#!/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.util 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)