def get_data(self):
octet_result = _lib.X509_EXTENSION_get_data(self._extension)<EOL>string_result = _ffi.cast('<STR_LIT>', octet_result)<EOL>char_result = _lib.ASN1_STRING_data(string_result)<EOL>result_length = _lib.ASN1_STRING_length(string_result)<EOL>return _ffi.buffer(char_result, result_length)[:]<EOL>
Returns the data of the X509 extension, encoded as ASN.1.

:return: The ASN.1 encoded data of this X509 extension.
:rtype: :py:data:`bytes`

.. versionadded:: 0.12