mirrors/git-annex
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages 1 Wiki Activity Actions

Added new encryption=sharedpubkey mode for special remotes.

Browse source 
This is useful for makking a special remote that anyone with a clone of the
repo and your public keys can upload files to, but only you can decrypt the
files stored in it.
This commit is contained in:
Joey Hess 2016-05-10 16:50:31 -04:00
parent 2d00523609
commit e219289c83
Failed to extract signature
7 changed files with 114 additions and 63 deletions
Download patch file Download diff file Expand all files Collapse all files

59
Crypto.hs
View file

@ -18,8 +18,8 @@ module Crypto (
StorableCipher(..),
genEncryptedCipher,
genSharedCipher,
updateEncryptedCipher,
describeCipher,
genSharedPubKeyCipher,
updateCipherKeyIds,
decryptCipher,
encryptKey,
isEncKey,
@ -74,7 +74,7 @@ cipherMac (Cipher c) = take cipherBeginning c
cipherMac (MacOnlyCipher c) = c
{- Creates a new Cipher, encrypted to the specified key id. -}
genEncryptedCipher :: Gpg.GpgCmd -> String -> EncryptedCipherVariant -> Bool -> IO StorableCipher
genEncryptedCipher :: Gpg.GpgCmd -> Gpg.KeyId -> EncryptedCipherVariant -> Bool -> IO StorableCipher
genEncryptedCipher cmd keyid variant highQuality = do
ks <- Gpg.findPubKeys cmd keyid
random <- Gpg.genRandom cmd highQuality size
@ -89,35 +89,40 @@ genSharedCipher :: Gpg.GpgCmd -> Bool -> IO StorableCipher
genSharedCipher cmd highQuality =
SharedCipher <$> Gpg.genRandom cmd highQuality cipherSize
{- Updates an existing Cipher, re-encrypting it to add or remove keyids,
- depending on whether the first component is True or False. -}
updateEncryptedCipher :: Gpg.GpgCmd -> [(Bool, String)] -> StorableCipher -> IO StorableCipher
updateEncryptedCipher _ _ SharedCipher{} = error "Cannot update shared cipher"
updateEncryptedCipher _ [] encipher = return encipher
updateEncryptedCipher cmd newkeys encipher@(EncryptedCipher _ variant (KeyIds ks)) = do
dropKeys <- listKeyIds [ k | (False, k) <- newkeys ]
forM_ dropKeys $ \k -> unless (k `elem` ks) $
{- Creates a new, shared Cipher, and looks up the gpg public key that will
- be used for encrypting content. -}
genSharedPubKeyCipher :: Gpg.GpgCmd -> Gpg.KeyId -> Bool -> IO StorableCipher
genSharedPubKeyCipher cmd keyid highQuality = do
ks <- Gpg.findPubKeys cmd keyid
random <- Gpg.genRandom cmd highQuality cipherSize
return $ SharedPubKeyCipher random ks
{- Updates an existing Cipher, making changes to its keyids.
-
- When the Cipher is encrypted, re-encrypts it. -}
updateCipherKeyIds :: Gpg.GpgCmd -> [(Bool, Gpg.KeyId)] -> StorableCipher -> IO StorableCipher
updateCipherKeyIds _ _ SharedCipher{} = error "Cannot update shared cipher"
updateCipherKeyIds _ [] c = return c
updateCipherKeyIds cmd changes encipher@(EncryptedCipher _ variant ks) = do
ks' <- updateCipherKeyIds' cmd changes ks
cipher <- decryptCipher cmd encipher
encryptCipher cmd cipher variant ks'
updateCipherKeyIds cmd changes (SharedPubKeyCipher cipher ks) =
SharedPubKeyCipher cipher <$> updateCipherKeyIds' cmd changes ks
updateCipherKeyIds' :: Gpg.GpgCmd -> [(Bool, Gpg.KeyId)] -> KeyIds -> IO KeyIds
updateCipherKeyIds' cmd changes (KeyIds ks) = do
dropkeys <- listKeyIds [ k | (False, k) <- changes ]
forM_ dropkeys $ \k -> unless (k `elem` ks) $
error $ "Key " ++ k ++ " was not present; cannot remove."
addKeys <- listKeyIds [ k | (True, k) <- newkeys ]
let ks' = (addKeys ++ ks) \\ dropKeys
addkeys <- listKeyIds [ k | (True, k) <- changes ]
let ks' = (addkeys ++ ks) \\ dropkeys
when (null ks') $
error "Cannot remove the last key."
cipher <- decryptCipher cmd encipher
encryptCipher cmd cipher variant $ KeyIds ks'
return $ KeyIds ks'
where
listKeyIds = concat <$$> mapM (keyIds <$$> Gpg.findPubKeys cmd)
describeCipher :: StorableCipher -> String
describeCipher (SharedCipher _) = "shared cipher"
describeCipher (EncryptedCipher _ variant (KeyIds ks)) =
scheme ++ " with gpg " ++ keys ks ++ " " ++ unwords ks
where
scheme = case variant of
Hybrid -> "hybrid cipher"
PubKey -> "pubkey crypto"
keys [_] = "key"
keys _ = "keys"
{- Encrypts a Cipher to the specified KeyIds. -}
encryptCipher :: Gpg.GpgCmd -> Cipher -> EncryptedCipherVariant -> KeyIds -> IO StorableCipher
encryptCipher cmd c variant (KeyIds ks) = do
@ -134,6 +139,7 @@ encryptCipher cmd c variant (KeyIds ks) = do
{- Decrypting an EncryptedCipher is expensive; the Cipher should be cached. -}
decryptCipher :: Gpg.GpgCmd -> StorableCipher -> IO Cipher
decryptCipher _ (SharedCipher t) = return $ Cipher t
decryptCipher _ (SharedPubKeyCipher t _) = return $ MacOnlyCipher t
decryptCipher cmd (EncryptedCipher t variant _) =
mkCipher <$> Gpg.pipeStrict cmd [ Param "--decrypt" ] t
where
@ -223,6 +229,7 @@ instance LensGpgEncParams RemoteConfig where
- look up the recipient keys and add them to the option list. -}
getGpgEncParams c = case M.lookup "encryption" c of
Just "pubkey" -> Gpg.pkEncTo $ maybe [] (split ",") $ M.lookup "cipherkeys" c
Just "sharedpubkey" -> Gpg.pkEncTo $ maybe [] (split ",") $ M.lookup "pubkeys" c
_ -> []
getGpgDecParams _ = []