Send custom data along with handshakeData in socket.io?

Question

So I have an application running node js with socket.io as a backend and normal javascript as frontend. My application has a login system which currently simply has the clie

Answer 1

Old thread but assuming you store your jwt token/session id in session cookies (standard stuff) this gets passed to the server by default anyway when doing handshake (socket.io-client) I've noticed. Is there anything wrong with just getting the auth information for the handshake (via middleware or on.connection) via cookie? eg.

io.on('connection', function(socket) {
  // assuming base64url token
  const cookieStr = socket.handshake.headers.cookie
  const matchRes =
    cookieStr == null
      ? false
      : cookieStr.match(/my-auth-token=([a-zA-Z0-9_.-]+)/)
  if (matchRes) {
    // verify your jwt...
    if ( tokenIsGood(matchRes[1]) {
      // handle authenticated new socket
    } else {
      socket.emit('AUTH_ERR_LOGOUT')
      socket.disconnect()
    }
  } else {
    socket.emit('AUTH_ERR_LOGOUT')
    socket.disconnect()
  }
}

I'm using this now for a project and it's working fine.