Haskell telnet client to run a command on a remote system

I've written a very simple little program using the Haskell Network.Socket library, that logs in to a remote system via telnet and runs a single command. It's the first Haskell that I've written in quite a long time, and it's nothing very impressive. In fact the hard part was getting the Socket library built on Windows Vista, it was all quite simple on Ubuntu.

Anyway, here's the current version of the code:

module Main where

import Control.Concurrent
import Data.Char
import Network
import Network.Socket
import System.IO
import System(getArgs)

telnetIAC :: Int
telnetIAC = 255

telnetWONT :: Int
telnetWONT = 252

newtype Credentials = Credential (String, String)

password :: Handle -> String -> IO ()
password h pwd = do
char <- hGetChar h      
case char of
  ':' -> do hPutStrLn h pwd
            hFlush h
  otherwise -> password h pwd


login :: Handle -> Credentials -> IO ()
login h c@(Credential (user, pwd)) = do
hPutStrLn h user
hFlush h
password h pwd
putStrLn "Logged in"


declineHandshakeOption :: Handle -> Credentials -> IO ()
declineHandshakeOption h c = do
ignoreChar <- hGetChar h      
optionChar <- hGetChar h
hPutChar h $ chr telnetIAC      
hPutChar h $ chr telnetWONT      
hPutChar h $ optionChar      
hFlush h      
handshakeAndLogin h c   

handleHandshakeInput :: Handle -> Char -> Credentials -> IO()
handleHandshakeInput h char credentials
| ord char == telnetIAC        = declineHandshakeOption h credentials
| char == ':'                  = login h credentials
| otherwise                    = handshakeAndLogin h credentials


handshakeAndLogin :: Handle -> Credentials -> IO ()
handshakeAndLogin h credentials = do
char <- hGetChar h     
handleHandshakeInput h char credentials    

main :: IO ()
main = withSocketsDo $ do       
 args <- getArgs      
 addrinfos <- getAddrInfo Nothing (Just (args !! 0)) (Just "23")       
 let serveraddr = head addrinfos       
 sock <- socket (addrFamily serveraddr) Stream defaultProtocol       
 connect sock (addrAddress serveraddr)       
 putStrLn "Connected"       
 h <- socketToHandle sock ReadWriteMode       
 hSetBuffering h (BlockBuffering Nothing)       
 handshakeAndLogin h $ Credential (args !! 1, args !! 2)       
 hPutStrLn h (args !! 3)       
 hFlush h       
 putStrLn "Command sent"       
 threadDelay 1000000 

To compile:
ghc -package network -o TelnetClient TelnetClient.hs

To run:
./TelnetClient localhost username password "./command.sh"