summaryrefslogtreecommitdiff
path: root/src/conf_mode/ssh.py
blob: 3b63fcb7d2ccd6c163f13cba12faa575ecb58284 (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
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
#!/usr/bin/env python3
#
# Copyright (C) 2018-2022 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 sys import exit
from syslog import syslog
from syslog import LOG_INFO

from vyos.config import Config
from vyos.configdict import dict_merge
from vyos.configdict import is_node_changed
from vyos.configverify import verify_vrf
from vyos.utils.process import call
from vyos.template import render
from vyos.xml import defaults
from vyos import ConfigError
from vyos import airbag
airbag.enable()

config_file = r'/run/sshd/sshd_config'
systemd_override = r'/run/systemd/system/ssh.service.d/override.conf'

sshguard_config_file = '/etc/sshguard/sshguard.conf'
sshguard_whitelist = '/etc/sshguard/whitelist'

key_rsa = '/etc/ssh/ssh_host_rsa_key'
key_dsa = '/etc/ssh/ssh_host_dsa_key'
key_ed25519 = '/etc/ssh/ssh_host_ed25519_key'

def get_config(config=None):
    if config:
        conf = config
    else:
        conf = Config()
    base = ['service', 'ssh']
    if not conf.exists(base):
        return None

    ssh = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True)

    tmp = is_node_changed(conf, base + ['vrf'])
    if tmp: ssh.update({'restart_required': {}})

    # We have gathered the dict representation of the CLI, but there are default
    # options which we need to update into the dictionary retrived.
    default_values = defaults(base)
    ssh = dict_merge(default_values, ssh)
    # pass config file path - used in override template
    ssh['config_file'] = config_file

    # Ignore default XML values if config doesn't exists
    # Delete key from dict
    if not conf.exists(base + ['dynamic-protection']):
         del ssh['dynamic_protection']

    return ssh

def verify(ssh):
    if not ssh:
        return None

    if 'rekey' in ssh and 'data' not in ssh['rekey']:
        raise ConfigError(f'Rekey data is required!')

    verify_vrf(ssh)
    return None

def generate(ssh):
    if not ssh:
        if os.path.isfile(config_file):
            os.unlink(config_file)
        if os.path.isfile(systemd_override):
            os.unlink(systemd_override)

        return None

    # This usually happens only once on a fresh system, SSH keys need to be
    # freshly generted, one per every system!
    if not os.path.isfile(key_rsa):
        syslog(LOG_INFO, 'SSH RSA host key not found, generating new key!')
        call(f'ssh-keygen -q -N "" -t rsa -f {key_rsa}')
    if not os.path.isfile(key_dsa):
        syslog(LOG_INFO, 'SSH DSA host key not found, generating new key!')
        call(f'ssh-keygen -q -N "" -t dsa -f {key_dsa}')
    if not os.path.isfile(key_ed25519):
        syslog(LOG_INFO, 'SSH ed25519 host key not found, generating new key!')
        call(f'ssh-keygen -q -N "" -t ed25519 -f {key_ed25519}')

    render(config_file, 'ssh/sshd_config.j2', ssh)
    render(systemd_override, 'ssh/override.conf.j2', ssh)

    if 'dynamic_protection' in ssh:
        render(sshguard_config_file, 'ssh/sshguard_config.j2', ssh)
        render(sshguard_whitelist, 'ssh/sshguard_whitelist.j2', ssh)
    # Reload systemd manager configuration
    call('systemctl daemon-reload')

    return None

def apply(ssh):
    systemd_service_ssh = 'ssh.service'
    systemd_service_sshguard = 'sshguard.service'
    if not ssh:
        # SSH access is removed in the commit
        call(f'systemctl stop {systemd_service_ssh}')
        call(f'systemctl stop {systemd_service_sshguard}')
        return None

    if 'dynamic_protection' not in ssh:
        call(f'systemctl stop {systemd_service_sshguard}')
    else:
        call(f'systemctl reload-or-restart {systemd_service_sshguard}')

    # we need to restart the service if e.g. the VRF name changed
    systemd_action = 'reload-or-restart'
    if 'restart_required' in ssh:
        systemd_action = 'restart'

    call(f'systemctl {systemd_action} {systemd_service_ssh}')
    return None

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)