20141103 【 信息安全 】 对称密码体系 —— DES 加密算法

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        stringconst 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;}