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  • Committer: Teddy Hogeborn
  • Date: 2008-01-18 22:04:19 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080118220419-z95418owrporioo5
* Makefile (client_debug): New.
* client.cpp (CERT_ROOT): New.

(Tested)

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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 © 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
28
 
# <http://www.gnu.org/licenses/>.
29
 
30
 
# Contact the authors at <mandos@fukt.bsnet.se>.
31
 
32
 
 
33
 
from __future__ import division
34
2
 
35
3
import SocketServer
36
4
import socket
 
5
import select
37
6
from optparse import OptionParser
38
7
import datetime
39
8
import errno
40
9
import gnutls.crypto
41
10
import gnutls.connection
42
11
import gnutls.errors
43
 
import gnutls.library.functions
44
 
import gnutls.library.constants
45
 
import gnutls.library.types
46
12
import ConfigParser
47
13
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
 
import pwd
58
 
 
59
 
import dbus
60
 
import gobject
61
 
import avahi
62
 
from dbus.mainloop.glib import DBusGMainLoop
63
 
import ctypes
64
 
import ctypes.util
65
 
 
66
 
version = "1.0.2"
67
 
 
68
 
logger = logging.Logger('mandos')
69
 
syslogger = logging.handlers.SysLogHandler\
70
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
71
 
             address = "/dev/log")
72
 
syslogger.setFormatter(logging.Formatter\
73
 
                        ('Mandos: %(levelname)s: %(message)s'))
74
 
logger.addHandler(syslogger)
75
 
 
76
 
console = logging.StreamHandler()
77
 
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
78
 
                                       ' %(message)s'))
79
 
logger.addHandler(console)
80
 
 
81
 
class AvahiError(Exception):
82
 
    def __init__(self, value):
83
 
        self.value = value
84
 
        super(AvahiError, self).__init__()
85
 
    def __str__(self):
86
 
        return repr(self.value)
87
 
 
88
 
class AvahiServiceError(AvahiError):
89
 
    pass
90
 
 
91
 
class AvahiGroupError(AvahiError):
92
 
    pass
93
 
 
94
 
 
95
 
class AvahiService(object):
96
 
    """An Avahi (Zeroconf) service.
97
 
    Attributes:
98
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
99
 
               Used to optionally bind to the specified interface.
100
 
    name: string; Example: 'Mandos'
101
 
    type: string; Example: '_mandos._tcp'.
102
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
103
 
    port: integer; what port to announce
104
 
    TXT: list of strings; TXT record for the service
105
 
    domain: string; Domain to publish on, default to .local if empty.
106
 
    host: string; Host to publish records for, default is localhost
107
 
    max_renames: integer; maximum number of renames
108
 
    rename_count: integer; counter so we only rename after collisions
109
 
                  a sensible number of times
110
 
    """
111
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
112
 
                 servicetype = None, port = None, TXT = None, domain = "",
113
 
                 host = "", max_renames = 32768):
114
 
        self.interface = interface
115
 
        self.name = name
116
 
        self.type = servicetype
117
 
        self.port = port
118
 
        if TXT is None:
119
 
            self.TXT = []
120
 
        else:
121
 
            self.TXT = TXT
122
 
        self.domain = domain
123
 
        self.host = host
124
 
        self.rename_count = 0
125
 
        self.max_renames = max_renames
126
 
    def rename(self):
127
 
        """Derived from the Avahi example code"""
128
 
        if self.rename_count >= self.max_renames:
129
 
            logger.critical(u"No suitable Zeroconf service name found"
130
 
                            u" after %i retries, exiting.",
131
 
                            self.rename_count)
132
 
            raise AvahiServiceError("Too many renames")
133
 
        self.name = server.GetAlternativeServiceName(self.name)
134
 
        logger.info(u"Changing Zeroconf service name to %r ...",
135
 
                    str(self.name))
136
 
        syslogger.setFormatter(logging.Formatter\
137
 
                               ('Mandos (%s): %%(levelname)s:'
138
 
                               ' %%(message)s' % self.name))
139
 
        self.remove()
140
 
        self.add()
141
 
        self.rename_count += 1
142
 
    def remove(self):
143
 
        """Derived from the Avahi example code"""
144
 
        if group is not None:
145
 
            group.Reset()
146
 
    def add(self):
147
 
        """Derived from the Avahi example code"""
148
 
        global group
149
 
        if group is None:
150
 
            group = dbus.Interface\
151
 
                    (bus.get_object(avahi.DBUS_NAME,
152
 
                                    server.EntryGroupNew()),
153
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
154
 
            group.connect_to_signal('StateChanged',
155
 
                                    entry_group_state_changed)
156
 
        logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
157
 
                     service.name, service.type)
158
 
        group.AddService(
159
 
                self.interface,         # interface
160
 
                avahi.PROTO_INET6,      # protocol
161
 
                dbus.UInt32(0),         # flags
162
 
                self.name, self.type,
163
 
                self.domain, self.host,
164
 
                dbus.UInt16(self.port),
165
 
                avahi.string_array_to_txt_array(self.TXT))
166
 
        group.Commit()
167
 
 
168
 
# From the Avahi example code:
169
 
group = None                            # our entry group
170
 
# End of Avahi example code
171
14
 
172
15
 
173
16
class Client(object):
174
 
    """A representation of a client host served by this server.
175
 
    Attributes:
176
 
    name:      string; from the config file, used in log messages
177
 
    fingerprint: string (40 or 32 hexadecimal digits); used to
178
 
                 uniquely identify the client
179
 
    secret:    bytestring; sent verbatim (over TLS) to client
180
 
    host:      string; available for use by the checker command
181
 
    created:   datetime.datetime(); object creation, not client host
182
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
183
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
184
 
                                     until this client is invalid
185
 
    interval:  datetime.timedelta(); How often to start a new checker
186
 
    stop_hook: If set, called by stop() as stop_hook(self)
187
 
    checker:   subprocess.Popen(); a running checker process used
188
 
                                   to see if the client lives.
189
 
                                   'None' if no process is running.
190
 
    checker_initiator_tag: a gobject event source tag, or None
191
 
    stop_initiator_tag:    - '' -
192
 
    checker_callback_tag:  - '' -
193
 
    checker_command: string; External command which is run to check if
194
 
                     client lives.  %() expansions are done at
195
 
                     runtime with vars(self) as dict, so that for
196
 
                     instance %(name)s can be used in the command.
197
 
    Private attibutes:
198
 
    _timeout: Real variable for 'timeout'
199
 
    _interval: Real variable for 'interval'
200
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
201
 
    _interval_milliseconds: - '' -
202
 
    """
203
 
    def _set_timeout(self, timeout):
204
 
        "Setter function for 'timeout' attribute"
205
 
        self._timeout = timeout
206
 
        self._timeout_milliseconds = ((self.timeout.days
207
 
                                       * 24 * 60 * 60 * 1000)
208
 
                                      + (self.timeout.seconds * 1000)
209
 
                                      + (self.timeout.microseconds
210
 
                                         // 1000))
211
 
    timeout = property(lambda self: self._timeout,
212
 
                       _set_timeout)
213
 
    del _set_timeout
214
 
    def _set_interval(self, interval):
215
 
        "Setter function for 'interval' attribute"
216
 
        self._interval = interval
217
 
        self._interval_milliseconds = ((self.interval.days
218
 
                                        * 24 * 60 * 60 * 1000)
219
 
                                       + (self.interval.seconds
220
 
                                          * 1000)
221
 
                                       + (self.interval.microseconds
222
 
                                          // 1000))
223
 
    interval = property(lambda self: self._interval,
224
 
                        _set_interval)
225
 
    del _set_interval
226
 
    def __init__(self, name = None, stop_hook=None, config=None):
227
 
        """Note: the 'checker' key in 'config' sets the
228
 
        'checker_command' attribute and *not* the 'checker'
229
 
        attribute."""
230
 
        if config is None:
231
 
            config = {}
 
17
    def __init__(self, name=None, options=None, dn=None,
 
18
                 password=None, passfile=None, fqdn=None,
 
19
                 timeout=None, interval=-1):
232
20
        self.name = name
233
 
        logger.debug(u"Creating client %r", self.name)
234
 
        # Uppercase and remove spaces from fingerprint for later
235
 
        # comparison purposes with return value from the fingerprint()
236
 
        # function
237
 
        self.fingerprint = config["fingerprint"].upper()\
238
 
                           .replace(u" ", u"")
239
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
240
 
        if "secret" in config:
241
 
            self.secret = config["secret"].decode(u"base64")
242
 
        elif "secfile" in config:
243
 
            secfile = open(os.path.expanduser(os.path.expandvars
244
 
                                              (config["secfile"])))
245
 
            self.secret = secfile.read()
246
 
            secfile.close()
 
21
        self.dn = dn
 
22
        if password:
 
23
            self.password = password
 
24
        elif passfile:
 
25
            self.password = open(passfile).readall()
247
26
        else:
248
 
            raise TypeError(u"No secret or secfile for client %s"
249
 
                            % self.name)
250
 
        self.host = config.get("host", "")
 
27
            print "No Password or Passfile in client config file"
 
28
            # raise RuntimeError XXX
 
29
            self.password = "gazonk"
 
30
        self.fqdn = fqdn
251
31
        self.created = datetime.datetime.now()
252
 
        self.last_checked_ok = None
253
 
        self.timeout = string_to_delta(config["timeout"])
254
 
        self.interval = string_to_delta(config["interval"])
255
 
        self.stop_hook = stop_hook
256
 
        self.checker = None
257
 
        self.checker_initiator_tag = None
258
 
        self.stop_initiator_tag = None
259
 
        self.checker_callback_tag = None
260
 
        self.check_command = config["checker"]
261
 
    def start(self):
262
 
        """Start this client's checker and timeout hooks"""
263
 
        # Schedule a new checker to be started an 'interval' from now,
264
 
        # and every interval from then on.
265
 
        self.checker_initiator_tag = gobject.timeout_add\
266
 
                                     (self._interval_milliseconds,
267
 
                                      self.start_checker)
268
 
        # Also start a new checker *right now*.
269
 
        self.start_checker()
270
 
        # Schedule a stop() when 'timeout' has passed
271
 
        self.stop_initiator_tag = gobject.timeout_add\
272
 
                                  (self._timeout_milliseconds,
273
 
                                   self.stop)
274
 
    def stop(self):
275
 
        """Stop this client.
276
 
        The possibility that a client might be restarted is left open,
277
 
        but not currently used."""
278
 
        # If this client doesn't have a secret, it is already stopped.
279
 
        if hasattr(self, "secret") and self.secret:
280
 
            logger.info(u"Stopping client %s", self.name)
281
 
            self.secret = None
282
 
        else:
283
 
            return False
284
 
        if getattr(self, "stop_initiator_tag", False):
285
 
            gobject.source_remove(self.stop_initiator_tag)
286
 
            self.stop_initiator_tag = None
287
 
        if getattr(self, "checker_initiator_tag", False):
288
 
            gobject.source_remove(self.checker_initiator_tag)
289
 
            self.checker_initiator_tag = None
290
 
        self.stop_checker()
291
 
        if self.stop_hook:
292
 
            self.stop_hook(self)
293
 
        # Do not run this again if called by a gobject.timeout_add
294
 
        return False
295
 
    def __del__(self):
296
 
        self.stop_hook = None
297
 
        self.stop()
298
 
    def checker_callback(self, pid, condition):
299
 
        """The checker has completed, so take appropriate actions."""
300
 
        now = datetime.datetime.now()
301
 
        self.checker_callback_tag = None
302
 
        self.checker = None
303
 
        if os.WIFEXITED(condition) \
304
 
               and (os.WEXITSTATUS(condition) == 0):
305
 
            logger.info(u"Checker for %(name)s succeeded",
306
 
                        vars(self))
307
 
            self.last_checked_ok = now
308
 
            gobject.source_remove(self.stop_initiator_tag)
309
 
            self.stop_initiator_tag = gobject.timeout_add\
310
 
                                      (self._timeout_milliseconds,
311
 
                                       self.stop)
312
 
        elif not os.WIFEXITED(condition):
313
 
            logger.warning(u"Checker for %(name)s crashed?",
314
 
                           vars(self))
315
 
        else:
316
 
            logger.info(u"Checker for %(name)s failed",
317
 
                        vars(self))
318
 
    def start_checker(self):
319
 
        """Start a new checker subprocess if one is not running.
320
 
        If a checker already exists, leave it running and do
321
 
        nothing."""
322
 
        # The reason for not killing a running checker is that if we
323
 
        # did that, then if a checker (for some reason) started
324
 
        # running slowly and taking more than 'interval' time, the
325
 
        # client would inevitably timeout, since no checker would get
326
 
        # a chance to run to completion.  If we instead leave running
327
 
        # checkers alone, the checker would have to take more time
328
 
        # than 'timeout' for the client to be declared invalid, which
329
 
        # is as it should be.
330
 
        if self.checker is None:
331
 
            try:
332
 
                # In case check_command has exactly one % operator
333
 
                command = self.check_command % self.host
334
 
            except TypeError:
335
 
                # Escape attributes for the shell
336
 
                escaped_attrs = dict((key, re.escape(str(val)))
337
 
                                     for key, val in
338
 
                                     vars(self).iteritems())
 
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
339
52
                try:
340
 
                    command = self.check_command % escaped_attrs
341
 
                except TypeError, error:
342
 
                    logger.error(u'Could not format string "%s":'
343
 
                                 u' %s', self.check_command, error)
344
 
                    return True # Try again later
345
 
            try:
346
 
                logger.info(u"Starting checker %r for %s",
347
 
                            command, self.name)
348
 
                # We don't need to redirect stdout and stderr, since
349
 
                # in normal mode, that is already done by daemon(),
350
 
                # and in debug mode we don't want to.  (Stdin is
351
 
                # always replaced by /dev/null.)
352
 
                self.checker = subprocess.Popen(command,
353
 
                                                close_fds=True,
354
 
                                                shell=True, cwd="/")
355
 
                self.checker_callback_tag = gobject.child_watch_add\
356
 
                                            (self.checker.pid,
357
 
                                             self.checker_callback)
358
 
            except OSError, error:
359
 
                logger.error(u"Failed to start subprocess: %s",
360
 
                             error)
361
 
        # Re-run this periodically if run by gobject.timeout_add
362
 
        return True
363
 
    def stop_checker(self):
364
 
        """Force the checker process, if any, to stop."""
365
 
        if self.checker_callback_tag:
366
 
            gobject.source_remove(self.checker_callback_tag)
367
 
            self.checker_callback_tag = None
368
 
        if getattr(self, "checker", None) is None:
369
 
            return
370
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
371
 
        try:
372
 
            os.kill(self.checker.pid, signal.SIGTERM)
373
 
            #os.sleep(0.5)
374
 
            #if self.checker.poll() is None:
375
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
376
 
        except OSError, error:
377
 
            if error.errno != errno.ESRCH: # No such process
378
 
                raise
379
 
        self.checker = None
380
 
    def still_valid(self):
381
 
        """Has the timeout not yet passed for this client?"""
382
 
        now = datetime.datetime.now()
383
 
        if self.last_checked_ok is None:
384
 
            return now < (self.created + self.timeout)
385
 
        else:
386
 
            return now < (self.last_checked_ok + self.timeout)
387
 
 
388
 
 
389
 
def peer_certificate(session):
390
 
    "Return the peer's OpenPGP certificate as a bytestring"
391
 
    # If not an OpenPGP certificate...
392
 
    if gnutls.library.functions.gnutls_certificate_type_get\
393
 
            (session._c_object) \
394
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
395
 
        # ...do the normal thing
396
 
        return session.peer_certificate
397
 
    list_size = ctypes.c_uint()
398
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
399
 
        (session._c_object, ctypes.byref(list_size))
400
 
    if list_size.value == 0:
401
 
        return None
402
 
    cert = cert_list[0]
403
 
    return ctypes.string_at(cert.data, cert.size)
404
 
 
405
 
 
406
 
def fingerprint(openpgp):
407
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
408
 
    # New GnuTLS "datum" with the OpenPGP public key
409
 
    datum = gnutls.library.types.gnutls_datum_t\
410
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
411
 
                     ctypes.POINTER(ctypes.c_ubyte)),
412
 
         ctypes.c_uint(len(openpgp)))
413
 
    # New empty GnuTLS certificate
414
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
415
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
416
 
        (ctypes.byref(crt))
417
 
    # Import the OpenPGP public key into the certificate
418
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
419
 
                    (crt, ctypes.byref(datum),
420
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
421
 
    # Verify the self signature in the key
422
 
    crtverify = ctypes.c_uint()
423
 
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
424
 
        (crt, 0, ctypes.byref(crtverify))
425
 
    if crtverify.value != 0:
426
 
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
427
 
        raise gnutls.errors.CertificateSecurityError("Verify failed")
428
 
    # New buffer for the fingerprint
429
 
    buf = ctypes.create_string_buffer(20)
430
 
    buf_len = ctypes.c_size_t()
431
 
    # Get the fingerprint from the certificate into the buffer
432
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
433
 
        (crt, ctypes.byref(buf), ctypes.byref(buf_len))
434
 
    # Deinit the certificate
435
 
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
436
 
    # Convert the buffer to a Python bytestring
437
 
    fpr = ctypes.string_at(buf, buf_len.value)
438
 
    # Convert the bytestring to hexadecimal notation
439
 
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
440
 
    return hex_fpr
441
 
 
442
 
 
443
 
class TCP_handler(SocketServer.BaseRequestHandler, object):
444
 
    """A TCP request handler class.
445
 
    Instantiated by IPv6_TCPServer for each request to handle it.
446
 
    Note: This will run in its own forked process."""
447
 
    
448
 
    def handle(self):
449
 
        logger.info(u"TCP connection from: %s",
450
 
                     unicode(self.client_address))
451
 
        session = gnutls.connection.ClientSession\
452
 
                  (self.request, gnutls.connection.X509Credentials())
453
 
        
454
 
        line = self.request.makefile().readline()
455
 
        logger.debug(u"Protocol version: %r", line)
456
 
        try:
457
 
            if int(line.strip().split()[0]) > 1:
458
 
                raise RuntimeError
459
 
        except (ValueError, IndexError, RuntimeError), error:
460
 
            logger.error(u"Unknown protocol version: %s", error)
461
 
            return
462
 
        
463
 
        # Note: gnutls.connection.X509Credentials is really a generic
464
 
        # GnuTLS certificate credentials object so long as no X.509
465
 
        # keys are added to it.  Therefore, we can use it here despite
466
 
        # using OpenPGP certificates.
467
 
        
468
 
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
469
 
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
470
 
        #                "+DHE-DSS"))
471
 
        priority = "NORMAL"             # Fallback default, since this
472
 
                                        # MUST be set.
473
 
        if self.server.settings["priority"]:
474
 
            priority = self.server.settings["priority"]
475
 
        gnutls.library.functions.gnutls_priority_set_direct\
476
 
            (session._c_object, priority, None)
477
 
        
478
 
        try:
479
 
            session.handshake()
480
 
        except gnutls.errors.GNUTLSError, error:
481
 
            logger.warning(u"Handshake failed: %s", error)
482
 
            # Do not run session.bye() here: the session is not
483
 
            # established.  Just abandon the request.
484
 
            return
485
 
        try:
486
 
            fpr = fingerprint(peer_certificate(session))
487
 
        except (TypeError, gnutls.errors.GNUTLSError), error:
488
 
            logger.warning(u"Bad certificate: %s", error)
489
 
            session.bye()
490
 
            return
491
 
        logger.debug(u"Fingerprint: %s", fpr)
492
 
        client = None
493
 
        for c in self.server.clients:
494
 
            if c.fingerprint == fpr:
495
 
                client = c
496
 
                break
497
 
        if not client:
498
 
            logger.warning(u"Client not found for fingerprint: %s",
499
 
                           fpr)
500
 
            session.bye()
501
 
            return
502
 
        # Have to check if client.still_valid(), since it is possible
503
 
        # that the client timed out while establishing the GnuTLS
504
 
        # session.
505
 
        if not client.still_valid():
506
 
            logger.warning(u"Client %(name)s is invalid",
507
 
                           vars(client))
508
 
            session.bye()
509
 
            return
510
 
        sent_size = 0
511
 
        while sent_size < len(client.secret):
512
 
            sent = session.send(client.secret[sent_size:])
513
 
            logger.debug(u"Sent: %d, remaining: %d",
514
 
                         sent, len(client.secret)
515
 
                         - (sent_size + sent))
516
 
            sent_size += sent
 
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"
 
90
 
 
91
 
 
92
class tcp_handler(SocketServer.BaseRequestHandler, object):
 
93
    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
517
116
        session.bye()
518
117
 
519
118
 
520
119
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
521
 
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
522
 
    Attributes:
523
 
        settings:       Server settings
524
 
        clients:        Set() of Client objects
525
 
        enabled:        Boolean; whether this server is activated yet
526
 
    """
527
 
    address_family = socket.AF_INET6
528
 
    def __init__(self, *args, **kwargs):
529
 
        if "settings" in kwargs:
530
 
            self.settings = kwargs["settings"]
531
 
            del kwargs["settings"]
532
 
        if "clients" in kwargs:
533
 
            self.clients = kwargs["clients"]
534
 
            del kwargs["clients"]
535
 
        self.enabled = False
536
 
        super(IPv6_TCPServer, self).__init__(*args, **kwargs)
537
 
    def server_bind(self):
538
 
        """This overrides the normal server_bind() function
539
 
        to bind to an interface if one was specified, and also NOT to
540
 
        bind to an address or port if they were not specified."""
541
 
        if self.settings["interface"]:
542
 
            # 25 is from /usr/include/asm-i486/socket.h
543
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
544
 
            try:
545
 
                self.socket.setsockopt(socket.SOL_SOCKET,
546
 
                                       SO_BINDTODEVICE,
547
 
                                       self.settings["interface"])
548
 
            except socket.error, error:
549
 
                if error[0] == errno.EPERM:
550
 
                    logger.error(u"No permission to"
551
 
                                 u" bind to interface %s",
552
 
                                 self.settings["interface"])
553
 
                else:
554
 
                    raise error
555
 
        # Only bind(2) the socket if we really need to.
556
 
        if self.server_address[0] or self.server_address[1]:
557
 
            if not self.server_address[0]:
558
 
                in6addr_any = "::"
559
 
                self.server_address = (in6addr_any,
560
 
                                       self.server_address[1])
561
 
            elif not self.server_address[1]:
562
 
                self.server_address = (self.server_address[0],
563
 
                                       0)
564
 
#                 if self.settings["interface"]:
565
 
#                     self.server_address = (self.server_address[0],
566
 
#                                            0, # port
567
 
#                                            0, # flowinfo
568
 
#                                            if_nametoindex
569
 
#                                            (self.settings
570
 
#                                             ["interface"]))
571
 
            return super(IPv6_TCPServer, self).server_bind()
572
 
    def server_activate(self):
573
 
        if self.enabled:
574
 
            return super(IPv6_TCPServer, self).server_activate()
575
 
    def enable(self):
576
 
        self.enabled = True
577
 
 
 
120
    __metaclass__ = server_metaclass
 
121
    request_queue_size = 1024
 
122
 
 
123
 
 
124
in6addr_any = "::"
 
125
 
 
126
cred = None
578
127
 
579
128
def string_to_delta(interval):
580
129
    """Parse a string and return a datetime.timedelta
589
138
    datetime.timedelta(1)
590
139
    >>> string_to_delta(u'1w')
591
140
    datetime.timedelta(7)
592
 
    >>> string_to_delta('5m 30s')
593
 
    datetime.timedelta(0, 330)
594
141
    """
595
 
    timevalue = datetime.timedelta(0)
596
 
    for s in interval.split():
597
 
        try:
598
 
            suffix = unicode(s[-1])
599
 
            value = int(s[:-1])
600
 
            if suffix == u"d":
601
 
                delta = datetime.timedelta(value)
602
 
            elif suffix == u"s":
603
 
                delta = datetime.timedelta(0, value)
604
 
            elif suffix == u"m":
605
 
                delta = datetime.timedelta(0, 0, 0, 0, value)
606
 
            elif suffix == u"h":
607
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
608
 
            elif suffix == u"w":
609
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
610
 
            else:
611
 
                raise ValueError
612
 
        except (ValueError, IndexError):
 
142
    try:
 
143
        suffix=unicode(interval[-1])
 
144
        value=int(interval[:-1])
 
145
        if suffix == u"d":
 
146
            delta = datetime.timedelta(value)
 
147
        elif suffix == u"s":
 
148
            delta = datetime.timedelta(0, value)
 
149
        elif suffix == u"m":
 
150
            delta = datetime.timedelta(0, 0, 0, 0, value)
 
151
        elif suffix == u"h":
 
152
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
153
        elif suffix == u"w":
 
154
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
155
        else:
613
156
            raise ValueError
614
 
        timevalue += delta
615
 
    return timevalue
616
 
 
617
 
 
618
 
def server_state_changed(state):
619
 
    """Derived from the Avahi example code"""
620
 
    if state == avahi.SERVER_COLLISION:
621
 
        logger.error(u"Zeroconf server name collision")
622
 
        service.remove()
623
 
    elif state == avahi.SERVER_RUNNING:
624
 
        service.add()
625
 
 
626
 
 
627
 
def entry_group_state_changed(state, error):
628
 
    """Derived from the Avahi example code"""
629
 
    logger.debug(u"Avahi state change: %i", state)
630
 
    
631
 
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
632
 
        logger.debug(u"Zeroconf service established.")
633
 
    elif state == avahi.ENTRY_GROUP_COLLISION:
634
 
        logger.warning(u"Zeroconf service name collision.")
635
 
        service.rename()
636
 
    elif state == avahi.ENTRY_GROUP_FAILURE:
637
 
        logger.critical(u"Avahi: Error in group state changed %s",
638
 
                        unicode(error))
639
 
        raise AvahiGroupError("State changed: %s", str(error))
640
 
 
641
 
def if_nametoindex(interface):
642
 
    """Call the C function if_nametoindex(), or equivalent"""
643
 
    global if_nametoindex
644
 
    try:
645
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
646
 
            (ctypes.util.find_library("c")).if_nametoindex
647
 
    except (OSError, AttributeError):
648
 
        if "struct" not in sys.modules:
649
 
            import struct
650
 
        if "fcntl" not in sys.modules:
651
 
            import fcntl
652
 
        def if_nametoindex(interface):
653
 
            "Get an interface index the hard way, i.e. using fcntl()"
654
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
655
 
            s = socket.socket()
656
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
657
 
                                struct.pack("16s16x", interface))
658
 
            s.close()
659
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
660
 
            return interface_index
661
 
    return if_nametoindex(interface)
662
 
 
663
 
 
664
 
def daemon(nochdir = False, noclose = False):
665
 
    """See daemon(3).  Standard BSD Unix function.
666
 
    This should really exist as os.daemon, but it doesn't (yet)."""
667
 
    if os.fork():
668
 
        sys.exit()
669
 
    os.setsid()
670
 
    if not nochdir:
671
 
        os.chdir("/")
672
 
    if os.fork():
673
 
        sys.exit()
674
 
    if not noclose:
675
 
        # Close all standard open file descriptors
676
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
677
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
678
 
            raise OSError(errno.ENODEV,
679
 
                          "/dev/null not a character device")
680
 
        os.dup2(null, sys.stdin.fileno())
681
 
        os.dup2(null, sys.stdout.fileno())
682
 
        os.dup2(null, sys.stderr.fileno())
683
 
        if null > 2:
684
 
            os.close(null)
685
 
 
 
157
    except (ValueError, IndexError):
 
158
        raise ValueError
 
159
    return delta
686
160
 
687
161
def main():
688
 
    parser = OptionParser(version = "%%prog %s" % version)
 
162
    parser = OptionParser()
689
163
    parser.add_option("-i", "--interface", type="string",
690
 
                      metavar="IF", help="Bind to interface IF")
691
 
    parser.add_option("-a", "--address", type="string",
692
 
                      help="Address to listen for requests on")
693
 
    parser.add_option("-p", "--port", type="int",
 
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,
694
179
                      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")
695
188
    parser.add_option("--check", action="store_true", default=False,
696
189
                      help="Run self-test")
697
 
    parser.add_option("--debug", action="store_true",
698
 
                      help="Debug mode; run in foreground and log to"
699
 
                      " terminal")
700
 
    parser.add_option("--priority", type="string", help="GnuTLS"
701
 
                      " priority string (see GnuTLS documentation)")
702
 
    parser.add_option("--servicename", type="string", metavar="NAME",
703
 
                      help="Zeroconf service name")
704
 
    parser.add_option("--configdir", type="string",
705
 
                      default="/etc/mandos", metavar="DIR",
706
 
                      help="Directory to search for configuration"
707
 
                      " files")
708
 
    options = parser.parse_args()[0]
709
 
    
 
190
    (options, args) = parser.parse_args()
 
191
 
710
192
    if options.check:
711
193
        import doctest
712
194
        doctest.testmod()
713
195
        sys.exit()
714
196
    
715
 
    # Default values for config file for server-global settings
716
 
    server_defaults = { "interface": "",
717
 
                        "address": "",
718
 
                        "port": "",
719
 
                        "debug": "False",
720
 
                        "priority":
721
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
722
 
                        "servicename": "Mandos",
723
 
                        }
724
 
    
725
 
    # Parse config file for server-global settings
726
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
727
 
    del server_defaults
728
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
729
 
    # Convert the SafeConfigParser object to a dict
730
 
    server_settings = server_config.defaults()
731
 
    # Use getboolean on the boolean config option
732
 
    server_settings["debug"] = server_config.getboolean\
733
 
                               ("DEFAULT", "debug")
734
 
    del server_config
735
 
    
736
 
    # Override the settings from the config file with command line
737
 
    # options, if set.
738
 
    for option in ("interface", "address", "port", "debug",
739
 
                   "priority", "servicename", "configdir"):
740
 
        value = getattr(options, option)
741
 
        if value is not None:
742
 
            server_settings[option] = value
743
 
    del options
744
 
    # Now we have our good server settings in "server_settings"
745
 
    
746
 
    debug = server_settings["debug"]
747
 
    
748
 
    if not debug:
749
 
        syslogger.setLevel(logging.WARNING)
750
 
        console.setLevel(logging.WARNING)
751
 
    
752
 
    if server_settings["servicename"] != "Mandos":
753
 
        syslogger.setFormatter(logging.Formatter\
754
 
                               ('Mandos (%s): %%(levelname)s:'
755
 
                                ' %%(message)s'
756
 
                                % server_settings["servicename"]))
757
 
    
758
 
    # Parse config file with clients
759
 
    client_defaults = { "timeout": "1h",
760
 
                        "interval": "5m",
761
 
                        "checker": "fping -q -- %(host)s",
762
 
                        "host": "",
763
 
                        }
764
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
765
 
    client_config.read(os.path.join(server_settings["configdir"],
766
 
                                    "clients.conf"))
767
 
    
768
 
    clients = Set()
769
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
770
 
                                 server_settings["port"]),
771
 
                                TCP_handler,
772
 
                                settings=server_settings,
773
 
                                clients=clients)
774
 
    pidfilename = "/var/run/mandos.pid"
775
 
    try:
776
 
        pidfile = open(pidfilename, "w")
777
 
    except IOError, error:
778
 
        logger.error("Could not open file %r", pidfilename)
779
 
    
780
 
    uid = 65534
781
 
    gid = 65534
782
 
    try:
783
 
        uid = pwd.getpwnam("mandos").pw_uid
784
 
    except KeyError:
785
 
        try:
786
 
            uid = pwd.getpwnam("nobody").pw_uid
787
 
        except KeyError:
788
 
            pass
789
 
    try:
790
 
        gid = pwd.getpwnam("mandos").pw_gid
791
 
    except KeyError:
792
 
        try:
793
 
            gid = pwd.getpwnam("nogroup").pw_gid
794
 
        except KeyError:
795
 
            pass
796
 
    try:
797
 
        os.setuid(uid)
798
 
        os.setgid(gid)
799
 
    except OSError, error:
800
 
        if error[0] != errno.EPERM:
801
 
            raise error
802
 
    
803
 
    global service
804
 
    service = AvahiService(name = server_settings["servicename"],
805
 
                           servicetype = "_mandos._tcp", )
806
 
    if server_settings["interface"]:
807
 
        service.interface = if_nametoindex\
808
 
                            (server_settings["interface"])
809
 
    
810
 
    global main_loop
811
 
    global bus
812
 
    global server
813
 
    # From the Avahi example code
814
 
    DBusGMainLoop(set_as_default=True )
815
 
    main_loop = gobject.MainLoop()
816
 
    bus = dbus.SystemBus()
817
 
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
818
 
                                           avahi.DBUS_PATH_SERVER),
819
 
                            avahi.DBUS_INTERFACE_SERVER)
820
 
    # End of Avahi example code
821
 
    
822
 
    def remove_from_clients(client):
823
 
        clients.remove(client)
824
 
        if not clients:
825
 
            logger.critical(u"No clients left, exiting")
826
 
            sys.exit()
827
 
    
828
 
    clients.update(Set(Client(name = section,
829
 
                              stop_hook = remove_from_clients,
830
 
                              config
831
 
                              = dict(client_config.items(section)))
832
 
                       for section in client_config.sections()))
833
 
    if not clients:
834
 
        logger.critical(u"No clients defined")
835
 
        sys.exit(1)
836
 
    
837
 
    if debug:
838
 
        # Redirect stdin so all checkers get /dev/null
839
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
840
 
        os.dup2(null, sys.stdin.fileno())
841
 
        if null > 2:
842
 
            os.close(null)
843
 
    else:
844
 
        # No console logging
845
 
        logger.removeHandler(console)
846
 
        # Close all input and output, do double fork, etc.
847
 
        daemon()
848
 
    
849
 
    try:
850
 
        pid = os.getpid()
851
 
        pidfile.write(str(pid) + "\n")
852
 
        pidfile.close()
853
 
        del pidfile
854
 
    except IOError:
855
 
        logger.error(u"Could not write to file %r with PID %d",
856
 
                     pidfilename, pid)
857
 
    except NameError:
858
 
        # "pidfile" was never created
859
 
        pass
860
 
    del pidfilename
861
 
    
862
 
    def cleanup():
863
 
        "Cleanup function; run on exit"
864
 
        global group
865
 
        # From the Avahi example code
866
 
        if not group is None:
867
 
            group.Free()
868
 
            group = None
869
 
        # End of Avahi example code
870
 
        
871
 
        while clients:
872
 
            client = clients.pop()
873
 
            client.stop_hook = None
874
 
            client.stop()
875
 
    
876
 
    atexit.register(cleanup)
877
 
    
878
 
    if not debug:
879
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
880
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
881
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
882
 
    
883
 
    for client in clients:
884
 
        client.start()
885
 
    
886
 
    tcp_server.enable()
887
 
    tcp_server.server_activate()
888
 
    
889
 
    # Find out what port we got
890
 
    service.port = tcp_server.socket.getsockname()[1]
891
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
892
 
                u" scope_id %d" % tcp_server.socket.getsockname())
893
 
    
894
 
    #service.interface = tcp_server.socket.getsockname()[3]
895
 
    
896
 
    try:
897
 
        # From the Avahi example code
898
 
        server.connect_to_signal("StateChanged", server_state_changed)
899
 
        try:
900
 
            server_state_changed(server.GetState())
901
 
        except dbus.exceptions.DBusException, error:
902
 
            logger.critical(u"DBusException: %s", error)
903
 
            sys.exit(1)
904
 
        # End of Avahi example code
905
 
        
906
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
907
 
                             lambda *args, **kwargs:
908
 
                             tcp_server.handle_request\
909
 
                             (*args[2:], **kwargs) or True)
910
 
        
911
 
        logger.debug(u"Starting main loop")
912
 
        main_loop.run()
913
 
    except AvahiError, error:
914
 
        logger.critical(u"AvahiError: %s" + unicode(error))
915
 
        sys.exit(1)
916
 
    except KeyboardInterrupt:
917
 
        if debug:
918
 
            print
919
 
 
920
 
if __name__ == '__main__':
 
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),
 
227
                                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__":
921
240
    main()
 
241