1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
#!/usr/bin/python
# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net>
#
# This file is part of paramiko.
#
# Paramiko is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at your option)
# any later version.
#
# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
"""
Sample script showing how to do local port forwarding over paramiko.
This script connects to the requested SSH server and sets up local port
forwarding (the openssh -L option) from a local port through a tunneled
connection to a destination reachable from the SSH server machine.
"""
import sys
import os
import socket
import select
import SocketServer
import getpass
import base64
from optparse import OptionParser
import paramiko
DEFAULT_PORT = 4000
SSH_PORT = 22
VERBOSE = True
READPASS = False
class ForwardServer (SocketServer.ThreadingTCPServer):
daemon_threads = True
allow_reuse_address = True
class Handler (SocketServer.BaseRequestHandler):
def handle(self):
try:
chan = self.ssh_transport.open_channel('direct-tcpip',
(self.chain_host, self.chain_port),
self.request.getpeername())
except Exception, e:
verbose('Incoming request to %s:%d failed: %s' % (self.chain_host,
self.chain_port,
repr(e)))
return
verbose('Connected! Tunnel open.')
while True:
r, w, x = select.select([self.request, chan], [], [])
if self.request in r:
data = self.request.recv(1024)
if len(data) == 0:
break
chan.send(data)
if chan in r:
data = chan.recv(1024)
if len(data) == 0:
break
self.request.send(data)
chan.close()
self.request.close()
verbose('Tunnel closed.')
def forward_tunnel(local_port, remote_host, remote_port, transport):
# this is a little convoluted, but lets me configure things for the Handler
# object. (SocketServer doesn't give Handlers any way to access the outer
# server normally.)
class SubHander (Handler):
chain_host = remote_host
chain_port = remote_port
ssh_transport = transport
ForwardServer(('', local_port), SubHander).serve_forever()
def find_default_key_file():
filename = os.path.expanduser('~/.ssh/id_rsa')
if os.access(filename, os.R_OK):
return filename
filename = os.path.expanduser('~/ssh/id_rsa')
if os.access(filename, os.R_OK):
return filename
filename = os.path.expanduser('~/.ssh/id_dsa')
if os.access(filename, os.R_OK):
return filename
filename = os.path.expanduser('~/ssh/id_dsa')
if os.access(filename, os.R_OK):
return filename
return ''
def verbose(s):
if VERBOSE:
print s
#####
parser = OptionParser(usage='usage: %prog [options] <remote-addr>:<remote-port>',
version='%prog 1.0')
parser.add_option('-q', '--quiet', action='store_false', dest='verbose', default=VERBOSE,
help='squelch all informational output')
parser.add_option('-l', '--local-port', action='store', type='int', dest='port',
default=DEFAULT_PORT,
help='local port to forward (default: %d)' % DEFAULT_PORT)
parser.add_option('-r', '--host', action='store', type='string', dest='ssh_host',
help='SSH host to tunnel through (required)')
parser.add_option('-p', '--port', action='store', type='int', dest='ssh_port', default=SSH_PORT,
help='SSH port to tunnel through (default: %d)' % SSH_PORT)
parser.add_option('-u', '--user', action='store', type='string', dest='user',
default=getpass.getuser(),
help='username for SSH authentication (default: %s)' % getpass.getuser())
parser.add_option('-K', '--key', action='store', type='string', dest='keyfile',
default=find_default_key_file(),
help='private key file to use for SSH authentication')
parser.add_option('', '--no-key', action='store_false', dest='use_key', default=True,
help='don\'t look for or use a private key file')
parser.add_option('-P', '--password', action='store_true', dest='readpass', default=READPASS,
help='read password (for key or password auth) from stdin')
options, args = parser.parse_args()
VERBOSE = options.verbose
READPASS = options.readpass
if len(args) != 1:
parser.error('Incorrect number of arguments.')
remote_host = args[0]
if ':' not in remote_host:
parser.error('Remote port missing.')
remote_host, remote_port = remote_host.split(':', 1)
try:
remote_port = int(remote_port)
except:
parser.error('Remote port must be a number.')
if not options.ssh_host:
parser.error('SSH host is required.')
if ':' in options.ssh_host:
options.ssh_host, options.ssh_port = options.ssh_host.split(':', 1)
try:
options.ssh_port = int(options.ssh_port)
except:
parser.error('SSH port must be a number.')
try:
host_keys = paramiko.util.load_host_keys(os.path.expanduser('~/.ssh/known_hosts'))
except IOError:
try:
host_keys = paramiko.util.load_host_keys(os.path.expanduser('~/ssh/known_hosts'))
except IOError:
print '*** Unable to open host keys file'
host_keys = {}
if not host_keys.has_key(options.ssh_host):
print '*** Warning: no host key for %s' % options.ssh_host
expected_host_key_type = None
expected_host_key = None
else:
expected_host_key_type = host_keys[options.ssh_host].keys()[0]
expected_host_key = host_keys[options.ssh_host][expected_host_key_type]
key = None
password = None
if options.use_key:
try:
key = paramiko.RSAKey.from_private_key_file(options.keyfile)
except paramiko.PasswordRequiredException:
if not READPASS:
print '*** Password needed for keyfile (use -P): %s' % options.keyfile
sys.exit(1)
key_password = getpass.getpass('Enter password for key: ')
try:
key = paramiko.RSAKey.from_private_key_file(options.keyfile, key_password)
except:
print '*** Unable to read keyfile: %s' % options.keyfile
sys.exit(1)
except:
pass
if key is None:
# try reading a password then
if not READPASS:
print '*** Either a valid private key or password is required (use -K or -P).'
sys.exit(1)
password = getpass.getpass('Enter password: ')
verbose('Connecting to ssh host %s:%d ...' % (options.ssh_host, options.ssh_port))
transport = paramiko.Transport((options.ssh_host, options.ssh_port))
transport.connect(hostkeytype=expected_host_key_type,
hostkey=expected_host_key,
username=options.user,
password=password,
pkey=key)
verbose('Now forwarding port %d to %s:%d ...' % (options.port, remote_host, remote_port))
try:
forward_tunnel(options.port, remote_host, remote_port, transport)
except KeyboardInterrupt:
print 'Port forwarding stopped.'
sys.exit(0)
|