## WebSockets Proxy ### wsproxy At the most basic level, wsproxy just translates WebSockets traffic to normal socket traffic. wsproxy accepts the WebSockets handshake, parses it, and then begins forwarding traffic between the client and the target in both directions. WebSockets payload data is UTF-8 encoded so in order to transport binary data it must use an encoding that can be encapsulated within UTF-8. wsproxy uses base64 to encode all traffic to and from the client. Also, WebSockets traffic starts with '\0' (0) and ends with '\xff' (255). Some buffering is done in case the data from the client is not a full WebSockets frame (i.e. does not end in 255). #### Additional wsproxy features These are not necessary for the basic operation. * Daemonizing: When the `-D` option is specified, wsproxy runs in the background as a daemon process. * SSL (the wss:// WebSockets URI): This is detected automatically by wsproxy by sniffing the first byte sent from the client and then wrapping the socket if the data starts with '\x16' or '\x80' (indicating SSL). * Flash security policy: wsproxy detects flash security policy requests (again by sniffing the first packet) and answers with an appropriate flash security policy response (and then closes the port). This means no separate flash security policy server is needed for supporting the flash WebSockets fallback emulator. * Session recording: This feature that allows recording of the traffic sent and received from the client to a file using the `--record` option. * Mini-webserver: wsproxy can detect and respond to normal web requests on the same port as the WebSockets proxy and Flash security policy. This functionality is activate with the `--web DIR` option where DIR is the root of the web directory to serve. * Wrap a program: see the "Wrap a Program" section below. #### Implementations of wsproxy There are three implementations of wsproxy: python, C, and Node (node.js). wswrapper is only implemented in C. Here is the feature support matrix for the the wsproxy implementations:
Program | Language | Multiprocess | Daemonize | SSL/wss | Flash Policy Server | Session Record | Web Server | Program Wrap |
---|---|---|---|---|---|---|---|---|
wsproxy.py | python | yes | yes | yes 1 | yes | yes | yes | yes |
wsproxy | C | yes | yes | yes | yes | no | no | no |
wsproxy.js | Node (node.js) | yes | no | no | no | no | no | no |