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