DES加密算法

    DES解密算法请大家自己思考一下哦！其实对于DES加密算法，只要弄清楚流程，编程起来就简单了。。16轮加密流程：

Ki --> Li --> f(i) --> R(i) --> K(i+1) --> L(i+1) --> ... */

#include

#include

#include

int 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,

              ,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};

//最后换位表

int IP_1[] = {40,8,48,16,56,24,,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}; 

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};

//密钥的压缩型换位表1

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};

//密钥的压缩型换位表2

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};

//扩展型换位表

int E[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};

//换位表P

int P[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};

void Binary_conversion(char data[8],int *q)

{

    int i,j,cursor;

    char ch;

for(i=0,cursor=7;i<8;i++)

    {

        ch=data[i];

     for(j=0;j<8;j++)

        {

            *(q+cursor)=ch%2;

            ch=ch/2;

            cursor--;

        }

        cursor+=16;

    }

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

    {

        if(i%8==0)

        {

            printf(" ");

        }

        printf("%d",*(q+i));

    }

    printf("\\n");

}

//提取密钥的初始C0,D0

void C0_D0(int *pc_1,int (*c)[28],int (*d)[28])

//此时pc_1中存储的是56位的二进制密钥

{

    int i;

for(i=0;i<28;i++)

    {

        *(*c+i)=*(pc_1+i);

        *(*d+i)=*(pc_1+i+28);

    }

}

//CD合并成完整密钥

void CD_Merger(int *pc_1,int (*c)[28],int (*d)[28],int i)

{

    int j;

for(j=0;j<28;j++)

    {

        *(pc_1+j)=*(*(c+i)+j);

        *(pc_1+j+28)=*(*(d+i)+j);

    }

}

//r_change R(i-1)E变换后与Ki异或1

void Get_B(int *r_change,int (*kout)[48],int i)

{

    int j;

for(j=0;j<48;j++)

    {

        *(r_change+j)^=*(*(kout+i-1)+j);//系统会将其变换为二进制，然后进行异或运算，相当于输出的是六位，B(j)

    }

    //存入R_change数组中

}

//E(A)变换，A=R(i-1),Right[17][32]

void Get_EA(int *r_change,int (*r)[32],int i)

{

    int j;

for(j=0;j<48;j++)//R_change有48位

    {

        *(r_change+j)=*(*(r+i-1)+E[j]-1);//虽然E[i]有48位，但最大为32，故，满足(*r)[32]

    }

}

void Get_MW(int *ip_1)

{

    int i,j,a,c,b,x[8];

for(i=0;i<=7;i++)

    {

        a=i*8;

        x[i]=0;

     for(j=7;j>=0;j--)

        {

            c=*(ip_1+a);

            b=(int)pow(2,j);

            x[i]=x[i]+b*c;

            a++;

        }

    }

    //    printf("密文为:");

for(i=0;i<=7;i++)

    {

        a=x[i]%127;

        printf("%c",(char)(a));

    }

    printf("\\n");

}

//R(i) P盒置换后与L(i-1)异或2

void Get_Ri(int (*l)[32],int (*r)[32],int *p,int i)

{

    int j;

for(j=0;j<32;j++)

    {

        *(*(r+i)+j)=*(*(l+i-1)+j)^*(p+j);//Ri={L(i-1)异或f(R(i-1),Ki)}

    }

    //printf("\\n");

}

void IP_Change(int *Data_IP,int *Data)//将Data数据经IP变换后存入DATA_IP中

{

    int i;

for(i=1;i<=;i++)

    {

        *(Data_IP+(i-1))=*(Data+IP[i-1]-1);

    }

}

void L0_R0(int *ip,int (*l)[32],int (*r)[32])

{

    int i;

for(i=0;i<32;i++)

    {

        *(*l+i)=*(ip+i);

    }

for(i=0;i<32;i++)

    {

        *(*r+i)=*(ip+i+32);

    }

}

//L(i)=R(i-1)

void Li_R(int (*l)[32],int (*r)[32],int i)

{

    int j;

for(j=0;j<=31;j++)

    {

        *(*(l+i)+j)=*(*(r+i-1)+j);

    }

    //printf("\\n");

}

//密钥生成时CD移位

void LS_Shift(int (*p)[28],int i)

{

    int j;

    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);

            else if(j==27)

                *(*(p+i)+j)=*(*(p+i-1)+1);

            else

                *(*(p+i)+j)=*(*(p+i-1)+j+2);

        }

    }

}

void MW_Merger_IP_1_Replace(int (*l)[32],int (*r)[32],int *ip_1,int a)

{

    int i,ip[];

for(i=0;i<=31;i++) //这里是将密文合并起来，r是上32位，l是下32位，存入IP数组中

    {

        ip[i]=*(*(r+a)+i);

        ip[i+32]=*(*(l+a)+i);

    }

for(i=0;i<=63;i++)

    {

        *(ip_1+i)=ip[IP_1[i]-1];//通过IP_1对IP进行置换，保存到IP_1数组中

    }

}

void P_replace(int *s_p,int *s)

{

    int i;

for(i=0;i<=31;i++)

    {

        *(s_p+i)=*(s+P[i]-1);

    }

}

void PC_1_Transform(int *Key,int *pc_1) //Key的位数由位变成了56位，并存入PC_1中

{

    int i;

for(i=0;i<56;i++)

    {

        *(pc_1+i)=*(Key+PC_1[i]-1);

    }

}

void PC_2_Transform(int (*kout)[48],int *pc_1,int i)//确定kout是第几个

{

    int j;

for(j=0;j<48;j++)

    {

        *(*(kout+i-1)+j)=*(pc_1+PC_2[j]-1);//子密钥是48位

    }

}

void S_Replace(int *r_change,int *s)

{

    int i,b,j,x,a;

    //printf("i j x");

for(b=0;b<=7;b++)

    {

        switch(b)

        {

        case 0:

            i=*(r_change+0)*2+*(r_change+5)*1+1;

            j=*(r_change+1)*8+*(r_change+2)*4+*(r_change+3)*2+*(r_change+4)+1;

            x=S1[i-1][j-1];

         for(a=3;a>=0;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        case 1:

            i=*(r_change+6)*2+*(r_change+11)*1+1;

            j=*(r_change+7)*8+*(r_change+8)*4+*(r_change+9)*2+*(r_change+10)+1;

            x=S2[i-1][j-1];

         for(a=7;a>=4;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        case 2:

            i=*(r_change+12)*2+*(r_change+17)*1+1;

            j=*(r_change+13)*8+*(r_change+14)*4+*(r_change+15)*2+*(r_change+16)+1;

            x=S3[i-1][j-1];

         for(a=11;a>=8;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        case 3:

            i=*(r_change+18)*2+*(r_change+23)*1+1;

            j=*(r_change+19)*8+*(r_change+20)*4+*(r_change+21)*2+*(r_change+22)+1;

            x=S4[i-1][j-1];

         for(a=15;a>=12;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        case 4:

            i=*(r_change+24)*2+*(r_change+29)*1+1;

            j=*(r_change+25)*8+*(r_change+26)*4+*(r_change+27)*2+*(r_change+28)+1;

            x=S5[i-1][j-1];

         for(a=19;a>=16;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        case 5:

            i=*(r_change+30)*2+*(r_change+35)*1+1;

            j=*(r_change+31)*8+*(r_change+32)*4+*(r_change+33)*2+*(r_change+34)+1;

            x=S6[i-1][j-1];

         for(a=23;a>=20;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        case 6:

            i=*(r_change+36)*2+*(r_change+41)*1+1;

            j=*(r_change+37)*8+*(r_change+38)*4+*(r_change+39)*2+*(r_change+40)+1;

            x=S7[i-1][j-1];

         for(a=27;a>=24;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        case 7:

            i=*(r_change+42)*2+*(r_change+47)*1+1;

            j=*(r_change+43)*8+*(r_change+44)*4+*(r_change+45)*2+*(r_change+46)+1;

            x=S8[i-1][j-1];

         for(a=31;a>=28;a--)

            {

                *(s+a)=x%2;

                x=x/2;

            }

            break;

        }

    }

}

void main()

{    

    int i,j;

    int R_change[48],DATA[],KEY[],DATA_IP[];

    int C[17][28],D[17][28],S[32],S_P[32];

    int Left[17][32],Right[17][32],key_out[16][48];

    int *r_change,*s,*p,*Data,*Key,*pc_1,*Data_IP,*ip_1,*s_p;

    int (*c)[28],(*d)[28],(*l)[32],(*r)[32],(*kout)[48];

    char mingwen[20],key_Origion[20];

    //  int S1[32],IP[],IP_1[],PC_1[56],P[32],miwens[20];

    // char c1;

    c=C;p=P;ip_1=IP_1;

    d=D;l=Left;r=Right;

    kout=key_out;Key=KEY;

    Data=DATA;pc_1=PC_1;r_change=R_change;

    s=S;Data_IP=DATA_IP;s_p=S_P;

    while(1)

    {

        printf("请输入8位明文字符：");

        scanf("%s",mingwen);

        i=strlen(mingwen);

        if(i==8)

        {

            break;

        }

        //printf("AABBCCDD\\n");

        //strcpy(mingwen,"AABBCCDD");

    }    

    Binary_conversion(mingwen,Data);//将明文用二进制的形式通过指针Data存放在DATA数组中

    while(1)

    {

        printf("请输入8位密钥字符：");

        scanf("%s",key_Origion);

        i=strlen(key_Origion);

        if(i==8)

        {

            break;

        }

//          printf("luojiayo\\n");

//         strcpy(key_Origion,"luojiayo");

    }

    Binary_conversion(key_Origion,Key);//将密钥用二进制的形式通过指针Key存放在KEY数组中

    //加密

    IP_Change(Data_IP,Data); 

    L0_R0(Data_IP,l,r);//将ip矩阵的上四行用指针l划给Left[1][32],下四行用指针r划给Right[1][32]，为什么不是左右列呢？？

    PC_1_Transform(Key,pc_1);//Key的位数由位变成了56位，并存入PC_1中

    C0_D0(pc_1,c,d);//获得C,D,//c,d 也是二进制数，此时的pc_1指针是指向56位的密钥Key

for(i=1;i<=16;i++)

    {

        LS_Shift(c,i);//C D分别循环左移

        LS_Shift(d,i);

        CD_Merger(pc_1,c,d,i);

        PC_2_Transform(kout,pc_1,i);//i确定是第几个c,d,并获得Ki

        Li_R(l,r,i);//L(i)=R(i-1)，求出L(i)

        Get_EA(r_change,r,i);//获得E(A),

        Get_B(r_change,kout,i);//E(A)异或J( J=K(i) )得到B,将其存入R_change,其为10进制数，是48位，kout也为10进制数.48位

     for(j=0;j<32;j++)

        {

            *(s+j)=0;

        }

        S_Replace(r_change,s);//S-盒替换,获得了C1~C8，存入S中

        P_replace(s_p,s);//P-盒替换，P固定置换S,存入固定置换S_P数组中

        Get_Ri(l,r,s_p,i);//L与P替换后的数组异或,并求出了Ri

    }

    MW_Merger_IP_1_Replace(l,r,ip_1,i-1);//密文保存在IP_1数组中

    printf("明文被加密后的密文：\\n");

    Get_MW(ip_1);

}