So, if you’ve got a Wordpress blog and you want to access it via HTTP and HTTPS then you might notice that when using the HTTPS version all the links (and form actions) are set to use the HTTP version. Thanks to a little help from a plugin and Paul Bain we came up with a solution of putting this into the wp-config.php file:

if( $_SERVER['HTTPS'] ) {
    define('WP_HOME', preg_replace('^http', 'https', WP_HOME));
    define('WP_SITEURL', preg_replace('^http', 'https', WP_SITEURL));
}

Seems to work pretty well!