#include<iostream>
#include<string>
#include<math.h>
using namespace std;
string a; //明文
string bb="securkey"; //密钥
int b1[64],key[64];
int C[28],D[28];//左右密文两部分
int LE[32],RE[32],Rtemp[32],Ltemp[32];
int countF=0; //加密轮数
int sKey[48];
int binaryans[64];
char answer[16];
//明文初始置换表
int IP[64] = { 58,50,42,34,26,18,10,2,
60,52,44,36,28,20,12,4,
62,54,46,38,30,22,14,6,
64,56,48,40,32,24,16,8,
57,49,41,33,25,17,9,1,
59,51,43,35,27,19,11,3,
61,53,45,37,29,21,13,5,
63,55,47,39,31,23,15,7};
int IP1[64] = {40,8,48,16,56,24,64,32,
39,7,47,15,55,23,63,31,
38,6,46,14,54,22,62,30,
37,5,45,13,53,21,61,29,
36,4,44,12,52,20,60,28,
35,3,43,11,51,19,59,27,
34,2,42,10,50,18,58,26,
33,1,41,9,49,17,57,25};
//密文第一次的置换选择表（64位输入，56位输出）
int mTable1[56] = {57,49,41,33,25,17,9,
1,58,50,42,34,26,18,
10,2,59,51,43,35,27,
19,11,3,60,52,44,36,
63,55,47,39,31,23,15,
7,62,54,46,38,30,22,
14,6,61,53,45,37,29,
21,13,5,28,20,12,4};
//密文第二次的置换选择表（64位输入，48位输出）
int mTable2[48] = {14,17,11,24,1,5,
3,28,15,6,21,10,
23,19,12,4,26,8,
16,7,27,20,13,2,
41,52,31,37,47,55,
30,40,51,45,33,48,
44,49,39,56,34,53,
46,42,50,36,29,32};
//循环左移表
int move[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
//明文右半部分扩展置换表
int ExpendIP[48] = {32,1,2,3,4,5,
4,5,6,7,8,9,
8,9,10,11,12,13,
12,13,14,15,16,17,
16,17,18,19,20,21,
20,21,22,23,24,25,
24,25,26,27,28,29,
28,29,30,31,32,1};
//8个S盒
int sTable[8][4][16] = { //S1
{{14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7},
{0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8},
{4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0},
{15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13}},
//S2
{{15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10},
{3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5},
{0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15},
{13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9}},
//S3
{{10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8},
{13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1},
{13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7},
{1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12}},
//S4
{{7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15},
{13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9},
{10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4},
{3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14}},
//S5
{{2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9},
{14,11,2,12,4,7,13,1,5,0,15,10,3,9,8,6},
{4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14},
{11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3}},
//S6
{{12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11},
{10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8},
{9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6},
{4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13}},
//S7
{{4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1},
{13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6},
{1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2},
{6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12}},
//S8
{{13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7},
{1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2},
{7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8},
{2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}}};
//置换P
int pTable[32] = { 16,7,20,21,
29,12,28,17,
1,15,23,26,
5,18,31,10,
2,8,24,14,
32,27,3,9,
19,13,30,6,
22,11,4,25};
//将明（密）文转换成64bit数据
void ctB64(string s,int* t){
int b[8];
int temp[8];
int k=0;
for(int i=0;i<8;i++){
b[i]=(int)s[i];
}
for(int i=0;i<8;i++){
for(int j=0;j<8;j++){
if(b[i]){
temp[7-j]=b[i]%2;
b[i]=b[i]/2;
}else{
temp[7-j]=0;
}
}
for(int j=0;j<8;j++){
t[k]=temp[j];
k++;
}
}
}
//明文初始置换
void IPtrans(int* s,int *LE,int *RE){
int temp[64];
for(int i=0;i<64;i++){
temp[i]=s[IP[i]-1];
}
/* for(int i=0;i<64;i++){
s[i]=temp[i];
}*/
for(int i=0;i<64;i++){
if(i<32){
LE[i]=temp[i];
}else{
RE[i-32]=temp[i];
}
}
}
//密文初始置换
void transPC_1(int *s, int *C ,int *D){
for(int i=0;i<56;i++){
if(i<28){
C[i]=key[mTable1[i]-1];
}else{
D[i-28]=key[mTable1[i]-1];
}
}
}
//密文循环左移＋置换生成子密钥
void mtrans2(int *C,int *D,int *sKey,int *move){
int num=0;
while(num<move[countF]){ //循环左移
for(int i=0;i<28;i++){
C[i]=C[(i+1)%28];
D[i]=D[(i+1)%28];
}
num++;
}
countF++;
for(int i=0;i<48;i++){
int temp=mTable2[i]-1;
if(temp>=28){
sKey[i]=D[temp-28];
}else{
sKey[i]=C[temp];
}
}
}
int BinaryToDemical(int *a,int n){
double dec = 0;
int c = n- 1, result;
for (int i = 0; i < n; ++i) {
dec = dec + a[i] * pow(2, c);
c--;
}
result = (int)dec;
return result;
}
void DemicalToBinary(int a, int* b) {
for (int i = 0; i < 4; i++) { //遍历4个位，确保转换后的二进制有4位
if (a) {
b[3-i] = a % 2;
a = a / 2;
} else {
b[3-i] = 0;
}
}
}
//明文右半部分加密过程
void Fx(int* sKey,int *R1,int *L){
int R2[48];
int row[2],col[4];
int r,c,rlen,clen,ans;
int temp[4];
int result[32],k=0;
int tt[32];
//扩展置换
for(int i=0;i<48;i++){
R2[i]=R1[ExpendIP[i]-1];
}
//和子钥异或
for(int i=0;i<48;i++){
if(R2[i]==sKey[i]){
R2[i]=0;
}else{
R2[i]=1;
}
}
//s盒替换选择
for(int i=0;i<43;i+=6){
row[0]=R2[i];
row[1]=R2[i+5];
col[0]=R2[i+1];
col[1]=R2[i+2];
col[2]=R2[i+3];
col[3]=R2[i+4];
rlen=2;
clen=4;
r=BinaryToDemical(row,rlen);
c=BinaryToDemical(col,clen);
ans=sTable[i/6][r][c];
DemicalToBinary(ans,temp);
for(int j=0;j<4;j++){
result[k]=temp[j];
k++;
}
}
//置换P
for(int i=0;i<32;i++){
tt[i]=result[i];
}
for(int i=0;i<32;i++){
result[i]=tt[pTable[i]-1];
}
//和左半部分异或
for(int i=0;i<32;i++){
if(L[i]==result[i]){
R1[i]=0;
}else{
R1[i]=1;
}
}
}
//密文ni初始置换
void antiIPtrans (int *a){
int temp[64];
for (int j = 0; j < 64; ++j) {
temp[j] = a[j];
}
for (int i = 0 ; i < 64; ++i) {
a[i] = temp[IP1[i]-1];
}
}
void BinaryToHexadecimal(int *in, char* out) {
for (int i = 0; i < 63; i+=4) {
double result = 0;
int c = 3;
char eve;
int temp[4] = {in[i], in[i+1], in[i+2], in[i+3]};
for (int j = 0; j < 4; ++j) {
result = result + temp[j] * pow(2, c);
c--;
}
eve = (char)result;
switch (eve) {
case 10:
out[i/4] = 'A';
break;
case 11:
out[i/4] = 'B';
break;
case 12:
out[i/4] = 'C';
break;
case 13:
out[i/4] = 'D';
break;
case 14:
out[i/4] = 'E';
break;
case 15:
out[i/4] = 'F';
break;
default:
out[i/4] = eve + (char)48;
break;
}
cout << out[i/4];
}
cout << endl;
}
int main(){
cout<<"请输入长度为8的明文：";
cin>>a;
ctB64(a,b1); //明文64bit
cout<<"明文16进制为：" ;
BinaryToHexadecimal(b1, answer);
ctB64(bb,key); // 密钥64bit
cout<<"密钥16进制为：" ;
BinaryToHexadecimal(key, answer);
IPtrans(b1,LE,RE); //明文初始变换
transPC_1(key,C,D); //密文初始变换
for(int i=0;i<=15;i++){
for(int j=0;j<32;j++){
Ltemp[j]=RE[j];
}
mtrans2(C,D,sKey,move);//子密钥
Fx(sKey,RE,LE);//明文右半部分加密
for(int j=0;j<32;j++){
LE[j]=Ltemp[j];
}
}
//32位互换
for(int i=0;i<64;i++){
if(i<32){
binaryans[i]=RE[i];
}else{
binaryans[i]=LE[i-32];
}
}
antiIPtrans(binaryans);
BinaryToHexadecimal(binaryans, answer);
}