#include "qaesencryption.h"
#include <QDebug>

// The lookup-tables are marked const so they can be placed in read-only storage instead of RAM
// The numbers below can be computed dynamically trading ROM for RAM -
// This can be useful in (embedded) bootloader applications, where ROM is often limited.
static const uint8_t sbox[256] =   {
  //0     1    2      3     4    5     6     7      8    9     A      B    C     D     E     F
  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 };

static const uint8_t rsbox[256] =
{ 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
  0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
  0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
  0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
  0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
  0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
  0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
  0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
  0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
  0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
  0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
  0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
  0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
  0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
  0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
  0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d };

// The round constant word array, Rcon[i], contains the values given by
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
static const uint8_t Rcon[256] = {
    0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a,
    0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39,
    0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a,
    0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8,
    0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef,
    0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc,
    0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b,
    0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3,
    0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94,
    0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20,
    0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35,
    0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f,
    0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04,
    0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63,
    0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd,
    0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d };

inline uint8_t xTime(uint8_t x){
  return ((x<<1) ^ (((x>>7) & 1) * 0x1b));
}

#define Multiply(x, y)                                \
      (  ((y & 1) * x) ^                              \
      ((y>>1 & 1) * xTime(x)) ^                       \
      ((y>>2 & 1) * xTime(xTime(x))) ^                \
      ((y>>3 & 1) * xTime(xTime(xTime(x)))) ^         \
      ((y>>4 & 1) * xTime(xTime(xTime(xTime(x))))))   \


QAESEncryption::QAESEncryption(QAESEncryption::AES level, QAESEncryption::MODE mode) : m_level(level), m_mode(mode)
{
    m_state->clear();
    qDebug() << "WTF";

    switch (level)
    {
    case AES_128: {
        AES128 aes;
        m_nk = aes.nk;
        m_keyLen = aes.keylen;
        m_nr = aes.nr;
        m_expandedKey = aes.expandedKey;
        qDebug() << "AES128";
        }
        break;
    case AES_192: {
        AES192 aes;
        m_nk = aes.nk;
        m_keyLen = aes.keylen;
        m_nr = aes.nr;
        m_expandedKey = aes.expandedKey;
        }
        break;
    case AES_256: {
        AES256 aes;
        m_nk = aes.nk;
        m_keyLen = aes.keylen;
        m_nr = aes.nr;
        m_expandedKey = aes.expandedKey;
        }
        break;
    default: {
        AES128 aes;
        m_nk = aes.nk;
        m_keyLen = aes.keylen;
        m_nr = aes.nr;
        m_expandedKey = aes.expandedKey;
        qDebug() << "AES128";
        }
        break;
    }

}

uint8_t QAESEncryption::getSBoxValue(uint8_t num)
{
  return sbox[num];
}

uint8_t QAESEncryption::getSBoxInvert(uint8_t num)
{
  return rsbox[num];
}

QByteArray QAESEncryption::expandKey(const QByteArray key)
{
  int i, k;
  uint8_t tempa[4]; // Used for the column/row operations
  QByteArray roundKey(key);

  // The first round key is the key itself.
  for(i = 0; i < m_nk; ++i)
  {
    roundKey.insert((i * 4) + 0, key.at((i * 4) + 0));
    roundKey.insert((i * 4) + 1, key.at((i * 4) + 1));
    roundKey.insert((i * 4) + 2, key.at((i * 4) + 2));
    roundKey.insert((i * 4) + 3, key.at((i * 4) + 3));
  }

  // All other round keys are found from the previous round keys.
  //i == Nk
  for(; i < m_nb * (m_nr + 1); ++i)
  {
    {
      tempa[0] = roundKey.at((i-1) * 4 + 0);
      tempa[1] = roundKey.at((i-1) * 4 + 1);
      tempa[2] = roundKey.at((i-1) * 4 + 2);
      tempa[3] = roundKey.at((i-1) * 4 + 3);
    }

    if (i % m_nk == 0)
    {
      // This function shifts the 4 bytes in a word to the left once.
      // [a0,a1,a2,a3] becomes [a1,a2,a3,a0]

      // Function RotWord()
      {
        k = tempa[0];
        tempa[0] = tempa[1];
        tempa[1] = tempa[2];
        tempa[2] = tempa[3];
        tempa[3] = k;
      }

      // SubWord() is a function that takes a four-byte input word and
      // applies the S-box to each of the four bytes to produce an output word.

      // Function Subword()
      {
        tempa[0] = getSBoxValue(tempa[0]);
        tempa[1] = getSBoxValue(tempa[1]);
        tempa[2] = getSBoxValue(tempa[2]);
        tempa[3] = getSBoxValue(tempa[3]);
      }

      tempa[0] =  tempa[0] ^ Rcon[i/m_nk];
    }
    if (m_level == AES_256 && i % m_nk == 4)
    {
      // Function Subword()
      {
        tempa[0] = getSBoxValue(tempa[0]);
        tempa[1] = getSBoxValue(tempa[1]);
        tempa[2] = getSBoxValue(tempa[2]);
        tempa[3] = getSBoxValue(tempa[3]);
      }
    }
    roundKey.insert(i * 4 + 0, roundKey.at((i - m_nk) * 4 + 0) ^ tempa[0]);
    roundKey.insert(i * 4 + 1, roundKey.at((i - m_nk) * 4 + 1) ^ tempa[1]);
    roundKey.insert(i * 4 + 2, roundKey.at((i - m_nk) * 4 + 2) ^ tempa[2]);
    roundKey.insert(i * 4 + 3, roundKey.at((i - m_nk) * 4 + 3) ^ tempa[3]);
  }

  return roundKey;
}

// This function adds the round key to state.
// The round key is added to the state by an XOR function.
void QAESEncryption::addRoundKey(int round, const QByteArray expKey)
{
  for(int i=0; i < 16; i++)
      m_state->insert(i, m_state->at(i) ^ expKey.at(round * m_nb * 4 + (i/4) * m_nb + (i%4)));
}

// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
void QAESEncryption::subBytes()
{
  for(int i = 0; i < 16; i++)
    m_state->insert(i, getSBoxValue(m_state->at(i)));
}

// The ShiftRows() function shifts the rows in the state to the left.
// Each row is shifted with different offset.
// Offset = Row number. So the first row is not shifted.
void QAESEncryption::shiftRows()
{
    uint8_t temp;

     //Shift 1
    temp = m_state->at(4);
    m_state->insert(4, m_state->at(4+1));
    m_state->insert(4+1, m_state->at(4+2));
    m_state->insert(4+2, m_state->at(4+3));
    m_state->insert(4+3, temp);

    //Shift 2
    temp = m_state->at(8);
    m_state->insert(8, m_state->at(8+2));
    m_state->insert(8+2, temp);
    temp = m_state->at(8+1);
    m_state->insert(8+1, m_state->at(8+3));
    m_state->insert(8+3, temp);

    //Shift 3
    temp = m_state->at(12);
    m_state->insert(12, m_state->at(12+3));
    m_state->insert(12+3, m_state->at(12+2));
    m_state->insert(12+2, m_state->at(12+1));
    m_state->insert(12+1, temp);
}

// MixColumns function mixes the columns of the state matrix
//optimized!!
void QAESEncryption::mixColumns()
{
  uint8_t Tmp,Tm,t;
  for(int i = 0; i < 16; i+=4)
  {
    t   = m_state->at(i);
    Tmp = m_state->at(i) ^ m_state->at(i+1) ^ m_state->at(i+2) ^ m_state->at(i+3) ;

    Tm  = m_state->at(i) ^ m_state->at(i+1);
    Tm = xTime(Tm);
    m_state->insert(i, m_state->at(i) ^ Tm ^ Tmp);

    Tm  = m_state->at(i+1) ^ m_state->at(i+2);
    Tm = xTime(Tm);
    m_state->insert(i+1, m_state->at(i+1) ^ Tm ^ Tmp);

    Tm  = m_state->at(i+2) ^ m_state->at(i+3);
    Tm = xTime(Tm);
    m_state->insert(i+2, m_state->at(i+2) ^ Tm ^ Tmp);

    Tm  = m_state->at(i+3) ^ t;
    Tm = xTime(Tm);
    m_state->insert(i+3, m_state->at(i+3) ^ Tm ^ Tmp);
  }
}

// MixColumns function mixes the columns of the state matrix.
// The method used to multiply may be difficult to understand for the inexperienced.
// Please use the references to gain more information.
void QAESEncryption::invMixColumns()
{
  uint8_t a,b,c,d;
  for(int i = 0; i < 16; i+=4)
  {
    a = m_state->at(i);
    b = m_state->at(i+1);
    c = m_state->at(i+2);
    d = m_state->at(i+3);

    m_state->insert(i, Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09));
    m_state->insert(i+1, Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d));
    m_state->insert(i+2, Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b));
    m_state->insert(i+3, Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e));
  }
}

// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
void QAESEncryption::invSubBytes()
{
  for(int i = 0; i < 16; ++i)
      m_state->insert(i, getSBoxInvert(m_state->at(i)));
}

void QAESEncryption::invShiftRows()
{
  uint8_t temp;

   //Shift 1 to right
  temp = m_state->at(4+3);
  m_state->insert(4+3, m_state->at(4+2));
  m_state->insert(4+2, m_state->at(4+1));
  m_state->insert(4+1, m_state->at(4));
  m_state->insert(4, temp);

  //Shift 2
  temp = m_state->at(8+2);
  m_state->insert(8+2, m_state->at(8));
  m_state->insert(8, temp);
  temp = m_state->at(8+3);
  m_state->insert(8+3, m_state->at(8+1));
  m_state->insert(8+1, temp);

  //Shift 3
  temp = m_state->at(12+3);
  m_state->insert(12+3, m_state->at(12));
  m_state->insert(12, m_state->at(12+1));
  m_state->insert(12+1, m_state->at(12+2));
  m_state->insert(12+2, temp);
}

// Cipher is the main function that encrypts the PlainText.
QByteArray QAESEncryption::cipher(const QByteArray expKey, const QByteArray in)
{

  //m_state is the input buffer.... handle it!
  QByteArray output(in);
  m_state = &output;
  uint8_t round = 0;

  qDebug() << "Cyper " << QString(expKey);

  // Add the First round key to the state before starting the rounds.
  addRoundKey(0, expKey);

  // There will be Nr rounds.
  // The first Nr-1 rounds are identical.
  // These Nr-1 rounds are executed in the loop below.
  for(round = 1; round < m_nr; ++round)
  {
    subBytes();
    shiftRows();
    mixColumns();
    addRoundKey(round, expKey);
  }

  // The last round is given below.
  // The MixColumns function is not here in the last round.
  subBytes();
  shiftRows();
  addRoundKey(m_nr, expKey);

  qDebug() << "Cyper " << QString(output);

  return output;
}

void QAESEncryption::invCipher()
{
  /*uint8_t round=0;

  // Add the First round key to the state before starting the rounds.
  addRoundKey(m_nr);

  // There will be Nr rounds.
  // The first Nr-1 rounds are identical.
  // These Nr-1 rounds are executed in the loop below.
  for(round=m_nr-1;round>0;round--)
  {
    invShiftRows();
    invSubBytes();
    addRoundKey(round);
    invMixColumns();
  }

  // The last round is given below.
  // The MixColumns function is not here in the last round.
  invShiftRows();
  invSubBytes();
  addRoundKey(0);*/
}

QByteArray QAESEncryption::encode(const QByteArray rawText, const QByteArray key, const QByteArray iv)
{
   //if (m_mode == CBC && iv == NULL)
   //    return NULL; //EMIT ERROR!

  qDebug() << "YAY";
  QByteArray expandedKey = expandKey(key);

  // The next function call encrypts the PlainText with the Key using AES algorithm.
  return cipher(expandedKey, rawText);
}

/*
QByteArray QAESEncryption::decode(const uint8_t* input, const uint8_t* key, uint8_t *output, const uint32_t length)
{
  // Copy input to output, and work in-memory on output
  memcpy(output, input, length);
  state = (state_t*)output;

  // The KeyExpansion routine must be called before encryption.
  Key = key;
  KeyExpansion();

  InvCipher();
}
*/