368 lines
12 KiB
Python
368 lines
12 KiB
Python
"""Basic ssh tunnel utilities, and convenience functions for tunneling
|
|
zeromq connections.
|
|
"""
|
|
|
|
# Copyright (C) 2010-2011 IPython Development Team
|
|
# Copyright (C) 2011- PyZMQ Developers
|
|
#
|
|
# Redistributed from IPython under the terms of the BSD License.
|
|
|
|
|
|
from __future__ import print_function
|
|
|
|
import atexit
|
|
import os
|
|
import re
|
|
import signal
|
|
import socket
|
|
import sys
|
|
import warnings
|
|
from getpass import getpass, getuser
|
|
from multiprocessing import Process
|
|
|
|
try:
|
|
with warnings.catch_warnings():
|
|
warnings.simplefilter('ignore', DeprecationWarning)
|
|
import paramiko
|
|
SSHException = paramiko.ssh_exception.SSHException
|
|
except ImportError:
|
|
paramiko = None
|
|
class SSHException(Exception):
|
|
pass
|
|
else:
|
|
from .forward import forward_tunnel
|
|
|
|
try:
|
|
import pexpect
|
|
except ImportError:
|
|
pexpect = None
|
|
|
|
from ..utils.strtypes import b
|
|
|
|
|
|
def select_random_ports(n):
|
|
"""Select and return n random ports that are available."""
|
|
ports = []
|
|
sockets = []
|
|
for i in range(n):
|
|
sock = socket.socket()
|
|
sock.bind(('', 0))
|
|
ports.append(sock.getsockname()[1])
|
|
sockets.append(sock)
|
|
for sock in sockets:
|
|
sock.close()
|
|
return ports
|
|
|
|
#-----------------------------------------------------------------------------
|
|
# Check for passwordless login
|
|
#-----------------------------------------------------------------------------
|
|
_password_pat = re.compile(b(r'pass(word|phrase):'), re.IGNORECASE)
|
|
|
|
def try_passwordless_ssh(server, keyfile, paramiko=None):
|
|
"""Attempt to make an ssh connection without a password.
|
|
This is mainly used for requiring password input only once
|
|
when many tunnels may be connected to the same server.
|
|
|
|
If paramiko is None, the default for the platform is chosen.
|
|
"""
|
|
if paramiko is None:
|
|
paramiko = sys.platform == 'win32'
|
|
if not paramiko:
|
|
f = _try_passwordless_openssh
|
|
else:
|
|
f = _try_passwordless_paramiko
|
|
return f(server, keyfile)
|
|
|
|
def _try_passwordless_openssh(server, keyfile):
|
|
"""Try passwordless login with shell ssh command."""
|
|
if pexpect is None:
|
|
raise ImportError("pexpect unavailable, use paramiko")
|
|
cmd = 'ssh -f '+ server
|
|
if keyfile:
|
|
cmd += ' -i ' + keyfile
|
|
cmd += ' exit'
|
|
|
|
# pop SSH_ASKPASS from env
|
|
env = os.environ.copy()
|
|
env.pop('SSH_ASKPASS', None)
|
|
|
|
ssh_newkey = 'Are you sure you want to continue connecting'
|
|
p = pexpect.spawn(cmd, env=env)
|
|
while True:
|
|
try:
|
|
i = p.expect([ssh_newkey, _password_pat], timeout=.1)
|
|
if i==0:
|
|
raise SSHException('The authenticity of the host can\'t be established.')
|
|
except pexpect.TIMEOUT:
|
|
continue
|
|
except pexpect.EOF:
|
|
return True
|
|
else:
|
|
return False
|
|
|
|
def _try_passwordless_paramiko(server, keyfile):
|
|
"""Try passwordless login with paramiko."""
|
|
if paramiko is None:
|
|
msg = "Paramiko unavailable, "
|
|
if sys.platform == 'win32':
|
|
msg += "Paramiko is required for ssh tunneled connections on Windows."
|
|
else:
|
|
msg += "use OpenSSH."
|
|
raise ImportError(msg)
|
|
username, server, port = _split_server(server)
|
|
client = paramiko.SSHClient()
|
|
client.load_system_host_keys()
|
|
client.set_missing_host_key_policy(paramiko.WarningPolicy())
|
|
try:
|
|
client.connect(server, port, username=username, key_filename=keyfile,
|
|
look_for_keys=True)
|
|
except paramiko.AuthenticationException:
|
|
return False
|
|
else:
|
|
client.close()
|
|
return True
|
|
|
|
|
|
def tunnel_connection(socket, addr, server, keyfile=None, password=None, paramiko=None, timeout=60):
|
|
"""Connect a socket to an address via an ssh tunnel.
|
|
|
|
This is a wrapper for socket.connect(addr), when addr is not accessible
|
|
from the local machine. It simply creates an ssh tunnel using the remaining args,
|
|
and calls socket.connect('tcp://localhost:lport') where lport is the randomly
|
|
selected local port of the tunnel.
|
|
|
|
"""
|
|
new_url, tunnel = open_tunnel(addr, server, keyfile=keyfile, password=password, paramiko=paramiko, timeout=timeout)
|
|
socket.connect(new_url)
|
|
return tunnel
|
|
|
|
|
|
def open_tunnel(addr, server, keyfile=None, password=None, paramiko=None, timeout=60):
|
|
"""Open a tunneled connection from a 0MQ url.
|
|
|
|
For use inside tunnel_connection.
|
|
|
|
Returns
|
|
-------
|
|
|
|
(url, tunnel) : (str, object)
|
|
The 0MQ url that has been forwarded, and the tunnel object
|
|
"""
|
|
|
|
lport = select_random_ports(1)[0]
|
|
transport, addr = addr.split('://')
|
|
ip,rport = addr.split(':')
|
|
rport = int(rport)
|
|
if paramiko is None:
|
|
paramiko = sys.platform == 'win32'
|
|
if paramiko:
|
|
tunnelf = paramiko_tunnel
|
|
else:
|
|
tunnelf = openssh_tunnel
|
|
|
|
tunnel = tunnelf(lport, rport, server, remoteip=ip, keyfile=keyfile, password=password, timeout=timeout)
|
|
return 'tcp://127.0.0.1:%i'%lport, tunnel
|
|
|
|
def openssh_tunnel(lport, rport, server, remoteip='127.0.0.1', keyfile=None, password=None, timeout=60):
|
|
"""Create an ssh tunnel using command-line ssh that connects port lport
|
|
on this machine to localhost:rport on server. The tunnel
|
|
will automatically close when not in use, remaining open
|
|
for a minimum of timeout seconds for an initial connection.
|
|
|
|
This creates a tunnel redirecting `localhost:lport` to `remoteip:rport`,
|
|
as seen from `server`.
|
|
|
|
keyfile and password may be specified, but ssh config is checked for defaults.
|
|
|
|
Parameters
|
|
----------
|
|
|
|
lport : int
|
|
local port for connecting to the tunnel from this machine.
|
|
rport : int
|
|
port on the remote machine to connect to.
|
|
server : str
|
|
The ssh server to connect to. The full ssh server string will be parsed.
|
|
user@server:port
|
|
remoteip : str [Default: 127.0.0.1]
|
|
The remote ip, specifying the destination of the tunnel.
|
|
Default is localhost, which means that the tunnel would redirect
|
|
localhost:lport on this machine to localhost:rport on the *server*.
|
|
|
|
keyfile : str; path to public key file
|
|
This specifies a key to be used in ssh login, default None.
|
|
Regular default ssh keys will be used without specifying this argument.
|
|
password : str;
|
|
Your ssh password to the ssh server. Note that if this is left None,
|
|
you will be prompted for it if passwordless key based login is unavailable.
|
|
timeout : int [default: 60]
|
|
The time (in seconds) after which no activity will result in the tunnel
|
|
closing. This prevents orphaned tunnels from running forever.
|
|
"""
|
|
if pexpect is None:
|
|
raise ImportError("pexpect unavailable, use paramiko_tunnel")
|
|
ssh="ssh "
|
|
if keyfile:
|
|
ssh += "-i " + keyfile
|
|
|
|
if ':' in server:
|
|
server, port = server.split(':')
|
|
ssh += " -p %s" % port
|
|
|
|
cmd = "%s -O check %s" % (ssh, server)
|
|
(output, exitstatus) = pexpect.run(cmd, withexitstatus=True)
|
|
if not exitstatus:
|
|
pid = int(output[output.find(b"(pid=")+5:output.find(b")")])
|
|
cmd = "%s -O forward -L 127.0.0.1:%i:%s:%i %s" % (
|
|
ssh, lport, remoteip, rport, server)
|
|
(output, exitstatus) = pexpect.run(cmd, withexitstatus=True)
|
|
if not exitstatus:
|
|
atexit.register(_stop_tunnel, cmd.replace("-O forward", "-O cancel", 1))
|
|
return pid
|
|
cmd = "%s -f -S none -L 127.0.0.1:%i:%s:%i %s sleep %i" % (
|
|
ssh, lport, remoteip, rport, server, timeout)
|
|
|
|
# pop SSH_ASKPASS from env
|
|
env = os.environ.copy()
|
|
env.pop('SSH_ASKPASS', None)
|
|
|
|
ssh_newkey = 'Are you sure you want to continue connecting'
|
|
tunnel = pexpect.spawn(cmd, env=env)
|
|
failed = False
|
|
while True:
|
|
try:
|
|
i = tunnel.expect([ssh_newkey, _password_pat], timeout=.1)
|
|
if i==0:
|
|
raise SSHException('The authenticity of the host can\'t be established.')
|
|
except pexpect.TIMEOUT:
|
|
continue
|
|
except pexpect.EOF:
|
|
if tunnel.exitstatus:
|
|
print(tunnel.exitstatus)
|
|
print(tunnel.before)
|
|
print(tunnel.after)
|
|
raise RuntimeError("tunnel '%s' failed to start"%(cmd))
|
|
else:
|
|
return tunnel.pid
|
|
else:
|
|
if failed:
|
|
print("Password rejected, try again")
|
|
password=None
|
|
if password is None:
|
|
password = getpass("%s's password: "%(server))
|
|
tunnel.sendline(password)
|
|
failed = True
|
|
|
|
def _stop_tunnel(cmd):
|
|
pexpect.run(cmd)
|
|
|
|
def _split_server(server):
|
|
if '@' in server:
|
|
username,server = server.split('@', 1)
|
|
else:
|
|
username = getuser()
|
|
if ':' in server:
|
|
server, port = server.split(':')
|
|
port = int(port)
|
|
else:
|
|
port = 22
|
|
return username, server, port
|
|
|
|
def paramiko_tunnel(lport, rport, server, remoteip='127.0.0.1', keyfile=None, password=None, timeout=60):
|
|
"""launch a tunner with paramiko in a subprocess. This should only be used
|
|
when shell ssh is unavailable (e.g. Windows).
|
|
|
|
This creates a tunnel redirecting `localhost:lport` to `remoteip:rport`,
|
|
as seen from `server`.
|
|
|
|
If you are familiar with ssh tunnels, this creates the tunnel:
|
|
|
|
ssh server -L localhost:lport:remoteip:rport
|
|
|
|
keyfile and password may be specified, but ssh config is checked for defaults.
|
|
|
|
|
|
Parameters
|
|
----------
|
|
|
|
lport : int
|
|
local port for connecting to the tunnel from this machine.
|
|
rport : int
|
|
port on the remote machine to connect to.
|
|
server : str
|
|
The ssh server to connect to. The full ssh server string will be parsed.
|
|
user@server:port
|
|
remoteip : str [Default: 127.0.0.1]
|
|
The remote ip, specifying the destination of the tunnel.
|
|
Default is localhost, which means that the tunnel would redirect
|
|
localhost:lport on this machine to localhost:rport on the *server*.
|
|
|
|
keyfile : str; path to public key file
|
|
This specifies a key to be used in ssh login, default None.
|
|
Regular default ssh keys will be used without specifying this argument.
|
|
password : str;
|
|
Your ssh password to the ssh server. Note that if this is left None,
|
|
you will be prompted for it if passwordless key based login is unavailable.
|
|
timeout : int [default: 60]
|
|
The time (in seconds) after which no activity will result in the tunnel
|
|
closing. This prevents orphaned tunnels from running forever.
|
|
|
|
"""
|
|
if paramiko is None:
|
|
raise ImportError("Paramiko not available")
|
|
|
|
if password is None:
|
|
if not _try_passwordless_paramiko(server, keyfile):
|
|
password = getpass("%s's password: "%(server))
|
|
|
|
p = Process(target=_paramiko_tunnel,
|
|
args=(lport, rport, server, remoteip),
|
|
kwargs=dict(keyfile=keyfile, password=password))
|
|
p.daemon = True
|
|
p.start()
|
|
return p
|
|
|
|
|
|
def _paramiko_tunnel(lport, rport, server, remoteip, keyfile=None, password=None):
|
|
"""Function for actually starting a paramiko tunnel, to be passed
|
|
to multiprocessing.Process(target=this), and not called directly.
|
|
"""
|
|
username, server, port = _split_server(server)
|
|
client = paramiko.SSHClient()
|
|
client.load_system_host_keys()
|
|
client.set_missing_host_key_policy(paramiko.WarningPolicy())
|
|
|
|
try:
|
|
client.connect(server, port, username=username, key_filename=keyfile,
|
|
look_for_keys=True, password=password)
|
|
# except paramiko.AuthenticationException:
|
|
# if password is None:
|
|
# password = getpass("%s@%s's password: "%(username, server))
|
|
# client.connect(server, port, username=username, password=password)
|
|
# else:
|
|
# raise
|
|
except Exception as e:
|
|
print('*** Failed to connect to %s:%d: %r' % (server, port, e))
|
|
sys.exit(1)
|
|
|
|
# Don't let SIGINT kill the tunnel subprocess
|
|
signal.signal(signal.SIGINT, signal.SIG_IGN)
|
|
|
|
try:
|
|
forward_tunnel(lport, remoteip, rport, client.get_transport())
|
|
except KeyboardInterrupt:
|
|
print('SIGINT: Port forwarding stopped cleanly')
|
|
sys.exit(0)
|
|
except Exception as e:
|
|
print("Port forwarding stopped uncleanly: %s"%e)
|
|
sys.exit(255)
|
|
|
|
if sys.platform == 'win32':
|
|
ssh_tunnel = paramiko_tunnel
|
|
else:
|
|
ssh_tunnel = openssh_tunnel
|
|
|
|
|
|
__all__ = ['tunnel_connection', 'ssh_tunnel', 'openssh_tunnel', 'paramiko_tunnel', 'try_passwordless_ssh']
|
|
|
|
|