DES算法代码及实验报告.docx
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DES算法代码及实验报告.docx
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DES算法代码及实验报告
实验名称DES算法实验报告实验(实习)日期得分指导教师沈剑
计算机系专业软件工程年级11班次3姓名张渊学号931
1、实验目的
理解对称加解密算法的原理和特点
理解DES算法的加解密原理
2、DES算法详述
DES算法把64位的明文输入块变为64位的密文输出块,它所使用的密钥也是64位,其功能是把输入的64位数据块按位重新组合,并把输出分为L0、R0两部分,每部分各长32位,其置换规则见下表:
58,50,12,34,26,18,10,2,60,52,44,36,28,20,12,4,
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,
即将输入的第58位换到第一位,第50位换到第2位,……,依此类推,最后一位是原来的第7位。
L0、R0则是换位输出后的两部分,L0是输出的左32位,R0是右32位,
例:
设置换前的输入值为D1D2D3……D64,则经过初始置换后的结果为:
L0=D550……D8;R0=D57D49...D7。
经过26次迭代运算后,得到L16、R16,将此作为输入,进行逆置换,即得到密文输出。
逆置换正好是初始置的逆运算,例如,第1位经过初始置换后,处于第40位,而通过逆置换,又将第40位换回到第1位,其逆置换规则如下表所示:
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,
34,2,42,10,50,18,5826,33,1,41,9,49,17,57,25,
放大换位表
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,
单纯换位表
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,
在f(Ri,Ki)算法描述图中,S1,S2...S8为选择函数,其功能是把6bit数据变为4bit数据。
下面给出选择函数Si(i=1,2......8)的功能表:
选择函数Si
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,
1.子密钥Ki(48bit)的生成算法
初始Key值为64位,但DES算法规定,其中第8、16、......64位是奇偶校验位,不参与DES运算。
故Key实际可用位数便只有56位。
即:
经过缩小选择换位表1的变换后,Key的位数由64位变成了56位,此56位分为C0、D0两部分,各28位,然后分别进行第1次循环左移,得到C1、D1,将C1(28位)、D1(28位)合并得到56位,再经过缩小选择换位2,从而便得到了密钥K0(48位)。
依此类推,便可得到K1、K2、......、K15,不过需要注意的是,16次循环左移对应的左移位数要依据下述规则进行:
循环左移位数1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
以上介绍了DES算法的加密过程。
DES算法的解密过程是一样的,区别仅仅在于第一次迭代时用子密钥K15,第二次K14、……,最后一次用K0,算法本身并没有任何变化。
3、代码
#include<>
#include<>
#include<>
//IP置换
intIP[]={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};
//IP逆置换
intIP_1[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};
//扩展变换E
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};
//P置换
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};
//置换选择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};
//置换选择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};
//8个s盒
intS1[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,
15,12,8,2,4,9,1,7,5,11,3,15,10,0,6,13},
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},
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},
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},
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},
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},
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},
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};
voiderjinzhi(charz[8],int*q);//二进制转换
voidPC_1_bianhuan(int*Key,int*pc_1);//PC_1变换
voidCD(int*pc_1,int(*c)[28],int(*d)[28]);//把明文分组为C、D
voidLS_yiwei(int(*p)[28],inti);//密钥L、S的移位
voidCD_hebin(int*pc_1,int(*c)[28],int(*d)[28],inti);//C、D变换
voidPC_2_bianhuan(int(*kout)[48],int*pc_1,inta);//PC_2变换
voidIP_change(int*ip,int*Data);//IP置换
voidL__R(int(*l)[32],int(*r)[32],inti);//把56位密钥分为L、S两组
voidE_change(int*r_change,int(*r)[32],inta);//E的扩展变换
voidyihuo1(int*r_change,int(*kout)[48],inta);//异或1
voidS_replace(int*r_change,int*s1);//S变换
voidP_replace(int*p,int*s1);//P变换
voidyihuo2(int(*l)[32],int(*r)[32],int*p,inta);//异或2
voidIP2(int(*l)[32],int(*r)[32],int*ip_1,inti);//IP逆置换
voidmiwen(int*ip_1);//得出密文
voidyihuo3(int*r_change,int(*kout)[48],inta);//异或3
//定义三个数组存放明文密钥密文
charmingwen[8],key_Origion[8],miwens[8];
/******************************************************************************/
//二进制转换
voiderjinzhi(charz[8],int*q)
{
charch;
inti,j,a=7;
for(i=0;i<8;i++)
{
ch=z[i];
for(j=0;j<8;j++)
{
*(q+a)=ch%2;
ch=ch/2;
a--;
}
a=a+16;
}
for(i=0;i<=63;i++)
{
if(i%8==0)printf("");
printf("%d",*(q+i));
}
printf("\n");
}
/*******************************************************************************************************/
//IP变换
voidIP_change(int*ip,int*Data)
{
inti,j;
for(i=1;i<=64;i++)
{
j=58-i/33+2*(((i-1)/8)%4)-8*((i-1)%8);
*(ip+(i-1))=*(Data+(j-1));
}
}
/*******************************************************************************************************/
//提取L0,R0分组
voidL0_R0(int*ip,int(*l)[32],int(*r)[32])
{
inti;
for(i=0;i<=31;i++)
{
*(*l+i)=*(ip+i);
}
for(i=0;i<=31;i++)
{
*(*r+i)=*(ip+i+32);
}
}
/**********************************************************************************************************/
//L(i)=R(i-1)
voidL__R(int(*l)[32],int(*r)[32],inti)
{
intj;
for(j=0;j<=31;j++)
{
*(*(l+i)+j)=*(*(r+i-1)+j);
}
//printf("\n");
}
/**********************************************************************************************************/
//E变换
voidE_change(int*r_change,int(*r)[32],inta)
{
inti;
for(i=0;i<=47;i++)
{
*(r_change+i)=*(*(r+a-1)+E[i]-1);
}
//printf("\n");
}
/**********************************************************************************************************/
//PC_1变换
voidPC_1_bianhuan(int*Key,int*pc_1)
{
inti;
for(i=0;i<=55;i++)
{
*(pc_1+i)=*(Key+PC_1[i]-1);
}
}
/*************************************************************************************************/
//提取密钥的初始C0,D0
voidCD(int*pc_1,int(*c)[28],int(*d)[28])
{
inti;
for(i=0;i<=27;i++)
{
*(*c+i)=*(pc_1+i);
*(*d+i)=*(pc_1+i+28);
}
}
/***************************************************************************************************/
//密钥生成时CD移位
voidLS_yiwei(int(*p)[28],inti)
{
intj;
if(i==1||i==2||i==9||i==16)
{
for(j=0;j<=27;j++)
{
if(j==27)
*(*(p+i)+j)=*(*(p+i-1)+0);
else
*(*(p+i)+j)=*(*(p+i-1)+j+1);
}
}
else
{
for(j=0;j<=27;j++)
{
if(j==26)
*(*(p+i)+j)=*(*(p+i-1)+0);
elseif(j==27)
*(*(p+i)+j)=*(*(p+i-1)+1);
else
*(*(p+i)+j)=*(*(p+i-1)+j+2);
}
}
}
/***************************************************************************************************/
//CD合并成完整密钥
voidCD_hebin(int*pc_1,int(*c)[28],int(*d)[28],inti)
{
intj;
for(j=
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