code: def aes_kdf(key, rounds, password=None, keyfile=None):
      
  
      cipher = AES.new(key, AES.MODE_ECB)
      key_composite = compute_key_composite(
          password=password,
          keyfile=keyfile
      )
  
      # get the number of rounds from the header and transform the key_composite
      transformed_key = key_composite
      for _ in range(0, rounds):
          transformed_key = cipher.encrypt(transformed_key)
  
      return hashlib.sha256(transformed_key).digest()
docs: Set up a context for AES128-ECB encryption to find transformed_key