plugin - repurpose invalid_appointments and adds misbehaving_proof

invalid_appointments in TowerInfo was used to stored invalid appointment responses from the tower when it was misbehaving (i.e. wrong or missing signature). However, a single item was stored since the tower is abandoned after misbehaving. data reported as invalid by the tower was not backed up.

invalid_appointments now stores the appointment rejected by the tower and reported as invalid.
misbehaving_proof stores the proof of misbehaviour by the tower (single item)

watchtower-plugin/net/http.py

@@ -42,9 +42,8 @@ def add_appointment(plugin, tower_id, tower, appointment_dict, signature):
                 raise TowerResponseError(message, status="subscription error")
 
             elif data.get("error_code") >= errors.INVALID_REQUEST_FORMAT:
-                # DISCUSS: It may be worth backing up the data since otherwise the update is dropped
                 message = f"Appointment sent to {tower_id} is invalid"
-                raise TowerResponseError(message, status="reachable")
+                raise TowerResponseError(message, status="reachable", invalid_appointment=True)
 
         elif status_code == constants.HTTP_SERVICE_UNAVAILABLE:
             # Flag appointment for retry
@@ -68,9 +67,13 @@ def send_appointment(tower_id, tower, appointment_dict, signature):
         raise SignatureError("The response does not contain the signature of the appointment", signature=None)
 
     rpk = Cryptographer.recover_pk(Appointment.from_dict(appointment_dict).serialize(), tower_signature)
-    if tower_id != Cryptographer.get_compressed_pk(rpk):
+    recovered_id = Cryptographer.get_compressed_pk(rpk)
+    if tower_id != recovered_id:
         raise SignatureError(
-            "The returned appointment's signature is invalid", tower_id=tower_id, rpk=rpk, signature=tower_signature
+            "The returned appointment's signature is invalid",
+            tower_id=tower_id,
+            recovered_id=recovered_id,
+            signature=tower_signature,
         )
 
     return response

watchtower-plugin/retrier.py

@@ -63,7 +63,11 @@ class Retrier:
 
             except SignatureError as e:
                 tower_update["status"] = "misbehaving"
-                tower_update["invalid_appointment"] = (appointment_dict, e.kwargs.get("signature"))
+                tower_update["misbehaving_proof"] = {
+                    "appointment": appointment_dict,
+                    "signature": e.kwargs.get("signature"),
+                    "recovered_id": e.kwargs.get("recovered_id"),
+                }
 
             except TowerConnectionError:
                 tower_update["status"] = "temporarily unreachable"
@@ -71,6 +75,9 @@ class Retrier:
             except TowerResponseError as e:
                 tower_update["status"] = e.kwargs.get("status")
 
+                if e.kwargs.get("invalid_appointment"):
+                    tower_update["invalid_appointment"] = (appointment_dict, signature)
+
             if tower_update["status"] in ["reachable", "misbehaving"]:
                 tower_update["pending_appointment"] = ([appointment_dict, signature], "remove")
 

watchtower-plugin/tower_info.py

@@ -1,32 +1,13 @@
 class TowerInfo:
-    def __init__(
-        self,
-        netaddr,
-        available_slots,
-        status="reachable",
-        appointments=None,
-        pending_appointments=None,
-        invalid_appointments=None,
-    ):
-
+    def __init__(self, netaddr, available_slots, status="reachable"):
         self.netaddr = netaddr
         self.available_slots = available_slots
         self.status = status
 
-        if not appointments:
-            self.appointments = {}
-        else:
-            self.appointments = appointments
-
-        if not pending_appointments:
-            self.pending_appointments = []
-        else:
-            self.pending_appointments = pending_appointments
-
-        if not invalid_appointments:
-            self.invalid_appointments = []
-        else:
-            self.invalid_appointments = invalid_appointments
+        self.appointments = {}
+        self.pending_appointments = []
+        self.invalid_appointments = []
+        self.misbehaving_proof = None
 
     @classmethod
     def from_dict(cls, tower_data):
@@ -36,6 +17,7 @@ class TowerInfo:
         appointments = tower_data.get("appointments")
         pending_appointments = tower_data.get("pending_appointments")
         invalid_appointments = tower_data.get("invalid_appointments")
+        misbehaving_proof = tower_data.get("misbehaving_proof")
 
         if any(
             v is None
@@ -43,7 +25,13 @@ class TowerInfo:
         ):
             raise ValueError("Wrong appointment data, some fields are missing")
 
-        return cls(netaddr, available_slots, status, appointments, pending_appointments, invalid_appointments)
+        tower = cls(netaddr, available_slots, status)
+        tower.appointments = appointments
+        tower.pending_appointments = pending_appointments
+        tower.invalid_appointments = invalid_appointments
+        tower.misbehaving_proof = misbehaving_proof
+
+        return tower
 
     def to_dict(self):
         return self.__dict__

watchtower-plugin/watchtower.py

@@ -71,6 +71,9 @@ class WTClient:
         if "invalid_appointment" in tower_update:
             tower_info.invalid_appointments.append(list(tower_update.get("invalid_appointment")))
 
+        if "misbehaving_proof" in tower_update:
+            tower_info.misbehaving_proof = tower_update.get("misbehaving_proof")
+
         self.towers[tower_id] = tower_info.get_summary()
         self.db_manager.store_tower_record(tower_id, tower_info)
         self.lock.release()
@@ -280,7 +283,11 @@ def on_commitment_revocation(plugin, **kwargs):
 
         except SignatureError as e:
             tower_update["status"] = "misbehaving"
-            tower_update["invalid_appointment"] = (appointment.to_dict(), e.kwargs.get("signature"))
+            tower_update["misbehaving_proof"] = {
+                "appointment": appointment.to_dict(),
+                "signature": e.kwargs.get("signature"),
+                "recovered_id": e.kwargs.get("recovered_id"),
+            }
 
         except TowerConnectionError:
             # All TowerConnectionError are transitory. Connections are tried on register so URLs cannot be malformed.
@@ -300,6 +307,9 @@ def on_commitment_revocation(plugin, **kwargs):
                 if tower_update["status"] == "temporarily unreachable":
                     tower_update["retry"] = True
 
+            if e.kwargs.get("invalid_appointment"):
+                tower_update["invalid_appointment"] = (appointment.to_dict(), signature)
+
         finally:
             # Update memory and TowersDB
             plugin.wt_client.update_tower_state(tower_id, tower_update)