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  • Committer: Teddy Hogeborn
  • Date: 2008-08-17 22:42:28 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080817224228-nhor2yuv230if01i
* Makefile (DOCBOOKTOMAN): Use the local manpages/docbook.xsl file, do
                           not rely on a stylesheet declaration.

* mandos.xml: Removed <?xml-stylesheet>.  New entity "&OVERVIEW;"
              refers to "overview.xml". Changed all single quotes to
              double quotes for consistency.
  (DESCRIPTION): Use the term "TLS" and not "GnuTLS" for the protocol.
                 Refer to the "OVERVIEW" section for reason for IPv6
                 link-local addresses.
  (PURPOSE): Shortened a lot.  Refer to "OVERVIEW" section for details.
  (OVERVIEW): New section.  Include &OVERVIEW; and add a paragraph
              about what the role of this program is.
  (SECURITY/CLIENTS): Refer to the "CHECKING" section for details on
                      checking.
  (SEE ALSO): Changed from an <itemizedlist> to a <variablelist>.
              Added a short text for each entry.  Removed reference to
              plugin-runner(8mandos).  Add reference to RFC 4291 and
              RFC 4346.

* overview.xml: New file, containing a single <para>.  The idea is to
                use this in all the man pages.

* plugins.d/password-request.c: Updated comments about spurious
                                warnings.

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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 <http://www.gnu.org/licenses/>.
 
28
# 
 
29
# Contact the authors at <mandos@fukt.bsnet.se>.
 
30
# 
 
31
 
 
32
from __future__ import division
2
33
 
3
34
import SocketServer
4
35
import socket
9
40
import gnutls.crypto
10
41
import gnutls.connection
11
42
import gnutls.errors
 
43
import gnutls.library.functions
 
44
import gnutls.library.constants
 
45
import gnutls.library.types
12
46
import ConfigParser
13
47
import sys
 
48
import re
 
49
import os
 
50
import signal
 
51
from sets import Set
 
52
import subprocess
 
53
import atexit
 
54
import stat
 
55
import logging
 
56
import logging.handlers
 
57
 
 
58
import dbus
 
59
import gobject
 
60
import avahi
 
61
from dbus.mainloop.glib import DBusGMainLoop
 
62
import ctypes
 
63
 
 
64
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
14
166
 
15
167
 
16
168
class Client(object):
17
 
    def __init__(self, name=None, options=None, dn=None,
18
 
                 password=None, passfile=None, fqdn=None,
19
 
                 timeout=None, interval=-1):
 
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."""
20
225
        self.name = name
21
 
        self.dn = dn
22
 
        if password:
23
 
            self.password = password
24
 
        elif passfile:
25
 
            self.password = open(passfile).readall()
 
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()
26
239
        else:
27
 
            print "No Password or Passfile in client config file"
28
 
            # raise RuntimeError XXX
29
 
            self.password = "gazonk"
30
 
        self.fqdn = fqdn
 
240
            raise TypeError(u"No secret or secfile for client %s"
 
241
                            % self.name)
 
242
        self.host = config.get("host", "")
31
243
        self.created = datetime.datetime.now()
32
 
        self.last_seen = None
33
 
        if timeout is None:
34
 
            timeout = options.timeout
35
 
        self.timeout = timeout
36
 
        if interval == -1:
37
 
            interval = options.interval
38
 
        self.interval = interval
39
 
        self.next_check = datetime.datetime.now()
40
 
 
41
 
 
42
 
class server_metaclass(type):
43
 
    "Common behavior for the UDP and TCP server classes"
44
 
    def __new__(cls, name, bases, attrs):
45
 
        attrs["address_family"] = socket.AF_INET6
46
 
        attrs["allow_reuse_address"] = True
47
 
        def server_bind(self):
48
 
            if self.options.interface:
49
 
                if not hasattr(socket, "SO_BINDTODEVICE"):
50
 
                    # From /usr/include/asm-i486/socket.h
51
 
                    socket.SO_BINDTODEVICE = 25
 
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
 
282
        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
 
294
        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.
 
322
        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())
52
331
                try:
53
 
                    self.socket.setsockopt(socket.SOL_SOCKET,
54
 
                                           socket.SO_BINDTODEVICE,
55
 
                                           self.options.interface)
56
 
                except socket.error, error:
57
 
                    if error[0] == errno.EPERM:
58
 
                        print "Warning: No permission to bind to interface", \
59
 
                              self.options.interface
60
 
                    else:
61
 
                        raise error
62
 
            return super(type(self), self).server_bind()
63
 
        attrs["server_bind"] = server_bind
64
 
        def init(self, *args, **kwargs):
65
 
            if "options" in kwargs:
66
 
                self.options = kwargs["options"]
67
 
                del kwargs["options"]
68
 
            if "clients" in kwargs:
69
 
                self.clients = kwargs["clients"]
70
 
                del kwargs["clients"]
71
 
            if "credentials" in kwargs:
72
 
                self.credentials = kwargs["credentials"]
73
 
                del kwargs["credentials"]
74
 
            return super(type(self), self).__init__(*args, **kwargs)
75
 
        attrs["__init__"] = init
76
 
        return type.__new__(cls, name, bases, attrs)
77
 
 
78
 
 
79
 
class udp_handler(SocketServer.DatagramRequestHandler, object):
80
 
    def handle(self):
81
 
        self.wfile.write("Polo")
82
 
        print "UDP request answered"
83
 
 
84
 
 
85
 
class IPv6_UDPServer(SocketServer.UDPServer, object):
86
 
    __metaclass__ = server_metaclass
87
 
    def verify_request(self, request, client_address):
88
 
        print "UDP request came"
89
 
        return request[0] == "Marco"
 
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
                self.checker = subprocess.Popen(command,
 
341
                                                close_fds=True,
 
342
                                                shell=True, cwd="/")
 
343
                self.checker_callback_tag = gobject.child_watch_add\
 
344
                                            (self.checker.pid,
 
345
                                             self.checker_callback)
 
346
            except subprocess.OSError, error:
 
347
                logger.error(u"Failed to start subprocess: %s",
 
348
                             error)
 
349
        # Re-run this periodically if run by gobject.timeout_add
 
350
        return True
 
351
    def stop_checker(self):
 
352
        """Force the checker process, if any, to stop."""
 
353
        if self.checker_callback_tag:
 
354
            gobject.source_remove(self.checker_callback_tag)
 
355
            self.checker_callback_tag = None
 
356
        if getattr(self, "checker", None) is None:
 
357
            return
 
358
        logger.debug(u"Stopping checker for %(name)s", vars(self))
 
359
        try:
 
360
            os.kill(self.checker.pid, signal.SIGTERM)
 
361
            #os.sleep(0.5)
 
362
            #if self.checker.poll() is None:
 
363
            #    os.kill(self.checker.pid, signal.SIGKILL)
 
364
        except OSError, error:
 
365
            if error.errno != errno.ESRCH: # No such process
 
366
                raise
 
367
        self.checker = None
 
368
    def still_valid(self):
 
369
        """Has the timeout not yet passed for this client?"""
 
370
        now = datetime.datetime.now()
 
371
        if self.last_checked_ok is None:
 
372
            return now < (self.created + self.timeout)
 
373
        else:
 
374
            return now < (self.last_checked_ok + self.timeout)
 
375
 
 
376
 
 
377
def peer_certificate(session):
 
378
    "Return the peer's OpenPGP certificate as a bytestring"
 
379
    # If not an OpenPGP certificate...
 
380
    if gnutls.library.functions.gnutls_certificate_type_get\
 
381
            (session._c_object) \
 
382
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
 
383
        # ...do the normal thing
 
384
        return session.peer_certificate
 
385
    list_size = ctypes.c_uint()
 
386
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
 
387
        (session._c_object, ctypes.byref(list_size))
 
388
    if list_size.value == 0:
 
389
        return None
 
390
    cert = cert_list[0]
 
391
    return ctypes.string_at(cert.data, cert.size)
 
392
 
 
393
 
 
394
def fingerprint(openpgp):
 
395
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
396
    # New GnuTLS "datum" with the OpenPGP public key
 
397
    datum = gnutls.library.types.gnutls_datum_t\
 
398
        (ctypes.cast(ctypes.c_char_p(openpgp),
 
399
                     ctypes.POINTER(ctypes.c_ubyte)),
 
400
         ctypes.c_uint(len(openpgp)))
 
401
    # New empty GnuTLS certificate
 
402
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
403
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
404
        (ctypes.byref(crt))
 
405
    # Import the OpenPGP public key into the certificate
 
406
    gnutls.library.functions.gnutls_openpgp_crt_import\
 
407
                    (crt, ctypes.byref(datum),
 
408
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
409
    # New buffer for the fingerprint
 
410
    buffer = ctypes.create_string_buffer(20)
 
411
    buffer_length = ctypes.c_size_t()
 
412
    # Get the fingerprint from the certificate into the buffer
 
413
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
 
414
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
 
415
    # Deinit the certificate
 
416
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
417
    # Convert the buffer to a Python bytestring
 
418
    fpr = ctypes.string_at(buffer, buffer_length.value)
 
419
    # Convert the bytestring to hexadecimal notation
 
420
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
 
421
    return hex_fpr
90
422
 
91
423
 
92
424
class tcp_handler(SocketServer.BaseRequestHandler, object):
 
425
    """A TCP request handler class.
 
426
    Instantiated by IPv6_TCPServer for each request to handle it.
 
427
    Note: This will run in its own forked process."""
 
428
    
93
429
    def handle(self):
94
 
        print "TCP request came"
95
 
        print "Request:", self.request
96
 
        print "Client Address:", self.client_address
97
 
        print "Server:", self.server
98
 
        session = gnutls.connection.ServerSession(self.request,
99
 
                                                  self.server.credentials)
100
 
        session.handshake()
101
 
        if session.peer_certificate:
102
 
            print "DN:", session.peer_certificate.subject
103
 
        try:
104
 
            session.verify_peer()
105
 
        except gnutls.errors.CertificateError, error:
106
 
            print "Verify failed", error
107
 
            session.bye()
108
 
            return
109
 
        try:
110
 
            session.send(dict((client.dn, client.password)
111
 
                              for client in self.server.clients)
112
 
                         [session.peer_certificate.subject])
113
 
        except KeyError:
114
 
            session.send("gazonk")
115
 
            # Log maybe? XXX
 
430
        logger.info(u"TCP connection from: %s",
 
431
                     unicode(self.client_address))
 
432
        session = gnutls.connection.ClientSession\
 
433
                  (self.request, gnutls.connection.X509Credentials())
 
434
        
 
435
        line = self.request.makefile().readline()
 
436
        logger.debug(u"Protocol version: %r", line)
 
437
        try:
 
438
            if int(line.strip().split()[0]) > 1:
 
439
                raise RuntimeError
 
440
        except (ValueError, IndexError, RuntimeError), error:
 
441
            logger.error(u"Unknown protocol version: %s", error)
 
442
            return
 
443
        
 
444
        # Note: gnutls.connection.X509Credentials is really a generic
 
445
        # GnuTLS certificate credentials object so long as no X.509
 
446
        # keys are added to it.  Therefore, we can use it here despite
 
447
        # using OpenPGP certificates.
 
448
        
 
449
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
 
450
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
 
451
        #                "+DHE-DSS"))
 
452
        priority = "NORMAL"             # Fallback default, since this
 
453
                                        # MUST be set.
 
454
        if self.server.settings["priority"]:
 
455
            priority = self.server.settings["priority"]
 
456
        gnutls.library.functions.gnutls_priority_set_direct\
 
457
            (session._c_object, priority, None);
 
458
        
 
459
        try:
 
460
            session.handshake()
 
461
        except gnutls.errors.GNUTLSError, error:
 
462
            logger.warning(u"Handshake failed: %s", error)
 
463
            # Do not run session.bye() here: the session is not
 
464
            # established.  Just abandon the request.
 
465
            return
 
466
        try:
 
467
            fpr = fingerprint(peer_certificate(session))
 
468
        except (TypeError, gnutls.errors.GNUTLSError), error:
 
469
            logger.warning(u"Bad certificate: %s", error)
 
470
            session.bye()
 
471
            return
 
472
        logger.debug(u"Fingerprint: %s", fpr)
 
473
        client = None
 
474
        for c in self.server.clients:
 
475
            if c.fingerprint == fpr:
 
476
                client = c
 
477
                break
 
478
        if not client:
 
479
            logger.warning(u"Client not found for fingerprint: %s",
 
480
                           fpr)
 
481
            session.bye()
 
482
            return
 
483
        # Have to check if client.still_valid(), since it is possible
 
484
        # that the client timed out while establishing the GnuTLS
 
485
        # session.
 
486
        if not client.still_valid():
 
487
            logger.warning(u"Client %(name)s is invalid",
 
488
                           vars(client))
 
489
            session.bye()
 
490
            return
 
491
        sent_size = 0
 
492
        while sent_size < len(client.secret):
 
493
            sent = session.send(client.secret[sent_size:])
 
494
            logger.debug(u"Sent: %d, remaining: %d",
 
495
                         sent, len(client.secret)
 
496
                         - (sent_size + sent))
 
497
            sent_size += sent
116
498
        session.bye()
117
499
 
118
500
 
119
501
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
120
 
    __metaclass__ = server_metaclass
121
 
    request_queue_size = 1024
122
 
 
123
 
 
124
 
in6addr_any = "::"
125
 
 
126
 
cred = None
 
502
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
 
503
    Attributes:
 
504
        settings:       Server settings
 
505
        clients:        Set() of Client objects
 
506
    """
 
507
    address_family = socket.AF_INET6
 
508
    def __init__(self, *args, **kwargs):
 
509
        if "settings" in kwargs:
 
510
            self.settings = kwargs["settings"]
 
511
            del kwargs["settings"]
 
512
        if "clients" in kwargs:
 
513
            self.clients = kwargs["clients"]
 
514
            del kwargs["clients"]
 
515
        return super(type(self), self).__init__(*args, **kwargs)
 
516
    def server_bind(self):
 
517
        """This overrides the normal server_bind() function
 
518
        to bind to an interface if one was specified, and also NOT to
 
519
        bind to an address or port if they were not specified."""
 
520
        if self.settings["interface"]:
 
521
            # 25 is from /usr/include/asm-i486/socket.h
 
522
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
523
            try:
 
524
                self.socket.setsockopt(socket.SOL_SOCKET,
 
525
                                       SO_BINDTODEVICE,
 
526
                                       self.settings["interface"])
 
527
            except socket.error, error:
 
528
                if error[0] == errno.EPERM:
 
529
                    logger.error(u"No permission to"
 
530
                                 u" bind to interface %s",
 
531
                                 self.settings["interface"])
 
532
                else:
 
533
                    raise error
 
534
        # Only bind(2) the socket if we really need to.
 
535
        if self.server_address[0] or self.server_address[1]:
 
536
            if not self.server_address[0]:
 
537
                in6addr_any = "::"
 
538
                self.server_address = (in6addr_any,
 
539
                                       self.server_address[1])
 
540
            elif not self.server_address[1]:
 
541
                self.server_address = (self.server_address[0],
 
542
                                       0)
 
543
#                 if self.settings["interface"]:
 
544
#                     self.server_address = (self.server_address[0],
 
545
#                                            0, # port
 
546
#                                            0, # flowinfo
 
547
#                                            if_nametoindex
 
548
#                                            (self.settings
 
549
#                                             ["interface"]))
 
550
            return super(type(self), self).server_bind()
 
551
 
127
552
 
128
553
def string_to_delta(interval):
129
554
    """Parse a string and return a datetime.timedelta
158
583
        raise ValueError
159
584
    return delta
160
585
 
 
586
 
 
587
def server_state_changed(state):
 
588
    """Derived from the Avahi example code"""
 
589
    if state == avahi.SERVER_COLLISION:
 
590
        logger.error(u"Server name collision")
 
591
        service.remove()
 
592
    elif state == avahi.SERVER_RUNNING:
 
593
        service.add()
 
594
 
 
595
 
 
596
def entry_group_state_changed(state, error):
 
597
    """Derived from the Avahi example code"""
 
598
    logger.debug(u"state change: %i", state)
 
599
    
 
600
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
 
601
        logger.debug(u"Service established.")
 
602
    elif state == avahi.ENTRY_GROUP_COLLISION:
 
603
        logger.warning(u"Service name collision.")
 
604
        service.rename()
 
605
    elif state == avahi.ENTRY_GROUP_FAILURE:
 
606
        logger.critical(u"Error in group state changed %s",
 
607
                        unicode(error))
 
608
        raise AvahiGroupError("State changed: %s", str(error))
 
609
 
 
610
def if_nametoindex(interface):
 
611
    """Call the C function if_nametoindex(), or equivalent"""
 
612
    global if_nametoindex
 
613
    try:
 
614
        if "ctypes.util" not in sys.modules:
 
615
            import ctypes.util
 
616
        if_nametoindex = ctypes.cdll.LoadLibrary\
 
617
            (ctypes.util.find_library("c")).if_nametoindex
 
618
    except (OSError, AttributeError):
 
619
        if "struct" not in sys.modules:
 
620
            import struct
 
621
        if "fcntl" not in sys.modules:
 
622
            import fcntl
 
623
        def if_nametoindex(interface):
 
624
            "Get an interface index the hard way, i.e. using fcntl()"
 
625
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
 
626
            s = socket.socket()
 
627
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
628
                                struct.pack("16s16x", interface))
 
629
            s.close()
 
630
            interface_index = struct.unpack("I", ifreq[16:20])[0]
 
631
            return interface_index
 
632
    return if_nametoindex(interface)
 
633
 
 
634
 
 
635
def daemon(nochdir = False, noclose = False):
 
636
    """See daemon(3).  Standard BSD Unix function.
 
637
    This should really exist as os.daemon, but it doesn't (yet)."""
 
638
    if os.fork():
 
639
        sys.exit()
 
640
    os.setsid()
 
641
    if not nochdir:
 
642
        os.chdir("/")
 
643
    if os.fork():
 
644
        sys.exit()
 
645
    if not noclose:
 
646
        # Close all standard open file descriptors
 
647
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
648
        if not stat.S_ISCHR(os.fstat(null).st_mode):
 
649
            raise OSError(errno.ENODEV,
 
650
                          "/dev/null not a character device")
 
651
        os.dup2(null, sys.stdin.fileno())
 
652
        os.dup2(null, sys.stdout.fileno())
 
653
        os.dup2(null, sys.stderr.fileno())
 
654
        if null > 2:
 
655
            os.close(null)
 
656
 
 
657
 
161
658
def main():
162
 
    parser = OptionParser()
 
659
    global main_loop_started
 
660
    main_loop_started = False
 
661
    
 
662
    parser = OptionParser(version = "%%prog %s" % version)
163
663
    parser.add_option("-i", "--interface", type="string",
164
 
                      default="eth0", metavar="IF",
165
 
                      help="Interface to bind to")
166
 
    parser.add_option("--cert", type="string", default="cert.pem",
167
 
                      metavar="FILE",
168
 
                      help="Public key certificate to use")
169
 
    parser.add_option("--key", type="string", default="key.pem",
170
 
                      metavar="FILE",
171
 
                      help="Private key to use")
172
 
    parser.add_option("--ca", type="string", default="ca.pem",
173
 
                      metavar="FILE",
174
 
                      help="Certificate Authority certificate to use")
175
 
    parser.add_option("--crl", type="string", default="crl.pem",
176
 
                      metavar="FILE",
177
 
                      help="Certificate Revokation List to use")
178
 
    parser.add_option("-p", "--port", type="int", default=49001,
 
664
                      metavar="IF", help="Bind to interface IF")
 
665
    parser.add_option("-a", "--address", type="string",
 
666
                      help="Address to listen for requests on")
 
667
    parser.add_option("-p", "--port", type="int",
179
668
                      help="Port number to receive requests on")
180
 
    parser.add_option("--dh", type="int", metavar="BITS",
181
 
                      help="DH group to use")
182
 
    parser.add_option("-t", "--timeout", type="string", # Parsed later
183
 
                      default="15m",
184
 
                      help="Amount of downtime allowed for clients")
185
 
    parser.add_option("--interval", type="string", # Parsed later
186
 
                      default="5m",
187
 
                      help="How often to check that a client is up")
188
669
    parser.add_option("--check", action="store_true", default=False,
189
670
                      help="Run self-test")
 
671
    parser.add_option("--debug", action="store_true",
 
672
                      help="Debug mode; run in foreground and log to"
 
673
                      " terminal")
 
674
    parser.add_option("--priority", type="string", help="GnuTLS"
 
675
                      " priority string (see GnuTLS documentation)")
 
676
    parser.add_option("--servicename", type="string", metavar="NAME",
 
677
                      help="Zeroconf service name")
 
678
    parser.add_option("--configdir", type="string",
 
679
                      default="/etc/mandos", metavar="DIR",
 
680
                      help="Directory to search for configuration"
 
681
                      " files")
190
682
    (options, args) = parser.parse_args()
191
 
 
 
683
    
192
684
    if options.check:
193
685
        import doctest
194
686
        doctest.testmod()
195
687
        sys.exit()
196
688
    
197
 
    # Parse the time arguments
198
 
    try:
199
 
        options.timeout = string_to_delta(options.timeout)
200
 
    except ValueError:
201
 
        parser.error("option --timeout: Unparseable time")
202
 
    
203
 
    try:
204
 
        options.interval = string_to_delta(options.interval)
205
 
    except ValueError:
206
 
        parser.error("option --interval: Unparseable time")
207
 
    
208
 
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
209
 
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
210
 
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
211
 
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
212
 
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
213
 
    
214
 
    # Parse config file
215
 
    defaults = {}
216
 
    client_config_object = ConfigParser.SafeConfigParser(defaults)
217
 
    client_config_object.read("mandos-clients.conf")
218
 
    clients = [Client(name=section, options=options,
219
 
                      **(dict(client_config_object.items(section))))
220
 
               for section in client_config_object.sections()]
221
 
    
222
 
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
223
 
                                udp_handler,
224
 
                                options=options)
225
 
    
226
 
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
 
689
    # Default values for config file for server-global settings
 
690
    server_defaults = { "interface": "",
 
691
                        "address": "",
 
692
                        "port": "",
 
693
                        "debug": "False",
 
694
                        "priority":
 
695
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
 
696
                        "servicename": "Mandos",
 
697
                        }
 
698
    
 
699
    # Parse config file for server-global settings
 
700
    server_config = ConfigParser.SafeConfigParser(server_defaults)
 
701
    del server_defaults
 
702
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
703
    server_section = "server"
 
704
    # Convert the SafeConfigParser object to a dict
 
705
    server_settings = dict(server_config.items(server_section))
 
706
    # Use getboolean on the boolean config option
 
707
    server_settings["debug"] = server_config.getboolean\
 
708
                               (server_section, "debug")
 
709
    del server_config
 
710
    
 
711
    # Override the settings from the config file with command line
 
712
    # options, if set.
 
713
    for option in ("interface", "address", "port", "debug",
 
714
                   "priority", "servicename", "configdir"):
 
715
        value = getattr(options, option)
 
716
        if value is not None:
 
717
            server_settings[option] = value
 
718
    del options
 
719
    # Now we have our good server settings in "server_settings"
 
720
    
 
721
    debug = server_settings["debug"]
 
722
    
 
723
    if not debug:
 
724
        syslogger.setLevel(logging.WARNING)
 
725
        console.setLevel(logging.WARNING)
 
726
    
 
727
    if server_settings["servicename"] != "Mandos":
 
728
        syslogger.setFormatter(logging.Formatter\
 
729
                               ('Mandos (%s): %%(levelname)s:'
 
730
                                ' %%(message)s'
 
731
                                % server_settings["servicename"]))
 
732
    
 
733
    # Parse config file with clients
 
734
    client_defaults = { "timeout": "1h",
 
735
                        "interval": "5m",
 
736
                        "checker": "fping -q -- %%(host)s",
 
737
                        }
 
738
    client_config = ConfigParser.SafeConfigParser(client_defaults)
 
739
    client_config.read(os.path.join(server_settings["configdir"],
 
740
                                    "clients.conf"))
 
741
    
 
742
    global service
 
743
    service = AvahiService(name = server_settings["servicename"],
 
744
                           type = "_mandos._tcp", );
 
745
    if server_settings["interface"]:
 
746
        service.interface = if_nametoindex(server_settings["interface"])
 
747
    
 
748
    global main_loop
 
749
    global bus
 
750
    global server
 
751
    # From the Avahi example code
 
752
    DBusGMainLoop(set_as_default=True )
 
753
    main_loop = gobject.MainLoop()
 
754
    bus = dbus.SystemBus()
 
755
    server = dbus.Interface(
 
756
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
 
757
            avahi.DBUS_INTERFACE_SERVER )
 
758
    # End of Avahi example code
 
759
    
 
760
    clients = Set()
 
761
    def remove_from_clients(client):
 
762
        clients.remove(client)
 
763
        if not clients:
 
764
            logger.critical(u"No clients left, exiting")
 
765
            sys.exit()
 
766
    
 
767
    clients.update(Set(Client(name = section,
 
768
                              stop_hook = remove_from_clients,
 
769
                              config
 
770
                              = dict(client_config.items(section)))
 
771
                       for section in client_config.sections()))
 
772
    if not clients:
 
773
        logger.critical(u"No clients defined")
 
774
        sys.exit(1)
 
775
    
 
776
    if not debug:
 
777
        logger.removeHandler(console)
 
778
        daemon()
 
779
    
 
780
    pidfilename = "/var/run/mandos/mandos.pid"
 
781
    pid = os.getpid()
 
782
    try:
 
783
        pidfile = open(pidfilename, "w")
 
784
        pidfile.write(str(pid) + "\n")
 
785
        pidfile.close()
 
786
        del pidfile
 
787
    except IOError, err:
 
788
        logger.error(u"Could not write %s file with PID %d",
 
789
                     pidfilename, os.getpid())
 
790
    
 
791
    def cleanup():
 
792
        "Cleanup function; run on exit"
 
793
        global group
 
794
        # From the Avahi example code
 
795
        if not group is None:
 
796
            group.Free()
 
797
            group = None
 
798
        # End of Avahi example code
 
799
        
 
800
        while clients:
 
801
            client = clients.pop()
 
802
            client.stop_hook = None
 
803
            client.stop()
 
804
    
 
805
    atexit.register(cleanup)
 
806
    
 
807
    if not debug:
 
808
        signal.signal(signal.SIGINT, signal.SIG_IGN)
 
809
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
 
810
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
 
811
    
 
812
    for client in clients:
 
813
        client.start()
 
814
    
 
815
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
816
                                 server_settings["port"]),
227
817
                                tcp_handler,
228
 
                                options=options,
229
 
                                clients=clients,
230
 
                                credentials=cred)
231
 
    
232
 
    while True:
233
 
        in_, out, err = select.select((udp_server,
234
 
                                       tcp_server), (), ())
235
 
        for server in in_:
236
 
            server.handle_request()
237
 
 
238
 
 
239
 
if __name__ == "__main__":
 
818
                                settings=server_settings,
 
819
                                clients=clients)
 
820
    # Find out what port we got
 
821
    service.port = tcp_server.socket.getsockname()[1]
 
822
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
 
823
                u" scope_id %d" % tcp_server.socket.getsockname())
 
824
    
 
825
    #service.interface = tcp_server.socket.getsockname()[3]
 
826
    
 
827
    try:
 
828
        # From the Avahi example code
 
829
        server.connect_to_signal("StateChanged", server_state_changed)
 
830
        try:
 
831
            server_state_changed(server.GetState())
 
832
        except dbus.exceptions.DBusException, error:
 
833
            logger.critical(u"DBusException: %s", error)
 
834
            sys.exit(1)
 
835
        # End of Avahi example code
 
836
        
 
837
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
838
                             lambda *args, **kwargs:
 
839
                             tcp_server.handle_request\
 
840
                             (*args[2:], **kwargs) or True)
 
841
        
 
842
        logger.debug(u"Starting main loop")
 
843
        main_loop_started = True
 
844
        main_loop.run()
 
845
    except AvahiError, error:
 
846
        logger.critical(u"AvahiError: %s" + unicode(error))
 
847
        sys.exit(1)
 
848
    except KeyboardInterrupt:
 
849
        if debug:
 
850
            print
 
851
 
 
852
if __name__ == '__main__':
240
853
    main()
241