factor non-type stuff out of Key

Types/Key.hs

@@ -5,30 +5,9 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-module Types.Key (
-	Key(..),
-	AssociatedFile,
-	stubKey,
-	key2file,
-	file2key,
-	nonChunkKey,
-	chunkKeyOffset,
-	isChunkKey,
-	isKeyPrefix,
-
-	prop_isomorphic_key_encode,
-	prop_isomorphic_key_decode
-) where
+module Types.Key where
 
 import System.Posix.Types
-import Data.Aeson
-import Data.Char
-import qualified Data.Text as T
-
-import Common
-import Utility.QuickCheck
-import Utility.Bloom
-import qualified Utility.SimpleProtocol as Proto
 
 {- A Key has a unique name, which is derived from a particular backend,
  - and may contain other optional metadata. -}
@@ -43,156 +22,3 @@ data Key = Key
 
 {- A filename may be associated with a Key. -}
 type AssociatedFile = Maybe FilePath
-
-stubKey :: Key
-stubKey = Key
-	{ keyName = ""
-	, keyBackendName = ""
-	, keySize = Nothing
-	, keyMtime = Nothing
-	, keyChunkSize = Nothing
-	, keyChunkNum = Nothing
-	}
-
--- Gets the parent of a chunk key.
-nonChunkKey :: Key -> Key
-nonChunkKey k = k
-	{ keyChunkSize = Nothing
-	, keyChunkNum = Nothing
-	}
-
--- Where a chunk key is offset within its parent.
-chunkKeyOffset :: Key -> Maybe Integer
-chunkKeyOffset k = (*)
-	<$> keyChunkSize k
-	<*> (pred <$> keyChunkNum k)
-
-isChunkKey :: Key -> Bool
-isChunkKey k = isJust (keyChunkSize k) && isJust (keyChunkNum k)
-
--- Checks if a string looks like at least the start of a key.
-isKeyPrefix :: String -> Bool
-isKeyPrefix s = [fieldSep, fieldSep] `isInfixOf` s
-
-fieldSep :: Char
-fieldSep = '-'
-
-{- Converts a key to a string that is suitable for use as a filename.
- - The name field is always shown last, separated by doubled fieldSeps,
- - and is the only field allowed to contain the fieldSep. -}
-key2file :: Key -> FilePath
-key2file Key { keyBackendName = b, keySize = s, keyMtime = m, keyChunkSize = cs, keyChunkNum = cn, keyName = n } =
-	b +++ ('s' ?: s) +++ ('m' ?: m) +++ ('S' ?: cs) +++ ('C' ?: cn) +++ (fieldSep : n)
-  where
-	"" +++ y = y
-	x +++ "" = x
-	x +++ y = x ++ fieldSep:y
-	f ?: (Just v) = f : show v
-	_ ?: _ = ""
-
-file2key :: FilePath -> Maybe Key
-file2key s
-	| key == Just stubKey || (keyName <$> key) == Just "" || (keyBackendName <$> key) == Just "" = Nothing
-	| otherwise = key
-  where
-	key = startbackend stubKey s
-
-	startbackend k v = sepfield k v addbackend
-		
-	sepfield k v a = case span (/= fieldSep) v of
-		(v', _:r) -> findfields r $ a k v'
-		_ -> Nothing
-
-	findfields (c:v) (Just k)
-		| c == fieldSep = addkeyname k v
-		| otherwise = sepfield k v $ addfield c
-	findfields _ v = v
-
-	addbackend k v = Just k { keyBackendName = v }
-
-	-- This is a strict parser for security reasons; a key
-	-- can contain only 4 fields, which all consist only of numbers.
-	-- Any key containing other fields, or non-numeric data is
-	-- rejected with Nothing.
-	--
-	-- If a key contained non-numeric fields, they could be used to
-	-- embed data used in a SHA1 collision attack, which would be a
-	-- problem since the keys are committed to git.
-	addfield _ _ v | not (all isDigit v) = Nothing
-	addfield 's' k v = do
-		sz <- readish v
-		return $ k { keySize = Just sz }
-	addfield 'm' k v = do
-		mtime <- readish v
-		return $ k { keyMtime = Just mtime }
-	addfield 'S' k v = do
-		chunksize <- readish v
-		return $ k { keyChunkSize = Just chunksize }
-	addfield 'C' k v = case readish v of
-		Just chunknum | chunknum > 0 ->
-			return $ k { keyChunkNum = Just chunknum }
-		_ -> Nothing
-	addfield _ _ _ = Nothing
-
-	addkeyname k v
-		| validKeyName k v = Just $ k { keyName = v }
-		| otherwise = Nothing
-
-{- A key with a backend ending in "E" is an extension preserving key,
- - using some hash.
- -
- - The length of the extension is limited in order to mitigate against
- - SHA1 collision attacks (specifically, chosen-prefix attacks).
- - In such an attack, the extension of the key could be made to contain
- - the collision generation data, with the result that a signed git commit
- - including such keys would not be secure. 
- -
- - The maximum extension length ever generated for such a key was 8
- - characters; 20 is used here to give a little future wiggle-room. 
- - The SHA1 common-prefix attack used 128 bytes of data.
- -
- - This code is here, and not in Backend.Hash (where it really belongs)
- - so that file2key can check it whenever a Key is constructed.
- -}
-validKeyName :: Key -> String -> Bool
-validKeyName k v
-	| end (keyBackendName k) == "E" = length (takeExtensions v) <= 20
-	| otherwise = True
-
-instance ToJSON Key where
-	toJSON = toJSON . key2file
-
-instance FromJSON Key where
-	parseJSON (String t) = maybe mempty pure $ file2key $ T.unpack t
-	parseJSON _ = mempty
-
-instance Proto.Serializable Key where
-	serialize = key2file
-	deserialize = file2key
-
-instance Arbitrary Key where
-	arbitrary = Key
-		<$> (listOf1 $ elements $ ['A'..'Z'] ++ ['a'..'z'] ++ ['0'..'9'] ++ "-_\r\n \t")
-		<*> (listOf1 $ elements ['A'..'Z']) -- BACKEND
-		<*> ((abs <$>) <$> arbitrary) -- size cannot be negative
-		<*> arbitrary
-		<*> ((abs <$>) <$> arbitrary) -- chunksize cannot be negative
-		<*> ((succ . abs <$>) <$> arbitrary) -- chunknum cannot be 0 or negative
-
-instance Hashable Key where
-	hashIO32 = hashIO32 . key2file
-	hashIO64 = hashIO64 . key2file
-
-prop_isomorphic_key_encode :: Key -> Bool
-prop_isomorphic_key_encode k = Just k == (file2key . key2file) k
-
-prop_isomorphic_key_decode :: FilePath -> Bool
-prop_isomorphic_key_decode f
-	| normalfieldorder = maybe True (\k -> key2file k == f) (file2key f)
-	| otherwise = True
-  where
-	-- file2key will accept the fields in any order, so don't
-	-- try the test unless the fields are in the normal order
-	normalfieldorder = fields `isPrefixOf` "smSC"
-	fields = map (f !!) $ filter (< length f) $ map succ $
-		elemIndices fieldSep f