Hides a text file within a BMP image

Steganography.cpp

/*
 * Author: Zac Blazic (210208880) 
 * Date: 24/03/2011
 * File: Steganography.cpp
 */

#include "Steganography.h"
#include <fstream>		
#include <string>			
#include <iostream>

using namespace std;

int GetFileSize(string fileName)
{
	long begin, end;

	ifstream inFile(fileName, ifstream::binary);	

	inFile.seekg(0, ios::beg);
	begin = long(inFile.tellg());

	inFile.seekg(0, ios::end);
	end = long(inFile.tellg());

	inFile.close();								   

	return end - begin;
}

int GetFileRemainderSize(string inputImageFileName, string inputTextFileName, const int HEADER_SIZE, const int PIXEL_SIZE)
{
	long begin, end;

	ifstream inputImageFile(inputImageFileName, ifstream::binary);
	ifstream inputTextFile(inputTextFileName, ifstream::binary);

	begin = (HEADER_SIZE + 1) + (GetFileSize(inputTextFileName) * PIXEL_SIZE);
	inputImageFile.seekg(0, ios::end);
	end = long(inputImageFile.tellg());

	inputImageFile.close();
	inputTextFile.close();
	
	return end - begin;
}

char* ReadTextFile(string fileName)
{
	char *buffer;
	int fileSize;
	ifstream inFile;

	fileSize = GetFileSize(fileName);
	buffer = new char[fileSize + 1];              //+1 is for null character

	inFile.open(fileName, ifstream::binary);
	inFile.seekg(0, ifstream::beg);               //Safeguard
	
	inFile.read(buffer, fileSize);                //Read entire text file into memory
	buffer[fileSize] = '\0';                      //Append null character to the end

	inFile.close();

	return buffer;
}

void WriteHeader(string inputImageFileName, string outputImageFileName, const int HEADER_SIZE)
{
    char *header;

	header = new char[HEADER_SIZE];

	ifstream inputImageFile(inputImageFileName, ifstream::binary);
	ofstream outputImageFile(outputImageFileName, ofstream::binary);

	//inputImageFile.seekg(0, ifstream::beg);         //Safeguard
	//outputImageFile.seekp(0, ofstream::beg);        //Safeguard

	inputImageFile.read(header, HEADER_SIZE);        //Read header from input image file
	outputImageFile.write(header, HEADER_SIZE);      //Write header to output image file

	inputImageFile.close();
	outputImageFile.close();

	delete [] header;
}

void WriteHiddenMessage(string inputImageFileName, string inputTextFileName, string outputImageFileName, char *textFileBuffer, const int HEADER_SIZE, const int PIXEL_SIZE)
{
	char *pixelBuffer;   //Pixel in memory
	
	pixelBuffer = new char[PIXEL_SIZE];

	ifstream inputImageFile(inputImageFileName, ifstream::binary);
	ofstream outputImageFile(outputImageFileName, ofstream::binary | ofstream::app);

	inputImageFile.seekg(HEADER_SIZE, ios::beg);   //check this  //Move the get pointer 54 bytes into the file
	outputImageFile.seekp(HEADER_SIZE, ios::beg);  //check this  //Move the put pointer 54 bytes into the file

	for(int index = 0; index < GetFileSize(inputTextFileName); index++)    //One iteration for each byte of the text file
	{
		inputImageFile.read(pixelBuffer, PIXEL_SIZE);               //Read in a pixel from input image
		pixelBuffer[3] = pixelBuffer[3] & char(0);                  //Bitwise AND 4th byte of the pixel with 00000000 (ASCII 0)
		pixelBuffer[3] = pixelBuffer[3] | textFileBuffer[index];    //Bitwise OR 4th byte of the pixel with text file character
		outputImageFile.write(pixelBuffer, PIXEL_SIZE);             //Write out a pixel to output image
	}

	inputImageFile.read(pixelBuffer, PIXEL_SIZE); 
	pixelBuffer[3] = pixelBuffer[3] & char(0);                  
	pixelBuffer[3] = pixelBuffer[3] | char(255);       //Add 11111111 to signal end of hidden text
	outputImageFile.write(pixelBuffer, PIXEL_SIZE);

	inputImageFile.close();
	outputImageFile.close();

	delete [] pixelBuffer;
}

void WriteRemainder(string inputImageFileName, string inputTextFileName, string outputImageFileName, const int HEADER_SIZE, const int PIXEL_SIZE)
{
	char *remainder;
	int fileSize;

	ifstream inputImageFile;
	ifstream inputTextFile;
	ofstream outputImageFile;

	fileSize = GetFileRemainderSize(inputImageFileName, inputTextFileName, HEADER_SIZE, PIXEL_SIZE);
	remainder = new char[fileSize];

	inputImageFile.open(inputImageFileName, ifstream::binary);
	inputTextFile.open(inputTextFileName, ifstream::binary);
	outputImageFile.open(outputImageFileName, ofstream::binary | ofstream::app);
	
	inputImageFile.seekg(HEADER_SIZE + (GetFileSize(inputTextFileName) * PIXEL_SIZE)); //check head size
	outputImageFile.seekp(HEADER_SIZE + (GetFileSize(inputTextFileName) * PIXEL_SIZE)); //check head size

	inputImageFile.read(remainder, fileSize);
	outputImageFile.write(remainder, fileSize);

	inputImageFile.close();
	inputTextFile.close();
	outputImageFile.close();

	delete [] remainder;
}

void HideTextFile(string inputImageFileName, string inputTextFileName, string outputImageFileName)
{
	const int HEADER_SIZE = 60;
	const int PIXEL_SIZE = 4;
	char *textFileBuffer;

	textFileBuffer = ReadTextFile(inputTextFileName);
	WriteHeader(inputImageFileName, outputImageFileName, HEADER_SIZE);
	WriteHiddenMessage(inputImageFileName, inputTextFileName, outputImageFileName, textFileBuffer, HEADER_SIZE, PIXEL_SIZE);
	WriteRemainder(inputImageFileName, inputTextFileName, outputImageFileName, HEADER_SIZE, PIXEL_SIZE);
	
	delete [] textFileBuffer;
}