Added registration.

Currently doesn't return any valid result, hence host believes device
failed to register, however, insecure storage of keys does occur.

IO.hpp

@@ -0,0 +1,6 @@
+#pragma once
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+std::vector<uint8_t> readBytes(const size_t count);