The WebSocket Protocol Explained
9 months ago
- #Protocol
- #Networking
- #WebSocket
- WebSockets provide a persistent two-way communication channel over a single TCP connection.
- WebSocket messages are made up of one or more frames, with simple message formats.
- Clients must mask messages sent to servers to prevent cross-protocol attacks.
- Masking involves XORing the payload with a 4-byte key, repeated as necessary.
- The most significant bit in the second byte indicates if the payload is masked, with the remaining 7 bits specifying payload length.
- WebSocket messages can span multiple frames, with boundaries determined by the FIN bit in the header.
- Header bytes include FIN, RSV1-3 (reserved), and opcode (indicating frame type like Text, Binary, Close, Ping, Pong).
- Compression and connection establishment are additional topics not covered in this summary.