # print "state change: %i" % state
599
383
    
600
384
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
601
 
        logger.debug(u"Service established.")
 
385
        pass
 
386
        # print "Service established."
602
387
    elif state == avahi.ENTRY_GROUP_COLLISION:
603
 
        logger.warning(u"Service name collision.")
604
 
        service.rename()
 
388
        
 
389
        rename_count = rename_count - 1
 
390
        if rename_count > 0:
 
391
            name = server.GetAlternativeServiceName(name)
 
392
            print "WARNING: Service name collision, changing name to '%s' ..." % name
 
393
            remove_service()
 
394
            add_service()
 
395
            
 
396
        else:
 
397
            print "ERROR: No suitable service name found after %i retries, exiting." % n_rename
 
398
            main_loop.quit()
605
399
    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))
 
400
        print "Error in group state changed", error
 
401
        main_loop.quit()
 
402
        return
 
403
 
609
404
 
610
405
def if_nametoindex(interface):
611
 
    """Call the C function if_nametoindex(), or equivalent"""
612
 
    global if_nametoindex
 
406
    """Call the C function if_nametoindex()"""
613
407
    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
618
 
    except (OSError, AttributeError):
 
408
        if "ctypes" not in sys.modules:
 
409
            import ctypes
 
410
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
411
        return libc.if_nametoindex(interface)
 
412
    except (ImportError, OSError, AttributeError):
619
413
        if "struct" not in sys.modules:
620
414
            import struct
621
415
        if "fcntl" not in sys.modules:
622
416
            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)
 
417
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
 
418
        s = socket.socket()
 
419
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
420
                            struct.pack("16s16x", interface))
 
421
        s.close()
 
422
        interface_index = struct.unpack("I", ifreq[16:20])[0]
 
423
        return interface_index
 
424
 
 
425
 
 
426
if __name__ == '__main__':
 
427
    parser = OptionParser()
663
428
    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",
 
429
                      default=None, metavar="IF",
 
430
                      help="Bind to interface IF")
 
431
    parser.add_option("--cert", type="string", default="cert.pem",
 
432
                      metavar="FILE",
 
433
                      help="Public key certificate PEM file to use")
 
434
    parser.add_option("--key", type="string", default="key.pem",
 
435
                      metavar="FILE",
 
436
                      help="Private key PEM file to use")
 
437
    parser.add_option("--ca", type="string", default="ca.pem",
 
438
                      metavar="FILE",
 
439
                      help="Certificate Authority certificate PEM file to use")
 
440
    parser.add_option("--crl", type="string", default="crl.pem",
 
441
                      metavar="FILE",
 
442
                      help="Certificate Revokation List PEM file to use")
 
443
    parser.add_option("-p", "--port", type="int", default=None,
668
444
                      help="Port number to receive requests on")
 
445
    parser.add_option("--timeout", type="string", # Parsed later
 
446
                      default="1h",
 
447
                      help="Amount of downtime allowed for clients")
 
448
    parser.add_option("--interval", type="string", # Parsed later
 
449
                      default="5m",
 
450
                      help="How often to check that a client is up")
669
451
    parser.add_option("--check", action="store_true", default=False,
670
452
                      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")
682
453
    (options, args) = parser.parse_args()
683
454
    
684
455
    if options.check:
686
457
        doctest.testmod()
687
458
        sys.exit()
688
459
    
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
 
460
    # Parse the time arguments
 
461
    try:
 
462
        options.timeout = string_to_delta(options.timeout)
 
463
    except ValueError:
 
464
        parser.error("option --timeout: Unparseable time")
 
465
    try:
 
466
        options.interval = string_to_delta(options.interval)
 
467
    except ValueError:
 
468
        parser.error("option --interval: Unparseable time")
 
469
    
 
470
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
 
471
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
 
472
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
 
473
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
 
474
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
 
475
    
 
476
    # Parse config file
 
477
    defaults = {}
 
478
    client_config = ConfigParser.SafeConfigParser(defaults)
 
479
    #client_config.readfp(open("secrets.conf"), "secrets.conf")
 
480
    client_config.read("mandos-clients.conf")
 
481
    
 
482
    # From the Avahi server example code
752
483
    DBusGMainLoop(set_as_default=True )
753
484
    main_loop = gobject.MainLoop()
754
485
    bus = dbus.SystemBus()
761
492
    def remove_from_clients(client):
762
493
        clients.remove(client)
763
494
        if not clients:
764
 
            logger.critical(u"No clients left, exiting")
765
 
            sys.exit()
 
495
            print "No clients left, exiting"
 
496
            main_loop.quit()
766
497
    
767
 
    clients.update(Set(Client(name = section,
 
498
    clients.update(Set(Client(name=section, options=options,
768
499
                              stop_hook = remove_from_clients,
769
 
                              config
770
 
                              = dict(client_config.items(section)))
 
500
                              **(dict(client_config\
 
501
                                      .items(section))))
771
502
                       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
503
    for client in clients:
813
504
        client.start()
814
505
    
815
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
816
 
                                 server_settings["port"]),
 
506
    tcp_server = IPv6_TCPServer((None, options.port),
817
507
                                tcp_handler,
818
 
                                settings=server_settings,
819
 
                                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
 
    
 
508
                                options=options,
 
509
                                clients=clients,
 
510
                                credentials=cred)
 
511
    # Find out what random port we got
 
512
    servicePort = tcp_server.socket.getsockname()[1]
 
513
    #sys.stderr.write("Now listening on port %d\n" % servicePort)
 
514
    
 
515
    if options.interface is not None:
 
516
        serviceInterface = if_nametoindex(options.interface)
 
517
    
 
518
    # From the Avahi server example code
 
519
    server.connect_to_signal("StateChanged", server_state_changed)
 
520
    server_state_changed(server.GetState())
 
521
    # End of Avahi example code
 
522
    
 
523
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
524
                         lambda *args, **kwargs:
 
525
                         tcp_server.handle_request(*args[2:],
 
526
                                                   **kwargs) or True)
827
527
    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
528
        main_loop.run()
845
 
    except AvahiError, error:
846
 
        logger.critical(u"AvahiError: %s" + unicode(error))
847
 
        sys.exit(1)
848
529
    except KeyboardInterrupt:
849
 
        if debug:
850
 
            print
 
530
        print
 
531
    
 
532
    # Cleanup here
851
533
 
852
 
if __name__ == '__main__':
853
 
    main()
 
534
    # From the Avahi server example code
 
535
    if not group is None:
 
536
        group.Free()
 
537
    # End of Avahi example code
 
538
    
 
539
    for client in clients:
 
540
        client.stop_hook = None
 
541
        client.stop()