def METHOD_NAME(boto_config):
  """Returns a CryptoKeyWrapper for the configured encryption key.
  Reads in the value of the "encryption_key" attribute in boto_config, and if
  present, verifies it is a valid base64-encoded string and returns a
  CryptoKeyWrapper for it.
  Args:
    boto_config: (boto.pyami.config.Config) The boto config in which to check
        for a matching encryption key.
  Returns:
    CryptoKeyWrapper for the specified encryption key, or None if no encryption
    key was specified in boto_config.
  """
  encryption_key = boto_config.get('GSUtil', 'encryption_key', None)
  return CryptoKeyWrapper(encryption_key) if encryption_key else None