Added registration.

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

U2F_Init_Response.hpp

@@ -0,0 +1,31 @@
+#include <cstdint>
+#include "U2FMessage.hpp"
+#include "Field.hpp"
+
+struct U2F_Init_Response : U2F_CMD
+{
+	uint32_t cid;
+	uint64_t nonce;
+	uint8_t  protocolVer;
+	uint8_t  majorDevVer;
+	uint8_t  minorDevVer;
+	uint8_t  buildDevVer;
+	uint8_t  capabilities;
+
+	void write()
+	{
+		U2FMessage m{};
+		m.cid = CID_BROADCAST;
+		m.cmd = U2FHID_INIT;
+
+		m.data.insert(m.data.begin() +  0, FIELD(nonce));
+		m.data.insert(m.data.begin() +  8, FIELD(cid));
+		m.data.insert(m.data.begin() + 12, FIELD(protocolVer));
+		m.data.insert(m.data.begin() + 13, FIELD(majorDevVer));
+		m.data.insert(m.data.begin() + 14, FIELD(minorDevVer));
+		m.data.insert(m.data.begin() + 15, FIELD(buildDevVer));
+		m.data.insert(m.data.begin() + 16, FIELD(capabilities));
+
+		m.write();
+	}
+};