How can I preserve session information when redirecting from one subdomain to another?

Question

I'm programming with PHP.

I want to redirect https://abc.example.com/blah1/blah2 to https://www.example.com/blah1/blah2 but I don't want to redirect https://abc.example.com redirect to https://www.example.com

Is it possible while preserving session information across the redirections?

Thank you.

Answer 1

Use a javascript redirect.

Answer 2

If you’re using a cookie for the session ID, then you need to set the cookie for a common domain. If you are using www.example.com and foobar.example.com, you need to set the cookie for example.com to have it valid for both www.example.com and foobar.example.com.

Answer 3

If you can use apache's Redirect you can try

RedirectMatch /(.+) https://www.domain.com/$1

with PHP it would be

<?php


    if ($_SERVER['REQUEST_URI'] != "/") {
        header("Location: ".$_SERVER['REQUEST_URI']);
        exit;
    }

?>

About session being invalidated, like Gumbo says, have the cookie issued for the main domain name instead of the specific ones.

Answer 4

You can continue using the redirects as you have them now, but adjust your session.cookie_domain to use the top-level domain (e.g. example.com). You can do this by using session_set_cookie_params or setting session.cookie_domain in your php.ini file (or in a .htaccess file after php_value directive). That should allow your session information to persist across all sub-domains of your site.

Answer 5

I'd say you can redirect by posting (POST) your sessionid to a new domain and store your session data in mysql with your own session handler.