C语言的DES和3DES算法能真正运行.docx

C语言的DES和3DES算法能真正运行.docx

《C语言的DES和3DES算法能真正运行.docx》由会员分享，可在线阅读，更多相关《C语言的DES和3DES算法能真正运行.docx（21页珍藏版）》请在冰豆网上搜索。

C语言的DES和3DES算法能真正运行

Linux下c语言实现DES和3DES算法

（2010-12-0920:

56:

21）

转载

标签：

linux

c

des

3des

加解密

对称算法

it

分类：

IT技术

一、DES算法理论

   DES算法属于对称加密算法，在一些对安全性要求较高的交易中运用广泛，如支付行业等。

关于DES算法的理论，网上有很多文章都有详细的讲解，写得很好，我这里不再赘述，这里给出链接：

 ，请朋友们自己去学习，我的代码也是依据这里的理论写的。

二、实现环境及文件

   a、环境：

RedhatLinux+c

   b、实现文件：

des.h

                des.c

                makefile

三、代码

   1、des.h文件

//功能：

实现DES及3DES加解密的算法

//作者：

XXX

//日期：

2008-9-23

#ifndefDES_H

#defineDES_H

staticintpc_1_table[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};

staticintpc_2_table[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};

staticintls_num_table[16]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};

staticintip_table[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};

staticintip_1_table[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};

staticinte_table[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};

staticintp_table[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};

staticints_box_table[8][4][16]={

                   {{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}},

                   {{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}},

                  {{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}},

                  {{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}},

                  {{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}},

                  {{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}},

                  {{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}},

                  {{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}}

                   };

//函数声明

intDo_DES（char*strSrc,char*strKey,char*strDest,charflag）;

#endif

   2、des.c文件

//功能：

实现DES及3DES加解密的算法

//作者：

XXX

//日期：

2008-9-23

#include

#include

#include

#include"des.h"

//函数声明

intDo_DES（char*strSrc,char*strKey,char*strDest,charflag）;

intDo_3DES（char*strSrc,char*strKey,char*strDest,charflag）;

//主函数

intmain（intargc,char**argv）

{

   charsrc16[16+1],key16[16+1],key48[48+1],dest16[16+1];

   if（argc!

=3）

  {

      fprintf（stderr,"Usage:

[%s-e|-ds|3]\n",argv[0]）;

      exit

（1）; 

  }

  if（strcmp（argv[2],"-s"）==0）

 {

     if（strcmp（argv[1],"-e"）==0）

    {

         fprintf（stderr,"Pleaseinputthestringthatyouwanttoencrypt（16hexnumber）:

\n"）;

         memset（src16,0,sizeof（src16））;

         scanf（"%s",src16）;

         fprintf（stderr,"PleaseinputtheKeystring（16hexnumber）:

\n"）;

          memset（key16,0,sizeof（key16））;

         scanf（"%s",key16）;

         memset（dest16,0,sizeof（dest16））;

         Do_DES（src16,key16,dest16,'e'）;

         fprintf（stderr,"Result:

[%s]\n",dest16）;

     }

     elseif（strcmp（argv[1],"-d"）==0）

    {

         fprintf（stderr,"Pleaseinputthestringthatyouwanttodecrypt（16hexnumber）:

\n"）;

         memset（src16,0,sizeof（src16））;

         scanf（"%s",src16）;

         fprintf（stderr,"PleaseinputtheKeystring（16hexnumber）:

\n"）;

          memset（key16,0,sizeof（key16））;

         scanf（"%s",key16）;

         memset（dest16,0,sizeof（dest16））;

         Do_DES（src16,key16,dest16,'d'）;

         fprintf（stderr,"Result:

[%s]\n",dest16）;

     }

     else

         return-1;

  }

  elseif（strcmp（argv[2],"-3"）==0）

 {

     if（strcmp（argv[1],"-e"）==0）

    {

         fprintf（stderr,"Pleaseinputthestringthatyouwanttoencrypt（16hexnumber）:

\n"）;

         memset（src16,0,sizeof（src16））;

         scanf（"%s",src16）;

         fprintf（stderr,"PleaseinputtheKeystring（16hexnumber）:

\n"）;

         memset（key48,0,sizeof（key48））;

         scanf（"%s",key48）;

         memset（dest16,0,sizeof（dest16））;

         Do_3DES（src16,key48,dest16,'e'）;

         fprintf（stderr,"Result:

[%s]\n",dest16）;

     }

     elseif（strcmp（argv[1],"-d"）==0）

     {

         fprintf（stderr,"Pleaseinputthestringthatyouwanttodecrypt（16hexnumber）:

\n"）;

         memset（src16,0,sizeof（src16））;

         scanf（"%s",src16）;

         fprintf（stderr,"PleaseinputtheKeystring（16hexnumber）:

\n"）;

         memset（key48,0,sizeof（key48））;

         scanf（"%s",key48）;

         memset（dest16,0,sizeof（dest16））;

         Do_3DES（src16,key48,dest16,'d'）;

         fprintf（stderr,"Result:

[%s]\n",dest16）;

     }

     else

         return-1;

  }

  else

      return-1;

  return0;  

}

//做DES加密或解密运算

intDo_DES（char*strSrc,char*strKey,char*strDest,charflag）

{

   inti,j;

  unsignedcharsubKey[16][48+1],byte8[8+1],bits[64+1],strTmp[64+1];

  unsignedcharL0[32+1],R0[32+1],Lx[32+1],Rx[32+1];

  if（!

（flag=='e'||flag=='E'||flag=='d'||flag=='D'））

      return-1;

  if（strSrc==NULL||strKey==NULL）

      return-2;

  if（flag=='e'||flag=='E'）

 {

      memset（byte8,0,sizeof（byte8））;

      BCDToByte（strKey,16,byte8）;

      memset（bits,0,sizeof（bits））;

      ByteToBit（byte8,8,bits）;

      Des_GenSubKey（bits,subKey）;

      BCDToByte（strSrc,16,byte8）;

      ByteToBit（byte8,8,bits）;

      Des_IP（bits,strTmp）;

      memcpy（L0,strTmp,32）;

      memcpy（R0,strTmp+32,32）;

      for（i=0;i<16;i++）

     {

         memcpy（Lx,R0,32）;

         Des_F（R0,subKey[i],Rx）;

         Do_XOR（L0,32,Rx）;

         memcpy（L0,Lx,32）;

         memcpy（R0,Rx,32）;

      }

     memcpy（bits,R0,32）;

     memcpy（bits+32,L0,32）;

     Des_IP_1（bits,strTmp）;

     BitToByte（strTmp,64,byte8）;

     ByteToBCD（byte8,8,strDest）;

 }

 else

 {

     memset（byte8,0,sizeof（byte8））;

     BCDToByte（strKey,16,byte8）;

     memset（bits,0,sizeof（bits））;

     ByteToBit（byte8,8,bits）;

     Des_GenSubKey（bits,subKey）;

     BCDToByte（strSrc,16,byte8）;

     ByteToBit（byte8,8,bits）;

     Des_IP（bits,strTmp）;

     memcpy（L0,strTmp,32）;

     memcpy（R0,strTmp+32,32）;

     for（i=0;i<16;i++）

    {

        memcpy（Lx,R0,32）;

        Des_F（R0,subKey[15-i],Rx）;

        Do_XOR（L0,32,Rx）;

        memcpy（L0,Lx,32）;

        memcpy（R0,Rx,32）;

    }

    memcpy（bits,R0,32）;

    memcpy（bits+32,L0,32）;

    Des_IP_1（bits,strTmp）;

    BitToByte（strTmp,64,byte8）;

    ByteToBCD（byte8,8,strDest）;

 }

 return0;