仿射加密与S-DES加密算法的实现

仿射加密

#include <iostream>
#include <cstdio>

using namespace std;
char letter[30];
char _letter[30];
char ans_letter[30];
int num[30],s_num[100],k1,k2;const int mod=27;
int exgcd(int a,int b,int &x,int &y){
    if(b==0){
        x=1;y=0;return a;
    }
    int d=exgcd(b,a%b,x,y),t;
    t=x;x=y;y=t-a/b*y;
    return d;
}
int decode(int key){
    int rev,y;
    int d=exgcd(k1,mod,rev,y);
    return ((((key-k2+mod)%mod)*rev)%mod+mod)%mod;
}
char text[100];
int main(){
    for(int i=0;i<26;++i){
        letter[i]='A'+i;
    }
    letter[26]=' ';
    letter[27]='\0';char c;int cc=0;
    while((c=getchar())!='\n'){
        text[cc++]=c;
    }
    int len=cc;text[len]='\0';
    for(int i=0;i<len;++i){
        if(text[i]==' ') s_num[i]=26;
        else              s_num[i]=text[i]-'A';
    }
    while(~scanf("%d%d",&k1,&k2)){
        int x,y;
        int d=exgcd(k1,k2,x,y);
        if(d!=1) {
            printf("k1 and k2 Not coprime!\n");
            continue;
        }
        for(int i=0;i<27;++i){
            _letter[i]=letter[num[i]=(k1*i+k2)%mod];
        }
        _letter[27]='\0';
        printf("AFTER LOCK::\n");
        for(int i=0;i<len;++i){
            printf("%d,",num[s_num[i]]);
        }
        printf("\n");
        printf("TRY SIMPLE DECODE::\n");
        for(int i=0;i<len;++i){
            printf("%c",letter[num[s_num[i]]]);
        }
        printf("\n");
        printf("AFT GET THE MODNUM AND DECODE::\n");
        for(int i=0;i<len;++i){
            printf("%c",letter[decode(num[s_num[i]])]);
        }
        printf("\n");
        printf("ith number represent the res which number i  after LOCK::\n");
        for(int i=0;i<27;++i){
            ans_letter[i]=letter[decode(num[i])];
        }
        ans_letter[27]='\0';
        for(int i=0;i<27;++i) printf("%d, ",num[i]);printf("\n");
        printf("letter:\n%s\n",letter);
        printf("_letter:\n%s\n",_letter);
        printf("ans_letter\n%s\n",ans_letter);
    }
    return 0;
}

 

S-DES

#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int p8[]={6,3,7,4,8,5,10,9};
int p10[]={3,5,2,7,4,10,1,9,8,6};
int p4[]={2,4,3,1};
int ep[]={4,1,2,3,2,3,4,1};
int ip[]={2,6,3,1,4,8,5,7};
int ip_rev[]={4,1,3,5,7,2,8,6};
int S0[4][4]={{1,0,3,2},{3,2,1,0},{0,2,1,3},{3,1,3,2}};
int S1[4][4]={{0,1,2,3},{2,0,1,3},{3,0,1,0},{2,1,0,3}};
int SourceKey[11]={10};
int K1[9]={8};
int K2[9]={8};
int SOURCE_STR[9]={8};
int LOCK_STR[9]={8};
int UNLOCKED_STR[9]={8};
void prt(int a[],int a_len){
    for(int i=1;i<=a_len;++i) printf("%d, ",a[i]);printf("\n");
}
void shift(int a[],int len,int offset){
    int b[len];
    for(int i=0;i<len;++i){
        b[i]=a[i+1];
    }
    for(int i=1;i<=len;++i){
        a[i]=b[(i-1+offset)%len];
    }
}
void P8(int a[],int &len){
    //抽取8位
    int b[len+1];
    for(int i=1;i<=len;++i){
        b[i]=a[i];
    }
    len=8;
    for(int i=1;i<=len;++i){
        a[i]=b[p8[i-1]];
    }
}
void P10(int a[],int len){
    int b[len+1];
    for(int i=1;i<=len;++i){
        b[i]=a[i];
    }
    for(int i=1;i<=len;++i){
        a[i]=b[p10[i-1]];
    }
}
void P4(int a[],int len){
    int b[len+1];
    for(int i=1;i<=len;++i){
        b[i]=a[i];
    }
    for(int i=1;i<=len;++i){
        a[i]=b[p4[i-1]];
    }
}
void IP(int a[],int len){
    if(len!=8) printf("IP::len must be 8!\n");
    int b[len+1];
    for(int i=1;i<=len;++i){
        b[i]=a[i];
    }
    for(int i=1;i<=len;++i){
        a[i]=b[ip[i-1]];
    }
}
void IP_REV(int a[],int len){
    if(len!=8) printf("IP_REV:len must be 8!\n");
    int b[len+1];
    for(int i=1;i<=len;++i){
        b[i]=a[i];
    }
    for(int i=1;i<=len;++i){
        a[i]=b[ip_rev[i-1]];
    }
}
void EP(int a[],int &len){
    if(len!=4) printf("EP::the len must be 4!\n");
    int b[len+1];
    for(int i=1;i<=len;++i){
        b[i]=a[i];
    }
    len*=2;
    for(int i=1;i<=len;++i){
        a[i]=b[ep[i-1]];
    }
}
void SW(int a[],int a_len,int b[],int b_len){
    if(a_len!=b_len) printf("SW::the a_len must be equal to b_len!\n");
    int c[a_len+1];
    for(int i=1;i<=a_len;++i){
        c[i]=a[i];
    }
    for(int i=1;i<=a_len;++i){
        a[i]=b[i];
    }
    for(int i=1;i<=a_len;++i){
        b[i]=c[i];
    }
}
void convert(int a[],int offset,int key){
    //从小到大，从高位到低位
    if(key==0){
        a[offset]=0;a[offset+1]=0;
    }
    else if(key==1){
        a[offset]=0;a[offset+1]=1;
    }
    else if(key==2){
        a[offset]=1;a[offset+1]=0;
    }
    else if(key==3){
        a[offset]=1;a[offset+1]=1;
    }
}
void fk(int ming[],int m_len,int K[],int left[],int right[]){
    int front[9]={4};
    for(int i=1;i<=front[0];++i){
        front[i]=ming[i];
        left[i]=ming[i];
    }
    int back[9]={4};
    int __EP[9]={4};
    for(int i=1;i<=back[0];++i){
        back[i]=ming[i+4];
        __EP[i]=ming[i+4];
        right[i]=ming[i+4];
    }
    EP(__EP,__EP[0]);
    //printf("__EP:: ");prt(__EP,__EP[0]);
    //yihuo
    if(K[0]!=__EP[0]) printf("fk::len err!\n");
    for(int i=1;i<=__EP[0];++i){
        __EP[i]=__EP[i]^K[i];
    }
    //printf("AFT XOR __EP:: ");prt(__EP,__EP[0]);
    int __EP1[9]={4},__EP2[9]={4};
    for(int i=1;i<=4;++i){
        __EP1[i]=__EP[i];
    }
    for(int i=1;i<=4;++i){
        __EP2[i]=__EP[i+4];
    }
    //printf("__EP1:: ");prt(__EP1,__EP1[0]);
    //printf("__EP2:: ");prt(__EP2,__EP2[0]);
    int L=S0[(__EP1[1]*2+__EP1[4]*1)][(__EP1[2]*2+__EP1[3]*1)];
    int R=S1[(__EP2[1]*2+__EP2[4]*1)][(__EP2[2]*2+__EP2[3]*1)];
    //printf("L:%d R:%d\n",L,R);
    int cc=0;int _P4[5]={4};
    convert(_P4,1,L);convert(_P4,3,R);
    //printf("_P4 AFT UNION:: ");prt(_P4,_P4[0]);
    P4(_P4,_P4[0]);
    //printf("_P4 AFT P4:: ");prt(_P4,_P4[0]);
    for(int i=1;i<=4;++i){
        front[i]=front[i]^_P4[i];
        left[i]=front[i];
    }
    //printf("left:: ");prt(left,left[0]);
    //printf("right:: ");prt(right,right[0]);
}

void init_K1_and_K2(int SK[],int K1[],int K2[]){
    //sourcekey
    int _SK[11]={10};
    for(int i=1;i<=10;++i) _SK[i]=SK[i];
    P10(_SK,_SK[0]);//forgot
    int SKL[6]={5},SKR[6]={5};
    for(int i=1;i<=5;++i){
        SKL[i]=_SK[i];
    }
    for(int i=1;i<=5;++i){
        SKR[i]=_SK[i+5];
    }
    shift(SKL,SKL[0],1);shift(SKR,SKR[0],1);
    //prt(SKL,SKL[0]);prt(SKR,SKR[0]);
    int t_SK[11]={10};
    for(int i=1;i<=5;++i) t_SK[i]=SKL[i];
    for(int i=6;i<=10;++i) t_SK[i]=SKR[i-5];
    //prt(t_SK,t_SK[0]);
    P8(t_SK,t_SK[0]);
    //prt(t_SK,t_SK[0]);
    for(int i=1;i<=8;++i) K1[i]=t_SK[i];
    t_SK[0]=10;
    shift(SKL,SKL[0],2);shift(SKR,SKR[0],2);
    //prt(SKL,SKL[0]);prt(SKR,SKR[0]);
    for(int i=1;i<=5;++i) t_SK[i]=SKL[i];
    for(int i=6;i<=10;++i) t_SK[i]=SKR[i-5];
    //prt(t_SK,t_SK[0]);
    P8(t_SK,t_SK[0]);
    //prt(t_SK,t_SK[0]);
    for(int i=1;i<=8;++i) K2[i]=t_SK[i];
}
void LOCK(int S_STR[],int SK[],int K1[],int K2[]){
    init_K1_and_K2(SK,K1,K2);
    int T_STR[9]={8};
    for(int i=1;i<=8;++i) T_STR[i]=S_STR[i];
    IP(T_STR,T_STR[0]);
    int left[5]={4},right[5]={4};
    fk(T_STR,T_STR[0],K1,left,right);
    SW(left,left[0],right,right[0]);
    fk(T_STR,T_STR[0],K2,left,right);
    int C_STR[9]={8};
    for(int i=1;i<=4;++i) C_STR[i]=left[i];
    for(int i=5;i<=8;++i) C_STR[i]=right[i-4];
    IP_REV(C_STR,C_STR[0]);
    for(int i=1;i<=8;++i) LOCK_STR[i]=C_STR[i];
}
void UNLOCK(int S_STR[],int SK[],int K1[],int K2[]){
    init_K1_and_K2(SK,K1,K2);
    int T_STR[9]={8};
    for(int i=1;i<=8;++i) T_STR[i]=S_STR[i];
    IP(T_STR,T_STR[0]);
    int left[5]={4},right[5]={4};
    fk(T_STR,T_STR[0],K2,left,right);//K2
    SW(left,left[0],right,right[0]);
    fk(T_STR,T_STR[0],K1,left,right);//K1
    int C_STR[9]={8};
    for(int i=1;i<=4;++i) C_STR[i]=left[i];
    for(int i=5;i<=8;++i) C_STR[i]=right[i-4];
    IP_REV(C_STR,C_STR[0]);
    for(int i=1;i<=8;++i) UNLOCKED_STR[i]=C_STR[i];
}
int main(){
    //testShift
    // int a[]={0,1,2,3,4};
    // shift(a,4,1);
    // for(int i=1;i<=4;++i) printf("%d, ",a[i]);printf("\n");
    //test p8
    // int a[]={10,0,1,2,3,4,5,6,7,8,9};
    // P8(a,a[0]);
    // for(int i=1;i<=a[0];++i) printf("%d, ",a[i]);printf("\n");
    //test SW
    // int a[]={4,1,2,3,4};int b[]={4,4,3,2,1};
    // int a_len=4,b_len=4;
    // SW(a,a_len,b,b_len);
    // prt(a,a_len);prt(b,b_len);
    //test EP 
    // int a[9]={4,1,2,3,4};
    // EP(a,a[0]);
    // prt(a,a[0]);
    int i;char s[11];s[0]='#';
    printf("input Source_Key:\n");
    scanf("%s",s+1);
    for(i=1;i<=10;++i) SourceKey[i]=s[i]-'0';
    init_K1_and_K2(SourceKey,K1,K2);
    prt(K1,K1[0]);prt(K2,K2[0]);
    printf("input Mod:\n");
    scanf("%s",s+1);
    for(i=1;i<=8;++i) SOURCE_STR[i]=s[i]-'0';
    // int left[5]={4},right[5]={4};
    // fk(SOURCE_STR,8,K1,left,right);
    // prt(left,left[0]);prt(right,right[0]);
    LOCK(SOURCE_STR,SourceKey,K1,K2);
    printf("LOCK_STR:: ");prt(LOCK_STR,LOCK_STR[0]);
    UNLOCK(LOCK_STR,SourceKey,K1,K2);
    printf("UNLOCKED_STR:: ");prt(UNLOCKED_STR,UNLOCKED_STR[0]);
    return 0;
}