What does "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" means in WebSocket Protocol

websocket guid magic-string
Hakju Oh picture Hakju Oh · Nov 19, 2012 · Viewed 12.5k times · Source

I don't understand the meaning of "258EAFA5-E914-47DA-95CA-C5AB0DC85B11" in RFC 6455. Why does the server need this magic string? And why does the WebSocket protocol need this mechanism?

Answer

David Schwartz picture David Schwartz · Nov 19, 2012

The RFC explains it. It is a GUID, selected because it is "unlikely to be used by network endpoints that do not understand the WebSocket Protocol". See RFC 6455.

If you're interested in the specifics of the format for GUIDs like that, see RFC 4122.

Related questions

Send message to specific client with socket.io and node.js

I'm working with socket.io and node.js and until now it seems pretty good, but I don't know how to send a message from the server to an specific client, something like this: client.send(message, receiverSessionId) But neither …

Read More
Which websocket library to use with Node.js?

Currently there is a plethora of websocket libraries for node.js, the most popular seem to be: https://github.com/Worlize/WebSocket-Node https://github.com/einaros/ws https://github.com/LearnBoost/engine.io https://github.com/learnboost/socket.io https://…

Read More
javax.websocket client simple example

Can someone please provide me very simple example of websocket client using javax.websocket? I want to connect to websocket (ws://socket.example.com:1234), send message (add channel) and listen to messages. All messages (sent & listened) are in JSON …

Read More