Before this, if a request was not coming from an existing user (no token
in the request or no user with the given token), then and only then
would we send the access captcha. This meant that if a user left a chat
message and became absent, they wouldn't be prompted to do the access
captcha again until their message was eventuallly rotated. (While
messages exist we don't delete the users who posted them.)
This commit makes it so if user['verified'] is None, the user is kicked
and prompted with the access captcha. This is automatically done for
absent users by a background task.
Client and server both close the connection if they don't hear from the
other party after a timeout period. This is a failsafe and should
improve reliability.
By default the buffer is exhausted every 4 seconds. This should defend against
a potential DoS against clients with JavaScript enabled. Before this, any
request with no token would generate a new user and immediately broadcast the
new user to all the websockets. It's best to lock down as much as possible the
number of places a client can cause the server to broadcasts to all the
websockets.
Incoming requests are handled in anonstream/routes/. Route handlers
mainly depend on files in anonstream/, which in turn depend on files in
anonstream/helpers/ and anonstream/utils/. Utils are pure functions and
helpers are almost pure functions; they don't mutate state but they
do depend on the global app config.
n9k