Botched user authentication

[Anon]

Ok, so I got some sample code and changed a bunch of stuff around so that this thing checks my database for my name & pass...no matter what data I enter for the user name and password I get prompted 3 times for them and get a blank page in return...somebody help!

<?php
if (!isset($PHP_AUTH_USER)) {

	// If empty, send header causing dialog box to appear
	header('WWW-Authenticate: Basic realm="My Private Stuff"');
	header('HTTP/1.0 401 Unauthorized');
	exit;
	} 
	else if (isset($PHP_AUTH_USER)) {

	// If non-empty, check the database for matches		
	// connect to MySQL

	mysql_connect("Default", "root", "") or die ("Unable to connect to database.");
	mysql_select_db("newsdb") or die ("Unable to select database.");	

	// Formulate the query
	$sql = "SELECT * FROM users WHERE name='$PHP_AUTH_USER' and pass='$PHP_AUTH_PW'";

	// Execute the query and put results in $result		
	$result = mysql_query($sql);

	// Get number of rows in $result. 0 if invalid, 1 if valid.
	$num = mysql_numrows($result);		
	if ($num != "0") {
		echo "<P>You're authorized!</p>";				
		exit;
		} 
		else {	
		header('WWW-Authenticate: Basic realm="My Private Stuff"');
		header('HTTP/1.0 401 Unauthorized');
		echo 'Authorization Required.';
		exit;		
		}	
	} ?>

[rrijnders]

The blank page is simply because you don't specify anything to send if authentication fails. Only three tries are allowed.

Why does authentication fail?

Change:

$sql = "SELECT * FROM users WHERE name='$PHP_AUTH_USER' and pass='$PHP_AUTH_PW'";

To:

$sql = "SELECT * FROM users WHERE name='" . $PHP_AUTH_USER ."' and pass='" . $PHP_AUTH_PW . "'";

...and you should be fine. Single quotes cause the variables to not be translated. In essance, you are checking your database against "$PHP_AUTH_USER" literally <i>not the value in the variable</i>

--Rich