[SOLVED] How can I make this more secure?

[Cory94bailly]

I just tested a script of mine and it let me enter characters that should not be allowed..

 

<?php
//**********Start Member Login!**********\\
ob_start();
error_reporting(E_ALL);
// Connects to your Database
mysql_connect("***", "***", "***") or die(mysql_error());
mysql_select_db("***") or die(mysql_error());

//Checks if there is a login cookie
if(isset($_COOKIE['ID_fcs_member']))

//if there is, it logs you in and directes you to the members page
{
$username = $_COOKIE['ID_fcs_member'];
$pass = $_COOKIE['Key_fcs_member'];
$check = mysql_query("SELECT * FROM members WHERE username = '$username'")or die(mysql_error());
while($info = mysql_fetch_array( $check ))
{
if ($pass != $info['password'])
{
}
else
{
header("Location: ***");

}
}
}

//if the login form is submitted
if (isset($_POST['submit'])) { // if form has been submitted

// makes sure they filled it in
if(!$_POST['username'] | !$_POST['pass']) {
die('You did not fill in a required field.');
}
// checks it against the database

if (!get_magic_quotes_gpc()) {
$_POST['email'] = addslashes($_POST['email']);
}
$check = mysql_query("SELECT * FROM members WHERE username = '".$_POST['username']."'")or die(mysql_error());

//Gives error if user dosen't exist
$check2 = mysql_num_rows($check);
if ($check2 == 0) {
die('That user does not exist in our database. <a href="register.php">Click Here to Register</a>');
}
while($info = mysql_fetch_array( $check ))
{
$_POST['pass'] = stripslashes($_POST['pass']);
$info['password'] = stripslashes($info['password']);
$_POST['pass'] = md5($_POST['pass']);

//gives error if the password is wrong
if ($_POST['pass'] != $info['password']) {
die('Incorrect password, please try again.');
}
else
{

// if login is ok then we add a cookie
$_POST['username'] = stripslashes($_POST['username']);
$hour = time() + 3600;
setcookie(ID_fcs_member, $_POST['username'], $hour);
setcookie(Key_fcs_member, $_POST['pass'], $hour);

//then redirect them to the members area
header("Location: ***");
}
}
}
else
{
//**********End Member Login!**********\\
?>

 

I heard that "mysql_real_escape_string" works but idk where to put it =/

[RichardRotterdam]

you place it around every posted variable since that could be the input of potention danger

mysql_real_escape_string($_POST['username'])

[GingerRobot]

I wouldn't escape a username - use regex to make sure only certain characters are allowed. For example, to allow alphanumeric characters plus spaces and underscores and to set a minimum of 3 and a maximum of 20 characters, use:

 

if(!preg_match('|^[a-z0-9 _]{3,20}$|i',$user)){
    //username not ok - alert user and do not enter into database
}

 

There would then be no need to use mysql_real_escape_string() on this field.

[Cory94bailly]

I wouldn't escape a username - use regex to make sure only certain characters are allowed. For example, to allow alphanumeric characters plus spaces and underscores and to set a minimum of 3 and a maximum of 20 characters, use:

 

if(!preg_match('|^[a-z0-9 _]{3,20}$|i',$user)){
    //username not ok - alert user and do not enter into database
}

 

There would then be no need to use mysql_real_escape_string() on this field.

 

Where do I put that?