网络安全-DES加密算法编程实现

C++代码：

#include 

using namespace std;
int IPF[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
             };
int IPL[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};
int PC1[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
             };
int PC2[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
             };
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
           };
int DES_S[8][4][16]= {14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7,        //S1
                      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,        //S2
                      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,        //S3
                      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,        //S4
                      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,        //S5
                      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,        //S6
                      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,        //S7
                      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,        //S8
                      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
                     };
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 BytetoBits(char B,char*b);
void Xor(char*In1,char*In2,int n,char*Out);
void myShift(char*a,int n,int l,char*out);
void myPermutation(char *In,char*Out,int n,int *P);
void GenerateKey(char kk[][48],char*k);
void SPermutation(char*s6,int sf[][16],char*s4);
void Encrypt(char*M,char keys[][48],char *cryp);
char BitstoByte(char *b);
int main()
{
    char A[8];
    cin>>A;
    char a[8][8],b[64];
    for(int i=0; i<8; i++)
        BytetoBits(A[i],a[i]);
    int k=0;
    for(int i=0; i<8; i++)//明文放到b数组
    {
        for(int j=0; j<8; j++)
            b[k++]=a[i][j];
    }
    char K[64]={'0','0','0','1','0','0','1','1',
                '0','0','1','1','0','1','0','0',
                '0','1','0','1','0','1','1','1',
                '0','1','1','1','1','0','0','1',
                '1','0','0','1','1','0','1','1',
                '1','0','1','1','1','1','0','0',
                '1','1','0','1','1','1','1','1',
                '1','1','1','1','0','0','0','1'};
    for(int i=0;i<64;i++)
    {
        K[i]=char(K[i]-48);
    }
    char keys[16][48];
    GenerateKey(keys,K);//子秘钥生成
    char cryp[64];
    Encrypt(b,keys,cryp);//加密

    char rekeys[16][48],clian[64];
    for(int i=0;i<16;i++)
    {
        for(int j=0;j<48;j++)
            rekeys[i][j]=keys[15-i][j];
    }
    Encrypt(cryp,rekeys,clian);//解密


    /*测试 输出*/
    cout<<"原文："<for(int i=0;i<64;i++)
    {
        if(i%8==0&&i!=0)
            cout<cout<<int(b[i])<<" ";

    }
    cout<<"\n加密："<for(int i=0;i<64;i++)
    {
        if(i%8==0&&i!=0)
            cout<cout<<int(cryp[i])<<" ";

    }
    cout<<"\n解密："<for(int i=0;i<64;i++)
    {
        if(i%8==0&&i!=0)
            cout<cout<<int(clian[i])<<" ";

    }
    return 0;

}
void BytetoBits(char B,char*b)
{
    for(int i=0; i<8; i++)
    {
        char m=1;
        b[7-i]=(B&(m<>i;
    }
}
char BitstoByte(char *b)
{
        char a=NULL;
        for(int i=0;i<8;i++)
        {
            a=(b[i]&a)<<1;
        }
        return a;
}
void Xor(char*In1,char*In2,int n,char*Out)
{
    for(int i=0; iif(In1[i]==In2[i])
            Out[i]=0;
        else
            Out[i]=1;
    }
}
void myShift(char*a,int n,int l,char*out)
{
    for(int i=0; ivoid myPermutation(char *In,char*Out,int n,int *P)
{
    for(int i=0; i1];
}
void GenerateKey(char kk[][48],char*k)
{
    char key[56],kc[17][28],kd[17][28];
    myPermutation(k,key,56,PC1);
    for(int i=0; i<28; i++)
    {
        kc[0][i]=key[i];
        kd[0][i]=key[i+28];
    }
    for(int i=0; i<16; i++)
    {
        if(i==0||i==1||i==8||i==15)
        {
            myShift(kc[i],28,1,kc[i+1]);
            myShift(kd[i],28,1,kd[i+1]);
        }
        else
        {
            myShift(kc[i],28,2,kc[i+1]);
            myShift(kd[i],28,2,kd[i+1]);
        }
        for(int j=0; j<28; j++)
        {
            key[j]=kc[i+1][j];
            key[j+28]=kd[i+1][j];
        }
        myPermutation(key,kk[i],48,PC2);
    }
}
void SPermutation(char*s6,int sf[][16],char*s4)
{
    int r,l,re;
    r=s6[0]*2+s6[5];
    l=s6[1]*8+s6[2]*4+s6[3]*2+s6[4];
    re=sf[r][l];
    for(int i=0; i<4; i++)
    {
        char m=1;
        s4[3-i]=(re&(m<>i;
    }
}
void Encrypt(char*M,char keys[][48],char *cryp)
{
    char c[64];
    myPermutation(M,c,64,IPF);//初始值换后放到c数组
    char L[17][32],R[17][32];
    for(int i=0; i<32; i++) //拆分
    {
        L[0][i]=c[i];
        R[0][i]=c[i+32];
    }


    char temp[48];
    for(int i=0; i<16; i++)
    {
        myPermutation(R[i],temp,48,E);
        Xor(temp,keys[i],48,temp);
        char s[8][6],rs[8][4];
        int k=0;
        for(int i=0; i<8; i++)
            for(int j=0; j<6; j++)
            {
                s[i][j]=temp[k++];
            }
        for(int i=0; i<8; i++)
        {
            SPermutation(s[i],DES_S[i],rs[i]);
        }
        char f[32],h[32];
        k=0;
        for(int i=0; i<8; i++)
            for(int j=0; j<4; j++)
                h[k++]=rs[i][j];
        myPermutation(h,f,32,P);
        Xor(f,L[i],32,R[i+1]);
        for(int j=0;j<32;j++)
            L[i+1][j]=R[i][j];
    }
    char pk[64];
    for(int i=0;i<32;i++)
    {
        pk[i]=R[16][i];
        pk[i+32]=L[16][i];
    }
    myPermutation(pk,cryp,64,IPL);
}