1
# Copyright (C) 2006-2010 Robey Pointer <robey@lag.net>
2
# Copyright (C) 2005, 2006, 2007 Canonical Ltd
4
# This program is free software; you can redistribute it and/or modify
5
# it under the terms of the GNU General Public License as published by
6
# the Free Software Foundation; either version 2 of the License, or
7
# (at your option) any later version.
9
# This program is distributed in the hope that it will be useful,
10
# but WITHOUT ANY WARRANTY; without even the implied warranty of
11
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12
# GNU General Public License for more details.
14
# You should have received a copy of the GNU General Public License
15
# along with this program; if not, write to the Free Software
16
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18
"""Foundation SSH support for SFTP and smart server."""
38
except ImportError, e:
39
# If we have an ssh subprocess, we don't strictly need paramiko for all ssh
43
from paramiko.sftp_client import SFTPClient
50
_paramiko_version = getattr(paramiko, '__version_info__', (0, 0, 0))
52
# Paramiko 1.5 tries to open a socket.AF_UNIX in order to connect
53
# to ssh-agent. That attribute doesn't exist on win32 (it does in cygwin)
54
# so we get an AttributeError exception. So we will not try to
55
# connect to an agent if we are on win32 and using Paramiko older than 1.6
56
_use_ssh_agent = (sys.platform != 'win32' or _paramiko_version >= (1, 6, 0))
59
class SSHVendorManager(object):
60
"""Manager for manage SSH vendors."""
62
# Note, although at first sign the class interface seems similar to
63
# bzrlib.registry.Registry it is not possible/convenient to directly use
64
# the Registry because the class just has "get()" interface instead of the
65
# Registry's "get(key)".
68
self._ssh_vendors = {}
69
self._cached_ssh_vendor = None
70
self._default_ssh_vendor = None
72
def register_default_vendor(self, vendor):
73
"""Register default SSH vendor."""
74
self._default_ssh_vendor = vendor
76
def register_vendor(self, name, vendor):
77
"""Register new SSH vendor by name."""
78
self._ssh_vendors[name] = vendor
80
def clear_cache(self):
81
"""Clear previously cached lookup result."""
82
self._cached_ssh_vendor = None
84
def _get_vendor_by_environment(self, environment=None):
85
"""Return the vendor or None based on BZR_SSH environment variable.
87
:raises UnknownSSH: if the BZR_SSH environment variable contains
90
if environment is None:
91
environment = os.environ
92
if 'BZR_SSH' in environment:
93
vendor_name = environment['BZR_SSH']
95
vendor = self._ssh_vendors[vendor_name]
97
vendor = self._get_vendor_from_path(vendor_name)
99
raise errors.UnknownSSH(vendor_name)
100
vendor.executable_path = vendor_name
104
def _get_ssh_version_string(self, args):
105
"""Return SSH version string from the subprocess."""
107
p = subprocess.Popen(args,
108
stdout=subprocess.PIPE,
109
stderr=subprocess.PIPE,
110
**os_specific_subprocess_params())
111
stdout, stderr = p.communicate()
114
return stdout + stderr
116
def _get_vendor_by_version_string(self, version, progname):
117
"""Return the vendor or None based on output from the subprocess.
119
:param version: The output of 'ssh -V' like command.
120
:param args: Command line that was run.
123
if 'OpenSSH' in version:
124
trace.mutter('ssh implementation is OpenSSH')
125
vendor = OpenSSHSubprocessVendor()
126
elif 'SSH Secure Shell' in version:
127
trace.mutter('ssh implementation is SSH Corp.')
128
vendor = SSHCorpSubprocessVendor()
129
# As plink user prompts are not handled currently, don't auto-detect
130
# it by inspection below, but keep this vendor detection for if a path
131
# is given in BZR_SSH. See https://bugs.launchpad.net/bugs/414743
132
elif 'plink' in version and progname == 'plink':
133
# Checking if "plink" was the executed argument as Windows
134
# sometimes reports 'ssh -V' incorrectly with 'plink' in it's
135
# version. See https://bugs.launchpad.net/bzr/+bug/107155
136
trace.mutter("ssh implementation is Putty's plink.")
137
vendor = PLinkSubprocessVendor()
140
def _get_vendor_by_inspection(self):
141
"""Return the vendor or None by checking for known SSH implementations."""
142
version = self._get_ssh_version_string(['ssh', '-V'])
143
return self._get_vendor_by_version_string(version, "ssh")
145
def _get_vendor_from_path(self, path):
146
"""Return the vendor or None using the program at the given path"""
147
version = self._get_ssh_version_string([path, '-V'])
148
return self._get_vendor_by_version_string(version,
149
os.path.splitext(os.path.basename(path))[0])
151
def get_vendor(self, environment=None):
152
"""Find out what version of SSH is on the system.
154
:raises SSHVendorNotFound: if no any SSH vendor is found
155
:raises UnknownSSH: if the BZR_SSH environment variable contains
158
if self._cached_ssh_vendor is None:
159
vendor = self._get_vendor_by_environment(environment)
161
vendor = self._get_vendor_by_inspection()
163
trace.mutter('falling back to default implementation')
164
vendor = self._default_ssh_vendor
166
raise errors.SSHVendorNotFound()
167
self._cached_ssh_vendor = vendor
168
return self._cached_ssh_vendor
170
_ssh_vendor_manager = SSHVendorManager()
171
_get_ssh_vendor = _ssh_vendor_manager.get_vendor
172
register_default_ssh_vendor = _ssh_vendor_manager.register_default_vendor
173
register_ssh_vendor = _ssh_vendor_manager.register_vendor
176
def _ignore_signals():
177
# TODO: This should possibly ignore SIGHUP as well, but bzr currently
178
# doesn't handle it itself.
179
# <https://launchpad.net/products/bzr/+bug/41433/+index>
181
signal.signal(signal.SIGINT, signal.SIG_IGN)
182
# GZ 2010-02-19: Perhaps make this check if breakin is installed instead
183
if signal.getsignal(signal.SIGQUIT) != signal.SIG_DFL:
184
signal.signal(signal.SIGQUIT, signal.SIG_IGN)
187
class SocketAsChannelAdapter(object):
188
"""Simple wrapper for a socket that pretends to be a paramiko Channel."""
190
def __init__(self, sock):
194
return "bzr SocketAsChannelAdapter"
196
def send(self, data):
197
return self.__socket.send(data)
201
return self.__socket.recv(n)
202
except socket.error, e:
203
if e.args[0] in (errno.EPIPE, errno.ECONNRESET, errno.ECONNABORTED,
205
# Connection has closed. Paramiko expects an empty string in
206
# this case, not an exception.
210
def recv_ready(self):
211
# TODO: jam 20051215 this function is necessary to support the
212
# pipelined() function. In reality, it probably should use
213
# poll() or select() to actually return if there is data
214
# available, otherwise we probably don't get any benefit
218
self.__socket.close()
221
class SSHVendor(object):
222
"""Abstract base class for SSH vendor implementations."""
224
def connect_sftp(self, username, password, host, port):
225
"""Make an SSH connection, and return an SFTPClient.
227
:param username: an ascii string
228
:param password: an ascii string
229
:param host: a host name as an ascii string
230
:param port: a port number
233
:raises: ConnectionError if it cannot connect.
235
:rtype: paramiko.sftp_client.SFTPClient
237
raise NotImplementedError(self.connect_sftp)
239
def connect_ssh(self, username, password, host, port, command):
240
"""Make an SSH connection.
242
:returns: an SSHConnection.
244
raise NotImplementedError(self.connect_ssh)
246
def _raise_connection_error(self, host, port=None, orig_error=None,
247
msg='Unable to connect to SSH host'):
248
"""Raise a SocketConnectionError with properly formatted host.
250
This just unifies all the locations that try to raise ConnectionError,
251
so that they format things properly.
253
raise errors.SocketConnectionError(host=host, port=port, msg=msg,
254
orig_error=orig_error)
257
class LoopbackVendor(SSHVendor):
258
"""SSH "vendor" that connects over a plain TCP socket, not SSH."""
260
def connect_sftp(self, username, password, host, port):
261
sock = socket.socket()
263
sock.connect((host, port))
264
except socket.error, e:
265
self._raise_connection_error(host, port=port, orig_error=e)
266
return SFTPClient(SocketAsChannelAdapter(sock))
268
register_ssh_vendor('loopback', LoopbackVendor())
271
class ParamikoVendor(SSHVendor):
272
"""Vendor that uses paramiko."""
274
def _connect(self, username, password, host, port):
275
global SYSTEM_HOSTKEYS, BZR_HOSTKEYS
280
t = paramiko.Transport((host, port or 22))
281
t.set_log_channel('bzr.paramiko')
283
except (paramiko.SSHException, socket.error), e:
284
self._raise_connection_error(host, port=port, orig_error=e)
286
server_key = t.get_remote_server_key()
287
server_key_hex = paramiko.util.hexify(server_key.get_fingerprint())
288
keytype = server_key.get_name()
289
if host in SYSTEM_HOSTKEYS and keytype in SYSTEM_HOSTKEYS[host]:
290
our_server_key = SYSTEM_HOSTKEYS[host][keytype]
291
our_server_key_hex = paramiko.util.hexify(
292
our_server_key.get_fingerprint())
293
elif host in BZR_HOSTKEYS and keytype in BZR_HOSTKEYS[host]:
294
our_server_key = BZR_HOSTKEYS[host][keytype]
295
our_server_key_hex = paramiko.util.hexify(
296
our_server_key.get_fingerprint())
298
trace.warning('Adding %s host key for %s: %s'
299
% (keytype, host, server_key_hex))
300
add = getattr(BZR_HOSTKEYS, 'add', None)
301
if add is not None: # paramiko >= 1.X.X
302
BZR_HOSTKEYS.add(host, keytype, server_key)
304
BZR_HOSTKEYS.setdefault(host, {})[keytype] = server_key
305
our_server_key = server_key
306
our_server_key_hex = paramiko.util.hexify(
307
our_server_key.get_fingerprint())
309
if server_key != our_server_key:
310
filename1 = os.path.expanduser('~/.ssh/known_hosts')
311
filename2 = osutils.pathjoin(config.config_dir(), 'ssh_host_keys')
312
raise errors.TransportError(
313
'Host keys for %s do not match! %s != %s' %
314
(host, our_server_key_hex, server_key_hex),
315
['Try editing %s or %s' % (filename1, filename2)])
317
_paramiko_auth(username, password, host, port, t)
320
def connect_sftp(self, username, password, host, port):
321
t = self._connect(username, password, host, port)
323
return t.open_sftp_client()
324
except paramiko.SSHException, e:
325
self._raise_connection_error(host, port=port, orig_error=e,
326
msg='Unable to start sftp client')
328
def connect_ssh(self, username, password, host, port, command):
329
t = self._connect(username, password, host, port)
331
channel = t.open_session()
332
cmdline = ' '.join(command)
333
channel.exec_command(cmdline)
334
return _ParamikoSSHConnection(channel)
335
except paramiko.SSHException, e:
336
self._raise_connection_error(host, port=port, orig_error=e,
337
msg='Unable to invoke remote bzr')
339
if paramiko is not None:
340
vendor = ParamikoVendor()
341
register_ssh_vendor('paramiko', vendor)
342
register_ssh_vendor('none', vendor)
343
register_default_ssh_vendor(vendor)
344
_sftp_connection_errors = (EOFError, paramiko.SSHException)
347
_sftp_connection_errors = (EOFError,)
350
class SubprocessVendor(SSHVendor):
351
"""Abstract base class for vendors that use pipes to a subprocess."""
353
def _connect(self, argv):
354
# Attempt to make a socketpair to use as stdin/stdout for the SSH
355
# subprocess. We prefer sockets to pipes because they support
356
# non-blocking short reads, allowing us to optimistically read 64k (or
359
my_sock, subproc_sock = socket.socketpair()
360
except (AttributeError, socket.error):
361
# This platform doesn't support socketpair(), so just use ordinary
363
stdin = stdout = subprocess.PIPE
366
stdin = stdout = subproc_sock
368
proc = subprocess.Popen(argv, stdin=stdin, stdout=stdout,
369
**os_specific_subprocess_params())
370
return SSHSubprocessConnection(proc, sock=sock)
372
def connect_sftp(self, username, password, host, port):
374
argv = self._get_vendor_specific_argv(username, host, port,
376
sock = self._connect(argv)
377
return SFTPClient(SocketAsChannelAdapter(sock))
378
except _sftp_connection_errors, e:
379
self._raise_connection_error(host, port=port, orig_error=e)
380
except (OSError, IOError), e:
381
# If the machine is fast enough, ssh can actually exit
382
# before we try and send it the sftp request, which
383
# raises a Broken Pipe
384
if e.errno not in (errno.EPIPE,):
386
self._raise_connection_error(host, port=port, orig_error=e)
388
def connect_ssh(self, username, password, host, port, command):
390
argv = self._get_vendor_specific_argv(username, host, port,
392
return self._connect(argv)
393
except (EOFError), e:
394
self._raise_connection_error(host, port=port, orig_error=e)
395
except (OSError, IOError), e:
396
# If the machine is fast enough, ssh can actually exit
397
# before we try and send it the sftp request, which
398
# raises a Broken Pipe
399
if e.errno not in (errno.EPIPE,):
401
self._raise_connection_error(host, port=port, orig_error=e)
403
def _get_vendor_specific_argv(self, username, host, port, subsystem=None,
405
"""Returns the argument list to run the subprocess with.
407
Exactly one of 'subsystem' and 'command' must be specified.
409
raise NotImplementedError(self._get_vendor_specific_argv)
412
class OpenSSHSubprocessVendor(SubprocessVendor):
413
"""SSH vendor that uses the 'ssh' executable from OpenSSH."""
415
executable_path = 'ssh'
417
def _get_vendor_specific_argv(self, username, host, port, subsystem=None,
419
args = [self.executable_path,
420
'-oForwardX11=no', '-oForwardAgent=no',
421
'-oClearAllForwardings=yes', '-oProtocol=2',
422
'-oNoHostAuthenticationForLocalhost=yes']
424
args.extend(['-p', str(port)])
425
if username is not None:
426
args.extend(['-l', username])
427
if subsystem is not None:
428
args.extend(['-s', host, subsystem])
430
args.extend([host] + command)
433
register_ssh_vendor('openssh', OpenSSHSubprocessVendor())
436
class SSHCorpSubprocessVendor(SubprocessVendor):
437
"""SSH vendor that uses the 'ssh' executable from SSH Corporation."""
439
executable_path = 'ssh'
441
def _get_vendor_specific_argv(self, username, host, port, subsystem=None,
443
args = [self.executable_path, '-x']
445
args.extend(['-p', str(port)])
446
if username is not None:
447
args.extend(['-l', username])
448
if subsystem is not None:
449
args.extend(['-s', subsystem, host])
451
args.extend([host] + command)
454
register_ssh_vendor('sshcorp', SSHCorpSubprocessVendor())
457
class PLinkSubprocessVendor(SubprocessVendor):
458
"""SSH vendor that uses the 'plink' executable from Putty."""
460
executable_path = 'plink'
462
def _get_vendor_specific_argv(self, username, host, port, subsystem=None,
464
args = [self.executable_path, '-x', '-a', '-ssh', '-2', '-batch']
466
args.extend(['-P', str(port)])
467
if username is not None:
468
args.extend(['-l', username])
469
if subsystem is not None:
470
args.extend(['-s', host, subsystem])
472
args.extend([host] + command)
475
register_ssh_vendor('plink', PLinkSubprocessVendor())
478
def _paramiko_auth(username, password, host, port, paramiko_transport):
479
auth = config.AuthenticationConfig()
480
# paramiko requires a username, but it might be none if nothing was
481
# supplied. If so, use the local username.
483
username = auth.get_user('ssh', host, port=port,
484
default=getpass.getuser())
486
agent = paramiko.Agent()
487
for key in agent.get_keys():
488
trace.mutter('Trying SSH agent key %s'
489
% paramiko.util.hexify(key.get_fingerprint()))
491
paramiko_transport.auth_publickey(username, key)
493
except paramiko.SSHException, e:
496
# okay, try finding id_rsa or id_dss? (posix only)
497
if _try_pkey_auth(paramiko_transport, paramiko.RSAKey, username, 'id_rsa'):
499
if _try_pkey_auth(paramiko_transport, paramiko.DSSKey, username, 'id_dsa'):
502
# If we have gotten this far, we are about to try for passwords, do an
503
# auth_none check to see if it is even supported.
504
supported_auth_types = []
506
# Note that with paramiko <1.7.5 this logs an INFO message:
507
# Authentication type (none) not permitted.
508
# So we explicitly disable the logging level for this action
509
old_level = paramiko_transport.logger.level
510
paramiko_transport.logger.setLevel(logging.WARNING)
512
paramiko_transport.auth_none(username)
514
paramiko_transport.logger.setLevel(old_level)
515
except paramiko.BadAuthenticationType, e:
516
# Supported methods are in the exception
517
supported_auth_types = e.allowed_types
518
except paramiko.SSHException, e:
519
# Don't know what happened, but just ignore it
521
# We treat 'keyboard-interactive' and 'password' auth methods identically,
522
# because Paramiko's auth_password method will automatically try
523
# 'keyboard-interactive' auth (using the password as the response) if
524
# 'password' auth is not available. Apparently some Debian and Gentoo
525
# OpenSSH servers require this.
526
# XXX: It's possible for a server to require keyboard-interactive auth that
527
# requires something other than a single password, but we currently don't
529
if ('password' not in supported_auth_types and
530
'keyboard-interactive' not in supported_auth_types):
531
raise errors.ConnectionError('Unable to authenticate to SSH host as'
532
'\n %s@%s\nsupported auth types: %s'
533
% (username, host, supported_auth_types))
537
paramiko_transport.auth_password(username, password)
539
except paramiko.SSHException, e:
542
# give up and ask for a password
543
password = auth.get_password('ssh', host, username, port=port)
544
# get_password can still return None, which means we should not prompt
545
if password is not None:
547
paramiko_transport.auth_password(username, password)
548
except paramiko.SSHException, e:
549
raise errors.ConnectionError(
550
'Unable to authenticate to SSH host as'
551
'\n %s@%s\n' % (username, host), e)
553
raise errors.ConnectionError('Unable to authenticate to SSH host as'
554
' %s@%s' % (username, host))
557
def _try_pkey_auth(paramiko_transport, pkey_class, username, filename):
558
filename = os.path.expanduser('~/.ssh/' + filename)
560
key = pkey_class.from_private_key_file(filename)
561
paramiko_transport.auth_publickey(username, key)
563
except paramiko.PasswordRequiredException:
564
password = ui.ui_factory.get_password(
565
prompt='SSH %(filename)s password', filename=filename)
567
key = pkey_class.from_private_key_file(filename, password)
568
paramiko_transport.auth_publickey(username, key)
570
except paramiko.SSHException:
571
trace.mutter('SSH authentication via %s key failed.'
572
% (os.path.basename(filename),))
573
except paramiko.SSHException:
574
trace.mutter('SSH authentication via %s key failed.'
575
% (os.path.basename(filename),))
581
def load_host_keys():
583
Load system host keys (probably doesn't work on windows) and any
584
"discovered" keys from previous sessions.
586
global SYSTEM_HOSTKEYS, BZR_HOSTKEYS
588
SYSTEM_HOSTKEYS = paramiko.util.load_host_keys(
589
os.path.expanduser('~/.ssh/known_hosts'))
591
trace.mutter('failed to load system host keys: ' + str(e))
592
bzr_hostkey_path = osutils.pathjoin(config.config_dir(), 'ssh_host_keys')
594
BZR_HOSTKEYS = paramiko.util.load_host_keys(bzr_hostkey_path)
596
trace.mutter('failed to load bzr host keys: ' + str(e))
600
def save_host_keys():
602
Save "discovered" host keys in $(config)/ssh_host_keys/.
604
global SYSTEM_HOSTKEYS, BZR_HOSTKEYS
605
bzr_hostkey_path = osutils.pathjoin(config.config_dir(), 'ssh_host_keys')
606
config.ensure_config_dir_exists()
609
f = open(bzr_hostkey_path, 'w')
610
f.write('# SSH host keys collected by bzr\n')
611
for hostname, keys in BZR_HOSTKEYS.iteritems():
612
for keytype, key in keys.iteritems():
613
f.write('%s %s %s\n' % (hostname, keytype, key.get_base64()))
616
trace.mutter('failed to save bzr host keys: ' + str(e))
619
def os_specific_subprocess_params():
620
"""Get O/S specific subprocess parameters."""
621
if sys.platform == 'win32':
622
# setting the process group and closing fds is not supported on
626
# We close fds other than the pipes as the child process does not need
629
# We also set the child process to ignore SIGINT. Normally the signal
630
# would be sent to every process in the foreground process group, but
631
# this causes it to be seen only by bzr and not by ssh. Python will
632
# generate a KeyboardInterrupt in bzr, and we will then have a chance
633
# to release locks or do other cleanup over ssh before the connection
635
# <https://launchpad.net/products/bzr/+bug/5987>
637
# Running it in a separate process group is not good because then it
638
# can't get non-echoed input of a password or passphrase.
639
# <https://launchpad.net/products/bzr/+bug/40508>
640
return {'preexec_fn': _ignore_signals,
645
_subproc_weakrefs = set()
647
def _close_ssh_proc(proc):
648
for func in [proc.stdin.close, proc.stdout.close, proc.wait]:
655
class SSHConnection(object):
656
"""Abstract base class for SSH connections."""
658
def get_sock_or_pipes(self):
659
"""Returns a (kind, io_object) pair.
661
If kind == 'socket', then io_object is a socket.
663
If kind == 'pipes', then io_object is a pair of file-like objects
664
(read_from, write_to).
666
raise NotImplementedError(self.get_sock_or_pipes)
669
raise NotImplementedError(self.close)
672
class SSHSubprocessConnection(SSHConnection):
673
"""A connection to an ssh subprocess via pipes or a socket.
675
This class is also socket-like enough to be used with
676
SocketAsChannelAdapter (it has 'send' and 'recv' methods).
679
def __init__(self, proc, sock=None):
682
:param proc: a subprocess.Popen
683
:param sock: if proc.stdin/out is a socket from a socketpair, then sock
684
should bzrlib's half of that socketpair. If not passed, proc's
685
stdin/out is assumed to be ordinary pipes.
689
# Add a weakref to proc that will attempt to do the same as self.close
690
# to avoid leaving processes lingering indefinitely.
692
_subproc_weakrefs.remove(ref)
693
_close_ssh_proc(proc)
694
_subproc_weakrefs.add(weakref.ref(self, terminate))
696
def send(self, data):
697
if self._sock is not None:
698
return self._sock.send(data)
700
return os.write(self.proc.stdin.fileno(), data)
702
def recv(self, count):
703
if self._sock is not None:
704
return self._sock.recv(count)
706
return os.read(self.proc.stdout.fileno(), count)
709
_close_ssh_proc(self.proc)
711
def get_sock_or_pipes(self):
712
if self._sock is not None:
713
return 'socket', self._sock
715
return 'pipes', (self.proc.stdout, self.proc.stdin)
718
class _ParamikoSSHConnection(SSHConnection):
719
"""An SSH connection via paramiko."""
721
def __init__(self, channel):
722
self.channel = channel
724
def get_sock_or_pipes(self):
725
return ('socket', self.channel)
728
return self.channel.close()
added
removed
bzrlib/transport/ssh.py
