C++ program to encrypt and decrypt text file by giving a pin or number password.

FileEncryptDecrypt.cpp

#include<iostream>
#include<conio.h>
#include<string>
#include<string.h>
#include<fstream>
#include<cstdlib>

using namespace std;

class passkey
{
private:
    int password, key, k;
public:
    passkey();
    void getkey();
    int checkkey(int );
    friend void encrypt(passkey);
    friend void decrypt(passkey);
}file1;

passkey::passkey()
{
    password = 88;
}

void passkey::getkey()
{
    cout << "Enter the key: ";
    cin >> key;
}

int passkey::checkkey(int a)
{
    if(a==key)
        return 1;
    else
        return 0;
}

char filenaam[40];

int main()
{
     int a, pw, x, k;
     string c;

         cout << "Enter the correct password: ";
     cin>>pw;
        if(pw!=88)
        {
            cout << "Sorry you entered the wrong password" << endl;
            getch();
            return 0;
        }

     cout << "For ENCRYPTION enter 1\nFor DECRYPTION enter 2\nTo terminate the program enter 3" << endl;
     cin>> a;
     if(a==1)
     {
         file1.getkey();

         cout << "Give your file a name\neg: \"Input_Data\"" << endl;
         cin >> filenaam;

         strcat(filenaam,".txt");

        cout << "Enter data to the file" << endl;

        ofstream InputData(filenaam);

        while(cin >> c)
        {
            InputData << c << " ";
        }

        InputData.close();

        encrypt(file1);

        getch();

        return 0;

     }
     else if(a==2)
     {
         file1.getkey();

         cout << "Enter name of your file\neg: Input_Data.txt" << endl;
         cin >> filenaam;

         strcat(filenaam,".txt");

        decrypt(file1);

        getch();

        return 0;

     }

     else if (a==3)
     {
         return 0;
     }
}

void encrypt(passkey file)
{
    char encfilenaam[50] = "Encrypted_";
    strcat(encfilenaam,filenaam);

    int n;

    srand(file.key);

    ifstream OutputData(filenaam);

    char ch[50] = "";

    ofstream InputData(encfilenaam);

    OutputData.getline(ch,49);
    do
    {
        n= 1 + rand()%9;
        for(int i=0; i<strlen(ch); i++)
        {
            ch[i] = ch[i] + n;
        }
        InputData << ch;
    }
    while(OutputData.getline(ch,49));

    OutputData.close();
    InputData.close();

    cout << "File is successfully encrypted"  << endl;
    cout << "Encrypted data is stored in file with name: " << encfilenaam << endl;
}

void decrypt(passkey file)
{
    char decfilenaam[50] = "Decrypted_";
    strcat(decfilenaam,filenaam);

    int m;

    srand(file.key);

    ifstream OutputData(filenaam);

    char ch[50] = "";

    ofstream InputData(decfilenaam);

    OutputData.getline(ch,49);
    do
    {
        m= 1 + rand()%9;
        for(int i=0; i<strlen(ch); i++)
        {
            ch[i] = ch[i] - m;
        }
        InputData << ch;
    }
    while(OutputData.getline(ch,49));

    OutputData.close();
    InputData.close();

    cout << "File successfully decrypted" << endl;
    cout << "Decrypted text is stored in " << decfilenaam << endl;
}

In the int main function of your code, when you choose encrypt option, there's a while loop to take input in a file after giving a filename. How to stop taking the input while running the code??

@dishvyas sorry for replying late. I don't remember exactly, but I used to use Windows at that time, when I wrote this code. Now tried in linux and seems pressing ctrl+d should exit the while loop.

Also, I used codeblocks to code this but only now I got to know that not all compilers will run this code. For sure #include<conio.h> will not work and should be removed.

Hi dishvyas can you please help me on text reverse and replace space by * and encryp and decrypt the file

hello can you get me how to stop the while loop. I am using it on windows
This is a very good code .

@astroboy619 try ctrl+z or ctrl+d. Don't have a windows machine so can't try it