git-annex/Command/Reinject.hs
Joey Hess 07f1e638ee
annex.securehashesonly
Cryptographically secure hashes can be forced to be used in a repository,
by setting annex.securehashesonly. This does not prevent the git repository
from containing files with insecure hashes, but it does prevent the content
of such files from being pulled into .git/annex/objects from another
repository.

We want to make sure that at no point does git-annex accept content into
.git/annex/objects that is hashed with an insecure key. Here's how it
was done:

* .git/annex/objects/xx/yy/KEY/ is kept frozen, so nothing can be
  written to it normally
* So every place that writes content must call, thawContent or modifyContent.
  We can audit for these, and be sure we've considered all cases.
* The main functions are moveAnnex, and linkToAnnex; these were made to
  check annex.securehashesonly, and are the main security boundary
  for annex.securehashesonly.
* Most other calls to modifyContent deal with other files in the KEY
  directory (inode cache etc). The other ones that mess with the content
  are:
	- Annex.Direct.toDirectGen, in which content already in the
	  annex directory is moved to the direct mode file, so not relevant.
	- fix and lock, which don't add new content
	- Command.ReKey.linkKey, which manually unlocks it to make a
	  copy.
* All other calls to thawContent appear safe.

Made moveAnnex return a Bool, so checked all callsites and made them
deal with a failure in appropriate ways.

linkToAnnex simply returns LinkAnnexFailed; all callsites already deal
with it failing in appropriate ways.

This commit was sponsored by Riku Voipio.
2017-02-27 13:33:59 -04:00

83 lines
1.9 KiB
Haskell

{- git-annex command
-
- Copyright 2011-2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Command.Reinject where
import Command
import Logs.Location
import Annex.Content
import Backend
import Types.KeySource
cmd :: Command
cmd = command "reinject" SectionUtility
"inject content of file back into annex"
(paramRepeating (paramPair "SRC" "DEST"))
(seek <$$> optParser)
data ReinjectOptions = ReinjectOptions
{ params :: CmdParams
, knownOpt :: Bool
}
optParser :: CmdParamsDesc -> Parser ReinjectOptions
optParser desc = ReinjectOptions
<$> cmdParams desc
<*> switch
( long "known"
<> help "inject all known files"
<> hidden
)
seek :: ReinjectOptions -> CommandSeek
seek os
| knownOpt os = withStrings startKnown (params os)
| otherwise = withWords startSrcDest (params os)
startSrcDest :: [FilePath] -> CommandStart
startSrcDest (src:dest:[])
| src == dest = stop
| otherwise = notAnnexed src $ do
showStart "reinject" dest
next $ ifAnnexed dest go stop
where
go key = ifM (verifyKeyContent DefaultVerify UnVerified key src)
( perform src key
, error "failed"
)
startSrcDest _ = giveup "specify a src file and a dest file"
startKnown :: FilePath -> CommandStart
startKnown src = notAnnexed src $ do
showStart "reinject" src
mkb <- genKey (KeySource src src Nothing) Nothing
case mkb of
Nothing -> error "Failed to generate key"
Just (key, _) -> ifM (isKnownKey key)
( next $ perform src key
, do
warning "Not known content; skipping"
next $ next $ return True
)
notAnnexed :: FilePath -> CommandStart -> CommandStart
notAnnexed src = ifAnnexed src $
giveup $ "cannot used annexed file as src: " ++ src
perform :: FilePath -> Key -> CommandPerform
perform src key = ifM move
( next $ cleanup key
, error "failed"
)
where
move = checkDiskSpaceToGet key False $
moveAnnex key src
cleanup :: Key -> CommandCleanup
cleanup key = do
logStatus key InfoPresent
return True