Atomicity does not seem to be given in certain scenarios

Start with the linked cryptofs_bug_reproducer and EclipseStoreMain, switching between the encrypted and unencrypted configurations. Reproduce the failure by stopping the JVM after “Committing” and before “Committed”, then inspect the file-reading path named in the trace, including ChunkCache and CleartextFileChannel. Done means the abrupt-stop scenario has a defined atomicity outcome and encrypted data remains readable, or the limitation is documented.

Hey,

We are currently trying to use cryptofs as the backing filesystem for https://github.com/eclipse-store.

EclipseStore offers a type of transaction object, where you can store multiple things and then commit them, flushing them to the storage target.

In this scenario the storage target is a cryptofs instance. When killing the JVM abruptly (not graceful), this will cause broken files that can't be decrypted anymore.

I have created a reproducer repo here:

https://github.com/Bios-Marcel/cryptofs_bug_reproducer

You can switch between the uncrypted and encrypted versions of the reproducer by commenting / uncommenting the respective first line in EclipseStoreMain.

To cause the issue, you need to kill the JVM after the console puts out Committing, but before it says Committed. Given that cryptofs is a filesystem abstraction, I am doubting that EclipseStore does anything wrong here, especially since there is no issue in reading / writing the data without encryption.

Here's the exception:

Exception in thread "main" org.eclipse.store.storage.exceptions.StorageException: Problem in channel #0
	at org.eclipse.store.storage.types.StorageChannelTask$Abstract.checkForProblems(StorageChannelTask.java:106)
	at org.eclipse.store.storage.types.StorageChannelTask$Abstract.waitOnCompletion(StorageChannelTask.java:168)
	at org.eclipse.store.storage.types.StorageSystem$Default.startThreads(StorageSystem.java:332)
	at org.eclipse.store.storage.types.StorageSystem$Default.internalStartUp(StorageSystem.java:515)
	at org.eclipse.store.storage.types.StorageSystem$Default.start(StorageSystem.java:601)
	at org.eclipse.store.storage.types.StorageSystem$Default.start(StorageSystem.java:71)
	at org.eclipse.store.storage.embedded.types.EmbeddedStorageManager$Default.start(EmbeddedStorageManager.java:247)
	at org.eclipse.store.storage.embedded.types.EmbeddedStorageManager$Default.start(EmbeddedStorageManager.java:95)
	at EclipseStoreMain.main(EclipseStoreMain.java:33)
Caused by: org.eclipse.store.storage.exceptions.StorageExceptionIoReading
	at org.eclipse.store.storage.types.StorageEntityInitializer$Default.fillBuffer(StorageEntityInitializer.java:279)
	at org.eclipse.store.storage.types.StorageEntityInitializer$Default.indexEntities(StorageEntityInitializer.java:181)
	at org.eclipse.store.storage.types.StorageEntityInitializer$Default.registerFileEntities(StorageEntityInitializer.java:127)
	at org.eclipse.store.storage.types.StorageEntityInitializer$Default.registerEntities(StorageEntityInitializer.java:103)
	at org.eclipse.store.storage.types.StorageEntityInitializer$Default.registerEntities(StorageEntityInitializer.java:85)
	at org.eclipse.store.storage.types.StorageEntityInitializer$Default.registerEntities(StorageEntityInitializer.java:48)
	at org.eclipse.store.storage.types.StorageFileManager$Default.initializeForExistingFiles(StorageFileManager.java:1002)
	at org.eclipse.store.storage.types.StorageFileManager$Default.initializeStorage(StorageFileManager.java:886)
	at org.eclipse.store.storage.types.StorageChannel$Default.initializeStorage(StorageChannel.java:782)
	at org.eclipse.store.storage.types.StorageChannelTaskInitialize$Default.succeed(StorageChannelTaskInitialize.java:200)
	at org.eclipse.store.storage.types.StorageChannelTaskInitialize$Default.succeed(StorageChannelTaskInitialize.java:34)
	at org.eclipse.store.storage.types.StorageChannelSynchronizingTask$AbstractCompletingTask.synchronizedComplete(StorageChannelSynchronizingTask.java:78)
	at org.eclipse.store.storage.types.StorageChannelSynchronizingTask$AbstractCompletingTask.complete(StorageChannelSynchronizingTask.java:126)
	at org.eclipse.store.storage.types.StorageChannelTask$Abstract.processBy(StorageChannelTask.java:260)
	at org.eclipse.store.storage.types.StorageChannel$Default.work(StorageChannel.java:453)
	at org.eclipse.store.storage.types.StorageChannel$Default.run(StorageChannel.java:536)
	at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: org.eclipse.store.storage.exceptions.StorageExceptionIoReading
	at org.eclipse.store.storage.types.StorageFile$Abstract.readBytes(StorageFile.java:176)
	at org.eclipse.store.storage.types.StorageEntityInitializer$Default.fillBuffer(StorageEntityInitializer.java:275)
	... 16 more
Caused by: org.eclipse.serializer.exceptions.IORuntimeException: java.io.IOException: org.cryptomator.cryptolib.api.AuthenticationFailedException: Content tag mismatch.
	at org.eclipse.store.afs.nio.types.NioIoHandler$Default.specificReadBytes(NioIoHandler.java:453)
	at org.eclipse.store.afs.nio.types.NioIoHandler$Default.specificReadBytes(NioIoHandler.java:81)
	at org.eclipse.serializer.afs.types.AIoHandler$Abstract.readBytes(AIoHandler.java:790)
	at org.eclipse.serializer.afs.types.AReadableFile.readBytes(AReadableFile.java:104)
	at org.eclipse.store.storage.types.StorageFile$Abstract.readBytes(StorageFile.java:172)
	... 17 more
Caused by: java.io.IOException: org.cryptomator.cryptolib.api.AuthenticationFailedException: Content tag mismatch.
	at org.cryptomator.cryptofs.fh.ChunkCache.getChunk(ChunkCache.java:123)
	at org.cryptomator.cryptofs.ch.CleartextFileChannel.readLocked(CleartextFileChannel.java:112)
	at org.cryptomator.cryptofs.ch.AbstractFileChannel.read(AbstractFileChannel.java:155)
	at org.eclipse.serializer.io.XIO.internalRead(XIO.java:1238)
	at org.eclipse.serializer.io.XIO.read(XIO.java:1198)
	at org.eclipse.store.afs.nio.types.NioIoHandler$Default.specificReadBytes(NioIoHandler.java:449)
	... 21 more
Caused by: org.cryptomator.cryptolib.api.AuthenticationFailedException: Content tag mismatch.
	at org.cryptomator.cryptolib.v2.FileContentCryptorImpl.decryptChunk(FileContentCryptorImpl.java:146)
	at org.cryptomator.cryptolib.v2.FileContentCryptorImpl.decryptChunk(FileContentCryptorImpl.java:97)
	at org.cryptomator.cryptofs.fh.ChunkLoader.load(ChunkLoader.java:40)
	at org.cryptomator.cryptofs.fh.ChunkCache.loadChunk(ChunkCache.java:133)
	at org.cryptomator.cryptofs.fh.ChunkCache.lambda$getChunk$2(ChunkCache.java:117)
	at com.github.benmanes.caffeine.cache.BoundedLocalCache.lambda$remap$16(BoundedLocalCache.java:2858)
	at java.base/java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1916)
	at com.github.benmanes.caffeine.cache.BoundedLocalCache.remap(BoundedLocalCache.java:2853)
	at com.github.benmanes.caffeine.cache.BoundedLocalCache.compute(BoundedLocalCache.java:2803)
	at com.github.benmanes.caffeine.cache.LocalCache.compute(LocalCache.java:99)
	at org.cryptomator.cryptofs.fh.ChunkCache.getChunk(ChunkCache.java:115)
	... 26 more
Caused by: javax.crypto.AEADBadTagException: Tag mismatch
	at java.base/com.sun.crypto.provider.GaloisCounterMode$GCMDecrypt.doFinal(GaloisCounterMode.java:1652)
	at java.base/com.sun.crypto.provider.GaloisCounterMode.engineDoFinal(GaloisCounterMode.java:458)
	at java.base/javax.crypto.Cipher.doFinal(Cipher.java:2543)
	at org.cryptomator.cryptolib.v2.FileContentCryptorImpl.decryptChunk(FileContentCryptorImpl.java:143)
	... 36 more