module Propellor.Property.Gpg where

import Propellor
import qualified Propellor.Property.Apt as Apt
import Utility.FileSystemEncoding

import System.PosixCompat

installed :: Property
installed = Apt.installed ["gnupg"]

type GpgKeyId = String

-- | Sets up a user with a gpg key from the privdata.
-- Note that if a secret key is exported using gpg -a --export-secret-key,
-- the public key is also included. Or just a public key could be
-- exported, and this would set it up just as well.
-- Recommend only using this for low-value dedicated role keys.
-- No attempt has been made to scrub the key out of memory once it's used.
-- The GpgKeyId does not have to be a numeric id; it can just as easily
-- be a description of the key.
keyImported :: GpgKeyId -> UserName -> Property
keyImported keyid user = flagFile' prop genflag
	`requires` installed
	desc = user ++ " has gpg key " ++ show keyid
	genflag = do
		d <- dotDir user
		return $ d </> ".propellor-imported-keyid-" ++ keyid
	prop = withPrivData GpgKey (Context keyid) $ \getkey ->
		property desc $ getkey $ \key -> makeChange $
			withHandle StdinHandle createProcessSuccess
				(proc "su" ["-c", "gpg --import", user]) $ \h -> do
					fileEncoding h
					hPutStr h key
					hClose h

dotDir :: UserName -> IO FilePath
dotDir user = do
	home <- homeDirectory <$> getUserEntryForName user
	return $ home </> ".gnupg"