git-annex/Command/P2PStdIO.hs
Joey Hess 9a8391078a
git-annex-shell: block relay requests
connRepo is only used when relaying git upload-pack and receive-pack.
That's only supposed to be used when git-annex-remotedaemon is serving
git-remote-tor-annex connections over tor. But, it was always set, and
so could be used in other places possibly.

Fixed by making connRepo optional in the P2P protocol interface.

In Command.EnableTor, it's not needed, because it only speaks the
protocol in order to check that it's able to connect back to itself via
the hidden service. So changed that to pass Nothing rather than the git
repo.

In Remote.Helper.Ssh, it's connecting to git-annex-shell p2pstdio,
so is making the requests, so will never need connRepo.

In git-annex-shell p2pstdio, it was accepting git upload-pack and
receive-pack requests over the P2P protocol, even though nothing sent
them. This is arguably a security hole, particularly if the user has
set environment variables like GIT_ANNEX_SHELL_LIMITED to prevent
git push/pull via git-annex-shell.
2024-06-10 14:16:27 -04:00

50 lines
1.4 KiB
Haskell

{- git-annex command
-
- Copyright 2018 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Command.P2PStdIO where
import Command
import P2P.IO
import P2P.Annex
import qualified P2P.Protocol as P2P
import qualified Annex
import Annex.UUID
import qualified CmdLine.GitAnnexShell.Checks as Checks
import System.IO.Error
cmd :: Command
cmd = noMessages $ command "p2pstdio" SectionPlumbing
"communicate in P2P protocol over stdio"
paramUUID (withParams seek)
seek :: CmdParams -> CommandSeek
seek [u] = commandAction $ start $ toUUID u
seek _ = giveup "missing UUID parameter"
start :: UUID -> CommandStart
start theiruuid = startingCustomOutput (ActionItemOther Nothing) $ do
servermode <- liftIO $ do
ro <- Checks.checkEnvSet Checks.readOnlyEnv
ao <- Checks.checkEnvSet Checks.appendOnlyEnv
return $ case (ro, ao) of
(True, _) -> P2P.ServeReadOnly
(False, True) -> P2P.ServeAppendOnly
(False, False) -> P2P.ServeReadWrite
myuuid <- getUUID
let conn = stdioP2PConnection Nothing
let server = do
P2P.net $ P2P.sendMessage (P2P.AUTH_SUCCESS myuuid)
P2P.serveAuthed servermode myuuid
runst <- liftIO $ mkRunState $ Serving theiruuid Nothing
runFullProto runst conn server >>= \case
Right () -> done
-- Avoid displaying an error when the client hung up on us.
Left (ProtoFailureIOError e) | isEOFError e -> done
Left e -> giveup (describeProtoFailure e)
where
done = next $ return True