Arch Linux

Franek

Member

Registered: 2010-05-16

Posts: 100

encfs filename decoding error (mounting works, mountpoint is empty)

Hi!

a fairly large (1.9 GB) encfs-encrypted directory of mine stopped working some time ago, and I am hoping someone here can help me regain access to the data.

This is the situation:
– The directory can still be mounted, but the mount directory appears empty.
– The encrypted data seems to be intact: There is a ".encfs6.xml" and a hierarchy of gibberish-named files and folders, which amount to 1.9 GB altogether.
– I can still write to the directory. (I. e. if I mount the dir, create file with "touch <file>", unmount, and remount again, the newly created file is still there.)
– When I run encfs with the "-vf" options, I see these error messages:

20:42:00 (DirNode.cpp:132) error decoding filename: be1k7L8fVkv63EsbHLLxoJtY
20:42:00 (DirNode.cpp:132) error decoding filename: .encfs6.xml

– When I do "ls" on the dir, the command works, while "encfs -vf" says:

20:57:09 (encfs.cpp:92) getxattr /home/carlos/mnt/ssh/morrigan/home/carlos/gemein/encfs/eZAORCDpP7ZyvSscCPZLuUwI
20:57:09 (encfs.cpp:99) getxattr error: Operation not supported

The full output of "encfs -vf" is quoted below. You may notice the the encrypted data is accessed through an sshfs mount. This is not the present source of the problem, as I can reproduce it directly on the server. It may, however, be its origin: The data could have been corrupted by a network interruption (or so I imagine).

There is a similar problem report on askubuntu. It is even from around the same time when it hit me (roughly two months ago):
http://askubuntu.com/questions/360847/e … g-the-data

Also, there apparently was a bug in the boost libraries in 2010 which produced similar errors (among others), but which does not seem to be connected in any way:
https://bbs.archlinux.org/viewtopic.php?id=92209

Any ideas?

$ encfs -vf /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/ /home/carlos/.gemein/encfs/
21:03:07 (main.cpp:523) Root directory: /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:03:07 (main.cpp:524) Fuse arguments: (fg) (threaded) (keyCheck) encfs /home/carlos/.gemein/encfs/ -f -s -o use_ino -o default_permissions 
21:03:07 (FileUtils.cpp:177) version = 20
21:03:07 (FileUtils.cpp:181) found new serialization format
21:03:07 (FileUtils.cpp:199) subVersion = 20100713
21:03:07 (Interface.cpp:165) checking if ssl/aes(3:0:2) implements ssl/aes(3:0:0)
21:03:07 (SSL_Cipher.cpp:370) allocated cipher ssl/aes, keySize 24, ivlength 16
21:03:07 (Interface.cpp:165) checking if ssl/aes(3:0:2) implements ssl/aes(3:0:0)
21:03:07 (SSL_Cipher.cpp:370) allocated cipher ssl/aes, keySize 24, ivlength 16
21:03:07 (FileUtils.cpp:1620) useStdin: 0
EncFS Password: 
21:03:20 (Interface.cpp:165) checking if ssl/aes(3:0:2) implements ssl/aes(3:0:0)
21:03:20 (SSL_Cipher.cpp:370) allocated cipher ssl/aes, keySize 24, ivlength 16
21:03:21 (FileUtils.cpp:1628) cipher key size = 44
21:03:21 (Interface.cpp:165) checking if nameio/block(3:0:1) implements nameio/block(3:0:0)
21:03:28 (DirNode.cpp:770) created FileNode for /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:03:28 (encfs.cpp:134) getattr /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:03:39 (DirNode.cpp:770) created FileNode for /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:03:39 (encfs.cpp:134) getattr /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:40 (DirNode.cpp:770) created FileNode for /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:40 (encfs.cpp:134) getattr /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:40 (DirNode.cpp:770) created FileNode for /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:40 (encfs.cpp:134) getattr /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:41 (encfs.cpp:213) getdir on /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:41 (BlockNameIO.cpp:185) padding, _bx, finalSize = 139, 16, -123
21:06:41 (DirNode.cpp:132) error decoding filename: be1k7L8fVkv63EsbHLLxoJtY
21:06:41 (DirNode.cpp:132) error decoding filename: .encfs6.xml
21:06:41 (DirNode.cpp:770) created FileNode for /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:41 (encfs.cpp:134) getattr /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/
21:06:41 (DirNode.cpp:770) created FileNode for /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/eZAORCDpP7ZyvSscCPZLuUwI
21:06:41 (encfs.cpp:134) getattr /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/eZAORCDpP7ZyvSscCPZLuUwI
21:06:41 (encfs.cpp:92) getxattr /home/carlos/mnt/ssh/server/home/carlos/gemein/encfs/eZAORCDpP7ZyvSscCPZLuUwI
21:06:41 (encfs.cpp:99) getxattr error: Operation not supported

Edit: I have by now resigned myself to the fact that the file .encfs6.xml must have been corrupted somehow, which means that the data are unrecoverably lost. Lesson learned: Backups are extra-important for encrypted data!

Last edited by Franek (2014-03-03 21:14:16)