public static void GSEncodeDecode(GDCryptKey ctx, byte *data, int size)
{
byte num1, num2, t;
fixed(byte *crypt = ctx.State)
{
num1 = ctx.X;
num2 = ctx.Y;
while (size-- > 0)
{
t = crypt[++num1];
num2 += t;
crypt[num1] = crypt[num2];
crypt[num2] = t;
t += crypt[num1];
*data++ ^= crypt[t];
}
ctx.X = num1;
ctx.Y = num2;
}
}
public static void GSCryptKeyInit(GDCryptKey ctx, byte *chall, byte *gamekey, int gameKeySize)
{
byte *challenge = stackalloc byte[16];
byte *l;
byte *l1;
byte *p;
byte *p1;
byte t;
byte t1;
ctx.X = 0;
ctx.Y = 0;
// Setup start 'M' chars to make it same with C code
for (int i = 0; i < 16; i++)
challenge[i] = 204;
fixed(byte *crypt = ctx.State)
{
p = challenge;
l = challenge + 16;
p1 = gamekey;
int counter = 0;
do
{
if (counter == gameKeySize)
{
p1 = gamekey;
counter = 0;
}
counter++;
*(p++) = (byte)(*(chall++) ^ *(p1++));
}while (p != l);
t1 = 255;
p1 = crypt;
l1 = crypt + 256;
do
{
*p1++ = t1--;
}while (p1 != l1);
t1++; // means t1 = 0;
p = crypt;
p1 = challenge;
do
{
t1 = (byte)(t1 + *p1 + *p);
t = crypt[t1];
crypt[t1] = *p;
*p = t;
p++;
p1++;
if (p1 == l)
{
p1 = challenge;
}
}while (p != l1);
}
}
