auth: improve pam flow and user status

backend/actions.py

@@ -133,8 +133,15 @@ def disable_user(
                     if play_sound:
                         _play_sound_if_available()
 
-    _run(["sudo", "pkill", "-KILL", "-u", user])
-    steps.append("sessions terminated")
+    try:
+        _run(["sudo", "pkill", "-KILL", "-u", user])
+        steps.append("sessions terminated")
+    except subprocess.CalledProcessError as exc:
+        if exc.returncode == 1:
+            # pkill returns 1 when no matching processes exist; not an error here.
+            steps.append("no sessions to terminate")
+        else:
+            raise
 
     if logged_in:
         _run(["sudo", "shutdown", "now"])

backend/app.py

@@ -11,6 +11,7 @@ from backend.auth import (
     authenticate_admin_user,
     get_current_admin,
     is_authorized_admin,
+    is_account_locked,
     issue_token,
     list_manageable_users,
 )
@@ -142,7 +143,14 @@ def oidc_status(settings: Settings = Depends(get_settings)) -> dict:
 def users(settings: Settings = Depends(get_settings)) -> List[UserStatus]:
     logged_in = set(actions.list_logged_in_users())
     targets = list_manageable_users(settings)
-    return [UserStatus(user=user, logged_in=user in logged_in) for user in targets]
+    return [
+        UserStatus(
+            user=user,
+            logged_in=user in logged_in,
+            account_locked=is_account_locked(user),
+        )
+        for user in targets
+    ]
 
 
 @app.post(
@@ -151,10 +159,16 @@ def users(settings: Settings = Depends(get_settings)) -> List[UserStatus]:
     dependencies=[Depends(get_current_admin)],
 )
 def disable_user(
+    current_user: str = Depends(get_current_admin),
     username: str = Depends(validate_user),
     payload: ActionRequest | None = Body(default=None),
     settings: Settings = Depends(get_settings),
 ) -> ActionResponse:
+    if username == current_user:
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail="Refusing to disable the currently authenticated user",
+        )
     try:
         steps = actions.disable_user(
             username,

backend/auth.py

@@ -1,6 +1,7 @@
 import datetime as dt
 import grp
 import pwd
+import spwd
 from typing import List, Set, Optional
 
 import jwt
@@ -119,3 +120,17 @@ def list_manageable_users(settings: Settings) -> List[str]:
         candidates.append(entry.pw_name)
     candidates.sort()
     return candidates
+
+
+def is_account_locked(username: str) -> bool:
+    """Return True when the account is locked in /etc/shadow."""
+    try:
+        shadow_entry = spwd.getspnam(username)
+    except KeyError:
+        return False
+    except PermissionError:
+        return False
+    shadow_password = shadow_entry.sp_pwdp or ""
+    if shadow_password in ("*", "!", "!!"):
+        return True
+    return shadow_password.startswith("!")

backend/models.py

@@ -23,6 +23,7 @@ class ActionResponse(BaseModel):
 class UserStatus(BaseModel):
     user: str
     logged_in: bool
+    account_locked: bool
 
 
 class LoginRequest(BaseModel):

backend/templates/index.html

@@ -154,7 +154,9 @@
       statusDiv.textContent = 'Lade...';
       try {
         const data = await api('/users');
-        statusDiv.textContent = data.map(u => `${u.user}: ${u.logged_in ? 'eingeloggt' : 'aus'}`).join('\n') || 'Keine Daten';
+        statusDiv.textContent = data
+          .map(u => `${u.user}: ${u.logged_in ? 'eingeloggt' : 'aus'} | ${u.account_locked ? 'deaktiviert' : 'aktiv'}`)
+          .join('\n') || 'Keine Daten';
         const select = document.getElementById('username');
         select.innerHTML = '<option value="">-- wählen --</option>';
         data.forEach(u => {