/*
**  ClanLib SDK
**  Copyright (c) 1997-2020 The ClanLib Team
**
**  This software is provided 'as-is', without any express or implied
**  warranty.  In no event will the authors be held liable for any damages
**  arising from the use of this software.
**
**  Permission is granted to anyone to use this software for any purpose,
**  including commercial applications, and to alter it and redistribute it
**  freely, subject to the following restrictions:
**
**  1. The origin of this software must not be misrepresented; you must not
**     claim that you wrote the original software. If you use this software
**     in a product, an acknowledgment in the product documentation would be
**     appreciated but is not required.
**  2. Altered source versions must be plainly marked as such, and must not be
**     misrepresented as being the original software.
**  3. This notice may not be removed or altered from any source distribution.
**
**  Note: Some of the libraries ClanLib may link to may have additional
**  requirements or restrictions.
**
**  File Author(s):
**
**    Mark Page
*/

#pragma once

#include "API/Core/System/cl_platform.h"
#include "API/Core/System/databuffer.h"
#include "aes_impl.h"

namespace clan
{
	class AES256_Encrypt_Impl : public AES_Impl
	{
	public:
		AES256_Encrypt_Impl();

		/// \brief Get encrypted data
		///
		/// This is the databuffer used internally to store the encrypted data.
		/// You may call "set_size()" to clear the buffer, inbetween calls to "add()"
		/// You may call "set_capacity()" to optimise storage requirements before the add() call
		DataBuffer get_data() const;

		/// \brief Resets the encryption
		void reset();

		/// \brief Purge the databuffer
		///
		/// See get_data()\n
		/// reset() calls this function
		void purge_data();

		/// \brief Sets the initialisation vector
		///
		/// This must be called before the initial add()
		void set_iv(const unsigned char iv[16]);

		/// \brief Sets the cipher key
		///
		/// This must be called before the initial add()
		void set_key(const unsigned char key[32]);

		void set_padding(bool value, bool use_pkcs7, unsigned int num_additional_padded_blocks);

		/// \brief Adds data to be encrypted
		void add(const void *data, int size);

		/// \brief Add data to be encrypted
		///
		/// \param data = Data Buffer
		void add(const DataBuffer &data);

		/// \brief Finalize decryption
		void calculate();

	private:
		void process_chunk();

		uint32_t key_expanded[aes256_nb_mult_nr_plus1];

		unsigned char chunk[aes256_block_size_bytes];
		uint32_t initialisation_vector_1;
		uint32_t initialisation_vector_2;
		uint32_t initialisation_vector_3;
		uint32_t initialisation_vector_4;

		int chunk_filled;

		bool initialisation_vector_set;
		bool cipher_key_set;
		bool calculated;
		bool padding_enabled;
		bool padding_pkcs7;
		unsigned int padding_num_additional_padded_blocks;

		DataBuffer databuffer;
	};
}
