Add 'construct_policy_id' function to crypto.utils and store active

policies under policy ID

nucypher/characters/control/interfaces.py

@@ -6,6 +6,7 @@ from umbral.keys import UmbralPublicKey
 from nucypher.characters.control.specifications import AliceSpecification, BobSpecification, EnricoSpecification
 from nucypher.crypto.kits import UmbralMessageKit
 from nucypher.crypto.powers import DecryptingPower, SigningPower
+from nucypher.crypto.utils import construct_policy_id
 from nucypher.network.middleware import NotFound
 
 

nucypher/crypto/utils.py

@@ -32,6 +32,14 @@ def fingerprint_from_key(public_key: Any):
     return keccak_digest(bytes(public_key)).hex().encode()
 
 
+def construct_policy_id(label: bytes, stamp: bytes) -> bytes:
+    """
+    Forms an ID unique to the policy per label and Bob's signing pubkey via
+    a keccak hash of the two.
+    """
+    return keccak_digest(label + stamp)
+
+
 def canonical_address_from_umbral_key(public_key: UmbralPublicKey) -> bytes:
     pubkey_raw_bytes = public_key.to_bytes(is_compressed=False)[1:]
     eth_pubkey = EthKeyAPI.PublicKey(pubkey_raw_bytes)

nucypher/policy/models.py

@@ -41,9 +41,9 @@ from nucypher.crypto.api import keccak_digest, encrypt_and_sign, secure_random
 from nucypher.crypto.constants import PUBLIC_ADDRESS_LENGTH, KECCAK_DIGEST_LENGTH
 from nucypher.crypto.kits import UmbralMessageKit, RevocationKit
 from nucypher.crypto.powers import SigningPower, DecryptingPower
-from nucypher.crypto.signing import Signature, InvalidSignature, signature_splitter
-from nucypher.crypto.splitters import capsule_splitter, key_splitter
-from nucypher.crypto.utils import canonical_address_from_umbral_key, recover_pubkey_from_signature
+from nucypher.crypto.signing import Signature, InvalidSignature
+from nucypher.crypto.splitters import key_splitter
+from nucypher.crypto.utils import canonical_address_from_umbral_key, recover_pubkey_from_signature, construct_policy_id
 from nucypher.network.exceptions import NodeSeemsToBeDown
 from nucypher.network.middleware import RestMiddleware, NotFound
 
@@ -165,11 +165,7 @@ class Policy:
 
     @property
     def id(self) -> bytes:
-        """
-        Forms an ID unique to the policy per label and Bob via a hash of the
-        label + bob's encrypting pubkey.
-        """
-        return keccak_digest(self.label + bytes(self.bob.stamp))
+        return construct_policy_id(self.label, bytes(self.bob.stamp))
 
     def hrac(self) -> bytes:
         """
@@ -271,7 +267,7 @@ class Policy:
         else:  # ...After *all* the policies are enacted
             # Create Alice's revocation kit
             self.revocation_kit = RevocationKit(self, self.alice.stamp)
-            self.alice.active_policies[bytes(self.public_key).hex()] = self
+            self.alice.active_policies[self.id] = self
 
             if publish is True:
                 return self.publish(network_middleware=network_middleware)