e83397a1db
This change adapt the auth combinator example to the new router code. In general, the server interpretation of user-written combinators will be affected by the new routing code. The change here also introduces a change in functionality: previously, wrong authentication triggered a "hard failure", whereas we now trigger a "soft failure", which is recoverable. For the simple example, this does not make a lot of difference. In general, I think having a soft failure is the right option to take here, although we want a more general story about the relative priorities of different error codes.
79 lines
2.2 KiB
Haskell
79 lines
2.2 KiB
Haskell
{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE TypeFamilies #-}
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{-# LANGUAGE DeriveGeneric #-}
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{-# LANGUAGE TypeOperators #-}
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{-# LANGUAGE FlexibleInstances #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# LANGUAGE ScopedTypeVariables #-}
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import Data.Aeson
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import Data.ByteString (ByteString)
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import Data.Text (Text)
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import GHC.Generics
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import Network.HTTP.Types
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import Network.Wai
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import Network.Wai.Handler.Warp
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import Servant
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import Servant.Server.Internal
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-- Pretty much stolen/adapted from
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-- https://github.com/haskell-servant/HaskellSGMeetup2015/blob/master/examples/authentication-combinator/AuthenticationCombinator.hs
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type DBLookup = ByteString -> IO Bool
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isGoodCookie :: DBLookup
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isGoodCookie = return . (== "good password")
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data AuthProtected
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instance HasServer rest => HasServer (AuthProtected :> rest) where
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type ServerT (AuthProtected :> rest) m = ServerT rest m
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route Proxy a = WithRequest $ \ request ->
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route (Proxy :: Proxy rest) $ do
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case lookup "Cookie" (requestHeaders request) of
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Nothing -> return $ failWith $ HttpError status401 (Just "Missing auth header.")
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Just v -> do
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authGranted <- isGoodCookie v
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if authGranted
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then a
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else return $ failWith $ HttpError status403 (Just "Invalid cookie.")
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type PrivateAPI = Get '[JSON] [PrivateData]
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type PublicAPI = Get '[JSON] [PublicData]
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type API = "private" :> AuthProtected :> PrivateAPI
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:<|> PublicAPI
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newtype PrivateData = PrivateData { ssshhh :: Text }
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deriving (Eq, Show, Generic)
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instance ToJSON PrivateData
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newtype PublicData = PublicData { somedata :: Text }
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deriving (Eq, Show, Generic)
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instance ToJSON PublicData
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api :: Proxy API
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api = Proxy
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server :: Server API
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server = return prvdata :<|> return pubdata
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where prvdata = [PrivateData "this is a secret"]
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pubdata = [PublicData "this is a public piece of data"]
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main :: IO ()
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main = run 8080 (serve api server)
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{- Sample session:
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$ curl http://localhost:8080/
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[{"somedata":"this is a public piece of data"}]
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$ curl http://localhost:8080/private
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Missing auth header.
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$ curl -H "Cookie: good password" http://localhost:8080/private
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[{"ssshhh":"this is a secret"}]
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$ curl -H "Cookie: bad password" http://localhost:8080/private
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Invalid cookie.
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-}
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