Add Arc4Crypt class skeleton

Chaos/Cipher/Arc4/Arc4Crypt.hpp

@@ -0,0 +1,63 @@
+#ifndef CHAOS_CIPHER_ARC4CRYPT_HPP
+#define CHAOS_CIPHER_ARC4CRYPT_HPP
+
+#include "Arc4Gen.hpp"
+#include "Service/ChaosException.hpp"
+
+namespace Chaos::Cipher::Arc4
+{
+
+class Arc4Crypt
+{
+public:
+    Arc4Crypt()
+        : IsInitialized_(false)
+    { }
+
+    template<typename InputIt>
+    Arc4Crypt(InputIt keyBegin, InputIt keyEnd)
+    {
+        RekeyImpl(keyBegin, keyEnd);
+    }
+
+    template<typename InputIt>
+    void Rekey(InputIt keyBegin, InputIt keyEnd)
+    {
+        RekeyImpl(keyBegin, keyEnd);
+    }
+
+    template<typename OutputIt, typename InputIt>
+    void Encrypt(OutputIt out, InputIt in, uint64_t count)
+    {
+        // TODO:
+    }
+
+    template<typename OutputIt, typename InputIt>
+    void Decrypt(OutputIt out, InputIt in, uint64_t count)
+    {
+        // TODO:
+    }
+
+private:
+    bool IsInitialized_;
+    Arc4Gen Gen_;
+
+    void EnsureInitialized() const
+    {
+        if (!IsInitialized_)
+        {
+            throw Service::ChaosException("Arc4Crypt: not initialized");
+        }
+    }
+
+    template<typename InputIt>
+    void RekeyImpl(InputIt keyBegin, InputIt keyEnd)
+    {
+        Gen_.Rekey(keyBegin, keyEnd);
+        IsInitialized_ = true;
+    }
+};
+
+} // namespace Chaos::Cipher::Arc4
+
+#endif