des.cpp

DES算法原理及实现,实现了3DES和DES的程序过程

/*
*	 Implementation file for class of representing des algorithm
*    Copyright (C) 2007  Stone
*
*    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 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 General Public License for more details.
*
*    You should have received a copy of the GNU General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*
*    Contact me by [e-mail] 
*
*/
#include "StdAfx.h"
#include "des.h"
#include "desdata.h"

des::des(void) : dkey(DEFAULT_KEY)
{
}

des::des(unsigned _int64 key) : dkey(key)
{
}

des::~des(void)
{
}

void des::setkey(unsigned _int64 key)
{
	dkey = deskey(key);
}

bool des::encrypt(unsigned _int64* dpointer,unsigned _int64 count)
{
	if (dpointer == NULL || count <= 0)
	{
		return false;
	}

	unsigned _int64* pointer = dpointer;
	desdata ddata;

	for (unsigned _int64 i = 0; i < count; ++ i, ++ pointer)
	{
		*pointer = ddata.encrypt(*pointer,dkey);
	}

	return true;
}

bool des::decrypt(unsigned _int64* dpointer,unsigned _int64 count)
{
	if (dpointer == NULL || count <= 0)
	{
		return false;
	}

	unsigned _int64* pointer = dpointer;
	desdata ddata;

	for (unsigned _int64 i = 0; i < count; ++ i, ++ pointer)
	{
		*pointer = ddata.decrypt(*pointer,dkey);
	}

	return true;
}