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file encryption and Decryption 8th December 2009, 7:04 pm
C0D3R
MITR Master
ေကာင္မေလးဆီ္စာပို႔မယ္ဆိုရင္ဒါေလးနဲ႔သာလုပ္ျပီးပို႔ ဟီး
အျခားလူေတြဖတ္လို႔မရေတာ႔ဘူး
ဒါကေတာ႔ Exe ဖိုင္ေလးပါ
မူရင္း source code
အျခားလူေတြဖတ္လို႔မရေတာ႔ဘူး
ဒါကေတာ႔ Exe ဖိုင္ေလးပါ
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မူရင္း source code
- Spoiler:
- #include <iostream.h> // We need this for input and output to the user
#include <fstream.h> // This is the header to read or write files
#include <stdio.h> // We only need this to delete a file using remove()
// As mentioned abode, we simply add 25 to a byte, change this to whatever you like.
#define ENCRYPTION_FORMULA (int) Byte + 25
// The decryption formula is the opposite to encryption formula, every "+" is a "-"
#define DECRYPTION_FORMULA (int) Byte - 25
///////////////////////////////////////////////////////////////////////////////////////////
// TIP: Everytime you see ENCRYPTION_FORMULA ot DECRYPTION_FORMULA mensioned, highlight it
// then press on definition and it will bring you up here! (Only on Visual C++)
///////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////
// Our main function, put this in your program, FILENAME is the file to encrypt
// and NEW_FILENAME is the new location of the encrypted file
/////////////////////////////////////////////////////////////////////////////////
int Encrypt (char * FILENAME, char * NEW_FILENAME)
{
ifstream inFile; // This is the file that we're going to encrypt and read
ofstream outFile; // Once we encrypt the file, this is it's new location
char Byte; // This is the FILENAME's byte, we'll add 25 to this later
///////////////////////////////////////////////////////////////
// Before we continue:
// ios:: in - Used for reading a file
// ios::out - Used for writing a file
// ios::binary - Used for reading or writing binary files
///////////////////////////////////////////////////////////////
inFile.open(FILENAME, ios::in | ios::binary); // We read this file in binary mode
outFile.open(NEW_FILENAME, ios::out | ios::binary); // And we write the file in binary mode
// eof() stands for End Of File, so while we are still reading the file, continue
while(!inFile.eof())
{
// Remember we need to change a byte so we add 25 to it
char NewByte;
//////////////////////////////////////////////////
// NOTE: Only use the .put() and .get() in loops
// because it only reads 1 Byte at a time!
//////////////////////////////////////////////////
// Out old byte is recieved from the file
Byte = inFile.get();
// If the file that we are reading has an error, turn 0
if (inFile.fail())
return 0;
//Remember our Encryption Formula above?
//Our new byte is recieved from it, see above
NewByte = ENCRYPTION_FORMULA;
// This simple puts the new byte, into the new file!
outFile.put(NewByte);
}
// We have to be neat so we close both the file that we're reading
// and the file that we're writing
inFile.close(); // (File to read)
outFile.close(); // (File to write)
return 1; // Success!
}
///////////////////////////////////////////////////////////////////////////////
// What's the point of encrypting a file if you can't decrypt it?
// If you're wondering why this is not commented it's because I've already
// explained everything above, notice that everything is the same except for
// two lines!
///////////////////////////////////////////////////////////////////////////////
int Decrypt (char * FILENAME, char * NEW_FILENAME)
{
ifstream inFile;
ofstream outFile;
char Byte;
inFile.open(FILENAME, ios::in | ios::binary);
outFile.open(NEW_FILENAME, ios::out | ios::binary);
while(!inFile.eof())
{
char NewByte;
Byte = inFile.get();
if (inFile.fail())
return 0;
/////////////////////////////////////////////////////
NewByte = DECRYPTION_FORMULA; // New Line! We just change the ENCRYPTION_FORMULA
// to DECRYPTION_FORMULA, see above
/////////////////////////////////////////////////////
outFile.put(NewByte);
}
inFile.close();
outFile.close();
return 1;
}
///////////////////////////////////////////////////////////////////////
// WARNING: If you choose to decrypt a file that it already decrypted
// then the file would be encrypted!
///////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////
// To use the functions in your program (doesn't have to be a DOS program),
// copy the 2 functions above, this is just an example, in the example I'm
// encrypting
///////////////////////////////////////////////////////////////////////////////////
int main()
{
///////////////////////////////////////////////////////////////////
// The functions can be used in not only DOS programs
// Since this is an example, I'll show you how to use them
///////////////////////////////////////////////////////////////////
char EncFile[200]; // This is the string for the file to be encrypted
char NewEncFile[200]; // This is the new location of the encrypted file
char DecFile[200]; // This is the string for the file to be decrypted
char NewDecFile[200]; // This is the new location of the decrypted file
int Choice; //The user's choice variable (1 = Encrypt 2 = Decrypt)
// In case you didn't know, all these "cout" just display a message
// Cin tells the user to input something
cout << "NOTE: You must encrypt the file with the same file extension!"<<endl;
cout << "Enter 1 to Encrypt / 2 to Decrypt"<<endl;
cin >> Choice; // In this case, our input is the user's choice
switch(Choice)
{
case 1: // Did the user choose to encrypt a file?
cout << "Enter the current Filename: ";
cin >> EncFile; // The user's input for the current file to be encrypted
cout << "Enter the new Filename: ";
cin >> NewEncFile; //The user's input for the new location of the encrypted file
Encrypt(EncFile, NewEncFile); /*********** ENCRYPT FUNCTION ************/
break;
case 2: // Or did the user choose to decrypt a file?
cout << "Enter the current Filename: ";
cin >> DecFile; //Already explained but with the decrypted file this time!
cout << "Enter the new Filename: ";
cin >> NewDecFile;
Decrypt(DecFile, NewDecFile); /*********** DECRYPT FUNCTION ************/
break;
}
return 0; //Exit!
}
