feat(Core/Authserver): TOTP rewrite (#5620)

src/server/shared/Secrets/SecretMgr.h

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2016+  AzerothCore <www.azerothcore.org>, released under GNU AGPL v3 license: https://github.com/azerothcore/azerothcore-wotlk/blob/master/LICENSE-AGPL3
+ * Copyright (C) 2021+  WarheadCore <https://github.com/WarheadCore>
+ */
+
+#ifndef __WARHEAD_SECRETMGR_H__
+#define __WARHEAD_SECRETMGR_H__
+
+#include "BigNumber.h"
+#include "Common.h"
+#include "Optional.h"
+#include "Log.h"
+#include <array>
+#include <mutex>
+#include <string>
+
+enum Secrets : uint32
+{
+    SECRET_TOTP_MASTER_KEY = 0,
+
+    // only add new indices right above this line
+    NUM_SECRETS
+};
+
+class AC_SHARED_API SecretMgr
+{
+private:
+    SecretMgr() {}
+    ~SecretMgr() {}
+
+public:
+    SecretMgr(SecretMgr const&) = delete;
+    static SecretMgr* instance();
+
+    struct Secret
+    {
+        public:
+            explicit operator bool() const { return (state == PRESENT); }
+            BigNumber const& operator*() const { return value; }
+            BigNumber const* operator->() const { return &value; }
+            bool IsAvailable() const { return (state != NOT_LOADED_YET) && (state != LOAD_FAILED); }
+
+        private:
+            std::mutex lock;
+            enum { NOT_LOADED_YET, LOAD_FAILED, NOT_PRESENT, PRESENT } state = NOT_LOADED_YET;
+            BigNumber value;
+
+        friend class SecretMgr;
+    };
+
+    void Initialize();
+    Secret const& GetSecret(Secrets i);
+
+private:
+    void AttemptLoad(Secrets i, LogLevel errorLevel, std::unique_lock<std::mutex> const&);
+    Optional<std::string> AttemptTransition(Secrets i, Optional<BigNumber> const& newSecret, Optional<BigNumber> const& oldSecret, bool hadOldSecret) const;
+
+    std::array<Secret, NUM_SECRETS> _secrets;
+};
+
+#define sSecretMgr SecretMgr::instance()
+
+#endif