Blowfish Source Code

/********** blowfish.h **********/

#ifndef ___BLOWFISH_H___
#define ___BLOWFISH_H___


#define NUM_SUBKEYS  18
#define NUM_S_BOXES  4
#define NUM_ENTRIES  256

#define MAX_STRING   256
#define MAX_PASSWD   56  // 448bits

// #define BIG_ENDIAN
// #define LITTLE_ENDIAN


#ifdef BIG_ENDIAN
struct WordByte
{
    unsigned int zero:8;
    unsigned int one:8;
    unsigned int two:8;
    unsigned int three:8;
};
#endif

#ifdef LITTLE_ENDIAN
struct WordByte
{
    unsigned int three:8;
    unsigned int two:8;
    unsigned int one:8;
    unsigned int zero:8;
};
#endif

union Word
{
    unsigned int word;
    WordByte byte;
};

struct DWord
{
    Word word0;
    Word word1;
};


class Blowfish
{
private:
  unsigned int PA[NUM_SUBKEYS];
  unsigned int SB[NUM_S_BOXES][NUM_ENTRIES];

  void Gen_Subkeys(char *);
  inline void BF_En(Word *,Word *);
  inline void BF_De(Word *,Word *);

public:
  Blowfish();
  ~Blowfish();

  void Reset();
  void Set_Passwd(char * = NULL);
  void Encrypt(void *,unsigned int);
  void Decrypt(void *,unsigned int);
};


#endif



/********** blowfish.cc **********/

#include <iostream.h>
#include <string.h>
#include "blowfish.h"


#define F(x)    (((SB[0][x.byte.zero] + SB[1][x.byte.one]) ^ SB[2][x.byte.two]) +"\aEnter your password: ";
    cin.get(New_Passwd,MAX_STRING,'\n');
    len = strlen(New_Passwd);
    }
    while (len > MAX_PASSWD);
    Passwd = New_Passwd;
  }
  else
    len = strlen(Passwd);

  Reset();
  if (len > 0)
    Gen_Subkeys(Passwd);

  for (i=0;i<MAX_STRING;i++)
    New_Passwd[i] = '\0';
   Passwd = NULL;
   len = 0;
}

void Blowfish::Encrypt(void *Ptr,unsigned int N_Bytes)
{
  unsigned int i;
  DWord *Work;

  if (N_Bytes%8)
  {
    cerr << "\aBlowfish requires the input to be a multiple of 8 bytes (64
bits) to work.\n";
    return;
  }

    N_Bytes /= 8;
  Work = (DWord *)Ptr;

  for (i=0;i<N_Bytes;i++)
  {
    BF_En(&Work->word0,&Work->word1);
    Work++;
  }

  Work = NULL;
}

void Blowfish::Decrypt(void *Ptr,unsigned int N_Bytes)
{
  unsigned int i;
  DWord *Work;

  if (N_Bytes%8)
  {
    cerr << "\aBlowfish requires the input to be a multiple of 8 bytes (64
bits) to work.\n";
    return;
  }

    N_Bytes /= 8;
  Work = (DWord *)Ptr;
  for (i=0;i<N_Bytes;i++)
  {
    BF_De(&Work->word0,&Work->word1);
    Work++;
  }

  Work = NULL;
}



/********* BFtest.cc **********/
#include <stdio.h>
#include <iostream.h>
#include <stdlib.h>
#include <time.h>
#include "blowfish.h"

#define BUFF_SIZE 1048576  // 1MB
#define NUM_TRIALS 100


int Test(Blowfish *);
double Speed(Blowfish *);


void main()
{
    int result;
    double speed;
    Blowfish BF;

    cout << "Blowfish verification: ";
    if (result = Test(&BF))
    {
        cout << "\aFailed " << (result>0?"en":"de") << "crypting test vector " <<
abs(result) << endl;
        return;
    }
    else
        cout << "Passed" << endl;

    if ((speed = Speed(&BF)) <= 0)
        cout << "Not enough time elapsed for the test, or something funny happend." <<
endl;
    else
        cout << "The throughput is " << speed << "MB/s" << endl;
}


int Test(Blowfish *BF)
{
    unsigned int i;
    DWord Test_Vect;
    char *Passwd[2] = {"abcdefghijklmnopqrstuvwxyz","Who is John Galt?"};
    unsigned int Clr0[2] = {0x424c4f57,0xfedcba98};
    unsigned int Clr1[2] = {0x46495348,0x76543210};
    unsigned int Crypt0[2] = {0x324ed0fe,0xcc91732b};
    unsigned int Crypt1[2] = {0xf413a203,0x8022f684};

    for (i=0;i<2;i++)
    {
        Test_Vect.word0.word = Clr0[i];
        Test_Vect.word1.word = Clr1[i];
        BF->Set_Passwd(Passwd[i]);
        BF->Encrypt((void *)&Test_Vect,8);
        if (Test_Vect.word0.word != Crypt0[i] || Test_Vect.word1.word != Crypt1[i])
            return (i+1);
        BF->Decrypt((void *)&Test_Vect,8);
        if (Test_Vect.word0.word != Clr0[i] || Test_Vect.word1.word != Clr1[i])
            return -(i+1);
    }
    return 0;
}


double Speed(Blowfish *BF)
{
    char *buff;
    unsigned int i;
    time_t begin,end;

    buff = new char[BUFF_SIZE];
    if (buff == NULL)
    {
        cerr << "\aRan out of memory for the test buffer\n";
        return 0;
    }

    srand(0);
    for (i=0;i<BUFF_SIZE;i++)
        buff[i] = rand()%256;
    BF->Set_Passwd("ianchan");

    begin = time(NULL);
    for (i=0;i<NUM_TRIALS;i++)
        BF->Encrypt((void *)buff,BUFF_SIZE);
    end = time(NULL);

    delete []buff;
    if (end-begin < 10)
        return 0;
    else
        return double(NUM_TRIALS)/(end-begin);
}