code: def compute_hkdf(ikm, salt):
      
      prk = hmac.new(salt, ikm, hashlib.sha256).digest()
      info_bits_update = info_bits + bytearray(chr(1), 'utf-8')
      hmac_hash = hmac.new(prk, info_bits_update, hashlib.sha256).digest()
      return hmac_hash[:16]
docs: Standard hkdf algorithm
      :param {Buffer} ikm Input key material.
      :param {Buffer} salt Salt value.
      :return {Buffer} Strong key material.
      @private