c標准des加密演算法

1. DES加密演算法C語言實現

/*********************************************************************/
/*-文件名：des.h */
/*- */
/*-功能： 實現DES加密演算法的加密解密功能 */
/*********************************************************************/
typedef int INT32;
typedef char INT8;
typedef unsigned char ULONG8;
typedef unsigned short ULONG16;
typedef unsigned long ULONG32;

/*如果採用c++編譯器的話採用如下宏定義
#define DllExport extern "C" __declspec(dllexport)
*/

#define DllExport __declspec(dllexport)

/*加密介面函數*/
DllExport INT32 DdesN(ULONG8 *data, ULONG8 **key, ULONG32 n_key,ULONG32 readlen);
DllExport INT32 desN(ULONG8 *data, ULONG8 **key, ULONG32 n_key,ULONG32 readlen);
DllExport INT32 des3(ULONG8 *data, ULONG8 *key,ULONG32 n ,ULONG32 readlen);
DllExport INT32 Ddes3(ULONG8 *data,ULONG8 *key,ULONG32 n ,ULONG32 readlen);
DllExport INT32 des(ULONG8 *data, ULONG8 *key,INT32 readlen);
DllExport INT32 Ddes(ULONG8 *data,ULONG8 *key,INT32 readlen);

*********************************************************************/
/*-文件名：des.c */
/*- */
/*-功能： 實現DES加密演算法的加密解密功能 */
//*********************************************************************/
＃include <stdlib.h>
＃include <stdio.h>
＃include <string.h>
＃include <memory.h>
＃include <malloc.h>
＃include "des.h"

#define SUCCESS 0
#define FAIL -1

#define READFILESIZE 512

#define WZ_COMMEND_NUM 4
#define WZUSEHELPNUM 19
#define DESONE 1
#define DESTHREE 2
#define DESMULTI 3
INT8 *WZ_Commend_Help[] =
{

"基於DES的加密解密工具v1.0 ",/*0*/
"追求卓越,勇於創新 ",
"----著者 : 吳真--- ",
" "
};

INT8 *WZ_USE_HELP[]={
"輸入5+n個參數:",
"\t1.可執行文件名 *.exe",
"\t2.操作類型 1:一層加密;2:一層解密;",
"\t\t13:N層單密鑰加密;23:N層單密鑰解密;",
"\t\t39:N層多密鑰加密;49:N層多密鑰解密",
"\t3.讀出數據的文件名*.txt",
"\t4.寫入數據的文件名*.txt",
"\t5.密鑰(8位元組例如:wuzhen12)",
"\t[6].N層單密鑰的層數或者...二層加密|解密密鑰",
"\t[7].三層加密|解密密鑰",
"\t[8]. ...",
"\t[N].N層加密|解密密鑰",
"\t 例1: des 1 1.txt 2.txt 12345678",
"\t : des 2 2.txt 3.txt 12345678",
"\t 例2: des 13 1.txt 2.txt tiantian 5",
"\t : des 23 2.txt 3.txt tiantian 5",
"\t 例3: des 39 1.txt 2.txt 12345678 tiantian gaoxinma",
"\t : des 49 2.txt 3.txt 12345678 tiantian gaoxinma",
"******************************"
};

INT32 hextofile( ULONG8 *buf ,FILE *writefile, ULONG32 length);/*以16進制寫入文件*/
INT32 encodehex(ULONG8 *tobuf,ULONG8 *frombuf,ULONG32 len);/*16進制解碼*/

INT32 file_enc(FILE *readfile,FILE *writefile,
ULONG8 *key,ULONG32 keynum,
ULONG8 **superkey,ULONG32 n_superkey,
ULONG8 flag);
INT32 file_dec(FILE *readfile,FILE *writefile,
ULONG8 *key,ULONG32 keynum,
ULONG8 **superkey,ULONG32 n_superkey,
ULONG8 flag);
void wz_print_help();

INT32 main(INT32 argc,INT8 *argv[])
{
INT8 *FILENAME1,*FILENAME2;
FILE *fp, *fp2;
ULONG8 *key ;
ULONG8 **superkey ;/*n層加密解密密鑰*/
ULONG8 n_superkey ;
ULONG32 num;

if ( argc >= 5 && (atoi(argv[1]) == 39 || atoi(argv[1]) == 49 ) )
{
n_superkey = argc - 4 ;
superkey = ( INT8 **)calloc(1, n_superkey*sizeof( void *) ) ;
for ( num = 0 ; num < n_superkey ; num++)
{
superkey[num] = argv[4+num] ;
}

}
else if ( argc == 6 && (atoi(argv[1]) == 13 || atoi(argv[1]) == 23 ) && (atoi(argv[5])) > 0)
{

}
else if ( argc == 5 && ( atoi(argv[1]) == 1 || atoi(argv[1]) == 2 ))
{

}
else
{
wz_print_help();
return FAIL;
}
FILENAME1 = argv[2];
FILENAME2 = argv[3];
if ((fp= fopen(FILENAME1,"rb")) == NULL || (fp2 = fopen(FILENAME2,"wb"))==NULL)
{

printf("Can't open file\n");
return FAIL;
}

key = argv[4] ;
switch( atoi(argv[1] ))
{
case 1: /*加密*/
file_enc(fp,fp2,key,0, NULL,0, DESONE);
printf("\n \tDES 一層加密完畢,密文存於%s文件\n",FILENAME2);
break;
case 2:
file_dec(fp,fp2,key,0, NULL, 0,DESONE);
printf("\n \tDES 一層解密完畢,密文存於%s文件\n",FILENAME2);
break;
case 13:
file_enc(fp,fp2,key,atoi(argv[5]),NULL,0,DESTHREE);
printf("\n \tDES %u層單密鑰加密完畢,密文存於%s文件\n",atoi(argv[5]),FILENAME2);
break;
case 23:
file_dec(fp,fp2,key,atoi(argv[5]),NULL,0,DESTHREE);
printf("\n \tDES %u層單密鑰解密完畢,密文存於%s文件\n",atoi(argv[5]),FILENAME2);
break;
case 39:
file_enc(fp,fp2,NULL,0,superkey,n_superkey,DESMULTI);
printf("\n \tDES 多密鑰加密完畢,密文存於%s文件\n",FILENAME2);
free(superkey);
superkey = NULL;
break;
case 49:
file_dec(fp,fp2,NULL,0,superkey,n_superkey,DESMULTI);
printf("\n \tDES 多密鑰加密完畢,密文存於%s文件\n",FILENAME2);
free(superkey);
superkey = NULL;
break;
default:
printf("請選擇是加密|解密 plese choose encrypt|deencrypt\n");
break;
}

fclose(fp);
fclose(fp2);
return SUCCESS;

}

void wz_print_help()
{
INT32 i ;
printf("\t");
for ( i = 0 ; i < 22 ; i++)
{
printf("%c ",5);
}
printf("\n");
for( i = 0 ; i < WZ_COMMEND_NUM ; i++)
{
printf("\t%c\t%s %c\n",5,WZ_Commend_Help[i],5);
}
printf("\t");
for ( i = 0 ; i < 22 ; i++)
{
printf("%c ",5);
}
printf("\n");
for( i = 0 ; i < WZUSEHELPNUM ; i++)
{
printf("\t%s\n",WZ_USE_HELP[i]);
}
return ;
}

INT32 file_enc(FILE *readfile,FILE *writefile,
ULONG8 *key,ULONG32 keynum,
ULONG8 **superkey,ULONG32 n_superkey,
ULONG8 flag)
{
INT32 filelen = 0,readlen = 0,writelen = 0;
ULONG32 totalfilelen = 0 ;/*統計實際的文件的長度*/
ULONG8 readbuf[READFILESIZE] = { 0 };
filelen = fread( readbuf, sizeof( INT8 ), READFILESIZE, readfile );
while( filelen == READFILESIZE )
{
totalfilelen += READFILESIZE;
switch(flag)
{
case DESONE:
des( readbuf,key,READFILESIZE);
break;
case DESTHREE:
des3( readbuf, key ,keynum,READFILESIZE);
break;
case DESMULTI:
desN( readbuf, superkey ,n_superkey,READFILESIZE);
break;
}
hextofile( readbuf, writefile, READFILESIZE );/*以16進制形式寫入文件*/
memset(readbuf,0,READFILESIZE);
filelen = fread( readbuf, sizeof( INT8 ), READFILESIZE, readfile );
}
/*這是從文件中讀出的最後一批數據,長度可能會等於0,所以要先判斷*/

if ( filelen > 0 )
{
/*如果從文件中讀出的長度不等於0,那麼肯定有8個位元組以上的空間
文件長度存在最後8個位元組中*/
totalfilelen += filelen;
memcpy( &readbuf[READFILESIZE-8], (ULONG8*)&totalfilelen,4);
switch(flag)
{
case DESONE:
des( readbuf,key,READFILESIZE);
break;
case DESTHREE:
des3( readbuf, key ,keynum,READFILESIZE);
break;
case DESMULTI:
desN( readbuf, superkey ,n_superkey,READFILESIZE);
break;
}
hextofile( readbuf, writefile,READFILESIZE );/*以16進制形式寫入文件*/
memset(readbuf,0 ,READFILESIZE);
}
else /*filelen == 0*/
{
memcpy( &readbuf[0], (ULONG8*)&totalfilelen,4);
switch(flag)
{
case DESONE:
des( readbuf,key,8);
break;
case DESTHREE:
des3( readbuf, key ,keynum,8);
break;
case DESMULTI:
desN( readbuf, superkey ,n_superkey,8);
break;
}
hextofile( readbuf, writefile, 8);/*以16進制形式寫入文件*/
}
return SUCCESS;
}

INT32 file_dec(FILE *readfile,FILE *writefile,
ULONG8 *key,ULONG32 keynum,
ULONG8 **superkey,ULONG32 n_superkey,
ULONG8 flag)
{
INT32 filelen = 0,readlen = 0,writelen = 0;
ULONG32 totalfilelen = 0 ;/*統計實際的文件的長度*/
INT32 num = 0;
ULONG8 readbuf[READFILESIZE] = { 0 };
ULONG8 sendbuf[READFILESIZE*2] = { 0 };

fseek(readfile,-16,SEEK_END);/*最後16個位元組的表示文件長度的空間*/
filelen = fread( sendbuf, sizeof( INT8 ), 16, readfile );
encodehex( readbuf,sendbuf,8);
switch(flag)
{
case DESONE:
Ddes( readbuf,key,8);
break;
case DESTHREE:
Ddes3( readbuf, key ,keynum,8);
break;
case DESMULTI:
DdesN( readbuf, superkey ,n_superkey,8);
break;
}
/*解密*/
memcpy((ULONG8*)&totalfilelen, &readbuf[0],4);/*得到文件總長*/
memset(readbuf,0 ,8);
memset(sendbuf,0 ,16);

num = totalfilelen/READFILESIZE;/*有幾個READFILESIZE組*/
totalfilelen %= READFILESIZE;

fseek(readfile,0,SEEK_SET);/*跳到文件頭*/
while(num--)
{
filelen = fread( sendbuf, sizeof( INT8 ), READFILESIZE*2, readfile );
encodehex( readbuf,sendbuf,READFILESIZE);
switch(flag)
{
case DESONE:
Ddes( readbuf,key,READFILESIZE);
break;
case DESTHREE:
Ddes3( readbuf, key ,keynum,READFILESIZE);
break;
case DESMULTI:
DdesN( readbuf, superkey ,n_superkey,READFILESIZE);
break;
}

writelen = fwrite(readbuf, sizeof( INT8 ), READFILESIZE, writefile);
memset(readbuf,0 ,READFILESIZE);
memset(sendbuf,0 ,READFILESIZE*2);
}
if ( totalfilelen > 0 )/*最後一塊有多餘的元素*/
{
filelen = fread( sendbuf, sizeof( INT8 ), READFILESIZE*2, readfile );
encodehex( readbuf,sendbuf,READFILESIZE);
switch(flag)
{
case DESONE:
Ddes( readbuf,key,READFILESIZE);
break;
case DESTHREE:
Ddes3( readbuf, key ,keynum,READFILESIZE);
break;
case DESMULTI:
DdesN( readbuf, superkey ,n_superkey,READFILESIZE);
break;
}
writelen = fwrite(readbuf, sizeof( INT8 ), totalfilelen, writefile);
memset(readbuf,0 ,READFILESIZE);
memset(sendbuf,0 ,READFILESIZE*2);

}
return SUCCESS;
}

INT32 hextofile( ULONG8 *buf ,FILE *writefile, ULONG32 length)
{
ULONG32 writelen = 0 ;
/*以16進制形式寫入文件*/
while( writelen < length)
{
if(buf[writelen] == 0)
{
fprintf( writefile, "%x", 0 );
fprintf( writefile, "%x", 0 );
}
else if (buf[writelen] < 0x10)
{
fprintf( writefile, "%x", 0 );
fprintf( writefile, "%x", buf[writelen] );
}
else
{
fprintf( writefile, "%x", buf[writelen] );

}
writelen++;

}
return SUCCESS;
}
INT32 encodehex(ULONG8 *tobuf,ULONG8 *frombuf,ULONG32 len)
{
ULONG8 *readfirst = frombuf ;
ULONG8 *readend = &frombuf[1] ;
INT8 *s;
ULONG8 y[2] ;
ULONG32 i;
for ( i = 0 ; i < len ; i++)
{
y[0] = *readfirst ;
y[1] = *readend ;
readfirst += 2 ;
readend += 2 ;
tobuf[i] = (ULONG8)strtol((INT8*)y, &s, 16);
}
return SUCCESS;
}

2. des加密演算法(c/c++)

des.h文件：

#ifndefCRYPTOPP_DES_H

#defineCRYPTOPP_DES_H

#include"cryptlib.h"

#include"misc.h"

NAMESPACE_BEGIN(CryptoPP)

classDES:publicBlockTransformation

{

public:

DES(constbyte*userKey,CipherDir);

voidProcessBlock(constbyte*inBlock,byte*outBlock)const;

voidProcessBlock(byte*inoutBlock)const

{DES::ProcessBlock(inoutBlock,inoutBlock);}

enum{KEYLENGTH=8,BLOCKSIZE=8};

unsignedintBlockSize()const{returnBLOCKSIZE;}

protected:

staticconstword32Spbox[8][64];

SecBlock<word32>k;

};

classDESEncryption:publicDES

{

public:

DESEncryption(constbyte*userKey)

:DES(userKey,ENCRYPTION){}

};

classDESDecryption:publicDES

{

public:

DESDecryption(constbyte*userKey)

:DES(userKey,DECRYPTION){}

};

classDES_EDE_Encryption:publicBlockTransformation

{

public:

DES_EDE_Encryption(constbyte*userKey)

:e(userKey,ENCRYPTION),d(userKey+DES::KEYLENGTH,DECRYPTION){}

voidProcessBlock(constbyte*inBlock,byte*outBlock)const;

voidProcessBlock(byte*inoutBlock)const;

enum{KEYLENGTH=16,BLOCKSIZE=8};

unsignedintBlockSize()const{returnBLOCKSIZE;}

private:

DESe,d;

};

classDES_EDE_Decryption:publicBlockTransformation

{

public:

DES_EDE_Decryption(constbyte*userKey)

:d(userKey,DECRYPTION),e(userKey+DES::KEYLENGTH,ENCRYPTION){}

voidProcessBlock(constbyte*inBlock,byte*outBlock)const;

voidProcessBlock(byte*inoutBlock)const;

enum{KEYLENGTH=16,BLOCKSIZE=8};

unsignedintBlockSize()const{returnBLOCKSIZE;}

private:

DESd,e;

};

classTripleDES_Encryption:publicBlockTransformation

{

public:

TripleDES_Encryption(constbyte*userKey)

:e1(userKey,ENCRYPTION),d(userKey+DES::KEYLENGTH,DECRYPTION),

e2(userKey+2*DES::KEYLENGTH,ENCRYPTION){}

voidProcessBlock(constbyte*inBlock,byte*outBlock)const;

voidProcessBlock(byte*inoutBlock)const;

enum{KEYLENGTH=24,BLOCKSIZE=8};

unsignedintBlockSize()const{returnBLOCKSIZE;}

private:

DESe1,d,e2;

};

classTripleDES_Decryption:publicBlockTransformation

{

public:

TripleDES_Decryption(constbyte*userKey)

:d1(userKey+2*DES::KEYLENGTH,DECRYPTION),e(userKey+DES::KEYLENGTH,ENCRYPTION),

d2(userKey,DECRYPTION){}

voidProcessBlock(constbyte*inBlock,byte*outBlock)const;

voidProcessBlock(byte*inoutBlock)const;

enum{KEYLENGTH=24,BLOCKSIZE=8};

unsignedintBlockSize()const{returnBLOCKSIZE;}

private:

DESd1,e,d2;

};

NAMESPACE_END

#endif

des.cpp文件：

//des.cpp-modifiedbyWeiDaifrom:

/*

*

*circa1987,'s1977

*publicdomaincode.,but

*theactualencrypt/

*Outerbridge'sDEScodeasprintedinSchneier's"AppliedCryptography."

*

*Thiscodeisinthepublicdomain.Iwouldappreciatebugreportsand

*enhancements.

*

*PhilKarnKA9Q,[email protected],August1994.

*/

#include"pch.h"

#include"misc.h"

#include"des.h"

NAMESPACE_BEGIN(CryptoPP)

/*

*Threeofthesetables,theinitialpermutation,thefinal

*,areregularenoughthat

*forspeed,wehard-codethem.They'rehereforreferenceonly.

*Also,,gensp.c,

*tobuildthecombinedSPbox,Spbox[].They'realsoherejust

*forreference.

*/

#ifdefnotdef

/*initialpermutationIP*/

staticbyteip[]={

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

};

/*finalpermutationIP^-1*/

staticbytefp[]={

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

};

/*expansionoperationmatrix*/

staticbyteei[]={

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

};

/*The(in)famousS-boxes*/

staticbytesbox[8][64]={

/*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

};

/*32--boxes*/

staticbytep32i[]={

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

};

#endif

/*permutedchoicetable(key)*/

staticconstbytepc1[]={

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

};

/*numberleftrotationsofpc1*/

staticconstbytetotrot[]={

1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28

};

/*permutedchoicekey(table)*/

staticconstbytepc2[]={

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

};

/*EndofDES-definedtables*/

/*bit0isleft-mostinbyte*/

staticconstintbytebit[]={

0200,0100,040,020,010,04,02,01

};

/*Setkey(initializekeyschelearray)*/

DES::DES(constbyte*key,CipherDirdir)

:k(32)

{

SecByteBlockbuffer(56+56+8);

byte*constpc1m=buffer;/*placetomodifypc1into*/

byte*constpcr=pc1m+56;/*placetorotatepc1into*/

byte*constks=pcr+56;

registerinti,j,l;

intm;

for(j=0;j<56;j++){/*convertpc1tobitsofkey*/

l=pc1[j]-1;/*integerbitlocation*/

m=l&07;/*findbit*/

pc1m[j]=(key[l>>3]&/*findwhichkeybytelisin*/

bytebit[m])/*andwhichbitofthatbyte*/

?1:0;/*andstore1-bitresult*/

}

for(i=0;i<16;i++){/*keychunkforeachiteration*/

memset(ks,0,8);/*Clearkeyschele*/

for(j=0;j<56;j++)/*rotatepc1therightamount*/

pcr[j]=pc1m[(l=j+totrot[i])<(j<28?28:56)?l:l-28];

/**/

for(j=0;j<48;j++){/*selectbitsindivially*/

/*checkbitthatgoestoks[j]*/

if(pcr[pc2[j]-1]){

/*maskitinifit'sthere*/

l=j%6;

ks[j/6]|=bytebit[l]>>2;

}

}

/*Nowconverttoodd/eveninterleavedformforuseinF*/

k[2*i]=((word32)ks[0]<<24)

|((word32)ks[2]<<16)

|((word32)ks[4]<<8)

|((word32)ks[6]);

k[2*i+1]=((word32)ks[1]<<24)

|((word32)ks[3]<<16)

|((word32)ks[5]<<8)

|((word32)ks[7]);

}

if(dir==DECRYPTION)//reversekeyscheleorder

for(i=0;i<16;i+=2)

{

std::swap(k[i],k[32-2-i]);

std::swap(k[i+1],k[32-1-i]);

}

}

/**/

/*Ccodeonlyinportableversion*/

//RichardOuterbridge'sinitialpermutationalgorithm

/*

inlinevoidIPERM(word32&left,word32&right)

{

word32work;

work=((left>>4)^right)&0x0f0f0f0f;

right^=work;

left^=work<<4;

work=((left>>16)^right)&0xffff;

right^=work;

left^=work<<16;

work=((right>>2)^left)&0x33333333;

left^=work;

right^=(work<<2);

work=((right>>8)^left)&0xff00ff;

left^=work;

right^=(work<<8);

right=rotl(right,1);

work=(left^right)&0xaaaaaaaa;

left^=work;

right^=work;

left=rotl(left,1);

}

inlinevoidFPERM(word32&left,word32&right)

{

word32work;

right=rotr(right,1);

work=(left^right)&0xaaaaaaaa;

left^=work;

right^=work;

left=rotr(left,1);

work=((left>>8)^right)&0xff00ff;

right^=work;

left^=work<<8;

work=((left>>2)^right)&0x33333333;

right^=work;

left^=work<<2;

work=((right>>16)^left)&0xffff;

left^=work;

right^=work<<16;

work=((right>>4)^left)&0x0f0f0f0f;

left^=work;

right^=work<<4;

}

*/

//WeiDai''sinitialpermutation

//algorithm,

//(likeinMSVC)

inlinevoidIPERM(word32&left,word32&right)

{

word32work;

right=rotl(right,4U);

work=(left^right)&0xf0f0f0f0;

left^=work;

right=rotr(right^work,20U);

work=(left^right)&0xffff0000;

left^=work;

right=rotr(right^work,18U);

work=(left^right)&0x33333333;

left^=work;

right=rotr(right^work,6U);

work=(left^right)&0x00ff00ff;

left^=work;

right=rotl(right^work,9U);

work=(left^right)&0xaaaaaaaa;

left=rotl(left^work,1U);

right^=work;

}

inlinevoidFPERM(word32&left,word32&right)

{

word32work;

right=rotr(right,1U);

work=(left^right)&0xaaaaaaaa;

right^=work;

left=rotr(left^work,9U);

work=(left^right)&0x00ff00ff;

right^=work;

left=rotl(left^work,6U);

work=(left^right)&0x33333333;

right^=work;

left=rotl(left^work,18U);

work=(left^right)&0xffff0000;

right^=work;

left=rotl(left^work,20U);

work=(left^right)&0xf0f0f0f0;

right^=work;

left=rotr(left^work,4U);

}

//

voidDES::ProcessBlock(constbyte*inBlock,byte*outBlock)const

{

word32l,r,work;

#ifdefIS_LITTLE_ENDIAN

l=byteReverse(*(word32*)inBlock);

r=byteReverse(*(word32*)(inBlock+4));

#else

l=*(word32*)inBlock;

r=*(word32*)(inBlock+4);

#endif

IPERM(l,r);

constword32*kptr=k;

for(unsignedi=0;i<8;i++)

{

work=rotr(r,4U)^kptr[4*i+0];

l^=Spbox[6][(work)&0x3f]

^Spbox[4][(work>>8)&0x3f]

^Spbox[2][(work>>16)&0x3f]

^Spbox[0][(work>>24)&0x3f];

work=r^kptr[4*i+1];

l^=Spbox[7][(work)&0x3f]

^Spbox[5][(work>>8)&0x3f]

^Spbox[3][(work>>16)&0x3f]

^Spbox[1][(work>>24)&0x3f];

work=rotr(l,4U)^kptr[4*i+2];

r^=Spbox[6][(work)&0x3f]

^Spbox[4][(work>>8)&0x3f]

^Spbox[2][(work>>16)&0x3f]

^Spbox[0][(work>>24)&0x3f];

work=l^kptr[4*i+3];

r^=Spbox[7][(work)&0x3f]

^Spbox[5][(work>>8)&0x3f]

^Spbox[3][(work>>16)&0x3f]

^Spbox[1][(work>>24)&0x3f];

}

FPERM(l,r);

#ifdefIS_LITTLE_ENDIAN

*(word32*)outBlock=byteReverse(r);

*(word32*)(outBlock+4)=byteReverse(l);

#else

*(word32*)outBlock=r;

*(word32*)(outBlock+4)=l;

#endif

}

voidDES_EDE_Encryption::ProcessBlock(byte*inoutBlock)const

{

e.ProcessBlock(inoutBlock);

d.ProcessBlock(inoutBlock);

e.ProcessBlock(inoutBlock);

}

voidDES_EDE_Encryption::ProcessBlock(constbyte*inBlock,byte*outBlock)const

{

e.ProcessBlock(inBlock,outBlock);

d.ProcessBlock(outBlock);

e.ProcessBlock(outBlock);

}

voidDES_EDE_Decryption::ProcessBlock(byte*inoutBlock)const

{

d.ProcessBlock(inoutBlock);

e.ProcessBlock(inoutBlock);

d.ProcessBlock(inoutBlock);

}

voidDES_EDE_Decryption::ProcessBlock(constbyte*inBlock,byte*outBlock)const

{

d.ProcessBlock(inBlock,outBlock);

e.ProcessBlock(outBlock);

d.ProcessBlock(outBlock);

}

voidTripleDES_Encryption::ProcessBlock(byte*inoutBlock)const

{

e1.ProcessBlock(inoutBlock);

d.ProcessBlock(inoutBlock);

e2.ProcessBlock(inoutBlock);

}

voidTripleDES_Encryption::ProcessBlock(constbyte*inBlock,byte*outBlock)const

{

e1.ProcessBlock(inBlock,outBlock);

d.ProcessBlock(outBlock);

e2.ProcessBlock(outBlock);

}

voidTripleDES_Decryption::ProcessBlock(byte*inoutBlock)const

{

d1.ProcessBlock(inoutBlock);

e.ProcessBlock(inoutBlock);

d2.ProcessBlock(inoutBlock);

}

voidTripleDES_Decryption::ProcessBlock(constbyte*inBlock,byte*outBlock)const

{

d1.ProcessBlock(inBlock,outBlock);

e.ProcessBlock(outBlock);

d2.ProcessBlock(outBlock);

}

NAMESPACE_END

程序運行如下：

3. 用C語言實現DES加密演算法！

l iceEncryptText 文本加密解密
http://dl.icese.net/src.php?f=iceEncryptText.src.rar

4. DES加密演算法 密鑰字元個數小於8時,也能正常加解密.求解

DES標准密鑰就是56bit，8個字元即8個位元組，每個位元組的最高位不用，即每個位元組只用7位，8個字元正好是56bit。如果少於8個字元，就用0填充，最後參與運算的一定是56bit。

5. 用c語言寫des加密演算法

首先c語言要熟悉，然後去圖書館借一本加密解密的書，要裡面有c語言des實現代碼的（這種書是有的，我看到過）。論文先對加密解密的歷史及發展現狀進行介紹，然後著重對des加密的發展歷史及原理進行闡述（以上內容要多借幾本相關書綜合一下用自己的語言表達出來）。然後對des的演算法寫個程序（可以利用書裡面的程序），然後運行結果截幾張圖下來。最後總結一下，論文就可以了。

6. 如何實現C語言的DES加密演算法實現，請關注

可能很長 ，這是在我以前一個程序里摘出來的。 原理：用戶輸入創建密碼，機器讀取，並把每一位密碼進行加密，這里就是把每一位的 ASCII碼加一（也可以有其他的加密方式），然後保存在文件里。解密時從文件中讀取保存的亂碼，然後把它每一位的asc

7. 用C語言來實現DES加密演算法（很急）兩天內

DES雖然不難但是挺繁復的，代碼如下，關鍵點都有英文解釋，仔細看。各個函數的功能都可以從函數名看出來。

#include "pch.h"
#include "misc.h"
#include "des.h"

NAMESPACE_BEGIN(CryptoPP)

/* Tables defined in the Data Encryption Standard documents
* Three of these tables, the initial permutation, the final
* permutation and the expansion operator, are regular enough that
* for speed, we hard-code them. They're here for reference only.
* Also, the S and P boxes are used by a separate program, gensp.c,
* to build the combined SP box, Spbox[]. They're also here just
* for reference.
*/
#ifdef notdef
/* initial permutation IP */
static byte ip[] = {
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
};

/* final permutation IP^-1 */
static byte fp[] = {
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
};
/* expansion operation matrix */
static byte ei[] = {
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
};
/* The (in)famous S-boxes */
static byte sbox[8][64] = {
/* 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
};

/* 32-bit permutation function P used on the output of the S-boxes */
static byte p32i[] = {
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
};
#endif

/* permuted choice table (key) */
static const byte pc1[] = {
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
};

/* number left rotations of pc1 */
static const byte totrot[] = {
1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28
};

/* permuted choice key (table) */
static const byte pc2[] = {
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
};

/* End of DES-defined tables */

/* bit 0 is left-most in byte */
static const int bytebit[] = {
0200,0100,040,020,010,04,02,01
};

/* Set key (initialize key schele array) */
DES::DES(const byte *key, CipherDir dir)
: k(32)
{
SecByteBlock buffer(56+56+8);
byte *const pc1m=buffer; /* place to modify pc1 into */
byte *const pcr=pc1m+56; /* place to rotate pc1 into */
byte *const ks=pcr+56;
register int i,j,l;
int m;

for (j=0; j<56; j++) { /* convert pc1 to bits of key */
l=pc1[j]-1; /* integer bit location */
m = l & 07; /* find bit */
pc1m[j]=(key[l>>3] & /* find which key byte l is in */
bytebit[m]) /* and which bit of that byte */
? 1 : 0; /* and store 1-bit result */
}
for (i=0; i<16; i++) { /* key chunk for each iteration */
memset(ks,0,8); /* Clear key schele */
for (j=0; j<56; j++) /* rotate pc1 the right amount */
pcr[j] = pc1m[(l=j+totrot[i])<(j<28? 28 : 56) ? l: l-28];
/* rotate left and right halves independently */
for (j=0; j<48; j++){ /* select bits indivially */
/* check bit that goes to ks[j] */
if (pcr[pc2[j]-1]){
/* mask it in if it's there */
l= j % 6;
ks[j/6] |= bytebit[l] >> 2;
}
}
/* Now convert to odd/even interleaved form for use in F */
k[2*i] = ((word32)ks[0] << 24)
| ((word32)ks[2] << 16)
| ((word32)ks[4] << 8)
| ((word32)ks[6]);
k[2*i+1] = ((word32)ks[1] << 24)
| ((word32)ks[3] << 16)
| ((word32)ks[5] << 8)
| ((word32)ks[7]);
}

if (dir==DECRYPTION) // reverse key schele order
for (i=0; i<16; i+=2)
{
std::swap(k[i], k[32-2-i]);
std::swap(k[i+1], k[32-1-i]);
}
}
/* End of C code common to both versions */

/* C code only in portable version */

// Richard Outerbridge's initial permutation algorithm
/*
inline void IPERM(word32 &left, word32 &right)
{
word32 work;

work = ((left >> 4) ^ right) & 0x0f0f0f0f;
right ^= work;
left ^= work << 4;
work = ((left >> 16) ^ right) & 0xffff;
right ^= work;
left ^= work << 16;
work = ((right >> 2) ^ left) & 0x33333333;
left ^= work;
right ^= (work << 2);
work = ((right >> 8) ^ left) & 0xff00ff;
left ^= work;
right ^= (work << 8);
right = rotl(right, 1);
work = (left ^ right) & 0xaaaaaaaa;
left ^= work;
right ^= work;
left = rotl(left, 1);
}
inline void FPERM(word32 &left, word32 &right)
{
word32 work;

right = rotr(right, 1);
work = (left ^ right) & 0xaaaaaaaa;
left ^= work;
right ^= work;
left = rotr(left, 1);
work = ((left >> 8) ^ right) & 0xff00ff;
right ^= work;
left ^= work << 8;
work = ((left >> 2) ^ right) & 0x33333333;
right ^= work;
left ^= work << 2;
work = ((right >> 16) ^ left) & 0xffff;
left ^= work;
right ^= work << 16;
work = ((right >> 4) ^ left) & 0x0f0f0f0f;
left ^= work;
right ^= work << 4;
}
*/

// Wei Dai's modification to Richard Outerbridge's initial permutation
// algorithm, this one is faster if you have access to rotate instructions
// (like in MSVC)
inline void IPERM(word32 &left, word32 &right)
{
word32 work;

right = rotl(right, 4U);
work = (left ^ right) & 0xf0f0f0f0;
left ^= work;
right = rotr(right^work, 20U);
work = (left ^ right) & 0xffff0000;
left ^= work;
right = rotr(right^work, 18U);
work = (left ^ right) & 0x33333333;
left ^= work;
right = rotr(right^work, 6U);
work = (left ^ right) & 0x00ff00ff;
left ^= work;
right = rotl(right^work, 9U);
work = (left ^ right) & 0xaaaaaaaa;
left = rotl(left^work, 1U);
right ^= work;
}

inline void FPERM(word32 &left, word32 &right)
{
word32 work;

right = rotr(right, 1U);
work = (left ^ right) & 0xaaaaaaaa;
right ^= work;
left = rotr(left^work, 9U);
work = (left ^ right) & 0x00ff00ff;
right ^= work;
left = rotl(left^work, 6U);
work = (left ^ right) & 0x33333333;
right ^= work;
left = rotl(left^work, 18U);
work = (left ^ right) & 0xffff0000;
right ^= work;
left = rotl(left^work, 20U);
work = (left ^ right) & 0xf0f0f0f0;
right ^= work;
left = rotr(left^work, 4U);
}

// Encrypt or decrypt a block of data in ECB mode
void DES::ProcessBlock(const byte *inBlock, byte * outBlock) const
{
word32 l,r,work;

#ifdef IS_LITTLE_ENDIAN
l = byteReverse(*(word32 *)inBlock);
r = byteReverse(*(word32 *)(inBlock+4));
#else
l = *(word32 *)inBlock;
r = *(word32 *)(inBlock+4);
#endif

IPERM(l,r);

const word32 *kptr=k;

for (unsigned i=0; i<8; i++)
{
work = rotr(r, 4U) ^ kptr[4*i+0];
l ^= Spbox[6][(work) & 0x3f]
^ Spbox[4][(work >> 8) & 0x3f]
^ Spbox[2][(work >> 16) & 0x3f]
^ Spbox[0][(work >> 24) & 0x3f];
work = r ^ kptr[4*i+1];
l ^= Spbox[7][(work) & 0x3f]
^ Spbox[5][(work >> 8) & 0x3f]
^ Spbox[3][(work >> 16) & 0x3f]
^ Spbox[1][(work >> 24) & 0x3f];

work = rotr(l, 4U) ^ kptr[4*i+2];
r ^= Spbox[6][(work) & 0x3f]
^ Spbox[4][(work >> 8) & 0x3f]
^ Spbox[2][(work >> 16) & 0x3f]
^ Spbox[0][(work >> 24) & 0x3f];
work = l ^ kptr[4*i+3];
r ^= Spbox[7][(work) & 0x3f]
^ Spbox[5][(work >> 8) & 0x3f]
^ Spbox[3][(work >> 16) & 0x3f]
^ Spbox[1][(work >> 24) & 0x3f];
}

FPERM(l,r);

#ifdef IS_LITTLE_ENDIAN
*(word32 *)outBlock = byteReverse(r);
*(word32 *)(outBlock+4) = byteReverse(l);
#else
*(word32 *)outBlock = r;
*(word32 *)(outBlock+4) = l;
#endif
}

void DES_EDE_Encryption::ProcessBlock(byte *inoutBlock) const
{
e.ProcessBlock(inoutBlock);
d.ProcessBlock(inoutBlock);
e.ProcessBlock(inoutBlock);
}

void DES_EDE_Encryption::ProcessBlock(const byte *inBlock, byte *outBlock) const
{
e.ProcessBlock(inBlock, outBlock);
d.ProcessBlock(outBlock);
e.ProcessBlock(outBlock);
}

void DES_EDE_Decryption::ProcessBlock(byte *inoutBlock) const
{
d.ProcessBlock(inoutBlock);
e.ProcessBlock(inoutBlock);
d.ProcessBlock(inoutBlock);
}

void DES_EDE_Decryption::ProcessBlock(const byte *inBlock, byte *outBlock) const
{
d.ProcessBlock(inBlock, outBlock);
e.ProcessBlock(outBlock);
d.ProcessBlock(outBlock);
}

void TripleDES_Encryption::ProcessBlock(byte *inoutBlock) const
{
e1.ProcessBlock(inoutBlock);
d.ProcessBlock(inoutBlock);
e2.ProcessBlock(inoutBlock);
}

void TripleDES_Encryption::ProcessBlock(const byte *inBlock, byte *outBlock) const
{
e1.ProcessBlock(inBlock, outBlock);
d.ProcessBlock(outBlock);
e2.ProcessBlock(outBlock);
}

void TripleDES_Decryption::ProcessBlock(byte *inoutBlock) const
{
d1.ProcessBlock(inoutBlock);
e.ProcessBlock(inoutBlock);
d2.ProcessBlock(inoutBlock);
}

void TripleDES_Decryption::ProcessBlock(const byte *inBlock, byte *outBlock) const
{
d1.ProcessBlock(inBlock, outBlock);
e.ProcessBlock(outBlock);
d2.ProcessBlock(outBlock);
}

8. DES 加密演算法是怎樣的一種演算法

DES演算法為密碼體制中的對稱密碼體制，又被稱為美國數據加密標准，是1972年美國IBM公司研製的對稱密碼體制加密演算法。
明文按64位進行分組，密鑰長64位，密鑰事實上是56位參與DES運算（第8、16、24、32、40、48、56、64位是校驗位， 使得每個密鑰都有奇數個1）分組後的明文組和56位的密鑰按位替代或交換的方法形成密文組的加密方法。

9. 求一個用c語言寫的DES加密演算法~~

using system;
using system.security.cryptography;
using system.io;
using system.text;

public class encryptstringdes {

public static void main(string);
return;
}

// 使用utf8函數加密輸入參數
utf8encoding utf8encoding = new utf8encoding();
byte.tochararray());

// 方式一：調用默認的des實現方法des_csp.
des des = des.create();
// 方式二：直接使用des_csp()實現des的實體
//des_csp des = new des_csp();

// 初始化des加密的密鑰和一個隨機的、8比特的初始化向量(iv)
byte iv = {0x12, 0x34, 0x56, 0x78, 0x90, 0xab, 0xcd, 0xef};
des.key = key;
des.iv = iv;

// 建立加密流
symmetricstreamencryptor sse = des.createencryptor();

// 使用cryptomemorystream方法獲取加密過程的輸出
cryptomemorystream cms = new cryptomemorystream();

// 將symmetricstreamencryptor流中的加密數據輸出到cryptomemorystream中
sse.setsink(cms);

// 加密完畢，將結果輸出到控制台
sse.write(inputbytearray);
sse.closestream();

// 獲取加密數據
byte);
}
console.writeline();

//上面演示了如何進行加密，下面演示如何進行解密
symmetricstreamdecryptor ssd = des.createdecryptor();
cms = new cryptomemorystream();
ssd.setsink(cms);
ssd.write(encrypteddata);
ssd.closestream();

byte decryptedchararray = utf8encoding.getchars(decrypteddata);
console.writeline("解密後數據：");
console.write(decryptedchararray);
console.writeline();
}
}

編譯：

d:\csharp>csc des_demo.cs
microsoft (r) c# compiler version 7.00.8905
right (c) microsoft corp 2000. all rights reserved.

運行實例：
d:\csharp>des_demo.exe 使用c#編寫des加密程序的framework

加密結果：
3d 22 64 c6 57 d1 c4 c3 cf 77 ce 2f d0 e1 78 2a 4d ed 7a a8 83 f9 0e 14 e1 ba 38
7b 06 41 8d b5 e9 3f 00 0d c3 28 d1 f9 6d 17 4b 6e a7 41 68 40