1 files changed, 47 insertions, 34 deletions

diff --git a/src/Crypto/Macaroon/Verifier.hs b/src/Crypto/Macaroon/Verifier.hs
index 713a971..7d5f094 100644
--- a/src/Crypto/Macaroon/Verifier.hs
+++ b/src/Crypto/Macaroon/Verifier.hs
@@ -1,5 +1,8 @@
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RankNTypes        #-}
+{-# LANGUAGE FlexibleInstances    #-}
+{-# LANGUAGE OverloadedStrings    #-}
+{-# LANGUAGE RankNTypes           #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE UndecidableInstances #-}
 {-|
 Module      : Crypto.Macaroon.Verifier
 Copyright   : (c) 2015 Julien Tanguy
@@ -13,50 +16,60 @@ Portability : portable
 
 -}
 module Crypto.Macaroon.Verifier (
-    Verifier
-  , verifyMacaroon
-  , verifySig
-  -- , verifyExact
-  -- , verifyFun
-  , module Data.Attoparsec.ByteString.Char8
-  , verifyCavs
+    verify
+  , ValidationError(ValidatorError, ParseError)
+  -- , (.<), (.<=), (.==), (.>), (.>=)
+  -- , module Data.Attoparsec.ByteString.Char8
 ) where
 
 
-import           Crypto.Hash
+import           Control.Monad
+import           Control.Monad.IO.Class
 import           Data.Attoparsec.ByteString
 import           Data.Attoparsec.ByteString.Char8
 import           Data.Bool
-import           Data.Byteable
 import qualified Data.ByteString                  as BS
-import           Data.Either
-import           Data.Either.Validation
-import           Data.Foldable
-import           Data.Function
-import           Data.Maybe
-import           Data.Traversable
+import           Data.Either.Combinators
 
 import           Crypto.Macaroon.Internal
+import           Crypto.Macaroon.Verifier.Internal
 
-type Verifier = Caveat -> Maybe (Either String Caveat)
 
-verifySig :: Key -> Macaroon -> Either String Macaroon
-verifySig k m = bool (Left "Signatures do not match") (Right m) $
-      signature m == foldl' hash (toBytes (hmac derivedKey (identifier m) :: HMAC SHA256)) (caveats m)
-  where
-    hash s c = toBytes (hmac s (vid c `BS.append` cid c) :: HMAC SHA256)
-    derivedKey = toBytes (hmac "macaroons-key-generator" k :: HMAC SHA256)
 
-verifyMacaroon :: Key -> [Verifier] -> Macaroon -> Either String Macaroon
-verifyMacaroon secret verifiers m = verifySig secret m >>= verifyCavs verifiers
 
-verifyCavs :: [Verifier] -> Macaroon -> Either String Macaroon
-verifyCavs verifiers m = case partitionEithers verifiedCaveats of
-    ([],_) -> Right m
-    (errs,_) -> Left (mconcat errs)
-  where
-    verifiedCaveats = map (\c -> defaultFail c $ foldMap (fmap eitherToValidation . ($c)) verifiers) $ caveats m
-    defaultFail c = maybe (Left ("No validation for this caveat: " ++ show c)) validationToEither
+-- (.<) :: (MonadIO m, Ord a, Parsable a) => Key -> m a -> Caveat -> m (Maybe (Either ValidationError Caveat))
+-- (.<) = verifyOpBool "Greater or equal" (<) "<"
+
+-- (.<=) :: (MonadIO m, Ord a, Parsable a) => Key -> m a -> Caveat -> m (Maybe (Either ValidationError Caveat))
+-- (.<=) = verifyOpBool "Strictly greater" (<=) "<="
+
+-- (.==) :: (MonadIO m, Eq a, Parsable a) => Key -> m a -> Caveat -> m (Maybe (Either ValidationError Caveat))
+-- (.==) = verifyOpBool "Not equal" (==) "="
+
+-- (.>) :: (MonadIO m, Ord a, Parsable a) => Key -> m a -> Caveat -> m (Maybe (Either ValidationError Caveat))
+-- (.>) = verifyOpBool "Less or equal" (>) ">"
+
+-- (.>=) :: (MonadIO m, Ord a, Parsable a) => Key -> m a -> Caveat -> m (Maybe (Either ValidationError Caveat))
+-- (.>=) = verifyOpBool "Strictly less" (>=) ">="
 
 
--- TODO: define API
+verify :: MonadIO m => Key -> [Caveat -> m (Maybe (Either ValidationError Caveat))] -> Macaroon -> m (Either ValidationError Macaroon)
+verify secret verifiers m = join <$> forM (verifySig secret m) (verifyCavs verifiers)
+
+
+-- verifyOpBool :: MonadIO m => String -> Parser a -> (a -> a -> Bool) -> BS.ByteString -> Key -> m a -> Caveat -> m (Maybe (Either ValidationError Caveat))
+-- verifyOpBool err p f op k val = verifyParser k valueParser $ \s -> do
+--     expected <- val
+--     return $ bool (Left $ ValidatorError err) (Right Win) =<< f expected <$> mapLeft ParseError (parseOnly p s)
+--   where
+--     valueParser = string op *> skipSpace *> takeByteString
+
+verifyParser :: (MonadIO m) => Key -> Parser a -> (a -> m (Either ValidationError Win)) -> Caveat -> m (Maybe (Either ValidationError Caveat))
+verifyParser k p f c = case parseOnly keyParser . cid $ c of
+    Left _ -> return Nothing
+    Right bs -> Just <$> case parseOnly p bs of
+      Left err -> return $ Left $ ParseError err
+      Right a -> fmap (const c) <$> f a
+  where
+    keyParser = string k *> skipSpace *> takeByteString
+