c++实现des算法

  1 //panda
  2 //2013-4-13
  3 //des
  4 
  5 //des.h
  6 
  7 class DES
  8 {
  9 private:
 10     //public:
 11     //明文
 12     char msg[8];
 13     bool bmsg[64];
 14     //密钥
 15     char key[8];
 16     bool bkey[64];
 17     //16个子密钥
 18     bool subkey[16][48];
 19     //l0 r0中间变量
 20     bool rmsgi[32],lmsgi[32];//第i个
 21     bool rmsgi1[32],lmsgi1[32];//第i+1个
 22     //密文
 23     bool bcryptedmsg[64];
 24     char cryptedmsg[8];
 25     //解密的结果
 26     bool bdecipher[64];
 27     char decipher[8];
 28 private:
 29     //静态常量
 30 
 31     //不允许在类内初始化
 32     //初始值换ip
 33     const static int ip[64];
 34     //子密钥
 35     //置换选择1
 36     const static int c0[28];
 37     const static int d0[28];
 38     //循环左移表
 39     const static int keyoff[16];
 40     //置换选择2
 41     const static int di[48];
 42     //加密函数
 43     //e运算
 44     const static int e_operate[48];
 45     //sbox
 46     const static int sbox[8][64];
 47     //置换运算p
 48     const static int p_operate[32];
 49     //逆初始置换ip
 50     const static int back_ip[64];
 51     //位掩码
 52     const static char bitmask[8];
 53 public:
 54     //设置明文和密钥
 55     //_length要小于或等于8
 56     void SetMsg(char* _msg,int _length);
 57     void SetKey(char* _msg,int _length);
 58     //生产子密钥
 59     void ProduceSubKey();
 60     //总的的加密流程
 61     void Crypte();
 62     //解密
 63     void Decipher();
 64     //输出密文
 65     void OutPutCryptedMsg();
 66     //二进制转成字符
 67     void Bit2Char(bool* _barray,char* _carray);//length=64
 68     //输出解密后的明文
 69     void OutPutDecipher();
 70 private:
 71     //字符转成二进制，并保存到64位bool数组中
 72     void Char2Bit(char* _carray,bool* _barray,int length);
 73     ////二进制转成字符
 74     //void Bit2Char(bool* _barray,char* _carray);//length=64
 75     //初始置换
 76     void InitSwap(bool in[64]);
 77     //初始逆置换
 78     void InitReSwap(bool out[64]);
 79     //循环左移
 80     void SubKeyOff(bool* _subkey,int _off);
 81     //e运算操作函数
 82     void EOperation(bool a[32],bool b[48]);
 83     //模2相加
 84     //相同为0 不同为1
 85     void Mode2Add(bool a[],bool b[],bool c[],int length);
 86     //sbox
 87     void DealSBox(bool in[48],bool out[32]);
 88     void _DealSBox(bool in[6],bool out[4],int box);
 89     //p opraration
 90     void POperation(bool temp[32],bool result[32]);
 91     //加密函数
 92     void CrypteFunction(bool in[32],int isubkey,bool out[32]);
 93 
 94     //数组之间赋值
 95     void CopyArray(bool array1[],bool array2[],int size);
 96 };
 97 
 98 
 99 
100 //2013-4-13
101 //panda
102 //des
103 #include<string>
104 #include<iostream>
105 #include"des.h"
106 using namespace std;
107 //静态常量
108 const int DES::ip[64]={
109     58,50,42,34,26,18,10,2,
110     60,52,44,36,28,20,12,4,
111     62,54,46,38,30,22,14,6,
112     64,56,48,40,32,24,16,8,
113     57,49,41,33,25,17,9,1,
114     59,51,43,35,27,19,11,3,
115     61,53,45,37,29,21,13,5,
116     63,55,47,39,31,23,15,7
117 };
118 const int DES::c0[28]={
119     57,49,41,33,25,17,9,
120     1,58,50,42,34,26,18,
121     10,2,59,51,43,35,27,
122     19,11,3,60,52,44,36
123 };
124 const int DES::d0[28]={
125     63,55,47,39,31,23,15,
126     7,62,54,46,38,30,22,
127     14,6,61,53,45,37,29,
128     21,13,5,28,20,12,4
129 };
130 const int DES::keyoff[16]={
131     1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
132 };
133 const int DES::di[48]={
134     14,17,11,24,1,5,
135     3,28,15,6,21,10,
136     23,19,12,4,26,8,
137     16,7,27,20,13,2,
138     41,52,31,37,47,55,
139     30,40,51,45,33,48,
140     44,49,39,56,34,53,
141     46,42,50,36,29,32
142 };
143 const int DES::e_operate[48]={
144     32,1,2,3,4,5,
145     4,5,6,7,8,9,
146     8,9,10,11,12,13,
147     12,13,14,15,16,17,
148     16,17,18,19,20,21,
149     20,21,22,23,24,25,
150     24,25,26,27,28,29,
151     28,29,30,31,32,1
152 };
153 const int DES::sbox[8][64]={
154     {  
155         14, 4, 13, 1, 1, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,  
156             0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,  
157             4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,  
158             15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13  
159     },  
160 
161     {  
162         15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,  
163             3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,  
164             0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,  
165             13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9  
166         },  
167 
168         {  
169             10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,  
170                 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,   
171                 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,  
172                 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12  
173         },  
174 
175         {  
176             7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,   
177                 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,  
178                 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,  
179                 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14  
180             },  
181 
182             {  
183                 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,  
184                     14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,  
185                     4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,  
186                     11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3  
187             },  
188 
189             {  
190                 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,  
191                     10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,  
192                     9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,  
193                     4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13  
194                 },  
195 
196                 {  
197                     4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,  
198                         13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,  
199                         1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,  
200                         6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12  
201                 },  
202 
203                 {  
204                     13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 13, 14, 5, 0, 12, 7,  
205                         1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,  
206                         7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,  
207                         2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11  
208                     }  
209 }; 
210 const int DES::p_operate[32]={
211     16,7,20,21,
212     29,12,28,17,
213     1,15,23,26,
214     5,18,31,10,
215     2,8,24,14,
216     32,27,3,9,
217     19,13,30,6,
218     22,11,4,25
219 };
220 const int DES::back_ip[64]={
221     40,8,48,16,56,24,64,32,
222     39,7,47,15,55,23,63,31,
223     38,6,46,14,54,22,62,30,
224     37,5,45,13,53,21,61,29,
225     36,4,44,12,52,20,60,28,
226     35,3,43,11,51,19,59,27,
227     34,2,42,10,50,18,58,26,
228     33,1,41,9,49,17,57,25
229 };
230 const char DES::bitmask[8]={ 128,64,32,16,8,4,2,1};
231 
232 //实现函数
233 
234 //
235 //设置明文
236 //
237 void DES::SetMsg(char* _msg,int _length)
238 {
239     if (_length>8)
240     {
241         return;
242     }
243     for (int i = 0; i < _length; i++)
244     {
245         msg[i]=_msg[i];
246     }
247     //转换成二进制
248     Char2Bit(msg,bmsg,8);
249 
250 };
251 //
252 //设置密钥
253 //
254 void DES::SetKey(char* _key,int _length)
255 {
256     if (_length>8)
257     {
258         return;
259     }
260     for (int i = 0; i < _length; i++)
261     {
262         key[i]=_key[i];
263     }
264     //转成二进制
265     Char2Bit(key,bkey,8);
266 };
267 //
268 //字符转成二进制
269 //ok   length字符数组的长度
270 void DES::Char2Bit(char* _carray,bool* _barray,int length)
271 {
272     //int index=0;
273     for (int i = 0; i <length; i++)
274     {
275         for (int j = 0; j < 8; j++)
276         {
277             _barray[i*8+7-j]=(_carray[i]>>j)&1;
278         }
279     }
280 };
281 //
282 //二进制转成字符
283 //
284 void DES::Bit2Char(bool* _barray,char* _carray)
285 {
286     char temp;
287     for (int i = 0; i < 8; i++)
288     {
289         //数学方法转成字符
290         temp=0;
291         for (int j = 0; j < 8; j++)
292         {
293             if (_barray[i*8+j]==1)
294             {
295                 temp|=bitmask[j];
296             }
297         }
298         //cout<<temp;
299         _carray[i]=temp;
300     }
301 };
302 //
303 //初始置换函数
304 //ok
305 void DES::InitSwap(bool in[64])
306 {
307     //打乱
308     for (int i = 0; i < 32; i++)
309     {
310         lmsgi[i]=in[ip[i]-1];
311         rmsgi[i]=in[ip[i+32]-1];
312     }
313 };
314 //
315 //初始逆置换函数
316 //ok
317 void DES::InitReSwap(bool out[64])
318 {
319     //组合成64数组
320     bool temp[64];
321     for (int i = 0; i < 32; i++)
322     {
323         temp[i]=rmsgi[i];
324         temp[32+i]=lmsgi[i];
325     }
326     //按照逆ip矩阵
327     for (int i = 0; i < 64; i++)
328     {
329         out[i]=temp[back_ip[i]-1];
330     }
331 };
332 //
333 //循环左移
334 //ok
335 void DES::SubKeyOff(bool* _subkey,int _off)
336 {
337     //有没有更好的办法???
338     bool temp;
339     for (int i = 0; i < _off; i++)
340     {
341         temp=_subkey[0];
342         for (int i = 0; i < 27; i++)
343         {
344             _subkey[i]=_subkey[i+1];
345         }
346         _subkey[27]=temp;
347     }
348 };
349 //
350 //生产子密钥
351 //ok
352 void DES::ProduceSubKey()
353 {
354     //置换选择1
355     bool ctemp[28],dtemp[28];
356     for (int i = 0; i < 28; i++)
357     {
358         ctemp[i]=bkey[c0[i]-1];
359         dtemp[i]=bkey[d0[i]-1];
360     }
361     bool keytemp[56];
362     for (int i = 0; i < 16; i++)
363     {
364         //循环左移
365         SubKeyOff(ctemp,keyoff[i]);
366         SubKeyOff(dtemp,keyoff[i]);
367         //合并成一个56数组
368         for (int j = 0; j <28; j++)
369         {
370             keytemp[j]=ctemp[j];
371             keytemp[28+j]=dtemp[j];
372         }
373         //置换选择2
374         for (int j = 0; j < 48; j++)
375         {
376             subkey[i][j]=keytemp[di[j]-1];
377         }
378     }
379 };
380 //
381 //e运算
382 //ok
383 void DES::EOperation(bool a[32],bool b[48])
384 {
385     for (int i = 0; i < 48; i++)
386     {
387         b[i]=a[e_operate[i]-1];
388     }
389 };
390 //
391 //模2想加
392 //ok
393 void DES::Mode2Add(bool a[],bool b[],bool c[],int length)
394 {
395     for (int i = 0; i < length; i++)
396     {
397         if (a[i]==b[i])
398         {
399             c[i]=0;
400         }else
401         {
402             c[i]=1;
403         }
404     }
405 };
406 //
407 //sbox处理
408 //ok
409 void DES::DealSBox(bool in[48],bool out[32])
410 {
411     bool _in[6],_out[4];
412     //8个盒子
413     for (int i = 0; i < 8; i++)
414     {
415         //提取盒子
416         for (int j = 0; j < 6; j++)
417         {
418             _in[j]=in[i*6+j];
419         }
420         //压缩
421         _DealSBox(_in,_out,i);
422         //放进out数组
423         for (int jj = 0; jj < 4; jj++)
424         {
425             out[i*4+jj]=_out[jj];
426         }
427     }
428 };
429 //
430 //_dealsbox
431 //ok
432 void DES::_DealSBox(bool in[6],bool out[4],int box)
433 {
434     int raw,col;
435     raw=in[0]*2+in[5];//转换成十进制 行
436     col=in[1]*2*2*2+in[2]*2*2+in[3]*2+in[4];//列
437     int result=sbox[box][raw*16+col];
438     //转成二进制
439     for (int i = 3; i >=0; i--)
440     {
441         out[i]=(result>>(3-i))&1;
442     }
443 };
444 //
445 //p操作
446 //ok
447 void DES::POperation(bool temp[32],bool result[32])
448 {
449     for (int i = 0; i < 32; i++)
450     {
451         result[i]=temp[p_operate[i]-1];
452     }
453 };
454 //
455 //加密函数
456 //isubkey表明用那个子密钥加密   ok
457 void DES::CrypteFunction(bool in[32],int isubkey,bool out[32])
458 {
459     //e 操作
460     bool temp1[48];
461     EOperation(in,temp1);
462     bool temp2[48];
463     Mode2Add(temp1,(bool *)subkey[isubkey],temp2,48);//ok
464     //盒子压缩
465     bool temp3[48];
466     DealSBox(temp2,temp3);
467     //置换运算p
468     POperation(temp3,out);
469 
470 };
471 //
472 // des加密流程
473 //ok
474 void DES::Crypte()
475 {
476     //直接用bmsg明文
477     //直接用cryptedmsg存放密文
478     bool temp1[32],temp2[32];
479     //初始置换ip
480     InitSwap(bmsg);
481     //16轮迭代
482     for (int i = 0; i < 16; i++)
483     {
484         if (i%2==0)
485         {
486             //L1=R0
487             CopyArray(rmsgi,lmsgi1,32);
488             //f(R0,k0)
489             CrypteFunction(rmsgi,i,temp1);
490             //L0+f(R0,k0)
491             Mode2Add(lmsgi,temp1,temp2,32);
492             //R1=L0+f(R0,k0)
493             CopyArray(temp2,rmsgi1,32);
494         }else
495         {
496             //L2=R1
497             CopyArray(rmsgi1,lmsgi,32);
498             //f(R1,k1)
499             CrypteFunction(rmsgi1,i,temp1);
500             //L1+f(R1,k1)
501             Mode2Add(lmsgi1,temp1,temp2,32);
502             //R2=L1+f(R1,k1)
503             CopyArray(temp2,rmsgi,32);
504         }
505     }
506 
507     //逆初始置换ip
508     InitReSwap(bcryptedmsg);
509     //转成字符
510     Bit2Char(bcryptedmsg,cryptedmsg);
511 };
512 //
513 //数组赋值
514 //ok
515 void DES::CopyArray(bool content[],bool empty[],int size)
516 {
517     for (int i = 0; i < size; i++)
518     {
519         empty[i]=content[i];
520     }
521 };
522 //
523 //解密
524 //ok
525 void DES::Decipher()
526 {
527     bool temp1[32],temp2[32];
528     //初始置换ip
529     InitSwap(bcryptedmsg);
530     //16轮迭代加密
531 
532     for (int i = 0; i < 16; i++)
533     {
534         if (i%2==0)
535         {
536             //L1=R0
537             CopyArray(rmsgi,lmsgi1,32);
538             //f(R0,k0)
539             CrypteFunction(rmsgi,15-i,temp1);
540             //L0+f(R0,k0)
541             Mode2Add(lmsgi,temp1,temp2,32);
542             //R1=L0+f(R0,k0)
543             CopyArray(temp2,rmsgi1,32);
544         }else
545         {
546             //L2=R1
547             CopyArray(rmsgi1,lmsgi,32);
548             //f(R1,k1)
549             CrypteFunction(rmsgi1,15-i,temp1);
550             //L1+f(R1,k1)
551             Mode2Add(lmsgi1,temp1,temp2,32);
552             //R2=L1+f(R1,k1)
553             CopyArray(temp2,rmsgi,32);
554         }
555     }
556     //逆初始置换ip
557     InitReSwap(bdecipher);
558     //转成字符
559     Bit2Char(bdecipher,decipher);
560 
561 };
562 //
563 //输出密文
564 //
565 void DES::OutPutCryptedMsg()
566 {
567     //Bit2Char(bcryptedmsg,cryptedmsg);
568     cout<<endl<<"密文:";
569     for (int i = 0; i < 8; i++)
570     {
571         cout<<cryptedmsg[i]<<‘ ‘;
572     }
573 };
574 //
575 //输出解密明文
576 //
577 void DES::OutPutDecipher()
578 {
579     //Bit2Char(bdecipher,decipher);
580     cout<<endl<<"解密:";
581     for (int i = 0; i < 8; i++)
582     {
583         cout<<decipher[i]<<‘ ‘;
584     }
585     cout<<endl;
586 };
587 
588 
589 #include<iostream>
590 #include"des.h"
591 #include<string.h>
592 using namespace std;
593 
594 int main()
595 {
596     //教材的测试数据
597     char msg[8]={‘0‘,‘1‘,‘2‘,‘3‘,‘4‘,‘5‘,‘6‘,‘7‘};
598     char key[8]={‘1‘,‘2‘,‘3‘,‘4‘,‘5‘,‘6‘,‘7‘,‘8‘};
599     cout<<"明文：";
600     for (int i = 0; i < 8; i++)
601     {
602         cout<<msg[i]<<‘ ‘;
603     }
604     DES des;
605     //设置明文
606     des.SetMsg(msg,8);
607     //设置密钥
608     des.SetKey(key,8);
609     //生产子密钥
610     des.ProduceSubKey();
611     //加密
612     des.Crypte();
613     //输出密文
614     des.OutPutCryptedMsg();
615     //解密
616     des.Decipher();
617     //输出解密后的明文
618     des.OutPutDecipher();
619 
620     system("pause");
621     return 0;
622 }