catacomb/__init__.py: Settle on SHAKE256 for X448 box-key generation.

This matches Ed448 hashing, which is probably a good thing.

diff --git a/catacomb/__init__.py b/catacomb/__init__.py
index 4840eef..5cbf993 100644 (file)
--- a/catacomb/__init__.py
+++ b/catacomb/__init__.py
@@ -889,7 +889,7 @@ class X448Pub (_XDHPub):
 class X448Priv (_XDHPriv, X448Pub):
   _KEYSZ = KeySZSet(X448_KEYSZ)
   def _op(me, k, X): return x448(k, X)
-  ##def _hashkey(me, z): return ???
+  def _hashkey(me, z): return Shake256().hash(z).done(salsa20.keysz.default)
 
 class _EdDSAPub (_BasePub):
   def beginhash(me): return me._HASH()