Ostiary uses a secure challenge/ response mechanism to run arbitrary scripts on a server. One particular use is opening ports in firewall configurations similar to port knocking tools but without the risk of replay attacks (e.g. in a public WiFi network.)
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
The source code for Ostiary can be found here:
(c) Ray Ingles (Ostiary)
(c) Ulrich Drepper (SHA256-based Unix crypt implementation)
(c) Christian Mueller (iOS Client)