#include "stdio.h"
#include "string.h"
#include "stdafx.h"

int _tmain(int argc, _TCHAR* argv[])
{

char password[ 1024 ];

int hexChar2int(char c)
{
        if(c >= 'A' && c <= 'F')
                return c - 'A' + 10;
        else if(c >= 'a' && c <= 'f')
                return c - 'a' + 10;
        else if(c >= '0' && c <= '9')
                return c - '0';

        return 0;
}

void decodePassword( const char *pass, const char *key )
{
        unsigned int n1, n2;
        typedef unsigned short ushort;
        int password_index = 0;
        unsigned char c;
        //if(key.length() == 0)
        //return pass;
        for( n1 = 0, n2 = 0; n1 < strlen( pass ); n1 += 4 )
        {
                ushort x = 0;

                if(n1 + 4 > strlen( pass ) )
                        break;

                x += hexChar2int( pass[ n1 ] ) * 4096;
                x += hexChar2int( pass[ n1+1 ] ) * 256;
                x += hexChar2int( pass[ n1+2 ] ) * 16;
                x += hexChar2int( pass[ n1+3 ] );

                c = ( unsigned char )( x ^ key[ n2++ ] );

                password[ password_index++ ] = c;

                if( n2 > strlen( key ) )
                        n2 = 0;
        }

}

int main( void )
{
        decodePassword( "Encrypted password from config.xml here", "user_name@jabber.org" );
        printf( "Password:%s\n", password );

        return 0;
}
}