':param enctext: XML document containing an encrypted part
:param key_file: The key to use for the decryption
:return: The decrypted document'

def decrypt(self, enctext, key_file, passphrase=None):

    logger.debug(('Decrypt    input    len:    %d' % len(enctext)))
    (_, fil) = make_temp(('%s' % enctext), decode=False)
    com_list = [self.xmlsec, '--decrypt', ('--id-attr:%s' % ID_ATTR), ENC_KEY_CLASS]
    (_stdout, _stderr, output) = self._run_xmlsec(com_list, [fil], exception=DecryptError, validate_output=False, key_file=key_file, passphrase=passphrase)
    return output
