exposes ferveo keypair derivation from secre randomness on the ritual power

nucypher/crypto/keypairs.py

@@ -1,3 +1,4 @@
+import ferveo_py
 import sha3
 from OpenSSL.SSL import TLSv1_2_METHOD
 from OpenSSL.crypto import X509
@@ -101,17 +102,15 @@ class DecryptingKeypair(Keypair):
 class RitualisticKeypair(Keypair):
     """A keypair for Ferveo"""
 
-    class FerveoKey:
-        """A Keypair wrapper/shim for Ferveo to expose the public key as a callable"""
-        def __init__(self):
-            self.keypair = FerveoKeypair.random()
-
-        def public_key(self):
-            return self.keypair.public_key
-
-    _private_key_source = FerveoKey
+    _private_key_source = ferveo_py.Keypair.random
     _public_key_method = "public_key"
 
+    @classmethod
+    def from_secure_randomness(cls, randomness: bytes) -> 'RitualisticKeypair':
+        """Create a keypair from a precomputed secure source of randomness"""
+        keypair = FerveoKeypair.from_secure_randomness(randomness)
+        return cls(private_key=keypair)
+
 
 class SigningKeypair(Keypair):
     """

nucypher/crypto/keystore.py

@@ -8,6 +8,7 @@ import stat
 import string
 import time
 from constant_sorrow.constants import KEYSTORE_LOCKED
+from ferveo_py import ferveo_py
 from mnemonic.mnemonic import Mnemonic
 from nucypher_core.umbral import SecretKeyFactory
 from pathlib import Path
@@ -418,7 +419,7 @@ class Keystore:
 
         elif issubclass(power_class, RitualisticPower):
             keypair_class: RitualisticKeypair = power_class._keypair_class
-            size = keypair_class.secure_randomness_size()
+            size = ferveo_py.Keypair.secure_randomness_size()
             blob = __skf.make_secret(info)[:size]
             keypair = keypair_class.from_secure_randomness(blob)
             power = power_class(keypair=keypair, *power_args, **power_kwargs)

nucypher/crypto/powers.py

@@ -1,15 +1,13 @@
+import ferveo_py
 import inspect
 from eth_account._utils.signing import to_standard_signature_bytes
 from eth_typing.evm import ChecksumAddress
 from ferveo_py import (
-    Keypair as FerveoKeypair,
     Transcript,
     AggregatedTranscript,
     ExternalValidator,
     DecryptionShareSimple,
-    DecryptionSharePrecomputed,
     Ciphertext,
-    DkgPublicParameters,
 )
 from hexbytes import HexBytes
 from nucypher_core.umbral import generate_kfrags, SecretKeyFactory, SecretKey, PublicKey
@@ -241,7 +239,7 @@ class DecryptingPower(KeyPairBasedPower):
 
 class RitualisticPower(KeyPairBasedPower):
     _keypair_class = RitualisticKeypair
-    _default_private_key_class = FerveoKeypair
+    _default_private_key_class = ferveo_py.Keypair
 
     not_found_error = NoRitualisticPower
     provides = ("derive_decryption_share", "generate_transcript")
@@ -265,7 +263,7 @@ class RitualisticPower(KeyPairBasedPower):
             threshold=threshold,
             nodes=nodes,
             aggregated_transcript=aggregated_transcript,
-            keypair=self.keypair._privkey.keypair,
+            keypair=self.keypair._privkey,
             ciphertext=ciphertext,
             aad=conditions,
             variant=variant

tests/unit/test_external_ip_utilities.py

@@ -71,7 +71,7 @@ class Dummy:  # Teacher
             operator_signature=dummy_signature,
             verifying_key=signer.verifying_key(),
             encrypting_key=SecretKey.random().public_key(),
-            ferveo_public_key=bytes(Keypair.random().public_key),
+            ferveo_public_key=bytes(Keypair.random().public_key()),
             certificate_der=b"not a certificate",
             host=MOCK_IP_ADDRESS,
             port=MOCK_PORT,