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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
 
 
65
 
logger = logging.Logger('mandos')
66
 
syslogger = logging.handlers.SysLogHandler\
67
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
68
 
             address = "/dev/log")
69
 
syslogger.setFormatter(logging.Formatter\
70
 
                        ('Mandos: %(levelname)s: %(message)s'))
71
 
logger.addHandler(syslogger)
72
 
 
73
 
 
74
 
class AvahiError(Exception):
75
 
    def __init__(self, value):
76
 
        self.value = value
77
 
    def __str__(self):
78
 
        return repr(self.value)
79
 
 
80
 
class AvahiServiceError(AvahiError):
81
 
    pass
82
 
 
83
 
class AvahiGroupError(AvahiError):
84
 
    pass
85
 
 
86
 
 
87
 
class AvahiService(object):
88
 
    """An Avahi (Zeroconf) service.
89
 
    Attributes:
90
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
91
 
               Used to optionally bind to the specified interface.
92
 
    name: string; Example: 'Mandos'
93
 
    type: string; Example: '_mandos._tcp'.
94
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
95
 
    port: integer; what port to announce
96
 
    TXT: list of strings; TXT record for the service
97
 
    domain: string; Domain to publish on, default to .local if empty.
98
 
    host: string; Host to publish records for, default is localhost
99
 
    max_renames: integer; maximum number of renames
100
 
    rename_count: integer; counter so we only rename after collisions
101
 
                  a sensible number of times
102
 
    """
103
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
104
 
                 type = None, port = None, TXT = None, domain = "",
105
 
                 host = "", max_renames = 32768):
106
 
        self.interface = interface
107
 
        self.name = name
108
 
        self.type = type
109
 
        self.port = port
110
 
        if TXT is None:
111
 
            self.TXT = []
112
 
        else:
113
 
            self.TXT = TXT
114
 
        self.domain = domain
115
 
        self.host = host
116
 
        self.rename_count = 0
117
 
    def rename(self):
118
 
        """Derived from the Avahi example code"""
119
 
        if self.rename_count >= self.max_renames:
120
 
            logger.critical(u"No suitable service name found after %i"
121
 
                            u" retries, exiting.", rename_count)
122
 
            raise AvahiServiceError("Too many renames")
123
 
        name = server.GetAlternativeServiceName(name)
124
 
        logger.error(u"Changing name to %r ...", name)
125
 
        syslogger.setFormatter(logging.Formatter\
126
 
                               ('Mandos (%s): %%(levelname)s:'
127
 
                               ' %%(message)s' % name))
128
 
        self.remove()
129
 
        self.add()
130
 
        self.rename_count += 1
131
 
    def remove(self):
132
 
        """Derived from the Avahi example code"""
133
 
        if group is not None:
134
 
            group.Reset()
135
 
    def add(self):
136
 
        """Derived from the Avahi example code"""
137
 
        global group
138
 
        if group is None:
139
 
            group = dbus.Interface\
140
 
                    (bus.get_object(avahi.DBUS_NAME,
141
 
                                    server.EntryGroupNew()),
142
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
143
 
            group.connect_to_signal('StateChanged',
144
 
                                    entry_group_state_changed)
145
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
146
 
                     service.name, service.type)
147
 
        group.AddService(
148
 
                self.interface,         # interface
149
 
                avahi.PROTO_INET6,      # protocol
150
 
                dbus.UInt32(0),         # flags
151
 
                self.name, self.type,
152
 
                self.domain, self.host,
153
 
                dbus.UInt16(self.port),
154
 
                avahi.string_array_to_txt_array(self.TXT))
155
 
        group.Commit()
156
 
 
157
 
# From the Avahi example code:
158
 
group = None                            # our entry group
 
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
159
41
# End of Avahi example code
160
42
 
161
43
 
162
44
class Client(object):
163
45
    """A representation of a client host served by this server.
164
46
    Attributes:
165
 
    name:      string; from the config file, used in log messages
166
 
    fingerprint: string (40 or 32 hexadecimal digits); used to
167
 
                 uniquely identify the client
168
 
    secret:    bytestring; sent verbatim (over TLS) to client
169
 
    host:      string; available for use by the checker command
170
 
    created:   datetime.datetime(); object creation, not client host
171
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
172
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
173
 
                                     until this client is invalid
 
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
174
53
    interval:  datetime.timedelta(); How often to start a new checker
 
54
    timeout_milliseconds: Used by gobject.timeout_add()
 
55
    interval_milliseconds: - '' -
175
56
    stop_hook: If set, called by stop() as stop_hook(self)
176
57
    checker:   subprocess.Popen(); a running checker process used
177
58
                                   to see if the client lives.
178
 
                                   'None' if no process is running.
 
59
                                   Is None if no process is running.
179
60
    checker_initiator_tag: a gobject event source tag, or None
180
61
    stop_initiator_tag:    - '' -
181
62
    checker_callback_tag:  - '' -
182
 
    checker_command: string; External command which is run to check if
183
 
                     client lives.  %() expansions are done at
184
 
                     runtime with vars(self) as dict, so that for
185
 
                     instance %(name)s can be used in the command.
186
 
    Private attibutes:
187
 
    _timeout: Real variable for 'timeout'
188
 
    _interval: Real variable for 'interval'
189
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
190
 
    _interval_milliseconds: - '' -
191
63
    """
192
 
    def _set_timeout(self, timeout):
193
 
        "Setter function for 'timeout' attribute"
194
 
        self._timeout = timeout
195
 
        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
196
93
                                       * 24 * 60 * 60 * 1000)
197
 
                                      + (self.timeout.seconds * 1000)
198
 
                                      + (self.timeout.microseconds
 
94
                                      + (self.interval.seconds * 1000)
 
95
                                      + (self.interval.microseconds
199
96
                                         // 1000))
200
 
    timeout = property(lambda self: self._timeout,
201
 
                       _set_timeout)
202
 
    del _set_timeout
203
 
    def _set_interval(self, interval):
204
 
        "Setter function for 'interval' attribute"
205
 
        self._interval = interval
206
 
        self._interval_milliseconds = ((self.interval.days
207
 
                                        * 24 * 60 * 60 * 1000)
208
 
                                       + (self.interval.seconds
209
 
                                          * 1000)
210
 
                                       + (self.interval.microseconds
211
 
                                          // 1000))
212
 
    interval = property(lambda self: self._interval,
213
 
                        _set_interval)
214
 
    del _set_interval
215
 
    def __init__(self, name = None, stop_hook=None, config={}):
216
 
        """Note: the 'checker' key in 'config' sets the
217
 
        'checker_command' attribute and *not* the 'checker'
218
 
        attribute."""
219
 
        self.name = name
220
 
        logger.debug(u"Creating client %r", self.name)
221
 
        # Uppercase and remove spaces from fingerprint for later
222
 
        # comparison purposes with return value from the fingerprint()
223
 
        # function
224
 
        self.fingerprint = config["fingerprint"].upper()\
225
 
                           .replace(u" ", u"")
226
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
227
 
        if "secret" in config:
228
 
            self.secret = config["secret"].decode(u"base64")
229
 
        elif "secfile" in config:
230
 
            sf = open(config["secfile"])
231
 
            self.secret = sf.read()
232
 
            sf.close()
233
 
        else:
234
 
            raise TypeError(u"No secret or secfile for client %s"
235
 
                            % self.name)
236
 
        self.host = config.get("host", "")
237
 
        self.created = datetime.datetime.now()
238
 
        self.last_checked_ok = None
239
 
        self.timeout = string_to_delta(config["timeout"])
240
 
        self.interval = string_to_delta(config["interval"])
241
97
        self.stop_hook = stop_hook
242
98
        self.checker = None
243
99
        self.checker_initiator_tag = None
244
100
        self.stop_initiator_tag = None
245
101
        self.checker_callback_tag = None
246
 
        self.check_command = config["checker"]
247
102
    def start(self):
248
 
        """Start this client's checker and timeout hooks"""
 
103
        """Start this clients checker and timeout hooks"""
249
104
        # Schedule a new checker to be started an 'interval' from now,
250
105
        # and every interval from then on.
251
 
        self.checker_initiator_tag = gobject.timeout_add\
252
 
                                     (self._interval_milliseconds,
253
 
                                      self.start_checker)
 
106
        self.checker_initiator_tag = gobject.\
 
107
                                     timeout_add(self.interval_milliseconds,
 
108
                                                 self.start_checker)
254
109
        # Also start a new checker *right now*.
255
110
        self.start_checker()
256
111
        # Schedule a stop() when 'timeout' has passed
257
 
        self.stop_initiator_tag = gobject.timeout_add\
258
 
                                  (self._timeout_milliseconds,
259
 
                                   self.stop)
 
112
        self.stop_initiator_tag = gobject.\
 
113
                                     timeout_add(self.timeout_milliseconds,
 
114
                                                 self.stop)
260
115
    def stop(self):
261
116
        """Stop this client.
262
 
        The possibility that a client might be restarted is left open,
263
 
        but not currently used."""
264
 
        # If this client doesn't have a secret, it is already stopped.
265
 
        if hasattr(self, "secret") and self.secret:
266
 
            logger.info(u"Stopping client %s", self.name)
267
 
            self.secret = None
268
 
        else:
269
 
            return False
270
 
        if getattr(self, "stop_initiator_tag", False):
 
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:
271
122
            gobject.source_remove(self.stop_initiator_tag)
272
123
            self.stop_initiator_tag = None
273
 
        if getattr(self, "checker_initiator_tag", False):
 
124
        if self.checker_initiator_tag:
274
125
            gobject.source_remove(self.checker_initiator_tag)
275
126
            self.checker_initiator_tag = None
276
127
        self.stop_checker()
279
130
        # Do not run this again if called by a gobject.timeout_add
280
131
        return False
281
132
    def __del__(self):
282
 
        self.stop_hook = None
283
 
        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()
284
143
    def checker_callback(self, pid, condition):
285
144
        """The checker has completed, so take appropriate actions."""
286
145
        now = datetime.datetime.now()
287
 
        self.checker_callback_tag = None
288
 
        self.checker = None
289
146
        if os.WIFEXITED(condition) \
290
147
               and (os.WEXITSTATUS(condition) == 0):
291
 
            logger.info(u"Checker for %(name)s succeeded",
292
 
                        vars(self))
293
 
            self.last_checked_ok = now
 
148
            #print "Checker for %(name)s succeeded" % vars(self)
 
149
            self.last_seen = now
294
150
            gobject.source_remove(self.stop_initiator_tag)
295
 
            self.stop_initiator_tag = gobject.timeout_add\
296
 
                                      (self._timeout_milliseconds,
297
 
                                       self.stop)
298
 
        elif not os.WIFEXITED(condition):
299
 
            logger.warning(u"Checker for %(name)s crashed?",
300
 
                           vars(self))
301
 
        else:
302
 
            logger.info(u"Checker for %(name)s failed",
303
 
                        vars(self))
 
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
304
161
    def start_checker(self):
305
162
        """Start a new checker subprocess if one is not running.
306
163
        If a checker already exists, leave it running and do
307
164
        nothing."""
308
 
        # The reason for not killing a running checker is that if we
309
 
        # did that, then if a checker (for some reason) started
310
 
        # running slowly and taking more than 'interval' time, the
311
 
        # client would inevitably timeout, since no checker would get
312
 
        # a chance to run to completion.  If we instead leave running
313
 
        # checkers alone, the checker would have to take more time
314
 
        # than 'timeout' for the client to be declared invalid, which
315
 
        # is as it should be.
316
165
        if self.checker is None:
317
 
            try:
318
 
                # In case check_command has exactly one % operator
319
 
                command = self.check_command % self.host
320
 
            except TypeError:
321
 
                # Escape attributes for the shell
322
 
                escaped_attrs = dict((key, re.escape(str(val)))
323
 
                                     for key, val in
324
 
                                     vars(self).iteritems())
325
 
                try:
326
 
                    command = self.check_command % escaped_attrs
327
 
                except TypeError, error:
328
 
                    logger.error(u'Could not format string "%s":'
329
 
                                 u' %s', self.check_command, error)
330
 
                    return True # Try again later
331
 
            try:
332
 
                logger.info(u"Starting checker %r for %s",
333
 
                            command, self.name)
334
 
                self.checker = subprocess.Popen(command,
335
 
                                                close_fds=True,
336
 
                                                shell=True, cwd="/")
337
 
                self.checker_callback_tag = gobject.child_watch_add\
338
 
                                            (self.checker.pid,
339
 
                                             self.checker_callback)
 
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)
340
178
            except subprocess.OSError, error:
341
 
                logger.error(u"Failed to start subprocess: %s",
342
 
                             error)
 
179
                sys.stderr.write(u"Failed to start subprocess: %s\n"
 
180
                                 % error)
343
181
        # Re-run this periodically if run by gobject.timeout_add
344
182
        return True
345
183
    def stop_checker(self):
346
184
        """Force the checker process, if any, to stop."""
347
 
        if self.checker_callback_tag:
348
 
            gobject.source_remove(self.checker_callback_tag)
349
 
            self.checker_callback_tag = None
350
 
        if getattr(self, "checker", None) is None:
 
185
        if not hasattr(self, "checker") or self.checker is None:
351
186
            return
352
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
353
 
        try:
354
 
            os.kill(self.checker.pid, signal.SIGTERM)
355
 
            #os.sleep(0.5)
356
 
            #if self.checker.poll() is None:
357
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
358
 
        except OSError, error:
359
 
            if error.errno != errno.ESRCH: # No such process
360
 
                raise
 
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)
361
192
        self.checker = None
362
 
    def still_valid(self):
 
193
    def still_valid(self, now=None):
363
194
        """Has the timeout not yet passed for this client?"""
364
 
        now = datetime.datetime.now()
365
 
        if self.last_checked_ok is None:
 
195
        if now is None:
 
196
            now = datetime.datetime.now()
 
197
        if self.last_seen is None:
366
198
            return now < (self.created + self.timeout)
367
199
        else:
368
 
            return now < (self.last_checked_ok + self.timeout)
369
 
 
370
 
 
371
 
def peer_certificate(session):
372
 
    "Return the peer's OpenPGP certificate as a bytestring"
373
 
    # If not an OpenPGP certificate...
374
 
    if gnutls.library.functions.gnutls_certificate_type_get\
375
 
            (session._c_object) \
376
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
377
 
        # ...do the normal thing
378
 
        return session.peer_certificate
379
 
    list_size = ctypes.c_uint()
380
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
381
 
        (session._c_object, ctypes.byref(list_size))
382
 
    if list_size.value == 0:
383
 
        return None
384
 
    cert = cert_list[0]
385
 
    return ctypes.string_at(cert.data, cert.size)
386
 
 
387
 
 
388
 
def fingerprint(openpgp):
389
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
390
 
    # New GnuTLS "datum" with the OpenPGP public key
391
 
    datum = gnutls.library.types.gnutls_datum_t\
392
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
393
 
                     ctypes.POINTER(ctypes.c_ubyte)),
394
 
         ctypes.c_uint(len(openpgp)))
395
 
    # New empty GnuTLS certificate
396
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
397
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
398
 
        (ctypes.byref(crt))
399
 
    # Import the OpenPGP public key into the certificate
400
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
401
 
                    (crt, ctypes.byref(datum),
402
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
403
 
    # New buffer for the fingerprint
404
 
    buffer = ctypes.create_string_buffer(20)
405
 
    buffer_length = ctypes.c_size_t()
406
 
    # Get the fingerprint from the certificate into the buffer
407
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
408
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
409
 
    # Deinit the certificate
410
 
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
411
 
    # Convert the buffer to a Python bytestring
412
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
413
 
    # Convert the bytestring to hexadecimal notation
414
 
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
415
 
    return hex_fpr
 
200
            return now < (self.last_seen + self.timeout)
416
201
 
417
202
 
418
203
class tcp_handler(SocketServer.BaseRequestHandler, object):
419
204
    """A TCP request handler class.
420
205
    Instantiated by IPv6_TCPServer for each request to handle it.
421
206
    Note: This will run in its own forked process."""
422
 
    
423
207
    def handle(self):
424
 
        logger.info(u"TCP connection from: %s",
425
 
                     unicode(self.client_address))
426
 
        session = gnutls.connection.ClientSession\
427
 
                  (self.request, gnutls.connection.X509Credentials())
428
 
        
429
 
        line = self.request.makefile().readline()
430
 
        logger.debug(u"Protocol version: %r", line)
431
 
        try:
432
 
            if int(line.strip().split()[0]) > 1:
433
 
                raise RuntimeError
434
 
        except (ValueError, IndexError, RuntimeError), error:
435
 
            logger.error(u"Unknown protocol version: %s", error)
436
 
            return
437
 
        
438
 
        # Note: gnutls.connection.X509Credentials is really a generic
439
 
        # GnuTLS certificate credentials object so long as no X.509
440
 
        # keys are added to it.  Therefore, we can use it here despite
441
 
        # using OpenPGP certificates.
442
 
        
443
 
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
444
 
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
445
 
        #                "+DHE-DSS"))
446
 
        priority = "NORMAL"             # Fallback default, since this
447
 
                                        # MUST be set.
448
 
        if self.server.settings["priority"]:
449
 
            priority = self.server.settings["priority"]
450
 
        gnutls.library.functions.gnutls_priority_set_direct\
451
 
            (session._c_object, priority, None);
452
 
        
 
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)
453
215
        try:
454
216
            session.handshake()
455
217
        except gnutls.errors.GNUTLSError, error:
456
 
            logger.warning(u"Handshake failed: %s", error)
 
218
            #sys.stderr.write(u"Handshake failed: %s\n" % error)
457
219
            # Do not run session.bye() here: the session is not
458
220
            # established.  Just abandon the request.
459
221
            return
 
222
        #if session.peer_certificate:
 
223
        #    print "DN:", session.peer_certificate.subject
460
224
        try:
461
 
            fpr = fingerprint(peer_certificate(session))
462
 
        except (TypeError, gnutls.errors.GNUTLSError), error:
463
 
            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)
464
228
            session.bye()
465
229
            return
466
 
        logger.debug(u"Fingerprint: %s", fpr)
467
230
        client = None
468
 
        for c in self.server.clients:
469
 
            if c.fingerprint == fpr:
 
231
        for c in clients:
 
232
            if c.dn == session.peer_certificate.subject:
470
233
                client = c
471
234
                break
472
 
        if not client:
473
 
            logger.warning(u"Client not found for fingerprint: %s",
474
 
                           fpr)
475
 
            session.bye()
476
 
            return
477
235
        # Have to check if client.still_valid(), since it is possible
478
236
        # that the client timed out while establishing the GnuTLS
479
237
        # session.
480
 
        if not client.still_valid():
481
 
            logger.warning(u"Client %(name)s is invalid",
482
 
                           vars(client))
483
 
            session.bye()
484
 
            return
485
 
        sent_size = 0
486
 
        while sent_size < len(client.secret):
487
 
            sent = session.send(client.secret[sent_size:])
488
 
            logger.debug(u"Sent: %d, remaining: %d",
489
 
                         sent, len(client.secret)
490
 
                         - (sent_size + sent))
491
 
            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
492
249
        session.bye()
493
250
 
494
251
 
495
252
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
496
253
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
497
254
    Attributes:
498
 
        settings:       Server settings
 
255
        options:        Command line options
499
256
        clients:        Set() of Client objects
 
257
        credentials:    GnuTLS X.509 credentials
500
258
    """
501
259
    address_family = socket.AF_INET6
502
260
    def __init__(self, *args, **kwargs):
503
 
        if "settings" in kwargs:
504
 
            self.settings = kwargs["settings"]
505
 
            del kwargs["settings"]
 
261
        if "options" in kwargs:
 
262
            self.options = kwargs["options"]
 
263
            del kwargs["options"]
506
264
        if "clients" in kwargs:
507
265
            self.clients = kwargs["clients"]
508
266
            del kwargs["clients"]
 
267
        if "credentials" in kwargs:
 
268
            self.credentials = kwargs["credentials"]
 
269
            del kwargs["credentials"]
509
270
        return super(type(self), self).__init__(*args, **kwargs)
510
271
    def server_bind(self):
511
272
        """This overrides the normal server_bind() function
512
273
        to bind to an interface if one was specified, and also NOT to
513
274
        bind to an address or port if they were not specified."""
514
 
        if self.settings["interface"]:
515
 
            # 25 is from /usr/include/asm-i486/socket.h
516
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
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
517
279
            try:
518
280
                self.socket.setsockopt(socket.SOL_SOCKET,
519
 
                                       SO_BINDTODEVICE,
520
 
                                       self.settings["interface"])
 
281
                                       socket.SO_BINDTODEVICE,
 
282
                                       self.options.interface)
521
283
            except socket.error, error:
522
284
                if error[0] == errno.EPERM:
523
 
                    logger.error(u"No permission to"
524
 
                                 u" bind to interface %s",
525
 
                                 self.settings["interface"])
 
285
                    sys.stderr.write(u"Warning: No permission to bind to interface %s\n"
 
286
                                     % self.options.interface)
526
287
                else:
527
288
                    raise error
528
289
        # Only bind(2) the socket if we really need to.
531
292
                in6addr_any = "::"
532
293
                self.server_address = (in6addr_any,
533
294
                                       self.server_address[1])
534
 
            elif not self.server_address[1]:
 
295
            elif self.server_address[1] is None:
535
296
                self.server_address = (self.server_address[0],
536
297
                                       0)
537
 
#                 if self.settings["interface"]:
538
 
#                     self.server_address = (self.server_address[0],
539
 
#                                            0, # port
540
 
#                                            0, # flowinfo
541
 
#                                            if_nametoindex
542
 
#                                            (self.settings
543
 
#                                             ["interface"]))
544
298
            return super(type(self), self).server_bind()
545
299
 
546
300
 
578
332
    return delta
579
333
 
580
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
 
581
369
def server_state_changed(state):
582
 
    """Derived from the Avahi example code"""
 
370
    """From the Avahi server example code"""
583
371
    if state == avahi.SERVER_COLLISION:
584
 
        logger.error(u"Server name collision")
585
 
        service.remove()
 
372
        print "WARNING: Server name collision"
 
373
        remove_service()
586
374
    elif state == avahi.SERVER_RUNNING:
587
 
        service.add()
 
375
        add_service()
588
376
 
589
377
 
590
378
def entry_group_state_changed(state, error):
591
 
    """Derived from the Avahi example code"""
592
 
    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
593
383
    
594
384
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
595
 
        logger.debug(u"Service established.")
 
385
        pass
 
386
        # print "Service established."
596
387
    elif state == avahi.ENTRY_GROUP_COLLISION:
597
 
        logger.warning(u"Service name collision.")
598
 
        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()
599
399
    elif state == avahi.ENTRY_GROUP_FAILURE:
600
 
        logger.critical(u"Error in group state changed %s",
601
 
                        unicode(error))
602
 
        raise AvahiGroupError("State changed: %s", str(error))
 
400
        print "Error in group state changed", error
 
401
        main_loop.quit()
 
402
        return
 
403
 
603
404
 
604
405
def if_nametoindex(interface):
605
 
    """Call the C function if_nametoindex(), or equivalent"""
606
 
    global if_nametoindex
 
406
    """Call the C function if_nametoindex()"""
607
407
    try:
608
 
        if "ctypes.util" not in sys.modules:
609
 
            import ctypes.util
610
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
611
 
            (ctypes.util.find_library("c")).if_nametoindex
612
 
    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):
613
413
        if "struct" not in sys.modules:
614
414
            import struct
615
415
        if "fcntl" not in sys.modules:
616
416
            import fcntl
617
 
        def if_nametoindex(interface):
618
 
            "Get an interface index the hard way, i.e. using fcntl()"
619
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
620
 
            s = socket.socket()
621
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
622
 
                                struct.pack("16s16x", interface))
623
 
            s.close()
624
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
625
 
            return interface_index
626
 
    return if_nametoindex(interface)
627
 
 
628
 
 
629
 
def daemon(nochdir = False, noclose = False):
630
 
    """See daemon(3).  Standard BSD Unix function.
631
 
    This should really exist as os.daemon, but it doesn't (yet)."""
632
 
    if os.fork():
633
 
        sys.exit()
634
 
    os.setsid()
635
 
    if not nochdir:
636
 
        os.chdir("/")
637
 
    if os.fork():
638
 
        sys.exit()
639
 
    if not noclose:
640
 
        # Close all standard open file descriptors
641
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
642
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
643
 
            raise OSError(errno.ENODEV,
644
 
                          "/dev/null not a character device")
645
 
        os.dup2(null, sys.stdin.fileno())
646
 
        os.dup2(null, sys.stdout.fileno())
647
 
        os.dup2(null, sys.stderr.fileno())
648
 
        if null > 2:
649
 
            os.close(null)
650
 
 
651
 
 
652
 
def main():
653
 
    global main_loop_started
654
 
    main_loop_started = False
655
 
    
 
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__':
656
427
    parser = OptionParser()
657
428
    parser.add_option("-i", "--interface", type="string",
658
 
                      metavar="IF", help="Bind to interface IF")
659
 
    parser.add_option("-a", "--address", type="string",
660
 
                      help="Address to listen for requests on")
661
 
    parser.add_option("-p", "--port", type="int",
 
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,
662
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")
663
451
    parser.add_option("--check", action="store_true", default=False,
664
452
                      help="Run self-test")
665
 
    parser.add_option("--debug", action="store_true",
666
 
                      help="Debug mode; run in foreground and log to"
667
 
                      " terminal")
668
 
    parser.add_option("--priority", type="string", help="GnuTLS"
669
 
                      " priority string (see GnuTLS documentation)")
670
 
    parser.add_option("--servicename", type="string", metavar="NAME",
671
 
                      help="Zeroconf service name")
672
 
    parser.add_option("--configdir", type="string",
673
 
                      default="/etc/mandos", metavar="DIR",
674
 
                      help="Directory to search for configuration"
675
 
                      " files")
676
453
    (options, args) = parser.parse_args()
677
454
    
678
455
    if options.check:
680
457
        doctest.testmod()
681
458
        sys.exit()
682
459
    
683
 
    # Default values for config file for server-global settings
684
 
    server_defaults = { "interface": "",
685
 
                        "address": "",
686
 
                        "port": "",
687
 
                        "debug": "False",
688
 
                        "priority":
689
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
690
 
                        "servicename": "Mandos",
691
 
                        }
692
 
    
693
 
    # Parse config file for server-global settings
694
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
695
 
    del server_defaults
696
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
697
 
    server_section = "server"
698
 
    # Convert the SafeConfigParser object to a dict
699
 
    server_settings = dict(server_config.items(server_section))
700
 
    # Use getboolean on the boolean config option
701
 
    server_settings["debug"] = server_config.getboolean\
702
 
                               (server_section, "debug")
703
 
    del server_config
704
 
    
705
 
    # Override the settings from the config file with command line
706
 
    # options, if set.
707
 
    for option in ("interface", "address", "port", "debug",
708
 
                   "priority", "servicename", "configdir"):
709
 
        value = getattr(options, option)
710
 
        if value is not None:
711
 
            server_settings[option] = value
712
 
    del options
713
 
    # Now we have our good server settings in "server_settings"
714
 
    
715
 
    debug = server_settings["debug"]
716
 
    
717
 
    if not debug:
718
 
        syslogger.setLevel(logging.WARNING)
719
 
    
720
 
    if server_settings["servicename"] != "Mandos":
721
 
        syslogger.setFormatter(logging.Formatter\
722
 
                               ('Mandos (%s): %%(levelname)s:'
723
 
                                ' %%(message)s'
724
 
                                % server_settings["servicename"]))
725
 
    
726
 
    # Parse config file with clients
727
 
    client_defaults = { "timeout": "1h",
728
 
                        "interval": "5m",
729
 
                        "checker": "fping -q -- %%(host)s",
730
 
                        }
731
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
732
 
    client_config.read(os.path.join(server_settings["configdir"],
733
 
                                    "clients.conf"))
734
 
    
735
 
    global service
736
 
    service = AvahiService(name = server_settings["servicename"],
737
 
                           type = "_mandos._tcp", );
738
 
    if server_settings["interface"]:
739
 
        service.interface = if_nametoindex(server_settings["interface"])
740
 
    
741
 
    global main_loop
742
 
    global bus
743
 
    global server
744
 
    # From the Avahi example code
 
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
745
483
    DBusGMainLoop(set_as_default=True )
746
484
    main_loop = gobject.MainLoop()
747
485
    bus = dbus.SystemBus()
750
488
            avahi.DBUS_INTERFACE_SERVER )
751
489
    # End of Avahi example code
752
490
    
753
 
    if debug:
754
 
        console = logging.StreamHandler()
755
 
        # console.setLevel(logging.DEBUG)
756
 
        console.setFormatter(logging.Formatter\
757
 
                             ('%(levelname)s: %(message)s'))
758
 
        logger.addHandler(console)
759
 
        del console
760
 
    
761
491
    clients = Set()
762
492
    def remove_from_clients(client):
763
493
        clients.remove(client)
764
494
        if not clients:
765
 
            logger.critical(u"No clients left, exiting")
766
 
            sys.exit()
 
495
            print "No clients left, exiting"
 
496
            main_loop.quit()
767
497
    
768
 
    clients.update(Set(Client(name = section,
 
498
    clients.update(Set(Client(name=section, options=options,
769
499
                              stop_hook = remove_from_clients,
770
 
                              config
771
 
                              = dict(client_config.items(section)))
 
500
                              **(dict(client_config\
 
501
                                      .items(section))))
772
502
                       for section in client_config.sections()))
773
 
    if not clients:
774
 
        logger.critical(u"No clients defined")
775
 
        sys.exit(1)
776
 
    
777
 
    if not debug:
778
 
        daemon()
779
 
    
780
 
    pidfilename = "/var/run/mandos/mandos.pid"
781
 
    pid = os.getpid()
782
 
    try:
783
 
        pidfile = open(pidfilename, "w")
784
 
        pidfile.write(str(pid) + "\n")
785
 
        pidfile.close()
786
 
        del pidfile
787
 
    except IOError, err:
788
 
        logger.error(u"Could not write %s file with PID %d",
789
 
                     pidfilename, os.getpid())
790
 
    
791
 
    def cleanup():
792
 
        "Cleanup function; run on exit"
793
 
        global group
794
 
        # From the Avahi example code
795
 
        if not group is None:
796
 
            group.Free()
797
 
            group = None
798
 
        # End of Avahi example code
799
 
        
800
 
        while clients:
801
 
            client = clients.pop()
802
 
            client.stop_hook = None
803
 
            client.stop()
804
 
    
805
 
    atexit.register(cleanup)
806
 
    
807
 
    if not debug:
808
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
809
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
810
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
811
 
    
812
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()