git-annex/Remote/Directory.hs
guilhem 8293ed619f Allow public-key encryption of file content.
With the initremote parameters "encryption=pubkey keyid=788A3F4C".

/!\ Adding or removing a key has NO effect on files that have already
been copied to the remote. Hence using keyid+= and keyid-= with such
remotes should be used with care, and make little sense unless the point
is to replace a (sub-)key by another. /!\

Also, a test case has been added to ensure that the cipher and file
contents are encrypted as specified by the chosen encryption scheme.
2013-09-03 14:34:16 -04:00

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{- A "remote" that is just a filesystem directory.
-
- Copyright 2011-2012 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Remote.Directory (remote) where
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString as S
import qualified Data.Map as M
import qualified Control.Exception as E
import Data.Int
import Common.Annex
import Types.Remote
import qualified Git
import Config.Cost
import Config
import Utility.FileMode
import Remote.Helper.Special
import Remote.Helper.Encryptable
import Remote.Helper.Chunked
import Crypto
import Annex.Content
import Utility.Metered
remote :: RemoteType
remote = RemoteType {
typename = "directory",
enumerate = findSpecialRemotes "directory",
generate = gen,
setup = directorySetup
}
gen :: Git.Repo -> UUID -> RemoteConfig -> RemoteGitConfig -> Annex Remote
gen r u c gc = do
cst <- remoteCost gc cheapRemoteCost
let chunksize = chunkSize c
return $ encryptableRemote c
(storeEncrypted dir (getGpgEncParams (c,gc)) chunksize)
(retrieveEncrypted dir chunksize)
Remote {
uuid = u,
cost = cst,
name = Git.repoDescribe r,
storeKey = store dir chunksize,
retrieveKeyFile = retrieve dir chunksize,
retrieveKeyFileCheap = retrieveCheap dir chunksize,
removeKey = remove dir,
hasKey = checkPresent dir chunksize,
hasKeyCheap = True,
whereisKey = Nothing,
config = M.empty,
repo = r,
gitconfig = gc,
localpath = Just dir,
readonly = False,
globallyAvailable = False,
remotetype = remote
}
where
dir = fromMaybe (error "missing directory") $ remoteAnnexDirectory gc
directorySetup :: UUID -> RemoteConfig -> Annex RemoteConfig
directorySetup u c = do
-- verify configuration is sane
let dir = fromMaybe (error "Specify directory=") $
M.lookup "directory" c
absdir <- liftIO $ absPath dir
liftIO $ unlessM (doesDirectoryExist absdir) $
error $ "Directory does not exist: " ++ absdir
c' <- encryptionSetup c
-- The directory is stored in git config, not in this remote's
-- persistant state, so it can vary between hosts.
gitConfigSpecialRemote u c' "directory" absdir
return $ M.delete "directory" c'
{- Locations to try to access a given Key in the Directory.
- We try more than since we used to write to different hash directories. -}
locations :: FilePath -> Key -> [FilePath]
locations d k = map (d </>) (keyPaths k)
{- Directory where the file(s) for a key are stored. -}
storeDir :: FilePath -> Key -> FilePath
storeDir d k = addTrailingPathSeparator $ d </> hashDirLower k </> keyFile k
{- Where we store temporary data for a key as it's being uploaded. -}
tmpDir :: FilePath -> Key -> FilePath
tmpDir d k = addTrailingPathSeparator $ d </> "tmp" </> keyFile k
withCheckedFiles :: (FilePath -> IO Bool) -> ChunkSize -> FilePath -> Key -> ([FilePath] -> IO Bool) -> IO Bool
withCheckedFiles _ _ [] _ _ = return False
withCheckedFiles check Nothing d k a = go $ locations d k
where
go [] = return False
go (f:fs) = ifM (check f) ( a [f] , go fs )
withCheckedFiles check (Just _) d k a = go $ locations d k
where
go [] = return False
go (f:fs) = do
let chunkcount = f ++ chunkCount
ifM (check chunkcount)
( do
chunks <- listChunks f <$> readFile chunkcount
ifM (all id <$> mapM check chunks)
( a chunks , return False )
, go fs
)
withStoredFiles :: ChunkSize -> FilePath -> Key -> ([FilePath] -> IO Bool) -> IO Bool
withStoredFiles = withCheckedFiles doesFileExist
store :: FilePath -> ChunkSize -> Key -> AssociatedFile -> MeterUpdate -> Annex Bool
store d chunksize k _f p = sendAnnex k (void $ remove d k) $ \src ->
metered (Just p) k $ \meterupdate ->
storeHelper d chunksize k k $ \dests ->
case chunksize of
Nothing -> do
let dest = Prelude.head dests
meteredWriteFile meterupdate dest
=<< L.readFile src
return [dest]
Just _ ->
storeSplit meterupdate chunksize dests
=<< L.readFile src
storeEncrypted :: FilePath -> [CommandParam] -> ChunkSize -> (Cipher, Key) -> Key -> MeterUpdate -> Annex Bool
storeEncrypted d gpgOpts chunksize (cipher, enck) k p = sendAnnex k (void $ remove d enck) $ \src ->
metered (Just p) k $ \meterupdate ->
storeHelper d chunksize enck k $ \dests ->
encrypt gpgOpts cipher (feedFile src) $ readBytes $ \b ->
case chunksize of
Nothing -> do
let dest = Prelude.head dests
meteredWriteFile meterupdate dest b
return [dest]
Just _ -> storeSplit meterupdate chunksize dests b
{- Splits a ByteString into chunks and writes to dests, obeying configured
- chunk size (not to be confused with the L.ByteString chunk size).
- Note: Must always write at least one file, even for empty ByteString. -}
storeSplit :: MeterUpdate -> ChunkSize -> [FilePath] -> L.ByteString -> IO [FilePath]
storeSplit _ Nothing _ _ = error "bad storeSplit call"
storeSplit _ _ [] _ = error "bad storeSplit call"
storeSplit meterupdate (Just chunksize) alldests@(firstdest:_) b
| L.null b = do
-- must always write at least one file, even for empty
L.writeFile firstdest b
return [firstdest]
| otherwise = storeSplit' meterupdate chunksize alldests (L.toChunks b) []
storeSplit' :: MeterUpdate -> Int64 -> [FilePath] -> [S.ByteString] -> [FilePath] -> IO [FilePath]
storeSplit' _ _ [] _ _ = error "ran out of dests"
storeSplit' _ _ _ [] c = return $ reverse c
storeSplit' meterupdate chunksize (d:dests) bs c = do
bs' <- E.bracket (openFile d WriteMode) hClose $
feed zeroBytesProcessed chunksize bs
storeSplit' meterupdate chunksize dests bs' (d:c)
where
feed _ _ [] _ = return []
feed bytes sz (l:ls) h = do
let len = S.length l
let s = fromIntegral len
if s <= sz || sz == chunksize
then do
S.hPut h l
let bytes' = addBytesProcessed bytes len
meterupdate bytes'
feed bytes' (sz - s) ls h
else return (l:ls)
storeHelper :: FilePath -> ChunkSize -> Key -> Key -> ([FilePath] -> IO [FilePath]) -> Annex Bool
storeHelper d chunksize key origkey storer = check <&&> go
where
tmpdir = tmpDir d key
destdir = storeDir d key
{- An encrypted key does not have a known size,
- so check that the size of the original key is available as free
- space. -}
check = do
liftIO $ createDirectoryIfMissing True tmpdir
checkDiskSpace (Just tmpdir) origkey 0
go = liftIO $ catchBoolIO $
storeChunks key tmpdir destdir chunksize storer recorder finalizer
finalizer tmp dest = do
void $ tryIO $ allowWrite dest -- may already exist
void $ tryIO $ removeDirectoryRecursive dest -- or not exist
createDirectoryIfMissing True (parentDir dest)
renameDirectory tmp dest
-- may fail on some filesystems
void $ tryIO $ do
mapM_ preventWrite =<< dirContents dest
preventWrite dest
recorder f s = do
void $ tryIO $ allowWrite f
writeFile f s
void $ tryIO $ preventWrite f
retrieve :: FilePath -> ChunkSize -> Key -> AssociatedFile -> FilePath -> MeterUpdate -> Annex Bool
retrieve d chunksize k _ f p = metered (Just p) k $ \meterupdate ->
liftIO $ withStoredFiles chunksize d k $ \files ->
catchBoolIO $ do
meteredWriteFileChunks meterupdate f files $ L.readFile
return True
retrieveEncrypted :: FilePath -> ChunkSize -> (Cipher, Key) -> Key -> FilePath -> MeterUpdate -> Annex Bool
retrieveEncrypted d chunksize (cipher, enck) k f p = metered (Just p) k $ \meterupdate ->
liftIO $ withStoredFiles chunksize d enck $ \files ->
catchBoolIO $ do
decrypt cipher (feeder files) $
readBytes $ meteredWriteFile meterupdate f
return True
where
feeder files h = forM_ files $ \file -> L.hPut h =<< L.readFile file
retrieveCheap :: FilePath -> ChunkSize -> Key -> FilePath -> Annex Bool
retrieveCheap _ (Just _) _ _ = return False -- no cheap retrieval for chunks
#ifndef mingw32_HOST_OS
retrieveCheap d _ k f = liftIO $ withStoredFiles Nothing d k go
where
go [file] = catchBoolIO $ createSymbolicLink file f >> return True
go _files = return False
#else
retrieveCheap _ _ _ _ = return False
#endif
remove :: FilePath -> Key -> Annex Bool
remove d k = liftIO $ do
void $ tryIO $ allowWrite dir
#ifdef mingw32_HOST_OS
{- Windows needs the files inside the directory to be writable
- before it can delete them. -}
void $ tryIO $ mapM_ allowWrite =<< dirContents dir
#endif
catchBoolIO $ do
removeDirectoryRecursive dir
return True
where
dir = storeDir d k
checkPresent :: FilePath -> ChunkSize -> Key -> Annex (Either String Bool)
checkPresent d chunksize k = liftIO $ catchMsgIO $ withStoredFiles chunksize d k $
const $ return True -- withStoredFiles checked that it exists