Files
linux-cloud-router/debian-package/src/usr/lib/vpn-router/vpnrouter_users.py
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2026-10-24 11:56:58 +02:00

567 lines
25 KiB
Python

"""The users and groups of the router's directory, for vpn-router-user, vpn-router-group and the web service.
A user is an entry in ou=users of the router's directory, of one of two kinds, fixed when it is
added. A VPN user is an inetOrgPerson with a first name, a last name and an e-mail address, whose
password OpenVPN checks, and a client certificate of the router CA with the user name as its
common name, which OpenVPN and IKEv2 accept. A Manager-only account is an account,
simpleSecurityObject and vpnRouterAccount (the package's schema) with a name, a password and
optionally an e-mail address, no names, no certificate and so no VPN access; it is added when
neither the first nor the last name is given, and can sign in to the web service. Users exist
whether or not a P2S system is enabled.
A group is a groupOfNames in ou=groups with a name, which follows the rules of user names, an
optional description and at least one member; a group cannot be empty, so the last member
cannot leave it and a user who is the last member of a group cannot be removed. Groups only
record membership; nothing on the router reads them.
A user may have a TOTP token: the user entry itself is an oathTOTPUser and oathTOTPToken whose
oathTOTPToken points to itself, with the secret in oathSecret and the parameters of
vpnrouter_ldap.TOTP_PARAMS. Enrolment stores nothing until a code of the new secret is
verified: otp_new makes a secret and its otpauth URI, and otp_enrol stores the secret given a
code of it. slapd's otp overlay then takes the password followed by a code at every bind.
A user is disabled when pwdAccountLockedTime holds LOCKED, and locked when the password
policy has set it after failed binds, for vpnrouter_ldap.LOCKOUT_SECONDS; unlock ends that.
login() checks a user's password and code with a bind. Members of ADMIN_GROUP manage the
router through the web service. The module knows only the directory; the callers revoke a
user's refresh tokens after the operations of vpnrouter_auth.REVOKING.
Every operation runs in a session(), which holds the lock that serializes changes and the
connection of the user manager account. A request that cannot be done raises Failure, whose
status says why: 2 the request is invalid, 3 the user does not exist, 4 the user exists, 5 a
login failed, 1 anything else. Answers are dicts with the keys of the JSON answers.
"""
import base64
import calendar
import contextlib
import fcntl
import pathlib
import re
import subprocess
import sys
import time
import ldap
import ldap.filter
import ldap.modlist
import pyotp
import vpnrouter
import vpnrouter_ldap
#: A user name is one lowercase DNS label, as it is also the common name of the certificate.
NAME = re.compile(r'^[a-z][a-z0-9-]{0,30}[a-z0-9]$|^[a-z]$')
PASSWORD_MIN = 8
PASSWORD_MAX = 128
#: The longest first or last name, in characters.
PERSON_NAME_MAX = 64
#: An e-mail address: one @, no spaces, and a dot in the domain.
EMAIL = re.compile(r'^[^@\s]+@[^@\s]+\.[^@\s]+$')
EMAIL_MAX = 254
#: The keys of the person attributes and their LDAP attributes.
PERSON = (('first_name', 'givenName'), ('last_name', 'sn'), ('email', 'mail'))
#: The attributes read for a user.
ATTRIBUTES = ['uid', 'objectClass', 'pwdAccountLockedTime', 'givenName', 'sn', 'mail', 'oathTOTPToken']
#: The object classes of a VPN user and of a Manager-only account.
VPN_USER_CLASSES = [b'inetOrgPerson']
MANAGER_ONLY_CLASSES = [b'account', b'simpleSecurityObject', b'vpnRouterAccount']
#: The readable attributes of a TOTP token; oathSecret is never readable.
TOKEN_ATTRIBUTES = ['oathTOTPToken', 'oathTOTPParams', 'oathSecretTime', 'oathTOTPLastTimeStep', 'oathTOTPTimeStepDrift',
'oathLastLogin', 'oathLastFailure', 'oathFailureCount']
#: A TOTP secret as otp_new makes it: 32 base32 characters, 160 bits.
TOTP_SECRET = re.compile(r'^[A-Z2-7]{32}$')
#: The attributes read for a group.
GROUP_ATTRIBUTES = ['cn', 'description', 'member']
#: The longest group description, in characters.
DESCRIPTION_MAX = 256
#: The value of pwdAccountLockedTime that disables an account until it is enabled.
LOCKED = b'000001010000Z'
#: The group whose members manage the router through the web service.
ADMIN_GROUP = 'admins'
#: The digits of a TOTP code given to login().
CODE = re.compile(r'^\d{6}$')
LOCK_FILE = pathlib.Path('/run/vpn-router/users.lock')
class Failure(Exception):
"""A request that cannot be done; status is 2 invalid, 3 no such user, 4 the user exists, 5 failed login, 1 other."""
def __init__(self, message, status=1):
super().__init__(message)
self.status = status
@contextlib.contextmanager
def session():
"""The connection of the user manager account, used under the lock that serializes changes."""
LOCK_FILE.parent.mkdir(parents=True, exist_ok=True)
with open(LOCK_FILE, 'w') as lock:
fcntl.flock(lock, fcntl.LOCK_EX)
connection = vpnrouter_ldap.manager()
try:
yield connection
finally:
connection.unbind_s()
def check_name(name):
if not isinstance(name, str) or not NAME.match(name):
raise Failure('a user name is 1 to 32 lowercase letters, digits and hyphens, starting with a letter', 2)
def check_password(value):
if not isinstance(value, str) or '\n' in value or '\r' in value:
raise Failure('the password must be a string of one line', 2)
if not PASSWORD_MIN <= len(value) <= PASSWORD_MAX:
raise Failure(f'the password must have {PASSWORD_MIN} to {PASSWORD_MAX} characters', 2)
def person(values, required):
"""The person attributes of values ({first_name, last_name, email}), checked, as {LDAP attribute: value}.
A key whose value is None is not given; with required, all three must be given.
"""
found = {}
for key, attribute in PERSON:
value = values.get(key)
if value is None:
if required:
raise Failure(f'{key} is required', 2)
continue
if not isinstance(value, str):
raise Failure(f'{key} must be a string', 2)
value = value.strip()
if key == 'email':
if len(value) > EMAIL_MAX or not EMAIL.match(value):
raise Failure(f'{value!r} is not an e-mail address', 2)
elif not value or len(value) > PERSON_NAME_MAX or any(not character.isprintable() for character in value):
raise Failure(f'the {key.replace("_", " ")} must have 1 to {PERSON_NAME_MAX} printable characters', 2)
found[attribute] = value
return found
def dn_of(name):
return f'uid={name},{vpnrouter_ldap.USERS}'
def certificate(name):
return vpnrouter.USER_CERT_DIR / f'{name}_cert.pem', vpnrouter.USER_CERT_DIR / f'{name}_key.pem'
def entry(connection, name):
"""The attributes of the user's entry; Failure with status 3 when there is none."""
check_name(name)
try:
return connection.search_s(dn_of(name), ldap.SCOPE_BASE, attrlist=ATTRIBUTES)[0][1]
except ldap.NO_SUCH_OBJECT:
raise Failure(f'user {name} does not exist', 3)
def simple_ca(*args):
result = subprocess.run([sys.executable, str(vpnrouter.SIMPLE_CA), *args], capture_output=True, text=True)
if result.returncode != 0:
raise Failure(f'simple-ca {args[0]} failed: {result.stderr.strip() or result.stdout.strip()}')
def publish_crl():
"""Give strongSwan the CRL after a revocation; OpenVPN reads it at every connection."""
if vpnrouter.install_file(vpnrouter.PKI_DIR / 'crl.pem', vpnrouter.CRL_DEST, 0o644):
subprocess.run(['swanctl', '--load-creds'], capture_output=True, text=True)
def locked_since(value):
"""The time a pwdAccountLockedTime value names, in seconds since the epoch, or 0 when it names none."""
try:
return calendar.timegm(time.strptime(value[:14].decode(), '%Y%m%d%H%M%S'))
except ValueError:
return 0
def manager_only(attributes):
"""Whether the entry is a Manager-only account."""
return b'account' in (value.lower() for value in attributes.get('objectClass', []))
def summary(attributes):
"""A user as the answers show it; a person attribute the entry does not have is None."""
name = attributes['uid'][0].decode()
lock = attributes.get('pwdAccountLockedTime', [None])[0]
user = {
'name': name,
'manager_only': manager_only(attributes),
'enabled': lock != LOCKED,
'locked': lock not in (None, LOCKED) and locked_since(lock) > time.time() - vpnrouter_ldap.LOCKOUT_SECONDS,
'certificate': certificate(name)[0].is_file(),
'otp': 'oathTOTPToken' in attributes,
}
for key, attribute in PERSON:
values = attributes.get(attribute)
user[key] = values[0].decode() if values else None
return user
def common_name(attributes, name):
"""The cn of an entry: the first and the last name, or the user name without them."""
full = ' '.join(value for value in (attributes.get('givenName'), attributes.get('sn')) if value)
return full or name
def list_users(connection):
found = connection.search_s(vpnrouter_ldap.USERS, ldap.SCOPE_ONELEVEL, '(|(objectClass=inetOrgPerson)(objectClass=account))',
ATTRIBUTES)
return {'users': sorted((summary(attributes) for _, attributes in found), key=lambda user: user['name'])}
def add(connection, name, password, values):
"""Add a user: a VPN user with its certificate when values gives all three person attributes, a Manager-only account
with at most the e-mail address when it gives neither name."""
check_name(name)
details = person(values, required=False)
vpn_user = 'givenName' in details or 'sn' in details
if vpn_user and len(details) != len(PERSON):
raise Failure('give first_name, last_name and email for a VPN user, or at most email for a Manager-only account', 2)
check_password(password)
if vpn_user and not (vpnrouter.PKI_DIR / 'ca_key.pem').is_file():
raise Failure('the router CA does not exist; vpn-router-setup creates it once a platform is chosen')
if vpn_user:
record = {'objectClass': VPN_USER_CLASSES, 'uid': [name.encode()], 'cn': [common_name(details, name).encode()]}
else:
# simpleSecurityObject requires a userPassword; passwd_s sets the real one at once.
record = {'objectClass': MANAGER_ONLY_CLASSES, 'uid': [name.encode()], 'userPassword': [b'{CRYPT}!']}
record.update({attribute: [value.encode()] for attribute, value in details.items()})
try:
connection.add_s(dn_of(name), ldap.modlist.addModlist(record))
except ldap.ALREADY_EXISTS:
raise Failure(f'user {name} exists', 4)
connection.passwd_s(dn_of(name), None, password)
if vpn_user:
vpnrouter.USER_CERT_DIR.mkdir(mode=0o700, parents=True, exist_ok=True)
for path in certificate(name):
path.unlink(missing_ok=True)
simple_ca('make-cert', '--ca-dir', str(vpnrouter.PKI_DIR), '--cert-dir', str(vpnrouter.USER_CERT_DIR), name)
return summary(entry(connection, name))
def update(connection, name, values):
"""Change the person attributes values gives; the cn follows the first and the last name.
A Manager-only account has only the e-mail address, which '' removes.
"""
current = entry(connection, name)
if manager_only(current):
if values.get('first_name') is not None or values.get('last_name') is not None:
raise Failure(f'user {name} is a Manager-only account, which has no first or last name', 2)
email = values.get('email')
if email is None:
raise Failure('give email', 2)
if isinstance(email, str) and email.strip() == '':
if 'mail' in current:
connection.modify_s(dn_of(name), [(ldap.MOD_DELETE, 'mail', None)])
else:
connection.modify_s(dn_of(name), [(ldap.MOD_REPLACE, 'mail', [person({'email': email}, required=False)['mail'].encode()])])
return summary(entry(connection, name))
details = person(values, required=False)
if not details:
raise Failure('give at least one of first_name, last_name and email', 2)
names = {attribute: current[attribute][0].decode() for attribute in ('givenName', 'sn') if current.get(attribute)}
names.update({attribute: details[attribute] for attribute in ('givenName', 'sn') if attribute in details})
changes = [(ldap.MOD_REPLACE, attribute, [value.encode()]) for attribute, value in details.items()]
changes.append((ldap.MOD_REPLACE, 'cn', [common_name(names, name).encode()]))
connection.modify_s(dn_of(name), changes)
return summary(entry(connection, name))
def passwd(connection, name, password):
check_password(password)
entry(connection, name)
connection.passwd_s(dn_of(name), None, password)
return summary(entry(connection, name))
def disable(connection, name):
if entry(connection, name).get('pwdAccountLockedTime') != [LOCKED]:
connection.modify_s(dn_of(name), [(ldap.MOD_REPLACE, 'pwdAccountLockedTime', [LOCKED])])
return summary(entry(connection, name))
def enable(connection, name):
if entry(connection, name).get('pwdAccountLockedTime') == [LOCKED]:
connection.modify_s(dn_of(name), [(ldap.MOD_DELETE, 'pwdAccountLockedTime', None)])
return summary(entry(connection, name))
def unlock(connection, name):
"""End a lockout after failed binds and clear the failure count; a disabled user stays disabled."""
entry(connection, name)
current = connection.search_s(dn_of(name), ldap.SCOPE_BASE, attrlist=['pwdAccountLockedTime', 'pwdFailureTime'])[0][1]
changes = [(ldap.MOD_DELETE, 'pwdFailureTime', None)] if 'pwdFailureTime' in current else []
if 'pwdAccountLockedTime' in current and current['pwdAccountLockedTime'] != [LOCKED]:
changes.append((ldap.MOD_DELETE, 'pwdAccountLockedTime', None))
if changes:
connection.modify_s(dn_of(name), changes)
return summary(entry(connection, name))
def login(name, password, code):
"""Check the user's password, and the TOTP code of an enrolled user, with a bind as the user.
A wrong name, password or code, a locked or a disabled user give the same Failure, status 5.
"""
refused = Failure('the name, the password or the code is wrong', 5)
if not isinstance(name, str) or not NAME.match(name) or not isinstance(password, str) or not password:
raise refused
if code is not None and code != '' and (not isinstance(code, str) or not CODE.match(code)):
raise refused
connection = ldap.initialize(vpnrouter_ldap.URI)
try:
connection.simple_bind_s(dn_of(name), password + (code or ''))
except ldap.INVALID_CREDENTIALS:
raise refused
finally:
connection.unbind_s()
def is_admin(connection, name):
"""Whether the user exists and is a member of ADMIN_GROUP."""
try:
entry(connection, name)
except Failure:
return False
return ADMIN_GROUP in groups_of(connection, name)
def totp(secret):
return pyotp.TOTP(secret, digits=vpnrouter_ldap.TOTP_DIGITS, interval=vpnrouter_ldap.TOTP_PERIOD)
def otp_new(connection, name):
"""A new TOTP secret for the user and its otpauth URI, issued by the router's wan.local_fqdn; nothing is stored."""
entry(connection, name)
secret = pyotp.random_base32()
issuer = vpnrouter.load_config()['wan']['local_fqdn'].strip()
return {'name': name, 'secret': secret, 'uri': totp(secret).provisioning_uri(name=name, issuer_name=issuer or None)}
def otp_enrol(connection, name, secret, code):
"""Store the secret of otp_new as the user's TOTP token, replacing one the user has, when code is a code of it."""
current = entry(connection, name)
if not isinstance(secret, str) or not TOTP_SECRET.match(secret):
raise Failure('the secret must be 32 base32 characters, as a new secret has them', 2)
if not isinstance(code, str) or not re.fullmatch(rf'\d{{{vpnrouter_ldap.TOTP_DIGITS}}}', code):
raise Failure(f'the code must be {vpnrouter_ldap.TOTP_DIGITS} digits', 2)
if not totp(secret).verify(code, valid_window=vpnrouter_ldap.TOTP_WINDOW):
raise Failure('the code does not match the secret; check the clock of the authenticator', 2)
changes = [] if 'oathTOTPToken' in current else [(ldap.MOD_ADD, 'objectClass', [b'oathTOTPUser', b'oathTOTPToken'])]
changes += [
(ldap.MOD_REPLACE, 'oathTOTPToken', [dn_of(name).encode()]),
(ldap.MOD_REPLACE, 'oathTOTPParams', [vpnrouter_ldap.TOTP_PARAMS.encode()]),
(ldap.MOD_REPLACE, 'oathSecret', [base64.b32decode(secret)]),
(ldap.MOD_REPLACE, 'oathSecretTime', [time.strftime('%Y%m%d%H%M%SZ', time.gmtime()).encode()]),
]
connection.modify_s(dn_of(name), changes)
return summary(entry(connection, name))
def otp_remove(connection, name):
"""Remove the user's TOTP token, when the user has one."""
if 'oathTOTPToken' in entry(connection, name):
token = connection.search_s(dn_of(name), ldap.SCOPE_BASE, attrlist=TOKEN_ATTRIBUTES)[0][1]
changes = [(ldap.MOD_DELETE, 'objectClass', [b'oathTOTPUser', b'oathTOTPToken']),
(ldap.MOD_DELETE, 'oathSecret', None)]
changes += [(ldap.MOD_DELETE, attribute, None) for attribute in token]
connection.modify_s(dn_of(name), changes)
return summary(entry(connection, name))
def remove(connection, name):
"""Remove the user from its groups and the directory, and revoke the certificate.
A user who is the last member of a group is not removed.
"""
entry(connection, name)
groups = groups_of(connection, name)
alone = sorted(group for group, members in groups.items() if members == [name])
if alone:
raise Failure(f'user {name} is the last member of {", ".join(alone)}; remove the group first', 2)
for group in groups:
connection.modify_s(group_dn(group), [(ldap.MOD_DELETE, 'member', [dn_of(name).encode()])])
cert, key = certificate(name)
if cert.is_file():
simple_ca('revoke-cert', '--ca-dir', str(vpnrouter.PKI_DIR), str(cert))
simple_ca('make-crl', '--ca-dir', str(vpnrouter.PKI_DIR), '--days', str(vpnrouter.CRL_DAYS))
publish_crl()
cert.unlink(missing_ok=True)
key.unlink(missing_ok=True)
connection.delete_s(dn_of(name))
return {'name': name, 'removed': True}
def profile(connection, name):
"""The OpenVPN client profile of the user, with the CA, the certificate and the key inline."""
entry(connection, name)
cfg = vpnrouter.load_config()
if not cfg['openvpn']['enabled']:
raise Failure('OpenVPN is not enabled', 2)
cert, key = certificate(name)
if not cert.is_file() or not key.is_file():
raise Failure(f'user {name} has no certificate')
fqdn = cfg['wan']['local_fqdn'].strip()
text = '\n'.join([
'client',
'dev tun',
f'proto {cfg["openvpn"]["protocol"]}',
f'remote {fqdn} {cfg["openvpn"]["port"]}',
'nobind',
'persist-key',
'persist-tun',
'remote-cert-tls server',
f'verify-x509-name {fqdn} name',
'auth-user-pass',
'auth-nocache',
'verb 3',
'<ca>', extract_pem(vpnrouter.CA_CERT_DEST.read_text(encoding='utf-8')), '</ca>',
'<cert>', extract_pem(cert.read_text(encoding='utf-8')), '</cert>',
'<key>', key.read_text(encoding='utf-8').strip(), '</key>',
'',
])
return {'name': name, 'profile': text}
def group_dn(name):
return f'cn={name},{vpnrouter_ldap.GROUPS}'
def check_group_name(name):
if not isinstance(name, str) or not NAME.match(name):
raise Failure('a group name is 1 to 32 lowercase letters, digits and hyphens, starting with a letter', 2)
def check_description(value):
"""The description, stripped; '' means none."""
if not isinstance(value, str):
raise Failure('the description must be a string', 2)
value = value.strip()
if len(value) > DESCRIPTION_MAX or any(not character.isprintable() for character in value):
raise Failure(f'the description must have at most {DESCRIPTION_MAX} printable characters', 2)
return value
def member_names(attributes):
"""The user names of a group's member DNs, sorted."""
names = []
for value in attributes.get('member', []):
dn = value.decode()
if dn.startswith('uid=') and dn.endswith(f',{vpnrouter_ldap.USERS}'):
names.append(dn[4:-len(f',{vpnrouter_ldap.USERS}')])
return sorted(names)
def group_summary(attributes):
"""A group as the answers show it."""
values = attributes.get('description')
return {
'name': attributes['cn'][0].decode(),
'description': values[0].decode() if values else '',
'members': member_names(attributes),
}
def group_entry(connection, name):
"""The attributes of the group's entry; Failure with status 3 when there is none."""
check_group_name(name)
try:
return connection.search_s(group_dn(name), ldap.SCOPE_BASE, attrlist=GROUP_ATTRIBUTES)[0][1]
except ldap.NO_SUCH_OBJECT:
raise Failure(f'group {name} does not exist', 3)
def groups_of(connection, name):
"""The groups the user is a member of, as {group name: its member names}."""
found = connection.search_s(vpnrouter_ldap.GROUPS, ldap.SCOPE_ONELEVEL,
f'(&(objectClass=groupOfNames)(member={ldap.filter.escape_filter_chars(dn_of(name))}))',
GROUP_ATTRIBUTES)
return {attributes['cn'][0].decode(): member_names(attributes) for _, attributes in found}
def list_groups(connection):
found = connection.search_s(vpnrouter_ldap.GROUPS, ldap.SCOPE_ONELEVEL, '(objectClass=groupOfNames)', GROUP_ATTRIBUTES)
return {'groups': sorted((group_summary(attributes) for _, attributes in found), key=lambda group: group['name'])}
def group_add(connection, name, description, members):
"""Add a group with a description ('' for none) and at least one member, each an existing user."""
check_group_name(name)
description = check_description(description if description is not None else '')
if not isinstance(members, list) or not members:
raise Failure('a group needs at least one member', 2)
for member in members:
entry(connection, member)
record = {'objectClass': [b'groupOfNames'], 'cn': [name.encode()],
'member': [dn_of(member).encode() for member in sorted(set(members))]}
if description:
record['description'] = [description.encode()]
try:
connection.add_s(group_dn(name), ldap.modlist.addModlist(record))
except ldap.ALREADY_EXISTS:
raise Failure(f'group {name} exists', 4)
return group_summary(group_entry(connection, name))
def group_update(connection, name, new_name=None, description=None):
"""Rename the group or change its description ('' removes it); at least one must be given."""
if new_name is None and description is None:
raise Failure('give a new name or a description', 2)
group_entry(connection, name)
if description is not None:
description = check_description(description)
change = (ldap.MOD_REPLACE, 'description', [description.encode()]) if description else \
(ldap.MOD_REPLACE, 'description', [])
connection.modify_s(group_dn(name), [change])
if new_name is not None and new_name != name:
check_group_name(new_name)
try:
connection.rename_s(group_dn(name), f'cn={new_name}', delold=1)
except ldap.ALREADY_EXISTS:
raise Failure(f'group {new_name} exists', 4)
name = new_name
return group_summary(group_entry(connection, name))
def group_remove(connection, name):
group_entry(connection, name)
connection.delete_s(group_dn(name))
return {'name': name, 'removed': True}
def group_member_add(connection, name, user):
attributes = group_entry(connection, name)
entry(connection, user)
if user not in member_names(attributes):
connection.modify_s(group_dn(name), [(ldap.MOD_ADD, 'member', [dn_of(user).encode()])])
return group_summary(group_entry(connection, name))
def group_member_remove(connection, name, user):
"""Take the user out of the group; the last member cannot leave."""
check_name(user)
members = member_names(group_entry(connection, name))
if user not in members:
raise Failure(f'user {user} is not a member of group {name}', 3)
if members == [user]:
raise Failure(f'user {user} is the last member of group {name}; remove the group instead', 2)
connection.modify_s(group_dn(name), [(ldap.MOD_DELETE, 'member', [dn_of(user).encode()])])
return group_summary(group_entry(connection, name))
def extract_pem(text):
"""The PEM blocks of the certificates in a file that also holds their text form."""
begin, end = '-----BEGIN CERTIFICATE-----', '-----END CERTIFICATE-----'
blocks = []
start = text.find(begin)
while start != -1:
stop = text.index(end, start) + len(end)
blocks.append(text[start:stop])
start = text.find(begin, stop)
return '\n'.join(blocks)