Introduce concept Key.

Chaos/Cipher/Block/Des/DesCrypt.hpp

@@ -10,6 +10,7 @@
 #include "Service/ChaosException.hpp"
 #include "Service/SeArray.hpp"
 
+#include "Cipher/Block/Key.hpp"
 #include "Cipher/Block/Encryptor.hpp"
 #include "Cipher/Block/Decryptor.hpp"
 
@@ -233,6 +234,8 @@ public:
         Inner_::RawKey Key_;
     };
 
+    static_assert(Chaos::Cipher::Block::Key<Key>);
+
     class Encryptor
     {
     public:

Chaos/Cipher/Block/Key.hpp

@@ -0,0 +1,18 @@
+#ifndef CHAOS_CIPHER_BLOCK_KEY_HPP
+#define CHAOS_CIPHER_BLOCK_KEY_HPP
+
+#include <concepts>
+#include <cstdint>
+
+namespace Chaos::Cipher::Block
+{
+
+template<typename T>
+concept Key = requires
+{
+    requires std::constructible_from<T, uint8_t *, uint8_t *>;
+};
+
+} // namespace Chaos::Cipher::Block
+
+#endif // CHAOS_CIPHER_BLOCK_KEY_HPP