#!/usr/bin/env python3
#
# Copyright (C) 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
import unittest

from glob import glob
from ipaddress import IPv4Network
from netifaces import interfaces

from base_vyostest_shim import VyOSUnitTestSHIM

from vyos.configsession import ConfigSession
from vyos.configsession import ConfigSessionError
from vyos.util import cmd
from vyos.util import process_named_running
from vyos.util import read_file
from vyos.template import address_from_cidr
from vyos.template import dec_ip
from vyos.template import inc_ip
from vyos.template import last_host_address
from vyos.template import netmask_from_cidr

PROCESS_NAME = 'openvpn'

base_path = ['interfaces', 'openvpn']
ca_cert  = '/config/auth/ovpn_test_ca.pem'
ssl_cert = '/config/auth/ovpn_test_server.pem'
ssl_key  = '/config/auth/ovpn_test_server.key'
dh_pem   = '/config/auth/ovpn_test_dh.pem'
s2s_key  = '/config/auth/ovpn_test_site2site.key'
auth_key = '/config/auth/ovpn_test_tls_auth.key'

remote_port = '1194'
protocol = 'udp'
path = []
interface = ''
remote_host = ''
vrf_name = 'orange'
dummy_if = 'dum1301'

def get_vrf(interface):
    for upper in glob(f'/sys/class/net/{interface}/upper*'):
        # an upper interface could be named: upper_bond0.1000.1100, thus
        # we need top drop the upper_ prefix
        tmp = os.path.basename(upper)
        tmp = tmp.replace('upper_', '')
        return tmp

class TestInterfacesOpenVPN(VyOSUnitTestSHIM.TestCase):
    def setUp(self):
        self.cli_set(['interfaces', 'dummy', dummy_if, 'address', '192.0.2.1/32'])
        self.cli_set(['vrf', 'name', vrf_name, 'table', '12345'])

    def tearDown(self):
        self.cli_delete(base_path)
        self.cli_delete(['interfaces', 'dummy', dummy_if])
        self.cli_delete(['vrf'])
        self.cli_commit()

    def test_openvpn_client_verify(self):
        # Create OpenVPN client interface and test verify() steps.
        interface = 'vtun2000'
        path = base_path + [interface]
        self.cli_set(path + ['mode', 'client'])

        # check validate() - cannot specify both "encryption disable-ncp" and
        # "encryption ncp-ciphers" at the same time
        self.cli_set(path + ['encryption', 'disable-ncp'])
        self.cli_set(path + ['encryption', 'ncp-ciphers', 'aes192gcm'])

        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['encryption', 'ncp-ciphers'])

        # check validate() - cannot specify local-port in client mode
        self.cli_set(path + ['local-port', '5000'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['local-port'])

        # check validate() - cannot specify local-host in client mode
        self.cli_set(path + ['local-host', '127.0.0.1'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['local-host'])

        # check validate() - cannot specify protocol tcp-passive in client mode
        self.cli_set(path + ['protocol', 'tcp-passive'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['protocol'])

        # check validate() - remote-host must be set in client mode
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['remote-host', '192.0.9.9'])

        # check validate() - cannot specify "tls dh-file" in client mode
        self.cli_set(path + ['tls', 'dh-file', dh_pem])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['tls'])

        # check validate() - must specify one of "shared-secret-key-file" and "tls"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['shared-secret-key-file', s2s_key])

        # check validate() - must specify one of "shared-secret-key-file" and "tls"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['shared-secret-key-file', s2s_key])

        self.cli_set(path + ['tls', 'ca-cert-file', ca_cert])
        self.cli_set(path + ['tls', 'cert-file', ssl_cert])
        self.cli_set(path + ['tls', 'key-file', ssl_key])

        # check validate() - can not have auth username without a password
        self.cli_set(path + ['authentication', 'username', 'vyos'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['authentication', 'password', 'vyos'])

        # client commit must pass
        self.cli_commit()

        self.assertTrue(process_named_running(PROCESS_NAME))
        self.assertIn(interface, interfaces())


    def test_openvpn_client_interfaces(self):
        # Create OpenVPN client interfaces connecting to different
        # server IP addresses. Validate configuration afterwards.
        num_range = range(10, 15)
        for ii in num_range:
            interface = f'vtun{ii}'
            remote_host = f'192.0.2.{ii}'
            path = base_path + [interface]
            auth_hash = 'sha1'

            self.cli_set(path + ['device-type', 'tun'])
            self.cli_set(path + ['encryption', 'cipher', 'aes256'])
            self.cli_set(path + ['hash', auth_hash])
            self.cli_set(path + ['mode', 'client'])
            self.cli_set(path + ['persistent-tunnel'])
            self.cli_set(path + ['protocol', protocol])
            self.cli_set(path + ['remote-host', remote_host])
            self.cli_set(path + ['remote-port', remote_port])
            self.cli_set(path + ['tls', 'ca-cert-file', ca_cert])
            self.cli_set(path + ['tls', 'cert-file', ssl_cert])
            self.cli_set(path + ['tls', 'key-file', ssl_key])
            self.cli_set(path + ['vrf', vrf_name])
            self.cli_set(path + ['authentication', 'username', interface+'user'])
            self.cli_set(path + ['authentication', 'password', interface+'secretpw'])

        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            remote_host = f'192.0.2.{ii}'
            config_file = f'/run/openvpn/{interface}.conf'
            pw_file = f'/run/openvpn/{interface}.pw'
            config = read_file(config_file)

            self.assertIn(f'dev {interface}', config)
            self.assertIn(f'dev-type tun', config)
            self.assertIn(f'persist-key', config)
            self.assertIn(f'proto {protocol}', config)
            self.assertIn(f'rport {remote_port}', config)
            self.assertIn(f'remote {remote_host}', config)
            self.assertIn(f'persist-tun', config)
            self.assertIn(f'auth {auth_hash}', config)
            self.assertIn(f'cipher aes-256-cbc', config)

            # TLS options
            self.assertIn(f'ca {ca_cert}', config)
            self.assertIn(f'cert {ssl_cert}', config)
            self.assertIn(f'key {ssl_key}', config)

            self.assertTrue(process_named_running(PROCESS_NAME))
            self.assertEqual(get_vrf(interface), vrf_name)
            self.assertIn(interface, interfaces())

            pw = cmd(f'sudo cat {pw_file}')
            self.assertIn(f'{interface}user', pw)
            self.assertIn(f'{interface}secretpw', pw)

        # check that no interface remained after deleting them
        self.cli_delete(base_path)
        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            self.assertNotIn(interface, interfaces())

    def test_openvpn_server_verify(self):
        # Create one OpenVPN server interface and check required verify() stages
        interface = 'vtun5000'
        path = base_path + [interface]

        # check validate() - must speciy operating mode
        self.cli_set(path)
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['mode', 'server'])

        # check validate() - cannot specify protocol tcp-active in server mode
        self.cli_set(path + ['protocol', 'tcp-active'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['protocol'])

        # check validate() - cannot specify local-port in client mode
        self.cli_set(path + ['remote-port', '5000'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['remote-port'])

        # check validate() - cannot specify local-host in client mode
        self.cli_set(path + ['remote-host', '127.0.0.1'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['remote-host'])

        # check validate() - must specify "tls dh-file" when not using EC keys
        # in server mode
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['tls', 'dh-file', dh_pem])

        # check validate() - must specify "server subnet" or add interface to
        # bridge in server mode
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()

        # check validate() - server client-ip-pool is too large
        # [100.64.0.4 -> 100.127.255.251 = 4194295], maximum is 65536 addresses.
        self.cli_set(path + ['server', 'subnet', '100.64.0.0/10'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()

        # check validate() - cannot specify more than 1 IPv4 and 1 IPv6 server subnet
        self.cli_set(path + ['server', 'subnet', '100.64.0.0/20'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['server', 'subnet', '100.64.0.0/10'])

        # check validate() - must specify "tls ca-cert-file"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['tls', 'ca-cert-file', ca_cert])

        # check validate() - must specify "tls cert-file"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['tls', 'cert-file', ssl_cert])

        # check validate() - must specify "tls key-file"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['tls', 'key-file', ssl_key])

        # check validate() - cannot specify "tls role" in client-server mode'
        self.cli_set(path + ['tls', 'role', 'active'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()

        # check validate() - cannot specify "tls role" in client-server mode'
        self.cli_set(path + ['tls', 'auth-file', auth_key])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()

        # check validate() - cannot specify "tcp-passive" when "tls role" is "active"
        self.cli_set(path + ['protocol', 'tcp-passive'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['protocol'])

        # check validate() - cannot specify "tls dh-file" when "tls role" is "active"
        self.cli_set(path + ['tls', 'dh-file', dh_pem])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['tls', 'dh-file'])

        # Now test the other path with tls role passive
        self.cli_set(path + ['tls', 'role', 'passive'])
        # check validate() - cannot specify "tcp-active" when "tls role" is "passive"
        self.cli_set(path + ['protocol', 'tcp-active'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['protocol'])


        # check validate() - must specify "tls dh-file" when "tls role" is "passive"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['tls', 'dh-file', dh_pem])

        self.cli_commit()

        self.assertTrue(process_named_running(PROCESS_NAME))
        self.assertIn(interface, interfaces())

    def test_openvpn_server_subnet_topology(self):
        # Create OpenVPN server interfaces using different client subnets.
        # Validate configuration afterwards.

        auth_hash = 'sha256'
        num_range = range(20, 25)
        port = ''
        client1_routes = ['10.0.0.0/8', '172.16.0.0/12', '192.168.0.0/16']
        for ii in num_range:
            interface = f'vtun{ii}'
            subnet = f'192.0.{ii}.0/24'
            client_ip = inc_ip(subnet, '5')
            path = base_path + [interface]
            port = str(2000 + ii)

            self.cli_set(path + ['device-type', 'tun'])
            self.cli_set(path + ['encryption', 'cipher', 'aes192'])
            self.cli_set(path + ['hash', auth_hash])
            self.cli_set(path + ['mode', 'server'])
            self.cli_set(path + ['local-port', port])
            self.cli_set(path + ['server', 'subnet', subnet])
            self.cli_set(path + ['server', 'topology', 'subnet'])
            self.cli_set(path + ['keep-alive', 'failure-count', '5'])
            self.cli_set(path + ['keep-alive', 'interval', '5'])

            # clients
            self.cli_set(path + ['server', 'client', 'client1', 'ip', client_ip])
            for route in client1_routes:
                self.cli_set(path + ['server', 'client', 'client1', 'subnet', route])

            self.cli_set(path + ['replace-default-route'])
            self.cli_set(path + ['tls', 'ca-cert-file', ca_cert])
            self.cli_set(path + ['tls', 'cert-file', ssl_cert])
            self.cli_set(path + ['tls', 'key-file', ssl_key])
            self.cli_set(path + ['tls', 'dh-file', dh_pem])
            self.cli_set(path + ['vrf', vrf_name])

        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            subnet = f'192.0.{ii}.0/24'

            start_addr = inc_ip(subnet, '2')
            stop_addr = last_host_address(subnet)

            client_ip = inc_ip(subnet, '5')
            client_netmask = netmask_from_cidr(subnet)

            port = str(2000 + ii)

            config_file = f'/run/openvpn/{interface}.conf'
            client_config_file = f'/run/openvpn/ccd/{interface}/client1'
            config = read_file(config_file)

            self.assertIn(f'dev {interface}', config)
            self.assertIn(f'dev-type tun', config)
            self.assertIn(f'persist-key', config)
            self.assertIn(f'proto udp', config) # default protocol
            self.assertIn(f'auth {auth_hash}', config)
            self.assertIn(f'cipher aes-192-cbc', config)
            self.assertIn(f'topology subnet', config)
            self.assertIn(f'lport {port}', config)
            self.assertIn(f'push "redirect-gateway def1"', config)
            self.assertIn(f'keepalive 5 25', config)

            # TLS options
            self.assertIn(f'ca {ca_cert}', config)
            self.assertIn(f'cert {ssl_cert}', config)
            self.assertIn(f'key {ssl_key}', config)
            self.assertIn(f'dh {dh_pem}', config)

            # IP pool configuration
            netmask = IPv4Network(subnet).netmask
            network = IPv4Network(subnet).network_address
            self.assertIn(f'server {network} {netmask} nopool', config)

            # Verify client
            client_config = read_file(client_config_file)

            self.assertIn(f'ifconfig-push {client_ip} {client_netmask}', client_config)
            for route in client1_routes:
                self.assertIn('iroute {} {}'.format(address_from_cidr(route), netmask_from_cidr(route)), client_config)

            self.assertTrue(process_named_running(PROCESS_NAME))
            self.assertEqual(get_vrf(interface), vrf_name)
            self.assertIn(interface, interfaces())

        # check that no interface remained after deleting them
        self.cli_delete(base_path)
        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            self.assertNotIn(interface, interfaces())

    def test_openvpn_server_net30_topology(self):
        # Create OpenVPN server interfaces (net30) using different client
        # subnets. Validate configuration afterwards.
        auth_hash = 'sha256'
        num_range = range(20, 25)
        port = ''
        for ii in num_range:
            interface = f'vtun{ii}'
            subnet = f'192.0.{ii}.0/24'
            path = base_path + [interface]
            port = str(2000 + ii)

            self.cli_set(path + ['device-type', 'tun'])
            self.cli_set(path + ['encryption', 'cipher', 'aes192'])
            self.cli_set(path + ['hash', auth_hash])
            self.cli_set(path + ['mode', 'server'])
            self.cli_set(path + ['local-port', port])
            self.cli_set(path + ['server', 'subnet', subnet])
            self.cli_set(path + ['server', 'topology', 'net30'])
            self.cli_set(path + ['replace-default-route'])
            self.cli_set(path + ['keep-alive', 'failure-count', '10'])
            self.cli_set(path + ['keep-alive', 'interval', '5'])
            self.cli_set(path + ['tls', 'ca-cert-file', ca_cert])
            self.cli_set(path + ['tls', 'cert-file', ssl_cert])
            self.cli_set(path + ['tls', 'key-file', ssl_key])
            self.cli_set(path + ['tls', 'dh-file', dh_pem])
            self.cli_set(path + ['vrf', vrf_name])

        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            subnet = f'192.0.{ii}.0/24'
            start_addr = inc_ip(subnet, '4')
            stop_addr = dec_ip(last_host_address(subnet), '1')
            port = str(2000 + ii)

            config_file = f'/run/openvpn/{interface}.conf'
            config = read_file(config_file)

            self.assertIn(f'dev {interface}', config)
            self.assertIn(f'dev-type tun', config)
            self.assertIn(f'persist-key', config)
            self.assertIn(f'proto udp', config) # default protocol
            self.assertIn(f'auth {auth_hash}', config)
            self.assertIn(f'cipher aes-192-cbc', config)
            self.assertIn(f'topology net30', config)
            self.assertIn(f'lport {port}', config)
            self.assertIn(f'push "redirect-gateway def1"', config)
            self.assertIn(f'keepalive 5 50', config)

            # TLS options
            self.assertIn(f'ca {ca_cert}', config)
            self.assertIn(f'cert {ssl_cert}', config)
            self.assertIn(f'key {ssl_key}', config)
            self.assertIn(f'dh {dh_pem}', config)

            # IP pool configuration
            netmask = IPv4Network(subnet).netmask
            network = IPv4Network(subnet).network_address
            self.assertIn(f'server {network} {netmask} nopool', config)
            self.assertIn(f'ifconfig-pool {start_addr} {stop_addr}', config)

            self.assertTrue(process_named_running(PROCESS_NAME))
            self.assertEqual(get_vrf(interface), vrf_name)
            self.assertIn(interface, interfaces())

        # check that no interface remained after deleting them
        self.cli_delete(base_path)
        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            self.assertNotIn(interface, interfaces())

    def test_openvpn_site2site_verify(self):
        # Create one OpenVPN site2site interface and check required
        # verify() stages

        interface = 'vtun5000'
        path = base_path + [interface]

        self.cli_set(path + ['mode', 'site-to-site'])

        # check validate() - encryption ncp-ciphers cannot be specified in site-to-site mode
        self.cli_set(path + ['encryption', 'ncp-ciphers', 'aes192gcm'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['encryption'])

        # check validate() - must specify "local-address" or add interface to bridge
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['local-address', '10.0.0.1'])
        self.cli_set(path + ['local-address', '2001:db8:1::1'])

        # check validate() - cannot specify more than 1 IPv4 local-address
        self.cli_set(path + ['local-address', '10.0.0.2'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['local-address', '10.0.0.2'])

        # check validate() - cannot specify more than 1 IPv6 local-address
        self.cli_set(path + ['local-address', '2001:db8:1::2'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['local-address', '2001:db8:1::2'])

        # check validate() - IPv4 "local-address" requires IPv4 "remote-address"
        # or IPv4 "local-address subnet"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['remote-address', '192.168.0.1'])
        self.cli_set(path + ['remote-address', '2001:db8:ffff::1'])

        # check validate() - Cannot specify more than 1 IPv4 "remote-address"
        self.cli_set(path + ['remote-address', '192.168.0.2'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['remote-address', '192.168.0.2'])

        # check validate() - Cannot specify more than 1 IPv6 "remote-address"
        self.cli_set(path + ['remote-address', '2001:db8:ffff::2'])
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_delete(path + ['remote-address', '2001:db8:ffff::2'])

        # check validate() - Must specify one of "shared-secret-key-file" and "tls"
        with self.assertRaises(ConfigSessionError):
            self.cli_commit()
        self.cli_set(path + ['shared-secret-key-file', s2s_key])

        self.cli_commit()

    def test_openvpn_site2site_interfaces_tun(self):
        # Create two OpenVPN site-to-site interfaces

        num_range = range(30, 35)
        port = ''
        local_address = ''
        remote_address = ''

        for ii in num_range:
            interface = f'vtun{ii}'
            local_address = f'192.0.{ii}.1'
            local_address_subnet = '255.255.255.252'
            remote_address = f'172.16.{ii}.1'
            path = base_path + [interface]
            port = str(3000 + ii)

            self.cli_set(path + ['local-address', local_address])

            # even numbers use tun type, odd numbers use tap type
            if ii % 2 == 0:
                self.cli_set(path + ['device-type', 'tun'])
            else:
                self.cli_set(path + ['device-type', 'tap'])
                self.cli_set(path + ['local-address', local_address, 'subnet-mask', local_address_subnet])

            self.cli_set(path + ['mode', 'site-to-site'])
            self.cli_set(path + ['local-port', port])
            self.cli_set(path + ['remote-port', port])
            self.cli_set(path + ['shared-secret-key-file', s2s_key])
            self.cli_set(path + ['remote-address', remote_address])
            self.cli_set(path + ['vrf', vrf_name])

        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            local_address = f'192.0.{ii}.1'
            remote_address = f'172.16.{ii}.1'
            port = str(3000 + ii)

            config_file = f'/run/openvpn/{interface}.conf'
            config = read_file(config_file)

            # even numbers use tun type, odd numbers use tap type
            if ii % 2 == 0:
                self.assertIn(f'dev-type tun', config)
                self.assertIn(f'ifconfig {local_address} {remote_address}', config)
            else:
                self.assertIn(f'dev-type tap', config)
                self.assertIn(f'ifconfig {local_address} {local_address_subnet}', config)

            self.assertIn(f'dev {interface}', config)
            self.assertIn(f'secret {s2s_key}', config)
            self.assertIn(f'lport {port}', config)
            self.assertIn(f'rport {port}', config)


            self.assertTrue(process_named_running(PROCESS_NAME))
            self.assertEqual(get_vrf(interface), vrf_name)
            self.assertIn(interface, interfaces())


        # check that no interface remained after deleting them
        self.cli_delete(base_path)
        self.cli_commit()

        for ii in num_range:
            interface = f'vtun{ii}'
            self.assertNotIn(interface, interfaces())


if __name__ == '__main__':
    # Our SSL certificates need a subject ...
    subject = '/C=DE/ST=BY/O=VyOS/localityName=Cloud/commonName=vyos/' \
              'organizationalUnitName=VyOS/emailAddress=maintainers@vyos.io/'

    if not (os.path.isfile(ssl_key) and os.path.isfile(ssl_cert)):
        # Generate mandatory SSL certificate
        tmp = f'openssl req -newkey rsa:4096 -new -nodes -x509 -days 3650 '\
              f'-keyout {ssl_key} -out {ssl_cert} -subj {subject}'
        cmd(tmp)

    if not os.path.isfile(ca_cert):
        # Generate "CA"
        tmp = f'openssl req -new -x509 -key {ssl_key} -out {ca_cert} -subj {subject}'
        cmd(tmp)

    if not os.path.isfile(dh_pem):
        # Generate "DH" key
        tmp = f'openssl dhparam -out {dh_pem} 2048'
        cmd(tmp)

    if not os.path.isfile(s2s_key):
        # Generate site-2-site key
        tmp = f'openvpn --genkey --secret {s2s_key}'
        cmd(tmp)

    if not os.path.isfile(auth_key):
        # Generate TLS auth key
        tmp = f'openvpn --genkey --secret {auth_key}'
        cmd(tmp)

    for file in [ca_cert, ssl_cert, ssl_key, dh_pem, s2s_key, auth_key]:
        cmd(f'sudo chown openvpn:openvpn {file}')

    unittest.main(verbosity=2)