fix: the shell runs as the console account of each member of admins, a local account or the user's own POSIX account in the directory, which also signs in with SSH and sudo, instead of one web.shell_user.

debian-package/src/usr/lib/vpn-router/setup

@@ -83,6 +83,15 @@ CADDY_PKI_DIR = pathlib.Path('/etc/caddy/vpn-router-pki')
 #: The timer of vpn-router-ca maintain, which keeps the CRLs fresh.
 PKI_TIMER = 'vpn-router-pki.timer'
 
+#: The system's side of console login (vpnrouter_users.console): nslcd's configuration, which serves the posixAccounts
+#: of the directory with console login on, the name service switch, the sudo rule of their group, and the drop-in of
+#: sshd that lets them sign in with their password while ssh.ldap_login is true.
+NSLCD_CONF = pathlib.Path('/etc/nslcd.conf')
+NSSWITCH = pathlib.Path('/etc/nsswitch.conf')
+SUDOERS = pathlib.Path('/etc/sudoers.d/vpn-router')
+SSHD_DROPIN = pathlib.Path('/etc/ssh/sshd_config.d/vpn-router.conf')
+PAM_SESSION = pathlib.Path('/etc/pam.d/common-session')
+
 FILTER_ANCHOR = '# End required lines'
 
 #: Configuration options left out wherever the configuration is shown.
@@ -529,6 +538,90 @@ def manage_metrics_account(ctx):
     return ''
 
 
+def write_if_changed(path, text, mode=0o644):
+    """Write the file when its content differs; whether it was written."""
+    try:
+        if path.read_text(encoding='utf-8') == text:
+            return False
+    except OSError:
+        pass
+    path.write_text(text, encoding='utf-8')
+    path.chmod(mode)
+    return True
+
+
+def manage_console(cfg):
+    """Make the system serve console login; the problem, or ''.
+
+    The local group vpnrouter_ldap.CONSOLE_GROUP is created when missing, and sudo lets its members run any command
+    with their password. nslcd serves the directory's posixAccounts with console login on through the local socket,
+    and checks their passwords by binding as the user; the passwd line of the name service switch gains ldap, and PAM
+    creates a home at the first login. While ssh.ldap_login is true, sshd accepts the password of the group's members;
+    a drop-in sshd -t refuses is removed again.
+    """
+    group = vpnrouter_ldap.CONSOLE_GROUP
+    try:
+        grp.getgrnam(group)
+    except KeyError:
+        result = run(['groupadd', '--system', group], check=False)
+        if result.returncode != 0:
+            return f'the group {group} cannot be created: {result.stderr.strip()}'
+
+    rule = f'%{group} ALL=(ALL:ALL) ALL\n'
+    try:
+        if not SUDOERS.is_file() or SUDOERS.read_text(encoding='utf-8') != rule:
+            staged = SUDOERS.with_name('.vpn-router.new')
+            staged.write_text(rule, encoding='utf-8')
+            staged.chmod(0o440)
+            checked = run(['visudo', '-cf', str(staged)], check=False)
+            if checked.returncode != 0:
+                staged.unlink()
+                return f'the sudo rule of {group} is refused: {checked.stdout.strip()} {checked.stderr.strip()}'
+            staged.replace(SUDOERS)
+
+        uri = 'ldapi://' + vpnrouter_ldap.SLAPD_SOCKET.replace('/', '%2f') + '/'
+        nslcd = '\n'.join([
+            'uid nslcd',
+            'gid nslcd',
+            f'uri {uri}',
+            f'base {vpnrouter_ldap.BASE}',
+            'filter passwd (&(objectClass=posixAccount)(vpnRouterConsoleLogin=TRUE))',
+            f'nss_min_uid {vpnrouter_ldap.CONSOLE_UID_MIN}',
+            'pam_authz_search (&(objectClass=posixAccount)(uid=$username)(vpnRouterConsoleLogin=TRUE))',
+            'pam_password_prohibit_message The password is changed in the Router Manager or with vpn-router-user.',
+            '',
+        ])
+        if write_if_changed(NSLCD_CONF, nslcd, 0o640) or not unit_is_active('nslcd'):
+            os.chown(NSLCD_CONF, 0, grp.getgrnam('nslcd').gr_gid)
+            run(['systemctl', 'enable', 'nslcd'], check=False)
+            run(['systemctl', 'restart', 'nslcd'], check=False)
+
+        lines = NSSWITCH.read_text(encoding='utf-8').splitlines(keepends=True)
+        switched = [line.rstrip('\n') + ' ldap\n' if line.startswith('passwd:') and 'ldap' not in line.split() else line
+                    for line in lines]
+        if switched != lines:
+            NSSWITCH.write_text(''.join(switched), encoding='utf-8')
+
+        if 'pam_mkhomedir' not in PAM_SESSION.read_text(encoding='utf-8'):
+            run(['pam-auth-update', '--enable', 'mkhomedir'], check=False)
+
+        if cfg['ssh']['ldap_login']:
+            changed = write_if_changed(SSHD_DROPIN, f'Match Group {group}\n    PasswordAuthentication yes\n')
+        else:
+            changed = SSHD_DROPIN.exists()
+            SSHD_DROPIN.unlink(missing_ok=True)
+        if changed:
+            checked = run(['sshd', '-t'], check=False)
+            if checked.returncode != 0:
+                SSHD_DROPIN.unlink(missing_ok=True)
+                return f'sshd refuses {SSHD_DROPIN}: {checked.stderr.strip()}'
+            if unit_is_active('ssh'):
+                run(['systemctl', 'reload', 'ssh'], check=False)
+    except (OSError, KeyError) as exc:
+        return f'console login cannot be set up: {exc}'
+    return ''
+
+
 def manage_openvpn(ctx, changed):
     """Run the OpenVPN server when it is configured, and stop it when it is not."""
     unit = 'openvpn-server@vpn-router'
@@ -796,6 +889,10 @@ def main():
         failed_step = 'metrics service account'
         progress('running', failed_step)
         problem = manage_metrics_account(ctx)
+    if not problem:
+        failed_step = 'console login'
+        progress('running', failed_step)
+        problem = manage_console(cfg)
     progress('running', 'OpenVPN')
     manage_openvpn(ctx, changed)
     progress('running', 'HTTPS proxy')

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

@@ -52,7 +52,8 @@ SCHEMA = {
     'openvpn':    {'enabled': False, 'address_pool': '', 'port': 1194, 'protocol': 'udp'},
     'docker':     {'mode': 'auto', 'exposed_ports': []},
     'web':        {'enabled': True, 'listen': DEFAULT_LISTEN, 'port': 7081, 'database': '', 'trusted_proxies': [],
-                   'status_content': 'basic', 'shell': False, 'shell_user': '', 'shell_idle_minutes': 15},
+                   'status_content': 'basic', 'shell': False, 'shell_idle_minutes': 15},
+    'ssh':        {'ldap_login': False},
     'https':      {'enabled': True, 'email': '', 'web_port': 7444, 'manager_port': 7443, 'caddy_source': 'ubuntu'},
     'pki':        {'root_name': 'VPN Router Root CA', 'root_days': 7300, 'ca_days': 3650, 'key': 'rsa-4096',
                    'crl_days': 7, 'root_crl_days': 180, 'publish': ['http'], 'p2s_name': 'VPN Router P2S CA',
@@ -194,9 +195,6 @@ CA_NAME_MAX = 64
 #: What / and /status of the web service show, web.status_content, from the least to the most.
 STATUS_CONTENTS = ('basic', 'standard', 'full')
 
-#: A system user the shell of the web service runs as, web.shell_user; root is refused.
-SHELL_USER = re.compile(r'^[a-z_][a-z0-9_-]{0,31}$')
-
 #: The longest web.shell_idle_minutes, a day.
 SHELL_IDLE_MAX = 1440
 
@@ -483,11 +481,6 @@ def validate(cfg):
         raise ConfigError(
             f'web.status_content: {status_content!r} is not one of {", ".join(STATUS_CONTENTS)}')
 
-    shell_user = _get(cfg, 'web', 'shell_user')
-    if shell_user and (not SHELL_USER.match(shell_user) or shell_user == 'root'):
-        raise ConfigError(f'web.shell_user: {shell_user!r} is not a system user name other than root')
-    if _get(cfg, 'web', 'shell') and not shell_user:
-        raise ConfigError('web.shell needs web.shell_user, the system user the shell runs as')
     shell_idle = _get(cfg, 'web', 'shell_idle_minutes')
     if not 1 <= shell_idle <= SHELL_IDLE_MAX:
         raise ConfigError(f'web.shell_idle_minutes: {shell_idle} is not between 1 and {SHELL_IDLE_MAX}')

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

@@ -12,6 +12,10 @@ a successful bind clears the count. slapd's otp overlay is configured on the dat
 bind of a user with a TOTP token takes the password followed by a current code.
 cn=totp,ou=policies holds the TOTP parameters the token of every user points to.
 
+A user with console login on its own account is also a posixAccount, with a uidNumber from
+CONSOLE_UID_MIN and the gidNumber of the local group CONSOLE_GROUP; nslcd serves those with
+vpnRouterConsoleLogin TRUE to the system over the local socket.
+
 ou=pki holds the router's PKI (vpnrouter_pki): an entry per CA, and under it an entry per
 certificate the CA issued. Private keys are readable by root alone, the database's root DN.
 """
@@ -27,6 +31,8 @@ import ldap.modlist
 import ldap.sasl
 
 URI = 'ldapi:///'
+#: The local socket ldapi:/// names, which slapd listens on.
+SLAPD_SOCKET = '/var/run/slapd/ldapi'
 BASE = 'dc=vpn-router,dc=local'
 USERS = f'ou=users,{BASE}'
 GROUPS = f'ou=groups,{BASE}'
@@ -57,8 +63,10 @@ OVERLAYS = ('ppolicy', 'otp')
 #: The package's own schema, under an OID of the UUID arc 2.25 (ITU-T X.667): attribute types
 #: under .1 and object classes under .2. vpnRouterAccount, auxiliary, adds properties of the
 #: package to a user of either kind: mail, for a Manager-only account, vpnRouterScope,
-#: authorization scopes, of which service marks a service account, and displayName and
-#: description, the labels of a service account. vpnRouterAuthority is a CA of the PKI: its
+#: authorization scopes, of which service marks a service account, displayName and
+#: description, the labels of a service account, and vpnRouterConsoleLogin and
+#: vpnRouterConsoleAccount, whether the user may use a console and the local account it runs as,
+#: without which it runs as the user's own posixAccount. vpnRouterAuthority is a CA of the PKI: its
 #: certificate and CRL (cACertificate and certificateRevocationList of RFC 4523), its key, the
 #: CSR it waits with for the offline root, the number of its last CRL, where the CRL came from,
 #: and when it was retired. vpnRouterCertificate is a certificate a CA issued, named by its
@@ -85,10 +93,15 @@ SCHEMA_ATTRIBUTE_TYPES = (
     f"( {SCHEMA_OID}.1.10 NAME 'vpnRouterNotAfter' DESC 'VPN router: when a certificate expires' {_TIME} )",
     f"( {SCHEMA_OID}.1.11 NAME 'vpnRouterRevoked' DESC 'VPN router: when a certificate was revoked' {_TIME} )",
     f"( {SCHEMA_OID}.1.12 NAME 'vpnRouterRevocationReason' DESC 'VPN router: why a certificate was revoked' {_STRING} )",
+    f"( {SCHEMA_OID}.1.13 NAME 'vpnRouterConsoleLogin' DESC 'VPN router: whether the user may use a console' "
+    "EQUALITY booleanMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.7 SINGLE-VALUE )",
+    f"( {SCHEMA_OID}.1.14 NAME 'vpnRouterConsoleAccount' DESC 'VPN router: the local account the console of the user runs as' "
+    f"{_STRING} )",
 )
 SCHEMA_OBJECT_CLASSES = (
     f"( {SCHEMA_OID}.2.1 NAME 'vpnRouterAccount' DESC 'VPN router: properties of a user or a Manager-only account' "
-    "SUP top AUXILIARY MAY ( mail $ vpnRouterScope $ displayName $ description ) )",
+    "SUP top AUXILIARY MAY ( mail $ vpnRouterScope $ displayName $ description $ vpnRouterConsoleLogin $ "
+    "vpnRouterConsoleAccount ) )",
     f"( {SCHEMA_OID}.2.2 NAME 'vpnRouterAuthority' DESC 'VPN router: a CA of the PKI' SUP top STRUCTURAL MUST cn "
     "MAY ( cACertificate $ certificateRevocationList $ vpnRouterPrivateKey $ vpnRouterCertificateRequest $ "
     "vpnRouterCRLNumber $ vpnRouterCRLSource $ vpnRouterRetired ) )",
@@ -103,6 +116,16 @@ TOTP_ALGORITHM = '1.2.840.113549.2.7'
 TOTP_PERIOD = 30
 TOTP_WINDOW = 1
 
+#: The indexes of the database.
+INDEXES = ('objectClass eq', 'uid eq', 'uidNumber eq', 'vpnRouterConsoleLogin eq')
+
+#: The POSIX accounts of console login (vpnrouter_users.console): the lowest uidNumber, which nslcd's nss_min_uid
+#: matches, the local group that is their primary group and grants sudo, the shell and the parent of their homes.
+CONSOLE_UID_MIN = 20000
+CONSOLE_GROUP = 'vpn-router-console'
+CONSOLE_SHELL = '/bin/bash'
+CONSOLE_HOMES = '/home'
+
 #: The ACLs of the database, in order.
 ACCESS = (
     'to attrs=vpnRouterPrivateKey by * none',
@@ -189,8 +212,9 @@ def _ensure_password_hash(connection):
 
 
 def _ensure_database(connection):
-    """The DN of the package's database in cn=config, created when missing; its ACLs are kept as ACCESS."""
-    found = connection.search_s('cn=config', ldap.SCOPE_ONELEVEL, f'(olcSuffix={BASE})', ['olcAccess'])
+    """The DN of the package's database in cn=config, created when missing; its ACLs are kept as ACCESS, and the
+    indexes of INDEXES it lacks are added, which slapd builds online."""
+    found = connection.search_s('cn=config', ldap.SCOPE_ONELEVEL, f'(olcSuffix={BASE})', ['olcAccess', 'olcDbIndex'])
     if not found:
         DB_DIRECTORY.mkdir(mode=0o700, parents=True, exist_ok=True)
         openldap = pwd.getpwnam('openldap')
@@ -201,13 +225,17 @@ def _ensure_database(connection):
             'olcSuffix': [BASE.encode()],
             'olcDbDirectory': [str(DB_DIRECTORY).encode()],
             'olcRootDN': [ROOT.encode()],
-            'olcDbIndex': [b'objectClass eq', b'uid eq'],
+            'olcDbIndex': [index.encode() for index in INDEXES],
             'olcAccess': [f'{{{index}}}{rule}'.encode() for index, rule in enumerate(ACCESS)],
         }))
-        found = connection.search_s('cn=config', ldap.SCOPE_ONELEVEL, f'(olcSuffix={BASE})', ['olcAccess'])
+        found = connection.search_s('cn=config', ldap.SCOPE_ONELEVEL, f'(olcSuffix={BASE})', ['olcAccess', 'olcDbIndex'])
     dn, attributes = found[0]
     if unordered(attributes.get('olcAccess', [])) != list(ACCESS):
         connection.modify_s(dn, [(ldap.MOD_REPLACE, 'olcAccess', [f'{{{index}}}{rule}'.encode() for index, rule in enumerate(ACCESS)])])
+    present = [value.decode() for value in attributes.get('olcDbIndex', [])]
+    missing = [index for index in INDEXES if index not in present]
+    if missing:
+        connection.modify_s(dn, [(ldap.MOD_ADD, 'olcDbIndex', [index.encode() for index in missing])])
     return dn
 
 

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

@@ -29,7 +29,12 @@ code of it. slapd's otp overlay then takes the password followed by a code at ev
 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
+router through the web service.
+
+A member of ADMIN_GROUP may have console login (console): the Shell page of the Router Manager,
+and SSH and sudo with the directory's password, followed by the code for an enrolled user. The
+console runs as a local account, or as the user's own posixAccount, which the user entry becomes
+and nslcd serves to the system. Leaving ADMIN_GROUP switches it off. 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, the PKI's
@@ -42,7 +47,10 @@ import base64
 import calendar
 import contextlib
 import fcntl
+import grp
+import pwd
 import re
+import subprocess
 import time
 
 import ldap
@@ -69,7 +77,8 @@ PERSON = (('first_name', 'givenName'), ('last_name', 'sn'), ('email', 'mail'))
 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']
+              'displayName', 'description', 'userCertificate;binary', 'vpnRouterConsoleLogin', 'vpnRouterConsoleAccount',
+              'uidNumber']
 #: The vpnRouterScope of a service account.
 SERVICE_SCOPE = 'service'
 #: The object classes of a VPN user and of a Manager-only account.
@@ -234,6 +243,7 @@ def summary(attributes):
         'locked': lock not in (None, LOCKED) and locked_since(lock) > time.time() - vpnrouter_ldap.LOCKOUT_SECONDS,
         'certificate': 'userCertificate;binary' in attributes,
         'otp': 'oathTOTPToken' in attributes,
+        'console': console_of(attributes),
     }
     for key, attribute in PERSON + LABELS:
         values = attributes.get(attribute)
@@ -241,6 +251,116 @@ def summary(attributes):
     return user
 
 
+def console_of(attributes):
+    """The console login of an entry as the answers show it: None when it was never set, else {enabled, account, local,
+    uid}: account the system account the console runs as, the local one of vpnRouterConsoleAccount (local true) or the
+    user's own posixAccount, and uid the uidNumber of that posixAccount, None without one."""
+    if 'vpnRouterConsoleLogin' not in attributes:
+        return None
+    local = attributes.get('vpnRouterConsoleAccount')
+    number = attributes.get('uidNumber')
+    return {
+        'enabled': attributes['vpnRouterConsoleLogin'] == [b'TRUE'],
+        'account': local[0].decode() if local else attributes['uid'][0].decode(),
+        'local': bool(local),
+        'uid': int(number[0]) if number else None,
+    }
+
+
+def classes(attributes):
+    """The object classes of an entry, in lower case."""
+    return {value.decode().lower() for value in attributes.get('objectClass', [])}
+
+
+def free_uid(connection):
+    """The lowest uidNumber from vpnrouter_ldap.CONSOLE_UID_MIN above every posixAccount's that no local account has."""
+    found = connection.search_s(vpnrouter_ldap.USERS, ldap.SCOPE_ONELEVEL, '(uidNumber=*)', ['uidNumber'])
+    number = max([vpnrouter_ldap.CONSOLE_UID_MIN - 1] + [int(attributes['uidNumber'][0]) for _, attributes in found]) + 1
+    while True:
+        try:
+            pwd.getpwuid(number)
+        except KeyError:
+            return number
+        number += 1
+
+
+def console(connection, name, enabled, account=None):
+    """Switch the console login of a member of ADMIN_GROUP on, as the local account given or, without one, as the
+    user's own posixAccount, or off.
+
+    The posixAccount is added the first time and kept when the console login is switched off, so its uidNumber and the
+    home it owns stay the user's. A local account must exist in the system's passwd with a uid from 1000 to below
+    vpnrouter_ldap.CONSOLE_UID_MIN, and not be nobody; the user's own account needs a name no local account has.
+    Switching off ends the sessions of the user's own account.
+    """
+    current = entry(connection, name)
+    if not isinstance(enabled, bool):
+        raise Failure('enabled must be true or false', 2)
+    if account is not None and (not isinstance(account, str) or not account):
+        raise Failure('account must be the name of a local account', 2)
+    changes = [] if 'vpnrouteraccount' in classes(current) else [(ldap.MOD_ADD, 'objectClass', [b'vpnRouterAccount'])]
+    if not enabled:
+        if 'vpnRouterConsoleLogin' not in current:
+            return summary(current)
+        connection.modify_s(dn_of(name), changes + [(ldap.MOD_REPLACE, 'vpnRouterConsoleLogin', [b'FALSE'])])
+        end_sessions(current)
+        return summary(entry(connection, name))
+    if service(current):
+        raise Failure(f'{name} is a service account, which has no console', 2)
+    if ADMIN_GROUP not in groups_of(connection, name):
+        raise Failure(f'user {name} is not a member of {ADMIN_GROUP}', 2)
+    if account is not None:
+        try:
+            local = pwd.getpwnam(account)
+        except KeyError:
+            raise Failure(f'there is no local account {account}', 2)
+        if not 1000 <= local.pw_uid < vpnrouter_ldap.CONSOLE_UID_MIN or account == 'nobody':
+            raise Failure(f'{account} is not a local user account with a uid from 1000 to {vpnrouter_ldap.CONSOLE_UID_MIN - 1}', 2)
+        changes.append((ldap.MOD_REPLACE, 'vpnRouterConsoleAccount', [account.encode()]))
+    else:
+        changes.append((ldap.MOD_REPLACE, 'vpnRouterConsoleAccount', []))
+        if 'posixaccount' not in classes(current):
+            try:
+                pwd.getpwnam(name)
+            except KeyError:
+                pass
+            else:
+                raise Failure(f'a local account {name} exists; give it as the account, or use another user', 4)
+            try:
+                group = grp.getgrnam(vpnrouter_ldap.CONSOLE_GROUP).gr_gid
+            except KeyError:
+                raise Failure(f'the group {vpnrouter_ldap.CONSOLE_GROUP} does not exist yet; vpn-router-setup creates it')
+            changes += [
+                (ldap.MOD_ADD, 'objectClass', [b'posixAccount']),
+                (ldap.MOD_REPLACE, 'uidNumber', [str(free_uid(connection)).encode()]),
+                (ldap.MOD_REPLACE, 'gidNumber', [str(group).encode()]),
+                (ldap.MOD_REPLACE, 'homeDirectory', [f'{vpnrouter_ldap.CONSOLE_HOMES}/{name}'.encode()]),
+                (ldap.MOD_REPLACE, 'loginShell', [vpnrouter_ldap.CONSOLE_SHELL.encode()]),
+            ]
+            if manager_only(current):
+                changes.append((ldap.MOD_REPLACE, 'cn', [name.encode()]))
+    changes.append((ldap.MOD_REPLACE, 'vpnRouterConsoleLogin', [b'TRUE']))
+    connection.modify_s(dn_of(name), changes)
+    return summary(entry(connection, name))
+
+
+def end_sessions(attributes):
+    """End the login sessions of the user's own posixAccount, when the entry has one; those of a local account stay."""
+    if 'posixaccount' in classes(attributes) and not attributes.get('vpnRouterConsoleAccount'):
+        subprocess.run(['loginctl', 'terminate-user', attributes['uid'][0].decode()], capture_output=True)
+
+
+def console_off(connection, names):
+    """Switch the console login off for each of the users that has it on; for those who leave ADMIN_GROUP."""
+    for name in names:
+        try:
+            current = entry(connection, name)
+        except Failure:
+            continue
+        if current.get('vpnRouterConsoleLogin') == [b'TRUE']:
+            console(connection, name, False)
+
+
 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)
@@ -441,11 +561,12 @@ def otp_remove(connection, name):
 
 
 def remove(connection, name):
-    """Remove the user from its groups and the directory, and revoke the certificate.
+    """Remove the user from its groups and the directory, revoke the certificate and end the sessions of its own
+    posixAccount.
 
     A user who is the last member of a group is not removed.
     """
-    entry(connection, name)
+    current = entry(connection, name)
     groups = groups_of(connection, name)
     alone = sorted(group for group, members in groups.items() if members == [name])
     if alone:
@@ -457,6 +578,7 @@ def remove(connection, name):
     except vpnrouter_pki.Failure as failure:
         raise Failure(f'the certificate cannot be revoked: {failure}', failure.status)
     connection.delete_s(dn_of(name))
+    end_sessions(current)
     return {'name': name, 'removed': True}
 
 
@@ -573,10 +695,11 @@ def group_add(connection, name, description, members):
 
 
 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."""
+    """Rename the group or change its description ('' removes it); at least one must be given. Renaming ADMIN_GROUP
+    switches the console login of its members off."""
     if new_name is None and description is None:
         raise Failure('give a new name or a description', 2)
-    group_entry(connection, name)
+    members = member_names(group_entry(connection, name))
     if description is not None:
         description = check_description(description)
         change = (ldap.MOD_REPLACE, 'description', [description.encode()]) if description else \
@@ -588,13 +711,18 @@ def group_update(connection, name, new_name=None, description=None):
             connection.rename_s(group_dn(name), f'cn={new_name}', delold=1)
         except ldap.ALREADY_EXISTS:
             raise Failure(f'group {new_name} exists', 4)
+        if name == ADMIN_GROUP:
+            console_off(connection, members)
         name = new_name
     return group_summary(group_entry(connection, name))
 
 
 def group_remove(connection, name):
-    group_entry(connection, name)
+    """Remove the group; removing ADMIN_GROUP switches the console login of its members off."""
+    members = member_names(group_entry(connection, name))
     connection.delete_s(group_dn(name))
+    if name == ADMIN_GROUP:
+        console_off(connection, members)
     return {'name': name, 'removed': True}
 
 
@@ -607,7 +735,8 @@ def group_member_add(connection, name, user):
 
 
 def group_member_remove(connection, name, user):
-    """Take the user out of the group; the last member cannot leave."""
+    """Take the user out of the group; the last member cannot leave. Leaving ADMIN_GROUP switches the user's console
+    login off."""
     check_name(user)
     members = member_names(group_entry(connection, name))
     if user not in members:
@@ -615,6 +744,8 @@ def group_member_remove(connection, name, user):
     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()])])
+    if name == ADMIN_GROUP:
+        console_off(connection, [user])
     return group_summary(group_entry(connection, name))
 
 

debian-package/src/usr/lib/vpn-router/web

@@ -34,7 +34,8 @@ Pages:
   /pki/<name>.crt, /pki/<name>.crl
            the DER certificate and CRL of the root (root) and of each issuing CA, which the
            certificates name in their AIA and CRL distribution points; no authentication
-  /shell   while web.shell is true, a login shell of web.shell_user on a terminal: POST signs the
+  /shell   while web.shell is true, a login shell of the user's console account on a terminal, for
+           a member of admins whose console login is on: POST signs the
            user in again for a one-time ticket (see shell_ticket()), GET with it is a WebSocket
            that carries the terminal (see Handler.shell())
   /auth   sign-in with a user's password and TOTP code, refresh and sign-out (see auth())
@@ -50,7 +51,8 @@ with vpnrouter_auth.WEB_KEY (see vpnrouter_auth.verify). A token of /auth names
 /account serves that user, and the other paths need a member of vpnrouter_users.ADMIN_GROUP. A
 token of vpn-router-token has the admin claim and names no user; it may call every path but
 /account, and only such a token may change ADMIN_GROUP: create, rename to it, change, remove it,
-add or take out its members, and remove one of its members. These paths and /auth are not
+add or take out its members, and remove one of its members, and switch a user's console login.
+These paths and /auth are not
 served (404) while the key does not exist. /auth is limited to AUTH_LIMIT calls per client
 address in AUTH_WINDOW seconds; the address of a call from one of web.trusted_proxies, by
 default the address the call came in on, is the last entry of its X-Forwarded-For header.
@@ -512,6 +514,8 @@ def users(state, method, path, body):
       POST   /users/<name>/otp        a new TOTP secret and its otpauth URI; nothing is stored
       PUT    /users/<name>/otp        store a TOTP secret: {"secret", "code"}, code a code of the secret
       DELETE /users/<name>/otp        remove the TOTP token
+      PUT    /users/<name>/console    switch console login on or off: {"enabled", "account"?}, account a local account,
+                                      without which the user's own posixAccount; only a token of vpn-router-token
 
     Service accounts are served by /service-accounts: they are not listed, and a request naming one is 404.
     """
@@ -535,6 +539,7 @@ def users(state, method, path, body):
         ('POST', 3, 'otp'): lambda connection: vpnrouter_users.otp_new(connection, name),
         ('PUT', 3, 'otp'): lambda connection: vpnrouter_users.otp_enrol(connection, name, body.get('secret'), body.get('code')),
         ('DELETE', 3, 'otp'): lambda connection: vpnrouter_users.otp_remove(connection, name),
+        ('PUT', 3, 'console'): lambda connection: vpnrouter_users.console(connection, name, body.get('enabled'), body.get('account')),
     }
     # The vpnrouter_users operation of each route that may revoke refresh tokens.
     operations = {('PUT', 3, 'password'): 'passwd', ('POST', 3, 'disable'): 'disable', ('POST', 3, 'unlock'): 'unlock',
@@ -979,8 +984,11 @@ def refusal(claims, method, path, body):
     with vpnrouter_users.session() as connection:
         if not vpnrouter_users.is_admin(connection, name):
             return f'user {name} is not a member of {admins}'
-        if changes_admins(connection, method, path.strip('/').split('/'), body if isinstance(body, dict) else {}):
+        parts = path.strip('/').split('/')
+        if changes_admins(connection, method, parts, body if isinstance(body, dict) else {}):
             return f'only a token of vpn-router-token may change the group {admins} or remove its members'
+        if parts[0] == 'users' and len(parts) == 3 and parts[2] == 'console' and method != 'GET':
+            return 'only a token of vpn-router-token may change console login'
     return ''
 
 
@@ -1026,7 +1034,7 @@ def shell_ticket(name, body):
 
     The user named by the token signs in again with {"password", "code"?}; a wrong password or code is 403 and counts
     as a failed login. The answer is {"ticket", "expires_in"}: a ticket that opens one shell (GET /shell) for the
-    same user within SHELL_TICKET_SECONDS. 403 while web.shell is false.
+    same user within SHELL_TICKET_SECONDS. 403 while web.shell is false or the user's console login is not on.
     """
     if not isinstance(name, str):
         return 403, {'error': 'the shell needs a token of a signed-in user'}
@@ -1035,6 +1043,8 @@ def shell_ticket(name, body):
     try:
         if not vpnrouter.load_config()['web']['shell']:
             return 403, {'error': 'the shell is disabled; vpn-config-edit set web.shell true enables it'}
+        if console_account(name) is None:
+            return 403, {'error': f'console login is not enabled for {name}; vpn-router-user console sets it'}
         vpnrouter_users.login(name, body.get('password'), body.get('code'))
     except vpnrouter_users.Failure as failure:
         if failure.status == 5:
@@ -1053,6 +1063,13 @@ def shell_ticket(name, body):
     return 200, {'ticket': ticket, 'expires_in': SHELL_TICKET_SECONDS}
 
 
+def console_account(name):
+    """The system account the console of the user runs as, or None while its console login is not on."""
+    with vpnrouter_users.session() as connection:
+        console = vpnrouter_users.summary(vpnrouter_users.entry(connection, name))['console']
+    return console['account'] if console and console['enabled'] else None
+
+
 def take_ticket(name, ticket):
     """Whether the ticket of POST /shell is unexpired and was given to the user; it is used up either way."""
     with _shell_lock:
@@ -1170,7 +1187,8 @@ class Handler(BaseHTTPRequestHandler):
                 return opcode, payload
 
     def shell(self, name):
-        """Answer GET /shell?ticket=<ticket>, a WebSocket handshake, with a login shell of web.shell_user on a terminal.
+        """Answer GET /shell?ticket=<ticket>, a WebSocket handshake, with a login shell of the user's console account
+        (vpnrouter_users.console) on a terminal.
 
         The ticket must come from POST /shell for the user named by the token. Binary messages of the client are its
         keystrokes, a text message {"cols", "rows"} sets the window size, and binary messages of the server are the
@@ -1199,9 +1217,15 @@ class Handler(BaseHTTPRequestHandler):
         if not options['shell']:
             return refuse(403, 'the shell is disabled; vpn-config-edit set web.shell true enables it')
         try:
-            account = pwd.getpwnam(options['shell_user'])
+            login = console_account(name)
+        except (vpnrouter_users.Failure, ldap.LDAPError, OSError) as exc:
+            return refuse(500, f'the user directory failed: {exc}')
+        if login is None:
+            return refuse(403, f'console login is not enabled for {name}')
+        try:
+            account = pwd.getpwnam(login)
         except KeyError:
-            return refuse(500, f'the system user {options["shell_user"]} of web.shell_user does not exist')
+            return refuse(500, f'the system does not know the account {login}; is nslcd running?')
         unit = f'vpn-router-shell-{secrets.token_hex(4)}'
         master, terminal = os.openpty()
         try:

debian-package/src/usr/sbin/vpn-router-user

@@ -24,6 +24,7 @@ user exists, 1 anything else. -h or --help shows the commands and their options.
   vpn-router-user [--json] otp-new <name>
   vpn-router-user [--json] otp-enrol <name> <code>   (secret on stdin)
   vpn-router-user [--json] otp-remove <name>
+  vpn-router-user [--json] console <name> (--posix | --account LOCAL | --off)
 """
 
 import argparse
@@ -56,6 +57,8 @@ HELP = {
     'otp-new': 'make a TOTP secret and its otpauth URI; nothing is stored',
     'otp-enrol': 'store the TOTP secret read from standard input, when the code is a code of it',
     'otp-remove': 'remove the TOTP token',
+    'console': "switch the console login of a member of admins on, as the user's own POSIX account in the directory "
+               'or as a local account, or off',
 }
 
 #: The help of the person options.
@@ -86,6 +89,11 @@ def parse(argv):
             sub.add_argument('--service', action='store_true', help='add a service account, which cannot sign in to the web service')
         if command == 'otp-enrol':
             sub.add_argument('code', help='a code of the secret from the authenticator')
+        if command == 'console':
+            choice = sub.add_mutually_exclusive_group(required=True)
+            choice.add_argument('--posix', action='store_true', help="run the console as the user's own POSIX account")
+            choice.add_argument('--account', metavar='LOCAL', help='run the console as this local account')
+            choice.add_argument('--off', action='store_true', help='switch console login off')
     return parser.parse_args(argv)
 
 
@@ -108,9 +116,18 @@ def run(connection, options, secret):
         return vpnrouter_users.passwd(connection, options.name, secret)
     if command == 'otp-enrol':
         return vpnrouter_users.otp_enrol(connection, options.name, secret, options.code)
+    if command == 'console':
+        return vpnrouter_users.console(connection, options.name, not options.off, options.account)
     return getattr(vpnrouter_users, command.replace('-', '_'))(connection, options.name)
 
 
+def console_text(console):
+    """The console login of a user as a cell: -, off, posix (uid N) or local and the account."""
+    if console is None or not console['enabled']:
+        return '-' if console is None else 'off'
+    return f'local {console["account"]}' if console['local'] else f'posix (uid {console["uid"]})'
+
+
 def text_of(answer):
     """The answer as text for people."""
     if 'profile' in answer:
@@ -122,11 +139,12 @@ def text_of(answer):
     users = answer['users'] if 'users' in answer else [answer]
     if not users:
         return 'no users'
-    head = ('USER', 'KIND', 'STATE', 'CERTIFICATE', 'OTP', 'FIRST NAME', 'LAST NAME', 'E-MAIL')
+    head = ('USER', 'KIND', 'STATE', 'CERTIFICATE', 'OTP', 'CONSOLE', 'FIRST NAME', 'LAST NAME', 'E-MAIL')
     rows = [(user['name'], 'internal' if user['internal'] else 'service' if user['service'] else 'manager' if user['manager_only'] else 'vpn',
              'disabled' if not user['enabled'] else 'locked' if user['locked'] else 'enabled',
              'issued' if user['certificate'] else 'missing',
-             'enrolled' if user['otp'] else '-', user['first_name'] or '-', user['last_name'] or '-', user['email'] or '-')
+             'enrolled' if user['otp'] else '-', console_text(user['console']),
+             user['first_name'] or '-', user['last_name'] or '-', user['email'] or '-')
             for user in users]
     widths = [max(len(row[column]) for row in (head, *rows)) for column in range(len(head))]
     return '\n'.join('  '.join(cell.ljust(width) for cell, width in zip(row, widths)).rstrip() for row in (head, *rows))

debian-package/src/usr/share/doc/vpn-router/vpn-router.json.example

@@ -63,9 +63,11 @@
     "trusted_proxies": [],
     "status_content": "basic",
     "shell": false,
-    "shell_user": "",
     "shell_idle_minutes": 15
   },
+  "ssh": {
+    "ldap_login": false
+  },
   "https": {
     "enabled": true,
     "email": "",