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  • Committer: Teddy Hogeborn
  • Date: 2008-01-30 17:28:18 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080130172818-fnrq2xmtg1wa8wo2
* client.cpp (main): Get t_old early since it is used on error exits.

* server.py (Client.checker): New attribute.
  (Client.check_action, Client.start_checker, Client.stop_checker,
  Client.fileno, Client.next_stop, Client.still_valid,
  Client.it_is_time_to_check): New methods.
  (Client.handle_request): Alias to "check_action".
  (main): Stop all started checkers on exit.  Exit cleanly on keyboard
  interrupt.

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#!/usr/bin/python
2
 
# -*- mode: python; coding: utf-8 -*-
3
 
4
 
# Mandos server - give out binary blobs to connecting clients.
5
 
6
 
# This program is partly derived from an example program for an Avahi
7
 
# service publisher, downloaded from
8
 
# <http://avahi.org/wiki/PythonPublishExample>.  This includes the
9
 
# methods "add" and "remove" in the "AvahiService" class, the
10
 
# "server_state_changed" and "entry_group_state_changed" functions,
11
 
# and some lines in "main".
12
 
13
 
# Everything else is
14
 
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
15
 
16
 
# This program is free software: you can redistribute it and/or modify
17
 
# it under the terms of the GNU General Public License as published by
18
 
# the Free Software Foundation, either version 3 of the License, or
19
 
# (at your option) any later version.
20
 
#
21
 
#     This program is distributed in the hope that it will be useful,
22
 
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
23
 
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24
 
#     GNU General Public License for more details.
25
 
26
 
# You should have received a copy of the GNU General Public License
27
 
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
28
 
29
 
# Contact the authors at <mandos@fukt.bsnet.se>.
30
 
31
 
 
32
 
from __future__ import division
33
2
 
34
3
import SocketServer
35
4
import socket
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
14
import re
49
15
import os
50
16
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
 
version = "1.0"
65
 
 
66
 
logger = logging.Logger('mandos')
67
 
syslogger = logging.handlers.SysLogHandler\
68
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
69
 
             address = "/dev/log")
70
 
syslogger.setFormatter(logging.Formatter\
71
 
                        ('Mandos: %(levelname)s: %(message)s'))
72
 
logger.addHandler(syslogger)
73
 
 
74
 
console = logging.StreamHandler()
75
 
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
76
 
                                       ' %(message)s'))
77
 
logger.addHandler(console)
78
 
 
79
 
class AvahiError(Exception):
80
 
    def __init__(self, value):
81
 
        self.value = value
82
 
    def __str__(self):
83
 
        return repr(self.value)
84
 
 
85
 
class AvahiServiceError(AvahiError):
86
 
    pass
87
 
 
88
 
class AvahiGroupError(AvahiError):
89
 
    pass
90
 
 
91
 
 
92
 
class AvahiService(object):
93
 
    """An Avahi (Zeroconf) service.
94
 
    Attributes:
95
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
96
 
               Used to optionally bind to the specified interface.
97
 
    name: string; Example: 'Mandos'
98
 
    type: string; Example: '_mandos._tcp'.
99
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
100
 
    port: integer; what port to announce
101
 
    TXT: list of strings; TXT record for the service
102
 
    domain: string; Domain to publish on, default to .local if empty.
103
 
    host: string; Host to publish records for, default is localhost
104
 
    max_renames: integer; maximum number of renames
105
 
    rename_count: integer; counter so we only rename after collisions
106
 
                  a sensible number of times
107
 
    """
108
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
109
 
                 type = None, port = None, TXT = None, domain = "",
110
 
                 host = "", max_renames = 32768):
111
 
        self.interface = interface
112
 
        self.name = name
113
 
        self.type = type
114
 
        self.port = port
115
 
        if TXT is None:
116
 
            self.TXT = []
117
 
        else:
118
 
            self.TXT = TXT
119
 
        self.domain = domain
120
 
        self.host = host
121
 
        self.rename_count = 0
122
 
        self.max_renames = max_renames
123
 
    def rename(self):
124
 
        """Derived from the Avahi example code"""
125
 
        if self.rename_count >= self.max_renames:
126
 
            logger.critical(u"No suitable service name found after %i"
127
 
                            u" retries, exiting.", rename_count)
128
 
            raise AvahiServiceError("Too many renames")
129
 
        self.name = server.GetAlternativeServiceName(self.name)
130
 
        logger.info(u"Changing name to %r ...", str(self.name))
131
 
        syslogger.setFormatter(logging.Formatter\
132
 
                               ('Mandos (%s): %%(levelname)s:'
133
 
                               ' %%(message)s' % self.name))
134
 
        self.remove()
135
 
        self.add()
136
 
        self.rename_count += 1
137
 
    def remove(self):
138
 
        """Derived from the Avahi example code"""
139
 
        if group is not None:
140
 
            group.Reset()
141
 
    def add(self):
142
 
        """Derived from the Avahi example code"""
143
 
        global group
144
 
        if group is None:
145
 
            group = dbus.Interface\
146
 
                    (bus.get_object(avahi.DBUS_NAME,
147
 
                                    server.EntryGroupNew()),
148
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
149
 
            group.connect_to_signal('StateChanged',
150
 
                                    entry_group_state_changed)
151
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
152
 
                     service.name, service.type)
153
 
        group.AddService(
154
 
                self.interface,         # interface
155
 
                avahi.PROTO_INET6,      # protocol
156
 
                dbus.UInt32(0),         # flags
157
 
                self.name, self.type,
158
 
                self.domain, self.host,
159
 
                dbus.UInt16(self.port),
160
 
                avahi.string_array_to_txt_array(self.TXT))
161
 
        group.Commit()
162
 
 
163
 
# From the Avahi example code:
164
 
group = None                            # our entry group
165
 
# End of Avahi example code
166
 
 
167
17
 
168
18
class Client(object):
169
 
    """A representation of a client host served by this server.
170
 
    Attributes:
171
 
    name:      string; from the config file, used in log messages
172
 
    fingerprint: string (40 or 32 hexadecimal digits); used to
173
 
                 uniquely identify the client
174
 
    secret:    bytestring; sent verbatim (over TLS) to client
175
 
    host:      string; available for use by the checker command
176
 
    created:   datetime.datetime(); object creation, not client host
177
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
178
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
179
 
                                     until this client is invalid
180
 
    interval:  datetime.timedelta(); How often to start a new checker
181
 
    stop_hook: If set, called by stop() as stop_hook(self)
182
 
    checker:   subprocess.Popen(); a running checker process used
183
 
                                   to see if the client lives.
184
 
                                   'None' if no process is running.
185
 
    checker_initiator_tag: a gobject event source tag, or None
186
 
    stop_initiator_tag:    - '' -
187
 
    checker_callback_tag:  - '' -
188
 
    checker_command: string; External command which is run to check if
189
 
                     client lives.  %() expansions are done at
190
 
                     runtime with vars(self) as dict, so that for
191
 
                     instance %(name)s can be used in the command.
192
 
    Private attibutes:
193
 
    _timeout: Real variable for 'timeout'
194
 
    _interval: Real variable for 'interval'
195
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
196
 
    _interval_milliseconds: - '' -
197
 
    """
198
 
    def _set_timeout(self, timeout):
199
 
        "Setter function for 'timeout' attribute"
200
 
        self._timeout = timeout
201
 
        self._timeout_milliseconds = ((self.timeout.days
202
 
                                       * 24 * 60 * 60 * 1000)
203
 
                                      + (self.timeout.seconds * 1000)
204
 
                                      + (self.timeout.microseconds
205
 
                                         // 1000))
206
 
    timeout = property(lambda self: self._timeout,
207
 
                       _set_timeout)
208
 
    del _set_timeout
209
 
    def _set_interval(self, interval):
210
 
        "Setter function for 'interval' attribute"
211
 
        self._interval = interval
212
 
        self._interval_milliseconds = ((self.interval.days
213
 
                                        * 24 * 60 * 60 * 1000)
214
 
                                       + (self.interval.seconds
215
 
                                          * 1000)
216
 
                                       + (self.interval.microseconds
217
 
                                          // 1000))
218
 
    interval = property(lambda self: self._interval,
219
 
                        _set_interval)
220
 
    del _set_interval
221
 
    def __init__(self, name = None, stop_hook=None, config={}):
222
 
        """Note: the 'checker' key in 'config' sets the
223
 
        'checker_command' attribute and *not* the 'checker'
224
 
        attribute."""
 
19
    def __init__(self, name=None, options=None, dn=None,
 
20
                 password=None, passfile=None, fqdn=None,
 
21
                 timeout=None, interval=-1):
225
22
        self.name = name
226
 
        logger.debug(u"Creating client %r", self.name)
227
 
        # Uppercase and remove spaces from fingerprint for later
228
 
        # comparison purposes with return value from the fingerprint()
229
 
        # function
230
 
        self.fingerprint = config["fingerprint"].upper()\
231
 
                           .replace(u" ", u"")
232
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
233
 
        if "secret" in config:
234
 
            self.secret = config["secret"].decode(u"base64")
235
 
        elif "secfile" in config:
236
 
            sf = open(config["secfile"])
237
 
            self.secret = sf.read()
238
 
            sf.close()
 
23
        self.dn = dn
 
24
        if password:
 
25
            self.password = password
 
26
        elif passfile:
 
27
            self.password = open(passfile).readall()
239
28
        else:
240
 
            raise TypeError(u"No secret or secfile for client %s"
241
 
                            % self.name)
242
 
        self.host = config.get("host", "")
 
29
            print "No Password or Passfile in client config file"
 
30
            # raise RuntimeError XXX
 
31
            self.password = "gazonk"
 
32
        self.fqdn = fqdn                # string
243
33
        self.created = datetime.datetime.now()
244
 
        self.last_checked_ok = None
245
 
        self.timeout = string_to_delta(config["timeout"])
246
 
        self.interval = string_to_delta(config["interval"])
247
 
        self.stop_hook = stop_hook
248
 
        self.checker = None
249
 
        self.checker_initiator_tag = None
250
 
        self.stop_initiator_tag = None
251
 
        self.checker_callback_tag = None
252
 
        self.check_command = config["checker"]
253
 
    def start(self):
254
 
        """Start this client's checker and timeout hooks"""
255
 
        # Schedule a new checker to be started an 'interval' from now,
256
 
        # and every interval from then on.
257
 
        self.checker_initiator_tag = gobject.timeout_add\
258
 
                                     (self._interval_milliseconds,
259
 
                                      self.start_checker)
260
 
        # Also start a new checker *right now*.
261
 
        self.start_checker()
262
 
        # Schedule a stop() when 'timeout' has passed
263
 
        self.stop_initiator_tag = gobject.timeout_add\
264
 
                                  (self._timeout_milliseconds,
265
 
                                   self.stop)
266
 
    def stop(self):
267
 
        """Stop this client.
268
 
        The possibility that a client might be restarted is left open,
269
 
        but not currently used."""
270
 
        # If this client doesn't have a secret, it is already stopped.
271
 
        if hasattr(self, "secret") and self.secret:
272
 
            logger.info(u"Stopping client %s", self.name)
273
 
            self.secret = None
274
 
        else:
275
 
            return False
276
 
        if getattr(self, "stop_initiator_tag", False):
277
 
            gobject.source_remove(self.stop_initiator_tag)
278
 
            self.stop_initiator_tag = None
279
 
        if getattr(self, "checker_initiator_tag", False):
280
 
            gobject.source_remove(self.checker_initiator_tag)
281
 
            self.checker_initiator_tag = None
 
34
        self.last_seen = None           # datetime.datetime()
 
35
        if timeout is None:
 
36
            timeout = options.timeout
 
37
        self.timeout = timeout          # datetime.timedelta()
 
38
        if interval == -1:
 
39
            interval = options.interval
 
40
        self.interval = interval        # datetime.timedelta()
 
41
        self.next_check = datetime.datetime.now() # datetime.datetime()
 
42
        self.checker = None             # or a subprocess.Popen()
 
43
    def check_action(self, now=None):
 
44
        """The checker said something and might have completed.
 
45
        Check if is has, and take appropriate actions."""
 
46
        if self.checker.poll() is None:
 
47
            # False alarm, no result yet
 
48
            #self.checker.read()
 
49
            return
 
50
        if now is None:
 
51
            now = datetime.datetime.now()
 
52
        if self.checker.returncode == 0:
 
53
            self.last_seen = now
 
54
        while self.next_check <= now:
 
55
            self.next_check += self.interval
 
56
    handle_request = check_action
 
57
    def start_checker(self):
282
58
        self.stop_checker()
283
 
        if self.stop_hook:
284
 
            self.stop_hook(self)
285
 
        # Do not run this again if called by a gobject.timeout_add
286
 
        return False
287
 
    def __del__(self):
288
 
        self.stop_hook = None
289
 
        self.stop()
290
 
    def checker_callback(self, pid, condition):
291
 
        """The checker has completed, so take appropriate actions."""
292
 
        now = datetime.datetime.now()
293
 
        self.checker_callback_tag = None
 
59
        try:
 
60
            self.checker = subprocess.Popen("sleep 1; fping -q -- %s"
 
61
                                            % re.escape(self.fqdn),
 
62
                                            stdout=subprocess.PIPE,
 
63
                                            close_fds=True,
 
64
                                            shell=True, cwd="/")
 
65
        except subprocess.OSError, e:
 
66
            print "Failed to start subprocess:", e
 
67
    def stop_checker(self):
 
68
        if self.checker is None:
 
69
            return
 
70
        os.kill(self.checker.pid, signal.SIGTERM)
 
71
        if self.checker.poll() is None:
 
72
            os.kill(self.checker.pid, signal.SIGKILL)
294
73
        self.checker = None
295
 
        if os.WIFEXITED(condition) \
296
 
               and (os.WEXITSTATUS(condition) == 0):
297
 
            logger.info(u"Checker for %(name)s succeeded",
298
 
                        vars(self))
299
 
            self.last_checked_ok = now
300
 
            gobject.source_remove(self.stop_initiator_tag)
301
 
            self.stop_initiator_tag = gobject.timeout_add\
302
 
                                      (self._timeout_milliseconds,
303
 
                                       self.stop)
304
 
        elif not os.WIFEXITED(condition):
305
 
            logger.warning(u"Checker for %(name)s crashed?",
306
 
                           vars(self))
307
 
        else:
308
 
            logger.info(u"Checker for %(name)s failed",
309
 
                        vars(self))
310
 
    def start_checker(self):
311
 
        """Start a new checker subprocess if one is not running.
312
 
        If a checker already exists, leave it running and do
313
 
        nothing."""
314
 
        # The reason for not killing a running checker is that if we
315
 
        # did that, then if a checker (for some reason) started
316
 
        # running slowly and taking more than 'interval' time, the
317
 
        # client would inevitably timeout, since no checker would get
318
 
        # a chance to run to completion.  If we instead leave running
319
 
        # checkers alone, the checker would have to take more time
320
 
        # than 'timeout' for the client to be declared invalid, which
321
 
        # is as it should be.
 
74
    __del__ = stop_checker
 
75
    def fileno(self):
322
76
        if self.checker is None:
323
 
            try:
324
 
                # In case check_command has exactly one % operator
325
 
                command = self.check_command % self.host
326
 
            except TypeError:
327
 
                # Escape attributes for the shell
328
 
                escaped_attrs = dict((key, re.escape(str(val)))
329
 
                                     for key, val in
330
 
                                     vars(self).iteritems())
 
77
            return None
 
78
        return self.checker.stdout.fileno()
 
79
    def next_stop(self):
 
80
        """The time when something must be done about this client"""
 
81
        return min(self.last_seen + self.timeout, self.next_check)
 
82
    def still_valid(self, now=None):
 
83
        """Has this client's timeout not passed?"""
 
84
        if now is None:
 
85
            now = datetime.datetime.now()
 
86
        return now < (self.last_seen + timeout)
 
87
    def it_is_time_to_check(self, now=None):
 
88
        if now is None:
 
89
            now = datetime.datetime.now()
 
90
        return self.next_check <= now
 
91
 
 
92
 
 
93
class server_metaclass(type):
 
94
    "Common behavior for the UDP and TCP server classes"
 
95
    def __new__(cls, name, bases, attrs):
 
96
        attrs["address_family"] = socket.AF_INET6
 
97
        attrs["allow_reuse_address"] = True
 
98
        def server_bind(self):
 
99
            if self.options.interface:
 
100
                if not hasattr(socket, "SO_BINDTODEVICE"):
 
101
                    # From /usr/include/asm-i486/socket.h
 
102
                    socket.SO_BINDTODEVICE = 25
331
103
                try:
332
 
                    command = self.check_command % escaped_attrs
333
 
                except TypeError, error:
334
 
                    logger.error(u'Could not format string "%s":'
335
 
                                 u' %s', self.check_command, error)
336
 
                    return True # Try again later
337
 
            try:
338
 
                logger.info(u"Starting checker %r for %s",
339
 
                            command, self.name)
340
 
                # We don't need to redirect stdout and stderr, since
341
 
                # in normal mode, that is already done by daemon(),
342
 
                # and in debug mode we don't want to.  (Stdin is
343
 
                # always replaced by /dev/null.)
344
 
                self.checker = subprocess.Popen(command,
345
 
                                                close_fds=True,
346
 
                                                shell=True, cwd="/")
347
 
                self.checker_callback_tag = gobject.child_watch_add\
348
 
                                            (self.checker.pid,
349
 
                                             self.checker_callback)
350
 
            except OSError, error:
351
 
                logger.error(u"Failed to start subprocess: %s",
352
 
                             error)
353
 
        # Re-run this periodically if run by gobject.timeout_add
354
 
        return True
355
 
    def stop_checker(self):
356
 
        """Force the checker process, if any, to stop."""
357
 
        if self.checker_callback_tag:
358
 
            gobject.source_remove(self.checker_callback_tag)
359
 
            self.checker_callback_tag = None
360
 
        if getattr(self, "checker", None) is None:
361
 
            return
362
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
363
 
        try:
364
 
            os.kill(self.checker.pid, signal.SIGTERM)
365
 
            #os.sleep(0.5)
366
 
            #if self.checker.poll() is None:
367
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
368
 
        except OSError, error:
369
 
            if error.errno != errno.ESRCH: # No such process
370
 
                raise
371
 
        self.checker = None
372
 
    def still_valid(self):
373
 
        """Has the timeout not yet passed for this client?"""
374
 
        now = datetime.datetime.now()
375
 
        if self.last_checked_ok is None:
376
 
            return now < (self.created + self.timeout)
377
 
        else:
378
 
            return now < (self.last_checked_ok + self.timeout)
379
 
 
380
 
 
381
 
def peer_certificate(session):
382
 
    "Return the peer's OpenPGP certificate as a bytestring"
383
 
    # If not an OpenPGP certificate...
384
 
    if gnutls.library.functions.gnutls_certificate_type_get\
385
 
            (session._c_object) \
386
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
387
 
        # ...do the normal thing
388
 
        return session.peer_certificate
389
 
    list_size = ctypes.c_uint()
390
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
391
 
        (session._c_object, ctypes.byref(list_size))
392
 
    if list_size.value == 0:
393
 
        return None
394
 
    cert = cert_list[0]
395
 
    return ctypes.string_at(cert.data, cert.size)
396
 
 
397
 
 
398
 
def fingerprint(openpgp):
399
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
400
 
    # New GnuTLS "datum" with the OpenPGP public key
401
 
    datum = gnutls.library.types.gnutls_datum_t\
402
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
403
 
                     ctypes.POINTER(ctypes.c_ubyte)),
404
 
         ctypes.c_uint(len(openpgp)))
405
 
    # New empty GnuTLS certificate
406
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
407
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
408
 
        (ctypes.byref(crt))
409
 
    # Import the OpenPGP public key into the certificate
410
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
411
 
                    (crt, ctypes.byref(datum),
412
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
413
 
    # Verify the self signature in the key
414
 
    crtverify = ctypes.c_uint();
415
 
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
416
 
        (crt, ctypes.c_uint(0), ctypes.byref(crtverify))
417
 
    if crtverify.value != 0:
418
 
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
419
 
        raise gnutls.errors.CertificateSecurityError("Verify failed")
420
 
    # New buffer for the fingerprint
421
 
    buffer = ctypes.create_string_buffer(20)
422
 
    buffer_length = ctypes.c_size_t()
423
 
    # Get the fingerprint from the certificate into the buffer
424
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
425
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
426
 
    # Deinit the certificate
427
 
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
428
 
    # Convert the buffer to a Python bytestring
429
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
430
 
    # Convert the bytestring to hexadecimal notation
431
 
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
432
 
    return hex_fpr
 
104
                    self.socket.setsockopt(socket.SOL_SOCKET,
 
105
                                           socket.SO_BINDTODEVICE,
 
106
                                           self.options.interface)
 
107
                except socket.error, error:
 
108
                    if error[0] == errno.EPERM:
 
109
                        print "Warning: No permission to bind to interface", \
 
110
                              self.options.interface
 
111
                    else:
 
112
                        raise error
 
113
            return super(type(self), self).server_bind()
 
114
        attrs["server_bind"] = server_bind
 
115
        def init(self, *args, **kwargs):
 
116
            if "options" in kwargs:
 
117
                self.options = kwargs["options"]
 
118
                del kwargs["options"]
 
119
            if "clients" in kwargs:
 
120
                self.clients = kwargs["clients"]
 
121
                del kwargs["clients"]
 
122
            if "credentials" in kwargs:
 
123
                self.credentials = kwargs["credentials"]
 
124
                del kwargs["credentials"]
 
125
            return super(type(self), self).__init__(*args, **kwargs)
 
126
        attrs["__init__"] = init
 
127
        return type.__new__(cls, name, bases, attrs)
 
128
 
 
129
 
 
130
class udp_handler(SocketServer.DatagramRequestHandler, object):
 
131
    def handle(self):
 
132
        self.wfile.write("Polo")
 
133
        print "UDP request answered"
 
134
 
 
135
 
 
136
class IPv6_UDPServer(SocketServer.UDPServer, object):
 
137
    __metaclass__ = server_metaclass
 
138
    def verify_request(self, request, client_address):
 
139
        print "UDP request came"
 
140
        return request[0] == "Marco"
433
141
 
434
142
 
435
143
class tcp_handler(SocketServer.BaseRequestHandler, object):
436
 
    """A TCP request handler class.
437
 
    Instantiated by IPv6_TCPServer for each request to handle it.
438
 
    Note: This will run in its own forked process."""
439
 
    
440
144
    def handle(self):
441
 
        logger.info(u"TCP connection from: %s",
442
 
                     unicode(self.client_address))
443
 
        session = gnutls.connection.ClientSession\
444
 
                  (self.request, gnutls.connection.X509Credentials())
445
 
        
446
 
        line = self.request.makefile().readline()
447
 
        logger.debug(u"Protocol version: %r", line)
448
 
        try:
449
 
            if int(line.strip().split()[0]) > 1:
450
 
                raise RuntimeError
451
 
        except (ValueError, IndexError, RuntimeError), error:
452
 
            logger.error(u"Unknown protocol version: %s", error)
453
 
            return
454
 
        
455
 
        # Note: gnutls.connection.X509Credentials is really a generic
456
 
        # GnuTLS certificate credentials object so long as no X.509
457
 
        # keys are added to it.  Therefore, we can use it here despite
458
 
        # using OpenPGP certificates.
459
 
        
460
 
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
461
 
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
462
 
        #                "+DHE-DSS"))
463
 
        priority = "NORMAL"             # Fallback default, since this
464
 
                                        # MUST be set.
465
 
        if self.server.settings["priority"]:
466
 
            priority = self.server.settings["priority"]
467
 
        gnutls.library.functions.gnutls_priority_set_direct\
468
 
            (session._c_object, priority, None);
469
 
        
470
 
        try:
471
 
            session.handshake()
472
 
        except gnutls.errors.GNUTLSError, error:
473
 
            logger.warning(u"Handshake failed: %s", error)
474
 
            # Do not run session.bye() here: the session is not
475
 
            # established.  Just abandon the request.
476
 
            return
477
 
        try:
478
 
            fpr = fingerprint(peer_certificate(session))
479
 
        except (TypeError, gnutls.errors.GNUTLSError), error:
480
 
            logger.warning(u"Bad certificate: %s", error)
481
 
            session.bye()
482
 
            return
483
 
        logger.debug(u"Fingerprint: %s", fpr)
484
 
        client = None
485
 
        for c in self.server.clients:
486
 
            if c.fingerprint == fpr:
487
 
                client = c
488
 
                break
489
 
        if not client:
490
 
            logger.warning(u"Client not found for fingerprint: %s",
491
 
                           fpr)
492
 
            session.bye()
493
 
            return
494
 
        # Have to check if client.still_valid(), since it is possible
495
 
        # that the client timed out while establishing the GnuTLS
496
 
        # session.
497
 
        if not client.still_valid():
498
 
            logger.warning(u"Client %(name)s is invalid",
499
 
                           vars(client))
500
 
            session.bye()
501
 
            return
502
 
        sent_size = 0
503
 
        while sent_size < len(client.secret):
504
 
            sent = session.send(client.secret[sent_size:])
505
 
            logger.debug(u"Sent: %d, remaining: %d",
506
 
                         sent, len(client.secret)
507
 
                         - (sent_size + sent))
508
 
            sent_size += sent
 
145
        print "TCP request came"
 
146
        print "Request:", self.request
 
147
        print "Client Address:", self.client_address
 
148
        print "Server:", self.server
 
149
        session = gnutls.connection.ServerSession(self.request,
 
150
                                                  self.server.credentials)
 
151
        session.handshake()
 
152
        if session.peer_certificate:
 
153
            print "DN:", session.peer_certificate.subject
 
154
        try:
 
155
            session.verify_peer()
 
156
        except gnutls.errors.CertificateError, error:
 
157
            print "Verify failed", error
 
158
            session.bye()
 
159
            return
 
160
        try:
 
161
            session.send(dict((client.dn, client.password)
 
162
                              for client in self.server.clients)
 
163
                         [session.peer_certificate.subject])
 
164
        except KeyError:
 
165
            session.send("gazonk")
 
166
            # Log maybe? XXX
509
167
        session.bye()
510
168
 
511
169
 
512
170
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
513
 
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
514
 
    Attributes:
515
 
        settings:       Server settings
516
 
        clients:        Set() of Client objects
517
 
    """
518
 
    address_family = socket.AF_INET6
519
 
    def __init__(self, *args, **kwargs):
520
 
        if "settings" in kwargs:
521
 
            self.settings = kwargs["settings"]
522
 
            del kwargs["settings"]
523
 
        if "clients" in kwargs:
524
 
            self.clients = kwargs["clients"]
525
 
            del kwargs["clients"]
526
 
        return super(type(self), self).__init__(*args, **kwargs)
527
 
    def server_bind(self):
528
 
        """This overrides the normal server_bind() function
529
 
        to bind to an interface if one was specified, and also NOT to
530
 
        bind to an address or port if they were not specified."""
531
 
        if self.settings["interface"]:
532
 
            # 25 is from /usr/include/asm-i486/socket.h
533
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
534
 
            try:
535
 
                self.socket.setsockopt(socket.SOL_SOCKET,
536
 
                                       SO_BINDTODEVICE,
537
 
                                       self.settings["interface"])
538
 
            except socket.error, error:
539
 
                if error[0] == errno.EPERM:
540
 
                    logger.error(u"No permission to"
541
 
                                 u" bind to interface %s",
542
 
                                 self.settings["interface"])
543
 
                else:
544
 
                    raise error
545
 
        # Only bind(2) the socket if we really need to.
546
 
        if self.server_address[0] or self.server_address[1]:
547
 
            if not self.server_address[0]:
548
 
                in6addr_any = "::"
549
 
                self.server_address = (in6addr_any,
550
 
                                       self.server_address[1])
551
 
            elif not self.server_address[1]:
552
 
                self.server_address = (self.server_address[0],
553
 
                                       0)
554
 
#                 if self.settings["interface"]:
555
 
#                     self.server_address = (self.server_address[0],
556
 
#                                            0, # port
557
 
#                                            0, # flowinfo
558
 
#                                            if_nametoindex
559
 
#                                            (self.settings
560
 
#                                             ["interface"]))
561
 
            return super(type(self), self).server_bind()
562
 
 
 
171
    __metaclass__ = server_metaclass
 
172
    request_queue_size = 1024
 
173
 
 
174
 
 
175
in6addr_any = "::"
563
176
 
564
177
def string_to_delta(interval):
565
178
    """Parse a string and return a datetime.timedelta
574
187
    datetime.timedelta(1)
575
188
    >>> string_to_delta(u'1w')
576
189
    datetime.timedelta(7)
577
 
    >>> string_to_delta('5m 30s')
578
 
    datetime.timedelta(0, 330)
579
190
    """
580
 
    timevalue = datetime.timedelta(0)
581
 
    for s in interval.split():
582
 
        try:
583
 
            suffix=unicode(s[-1])
584
 
            value=int(s[:-1])
585
 
            if suffix == u"d":
586
 
                delta = datetime.timedelta(value)
587
 
            elif suffix == u"s":
588
 
                delta = datetime.timedelta(0, value)
589
 
            elif suffix == u"m":
590
 
                delta = datetime.timedelta(0, 0, 0, 0, value)
591
 
            elif suffix == u"h":
592
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
593
 
            elif suffix == u"w":
594
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
595
 
            else:
596
 
                raise ValueError
597
 
        except (ValueError, IndexError):
 
191
    try:
 
192
        suffix=unicode(interval[-1])
 
193
        value=int(interval[:-1])
 
194
        if suffix == u"d":
 
195
            delta = datetime.timedelta(value)
 
196
        elif suffix == u"s":
 
197
            delta = datetime.timedelta(0, value)
 
198
        elif suffix == u"m":
 
199
            delta = datetime.timedelta(0, 0, 0, 0, value)
 
200
        elif suffix == u"h":
 
201
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
202
        elif suffix == u"w":
 
203
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
204
        else:
598
205
            raise ValueError
599
 
        timevalue += delta
600
 
    return timevalue
601
 
 
602
 
 
603
 
def server_state_changed(state):
604
 
    """Derived from the Avahi example code"""
605
 
    if state == avahi.SERVER_COLLISION:
606
 
        logger.error(u"Server name collision")
607
 
        service.remove()
608
 
    elif state == avahi.SERVER_RUNNING:
609
 
        service.add()
610
 
 
611
 
 
612
 
def entry_group_state_changed(state, error):
613
 
    """Derived from the Avahi example code"""
614
 
    logger.debug(u"state change: %i", state)
615
 
    
616
 
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
617
 
        logger.debug(u"Service established.")
618
 
    elif state == avahi.ENTRY_GROUP_COLLISION:
619
 
        logger.warning(u"Service name collision.")
620
 
        service.rename()
621
 
    elif state == avahi.ENTRY_GROUP_FAILURE:
622
 
        logger.critical(u"Error in group state changed %s",
623
 
                        unicode(error))
624
 
        raise AvahiGroupError("State changed: %s", str(error))
625
 
 
626
 
def if_nametoindex(interface):
627
 
    """Call the C function if_nametoindex(), or equivalent"""
628
 
    global if_nametoindex
629
 
    try:
630
 
        if "ctypes.util" not in sys.modules:
631
 
            import ctypes.util
632
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
633
 
            (ctypes.util.find_library("c")).if_nametoindex
634
 
    except (OSError, AttributeError):
635
 
        if "struct" not in sys.modules:
636
 
            import struct
637
 
        if "fcntl" not in sys.modules:
638
 
            import fcntl
639
 
        def if_nametoindex(interface):
640
 
            "Get an interface index the hard way, i.e. using fcntl()"
641
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
642
 
            s = socket.socket()
643
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
644
 
                                struct.pack("16s16x", interface))
645
 
            s.close()
646
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
647
 
            return interface_index
648
 
    return if_nametoindex(interface)
649
 
 
650
 
 
651
 
def daemon(nochdir = False, noclose = False):
652
 
    """See daemon(3).  Standard BSD Unix function.
653
 
    This should really exist as os.daemon, but it doesn't (yet)."""
654
 
    if os.fork():
655
 
        sys.exit()
656
 
    os.setsid()
657
 
    if not nochdir:
658
 
        os.chdir("/")
659
 
    if os.fork():
660
 
        sys.exit()
661
 
    if not noclose:
662
 
        # Close all standard open file descriptors
663
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
664
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
665
 
            raise OSError(errno.ENODEV,
666
 
                          "/dev/null not a character device")
667
 
        os.dup2(null, sys.stdin.fileno())
668
 
        os.dup2(null, sys.stdout.fileno())
669
 
        os.dup2(null, sys.stderr.fileno())
670
 
        if null > 2:
671
 
            os.close(null)
 
206
    except (ValueError, IndexError):
 
207
        raise ValueError
 
208
    return delta
672
209
 
673
210
 
674
211
def main():
675
 
    global main_loop_started
676
 
    main_loop_started = False
677
 
    
678
 
    parser = OptionParser(version = "%%prog %s" % version)
 
212
    parser = OptionParser()
679
213
    parser.add_option("-i", "--interface", type="string",
680
 
                      metavar="IF", help="Bind to interface IF")
681
 
    parser.add_option("-a", "--address", type="string",
682
 
                      help="Address to listen for requests on")
683
 
    parser.add_option("-p", "--port", type="int",
 
214
                      default="eth0", metavar="IF",
 
215
                      help="Interface to bind to")
 
216
    parser.add_option("--cert", type="string", default="cert.pem",
 
217
                      metavar="FILE",
 
218
                      help="Public key certificate to use")
 
219
    parser.add_option("--key", type="string", default="key.pem",
 
220
                      metavar="FILE",
 
221
                      help="Private key to use")
 
222
    parser.add_option("--ca", type="string", default="ca.pem",
 
223
                      metavar="FILE",
 
224
                      help="Certificate Authority certificate to use")
 
225
    parser.add_option("--crl", type="string", default="crl.pem",
 
226
                      metavar="FILE",
 
227
                      help="Certificate Revokation List to use")
 
228
    parser.add_option("-p", "--port", type="int", default=49001,
684
229
                      help="Port number to receive requests on")
 
230
    parser.add_option("--dh", type="int", metavar="BITS",
 
231
                      help="DH group to use")
 
232
    parser.add_option("-t", "--timeout", type="string", # Parsed later
 
233
                      default="15m",
 
234
                      help="Amount of downtime allowed for clients")
 
235
    parser.add_option("--interval", type="string", # Parsed later
 
236
                      default="5m",
 
237
                      help="How often to check that a client is up")
685
238
    parser.add_option("--check", action="store_true", default=False,
686
239
                      help="Run self-test")
687
 
    parser.add_option("--debug", action="store_true",
688
 
                      help="Debug mode; run in foreground and log to"
689
 
                      " terminal")
690
 
    parser.add_option("--priority", type="string", help="GnuTLS"
691
 
                      " priority string (see GnuTLS documentation)")
692
 
    parser.add_option("--servicename", type="string", metavar="NAME",
693
 
                      help="Zeroconf service name")
694
 
    parser.add_option("--configdir", type="string",
695
 
                      default="/etc/mandos", metavar="DIR",
696
 
                      help="Directory to search for configuration"
697
 
                      " files")
698
240
    (options, args) = parser.parse_args()
699
 
    
 
241
 
700
242
    if options.check:
701
243
        import doctest
702
244
        doctest.testmod()
703
245
        sys.exit()
704
246
    
705
 
    # Default values for config file for server-global settings
706
 
    server_defaults = { "interface": "",
707
 
                        "address": "",
708
 
                        "port": "",
709
 
                        "debug": "False",
710
 
                        "priority":
711
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
712
 
                        "servicename": "Mandos",
713
 
                        }
714
 
    
715
 
    # Parse config file for server-global settings
716
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
717
 
    del server_defaults
718
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
719
 
    # Convert the SafeConfigParser object to a dict
720
 
    server_settings = server_config.defaults()
721
 
    # Use getboolean on the boolean config option
722
 
    server_settings["debug"] = server_config.getboolean\
723
 
                               ("DEFAULT", "debug")
724
 
    del server_config
725
 
    
726
 
    # Override the settings from the config file with command line
727
 
    # options, if set.
728
 
    for option in ("interface", "address", "port", "debug",
729
 
                   "priority", "servicename", "configdir"):
730
 
        value = getattr(options, option)
731
 
        if value is not None:
732
 
            server_settings[option] = value
733
 
    del options
734
 
    # Now we have our good server settings in "server_settings"
735
 
    
736
 
    debug = server_settings["debug"]
737
 
    
738
 
    if not debug:
739
 
        syslogger.setLevel(logging.WARNING)
740
 
        console.setLevel(logging.WARNING)
741
 
    
742
 
    if server_settings["servicename"] != "Mandos":
743
 
        syslogger.setFormatter(logging.Formatter\
744
 
                               ('Mandos (%s): %%(levelname)s:'
745
 
                                ' %%(message)s'
746
 
                                % server_settings["servicename"]))
747
 
    
748
 
    # Parse config file with clients
749
 
    client_defaults = { "timeout": "1h",
750
 
                        "interval": "5m",
751
 
                        "checker": "fping -q -- %(host)s",
752
 
                        "host": "",
753
 
                        }
754
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
755
 
    client_config.read(os.path.join(server_settings["configdir"],
756
 
                                    "clients.conf"))
757
 
    
758
 
    global service
759
 
    service = AvahiService(name = server_settings["servicename"],
760
 
                           type = "_mandos._tcp", );
761
 
    if server_settings["interface"]:
762
 
        service.interface = if_nametoindex(server_settings["interface"])
763
 
    
764
 
    global main_loop
765
 
    global bus
766
 
    global server
767
 
    # From the Avahi example code
768
 
    DBusGMainLoop(set_as_default=True )
769
 
    main_loop = gobject.MainLoop()
770
 
    bus = dbus.SystemBus()
771
 
    server = dbus.Interface(
772
 
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
773
 
            avahi.DBUS_INTERFACE_SERVER )
774
 
    # End of Avahi example code
775
 
    
776
 
    clients = Set()
777
 
    def remove_from_clients(client):
778
 
        clients.remove(client)
779
 
        if not clients:
780
 
            logger.critical(u"No clients left, exiting")
781
 
            sys.exit()
782
 
    
783
 
    clients.update(Set(Client(name = section,
784
 
                              stop_hook = remove_from_clients,
785
 
                              config
786
 
                              = dict(client_config.items(section)))
787
 
                       for section in client_config.sections()))
788
 
    if not clients:
789
 
        logger.critical(u"No clients defined")
790
 
        sys.exit(1)
791
 
    
792
 
    if debug:
793
 
        # Redirect stdin so all checkers get /dev/null
794
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
795
 
        os.dup2(null, sys.stdin.fileno())
796
 
        if null > 2:
797
 
            os.close(null)
798
 
    else:
799
 
        # No console logging
800
 
        logger.removeHandler(console)
801
 
        # Close all input and output, do double fork, etc.
802
 
        daemon()
803
 
    
804
 
    pidfilename = "/var/run/mandos/mandos.pid"
805
 
    pid = os.getpid()
806
 
    try:
807
 
        pidfile = open(pidfilename, "w")
808
 
        pidfile.write(str(pid) + "\n")
809
 
        pidfile.close()
810
 
        del pidfile
811
 
    except IOError, err:
812
 
        logger.error(u"Could not write %s file with PID %d",
813
 
                     pidfilename, os.getpid())
814
 
    
815
 
    def cleanup():
816
 
        "Cleanup function; run on exit"
817
 
        global group
818
 
        # From the Avahi example code
819
 
        if not group is None:
820
 
            group.Free()
821
 
            group = None
822
 
        # End of Avahi example code
823
 
        
824
 
        while clients:
825
 
            client = clients.pop()
826
 
            client.stop_hook = None
827
 
            client.stop()
828
 
    
829
 
    atexit.register(cleanup)
830
 
    
831
 
    if not debug:
832
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
833
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
834
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
835
 
    
 
247
    # Parse the time arguments
 
248
    try:
 
249
        options.timeout = string_to_delta(options.timeout)
 
250
    except ValueError:
 
251
        parser.error("option --timeout: Unparseable time")
 
252
    
 
253
    try:
 
254
        options.interval = string_to_delta(options.interval)
 
255
    except ValueError:
 
256
        parser.error("option --interval: Unparseable time")
 
257
    
 
258
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
 
259
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
 
260
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
 
261
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
 
262
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
 
263
    
 
264
    # Parse config file
 
265
    defaults = {}
 
266
    client_config_object = ConfigParser.SafeConfigParser(defaults)
 
267
    client_config_object.read("mandos-clients.conf")
 
268
    clients = [Client(name=section, options=options,
 
269
                      **(dict(client_config_object.items(section))))
 
270
               for section in client_config_object.sections()]
 
271
    
 
272
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
 
273
                                udp_handler,
 
274
                                options=options)
 
275
    
 
276
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
 
277
                                tcp_handler,
 
278
                                options=options,
 
279
                                clients=clients,
 
280
                                credentials=cred)
 
281
    
 
282
    while True:
 
283
        try:
 
284
            input, out, err = select.select((udp_server,
 
285
                                             tcp_server), (), ())
 
286
            if not input:
 
287
                pass
 
288
            else:
 
289
                for obj in input:
 
290
                    obj.handle_request()
 
291
        except KeyboardInterrupt:
 
292
            break
 
293
    
 
294
    # Cleanup here
836
295
    for client in clients:
837
 
        client.start()
838
 
    
839
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
840
 
                                 server_settings["port"]),
841
 
                                tcp_handler,
842
 
                                settings=server_settings,
843
 
                                clients=clients)
844
 
    # Find out what port we got
845
 
    service.port = tcp_server.socket.getsockname()[1]
846
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
847
 
                u" scope_id %d" % tcp_server.socket.getsockname())
848
 
    
849
 
    #service.interface = tcp_server.socket.getsockname()[3]
850
 
    
851
 
    try:
852
 
        # From the Avahi example code
853
 
        server.connect_to_signal("StateChanged", server_state_changed)
854
 
        try:
855
 
            server_state_changed(server.GetState())
856
 
        except dbus.exceptions.DBusException, error:
857
 
            logger.critical(u"DBusException: %s", error)
858
 
            sys.exit(1)
859
 
        # End of Avahi example code
860
 
        
861
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
862
 
                             lambda *args, **kwargs:
863
 
                             tcp_server.handle_request\
864
 
                             (*args[2:], **kwargs) or True)
865
 
        
866
 
        logger.debug(u"Starting main loop")
867
 
        main_loop_started = True
868
 
        main_loop.run()
869
 
    except AvahiError, error:
870
 
        logger.critical(u"AvahiError: %s" + unicode(error))
871
 
        sys.exit(1)
872
 
    except KeyboardInterrupt:
873
 
        if debug:
874
 
            print
875
 
 
876
 
if __name__ == '__main__':
 
296
        client.stop_checker()
 
297
 
 
298
 
 
299
if __name__ == "__main__":
877
300
    main()
 
301