private void DesBegin(byte[] inputBuffer, int inputOffset, out uint L, out uint R)
{
ulong p = BitPacking.UInt64FromBEBytes(inputBuffer, inputOffset);
ulong pp = Permute(IP, p, 64); p = 0;
L = (uint)(pp >> 32); R = (uint)pp;
}
void ExpandKey(byte[] key)
{
Dispose();
int[] pc1 = PC1, rotations = Rotations, pc2 = PC2;
uint[] c = new uint[16], d = new uint[16];
ulong[] kex = new ulong[16];
ulong k = BitPacking.UInt64FromBEBytes(key, 0);
ulong kp = Permute(PC1, k, 64); k = 0;
uint cn = (uint)(kp >> 28);
uint dn = (uint)(kp & 0xfffffff);
kp = 0;
for (int i = 0; i < c.Length; i++)
{
c[i] = cn = R(cn, rotations[i]);
}
cn = 0;
for (int i = 0; i < c.Length; i++)
{
d[i] = dn = R(dn, rotations[i]);
}
dn = 0;
for (int i = 0; i < kex.Length; i++)
{
ulong cd = (ulong)c[i] << 28 | d[i];
kex[i] = Permute(PC2, cd, 56);
cd = 0;
}
Security.Clear(c); Security.Clear(d);
Kex = kex;
}