inline gf2_8
gf2_8_multiply(gf2_8 x, gf2_8 y) {
gf2_8 z = 0;
if (y & 1) z ^= x; x = gf2_8_shift(x);
if (y & 2) z ^= x; x = gf2_8_shift(x);
if (y & 4) z ^= x; x = gf2_8_shift(x);
if (y & 8) z ^= x; x = gf2_8_shift(x);
if (y & 16) z ^= x; x = gf2_8_shift(x);
if (y & 32) z ^= x; x = gf2_8_shift(x);
if (y & 64) z ^= x; x = gf2_8_shift(x);
if (y & 128) z ^= x;
return z;
}
void
aes_compute_tables(void) {
int i;
uint32_t x1, x2, x3;
v32_t tmp;
/* initialize substitution table */
aes_init_sbox();
/* combine sbox with linear operations to form 8-bit to 32-bit tables */
for (i=0; i < 256; i++) {
x1 = aes_sbox[i];
x2 = gf2_8_shift(x1);
x3 = x2 ^ x1;
tmp.v8[0] = x2;
tmp.v8[1] = x1;
tmp.v8[2] = x1;
tmp.v8[3] = x3;
T0[i] = tmp.value;
tmp.v8[0] = x3;
tmp.v8[1] = x2;
tmp.v8[2] = x1;
tmp.v8[3] = x1;
T1[i] = tmp.value;
tmp.v8[0] = x1;
tmp.v8[1] = x3;
tmp.v8[2] = x2;
tmp.v8[3] = x1;
T2[i] = tmp.value;
tmp.v8[0] = x1;
tmp.v8[1] = x1;
tmp.v8[2] = x3;
tmp.v8[3] = x2;
T3[i] = tmp.value;
}
}