Remove repeated casting to bytes from hashing calls

umbral/hashing.py

@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING, Optional, Type, Iterable
+from typing import TYPE_CHECKING, Optional, Type, Iterable, Union
 
 from cryptography.hazmat.primitives import hashes
 
@@ -7,7 +7,8 @@ from .curve import CURVE
 from .curve_scalar import CurveScalar
 from .curve_point import CurvePoint
 from .keys import PublicKey, SecretKey, Signature
-from .serializable import serialize_bool
+from .serializable import Serializable, serialize_bool
+
 if TYPE_CHECKING: # pragma: no cover
     from .key_frag import KeyFragID
 
@@ -23,8 +24,8 @@ class Hash:
         len_dst = len(dst).to_bytes(4, byteorder='big')
         self.update(len_dst + dst)
 
-    def update(self, data: bytes) -> None:
-        self._hash.update(data)
+    def update(self, data: Union[bytes, Serializable]) -> None:
+        self._hash.update(bytes(data))
 
     def finalize(self) -> bytes:
         return self._hash.finalize()
@@ -36,17 +37,17 @@ def hash_to_polynomial_arg(precursor: CurvePoint,
                            kfrag_id: 'KeyFragID',
                            ) -> CurveScalar:
     digest = Hash(b"POLYNOMIAL_ARG")
-    digest.update(bytes(precursor))
-    digest.update(bytes(pubkey))
-    digest.update(bytes(dh_point))
-    digest.update(bytes(kfrag_id))
+    digest.update(precursor)
+    digest.update(pubkey)
+    digest.update(dh_point)
+    digest.update(kfrag_id)
     return CurveScalar.from_digest(digest)
 
 
 def hash_capsule_points(e: CurvePoint, v: CurvePoint) -> CurveScalar:
     digest = Hash(b"CAPSULE_POINTS")
-    digest.update(bytes(e))
-    digest.update(bytes(v))
+    digest.update(e)
+    digest.update(v)
     return CurveScalar.from_digest(digest)
 
 
@@ -55,9 +56,9 @@ def hash_to_shared_secret(precursor: CurvePoint,
                           dh_point: CurvePoint
                           ) -> CurveScalar:
     digest = Hash(b"SHARED_SECRET")
-    digest.update(bytes(precursor))
-    digest.update(bytes(pubkey))
-    digest.update(bytes(dh_point))
+    digest.update(precursor)
+    digest.update(pubkey)
+    digest.update(dh_point)
     return CurveScalar.from_digest(digest)
 
 
@@ -65,7 +66,7 @@ def hash_to_shared_secret(precursor: CurvePoint,
 def hash_to_cfrag_verification(points: Iterable[CurvePoint], metadata: Optional[bytes] = None) -> CurveScalar:
     digest = Hash(b"CFRAG_VERIFICATION")
     for point in points:
-        digest.update(bytes(point))
+        digest.update(point)
     if metadata is not None:
         digest.update(metadata)
     return CurveScalar.from_digest(digest)
@@ -79,19 +80,19 @@ def hash_to_cfrag_signature(kfrag_id: 'KeyFragID',
                             ) -> 'SignatureDigest':
 
     digest = SignatureDigest(b"CFRAG_SIGNATURE")
-    digest.update(bytes(kfrag_id))
-    digest.update(bytes(commitment))
-    digest.update(bytes(precursor))
+    digest.update(kfrag_id)
+    digest.update(commitment)
+    digest.update(precursor)
 
     if maybe_delegating_pk:
         digest.update(serialize_bool(True))
-        digest.update(bytes(maybe_delegating_pk))
+        digest.update(maybe_delegating_pk)
     else:
         digest.update(serialize_bool(False))
 
     if maybe_receiving_pk:
         digest.update(serialize_bool(True))
-        digest.update(bytes(maybe_receiving_pk))
+        digest.update(maybe_receiving_pk)
     else:
         digest.update(serialize_bool(False))