change Aes256 to accept buffer

include/buffer.hpp

@@ -9,7 +9,7 @@ class Buffer
 public:
 	uint8_t *buffer = nullptr;
 	size_t taken = 0;
-	size_t size = 0;
+
 	std::string file_path;
 
 	Buffer(size_t size);
@@ -35,6 +35,8 @@ public:
 
 	bool load_from_file();
 	bool load_from_file(std::string file_path);
+private:
+		size_t size = 0;
 };
 
-#endif
+#endif //BUFFER_HPP