* @return string An hmac hash of the data + key
*/
public static function hmac( $data, $key, $raw = true ) {
+ if ( !is_string( $key ) ) {
+ // a fatal error in HHVM; an exception will at least give us a stack trace
+ throw new InvalidArgumentException( 'Invalid key type: ' . gettype( $key ) );
+ }
return hash_hmac( self::hashAlgo(), $data, $key, $raw );
}