How to make safe login script

Question

I am trying to make login script safe to stop hacking of my website. I am trying to use mysql_real_escape_string in my script can anyone guide me if i am wrong in this.

Here is my code

    <?php
session_start();
include("lib/conn.php");

?>
<?php
$email=$_POST['user'];
$password=$_POST['password'];

if ($email && $password){

$query = "SELECT * FROM register WHERE email = '$email' AND password= '$password' and status = '1'";

mysql_real_escape_string($email);
mysql_real_escape_string($password);

$result = mysql_query( $query ) or die ("didn't query");
$num = mysql_num_rows( $result );
if ($num == 1){

$_SESSION['ocer']=$email;




header("Location: admin.php"); 


    } 
    else {







header("Location: index.php?l=1");


}
}

?>

Answer 1

First of all. Use PDO with bind parameter. Then you don't have to worry about injections.

mysql_real_escape_string returns the escaped string and should be used before constructing your query. Use is as so:

$password = mysql_real_escape_string($password);

Also. Don not retrieve by password and email. retrieve password by email and validate that there the same.

Hope it helps

Here is the example:

session_start();
include("lib/conn.php");

//using isset to avoid warnings.
$email = isset($_POST['user']) ? $_POST['user'] : null;
$password = isset($_POST['password']) ? $_POST['password'] : null;

//check if values are not null
if ($email !== null && $password !== null){

    //escape email
    $email = mysql_real_escape_string($email);

    //retrieve password by email and limit 1 result
    $query = "SELECT password FROM register WHERE email = '{$email}' and                         status = '1' LIMIT 1";

    //run query
    $result = mysql_query( $query ) or die ("didn't query");

    //validate if query run correctly
    if (!$result) {
        echo 'Could not run query: ' . mysql_error();
        exit;
    }

    //fetch row
    $row = mysql_fetch_row($result);

    //validate result
    if ($row['password'] == $password){
        $_SESSION['ocer']=$email;
        header("Location: admin.php"); 
    } else {
        header("Location: index.php?l=1");
    }
}