From 0d5ac59894ae7c10bd9d69047fa7098de66f835f Mon Sep 17 00:00:00 2001 From: sarthurdev <965089+sarthurdev@users.noreply.github.com> Date: Sat, 25 Jun 2022 23:04:31 +0200 Subject: openvpn: T4485: Accept multiple `tls ca-certificate` values --- .../include/pki/ca-certificate-multi.xml.i | 15 ++++++++ interface-definitions/interfaces-openvpn.xml.in | 2 +- python/vyos/pki.py | 32 ++++++++++++++++ python/vyos/util.py | 4 +- src/conf_mode/interfaces-openvpn.py | 43 +++++++++++++++------- 5 files changed, 79 insertions(+), 17 deletions(-) create mode 100644 interface-definitions/include/pki/ca-certificate-multi.xml.i diff --git a/interface-definitions/include/pki/ca-certificate-multi.xml.i b/interface-definitions/include/pki/ca-certificate-multi.xml.i new file mode 100644 index 000000000..646131b54 --- /dev/null +++ b/interface-definitions/include/pki/ca-certificate-multi.xml.i @@ -0,0 +1,15 @@ + + + + Certificate Authority chain in PKI configuration + + pki ca + + + txt + Name of CA in PKI configuration + + + + + diff --git a/interface-definitions/interfaces-openvpn.xml.in b/interface-definitions/interfaces-openvpn.xml.in index f1cbf8468..6cbd91ff4 100644 --- a/interface-definitions/interfaces-openvpn.xml.in +++ b/interface-definitions/interfaces-openvpn.xml.in @@ -741,7 +741,7 @@ #include - #include + #include Diffie Hellman parameters (server only) diff --git a/python/vyos/pki.py b/python/vyos/pki.py index fd91fc9bf..648064a3a 100644 --- a/python/vyos/pki.py +++ b/python/vyos/pki.py @@ -332,6 +332,25 @@ def verify_certificate(cert, ca_cert): except InvalidSignature: return False +def verify_ca_chain(sorted_names, pki_node): + if len(sorted_names) == 1: # Single cert, no chain + return True + + for name in sorted_names: + cert = load_certificate(pki_node[name]['certificate']) + verified = False + for ca_name in sorted_names: + if name == ca_name: + continue + ca_cert = load_certificate(pki_node[ca_name]['certificate']) + if verify_certificate(cert, ca_cert): + verified = True + break + if not verified and name != sorted_names[-1]: + # Only permit top-most certificate to fail verify (e.g. signed by public CA not explicitly in chain) + return False + return True + # Certificate chain def find_parent(cert, ca_certs): @@ -357,3 +376,16 @@ def find_chain(cert, ca_certs): chain.append(parent) return chain + +def sort_ca_chain(ca_names, pki_node): + def ca_cmp(ca_name1, ca_name2, pki_node): + cert1 = load_certificate(pki_node[ca_name1]['certificate']) + cert2 = load_certificate(pki_node[ca_name2]['certificate']) + + if verify_certificate(cert1, cert2): # cert1 is child of cert2 + return -1 + return 1 + + from functools import cmp_to_key + return sorted(ca_names, key=cmp_to_key(lambda cert1, cert2: ca_cmp(cert1, cert2, pki_node))) + diff --git a/python/vyos/util.py b/python/vyos/util.py index 0d62fbfe9..bee5d7aec 100644 --- a/python/vyos/util.py +++ b/python/vyos/util.py @@ -197,7 +197,7 @@ def read_file(fname, defaultonfailure=None): return defaultonfailure raise e -def write_file(fname, data, defaultonfailure=None, user=None, group=None, mode=None): +def write_file(fname, data, defaultonfailure=None, user=None, group=None, mode=None, append=False): """ Write content of data to given fname, should defaultonfailure be not None, it is returned on failure to read. @@ -212,7 +212,7 @@ def write_file(fname, data, defaultonfailure=None, user=None, group=None, mode=N try: """ Write a file to string """ bytes = 0 - with open(fname, 'w') as f: + with open(fname, 'w' if not append else 'a') as f: bytes = f.write(data) chown(fname, user, group) chmod(fname, mode) diff --git a/src/conf_mode/interfaces-openvpn.py b/src/conf_mode/interfaces-openvpn.py index 4750ca3e8..280a62b9a 100755 --- a/src/conf_mode/interfaces-openvpn.py +++ b/src/conf_mode/interfaces-openvpn.py @@ -39,6 +39,8 @@ from vyos.configverify import verify_mirror_redirect from vyos.ifconfig import VTunIf from vyos.pki import load_dh_parameters from vyos.pki import load_private_key +from vyos.pki import sort_ca_chain +from vyos.pki import verify_ca_chain from vyos.pki import wrap_certificate from vyos.pki import wrap_crl from vyos.pki import wrap_dh_parameters @@ -148,8 +150,14 @@ def verify_pki(openvpn): if 'ca_certificate' not in tls: raise ConfigError(f'Must specify "tls ca-certificate" on openvpn interface {interface}') - if tls['ca_certificate'] not in pki['ca']: - raise ConfigError(f'Invalid CA certificate on openvpn interface {interface}') + for ca_name in tls['ca_certificate']: + if ca_name not in pki['ca']: + raise ConfigError(f'Invalid CA certificate on openvpn interface {interface}') + + if len(tls['ca_certificate']) > 1: + sorted_chain = sort_ca_chain(tls['ca_certificate'], pki['ca']) + if not verify_ca_chain(sorted_chain, pki['ca']): + raise ConfigError(f'CA certificates are not a valid chain') if mode != 'client' and 'auth_key' not in tls: if 'certificate' not in tls: @@ -516,21 +524,28 @@ def generate_pki_files(openvpn): if tls: if 'ca_certificate' in tls: - cert_name = tls['ca_certificate'] - pki_ca = pki['ca'][cert_name] + cert_path = os.path.join(cfg_dir, f'{interface}_ca.pem') + crl_path = os.path.join(cfg_dir, f'{interface}_crl.pem') - if 'certificate' in pki_ca: - cert_path = os.path.join(cfg_dir, f'{interface}_ca.pem') - write_file(cert_path, wrap_certificate(pki_ca['certificate']), - user=user, group=group, mode=0o600) + if os.path.exists(cert_path): + os.unlink(cert_path) + + if os.path.exists(crl_path): + os.unlink(crl_path) + + for cert_name in sort_ca_chain(tls['ca_certificate'], pki['ca']): + pki_ca = pki['ca'][cert_name] + + if 'certificate' in pki_ca: + write_file(cert_path, wrap_certificate(pki_ca['certificate']) + "\n", + user=user, group=group, mode=0o600, append=True) - if 'crl' in pki_ca: - for crl in pki_ca['crl']: - crl_path = os.path.join(cfg_dir, f'{interface}_crl.pem') - write_file(crl_path, wrap_crl(crl), user=user, group=group, - mode=0o600) + if 'crl' in pki_ca: + for crl in pki_ca['crl']: + write_file(crl_path, wrap_crl(crl) + "\n", user=user, group=group, + mode=0o600, append=True) - openvpn['tls']['crl'] = True + openvpn['tls']['crl'] = True if 'certificate' in tls: cert_name = tls['certificate'] -- cgit v1.2.3