update function login

src/util/crypto_util.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <string>
+
+namespace lm {
+
+class CryptoUtil
+{
+public:
+  static std::string sha256Hex(const std::string& data);
+  static std::string randomToken(std::size_t bytes = 32);
+  static std::string hashPassword(const std::string& salt, const std::string& password);
+  static std::string hashPin(const std::string& salt, const std::string& pin);
+};
+
+}  // namespace lm