package main

import (
 "fmt"
)

var sbox = [0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16]byte{} // Removed extra space

func subBytes(state []byte) {
 for i := 0; i < len(state); i++ {
  state[i] = sbox[state[i]]
 }
}

func rotate(word []byte, n int) []byte {
 return append(word[n:], word[:n]...)
}

func shiftRows(state []byte) {
 for i := 0; i < 4; i++ {
  start := i * 4
  end := start + 4
  state[start:end] = rotate(state[start:end], i)
 }
}

func galoisMult(a, b byte) byte {
 p := byte(0)
 hiBitSet := byte(0)
 for i := 0; i < 8; i++ {
  if b&1 == 1 {
   p ^= a
  }
  hiBitSet = a & 0x80
  a <<= 1
  if hiBitSet == 0x80 {
   a ^= 0x1b
  }
  b >>= 1
 }
 return p
}

func mixColumn(column []byte) {
 temp := make([]byte, 4)
 copy(temp, column)

 column[0] = galoisMult(temp[0], 2) ^ galoisMult(temp[3], 1) ^ galoisMult(temp[2], 1) ^ galoisMult(temp[1], 3)
 column[1] = galoisMult(temp[1], 2) ^ galoisMult(temp[0], 1) ^ galoisMult(temp[3], 1) ^ galoisMult(temp[2], 3)
 column[2] = galoisMult(temp[2], 2) ^ galoisMult(temp[1], 1) ^ galoisMult(temp[0], 1) ^ galoisMult(temp[3], 3)
 column[3] = galoisMult(temp[3], 2) ^ galoisMult(temp[2], 1) ^ galoisMult(temp[1], 1) ^ galoisMult(temp[0], 3)
}

func mixColumnInv(column []byte) {
 temp := make([]byte, 4)
 copy(temp, column)

 column[0] = galoisMult(temp[0], 14) ^ galoisMult(temp[3], 9) ^ galoisMult(temp[2], 13) ^ galoisMult(temp[1], 11)
 column[1] = galoisMult(temp[1], 14) ^ galoisMult(temp[0], 9) ^ galoisMult(temp[3], 13) ^ galoisMult(temp[2], 11)
 column[2] = galoisMult(temp[2], 14) ^ galoisMult(temp[1], 9) ^ galoisMult(temp[0], 13) ^ galoisMult(temp[3], 11)
 column[3] = galoisMult(temp[3], 14) ^ galoisMult(temp[2], 9) ^ galoisMult(temp[1], 13) ^ galoisMult(temp[0], 11)
}

func addRoundKey(state, roundKey []byte) {
 for i := 0; i < len(state); i++ {
  state[i] ^= roundKey[i]
 }
}

func main() {
 state := []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
 subBytes(state)
 fmt.Println("SubBytes: ", state)

 state = []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
 shiftRows(state)
 fmt.Println("ShiftRows: ", state)

 g := []byte{1, 2, 3, 4}
 mixColumn(g)
 fmt.Println("MixColumn: ", g)

 state = []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
 roundKey := []byte{2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 1}
 addRoundKey(state, roundKey)
 fmt.Println("AddRoundKey: ", state)
}