Short values only! (56 chars max)
$secret = $ssl->encrypt( $value, $client_certificate );
Looks like:
Nlmc97wDavLSF7R078NcluVX8SrYMXdDFu9otugP5LDIPTW++VUQ5DOstt3fZWm2
Z9qVS9+AL01gv1H2Ub8eNRcV67WgQw/5lMA92+T5KprSqV+CP/FXfcNCwUzBox4a
nd3pq/H6TkP0LTF7zX9Q7GZg/4UuMHmc9EcGHhoOxBM=