def SetupPSKS(pkR, info, psk, psk_id):
  shared_secret, enc = Encap(pkR)
  return enc, KeyScheduleS(mode_psk, shared_secret, info,
                           psk, psk_id)

def SetupPSKR(enc, skR, info, psk, psk_id):
  shared_secret = Decap(enc, skR)
  return KeyScheduleR(mode_psk, shared_secret, info, psk, psk_id)