How to use cookies to resume session manually?

Question

Related: session variable not carrying over

Problem

Any $_SESSION[""] variables are lost when I navigate from a page to another, though I'm using session_start(); before trying to acces them.

It seems that session_start() will automatically start a new session unless a session_name() or a session_id() is passed to it to specify what session to resume.

So, when it's time to show/hide buttons from server-side, the buttons never get shown, though a verified user has previously been authenticated.

I have read in a few articles that state that setcookie() would do the trick.

EDIT

I have to set the cookie manually for session id as stated here:

Can I restore a PHP SESSION by its ID?

Code Samples

login.php

<?php
require_once "logout.php";
require_once "../data/data_access.php";

$sid = session_id();
if (empty($sid)) session_start(); 

$userName = "";
$password = "";

if (isSet($_REQUEST["userName"])) $userName = $_REQUEST["userName"];
if (isSet($_REQUEST["password"])) $password = $_REQUEST["password"];

echo login($userName, $password);

function login($login, $pass) {
    if (isAuthenticUser($userName, $password)) {
        session_regenerate_id(true);
        $_SESSION["authenticated"] = true;
        setcookie("cookie_name", session_id(), time() + 1200);
    } else $_SESSION["authenticated"] = false;

    return $_SESSION["authenticated"];
}

another_file.php

<?php
$sid = session_id();
if (empty($sid)) session_start($_COOKIE["cookie_name"]); // Will this make it?
?>

Does it suffice to retrieve the session id through $_COOKIE["cookie_name"] or shall I do something else in order to be able to carry over my session variables values?

UPDATE

Ater some deeper digging, I see that under normal circumstances, one doesn't need to work with cookies to restore a session, as PHP does it automatically through the PHPSESSID cookie, which I don't have to care about.

However, I'using jQuery $.post() and $.ajax() functions to communicate with the PHP server, so it can't use the URL to GET/POST the SID automatically as it normally would.

Considering this, I managed to find a way to work with cookies manually, so I don't mix things up with session and cookies as mentioned here to another SO user:

PHP Session Not Restoring from Cookies

UPDATE #2

As per the answer I received, I have verified the PHP.ini configuration file to see if the cookies were enabled, etc.

Here it is:

session.save_path = "c:/wamp/tmp"
session.use_cookies = 1
session.use_only_cookies = 1
session.name = PHPSESSID
session.auto_start = 0
session.cookie_lifetime = 0
session.cookie_path = /
session.cookie_domain =
session.cookie_httponly = 
session.serialize_handler = php
session.gc_probability = 1
session.gc_divisor = 100
session.gc_maxlifetime = 1440

That's it for the cookies and sessions! And though this configuration shall work flawlessly the majority, it doesn't work. The session_start() function always starts over a new session. The best example is when I go to a section where a session_start() has been called and that I cannot access my $_SESSION["authenticated"].

Answer 1

if you want to use Session's you dont need to create Cookie, since its created by php, like you said.

In order to work with session place session_start() in the beginning of every php page.

If you want to change the cookie name created by PHP session, use session_name("CookieName")

//Sample Php Page
<?php
session_name("eNGiT");
session_start();
/*Do your Session Based Stuff Below using $_SESSION variable*/
?>

Answer 2

you don`t need to set cookie name when using session. php handles every thing sessions need. php sets cookie with name PHPSESSION and handle session id with cookie. your project should be like this.

login.php

<?php
session_start(); 

require_once "logout.php";
require_once "../data/data_access.php";



$userName = "";
$password = "";

if (isSet($_REQUEST["userName"])) $userName = $_REQUEST["userName"];
if (isSet($_REQUEST["password"])) $password = $_REQUEST["password"];

echo login($userName, $password);

function login($login, $pass) {
    if (isAuthenticUser($userName, $password)) {
        $_SESSION["authenticated"] = true;
    } else $_SESSION["authenticated"] = false;

    return $_SESSION["authenticated"];
}

another_file.php

<?php
session_start();

echo $_SESSION["authenticated"];
?>

But remember you should call session_start() function in begining of file or set session.auto_start = true in php.ini [ php configuration file ]