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Algorithm.cpp
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Algorithm.cpp
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#include <iostream>
#include "Algorithm.h"
using namespace std;
int PlayWithWaveBuffer(vector<char>& buffer, string& msg, string& inputExt)
{
char* modulusBytes = new char[4] {0}; // Max number of modulus in bytes
char* customHeader = new char[MY_HEADER] {0}; // Custom header
string fileExtension = "";
string end = "@<;;";
msg += end;
// How many times the buffer is bigger than the message
long modulus = ((buffer.size() - WAV_HEADER - START_SPACE) / (msg.size() + MY_HEADER));
cout << "Spreading level: " << modulus << endl;
// Verify if it is safe to hide the message. Must me at must half the size of the space avaible
if(modulus <= 3)
{
cout << "The message might be to big for the audio file" << endl;
return ERROR;
}
CreateHeader(modulus, modulusBytes, customHeader, fileExtension, false);
int n = 0;
int pos = 0;
// Write my custom header first (Spread)
for (vector<char>::iterator it = buffer.begin() + WAV_HEADER + START_SPACE;
it != buffer.end(); ++it)
{
if (n % MY_HEADER_MODULE == 0)
{
*it = customHeader[pos];
pos++;
//cout << "Header -> " << *it << endl; // Uncomment this to see the message being written
if (pos == MY_HEADER)
{
cout << "Header wrote" << endl;
break;
}
}
n++;
}
// Delete arrays we are not using it anymore
modulusBytes = new char[1]; // Relocate memory
delete[] modulusBytes;
delete[] customHeader;
int j = 0;
pos = 0;
// Since the actual data of the wav starts at byte 44. Everything above is just header things that we don't care atm
for (vector<char>::iterator it = buffer.begin() + WAV_HEADER + n + MY_HEADER_MODULE + START_SPACE;
it != buffer.end(); ++it)
{
if (j % modulus == 0)
{
*it = msg.at(pos);
pos++;
//cout << *it << endl; // Uncomment this to see the message being written
if (pos >= msg.size())
break;
}
j++;
}
if (pos < msg.size())
{
cout << "Maybe the whole file was not written in" << endl;
}
return OutputBindedData(buffer, inputExt);
}
int PlayWithWaveBuffer(vector<char>& buffer, vector<char>& msgBuffer, string& fileExtension, string& inputExt)
{
char* modulusBytes = new char[4] {0}; // Max number of modulus in bytes
char* customHeader = new char[MY_HEADER] {0}; // Custom header
if (buffer.size()/4 <= msgBuffer.size())
{
cout << "The message might be to big for the audio file" << endl;
return ERROR;
}
msgBuffer.push_back('@');
msgBuffer.push_back('<');
msgBuffer.push_back(';');
msgBuffer.push_back(';');
// How many times the buffer is bigger than the message
// buffer.size() - (HEADER SIZE = 44 bytes) - (My own tags to de hidden file = 3 bytes)
long modulus = ((buffer.size() - WAV_HEADER - START_SPACE) / (msgBuffer.size() + MY_HEADER));
cout << "Spreading level: " << modulus << endl;
// Verify if it is safe to hide the message. Must me at must half the size of the space avaible
if(modulus <= 3)
{
cout << "The message might be to big for the audio file" << endl;
return ERROR;
}
CreateHeader(modulus, modulusBytes, customHeader, fileExtension, true);
int n = 0;
int pos = 0;
// Write my custom header first (Spread)
for (vector<char>::iterator it = buffer.begin() + WAV_HEADER + START_SPACE;
it != buffer.end(); ++it)
{
if (n % MY_HEADER_MODULE == 0)
{
*it = customHeader[pos];
pos++;
//cout << "Header -> " << *it << endl; // Uncomment this to see the message being written
if (pos == MY_HEADER)
{
cout << "Header wrote" << endl;
break;
}
}
n++;
}
// Delete arrays we are not using it anymore
modulusBytes = new char[1]; // Relocate memory
delete[] modulusBytes;
delete[] customHeader;
int j = 0;
pos = 0;
for (vector<char>::iterator it = buffer.begin() + WAV_HEADER + n + MY_HEADER_MODULE + START_SPACE;
it != buffer.end(); ++it)
{
if (j % modulus == 0)
{
*it = msgBuffer.at(pos);
pos++;
//cout << *it << endl; // Uncomment this to see the message being written
if (pos >= msgBuffer.size())
break;
}
j++;
}
if (pos < msgBuffer.size())
{
cout << "Maybe the whole file was not written in" << endl;
}
return OutputBindedData(buffer, inputExt);
}
/**
* Look for the custom header and define what type of message is in it
*
* @param buffer: File loaded into a buffer
* */
int FindHiddenMessage(vector<char>& buffer)
{
char* customHeader = new char[MY_HEADER] {0}; // Custom header
int n = 0;
int pos = 0;
cout << "Looking for the hidden message..." << endl;
// Since the actual data of the wav starts at byte 44 we start from it. Everything above is just header things that we don't care atm
for (vector<char>::iterator it = buffer.begin() + WAV_HEADER + START_SPACE;
it != buffer.end(); ++it)
{
if (n % MY_HEADER_MODULE == 0)
{
customHeader[pos] = *it;
//cout << "Custom Header: " << customHeader[pos] << endl; // Uncomment this if you want to see the header being read
pos++;
if (pos == MY_HEADER)
{
//cout << "Header has been read " << endl;
break;
}
}
n++;
}
CustomHeader cHeader (customHeader);
// Clean memory
delete[] customHeader;
if (cHeader.GetType() == 'b')
{
cout << "File detected. Retrieving it..." << endl;
cHeader.SetLastPosition(n);
return FindHiddenBinaryInWave(buffer, cHeader);
}
else if (cHeader.GetType() == 't'){
cout << "String detected. Retrieving it..." << endl;
cHeader.SetLastPosition(n);
return FindHiddenTextInWave(buffer, cHeader);
}
else{
// If it hits here it's because there was no message found in the file
cout << "Failed to detect a hidden file." << endl;
cout << "No custom header was found." << endl;
return ERROR;
}
}
int FindHiddenTextInWave(vector<char>& buffer, CustomHeader& customHeader)
{
string msgText;
int modulus = customHeader.GetModulus();
int lastPos = customHeader.GetLastPosition();
int n = 0;
int pos = 0;
vector<char>::iterator tempIterator;
// Since the actual data of the wav starts at byte 44. Everything above is just header things that we don't care atm
for (vector<char>::iterator it = buffer.begin() + WAV_HEADER + lastPos + MY_HEADER_MODULE + START_SPACE;
it != buffer.end(); ++it)
{
if (n % modulus == 0)
{
if (*it == 64)
{
// @
//Setting the iterator to the next possible position
tempIterator = buffer.begin() + n + 44 + MY_HEADER_MODULE + START_SPACE + lastPos + modulus;
if (*tempIterator == 60) {
//<
//Setting the iterator to the next possible position
tempIterator = buffer.begin() + n + 44 + MY_HEADER_MODULE + START_SPACE + lastPos + (2* modulus);
if (*tempIterator == 59) {
// ;
// Setting the iterator to next possible flag
tempIterator = buffer.begin() + n + 44 + MY_HEADER_MODULE + START_SPACE + lastPos + (3 * modulus);
if (*tempIterator == 59){
// End of message reached
cout << "Message recovered size: " << pos << " bytes" << endl;
// Output text
cout << "Message: " << msgText.c_str() << endl;
return SUCCESS;
}
}
}
}
msgText[pos] = *it;
//cout << msgText[pos] << endl; // Uncomment this if yuo want to see the characters being read
pos++;
}
n++;
}
// If it hits here it's because there was no message found in the file
cout << "No message found :(" << endl;
return ERROR;
}
int FindHiddenBinaryInWave(vector<char>& buffer, CustomHeader& customHeader)
{
vector<char> msgBuffer;
int modulus = customHeader.GetModulus();
int lastPos = customHeader.GetLastPosition();
int n = 0;
int pos = 0;
vector<char>::iterator tempIterator;
// Since the actual data of the wav starts at byte 44. Everything above is just header things that we don't care atm
for (vector<char>::iterator it = buffer.begin() + + WAV_HEADER + lastPos + MY_HEADER_MODULE + START_SPACE;
it != buffer.end(); ++it)
{
if (n % modulus == 0)
{
if (*it == 64)
{
// @
//Setting the iterator to the next possible position
tempIterator = buffer.begin() + n + 44 + MY_HEADER_MODULE + START_SPACE + lastPos + modulus;
if (*tempIterator == 60) {
//<
//Setting the iterator to the next possible position
tempIterator = buffer.begin() + n + 44 + MY_HEADER_MODULE + START_SPACE + lastPos + (2* modulus);
if (*tempIterator == 59) {
// ;
// Setting the iterator to next possible flag
tempIterator = buffer.begin() + n + 44 + MY_HEADER_MODULE + START_SPACE + lastPos + (3 * modulus);
if (*tempIterator == 59){
// End of message reached
cout << "Message recovered size: " << pos << " bytes" << endl;
return OutputBinFile(msgBuffer, customHeader);
}
}
}
}
msgBuffer.push_back(*it);
//cout << "Data recovered: " << msgBuffer[pos] << endl; // Uncomment this if you want to see the characters being read
pos++;
}
n++;
}
// If it hits here it's because there was no message found in the file
cout << "Could not find the end tags of the hidden file :(" << endl;
return ERROR;
}
int WriteMessageFromEnd(vector<char>& buffer, string msg)
{
// Verify if it is safe to hide the message in the buffer
if ((buffer.size() / 4) < msg.size())
{
cout << "The message might be to big for the audio file" << endl;
return ERROR;
}
// Inverse iterator runs backwards
int n = 0;
int pos = 0;
for (vector<char>::reverse_iterator i = buffer.rbegin();
i != buffer.rend(); ++i)
{
if (n%1000 == 0)
{
*i = msg.at(pos);
pos++;
cout << *i << endl;
if (pos >= msg.size())
break;
}
n++;
}
return SUCCESS;
}
int OutputBindedData(vector<char>& buffer, string& fileExtension)
{
string fileName;
if (fileExtension == "")
fileName = "output";
else
fileName = "output." + fileExtension;
ofstream output(fileName, std::ios::binary);
output.write((const char*)&buffer[0], buffer.size());
output.close();
cout << "File has been saved as: " << fileName << endl;
return SUCCESS;
}
int OutputBinFile(vector<char>& buffer, CustomHeader& cHeader)
{
string fileName;
if (cHeader.GetExtension() == "")
fileName = "output";
else
fileName = "output." + cHeader.GetExtension();
ofstream output(fileName, std::ios::binary);
output.write((const char*)&buffer[0], buffer.size());
output.close();
cout << "File has been saved as: " << fileName << endl;
return SUCCESS;
}
void CreateHeader(long& modulus, char* modulusBytes, char* customHeader, string& fileExtension, bool isBinaryType)
{
/**
* Create custom header (9 bytes):
* Modulus value: 4 bytes
* File extension: 4 bytes
* Message type (text or file): 1 byte
* */
// If modulus is lesser than the max int value of 4 bytes assign it.
// Otherwise, set a flag to use DEF_MODULE constant
if (modulus <= 42946729)
modulusBytes = reinterpret_cast<char*>(&modulus);
else
modulusBytes[0] = DEF_MODULE;
int y, i;
// Assign modulus to header
for (i = 0; i < 4; i++)
customHeader[i] = modulusBytes[i];
// Assign the file extension to recover later
for(y = 0, i = 4; i < 8; i++)
{
// Dinamically fill the 4 bytes of the file extension even if its less than 4 characters
if(fileExtension.size() > y )
customHeader[i] = fileExtension.at(y);
else
customHeader[i] = ' ';
y++;
}
// Assign the type of the message
if (isBinaryType)
customHeader[8] = 'b';
else
customHeader[8] = 't';
}