) << 24) } else if nk > 6 && i%nk == 4 { t = subw(t) } c.enc[i] = c.enc[i-nk] ^ t } // Derive decryption key from encryption key. // Reverse the 4-word round key sets from enc to produce dec. // All sets but the first and last get the MixColumn transform applied. n := c.roundKeysSize() for i := 0; i < n; i += 4 { ei := n - i - 4 for j := 0; j < 4; j++ { x := c.enc[ei+j] if i > 0 && i+4 < n { x = td0[sbox0[x>>24]] ^ td1[sbox0[x>>16&0xff]] ^ td2[sbox0[x>>8&0xff]] ^ td3[sbox0[x&0xff]] } c.dec[i+j] =...