RC4 Encryption

[Joeheg]

/////////////////////////////////////////////////////////
RC4.cpp
////////////////////////////////////////////////////////
// Rc4.cpp: implementation of the CRc4 class.
// Arranged by: SonicMouse
// web: http://www.mouseindustries.com
//////////////////////////////////////////////////////////////////////

#include "Rc4.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
CRc4::CRc4()
{

}

CRc4::~CRc4()
{

}

//////////////////////////////////////////////////////////////////////
// inits a new rc4 session
//////////////////////////////////////////////////////////////////////
void CRc4::rc4_init(const char* key, int keylen){
int keypos = 0, x;
unsigned char K[256];
for(x = 0; x < 256; ++x){
S[x] = x;
K[x] = key[keypos++];
if(keypos >= keylen) keypos=0;
}
for(j = x = 0; x < 256; ++x){
j += S[x] + K[x];
t = S[x];
S[x] = S[j];
S[j] = t;
}
i = j = 0;
}

//////////////////////////////////////////////////////////////////////
// encrypts a char array
//////////////////////////////////////////////////////////////////////
unsigned char* CRc4::rc4_encrypt_array(unsigned char* arr, int nLen){
for(int q = 0; q < nLen; q++)
arr[q] = arr[q] ^ next_rand();
return &arr[0];
}

//////////////////////////////////////////////////////////////////////
// encryption routine
//////////////////////////////////////////////////////////////////////
inline unsigned char CRc4::next_rand(){
++i;
j += S[i];
t = S[i];
S[i] = S[j];
S[j] = t;
t = S[i] + S[j];
return S[t];
}

//////////////////////////////////////////////////////////////////////
// Utilitys to take a byte array and change it to uppercase hex
//////////////////////////////////////////////////////////////////////
char* CRc4::UCharArrayToHexString(const unsigned char* arr, int nLen){
char* hex = new char[nLen*2+1];
char tmp[3];
int i;
for(i = 0; i < nLen; i++){
sprintf(tmp, "%02X", (unsigned int)arr[i]);
hex[i*2]=tmp[0];
hex[i*2+1]=tmp[1];
}
hex[i*2]=0;
return &hex[0];
}








///////////////////////////////////////////////////////
rc4.h
//////////////////////////////////////////////////////
// Rc4.h: interface for the CRc4 class.
// Arranged by: SonicMouse
// web: http://www.mouseindustries.com/
//////////////////////////////////////////////////////////////////////

#ifndef __RC4_H__
#define __RC4_H__

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class CRc4
{
public:
CRc4();
virtual ~CRc4();

void rc4_init(const char *key, int keylen);
unsigned char* rc4_encrypt_array(unsigned char* arr, int nLen);

// utility
char* UCharArrayToHexString(const unsigned char* arr, int nLen);

private:
inline unsigned char next_rand();

private:
unsigned char S[256];
unsigned char i;
unsigned char j;
unsigned char t;

};

#endif /* __RC4_H__ */







ANY one ne idea how i can translate that to VB?

[CornedBee]

Umm...

Instruction by instruction I'd recommend

The only difficult thing is the single bitwise XOR in there.

[CornedBee]

Just a few hints:
unsigned char <=> Byte
char * <=> String
int <=> Long

[] is for array indexing, array indices start at 0.