Create a serialized message packet as per spec: $key:$value\n .
function _openid_create_message($data) {
$serialized = '';
foreach ($data as $key => $value) {
if (strpos($key, ':') !== FALSE || strpos($key, "\n") !== FALSE || strpos($value, "\n") !== FALSE) {
return NULL;
}
$serialized .= "{$key}:{$value}\n";
}
return $serialized;
}