How can I force users to a particular subdomain to log in for MU (Multisite)?

Question

I have a Multi-Site installation of Wordpress, with multiple subdomains, but only one of the subdomains has an SSL certificate.

The domains are such:

www.example.com
blog1.example.com
blog2.example.com

secure.example.com

secure.example.com is the subdomain which has a SSL cert installed.

If someone types in blog1.example.com/wp-admin/dashboard.php, how can I force them to secure.example.com/wp-admin and then after they log in redirect them back to blog1.example.com/wp-admin/dashboard.php?

Answer 1

I would recommend using Peters Login Redirect to redirect users after login I have used it before and works well.

You could redirect users to the secure area by adding the below to your .htaccess file :

Redirect 301 blog1.example.com/wp-admin/dashboard.php secure.example.com/wp-admin 

Answer 2

I would get a wildcard SSL certificate. It allows an unlimited number of subdomains to be secured for your main domain.

Then I would force SSL login in wp-config.php:

define('FORCE_SSL_LOGIN', true);
/* That's all, stop editing! Happy blogging. */
require_once(ABSPATH . 'wp-settings.php');

Administration Over SSL