rsaAutentification

gistfile1.php

<a href="home.php">Regresar</a><br/>
<?php

validar($_POST['user'], $_POST['respuesta'], $_POST['x']);

function validar($usuario, $r, $x)
{
  $lista = getUser($usuario);
  if($lista)
    {
      $e = $lista[0];
      $n = $lista[1];
      
      $y = f($x);
      $num = fastmodexp($r, $e, $n);
      
      if($y == $num)
	{
	  echo "<h3>Welcome $usuario</h3>";
	  echo "You can see 9gag<br/><br/>";
	  echo "<iframe src='http://www.9gag.com' width='900' height='900'></iframe>";
	}
      else echo "Fail..!";
      echo "<br/><br/>";
    } 
  else
    {
      echo "<h1>Usuario invalido<h1>";
      die();
    }
}

function getUser($usuario)
{
  include 'parametrosLogin/loginConnection.php';

  $link_C = "SELECT e, n FROM rsa_cripto where usuario = '".$usuario."'";

  $link_CR = mysql_query($link_C, $conexion) or die(mysql_error());
  $link_C_rows = mysql_num_rows($link_CR);

  if ($link_C_rows> 0) {
    while ($link_C_Rrows = mysql_fetch_assoc($link_CR)) {
      $e = $link_C_Rrows['e'];
      $n = $link_C_Rrows['n'];
    }
    $lista = array($e, $n);
    return $lista;
  }

  else return False;
}

function f($x)
{
  return ($x*2)+5;
}

function fastmodexp($x, $y, $mod)
{
  $p = 1;
  $aux = $x;
  while($y > 0){
    if ($y % 2 == 1){
      $p = ($p * $aux) % $mod;
    } 
    $aux = ($aux * $aux) % $mod;
    $y = $y >> 1;
  }
  return ($p);
}

?>