DES加密算法：
开始的时候想用unsigned long long（就是64位无符号整数）存储加密的信息的；
后来发现各种顺序，方向都混乱了。
然后又改用vector<int>来存储；
结果又因为无法使用=号直接赋值；
写的函数都废掉了。
最后暴力上string来存储；
终于完成了。
一个字——烦！！！
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <iostream>
#include <algorithm>
#include <string>
using namespace std;
#define bit(x, d) ( ((x)>>(d-1))&1 )
#define to(c) ( (c)-'0' )
#define data string
const int MAXN = 100;
const char SLIP = 0xEE;
data keys[16];
//data TM = "0000000100100011010001010110011110001001101010111100110111101111";
//data TK = "0001001100110100010101110111100110011011101111001101111111110001";
//测试用数据
const int IPt[8 * 8] = {
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
};
const int reIPt[8 * 8] = {
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
};
const int Et[8 * 6] = {
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
};
const int Pt[4 * 8] = {
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
};
const int PC1[8 * 7] = {
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
};
const int PC2[6 * 8] = {
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, 47, 44, 49, 39, 56,
34, 53, 46, 42, 50, 36, 29, 32
};
const int H[16] = {
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};
const int Sbox[8 * 4 * 16] = {
//1
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,
//2
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,
//3
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,
//4
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,
//5
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,
//6
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,
//7
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,
//8
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
};
void show(data x, int state=1){
string res;
switch( state ){
case 1: // 1bit Binary
res = x;
break;
case 4: // 4bit Hex
char s[100];
for(int i=0, j, cnt; i<x.size(); i+=4){
for(j=0, cnt=0; j<4; j++)
cnt=cnt<<1|to(x[i+j]);
itoa(cnt, s, 16);
res += ( s[0]<'a' ? s[0] : s[0]-32 );
}
break;
case 8: // 8bit Character
for(int i=0, j, cnt; i<x.size(); i+=8){
for(j=0, cnt=0; j<8; j++)
cnt=cnt<<1|to(x[i+j]);
res += char(cnt);
}
break;
default:
res = "*** No The Change ***";
}
cout<<res<<endl;
}
data _byte(string s, int state=0){ //0text 1key
data byte;
int len = s.length()*8;
for(int i=0; s[i]; i++)
for(int j=8; j>0; j--)
byte += bit(s[i], j) + '0';
if( 1==state ) // 56bit密钥 奇偶校验填充至 64bit
for(int i=0, cnt=0, no=0; byte[i]; i++){
cnt += to( byte[i] );
if( ++no == 7 ){
byte.insert(byte.begin()+i, (cnt&1)+'0');
i++;
cnt = no = 0;
}
}
if( byte.length()<64 ){ // 56bit密钥 增ZERO填充至 64bit
int cnt = 64-byte.length();
while( cnt-- ) byte += '0';
}
return byte;
}
data _change(data x, const int a[], int len){
data change;
for(int i=0; i<len; i++) change += x[ a[i]-1 ];
return change;
}
data _copy(data x, int ss, int ee){
data cp;
for(int i=ss; i<=ee; i++) cp += x[i];
return cp;
}
void _createKeys(data key){
data tmp = _change(key, PC1, 8*7);
data C = _copy(tmp, 0, 27);
data D = _copy(tmp, 28, 55);
for(int i=0; i<16; i++){
tmp = _copy(C, 0, H[i]-1);
C = _copy(C, H[i], 27) + tmp;
tmp = _copy(D, 0, H[i]-1);
D = _copy(D, H[i], 27) + tmp;
keys[i] = _change(C+D, PC2, 6*8);
}
}
data _xor(data a, data b){
data xx;
for(int i=0; i<a.size(); i++)
xx += ( to(a[i])^to(b[i]) ) + '0';
return xx;
}
data _toF(data R, data key){
data E = _change(R, Et, 8*6);
data x = _xor(E, key);
data P;
for(int i=0, s=0; i<8; i++, s+=6){
int a = to(x[s])<<1|to(x[s+5]);
int b = to(x[s+1])*8 + to(x[s+2])*4 + to(x[s+3])*2 + to(x[s+4]);
int t = Sbox[ i*64 + a*16 + b ];
for(int j=1; j<=4; j++) P += bit(t, j) + '0';
}
return _change(P, Pt, 4*8);
}
data _des(data text, data key, int state=0){
_createKeys(key);
text = _change(text, IPt, 8*8);
data L = _copy(text, 0, 31);
data R = _copy(text, 32, 63);
if( 0==state ) // 默认0加密
for(int i=0; i<16; i++){
data tmp = R;
R = _toF(R, keys[i]);
R = _xor(L, R);
L = tmp;
}
else if( 1==state ) // 1解密
for(int i=16-1; i>=0; i--){
data tmp = L;
L = _toF(L, keys[i]);
L = _xor(L, R);
R = tmp;
}
string res = _change(L+R, reIPt, 8*8);
return res;
}
int main(){ // freopen("1.in", "r", stdin);
// freopen("1.out", "w", stdout);
string Message, Keyword;
printf("输入明文(64bit)："); getline(cin, Message);
printf("输入密钥(64bit)："); getline(cin, Keyword);
printf("你的明文为：< %s >\n", Message.c_str());
printf("你的密钥为：< %s >\n", Keyword.c_str());
data Ciphertext = _des(_byte(Message), _byte(Keyword, 1));
printf("加密密文（B）："); show(Ciphertext, 1);
printf("加密密文（H）："); show(Ciphertext, 4);
printf("加密密文（S）："); show(Ciphertext, 8);
data Plaintext = _des(Ciphertext, _byte(Keyword, 1), 1);
printf("解密（S）："); show(Plaintext, 8);
return 0;
}