diff options
Diffstat (limited to 'Remote/Helper/Encryptable.hs')
| -rw-r--r-- | Remote/Helper/Encryptable.hs | 84 |
1 files changed, 59 insertions, 25 deletions
diff --git a/Remote/Helper/Encryptable.hs b/Remote/Helper/Encryptable.hs index 22e1c9fc0..29e51c002 100644 --- a/Remote/Helper/Encryptable.hs +++ b/Remote/Helper/Encryptable.hs @@ -23,30 +23,52 @@ import Utility.Metered - updated to be accessible to an additional encryption key. Or the user - could opt to use a shared cipher, which is stored unencrypted. -} encryptionSetup :: RemoteConfig -> Annex RemoteConfig -encryptionSetup c = case (M.lookup "encryption" c, extractCipher c) of - (Nothing, Nothing) -> error "Specify encryption=key or encryption=none or encryption=shared" - (Just "none", Nothing) -> return c - (Nothing, Just _) -> return c - (Just "shared", Just (SharedCipher _)) -> return c - (Just "none", Just _) -> cannotchange - (Just "shared", Just (EncryptedCipher _ _)) -> cannotchange - (Just _, Just (SharedCipher _)) -> cannotchange - (Just "shared", Nothing) -> use "encryption setup" . genSharedCipher - =<< highRandomQuality - (Just keyid, Nothing) -> use "encryption setup" . genEncryptedCipher keyid - =<< highRandomQuality - (Just keyid, Just v) -> use "encryption update" $ updateEncryptedCipher keyid v +encryptionSetup c = maybe genCipher updateCipher $ extractCipher c where - cannotchange = error "Cannot change encryption type of existing remote." + -- The type of encryption + encryption = M.lookup "encryption" c + -- Generate a new cipher, depending on the chosen encryption scheme + genCipher = case encryption of + _ | M.member "cipher" c || M.member "cipherkeys" c -> cannotchange + Just "none" -> return c + Just "shared" -> use "encryption setup" . genSharedCipher + =<< highRandomQuality + -- hybrid encryption is the default when a keyid is + -- specified but no encryption + _ | maybe (M.member "keyid" c) (== "hybrid") encryption -> + use "encryption setup" . genEncryptedCipher key HybridCipher + =<< highRandomQuality + Just "pubkey" -> use "encryption setup" . genEncryptedCipher key PubKeyCipher + =<< highRandomQuality + _ -> error $ "Specify " ++ intercalate " or " + (map ("encryption=" ++) + ["none","shared","hybrid","pubkey"]) + ++ "." + key = fromMaybe (error "Specifiy keyid=...") $ M.lookup "keyid" c + newkeys = maybe [] (\k -> [(True,k)]) (M.lookup "keyid+" c) ++ + maybe [] (\k -> [(False,k)]) (M.lookup "keyid-" c) + cannotchange = error "Cannot set encryption type of existing remotes." + -- Update an existing cipher if possible. + updateCipher v = case v of + SharedCipher _ | maybe True (== "shared") encryption -> return c' + EncryptedCipher _ variant _ + | maybe True (== if variant == HybridCipher then "hybrid" else "pubkey") encryption -> + use "encryption update" $ updateEncryptedCipher newkeys v + _ -> cannotchange use m a = do showNote m cipher <- liftIO a showNote $ describeCipher cipher - return $ M.delete "encryption" $ M.delete "highRandomQuality" $ - storeCipher c cipher + return $ storeCipher c' cipher highRandomQuality = (&&) (maybe True ( /= "false") $ M.lookup "highRandomQuality" c) <$> fmap not (Annex.getState Annex.fast) + c' = foldr M.delete c + -- git-annex used to remove 'encryption' as well, since + -- it was redundant; we now need to keep it for + -- public-key incryption, hence we leave it on newer + -- remotes (while being backward-compatible). + [ "keyid", "keyid+", "keyid-", "highRandomQuality" ] {- Modifies a Remote to support encryption. - @@ -111,27 +133,39 @@ embedCreds c | isJust (M.lookup "cipherkeys" c) && isJust (M.lookup "cipher" c) = True | otherwise = False -{- Gets encryption Cipher, and encrypted version of Key. -} +{- Gets encryption Cipher, and encrypted version of Key. In case we want + - asymmetric encryption, leave the first empty, but encrypt the Key + - regardless. (Empty ciphers imply asymmetric encryption.) We could + - also check how long is the cipher (MAC'ing-only ciphers are shorter), + - but we don't want to rely on that only. -} cipherKey :: RemoteConfig -> Key -> Annex (Maybe (Cipher, Key)) -cipherKey c k = maybe Nothing make <$> remoteCipher c +cipherKey c k = fmap make <$> remoteCipher c where - make ciphertext = Just (ciphertext, encryptKey mac ciphertext k) + make ciphertext = (cipContent ciphertext, encryptKey mac ciphertext k) + cipContent + | M.lookup "encryption" c /= Just "pubkey" = id + | otherwise = const $ Cipher "" mac = fromMaybe defaultMac $ M.lookup "mac" c >>= readMac {- Stores an StorableCipher in a remote's configuration. -} storeCipher :: RemoteConfig -> StorableCipher -> RemoteConfig storeCipher c (SharedCipher t) = M.insert "cipher" (toB64 t) c -storeCipher c (EncryptedCipher t ks) = +storeCipher c (EncryptedCipher t _ ks) = M.insert "cipher" (toB64 t) $ M.insert "cipherkeys" (showkeys ks) c where showkeys (KeyIds l) = intercalate "," l {- Extracts an StorableCipher from a remote's configuration. -} extractCipher :: RemoteConfig -> Maybe StorableCipher -extractCipher c = - case (M.lookup "cipher" c, M.lookup "cipherkeys" c) of - (Just t, Just ks) -> Just $ EncryptedCipher (fromB64 t) (readkeys ks) - (Just t, Nothing) -> Just $ SharedCipher (fromB64 t) - _ -> Nothing +extractCipher c = case (M.lookup "cipher" c, + M.lookup "cipherkeys" c, + M.lookup "encryption" c) of + (Just t, Just ks, encryption) | maybe True (== "hybrid") encryption -> + Just $ EncryptedCipher (fromB64 t) HybridCipher (readkeys ks) + (Just t, Just ks, Just "pubkey") -> + Just $ EncryptedCipher (fromB64 t) PubKeyCipher (readkeys ks) + (Just t, Nothing, encryption) | maybe True (== "shared") encryption -> + Just $ SharedCipher (fromB64 t) + _ -> Nothing where readkeys = KeyIds . split "," |