Link to home
Start Free TrialLog in
Avatar of Crazy Horse
Crazy HorseFlag for South Africa

asked on

Reverse asset logic not working

If I do this:

if(isset($_SESSION['sessionID']) || isset($_COOKIE['userID'])) {

echo "Welcome";

} else {

header("location:login.php");
exit;
}

Open in new window


then it works fine. If no session or cookie is set then the user is redirected. I don't want to do it this way because I don't actually want to do anything if the user is logged in, I only want to worry about if the cookie or session isn't set so I can redirect them. I tried to reverse the logic like this:

if(!isset($_SESSION['sessionID']) || !isset($_COOKIE['userID'])) {
	
	header("location:login.php");
	exit;
	
	}

Open in new window


but it doesn't work. I THINK it is saying, if no session is found OR if no cookie is found, redirect. If I enter correct login details it doesn't log me in, just sends me back to the login page.
Avatar of Ray Paseur
Ray Paseur
Flag of United States of America image

Not sure whether this is the problem or not, but isset() may be too sensitive a test.  You might want to use empty() instead.  A field can be TRUE for isset() but FALSE for empty(), according to the man pages.  

The best approach might be to follow the design pattern in this article.
https://www.experts-exchange.com/articles/2391/PHP-Client-Registration-Login-Logout-and-Easy-Access-Control.html
Avatar of Crazy Horse

ASKER

Sorry, I did type isset but I noticed when typing it now that spell check changed it to asset, haha!

Thanks, Ray. I have been reading that from your previous post on my last question.

I think this is your code which is doing a similar thing:

function access_control($test=FALSE)
{
    // REMEMBER HOW WE GOT HERE
    $_SESSION["entry_uri"] = $_SERVER["REQUEST_URI"];

    // IF THE UID IS SET, WE ARE LOGGED IN
    if (isset($_SESSION["uid"])) return $_SESSION["uid"];

    // IF WE ARE NOT LOGGED IN - RESPOND TO THE TEST REQUEST
    if ($test) return FALSE;

    // IF THIS IS NOT A TEST, REDIRECT TO CALL FOR A LOGIN
    header("Location: RAY_EE_login.php");
    exit;
}

Open in new window


But then you also have this going on:

if (!isset($_SESSION["uid"]))
{

    // DETERMINE IF THE CLIENT IS ALREADY LOGGED IN BECAUSE OF "REMEMBER ME" FEATURE
    if (isset($_COOKIE["uuk"]))
    {

Open in new window

PS. I did try empty and I got the same result:

if(empty($_SESSION['sessionID']) || empty($_COOKIE['userID'])) {
	
	header("location:login.php");
	exit;
	
	}

Open in new window

SOLUTION
Avatar of Ray Paseur
Ray Paseur
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
ASKER CERTIFIED SOLUTION
Avatar of Dave Baldwin
Dave Baldwin
Flag of United States of America image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Ah, can't believe I didn't see that as that seems really obvious now that you pointed it out!
Regarding this...

  $_SESSION["entry_uri"] = $_SERVER["REQUEST_URI"];

Open in new window


Would you only use this as an extra security layer with a session based login because then you will always have to come from the login page to get to your account area? But it would not  work with cookies because I might just open my browser and go directly to the account page and completely bypass the login page?
$_SERVER["REQUEST_URI"] is the page you are currently on.  If you want to see where you came from, use $_SERVER["HTTP_REFERER"].  $_SERVER["HTTP_REFERER"] is Not set if you went directly to the page instead of from another page.  And since it can be spoofed, you should not rely only on it.  I do use it on a lot of pages though.  If they can't get that right, they shouldn't be there anyway.

http://php.net/manual/en/reserved.variables.server.php
This is a complicated issue that produces a simple, intuitive, "good-UX" result.  If you read the article and still have questions about why we use that, please post a new question and I'll try to explain.
$_SESSION["entry_uri"] = $_SERVER["REQUEST_URI"];

Open in new window

Thanks guys. Ray, I have read the part of the article which explains it and I have looked at the code but I still can't understand why exactly you do it. I initially thought that maybe it was for if you are browsing a site and for example find a page with a particular product or article and you want to make a purchase, then if you login you will stay on that page instead of being taken to your dashboard and you have to hunt for that page again. But that probably isn't it. I will open a related question.
I posted in the related question.  HTH, ~Ray