密鑰短語加密解密c代碼

❶ 用C語言設計一個加密 解密 密碼 的程序。

// playFair 加密 你參考下 ...
#include"stdio.h"
#include"string.h"
#include"stdlib.h"
#define x 50
char MiYao[x],PassWord[x],AddPass[x],Table[5][5],Map[25];
bool Visit[27]={false};
char English[27]="abcdefghijklmnopqrstuvwxyz";
void Input()
{
printf("請輸入密鑰:\t"); scanf("%s",MiYao);
printf("請輸入待加密密碼:\t"); scanf("%s",PassWord);
}
void Fun_5x5()
{
int count = 0,V =0;
/*標記密鑰內字元為: true*/
for(int i=0;MiYao[i]!='\0';i++)
if(strchr(English,MiYao[i])!=NULL)
Visit[strchr(English,MiYao[i])-English] = true;
/*執行密鑰矩陣操作 並標記已使用字元:true*/
for(int i=0;i<5;i++)
for(int j=0;j<5;j++)
{
if(count<strlen(MiYao))
Table[i][j] = MiYao[count++];
else
{
while(Visit[V] != false) V++;
Table[i][j] = English[V];
Visit[V++] = true;
}
}
puts("∞∞∞密鑰矩陣為∞∞∞");
for(int i=0;i<5;i++)
{ for(int j=0;j<5;j++)
printf("%3c",Table[i][j]);
puts("");
}
puts("∞∞∞∞∞∞∞∞∞∞∞");

}
int IsVisited(char ch)
{
return Visit[strchr(English,ch)-English]; //false 未出現過
}
void TabletoMap()
{ int count=0;
for(int i=0;i<5;i++)
for(int j=0;j<5;j++)
Map[count++]=Table[i][j];
Map[count]='\0';
}
void Judge()
{
int len = strlen(PassWord),i,j,k;
memset(AddPass,0,sizeof(char));
/*一對對去字母,剩下單個字母,則不變化,直接放入加密串中.*/
if(len%2){
AddPass[len-1] = PassWord[len-1];
len -=1;
}
/*一對中 密鑰矩陣中 存在矩陣 eg.ab 先輸出a同行頂點在輸出b同行頂點*/
int row1,low1,row2,low2,a1,a2;
for(i=0;i<len;i+=2)
{
char c1,c2;
c1 = PassWord[i];
c2 = PassWord[i+1];
/*一對中 兩字母相同 無變化*/
/*一對中 有字母不在密鑰矩陣中 無變化*/
if(c1 == c2 || ( !IsVisited(c1)||!IsVisited(c2)))
{ AddPass[i] = c1;
AddPass[i+1]=c2;
}else{
a1 = strchr(Map,c1)-Map;
row1 = a1/5; low1 = a1%5;
a2 = strchr(Map,c2)-Map;
row2 = a2/5; low2 = a2%5;
/*一對中 字元出現在同行或同列 簡單swap字元*/
if(row1 == row2 || low1 == low2)
{
AddPass[i] = c2;
AddPass[i+1] = c1;
}else{
AddPass[i] = Table[row1][low2];
AddPass[i+1] = Table[row2][low1];
}
}
}AddPass[len+1]='\0';
puts("加密後字元串:");
puts(AddPass);
puts("原串是:");
puts(PassWord);
}
int main()
{
Input();
Fun_5x5();
TabletoMap();
Judge();
return 0;
}

❷ 多表式密碼對密文加密解密演算法的c語言代碼

#include<stdio.h>
#include<string.h>
void MtoC(char m[50],char k[10],char c[50])
{
int m1[50],k1[10],c1[50],i,j;
for(i=0;i<strlen(k);i++)
k1[i]=k[i]-'a';
for(j=0;j<strlen(m);j++)
{
m1[j]=m[j]-'a';
c1[j]=(m1[j]+k1[j%strlen(k)])%26;
c[j]=c1[j]+'a';
printf("%c------%c\n",m[j],c[j]);
}
}
void CtoM(char c[50],char k[10],char m[50])
{
int m1[50],k1[10],c1[50],i,j;
for(i=0;i<strlen(k);i++)
k1[i]=k[i]-'a';
for(j=0;j<strlen(m);j++)
{
c1[j]=c[j]-'a';
m1[j]=(c1[j]-k1[j%strlen(k)]+26)%26;
m[j]=m1[j]+'a';
printf("%c------%c\n",c[j],m[j]);
}
}
int main(void)
{
int i,j;
char m[50], k[10], c[50],t[50];
printf("輸入明文：");
gets(t);
j=0;
for(i=0;t[i]!='\0';i++){
if(t[i]<='Z'&&t[i]>='A'){
m[j]=t[i]+32;
j++;
}
else if(t[i]<='z'&&t[i]>='a'){
m[j]=t[i];
j++;
}
}
m[j]='\0';

printf("輸入密鑰：");
scanf("%s",k);
printf("明文轉換為密文：n");
MtoC(m,k,c);
printf("密文轉換為明文：n");
CtoM(c,k,m);
}

❸ 用C語言編程愷撒密碼加密解密程序

這個我之前寫過

未加密文字：。（屠夫、麵包師和蠟燭匠）。
關鍵密鑰：
加密文字：

#include<stdio.h>
#include<string.h>
voidmain()
{
	charstr[99],k[10],m[99]="";
	unsignedi,j=0,n;
	printf("輸入要加密的內容
");
	gets(str);
	printf("輸入密匙
");
	gets(k);
	n=strlen(k);
	for(i=0;i<strlen(str);i++)
	{
		if(str[i]=='')m[i]='';
		else
		{
			m[i]=str[i]+k[j]-'A';
			if(m[i]>'Z')m[i]=m[i]-26;
			j++;
		}
		if(j==n)j=0;
	}
	printf("加密後
");
	puts(m);
}

❹ c語言文件加密和解密

c語言文件加密和解密方法如下：

1、首先打開VC++6.0；

voidDecryptFile(FILE*sfp,FILE*dfp,charpwd)
{
charch;
while((ch=fgetc(sfp))!=EOF)
{
if((ch>='a')&&(ch<='z'))
{
ch=ch^pwd;
ch=(ch-'a'+25)%26+'a';
}
if((ch>='A')&&(ch<='Z'))
{
ch=ch^pwd;
ch=(ch-'A'+25)%26+'A';
}
fputc(ch,dfp);
}
}

輸出函數，輸出文件內容
voidOutputFile(FILE*fp)
{
charch;
while((ch=fgetc(fp))!=EOF)
putchar(ch);
}
主函數，主要調用這幾個函數
intmain()
{
/*用戶輸入的要加密的文件名*/
charsfilename[20];
/*用戶輸入加密後保存的文件名*/
chardfilename[20];
/*用來保存密碼字元*/
charpwd;
FILE*sfp,*dfp;

printf(": ");
/*得到要加密的文件名*/
gets(sfilename);
/*得到加密後你要的文件名*/
printf(": ");
gets(dfilename);
/*得到加密字元*/
printf("PleaseinputyourPassword: ");
//scanf("%c",&pwd);
pwd=getch();
/*屏幕以*來表示輸入的加密字元*/
printf("* ");
/*以只讀方式打開要加密的文件*/
if((sfp=fopen(sfilename,"r"))==0)
{
printf("Can'topenthefile:%s ",sfilename);
exit(0);
}
/*輸出要加密的文件*/
printf(": ");
OutputFile(sfp);
/*建立加密後的文件*/
if((dfp=fopen(dfilename,"w+"))==0)
{
printf("Can'topenorcreatethefile:%s ",dfilename);
//exit(0);
}
/*文件加密*/
fseek(sfp,0L,SEEK_SET);
EncryptFile(sfp,dfp,pwd);
printf(" Encryptedthefilesuccessfully! ");
/*輸出加密後的文件*/
printf(": ");
fseek(dfp,0L,SEEK_SET);
OutputFile(dfp);
fclose(sfp);
fclose(dfp);
getch();
return0;
}

❺ C語言編程： 文件移位加密與解密。

這樣就可以了
#include<stdio.h>
void code(char *p,int key)
{
while(*p!='\0')
{
*p=97+(*p-97+key)%26;
p++;
}
}
void uncode(char *p,int key)
{
while(*p!='\0')
{
*p=97+(*p-71-key)%26;
p++;
}
}
main()
{
char str[100];
int n,key;
printf("輸春襪入密匙：");
scanf("%d",&key);
printf("輸入1加密，輸入2解密:");
scanf("%d",&n);
printf("輸入字元串:");
scanf("櫻差%s",str);
if(n==1)
{
code(str,key);
printf("密文為%s\n",str);
}
else if(n==2)
{
uncode(str,key);
printf("扒頌激原文為%s\n",str);
}
}

❻ aes加密解密完整可編譯的C代碼~~~急求

#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);
/*位元組轉換成二進制*/
int ByteToBit(ElemType ch, ElemType bit[8]){
int cnt;
for(cnt = 0;cnt < 8; cnt++){
*(bit+cnt) = (ch>>cnt)&1;
}
return 0;
}
/*二進制轉換成位元組*/
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的字元串轉為二進制位串*/
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的字元串*/
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);
/*後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 Right[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(Right,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(Right);
/*將右半部分與子密鑰進行異或操作*/
DES_XOR(Right,subKeys[cnt],48);
/*異或結果進入S盒，輸出32位結果*/
DES_SBOX(Right);
/*P置換*/
DES_P_Transform(Right);
/*將明文左半部分與右半部分進行異或*/
DES_XOR(plainBits,Right,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 Right[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(Right,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(Right);
/*將右半部分與子密鑰進行異或操作*/
DES_XOR(Right,subKeys[cnt],48);
/*異或結果進入S盒，輸出32位結果*/
DES_SBOX(Right);
/*P置換*/
DES_P_Transform(Right);
/*將明文左半部分與右半部分進行異或*/
DES_XOR(cipherBits,Right,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個位元組，並返回成功讀取的位元組數*/
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);
/*最後一個字元保存包括最後一個字元在內的所填充的字元數量*/
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){
/*密文的位元組數一定是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 main()
{
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;
}