Secure Socket Funneling (SSF) is a network tool and toolkit. It provides simple and efficient ways to forward data from multiple sockets (TCP or UDP) through a single secure TLS link to a remote computer.
- Local and remote TCP port forwarding
- Local and remote UDP port forwarding
- Local and remote SOCKS server
- Local and remote shell through socket
- Native relay protocol
- TLS connection with strongest cipher-suites
The initial aim of SSF was to provide an easy way for users and developers to multiplex and demultiplex various network data flows. It was designed to:
- be cross platform
- be lightweight (preferably standalone)
- be easily extendible
- provide modern (TLS 1.2) secure point-to-point communication with the strongest cipher-suites
- provide high performance communications by using the benefits of modern multi-core / multi-threaded architecture
These requirements excluded SSH which showed limitations on all items (particularly in performance, but also by the lack of server side application on Windows). Classic VPN software was also excluded because the requirement of administrator rights was too limiting.
- One feature which was not present in any another equivalent network tool was UDP forwarding. UDP is nonetheless widely used in real-time services (VoIP, online gaming, …) and for DNS. Therefore, SSF is able to forward both TCP and UDP from the client to the server (options -L and -U) as well as from the server to the client (options -R and -V)
- SSF also allows dynamic port forwarding with a SOCKS server from the client to the server (option -D just like SSH) and from the server to the client (option -F which SSH does not allow)
- The bouncing feature allows to simply forward the traffic from one point to another, through a list of intermediary relay servers
SSF command-line was designed as a drop-in replacement for SSH (on equivalent features, such as port forwarding or SOCKS), so that you can benefit of the performance and security gain with minimal – or even, not a single – update for your scripts and tools.