lib: add user attribute "goauthentik.io/user/override-ips" to allow overriding of client ips

Signed-off-by: Jens Langhammer <jens.langhammer@beryju.org>

authentik/lib/utils/http.py

@@ -3,6 +3,9 @@ from typing import Any, Optional
 
 from django.http import HttpRequest
 
+OUTPOST_REMOTE_IP_HEADER = "HTTP_X_AUTHENTIK_REMOTE_IP"
+USER_ATTRIBUTE_CAN_OVERRIDE_IP = "goauthentik.io/user/override-ips"
+
 
 def _get_client_ip_from_meta(meta: dict[str, Any]) -> Optional[str]:
     """Attempt to get the client's IP by checking common HTTP Headers.
@@ -18,9 +21,27 @@ def _get_client_ip_from_meta(meta: dict[str, Any]) -> Optional[str]:
     return None
 
 
+def _get_outpost_override_ip(request: HttpRequest) -> Optional[str]:
+    """Get the actual remote IP when set by an outpost. Only
+    allowed when the request is authenticated, by a user with USER_ATTRIBUTE_CAN_OVERRIDE_IP set
+    to outpost"""
+    if not hasattr(request, "user"):
+        return None
+    if not request.user.is_authenticated:
+        return None
+    if OUTPOST_REMOTE_IP_HEADER not in request.META:
+        return None
+    if request.user.attributes.get(USER_ATTRIBUTE_CAN_OVERRIDE_IP, False):
+        return None
+    return request.META[OUTPOST_REMOTE_IP_HEADER]
+
+
 def get_client_ip(request: Optional[HttpRequest]) -> Optional[str]:
     """Attempt to get the client's IP by checking common HTTP Headers.
     Returns none if no IP Could be found"""
     if request:
+        override = _get_outpost_override_ip(request)
+        if override:
+            return override
         return _get_client_ip_from_meta(request.META)
     return None