Login remotely and keep the session active

Question

I made a simple PHP login system to login remotely, but the SESSION won't store any data. Please look at the pseudo code below. Please note that mainserver and remoteserver are actually real web addresses. I just don't have enough reputation to post 2 links:

File: mainserver/login.php

$username = $_POST[ "username" ];
$userpassword = $_POST[ "password" ];

$result = check_logIn( $username, $password );
if ( $result ) {

    $_SESSION[ "is_loggedIn" ] = true;
    die ( true );

} else die( false );

File: remoteserver/remoteLogin.php

$http_query = http_build_query( array( 

        "username" => "Username goes here",
        "password" => "Password goes here"

) );


$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL,"mainserver/login.php");
curl_setopt( $ch, CURLOPT_COOKIEJAR, md5( rand() ) .".txt" );
curl_setopt( $ch, CURLOPT_POST, 1 );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $http_query );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
$output = curl_exec ( $ch );
curl_close( $ch );

Even when the mainserver returns true (after the login was done successfully), I visit the http://mainserver.com/ but the $_SESSION[ "is_loggedIn" ] is still not there; and technically, I'm still treated as a logged out person.

Is there anything missing that I should address?

Answer 1

Your problem is this: Like when you log in via chrome, you are not logged in in firefox. The same goes for your server running the script, the "mainserver"'s session is linked to "remoteserver"'s CURL request and not you or your browser. Even if you share an IP or physical machine.

To achieve SSO you can look at Single Sign On across multiple domains

Despite it being closed it has some useful answers.

Or try posting a more specific question that fits your (new) needs.