/mandos/trunk

To get this branch, use:
bzr branch http://bzr.recompile.se/loggerhead/mandos/trunk

« back to all changes in this revision

Viewing changes to mandos

  • Committer: Teddy Hogeborn
  • Date: 2008-08-07 21:45:41 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080807214541-pyg8itw6kphz1dy5
* plugbasedclient.c: Renamed to "mandos-client.c".  All users changed.

* plugins.d/mandosclient.c: Renamed to "plugins.d/password-request.c".
                            All users changed.

* plugins.d/passprompt.c: Renamed to "plugins.d/password-prompt.c".
                          All users changed.

* server.conf: Renamed to "mandos.conf".  All users changed.

* server.py: Renamed to "mandos".
  (daemon): Have default values for arguments. Caller changed.

* Makefile (distclean, mostlyclean, maintainer-clean): New aliases for
                                                       "clean".
  (check, run-client, run-server): New.

* network-protocol.txt: New.

Show diffs side-by-side

added added

removed removed

Lines of Context:
mandos
1
1
#!/usr/bin/python
 
2
# -*- mode: python; coding: utf-8 -*-
 
3
# 
 
4
# Mandos server - give out binary blobs to connecting clients.
 
5
# 
 
6
# This program is partly derived from an example program for an Avahi
 
7
# service publisher, downloaded from
 
8
# <http://avahi.org/wiki/PythonPublishExample>.  This includes the
 
9
# methods "add" and "remove" in the "AvahiService" class, the
 
10
# "server_state_changed" and "entry_group_state_changed" functions,
 
11
# and some lines in "main".
 
12
# 
 
13
# Everything else is
 
14
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
 
15
# 
 
16
# This program is free software: you can redistribute it and/or modify
 
17
# it under the terms of the GNU General Public License as published by
 
18
# the Free Software Foundation, either version 3 of the License, or
 
19
# (at your option) any later version.
 
20
#
 
21
#     This program is distributed in the hope that it will be useful,
 
22
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
 
23
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
24
#     GNU General Public License for more details.
 
25
# 
 
26
# You should have received a copy of the GNU General Public License
 
27
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
28
# 
 
29
# Contact the authors at <mandos@fukt.bsnet.se>.
 
30
# 
 
31
 
 
32
from __future__ import division
2
33
 
3
34
import SocketServer
4
35
import socket
9
40
import gnutls.crypto
10
41
import gnutls.connection
11
42
import gnutls.errors
 
43
import gnutls.library.functions
 
44
import gnutls.library.constants
 
45
import gnutls.library.types
12
46
import ConfigParser
13
47
import sys
 
48
import re
 
49
import os
 
50
import signal
 
51
from sets import Set
 
52
import subprocess
 
53
import atexit
 
54
import stat
 
55
import logging
 
56
import logging.handlers
 
57
 
 
58
import dbus
 
59
import gobject
 
60
import avahi
 
61
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
syslogger.setFormatter(logging.Formatter\
 
69
                        ('%(levelname)s: %(message)s'))
 
70
logger.addHandler(syslogger)
 
71
del 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 = 12):
 
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
        self.remove()
 
126
        self.add()
 
127
        self.rename_count += 1
 
128
    def remove(self):
 
129
        """Derived from the Avahi example code"""
 
130
        if group is not None:
 
131
            group.Reset()
 
132
    def add(self):
 
133
        """Derived from the Avahi example code"""
 
134
        global group
 
135
        if group is None:
 
136
            group = dbus.Interface\
 
137
                    (bus.get_object(avahi.DBUS_NAME,
 
138
                                    server.EntryGroupNew()),
 
139
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
140
            group.connect_to_signal('StateChanged',
 
141
                                    entry_group_state_changed)
 
142
        logger.debug(u"Adding service '%s' of type '%s' ...",
 
143
                     service.name, service.type)
 
144
        group.AddService(
 
145
                self.interface,         # interface
 
146
                avahi.PROTO_INET6,      # protocol
 
147
                dbus.UInt32(0),         # flags
 
148
                self.name, self.type,
 
149
                self.domain, self.host,
 
150
                dbus.UInt16(self.port),
 
151
                avahi.string_array_to_txt_array(self.TXT))
 
152
        group.Commit()
 
153
 
 
154
# From the Avahi example code:
 
155
group = None                            # our entry group
 
156
# End of Avahi example code
14
157
 
15
158
 
16
159
class Client(object):
17
 
    def __init__(self, name=None, options=None, dn=None,
18
 
                 password=None, passfile=None, fqdn=None,
19
 
                 timeout=None, interval=-1):
 
160
    """A representation of a client host served by this server.
 
161
    Attributes:
 
162
    name:      string; from the config file, used in log messages
 
163
    fingerprint: string (40 or 32 hexadecimal digits); used to
 
164
                 uniquely identify the client
 
165
    secret:    bytestring; sent verbatim (over TLS) to client
 
166
    fqdn:      string (FQDN); available for use by the checker command
 
167
    created:   datetime.datetime(); object creation, not client host
 
168
    last_checked_ok: datetime.datetime() or None if not yet checked OK
 
169
    timeout:   datetime.timedelta(); How long from last_checked_ok
 
170
                                     until this client is invalid
 
171
    interval:  datetime.timedelta(); How often to start a new checker
 
172
    stop_hook: If set, called by stop() as stop_hook(self)
 
173
    checker:   subprocess.Popen(); a running checker process used
 
174
                                   to see if the client lives.
 
175
                                   'None' if no process is running.
 
176
    checker_initiator_tag: a gobject event source tag, or None
 
177
    stop_initiator_tag:    - '' -
 
178
    checker_callback_tag:  - '' -
 
179
    checker_command: string; External command which is run to check if
 
180
                     client lives.  %() expansions are done at
 
181
                     runtime with vars(self) as dict, so that for
 
182
                     instance %(name)s can be used in the command.
 
183
    Private attibutes:
 
184
    _timeout: Real variable for 'timeout'
 
185
    _interval: Real variable for 'interval'
 
186
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
187
    _interval_milliseconds: - '' -
 
188
    """
 
189
    def _set_timeout(self, timeout):
 
190
        "Setter function for 'timeout' attribute"
 
191
        self._timeout = timeout
 
192
        self._timeout_milliseconds = ((self.timeout.days
 
193
                                       * 24 * 60 * 60 * 1000)
 
194
                                      + (self.timeout.seconds * 1000)
 
195
                                      + (self.timeout.microseconds
 
196
                                         // 1000))
 
197
    timeout = property(lambda self: self._timeout,
 
198
                       _set_timeout)
 
199
    del _set_timeout
 
200
    def _set_interval(self, interval):
 
201
        "Setter function for 'interval' attribute"
 
202
        self._interval = interval
 
203
        self._interval_milliseconds = ((self.interval.days
 
204
                                        * 24 * 60 * 60 * 1000)
 
205
                                       + (self.interval.seconds
 
206
                                          * 1000)
 
207
                                       + (self.interval.microseconds
 
208
                                          // 1000))
 
209
    interval = property(lambda self: self._interval,
 
210
                        _set_interval)
 
211
    del _set_interval
 
212
    def __init__(self, name = None, stop_hook=None, config={}):
 
213
        """Note: the 'checker' key in 'config' sets the
 
214
        'checker_command' attribute and *not* the 'checker'
 
215
        attribute."""
20
216
        self.name = name
21
 
        self.dn = dn
22
 
        if password:
23
 
            self.password = password
24
 
        elif passfile:
25
 
            self.password = open(passfile).readall()
 
217
        logger.debug(u"Creating client %r", self.name)
 
218
        # Uppercase and remove spaces from fingerprint for later
 
219
        # comparison purposes with return value from the fingerprint()
 
220
        # function
 
221
        self.fingerprint = config["fingerprint"].upper()\
 
222
                           .replace(u" ", u"")
 
223
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
 
224
        if "secret" in config:
 
225
            self.secret = config["secret"].decode(u"base64")
 
226
        elif "secfile" in config:
 
227
            sf = open(config["secfile"])
 
228
            self.secret = sf.read()
 
229
            sf.close()
26
230
        else:
27
 
            print "No Password or Passfile in client config file"
28
 
            # raise RuntimeError XXX
29
 
            self.password = "gazonk"
30
 
        self.fqdn = fqdn
 
231
            raise TypeError(u"No secret or secfile for client %s"
 
232
                            % self.name)
 
233
        self.fqdn = config.get("fqdn", "")
31
234
        self.created = datetime.datetime.now()
32
 
        self.last_seen = None
33
 
        if timeout is None:
34
 
            timeout = options.timeout
35
 
        self.timeout = timeout
36
 
        if interval == -1:
37
 
            interval = options.interval
38
 
        self.interval = interval
39
 
        self.next_check = datetime.datetime.now()
40
 
 
41
 
 
42
 
class server_metaclass(type):
43
 
    "Common behavior for the UDP and TCP server classes"
44
 
    def __new__(cls, name, bases, attrs):
45
 
        attrs["address_family"] = socket.AF_INET6
46
 
        attrs["allow_reuse_address"] = True
47
 
        def server_bind(self):
48
 
            if self.options.interface:
49
 
                if not hasattr(socket, "SO_BINDTODEVICE"):
50
 
                    # From /usr/include/asm-i486/socket.h
51
 
                    socket.SO_BINDTODEVICE = 25
 
235
        self.last_checked_ok = None
 
236
        self.timeout = string_to_delta(config["timeout"])
 
237
        self.interval = string_to_delta(config["interval"])
 
238
        self.stop_hook = stop_hook
 
239
        self.checker = None
 
240
        self.checker_initiator_tag = None
 
241
        self.stop_initiator_tag = None
 
242
        self.checker_callback_tag = None
 
243
        self.check_command = config["checker"]
 
244
    def start(self):
 
245
        """Start this client's checker and timeout hooks"""
 
246
        # Schedule a new checker to be started an 'interval' from now,
 
247
        # and every interval from then on.
 
248
        self.checker_initiator_tag = gobject.timeout_add\
 
249
                                     (self._interval_milliseconds,
 
250
                                      self.start_checker)
 
251
        # Also start a new checker *right now*.
 
252
        self.start_checker()
 
253
        # Schedule a stop() when 'timeout' has passed
 
254
        self.stop_initiator_tag = gobject.timeout_add\
 
255
                                  (self._timeout_milliseconds,
 
256
                                   self.stop)
 
257
    def stop(self):
 
258
        """Stop this client.
 
259
        The possibility that a client might be restarted is left open,
 
260
        but not currently used."""
 
261
        # If this client doesn't have a secret, it is already stopped.
 
262
        if self.secret:
 
263
            logger.info(u"Stopping client %s", self.name)
 
264
            self.secret = None
 
265
        else:
 
266
            return False
 
267
        if getattr(self, "stop_initiator_tag", False):
 
268
            gobject.source_remove(self.stop_initiator_tag)
 
269
            self.stop_initiator_tag = None
 
270
        if getattr(self, "checker_initiator_tag", False):
 
271
            gobject.source_remove(self.checker_initiator_tag)
 
272
            self.checker_initiator_tag = None
 
273
        self.stop_checker()
 
274
        if self.stop_hook:
 
275
            self.stop_hook(self)
 
276
        # Do not run this again if called by a gobject.timeout_add
 
277
        return False
 
278
    def __del__(self):
 
279
        self.stop_hook = None
 
280
        self.stop()
 
281
    def checker_callback(self, pid, condition):
 
282
        """The checker has completed, so take appropriate actions."""
 
283
        now = datetime.datetime.now()
 
284
        self.checker_callback_tag = None
 
285
        self.checker = None
 
286
        if os.WIFEXITED(condition) \
 
287
               and (os.WEXITSTATUS(condition) == 0):
 
288
            logger.info(u"Checker for %(name)s succeeded",
 
289
                        vars(self))
 
290
            self.last_checked_ok = now
 
291
            gobject.source_remove(self.stop_initiator_tag)
 
292
            self.stop_initiator_tag = gobject.timeout_add\
 
293
                                      (self._timeout_milliseconds,
 
294
                                       self.stop)
 
295
        elif not os.WIFEXITED(condition):
 
296
            logger.warning(u"Checker for %(name)s crashed?",
 
297
                           vars(self))
 
298
        else:
 
299
            logger.info(u"Checker for %(name)s failed",
 
300
                        vars(self))
 
301
    def start_checker(self):
 
302
        """Start a new checker subprocess if one is not running.
 
303
        If a checker already exists, leave it running and do
 
304
        nothing."""
 
305
        # The reason for not killing a running checker is that if we
 
306
        # did that, then if a checker (for some reason) started
 
307
        # running slowly and taking more than 'interval' time, the
 
308
        # client would inevitably timeout, since no checker would get
 
309
        # a chance to run to completion.  If we instead leave running
 
310
        # checkers alone, the checker would have to take more time
 
311
        # than 'timeout' for the client to be declared invalid, which
 
312
        # is as it should be.
 
313
        if self.checker is None:
 
314
            try:
 
315
                # In case check_command has exactly one % operator
 
316
                command = self.check_command % self.fqdn
 
317
            except TypeError:
 
318
                # Escape attributes for the shell
 
319
                escaped_attrs = dict((key, re.escape(str(val)))
 
320
                                     for key, val in
 
321
                                     vars(self).iteritems())
52
322
                try:
53
 
                    self.socket.setsockopt(socket.SOL_SOCKET,
54
 
                                           socket.SO_BINDTODEVICE,
55
 
                                           self.options.interface)
56
 
                except socket.error, error:
57
 
                    if error[0] == errno.EPERM:
58
 
                        print "Warning: No permission to bind to interface", \
59
 
                              self.options.interface
60
 
                    else:
61
 
                        raise error
62
 
            return super(type(self), self).server_bind()
63
 
        attrs["server_bind"] = server_bind
64
 
        def init(self, *args, **kwargs):
65
 
            if "options" in kwargs:
66
 
                self.options = kwargs["options"]
67
 
                del kwargs["options"]
68
 
            if "clients" in kwargs:
69
 
                self.clients = kwargs["clients"]
70
 
                del kwargs["clients"]
71
 
            if "credentials" in kwargs:
72
 
                self.credentials = kwargs["credentials"]
73
 
                del kwargs["credentials"]
74
 
            return super(type(self), self).__init__(*args, **kwargs)
75
 
        attrs["__init__"] = init
76
 
        return type.__new__(cls, name, bases, attrs)
77
 
 
78
 
 
79
 
class udp_handler(SocketServer.DatagramRequestHandler, object):
80
 
    def handle(self):
81
 
        self.wfile.write("Polo")
82
 
        print "UDP request answered"
83
 
 
84
 
 
85
 
class IPv6_UDPServer(SocketServer.UDPServer, object):
86
 
    __metaclass__ = server_metaclass
87
 
    def verify_request(self, request, client_address):
88
 
        print "UDP request came"
89
 
        return request[0] == "Marco"
 
323
                    command = self.check_command % escaped_attrs
 
324
                except TypeError, error:
 
325
                    logger.error(u'Could not format string "%s":'
 
326
                                 u' %s', self.check_command, error)
 
327
                    return True # Try again later
 
328
            try:
 
329
                logger.info(u"Starting checker %r for %s",
 
330
                            command, self.name)
 
331
                self.checker = subprocess.Popen(command,
 
332
                                                close_fds=True,
 
333
                                                shell=True, cwd="/")
 
334
                self.checker_callback_tag = gobject.child_watch_add\
 
335
                                            (self.checker.pid,
 
336
                                             self.checker_callback)
 
337
            except subprocess.OSError, error:
 
338
                logger.error(u"Failed to start subprocess: %s",
 
339
                             error)
 
340
        # Re-run this periodically if run by gobject.timeout_add
 
341
        return True
 
342
    def stop_checker(self):
 
343
        """Force the checker process, if any, to stop."""
 
344
        if self.checker_callback_tag:
 
345
            gobject.source_remove(self.checker_callback_tag)
 
346
            self.checker_callback_tag = None
 
347
        if getattr(self, "checker", None) is None:
 
348
            return
 
349
        logger.debug("Stopping checker for %(name)s", vars(self))
 
350
        try:
 
351
            os.kill(self.checker.pid, signal.SIGTERM)
 
352
            #os.sleep(0.5)
 
353
            #if self.checker.poll() is None:
 
354
            #    os.kill(self.checker.pid, signal.SIGKILL)
 
355
        except OSError, error:
 
356
            if error.errno != errno.ESRCH: # No such process
 
357
                raise
 
358
        self.checker = None
 
359
    def still_valid(self):
 
360
        """Has the timeout not yet passed for this client?"""
 
361
        now = datetime.datetime.now()
 
362
        if self.last_checked_ok is None:
 
363
            return now < (self.created + self.timeout)
 
364
        else:
 
365
            return now < (self.last_checked_ok + self.timeout)
 
366
 
 
367
 
 
368
def peer_certificate(session):
 
369
    "Return the peer's OpenPGP certificate as a bytestring"
 
370
    # If not an OpenPGP certificate...
 
371
    if gnutls.library.functions.gnutls_certificate_type_get\
 
372
            (session._c_object) \
 
373
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
 
374
        # ...do the normal thing
 
375
        return session.peer_certificate
 
376
    list_size = ctypes.c_uint()
 
377
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
 
378
        (session._c_object, ctypes.byref(list_size))
 
379
    if list_size.value == 0:
 
380
        return None
 
381
    cert = cert_list[0]
 
382
    return ctypes.string_at(cert.data, cert.size)
 
383
 
 
384
 
 
385
def fingerprint(openpgp):
 
386
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
387
    # New GnuTLS "datum" with the OpenPGP public key
 
388
    datum = gnutls.library.types.gnutls_datum_t\
 
389
        (ctypes.cast(ctypes.c_char_p(openpgp),
 
390
                     ctypes.POINTER(ctypes.c_ubyte)),
 
391
         ctypes.c_uint(len(openpgp)))
 
392
    # New empty GnuTLS certificate
 
393
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
394
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
395
        (ctypes.byref(crt))
 
396
    # Import the OpenPGP public key into the certificate
 
397
    gnutls.library.functions.gnutls_openpgp_crt_import\
 
398
                    (crt, ctypes.byref(datum),
 
399
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
400
    # New buffer for the fingerprint
 
401
    buffer = ctypes.create_string_buffer(20)
 
402
    buffer_length = ctypes.c_size_t()
 
403
    # Get the fingerprint from the certificate into the buffer
 
404
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
 
405
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
 
406
    # Deinit the certificate
 
407
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
408
    # Convert the buffer to a Python bytestring
 
409
    fpr = ctypes.string_at(buffer, buffer_length.value)
 
410
    # Convert the bytestring to hexadecimal notation
 
411
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
 
412
    return hex_fpr
90
413
 
91
414
 
92
415
class tcp_handler(SocketServer.BaseRequestHandler, object):
 
416
    """A TCP request handler class.
 
417
    Instantiated by IPv6_TCPServer for each request to handle it.
 
418
    Note: This will run in its own forked process."""
 
419
    
93
420
    def handle(self):
94
 
        print "TCP request came"
95
 
        print "Request:", self.request
96
 
        print "Client Address:", self.client_address
97
 
        print "Server:", self.server
98
 
        session = gnutls.connection.ServerSession(self.request,
99
 
                                                  self.server.credentials)
100
 
        session.handshake()
101
 
        if session.peer_certificate:
102
 
            print "DN:", session.peer_certificate.subject
103
 
        try:
104
 
            session.verify_peer()
105
 
        except gnutls.errors.CertificateError, error:
106
 
            print "Verify failed", error
107
 
            session.bye()
108
 
            return
109
 
        try:
110
 
            session.send(dict((client.dn, client.password)
111
 
                              for client in self.server.clients)
112
 
                         [session.peer_certificate.subject])
113
 
        except KeyError:
114
 
            session.send("gazonk")
115
 
            # Log maybe? XXX
 
421
        logger.info(u"TCP connection from: %s",
 
422
                     unicode(self.client_address))
 
423
        session = gnutls.connection.ClientSession\
 
424
                  (self.request, gnutls.connection.X509Credentials())
 
425
        
 
426
        line = self.request.makefile().readline()
 
427
        logger.debug(u"Protocol version: %r", line)
 
428
        try:
 
429
            if int(line.strip().split()[0]) > 1:
 
430
                raise RuntimeError
 
431
        except (ValueError, IndexError, RuntimeError), error:
 
432
            logger.error(u"Unknown protocol version: %s", error)
 
433
            return
 
434
        
 
435
        # Note: gnutls.connection.X509Credentials is really a generic
 
436
        # GnuTLS certificate credentials object so long as no X.509
 
437
        # keys are added to it.  Therefore, we can use it here despite
 
438
        # using OpenPGP certificates.
 
439
        
 
440
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
 
441
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
 
442
        #                "+DHE-DSS"))
 
443
        priority = "NORMAL"             # Fallback default, since this
 
444
                                        # MUST be set.
 
445
        if self.server.settings["priority"]:
 
446
            priority = self.server.settings["priority"]
 
447
        gnutls.library.functions.gnutls_priority_set_direct\
 
448
            (session._c_object, priority, None);
 
449
        
 
450
        try:
 
451
            session.handshake()
 
452
        except gnutls.errors.GNUTLSError, error:
 
453
            logger.warning(u"Handshake failed: %s", error)
 
454
            # Do not run session.bye() here: the session is not
 
455
            # established.  Just abandon the request.
 
456
            return
 
457
        try:
 
458
            fpr = fingerprint(peer_certificate(session))
 
459
        except (TypeError, gnutls.errors.GNUTLSError), error:
 
460
            logger.warning(u"Bad certificate: %s", error)
 
461
            session.bye()
 
462
            return
 
463
        logger.debug(u"Fingerprint: %s", fpr)
 
464
        client = None
 
465
        for c in self.server.clients:
 
466
            if c.fingerprint == fpr:
 
467
                client = c
 
468
                break
 
469
        if not client:
 
470
            logger.warning(u"Client not found for fingerprint: %s",
 
471
                           fpr)
 
472
            session.bye()
 
473
            return
 
474
        # Have to check if client.still_valid(), since it is possible
 
475
        # that the client timed out while establishing the GnuTLS
 
476
        # session.
 
477
        if not client.still_valid():
 
478
            logger.warning(u"Client %(name)s is invalid",
 
479
                           vars(client))
 
480
            session.bye()
 
481
            return
 
482
        sent_size = 0
 
483
        while sent_size < len(client.secret):
 
484
            sent = session.send(client.secret[sent_size:])
 
485
            logger.debug(u"Sent: %d, remaining: %d",
 
486
                         sent, len(client.secret)
 
487
                         - (sent_size + sent))
 
488
            sent_size += sent
116
489
        session.bye()
117
490
 
118
491
 
119
492
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
120
 
    __metaclass__ = server_metaclass
121
 
    request_queue_size = 1024
122
 
 
123
 
 
124
 
in6addr_any = "::"
125
 
 
126
 
cred = None
 
493
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
 
494
    Attributes:
 
495
        settings:       Server settings
 
496
        clients:        Set() of Client objects
 
497
    """
 
498
    address_family = socket.AF_INET6
 
499
    def __init__(self, *args, **kwargs):
 
500
        if "settings" in kwargs:
 
501
            self.settings = kwargs["settings"]
 
502
            del kwargs["settings"]
 
503
        if "clients" in kwargs:
 
504
            self.clients = kwargs["clients"]
 
505
            del kwargs["clients"]
 
506
        return super(type(self), self).__init__(*args, **kwargs)
 
507
    def server_bind(self):
 
508
        """This overrides the normal server_bind() function
 
509
        to bind to an interface if one was specified, and also NOT to
 
510
        bind to an address or port if they were not specified."""
 
511
        if self.settings["interface"]:
 
512
            # 25 is from /usr/include/asm-i486/socket.h
 
513
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
514
            try:
 
515
                self.socket.setsockopt(socket.SOL_SOCKET,
 
516
                                       SO_BINDTODEVICE,
 
517
                                       self.settings["interface"])
 
518
            except socket.error, error:
 
519
                if error[0] == errno.EPERM:
 
520
                    logger.error(u"No permission to"
 
521
                                 u" bind to interface %s",
 
522
                                 self.settings["interface"])
 
523
                else:
 
524
                    raise error
 
525
        # Only bind(2) the socket if we really need to.
 
526
        if self.server_address[0] or self.server_address[1]:
 
527
            if not self.server_address[0]:
 
528
                in6addr_any = "::"
 
529
                self.server_address = (in6addr_any,
 
530
                                       self.server_address[1])
 
531
            elif self.server_address[1] is None:
 
532
                self.server_address = (self.server_address[0],
 
533
                                       0)
 
534
            return super(type(self), self).server_bind()
 
535
 
127
536
 
128
537
def string_to_delta(interval):
129
538
    """Parse a string and return a datetime.timedelta
158
567
        raise ValueError
159
568
    return delta
160
569
 
 
570
 
 
571
def server_state_changed(state):
 
572
    """Derived from the Avahi example code"""
 
573
    if state == avahi.SERVER_COLLISION:
 
574
        logger.error(u"Server name collision")
 
575
        service.remove()
 
576
    elif state == avahi.SERVER_RUNNING:
 
577
        service.add()
 
578
 
 
579
 
 
580
def entry_group_state_changed(state, error):
 
581
    """Derived from the Avahi example code"""
 
582
    logger.debug(u"state change: %i", state)
 
583
    
 
584
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
 
585
        logger.debug(u"Service established.")
 
586
    elif state == avahi.ENTRY_GROUP_COLLISION:
 
587
        logger.warning(u"Service name collision.")
 
588
        service.rename()
 
589
    elif state == avahi.ENTRY_GROUP_FAILURE:
 
590
        logger.critical(u"Error in group state changed %s",
 
591
                        unicode(error))
 
592
        raise AvahiGroupError("State changed: %s", str(error))
 
593
 
 
594
def if_nametoindex(interface):
 
595
    """Call the C function if_nametoindex(), or equivalent"""
 
596
    global if_nametoindex
 
597
    try:
 
598
        if "ctypes.util" not in sys.modules:
 
599
            import ctypes.util
 
600
        if_nametoindex = ctypes.cdll.LoadLibrary\
 
601
            (ctypes.util.find_library("c")).if_nametoindex
 
602
    except (OSError, AttributeError):
 
603
        if "struct" not in sys.modules:
 
604
            import struct
 
605
        if "fcntl" not in sys.modules:
 
606
            import fcntl
 
607
        def if_nametoindex(interface):
 
608
            "Get an interface index the hard way, i.e. using fcntl()"
 
609
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
 
610
            s = socket.socket()
 
611
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
612
                                struct.pack("16s16x", interface))
 
613
            s.close()
 
614
            interface_index = struct.unpack("I", ifreq[16:20])[0]
 
615
            return interface_index
 
616
    return if_nametoindex(interface)
 
617
 
 
618
 
 
619
def daemon(nochdir = False, noclose = False):
 
620
    """See daemon(3).  Standard BSD Unix function.
 
621
    This should really exist as os.daemon, but it doesn't (yet)."""
 
622
    if os.fork():
 
623
        sys.exit()
 
624
    os.setsid()
 
625
    if not nochdir:
 
626
        os.chdir("/")
 
627
    if os.fork():
 
628
        sys.exit()
 
629
    if not noclose:
 
630
        # Close all standard open file descriptors
 
631
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
632
        if not stat.S_ISCHR(os.fstat(null).st_mode):
 
633
            raise OSError(errno.ENODEV,
 
634
                          "/dev/null not a character device")
 
635
        os.dup2(null, sys.stdin.fileno())
 
636
        os.dup2(null, sys.stdout.fileno())
 
637
        os.dup2(null, sys.stderr.fileno())
 
638
        if null > 2:
 
639
            os.close(null)
 
640
 
 
641
 
161
642
def main():
 
643
    global main_loop_started
 
644
    main_loop_started = False
 
645
    
162
646
    parser = OptionParser()
163
647
    parser.add_option("-i", "--interface", type="string",
164
 
                      default="eth0", metavar="IF",
165
 
                      help="Interface to bind to")
166
 
    parser.add_option("--cert", type="string", default="cert.pem",
167
 
                      metavar="FILE",
168
 
                      help="Public key certificate to use")
169
 
    parser.add_option("--key", type="string", default="key.pem",
170
 
                      metavar="FILE",
171
 
                      help="Private key to use")
172
 
    parser.add_option("--ca", type="string", default="ca.pem",
173
 
                      metavar="FILE",
174
 
                      help="Certificate Authority certificate to use")
175
 
    parser.add_option("--crl", type="string", default="crl.pem",
176
 
                      metavar="FILE",
177
 
                      help="Certificate Revokation List to use")
178
 
    parser.add_option("-p", "--port", type="int", default=49001,
 
648
                      metavar="IF", help="Bind to interface IF")
 
649
    parser.add_option("-a", "--address", type="string",
 
650
                      help="Address to listen for requests on")
 
651
    parser.add_option("-p", "--port", type="int",
179
652
                      help="Port number to receive requests on")
180
 
    parser.add_option("--dh", type="int", metavar="BITS",
181
 
                      help="DH group to use")
182
 
    parser.add_option("-t", "--timeout", type="string", # Parsed later
183
 
                      default="15m",
184
 
                      help="Amount of downtime allowed for clients")
185
 
    parser.add_option("--interval", type="string", # Parsed later
186
 
                      default="5m",
187
 
                      help="How often to check that a client is up")
188
653
    parser.add_option("--check", action="store_true", default=False,
189
654
                      help="Run self-test")
 
655
    parser.add_option("--debug", action="store_true", default=False,
 
656
                      help="Debug mode; run in foreground and log to"
 
657
                      " terminal")
 
658
    parser.add_option("--priority", type="string", help="GnuTLS"
 
659
                      " priority string (see GnuTLS documentation)")
 
660
    parser.add_option("--servicename", type="string", metavar="NAME",
 
661
                      help="Zeroconf service name")
 
662
    parser.add_option("--configdir", type="string",
 
663
                      default="/etc/mandos", metavar="DIR",
 
664
                      help="Directory to search for configuration"
 
665
                      " files")
190
666
    (options, args) = parser.parse_args()
191
 
 
 
667
    
192
668
    if options.check:
193
669
        import doctest
194
670
        doctest.testmod()
195
671
        sys.exit()
196
672
    
197
 
    # Parse the time arguments
198
 
    try:
199
 
        options.timeout = string_to_delta(options.timeout)
200
 
    except ValueError:
201
 
        parser.error("option --timeout: Unparseable time")
202
 
    
203
 
    try:
204
 
        options.interval = string_to_delta(options.interval)
205
 
    except ValueError:
206
 
        parser.error("option --interval: Unparseable time")
207
 
    
208
 
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
209
 
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
210
 
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
211
 
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
212
 
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
213
 
    
214
 
    # Parse config file
215
 
    defaults = {}
216
 
    client_config_object = ConfigParser.SafeConfigParser(defaults)
217
 
    client_config_object.read("mandos-clients.conf")
218
 
    clients = [Client(name=section, options=options,
219
 
                      **(dict(client_config_object.items(section))))
220
 
               for section in client_config_object.sections()]
221
 
    
222
 
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
223
 
                                udp_handler,
224
 
                                options=options)
225
 
    
226
 
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
 
673
    # Default values for config file for server-global settings
 
674
    server_defaults = { "interface": "",
 
675
                        "address": "",
 
676
                        "port": "",
 
677
                        "debug": "False",
 
678
                        "priority":
 
679
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
 
680
                        "servicename": "Mandos",
 
681
                        }
 
682
    
 
683
    # Parse config file for server-global settings
 
684
    server_config = ConfigParser.SafeConfigParser(server_defaults)
 
685
    del server_defaults
 
686
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
687
    server_section = "server"
 
688
    # Convert the SafeConfigParser object to a dict
 
689
    server_settings = dict(server_config.items(server_section))
 
690
    # Use getboolean on the boolean config option
 
691
    server_settings["debug"] = server_config.getboolean\
 
692
                               (server_section, "debug")
 
693
    del server_config
 
694
    
 
695
    # Override the settings from the config file with command line
 
696
    # options, if set.
 
697
    for option in ("interface", "address", "port", "debug",
 
698
                   "priority", "servicename", "configdir"):
 
699
        value = getattr(options, option)
 
700
        if value is not None:
 
701
            server_settings[option] = value
 
702
    del options
 
703
    # Now we have our good server settings in "server_settings"
 
704
    
 
705
    # Parse config file with clients
 
706
    client_defaults = { "timeout": "1h",
 
707
                        "interval": "5m",
 
708
                        "checker": "fping -q -- %%(fqdn)s",
 
709
                        }
 
710
    client_config = ConfigParser.SafeConfigParser(client_defaults)
 
711
    client_config.read(os.path.join(server_settings["configdir"],
 
712
                                    "clients.conf"))
 
713
    
 
714
    global service
 
715
    service = AvahiService(name = server_settings["servicename"],
 
716
                           type = "_mandos._tcp", );
 
717
    if server_settings["interface"]:
 
718
        service.interface = if_nametoindex(server_settings["interface"])
 
719
    
 
720
    global main_loop
 
721
    global bus
 
722
    global server
 
723
    # From the Avahi example code
 
724
    DBusGMainLoop(set_as_default=True )
 
725
    main_loop = gobject.MainLoop()
 
726
    bus = dbus.SystemBus()
 
727
    server = dbus.Interface(
 
728
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
 
729
            avahi.DBUS_INTERFACE_SERVER )
 
730
    # End of Avahi example code
 
731
    
 
732
    debug = server_settings["debug"]
 
733
    
 
734
    if debug:
 
735
        console = logging.StreamHandler()
 
736
        # console.setLevel(logging.DEBUG)
 
737
        console.setFormatter(logging.Formatter\
 
738
                             ('%(levelname)s: %(message)s'))
 
739
        logger.addHandler(console)
 
740
        del console
 
741
    
 
742
    clients = Set()
 
743
    def remove_from_clients(client):
 
744
        clients.remove(client)
 
745
        if not clients:
 
746
            logger.critical(u"No clients left, exiting")
 
747
            sys.exit()
 
748
    
 
749
    clients.update(Set(Client(name = section,
 
750
                              stop_hook = remove_from_clients,
 
751
                              config
 
752
                              = dict(client_config.items(section)))
 
753
                       for section in client_config.sections()))
 
754
    
 
755
    if not debug:
 
756
        daemon()
 
757
    
 
758
    def cleanup():
 
759
        "Cleanup function; run on exit"
 
760
        global group
 
761
        # From the Avahi example code
 
762
        if not group is None:
 
763
            group.Free()
 
764
            group = None
 
765
        # End of Avahi example code
 
766
        
 
767
        while clients:
 
768
            client = clients.pop()
 
769
            client.stop_hook = None
 
770
            client.stop()
 
771
    
 
772
    atexit.register(cleanup)
 
773
    
 
774
    if not debug:
 
775
        signal.signal(signal.SIGINT, signal.SIG_IGN)
 
776
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
 
777
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
 
778
    
 
779
    for client in clients:
 
780
        client.start()
 
781
    
 
782
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
783
                                 server_settings["port"]),
227
784
                                tcp_handler,
228
 
                                options=options,
229
 
                                clients=clients,
230
 
                                credentials=cred)
231
 
    
232
 
    while True:
233
 
        in_, out, err = select.select((udp_server,
234
 
                                       tcp_server), (), ())
235
 
        for server in in_:
236
 
            server.handle_request()
237
 
 
238
 
 
239
 
if __name__ == "__main__":
 
785
                                settings=server_settings,
 
786
                                clients=clients)
 
787
    # Find out what port we got
 
788
    service.port = tcp_server.socket.getsockname()[1]
 
789
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
 
790
                u" scope_id %d" % tcp_server.socket.getsockname())
 
791
    
 
792
    #service.interface = tcp_server.socket.getsockname()[3]
 
793
    
 
794
    try:
 
795
        # From the Avahi example code
 
796
        server.connect_to_signal("StateChanged", server_state_changed)
 
797
        try:
 
798
            server_state_changed(server.GetState())
 
799
        except dbus.exceptions.DBusException, error:
 
800
            logger.critical(u"DBusException: %s", error)
 
801
            sys.exit(1)
 
802
        # End of Avahi example code
 
803
        
 
804
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
805
                             lambda *args, **kwargs:
 
806
                             tcp_server.handle_request\
 
807
                             (*args[2:], **kwargs) or True)
 
808
        
 
809
        logger.debug("Starting main loop")
 
810
        main_loop_started = True
 
811
        main_loop.run()
 
812
    except AvahiError, error:
 
813
        logger.critical(u"AvahiError: %s" + unicode(error))
 
814
        sys.exit(1)
 
815
    except KeyboardInterrupt:
 
816
        if debug:
 
817
            print
 
818
 
 
819
if __name__ == '__main__':
240
820
    main()
241