How can I force users to access my page over HTTPS instead of HTTP?

Question

I\'ve got just one page that I want to force to be accessed as an HTTPS page (PHP on Apache). How do I do this without making the whole directory require HTTPS? Or, if you s

Answer 1

Had to do something like this when running behind a load balancer. Hat tip https://stackoverflow.com/a/16076965/766172

function isSecure() {
    return (
        (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off')
     || $_SERVER['SERVER_PORT'] == 443
     || (
            (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https')
         || (!empty($_SERVER['HTTP_X_FORWARDED_SSL'])   && $_SERVER['HTTP_X_FORWARDED_SSL'] == 'on')
        )
    );
}

function requireHTTPS() {
    if (!isSecure()) {
        header('Location: https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'], TRUE, 301);
        exit;
    }
}