From 88a7bb50033baab3c2d0eed7e4be868e8966300a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Roman=20Smr=C5=BE?= Date: Fri, 17 Nov 2023 20:28:44 +0100 Subject: Split to library and executable parts --- src/Erebos/Channel.hs | 174 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 src/Erebos/Channel.hs (limited to 'src/Erebos/Channel.hs') diff --git a/src/Erebos/Channel.hs b/src/Erebos/Channel.hs new file mode 100644 index 0000000..c10f971 --- /dev/null +++ b/src/Erebos/Channel.hs @@ -0,0 +1,174 @@ +module Erebos.Channel ( + Channel, + ChannelRequest, ChannelRequestData(..), + ChannelAccept, ChannelAcceptData(..), + + createChannelRequest, + acceptChannelRequest, + acceptedChannel, + + channelEncrypt, + channelDecrypt, +) where + +import Control.Concurrent.MVar +import Control.Monad +import Control.Monad.Except + +import Crypto.Cipher.ChaChaPoly1305 +import Crypto.Error + +import Data.Binary +import Data.ByteArray (ByteArray, Bytes, ScrubbedBytes, convert) +import Data.ByteArray qualified as BA +import Data.ByteString.Lazy qualified as BL +import Data.List + +import Erebos.Identity +import Erebos.PubKey +import Erebos.Storage + +data Channel = Channel + { chPeers :: [Stored (Signed IdentityData)] + , chKey :: ScrubbedBytes + , chNonceFixedOur :: Bytes + , chNonceFixedPeer :: Bytes + , chCounterNextOut :: MVar Word64 + , chCounterNextIn :: MVar Word64 + } + +type ChannelRequest = Signed ChannelRequestData + +data ChannelRequestData = ChannelRequest + { crPeers :: [Stored (Signed IdentityData)] + , crKey :: Stored PublicKexKey + } + deriving (Show) + +type ChannelAccept = Signed ChannelAcceptData + +data ChannelAcceptData = ChannelAccept + { caRequest :: Stored ChannelRequest + , caKey :: Stored PublicKexKey + } + + +instance Storable ChannelRequestData where + store' cr = storeRec $ do + mapM_ (storeRef "peer") $ crPeers cr + storeRef "key" $ crKey cr + + load' = loadRec $ do + ChannelRequest + <$> loadRefs "peer" + <*> loadRef "key" + +instance Storable ChannelAcceptData where + store' ca = storeRec $ do + storeRef "req" $ caRequest ca + storeRef "key" $ caKey ca + + load' = loadRec $ do + ChannelAccept + <$> loadRef "req" + <*> loadRef "key" + + +keySize :: Int +keySize = 32 + +createChannelRequest :: (MonadStorage m, MonadIO m, MonadError String m) => UnifiedIdentity -> UnifiedIdentity -> m (Stored ChannelRequest) +createChannelRequest self peer = do + (_, xpublic) <- liftIO . generateKeys =<< getStorage + skey <- loadKey $ idKeyMessage self + mstore =<< sign skey =<< mstore ChannelRequest { crPeers = sort [idData self, idData peer], crKey = xpublic } + +acceptChannelRequest :: (MonadStorage m, MonadIO m, MonadError String m) => UnifiedIdentity -> UnifiedIdentity -> Stored ChannelRequest -> m (Stored ChannelAccept, Channel) +acceptChannelRequest self peer req = do + case sequence $ map validateIdentity $ crPeers $ fromStored $ signedData $ fromStored req of + Nothing -> throwError $ "invalid peers in channel request" + Just peers -> do + when (not $ any (self `sameIdentity`) peers) $ + throwError $ "self identity missing in channel request peers" + when (not $ any (peer `sameIdentity`) peers) $ + throwError $ "peer identity missing in channel request peers" + when (idKeyMessage peer `notElem` (map (sigKey . fromStored) $ signedSignature $ fromStored req)) $ + throwError $ "channel requent not signed by peer" + + (xsecret, xpublic) <- liftIO . generateKeys =<< getStorage + skey <- loadKey $ idKeyMessage self + acc <- mstore =<< sign skey =<< mstore ChannelAccept { caRequest = req, caKey = xpublic } + liftIO $ do + let chPeers = crPeers $ fromStored $ signedData $ fromStored req + chKey = BA.take keySize $ dhSecret xsecret $ + fromStored $ crKey $ fromStored $ signedData $ fromStored req + chNonceFixedOur = BA.pack [ 2, 0, 0, 0 ] + chNonceFixedPeer = BA.pack [ 1, 0, 0, 0 ] + chCounterNextOut <- newMVar 0 + chCounterNextIn <- newMVar 0 + + return (acc, Channel {..}) + +acceptedChannel :: (MonadIO m, MonadError String m) => UnifiedIdentity -> UnifiedIdentity -> Stored ChannelAccept -> m Channel +acceptedChannel self peer acc = do + let req = caRequest $ fromStored $ signedData $ fromStored acc + case sequence $ map validateIdentity $ crPeers $ fromStored $ signedData $ fromStored req of + Nothing -> throwError $ "invalid peers in channel accept" + Just peers -> do + when (not $ any (self `sameIdentity`) peers) $ + throwError $ "self identity missing in channel accept peers" + when (not $ any (peer `sameIdentity`) peers) $ + throwError $ "peer identity missing in channel accept peers" + when (idKeyMessage peer `notElem` (map (sigKey . fromStored) $ signedSignature $ fromStored acc)) $ + throwError $ "channel accept not signed by peer" + when (idKeyMessage self `notElem` (map (sigKey . fromStored) $ signedSignature $ fromStored req)) $ + throwError $ "original channel request not signed by us" + + xsecret <- loadKey $ crKey $ fromStored $ signedData $ fromStored req + let chPeers = crPeers $ fromStored $ signedData $ fromStored req + chKey = BA.take keySize $ dhSecret xsecret $ + fromStored $ caKey $ fromStored $ signedData $ fromStored acc + chNonceFixedOur = BA.pack [ 1, 0, 0, 0 ] + chNonceFixedPeer = BA.pack [ 2, 0, 0, 0 ] + chCounterNextOut <- liftIO $ newMVar 0 + chCounterNextIn <- liftIO $ newMVar 0 + + return Channel {..} + + +channelEncrypt :: (ByteArray ba, MonadIO m, MonadError String m) => Channel -> ba -> m (ba, Word64) +channelEncrypt Channel {..} plain = do + count <- liftIO $ modifyMVar chCounterNextOut $ \c -> return (c + 1, c) + let cbytes = convert $ BL.toStrict $ encode count + nonce = nonce8 chNonceFixedOur cbytes + state <- case initialize chKey =<< nonce of + CryptoPassed state -> return state + CryptoFailed err -> throwError $ "failed to init chacha-poly1305 cipher: " <> show err + + let (ctext, state') = encrypt plain state + tag = finalize state' + return (BA.concat [ convert $ BA.drop 7 cbytes, ctext, convert tag ], count) + +channelDecrypt :: (ByteArray ba, MonadIO m, MonadError String m) => Channel -> ba -> m (ba, Word64) +channelDecrypt Channel {..} body = do + when (BA.length body < 17) $ do + throwError $ "invalid encrypted data length" + + expectedCount <- liftIO $ readMVar chCounterNextIn + let countByte = body `BA.index` 0 + body' = BA.dropView body 1 + guessedCount = expectedCount - 128 + fromIntegral (countByte - fromIntegral expectedCount + 128 :: Word8) + nonce = nonce8 chNonceFixedPeer $ convert $ BL.toStrict $ encode guessedCount + blen = BA.length body' - 16 + ctext = BA.takeView body' blen + tag = BA.dropView body' blen + state <- case initialize chKey =<< nonce of + CryptoPassed state -> return state + CryptoFailed err -> throwError $ "failed to init chacha-poly1305 cipher: " <> show err + + let (plain, state') = decrypt (convert ctext) state + when (not $ tag `BA.constEq` finalize state') $ do + throwError $ "tag validation falied" + + liftIO $ modifyMVar_ chCounterNextIn $ return . max (guessedCount + 1) + return (plain, guessedCount) -- cgit v1.2.3