In OpenCart i saw the following code:
// Check if SSL
if ((isset($_SERVER['HTTPS']) && (($_SERVER['HTTPS'] == 'on') || ($_SERVER['HTTPS'] == '1'))) || (isset($_SERVER['HTTPS']) && $_SERVER['SERVER_PORT'] == 443)) {
$_SERVER['HTTPS'] = true;
} elseif (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] == 'https' || !empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] == 'on') {
$_SERVER['HTTPS'] = true;
} else {
$_SERVER['HTTPS'] = false;
}
What is $_SERVER['HTTP_X_FORWARDED_PROTO'] or $_SERVER['HTTP_X_FORWARDED_SSL']? I could't find them in PHP Manual.