[嵌入式]常用工具函数记录---xor 异或加解密

int xorkey[] =
{
    0x41, 0xB6, 0x7F, 0x58, 0x38,0x0C, 0xF0, 0x2D, 0x7B, 0x39,
    0x08, 0xFE, 0x21, 0xBB, 0x41,0x58
};




//加密函数将会直接修改传入的pbData内存数据，使用时请注意
void __fastcall xor_encrypt(LPBYTE pbData, int nSize)
{
    BYTE byTemp = 0;
    if (pbData)
    {
        for (int i = 0; i < nSize; ++i)
        {
            pbData[i] = pbData[i] ^ byTemp + xorkey[i & 15];
            byTemp = pbData[i];
        }
    }
}



void __fastcall xor_decrypt(LPBYTE pbData, int nSize)
{

    BYTE byPrev = 0;
    BYTE byTemp = 0;

    if (pbData)
    {
        for (int i = 0; i < nSize; ++i)
        {
            byPrev = pbData[i];
            pbData[i] = pbData[i] ^ byTemp + xorkey[i & 15];
            byTemp = byPrev;
        }
    }
}