yesod/yesod-auth/Yesod/Auth/HashDB.hs
2013-03-14 09:28:51 +02:00

273 lines
9.6 KiB
Haskell

{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE GADTs #-}
{-# LANGUAGE CPP #-}
-------------------------------------------------------------------------------
-- |
-- Module : Yesod.Auth.HashDB
-- Copyright : (c) Patrick Brisbin 2010
-- License : as-is
--
-- Maintainer : pbrisbin@gmail.com
-- Stability : Stable
-- Portability : Portable
--
-- A yesod-auth AuthPlugin designed to look users up in Persist where
-- their user id's and a salted SHA1 hash of their password is stored.
--
-- Example usage:
--
-- > -- import the function
-- > import Auth.HashDB
-- >
-- > -- make sure you have an auth route
-- > mkYesodData "MyApp" [$parseRoutes|
-- > / RootR GET
-- > /auth AuthR Auth getAuth
-- > |]
-- >
-- >
-- > -- make your app an instance of YesodAuth using this plugin
-- > instance YesodAuth MyApp where
-- > type AuthId MyApp = UserId
-- >
-- > loginDest _ = RootR
-- > logoutDest _ = RootR
-- > getAuthId = getAuthIdHashDB AuthR (Just . UniqueUser)
-- > authPlugins = [authHashDB (Just . UniqueUser)]
-- >
-- >
-- > -- include the migration function in site startup
-- > withServer :: (Application -> IO a) -> IO a
-- > withServer f = withConnectionPool $ \p -> do
-- > runSqlPool (runMigration migrateUsers) p
-- > let h = DevSite p
--
-- Note that function which converts username to unique identifier must be same.
--
-- Your app must be an instance of YesodPersist. and the username,
-- salt and hashed-passwords should be added to the database.
--
-- > echo -n 'MySaltMyPassword' | sha1sum
--
-- can be used to get the hash from the commandline.
--
-------------------------------------------------------------------------------
module Yesod.Auth.HashDB
( HashDBUser(..)
, Unique (..)
, setPassword
-- * Authentification
, validateUser
, authHashDB
, getAuthIdHashDB
-- * Predefined data type
, User
, UserGeneric (..)
, UserId
, migrateUsers
) where
import Yesod.Persist
import Yesod.Form
import Yesod.Auth
import Yesod.Core
import Text.Hamlet (hamlet)
import Control.Applicative ((<$>), (<*>))
import Control.Monad (replicateM,liftM)
import Control.Monad.IO.Class (MonadIO, liftIO)
import Control.Monad.Trans.Class (lift)
import qualified Data.ByteString.Lazy.Char8 as BS (pack)
import Data.Digest.Pure.SHA (sha1, showDigest)
import Data.Text (Text, pack, unpack, append)
import Data.Maybe (fromMaybe)
import System.Random (randomRIO)
-- | Interface for data type which holds user info. It's just a
-- collection of getters and setters
class HashDBUser user where
-- | Retrieve password hash from user data
userPasswordHash :: user -> Maybe Text
-- | Retrieve salt for password
userPasswordSalt :: user -> Maybe Text
-- | Deprecated for the better named setSaltAndPasswordHash
setUserHashAndSalt :: Text -- ^ Salt
-> Text -- ^ Password hash
-> user -> user
setUserHashAndSalt = setSaltAndPasswordHash
-- | a callback for setPassword
setSaltAndPasswordHash :: Text -- ^ Salt
-> Text -- ^ Password hash
-> user -> user
setSaltAndPasswordHash = setUserHashAndSalt
-- | Generate random salt. Length of 8 is chosen arbitrarily
randomSalt :: MonadIO m => m Text
randomSalt = pack `liftM` liftIO (replicateM 8 (randomRIO ('0','z')))
-- | Calculate salted hash using SHA1.
saltedHash :: Text -- ^ Salt
-> Text -- ^ Password
-> Text
saltedHash salt =
pack . showDigest . sha1 . BS.pack . unpack . append salt
-- | Set password for user. This function should be used for setting
-- passwords. It generates random salt and calculates proper hashes.
setPassword :: (MonadIO m, HashDBUser user) => Text -> user -> m user
setPassword pwd u = do salt <- randomSalt
return $ setSaltAndPasswordHash salt (saltedHash salt pwd) u
----------------------------------------------------------------
-- Authentification
----------------------------------------------------------------
-- | Given a user ID and password in plaintext, validate them against
-- the database values.
validateUser :: ( YesodPersist yesod
, b ~ YesodPersistBackend yesod
, PersistMonadBackend (b (HandlerT yesod IO)) ~ PersistEntityBackend user
, PersistUnique (b (HandlerT yesod IO))
, PersistEntity user
, HashDBUser user
) =>
Unique user -- ^ User unique identifier
-> Text -- ^ Password in plaint-text
-> HandlerT yesod IO Bool
validateUser userID passwd = do
-- Checks that hash and password match
let validate u = do hash <- userPasswordHash u
salt <- userPasswordSalt u
return $ hash == saltedHash salt passwd
-- Get user data
user <- runDB $ getBy userID
return $ fromMaybe False $ validate . entityVal =<< user
login :: AuthRoute
login = PluginR "hashdb" ["login"]
-- | Handle the login form. First parameter is function which maps
-- username (whatever it might be) to unique user ID.
postLoginR :: ( YesodAuth y, YesodPersist y
, HashDBUser user, PersistEntity user
, b ~ YesodPersistBackend y
, PersistMonadBackend (b (HandlerT y IO)) ~ PersistEntityBackend user
, PersistUnique (b (HandlerT y IO))
)
=> (Text -> Maybe (Unique user))
-> HandlerT Auth (HandlerT y IO) ()
postLoginR uniq = do
(mu,mp) <- lift $ runInputPost $ (,)
<$> iopt textField "username"
<*> iopt textField "password"
isValid <- lift $ fromMaybe (return False)
(validateUser <$> (uniq =<< mu) <*> mp)
if isValid
then lift $ setCreds True $ Creds "hashdb" (fromMaybe "" mu) []
else do setMessage "Invalid username/password"
redirect LoginR
-- | A drop in for the getAuthId method of your YesodAuth instance which
-- can be used if authHashDB is the only plugin in use.
getAuthIdHashDB :: ( YesodAuth master, YesodPersist master
, HashDBUser user, PersistEntity user
, Key user ~ AuthId master
, b ~ YesodPersistBackend master
, PersistMonadBackend (b (HandlerT master IO)) ~ PersistEntityBackend user
, PersistUnique (b (HandlerT master IO))
)
=> (AuthRoute -> Route master) -- ^ your site's Auth Route
-> (Text -> Maybe (Unique user)) -- ^ gets user ID
-> Creds master -- ^ the creds argument
-> HandlerT master IO (Maybe (AuthId master))
getAuthIdHashDB authR uniq creds = do
muid <- maybeAuthId
case muid of
-- user already authenticated
Just uid -> return $ Just uid
Nothing -> do
x <- case uniq (credsIdent creds) of
Nothing -> return Nothing
Just u -> runDB (getBy u)
case x of
-- user exists
Just (Entity uid _) -> return $ Just uid
Nothing -> do
setMessage "User not found"
redirect $ authR LoginR
-- | Prompt for username and password, validate that against a database
-- which holds the username and a hash of the password
authHashDB :: ( YesodAuth m, YesodPersist m
, HashDBUser user
, PersistEntity user
, b ~ YesodPersistBackend m
, PersistMonadBackend (b (HandlerT m IO)) ~ PersistEntityBackend user
, PersistUnique (b (HandlerT m IO)))
=> (Text -> Maybe (Unique user)) -> AuthPlugin m
authHashDB uniq = AuthPlugin "hashdb" dispatch $ \tm -> toWidget [hamlet|
$newline never
<div id="header">
<h1>Login
<div id="login">
<form method="post" action="@{tm login}">
<table>
<tr>
<th>Username:
<td>
<input id="x" name="username" autofocus="" required>
<tr>
<th>Password:
<td>
<input type="password" name="password" required>
<tr>
<td>&nbsp;
<td>
<input type="submit" value="Login">
<script>
if (!("autofocus" in document.createElement("input"))) {
document.getElementById("x").focus();
}
|]
where
dispatch "POST" ["login"] = postLoginR uniq >>= sendResponse
dispatch _ _ = notFound
----------------------------------------------------------------
-- Predefined datatype
----------------------------------------------------------------
-- | Generate data base instances for a valid user
share [mkPersist sqlSettings, mkMigrate "migrateUsers"]
[persistUpperCase|
User
username Text Eq
password Text
salt Text
UniqueUser username
|]
instance HashDBUser (UserGeneric backend) where
userPasswordHash = Just . userPassword
userPasswordSalt = Just . userSalt
setSaltAndPasswordHash s h u = u { userSalt = s
, userPassword = h
}