connection

Simple and easy network connections API http://github.com/vincenthz/hs-connection

Version on this page:0.2.5
LTS Haskell 8.20:0.2.8
Stackage Nightly 2017-06-26:0.2.8
Latest on Hackage:0.2.8
BSD3 licensed and maintained by Vincent Hanquez

Module documentation for 0.2.5

haskell Connection library

Simple network library for all your connection need.

Features:

  • Really simple to use
  • SSL/TLS
  • SOCKS

Usage

Connect to www.example.com on port 4567 (without socks or tls), then send a byte, receive a single byte, print it, and close the connection:

import qualified Data.ByteString as B
import Network.Connection
import Data.Default

main = do
    ctx <- initConnectionContext
    con <- connectTo ctx $ ConnectionParams
                              { connectionHostname  = "www.example.com"
                              , connectionPort      = 4567
                              , connectionUseSecure = Nothing
                              , connectionUseSocks  = Nothing
                              }
    connectionPut con (B.singleton 0xa)
    r <- connectionGet con 1
    putStrLn $ show r
    connectionClose con

Using a socks proxy is easy, we just need replacing the connectionSocks parameter, for example connecting to the same host, but using a socks proxy at localhost:1080:

con <- connectTo ctx $ ConnectionParams
                       { connectionHostname  = "www.example.com"
                       , connectionPort      = 4567
                       , connectionUseSecure = Nothing
                       , connectionUseSocks  = Just $ SockSettingsSimple "localhost" 1080
                       }

Connecting to a SSL style socket is equally easy, and need to set the UseSecure fields in ConnectionParams:

con <- connectTo ctx $ ConnectionParams
                       { connectionHostname  = "www.example.com"
                       , connectionPort      = 4567
                       , connectionUseSecure = Just def
                       , connectionUseSocks  = Nothing
                       }

And finally, you can start TLS in the middle of an insecure connection. This is great for protocol using STARTTLS (e.g. IMAP, SMTP):

{-# LANGUAGE OverloadedStrings #-}
import qualified Data.ByteString as B
import Data.ByteString.Char8 ()
import Network.Connection
import Data.Default

main = do
    ctx <- initConnectionContext
    con <- connectTo ctx $ ConnectionParams
                              { connectionHostname  = "www.example.com"
                              , connectionPort      = 4567
                              , connectionUseSecure = Nothing
                              , connectionUseSocks  = Nothing
                              }
    -- talk to the other side with no TLS: says hello and starttls
    connectionPut con "HELLO\n"
    connectionPut con "STARTTLS\n"

    -- switch to TLS
    connectionSetSecure ctx con def

    -- the connection is from now on using TLS, we can send secret for example
    connectionPut con "PASSWORD 123\n"
    connectionClose con

Changes

Version 0.2.1 (16 April 2014)

  • Fix a difference between TLSSettings and TLSSettingsSimple, where connection would override the connection hostname and port in the simple case, but leave the field as is with TLSSettings. TLSSettings can now be used properly as template, and will be correctly overriden at the identification level only.
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