/mandos/trunk

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Viewing changes to server.py

  • Committer: Björn Påhlsson
  • Date: 2007-10-20 21:38:25 UTC
  • Revision ID: belorn@tower-20071020213825-abf6f0d1c33ee961
First working version with: IPv6, GnuTLS, X.509 certificates, DN
retrieval.

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#!/usr/bin/python
2
 
 
3
 
import SocketServer
4
 
import socket
5
 
import select
6
 
from optparse import OptionParser
7
 
import datetime
8
 
import errno
9
 
import gnutls.crypto
10
 
import gnutls.connection
11
 
import gnutls.errors
12
 
import ConfigParser
13
 
import sys
14
 
import re
15
 
import os
16
 
import signal
17
 
 
18
 
class Client(object):
19
 
    def __init__(self, name=None, options=None, dn=None,
20
 
                 password=None, passfile=None, fqdn=None,
21
 
                 timeout=None, interval=-1):
22
 
        self.name = name
23
 
        self.dn = dn
24
 
        if password:
25
 
            self.password = password
26
 
        elif passfile:
27
 
            self.password = open(passfile).readall()
28
 
        else:
29
 
            print "No Password or Passfile in client config file"
30
 
            # raise RuntimeError XXX
31
 
            self.password = "gazonk"
32
 
        self.fqdn = fqdn                # string
33
 
        self.created = datetime.datetime.now()
34
 
        self.last_seen = None           # datetime.datetime()
35
 
        if timeout is None:
36
 
            timeout = options.timeout
37
 
        self.timeout = timeout          # datetime.timedelta()
38
 
        if interval == -1:
39
 
            interval = options.interval
40
 
        self.interval = interval        # datetime.timedelta()
41
 
        self.next_check = datetime.datetime.now() # datetime.datetime()
42
 
        self.checker = None             # or a subprocess.Popen()
43
 
    def check_action(self, now=None):
44
 
        """The checker said something and might have completed.
45
 
        Check if is has, and take appropriate actions."""
46
 
        if self.checker.poll() is None:
47
 
            # False alarm, no result yet
48
 
            #self.checker.read()
49
 
            return
50
 
        if now is None:
51
 
            now = datetime.datetime.now()
52
 
        if self.checker.returncode == 0:
53
 
            self.last_seen = now
54
 
        while self.next_check <= now:
55
 
            self.next_check += self.interval
56
 
    handle_request = check_action
57
 
    def start_checker(self):
58
 
        self.stop_checker()
59
 
        try:
60
 
            self.checker = subprocess.Popen("sleep 1; fping -q -- %s"
61
 
                                            % re.escape(self.fqdn),
62
 
                                            stdout=subprocess.PIPE,
63
 
                                            close_fds=True,
64
 
                                            shell=True, cwd="/")
65
 
        except subprocess.OSError, e:
66
 
            print "Failed to start subprocess:", e
67
 
    def stop_checker(self):
68
 
        if self.checker is None:
69
 
            return
70
 
        os.kill(self.checker.pid, signal.SIGTERM)
71
 
        if self.checker.poll() is None:
72
 
            os.kill(self.checker.pid, signal.SIGKILL)
73
 
        self.checker = None
74
 
    __del__ = stop_checker
75
 
    def fileno(self):
76
 
        if self.checker is None:
77
 
            return None
78
 
        return self.checker.stdout.fileno()
79
 
    def next_stop(self):
80
 
        """The time when something must be done about this client"""
81
 
        return min(self.last_seen + self.timeout, self.next_check)
82
 
    def still_valid(self, now=None):
83
 
        """Has this client's timeout not passed?"""
84
 
        if now is None:
85
 
            now = datetime.datetime.now()
86
 
        return now < (self.last_seen + timeout)
87
 
    def it_is_time_to_check(self, now=None):
88
 
        if now is None:
89
 
            now = datetime.datetime.now()
90
 
        return self.next_check <= now
91
 
 
92
 
 
93
 
class server_metaclass(type):
94
 
    "Common behavior for the UDP and TCP server classes"
95
 
    def __new__(cls, name, bases, attrs):
96
 
        attrs["address_family"] = socket.AF_INET6
97
 
        attrs["allow_reuse_address"] = True
98
 
        def server_bind(self):
99
 
            if self.options.interface:
100
 
                if not hasattr(socket, "SO_BINDTODEVICE"):
101
 
                    # From /usr/include/asm-i486/socket.h
102
 
                    socket.SO_BINDTODEVICE = 25
103
 
                try:
104
 
                    self.socket.setsockopt(socket.SOL_SOCKET,
105
 
                                           socket.SO_BINDTODEVICE,
106
 
                                           self.options.interface)
107
 
                except socket.error, error:
108
 
                    if error[0] == errno.EPERM:
109
 
                        print "Warning: No permission to bind to interface", \
110
 
                              self.options.interface
111
 
                    else:
112
 
                        raise error
113
 
            return super(type(self), self).server_bind()
114
 
        attrs["server_bind"] = server_bind
115
 
        def init(self, *args, **kwargs):
116
 
            if "options" in kwargs:
117
 
                self.options = kwargs["options"]
118
 
                del kwargs["options"]
119
 
            if "clients" in kwargs:
120
 
                self.clients = kwargs["clients"]
121
 
                del kwargs["clients"]
122
 
            if "credentials" in kwargs:
123
 
                self.credentials = kwargs["credentials"]
124
 
                del kwargs["credentials"]
125
 
            return super(type(self), self).__init__(*args, **kwargs)
126
 
        attrs["__init__"] = init
127
 
        return type.__new__(cls, name, bases, attrs)
128
 
 
129
 
 
130
 
class udp_handler(SocketServer.DatagramRequestHandler, object):
131
 
    def handle(self):
132
 
        self.wfile.write("Polo")
133
 
        print "UDP request answered"
134
 
 
135
 
 
136
 
class IPv6_UDPServer(SocketServer.UDPServer, object):
137
 
    __metaclass__ = server_metaclass
138
 
    def verify_request(self, request, client_address):
139
 
        print "UDP request came"
140
 
        return request[0] == "Marco"
141
 
 
142
 
 
143
 
class tcp_handler(SocketServer.BaseRequestHandler, object):
144
 
    def handle(self):
145
 
        print "TCP request came"
146
 
        print "Request:", self.request
147
 
        print "Client Address:", self.client_address
148
 
        print "Server:", self.server
149
 
        session = gnutls.connection.ServerSession(self.request,
150
 
                                                  self.server.credentials)
151
 
        session.handshake()
152
 
        if session.peer_certificate:
153
 
            print "DN:", session.peer_certificate.subject
154
 
        try:
155
 
            session.verify_peer()
156
 
        except gnutls.errors.CertificateError, error:
157
 
            print "Verify failed", error
158
 
            session.bye()
159
 
            return
160
 
        try:
161
 
            session.send(dict((client.dn, client.password)
162
 
                              for client in self.server.clients)
163
 
                         [session.peer_certificate.subject])
164
 
        except KeyError:
165
 
            session.send("gazonk")
166
 
            # Log maybe? XXX
167
 
        session.bye()
168
 
 
169
 
 
170
 
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
171
 
    __metaclass__ = server_metaclass
172
 
    request_queue_size = 1024
173
 
 
174
 
 
175
 
in6addr_any = "::"
176
 
 
177
 
def string_to_delta(interval):
178
 
    """Parse a string and return a datetime.timedelta
179
 
 
180
 
    >>> string_to_delta('7d')
181
 
    datetime.timedelta(7)
182
 
    >>> string_to_delta('60s')
183
 
    datetime.timedelta(0, 60)
184
 
    >>> string_to_delta('60m')
185
 
    datetime.timedelta(0, 3600)
186
 
    >>> string_to_delta('24h')
187
 
    datetime.timedelta(1)
188
 
    >>> string_to_delta(u'1w')
189
 
    datetime.timedelta(7)
190
 
    """
191
 
    try:
192
 
        suffix=unicode(interval[-1])
193
 
        value=int(interval[:-1])
194
 
        if suffix == u"d":
195
 
            delta = datetime.timedelta(value)
196
 
        elif suffix == u"s":
197
 
            delta = datetime.timedelta(0, value)
198
 
        elif suffix == u"m":
199
 
            delta = datetime.timedelta(0, 0, 0, 0, value)
200
 
        elif suffix == u"h":
201
 
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
202
 
        elif suffix == u"w":
203
 
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
204
 
        else:
205
 
            raise ValueError
206
 
    except (ValueError, IndexError):
207
 
        raise ValueError
208
 
    return delta
209
 
 
210
 
 
211
 
def main():
212
 
    parser = OptionParser()
213
 
    parser.add_option("-i", "--interface", type="string",
214
 
                      default="eth0", metavar="IF",
215
 
                      help="Interface to bind to")
216
 
    parser.add_option("--cert", type="string", default="cert.pem",
217
 
                      metavar="FILE",
218
 
                      help="Public key certificate to use")
219
 
    parser.add_option("--key", type="string", default="key.pem",
220
 
                      metavar="FILE",
221
 
                      help="Private key to use")
222
 
    parser.add_option("--ca", type="string", default="ca.pem",
223
 
                      metavar="FILE",
224
 
                      help="Certificate Authority certificate to use")
225
 
    parser.add_option("--crl", type="string", default="crl.pem",
226
 
                      metavar="FILE",
227
 
                      help="Certificate Revokation List to use")
228
 
    parser.add_option("-p", "--port", type="int", default=49001,
229
 
                      help="Port number to receive requests on")
230
 
    parser.add_option("--dh", type="int", metavar="BITS",
231
 
                      help="DH group to use")
232
 
    parser.add_option("-t", "--timeout", type="string", # Parsed later
233
 
                      default="15m",
234
 
                      help="Amount of downtime allowed for clients")
235
 
    parser.add_option("--interval", type="string", # Parsed later
236
 
                      default="5m",
237
 
                      help="How often to check that a client is up")
238
 
    parser.add_option("--check", action="store_true", default=False,
239
 
                      help="Run self-test")
240
 
    (options, args) = parser.parse_args()
241
 
 
242
 
    if options.check:
243
 
        import doctest
244
 
        doctest.testmod()
245
 
        sys.exit()
246
 
    
247
 
    # Parse the time arguments
248
 
    try:
249
 
        options.timeout = string_to_delta(options.timeout)
250
 
    except ValueError:
251
 
        parser.error("option --timeout: Unparseable time")
252
 
    
253
 
    try:
254
 
        options.interval = string_to_delta(options.interval)
255
 
    except ValueError:
256
 
        parser.error("option --interval: Unparseable time")
257
 
    
258
 
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
259
 
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
260
 
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
261
 
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
262
 
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
263
 
    
264
 
    # Parse config file
265
 
    defaults = {}
266
 
    client_config_object = ConfigParser.SafeConfigParser(defaults)
267
 
    client_config_object.read("mandos-clients.conf")
268
 
    clients = [Client(name=section, options=options,
269
 
                      **(dict(client_config_object.items(section))))
270
 
               for section in client_config_object.sections()]
271
 
    
272
 
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
273
 
                                udp_handler,
274
 
                                options=options)
275
 
    
276
 
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
277
 
                                tcp_handler,
278
 
                                options=options,
279
 
                                clients=clients,
280
 
                                credentials=cred)
281
 
    
282
 
    while True:
283
 
        try:
284
 
            input, out, err = select.select((udp_server,
285
 
                                             tcp_server), (), ())
286
 
            if not input:
287
 
                pass
288
 
            else:
289
 
                for obj in input:
290
 
                    obj.handle_request()
291
 
        except KeyboardInterrupt:
292
 
            break
293
 
    
294
 
    # Cleanup here
295
 
    for client in clients:
296
 
        client.stop_checker()
297
 
 
298
 
 
299
 
if __name__ == "__main__":
300
 
    main()
301