#include "stdio.h"

#include "time.h"

#include "stdlib.h"

#define PLAIN_FILE_OPEN_ERROR -1

#define KEY_FILE_OPEN_ERROR -2

#define CIPHER_FILE_OPEN_ERROR -3

#define OK 1;

typedef char ElemType;

      

int IP_Table[64] = { 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,

                                 56,48,40,32,24,16,8,0,

                                 58,50,42,34,26,18,10,2,

                                 60,52,44,36,28,20,12,4,

                                 62,54,46,38,30,22,14,6};

 

int IP_1_Table[64] = {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,

           32,0,40,8,48,16,56,24};

int E_Table[48] = {31, 0, 1, 2, 3, 4,

                  3, 4, 5, 6, 7, 8,

                  7, 8,9,10,11,12,

                  11,12,13,14,15,16,

                  15,16,17,18,19,20,

                  19,20,21,22,23,24,

                  23,24,25,26,27,28,

                  27,28,29,30,31, 0};

int P_Table[32] = {15,6,19,20,28,11,27,16,

                  0,14,22,25,4,17,30,9,

                  1,7,23,13,31,26,2,8,

                  18,12,29,5,21,10,3,24};

int S[8][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}},

 

{{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}},

 

{{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}},

 

{{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}},

 

{{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}},

 

{{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}},

 

{{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}},

 

{{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}}};

 

int PC_1[56] = {56,48,40,32,24,16,8,

              0,57,49,41,33,25,17,

              9,1,58,50,42,34,26,

              18,10,2,59,51,43,35,

              62,54,46,38,30,22,14,

              6,61,53,45,37,29,21,

              13,5,60,52,44,36,28,

              20,12,4,27,19,11,3};

int PC_2[48] = {13,16,10,23,0,4,2,27,

              14,5,20,9,22,18,11,3,

              25,7,15,6,26,19,12,1,

              40,51,30,36,46,54,29,39,

              50,44,32,46,43,48,38,55,

              33,52,45,41,49,35,28,31};

int MOVE_TIMES[16] = {1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};

int ByteToBit(ElemType ch,ElemType bit[8]);

int BitToByte(ElemType bit[8],ElemType *ch);

int Char8ToBit64(ElemType ch[8],ElemType bit[64]);

int Bit64ToChar8(ElemType bit[64],ElemType ch[8]);

int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]);

int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]);

int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]);

int DES_ROL(ElemType data[56], int time);

int DES_IP_Transform(ElemType data[64]);

int DES_IP_1_Transform(ElemType data[64]);

int DES_E_Transform(ElemType data[48]);

int DES_P_Transform(ElemType data[32]);

int DES_SBOX(ElemType data[48]);

int DES_XOR(ElemType R[48], ElemType L[48],int count);

int DES_Swap(ElemType left[32],ElemType right[32]);

int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]);

int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48], ElemType plainBlock[8]);

int DES_Encrypt(char *plainFile, char *keyStr,char *cipherFile);

int DES_Decrypt(char *cipherFile, char *keyStr,char *plainFile);

                            

int ByteToBit(ElemType ch, ElemType bit[8]){

    int cnt;

    for(cnt = 0;cnt < 8; cnt++){

        *(bit+cnt) = (ch>>cnt)&1;

    }

    return 0;

}

int BitToByte(ElemType bit[8],ElemType *ch){

    int cnt;

    for(cnt = 0;cnt < 8; cnt++){

        *ch |= *(bit + cnt)<<cnt;

    }

    return 0;

}

int Char8ToBit64(ElemType ch[8],ElemType bit[64]){

    int cnt;

    for(cnt = 0; cnt < 8; cnt++){       

        ByteToBit(*(ch+cnt),bit+(cnt<<3));

    }

    return 0;

}

int Bit64ToChar8(ElemType bit[64],ElemType ch[8]){

    int cnt;

    memset(ch,0,8);

    for(cnt = 0; cnt < 8; cnt++){

        BitToByte(bit+(cnt<<3),ch+cnt);

    }

    return 0;

}

int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]){

    ElemType temp[56];

    int cnt;

    DES_PC1_Transform(key,temp);

    for(cnt = 0; cnt < 16; cnt++){

        DES_ROL(temp,MOVE_TIMES[cnt]);

        DES_PC2_Transform(temp,subKeys[cnt]);

    }

    return 0;

}

int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]){

    int cnt;   

    for(cnt = 0; cnt < 56; cnt++){

        tempbts[cnt] = key[PC_1[cnt]];

    }

    return 0;

}

int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]){

    int cnt;

    for(cnt = 0; cnt < 48; cnt++){

        tempbts[cnt] = key[PC_2[cnt]];

    }

    return 0;

}

int DES_ROL(ElemType data[56], int time){   

    ElemType temp[56];

   

    memcpy(temp,data,time);

    memcpy(temp+time,data+28,time);

   

   

    memcpy(data,data+time,28-time);

    memcpy(data+28-time,temp,time);

   

    memcpy(data+28,data+28+time,28-time);

    memcpy(data+56-time,temp+time,time);   

    return 0;

}

int DES_IP_Transform(ElemType data[64]){

    int cnt;

    ElemType temp[64];

    for(cnt = 0; cnt < 64; cnt++){

        temp[cnt] = data[IP_Table[cnt]];

    }

    memcpy(data,temp,64);

    return 0;

}

int DES_IP_1_Transform(ElemType data[64]){

    int cnt;

    ElemType temp[64];

    for(cnt = 0; cnt < 64; cnt++){

        temp[cnt] = data[IP_1_Table[cnt]];

    }

    memcpy(data,temp,64);

    return 0;

}

int DES_E_Transform(ElemType data[48]){

    int cnt;

    ElemType temp[48];

    for(cnt = 0; cnt < 48; cnt++){

        temp[cnt] = data[E_Table[cnt]];

    }   

    memcpy(data,temp,48);

    return 0;

}

int DES_P_Transform(ElemType data[32]){

    int cnt;

    ElemType temp[32];

    for(cnt = 0; cnt < 32; cnt++){

        temp[cnt] = data[P_Table[cnt]];

    }   

    memcpy(data,temp,32);

    return 0;

}

int DES_XOR(ElemType R[48], ElemType L[48] ,int count){

    int cnt;

    for(cnt = 0; cnt < count; cnt++){

        R[cnt] ^= L[cnt];

    }

    return 0;

}

int DES_SBOX(ElemType data[48]){

    int cnt;

    int line,row,output;

    int cur1,cur2;

    for(cnt = 0; cnt < 8; cnt++){

        cur1 = cnt*6;

        cur2 = cnt<<2;

       

       

        line = (data[cur1]<<1) + data[cur1+5];

        row = (data[cur1+1]<<3) + (data[cur1+2]<<2)

            + (data[cur1+3]<<1) + data[cur1+4];

        output = S[cnt][line][row];

       

        data[cur2] = (output&0X08)>>3;

        data[cur2+1] = (output&0X04)>>2;

        data[cur2+2] = (output&0X02)>>1;

        data[cur2+3] = output&0x01;

    }   

    return 0;

}

int DES_Swap(ElemType left[32], ElemType right[32]){

    ElemType temp[32];

    memcpy(temp,left,32);   

    memcpy(left,right,32);   

    memcpy(right,temp,32);

    return 0;

}

int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]){

    ElemType plainBits[64];

    ElemType copyRight[48];

    int cnt;

    Char8ToBit64(plainBlock,plainBits);       

   

    DES_IP_Transform(plainBits);

   

    for(cnt = 0; cnt < 16; cnt++){       

        memcpy(copyRight,plainBits+32,32);

       

        DES_E_Transform(copyRight);

       

        DES_XOR(copyRight,subKeys[cnt],48);   

       

        DES_SBOX(copyRight);

       

        DES_P_Transform(copyRight);

       

        DES_XOR(plainBits,copyRight,32);

        if(cnt != 15){

           

            DES_Swap(plainBits,plainBits+32);

        }

    }

   

    DES_IP_1_Transform(plainBits);

    Bit64ToChar8(plainBits,cipherBlock);

    return 0;

}

int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48],ElemType plainBlock[8]){

    ElemType cipherBits[64];

    ElemType copyRight[48];

    int cnt;

    Char8ToBit64(cipherBlock,cipherBits);       

   

    DES_IP_Transform(cipherBits);

   

   

    for(cnt = 15; cnt >= 0; cnt--){       

        memcpy(copyRight,cipherBits+32,32);

       

        DES_E_Transform(copyRight);

       

        DES_XOR(copyRight,subKeys[cnt],48);       

       

        DES_SBOX(copyRight);

       

        DES_P_Transform(copyRight);       

       

        DES_XOR(cipherBits,copyRight,32);

        if(cnt != 0){

           

            DES_Swap(cipherBits,cipherBits+32);

        }

    }

   

    DES_IP_1_Transform(cipherBits);

    Bit64ToChar8(cipherBits,plainBlock);

    return 0;

}

int DES_Encrypt(char *plainFile, char *keyStr,char *cipherFile){

    FILE *plain,*cipher;

    int count;

    ElemType plainBlock[8],cipherBlock[8],keyBlock[8];

    ElemType bKey[64];

    ElemType subKeys[16][48];

    if((plain = fopen(plainFile,"rb")) == NULL){

        return PLAIN_FILE_OPEN_ERROR;

    }   

    if((cipher = fopen(cipherFile,"wb")) == NULL){

        return CIPHER_FILE_OPEN_ERROR;

    }

   

    memcpy(keyBlock,keyStr,8);

   

    Char8ToBit64(keyBlock,bKey);

   

    DES_MakeSubKeys(bKey,subKeys);

   

    while(!feof(plain)){

       

        if((count = fread(plainBlock,sizeof(char),8,plain)) == 8){

            DES_EncryptBlock(plainBlock,subKeys,cipherBlock);

            fwrite(cipherBlock,sizeof(char),8,cipher);   

        }

    }

    if(count){

       

        memset(plainBlock + count,'\0',7 - count);

       

        plainBlock[7] = 8 - count;

        DES_EncryptBlock(plainBlock,subKeys,cipherBlock);

        fwrite(cipherBlock,sizeof(char),8,cipher);

    }

    fclose(plain);

    fclose(cipher);

return OK;

}

int DES_Decrypt(char *cipherFile, char *keyStr,char *plainFile){

    FILE *plain, *cipher;

    int count,times = 0;

    long fileLen;

    ElemType plainBlock[8],cipherBlock[8],keyBlock[8];

    ElemType bKey[64];

    ElemType subKeys[16][48];

    if((cipher = fopen(cipherFile,"rb")) == NULL){

        return CIPHER_FILE_OPEN_ERROR;

    }

    if((plain = fopen(plainFile,"wb")) == NULL){

        return PLAIN_FILE_OPEN_ERROR;

    }

   

    memcpy(keyBlock,keyStr,8);

   

    Char8ToBit64(keyBlock,bKey);

   

    DES_MakeSubKeys(bKey,subKeys);

   

    fseek(cipher,0,SEEK_END);   

    fileLen = ftell(cipher);   

    rewind(cipher);               

    while(1){

       

        fread(cipherBlock,sizeof(char),8,cipher);

        DES_DecryptBlock(cipherBlock,subKeys,plainBlock);                       

        times += 8;

        if(times < fileLen){

            fwrite(plainBlock,sizeof(char),8,plain);

        }

        else{

            break;

        }

    }

   

    if(plainBlock[7] < 8){

        for(count = 8 - plainBlock[7]; count < 7; count++){

            if(plainBlock[count] != '\0'){

                break;

            }

        }

    }   

    if(count == 7){

        fwrite(plainBlock,sizeof(char),8 - plainBlock[7],plain);

    }

    else{

        fwrite(plainBlock,sizeof(char),8,plain);

    }

    fclose(plain);

    fclose(cipher);

return OK;

}

int main()

{    DES_Encrypt("1.txt","key.txt","2.txt");
    system("pause");
    DES_Decrypt("2.txt","key.txt","3.txt");

    getchar();

    return 0;

}