Rijndael::Rijndael(const byte *userKey, unsigned int keylen)
: k_len(keylen/4), key(k_len*5 + 24)
{
assert(keylen == KeyLength(keylen));
word32 t;
int i;
GetUserKeyLittleEndian(key.ptr, k_len, userKey, keylen);
switch(k_len)
{
case 4: t = key[3];
for(i = 0; i < 10; ++i)
{
t = rotrFixed(t, 8);
t = ls_box(t) ^ rco_tab[i];
key[4 * i + 4] = t ^= key[4 * i];
key[4 * i + 5] = t ^= key[4 * i + 1];
key[4 * i + 6] = t ^= key[4 * i + 2];
key[4 * i + 7] = t ^= key[4 * i + 3];
}
break;
case 6: t = key[5];
for(i = 0; i < 8; ++i)
{
t = rotrFixed(t, 8);
t = ls_box(t) ^ rco_tab[i];
key[6 * i + 6] = t ^= key[6 * i];
key[6 * i + 7] = t ^= key[6 * i + 1];
key[6 * i + 8] = t ^= key[6 * i + 2];
key[6 * i + 9] = t ^= key[6 * i + 3];
key[6 * i + 10] = t ^= key[6 * i + 4];
key[6 * i + 11] = t ^= key[6 * i + 5];
}
break;
case 8: t = key[7];
for(i = 0; i < 7; ++i)
{
t = rotrFixed(t, 8);
t = ls_box(t) ^ rco_tab[i];
key[8 * i + 8] = t ^= key[8 * i];
key[8 * i + 9] = t ^= key[8 * i + 1];
key[8 * i + 10] = t ^= key[8 * i + 2];
key[8 * i + 11] = t ^= key[8 * i + 3];
key[8 * i + 12] = t = key[8 * i + 4] ^ ls_box(t); \
key[8 * i + 13] = t ^= key[8 * i + 5];
key[8 * i + 14] = t ^= key[8 * i + 6];
key[8 * i + 15] = t ^= key[8 * i + 7];
}
break;
}
}
/*-----------------------------------------------------------
* RijndaelKeySchedule
* Initialise the key schedule from a supplied key
*/
void RijndaelKeySchedule(u8 key[16])
{
u32 t;
u32 *ek=Ekey, /* pointer to the expanded key */
*rc=rnd_con; /* pointer to the round constant */
Ekey[0] = u32_in(key );
Ekey[1] = u32_in(key + 4);
Ekey[2] = u32_in(key + 8);
Ekey[3] = u32_in(key + 12);
while(ek < Ekey + 40) {
t = rot3(ek[3]);
ek[4] = ek[0] ^ ls_box(t) ^ *rc++;
ek[5] = ek[1] ^ ek[4];
ek[6] = ek[2] ^ ek[5];
ek[7] = ek[3] ^ ek[6];
ek += 4;
}
}