PHP Error 500 & Post data returns an empty string

Question

So a quick introduction... I'm trying to create a database system for a local website hosted off my computer.

I have this logon script in PHP and I have come across an error that is shown at the bottom on this question.

I am running this on a Debian OS and have PHP5 installed along with Apache2 and MySQL. I am unable to find the error log on both Apache and PHP.

When trying to get '$_POST['Anything']', it returns an empty string.

This is my code:

<?php
ob_start();
$host="localhost";
$username="MySQLUser";
$password="*************";
$db_name="test";
$tbl_name="members";
mysql_connect("$host", "$username", "$password") or die("Cannot connect"); 
mysql_select_db("$db_name")or die("Cannot select DB");
$myusername=$_POST["vuser"]; 
$mypassword=$_POST["vpass"]; 
$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);
$mypassword = md5(md5(md5(md5(md5(md5($mypassword)))))); // This is for tests.
$sql="SELECT * FROM $tbl_name WHERE Username='$myusername' and Password='$mypassword'";
$result=mysql_query($sql);
$count=mysql_num_rows($result);
if($count==1){
    session_register("vuser");
    session_register("vpass"); 
    header("location:login_success.php");
} else {
    echo "Wrong Username or Password";
}
ob_end_flush();
?>

I even changed

echo "Wrong Username or Password";

to

echo "Wrong Username or Password, $mypassword and $myusername, $_POST['vuser'] and $_POST['vpass']";

And the vuser, vpass are shown as blank spaces. I echo the username and password so I can read it. Basically it's for tests. (This is before it broke)

After I did something, I have no idea what... This is what I receive:

What I am asking is, why is the $_POST thing not showing the data and what's the problem with the error page?

Answer 1

Not sure since unable to test it now. Little busy, but just try removing the single-quotes around username and password like in the below query:

$sql="SELECT * FROM $tbl_name WHERE Username=$myusername and Password=$mypassword";

or use below:

$sql="SELECT * FROM $tbl_name WHERE Username='". $myusername ."' and Password='" . $mypassword . "'";

Answer 2

Ok..

Don't use "session_register", according to php.net, this function is DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.

<?php

// initialize session
session_start();

define('DB_HOST', 'my.host.com');
define('DB_USER', 'youruser');
define('DB_PASS', 'yourpass');
define('DB_NAME', 'dbname');

// connect 
mysql_connect(DB_HOST, DB_USER, DB_PASS) or die("Cannot connect");
mysql_select_db(DB_NAME) or die("Cannot select DB");


function clean($value)
{
    if (get_magic_quotes_gpc()) {
        $value = mysql_real_escape_string(stripslashes($value));
    } else {
        $value = mysql_real_escape_string($value);
    }
    return $value;
}


$user = isset($_POST['vuser']) ? trim($_POST['vuser']) : null;
$pass = isset($_POST['vpass']) ? trim($_POST['vpass']) : null;

if (!$user || !$pass) {
    echo 'Wrong username or password';
    die;
}

$user = clean($user);
$pass = clean($pass);

$sql = sprintf("select * from members where username = '%s' and password = '%s'", $user, $pass);

$query = mysql_query($sql);

if ($query) {

    $data = mysql_fetch_array($query, MYSQL_ASSOC);

    if (sizeof($data) > 0) {
        // save sessions...
        // redirect...
        // user ok
        die;
    }

}

echo 'Incorrect!';
die;