Introduce BlockAdapter.

Chaos/Cipher/Block/BlockAdapter.hpp

@@ -0,0 +1,53 @@
+#ifndef CHAOS_CIPHER_BLOCK_BLOCKADAPTER_HPP
+#define CHAOS_CIPHER_BLOCK_BLOCKADAPTER_HPP
+
+#include <cstdint>
+#include <vector>
+
+namespace Chaos::Cipher::Block
+{
+
+template<typename ModeT>
+class BlockAdapter
+{
+public:
+    class Key
+    {
+        friend class BlockAdapter;
+    public:
+        template<typename InputIt>
+        Key(InputIt keyBegin, InputIt keyEnd)
+            : Key_(keyBegin, keyEnd)
+        { }
+
+        template<typename Byte>
+        Key(const std::vector<Byte> & key)
+            : Key_(key.cbegin(), key.cend())
+        { }
+
+    private:
+        ModeT::Cipher::Key Key_;
+    };
+
+    template<typename Byte>
+    static std::vector<Byte> Encrypt(const Key & key, const std::vector<Byte> & plaintext)
+    {
+        typename ModeT::Encryptor encryptor(key.Key_);
+
+        std::vector<Byte> result;
+        const uint64_t maxResultSize = encryptor.PredictMaxUpdateOutput(plaintext.size()) +
+                                       encryptor.PredictMaxFinishOutput();
+        result.resize(maxResultSize);
+
+        uint64_t written = encryptor.Update(result.begin(), result.end(),
+                                            plaintext.begin(), plaintext.end());
+        written += encryptor.Finish(result.begin() + written, result.end());
+
+        result.resize(written);
+        return result;
+    }
+};
+
+} // namespace Chaos::Cipher::Block
+
+#endif // CHAOS_CIPHER_BLOCK_BLOCKADAPTER_HPP