Wuss

Wuss is a library that lets you easily create secure WebSocket clients over the WSS protocol. It is a small addition to the websockets package and is adapted from existing solutions by @jaspervdj, @mpickering, and @elfenlaid.

Example

import Wuss

import Control.Concurrent (forkIO)
import Control.Monad (forever, unless, void)
import Data.Text (Text, pack)
import Network.WebSockets (ClientApp, receiveData, sendClose, sendTextData)

main :: IO ()
main = runSecureClient "echo.websocket.org" 443 "/" ws

ws :: ClientApp ()
ws connection = do
    putStrLn "Connected!"

    void . forkIO . forever $ do
        message <- receiveData connection
        print (message :: Text)

    let loop = do
            line <- getLine
            unless (null line) $ do
                sendTextData connection (pack line)
                loop
    loop

    sendClose connection (pack "Bye!")

Retry

Note that it is possible for the connection itself or any message to fail and need to be retried. Fortunately this can be handled by something like the retry package. See this comment for an example.

Documentation

runSecureClient

Arguments

:: MonadIO m

=> MonadMask m

=> HostName

Host

-> PortNumber

Port

-> String

Path

-> ClientApp a

Application

-> m a

A secure replacement for runClient.

>>> let app _connection = return ()
>>> runSecureClient "echo.websocket.org" 443 "/" app

runSecureClientWith

Arguments

:: MonadIO m

=> MonadMask m

=> HostName

Host

-> PortNumber

Port

-> String

Path

-> ConnectionOptions

Options

-> Headers

Headers

-> ClientApp a

Application

-> m a

A secure replacement for runClientWith.

>>> let options = defaultConnectionOptions
>>> let headers = []
>>> let app _connection = return ()
>>> runSecureClientWith "echo.websocket.org" 443 "/" options headers app

If you want to run a secure client without certificate validation, use runClientWithStream. For example:

let host = "echo.websocket.org"
let port = 443
let path = "/"
let options = defaultConnectionOptions
let headers = []
let tlsSettings = TLSSettingsSimple
    -- This is the important setting.
    { settingDisableCertificateValidation = True
    , settingDisableSession = False
    , settingUseServerName = False
    }
let connectionParams = ConnectionParams
    { connectionHostname = host
    , connectionPort = port
    , connectionUseSecure = Just tlsSettings
    , connectionUseSocks = Nothing
    }

context <- initConnectionContext
connection <- connectTo context connectionParams
stream <- makeStream
    (fmap Just (connectionGetChunk connection))
    (maybe (return ()) (connectionPut connection . toStrict))
runClientWithStream stream host path options headers $ \ connection -> do
    -- Do something with the connection.
    return ()

newtype Config

Configures a secure WebSocket connection.

Constructors

Config

Fields

• connectionGet :: Connection -> IO ByteString

  How to get bytes from the connection. Typically connectionGetChunk, but could be something else like connectionGetLine.

defaultConfig :: Config

The default Config value used by runSecureClientWith.

runSecureClientWithConfig

Arguments

:: MonadIO m

=> MonadMask m

=> HostName

Host

-> PortNumber

Port

-> String

Path

-> Config

Config

-> ConnectionOptions

Options

-> Headers

Headers

-> ClientApp a

Application

-> m a

Runs a secure WebSockets client with the given Config.