1 files changed, 85 insertions, 0 deletions
diff --git a/src/Erebos/Storage/Key.hs b/src/Erebos/Storage/Key.hs
new file mode 100644
index 0000000..b6afc20
--- /dev/null
+++ b/src/Erebos/Storage/Key.hs
@@ -0,0 +1,85 @@
+module Erebos.Storage.Key (
+    KeyPair(..),
+    storeKey, loadKey, loadKeyMb,
+    moveKeys,
+) where
+
+import Control.Concurrent.MVar
+import Control.Monad
+import Control.Monad.Except
+import Control.Monad.IO.Class
+
+import Data.ByteArray
+import qualified Data.ByteString.Char8 as BC
+import qualified Data.ByteString.Lazy as BL
+import qualified Data.Map as M
+
+import System.Directory
+import System.FilePath
+import System.IO.Error
+
+import Erebos.Storage
+import Erebos.Storage.Internal
+
+class Storable pub => KeyPair sec pub | sec -> pub, pub -> sec where
+    generateKeys :: Storage -> IO (sec, Stored pub)
+    keyGetPublic :: sec -> Stored pub
+    keyGetData :: sec -> ScrubbedBytes
+    keyFromData :: ScrubbedBytes -> Stored pub -> Maybe sec
+
+
+keyFilePath :: KeyPair sec pub => FilePath -> Stored pub -> FilePath
+keyFilePath sdir pkey = sdir </> "keys" </> (BC.unpack $ showRef $ storedRef pkey)
+
+storeKey :: KeyPair sec pub => sec -> IO ()
+storeKey key = do
+    let spub = keyGetPublic key
+    case stBacking $ storedStorage spub of
+         StorageDir { dirPath = dir } -> writeFileOnce (keyFilePath dir spub) (BL.fromStrict $ convert $ keyGetData key)
+         StorageMemory { memKeys = kstore } -> modifyMVar_ kstore $ return . M.insert (refDigest $ storedRef spub) (keyGetData key)
+
+loadKey :: (KeyPair sec pub, MonadIO m, MonadError String m) => Stored pub -> m sec
+loadKey pub = maybe (throwError $ "secret key not found for " <> show (storedRef pub)) return =<< loadKeyMb pub
+
+loadKeyMb :: (KeyPair sec pub, MonadIO m) => Stored pub -> m (Maybe sec)
+loadKeyMb spub = liftIO $ run $ storedStorage spub
+  where
+    run st = tryOneLevel (stBacking st) >>= \case
+        key@Just {} -> return key
+        Nothing | Just parent <- stParent st -> run parent
+                | otherwise -> return Nothing
+    tryOneLevel = \case
+        StorageDir { dirPath = dir } -> tryIOError (BC.readFile (keyFilePath dir spub)) >>= \case
+            Right kdata -> return $ keyFromData (convert kdata) spub
+            Left _ -> return Nothing
+        StorageMemory { memKeys = kstore } -> (flip keyFromData spub <=< M.lookup (refDigest $ storedRef spub)) <$> readMVar kstore
+
+moveKeys :: MonadIO m => Storage -> Storage -> m ()
+moveKeys from to = liftIO $ do
+    case (stBacking from, stBacking to) of
+        (StorageDir { dirPath = fromPath }, StorageDir { dirPath = toPath }) -> do
+            files <- listDirectory (fromPath </> "keys")
+            forM_ files $ \file -> do
+                renameFile (fromPath </> "keys" </> file) (toPath </> "keys" </> file)
+
+        (StorageDir { dirPath = fromPath }, StorageMemory { memKeys = toKeys }) -> do
+            let move m file
+                    | Just dgst <- readRefDigest (BC.pack file) = do
+                        let path = fromPath </> "keys" </> file
+                        key <- convert <$> BC.readFile path
+                        removeFile path
+                        return $ M.insert dgst key m
+                    | otherwise = return m
+            files <- listDirectory (fromPath </> "keys")
+            modifyMVar_ toKeys $ \keys -> foldM move keys files
+
+        (StorageMemory { memKeys = fromKeys }, StorageDir { dirPath = toPath }) -> do
+            modifyMVar_ fromKeys $ \keys -> do
+                forM_ (M.assocs keys) $ \(dgst, key) ->
+                    writeFileOnce (toPath </> "keys" </> (BC.unpack $ showRefDigest dgst)) (BL.fromStrict $ convert key)
+                return M.empty
+
+        (StorageMemory { memKeys = fromKeys }, StorageMemory { memKeys = toKeys }) -> do
+            modifyMVar_ fromKeys $ \fkeys -> do
+                modifyMVar_ toKeys $ return . M.union fkeys
+                return M.empty