feature: a VPN user has WireGuard peers, each a device with its public key and IPs, kept in the directory and written into wg0.conf by setup.

debian-package/src/usr/lib/vpn-router/vpnrouter_users.py

@@ -20,6 +20,10 @@ optional description and at least one member; a group cannot be empty, so the la
 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 VPN user may have WireGuard peers, each a device with its public key and its IPs, in
+vpnRouterWireGuardPeer; vpn-router-setup writes a [Peer] of wg0.conf for each peer of a user who
+is not disabled.
+
 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
@@ -48,6 +52,7 @@ import calendar
 import contextlib
 import fcntl
 import grp
+import ipaddress
 import pwd
 import re
 import subprocess
@@ -78,7 +83,9 @@ LABELS = (('display_name', 'displayName'), ('description', 'description'))
 #: The attributes read for a user.
 ATTRIBUTES = ['uid', 'objectClass', 'pwdAccountLockedTime', 'givenName', 'sn', 'mail', 'oathTOTPToken', 'vpnRouterScope',
               'displayName', 'description', 'userCertificate;binary', 'vpnRouterConsoleLogin', 'vpnRouterConsoleAccount',
-              'uidNumber']
+              'uidNumber', 'vpnRouterWireGuardPeer']
+#: The most WireGuard peers of one user.
+WIREGUARD_PEERS_MAX = 16
 #: The vpnRouterScope of a service account.
 SERVICE_SCOPE = 'service'
 #: The object classes of a VPN user and of a Manager-only account.
@@ -94,7 +101,7 @@ 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'
+LOCKED = vpnrouter_ldap.DISABLED.encode()
 #: The group whose members manage the router through the web service.
 ADMIN_GROUP = 'admins'
 #: The digits of a TOTP code given to login().
@@ -244,6 +251,7 @@ def summary(attributes):
         'certificate': 'userCertificate;binary' in attributes,
         'otp': 'oathTOTPToken' in attributes,
         'console': console_of(attributes),
+        'wireguard_peers': peers_of(attributes),
     }
     for key, attribute in PERSON + LABELS:
         values = attributes.get(attribute)
@@ -267,6 +275,62 @@ def console_of(attributes):
     }
 
 
+def peers_of(attributes):
+    """The WireGuard peers of an entry as the answers show them: [{public_key, ips}], in the order they are stored."""
+    peers = []
+    for value in attributes.get('vpnRouterWireGuardPeer', []):
+        key, _, ips = value.decode().partition(' ')
+        peers.append({'public_key': key, 'ips': ips.split(',')})
+    return peers
+
+
+def checked_peers(connection, name, peers):
+    """The values of vpnRouterWireGuardPeer for the user's WireGuard peers, [{public_key, ips}], when they are valid.
+
+    A public key is 32 bytes in base64, used by no other peer of any user; each peer has at least one IP, an IPv4
+    address or network, which no other peer of any user covers and which does not cover the router's own address of
+    wireguard.address. A user has at most WIREGUARD_PEERS_MAX peers.
+    """
+    if not isinstance(peers, list) or len(peers) > WIREGUARD_PEERS_MAX:
+        raise Failure(f'wireguard_peers must be a list of at most {WIREGUARD_PEERS_MAX} peers', 2)
+    router = vpnrouter.load_config()['wireguard']['address'].strip()
+    taken = [(other['name'], key, network)
+             for other in list_users(connection)['users'] if other['name'] != name
+             for peer in other['wireguard_peers'] for key in [peer['public_key']]
+             for network in (ipaddress.ip_network(ip) for ip in peer['ips'])]
+    values = []
+    for peer in peers:
+        key = peer.get('public_key') if isinstance(peer, dict) else None
+        ips = peer.get('ips') if isinstance(peer, dict) else None
+        try:
+            if not isinstance(key, str) or len(base64.b64decode(key.strip(), validate=True)) != 32:
+                raise ValueError
+        except ValueError:
+            raise Failure(f'{key!r} is not a WireGuard public key: 32 bytes in base64', 2)
+        key = key.strip()
+        if not isinstance(ips, list) or not ips or not all(isinstance(ip, str) for ip in ips):
+            raise Failure(f'the peer {key} needs at least one IP', 2)
+        networks = []
+        for ip in ips:
+            try:
+                network = ipaddress.ip_network(ip.strip(), strict=True)
+            except ValueError:
+                raise Failure(f'{ip!r} is not an IPv4 address or network of the peer {key}', 2)
+            if network.version != 4:
+                raise Failure(f'{ip!r} of the peer {key} is not IPv4', 2)
+            if router and ipaddress.ip_interface(router).ip in network:
+                raise Failure(f'{network} of the peer {key} covers the router\'s own address {router}', 2)
+            for owner, other_key, other in taken:
+                if other_key == key:
+                    raise Failure(f'the key {key} is a peer of {owner}', 4)
+                if network.overlaps(other):
+                    raise Failure(f'{network} of the peer {key} overlaps {other} of {owner}', 4)
+            networks.append(network)
+        taken += [(name, key, network) for network in networks]
+        values.append(f'{key} {",".join(str(network) for network in networks)}'.encode())
+    return values
+
+
 def classes(attributes):
     """The object classes of an entry, in lower case."""
     return {value.decode().lower() for value in attributes.get('objectClass', [])}
@@ -412,7 +476,8 @@ def add(connection, name, password, values, service=False):
 
 
 def update(connection, name, values):
-    """Change the person attributes values gives; the cn follows the first and the last name.
+    """Change the person attributes values gives, the cn following the first and the last name, and of a VPN user the
+    WireGuard peers, wireguard_peers, which replace the user's peers (checked_peers).
 
     A Manager-only account has only the e-mail address, which '' removes; a service account also its labels
     (update_service).
@@ -421,6 +486,8 @@ def update(connection, name, values):
     if service(current):
         return update_service(connection, name, values)
     if manager_only(current):
+        if values.get('wireguard_peers') is not None:
+            raise Failure(f'user {name} is a Manager-only account, which has no VPN access and so no WireGuard peers', 2)
         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')
@@ -433,16 +500,30 @@ def update(connection, name, values):
             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()]))
+    peers = values.get('wireguard_peers')
+    if not details and peers is None:
+        raise Failure('give at least one of first_name, last_name, email and wireguard_peers', 2)
+    changes = []
+    if details:
+        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()]))
+    if peers is not None:
+        if 'vpnrouteraccount' not in classes(current):
+            changes.append((ldap.MOD_ADD, 'objectClass', [b'vpnRouterAccount']))
+        changes.append((ldap.MOD_REPLACE, 'vpnRouterWireGuardPeer', checked_peers(connection, name, peers)))
     connection.modify_s(dn_of(name), changes)
+    if peers is not None:
+        apply_wireguard()
     return summary(entry(connection, name))
 
 
+def apply_wireguard():
+    """Have vpn-router-setup write the WireGuard peers of the users into wg0.conf, without waiting for it."""
+    subprocess.run(['systemctl', 'restart', '--no-block', 'vpn-router-setup.service'], capture_output=True)
+
+
 def update_service(connection, name, values):
     """Change any of the e-mail address and the labels (labels) of a service account that values gives; '' removes one."""
     if not service(entry(connection, name)):
@@ -466,14 +547,22 @@ def passwd(connection, name, password):
 
 
 def disable(connection, name):
-    if entry(connection, name).get('pwdAccountLockedTime') != [LOCKED]:
+    """Lock the user out; the WireGuard peers of a disabled user are left out of wg0.conf."""
+    current = entry(connection, name)
+    if current.get('pwdAccountLockedTime') != [LOCKED]:
         connection.modify_s(dn_of(name), [(ldap.MOD_REPLACE, 'pwdAccountLockedTime', [LOCKED])])
+        if 'vpnRouterWireGuardPeer' in current:
+            apply_wireguard()
     return summary(entry(connection, name))
 
 
 def enable(connection, name):
-    if entry(connection, name).get('pwdAccountLockedTime') == [LOCKED]:
+    """Let the user in again, with the WireGuard peers."""
+    current = entry(connection, name)
+    if current.get('pwdAccountLockedTime') == [LOCKED]:
         connection.modify_s(dn_of(name), [(ldap.MOD_DELETE, 'pwdAccountLockedTime', None)])
+        if 'vpnRouterWireGuardPeer' in current:
+            apply_wireguard()
     return summary(entry(connection, name))
 
 
@@ -579,6 +668,8 @@ def remove(connection, name):
         raise Failure(f'the certificate cannot be revoked: {failure}', failure.status)
     connection.delete_s(dn_of(name))
     end_sessions(current)
+    if 'vpnRouterWireGuardPeer' in current:
+        apply_wireguard()
     return {'name': name, 'removed': True}