//Rijndael.h

#ifndef __RIJNDAEL_H__
#define __RIJNDAEL_H__

//Rijndael (pronounced Reindaal) is a block cipher, designed by Joan Daemen and Vincent Rijmen as a candidate algorithm for the AES.
//The cipher has a variable block length and key length. The authors currently specify how to use keys with a length
//of 128, 192, or 256 bits to encrypt blocks with al length of 128, 192 or 256 bits (all nine combinations of
//key length and block length are possible). Both block length and key length can be extended very easily to
// multiples of 32 bits.
//Rijndael can be implemented very efficiently on a wide range of processors and in hardware. 
//This implementation is based on the Java Implementation used with the Cryptix toolkit found at:
//http://www.esat.kuleuven.ac.be/~rijmen/rijndael/rijndael.zip
//Java code authors: Raif S. Naffah, Paulo S. L. M. Barreto
//This Implementation was tested against KAT test published by the authors of the method and the
//results were identical.
class CRijndael
{
private:
	enum { DEFAULT_BLOCK_SIZE=16 };
	enum { MAX_BLOCK_SIZE=32, MAX_ROUNDS=14, MAX_KC=8, MAX_BC=8 };

public:
	//CONSTRUCTOR
	CRijndael();

	//DESTRUCTOR
	virtual ~CRijndael();

	//Expand a user-supplied key material into a session key.
	// key        - The 128/192/256-bit user-key to use.
	// chain      - initial chain block
	// keylength  - 16, 24 or 32 bytes
	// blockSize  - The block size in bytes of this Rijndael (16, 24 or 32 bytes).
	int MakeKey(BYTE const* key, char const* chain, int keylength, int blockSize);

private:
	//Auxiliary Function
	void Xor(char* buff, char const* chain)
	{
		for (int i = 0; i < m_blockSize; i++)
			*(buff++) ^= *(chain++);
	}

	//Convenience method to encrypt exactly one block of plaintext, assuming
	//Rijndael's default block size (128-bit).
	// in         - The plaintext
	// result     - The ciphertext generated from a plaintext using the key
	void DefEncryptBlock(char const* in, char* result);

	//Convenience method to decrypt exactly one block of plaintext, assuming
	//Rijndael's default block size (128-bit).
	// in         - The ciphertext.
	// result     - The plaintext generated from a ciphertext using the session key.
	void DefDecryptBlock(char const* in, char* result);

public:
	//Encrypt exactly one block of plaintext.
	// in           - The plaintext.
    // result       - The ciphertext generated from a plaintext using the key.
    void EncryptBlock(char const* in, char* result);
	
	//Decrypt exactly one block of ciphertext.
	// in         - The ciphertext.
	// result     - The plaintext generated from a ciphertext using the session key.
	void DecryptBlock(char const* in, char* result);

	int Encrypt(void const* in, void* result, size_t n);
	
	int Decrypt(void const* in, void* result, size_t n);

	//Get Key Length
	int GetKeyLength()
	{
		return m_keylength;
	}

	//Block Size
	int	GetBlockSize()
	{
		return m_blockSize;
	}
	
	//Number of Rounds
	int GetRounds()
	{
		return m_iROUNDS;
	}

	void ResetChain()
	{
		memcpy(m_chain, m_chain0, m_blockSize);
	}

public:
	//Null chain
	static char const* sm_chain0;

private:
	//Key Initialization Flag
	bool m_bKeyInit;
	//Encryption (m_Ke) round key
	int m_Ke[MAX_ROUNDS + 1][MAX_BC];
	//Decryption (m_Kd) round key
	int m_Kd[MAX_ROUNDS + 1][MAX_BC];
	//Key Length
	int m_keylength;
	//Block Size
	int m_blockSize;
	//Number of Rounds
	int m_iROUNDS;
	//Chain Block
	char m_chain0[MAX_BLOCK_SIZE];
	char m_chain[MAX_BLOCK_SIZE];
	//Auxiliary private use buffers
	int tk[MAX_KC];
	int a[MAX_BC];
	int t[MAX_BC];
};

#endif // __RIJNDAEL_H__