Fix caching of decrypted ciphers, which failed when drop had to check multiple different encrypted special remotes.

Annex.hs

@@ -36,6 +36,7 @@ import Types.BranchState
 import Types.TrustLevel
 import Types.UUID
 import qualified Utility.Matcher
+import qualified Data.Map as M
 
 -- git-annex's monad
 newtype Annex a = Annex { runAnnex :: StateT AnnexState IO a }
@@ -70,7 +71,7 @@ data AnnexState = AnnexState
 	, limit :: Either [Utility.Matcher.Token (FilePath -> Annex Bool)] (Utility.Matcher.Matcher (FilePath -> Annex Bool))
 	, forcetrust :: [(UUID, TrustLevel)]
 	, trustmap :: Maybe TrustMap
-	, cipher :: Maybe Cipher
+	, ciphers :: M.Map EncryptedCipher Cipher
 	}
 
 newState :: Git.Repo -> AnnexState
@@ -93,7 +94,7 @@ newState gitrepo = AnnexState
 	, limit = Left []
 	, forcetrust = []
 	, trustmap = Nothing
-	, cipher = Nothing
+	, ciphers = M.empty
 	}
 
 {- Create and returns an Annex state object for the specified git repo. -}

Remote/Helper/Encryptable.hs

@@ -61,19 +61,22 @@ encryptableRemote c storeKeyEncrypted retrieveKeyFileEncrypted r =
 		withkey a k = cip k >>= maybe (a k) (a . snd)
 		cip = cipherKey c
 
-{- Gets encryption Cipher. The decrypted Cipher is cached in the Annex
+{- Gets encryption Cipher. The decrypted Ciphers are cached in the Annex
  - state. -}
 remoteCipher :: RemoteConfig -> Annex (Maybe Cipher)
-remoteCipher c = maybe expensive cached =<< Annex.getState Annex.cipher
+remoteCipher c = go $ extractCipher c
 	where
-		cached cipher = return $ Just cipher
-		expensive = case extractCipher c of
-			Nothing -> return Nothing
-			Just encipher -> do
-				showNote "gpg"
-				cipher <- liftIO $ decryptCipher c encipher
-				Annex.changeState (\s -> s { Annex.cipher = Just cipher })
-				return $ Just cipher
+		go Nothing = return Nothing
+		go (Just encipher) = do
+			cache <- Annex.getState Annex.ciphers
+			case M.lookup encipher cache of
+				Just cipher -> return $ Just cipher
+				Nothing -> decrypt encipher cache
+		decrypt encipher cache = do
+			showNote "gpg"
+			cipher <- liftIO $ decryptCipher c encipher
+			Annex.changeState (\s -> s { Annex.ciphers = M.insert encipher cipher cache })
+			return $ Just cipher
 
 {- Gets encryption Cipher, and encrypted version of Key. -}
 cipherKey :: Maybe RemoteConfig -> Key -> Annex (Maybe (Cipher, Key))

Types/Crypto.hs

@@ -11,5 +11,7 @@ module Types.Crypto where
 newtype Cipher = Cipher String
 
 data EncryptedCipher = EncryptedCipher String KeyIds
+	deriving (Ord, Eq)
 
 newtype KeyIds = KeyIds [String]
+	deriving (Ord, Eq)

debian/changelog

@@ -5,6 +5,8 @@ git-annex (3.20111204) UNRELEASED; urgency=low
   * Prevent key names from containing newlines.
   * add: If interrupted, add can leave files converted to symlinks but not
     yet added to git. Running the add again will now clean up this situtation.
+  * Fix caching of decrypted ciphers, which failed when drop had to check
+    multiple different encrypted special remotes.
 
  -- Joey Hess <joeyh@debian.org>  Sun, 04 Dec 2011 12:22:37 -0400
 

doc/bugs/git-annex_losing_rsync_remotes_with_encryption_enabled.mdwn

@@ -92,3 +92,10 @@ git annex copy --to remoteserver -d tools/md5_sha1_utility.exe
 > Running: sh ["-c","rsync --quiet 'REMOVED_HOST:annex/work/1F/PQ/'\"'\"'GPGHMACSHA1--ff075e57f649300c5698e346be74fb6e22d70e35/GPGHMACSHA1--ff075e57f649300c5698e346be74fb6e22d70e35'\"'\"'' 2>/dev/null"]
 
 And yes, only the hash *annex copy* is checking for exists on the remote side. --[[gebi]]
+
+> Ok, this is due to too aggressive caching of the decrypted cipher
+> for a remote. When dopping, it decrypts localserver's cipher, 
+> caches it, and then when checking remoteserver it says hey, 
+> here's an already decrypted cipher -- it must be the right one!
+> 
+> Problem reproduced here, and fixed. [[done]] --[[Joey]]