C语言版DES算法.docx
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C语言版DES算法
C语言版DES算法
(明文可以通过MAX设置明文的最大位数)
(明文和密钥中都可以有空格)
完成者:
周红福
邮箱:
zhouhongfu2012@
#include
#include
#defineMAX100
//初始置换表
intIp[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};
//末置换表
intIpr[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};
//密钥的置换选择表1
intPc_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};
//密钥的置换选择表2
intPc_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};
//各层移位次数
intShTb[16]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
//扩展运算表
intE[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};
//置换运算表P
intP[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};
//S盒代替表
intS[8][4][16]={/*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};
charl[32],r[32];
chark[16][48];
//把8位明文转换成64位二进制
voidCreateRandL(char*input)
{
charinput1[64];
intinput11,i;
for(i=0;i<8;i++)//把八位字符转换成64位二进制数
{
input11=input[i];
if(input11<0)
input11+=256;
input1[i*8+7]=input11/128+'0';input11=input11%128;
input1[i*8+6]=input11/64+'0';input11=input11%64;
input1[i*8+5]=input11/32+'0';input11=input11%32;
input1[i*8+4]=input11/16+'0';input11=input11%16;
input1[i*8+3]=input11/8+'0';input11=input11%8;
input1[i*8+2]=input11/4+'0';input11=input11%4;
input1[i*8+1]=input11/2+'0';input11=input11%2;
input1[i*8+0]=input11+'0';
}
//通过初始置换,把64位明文转成左右两个32位
for(i=0;i<32;i++)
{
l[i]=input1[Ip[i]-1];
r[i]=input1[Ip[i+32]-1];
}
}
//输入密钥key,得出16个子密钥k[16][]
voidCreateSubkey(char*key)
{
charkey1[64],l1,r1,key12[48];
charC[28],D[28];
intkey11,i,j,w,mov;
for(i=0;i<8;i++)//把八位密钥字符转换成64位二进制数,每八位是:
低->高
{
key11=key[i];
key1[i*8+7]=key11/128+'0';key11=key11%128;
key1[i*8+6]=key11/64+'0';key11=key11%64;
key1[i*8+5]=key11/32+'0';key11=key11%32;
key1[i*8+4]=key11/16+'0';key11=key11%16;
key1[i*8+3]=key11/8+'0';key11=key11%8;
key1[i*8+2]=key11/4+'0';key11=key11%4;
key1[i*8+1]=key11/2+'0';key11=key11%2;
key1[i*8+0]=key11+'0';
}
//56位密钥被分成两部分,前28位为C,后28位为D
for(i=0;i<28;i++)
{
C[i]=key1[Pc_1[i]-1];
D[i]=key1[Pc_1[i+28]-1];
}
//16轮循环左移
for(j=0;j<16;j++)
{
if(j==0||j==1||j==8||j==15)//判断移位的次数
mov=1;
elsemov=2;
for(w=0;w{
l1=C[0];r1=D[0];
for(i=1;i<28;i++)
{
C[i-1]=C[i];
D[i-1]=D[i];
}
C[27]=l1;D[27]=r1;
}
for(i=0;i<28;i++)
{
key12[i]=C[i];
key12[i+28]=D[i];
}
//通过压缩置换,把56位转换成48位
for(i=0;i<48;i++)
{
k[j][i]=key12[Pc_2[i]-1];
}
}
}
voidF(char*rr,char*kk,char*fresult)//rr[32],kk[48],输出fresult[32]
{
charr1[8][6],k1[8][6];
inti,j;
inthang,lie,ss;
for(i=0;i<8;i++)//子密钥k[8][6],把一维转换成二维,便于与右48位进行异或操作
{
k1[i][0]=kk[i*6+0];
k1[i][1]=kk[i*6+1];
k1[i][2]=kk[i*6+2];
k1[i][3]=kk[i*6+3];
k1[i][4]=kk[i*6+4];
k1[i][5]=kk[i*6+5];
}
//进行扩展运算,把右32位扩展成48位
r1[0][0]=rr[31];r1[0][1]=rr[0];r1[0][2]=rr[1];r1[0][3]=rr[2];r1[0][4]=rr[3];r1[0][5]=rr[4];//1
for(i=0;i<6;i++)
{
r1[1][i]=rr[3+i];//2
r1[2][i]=rr[7+i];//3
r1[3][i]=rr[11+i];//4
r1[4][i]=rr[15+i];//5
r1[5][i]=rr[19+i];//6
r1[6][i]=rr[23+i];//7
}
r1[7][0]=rr[27];r1[7][1]=rr[28];r1[7][2]=rr[29];r1[7][3]=rr[30];r1[7][4]=rr[31];r1[7][5]=rr[0];//8
//扩展后的48位数与子密钥kk进行异或运算
for(i=0;i<8;i++)
for(j=0;j<6;j++)
{
//进行异或运算
if((r1[i][j]=='1'&&k1[i][j]=='0')||(r1[i][j]=='0'&&k1[i][j]=='1'))
r1[i][j]='1';
elser1[i][j]='0';
}
//通过S盒进行代换选择
for(i=0;i<8;i++)
{
hang=(r1[i][0]-'0')*2+(r1[i][5]-'0');
lie=(r1[i][1]-'0')*8+(r1[i][2]-'0')*4+(r1[i][3]-'0')*2+(r1[i][4]-'0');
ss=S[i][hang][lie];//第i个盒的hang行lie列的数赋给ss
//把S子盒中的十进制数换成二进制数
rr[i*4+3]=ss/8+'0';ss=ss%8;
rr[i*4+2]=ss/4+'0';ss=ss%4;
rr[i*4+1]=ss/2+'0';ss=ss%2;
rr[i*4+0]=ss+'0';
}
//P盒转换,置换运算P为一维数组
for(i=0;i<32;i++)
fresult[i]=rr[P[i]-1];
}
//进行末置换,通过参数把,DES最后一轮后的左半部分和右半部分交换
voidReverseIP(char*ll,char*rr,char*output)
{
inti,result;
charZh[64],output1[64];
for(i=0;i<32;i++)
{
Zh[i]=ll[i];
Zh[i+32]=rr[i];
}
//末置换
for(i=0;i<64;i++)
{
output1[i]=Zh[Ipr[i]-1];
}
//64位明文变成8位字符,即密文
for(i=0;i<8;i++)
{
result=(output1[i*8+7]-'0')*128+(output1[i*8+6]-'0')*64+(output1[i*8+5]-'0')*32+(output1[i*8+4]-'0')*16+
(output1[i*8+3]-'0')*8+(output1[i*8+2]-'0')*4+(output1[i*8+1]-'0')*2+(output1[i*8+0]-'0');
output[i]=result;
}
}
//DES算法,输入明文input,密钥key和jiaorjie,jiaorjie为1进行加密,jiaorjie为0进行解密
voidDES(char*input,char*key,booljiaorjie)
{
inti,j;
charFresult[32],ss[32];
//初始置换IP,一维,并得出r[32]与l[32]
CreateRandL(input);
//计算出16个子密钥k
CreateSubkey(key);
//进行16轮的转换运算
if(jiaorjie)//加密操作
{
for(i=0;i<16;i++)
{
for(j=0;j<32;j++)
ss[j]=r[j];
//进行F函数,密钥按k[1]到k[15]的顺序带入,结果通过Fresult带回
F(r,k[i],Fresult);
for(j=0;j<32;j++)
{
//进行异或运算
if((l[j]=='1'&&Fresult[j]=='0')||(l[j]=='0'&&Fresult[j]=='1'))
r[j]='1';
elser[j]='0';
}
//本轮的右32位作为下一轮的左32位
for(j=0;j<32;j++)
{
l[j]=ss[j];
}
}
}
else//解密操作
{
for(i=0;i<16;i++)
{
for(j=0;j<32;j++)
ss[j]=r[j];
//进行F函数,密钥按k[15]到k[1]的顺序带入,结果通过Fresult带回
F(r,k[15-i],Fresult);
for(j=0;j<32;j++)
{
if((l[j]=='1'&&Fresult[j]=='0')||(l[j]=='0'&&Fresult[j]=='1'))
r[j]='1';
elser[j]='0';
}
//本轮的右32位作为下一轮的左32位
for(j=0;j<32;j++)
l[j]=ss[j];
}
}
//进行逆初始置换,并通过参数交换左部分和右部分
ReverseIP(r,l,input);
}
intmain()
{
intlen,len1,i;
charinput[MAX],key[9];
printf("*********************DES加密|解密运算*********************\n");
printf("************************DES加密操作***********************\n");
printf("明文:
");
gets(input);//明文可以有空格
printf("密钥(8位):
");
gets(key);//密钥里可以有空格
len=strlen(input);//len为明文的位数
if(len%8!
=0)//明文位数不是8的倍数,后面补'0'
{
strcat(input,"00000000");
input[len-len%8+8]='\0';
}
len1=strlen(input);//补'0'后,明文的位数
for(i=0;iDES(&input[i*8],key,1);
printf("*************************加密结果*************************\n");
printf("密文:
%s\n",input);
printf("**********************************************************\n\n");
printf("************************DES解密操作***********************\n");
printf("密文:
%s\n",input);
printf("密钥(8位):
");
gets(key);
for(i=0;iDES(&input[i*8],key,0);
input[len]='\0';//把明文补的'0'去掉
printf("*************************解密结果*************************\n");
printf("明文:
%s\n",input);
printf("**********************************************************\n\n");
return0;
}