Code:
// -------------------------------------------------------------
// Chuong trinh ma hoa - giai ma file
//
// - Ma hoa tu cac file .txt
// - Chuyen thanh cac file .dat
// - Co the nhap noi dung can ma hoa tu ban phim
// - Phan nhap noi dung chua hoan chinh, chi gom cac thao tac sau:
// - Cac phim thong thuong
// - Phim Enter de xuong hang
// - Phim Backspace de xoa ky tu nhap sai
// - Khong su dung duoc cac phim mui ten ( se bo sung )
// - Thoat khoi che do nhap bang cach nhan phim Esc
//
// * Nhap ten file: khong nhap phan mo rong, chi nhap ten file.
// VD: file test.txt thi nhap: test
// * Mat khau co the la so hoac chu
// * File mahoa.dat dinh kem co mat khau: 123456
// -------------------------------------------------------------
#include <iostream.h>
#include <string.h>
#include <fstream.h>
#include <stdlib.h>
#include <conio.h>
#include <stdio.h>
#include <windows.h>
const char duoi[5] = ".txt";
const char duoiSave[5]= ".dat";
/************************************************************************/
/* Nguyen mau ham */
/************************************************************************/
void mahoa(char*tenfile);
void giaima(char*tenfile);
void mahoavb();
char fm(char); //Ham ma hoa
char fg(char); //Ham giai ma
int mod(int a,int b); //Dinh nghia lai phep chia lay du
char* nhapkey(); //Dung de nhap mat khau
void add(char* x,char y); //Them 1 ky tu vao chuoi
void move(char* x); //Xoa ky tu cuoi ra khoi chuoi
char* NhapMatKhau();
// 3 ham di copy duoc !
void gotoxy(int x, int y);
int wherex();
int wherey();
/************************************************************************/
/* */
/************************************************************************/
void main()
{
int chon;
do
{
system("cls");
cout<<"\tCHUONG TRINH MA HOA VA GIAI MA FILE"<<endl;
cout<<"\t\tChuc nang:\n";
cout<<"\t\t1. Ma hoa file.\n";
cout<<"\t\t2. Giai ma file.\n";
cout<<"\t\t3. Nhap van ban can ma hoa.\n";
cout<<"\t\t4. Thoat.\n";
cout<<"\t\tLua chon?: ";
cin>>chon;
cin.ignore();
if(chon ==1)
{
char tenfile[30];
cout<<"Nhap ten file can ma hoa: ";
cin.getline(tenfile,30);
strcat(tenfile,duoi);
cout<<endl;
mahoa(tenfile);
cout.flush();
getch();
}
else if(chon ==2)
{
char tenfile[30];
cout<<"Nhap ten file can giai ma : ";
cin.getline(tenfile,30);
strcat(tenfile,duoiSave);
giaima(tenfile);
cout.flush();
getch();
}
else if (chon ==3)
{
mahoavb();
cout.flush();
getch();
}
cout.flush();
} while(chon !=4);
}
/************************************************************************/
/* Dinh nghia cac ham */
/************************************************************************/
void mahoa(char*tenfile)
{
ifstream fin(tenfile,ios::nocreate);
if(fin.is_open())
{
cout<<"Noi dung cua file can ma hoa: "<<endl;
cout<<"---------------------------"<<endl;
char ch;
fin.get(ch);
while(!fin.eof())
{
cout<<ch;
fin.get(ch);
}
cout<<endl<<"---------------------------"<<endl;
fin.close();
char* key;
key=NhapMatKhau();
char tenfilemh[30];
cout<<"\nLuu file ma hoa voi ten: ";
cin.getline(tenfilemh,30);
strcat(tenfilemh,duoiSave);
fin.open(tenfile,ios::nocreate);
ofstream fout(tenfilemh,ios::noreplace);
if(!fout)
{
cout<<"File \""<<tenfilemh<<"\" da ton tai."<<endl;
}
else
{
int i=0;
while(key[i]!=0)
{
fout<<fm(key[i]);
i++;
}
fout<<endl;
char ch;
fin.get(ch);
char h;
h=fm(ch);
while(!fin.eof())
{
fout.put(h);
fin.get(ch);
h=fm(ch);
}
fin.close();
fout.close();
cout<<"Ghi file thanh cong!"<<endl;
cout<<"Co muon xoa file nguon khong? [C/K]: ";
cout.flush();
char del=getch();
if(del=='c' || del=='C')
remove(tenfile);
}
}
else
cout<<"Khong doc duoc file "<<tenfile;
}
void giaima(char*tenfile)
{
ifstream fin(tenfile,ios::nocreate);
if(fin.is_open())
{
char* key1;
key1=new char[20];
key1[0]='\0';
char*key;
key=new char[20];
char ch;
while (fin.get(ch))
{
if(ch=='\n')
break;
add(key1,fg(ch));
}
do
{
cout<<"Nhap mat khau: ";
key=nhapkey();
if(strcmp(key,key1)!=0)
cout<<"SAI MAT KHAU! HAY THU LAI."<<endl;
} while(strcmp(key,key1)!=0);
cout<<"Noi dung giai ma duoc : "<<endl;
cout<<"---------------------------"<<endl;
fin.get(ch);
while (!fin.eof())
{
cout<<fg(ch);
fin.get(ch);
}
cout<<endl<<"---------------------------"<<endl;
fin.close();
char tenFileSave[30];
cout<<"Luu file giai ma voi ten: ";
cin.getline(tenFileSave,30);
strcat(tenFileSave,duoi);
ofstream fout(tenFileSave,ios::noreplace);
if(!fout)
{
cout<<"File \""<<tenFileSave<<"\" da ton tai."<<endl;
}
else
{
fin.open(tenfile,ios::nocreate);
fin.ignore(20,'\n');
fin.get(ch);
char h;
h=fg(ch);
while(!fin.eof())
{
fout.put(h);
fin.get(ch);
h=fg(ch);
}
fin.close();
fout.close();
cout<<"Ghi file thanh cong!"<<endl;
}
}
else
cout<<"Khong doc duoc file "<<tenfile;
}
void mahoavb()
{
char text[1000];
text[0]='\0';
char ch;
// Cho phep xoa ky tu da nhap
int dongdautien;
int vitrixuonghang[200];
int dong=0;
cout<<"Nhap van ban can ma hoa, nhan phim Esc de ket thuc: "<<endl;
cout<<"---------------------------";
cout.flush();
gotoxy(5,wherey()+1);
dongdautien=wherey();
do
{
cout.flush();
ch=getch();
int dau=wherey();
if(int(ch) == 27)
{
add(text,'\0');
break;
}
else if(ch ==13)
{
add(text,'\n');
vitrixuonghang[dong]=wherex();
dong++;
gotoxy(5,wherey()+1);
}
else if(int(ch) ==8)
{
if(wherey()!=dongdautien || wherex() !=5)
{
if(wherex()==5)
{
dong--;
gotoxy(vitrixuonghang[dong],wherey()-1);
}
cout<<"\b";
cout<<" ";
cout<<"\b";
move(text);
}
}
else if(ch !=72 &&ch !=75 && ch !=77 && ch != 80 && ch !=-32)
{
add(text,ch);
cout<<ch;
if(wherex()==75)
{
vitrixuonghang[dong]=75;
dong++;
gotoxy(5,wherey()+1);
}
}
} while(1);
cout<<endl<<"---------------------------"<<endl;
char tenFileSave[30];
cout<<"Nhap ten file de luu lai: ";
cin.getline(tenFileSave,30);
strcat(tenFileSave,duoiSave);
ofstream fout(tenFileSave,ios::noreplace);
if (!fout)
{
cout<<"File "<<tenFileSave<<" da ton tai."<<endl;
}
else
{
char* key;
key=NhapMatKhau();
int i=0;
while(key[i]!=0)
{
fout<<fm(key[i]);
i++;
}
fout<<endl;
i=0;
while (text[i]!=0)
{
fout<<fm(text[i]);
i++;
}
fout.close();
cout<<"Ghi file thanh cong!";
}
}
char fm(char a)//ma hoa
{
int y=mod((int(a)*9+17),128);
return char(y);
}
char fg(char a)//giai ma
{
int y=mod((int(a)-17)*57,128);
return char(y);
}
int mod(int a,int b)//Dinh nghia phep chia lay phan du
{
if(a>=0)
return a%b;
else
{
int x=a/b-1;
return a-(b*x);
}
}
char* nhapkey()
{
cout.flush();
char ch;
char* key;
key=new char[20];
key[0]='\0';
int dau=wherex();
do
{
ch=getch();
if(ch == 13)
break;
else if(ch ==8)
{
if(wherex()>dau)
{
cout<<"\b";
cout<<" ";
cout<<"\b";
cout.flush();
move(key);
//Hoac dung cach nay:
//gotoxy(wherex()-1,wherey());
//cout<<" ";
//cout.flush();
//gotoxy(wherex()-1,wherey());
}
else;
}
else
{
add(key,ch);
cout<<"*";
cout.flush();
}
} while(ch !=13);
cout<<endl;
return key;
}
char* NhapMatKhau()
{
char* key;
char* key1;
do
{
cout<<"Nhap mat khau dai toi da 20 ky tu: ";
key=nhapkey();
cout<<"Nhap lai mat khau: ";
key1=nhapkey();
if (strcmp(key,key1) != 0)
cout<<"MAT KHAU KHONG CHINH XAC! HAY NHAP LAI.\n"<<endl;
} while(strcmp(key,key1) != 0);
return key;
}
void add(char* x,char y)
{
int i=strlen(x);
x[i]=y;
x[i+1]='\0';
}
void move(char* x)
{
int i=strlen(x);
if(x[i-1]=='\n') //Loai bo ky tu xuong hang,
i--;
x[i-1]='\0';
}
void gotoxy(int x, int y)
{
HANDLE hCon = GetStdHandle(STD_OUTPUT_HANDLE);
COORD pos;
pos.X=x;
pos.Y=y;
SetConsoleCursorPosition(hCon, pos);
}
/* Chu y: phai flush ra truoc khi lay toa do
/*-------------------------wherex()------------------------------------*/
int wherex()
{
CONSOLE_SCREEN_BUFFER_INFO csbi;
HANDLE hCon = GetStdHandle(STD_OUTPUT_HANDLE);
GetConsoleScreenBufferInfo(hCon, &csbi);
return csbi.dwCursorPosition.X;
}
/*-------------------------wherey()----------------------------------*/
int wherey()
{
CONSOLE_SCREEN_BUFFER_INFO csbi;
HANDLE hCon = GetStdHandle(STD_OUTPUT_HANDLE);
GetConsoleScreenBufferInfo(hCon, &csbi);
return csbi.dwCursorPosition.Y;
}
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