/mandos/release : revision 237.2.9

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

15

16

#

17

# This program is free software: you can redistribute it and/or modify

18

# it under the terms of the GNU General Public License as published by

19

# the Free Software Foundation, either version 3 of the License, or

20

# (at your option) any later version.

21

#

22

# This program is distributed in the hope that it will be useful,

23

# but WITHOUT ANY WARRANTY; without even the implied warranty of

24

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

25

# GNU General Public License for more details.

26

#

27

# You should have received a copy of the GNU General Public License

28

# along with this program. If not, see

29

# <http://www.gnu.org/licenses/>.

30

#

31

# Contact the authors at <mandos@fukt.bsnet.se>.

32

#

33

34

from __future__ import division, with_statement, absolute_import

2

35

3

36

import SocketServer

4

37

import socket

5

import select

6

38

from optparse import OptionParser

7

39

import datetime

8

40

import errno

9

41

import gnutls.crypto

10

42

import gnutls.connection

11

43

import gnutls.errors

44

import gnutls.library.functions

45

import gnutls.library.constants

46

import gnutls.library.types

12

47

import ConfigParser

13

14

class Client(object):

15

def __init__(self, name=None, dn=None, password=None,

16

passfile=None, fqdn=None, timeout=None,

17

interval=-1):

18

self.name = name

19

self.dn = dn

20

if password:

21

self.password = password

22

elif passfile:

23

self.password = open(passfile).readall()

24

else:

25

print "No Password or Passfile in client config file"

26

# raise RuntimeError XXX

27

self.password = "gazonk"

28

self.fqdn = fqdn

29

# self.created = ...

30

self.last_seen = None

31

if timeout is None:

32

timeout = self.server.options.timeout

33

self.timeout = timeout

34

if interval == -1:

35

interval = self.server.options.interval

36

self.interval = interval

37

38

def server_bind(self):

39

if self.options.interface:

40

if not hasattr(socket, "SO_BINDTODEVICE"):

41

# From /usr/include/asm-i486/socket.h

42

socket.SO_BINDTODEVICE = 25

43

try:

44

self.socket.setsockopt(socket.SOL_SOCKET,

45

socket.SO_BINDTODEVICE,

46

self.options.interface)

47

except socket.error, error:

48

if error[0] == errno.EPERM:

49

print "Warning: Denied permission to bind to interface", \

50

self.options.interface

48

import sys

49

import re

50

import os

51

import signal

52

from sets import Set

53

import subprocess

54

import atexit

55

import stat

56

import logging

57

import logging.handlers

58

import pwd

59

from contextlib import closing

60

61

import dbus

62

import dbus.service

63

import gobject

64

import avahi

65

from dbus.mainloop.glib import DBusGMainLoop

66

import ctypes

67

import ctypes.util

68

69

version = "1.0.2"

70

71

logger = logging.Logger('mandos')

72

syslogger = (logging.handlers.SysLogHandler

73

(facility = logging.handlers.SysLogHandler.LOG_DAEMON,

74

address = "/dev/log"))

75

syslogger.setFormatter(logging.Formatter

76

('Mandos: %(levelname)s: %(message)s'))

77

logger.addHandler(syslogger)

78

79

console = logging.StreamHandler()

80

console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'

81

' %(message)s'))

82

logger.addHandler(console)

83

84

class AvahiError(Exception):

85

def __init__(self, value, *args, **kwargs):

86

self.value = value

87

super(AvahiError, self).__init__(value, *args, **kwargs)

88

def __unicode__(self):

89

return unicode(repr(self.value))

90

91

class AvahiServiceError(AvahiError):

92

pass

93

94

class AvahiGroupError(AvahiError):

95

pass

96

97

98

class AvahiService(object):

99

"""An Avahi (Zeroconf) service.

100

Attributes:

101

interface: integer; avahi.IF_UNSPEC or an interface index.

102

Used to optionally bind to the specified interface.

103

name: string; Example: 'Mandos'

104

type: string; Example: '_mandos._tcp'.

105

See <http://www.dns-sd.org/ServiceTypes.html>

106

port: integer; what port to announce

107

TXT: list of strings; TXT record for the service

108

domain: string; Domain to publish on, default to .local if empty.

109

host: string; Host to publish records for, default is localhost

110

max_renames: integer; maximum number of renames

111

rename_count: integer; counter so we only rename after collisions

112

a sensible number of times

113

"""

114

def __init__(self, interface = avahi.IF_UNSPEC, name = None,

115

servicetype = None, port = None, TXT = None,

116

domain = "", host = "", max_renames = 32768):

117

self.interface = interface

118

self.name = name

119

self.type = servicetype

120

self.port = port

121

self.TXT = TXT if TXT is not None else []

122

self.domain = domain

123

self.host = host

124

self.rename_count = 0

125

self.max_renames = max_renames

126

def rename(self):

127

"""Derived from the Avahi example code"""

128

if self.rename_count >= self.max_renames:

129

logger.critical(u"No suitable Zeroconf service name found"

130

u" after %i retries, exiting.",

131

self.rename_count)

132

raise AvahiServiceError(u"Too many renames")

133

self.name = server.GetAlternativeServiceName(self.name)

134

logger.info(u"Changing Zeroconf service name to %r ...",

135

str(self.name))

136

syslogger.setFormatter(logging.Formatter

137

('Mandos (%s): %%(levelname)s:'

138

' %%(message)s' % self.name))

139

self.remove()

140

self.add()

141

self.rename_count += 1

142

def remove(self):

143

"""Derived from the Avahi example code"""

144

if group is not None:

145

group.Reset()

146

def add(self):

147

"""Derived from the Avahi example code"""

148

global group

149

if group is None:

150

group = dbus.Interface(bus.get_object

151

(avahi.DBUS_NAME,

152

server.EntryGroupNew()),

153

avahi.DBUS_INTERFACE_ENTRY_GROUP)

154

group.connect_to_signal('StateChanged',

155

entry_group_state_changed)

156

logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",

157

service.name, service.type)

158

group.AddService(

159

self.interface, # interface

160

avahi.PROTO_INET6, # protocol

161

dbus.UInt32(0), # flags

162

self.name, self.type,

163

self.domain, self.host,

164

dbus.UInt16(self.port),

165

avahi.string_array_to_txt_array(self.TXT))

166

group.Commit()

167

168

# From the Avahi example code:

169

group = None # our entry group

170

# End of Avahi example code

171

172

173

def _datetime_to_dbus(dt, variant_level=0):

174

"""Convert a UTC datetime.datetime() to a D-Bus type."""

175

return dbus.String(dt.isoformat(), variant_level=variant_level)

176

177

178

class Client(dbus.service.Object):

179

"""A representation of a client host served by this server.

180

Attributes:

181

name: string; from the config file, used in log messages

182

fingerprint: string (40 or 32 hexadecimal digits); used to

183

uniquely identify the client

184

secret: bytestring; sent verbatim (over TLS) to client

185

host: string; available for use by the checker command

186

created: datetime.datetime(); (UTC) object creation

187

last_enabled: datetime.datetime(); (UTC)

188

enabled: bool()

189

last_checked_ok: datetime.datetime(); (UTC) or None

190

timeout: datetime.timedelta(); How long from last_checked_ok

191

until this client is invalid

192

interval: datetime.timedelta(); How often to start a new checker

193

disable_hook: If set, called by disable() as disable_hook(self)

194

checker: subprocess.Popen(); a running checker process used

195

to see if the client lives.

196

'None' if no process is running.

197

checker_initiator_tag: a gobject event source tag, or None

198

disable_initiator_tag: - '' -

199

checker_callback_tag: - '' -

200

checker_command: string; External command which is run to check if

201

client lives. %() expansions are done at

202

runtime with vars(self) as dict, so that for

203

instance %(name)s can be used in the command.

204

use_dbus: bool(); Whether to provide D-Bus interface and signals

205

dbus_object_path: dbus.ObjectPath ; only set if self.use_dbus

206

"""

207

def timeout_milliseconds(self):

208

"Return the 'timeout' attribute in milliseconds"

209

return ((self.timeout.days * 24 * 60 * 60 * 1000)

210

+ (self.timeout.seconds * 1000)

211

+ (self.timeout.microseconds // 1000))

212

213

def interval_milliseconds(self):

214

"Return the 'interval' attribute in milliseconds"

215

return ((self.interval.days * 24 * 60 * 60 * 1000)

216

+ (self.interval.seconds * 1000)

217

+ (self.interval.microseconds // 1000))

218

219

def __init__(self, name = None, disable_hook=None, config=None,

220

use_dbus=True):

221

"""Note: the 'checker' key in 'config' sets the

222

'checker_command' attribute and *not* the 'checker'

223

attribute."""

224

self.name = name

225

if config is None:

226

config = {}

227

logger.debug(u"Creating client %r", self.name)

228

self.use_dbus = use_dbus

229

if self.use_dbus:

230

self.dbus_object_path = (dbus.ObjectPath

231

("/Mandos/clients/"

232

+ self.name.replace(".", "_")))

233

dbus.service.Object.__init__(self, bus,

234

self.dbus_object_path)

235

# Uppercase and remove spaces from fingerprint for later

236

# comparison purposes with return value from the fingerprint()

237

# function

238

self.fingerprint = (config["fingerprint"].upper()

239

.replace(u" ", u""))

240

logger.debug(u" Fingerprint: %s", self.fingerprint)

241

if "secret" in config:

242

self.secret = config["secret"].decode(u"base64")

243

elif "secfile" in config:

244

with closing(open(os.path.expanduser

245

(os.path.expandvars

246

(config["secfile"])))) as secfile:

247

self.secret = secfile.read()

248

else:

249

raise TypeError(u"No secret or secfile for client %s"

250

% self.name)

251

self.host = config.get("host", "")

252

self.created = datetime.datetime.utcnow()

253

self.enabled = False

254

self.last_enabled = None

255

self.last_checked_ok = None

256

self.timeout = string_to_delta(config["timeout"])

257

self.interval = string_to_delta(config["interval"])

258

self.disable_hook = disable_hook

259

self.checker = None

260

self.checker_initiator_tag = None

261

self.disable_initiator_tag = None

262

self.checker_callback_tag = None

263

self.checker_command = config["checker"]

264

265

def enable(self):

266

"""Start this client's checker and timeout hooks"""

267

self.last_enabled = datetime.datetime.utcnow()

268

# Schedule a new checker to be started an 'interval' from now,

269

# and every interval from then on.

270

self.checker_initiator_tag = (gobject.timeout_add

271

(self.interval_milliseconds(),

272

self.start_checker))

273

# Also start a new checker *right now*.

274

self.start_checker()

275

# Schedule a disable() when 'timeout' has passed

276

self.disable_initiator_tag = (gobject.timeout_add

277

(self.timeout_milliseconds(),

278

self.disable))

279

self.enabled = True

280

if self.use_dbus:

281

# Emit D-Bus signals

282

self.PropertyChanged(dbus.String(u"enabled"),

283

dbus.Boolean(True, variant_level=1))

284

self.PropertyChanged(dbus.String(u"last_enabled"),

285

(_datetime_to_dbus(self.last_enabled,

286

variant_level=1)))

287

288

def disable(self):

289

"""Disable this client."""

290

if not getattr(self, "enabled", False):

291

return False

292

logger.info(u"Disabling client %s", self.name)

293

if getattr(self, "disable_initiator_tag", False):

294

gobject.source_remove(self.disable_initiator_tag)

295

self.disable_initiator_tag = None

296

if getattr(self, "checker_initiator_tag", False):

297

gobject.source_remove(self.checker_initiator_tag)

298

self.checker_initiator_tag = None

299

self.stop_checker()

300

if self.disable_hook:

301

self.disable_hook(self)

302

self.enabled = False

303

if self.use_dbus:

304

# Emit D-Bus signal

305

self.PropertyChanged(dbus.String(u"enabled"),

306

dbus.Boolean(False, variant_level=1))

307

# Do not run this again if called by a gobject.timeout_add

308

return False

309

310

def __del__(self):

311

self.disable_hook = None

312

self.disable()

313

314

def checker_callback(self, pid, condition, command):

315

"""The checker has completed, so take appropriate actions."""

316

self.checker_callback_tag = None

317

self.checker = None

318

if self.use_dbus:

319

# Emit D-Bus signal

320

self.PropertyChanged(dbus.String(u"checker_running"),

321

dbus.Boolean(False, variant_level=1))

322

if (os.WIFEXITED(condition)

323

and (os.WEXITSTATUS(condition) == 0)):

324

logger.info(u"Checker for %(name)s succeeded",

325

vars(self))

326

if self.use_dbus:

327

# Emit D-Bus signal

328

self.CheckerCompleted(dbus.Boolean(True),

329

dbus.UInt16(condition),

330

dbus.String(command))

331

self.bump_timeout()

332

elif not os.WIFEXITED(condition):

333

logger.warning(u"Checker for %(name)s crashed?",

334

vars(self))

335

if self.use_dbus:

336

# Emit D-Bus signal

337

self.CheckerCompleted(dbus.Boolean(False),

338

dbus.UInt16(condition),

339

dbus.String(command))

340

else:

341

logger.info(u"Checker for %(name)s failed",

342

vars(self))

343

if self.use_dbus:

344

# Emit D-Bus signal

345

self.CheckerCompleted(dbus.Boolean(False),

346

dbus.UInt16(condition),

347

dbus.String(command))

348

349

def bump_timeout(self):

350

"""Bump up the timeout for this client.

351

This should only be called when the client has been seen,

352

alive and well.

353

"""

354

self.last_checked_ok = datetime.datetime.utcnow()

355

gobject.source_remove(self.disable_initiator_tag)

356

self.disable_initiator_tag = (gobject.timeout_add

357

(self.timeout_milliseconds(),

358

self.disable))

359

if self.use_dbus:

360

# Emit D-Bus signal

361

self.PropertyChanged(

362

dbus.String(u"last_checked_ok"),

363

(_datetime_to_dbus(self.last_checked_ok,

364

variant_level=1)))

365

366

def start_checker(self):

367

"""Start a new checker subprocess if one is not running.

368

If a checker already exists, leave it running and do

369

nothing."""

370

# The reason for not killing a running checker is that if we

371

# did that, then if a checker (for some reason) started

372

# running slowly and taking more than 'interval' time, the

373

# client would inevitably timeout, since no checker would get

374

# a chance to run to completion. If we instead leave running

375

# checkers alone, the checker would have to take more time

376

# than 'timeout' for the client to be declared invalid, which

377

# is as it should be.

378

if self.checker is None:

379

try:

380

# In case checker_command has exactly one % operator

381

command = self.checker_command % self.host

382

except TypeError:

383

# Escape attributes for the shell

384

escaped_attrs = dict((key, re.escape(str(val)))

385

for key, val in

386

vars(self).iteritems())

387

try:

388

command = self.checker_command % escaped_attrs

389

except TypeError, error:

390

logger.error(u'Could not format string "%s":'

391

u' %s', self.checker_command, error)

392

return True # Try again later

393

try:

394

logger.info(u"Starting checker %r for %s",

395

command, self.name)

396

# We don't need to redirect stdout and stderr, since

397

# in normal mode, that is already done by daemon(),

398

# and in debug mode we don't want to. (Stdin is

399

# always replaced by /dev/null.)

400

self.checker = subprocess.Popen(command,

401

close_fds=True,

402

shell=True, cwd="/")

403

if self.use_dbus:

404

# Emit D-Bus signal

405

self.CheckerStarted(command)

406

self.PropertyChanged(

407

dbus.String("checker_running"),

408

dbus.Boolean(True, variant_level=1))

409

self.checker_callback_tag = (gobject.child_watch_add

410

(self.checker.pid,

411

self.checker_callback,

412

data=command))

413

except OSError, error:

414

logger.error(u"Failed to start subprocess: %s",

415

error)

416

# Re-run this periodically if run by gobject.timeout_add

417

return True

418

419

def stop_checker(self):

420

"""Force the checker process, if any, to stop."""

421

if self.checker_callback_tag:

422

gobject.source_remove(self.checker_callback_tag)

423

self.checker_callback_tag = None

424

if getattr(self, "checker", None) is None:

425

return

426

logger.debug(u"Stopping checker for %(name)s", vars(self))

427

try:

428

os.kill(self.checker.pid, signal.SIGTERM)

429

#os.sleep(0.5)

430

#if self.checker.poll() is None:

431

# os.kill(self.checker.pid, signal.SIGKILL)

432

except OSError, error:

433

if error.errno != errno.ESRCH: # No such process

434

raise

435

self.checker = None

436

if self.use_dbus:

437

self.PropertyChanged(dbus.String(u"checker_running"),

438

dbus.Boolean(False, variant_level=1))

439

440

def still_valid(self):

441

"""Has the timeout not yet passed for this client?"""

442

if not getattr(self, "enabled", False):

443

return False

444

now = datetime.datetime.utcnow()

445

if self.last_checked_ok is None:

446

return now < (self.created + self.timeout)

447

else:

448

return now < (self.last_checked_ok + self.timeout)

449

450

## D-Bus methods & signals

451

_interface = u"org.mandos_system.Mandos.Client"

452

453

# BumpTimeout - method

454

BumpTimeout = dbus.service.method(_interface)(bump_timeout)

455

BumpTimeout.__name__ = "BumpTimeout"

456

457

# CheckerCompleted - signal

458

@dbus.service.signal(_interface, signature="bqs")

459

def CheckerCompleted(self, success, condition, command):

460

"D-Bus signal"

461

pass

462

463

# CheckerStarted - signal

464

@dbus.service.signal(_interface, signature="s")

465

def CheckerStarted(self, command):

466

"D-Bus signal"

467

pass

468

469

# GetAllProperties - method

470

@dbus.service.method(_interface, out_signature="a{sv}")

471

def GetAllProperties(self):

472

"D-Bus method"

473

return dbus.Dictionary({

474

dbus.String("name"):

475

dbus.String(self.name, variant_level=1),

476

dbus.String("fingerprint"):

477

dbus.String(self.fingerprint, variant_level=1),

478

dbus.String("host"):

479

dbus.String(self.host, variant_level=1),

480

dbus.String("created"):

481

_datetime_to_dbus(self.created, variant_level=1),

482

dbus.String("last_enabled"):

483

(_datetime_to_dbus(self.last_enabled,

484

variant_level=1)

485

if self.last_enabled is not None

486

else dbus.Boolean(False, variant_level=1)),

487

dbus.String("enabled"):

488

dbus.Boolean(self.enabled, variant_level=1),

489

dbus.String("last_checked_ok"):

490

(_datetime_to_dbus(self.last_checked_ok,

491

variant_level=1)

492

if self.last_checked_ok is not None

493

else dbus.Boolean (False, variant_level=1)),

494

dbus.String("timeout"):

495

dbus.UInt64(self.timeout_milliseconds(),

496

variant_level=1),

497

dbus.String("interval"):

498

dbus.UInt64(self.interval_milliseconds(),

499

variant_level=1),

500

dbus.String("checker"):

501

dbus.String(self.checker_command,

502

variant_level=1),

503

dbus.String("checker_running"):

504

dbus.Boolean(self.checker is not None,

505

variant_level=1),

506

}, signature="sv")

507

508

# IsStillValid - method

509

IsStillValid = (dbus.service.method(_interface, out_signature="b")

510

(still_valid))

511

IsStillValid.__name__ = "IsStillValid"

512

513

# PropertyChanged - signal

514

@dbus.service.signal(_interface, signature="sv")

515

def PropertyChanged(self, property, value):

516

"D-Bus signal"

517

pass

518

519

# SetChecker - method

520

@dbus.service.method(_interface, in_signature="s")

521

def SetChecker(self, checker):

522

"D-Bus setter method"

523

self.checker_command = checker

524

# Emit D-Bus signal

525

self.PropertyChanged(dbus.String(u"checker"),

526

dbus.String(self.checker_command,

527

variant_level=1))

528

529

# SetHost - method

530

@dbus.service.method(_interface, in_signature="s")

531

def SetHost(self, host):

532

"D-Bus setter method"

533

self.host = host

534

# Emit D-Bus signal

535

self.PropertyChanged(dbus.String(u"host"),

536

dbus.String(self.host, variant_level=1))

537

538

# SetInterval - method

539

@dbus.service.method(_interface, in_signature="t")

540

def SetInterval(self, milliseconds):

541

self.interval = datetime.timedelta(0, 0, 0, milliseconds)

542

# Emit D-Bus signal

543

self.PropertyChanged(dbus.String(u"interval"),

544

(dbus.UInt64(self.interval_milliseconds(),

545

variant_level=1)))

546

547

# SetSecret - method

548

@dbus.service.method(_interface, in_signature="ay",

549

byte_arrays=True)

550

def SetSecret(self, secret):

551

"D-Bus setter method"

552

self.secret = str(secret)

553

554

# SetTimeout - method

555

@dbus.service.method(_interface, in_signature="t")

556

def SetTimeout(self, milliseconds):

557

self.timeout = datetime.timedelta(0, 0, 0, milliseconds)

558

# Emit D-Bus signal

559

self.PropertyChanged(dbus.String(u"timeout"),

560

(dbus.UInt64(self.timeout_milliseconds(),

561

variant_level=1)))

562

563

# Enable - method

564

Enable = dbus.service.method(_interface)(enable)

565

Enable.__name__ = "Enable"

566

567

# StartChecker - method

568

@dbus.service.method(_interface)

569

def StartChecker(self):

570

"D-Bus method"

571

self.start_checker()

572

573

# Disable - method

574

@dbus.service.method(_interface)

575

def Disable(self):

576

"D-Bus method"

577

self.disable()

578

579

# StopChecker - method

580

StopChecker = dbus.service.method(_interface)(stop_checker)

581

StopChecker.__name__ = "StopChecker"

582

583

del _interface

584

585

586

def peer_certificate(session):

587

"Return the peer's OpenPGP certificate as a bytestring"

588

# If not an OpenPGP certificate...

589

if (gnutls.library.functions

590

.gnutls_certificate_type_get(session._c_object)

591

!= gnutls.library.constants.GNUTLS_CRT_OPENPGP):

592

# ...do the normal thing

593

return session.peer_certificate

594

list_size = ctypes.c_uint()

595

cert_list = (gnutls.library.functions

596

.gnutls_certificate_get_peers

597

(session._c_object, ctypes.byref(list_size)))

598

if list_size.value == 0:

599

return None

600

cert = cert_list[0]

601

return ctypes.string_at(cert.data, cert.size)

602

603

604

def fingerprint(openpgp):

605

"Convert an OpenPGP bytestring to a hexdigit fingerprint string"

606

# New GnuTLS "datum" with the OpenPGP public key

607

datum = (gnutls.library.types

608

.gnutls_datum_t(ctypes.cast(ctypes.c_char_p(openpgp),

609

ctypes.POINTER

610

(ctypes.c_ubyte)),

611

ctypes.c_uint(len(openpgp))))

612

# New empty GnuTLS certificate

613

crt = gnutls.library.types.gnutls_openpgp_crt_t()

614

(gnutls.library.functions

615

.gnutls_openpgp_crt_init(ctypes.byref(crt)))

616

# Import the OpenPGP public key into the certificate

617

(gnutls.library.functions

618

.gnutls_openpgp_crt_import(crt, ctypes.byref(datum),

619

gnutls.library.constants

620

.GNUTLS_OPENPGP_FMT_RAW))

621

# Verify the self signature in the key

622

crtverify = ctypes.c_uint()

623

(gnutls.library.functions

624

.gnutls_openpgp_crt_verify_self(crt, 0, ctypes.byref(crtverify)))

625

if crtverify.value != 0:

626

gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)

627

raise gnutls.errors.CertificateSecurityError("Verify failed")

628

# New buffer for the fingerprint

629

buf = ctypes.create_string_buffer(20)

630

buf_len = ctypes.c_size_t()

631

# Get the fingerprint from the certificate into the buffer

632

(gnutls.library.functions

633

.gnutls_openpgp_crt_get_fingerprint(crt, ctypes.byref(buf),

634

ctypes.byref(buf_len)))

635

# Deinit the certificate

636

gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)

637

# Convert the buffer to a Python bytestring

638

fpr = ctypes.string_at(buf, buf_len.value)

639

# Convert the bytestring to hexadecimal notation

640

hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)

641

return hex_fpr

642

643

644

class TCP_handler(SocketServer.BaseRequestHandler, object):

645

"""A TCP request handler class.

646

Instantiated by IPv6_TCPServer for each request to handle it.

647

Note: This will run in its own forked process."""

648

649

def handle(self):

650

logger.info(u"TCP connection from: %s",

651

unicode(self.client_address))

652

session = (gnutls.connection

653

.ClientSession(self.request,

654

gnutls.connection

655

.X509Credentials()))

656

657

line = self.request.makefile().readline()

658

logger.debug(u"Protocol version: %r", line)

659

try:

660

if int(line.strip().split()[0]) > 1:

661

raise RuntimeError

662

except (ValueError, IndexError, RuntimeError), error:

663

logger.error(u"Unknown protocol version: %s", error)

664

return

665

666

# Note: gnutls.connection.X509Credentials is really a generic

667

# GnuTLS certificate credentials object so long as no X.509

668

# keys are added to it. Therefore, we can use it here despite

669

# using OpenPGP certificates.

670

671

#priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",

672

# "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",

673

# "+DHE-DSS"))

674

# Use a fallback default, since this MUST be set.

675

priority = self.server.settings.get("priority", "NORMAL")

676

(gnutls.library.functions

677

.gnutls_priority_set_direct(session._c_object,

678

priority, None))

679

680

try:

681

session.handshake()

682

except gnutls.errors.GNUTLSError, error:

683

logger.warning(u"Handshake failed: %s", error)

684

# Do not run session.bye() here: the session is not

685

# established. Just abandon the request.

686

return

687

try:

688

fpr = fingerprint(peer_certificate(session))

689

except (TypeError, gnutls.errors.GNUTLSError), error:

690

logger.warning(u"Bad certificate: %s", error)

691

session.bye()

692

return

693

logger.debug(u"Fingerprint: %s", fpr)

694

for c in self.server.clients:

695

if c.fingerprint == fpr:

696

client = c

697

break

698

else:

699

logger.warning(u"Client not found for fingerprint: %s",

700

fpr)

701

session.bye()

702

return

703

# Have to check if client.still_valid(), since it is possible

704

# that the client timed out while establishing the GnuTLS

705

# session.

706

if not client.still_valid():

707

logger.warning(u"Client %(name)s is invalid",

708

vars(client))

709

session.bye()

710

return

711

## This won't work here, since we're in a fork.

712

# client.bump_timeout()

713

sent_size = 0

714

while sent_size < len(client.secret):

715

sent = session.send(client.secret[sent_size:])

716

logger.debug(u"Sent: %d, remaining: %d",

717

sent, len(client.secret)

718

- (sent_size + sent))

719

sent_size += sent

720

session.bye()

721

722

723

class IPv6_TCPServer(SocketServer.ForkingMixIn,

724

SocketServer.TCPServer, object):

725

"""IPv6 TCP server. Accepts 'None' as address and/or port.

726

Attributes:

727

settings: Server settings

728

clients: Set() of Client objects

729

enabled: Boolean; whether this server is activated yet

730

"""

731

address_family = socket.AF_INET6

732

def __init__(self, *args, **kwargs):

733

if "settings" in kwargs:

734

self.settings = kwargs["settings"]

735

del kwargs["settings"]

736

if "clients" in kwargs:

737

self.clients = kwargs["clients"]

738

del kwargs["clients"]

739

self.enabled = False

740

super(IPv6_TCPServer, self).__init__(*args, **kwargs)

741

def server_bind(self):

742

"""This overrides the normal server_bind() function

743

to bind to an interface if one was specified, and also NOT to

744

bind to an address or port if they were not specified."""

745

if self.settings["interface"]:

746

# 25 is from /usr/include/asm-i486/socket.h

747

SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)

748

try:

749

self.socket.setsockopt(socket.SOL_SOCKET,

750

SO_BINDTODEVICE,

751

self.settings["interface"])

752

except socket.error, error:

753

if error[0] == errno.EPERM:

754

logger.error(u"No permission to"

755

u" bind to interface %s",

756

self.settings["interface"])

757

else:

758

raise error

759

# Only bind(2) the socket if we really need to.

760

if self.server_address[0] or self.server_address[1]:

761

if not self.server_address[0]:

762

in6addr_any = "::"

763

self.server_address = (in6addr_any,

764

self.server_address[1])

765

elif not self.server_address[1]:

766

self.server_address = (self.server_address[0],

767

0)

768

# if self.settings["interface"]:

769

# self.server_address = (self.server_address[0],

770

# 0, # port

771

# 0, # flowinfo

772

# if_nametoindex

773

# (self.settings

774

# ["interface"]))

775

return super(IPv6_TCPServer, self).server_bind()

776

def server_activate(self):

777

if self.enabled:

778

return super(IPv6_TCPServer, self).server_activate()

779

def enable(self):

780

self.enabled = True

781

782

783

def string_to_delta(interval):

784

"""Parse a string and return a datetime.timedelta

785

786

>>> string_to_delta('7d')

787

datetime.timedelta(7)

788

>>> string_to_delta('60s')

789

datetime.timedelta(0, 60)

790

>>> string_to_delta('60m')

791

datetime.timedelta(0, 3600)

792

>>> string_to_delta('24h')

793

datetime.timedelta(1)

794

>>> string_to_delta(u'1w')

795

datetime.timedelta(7)

796

>>> string_to_delta('5m 30s')

797

datetime.timedelta(0, 330)

798

"""

799

timevalue = datetime.timedelta(0)

800

for s in interval.split():

801

try:

802

suffix = unicode(s[-1])

803

value = int(s[:-1])

804

if suffix == u"d":

805

delta = datetime.timedelta(value)

806

elif suffix == u"s":

807

delta = datetime.timedelta(0, value)

808

elif suffix == u"m":

809

delta = datetime.timedelta(0, 0, 0, 0, value)

810

elif suffix == u"h":

811

delta = datetime.timedelta(0, 0, 0, 0, 0, value)

812

elif suffix == u"w":

813

delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)

51

814

else:

52

raise error

53

return super(type(self), self).server_bind()

54

55

56

def init_with_options(self, *args, **kwargs):

57

if "options" in kwargs:

58

self.options = kwargs["options"]

59

del kwargs["options"]

60

if "clients" in kwargs:

61

self.clients = kwargs["clients"]

62

del kwargs["clients"]

63

if "credentials" in kwargs:

64

self.credentials = kwargs["credentials"]

65

del kwargs["credentials"]

66

return super(type(self), self).__init__(*args, **kwargs)

67

68

69

class udp_handler(SocketServer.DatagramRequestHandler, object):

70

def handle(self):

71

self.wfile.write("Polo")

72

print "UDP request answered"

73

74

75

class IPv6_UDPServer(SocketServer.UDPServer, object):

76

__init__ = init_with_options

77

address_family = socket.AF_INET6

78

allow_reuse_address = True

79

server_bind = server_bind

80

def verify_request(self, request, client_address):

81

print "UDP request came"

82

return request[0] == "Marco"

83

84

85

class tcp_handler(SocketServer.BaseRequestHandler, object):

86

def handle(self):

87

print "TCP request came"

88

print "Request:", self.request

89

print "Client Address:", self.client_address

90

print "Server:", self.server

91

session = gnutls.connection.ServerSession(self.request,

92

self.server.credentials)

93

session.handshake()

94

if session.peer_certificate:

95

print "DN:", session.peer_certificate.subject

96

try:

97

session.verify_peer()

98

except gnutls.errors.CertificateError, error:

99

print "Verify failed", error

100

session.bye()

101

return

102

try:

103

session.send(dict((client.dn, client.password)

104

for client in self.server.clients)

105

[session.peer_certificate.subject])

106

except KeyError:

107

session.send("gazonk")

108

# Log maybe? XXX

109

session.bye()

110

111

class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):

112

__init__ = init_with_options

113

address_family = socket.AF_INET6

114

allow_reuse_address = True

115

request_queue_size = 1024

116

server_bind = server_bind

117

118

119

in6addr_any = "::"

120

121

cred = None

815

raise ValueError

816

except (ValueError, IndexError):

817

raise ValueError

818

timevalue += delta

819

return timevalue

820

821

822

def server_state_changed(state):

823

"""Derived from the Avahi example code"""

824

if state == avahi.SERVER_COLLISION:

825

logger.error(u"Zeroconf server name collision")

826

service.remove()

827

elif state == avahi.SERVER_RUNNING:

828

service.add()

829

830

831

def entry_group_state_changed(state, error):

832

"""Derived from the Avahi example code"""

833

logger.debug(u"Avahi state change: %i", state)

834

835

if state == avahi.ENTRY_GROUP_ESTABLISHED:

836

logger.debug(u"Zeroconf service established.")

837

elif state == avahi.ENTRY_GROUP_COLLISION:

838

logger.warning(u"Zeroconf service name collision.")

839

service.rename()

840

elif state == avahi.ENTRY_GROUP_FAILURE:

841

logger.critical(u"Avahi: Error in group state changed %s",

842

unicode(error))

843

raise AvahiGroupError(u"State changed: %s" % unicode(error))

844

845

def if_nametoindex(interface):

846

"""Call the C function if_nametoindex(), or equivalent"""

847

global if_nametoindex

848

try:

849

if_nametoindex = (ctypes.cdll.LoadLibrary

850

(ctypes.util.find_library("c"))

851

.if_nametoindex)

852

except (OSError, AttributeError):

853

if "struct" not in sys.modules:

854

import struct

855

if "fcntl" not in sys.modules:

856

import fcntl

857

def if_nametoindex(interface):

858

"Get an interface index the hard way, i.e. using fcntl()"

859

SIOCGIFINDEX = 0x8933 # From /usr/include/linux/sockios.h

860

with closing(socket.socket()) as s:

861

ifreq = fcntl.ioctl(s, SIOCGIFINDEX,

862

struct.pack("16s16x", interface))

863

interface_index = struct.unpack("I", ifreq[16:20])[0]

864

return interface_index

865

return if_nametoindex(interface)

866

867

868

def daemon(nochdir = False, noclose = False):

869

"""See daemon(3). Standard BSD Unix function.

870

This should really exist as os.daemon, but it doesn't (yet)."""

871

if os.fork():

872

sys.exit()

873

os.setsid()

874

if not nochdir:

875

os.chdir("/")

876

if os.fork():

877

sys.exit()

878

if not noclose:

879

# Close all standard open file descriptors

880

null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)

881

if not stat.S_ISCHR(os.fstat(null).st_mode):

882

raise OSError(errno.ENODEV,

883

"/dev/null not a character device")

884

os.dup2(null, sys.stdin.fileno())

885

os.dup2(null, sys.stdout.fileno())

886

os.dup2(null, sys.stderr.fileno())

887

if null > 2:

888

os.close(null)

889

122

890

123

891

def main():

124

parser = OptionParser()

892

parser = OptionParser(version = "%%prog %s" % version)

125

893

parser.add_option("-i", "--interface", type="string",

126

default="eth0", metavar="IF",

127

help="Interface to bind to")

128

parser.add_option("--cert", type="string", default="cert.pem",

129

metavar="FILE",

130

help="Public key certificate to use")

131

parser.add_option("--key", type="string", default="key.pem",

132

metavar="FILE",

133

help="Private key to use")

134

parser.add_option("--ca", type="string", default="ca.pem",

135

metavar="FILE",

136

help="Certificate Authority certificate to use")

137

parser.add_option("--crl", type="string", default="crl.pem",

138

metavar="FILE",

139

help="Certificate Revokation List to use")

140

parser.add_option("-p", "--port", type="int", default=49001,

894

metavar="IF", help="Bind to interface IF")

895

parser.add_option("-a", "--address", type="string",

896

help="Address to listen for requests on")

897

parser.add_option("-p", "--port", type="int",

141

898

help="Port number to receive requests on")

142

parser.add_option("--dh", type="int", metavar="BITS",

143

help="DH group to use")

144

parser.add_option("-t", "--timeout", type="string", # Parsed later

145

default="15m",

146

help="Amount of downtime allowed for clients")

147

(options, args) = parser.parse_args()

148

149

# Parse the time argument

150

try:

151

suffix=options.timeout[-1]

152

value=int(options.timeout[:-1])

153

if suffix == "d":

154

options.timeout = datetime.timedelta(value)

155

elif suffix == "s":

156

options.timeout = datetime.timedelta(0, value)

157

elif suffix == "m":

158

options.timeout = datetime.timedelta(0, 0, 0, 0, value)

159

elif suffix == "h":

160

options.timeout = datetime.timedelta(0, 0, 0, 0, 0, value)

161

elif suffix == "w":

162

options.timeout = datetime.timedelta(0, 0, 0, 0, 0, 0,

163

value)

164

else:

165

raise ValueError

166

except (ValueError, IndexError):

167

parser.error("option --timeout: Unparseable time")

168

169

cert = gnutls.crypto.X509Certificate(open(options.cert).read())

170

key = gnutls.crypto.X509PrivateKey(open(options.key).read())

171

ca = gnutls.crypto.X509Certificate(open(options.ca).read())

172

crl = gnutls.crypto.X509CRL(open(options.crl).read())

173

cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])

174

175

# Parse config file

176

defaults = {}

177

client_config_object = ConfigParser.SafeConfigParser(defaults)

178

client_config_object.read("mandos-clients.conf")

179

clients = [Client(name=section,

180

**(dict(client_config_object.items(section))))

181

for section in client_config_object.sections()]

182

183

udp_server = IPv6_UDPServer((in6addr_any, options.port),

184

udp_handler,

185

options=options)

186

187

tcp_server = IPv6_TCPServer((in6addr_any, options.port),

188

tcp_handler,

189

options=options,

190

clients=clients,

191

credentials=cred)

192

193

while True:

194

in_, out, err = select.select((udp_server,

195

tcp_server), (), ())

196

for server in in_:

197

server.handle_request()

198

199

200

if __name__ == "__main__":

899

parser.add_option("--check", action="store_true",

900

help="Run self-test")

901

parser.add_option("--debug", action="store_true",

902

help="Debug mode; run in foreground and log to"

903

" terminal")

904

parser.add_option("--priority", type="string", help="GnuTLS"

905

" priority string (see GnuTLS documentation)")

906

parser.add_option("--servicename", type="string", metavar="NAME",

907

help="Zeroconf service name")

908

parser.add_option("--configdir", type="string",

909

default="/etc/mandos", metavar="DIR",

910

help="Directory to search for configuration"

911

" files")

912

parser.add_option("--no-dbus", action="store_false",

913

dest="use_dbus",

914

help="Do not provide D-Bus system bus"

915

" interface")

916

options = parser.parse_args()[0]

917

918

if options.check:

919

import doctest

920

doctest.testmod()

921

sys.exit()

922

923

# Default values for config file for server-global settings

924

server_defaults = { "interface": "",

925

"address": "",

926

"port": "",

927

"debug": "False",

928

"priority":

929

"SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",

930

"servicename": "Mandos",

931

"use_dbus": "True",

932

}

933

934

# Parse config file for server-global settings

935

server_config = ConfigParser.SafeConfigParser(server_defaults)

936

del server_defaults

937

server_config.read(os.path.join(options.configdir, "mandos.conf"))

938

# Convert the SafeConfigParser object to a dict

939

server_settings = server_config.defaults()

940

# Use getboolean on the boolean config options

941

server_settings["debug"] = (server_config.getboolean

942

("DEFAULT", "debug"))

943

server_settings["use_dbus"] = (server_config.getboolean

944

("DEFAULT", "use_dbus"))

945

del server_config

946

947

# Override the settings from the config file with command line

948

# options, if set.

949

for option in ("interface", "address", "port", "debug",

950

"priority", "servicename", "configdir",

951

"use_dbus"):

952

value = getattr(options, option)

953

if value is not None:

954

server_settings[option] = value

955

del options

956

# Now we have our good server settings in "server_settings"

957

958

# For convenience

959

debug = server_settings["debug"]

960

use_dbus = server_settings["use_dbus"]

961

962

if not debug:

963

syslogger.setLevel(logging.WARNING)

964

console.setLevel(logging.WARNING)

965

966

if server_settings["servicename"] != "Mandos":

967

syslogger.setFormatter(logging.Formatter

968

('Mandos (%s): %%(levelname)s:'

969

' %%(message)s'

970

% server_settings["servicename"]))

971

972

# Parse config file with clients

973

client_defaults = { "timeout": "1h",

974

"interval": "5m",

975

"checker": "fping -q -- %(host)s",

976

"host": "",

977

}

978

client_config = ConfigParser.SafeConfigParser(client_defaults)

979

client_config.read(os.path.join(server_settings["configdir"],

980

"clients.conf"))

981

982

clients = Set()

983

tcp_server = IPv6_TCPServer((server_settings["address"],

984

server_settings["port"]),

985

TCP_handler,

986

settings=server_settings,

987

clients=clients)

988

pidfilename = "/var/run/mandos.pid"

989

try:

990

pidfile = open(pidfilename, "w")

991

except IOError, error:

992

logger.error("Could not open file %r", pidfilename)

993

994

try:

995

uid = pwd.getpwnam("_mandos").pw_uid

996

except KeyError:

997

try:

998

uid = pwd.getpwnam("mandos").pw_uid

999

except KeyError:

1000

try:

1001

uid = pwd.getpwnam("nobody").pw_uid

1002

except KeyError:

1003

uid = 65534

1004

try:

1005

gid = pwd.getpwnam("_mandos").pw_gid

1006

except KeyError:

1007

try:

1008

gid = pwd.getpwnam("mandos").pw_gid

1009

except KeyError:

1010

try:

1011

gid = pwd.getpwnam("nogroup").pw_gid

1012

except KeyError:

1013

gid = 65534

1014

try:

1015

os.setuid(uid)

1016

os.setgid(gid)

1017

except OSError, error:

1018

if error[0] != errno.EPERM:

1019

raise error

1020

1021

global service

1022

service = AvahiService(name = server_settings["servicename"],

1023

servicetype = "_mandos._tcp", )

1024

if server_settings["interface"]:

1025

service.interface = (if_nametoindex

1026

(server_settings["interface"]))

1027

1028

global main_loop

1029

global bus

1030

global server

1031

# From the Avahi example code

1032

DBusGMainLoop(set_as_default=True )

1033

main_loop = gobject.MainLoop()

1034

bus = dbus.SystemBus()

1035

server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,

1036

avahi.DBUS_PATH_SERVER),

1037

avahi.DBUS_INTERFACE_SERVER)

1038

# End of Avahi example code

1039

if use_dbus:

1040

bus_name = dbus.service.BusName(u"org.mandos-system.Mandos",

1041

bus)

1042

1043

clients.update(Set(Client(name = section,

1044

config

1045

= dict(client_config.items(section)),

1046

use_dbus = use_dbus)

1047

for section in client_config.sections()))

1048

if not clients:

1049

logger.warning(u"No clients defined")

1050

1051

if debug:

1052

# Redirect stdin so all checkers get /dev/null

1053

null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)

1054

os.dup2(null, sys.stdin.fileno())

1055

if null > 2:

1056

os.close(null)

1057

else:

1058

# No console logging

1059

logger.removeHandler(console)

1060

# Close all input and output, do double fork, etc.

1061

daemon()

1062

1063

try:

1064

pid = os.getpid()

1065

pidfile.write(str(pid) + "\n")

1066

pidfile.close()

1067

del pidfile

1068

except IOError:

1069

logger.error(u"Could not write to file %r with PID %d",

1070

pidfilename, pid)

1071

except NameError:

1072

# "pidfile" was never created

1073

pass

1074

del pidfilename

1075

1076

def cleanup():

1077

"Cleanup function; run on exit"

1078

global group

1079

# From the Avahi example code

1080

if not group is None:

1081

group.Free()

1082

group = None

1083

# End of Avahi example code

1084

1085

while clients:

1086

client = clients.pop()

1087

client.disable_hook = None

1088

client.disable()

1089

1090

atexit.register(cleanup)

1091

1092

if not debug:

1093

signal.signal(signal.SIGINT, signal.SIG_IGN)

1094

signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())

1095

signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())

1096

1097

if use_dbus:

1098

class MandosServer(dbus.service.Object):

1099

"""A D-Bus proxy object"""

1100

def __init__(self):

1101

dbus.service.Object.__init__(self, bus,

1102

"/Mandos")

1103

_interface = u"org.mandos_system.Mandos"

1104

1105

@dbus.service.signal(_interface, signature="oa{sv}")

1106

def ClientAdded(self, objpath, properties):

1107

"D-Bus signal"

1108

pass

1109

1110

@dbus.service.signal(_interface, signature="o")

1111

def ClientRemoved(self, objpath):

1112

"D-Bus signal"

1113

pass

1114

1115

@dbus.service.method(_interface, out_signature="ao")

1116

def GetAllClients(self):

1117

return dbus.Array(c.dbus_object_path for c in clients)

1118

1119

@dbus.service.method(_interface, out_signature="a{oa{sv}}")

1120

def GetAllClientsWithProperties(self):

1121

return dbus.Dictionary(

1122

((c.dbus_object_path, c.GetAllProperties())

1123

for c in clients),

1124

signature="oa{sv}")

1125

1126

@dbus.service.method(_interface, in_signature="o")

1127

def RemoveClient(self, object_path):

1128

for c in clients:

1129

if c.dbus_object_path == object_path:

1130

clients.remove(c)

1131

# Don't signal anything except ClientRemoved

1132

c.use_dbus = False

1133

c.disable()

1134

# Emit D-Bus signal

1135

self.ClientRemoved(object_path)

1136

return

1137

raise KeyError

1138

@dbus.service.method(_interface)

1139

def Quit(self):

1140

main_loop.quit()

1141

1142

del _interface

1143

1144

mandos_server = MandosServer()

1145

1146

for client in clients:

1147

if use_dbus:

1148

# Emit D-Bus signal

1149

mandos_server.ClientAdded(client.dbus_object_path,

1150

client.GetAllProperties())

1151

client.enable()

1152

1153

tcp_server.enable()

1154

tcp_server.server_activate()

1155

1156

# Find out what port we got

1157

service.port = tcp_server.socket.getsockname()[1]

1158

logger.info(u"Now listening on address %r, port %d, flowinfo %d,"

1159

u" scope_id %d" % tcp_server.socket.getsockname())

1160

1161

#service.interface = tcp_server.socket.getsockname()[3]

1162

1163

try:

1164

# From the Avahi example code

1165

server.connect_to_signal("StateChanged", server_state_changed)

1166

try:

1167

server_state_changed(server.GetState())

1168

except dbus.exceptions.DBusException, error:

1169

logger.critical(u"DBusException: %s", error)

1170

sys.exit(1)

1171

# End of Avahi example code

1172

1173

gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,

1174

lambda *args, **kwargs:

1175

(tcp_server.handle_request

1176

(*args[2:], **kwargs) or True))

1177

1178

logger.debug(u"Starting main loop")

1179

main_loop.run()

1180

except AvahiError, error:

1181

logger.critical(u"AvahiError: %s", error)

1182

sys.exit(1)

1183

except KeyboardInterrupt:

1184

if debug:

1185

print

1186

1187

if __name__ == '__main__':

201

1188

main()

202