Merge pull request #3193 from derekpierre/no-exposed-variant

Don't expose Ferveo variant in python Bob public API

newsfragments/3193.misc.rst

@@ -0,0 +1 @@
+Don't allow users to specify the FerveoVariant to use for threshold decryption. The default, simple variant, will be used.

nucypher/characters/lawful.py

@@ -438,7 +438,7 @@ class Alice(Character, actors.PolicyAuthor):
 
 class Bob(Character):
     banner = BOB_BANNER
-    default_dkg_variant = FerveoVariant.SIMPLE
+    _default_dkg_variant = FerveoVariant.SIMPLE
     _default_crypto_powerups = [SigningPower, DecryptingPower]
     _threshold_decryption_client_class = ThresholdDecryptionClient
 
@@ -622,7 +622,7 @@ class Bob(Character):
         return cohort
 
     @staticmethod
-    def make_decryption_request(
+    def __make_decryption_request(
         ritual_id: int,
         ciphertext: Ciphertext,
         lingo: Lingo,
@@ -712,7 +712,6 @@ class Bob(Character):
         conditions: Lingo,
         context: Optional[dict] = None,
         ursulas: Optional[List["Ursula"]] = None,
-        variant: str = "simple",
         peering_timeout: int = 60,
     ) -> bytes:
         ritual = self.get_ritual_from_id(ritual_id)
@@ -730,20 +729,14 @@ class Bob(Character):
                     )
                 self.remember_node(ursula)
 
-        try:
-            variant = FerveoVariant(getattr(FerveoVariant, variant.upper()).value)
-        except AttributeError:
-            raise ValueError(
-                f"Invalid variant: {variant}; Options are: {list(v.name.lower() for v in list(FerveoVariant))}"
-            )
-
+        variant = self._default_dkg_variant
         threshold = (
             (ritual.shares // 2) + 1
             if variant == FerveoVariant.SIMPLE
             else ritual.shares
         )  # TODO: #3095 get this from the ritual / put it on-chain?
 
-        decryption_request = self.make_decryption_request(
+        decryption_request = self.__make_decryption_request(
             ritual_id=ritual_id,
             ciphertext=ciphertext,
             lingo=conditions,
@@ -758,12 +751,12 @@ class Bob(Character):
             threshold=threshold,
         )
 
-        return self._decrypt(
+        return self.__decrypt(
             list(decryption_shares.values()), ciphertext, conditions, variant
         )
 
     @staticmethod
-    def _decrypt(
+    def __decrypt(
         shares: List[Union[DecryptionShareSimple, DecryptionSharePrecomputed]],
         ciphertext: Ciphertext,
         conditions: Lingo,
@@ -1453,7 +1446,6 @@ class Enrico:
     """A data source that encrypts data for some policy's public key"""
 
     banner = ENRICO_BANNER
-    default_dkg_variant = FerveoVariant.SIMPLE
 
     def __init__(self, encrypting_key: Union[PublicKey, DkgPublicKey]):
         self.signing_power = SigningPower()
@@ -1480,29 +1472,6 @@ class Enrico:
         ciphertext = encrypt(plaintext, conditions_bytes, self.policy_pubkey)
         return ciphertext
 
-    def encrypt_for_dkg_and_produce_decryption_request(
-        self,
-        plaintext: bytes,
-        conditions: Lingo,
-        ritual_id: int,
-        variant: int = None,
-        context: Optional[bytes] = None,
-    ) -> Tuple[Ciphertext, ThresholdDecryptionRequest]:
-        ciphertext = self.encrypt_for_dkg(plaintext=plaintext, conditions=conditions)
-
-        if variant is None:
-            variant = self.default_dkg_variant.value
-
-        tdr = ThresholdDecryptionRequest(
-            ritual_id=ritual_id,
-            ciphertext=ciphertext,
-            conditions=Conditions(json.dumps(conditions)),
-            context=context,
-            variant=variant,
-        )
-
-        return ciphertext, tdr
-
     @classmethod
     def from_alice(cls, alice: Alice, label: bytes):
         """

nucypher/crypto/ferveo/dkg.py

@@ -78,6 +78,7 @@ def verify_aggregate(
 ):
     pvss_aggregated.verify(shares, transcripts)
 
+
 def derive_decryption_share(
     nodes: List[Validator],
     aggregated_transcript: AggregatedTranscript,
@@ -93,7 +94,7 @@ def derive_decryption_share(
     try:
         derive_share = _VARIANTS[variant]
     except KeyError:
-        raise Exception(f"invalid variant {variant}")
+        raise ValueError(f"Invalid variant {variant}")
     share = derive_share(
         # first arg here is intended to be "self" since the method is unbound
         aggregated_transcript,

tests/acceptance/actors/test_dkg_ritual.py

@@ -134,7 +134,6 @@ def test_ursula_ritualist(testerchain, coordinator_agent, cohort, alice, bob):
             ritual_id=RITUAL_ID,
             ciphertext=ciphertext,
             conditions=CONDITIONS,
-            # params=cohort[0].dkg_storage.get_dkg_params(RITUAL_ID),
             peering_timeout=0
         )
         assert bytes(cleartext) == PLAINTEXT.encode()

tests/integration/blockchain/test_dkg_ritual.py

@@ -1,5 +1,6 @@
 from time import time
 from typing import List
+from unittest.mock import PropertyMock, patch
 
 import pytest
 import pytest_twisted
@@ -9,6 +10,7 @@ from web3.datastructures import AttributeDict
 
 from nucypher.blockchain.eth.agents import CoordinatorAgent
 from nucypher.characters.lawful import Enrico, Ursula
+from nucypher.crypto.ferveo.dkg import FerveoVariant
 from nucypher.policy.conditions.lingo import ConditionLingo
 from tests.constants import TESTERCHAIN_CHAIN_ID
 from tests.mock.coordinator import MockCoordinatorAgent
@@ -31,17 +33,17 @@ ROUND_1_EVENT_NAME = "StartRitual"
 ROUND_2_EVENT_NAME = "StartAggregationRound"
 
 PARAMS = [  # dkg_size, ritual_id, variant
-    (2, 0, "precomputed"),
-    (4, 1, "precomputed"),
-    (8, 2, "precomputed"),
-    (2, 3, "simple"),
-    (4, 4, "simple"),
-    (8, 5, "simple"),
+    (2, 0, FerveoVariant.PRECOMPUTED),
+    (4, 1, FerveoVariant.PRECOMPUTED),
+    (8, 2, FerveoVariant.PRECOMPUTED),
+    (2, 3, FerveoVariant.SIMPLE),
+    (4, 4, FerveoVariant.SIMPLE),
+    (8, 5, FerveoVariant.SIMPLE),
     # TODO: slow and need additional accounts for testing
-    # (16, 6, "precomputed"),
-    # (16, 7, "simple"),
-    # (32, 8, "precomputed"),
-    # (32, 9, "simple"),
+    # (16, 6, FerveoVariant.PRECOMPUTED),
+    # (16, 7, FerveoVariant.SIMPLE),
+    # (32, 8, FerveoVariant.PRECOMPUTED),
+    # (32, 9, FerveoVariant.SIMPLE),
 ]
 
 BLOCKS = list(reversed(range(1, 1000)))
@@ -127,7 +129,6 @@ def test_ursula_ritualist(
     test_registry_source_manager,
 ):
     """Tests the DKG and the encryption/decryption of a message"""
-
     cohort = cohort[:dkg_size]
 
     def initialize():
@@ -185,24 +186,18 @@ def test_ursula_ritualist(
         print("==================== DKG DECRYPTION ====================")
         bob.start_learning_loop(now=True)
 
-        cleartext = bob.threshold_decrypt(
-            ritual_id=ritual_id,
-            ciphertext=ciphertext,
-            conditions=CONDITIONS,
-            peering_timeout=0,
-            variant=variant
-        )
-        assert bytes(cleartext) == PLAINTEXT.encode()
+        # mock the use of non-default variants since it can no longer be specified
+        with patch.object(
+            bob, "_default_dkg_variant", new_callable=PropertyMock(return_value=variant)
+        ):
+            cleartext = bob.threshold_decrypt(
+                ritual_id=ritual_id,
+                ciphertext=ciphertext,
+                conditions=CONDITIONS,
+                peering_timeout=0,
+            )
+            assert bytes(cleartext) == PLAINTEXT.encode()
 
-        # again, but without `params`
-        cleartext = bob.threshold_decrypt(
-            ritual_id=ritual_id,
-            ciphertext=ciphertext,
-            conditions=CONDITIONS,
-            peering_timeout=0,
-            variant=variant
-        )
-        assert bytes(cleartext) == PLAINTEXT.encode()
         print("==================== DECRYPTION SUCCESSFUL ====================")
 
     def error_handler(e):

tests/integration/config/test_keystore_integration.py

@@ -15,6 +15,7 @@ from nucypher_core.umbral import SecretKey, Signer
 from nucypher.blockchain.eth.signers.software import Web3Signer
 from nucypher.characters.lawful import Alice, Bob, Enrico, Ursula
 from nucypher.config.constants import TEMPORARY_DOMAIN
+from nucypher.crypto.ferveo.dkg import FerveoVariant
 from nucypher.crypto.keystore import Keystore
 from nucypher.crypto.powers import (
     DecryptingPower,
@@ -191,7 +192,7 @@ def test_ritualist(temp_dir_path, testerchain, dkg_public_key):
     ciphertext = enrico.encrypt_for_dkg(plaintext=plaintext, conditions=CONDITIONS)
     decryption_request = ThresholdDecryptionRequest(
         ritual_id=ritual_id,
-        variant=0,
+        variant=FerveoVariant.SIMPLE.value,
         ciphertext=ciphertext,
         conditions=Conditions(json.dumps(CONDITIONS)),
     )