summaryrefslogtreecommitdiff
path: root/paramiko/config.py
blob: 1e3d6802598cf57ed624eab1b72f43c83fd147f1 (plain)
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
# Copyright (C) 2006-2007  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.

"""
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
        """
        config = 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':
                # do we have a pre-existing host config to append to?
                matches = [c for c in self._config if c['host'] == value]
                if len(matches) > 0:
                    config = matches[0]
                else:
                    config = { 'host': value }
                    self._config.append(config)
            else:
                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