//////////////////////////////////////////////////////////////////////////////
// This file is part of the Journey MMORPG client                           //
// Copyright © 2015-2016 Daniel Allendorf                                   //
//                                                                          //
// This program is free software: you can redistribute it and/or modify     //
// it under the terms of the GNU Affero General Public License as           //
// published by the Free Software Foundation, either version 3 of the       //
// License, or (at your option) any later version.                          //
//                                                                          //
// This program is distributed in the hope that it will be useful,          //
// but WITHOUT ANY WARRANTY; without even the implied warranty of           //
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            //
// GNU Affero General Public License for more details.                      //
//                                                                          //
// You should have received a copy of the GNU Affero General Public License //
// along with this program.  If not, see <http://www.gnu.org/licenses/>.    //
//////////////////////////////////////////////////////////////////////////////
#pragma once
#include "NetConstants.h"

#include "../Journey.h"

#include <cstdint>
#include <cstddef>

namespace jrc
{
    // Used to encrypt and decrypt packets for communication with the server.
    class Cryptography
    {
    public:
        // Obtain the initialization vector from the handshake.
        Cryptography(const int8_t* handshake);
        Cryptography();
        ~Cryptography();

        // Encrypt a byte array with the given length and iv.
        void encrypt(int8_t* bytes, std::size_t length);
        // Decrypt a byte array with the given length and iv.
        void decrypt(int8_t* bytes, std::size_t length);
        // Generate a header for the specified length and key.
        void create_header(int8_t* buffer, std::size_t length) const;
        // Use the 4-byte header of a received packet to determine its length.
        std::size_t check_length(const int8_t* header) const;

    private:
        // Add the maple custom encryption.
        void mapleencrypt(int8_t* bytes, std::size_t length) const;
        // Remove the maple custom encryption.
        void mapledecrypt(int8_t* bytes, std::size_t length) const;
        // Update a key.
        void updateiv(uint8_t* iv) const;
        // Perform a roll-left operation.
        int8_t rollleft(int8_t byte, std::size_t count) const;
        // Perform a roll-right operation.
        int8_t rollright(int8_t byte, std::size_t count) const;

        // Apply aesofb to a byte array.
        void aesofb(int8_t* bytes, std::size_t length, uint8_t* iv) const;
        // Encrypt a byte array with AES.
        void aesencrypt(uint8_t* bytes) const;
        // AES addroundkey step.
        void addroundkey(uint8_t* bytes, uint8_t round) const;
        // AES subbytes step.
        void subbytes(uint8_t* bytes) const;
        // AES shiftrows step.
        void shiftrows(uint8_t* bytes) const;
        // Aes mixcolumns step.
        void mixcolumns(uint8_t* bytes) const;
        // Perform a gauloise multiplication.
        uint8_t gmul(uint8_t byte) const;

#ifdef JOURNEY_USE_CRYPTO
        uint8_t sendiv[HEADER_LENGTH];
        uint8_t recviv[HEADER_LENGTH];
#endif
    };
}