I'm working on a shopping cart website and I would like to redirect the user to a HTTPS page when he's entering his billing details and maintain the HTTPS connection for the next pages until he logs out.
What do I need to install on the server (I'm using Apache) in order to do this, and how can this redirect be done from PHP?
Try something like this (should work for Apache and IIS):
if (empty($_SERVER['HTTPS']) || $_SERVER['HTTPS'] === "off") {
$location = 'https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
header('HTTP/1.1 301 Moved Permanently');
header('Location: ' . $location);
exit;
}