Use new Delayed type to capture authentication

servant-server/src/Servant/Server/Internal/Authentication.hs

@@ -31,18 +31,14 @@ import           Data.Word8                 (isSpace, toLower, _colon)
 import           GHC.TypeLits               (KnownSymbol, symbolVal)
 import           Data.Text.Encoding         (decodeUtf8)
 import           Data.Text                  (splitOn)
-import           Network.HTTP.Types.Status  (status401)
+import           Network.Wai                (Request, requestHeaders)
-import           Network.Wai                (Request, Response, requestHeaders,
+import Servant.Server.Internal.ServantErr (err401, ServantErr(errHeaders))
-                                             responseBuilder)
 import           Servant.API.Authentication (AuthPolicy (Strict, Lax),
                                              AuthProtected,
                                              BasicAuth (BasicAuth),
-                                             JWTAuth (..))
+                                             JWTAuth(..))
-                                             JWTAuth)
+import            Web.JWT                    (decodeAndVerifySignature, JWT, VerifiedJWT, Secret)
-import           Servant.Server.Internal.RoutingApplication (RouteResult(FailFatal))
+import qualified  Web.JWT as JWT             (decode)
-
-import            Web.JWT                    (JWT, VerifiedJWT, Secret)
-import qualified  Web.JWT as JWT             (decode, decodeAndVerifySignature, secret)
 
 -- | Class to represent the ability to extract authentication-related
 -- data from a 'Request' object.
@@ -52,10 +48,10 @@ class AuthData a where
 -- | handlers to deal with authentication failures.
 data AuthHandlers authData = AuthHandlers
     {   -- we couldn't find the right type of auth data (or any, for that matter)
-        onMissingAuthData :: IO ServantError
+        onMissingAuthData :: IO ServantErr
     ,
         -- we found the right type of auth data in the request but the check failed
-        onUnauthenticated :: authData -> IO ServantError
+        onUnauthenticated :: authData -> IO ServantErr
     }
 
 -- | concrete type to provide when in 'Strict' mode.
@@ -100,7 +96,8 @@ basicAuthHandlers :: forall realm. KnownSymbol realm => AuthHandlers (BasicAuth
 basicAuthHandlers =
     let realmBytes = (fromString . symbolVal) (Proxy :: Proxy realm)
         headerBytes = "Basic realm=\"" <> realmBytes <> "\""
-        authFailure = responseBuilder status401 [("WWW-Authenticate", headerBytes)] mempty in
+        authFailure = err401 { errHeaders = [("WWW-Authenticate", headerBytes)] }
+    in
         AuthHandlers (return authFailure)  ((const . return) authFailure)
 
 -- | Basic authentication combinator with strict failure.
@@ -130,8 +127,7 @@ instance AuthData JWTAuth where
 jwtAuthHandlers :: AuthHandlers JWTAuth
 jwtAuthHandlers = AuthHandlers (return missingData) ((const . return) authFailure)
   where
-    withError e =
+    withError e = err401 { errHeaders = [("WWW-Authenticate", "Bearer error=\""<>e<>"\"")] }
-      responseBuilder status401 [("WWW-Authenticate", "Bearer error=\""<>e<>"\"")] mempty
     missingData = withError "invalid_request"
     authFailure = withError "invalid_token"
 
@@ -141,5 +137,5 @@ jwtAuthHandlers = AuthHandlers (return missingData) ((const . return) authFailur
 -- One can use  strictProtect and laxProtect to make more complex authentication
 -- and authorization schemes.
 jwtAuthStrict :: Secret -> subserver -> AuthProtected JWTAuth (JWT VerifiedJWT) subserver 'Strict
-jwtAuthStrict secret subserver = strictProtect (return . JWT.decodeAndVerifySignature secret . unJWTAuth) jwtAuthHandlers subserver
+jwtAuthStrict secret subserver = strictProtect (return . decodeAndVerifySignature secret . unJWTAuth) jwtAuthHandlers subserver
 

servant-server/src/Servant/Server/Internal/RoutingApplication.hs

@@ -179,11 +179,13 @@ addMethodCheck :: Delayed a
 addMethodCheck (Delayed captures method auth body server) new =
   Delayed captures (combineRouteResults const method new) auth body server
 
+-- | Add a method to perform authorization in strict mode.
 addAuthStrictCheck :: Delayed (AuthProtected auth usr (usr -> a) 'Strict)
-                  -> IO (RouteResult (Maybe usr))
+                  -> IO (RouteResult (Maybe auth))
                   -> Delayed a
-addAuthStrictCheck delayed@(Delayed captures method _ body server) new =
+                  -- -> Delayed a
-    let newAuth = runDelayed delayed `bindRouteResults` \ authProtectionStrict -> new `bindRouteResults` \ mAuthData -> case mAuthData of
+addAuthStrictCheck delayed@(Delayed captures method _ body _) new =
+    let newAuth = runDelayed delayed `bindRouteResults` \authProtectionStrict -> new `bindRouteResults` \mAuthData -> case mAuthData of
 
             Nothing -> do
                 -- we're in strict mode: don't let the request go
@@ -192,26 +194,25 @@ addAuthStrictCheck delayed@(Delayed captures method _ body server) new =
                 return $ FailFatal resp
 
             -- successfully pulled auth data out of the request
-            Just authData -> do
+            Just aData -> do
-                mUsr <- (checkAuthStrict authProtectionStrict) authData
+                mUsr <- (checkAuthStrict authProtectionStrict) aData
                 case mUsr of
                     -- this user is not authenticated
                     Nothing -> do
-                        resp <- onUnauthenticated (authHandlers authProtectionStrict) authData
+                        resp <- onUnauthenticated (authHandlers authProtectionStrict) aData
                         return $ FailFatal resp
 
                     -- this user is authenticated
                     Just usr ->
                         (return . Route . subServerStrict authProtectionStrict) usr
-    in Delayed captures method newAuth body server
+    in Delayed captures method newAuth body (\_ y _ -> Route y)
-
 
 -- | Add a body check to the end of the body block.
 addBodyCheck :: Delayed (a -> b)
              -> IO (RouteResult a)
              -> Delayed b
 addBodyCheck (Delayed captures method auth body server) new =
-  Delayed captures method auth (combineRouteResults (,) body new) (\ x (y, v) z -> ($ v) <$> server x y z)
+  Delayed captures method auth (combineRouteResults (,) body new) (\ x y (z, v) -> ($ v) <$> server x y z)
 
 -- | Add an accept header check to the end of the body block.
 -- The accept header check should occur after the body check,
@@ -255,11 +256,12 @@ combineRouteResults f m1 m2 =
 -- blocks on to the actual handler.
 runDelayed :: Delayed a
            -> IO (RouteResult a)
-runDelayed (Delayed captures method body server) =
+runDelayed (Delayed captures method auth body server) =
   captures `bindRouteResults` \ c ->
   method   `bindRouteResults` \ _ ->
+  auth     `bindRouteResults` \ a ->
   body     `bindRouteResults` \ b ->
-  return (server c b)
+  return (server c a b)
 
 -- | Runs a delayed server and the resulting action.
 -- Takes a continuation that lets us send a response.