From b4adaf75a36d6d6425df820c46023a32e79bb6df Mon Sep 17 00:00:00 2001 From: Joey Hess Date: Sat, 12 Nov 2016 01:34:19 -0400 Subject: The propellor wrapper checks if ./config.hs exists; if so it runs using the configuration in the current directory, rather than ~/.propellor/config.hs The config,hs name now seems a bit badly chosen, propellor.hs would be less ambiguous. To avoid accidentially running with a config.hs for something else, the file content has to contain "Propellor". Note that checkRepoUpToDate is only run for ~/.propellor/. I guess propellor configs in other directories won't have been set up that way, and it would take some changes to make that not hardcode use of dotPropellor. There's a new security boundary here, since running propellor looks at the cwd, whose contents might not be user the user's control. The security checks I added for this seem pretty good, but even if they can be bypassed, this is not much different than `make` using the Makefile in cwd. This commit was sponsored by Ole-Morten Duesund on Patreon. --- src/wrapper.hs | 43 ++++++++++++++++++++++++++++++++++++------- 1 file changed, 36 insertions(+), 7 deletions(-) (limited to 'src/wrapper.hs') diff --git a/src/wrapper.hs b/src/wrapper.hs index dab77358..6b24a368 100644 --- a/src/wrapper.hs +++ b/src/wrapper.hs @@ -6,6 +6,9 @@ -- This is not the propellor main program (that's config.hs). -- This bootstraps ~/.propellor/config.hs, builds it if -- it's not already built, and runs it. +-- +-- If ./config.hs exists, it instead builds and runs in the +-- current working directory. module Main where @@ -14,31 +17,57 @@ import Propellor.Message import Propellor.Bootstrap import Utility.Monad import Utility.Directory +import Utility.FileMode import Utility.Process import Utility.Process.NonConcurrent import System.Environment (getArgs) import System.Exit -import System.Posix.Directory +import System.Posix import Control.Monad.IfElse main :: IO () main = withConcurrentOutput $ go =<< getArgs where go ["--init"] = interactiveInit - go args = ifM (doesDirectoryExist =<< dotPropellor) - ( do - checkRepoUpToDate - buildRunConfig args - , error "Seems that ~/.propellor/ does not exist. To set it up, run: propellor --init" + go args = ifM configInCurrentWorkingDirectory + ( buildRunConfig args + , ifM (doesDirectoryExist =<< dotPropellor) + ( do + checkRepoUpToDate + changeWorkingDirectory =<< dotPropellor + buildRunConfig args + , error "Seems that ~/.propellor/ does not exist. To set it up, run: propellor --init" + ) ) buildRunConfig :: [String] -> IO () buildRunConfig args = do - changeWorkingDirectory =<< dotPropellor unlessM (doesFileExist "propellor") $ do buildPropellor Nothing putStrLn "" putStrLn "" (_, _, _, pid) <- createProcessNonConcurrent (proc "./propellor" args) exitWith =<< waitForProcessNonConcurrent pid + +configInCurrentWorkingDirectory :: IO Bool +configInCurrentWorkingDirectory = ifM (doesFileExist "config.hs") + ( do + -- This is a security check to avoid using the current + -- working directory as the propellor configuration + -- if it's not owned by the user, or is world-writable, + -- or group writable. (Some umasks may make directories + -- group writable, but typical ones do not.) + s <- getFileStatus "." + uid <- getRealUserID + if fileOwner s /= uid + then unsafe "you don't own the current directory" + else if checkMode groupWriteMode (fileMode s) + then unsafe "the current directory is group writable" + else if checkMode otherWriteMode (fileMode s) + then unsafe "the current directory is world-writable" + else return True + , return False + ) + where + unsafe s = error $ "Not using ./config.hs because " ++ s ++ ". This seems unsafe." -- cgit v1.2.3