git.iko.soy/typeable/aeson
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Switch cffi flag default.

Also added on additional check in the pure parser, which should catch buffer overflows hopefully soon enough to prevent any harm.

commitcf0cbb290c6b8d6288d36a2f415b7ddabcd50844 authorRobert Klotzner <robert.klotzner@gmx.at> dateMon 3 Apr 2017, 11:00 (10 years ago) parent83f2830
2 files changed+11−4
compare with master
unifiedsplit
aeson.cabal+2−2 pure/Data/Aeson/Parser/UnescapePure.hs+9−2
aeson.cabal+2−2
@@ -74,8 +74,8 @@ flag bytestring-builder
7474 manual: False
7575
7676flag cffi
77− description: Controls whether to include c-ffi bits or pure haskell
78− default: True
77+ description: Controls whether to include c-ffi bits or pure haskell. Default to False for security.
78+ default: False
7979 manual: True
8080
8181library
pure/Data/Aeson/Parser/UnescapePure.hs+9−2
@@ -1,3 +1,10 @@
1+-- WARNING: This file is security sensitive as it uses unsafeWrite which does
2+-- not check bounds. Any changes should be made with care and I would love to
3+-- get informed about them, just cc me in any PR targetting this file: @eskimor
4+-- I would be happy to review the changes!
5+
6+-- The security check at the end (pos > length) only works if pos grows
7+-- monotonously, if this condition does not hold, the check is flawed.
18module Data.Aeson.Parser.UnescapePure
29 (
310 unescapeText
@@ -145,8 +152,8 @@ unescapeText' bs = runText $ \done -> do
145152 dest <- A.new len
146153 (pos, finalState) <- B.foldl' (f' dest) (return (0, StateNone)) bs
147154
148− -- Check final state.
149− when ( finalState /= StateNone)
155+ -- Check final state. Currently pos gets only increased over time, so this check should catch overflows.
156+ when ( finalState /= StateNone || pos > len)
150157 throwDecodeError
151158
152159 done dest pos -- TODO: pos, pos-1??? XXX