git-annex/Utility/SafeOutput.hs
Joey Hess cd544e548b
filter out control characters in error messages
giveup changed to filter out control characters. (It is too low level to
make it use StringContainingQuotedPath.)

error still does not, but it should only be used for internal errors,
where the message is not attacker-controlled.

Changed a lot of existing error to giveup when it is not strictly an
internal error.

Of course, other exceptions can still be thrown, either by code in
git-annex, or a library, that include some attacker-controlled value.
This does not guard against those.

Sponsored-by: Noam Kremen on Patreon
2023-04-10 13:50:51 -04:00

24 lines
627 B
Haskell

{- Safe output to the terminal of possibly attacker-controlled strings,
- avoiding displaying control characters.
-
- Copyright 2023 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE TypeSynonymInstances, FlexibleInstances #-}
{-# OPTIONS_GHC -fno-warn-tabs #-}
module Utility.SafeOutput (safeOutput) where
import Data.Char
import qualified Data.ByteString as S
class SafeOutputtable t where
safeOutput :: t -> t
instance SafeOutputtable String where
safeOutput = filter (not . isControl)
instance SafeOutputtable S.ByteString where
safeOutput = S.filter (not . isControl . chr . fromIntegral)