fradrive/src/Utils.hs
2019-01-30 16:00:18 +01:00

665 lines
22 KiB
Haskell

{-# OPTIONS_GHC -fno-warn-orphans #-} -- Monad FormResult
module Utils
( module Utils
) where
import ClassyPrelude.Yesod hiding (foldlM)
-- import Data.Double.Conversion.Text -- faster implementation for textPercent?
import qualified Data.Foldable as Fold
import Data.Foldable as Utils (foldlM, foldrM)
import Data.Monoid (Sum(..))
import Data.CaseInsensitive (CI)
import qualified Data.CaseInsensitive as CI
import qualified Data.ByteString as BS
import qualified Data.ByteString.Lazy as LBS
import qualified Data.Text as Text
import Utils.DB as Utils
import Utils.TH as Utils
import Utils.DateTime as Utils
import Utils.PathPiece as Utils
import Utils.Message as Utils
import Utils.Lang as Utils
import Control.Lens as Utils (none)
import Text.Blaze (Markup, ToMarkup)
import Data.Char (isDigit, isSpace)
import Data.Text (dropWhileEnd, takeWhileEnd, justifyRight)
import Numeric (showFFloat)
import Control.Lens
import Data.Set (Set)
import qualified Data.Set as Set
import Data.Map (Map)
import qualified Data.Map as Map
-- import qualified Data.List as List
import Control.Monad.Trans.Except (ExceptT(..), throwE, runExceptT)
import Control.Monad.Except (MonadError(..))
import Control.Monad.Trans.Maybe (MaybeT(..))
import Control.Monad.Catch hiding (throwM)
import qualified Database.Esqueleto as E (Value, unValue)
import Language.Haskell.TH
import Instances.TH.Lift ()
import Text.Shakespeare.Text (st)
import qualified Data.Aeson as Aeson
import Data.Universe
import qualified Crypto.Saltine.Internal.ByteSizes as Saltine
import qualified Data.ByteString.Base64.URL as Base64
import qualified Crypto.Saltine.Core.SecretBox as SecretBox
import qualified Crypto.Saltine.Class as Saltine
import qualified Crypto.Data.PKCS7 as PKCS7
import Data.Fixed (Centi)
import Data.Ratio ((%))
-----------
-- Yesod --
-----------
newtype MsgRendererS site = MsgRenderer { render :: forall msg. RenderMessage site msg => msg -> Text }
getMsgRenderer :: forall m site. (MonadHandler m, HandlerSite m ~ site) => m (MsgRendererS site)
getMsgRenderer = do
mr <- getMessageRender
return $ MsgRenderer (mr . SomeMessage :: forall msg. RenderMessage site msg => msg -> Text)
instance Monad FormResult where
FormMissing >>= _ = FormMissing
(FormFailure errs) >>= _ = FormFailure errs
(FormSuccess a) >>= f = f a
guardAuthResult :: MonadHandler m => AuthResult -> m ()
guardAuthResult AuthenticationRequired = notAuthenticated
guardAuthResult (Unauthorized t) = permissionDenied t
guardAuthResult Authorized = return ()
data UnsupportedAuthPredicate route = UnsupportedAuthPredicate Text route
deriving (Eq, Ord, Typeable, Show)
instance (Show route, Typeable route) => Exception (UnsupportedAuthPredicate route)
unsupportedAuthPredicate :: ExpQ
unsupportedAuthPredicate = do
logFunc <- logErrorS
[e| \tag route -> do
$(return logFunc) "AccessControl" [st|"!#{toPathPiece tag}" used on route that doesn't support it: #{tshow route}|]
unauthorizedI (UnsupportedAuthPredicate (toPathPiece tag) route)
|]
class RedirectUrl site url => HasRoute site url where
urlRoute :: url -> Route site
instance HasRoute site (Route site) where
urlRoute = id
instance (key ~ Text, val ~ Text) => HasRoute site (Route site, Map key val) where
urlRoute = view _1
instance (key ~ Text, val ~ Text) => HasRoute site (Route site, [(key, val)]) where
urlRoute = view _1
instance (HasRoute site a, PathPiece b) => HasRoute site (Fragment a b) where
urlRoute (a :#: _) = urlRoute a
data SomeRoute site = forall url. HasRoute site url => SomeRoute url
instance RedirectUrl site (SomeRoute site) where
toTextUrl (SomeRoute url) = toTextUrl url
instance HasRoute site (SomeRoute site) where
urlRoute (SomeRoute url) = urlRoute url
---------------------
-- Text and String --
---------------------
tickmark :: IsString a => a
tickmark = fromString ""
-- Avoid annoying warnings:
tickmarkS :: String
tickmarkS = tickmark
tickmarkT :: Text
tickmarkT = tickmark
text2Html :: Text -> Html
text2Html = toHtml -- prevents ambiguous types
toWgt :: (ToMarkup a, MonadBaseControl IO m, MonadThrow m, MonadIO m)
=> a -> WidgetT site m ()
toWgt = toWidget . toHtml
-- Convenience Functions to avoid type signatures:
text2widget :: (MonadBaseControl IO m, MonadThrow m, MonadIO m)
=> Text -> WidgetT site m ()
text2widget t = [whamlet|#{t}|]
citext2widget :: (MonadBaseControl IO m, MonadThrow m, MonadIO m)
=> CI Text -> WidgetT site m ()
citext2widget t = [whamlet|#{CI.original t}|]
str2widget :: (MonadBaseControl IO m, MonadThrow m, MonadIO m)
=> String -> WidgetT site m ()
str2widget s = [whamlet|#{s}|]
display2widget :: (MonadBaseControl IO m, MonadThrow m, MonadIO m, DisplayAble a)
=> a -> WidgetT site m ()
display2widget = text2widget . display
withFragment :: Monad m => MForm m (a, WidgetT site IO ()) -> Markup -> MForm m (a, WidgetT site IO ())
withFragment form html = flip fmap form $ over _2 (toWidget html >>)
-- Types that can be converted to Text for direct displayed to User! (Show for debugging, Display for Production)
{- (not so sure we really want to get rid of display?!) DEPRECATED display "Create RenderMessage Instances instead!" -}
class DisplayAble a where
display :: a -> Text
-- Default definitions for types belonging to Show (allows empty instance declarations)
default display :: Show a => a -> Text
display = pack . show
instance DisplayAble Text where
display = id
instance DisplayAble String where
display = pack
instance DisplayAble Int
instance DisplayAble Int64
instance DisplayAble Integer
instance DisplayAble Rational where
display r = showFFloat (Just 2) (rat2float r) ""
& pack
& dropWhileEnd ('0'==)
& dropWhileEnd ('.'==)
where
rat2float :: Rational -> Double
rat2float = fromRational
instance DisplayAble a => DisplayAble (Maybe a) where
display Nothing = ""
display (Just x) = display x
instance DisplayAble a => DisplayAble (E.Value a) where
display = display . E.unValue
instance DisplayAble a => DisplayAble (CI a) where
display = display . CI.original
{- We do not want DisplayAble for every Show-Class:
We want to explicitly verify that the resulting text can be displayed to the User!
For example: UTCTime values were shown without proper format rendering!
instance {-# OVERLAPPABLE #-} Show a => DisplayAble a where -- The easy way out of UndecidableInstances (TypeFamilies would have been proper, but are much more complicated)
display = pack . show
-}
textPercent :: Real a => a -> Text -- slow, maybe use Data.Double.Conversion.Text.toFixed instead?
textPercent x = lz <> pack (show rx) <> "%"
where
rx :: Centi
rx = realToFrac (x * 100)
lz = if rx < 10.0 then "0" else ""
textPercentInt :: Integral a => a -> a -> Text -- slow, maybe use Data.Double.Conversion.Text.toFixed instead?
textPercentInt part whole = textPercent $ fromIntegral part % fromIntegral whole
stepTextCounterCI :: CI Text -> CI Text -- find and increment rightmost-number, preserving leading zeroes
stepTextCounterCI = CI.map stepTextCounter
stepTextCounter :: Text -> Text -- find and increment rightmost-number, preserving leading zeroes
stepTextCounter text
| (Just i) <- readMay number =
let iplus1 = tshow (succ i :: Int)
zeroip = justifyRight (length number) '0' iplus1
in prefix <> zeroip <> suffix
| otherwise = text
where -- no splitWhile nor findEnd in Data.Text
suffix = takeWhileEnd (not . isDigit) text
number = takeWhileEnd isDigit $ dropWhileEnd (not . isDigit) text
prefix = dropWhileEnd isDigit $ dropWhileEnd (not . isDigit) text
-- Data.Text.groupBy ((==) `on` isDigit) $ Data.Text.pack "12.ProMo Ue3bung00322 34 (H)"
-- ["12",".ProMo Ue","3","bung","00322"," ","34"," (H)"]
------------
-- Tuples --
------------
fst3 :: (a,b,c) -> a
fst3 (x,_,_) = x
snd3 :: (a,b,c) -> b
snd3 (_,y,_) = y
trd3 :: (a,b,c) -> c
trd3 (_,_,z) = z
-- Further projections are available via TemplateHaskell, defined in Utils.Common:
-- $(projN n m) :: (t1,..,tn) -> tm (for m<=n)
-- snd3 = $(projNI 3 2)
-----------
-- Lists --
-----------
-- notNull = not . null
lastMaybe :: [a] -> Maybe a
lastMaybe [] = Nothing
lastMaybe [h] = Just h
lastMaybe (_:t) = lastMaybe t
lastMaybe' :: [a] -> Maybe a
lastMaybe' l = fmap snd $ l ^? _Snoc
mergeAttrs :: [(Text, Text)] -> [(Text, Text)] -> [(Text, Text)]
mergeAttrs = mergeAttrs' `on` sort
where
special = [ ("class", \v1 v2 -> v1 <> " " <> v2)
]
mergeAttrs' (x1@(n1, v1):xs1) (x2@(n2, v2):xs2)
| Just merge <- lookup n1 special
, n2 == n1
= mergeAttrs' ((n1, merge v1 v2) : xs1) xs2
| Just _ <- lookup n1 special
, n1 < n2
= x2 : mergeAttrs' (x1:xs1) xs2
| otherwise = x1 : mergeAttrs' xs1 (x2:xs2)
mergeAttrs' [] xs2 = xs2
mergeAttrs' xs1 [] = xs1
----------
-- Maps --
----------
infixl 5 !!!
(!!!) :: (Ord k, Monoid v) => Map k v -> k -> v
(!!!) m k = fromMaybe mempty $ Map.lookup k m
groupMap :: (Ord k, Ord v) => [(k,v)] -> Map k (Set v)
groupMap l = Map.fromListWith mappend [(k, Set.singleton v) | (k,v) <- l]
partMap :: (Ord k, Monoid v) => [(k,v)] -> Map k v
partMap = Map.fromListWith mappend
invertMap :: (Ord k, Ord v) => Map k v -> Map v (Set k)
invertMap = groupMap . map swap . Map.toList
-----------
-- Maybe --
-----------
toMaybe :: Bool -> a -> Maybe a
toMaybe True = Just
toMaybe False = const Nothing
toNothing :: a -> Maybe b
toNothing = const Nothing
toNothingS :: String -> Maybe b
toNothingS = const Nothing
maybeAdd :: Num a => Maybe a -> Maybe a -> Maybe a -- treats Nothing as neutral/zero, unlike fmap/ap
maybeAdd (Just x) (Just y) = Just (x + y)
maybeAdd Nothing y = y
maybeAdd x Nothing = x
maybeEmpty :: Monoid m => Maybe a -> (a -> m) -> m
maybeEmpty = flip foldMap
whenIsJust :: Monad m => Maybe a -> (a -> m ()) -> m ()
whenIsJust (Just x) f = f x
whenIsJust Nothing _ = return ()
ifMaybeM :: Monad m => Maybe a -> b -> (a -> m b) -> m b -- more convenient argument order as compared to maybeM
ifMaybeM Nothing dft _ = return dft
ifMaybeM (Just x) _ act = act x
maybePositive :: (Num a, Ord a) => a -> Maybe a -- convenient for Shakespeare: one $maybe instead of $with & $if
maybePositive a | a > 0 = Just a
| otherwise = Nothing
positiveSum :: (Num a, Ord a) => Sum a -> Maybe a -- like maybePositive
positiveSum = maybePositive . getSum
maybeM :: Monad m => m b -> (a -> m b) -> m (Maybe a) -> m b
maybeM dft act mb = mb >>= maybe dft act
maybeT :: Monad m => m a -> MaybeT m a -> m a
maybeT x m = runMaybeT m >>= maybe x return
maybeT_ :: Monad m => MaybeT m () -> m ()
maybeT_ = void . runMaybeT
hoistMaybe :: MonadPlus m => Maybe a -> m a
-- ^ `hoist` regarding `Maybe` as if identical to @MaybeT Identity@
hoistMaybe = maybe mzero return
catchIfMaybeT :: (MonadCatch m, Exception e) => (e -> Bool) -> m a -> MaybeT m a
catchIfMaybeT p act = catchIf p (lift act) (const mzero)
mcons :: Maybe a -> [a] -> [a]
mcons Nothing xs = xs
mcons (Just x) xs = x:xs
newtype NTop a = NTop { nBot :: a } -- treat Nothing as Top for Ord (Maybe a); default implementation treats Nothing as bottom
instance Eq a => Eq (NTop (Maybe a)) where
(NTop x) == (NTop y) = x == y
instance Ord a => Ord (NTop (Maybe a)) where
compare (NTop Nothing) (NTop Nothing) = EQ
compare (NTop Nothing) _ = GT
compare _ (NTop Nothing) = LT
compare (NTop (Just x)) (NTop (Just y)) = compare x y
exceptTMaybe :: Monad m => ExceptT e m a -> MaybeT m a
exceptTMaybe = MaybeT . fmap (either (const Nothing) Just) . runExceptT
------------
-- Either --
------------
maybeLeft :: Either a b -> Maybe a
maybeLeft (Left a) = Just a
maybeLeft _ = Nothing
maybeRight :: Either a b -> Maybe b
maybeRight (Right b) = Just b
maybeRight _ = Nothing
whenIsLeft :: Monad m => Either a b -> (a -> m ()) -> m ()
whenIsLeft (Left x) f = f x
whenIsLeft (Right _) _ = return ()
whenIsRight :: Monad m => Either a b -> (b -> m ()) -> m ()
whenIsRight (Right x) f = f x
whenIsRight (Left _) _ = return ()
---------------
-- Exception --
---------------
maybeExceptT :: Monad m => e -> m (Maybe b) -> ExceptT e m b
maybeExceptT err act = lift act >>= maybe (throwE err) return
maybeMExceptT :: Monad m => m e -> m (Maybe b) -> ExceptT e m b
maybeMExceptT err act = lift act >>= maybe (lift err >>= throwE) return
whenExceptT :: Monad m => Bool -> e -> ExceptT e m ()
whenExceptT b err = when b $ throwE err
whenMExceptT :: Monad m => Bool -> m e -> ExceptT e m ()
whenMExceptT b err = when b $ lift err >>= throwE
guardExceptT :: Monad m => Bool -> e -> ExceptT e m ()
guardExceptT b err = unless b $ throwE err
guardMExceptT :: Monad m => Bool -> m e -> ExceptT e m ()
guardMExceptT b err = unless b $ lift err >>= throwE
exceptT :: Monad m => (e -> m b) -> (a -> m b) -> ExceptT e m a -> m b
exceptT f g = either f g <=< runExceptT
catchIfMExceptT :: (MonadCatch m, Exception e) => (e -> m e') -> (e -> Bool) -> m a -> ExceptT e' m a
catchIfMExceptT err p act = catchIf p (lift act) (throwE <=< lift . err)
throwExceptT :: ( Exception e, MonadThrow m )
=> ExceptT e m a -> m a
throwExceptT = exceptT throwM return
------------
-- Monads --
------------
shortCircuitM :: Monad m => (a -> Bool) -> (a -> a -> a) -> m a -> m a -> m a
shortCircuitM sc binOp mx my = do
x <- mx
if
| sc x -> return x
| otherwise -> binOp <$> pure x <*> my
guardM :: MonadPlus m => m Bool -> m ()
guardM f = guard =<< f
assertM :: MonadPlus m => (a -> Bool) -> m a -> m a
assertM f x = x >>= assertM' f
assertM_ :: MonadPlus m => (a -> Bool) -> m a -> m ()
assertM_ f x = guard . f =<< x
assertM' :: MonadPlus m => (a -> Bool) -> a -> m a
assertM' f x = x <$ guard (f x)
-- Some Utility Functions from Agda.Utils.Monad
-- | Monadic if-then-else.
ifM :: Monad m => m Bool -> m a -> m a -> m a
ifM c m m' =
do b <- c
if b then m else m'
-- | @ifNotM mc = ifM (not <$> mc)@
ifNotM :: Monad m => m Bool -> m a -> m a -> m a
ifNotM c = flip $ ifM c
and2M, or2M :: Monad m => m Bool -> m Bool -> m Bool
and2M ma mb = ifM ma mb (return False)
or2M ma = ifM ma (return True)
andM, orM :: (Foldable f, Monad m) => f (m Bool) -> m Bool
andM = Fold.foldr and2M (return True)
orM = Fold.foldr or2M (return False)
allM, anyM :: (Functor f, Foldable f, Monad m) => f a -> (a -> m Bool) -> m Bool
allM xs f = andM $ fmap f xs
anyM xs f = orM $ fmap f xs
ofoldr1M, ofoldl1M :: (MonoFoldable mono, Monad m) => (Element mono -> Element mono -> m (Element mono)) -> NonNull mono -> m (Element mono)
ofoldr1M f (otoList -> x:xs) = foldrM f x xs
ofoldr1M _ _ = error "otoList of NonNull is empty"
ofoldl1M f (otoList -> x:xs) = foldlM f x xs
ofoldl1M _ _ = error "otoList of NonNull is empty"
partitionM :: forall mono m .
( MonoFoldable mono
, Monoid mono
, MonoPointed mono
, Monad m)
=> (Element mono -> m Bool) -> mono -> m (mono, mono)
partitionM crit = ofoldlM dist mempty
where
dist :: (mono,mono) -> Element mono -> m (mono,mono)
dist acc x = do
okay <- crit x
return $ if
| okay -> acc `mappend` (opoint x, mempty)
| otherwise -> acc `mappend` (mempty, opoint x)
mconcatMapM :: (Monoid b, Monad m, Foldable f) => (a -> m b) -> f a -> m b
mconcatMapM f = foldM (\x my -> mappend x <$> my) mempty . map f . Fold.toList
mconcatForM :: (Monoid b, Monad m, Foldable f) => f a -> (a -> m b) -> m b
mconcatForM = flip mconcatMapM
--------------
-- Sessions --
--------------
setSessionJson :: (PathPiece k, ToJSON v, MonadHandler m) => k -> v -> m ()
setSessionJson (toPathPiece -> key) (LBS.toStrict . Aeson.encode -> val) = setSessionBS key val
lookupSessionJson :: (PathPiece k, FromJSON v, MonadHandler m) => k -> m (Maybe v)
lookupSessionJson (toPathPiece -> key) = (Aeson.decode' . LBS.fromStrict =<<) <$> lookupSessionBS key
modifySessionJson :: (PathPiece k, FromJSON v, ToJSON v, MonadHandler m) => k -> (Maybe v -> Maybe v) -> m ()
modifySessionJson (toPathPiece -> key) f = lookupSessionJson key >>= maybe (deleteSession key) (setSessionJson key) . f
tellSessionJson :: (PathPiece k, FromJSON v, ToJSON v, MonadHandler m, Monoid v) => k -> v -> m ()
tellSessionJson key val = modifySessionJson key $ Just . (`mappend` val) . fromMaybe mempty
getSessionJson :: (PathPiece k, FromJSON v, MonadHandler m) => k -> m (Maybe v)
-- ^ `lookupSessionJson` followed by `deleteSession`
getSessionJson key = lookupSessionJson key <* deleteSession (toPathPiece key)
--------------------
-- GET Parameters --
--------------------
data GlobalGetParam = GetReferer
deriving (Eq, Ord, Enum, Bounded, Read, Show, Generic)
instance Universe GlobalGetParam
instance Finite GlobalGetParam
nullaryPathPiece ''GlobalGetParam (camelToPathPiece' 1)
lookupGlobalGetParam :: (MonadHandler m, PathPiece result) => GlobalGetParam -> m (Maybe result)
lookupGlobalGetParam ident = (>>= fromPathPiece) <$> lookupGetParam (toPathPiece ident)
hasGlobalGetParam :: MonadHandler m => GlobalGetParam -> m Bool
hasGlobalGetParam ident = isJust <$> lookupGetParam (toPathPiece ident)
data GlobalPostParam = PostDeleteTarget
deriving (Eq, Ord, Enum, Bounded, Read, Show, Generic)
instance Universe GlobalPostParam
instance Finite GlobalPostParam
nullaryPathPiece ''GlobalPostParam (camelToPathPiece' 1)
lookupGlobalPostParam :: (MonadHandler m, PathPiece result) => GlobalPostParam -> m (Maybe result)
lookupGlobalPostParam ident = (>>= fromPathPiece) <$> lookupPostParam (toPathPiece ident)
hasGlobalPostParam :: MonadHandler m => GlobalPostParam -> m Bool
hasGlobalPostParam ident = isJust <$> lookupPostParam (toPathPiece ident)
---------------------------------
-- Custom HTTP Request-Headers --
---------------------------------
data CustomHeader = HeaderIsModal | HeaderDBTableShortcircuit
deriving (Eq, Ord, Enum, Bounded, Read, Show, Generic)
instance Universe CustomHeader
instance Finite CustomHeader
nullaryPathPiece ''CustomHeader (intercalate "-" . drop 1 . splitCamel)
lookupCustomHeader :: (MonadHandler m, PathPiece result) => CustomHeader -> m (Maybe result)
lookupCustomHeader ident = (>>= fromPathPiece . decodeUtf8) <$> lookupHeader (CI.mk . encodeUtf8 $ toPathPiece ident)
hasCustomHeader :: MonadHandler m => CustomHeader -> m Bool
hasCustomHeader ident = isJust <$> lookupHeader (CI.mk . encodeUtf8 $ toPathPiece ident)
------------------
-- Cryptography --
------------------
data SecretBoxEncoding = SecretBoxShort | SecretBoxPretty
deriving (Eq, Ord, Enum, Bounded, Read, Show, Generic, Typeable)
instance Universe SecretBoxEncoding
instance Finite SecretBoxEncoding
instance Default SecretBoxEncoding where
def = SecretBoxShort
encodedSecretBoxBlocksize :: Word8
-- | `encodedSecretBox'` tries to hide plaintext length by ensuring the message
-- length (before addition of HMAC and nonce) is always a multiple of
-- `encodedSecretBlocksize`.
-- Bigger blocksizes hide exact message length better but lead to longer messages
encodedSecretBoxBlocksize = maxBound
encodedSecretBox' :: ( ToJSON a, MonadIO m )
=> SecretBox.Key
-> SecretBoxEncoding
-> a -> m Text
encodedSecretBox' sKey pretty val = liftIO $ do
nonce <- SecretBox.newNonce
let
encrypt = SecretBox.secretbox sKey nonce
base64 = decodeUtf8 . Base64.encode
pad = PKCS7.padBytesN (fromIntegral encodedSecretBoxBlocksize)
attachNonce = mappend $ Saltine.encode nonce
chunk
| SecretBoxPretty <- pretty = Text.intercalate "\n" . Text.chunksOf 76
| otherwise = id
return . chunk . base64 . attachNonce . encrypt . pad . toStrict $ Aeson.encode val
data EncodedSecretBoxException
= EncodedSecretBoxInvalidBase64 !String
| EncodedSecretBoxInvalidPadding
| EncodedSecretBoxCiphertextTooShort
| EncodedSecretBoxCouldNotDecodeNonce
| EncodedSecretBoxCouldNotOpenSecretBox
| EncodedSecretBoxCouldNotDecodePlaintext !String
deriving (Eq, Ord, Show, Read, Generic, Typeable)
instance Exception EncodedSecretBoxException
encodedSecretBoxOpen' :: (FromJSON a, MonadError EncodedSecretBoxException m)
=> SecretBox.Key
-> Text -> m a
encodedSecretBoxOpen' sKey chunked = do
let unchunked = Text.filter (not . isSpace) chunked
decoded <- either (throwError . EncodedSecretBoxInvalidBase64) return . Base64.decode $ encodeUtf8 unchunked
unless (BS.length decoded >= Saltine.secretBoxNonce + Saltine.secretBoxMac) $
throwError EncodedSecretBoxCiphertextTooShort
let (nonceBS, encrypted) = BS.splitAt Saltine.secretBoxNonce decoded
nonce <- maybe (throwError EncodedSecretBoxCouldNotDecodeNonce) return $ Saltine.decode nonceBS
padded <- maybe (throwError EncodedSecretBoxCouldNotOpenSecretBox) return $ SecretBox.secretboxOpen sKey nonce encrypted
unpadded <- maybe (throwError EncodedSecretBoxInvalidPadding) return $ PKCS7.unpadBytesN (fromIntegral encodedSecretBoxBlocksize) padded
either (throwError . EncodedSecretBoxCouldNotDecodePlaintext) return $ Aeson.eitherDecodeStrict' unpadded
class Monad m => MonadSecretBox m where
secretBoxKey :: m SecretBox.Key
instance MonadSecretBox ((->) SecretBox.Key) where
secretBoxKey = id
instance Monad m => MonadSecretBox (ReaderT SecretBox.Key m) where
secretBoxKey = ask
encodedSecretBox :: ( ToJSON a, MonadSecretBox m, MonadIO m )
=> SecretBoxEncoding
-> a -> m Text
encodedSecretBox pretty val = do
sKey <- secretBoxKey
encodedSecretBox' sKey pretty val
encodedSecretBoxOpen :: ( FromJSON a, MonadError EncodedSecretBoxException m, MonadSecretBox m )
=> Text -> m a
encodedSecretBoxOpen ciphertext = do
sKey <- secretBoxKey
encodedSecretBoxOpen' sKey ciphertext