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  • Committer: Teddy Hogeborn
  • Date: 2008-09-13 15:36:18 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080913153618-atp386q2bqj0ku99
* Makefile (install-client-nokey): Do "&&" instead of ";" to catch
                                   errors.

* README: Kill the straight quotes.  Add copyright notice.

* overview.xml: Improved wording.

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mandos
1
1
#!/usr/bin/python
 
2
# -*- mode: python; coding: utf-8 -*-
 
3
# 
 
4
# Mandos server - give out binary blobs to connecting clients.
 
5
# 
 
6
# This program is partly derived from an example program for an Avahi
 
7
# service publisher, downloaded from
 
8
# <http://avahi.org/wiki/PythonPublishExample>.  This includes the
 
9
# methods "add" and "remove" in the "AvahiService" class, the
 
10
# "server_state_changed" and "entry_group_state_changed" functions,
 
11
# and some lines in "main".
 
12
# 
 
13
# Everything else is
 
14
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
 
15
# 
 
16
# This program is free software: you can redistribute it and/or modify
 
17
# it under the terms of the GNU General Public License as published by
 
18
# the Free Software Foundation, either version 3 of the License, or
 
19
# (at your option) any later version.
 
20
#
 
21
#     This program is distributed in the hope that it will be useful,
 
22
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
 
23
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
24
#     GNU General Public License for more details.
 
25
# 
 
26
# You should have received a copy of the GNU General Public License
 
27
# along with this program.  If not, see
 
28
# <http://www.gnu.org/licenses/>.
 
29
# 
 
30
# Contact the authors at <mandos@fukt.bsnet.se>.
 
31
# 
 
32
 
 
33
from __future__ import division
2
34
 
3
35
import SocketServer
4
36
import socket
9
41
import gnutls.crypto
10
42
import gnutls.connection
11
43
import gnutls.errors
 
44
import gnutls.library.functions
 
45
import gnutls.library.constants
 
46
import gnutls.library.types
12
47
import ConfigParser
 
48
import sys
 
49
import re
 
50
import os
 
51
import signal
 
52
from sets import Set
 
53
import subprocess
 
54
import atexit
 
55
import stat
 
56
import logging
 
57
import logging.handlers
 
58
import pwd
 
59
 
 
60
import dbus
 
61
import gobject
 
62
import avahi
 
63
from dbus.mainloop.glib import DBusGMainLoop
 
64
import ctypes
 
65
 
 
66
version = "1.0"
 
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
    def __str__(self):
 
85
        return repr(self.value)
 
86
 
 
87
class AvahiServiceError(AvahiError):
 
88
    pass
 
89
 
 
90
class AvahiGroupError(AvahiError):
 
91
    pass
 
92
 
 
93
 
 
94
class AvahiService(object):
 
95
    """An Avahi (Zeroconf) service.
 
96
    Attributes:
 
97
    interface: integer; avahi.IF_UNSPEC or an interface index.
 
98
               Used to optionally bind to the specified interface.
 
99
    name: string; Example: 'Mandos'
 
100
    type: string; Example: '_mandos._tcp'.
 
101
                  See <http://www.dns-sd.org/ServiceTypes.html>
 
102
    port: integer; what port to announce
 
103
    TXT: list of strings; TXT record for the service
 
104
    domain: string; Domain to publish on, default to .local if empty.
 
105
    host: string; Host to publish records for, default is localhost
 
106
    max_renames: integer; maximum number of renames
 
107
    rename_count: integer; counter so we only rename after collisions
 
108
                  a sensible number of times
 
109
    """
 
110
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
 
111
                 type = None, port = None, TXT = None, domain = "",
 
112
                 host = "", max_renames = 32768):
 
113
        self.interface = interface
 
114
        self.name = name
 
115
        self.type = type
 
116
        self.port = port
 
117
        if TXT is None:
 
118
            self.TXT = []
 
119
        else:
 
120
            self.TXT = TXT
 
121
        self.domain = domain
 
122
        self.host = host
 
123
        self.rename_count = 0
 
124
        self.max_renames = max_renames
 
125
    def rename(self):
 
126
        """Derived from the Avahi example code"""
 
127
        if self.rename_count >= self.max_renames:
 
128
            logger.critical(u"No suitable Zeroconf service name found"
 
129
                            u" after %i retries, exiting.",
 
130
                            rename_count)
 
131
            raise AvahiServiceError("Too many renames")
 
132
        self.name = server.GetAlternativeServiceName(self.name)
 
133
        logger.info(u"Changing Zeroconf service name to %r ...",
 
134
                    str(self.name))
 
135
        syslogger.setFormatter(logging.Formatter\
 
136
                               ('Mandos (%s): %%(levelname)s:'
 
137
                               ' %%(message)s' % self.name))
 
138
        self.remove()
 
139
        self.add()
 
140
        self.rename_count += 1
 
141
    def remove(self):
 
142
        """Derived from the Avahi example code"""
 
143
        if group is not None:
 
144
            group.Reset()
 
145
    def add(self):
 
146
        """Derived from the Avahi example code"""
 
147
        global group
 
148
        if group is None:
 
149
            group = dbus.Interface\
 
150
                    (bus.get_object(avahi.DBUS_NAME,
 
151
                                    server.EntryGroupNew()),
 
152
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
153
            group.connect_to_signal('StateChanged',
 
154
                                    entry_group_state_changed)
 
155
        logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
 
156
                     service.name, service.type)
 
157
        group.AddService(
 
158
                self.interface,         # interface
 
159
                avahi.PROTO_INET6,      # protocol
 
160
                dbus.UInt32(0),         # flags
 
161
                self.name, self.type,
 
162
                self.domain, self.host,
 
163
                dbus.UInt16(self.port),
 
164
                avahi.string_array_to_txt_array(self.TXT))
 
165
        group.Commit()
 
166
 
 
167
# From the Avahi example code:
 
168
group = None                            # our entry group
 
169
# End of Avahi example code
 
170
 
13
171
 
14
172
class Client(object):
15
 
    def __init__(self, name=None, dn=None, password=None,
16
 
                 passfile=None, fqdn=None, timeout=None,
17
 
                 interval=-1):
 
173
    """A representation of a client host served by this server.
 
174
    Attributes:
 
175
    name:      string; from the config file, used in log messages
 
176
    fingerprint: string (40 or 32 hexadecimal digits); used to
 
177
                 uniquely identify the client
 
178
    secret:    bytestring; sent verbatim (over TLS) to client
 
179
    host:      string; available for use by the checker command
 
180
    created:   datetime.datetime(); object creation, not client host
 
181
    last_checked_ok: datetime.datetime() or None if not yet checked OK
 
182
    timeout:   datetime.timedelta(); How long from last_checked_ok
 
183
                                     until this client is invalid
 
184
    interval:  datetime.timedelta(); How often to start a new checker
 
185
    stop_hook: If set, called by stop() as stop_hook(self)
 
186
    checker:   subprocess.Popen(); a running checker process used
 
187
                                   to see if the client lives.
 
188
                                   'None' if no process is running.
 
189
    checker_initiator_tag: a gobject event source tag, or None
 
190
    stop_initiator_tag:    - '' -
 
191
    checker_callback_tag:  - '' -
 
192
    checker_command: string; External command which is run to check if
 
193
                     client lives.  %() expansions are done at
 
194
                     runtime with vars(self) as dict, so that for
 
195
                     instance %(name)s can be used in the command.
 
196
    Private attibutes:
 
197
    _timeout: Real variable for 'timeout'
 
198
    _interval: Real variable for 'interval'
 
199
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
200
    _interval_milliseconds: - '' -
 
201
    """
 
202
    def _set_timeout(self, timeout):
 
203
        "Setter function for 'timeout' attribute"
 
204
        self._timeout = timeout
 
205
        self._timeout_milliseconds = ((self.timeout.days
 
206
                                       * 24 * 60 * 60 * 1000)
 
207
                                      + (self.timeout.seconds * 1000)
 
208
                                      + (self.timeout.microseconds
 
209
                                         // 1000))
 
210
    timeout = property(lambda self: self._timeout,
 
211
                       _set_timeout)
 
212
    del _set_timeout
 
213
    def _set_interval(self, interval):
 
214
        "Setter function for 'interval' attribute"
 
215
        self._interval = interval
 
216
        self._interval_milliseconds = ((self.interval.days
 
217
                                        * 24 * 60 * 60 * 1000)
 
218
                                       + (self.interval.seconds
 
219
                                          * 1000)
 
220
                                       + (self.interval.microseconds
 
221
                                          // 1000))
 
222
    interval = property(lambda self: self._interval,
 
223
                        _set_interval)
 
224
    del _set_interval
 
225
    def __init__(self, name = None, stop_hook=None, config={}):
 
226
        """Note: the 'checker' key in 'config' sets the
 
227
        'checker_command' attribute and *not* the 'checker'
 
228
        attribute."""
18
229
        self.name = name
19
 
        self.dn = dn
20
 
        if password:
21
 
            self.password = password
22
 
        elif passfile:
23
 
            self.password = open(passfile).readall()
24
 
        else:
25
 
            print "No Password or Passfile in client config file"
26
 
            # raise RuntimeError XXX
27
 
            self.password = "gazonk"
28
 
        self.fqdn = fqdn
29
 
        # self.created = ...
30
 
        self.last_seen = None
31
 
        if timeout is None:
32
 
            timeout = self.server.options.timeout
33
 
        self.timeout = timeout
34
 
        if interval == -1:
35
 
            interval = self.server.options.interval
36
 
        self.interval = interval
37
 
 
38
 
def server_bind(self):
39
 
    if self.options.interface:
40
 
        if not hasattr(socket, "SO_BINDTODEVICE"):
41
 
            # From /usr/include/asm-i486/socket.h
42
 
            socket.SO_BINDTODEVICE = 25
 
230
        logger.debug(u"Creating client %r", self.name)
 
231
        # Uppercase and remove spaces from fingerprint for later
 
232
        # comparison purposes with return value from the fingerprint()
 
233
        # function
 
234
        self.fingerprint = config["fingerprint"].upper()\
 
235
                           .replace(u" ", u"")
 
236
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
 
237
        if "secret" in config:
 
238
            self.secret = config["secret"].decode(u"base64")
 
239
        elif "secfile" in config:
 
240
            sf = open(config["secfile"])
 
241
            self.secret = sf.read()
 
242
            sf.close()
 
243
        else:
 
244
            raise TypeError(u"No secret or secfile for client %s"
 
245
                            % self.name)
 
246
        self.host = config.get("host", "")
 
247
        self.created = datetime.datetime.now()
 
248
        self.last_checked_ok = None
 
249
        self.timeout = string_to_delta(config["timeout"])
 
250
        self.interval = string_to_delta(config["interval"])
 
251
        self.stop_hook = stop_hook
 
252
        self.checker = None
 
253
        self.checker_initiator_tag = None
 
254
        self.stop_initiator_tag = None
 
255
        self.checker_callback_tag = None
 
256
        self.check_command = config["checker"]
 
257
    def start(self):
 
258
        """Start this client's checker and timeout hooks"""
 
259
        # Schedule a new checker to be started an 'interval' from now,
 
260
        # and every interval from then on.
 
261
        self.checker_initiator_tag = gobject.timeout_add\
 
262
                                     (self._interval_milliseconds,
 
263
                                      self.start_checker)
 
264
        # Also start a new checker *right now*.
 
265
        self.start_checker()
 
266
        # Schedule a stop() when 'timeout' has passed
 
267
        self.stop_initiator_tag = gobject.timeout_add\
 
268
                                  (self._timeout_milliseconds,
 
269
                                   self.stop)
 
270
    def stop(self):
 
271
        """Stop this client.
 
272
        The possibility that a client might be restarted is left open,
 
273
        but not currently used."""
 
274
        # If this client doesn't have a secret, it is already stopped.
 
275
        if hasattr(self, "secret") and self.secret:
 
276
            logger.info(u"Stopping client %s", self.name)
 
277
            self.secret = None
 
278
        else:
 
279
            return False
 
280
        if getattr(self, "stop_initiator_tag", False):
 
281
            gobject.source_remove(self.stop_initiator_tag)
 
282
            self.stop_initiator_tag = None
 
283
        if getattr(self, "checker_initiator_tag", False):
 
284
            gobject.source_remove(self.checker_initiator_tag)
 
285
            self.checker_initiator_tag = None
 
286
        self.stop_checker()
 
287
        if self.stop_hook:
 
288
            self.stop_hook(self)
 
289
        # Do not run this again if called by a gobject.timeout_add
 
290
        return False
 
291
    def __del__(self):
 
292
        self.stop_hook = None
 
293
        self.stop()
 
294
    def checker_callback(self, pid, condition):
 
295
        """The checker has completed, so take appropriate actions."""
 
296
        now = datetime.datetime.now()
 
297
        self.checker_callback_tag = None
 
298
        self.checker = None
 
299
        if os.WIFEXITED(condition) \
 
300
               and (os.WEXITSTATUS(condition) == 0):
 
301
            logger.info(u"Checker for %(name)s succeeded",
 
302
                        vars(self))
 
303
            self.last_checked_ok = now
 
304
            gobject.source_remove(self.stop_initiator_tag)
 
305
            self.stop_initiator_tag = gobject.timeout_add\
 
306
                                      (self._timeout_milliseconds,
 
307
                                       self.stop)
 
308
        elif not os.WIFEXITED(condition):
 
309
            logger.warning(u"Checker for %(name)s crashed?",
 
310
                           vars(self))
 
311
        else:
 
312
            logger.info(u"Checker for %(name)s failed",
 
313
                        vars(self))
 
314
    def start_checker(self):
 
315
        """Start a new checker subprocess if one is not running.
 
316
        If a checker already exists, leave it running and do
 
317
        nothing."""
 
318
        # The reason for not killing a running checker is that if we
 
319
        # did that, then if a checker (for some reason) started
 
320
        # running slowly and taking more than 'interval' time, the
 
321
        # client would inevitably timeout, since no checker would get
 
322
        # a chance to run to completion.  If we instead leave running
 
323
        # checkers alone, the checker would have to take more time
 
324
        # than 'timeout' for the client to be declared invalid, which
 
325
        # is as it should be.
 
326
        if self.checker is None:
 
327
            try:
 
328
                # In case check_command has exactly one % operator
 
329
                command = self.check_command % self.host
 
330
            except TypeError:
 
331
                # Escape attributes for the shell
 
332
                escaped_attrs = dict((key, re.escape(str(val)))
 
333
                                     for key, val in
 
334
                                     vars(self).iteritems())
 
335
                try:
 
336
                    command = self.check_command % escaped_attrs
 
337
                except TypeError, error:
 
338
                    logger.error(u'Could not format string "%s":'
 
339
                                 u' %s', self.check_command, error)
 
340
                    return True # Try again later
 
341
            try:
 
342
                logger.info(u"Starting checker %r for %s",
 
343
                            command, self.name)
 
344
                # We don't need to redirect stdout and stderr, since
 
345
                # in normal mode, that is already done by daemon(),
 
346
                # and in debug mode we don't want to.  (Stdin is
 
347
                # always replaced by /dev/null.)
 
348
                self.checker = subprocess.Popen(command,
 
349
                                                close_fds=True,
 
350
                                                shell=True, cwd="/")
 
351
                self.checker_callback_tag = gobject.child_watch_add\
 
352
                                            (self.checker.pid,
 
353
                                             self.checker_callback)
 
354
            except OSError, error:
 
355
                logger.error(u"Failed to start subprocess: %s",
 
356
                             error)
 
357
        # Re-run this periodically if run by gobject.timeout_add
 
358
        return True
 
359
    def stop_checker(self):
 
360
        """Force the checker process, if any, to stop."""
 
361
        if self.checker_callback_tag:
 
362
            gobject.source_remove(self.checker_callback_tag)
 
363
            self.checker_callback_tag = None
 
364
        if getattr(self, "checker", None) is None:
 
365
            return
 
366
        logger.debug(u"Stopping checker for %(name)s", vars(self))
43
367
        try:
44
 
            self.socket.setsockopt(socket.SOL_SOCKET,
45
 
                                   socket.SO_BINDTODEVICE,
46
 
                                   self.options.interface)
47
 
        except socket.error, error:
48
 
            if error[0] == errno.EPERM:
49
 
                print "Warning: Denied permission to bind to interface", \
50
 
                      self.options.interface
51
 
            else:
52
 
                raise error
53
 
    return super(type(self), self).server_bind()
54
 
 
55
 
 
56
 
def init_with_options(self, *args, **kwargs):
57
 
    if "options" in kwargs:
58
 
        self.options = kwargs["options"]
59
 
        del kwargs["options"]
60
 
    if "clients" in kwargs:
61
 
        self.clients = kwargs["clients"]
62
 
        del kwargs["clients"]
63
 
    if "credentials" in kwargs:
64
 
        self.credentials = kwargs["credentials"]
65
 
        del kwargs["credentials"]
66
 
    return super(type(self), self).__init__(*args, **kwargs)
67
 
 
68
 
 
69
 
class udp_handler(SocketServer.DatagramRequestHandler, object):
70
 
    def handle(self):
71
 
        self.wfile.write("Polo")
72
 
        print "UDP request answered"
73
 
 
74
 
 
75
 
class IPv6_UDPServer(SocketServer.UDPServer, object):
76
 
    __init__ = init_with_options
77
 
    address_family = socket.AF_INET6
78
 
    allow_reuse_address = True
79
 
    server_bind = server_bind
80
 
    def verify_request(self, request, client_address):
81
 
        print "UDP request came"
82
 
        return request[0] == "Marco"
 
368
            os.kill(self.checker.pid, signal.SIGTERM)
 
369
            #os.sleep(0.5)
 
370
            #if self.checker.poll() is None:
 
371
            #    os.kill(self.checker.pid, signal.SIGKILL)
 
372
        except OSError, error:
 
373
            if error.errno != errno.ESRCH: # No such process
 
374
                raise
 
375
        self.checker = None
 
376
    def still_valid(self):
 
377
        """Has the timeout not yet passed for this client?"""
 
378
        now = datetime.datetime.now()
 
379
        if self.last_checked_ok is None:
 
380
            return now < (self.created + self.timeout)
 
381
        else:
 
382
            return now < (self.last_checked_ok + self.timeout)
 
383
 
 
384
 
 
385
def peer_certificate(session):
 
386
    "Return the peer's OpenPGP certificate as a bytestring"
 
387
    # If not an OpenPGP certificate...
 
388
    if gnutls.library.functions.gnutls_certificate_type_get\
 
389
            (session._c_object) \
 
390
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
 
391
        # ...do the normal thing
 
392
        return session.peer_certificate
 
393
    list_size = ctypes.c_uint()
 
394
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
 
395
        (session._c_object, ctypes.byref(list_size))
 
396
    if list_size.value == 0:
 
397
        return None
 
398
    cert = cert_list[0]
 
399
    return ctypes.string_at(cert.data, cert.size)
 
400
 
 
401
 
 
402
def fingerprint(openpgp):
 
403
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
404
    # New GnuTLS "datum" with the OpenPGP public key
 
405
    datum = gnutls.library.types.gnutls_datum_t\
 
406
        (ctypes.cast(ctypes.c_char_p(openpgp),
 
407
                     ctypes.POINTER(ctypes.c_ubyte)),
 
408
         ctypes.c_uint(len(openpgp)))
 
409
    # New empty GnuTLS certificate
 
410
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
411
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
412
        (ctypes.byref(crt))
 
413
    # Import the OpenPGP public key into the certificate
 
414
    gnutls.library.functions.gnutls_openpgp_crt_import\
 
415
                    (crt, ctypes.byref(datum),
 
416
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
417
    # Verify the self signature in the key
 
418
    crtverify = ctypes.c_uint();
 
419
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
 
420
        (crt, 0, ctypes.byref(crtverify))
 
421
    if crtverify.value != 0:
 
422
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
423
        raise gnutls.errors.CertificateSecurityError("Verify failed")
 
424
    # New buffer for the fingerprint
 
425
    buffer = ctypes.create_string_buffer(20)
 
426
    buffer_length = ctypes.c_size_t()
 
427
    # Get the fingerprint from the certificate into the buffer
 
428
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
 
429
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
 
430
    # Deinit the certificate
 
431
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
432
    # Convert the buffer to a Python bytestring
 
433
    fpr = ctypes.string_at(buffer, buffer_length.value)
 
434
    # Convert the bytestring to hexadecimal notation
 
435
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
 
436
    return hex_fpr
83
437
 
84
438
 
85
439
class tcp_handler(SocketServer.BaseRequestHandler, object):
 
440
    """A TCP request handler class.
 
441
    Instantiated by IPv6_TCPServer for each request to handle it.
 
442
    Note: This will run in its own forked process."""
 
443
    
86
444
    def handle(self):
87
 
        print "TCP request came"
88
 
        print "Request:", self.request
89
 
        print "Client Address:", self.client_address
90
 
        print "Server:", self.server
91
 
        session = gnutls.connection.ServerSession(self.request,
92
 
                                                  self.server.credentials)
93
 
        session.handshake()
94
 
        if session.peer_certificate:
95
 
            print "DN:", session.peer_certificate.subject
96
 
        try:
97
 
            session.verify_peer()
98
 
        except gnutls.errors.CertificateError, error:
99
 
            print "Verify failed", error
100
 
            session.bye()
101
 
            return
102
 
        try:
103
 
            session.send(dict((client.dn, client.password)
104
 
                              for client in self.server.clients)
105
 
                         [session.peer_certificate.subject])
106
 
        except KeyError:
107
 
            session.send("gazonk")
108
 
            # Log maybe? XXX
 
445
        logger.info(u"TCP connection from: %s",
 
446
                     unicode(self.client_address))
 
447
        session = gnutls.connection.ClientSession\
 
448
                  (self.request, gnutls.connection.X509Credentials())
 
449
        
 
450
        line = self.request.makefile().readline()
 
451
        logger.debug(u"Protocol version: %r", line)
 
452
        try:
 
453
            if int(line.strip().split()[0]) > 1:
 
454
                raise RuntimeError
 
455
        except (ValueError, IndexError, RuntimeError), error:
 
456
            logger.error(u"Unknown protocol version: %s", error)
 
457
            return
 
458
        
 
459
        # Note: gnutls.connection.X509Credentials is really a generic
 
460
        # GnuTLS certificate credentials object so long as no X.509
 
461
        # keys are added to it.  Therefore, we can use it here despite
 
462
        # using OpenPGP certificates.
 
463
        
 
464
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
 
465
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
 
466
        #                "+DHE-DSS"))
 
467
        priority = "NORMAL"             # Fallback default, since this
 
468
                                        # MUST be set.
 
469
        if self.server.settings["priority"]:
 
470
            priority = self.server.settings["priority"]
 
471
        gnutls.library.functions.gnutls_priority_set_direct\
 
472
            (session._c_object, priority, None);
 
473
        
 
474
        try:
 
475
            session.handshake()
 
476
        except gnutls.errors.GNUTLSError, error:
 
477
            logger.warning(u"Handshake failed: %s", error)
 
478
            # Do not run session.bye() here: the session is not
 
479
            # established.  Just abandon the request.
 
480
            return
 
481
        try:
 
482
            fpr = fingerprint(peer_certificate(session))
 
483
        except (TypeError, gnutls.errors.GNUTLSError), error:
 
484
            logger.warning(u"Bad certificate: %s", error)
 
485
            session.bye()
 
486
            return
 
487
        logger.debug(u"Fingerprint: %s", fpr)
 
488
        client = None
 
489
        for c in self.server.clients:
 
490
            if c.fingerprint == fpr:
 
491
                client = c
 
492
                break
 
493
        if not client:
 
494
            logger.warning(u"Client not found for fingerprint: %s",
 
495
                           fpr)
 
496
            session.bye()
 
497
            return
 
498
        # Have to check if client.still_valid(), since it is possible
 
499
        # that the client timed out while establishing the GnuTLS
 
500
        # session.
 
501
        if not client.still_valid():
 
502
            logger.warning(u"Client %(name)s is invalid",
 
503
                           vars(client))
 
504
            session.bye()
 
505
            return
 
506
        sent_size = 0
 
507
        while sent_size < len(client.secret):
 
508
            sent = session.send(client.secret[sent_size:])
 
509
            logger.debug(u"Sent: %d, remaining: %d",
 
510
                         sent, len(client.secret)
 
511
                         - (sent_size + sent))
 
512
            sent_size += sent
109
513
        session.bye()
110
514
 
 
515
 
111
516
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
112
 
    __init__ = init_with_options
 
517
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
 
518
    Attributes:
 
519
        settings:       Server settings
 
520
        clients:        Set() of Client objects
 
521
        enabled:        Boolean; whether this server is activated yet
 
522
    """
113
523
    address_family = socket.AF_INET6
114
 
    allow_reuse_address = True
115
 
    request_queue_size = 1024
116
 
    server_bind = server_bind
117
 
 
118
 
 
119
 
in6addr_any = "::"
120
 
 
121
 
cred = None
 
524
    def __init__(self, *args, **kwargs):
 
525
        if "settings" in kwargs:
 
526
            self.settings = kwargs["settings"]
 
527
            del kwargs["settings"]
 
528
        if "clients" in kwargs:
 
529
            self.clients = kwargs["clients"]
 
530
            del kwargs["clients"]
 
531
        self.enabled = False
 
532
        return super(type(self), self).__init__(*args, **kwargs)
 
533
    def server_bind(self):
 
534
        """This overrides the normal server_bind() function
 
535
        to bind to an interface if one was specified, and also NOT to
 
536
        bind to an address or port if they were not specified."""
 
537
        if self.settings["interface"]:
 
538
            # 25 is from /usr/include/asm-i486/socket.h
 
539
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
540
            try:
 
541
                self.socket.setsockopt(socket.SOL_SOCKET,
 
542
                                       SO_BINDTODEVICE,
 
543
                                       self.settings["interface"])
 
544
            except socket.error, error:
 
545
                if error[0] == errno.EPERM:
 
546
                    logger.error(u"No permission to"
 
547
                                 u" bind to interface %s",
 
548
                                 self.settings["interface"])
 
549
                else:
 
550
                    raise error
 
551
        # Only bind(2) the socket if we really need to.
 
552
        if self.server_address[0] or self.server_address[1]:
 
553
            if not self.server_address[0]:
 
554
                in6addr_any = "::"
 
555
                self.server_address = (in6addr_any,
 
556
                                       self.server_address[1])
 
557
            elif not self.server_address[1]:
 
558
                self.server_address = (self.server_address[0],
 
559
                                       0)
 
560
#                 if self.settings["interface"]:
 
561
#                     self.server_address = (self.server_address[0],
 
562
#                                            0, # port
 
563
#                                            0, # flowinfo
 
564
#                                            if_nametoindex
 
565
#                                            (self.settings
 
566
#                                             ["interface"]))
 
567
            return super(type(self), self).server_bind()
 
568
    def server_activate(self):
 
569
        if self.enabled:
 
570
            return super(type(self), self).server_activate()
 
571
    def enable(self):
 
572
        self.enabled = True
 
573
 
 
574
 
 
575
def string_to_delta(interval):
 
576
    """Parse a string and return a datetime.timedelta
 
577
 
 
578
    >>> string_to_delta('7d')
 
579
    datetime.timedelta(7)
 
580
    >>> string_to_delta('60s')
 
581
    datetime.timedelta(0, 60)
 
582
    >>> string_to_delta('60m')
 
583
    datetime.timedelta(0, 3600)
 
584
    >>> string_to_delta('24h')
 
585
    datetime.timedelta(1)
 
586
    >>> string_to_delta(u'1w')
 
587
    datetime.timedelta(7)
 
588
    >>> string_to_delta('5m 30s')
 
589
    datetime.timedelta(0, 330)
 
590
    """
 
591
    timevalue = datetime.timedelta(0)
 
592
    for s in interval.split():
 
593
        try:
 
594
            suffix=unicode(s[-1])
 
595
            value=int(s[:-1])
 
596
            if suffix == u"d":
 
597
                delta = datetime.timedelta(value)
 
598
            elif suffix == u"s":
 
599
                delta = datetime.timedelta(0, value)
 
600
            elif suffix == u"m":
 
601
                delta = datetime.timedelta(0, 0, 0, 0, value)
 
602
            elif suffix == u"h":
 
603
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
604
            elif suffix == u"w":
 
605
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
606
            else:
 
607
                raise ValueError
 
608
        except (ValueError, IndexError):
 
609
            raise ValueError
 
610
        timevalue += delta
 
611
    return timevalue
 
612
 
 
613
 
 
614
def server_state_changed(state):
 
615
    """Derived from the Avahi example code"""
 
616
    if state == avahi.SERVER_COLLISION:
 
617
        logger.error(u"Zeroconf server name collision")
 
618
        service.remove()
 
619
    elif state == avahi.SERVER_RUNNING:
 
620
        service.add()
 
621
 
 
622
 
 
623
def entry_group_state_changed(state, error):
 
624
    """Derived from the Avahi example code"""
 
625
    logger.debug(u"Avahi state change: %i", state)
 
626
    
 
627
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
 
628
        logger.debug(u"Zeroconf service established.")
 
629
    elif state == avahi.ENTRY_GROUP_COLLISION:
 
630
        logger.warning(u"Zeroconf service name collision.")
 
631
        service.rename()
 
632
    elif state == avahi.ENTRY_GROUP_FAILURE:
 
633
        logger.critical(u"Avahi: Error in group state changed %s",
 
634
                        unicode(error))
 
635
        raise AvahiGroupError("State changed: %s", str(error))
 
636
 
 
637
def if_nametoindex(interface):
 
638
    """Call the C function if_nametoindex(), or equivalent"""
 
639
    global if_nametoindex
 
640
    try:
 
641
        if "ctypes.util" not in sys.modules:
 
642
            import ctypes.util
 
643
        if_nametoindex = ctypes.cdll.LoadLibrary\
 
644
            (ctypes.util.find_library("c")).if_nametoindex
 
645
    except (OSError, AttributeError):
 
646
        if "struct" not in sys.modules:
 
647
            import struct
 
648
        if "fcntl" not in sys.modules:
 
649
            import fcntl
 
650
        def if_nametoindex(interface):
 
651
            "Get an interface index the hard way, i.e. using fcntl()"
 
652
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
 
653
            s = socket.socket()
 
654
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
655
                                struct.pack("16s16x", interface))
 
656
            s.close()
 
657
            interface_index = struct.unpack("I", ifreq[16:20])[0]
 
658
            return interface_index
 
659
    return if_nametoindex(interface)
 
660
 
 
661
 
 
662
def daemon(nochdir = False, noclose = False):
 
663
    """See daemon(3).  Standard BSD Unix function.
 
664
    This should really exist as os.daemon, but it doesn't (yet)."""
 
665
    if os.fork():
 
666
        sys.exit()
 
667
    os.setsid()
 
668
    if not nochdir:
 
669
        os.chdir("/")
 
670
    if os.fork():
 
671
        sys.exit()
 
672
    if not noclose:
 
673
        # Close all standard open file descriptors
 
674
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
675
        if not stat.S_ISCHR(os.fstat(null).st_mode):
 
676
            raise OSError(errno.ENODEV,
 
677
                          "/dev/null not a character device")
 
678
        os.dup2(null, sys.stdin.fileno())
 
679
        os.dup2(null, sys.stdout.fileno())
 
680
        os.dup2(null, sys.stderr.fileno())
 
681
        if null > 2:
 
682
            os.close(null)
 
683
 
122
684
 
123
685
def main():
124
 
    parser = OptionParser()
 
686
    global main_loop_started
 
687
    main_loop_started = False
 
688
    
 
689
    parser = OptionParser(version = "%%prog %s" % version)
125
690
    parser.add_option("-i", "--interface", type="string",
126
 
                      default="eth0", metavar="IF",
127
 
                      help="Interface to bind to")
128
 
    parser.add_option("--cert", type="string", default="cert.pem",
129
 
                      metavar="FILE",
130
 
                      help="Public key certificate to use")
131
 
    parser.add_option("--key", type="string", default="key.pem",
132
 
                      metavar="FILE",
133
 
                      help="Private key to use")
134
 
    parser.add_option("--ca", type="string", default="ca.pem",
135
 
                      metavar="FILE",
136
 
                      help="Certificate Authority certificate to use")
137
 
    parser.add_option("--crl", type="string", default="crl.pem",
138
 
                      metavar="FILE",
139
 
                      help="Certificate Revokation List to use")
140
 
    parser.add_option("-p", "--port", type="int", default=49001,
 
691
                      metavar="IF", help="Bind to interface IF")
 
692
    parser.add_option("-a", "--address", type="string",
 
693
                      help="Address to listen for requests on")
 
694
    parser.add_option("-p", "--port", type="int",
141
695
                      help="Port number to receive requests on")
142
 
    parser.add_option("--dh", type="int", metavar="BITS",
143
 
                      help="DH group to use")
144
 
    parser.add_option("-t", "--timeout", type="string", # Parsed later
145
 
                      default="15m",
146
 
                      help="Amount of downtime allowed for clients")
 
696
    parser.add_option("--check", action="store_true", default=False,
 
697
                      help="Run self-test")
 
698
    parser.add_option("--debug", action="store_true",
 
699
                      help="Debug mode; run in foreground and log to"
 
700
                      " terminal")
 
701
    parser.add_option("--priority", type="string", help="GnuTLS"
 
702
                      " priority string (see GnuTLS documentation)")
 
703
    parser.add_option("--servicename", type="string", metavar="NAME",
 
704
                      help="Zeroconf service name")
 
705
    parser.add_option("--configdir", type="string",
 
706
                      default="/etc/mandos", metavar="DIR",
 
707
                      help="Directory to search for configuration"
 
708
                      " files")
147
709
    (options, args) = parser.parse_args()
148
710
    
149
 
    # Parse the time argument
150
 
    try:
151
 
        suffix=options.timeout[-1]
152
 
        value=int(options.timeout[:-1])
153
 
        if suffix == "d":
154
 
            options.timeout = datetime.timedelta(value)
155
 
        elif suffix == "s":
156
 
            options.timeout = datetime.timedelta(0, value)
157
 
        elif suffix == "m":
158
 
            options.timeout = datetime.timedelta(0, 0, 0, 0, value)
159
 
        elif suffix == "h":
160
 
            options.timeout = datetime.timedelta(0, 0, 0, 0, 0, value)
161
 
        elif suffix == "w":
162
 
            options.timeout = datetime.timedelta(0, 0, 0, 0, 0, 0,
163
 
                                                 value)
164
 
        else:
165
 
            raise ValueError
166
 
    except (ValueError, IndexError):
167
 
        parser.error("option --timeout: Unparseable time")
168
 
    
169
 
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
170
 
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
171
 
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
172
 
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
173
 
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
174
 
    
175
 
    # Parse config file
176
 
    defaults = {}
177
 
    client_config_object = ConfigParser.SafeConfigParser(defaults)
178
 
    client_config_object.read("mandos-clients.conf")
179
 
    clients = [Client(name=section,
180
 
                      **(dict(client_config_object.items(section))))
181
 
               for section in client_config_object.sections()]
182
 
    
183
 
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
184
 
                                udp_handler,
185
 
                                options=options)
186
 
    
187
 
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
 
711
    if options.check:
 
712
        import doctest
 
713
        doctest.testmod()
 
714
        sys.exit()
 
715
    
 
716
    # Default values for config file for server-global settings
 
717
    server_defaults = { "interface": "",
 
718
                        "address": "",
 
719
                        "port": "",
 
720
                        "debug": "False",
 
721
                        "priority":
 
722
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
 
723
                        "servicename": "Mandos",
 
724
                        }
 
725
    
 
726
    # Parse config file for server-global settings
 
727
    server_config = ConfigParser.SafeConfigParser(server_defaults)
 
728
    del server_defaults
 
729
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
730
    # Convert the SafeConfigParser object to a dict
 
731
    server_settings = server_config.defaults()
 
732
    # Use getboolean on the boolean config option
 
733
    server_settings["debug"] = server_config.getboolean\
 
734
                               ("DEFAULT", "debug")
 
735
    del server_config
 
736
    
 
737
    # Override the settings from the config file with command line
 
738
    # options, if set.
 
739
    for option in ("interface", "address", "port", "debug",
 
740
                   "priority", "servicename", "configdir"):
 
741
        value = getattr(options, option)
 
742
        if value is not None:
 
743
            server_settings[option] = value
 
744
    del options
 
745
    # Now we have our good server settings in "server_settings"
 
746
    
 
747
    debug = server_settings["debug"]
 
748
    
 
749
    if not debug:
 
750
        syslogger.setLevel(logging.WARNING)
 
751
        console.setLevel(logging.WARNING)
 
752
    
 
753
    if server_settings["servicename"] != "Mandos":
 
754
        syslogger.setFormatter(logging.Formatter\
 
755
                               ('Mandos (%s): %%(levelname)s:'
 
756
                                ' %%(message)s'
 
757
                                % server_settings["servicename"]))
 
758
    
 
759
    # Parse config file with clients
 
760
    client_defaults = { "timeout": "1h",
 
761
                        "interval": "5m",
 
762
                        "checker": "fping -q -- %(host)s",
 
763
                        "host": "",
 
764
                        }
 
765
    client_config = ConfigParser.SafeConfigParser(client_defaults)
 
766
    client_config.read(os.path.join(server_settings["configdir"],
 
767
                                    "clients.conf"))
 
768
    
 
769
    clients = Set()
 
770
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
771
                                 server_settings["port"]),
188
772
                                tcp_handler,
189
 
                                options=options,
190
 
                                clients=clients,
191
 
                                credentials=cred)
192
 
    
193
 
    while True:
194
 
        in_, out, err = select.select((udp_server,
195
 
                                       tcp_server), (), ())
196
 
        for server in in_:
197
 
            server.handle_request()
198
 
 
199
 
 
200
 
if __name__ == "__main__":
 
773
                                settings=server_settings,
 
774
                                clients=clients)
 
775
    pidfilename = "/var/run/mandos.pid"
 
776
    try:
 
777
        pidfile = open(pidfilename, "w")
 
778
    except IOError, error:
 
779
        logger.error("Could not open file %r", pidfilename)
 
780
    
 
781
    uid = 65534
 
782
    gid = 65534
 
783
    try:
 
784
        uid = pwd.getpwnam("mandos").pw_uid
 
785
    except KeyError:
 
786
        try:
 
787
            uid = pwd.getpwnam("nobody").pw_uid
 
788
        except KeyError:
 
789
            pass
 
790
    try:
 
791
        gid = pwd.getpwnam("mandos").pw_gid
 
792
    except KeyError:
 
793
        try:
 
794
            gid = pwd.getpwnam("nogroup").pw_gid
 
795
        except KeyError:
 
796
            pass
 
797
    try:
 
798
        os.setuid(uid)
 
799
        os.setgid(gid)
 
800
    except OSError, error:
 
801
        if error[0] != errno.EPERM:
 
802
            raise error
 
803
    
 
804
    global service
 
805
    service = AvahiService(name = server_settings["servicename"],
 
806
                           type = "_mandos._tcp", );
 
807
    if server_settings["interface"]:
 
808
        service.interface = if_nametoindex\
 
809
                            (server_settings["interface"])
 
810
    
 
811
    global main_loop
 
812
    global bus
 
813
    global server
 
814
    # From the Avahi example code
 
815
    DBusGMainLoop(set_as_default=True )
 
816
    main_loop = gobject.MainLoop()
 
817
    bus = dbus.SystemBus()
 
818
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
 
819
                                           avahi.DBUS_PATH_SERVER),
 
820
                            avahi.DBUS_INTERFACE_SERVER)
 
821
    # End of Avahi example code
 
822
    
 
823
    def remove_from_clients(client):
 
824
        clients.remove(client)
 
825
        if not clients:
 
826
            logger.critical(u"No clients left, exiting")
 
827
            sys.exit()
 
828
    
 
829
    clients.update(Set(Client(name = section,
 
830
                              stop_hook = remove_from_clients,
 
831
                              config
 
832
                              = dict(client_config.items(section)))
 
833
                       for section in client_config.sections()))
 
834
    if not clients:
 
835
        logger.critical(u"No clients defined")
 
836
        sys.exit(1)
 
837
    
 
838
    if debug:
 
839
        # Redirect stdin so all checkers get /dev/null
 
840
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
841
        os.dup2(null, sys.stdin.fileno())
 
842
        if null > 2:
 
843
            os.close(null)
 
844
    else:
 
845
        # No console logging
 
846
        logger.removeHandler(console)
 
847
        # Close all input and output, do double fork, etc.
 
848
        daemon()
 
849
    
 
850
    try:
 
851
        pid = os.getpid()
 
852
        pidfile.write(str(pid) + "\n")
 
853
        pidfile.close()
 
854
        del pidfile
 
855
    except IOError, err:
 
856
        logger.error(u"Could not write to file %r with PID %d",
 
857
                     pidfilename, pid)
 
858
    except NameError:
 
859
        # "pidfile" was never created
 
860
        pass
 
861
    del pidfilename
 
862
    
 
863
    def cleanup():
 
864
        "Cleanup function; run on exit"
 
865
        global group
 
866
        # From the Avahi example code
 
867
        if not group is None:
 
868
            group.Free()
 
869
            group = None
 
870
        # End of Avahi example code
 
871
        
 
872
        while clients:
 
873
            client = clients.pop()
 
874
            client.stop_hook = None
 
875
            client.stop()
 
876
    
 
877
    atexit.register(cleanup)
 
878
    
 
879
    if not debug:
 
880
        signal.signal(signal.SIGINT, signal.SIG_IGN)
 
881
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
 
882
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
 
883
    
 
884
    for client in clients:
 
885
        client.start()
 
886
    
 
887
    tcp_server.enable()
 
888
    tcp_server.server_activate()
 
889
    
 
890
    # Find out what port we got
 
891
    service.port = tcp_server.socket.getsockname()[1]
 
892
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
 
893
                u" scope_id %d" % tcp_server.socket.getsockname())
 
894
    
 
895
    #service.interface = tcp_server.socket.getsockname()[3]
 
896
    
 
897
    try:
 
898
        # From the Avahi example code
 
899
        server.connect_to_signal("StateChanged", server_state_changed)
 
900
        try:
 
901
            server_state_changed(server.GetState())
 
902
        except dbus.exceptions.DBusException, error:
 
903
            logger.critical(u"DBusException: %s", error)
 
904
            sys.exit(1)
 
905
        # End of Avahi example code
 
906
        
 
907
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
908
                             lambda *args, **kwargs:
 
909
                             tcp_server.handle_request\
 
910
                             (*args[2:], **kwargs) or True)
 
911
        
 
912
        logger.debug(u"Starting main loop")
 
913
        main_loop_started = True
 
914
        main_loop.run()
 
915
    except AvahiError, error:
 
916
        logger.critical(u"AvahiError: %s" + unicode(error))
 
917
        sys.exit(1)
 
918
    except KeyboardInterrupt:
 
919
        if debug:
 
920
            print
 
921
 
 
922
if __name__ == '__main__':
201
923
    main()
202