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
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
|
# Copyright (C) 2006-2007 Robey Pointer <robeypointer@gmail.com>
# Copyright (C) 2012 Olle Lundberg <geek@nerd.sh>
#
# 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 distributed 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.
"""
Configuration file (aka ``ssh_config``) support.
"""
import fnmatch
import os
import re
import socket
SSH_PORT = 22
proxy_re = re.compile(r"^(proxycommand)\s*=*\s*(.*)", re.I)
class SSHConfig (object):
"""
Representation of config information as stored in the format used by
OpenSSH. Queries can be made via `lookup`. The format is described in
OpenSSH's ``ssh_config`` man page. This class is provided primarily as a
convenience to posix users (since the OpenSSH format is a de-facto
standard on posix) but should work fine on Windows too.
.. versionadded:: 1.6
"""
def __init__(self):
"""
Create a new OpenSSH config object.
"""
self._config = []
def parse(self, file_obj):
"""
Read an OpenSSH config from the given file object.
:param file file_obj: a file-like object to read the config file from
"""
host = {"host": ['*'], "config": {}}
for line in file_obj:
line = line.rstrip('\r\n').lstrip()
if (line == '') or (line[0] == '#'):
continue
if '=' in line:
# Ensure ProxyCommand gets properly split
if line.lower().strip().startswith('proxycommand'):
match = proxy_re.match(line)
key, value = match.group(1).lower(), match.group(2)
else:
key, value = line.split('=', 1)
key = key.strip().lower()
else:
# find first whitespace, and split there
i = 0
while (i < len(line)) and not line[i].isspace():
i += 1
if i == len(line):
raise Exception('Unparsable line: %r' % line)
key = line[:i].lower()
value = line[i:].lstrip()
if key == 'host':
self._config.append(host)
value = value.split()
host = {key: value, 'config': {}}
#identityfile, localforward, remoteforward keys are special cases, since they are allowed to be
# specified multiple times and they should be tried in order
# of specification.
elif key in ['identityfile', 'localforward', 'remoteforward']:
if key in host['config']:
host['config'][key].append(value)
else:
host['config'][key] = [value]
elif key not in host['config']:
host['config'].update({key: value})
self._config.append(host)
def lookup(self, hostname):
"""
Return a dict of config options for a given hostname.
The host-matching rules of OpenSSH's ``ssh_config`` man page are used,
which means that all configuration options from matching host
specifications are merged, with more specific hostmasks taking
precedence. In other words, if ``"Port"`` is set under ``"Host *"``
and also ``"Host *.example.com"``, and the lookup is for
``"ssh.example.com"``, then the port entry for ``"Host *.example.com"``
will win out.
The keys in the returned dict are all normalized to lowercase (look for
``"port"``, not ``"Port"``. The values are processed according to the
rules for substitution variable expansion in ``ssh_config``.
:param str hostname: the hostname to lookup
"""
matches = [config for config in self._config if
self._allowed(hostname, config['host'])]
ret = {}
for match in matches:
for key, value in match['config'].items():
if key not in ret:
# Create a copy of the original value,
# else it will reference the original list
# in self._config and update that value too
# when the extend() is being called.
ret[key] = value[:]
elif key == 'identityfile':
ret[key].extend(value)
ret = self._expand_variables(ret, hostname)
return ret
def _allowed(self, hostname, hosts):
match = False
for host in hosts:
if host.startswith('!') and fnmatch.fnmatch(hostname, host[1:]):
return False
elif fnmatch.fnmatch(hostname, host):
match = True
return match
def _expand_variables(self, config, hostname):
"""
Return a dict of config options with expanded substitutions
for a given hostname.
Please refer to man ``ssh_config`` for the parameters that
are replaced.
:param dict config: the config for the hostname
:param str hostname: the hostname that the config belongs to
"""
if 'hostname' in config:
config['hostname'] = config['hostname'].replace('%h', hostname)
else:
config['hostname'] = hostname
if 'port' in config:
port = config['port']
else:
port = SSH_PORT
user = os.getenv('USER')
if 'user' in config:
remoteuser = config['user']
else:
remoteuser = user
host = socket.gethostname().split('.')[0]
fqdn = LazyFqdn(config, host)
homedir = os.path.expanduser('~')
replacements = {'controlpath':
[
('%h', config['hostname']),
('%l', fqdn),
('%L', host),
('%n', hostname),
('%p', port),
('%r', remoteuser),
('%u', user)
],
'identityfile':
[
('~', homedir),
('%d', homedir),
('%h', config['hostname']),
('%l', fqdn),
('%u', user),
('%r', remoteuser)
],
'proxycommand':
[
('%h', config['hostname']),
('%p', port),
('%r', remoteuser)
]
}
for k in config:
if k in replacements:
for find, replace in replacements[k]:
if isinstance(config[k], list):
for item in range(len(config[k])):
if find in config[k][item]:
config[k][item] = config[k][item].\
replace(find, str(replace))
else:
if find in config[k]:
config[k] = config[k].replace(find, str(replace))
return config
class LazyFqdn(object):
"""
Returns the host's fqdn on request as string.
"""
def __init__(self, config, host=None):
self.fqdn = None
self.config = config
self.host = host
def __str__(self):
if self.fqdn is None:
#
# If the SSH config contains AddressFamily, use that when
# determining the local host's FQDN. Using socket.getfqdn() from
# the standard library is the most general solution, but can
# result in noticeable delays on some platforms when IPv6 is
# misconfigured or not available, as it calls getaddrinfo with no
# address family specified, so both IPv4 and IPv6 are checked.
#
# Handle specific option
fqdn = None
address_family = self.config.get('addressfamily', 'any').lower()
if address_family != 'any':
try:
family = socket.AF_INET if address_family == 'inet' \
else socket.AF_INET6
results = socket.getaddrinfo(
self.host,
None,
family,
socket.SOCK_DGRAM,
socket.IPPROTO_IP,
socket.AI_CANONNAME
)
for res in results:
af, socktype, proto, canonname, sa = res
if canonname and '.' in canonname:
fqdn = canonname
break
# giaerror -> socket.getaddrinfo() can't resolve self.host
# (which is from socket.gethostname()). Fall back to the
# getfqdn() call below.
except socket.gaierror:
pass
# Handle 'any' / unspecified
if fqdn is None:
fqdn = socket.getfqdn()
# Cache
self.fqdn = fqdn
return self.fqdn
|
