static void rc4_setup(ref rc4_state s, byte[] key, int length)
{
int i, j, k, a;
int[] m = new int[256];
s.x = 0;
s.y = 0;
m = s.m;
for (i = 0; i < 256; i++)
{
m[i] = i;
}
j = k = 0;
for (i = 0; i < 256; i++)
{
a = m[i];
j = (byte)(j + a + key[k]);
m[i] = m[j]; m[j] = a;
if (++k >= length)
{
k = 0;
}
}
}
static void rc4_crypt(ref rc4_state s, ref byte[] data, int length)
{
int i, x, y, a, b;
int[] m = new int[256];
x = s.x;
y = s.y;
m = s.m;
for (i = 0; i < length; i++)
{
x = (byte)(x + 1); a = m[x];
y = (byte)(y + a);
m[x] = b = m[y];
m[y] = a;
data[i] ^= (byte)m[(byte)(a + b)];
}
s.x = x;
s.y = y;
}