myvtm/Module/mod_cardswiper/public.cpp

#include "StdAfx.h"

#include "public.h"
#include <time.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

const unsigned char hextable[]={"0123456789ABCDEF"};
void ConvAscii(unsigned char *Hex,char *Ascii,unsigned int len)
{
	unsigned int i;
	for(i=0;i<len;i++)
    {
        Ascii[2*i]=hextable[Hex[i]>>4];
		Ascii[2*i+1]=hextable[Hex[i]&0xf];
	}
	Ascii[2*len]=0;
}
//*******************************************************************************
void AsciiToHex(char *Ascii,unsigned char *Hex,int len)
{
	int i;
	unsigned char ch;
	for(i=0;i<len;i=i+2)
    {
        ch=(Ascii[i]&0xf);
		if(Ascii[i]>'9')
            ch+=9;

		Hex[i/2]=ch<<4;

        ch=Ascii[i+1]&0xf;
		if(Ascii[i+1]>'9')
            ch+=9;

		Hex[i/2]+=ch;
	}
}

int convTo3x(unsigned char*from,int flen,char*to)
{
	int i = 0;
	unsigned char ch;
	for(i=0;i<flen;++i) {
		ch=from[i];
		ch>>=4;
		ch&=0x0f;
		ch|=0x30; 
		to[i*2] = ch;
		ch=from[i];
		ch&=0x0f;
		ch|=0x30; 
		to[i*2+1]=ch;
	}

	return flen*2;
}

int _3xToHex(char *Ascii,unsigned char *Hex,int len)
{
	int i = 0,j=0;
	unsigned char tmp[512] = {0};
	unsigned char ch;
	for(i = 0;i<len;i++)
	{
		j = 2*i;
		ch = Ascii[j]&0x0F;
		ch<<=4;
		ch |= (Ascii[j+1]&0x0F);

		tmp[j/2] = ch;
	}

	memcpy(Hex,tmp,len/2);
	return (len/2);
}

int get_random(int len,unsigned char*random)
{
	int iloop;
	unsigned char ch;

	srand((int)time(NULL));
	
	for(iloop=0;iloop<len;iloop++)
	{
		ch = rand()%256;
		if(ch==0)
		{
			iloop--;
			continue;
		}
		random[iloop]=ch;
	}

	return iloop;
}

int RSA_GetBitLen(unsigned char *a, int alen) 
{
	int i;
	int temp;
	int bitlen;
	if (0 == alen)
		return 0;	
	
	for(i = alen-1;i >= 0; i--)
	{
		if(a[i] > 0)
			break;
	}
	if(i == -1)
	{
		return 0;
	}
	temp = i;	
	bitlen = temp << 3;	
	
	for (i = 7; i >= 0; i--)
	{
		if (a[temp] & (1 << i))
			break;
	}
	bitlen += (int)(i + 1);
	return bitlen;
}