rc5_321216.cpp

网络游戏魔域源代码 测试可以完整变异

// RC5加密算法(32/12/16)
// 仙剑修，2001.11.16

//#include "stdafx.h"
#include <WINDOWS.h>
#include "stdlib.h"
#include "rc5_321216.h"


////////////////////////////////////////////////////////////////////////////////////////////////

unsigned long	rotate_left(unsigned long nData, unsigned long nCount);
unsigned long	rotate_right(unsigned long nData, unsigned long nCount);

////////////////////////////////////////////////////////////////////////////////////////////////
void CRc5_321216::Rc5InitKey(const unsigned char bufKey[RC5_16])
{
	// 保存m_bufKey
	try{
		memcpy(m_bufKey, bufKey, RC5_16);
	}catch(...) {
#ifdef	_DEBUG
//		ASSERT(!"InitRc5Key()");
#endif
	}

	// 初始化m_bufSub
	m_bufSub[0] = RC5_PW32;
        int i, j, k;
	for(i = 1; i < RC5_SUB; i++)
	{
		m_bufSub[i] = m_bufSub[i-1] + RC5_QW32;
	}

	// 生成m_bufSub
	unsigned long	x, y;
	i = j = x = y = 0;
	for(k = 0; k < 3 * max(RC5_KEY, RC5_SUB); k++)
	{
		m_bufSub[i] = rotate_left((m_bufSub[i] + x + y), 3);
		x = m_bufSub[i];
		i = (i + 1) % RC5_SUB;
		m_bufKey[j] = rotate_left((m_bufKey[j] + x + y), (x + y));
		y = m_bufKey[j];
		j = (j + 1) % RC5_KEY;
	}
}

////////////////////////////////////////////////////////////////////////////////////////////////
void CRc5_321216::Rc5Encrypt(void* buf, int nLen8)
{
//	ASSERT(nLen8 % 8 == 0);
	nLen8 = (nLen8/8) * 8;
	if(nLen8 <= 0)
		return;

	unsigned long* bufData = (unsigned long*)buf;
	for(int k = 0; k < nLen8/8; k++)
	{
		unsigned long	a = bufData[2*k];
		unsigned long	b = bufData[2*k + 1];

		// 加密a b
		unsigned long	le	= a + m_bufSub[0];
		unsigned long	re	= b + m_bufSub[1];
		for(int i = 1; i <= RC5_12; i++)
		{
			le = rotate_left((le ^ re), re) + m_bufSub[2*i];
			re = rotate_left((re ^ le), le) + m_bufSub[2*i + 1];
		}

		bufData[2*k]		= le;
		bufData[2*k + 1]	= re;
	}
}

////////////////////////////////////////////////////////////////////////////////////////////////
/*void CRc5_321216::Rc5Decrypt(void* buf, int nLen8)
{
//	ASSERT(nLen8 % 8 == 0);
	nLen8 = (nLen8/8) * 8;
	if(nLen8 <= 0)
		return;

	unsigned long* bufData = (unsigned long*)buf;
	for(int k = 0; k < nLen8/8; k++)
	{
		// 解密 ld rd
		unsigned long	ld	= bufData[2*k];
		unsigned long	rd	= bufData[2*k + 1];
		for(int i = RC5_12; i >= 1; i--)
		{
			rd = rotate_right((rd - m_bufSub[2*i + 1]),  ld) ^ ld;
			ld = rotate_right((ld - m_bufSub[2*i]),  rd) ^ rd;
		}

		unsigned long	b = rd - m_bufSub[1];
		unsigned long	a = ld - m_bufSub[0];

		bufData[2*k]		= a;
		bufData[2*k + 1]	= b;
	}
}
*/
////////////////////////////////////////////////////////////////////////////////////////////////
// 公用函数
////////////////////////////////////////////////////////////////////////////////////////////////
unsigned long	rotate_left(unsigned long nData, unsigned long nCount)
{
	nCount %= 32;

	unsigned long	nHigh = nData >> (32-nCount);
	return (nData << nCount) | nHigh;
}

////////////////////////////////////////////////////////////////////////////////////////////////
unsigned long	rotate_right(unsigned long nData, unsigned long nCount)
{
	nCount %= 32;

	unsigned long	nLow = nData << (32-nCount);
	return (nData >> nCount) | nLow;
}