/*************************************************************************** *   Copyright (C) 2005-2006 by Tarek Saidi                                * *   tarek.saidi@arcor.de                                                  * *                                                                         * *   This program is free software; you can redistribute it and/or modify  * *   it under the terms of the GNU General Public License as published by  * *   the Free Software Foundation; either version 2 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 General Public License for more details.                          * *                                                                         * *   You should have received a copy of the GNU General Public License     * *   along with this program; if not, write to the                         * *   Free Software Foundation, Inc.,                                       * *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             * ***************************************************************************/#include <QByteArray>#include "arcfour.h"static inline void swap_byte(unsigned char *a, unsigned char *b)    {        unsigned char swapByte;        swapByte = *a;        *a = *b;              *b = swapByte;    } void CArcFour::setKey(byte* key_data_ptr, int key_data_len){RawKey=QByteArray((const char*)key_data_ptr,key_data_len);}void CArcFour::prepareKey(){ unsigned char swapByte; unsigned char index1; unsigned char index2; unsigned char* state; short counter;     state = &key.state[0];         for(counter = 0; counter < 256; counter++)               state[counter] = counter;               key.x = 0;     key.y = 0;     index1 = 0;     index2 = 0;             for(counter = 0; counter < 256; counter++)       {                 index2 = (RawKey.at(index1) + state[counter] + index2) % 256;                   swap_byte(&state[counter], &state[index2]);               index1 = (index1 + 1) % RawKey.size();    }      }void CArcFour::encrypt(const byte* src, byte* dst,int length){//qDebug("Key:%s",RawKey.data());		prepareKey();        unsigned char x;        unsigned char y;        unsigned char* state;        unsigned char xorIndex;        short counter;                      x = key.x;            y = key.y;            state = &key.state[0];                for(counter = 0; counter < length; counter ++)              {                           x = (x + 1) % 256;                                   y = (state[x] + y) % 256;                           swap_byte(&state[x], &state[y]);                                     xorIndex = (state[x] + state[y]) % 256;                			 dst[counter]=src[counter]^state[xorIndex];                 }                       key.x = x;             key.y = y;}