-- | @Noise_XK(s, rs):
--  <- s
--  ...
--  -> e, es
--  <- e, ee
--  -> s, se@
noiseXK :: HandshakePattern
noiseXK = handshakePattern "XK" $
  preResponder s      *>
  initiator (e *> es) *>
  responder (e *> ee) *>
  initiator (s *> se)
noiseXK :: HandshakePattern
noiseXK = handshakePattern "XK" $
  preResponder s      *>
  initiator (e *> es) *>
  responder (e *> ee) *>
  initiator (s *> se)
noiseXK = handshakePattern "XK" $
  preResponder s      *>
  initiator (e *> es) *>
  responder (e *> ee) *>
  initiator (s *> se)