git-annex/Command/RecvKey.hs
Joey Hess 995e1e3c5d fix transferring to gcrypt repo from direct mode repo
recvkey was told it was receiving a HMAC key from a direct mode repo,
and that confused it into rejecting the transfer, since it has no way to
verify a key using that backend, since there is no HMAC backend.

I considered making recvkey skip verification in the case of an unknown
backend. However, that could lead to bad results; a key can legitimately be
in the annex with a backend that the remote git-annex-shell doesn't know
about. Better to keep it rejecting if it cannot verify.

Instead, made the gcrypt special remote not set the direct mode flag when
sending (and receiving) files.

Also, added some recvkey messages when its checks fail, since otherwise
all that is shown is a confusing error message from rsync when the remote
git-annex-shell exits nonzero.
2013-10-01 14:19:24 -04:00

89 lines
2.4 KiB
Haskell

{- git-annex command
-
- Copyright 2010 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.RecvKey where
import System.PosixCompat.Files
import Common.Annex
import Command
import CmdLine
import Annex.Content
import Annex
import Utility.Rsync
import Logs.Transfer
import Command.SendKey (fieldTransfer)
import qualified Fields
import qualified Types.Key
import qualified Types.Backend
import qualified Backend
def :: [Command]
def = [noCommit $ command "recvkey" paramKey seek
SectionPlumbing "runs rsync in server mode to receive content"]
seek :: [CommandSeek]
seek = [withKeys start]
start :: Key -> CommandStart
start key = ifM (inAnnex key)
( error "key is already present in annex"
, fieldTransfer Download key $ \_p ->
ifM (getViaTmp key go)
( do
-- forcibly quit after receiving one key,
-- and shutdown cleanly
_ <- shutdown True
return True
, return False
)
)
where
go tmp = do
opts <- filterRsyncSafeOptions . maybe [] words
<$> getField "RsyncOptions"
ok <- liftIO $ rsyncServerReceive (map Param opts) tmp
-- The file could have been received with permissions that
-- do not allow reading it, so this is done before the
-- directcheck.
freezeContent tmp
if ok
then ifM (isJust <$> Fields.getField Fields.direct)
( directcheck tmp
, return True
)
else return False
{- If the sending repository uses direct mode, the file
- it sends could be modified as it's sending it. So check
- that the right size file was received, and that the key/value
- Backend is happy with it. -}
directcheck tmp = do
oksize <- case Types.Key.keySize key of
Nothing -> return True
Just size -> do
size' <- fromIntegral . fileSize
<$> liftIO (getFileStatus tmp)
return $ size == size'
if oksize
then case Backend.maybeLookupBackendName (Types.Key.keyBackendName key) of
Nothing -> do
warning "recvkey: received key from direct mode repository using unknown backend; cannot check; discarding"
return False
Just backend -> maybe (return True) runfsck
(Types.Backend.fsckKey backend)
else do
warning "recvkey: received key with wrong size; discarding"
return False
where
runfsck check = ifM (check key tmp)
( return True
, do
warning "recvkey: received key from direct mode repository seems to have changed as it was transferred; discarding"
return False
)