diff options
| -rw-r--r-- | src/conf_mode/vpn_ipsec.py | 526 |
1 files changed, 526 insertions, 0 deletions
diff --git a/src/conf_mode/vpn_ipsec.py b/src/conf_mode/vpn_ipsec.py new file mode 100644 index 000000000..a359361f3 --- /dev/null +++ b/src/conf_mode/vpn_ipsec.py @@ -0,0 +1,526 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2021 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 ipaddress +import os + +from sys import exit +from time import sleep +from time import time + +from vyos.config import Config +from vyos.configdict import leaf_node_changed +from vyos.configverify import verify_interface_exists +from vyos.configdict import dict_merge +from vyos.ifconfig import Interface +from vyos.pki import encode_public_key +from vyos.pki import load_private_key +from vyos.pki import wrap_certificate +from vyos.pki import wrap_crl +from vyos.pki import wrap_public_key +from vyos.pki import wrap_private_key +from vyos.template import ip_from_cidr +from vyos.template import render +from vyos.validate import is_ipv6_link_local +from vyos.util import call +from vyos.util import dict_search_args +from vyos.util import run +from vyos.xml import defaults +from vyos import ConfigError +from vyos import airbag +airbag.enable() + +dhcp_wait_attempts = 2 +dhcp_wait_sleep = 1 + +swanctl_dir = '/etc/swanctl' +ipsec_conf = '/etc/ipsec.conf' +ipsec_secrets = '/etc/ipsec.secrets' +charon_conf = '/etc/strongswan.d/charon.conf' +charon_dhcp_conf = '/etc/strongswan.d/charon/dhcp.conf' +interface_conf = '/etc/strongswan.d/interfaces_use.conf' +swanctl_conf = f'{swanctl_dir}/swanctl.conf' + +default_install_routes = 'yes' + +vici_socket = '/var/run/charon.vici' + +CERT_PATH = f'{swanctl_dir}/x509/' +PUBKEY_PATH = f'{swanctl_dir}/pubkey/' +KEY_PATH = f'{swanctl_dir}/private/' +CA_PATH = f'{swanctl_dir}/x509ca/' +CRL_PATH = f'{swanctl_dir}/x509crl/' + +DHCP_BASE = '/var/lib/dhcp/dhclient' +DHCP_HOOK_IFLIST = '/tmp/ipsec_dhcp_waiting' + +def get_config(config=None): + if config: + conf = config + else: + conf = Config() + base = ['vpn', 'ipsec'] + l2tp_base = ['vpn', 'l2tp', 'remote-access', 'ipsec-settings'] + if not conf.exists(base): + return None + + # retrieve common dictionary keys + ipsec = conf.get_config_dict(base, key_mangling=('-', '_'), + get_first_key=True, no_tag_node_value_mangle=True) + + # 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) + # XXX: T2665: we must safely remove default values for tag nodes, those are + # added in a more fine grained way later on + del default_values['esp_group'] + del default_values['ike_group'] + del default_values['remote_access'] + ipsec = dict_merge(default_values, ipsec) + + if 'esp_group' in ipsec: + default_values = defaults(base + ['esp-group']) + for group in ipsec['esp_group']: + ipsec['esp_group'][group] = dict_merge(default_values, + ipsec['esp_group'][group]) + if 'ike_group' in ipsec: + default_values = defaults(base + ['ike-group']) + for group in ipsec['ike_group']: + ipsec['ike_group'][group] = dict_merge(default_values, + ipsec['ike_group'][group]) + if 'remote_access' in ipsec: + default_values = defaults(base + ['remote-access']) + for rw in ipsec['remote_access']: + ipsec['remote_access'][rw] = dict_merge(default_values, + ipsec['remote_access'][rw]) + + ipsec['dhcp_no_address'] = {} + ipsec['install_routes'] = 'no' if conf.exists(base + ["options", "disable-route-autoinstall"]) else default_install_routes + ipsec['interface_change'] = leaf_node_changed(conf, base + ['interface']) + ipsec['nhrp_exists'] = conf.exists(['protocols', 'nhrp', 'tunnel']) + ipsec['pki'] = conf.get_config_dict(['pki'], key_mangling=('-', '_'), + get_first_key=True, + no_tag_node_value_mangle=True) + + ipsec['l2tp'] = conf.get_config_dict(l2tp_base, key_mangling=('-', '_'), + get_first_key=True, + no_tag_node_value_mangle=True) + if ipsec['l2tp']: + l2tp_defaults = defaults(l2tp_base) + ipsec['l2tp'] = dict_merge(l2tp_defaults, ipsec['l2tp']) + ipsec['l2tp_outside_address'] = conf.return_value(['vpn', 'l2tp', 'remote-access', 'outside-address']) + ipsec['l2tp_ike_default'] = 'aes256-sha1-modp1024,3des-sha1-modp1024,3des-sha1-modp1024' + ipsec['l2tp_esp_default'] = 'aes256-sha1,3des-sha1' + + return ipsec + +def get_dhcp_address(iface): + addresses = Interface(iface).get_addr() + if not addresses: + return None + for address in addresses: + if not is_ipv6_link_local(address): + return ip_from_cidr(address) + return None + +def verify_pki_x509(pki, x509_conf): + if not pki or 'ca' not in pki or 'certificate' not in pki: + raise ConfigError(f'PKI is not configured') + + ca_cert_name = x509_conf['ca_certificate'] + cert_name = x509_conf['certificate'] + + if not dict_search_args(pki, 'ca', ca_cert_name, 'certificate'): + raise ConfigError(f'Missing CA certificate on specified PKI CA certificate "{ca_cert_name}"') + + if not dict_search_args(pki, 'certificate', cert_name, 'certificate'): + raise ConfigError(f'Missing certificate on specified PKI certificate "{cert_name}"') + + if not dict_search_args(pki, 'certificate', cert_name, 'private', 'key'): + raise ConfigError(f'Missing private key on specified PKI certificate "{cert_name}"') + + return True + +def verify_pki_rsa(pki, rsa_conf): + if not pki or 'key_pair' not in pki: + raise ConfigError(f'PKI is not configured') + + local_key = rsa_conf['local_key'] + remote_key = rsa_conf['remote_key'] + + if not dict_search_args(pki, 'key_pair', local_key, 'private', 'key'): + raise ConfigError(f'Missing private key on specified local-key "{local_key}"') + + if not dict_search_args(pki, 'key_pair', remote_key, 'public', 'key'): + raise ConfigError(f'Missing public key on specified remote-key "{remote_key}"') + + return True + +def verify(ipsec): + if not ipsec: + return None + + if 'interfaces' in ipsec : + for ifname in ipsec['interface']: + verify_interface_exists(ifname) + + if ipsec['l2tp']: + if 'esp_group' in ipsec['l2tp']: + if 'esp_group' not in ipsec or ipsec['l2tp']['esp_group'] not in ipsec['esp_group']: + raise ConfigError(f"Invalid esp-group on L2TP remote-access config") + + if 'ike_group' in ipsec['l2tp']: + if 'ike_group' not in ipsec or ipsec['l2tp']['ike_group'] not in ipsec['ike_group']: + raise ConfigError(f"Invalid ike-group on L2TP remote-access config") + + if 'authentication' not in ipsec['l2tp']: + raise ConfigError(f'Missing authentication settings on L2TP remote-access config') + + if 'mode' not in ipsec['l2tp']['authentication']: + raise ConfigError(f'Missing authentication mode on L2TP remote-access config') + + if not ipsec['l2tp_outside_address']: + raise ConfigError(f'Missing outside-address on L2TP remote-access config') + + if ipsec['l2tp']['authentication']['mode'] == 'pre-shared-secret': + if 'pre_shared_secret' not in ipsec['l2tp']['authentication']: + raise ConfigError(f'Missing pre shared secret on L2TP remote-access config') + + if ipsec['l2tp']['authentication']['mode'] == 'x509': + if 'x509' not in ipsec['l2tp']['authentication']: + raise ConfigError(f'Missing x509 settings on L2TP remote-access config') + + x509 = ipsec['l2tp']['authentication']['x509'] + + if 'ca_certificate' not in x509 or 'certificate' not in x509: + raise ConfigError(f'Missing x509 certificates on L2TP remote-access config') + + verify_pki_x509(ipsec['pki'], x509) + + if 'profile' in ipsec: + for profile, profile_conf in ipsec['profile'].items(): + if 'esp_group' in profile_conf: + if 'esp_group' not in ipsec or profile_conf['esp_group'] not in ipsec['esp_group']: + raise ConfigError(f"Invalid esp-group on {profile} profile") + else: + raise ConfigError(f"Missing esp-group on {profile} profile") + + if 'ike_group' in profile_conf: + if 'ike_group' not in ipsec or profile_conf['ike_group'] not in ipsec['ike_group']: + raise ConfigError(f"Invalid ike-group on {profile} profile") + else: + raise ConfigError(f"Missing ike-group on {profile} profile") + + if 'authentication' not in profile_conf: + raise ConfigError(f"Missing authentication on {profile} profile") + + if 'remote_access' in ipsec: + for name, ra_conf in ipsec['remote_access'].items(): + if 'esp_group' in ra_conf: + if 'esp_group' not in ipsec or ra_conf['esp_group'] not in ipsec['esp_group']: + raise ConfigError(f"Invalid esp-group on {name} remote-access config") + else: + raise ConfigError(f"Missing esp-group on {name} remote-access config") + + if 'ike_group' in ra_conf: + if 'ike_group' not in ipsec or ra_conf['ike_group'] not in ipsec['ike_group']: + raise ConfigError(f"Invalid ike-group on {name} remote-access config") + else: + raise ConfigError(f"Missing ike-group on {name} remote-access config") + + if 'authentication' not in ra_conf: + raise ConfigError(f"Missing authentication on {name} remote-access config") + + if ra_conf['authentication']['server_mode'] == 'x509': + if 'x509' not in ra_conf['authentication']: + raise ConfigError(f"Missing x509 settings on {name} remote-access config") + + x509 = ra_conf['authentication']['x509'] + + if 'ca_certificate' not in x509 or 'certificate' not in x509: + raise ConfigError(f"Missing x509 certificates on {name} remote-access config") + + verify_pki_x509(ipsec['pki'], x509) + elif ra_conf['authentication']['server_mode'] == 'pre-shared-secret': + if 'pre_shared_secret' not in ra_conf['authentication']: + raise ConfigError(f"Missing pre-shared-key on {name} remote-access config") + + if 'site_to_site' in ipsec and 'peer' in ipsec['site_to_site']: + for peer, peer_conf in ipsec['site_to_site']['peer'].items(): + has_default_esp = False + if 'default_esp_group' in peer_conf: + has_default_esp = True + if 'esp_group' not in ipsec or peer_conf['default_esp_group'] not in ipsec['esp_group']: + raise ConfigError(f"Invalid esp-group on site-to-site peer {peer}") + + if 'ike_group' in peer_conf: + if 'ike_group' not in ipsec or peer_conf['ike_group'] not in ipsec['ike_group']: + raise ConfigError(f"Invalid ike-group on site-to-site peer {peer}") + else: + raise ConfigError(f"Missing ike-group on site-to-site peer {peer}") + + if 'authentication' not in peer_conf or 'mode' not in peer_conf['authentication']: + raise ConfigError(f"Missing authentication on site-to-site peer {peer}") + + if peer_conf['authentication']['mode'] == 'x509': + if 'x509' not in peer_conf['authentication']: + raise ConfigError(f"Missing x509 settings on site-to-site peer {peer}") + + x509 = peer_conf['authentication']['x509'] + + if 'ca_certificate' not in x509 or 'certificate' not in x509: + raise ConfigError(f"Missing x509 certificates on site-to-site peer {peer}") + + verify_pki_x509(ipsec['pki'], x509) + elif peer_conf['authentication']['mode'] == 'rsa': + if 'rsa' not in peer_conf['authentication']: + raise ConfigError(f"Missing RSA settings on site-to-site peer {peer}") + + rsa = peer_conf['authentication']['rsa'] + + if 'local_key' not in rsa: + raise ConfigError(f"Missing RSA local-key on site-to-site peer {peer}") + + if 'remote_key' not in rsa: + raise ConfigError(f"Missing RSA remote-key on site-to-site peer {peer}") + + verify_pki_rsa(ipsec['pki'], rsa) + + if 'local_address' not in peer_conf and 'dhcp_interface' not in peer_conf: + raise ConfigError(f"Missing local-address or dhcp-interface on site-to-site peer {peer}") + + if 'dhcp_interface' in peer_conf: + dhcp_interface = peer_conf['dhcp_interface'] + + verify_interface_exists(dhcp_interface) + + if not os.path.exists(f'{DHCP_BASE}_{dhcp_interface}.conf'): + raise ConfigError(f"Invalid dhcp-interface on site-to-site peer {peer}") + + address = get_dhcp_address(dhcp_interface) + count = 0 + while not address and count < dhcp_wait_attempts: + address = get_dhcp_address(dhcp_interface) + count += 1 + sleep(dhcp_wait_sleep) + + if not address: + ipsec['dhcp_no_address'][peer] = dhcp_interface + print(f"Failed to get address from dhcp-interface on site-to-site peer {peer} -- skipped") + continue + + if 'vti' in peer_conf: + if 'local_address' in peer_conf and 'dhcp_interface' in peer_conf: + raise ConfigError(f"A single local-address or dhcp-interface is required when using VTI on site-to-site peer {peer}") + + if 'bind' in peer_conf['vti']: + vti_interface = peer_conf['vti']['bind'] + if not os.path.exists(f'/sys/class/net/{vti_interface}'): + raise ConfigError(f'VTI interface {vti_interface} for site-to-site peer {peer} does not exist!') + + if 'vti' not in peer_conf and 'tunnel' not in peer_conf: + raise ConfigError(f"No VTI or tunnel specified on site-to-site peer {peer}") + + if 'tunnel' in peer_conf: + for tunnel, tunnel_conf in peer_conf['tunnel'].items(): + if 'esp_group' not in tunnel_conf and not has_default_esp: + raise ConfigError(f"Missing esp-group on tunnel {tunnel} for site-to-site peer {peer}") + + esp_group_name = tunnel_conf['esp_group'] if 'esp_group' in tunnel_conf else peer_conf['default_esp_group'] + + if esp_group_name not in ipsec['esp_group']: + raise ConfigError(f"Invalid esp-group on tunnel {tunnel} for site-to-site peer {peer}") + + esp_group = ipsec['esp_group'][esp_group_name] + + if 'mode' in esp_group and esp_group['mode'] == 'transport': + if 'protocol' in tunnel_conf and ((peer in ['any', '0.0.0.0']) or ('local_address' not in peer_conf or peer_conf['local_address'] in ['any', '0.0.0.0'])): + raise ConfigError(f"Fixed local-address or peer required when a protocol is defined with ESP transport mode on tunnel {tunnel} for site-to-site peer {peer}") + + if ('local' in tunnel_conf and 'prefix' in tunnel_conf['local']) or ('remote' in tunnel_conf and 'prefix' in tunnel_conf['remote']): + raise ConfigError(f"Local/remote prefix cannot be used with ESP transport mode on tunnel {tunnel} for site-to-site peer {peer}") + +def cleanup_pki_files(): + for path in [CERT_PATH, CA_PATH, CRL_PATH, KEY_PATH, PUBKEY_PATH]: + if not os.path.exists(path): + continue + for file in os.listdir(path): + file_path = os.path.join(path, file) + if os.path.isfile(file_path): + os.unlink(file_path) + +def generate_pki_files_x509(pki, x509_conf): + ca_cert_name = x509_conf['ca_certificate'] + ca_cert_data = dict_search_args(pki, 'ca', ca_cert_name, 'certificate') + ca_cert_crls = dict_search_args(pki, 'ca', ca_cert_name, 'crl') or [] + crl_index = 1 + + cert_name = x509_conf['certificate'] + cert_data = dict_search_args(pki, 'certificate', cert_name, 'certificate') + key_data = dict_search_args(pki, 'certificate', cert_name, 'private', 'key') + protected = 'passphrase' in x509_conf + + with open(os.path.join(CA_PATH, f'{ca_cert_name}.pem'), 'w') as f: + f.write(wrap_certificate(ca_cert_data)) + + for crl in ca_cert_crls: + with open(os.path.join(CRL_PATH, f'{ca_cert_name}_{crl_index}.pem'), 'w') as f: + f.write(wrap_crl(crl)) + crl_index += 1 + + with open(os.path.join(CERT_PATH, f'{cert_name}.pem'), 'w') as f: + f.write(wrap_certificate(cert_data)) + + with open(os.path.join(KEY_PATH, f'x509_{cert_name}.pem'), 'w') as f: + f.write(wrap_private_key(key_data, protected)) + +def generate_pki_files_rsa(pki, rsa_conf): + local_key_name = rsa_conf['local_key'] + local_key_data = dict_search_args(pki, 'key_pair', local_key_name, 'private', 'key') + protected = 'passphrase' in rsa_conf + remote_key_name = rsa_conf['remote_key'] + remote_key_data = dict_search_args(pki, 'key_pair', remote_key_name, 'public', 'key') + + local_key = load_private_key(local_key_data, rsa_conf['passphrase'] if protected else None) + + with open(os.path.join(KEY_PATH, f'rsa_{local_key_name}.pem'), 'w') as f: + f.write(wrap_private_key(local_key_data, protected)) + + with open(os.path.join(PUBKEY_PATH, f'{local_key_name}.pem'), 'w') as f: + f.write(encode_public_key(local_key.public_key())) + + with open(os.path.join(PUBKEY_PATH, f'{remote_key_name}.pem'), 'w') as f: + f.write(wrap_public_key(remote_key_data)) + +def generate(ipsec): + cleanup_pki_files() + + if not ipsec: + for config_file in [ipsec_conf, ipsec_secrets, charon_dhcp_conf, interface_conf, swanctl_conf]: + if os.path.isfile(config_file): + os.unlink(config_file) + render(charon_conf, 'ipsec/charon.tmpl', {'install_routes': default_install_routes}) + return + + if ipsec['dhcp_no_address']: + with open(DHCP_HOOK_IFLIST, 'w') as f: + f.write(" ".join(ipsec['dhcp_no_address'].values())) + + for path in [swanctl_dir, CERT_PATH, CA_PATH, CRL_PATH, PUBKEY_PATH]: + if not os.path.exists(path): + os.mkdir(path, mode=0o755) + + if not os.path.exists(KEY_PATH): + os.mkdir(KEY_PATH, mode=0o700) + + if ipsec['l2tp']: + if 'authentication' in ipsec['l2tp'] and 'x509' in ipsec['l2tp']['authentication']: + generate_pki_files_x509(ipsec['pki'], ipsec['l2tp']['authentication']['x509']) + + if 'remote_access' in ipsec: + for rw, rw_conf in ipsec['remote_access'].items(): + if 'authentication' in rw_conf and 'x509' in rw_conf['authentication']: + generate_pki_files_x509(ipsec['pki'], rw_conf['authentication']['x509']) + + if 'site_to_site' in ipsec and 'peer' in ipsec['site_to_site']: + for peer, peer_conf in ipsec['site_to_site']['peer'].items(): + if peer in ipsec['dhcp_no_address']: + continue + + if peer_conf['authentication']['mode'] == 'x509': + generate_pki_files_x509(ipsec['pki'], peer_conf['authentication']['x509']) + elif peer_conf['authentication']['mode'] == 'rsa': + generate_pki_files_rsa(ipsec['pki'], peer_conf['authentication']['rsa']) + + local_ip = '' + if 'local_address' in peer_conf: + local_ip = peer_conf['local_address'] + elif 'dhcp_interface' in peer_conf: + local_ip = get_dhcp_address(peer_conf['dhcp_interface']) + + ipsec['site_to_site']['peer'][peer]['local_address'] = local_ip + + if 'tunnel' in peer_conf: + for tunnel, tunnel_conf in peer_conf['tunnel'].items(): + local_prefixes = dict_search_args(tunnel_conf, 'local', 'prefix') + remote_prefixes = dict_search_args(tunnel_conf, 'remote', 'prefix') + + if not local_prefixes or not remote_prefixes: + continue + + passthrough = [] + + for local_prefix in local_prefixes: + for remote_prefix in remote_prefixes: + local_net = ipaddress.ip_network(local_prefix) + remote_net = ipaddress.ip_network(remote_prefix) + if local_net.overlaps(remote_net): + passthrough.append(local_prefix) + + ipsec['site_to_site']['peer'][peer]['tunnel'][tunnel]['passthrough'] = passthrough + + + render(ipsec_conf, 'ipsec/ipsec.conf.tmpl', ipsec) + render(ipsec_secrets, 'ipsec/ipsec.secrets.tmpl', ipsec) + render(charon_conf, 'ipsec/charon.tmpl', ipsec) + render(charon_dhcp_conf, 'ipsec/charon/dhcp.conf.tmpl', ipsec) + render(interface_conf, 'ipsec/interfaces_use.conf.tmpl', ipsec) + render(swanctl_conf, 'ipsec/swanctl.conf.tmpl', ipsec) + +def resync_nhrp(ipsec): + if ipsec and not ipsec['nhrp_exists']: + return + + tmp = run('/usr/libexec/vyos/conf_mode/protocols_nhrp.py') + if tmp > 0: + print('ERROR: failed to reapply NHRP settings!') + +def wait_for_vici_socket(timeout=5, sleep_interval=0.1): + start_time = time() + test_command = f'sudo socat -u OPEN:/dev/null UNIX-CONNECT:{vici_socket}' + while True: + if (start_time + timeout) < time(): + return None + result = run(test_command) + if result == 0: + return True + sleep(sleep_interval) + +def apply(ipsec): + if not ipsec: + call('sudo ipsec stop') + else: + args = '' + if 'auto_update' in ipsec: + args = '--auto-update ' + ipsec['auto_update'] + call(f'sudo ipsec restart {args}') + call('sudo ipsec rereadall') + call('sudo ipsec reload') + + if wait_for_vici_socket(): + call('sudo swanctl -q') + + resync_nhrp(ipsec) + +if __name__ == '__main__': + try: + ipsec = get_config() + verify(ipsec) + generate(ipsec) + apply(ipsec) + except ConfigError as e: + print(e) + exit(1) |