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  • Committer: Teddy Hogeborn
  • Date: 2008-07-22 06:23:29 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080722062329-jaex5y5mslf6sqjx
* mandos-clients.conf ([DEFAULT]): New section.

* plugins.d/mandosclient.c (start_mandos_communication): Only print if
                                                         debugging.
                                                         Print server
                                                         name.
                                                         Bug fix: Loop
                                                         until suc-
                                                         cess.

* server.py (serverName): Set via option, not globally.
  (Client.__init__): Removed argument "options".  Require "timeout"
                     and "interval" arguments.
  (tcp_handler.handle): Set "priority" from self.server.options.
  (main): Removed "--timeout" and "--interval" options.  New options
          "--priority" and "--servicename".  Add defaults for
          "timeout" and "interval".  Set "serviceName" from options.
          Do not pass "options" to "Client()".

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server.py
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
# following functions: "add_service", "remove_service",
 
10
# "server_state_changed", "entry_group_state_changed", and some lines
 
11
# in "main".
 
12
# 
 
13
# Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
 
14
# 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 <https://www.fukt.bsnet.se/~belorn/> and
 
30
# <https://www.fukt.bsnet.se/~teddy/>.
 
31
# 
2
32
 
3
33
from __future__ import division
4
34
 
11
41
import gnutls.crypto
12
42
import gnutls.connection
13
43
import gnutls.errors
 
44
import gnutls.library.functions
 
45
import gnutls.library.constants
 
46
import gnutls.library.types
14
47
import ConfigParser
15
48
import sys
16
49
import re
18
51
import signal
19
52
from sets import Set
20
53
import subprocess
 
54
import atexit
 
55
import stat
 
56
import logging
 
57
import logging.handlers
 
58
 
 
59
import dbus
 
60
import gobject
 
61
import avahi
 
62
from dbus.mainloop.glib import DBusGMainLoop
 
63
import ctypes
 
64
 
 
65
# Brief description of the operation of this program:
 
66
# 
 
67
# This server announces itself as a Zeroconf service.  Connecting
 
68
# clients use the TLS protocol, with the unusual quirk that this
 
69
# server program acts as a TLS "client" while the connecting clients
 
70
# acts as a TLS "server".  The clients (acting as a TLS "server") must
 
71
# supply an OpenPGP certificate, and the fingerprint of this
 
72
# certificate is used by this server to look up (in a list read from a
 
73
# file at start time) which binary blob to give the client.  No other
 
74
# authentication or authorization is done by this server.
 
75
 
 
76
 
 
77
logger = logging.Logger('mandos')
 
78
syslogger = logging.handlers.SysLogHandler\
 
79
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON)
 
80
syslogger.setFormatter(logging.Formatter\
 
81
                        ('%(levelname)s: %(message)s'))
 
82
logger.addHandler(syslogger)
 
83
del syslogger
 
84
 
 
85
# This variable is used to optionally bind to a specified interface.
 
86
# It is a global variable to fit in with the other variables from the
 
87
# Avahi example code.
 
88
serviceInterface = avahi.IF_UNSPEC
 
89
# From the Avahi example code:
 
90
serviceName = None
 
91
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
 
92
servicePort = None                      # Not known at startup
 
93
serviceTXT = []                         # TXT record for the service
 
94
domain = ""                  # Domain to publish on, default to .local
 
95
host = ""          # Host to publish records for, default to localhost
 
96
group = None #our entry group
 
97
rename_count = 12       # Counter so we only rename after collisions a
 
98
                        # sensible number of times
 
99
# End of Avahi example code
 
100
 
21
101
 
22
102
class Client(object):
23
 
    def __init__(self, name=None, options=None, dn=None,
24
 
                 password=None, passfile=None, fqdn=None,
25
 
                 timeout=None, interval=-1):
 
103
    """A representation of a client host served by this server.
 
104
    Attributes:
 
105
    name:      string; from the config file, used in log messages
 
106
    fingerprint: string (40 or 32 hexadecimal digits); used to
 
107
                 uniquely identify the client
 
108
    secret:    bytestring; sent verbatim (over TLS) to client
 
109
    fqdn:      string (FQDN); available for use by the checker command
 
110
    created:   datetime.datetime()
 
111
    last_seen: datetime.datetime() or None if not yet seen
 
112
    timeout:   datetime.timedelta(); How long from last_seen until
 
113
                                     this client is invalid
 
114
    interval:  datetime.timedelta(); How often to start a new checker
 
115
    stop_hook: If set, called by stop() as stop_hook(self)
 
116
    checker:   subprocess.Popen(); a running checker process used
 
117
                                   to see if the client lives.
 
118
                                   Is None if no process is running.
 
119
    checker_initiator_tag: a gobject event source tag, or None
 
120
    stop_initiator_tag:    - '' -
 
121
    checker_callback_tag:  - '' -
 
122
    checker_command: string; External command which is run to check if
 
123
                     client lives.  %()s expansions are done at
 
124
                     runtime with vars(self) as dict, so that for
 
125
                     instance %(name)s can be used in the command.
 
126
    Private attibutes:
 
127
    _timeout: Real variable for 'timeout'
 
128
    _interval: Real variable for 'interval'
 
129
    _timeout_milliseconds: Used by gobject.timeout_add()
 
130
    _interval_milliseconds: - '' -
 
131
    """
 
132
    def _set_timeout(self, timeout):
 
133
        "Setter function for 'timeout' attribute"
 
134
        self._timeout = timeout
 
135
        self._timeout_milliseconds = ((self.timeout.days
 
136
                                       * 24 * 60 * 60 * 1000)
 
137
                                      + (self.timeout.seconds * 1000)
 
138
                                      + (self.timeout.microseconds
 
139
                                         // 1000))
 
140
    timeout = property(lambda self: self._timeout,
 
141
                       _set_timeout)
 
142
    del _set_timeout
 
143
    def _set_interval(self, interval):
 
144
        "Setter function for 'interval' attribute"
 
145
        self._interval = interval
 
146
        self._interval_milliseconds = ((self.interval.days
 
147
                                        * 24 * 60 * 60 * 1000)
 
148
                                       + (self.interval.seconds
 
149
                                          * 1000)
 
150
                                       + (self.interval.microseconds
 
151
                                          // 1000))
 
152
    interval = property(lambda self: self._interval,
 
153
                        _set_interval)
 
154
    del _set_interval
 
155
    def __init__(self, name=None, stop_hook=None, fingerprint=None,
 
156
                 secret=None, secfile=None, fqdn=None, timeout=None,
 
157
                 interval=-1, checker=None):
 
158
        """Note: the 'checker' argument sets the 'checker_command'
 
159
        attribute and not the 'checker' attribute.."""
26
160
        self.name = name
27
 
        self.dn = dn
28
 
        if password:
29
 
            self.password = password
30
 
        elif passfile:
31
 
            self.password = open(passfile).readall()
 
161
        logger.debug(u"Creating client %r", self.name)
 
162
        # Uppercase and remove spaces from fingerprint
 
163
        # for later comparison purposes with return value of
 
164
        # the fingerprint() function
 
165
        self.fingerprint = fingerprint.upper().replace(u" ", u"")
 
166
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
 
167
        if secret:
 
168
            self.secret = secret.decode(u"base64")
 
169
        elif secfile:
 
170
            sf = open(secfile)
 
171
            self.secret = sf.read()
 
172
            sf.close()
32
173
        else:
33
 
            print "No Password or Passfile in client config file"
34
 
            # raise RuntimeError XXX
35
 
            self.password = "gazonk"
 
174
            raise RuntimeError(u"No secret or secfile for client %s"
 
175
                               % self.name)
36
176
        self.fqdn = fqdn                # string
37
177
        self.created = datetime.datetime.now()
38
 
        self.last_seen = None           # datetime.datetime()
39
 
        if timeout is None:
40
 
            timeout = options.timeout
41
 
        self.timeout = timeout          # datetime.timedelta()
42
 
        if interval == -1:
43
 
            interval = options.interval
 
178
        self.last_seen = None
 
179
        self.timeout = string_to_delta(timeout)
 
180
        self.interval = string_to_delta(interval)
 
181
        self.stop_hook = stop_hook
 
182
        self.checker = None
 
183
        self.checker_initiator_tag = None
 
184
        self.stop_initiator_tag = None
 
185
        self.checker_callback_tag = None
 
186
        self.check_command = checker
 
187
    def start(self):
 
188
        """Start this client's checker and timeout hooks"""
 
189
        # Schedule a new checker to be started an 'interval' from now,
 
190
        # and every interval from then on.
 
191
        self.checker_initiator_tag = gobject.timeout_add\
 
192
                                     (self._interval_milliseconds,
 
193
                                      self.start_checker)
 
194
        # Also start a new checker *right now*.
 
195
        self.start_checker()
 
196
        # Schedule a stop() when 'timeout' has passed
 
197
        self.stop_initiator_tag = gobject.timeout_add\
 
198
                                  (self._timeout_milliseconds,
 
199
                                   self.stop)
 
200
    def stop(self):
 
201
        """Stop this client.
 
202
        The possibility that this client might be restarted is left
 
203
        open, but not currently used."""
 
204
        # If this client doesn't have a secret, it is already stopped.
 
205
        if self.secret:
 
206
            logger.debug(u"Stopping client %s", self.name)
 
207
            self.secret = None
44
208
        else:
45
 
            interval = string_to_delta(interval)
46
 
        self.interval = interval        # datetime.timedelta()
47
 
        self.next_check = datetime.datetime.now() # datetime.datetime()
48
 
        # Note: next_check may be in the past if checker is not None
49
 
        self.checker = None             # or a subprocess.Popen()
50
 
    def check_action(self):
51
 
        """The checker said something and might have completed.
52
 
        Check if is has, and take appropriate actions."""
53
 
        if self.checker.poll() is None:
54
 
            # False alarm, no result yet
55
 
            #self.checker.read()
56
 
            #print "Checker for %(name)s said nothing?" % vars(self)
57
 
            return
 
209
            return False
 
210
        if hasattr(self, "stop_initiator_tag") \
 
211
               and self.stop_initiator_tag:
 
212
            gobject.source_remove(self.stop_initiator_tag)
 
213
            self.stop_initiator_tag = None
 
214
        if hasattr(self, "checker_initiator_tag") \
 
215
               and self.checker_initiator_tag:
 
216
            gobject.source_remove(self.checker_initiator_tag)
 
217
            self.checker_initiator_tag = None
 
218
        self.stop_checker()
 
219
        if self.stop_hook:
 
220
            self.stop_hook(self)
 
221
        # Do not run this again if called by a gobject.timeout_add
 
222
        return False
 
223
    def __del__(self):
 
224
        self.stop_hook = None
 
225
        self.stop()
 
226
    def checker_callback(self, pid, condition):
 
227
        """The checker has completed, so take appropriate actions."""
58
228
        now = datetime.datetime.now()
59
 
        if self.checker.returncode == 0:
60
 
            print "Checker for %(name)s succeeded" % vars(self)
 
229
        self.checker_callback_tag = None
 
230
        self.checker = None
 
231
        if os.WIFEXITED(condition) \
 
232
               and (os.WEXITSTATUS(condition) == 0):
 
233
            logger.debug(u"Checker for %(name)s succeeded",
 
234
                         vars(self))
61
235
            self.last_seen = now
 
236
            gobject.source_remove(self.stop_initiator_tag)
 
237
            self.stop_initiator_tag = gobject.timeout_add\
 
238
                                      (self._timeout_milliseconds,
 
239
                                       self.stop)
 
240
        elif not os.WIFEXITED(condition):
 
241
            logger.warning(u"Checker for %(name)s crashed?",
 
242
                           vars(self))
62
243
        else:
63
 
            print "Checker for %(name)s failed" % vars(self)
64
 
        while self.next_check <= now:
65
 
            self.next_check += self.interval
66
 
        self.checker = None
67
 
    handle_request = check_action
 
244
            logger.debug(u"Checker for %(name)s failed",
 
245
                         vars(self))
68
246
    def start_checker(self):
69
 
        self.stop_checker()
70
 
        try:
71
 
            self.checker = subprocess.Popen("sleep 10; fping -q -- %s"
72
 
                                            % re.escape(self.fqdn),
73
 
                                            stdout=subprocess.PIPE,
74
 
                                            close_fds=True,
75
 
                                            shell=True, cwd="/")
76
 
        except subprocess.OSError, e:
77
 
            print "Failed to start subprocess:", e
 
247
        """Start a new checker subprocess if one is not running.
 
248
        If a checker already exists, leave it running and do
 
249
        nothing."""
 
250
        # The reason for not killing a running checker is that if we
 
251
        # did that, then if a checker (for some reason) started
 
252
        # running slowly and taking more than 'interval' time, the
 
253
        # client would inevitably timeout, since no checker would get
 
254
        # a chance to run to completion.  If we instead leave running
 
255
        # checkers alone, the checker would have to take more time
 
256
        # than 'timeout' for the client to be declared invalid, which
 
257
        # is as it should be.
 
258
        if self.checker is None:
 
259
            try:
 
260
                command = self.check_command % self.fqdn
 
261
            except TypeError:
 
262
                escaped_attrs = dict((key, re.escape(str(val)))
 
263
                                     for key, val in
 
264
                                     vars(self).iteritems())
 
265
                try:
 
266
                    command = self.check_command % escaped_attrs
 
267
                except TypeError, error:
 
268
                    logger.critical(u'Could not format string "%s":'
 
269
                                    u' %s', self.check_command, error)
 
270
                    return True # Try again later
 
271
            try:
 
272
                logger.debug(u"Starting checker %r for %s",
 
273
                             command, self.name)
 
274
                self.checker = subprocess.\
 
275
                               Popen(command,
 
276
                                     close_fds=True, shell=True,
 
277
                                     cwd="/")
 
278
                self.checker_callback_tag = gobject.child_watch_add\
 
279
                                            (self.checker.pid,
 
280
                                             self.checker_callback)
 
281
            except subprocess.OSError, error:
 
282
                logger.error(u"Failed to start subprocess: %s",
 
283
                             error)
 
284
        # Re-run this periodically if run by gobject.timeout_add
 
285
        return True
78
286
    def stop_checker(self):
79
 
        if self.checker is None:
 
287
        """Force the checker process, if any, to stop."""
 
288
        if self.checker_callback_tag:
 
289
            gobject.source_remove(self.checker_callback_tag)
 
290
            self.checker_callback_tag = None
 
291
        if not hasattr(self, "checker") or self.checker is None:
80
292
            return
81
 
        os.kill(self.checker.pid, signal.SIGTERM)
82
 
        if self.checker.poll() is None:
83
 
            os.kill(self.checker.pid, signal.SIGKILL)
 
293
        logger.debug("Stopping checker for %(name)s", vars(self))
 
294
        try:
 
295
            os.kill(self.checker.pid, signal.SIGTERM)
 
296
            #os.sleep(0.5)
 
297
            #if self.checker.poll() is None:
 
298
            #    os.kill(self.checker.pid, signal.SIGKILL)
 
299
        except OSError, error:
 
300
            if error.errno != errno.ESRCH:
 
301
                raise
84
302
        self.checker = None
85
 
    __del__ = stop_checker
86
 
    def fileno(self):
87
 
        if self.checker is None:
88
 
            return None
89
 
        return self.checker.stdout.fileno()
90
 
    def next_stop(self):
91
 
        """The time when something must be done about this client
92
 
        May be in the past."""
93
 
        if self.last_seen is None:
94
 
            # This client has never been seen
95
 
            next_timeout = self.created + self.timeout
96
 
        else:
97
 
            next_timeout = self.last_seen + self.timeout
98
 
        if self.checker is None:
99
 
            return min(next_timeout, self.next_check)
100
 
        else:
101
 
            return next_timeout
102
303
    def still_valid(self, now=None):
103
 
        """Has this client's timeout not passed?"""
 
304
        """Has the timeout not yet passed for this client?"""
104
305
        if now is None:
105
306
            now = datetime.datetime.now()
106
307
        if self.last_seen is None:
107
308
            return now < (self.created + self.timeout)
108
309
        else:
109
310
            return now < (self.last_seen + self.timeout)
110
 
    def it_is_time_to_check(self, now=None):
111
 
        if now is None:
112
 
            now = datetime.datetime.now()
113
 
        return self.next_check <= now
114
 
 
115
 
 
116
 
class server_metaclass(type):
117
 
    "Common behavior for the UDP and TCP server classes"
118
 
    def __new__(cls, name, bases, attrs):
119
 
        attrs["address_family"] = socket.AF_INET6
120
 
        attrs["allow_reuse_address"] = True
121
 
        def server_bind(self):
122
 
            if self.options.interface:
123
 
                if not hasattr(socket, "SO_BINDTODEVICE"):
124
 
                    # From /usr/include/asm-i486/socket.h
125
 
                    socket.SO_BINDTODEVICE = 25
126
 
                try:
127
 
                    self.socket.setsockopt(socket.SOL_SOCKET,
128
 
                                           socket.SO_BINDTODEVICE,
129
 
                                           self.options.interface)
130
 
                except socket.error, error:
131
 
                    if error[0] == errno.EPERM:
132
 
                        print "Warning: No permission to bind to interface", \
133
 
                              self.options.interface
134
 
                    else:
135
 
                        raise error
136
 
            return super(type(self), self).server_bind()
137
 
        attrs["server_bind"] = server_bind
138
 
        def init(self, *args, **kwargs):
139
 
            if "options" in kwargs:
140
 
                self.options = kwargs["options"]
141
 
                del kwargs["options"]
142
 
            if "clients" in kwargs:
143
 
                self.clients = kwargs["clients"]
144
 
                del kwargs["clients"]
145
 
            if "credentials" in kwargs:
146
 
                self.credentials = kwargs["credentials"]
147
 
                del kwargs["credentials"]
148
 
            return super(type(self), self).__init__(*args, **kwargs)
149
 
        attrs["__init__"] = init
150
 
        return type.__new__(cls, name, bases, attrs)
151
 
 
152
 
 
153
 
class udp_handler(SocketServer.DatagramRequestHandler, object):
154
 
    def handle(self):
155
 
        self.wfile.write("Polo")
156
 
        print "UDP request answered"
157
 
 
158
 
 
159
 
class IPv6_UDPServer(SocketServer.UDPServer, object):
160
 
    __metaclass__ = server_metaclass
161
 
    def verify_request(self, request, client_address):
162
 
        print "UDP request came"
163
 
        return request[0] == "Marco"
 
311
 
 
312
 
 
313
def peer_certificate(session):
 
314
    "Return the peer's OpenPGP certificate as a bytestring"
 
315
    # If not an OpenPGP certificate...
 
316
    if gnutls.library.functions.gnutls_certificate_type_get\
 
317
            (session._c_object) \
 
318
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
 
319
        # ...do the normal thing
 
320
        return session.peer_certificate
 
321
    list_size = ctypes.c_uint()
 
322
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
 
323
        (session._c_object, ctypes.byref(list_size))
 
324
    if list_size.value == 0:
 
325
        return None
 
326
    cert = cert_list[0]
 
327
    return ctypes.string_at(cert.data, cert.size)
 
328
 
 
329
 
 
330
def fingerprint(openpgp):
 
331
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
332
    # New empty GnuTLS certificate
 
333
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
334
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
335
        (ctypes.byref(crt))
 
336
    # New GnuTLS "datum" with the OpenPGP public key
 
337
    datum = gnutls.library.types.gnutls_datum_t\
 
338
        (ctypes.cast(ctypes.c_char_p(openpgp),
 
339
                     ctypes.POINTER(ctypes.c_ubyte)),
 
340
         ctypes.c_uint(len(openpgp)))
 
341
    # Import the OpenPGP public key into the certificate
 
342
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
 
343
        (crt,
 
344
         ctypes.byref(datum),
 
345
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
346
    # New buffer for the fingerprint
 
347
    buffer = ctypes.create_string_buffer(20)
 
348
    buffer_length = ctypes.c_size_t()
 
349
    # Get the fingerprint from the certificate into the buffer
 
350
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
 
351
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
 
352
    # Deinit the certificate
 
353
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
354
    # Convert the buffer to a Python bytestring
 
355
    fpr = ctypes.string_at(buffer, buffer_length.value)
 
356
    # Convert the bytestring to hexadecimal notation
 
357
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
 
358
    return hex_fpr
164
359
 
165
360
 
166
361
class tcp_handler(SocketServer.BaseRequestHandler, object):
 
362
    """A TCP request handler class.
 
363
    Instantiated by IPv6_TCPServer for each request to handle it.
 
364
    Note: This will run in its own forked process."""
 
365
    
167
366
    def handle(self):
168
 
        print "TCP request came"
169
 
        print "Request:", self.request
170
 
        print "Client Address:", self.client_address
171
 
        print "Server:", self.server
172
 
        session = gnutls.connection.ServerSession(self.request,
173
 
                                                  self.server.credentials)
174
 
        session.handshake()
175
 
        if session.peer_certificate:
176
 
            print "DN:", session.peer_certificate.subject
177
 
        try:
178
 
            session.verify_peer()
179
 
        except gnutls.errors.CertificateError, error:
180
 
            print "Verify failed", error
181
 
            session.bye()
182
 
            return
183
 
        try:
184
 
            session.send([client.password
185
 
                          for client in self.server.clients
186
 
                          if (client.dn ==
187
 
                              session.peer_certificate.subject)][0])
188
 
        except IndexError:
189
 
            session.send("gazonk")
190
 
            # Log maybe? XXX
 
367
        logger.debug(u"TCP connection from: %s",
 
368
                     unicode(self.client_address))
 
369
        session = gnutls.connection.ClientSession(self.request,
 
370
                                                  gnutls.connection.\
 
371
                                                  X509Credentials())
 
372
        
 
373
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
 
374
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
 
375
        #                "+DHE-DSS"))
 
376
        priority = "NORMAL"
 
377
        if self.server.options.priority:
 
378
            priority = self.server.options.priority
 
379
        gnutls.library.functions.gnutls_priority_set_direct\
 
380
            (session._c_object, priority, None);
 
381
        
 
382
        try:
 
383
            session.handshake()
 
384
        except gnutls.errors.GNUTLSError, error:
 
385
            logger.debug(u"Handshake failed: %s", error)
 
386
            # Do not run session.bye() here: the session is not
 
387
            # established.  Just abandon the request.
 
388
            return
 
389
        try:
 
390
            fpr = fingerprint(peer_certificate(session))
 
391
        except (TypeError, gnutls.errors.GNUTLSError), error:
 
392
            logger.debug(u"Bad certificate: %s", error)
 
393
            session.bye()
 
394
            return
 
395
        logger.debug(u"Fingerprint: %s", fpr)
 
396
        client = None
 
397
        for c in self.server.clients:
 
398
            if c.fingerprint == fpr:
 
399
                client = c
 
400
                break
 
401
        # Have to check if client.still_valid(), since it is possible
 
402
        # that the client timed out while establishing the GnuTLS
 
403
        # session.
 
404
        if (not client) or (not client.still_valid()):
 
405
            if client:
 
406
                logger.debug(u"Client %(name)s is invalid",
 
407
                             vars(client))
 
408
            else:
 
409
                logger.debug(u"Client not found for fingerprint: %s",
 
410
                             fpr)
 
411
            session.bye()
 
412
            return
 
413
        sent_size = 0
 
414
        while sent_size < len(client.secret):
 
415
            sent = session.send(client.secret[sent_size:])
 
416
            logger.debug(u"Sent: %d, remaining: %d",
 
417
                         sent, len(client.secret)
 
418
                         - (sent_size + sent))
 
419
            sent_size += sent
191
420
        session.bye()
192
421
 
193
422
 
194
423
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
195
 
    __metaclass__ = server_metaclass
 
424
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
 
425
    Attributes:
 
426
        options:        Command line options
 
427
        clients:        Set() of Client objects
 
428
    """
 
429
    address_family = socket.AF_INET6
 
430
    def __init__(self, *args, **kwargs):
 
431
        if "options" in kwargs:
 
432
            self.options = kwargs["options"]
 
433
            del kwargs["options"]
 
434
        if "clients" in kwargs:
 
435
            self.clients = kwargs["clients"]
 
436
            del kwargs["clients"]
 
437
        return super(type(self), self).__init__(*args, **kwargs)
 
438
    def server_bind(self):
 
439
        """This overrides the normal server_bind() function
 
440
        to bind to an interface if one was specified, and also NOT to
 
441
        bind to an address or port if they were not specified."""
 
442
        if self.options.interface:
 
443
            if not hasattr(socket, "SO_BINDTODEVICE"):
 
444
                # From /usr/include/asm-i486/socket.h
 
445
                socket.SO_BINDTODEVICE = 25
 
446
            try:
 
447
                self.socket.setsockopt(socket.SOL_SOCKET,
 
448
                                       socket.SO_BINDTODEVICE,
 
449
                                       self.options.interface)
 
450
            except socket.error, error:
 
451
                if error[0] == errno.EPERM:
 
452
                    logger.warning(u"No permission to"
 
453
                                   u" bind to interface %s",
 
454
                                   self.options.interface)
 
455
                else:
 
456
                    raise error
 
457
        # Only bind(2) the socket if we really need to.
 
458
        if self.server_address[0] or self.server_address[1]:
 
459
            if not self.server_address[0]:
 
460
                in6addr_any = "::"
 
461
                self.server_address = (in6addr_any,
 
462
                                       self.server_address[1])
 
463
            elif self.server_address[1] is None:
 
464
                self.server_address = (self.server_address[0],
 
465
                                       0)
 
466
            return super(type(self), self).server_bind()
196
467
 
197
468
 
198
469
def string_to_delta(interval):
229
500
    return delta
230
501
 
231
502
 
 
503
def add_service():
 
504
    """Derived from the Avahi example code"""
 
505
    global group, serviceName, serviceType, servicePort, serviceTXT, \
 
506
           domain, host
 
507
    if group is None:
 
508
        group = dbus.Interface(
 
509
                bus.get_object( avahi.DBUS_NAME,
 
510
                                server.EntryGroupNew()),
 
511
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
512
        group.connect_to_signal('StateChanged',
 
513
                                entry_group_state_changed)
 
514
    logger.debug(u"Adding service '%s' of type '%s' ...",
 
515
                 serviceName, serviceType)
 
516
    
 
517
    group.AddService(
 
518
            serviceInterface,           # interface
 
519
            avahi.PROTO_INET6,          # protocol
 
520
            dbus.UInt32(0),             # flags
 
521
            serviceName, serviceType,
 
522
            domain, host,
 
523
            dbus.UInt16(servicePort),
 
524
            avahi.string_array_to_txt_array(serviceTXT))
 
525
    group.Commit()
 
526
 
 
527
 
 
528
def remove_service():
 
529
    """From the Avahi example code"""
 
530
    global group
 
531
    
 
532
    if not group is None:
 
533
        group.Reset()
 
534
 
 
535
 
 
536
def server_state_changed(state):
 
537
    """Derived from the Avahi example code"""
 
538
    if state == avahi.SERVER_COLLISION:
 
539
        logger.warning(u"Server name collision")
 
540
        remove_service()
 
541
    elif state == avahi.SERVER_RUNNING:
 
542
        add_service()
 
543
 
 
544
 
 
545
def entry_group_state_changed(state, error):
 
546
    """Derived from the Avahi example code"""
 
547
    global serviceName, server, rename_count
 
548
    
 
549
    logger.debug(u"state change: %i", state)
 
550
    
 
551
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
 
552
        logger.debug(u"Service established.")
 
553
    elif state == avahi.ENTRY_GROUP_COLLISION:
 
554
        
 
555
        rename_count = rename_count - 1
 
556
        if rename_count > 0:
 
557
            name = server.GetAlternativeServiceName(name)
 
558
            logger.warning(u"Service name collision, "
 
559
                           u"changing name to '%s' ...", name)
 
560
            remove_service()
 
561
            add_service()
 
562
            
 
563
        else:
 
564
            logger.error(u"No suitable service name found after %i"
 
565
                         u" retries, exiting.", n_rename)
 
566
            killme(1)
 
567
    elif state == avahi.ENTRY_GROUP_FAILURE:
 
568
        logger.error(u"Error in group state changed %s",
 
569
                     unicode(error))
 
570
        killme(1)
 
571
 
 
572
 
 
573
def if_nametoindex(interface):
 
574
    """Call the C function if_nametoindex()"""
 
575
    try:
 
576
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
577
        return libc.if_nametoindex(interface)
 
578
    except (OSError, AttributeError):
 
579
        if "struct" not in sys.modules:
 
580
            import struct
 
581
        if "fcntl" not in sys.modules:
 
582
            import fcntl
 
583
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
 
584
        s = socket.socket()
 
585
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
586
                            struct.pack("16s16x", interface))
 
587
        s.close()
 
588
        interface_index = struct.unpack("I", ifreq[16:20])[0]
 
589
        return interface_index
 
590
 
 
591
 
 
592
def daemon(nochdir, noclose):
 
593
    """See daemon(3).  Standard BSD Unix function.
 
594
    This should really exist as os.daemon, but it doesn't (yet)."""
 
595
    if os.fork():
 
596
        sys.exit()
 
597
    os.setsid()
 
598
    if not nochdir:
 
599
        os.chdir("/")
 
600
    if not noclose:
 
601
        # Close all standard open file descriptors
 
602
        null = os.open("/dev/null", os.O_NOCTTY | os.O_RDWR)
 
603
        if not stat.S_ISCHR(os.fstat(null).st_mode):
 
604
            raise OSError(errno.ENODEV,
 
605
                          "/dev/null not a character device")
 
606
        os.dup2(null, sys.stdin.fileno())
 
607
        os.dup2(null, sys.stdout.fileno())
 
608
        os.dup2(null, sys.stderr.fileno())
 
609
        if null > 2:
 
610
            os.close(null)
 
611
 
 
612
 
 
613
def killme(status = 0):
 
614
    logger.debug("Stopping server with exit status %d", status)
 
615
    exitstatus = status
 
616
    if main_loop_started:
 
617
        main_loop.quit()
 
618
    else:
 
619
        sys.exit(status)
 
620
 
 
621
 
232
622
def main():
 
623
    global exitstatus
 
624
    exitstatus = 0
 
625
    global main_loop_started
 
626
    main_loop_started = False
 
627
    
233
628
    parser = OptionParser()
234
629
    parser.add_option("-i", "--interface", type="string",
235
 
                      default="eth0", metavar="IF",
236
 
                      help="Interface to bind to")
237
 
    parser.add_option("--cert", type="string", default="cert.pem",
238
 
                      metavar="FILE",
239
 
                      help="Public key certificate to use")
240
 
    parser.add_option("--key", type="string", default="key.pem",
241
 
                      metavar="FILE",
242
 
                      help="Private key to use")
243
 
    parser.add_option("--ca", type="string", default="ca.pem",
244
 
                      metavar="FILE",
245
 
                      help="Certificate Authority certificate to use")
246
 
    parser.add_option("--crl", type="string", default="crl.pem",
247
 
                      metavar="FILE",
248
 
                      help="Certificate Revokation List to use")
249
 
    parser.add_option("-p", "--port", type="int", default=49001,
 
630
                      default=None, metavar="IF",
 
631
                      help="Bind to interface IF")
 
632
    parser.add_option("-a", "--address", type="string", default=None,
 
633
                      help="Address to listen for requests on")
 
634
    parser.add_option("-p", "--port", type="int", default=None,
250
635
                      help="Port number to receive requests on")
251
 
    parser.add_option("--dh", type="int", metavar="BITS",
252
 
                      help="DH group to use")
253
 
    parser.add_option("-t", "--timeout", type="string", # Parsed later
254
 
                      default="15m",
255
 
                      help="Amount of downtime allowed for clients")
256
 
    parser.add_option("--interval", type="string", # Parsed later
257
 
                      default="5m",
258
 
                      help="How often to check that a client is up")
259
636
    parser.add_option("--check", action="store_true", default=False,
260
637
                      help="Run self-test")
 
638
    parser.add_option("--debug", action="store_true", default=False,
 
639
                      help="Debug mode")
 
640
    parser.add_option("--priority", type="string",
 
641
                      default="SECURE256",
 
642
                      help="GnuTLS priority string"
 
643
                      " (see GnuTLS documentation)")
 
644
    parser.add_option("--servicename", type="string",
 
645
                      default="Mandos", help="Zeroconf service name")
261
646
    (options, args) = parser.parse_args()
262
 
 
 
647
    
263
648
    if options.check:
264
649
        import doctest
265
650
        doctest.testmod()
266
651
        sys.exit()
267
652
    
268
 
    # Parse the time arguments
269
 
    try:
270
 
        options.timeout = string_to_delta(options.timeout)
271
 
    except ValueError:
272
 
        parser.error("option --timeout: Unparseable time")
273
 
    
274
 
    try:
275
 
        options.interval = string_to_delta(options.interval)
276
 
    except ValueError:
277
 
        parser.error("option --interval: Unparseable time")
278
 
    
279
 
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
280
 
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
281
 
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
282
 
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
283
 
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
284
 
    
285
653
    # Parse config file
286
 
    defaults = {}
287
 
    client_config_object = ConfigParser.SafeConfigParser(defaults)
288
 
    client_config_object.read("mandos-clients.conf")
289
 
    clients = Set(Client(name=section, options=options,
290
 
                         **(dict(client_config_object\
291
 
                                 .items(section))))
292
 
                  for section in client_config_object.sections())
293
 
    
294
 
    in6addr_any = "::"
295
 
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
296
 
                                udp_handler,
297
 
                                options=options)
298
 
    
299
 
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
 
654
    defaults = { "timeout": "1h",
 
655
                 "interval": "5m",
 
656
                 "checker": "fping -q -- %%(fqdn)s",
 
657
                 }
 
658
    client_config = ConfigParser.SafeConfigParser(defaults)
 
659
    #client_config.readfp(open("global.conf"), "global.conf")
 
660
    client_config.read("mandos-clients.conf")
 
661
    
 
662
    global serviceName
 
663
    serviceName = options.servicename;
 
664
    
 
665
    global main_loop
 
666
    global bus
 
667
    global server
 
668
    # From the Avahi example code
 
669
    DBusGMainLoop(set_as_default=True )
 
670
    main_loop = gobject.MainLoop()
 
671
    bus = dbus.SystemBus()
 
672
    server = dbus.Interface(
 
673
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
 
674
            avahi.DBUS_INTERFACE_SERVER )
 
675
    # End of Avahi example code
 
676
    
 
677
    debug = options.debug
 
678
    
 
679
    if debug:
 
680
        console = logging.StreamHandler()
 
681
        # console.setLevel(logging.DEBUG)
 
682
        console.setFormatter(logging.Formatter\
 
683
                             ('%(levelname)s: %(message)s'))
 
684
        logger.addHandler(console)
 
685
        del console
 
686
    
 
687
    clients = Set()
 
688
    def remove_from_clients(client):
 
689
        clients.remove(client)
 
690
        if not clients:
 
691
            logger.debug(u"No clients left, exiting")
 
692
            killme()
 
693
    
 
694
    clients.update(Set(Client(name=section,
 
695
                              stop_hook = remove_from_clients,
 
696
                              **(dict(client_config\
 
697
                                      .items(section))))
 
698
                       for section in client_config.sections()))
 
699
    
 
700
    if not debug:
 
701
        daemon(False, False)
 
702
    
 
703
    def cleanup():
 
704
        "Cleanup function; run on exit"
 
705
        global group
 
706
        # From the Avahi example code
 
707
        if not group is None:
 
708
            group.Free()
 
709
            group = None
 
710
        # End of Avahi example code
 
711
        
 
712
        while clients:
 
713
            client = clients.pop()
 
714
            client.stop_hook = None
 
715
            client.stop()
 
716
    
 
717
    atexit.register(cleanup)
 
718
    
 
719
    if not debug:
 
720
        signal.signal(signal.SIGINT, signal.SIG_IGN)
 
721
    signal.signal(signal.SIGHUP, lambda signum, frame: killme())
 
722
    signal.signal(signal.SIGTERM, lambda signum, frame: killme())
 
723
    
 
724
    for client in clients:
 
725
        client.start()
 
726
    
 
727
    tcp_server = IPv6_TCPServer((options.address, options.port),
300
728
                                tcp_handler,
301
729
                                options=options,
302
 
                                clients=clients,
303
 
                                credentials=cred)
304
 
    
305
 
    while True:
306
 
        if not clients:
307
 
            break
308
 
        try:
309
 
            next_stop = min(client.next_stop() for client in clients)
310
 
            now = datetime.datetime.now()
311
 
            if next_stop > now:
312
 
                delay = next_stop - now
313
 
                delay_seconds = (delay.days * 24 * 60 * 60
314
 
                                 + delay.seconds
315
 
                                 + delay.microseconds / 1000000)
316
 
                clients_with_checkers = tuple(client for client in
317
 
                                              clients
318
 
                                              if client.checker
319
 
                                              is not None)
320
 
                input_checks = (udp_server, tcp_server) \
321
 
                               + clients_with_checkers
322
 
                print "Waiting for network",
323
 
                if clients_with_checkers:
324
 
                    print "and checkers for:",
325
 
                    for client in clients_with_checkers:
326
 
                        print client.name,
327
 
                print
328
 
                input, out, err = select.select(input_checks, (), (),
329
 
                                                delay_seconds)
330
 
                for obj in input:
331
 
                    obj.handle_request()
332
 
            # start new checkers
333
 
            for client in clients:
334
 
                if client.it_is_time_to_check(now=now) and \
335
 
                       client.checker is None:
336
 
                    print "Starting checker for client %(name)s" \
337
 
                          % vars(client)
338
 
                    client.start_checker()
339
 
            # delete timed-out clients
340
 
            for client in clients.copy():
341
 
                if not client.still_valid(now=now):
342
 
                    # log xxx
343
 
                    print "Removing client %(name)s" % vars(client)
344
 
                    clients.remove(client)
345
 
        except KeyboardInterrupt:
346
 
            break
347
 
    
348
 
    # Cleanup here
349
 
    for client in clients:
350
 
        client.stop_checker()
351
 
 
352
 
 
353
 
if __name__ == "__main__":
 
730
                                clients=clients)
 
731
    # Find out what random port we got
 
732
    global servicePort
 
733
    servicePort = tcp_server.socket.getsockname()[1]
 
734
    logger.debug(u"Now listening on port %d", servicePort)
 
735
    
 
736
    if options.interface is not None:
 
737
        global serviceInterface
 
738
        serviceInterface = if_nametoindex(options.interface)
 
739
    
 
740
    # From the Avahi example code
 
741
    server.connect_to_signal("StateChanged", server_state_changed)
 
742
    try:
 
743
        server_state_changed(server.GetState())
 
744
    except dbus.exceptions.DBusException, error:
 
745
        logger.critical(u"DBusException: %s", error)
 
746
        killme(1)
 
747
    # End of Avahi example code
 
748
    
 
749
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
750
                         lambda *args, **kwargs:
 
751
                         tcp_server.handle_request(*args[2:],
 
752
                                                   **kwargs) or True)
 
753
    try:
 
754
        logger.debug("Starting main loop")
 
755
        main_loop_started = True
 
756
        main_loop.run()
 
757
    except KeyboardInterrupt:
 
758
        if debug:
 
759
            print
 
760
    
 
761
    sys.exit(exitstatus)
 
762
 
 
763
if __name__ == '__main__':
354
764
    main()
355