Using.get_size() for fragments.

nucypher/crypto/constants.py

@@ -7,7 +7,5 @@ BLAKE2B_DIGEST_LENGTH = 64
 KECCAK_DIGEST_LENGTH = 32
 
 # These lengths are specific to secp256k1
-KFRAG_LENGTH(194)
-CFRAG_LENGTH_WITHOUT_PROOF(131)
 CAPSULE_LENGTH(98)
 PUBLIC_KEY_LENGTH(33)

nucypher/keystore/keystore.py

@@ -1,6 +1,5 @@
 from typing import Union
 
-from nucypher.crypto.constants import KFRAG_LENGTH
 from nucypher.crypto.signature import Signature
 from bytestring_splitter import BytestringSplitter
 from nucypher.keystore.db.models import Key, PolicyArrangement, Workorder
@@ -22,7 +21,7 @@ class KeyStore(object):
     """
     A storage class of cryptographic keys.
     """
-    kfrag_splitter = BytestringSplitter(Signature, (KFrag, KFRAG_LENGTH))
+    kfrag_splitter = BytestringSplitter(Signature, (KFrag, KFrag.get_size()))
 
     def __init__(self, sqlalchemy_engine=None):
         """

tests/characters/test_bob_handles_frags.py

@@ -2,7 +2,7 @@ import pytest
 
 from nucypher.crypto.powers import EncryptingPower
 from umbral import pre
-from umbral.fragments import KFrag
+from umbral.fragments import KFrag, CapsuleFrag
 from nucypher.crypto.constants import CFRAG_LENGTH_WITHOUT_PROOF
 
 
@@ -134,7 +134,7 @@ def test_bob_can_issue_a_work_order_to_a_specific_ursula(enacted_policy, bob,
     the_correct_cfrag = pre.reencrypt(the_kfrag, capsule)
 
     # The first CFRAG_LENGTH_WITHOUT_PROOF bytes (ie, the cfrag proper, not the proof material), are the same:
-    assert bytes(the_cfrag)[:CFRAG_LENGTH_WITHOUT_PROOF] == bytes(the_correct_cfrag)[:CFRAG_LENGTH_WITHOUT_PROOF]  # It's the correct cfrag!
+    assert bytes(the_cfrag)[:CapsuleFrag.get_size()] == bytes(the_correct_cfrag)[:CapsuleFrag.get_size()]  # It's the correct cfrag!
 
     assert the_correct_cfrag.verify_correctness(capsule,
                                                 pubkey_a=enacted_policy.public_key,

tests/conftest.py

@@ -1,10 +1,10 @@
 from cryptography.hazmat.primitives.asymmetric import ec
 from umbral.config import set_default_curve
+set_default_curve(ec.SECP256K1())
+
 from .eth_fixtures import *
 from .fixtures import *
 
-set_default_curve(ec.SECP256K1())
-
 
 import pytest
 def pytest_addoption(parser):