paramiko/ssh/config.py

111 lines
4.0 KiB
Python

# Copyright (C) 2006-2007 Robey Pointer <robeypointer@gmail.com>
#
# This file is part of ssh.
#
# 'ssh' 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.
#
# 'ssh' 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 'ssh'; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
"""
L{SSHConfig}.
"""
import fnmatch
class SSHConfig (object):
"""
Representation of config information as stored in the format used by
OpenSSH. Queries can be made via L{lookup}. The format is described in
OpenSSH's C{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.
@since: 1.6
"""
def __init__(self):
"""
Create a new OpenSSH config object.
"""
self._config = [ { 'host': '*' } ]
def parse(self, file_obj):
"""
Read an OpenSSH config from the given file object.
@param file_obj: a file-like object to read the config file from
@type file_obj: file
"""
configs = [self._config[0]]
for line in file_obj:
line = line.rstrip('\n').lstrip()
if (line == '') or (line[0] == '#'):
continue
if '=' in line:
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':
del configs[:]
# the value may be multiple hosts, space-delimited
for host in value.split():
# do we have a pre-existing host config to append to?
matches = [c for c in self._config if c['host'] == host]
if len(matches) > 0:
configs.append(matches[0])
else:
config = { 'host': host }
self._config.append(config)
configs.append(config)
else:
for config in configs:
config[key] = value
def lookup(self, hostname):
"""
Return a dict of config options for a given hostname.
The host-matching rules of OpenSSH's C{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 C{"Port"} is set under C{"Host *"}
and also C{"Host *.example.com"}, and the lookup is for
C{"ssh.example.com"}, then the port entry for C{"Host *.example.com"}
will win out.
The keys in the returned dict are all normalized to lowercase (look for
C{"port"}, not C{"Port"}. No other processing is done to the keys or
values.
@param hostname: the hostname to lookup
@type hostname: str
"""
matches = [x for x in self._config if fnmatch.fnmatch(hostname, x['host'])]
# sort in order of shortest match (usually '*') to longest
matches.sort(lambda x,y: cmp(len(x['host']), len(y['host'])))
ret = {}
for m in matches:
ret.update(m)
del ret['host']
return ret