Added registration.

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

Storage.hpp

@@ -0,0 +1,25 @@
+#include <map>
+#include <array>
+#include <string>
+#include <fstream>
+
+class Storage
+{
+public:
+	using KeyHandle = uint32_t;
+	using AppParam  = std::array<uint8_t, 32>;
+	using PrivKey   = std::array<uint8_t, 32>;
+	using PubKey    = std::array<uint8_t, 65>;
+
+	protected:
+		Storage() = default;
+
+		static std::string filename;
+
+	public:
+		static void init(const std::string &dirPrefix = "");
+		static void save();
+		static std::map<KeyHandle, AppParam> appParams;
+		static std::map<KeyHandle, PrivKey>  privKeys;
+		static std::map<KeyHandle, PubKey>   pubKeys;
+};