Bob includes the encrypted KFrag in the WorkOrder, which we previously used in Ursula's side to get the Kfrag from the re-encryption request

nucypher/characters/lawful.py

@@ -713,13 +713,14 @@ class Bob(Character):
 
             # TODO: Bob crashes if he hasn't learned about this Ursula #999
             ursula = self.known_nodes[ursula_address]
-
+            encrypted_kfrag = bytes(treasure_map[ursula_address])
             if capsules_to_include:
                 work_order = WorkOrder.construct_by_bob(arrangement_id=arrangement_id,
                                                         alice_verifying=alice_verifying_key,
                                                         capsules=capsules_to_include,
                                                         ursula=ursula,
-                                                        bob=self)
+                                                        bob=self,
+                                                        encrypted_kfrag=encrypted_kfrag)
                 incomplete_work_orders[ursula_address] = work_order
             else:
                 self.log.debug(f"All of these Capsules already have WorkOrders for this node: {ursula_address}")

nucypher/policy/collections.py

@@ -342,6 +342,7 @@ class WorkOrder:
     def __init__(self,
                  bob: Bob,
                  arrangement_id,
+                 encrypted_kfrag: bytes,
                  alice_address: bytes,
                  tasks: dict,
                  receipt_signature,
@@ -371,7 +372,7 @@ class WorkOrder:
         return len(self.tasks)
 
     @classmethod
-    def construct_by_bob(cls, arrangement_id, alice_verifying, capsules, ursula, bob):
+    def construct_by_bob(cls, arrangement_id, alice_verifying, capsules, ursula, bob, encrypted_kfrag):
         ursula.mature()
         alice_address = canonical_address_from_umbral_key(alice_verifying)
 
@@ -394,10 +395,14 @@ class WorkOrder:
         receipt_bytes = cls.HEADER + bytes(ursula.stamp) + capsules
         receipt_signature = bob.stamp(receipt_bytes)
 
-        return cls(bob=bob, arrangement_id=arrangement_id, tasks=tasks,
+        return cls(bob=bob,
+                   arrangement_id=arrangement_id,
+                   encrypted_kfrag=encrypted_kfrag,
+                   tasks=tasks,
                    receipt_signature=receipt_signature,
                    alice_address=alice_address,
-                   ursula=ursula, blockhash=blockhash)
+                   ursula=ursula,
+                   blockhash=blockhash)
 
     @classmethod
     def from_rest_payload(cls, arrangement_id, rest_payload, ursula, alice_address):
@@ -431,6 +436,7 @@ class WorkOrder:
         bob = Bob.from_public_keys(verifying_key=bob_verifying_key)
         return cls(bob=bob,
                    ursula=ursula,
+                   encrypted_kfrag=None,
                    arrangement_id=arrangement_id,
                    tasks=tasks,
                    alice_address=alice_address,

tests/unit/test_work_orders.py

@@ -110,6 +110,7 @@ def test_work_order_with_multiple_capsules(mock_ursula_reencrypts,
 
     # Test construction of WorkOrders by Bob
     work_order = WorkOrder.construct_by_bob(arrangement_id=arrangement_id,
+                                            encrypted_kfrag=None,  # FIXME
                                             bob=federated_bob,
                                             alice_verifying=federated_alice.stamp.as_umbral_pubkey(),
                                             ursula=ursula,

tests/utils/ursula.py

@@ -195,4 +195,15 @@ def _mock_ursula_reencrypts(ursula):
     cfrag_signature = ursula.stamp(bytes(cfrag))
 
     bob = Bob.from_public_keys(verifying_key=pub_key_bob)
-    return WorkOrder.PRETask(capsule, task_signature, cfrag, cfrag_signature)
+    task = WorkOrder.PRETask(capsule, task_signature, cfrag, cfrag_signature)
+    work_order = WorkOrder(bob=bob,
+                           encrypted_kfrag=None,  # FIXME
+                           arrangement_id=None,
+                           alice_address=alice_address,
+                           tasks={capsule: task},
+                           receipt_signature=None,
+                           ursula=ursula,
+                           blockhash=blockhash)
+
+    evidence = IndisputableEvidence(task, work_order)
+    return evidence