internal override void SetKey(
byte[] key)
{
uint Cm = 0x5a827999;
uint Mm = 0x6ed9eba1;
int Cr = 19;
int Mr = 17;
/*
* Determine the key size here, if required
*
* if keysize < 256 bytes, pad with 0
*
* Typical key sizes => 128, 160, 192, 224, 256
*/
for (int i=0; i< 24; i++)
{
for (int j=0; j< 8; j++)
{
_Tm[i*8 + j] = Cm;
Cm += Mm; //mod 2^32;
_Tr[i*8 + j] = Cr;
Cr = (Cr + Mr) & 0x1f; // mod 32
}
}
byte[] tmpKey = new byte[64];
key.CopyTo(tmpKey, 0);
// now create ABCDEFGH
for (int i = 0; i < 8; i++)
{
_workingKey[i] = Pack.BE_To_UInt32(tmpKey, i*4);
}
// Generate the key schedule
for (int i = 0; i < 12; i++)
{
// KAPPA <- W2i(KAPPA)
int i2 = i*2 *8;
_workingKey[6] ^= F1(_workingKey[7], _Tm[i2], _Tr[i2]);
_workingKey[5] ^= F2(_workingKey[6], _Tm[i2+1], _Tr[i2+1]);
_workingKey[4] ^= F3(_workingKey[5], _Tm[i2+2], _Tr[i2+2]);
_workingKey[3] ^= F1(_workingKey[4], _Tm[i2+3], _Tr[i2+3]);
_workingKey[2] ^= F2(_workingKey[3], _Tm[i2+4], _Tr[i2+4]);
_workingKey[1] ^= F3(_workingKey[2], _Tm[i2+5], _Tr[i2+5]);
_workingKey[0] ^= F1(_workingKey[1], _Tm[i2+6], _Tr[i2+6]);
_workingKey[7] ^= F2(_workingKey[0], _Tm[i2+7], _Tr[i2+7]);
// KAPPA <- W2i+1(KAPPA)
i2 = (i*2 + 1)*8;
_workingKey[6] ^= F1(_workingKey[7], _Tm[i2], _Tr[i2]);
_workingKey[5] ^= F2(_workingKey[6], _Tm[i2+1], _Tr[i2+1]);
_workingKey[4] ^= F3(_workingKey[5], _Tm[i2+2], _Tr[i2+2]);
_workingKey[3] ^= F1(_workingKey[4], _Tm[i2+3], _Tr[i2+3]);
_workingKey[2] ^= F2(_workingKey[3], _Tm[i2+4], _Tr[i2+4]);
_workingKey[1] ^= F3(_workingKey[2], _Tm[i2+5], _Tr[i2+5]);
_workingKey[0] ^= F1(_workingKey[1], _Tm[i2+6], _Tr[i2+6]);
_workingKey[7] ^= F2(_workingKey[0], _Tm[i2+7], _Tr[i2+7]);
// Kr_(i) <- KAPPA
_Kr[i*4] = (int)(_workingKey[0] & 0x1f);
_Kr[i*4 + 1] = (int)(_workingKey[2] & 0x1f);
_Kr[i*4 + 2] = (int)(_workingKey[4] & 0x1f);
_Kr[i*4 + 3] = (int)(_workingKey[6] & 0x1f);
// Km_(i) <- KAPPA
_Km[i*4] = _workingKey[7];
_Km[i*4 + 1] = _workingKey[5];
_Km[i*4 + 2] = _workingKey[3];
_Km[i*4 + 3] = _workingKey[1];
}
}
