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
|
#!/usr/bin/env python3
#
# Copyright (C) 2018-2020 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import os
from netifaces import interfaces
from sys import exit
from vyos.config import Config
from vyos import ConfigError
from vyos.util import call
from vyos.template import render
from vyos import airbag
airbag.enable()
config_file = r'/etc/ssh/sshd_config'
systemd_override = r'/etc/systemd/system/ssh.service.d/override.conf'
default_config_data = {
'port' : ['22'],
'log_level': 'INFO',
'password_authentication': 'yes',
'host_validation': 'yes',
'vrf': ''
}
def get_config():
ssh = default_config_data
conf = Config()
base = ['service', 'ssh']
if not conf.exists(base):
return None
else:
conf.set_level(base)
tmp = ['access-control', 'allow', 'user']
if conf.exists(tmp):
ssh['allow_users'] = conf.return_values(tmp)
tmp = ['access-control', 'allow', 'group']
if conf.exists(tmp):
ssh['allow_groups'] = conf.return_values(tmp)
tmp = ['access-control', 'deny' 'user']
if conf.exists(tmp):
ssh['deny_users'] = conf.return_values(tmp)
tmp = ['access-control', 'deny', 'group']
if conf.exists(tmp):
ssh['deny_groups'] = conf.return_values(tmp)
tmp = ['ciphers']
if conf.exists(tmp):
ssh['ciphers'] = conf.return_values(tmp)
tmp = ['key-exchange']
if conf.exists(tmp):
ssh['key_exchange'] = conf.return_values(tmp)
if conf.exists(['disable-host-validation']):
ssh['host_validation'] = 'no'
if conf.exists(['disable-password-authentication']):
ssh['password_authentication'] = 'no'
tmp = ['listen-address']
if conf.exists(tmp):
# We can listen on both IPv4 and IPv6 addresses
# Maybe there could be a check in the future if the configured IP address
# is configured on this system at all?
ssh['listen_on'] = conf.return_values(tmp)
tmp = ['loglevel']
if conf.exists(tmp):
ssh['log_level'] = conf.return_value(tmp)
tmp = ['mac']
if conf.exists(tmp):
ssh['mac'] = conf.return_values(tmp)
tmp = ['port']
if conf.exists(tmp):
ssh['port'] = conf.return_values(tmp)
tmp = ['client-keepalive-interval']
if conf.exists(tmp):
ssh['client_keepalive'] = conf.return_value(tmp)
tmp = ['vrf']
if conf.exists(tmp):
ssh['vrf'] = conf.return_value(tmp)
return ssh
def verify(ssh):
if not ssh:
return None
if 'loglevel' in ssh.keys():
allowed_loglevel = 'QUIET, FATAL, ERROR, INFO, VERBOSE'
if not ssh['loglevel'] in allowed_loglevel:
raise ConfigError('loglevel must be one of "{0}"\n'.format(allowed_loglevel))
if ssh['vrf'] and ssh['vrf'] not in interfaces():
raise ConfigError('VRF "{vrf}" does not exist'.format(**ssh))
return None
def generate(ssh):
if not ssh:
return None
render(config_file, 'ssh/sshd_config.tmpl', ssh, trim_blocks=True)
render(systemd_override, 'ssh/override.conf.tmpl', ssh, trim_blocks=True)
return None
def apply(ssh):
if not ssh:
# SSH access is removed in the commit
call('systemctl stop ssh.service')
if os.path.isfile(config_file):
os.unlink(config_file)
if os.path.isfile(systemd_override):
os.unlink(systemd_override)
# Reload systemd manager configuration
call('systemctl daemon-reload')
if ssh:
call('systemctl restart ssh.service')
return None
if __name__ == '__main__':
try:
c = get_config()
verify(c)
generate(c)
apply(c)
except ConfigError as e:
print(e)
exit(1)
|
