Added a FeistelManager to en/decipher arbitrarily long messages using cipher block chaining

FeistelMan.h

@@ -0,0 +1,38 @@
+#pragma once
+#include "Feistel.h"
+#include "Flexblock.h"
+
+/** Class to apply a block cipher to messages of arbitrary length in a distributed manner
+*/
+class FeistelMan
+{
+public:
+	explicit FeistelMan(const Block& key);
+	explicit FeistelMan(const std::string& password);
+
+	FeistelMan(const FeistelMan& other) = delete;
+	FeistelMan(FeistelMan&& other) noexcept = delete;
+	
+	~FeistelMan();
+
+	//! Will set the key
+	void SetKey(const Block& key);
+
+	//! Will set the key from a password
+	void SetPassword(const std::string& password);
+
+	//! Will encipher a flexblock of data
+	Flexblock Encipher(const Flexblock& data) const;
+
+	//! Will decipher a flexblock of data
+	Flexblock Decipher(const Flexblock& data) const;
+
+private:
+	Block key;
+
+	//! Will zero the memory used by the key
+	void ZeroKeyMemory();
+
+	// Initial value for cipher block chaining
+	static const Block emptyBlock;
+};