-- | @Noise_XN(s):
--  -> e
--  <- e, ee
--  -> s, se@
noiseXN :: HandshakePattern
noiseXN = handshakePattern "XN" $
  initiator e         *>
  responder (e *> ee) *>
  initiator (s *> se)
noiseXN :: HandshakePattern
noiseXN = handshakePattern "XN" $
  initiator e         *>
  responder (e *> ee) *>
  initiator (s *> se)
noiseXN = handshakePattern "XN" $
  initiator e         *>
  responder (e *> ee) *>
  initiator (s *> se)