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| // Include stdio.h for standard input/output.
// Used for giving output to the screen.
#include<stdio.h>
#include<iostream>
#include<fstream>
#include<stdlib.h>
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4
// The number of rounds in AES Cipher. It is simply initiated to zero. The actual value is recieved in the program.
int Nr=0;
// The number of 32 bit words in the key. It is simply initiated to zero. The actual value is recieved in the program.
int Nk=0;
// in - it is the array that holds the plain text to be encrypted.
// out - it is the array that holds the key for encryption.
// state - the array that holds the intermediate results during encryption.
unsigned char in[16], out[16], state[4][4];
// The array that stores the round keys.
unsigned char RoundKey[240];
// The Key input to the AES Program
unsigned char Key[32];
int 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, //0
0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, //1
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, //2
0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, //3
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, //4
0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, //5
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, //6
0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, //7
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, //8
0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, //9
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, //A
0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, //B
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, //C
0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, //D
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, //E
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; //F
int xtimeTab[]={ 0x0 ,
0x2 , 0x4 , 0x6 , 0x8 , 0xa , 0xc , 0xe , 0x10 , 0x12 , 0x14 , 0x16 , 0x18 , 0x1a , 0x1c , 0x1e ,
0x20 , 0x22 , 0x24 , 0x26 , 0x28 , 0x2a , 0x2c , 0x2e , 0x30 , 0x32 , 0x34 , 0x36 , 0x38 , 0x3a , 0x3c ,
0x3e , 0x40 , 0x42 , 0x44 , 0x46 , 0x48 , 0x4a , 0x4c , 0x4e , 0x50 , 0x52 , 0x54 , 0x56 , 0x58 , 0x5a ,
0x5c , 0x5e , 0x60 , 0x62 , 0x64 , 0x66 , 0x68 , 0x6a , 0x6c , 0x6e , 0x70 , 0x72 , 0x74 , 0x76 , 0x78 ,
0x7a , 0x7c , 0x7e , 0x80 , 0x82 , 0x84 , 0x86 , 0x88 , 0x8a , 0x8c , 0x8e , 0x90 , 0x92 , 0x94 , 0x96 ,
0x98 , 0x9a , 0x9c , 0x9e , 0xa0 , 0xa2 , 0xa4 , 0xa6 , 0xa8 , 0xaa , 0xac , 0xae , 0xb0 , 0xb2 , 0xb4 ,
0xb6 , 0xb8 , 0xba , 0xbc , 0xbe , 0xc0 , 0xc2 , 0xc4 , 0xc6 , 0xc8 , 0xca , 0xcc , 0xce , 0xd0 , 0xd2 ,
0xd4 , 0xd6 , 0xd8 , 0xda , 0xdc , 0xde , 0xe0 , 0xe2 , 0xe4 , 0xe6 , 0xe8 , 0xea , 0xec , 0xee , 0xf0 ,
0xf2 , 0xf4 , 0xf6 , 0xf8 , 0xfa , 0xfc , 0xfe , 0x1b , 0x19 , 0x1f , 0x1d , 0x13 , 0x11 , 0x17 , 0x15 ,
0xb , 0x9 , 0xf , 0xd , 0x3 , 0x1 , 0x7 , 0x5 , 0x3b , 0x39 , 0x3f , 0x3d , 0x33 , 0x31 , 0x37 ,
0x35 , 0x2b , 0x29 , 0x2f , 0x2d , 0x23 , 0x21 , 0x27 , 0x25 , 0x5b , 0x59 , 0x5f , 0x5d , 0x53 , 0x51 ,
0x57 , 0x55 , 0x4b , 0x49 , 0x4f , 0x4d , 0x43 , 0x41 , 0x47 , 0x45 , 0x7b , 0x79 , 0x7f , 0x7d , 0x73 ,
0x71 , 0x77 , 0x75 , 0x6b , 0x69 , 0x6f , 0x6d , 0x63 , 0x61 , 0x67 , 0x65 , 0x9b , 0x99 , 0x9f , 0x9d ,
0x93 , 0x91 , 0x97 , 0x95 , 0x8b , 0x89 , 0x8f , 0x8d , 0x83 , 0x81 , 0x87 , 0x85 , 0xbb , 0xb9 , 0xbf ,
0xbd , 0xb3 , 0xb1 , 0xb7 , 0xb5 , 0xab , 0xa9 , 0xaf , 0xad , 0xa3 , 0xa1 , 0xa7 , 0xa5 , 0xdb , 0xd9 ,
0xdf , 0xdd , 0xd3 , 0xd1 , 0xd7 , 0xd5 , 0xcb , 0xc9 , 0xcf , 0xcd , 0xc3 , 0xc1 , 0xc7 , 0xc5 , 0xfb ,
0xf9 , 0xff , 0xfd , 0xf3 , 0xf1 , 0xf7 , 0xf5 , 0xeb , 0xe9 , 0xef , 0xed , 0xe3 , 0xe1 , 0xe7 , 0xe5 };
// 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(28)
// Note that i starts at 1, not 0).
int Rcon[255] = {
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 };
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to encrypt the states.
void KeyExpansion(){
int i,j;
unsigned char temp[4],k;
// The first round key is the key itself.
for(i=0;i<Nk;i++)
{
RoundKey[i*4]=Key[i*4];
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.
while (i < (Nb * (Nr+1))){
for(j=0;j<4;j++)
temp[j]=RoundKey[(i-1) * 4 + j];
if (i % Nk == 0){
// Function RotWord()
{
k = temp[0];
temp[0] = temp[1];
temp[1] = temp[2];
temp[2] = temp[3];
temp[3] = k;
}
// Function Subword()
{
temp[0]=sbox[temp[0]];
temp[1]=sbox[temp[1]];
temp[2]=sbox[temp[2]];
temp[3]=sbox[temp[3]];
}
temp[0] ^= Rcon[i/Nk];
}
else if (Nk > 6 && i % Nk == 4){
// Function Subword()
{
temp[0]=sbox[temp[0]];
temp[1]=sbox[temp[1]];
temp[2]=sbox[temp[2]];
temp[3]=sbox[temp[3]];
}
}
RoundKey[i*4] = RoundKey[(i-Nk)*4] ^ temp[0];
RoundKey[i*4+1] = RoundKey[(i-Nk)*4+1] ^ temp[1];
RoundKey[i*4+2] = RoundKey[(i-Nk)*4+2] ^ temp[2];
RoundKey[i*4+3] = RoundKey[(i-Nk)*4+3] ^ temp[3];
++i;
}
}
#define NB4 Nb * 4
void AddRoundKey(int round){
for(int i=0; i<4; ++i)
for(int j=0; j<4; ++j)
state[j][i] ^= RoundKey[round * NB4 + i * Nb + j];
}
void SubBytes(){
for(int i=0; i<4; ++i)
for(int j=0; j<4; ++j)
state[i][j] = sbox[state[i][j]];
}
void ShiftRows(){
unsigned char temp;
// Rotate first row 1 columns to left
temp=state[1][0];
state[1][0]=state[1][1];
state[1][1]=state[1][2];
state[1][2]=state[1][3];
state[1][3]=temp;
// Rotate second row 2 columns to left
temp=state[2][0];
state[2][0]=state[2][2];
state[2][2]=temp;
temp=state[2][1];
state[2][1]=state[2][3];
state[2][3]=temp;
// Rotate third row 3 columns to left
temp=state[3][0];
state[3][0]=state[3][3];
state[3][3]=state[3][2];
state[3][2]=state[3][1];
state[3][1]=temp;
}
// xtime is a macro that finds the product of {02} and the argument to xtime modulo {1b}
#define xtime(x) ((x<<1) ^ (((x>>7) & 1) * 0x1b))
// MixColumns function mixes the columns of the state matrix
void MixColumns(){
unsigned char Tmp,Tm,t;
for(int i = 0; i < 4; ++i){
t=state[0][i];
Tmp = state[0][i] ^ state[1][i] ^ state[2][i] ^ state[3][i] ;
state[0][i] ^= xtimeTab[state[0][i] ^ state[1][i]] ^ Tmp ;
state[1][i] ^= xtimeTab[state[1][i] ^ state[2][i]] ^ Tmp ;
state[2][i] ^= xtimeTab[state[2][i] ^ state[3][i]] ^ Tmp ;
state[3][i] ^= xtimeTab[state[3][i] ^ t] ^ Tmp ;
}
}
int cmpt = 0;
// Cipher is the main function that encrypts the PlainText.
void Cipher(){
int i,j,round;
//Copy the input PlainText to state array.
for(i=0;i<4;++i)
for(j=0;j<4;++j)
state[j][i] = in[i*4 + j];
// Add the First round key to the state before starting the rounds.
AddRoundKey(0);
// 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 < Nr; ++round){
SubBytes();
ShiftRows();
MixColumns();
AddRoundKey(round);
}
// The last round is given below.
// The MixColumns function is not here in the last round.
SubBytes();
ShiftRows();
AddRoundKey(Nr);
// The encryption process is over.
// Copy the state array to output array.
for(i=0; i<4; ++i)
for(j=0; j<4; ++j)
out[i*4+j] = state[j][i];
++cmpt;
}
int main(){
int i;
/*unsigned char a;
printf("int xtimeTab[]={ ");
for (i = 0; i < 256; ++i){
a = xtime(i);
printf("0x%x , ",a);
if(i%15 == 0)
printf("\n");
}
exit(1);*/
Nr = 128;
// Calculate Nk and Nr from the recieved value.
Nk = Nr / 32;
Nr = Nk + 6;
// Part 1 is for demonstrative purpose. The key and plaintext are given in the program itself.
// Part 1: ********************************************************
// The array temp stores the key.
// The array temp2 stores the plaintext.
unsigned char temp[32] = {0x00 ,0x01 ,0x02 ,0x03 ,0x04 ,0x05 ,0x06 ,0x07 ,0x08 ,0x09 ,0x0a ,0x0b ,0x0c ,0x0d ,0x0e ,0x0f};
unsigned char temp2[32]= {0x00 ,0x11 ,0x22 ,0x33 ,0x44 ,0x55 ,0x66 ,0x77 ,0x88 ,0x99 ,0xaa ,0xbb ,0xcc ,0xdd ,0xee ,0xff};
// Copy the Key and PlainText
for(i=0;i<Nk*4;i++){
Key[i]=temp[i];
in[i]=temp2[i];
}
// The KeyExpansion routine must be called before encryption.
KeyExpansion();
// The next function call encrypts the PlainText with the Key using AES algorithm.
for (i = 0; i < 200000000; ++i)// 200000000*16 octet => 3051,75781 Mo
Cipher();
printf("%d\n",cmpt);
// Output the encrypted text.
printf("\nText after encryption:\n");
for(i=0;i<Nb*4;i++){
printf("%02x ",out[i]);
}
printf("\n\n");
} |
