// DES.cpp : 定義控制臺應用程序的入口點。
//

#include "stdafx.h"
#include "stdio.h"
#include "memory.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;

//初始置換表IP
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
};
//逆初始置換表IP^-1
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
};

//擴充置換表E
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
};

//置換函數P
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
};

//S盒
int S[8][4][16] =//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}}};
//置換選擇1
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
};

//置換選擇2
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
};

//對左移次數的規定
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);

//字節轉換成二進制
int ByteToBit(ElemType ch, ElemType bit[8]){
?? ?int cnt;
?? ?for(cnt = 0;cnt < 8; cnt++){
?? ??? ?*(bit+cnt) = (ch>>cnt)&1;
?? ?}
?? ?return 0;
}

//二進制轉換成字節
int BitToByte(ElemType bit[8],ElemType *ch){
?? ?int cnt;
?? ?for(cnt = 0;cnt < 8; cnt++){
?? ??? ?*ch |= *(bit + cnt)<<cnt;
?? ?}
?? ?return 0;
}

//將長度為8的字符串轉為二進制位串
int Char8ToBit64(ElemType ch[8],ElemType bit[64]){
?? ?int cnt;
?? ?for(cnt = 0; cnt < 8; cnt++){?? ??? ?
?? ??? ?ByteToBit(*(ch+cnt),bit+(cnt<<3));
?? ?}
?? ?return 0;
}

//將二進制位串轉為長度為8的字符串
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;
}

//生成子密鑰
int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]){
?? ?ElemType temp[56];
?? ?int cnt;
?? ?DES_PC1_Transform(key,temp);//PC1置換
?? ?for(cnt = 0; cnt < 16; cnt++){//16輪跌代，產生16個子密鑰
?? ??? ?DES_ROL(temp,MOVE_TIMES[cnt]);//循環左移
?? ??? ?DES_PC2_Transform(temp,subKeys[cnt]);//PC2置換，產生子密鑰
?? ?}
?? ?return 0;
}

//密鑰置換1
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;
}

//密鑰置換2
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;
}

//循環左移
int DES_ROL(ElemType data[56], int time){?? ?
?? ?ElemType temp[56];

?? ?//保存將要循環移動到右邊的位
?? ?memcpy(temp,data,time);
?? ?memcpy(temp+time,data+28,time);

?? ?//前28位移動
?? ?memcpy(data,data+time,28-time);
?? ?memcpy(data+28-time,temp,time);

?? ?//后28位移動
?? ?memcpy(data+28,data+28+time,28-time);
?? ?memcpy(data+56-time,temp+time,time);?? ?

?? ?return 0;
}

//IP置換
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;
}

//IP逆置換
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;
}

//擴展置換
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;
}

//P置換
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;
}

//異或
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;
}

//S盒置換
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;

?? ??? ?//計算在S盒中的行與列
?? ??? ?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];

?? ??? ?//化為2進制
?? ??? ?data[cur2] = (output&0X08)>>3;
?? ??? ?data[cur2+1] = (output&0X04)>>2;
?? ??? ?data[cur2+2] = (output&0X02)>>1;
?? ??? ?data[cur2+3] = output&0x01;
?? ?}?? ?
?? ?return 0;
}

//交換
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;
}

//加密單個分組
int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]){
?? ?ElemType plainBits[64];
?? ?ElemType copyRight[48];
?? ?int cnt;

?? ?Char8ToBit64(plainBlock,plainBits);?? ??? ?
?? ?//初始置換（IP置換）
?? ?DES_IP_Transform(plainBits);

?? ?//16輪迭代
?? ?for(cnt = 0; cnt < 16; cnt++){?? ??? ?
?? ??? ?memcpy(copyRight,plainBits+32,32);
?? ??? ?//將右半部分進行擴展置換，從32位擴展到48位
?? ??? ?DES_E_Transform(copyRight);
?? ??? ?//將右半部分與子密鑰進行異或操作
?? ??? ?DES_XOR(copyRight,subKeys[cnt],48);?? ?
?? ??? ?//異或結果進入S盒，輸出32位結果
?? ??? ?DES_SBOX(copyRight);
?? ??? ?//P置換
?? ??? ?DES_P_Transform(copyRight);
?? ??? ?//將明文左半部分與右半部分進行異或
?? ??? ?DES_XOR(plainBits,copyRight,32);
?? ??? ?if(cnt != 15){
?? ??? ??? ?//最終完成左右部的交換
?? ??? ??? ?DES_Swap(plainBits,plainBits+32);
?? ??? ?}
?? ?}
?? ?//逆初始置換（IP^1置換）
?? ?DES_IP_1_Transform(plainBits);
?? ?Bit64ToChar8(plainBits,cipherBlock);
?? ?return 0;
}

//解密單個分組
int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48],ElemType plainBlock[8]){
?? ?ElemType cipherBits[64];
?? ?ElemType copyRight[48];
?? ?int cnt;

?? ?Char8ToBit64(cipherBlock,cipherBits);?? ??? ?
?? ?//初始置換（IP置換）
?? ?DES_IP_Transform(cipherBits);

?? ?//16輪迭代
?? ?for(cnt = 15; cnt >= 0; cnt--){?? ??? ?
?? ??? ?memcpy(copyRight,cipherBits+32,32);
?? ??? ?//將右半部分進行擴展置換，從32位擴展到48位
?? ??? ?DES_E_Transform(copyRight);
?? ??? ?//將右半部分與子密鑰進行異或操作
?? ??? ?DES_XOR(copyRight,subKeys[cnt],48);?? ??? ?
?? ??? ?//異或結果進入S盒，輸出32位結果
?? ??? ?DES_SBOX(copyRight);
?? ??? ?//P置換
?? ??? ?DES_P_Transform(copyRight);?? ??? ?
?? ??? ?//將明文左半部分與右半部分進行異或
?? ??? ?DES_XOR(cipherBits,copyRight,32);
?? ??? ?if(cnt != 0){
?? ??? ??? ?//最終完成左右部的交換
?? ??? ??? ?DES_Swap(cipherBits,cipherBits+32);
?? ??? ?}
?? ?}
?? ?//逆初始置換（IP^1置換）
?? ?DES_IP_1_Transform(cipherBits);
?? ?Bit64ToChar8(cipherBits,plainBlock);
?? ?return 0;
}

//加密文件
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;
?? ?}
?? ?//設置密鑰
?? ?memcpy(keyBlock,keyStr,8);
?? ?//將密鑰轉換為二進制流
?? ?Char8ToBit64(keyBlock,bKey);
?? ?//生成子密鑰
?? ?DES_MakeSubKeys(bKey,subKeys);

?? ?while(!feof(plain)){
?? ??? ?//每次讀8個字節，并返回成功讀取的字節數
?? ??? ?if((count = fread(plainBlock,sizeof(char),8,plain)) == 8){
?? ??? ??? ?DES_EncryptBlock(plainBlock,subKeys,cipherBlock);
?? ??? ??? ?fwrite(cipherBlock,sizeof(char),8,cipher);?? ?
?? ??? ?}
?? ?}
?? ?if(count){
?? ??? ?//填充
?? ??? ?memset(plainBlock + count,'\0',7 - count);
?? ??? ?//最后一個字符保存包括最后一個字符在內的所填充的字符數量
?? ??? ?plainBlock[7] = 8 - count;
?? ??? ?DES_EncryptBlock(plainBlock,subKeys,cipherBlock);
?? ??? ?fwrite(cipherBlock,sizeof(char),8,cipher);
?? ?}
?? ?fclose(plain);
?? ?fclose(cipher);
?? ?return OK;
}

//解密文件
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;
?? ?}

?? ?//設置密鑰
?? ?memcpy(keyBlock,keyStr,8);
?? ?//將密鑰轉換為二進制流
?? ?Char8ToBit64(keyBlock,bKey);
?? ?//生成子密鑰
?? ?DES_MakeSubKeys(bKey,subKeys);

?? ?//取文件長度?? ?
?? ?fseek(cipher,0,SEEK_END);?? ?//將文件指針置尾
?? ?fileLen = ftell(cipher);?? ?//取文件指針當前位置
?? ?rewind(cipher);?? ??? ??? ??? ?//將文件指針重指向文件頭
?? ?while(1){
?? ??? ?//密文的字節數一定是8的整數倍
?? ??? ?fread(cipherBlock,sizeof(char),8,cipher);
?? ??? ?DES_DecryptBlock(cipherBlock,subKeys,plainBlock);?? ??? ??? ??? ??? ??? ?
?? ??? ?times += 8;
?? ??? ?if(times < fileLen){
?? ??? ??? ?fwrite(plainBlock,sizeof(char),8,plain);
?? ??? ?}
?? ??? ?else{
?? ??? ??? ?break;
?? ??? ?}
?? ?}
?? ?//判斷末尾是否被填充
?? ?if(plainBlock[7] < 8){
?? ??? ?for(count = 8 - plainBlock[7]; count < 7; count++){
?? ??? ??? ?if(plainBlock[count] != '\0'){
?? ??? ??? ??? ?break;
?? ??? ??? ?}
?? ??? ?}
?? ?}?? ?
?? ?if(count == 7){//有填充
?? ??? ?fwrite(plainBlock,sizeof(char),8 - plainBlock[7],plain);
?? ?}
?? ?else{//無填充
?? ??? ?fwrite(plainBlock,sizeof(char),8,plain);
?? ?}

?? ?fclose(plain);
?? ?fclose(cipher);
?? ?return OK;
}

int _tmain(int argc, _TCHAR* argv[])
{
?? ?clock_t a,b; ?
?? ?a = clock(); ?
?? ?DES_Encrypt("1.txt","key.txt","2.txt"); ?
?? ?b = clock(); ?
?? ?printf("加密消耗%d毫秒\n",b-a); ?

?? ?system("pause"); ?
?? ?a = clock(); ?
?? ?DES_Decrypt("2.txt","key.txt","3.txt"); ?
?? ?b = clock(); ?
?? ?printf("解密消耗%d毫秒\n",b-a); ?
?? ?getchar(); ?
?? ?return 0; ?
}

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