git-annex/Git/GCrypt.hs
Joey Hess e8e209f4e5 better probing for gcrypt repositories using new --check option
Now can tell if a repo uses gcrypt or not, and whether it's decryptable
with the current gpg keys.

This closes the hole that undecryptable gcrypt repos could have before been
combined into the repo in encrypted mode.
2013-09-19 12:53:24 -04:00

104 lines
3.1 KiB
Haskell

{- git-remote-gcrypt support
-
- https://github.com/blake2-ppc/git-remote-gcrypt
-
- Copyright 2013 Joey Hess <joey@kitenet.net>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module Git.GCrypt where
import Common
import Git.Types
import Git.Construct
import qualified Git.Config as Config
import qualified Git.Command as Command
import Utility.Gpg
urlPrefix :: String
urlPrefix = "gcrypt::"
isEncrypted :: Repo -> Bool
isEncrypted Repo { location = Url url } = urlPrefix `isPrefixOf` show url
isEncrypted _ = False
{- The first Repo is the git repository that has the second Repo
- as one of its remotes.
-
- When the remote Repo uses gcrypt, returns the actual underlying
- git repository that gcrypt is using to store its data.
-
- Throws an exception if an url is invalid or the repo does not use
- gcrypt.
-}
encryptedRemote :: Repo -> Repo -> IO Repo
encryptedRemote baserepo = go
where
go Repo { location = Url url }
| urlPrefix `isPrefixOf` u =
fromRemoteLocation (drop plen u) baserepo
| otherwise = notencrypted
where
u = show url
plen = length urlPrefix
go _ = notencrypted
notencrypted = error "not a gcrypt encrypted repository"
data ProbeResult = Decryptable | NotDecryptable | NotEncrypted
{- Checks if the git repo at a location uses gcrypt.
-
- Rather expensive -- many need to fetch the entire repo contents.
- (Which is fine if the repo is going to be added as a remote..)
-}
probeRepo :: String -> Repo -> IO ProbeResult
probeRepo loc baserepo = do
let p = proc "git" $ toCommand $ Command.gitCommandLine
[ Param "remote-gcrypt"
, Param "--check"
, Param loc
] baserepo
(_, _, _, pid) <- createProcess p
code <- waitForProcess pid
return $ case code of
ExitSuccess -> Decryptable
ExitFailure 1 -> NotDecryptable
ExitFailure _ -> NotEncrypted
type RemoteName = String
type GCryptId = String
{- gcrypt gives each encrypted repository a uique gcrypt-id,
- which is stored in the repository (in encrypted form)
- and cached in a per-remote gcrypt-id configuration setting. -}
remoteRepoId :: Repo -> Maybe RemoteName -> Maybe GCryptId
remoteRepoId = getRemoteConfig "gcrypt-id"
getRemoteConfig :: String -> Repo -> Maybe RemoteName -> Maybe String
getRemoteConfig field repo remotename = do
n <- remotename
Config.getMaybe (remoteConfigKey field n) repo
{- Gpg keys that the remote is encrypted for.
- If empty, gcrypt uses --default-recipient-self -}
getParticiantList :: Maybe Repo -> Repo -> Maybe RemoteName -> KeyIds
getParticiantList globalconfigrepo repo remotename = KeyIds $ parse $ firstJust
[ getRemoteConfig "gcrypt-participants" repo remotename
, Config.getMaybe defaultkey repo
, Config.getMaybe defaultkey =<< globalconfigrepo
]
where
defaultkey = "gcrypt.participants"
parse (Just "simple") = []
parse (Just l) = words l
parse Nothing = []
remoteParticipantConfigKey :: RemoteName -> String
remoteParticipantConfigKey = remoteConfigKey "gcrypt-participants"
remoteSigningKey :: RemoteName -> String
remoteSigningKey = remoteConfigKey "gcrypt-signingkey"
remoteConfigKey :: String -> RemoteName -> String
remoteConfigKey key remotename = "remote." ++ remotename ++ "." ++ key