Facebook Authentication Error when using apps.facebook.com as URL
- by Adi Mathur
I am trying to login on my website using Facebook Authentication and it works fine . How ever when i access the Application by using https://apps.facebook.com/myApp then i get an error
The state does not match. You may be a victim of CSRF
Here is the code that i am using from facebook , I think there is a problem in
$my_url
<?php
$app_id = "YOUR_APP_ID";
$app_secret = "YOUR_APP_SECRET";
$my_url = "https://www.example.com/login.php";
session_start();
$code = $_REQUEST["code"];
if(empty($code)) {
$_SESSION['state'] = md5(uniqid(rand(), TRUE)); //CSRF protection
$dialog_url = "https://www.facebook.com/dialog/oauth?client_id="
. $app_id . "&redirect_uri=" . urlencode($my_url) . "&state="
. $_SESSION['state'];
echo("<script> top.location.href='" . $dialog_url . "'</script>");
}
if($_REQUEST['state'] == $_SESSION['state']) {
$token_url = "https://graph.facebook.com/oauth/access_token?"
. "client_id=" . $app_id . "&redirect_uri=" . urlencode($my_url)
. "&client_secret=" . $app_secret . "&code=" . $code;
$response = file_get_contents($token_url);
$params = null;
parse_str($response, $params);
$graph_url = "https://graph.facebook.com/me?access_token="
. $params['access_token'];
$user = json_decode(file_get_contents($graph_url));
echo("Hello " . $user->name);
}
else {
echo("The state does not match. You may be a victim of CSRF.");
}
?>
