def LabeledExtract(salt, label, ikm):
  labeled_ikm = concat("HPKE-v1", suite_id, label, ikm)
  return Extract(salt, labeled_ikm)

def LabeledExpand(prk, label, info, L):
  labeled_info = concat(I2OSP(L, 2), "HPKE-v1", suite_id,
                        label, info)
  return Expand(prk, labeled_info, L)