//Download all files @ http://nexos.bplaced.net/otp_xor.rar

#include <sstream>

#include <string>

#include <iostream>

#include <fstream>

#include <iterator>

 

//random

#include "mersenne.cpp"

#include <time.h>

 

using namespace std;

 

//mersenne random number generator crap

  template <class RG1, class RG2>

  class TRandomCombined : private RG1, private RG2 {

    public:

    TRandomCombined(int32 seed = 19) : RG1(seed), RG2(seed+1) {};

 

     void RandomInit(int32 seed) {        // re-seed

      RG1::RandomInit(seed);

      RG2::RandomInit(seed+1);}

 

    double Random() {

      long double r = RG1::Random() + RG2::Random();

      if (r >= 1.) r -= 1.;

     return r;}

 

    long IRandom(long min, long max){       // output random integer

      // get integer random number in desired interval

      int iinterval = max - min + 1;

      if (iinterval <= 0) return -1; // error

      int i = int(iinterval * Random()); // truncate

      if (i >= iinterval) i = iinterval-1;

     return min + i;}};

 

//stream/string functions

  string IntToString(int iValue)

  {

      stringstream ssStream;

      ssStream << iValue;

    return ssStream.str();

  }

 

  string GetData(string strFileName)

  {

     cout<<endl<<"... reading files ..."<<endl;

       ifstream FStream;

        FStream.open(strFileName.c_str(), ios::in | ios::binary );

 

        FStream.unsetf(ios_base::skipws);

        istream_iterator<char> begin(FStream), end;

        string strFileData(begin, end);

 

       FStream.close();

 

      return strFileData;

  }

 

//encrypt + decrypt

void encrypt(string strPlainFile, string strKeyFile, string strOutputFile)

{

        string strPlainFileData    = GetData(strPlainFile);

 

        ofstream OutputFStream;

        ofstream KeyFStream;

 

        OutputFStream.open(strOutputFile.c_str(), ios::out | ios::binary);

        KeyFStream.open(strKeyFile.c_str(), ios::out | ios::binary);

 

   int32 seed = (int32)time(0);

   CRandomMersenne rg(seed);

 

      cout<<endl<<"... doing encryption ..."<<endl<<endl;

 

        for (int i = 0; i < (int) strPlainFileData.size(); i++)

        {

                char Key        = rg.IRandom(0,9);

                char Input      = strPlainFileData[i];

                char Crypted    = Input ^ Key;

 

                OutputFStream << Crypted;

                KeyFStream << Key;

        }

 

        OutputFStream.close();

        KeyFStream.close();

 

      cout<<"encryption finished!"<<endl;

}

 

void decrypt(string strPlainFile, string strKeyFile, string strCryptedFile)

{

        string strCryptedFileData  = GetData(strCryptedFile);

        string strKeyFileData      = GetData(strKeyFile);

 

        ofstream PlainFileOFStream;

        PlainFileOFStream.open(strPlainFile.c_str(), ios::out | ios::binary);

 

     cout<<endl<<"... doing decryption ..."<<endl<<endl;

 

        for (int i = 0; i < (int) strCryptedFileData.size(); i++)

        {

                char Key        = strKeyFileData[i];

                char Crypted    = strCryptedFileData[i];

                char Plain     = Crypted ^ Key;

 

                PlainFileOFStream << Plain;

        }

 

        PlainFileOFStream.close();

     cout<<"decryption finished!"<<endl;

}

 

int main(int argc, char* argv[])

{

 

    if(argc != 5 )

    {

        cout<<"onetimepad xor file encrypter with mersenne twister random number algorythm by nexos"<<endl;

        cout<<endl<< "Usage: " << argv[0] << " <0/1> <Plaintext File> <Key File> <Crypted File>" <<endl<<endl;

        cout<< "<0>: decrypts <Crypted File> with <Key File> to <Plaintext File>" <<endl<<endl;

        cout<< "<1>: encrypts <Plaintext File> with <Key File> (Key is generated) to <Crypted File>" <<endl<<endl;

        cout<< "existing files are overwritten" << endl;

        return 0;

    }

 

  if ( atoi( argv[1]) == 0 )

   decrypt(argv[2],argv[3],argv[4]);

 

  if ( atoi( argv[1]) == 1 )

   encrypt(argv[2],argv[3],argv[4]);

 

        return 0;

}