DES算法(基于C语言,加密解密代码)
/* Note:Your choice is C IDE */
#include"stdio.h"
#include"string.h"
#define uchar unsigned char
/****************************************************************************
******************************明文转换声明部分*******************************/ //IP1置换表
int IP_1[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};
//IP2逆置换表
int IP_2[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};
//E扩展置换表
int E_case[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};
//S盒压缩
int S1[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};
int S2[4][16]={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};
int S3[4][16]={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};
int S4[4][16]={ 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};
int S5[4][16]={ 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};
int S6[4][16]={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};
int S7[4][16]={ 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};
int S8[4][16]={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}; //P盒置换
int Permute[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};
/****************************************************************************
**************************字节与二进制相互变换部分***************************
*****************************************************************************/
//字节转换成二进制
int ByteToBit(char ch,char bit[8])
{
uchar x;
for(x=0;x<8;x++)
{
*(bit+x)=((ch<
}
return 0;
}
//字符串转换成二进制位串
int Char8ToBit64(char ch[8],char bit[64]) {
uchar x;
for(x=0;x<8;x++)
{
ByteToBit(*(ch+x),bit+(x<<3));
}
return 0;
}
//二进制转换成字节
int BitToByte(char bit[8],char*ch)
{
uchar x;
for(x=0;x<8;x++)
{
*ch|=*(bit+x)<<(7-x);
}
return 0;
}
//将二进制串转换成字符串
int Bit64ToChar8(char bit[64],char ch[8])
{
uchar x;
memset(ch,0,8); //把ch[8]全部清零。
for(x=0;x<8;x++)
{
BitToByte(bit+(x<<3),ch+x);
}
return 0;
}
/***************************************************************************************
********************************密钥声明部分********************************************/ //密钥PC—1置换表
int PC_1[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};
//密钥PC—2置换表
int PC_2[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};
//密钥每次轮回移位表
uchar Left_Move[16]={1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1};
/*************************************************************************************
**********************************密钥的生成函数部分************************************** **************************************************************************************/
//PC-1置换函数
int PC1_permute(char pc1[64],char PC1_Buff[56]) {
uchar x;
for(x=0;x<56;x++)
{
PC1_Buff[x]=pc1[PC_1[x]-1];
}
return 0;
}
//PC密钥左移
int KeyLeftMove(char pcB[56],char Move)
{
uchar x;
char Cn[28],Dn[28];
char a_buff,b_buff,c_buff,d_buff;
//**********PC-1密钥56位分离成左右各28位************** memcpy(Cn,pcB,28);
memcpy(Dn,pcB+28,28);
//*****************PC密钥左移部分******************* a_buff=Cn[0];
b_buff=Dn[0];
if(2==Move)
{
c_buff=Cn[1];
d_buff=Dn[1];
}
for(x=0;x<28;x++)
{
if(27==x)
{
if(1==Move)
{
Cn[27]=a_buff;
Dn[27]=b_buff;
}
if(2==Move)
{
Cn[26]=a_buff;
Cn[27]=c_buff;
Dn[26]=b_buff;
Dn[27]=d_buff;
}
}
else
{
Cn[x]=Cn[x+Move];
Dn[x]=Dn[x+Move];
}
}
//******************28bit合成56bit******************** memcpy(pcB,Cn,28);
memcpy(pcB+28,Dn,28);
return 0;
}
//PC-2逆置换函数
int PC2_permut(char pc2[56],char PC2_Buff[48]) {
uchar x;
for(x=0;x<48;x++)
{
PC2_Buff[x]=pc2[PC_2[x]-1];
}
return 0;
}
//产生16轮的子密钥函数
int Key16Itera(char key[64],char subKeys[16][48])
{
uchar x,move;
char temp1[56];
PC1_permute(key,temp1);//PC1置换，返回值temp
for(x=0;x<16;x++)
{
move=Left_Move[x];
KeyLeftMove(temp1,move);//移位，返回值temp，56bit
PC2_permut(temp1,subKeys[x]);
}
return 0;
}
/************************************************************************************
*******************************明文加密函数部分**************************************/
//IP置换
int IP1_permute(char IP1[64])
{
uchar x;
char IP1Buff[64];
for(x=0;x<64;x++)
IP1Buff[x]=IP1[IP_1[x]-1];
}
memcpy(IP1,IP1Buff,64);
return 0;
}
//32bit经E盒扩展成48bit
int R_Expand48bit(char R[32],char RE[48]) {
uchar x;
for(x=0;x<48;x++)
{
RE[x]=R[E_case[x]-1];
}
return 0;
}
//IP64逆置换
int IP2_permute(char IP2[64])
{
uchar x;
char temp2[64];
for(x=0;x<64;x++)
temp2[x]=IP2[IP_2[x]-1];
}
memcpy(IP2,temp2,64);
return 0;
}
//经P盒置换
int Pcase(char S8Byte[32])
{
uchar x;
char temp3[32];
for(x=0;x<32;x++)
{
temp3[x]=S8Byte[Permute[x]-1];
}
memcpy(S8Byte,temp3,32);
return 0;
}
//经S盒压缩成32bit
int Reduceto32bit(char EKey[48],char S32bit[32]) {
uchar x,Rank,Line;
int out;
for(x=0;x<8;x++)
{
Rank=(EKey[1+6*x]<<3)|(EKey[2+6*x]<<2)|(EKey[3+6*x]<<1)|(EKey[4+6*x]);
Line=(EKey[6*x]<<1)|(EKey[5+6*x]);
//在S盒寻找需要的数
if(0==x) { out=S1[Line][Rank];}
if(1==x) { out=S2[Line][Rank];}
if(2==x) { out=S3[Line][Rank];}
if(3==x) { out=S4[Line][Rank];}
if(4==x) { out=S5[Line][Rank];}
if(5==x) { out=S6[Line][Rank];}
if(6==x) { out=S7[Line][Rank];}
if(7==x) { out=S8[Line][Rank];}
//把一位数拆成数四位数
S32bit[4*x+0]=(((char)(out))&0x08)>>3;
S32bit[4*x+1]=(((char)(out))&0x04)>>2;
S32bit[4*x+2]=(((char)(out))&0x02)>>1;
S32bit[4*x+3]=(((char)(out))&0x01);
}
return 0;
}
/*******************明文16次迭代,加密，**********************
**********************输入值：mw[64]\子密钥：miyue[16][48]*************************
**********************返回值：data[64]***********************/
int Encryp(char data[64],char Zkey16[16][48])
{
uchar x,y;
char Left[32],Right[32],EKbuff[48];
char SE32bit[32];
IP1_permute(data);//IP置换
memcpy(Left,data,32);//分离32bit
memcpy(Right,data+32,32);
for(x=0;x<16;x++)
{
R_Expand48bit(Right,EKbuff);//E盒扩展
for(y=0;y<48;y++) //与密钥异或
{
EKbuff[y]^=Zkey16[x][y];
}
Reduceto32bit(EKbuff,SE32bit);//经S盒压缩32bit,返回值SE32bit
Pcase(SE32bit); //经P盒置换，返回值SE32bit
for(y=0;y<32;y++) //与左半部分Left 32bit异或
{
SE32bit[y]^=Left[y];
}
memcpy(Left,Right,32);
memcpy(Right,SE32bit,32);
}
memcpy(data,Right,32);//合成64bit
memcpy(data+32,Left,32);
IP2_permute(data); //IP逆置换
return 0;
}
/**********************密文输入，解密，16次迭代************************ **************************输入值：miwen[64]****************************
***************************输出值：mw[64]******************************/
int Decryp(char miwen[64],char D_Zkey16[16][48])
{
uchar x,y;
char D_Left[32],D_Right[32];
char D_EKbuff[48],D_SE32bit[32];
IP1_permute(miwen); //IP1置换。
memcpy(D_Left,miwen,32);//分离32bit
memcpy(D_Right,miwen+32,32);
for(x=16;x>0;x--) //16轮迭代
{
R_Expand48bit(D_Right,D_EKbuff);//E盒扩展
for(y=0;y<48;y++) //与密钥异或
{
D_EKbuff[y]^=D_Zkey16[x-1][y];
}
Reduceto32bit(D_EKbuff,D_SE32bit);//经S盒压缩32bit,返回值D_SE32bit。
Pcase(D_SE32bit); //经P盒置换，返回值SE32bit
for(y=0;y<32;y++)
{
D_SE32bit[y]^=D_Left[y];
}
memcpy(D_Left,D_Right,32);
memcpy(D_Right,D_SE32bit,32);
}
memcpy(miwen,D_Right,32); //合成64bit
memcpy(miwen+32,D_Left,32);
IP2_permute(miwen); //IP逆置换
return 0;
}
/*************************************主函数部分*********************************/
int main(void)
{
uchar x;
char MingW64bit[64],MingW8Byte[8];
char Key64bit[64],Key8Byte[8];
char Key16[16][48],temp2[64];
char Mybuff[8];
printf("请输入密钥：\n");
scanf("%s",Key8Byte);
Char8ToBit64(Key8Byte,Key64bit); //密钥字符串置换成二进制串for(x=0;x<8;x++) //补偿足8位奇偶校验位
{
memcpy(temp2+8*x,Key64bit+7*x,7);
temp2[x*8+7]=1;
}
memcpy(Key64bit,temp2,64);
Key16Itera(Key64bit,Key16);//生成子密钥
printf("请输入明文：\n");
scanf("%s",MingW8Byte);
Char8ToBit64(MingW8Byte,MingW64bit);//明文字符串置换成二进制串
/*************************************************************************
**************************解密部分****************************************
**************************************************************************/
Encryp(MingW64bit,Key16); //加密函数
printf("\n密文二进制串64bit:");
for(x=0;x<64;x++) //打印加密后的明文
{
if(x%8==0) printf("\n");
printf("%3d",MingW64bit[x]);
}
Bit64ToChar8(MingW64bit,Mybuff); //把密文二进制串转换成字符串printf("\n显示密文\n");
printf("%s",Mybuff); //把密文字符串打印出来
printf("\n");
/************************************************************************
*************************解密部分****************************************
*************************************************************************/
Decryp(MingW64bit,Key16);//解密函数，输入密文MingW64bit，和密钥Key16。
printf("\n明文二进制串的64bit:");
for(x=0;x<64;x++)//打印解密后的明文
{
if(x%8==0) printf("\n");
printf("%3d",MingW64bit[x]);
}
Bit64ToChar8(MingW64bit,Mybuff); //把明文的二进制串转换成字符串printf("\n");
printf("%s",Mybuff); //把明文的字符串显示出来
return 0;
}