This proposal is the counterpart of the modifications from the `-badname`
parameter. It modifies the plain -> cipher mapping for filenames when using
`-badname` parameter. The new function `EncryptAndHashBadName` tries to find a
cipher filename for the given plain name with the following steps:
1. If `badname` is disabled or direct mapping is successful: Map directly
(default and current behaviour)
2. If a file with badname flag has a valid cipher file, this is returned
(=File just ends with the badname flag)
3. If a file with a badname flag exists where only the badname flag was added,
this is returned (=File cipher name could not be decrypted by function
`DecryptName` and just the badname flag was added)
4. Search for all files which cipher file name extists when cropping more and
more characters from the end. If only 1 file is found, return this
5. Return an error otherwise
This allows file access in the file browsers but most important it allows that
you rename files with undecryptable cipher names in the plain directories.
Renaming those files will then generate a proper cipher filename One
backdraft: When mounting the cipher dir with -badname parameter, you can never
create (or rename to) files whose file name ends with the badname file flag
(at the moment this is " GOCRYPTFS_BAD_NAME"). This will cause an error.
I modified the CLI test function to cover additional test cases. Test [Case
7](https://github.com/DerDonut/gocryptfs/blob/badnamecontent/tests/cli/cli_test.go#L712)
cannot be performed since the cli tests are executed in panic mode. The
testing is stopped on error. Since the function`DecryptName` produces internal
errors when hitting non-decryptable file names, this test was omitted.
This implementation is a proposal where I tried to change the minimum amount
of existing code. Another possibility would be instead of creating the new
function `EncryptAndHashBadName` to modify the signature of the existing
function `EncryptAndHashName(name string, iv []byte)` to
`EncryptAndHashName(name string, iv []byte, dirfd int)` and integrate the
functionality into this function directly. You may allow calling with dirfd=-1
or other invalid values an then performing the current functionality.
gocryptfs 2.0 introduced the regression that the size
reported at symlink creation was the ciphertext size,
which is wrong.
Report the plaintext size.
Fixes https://github.com/rfjakob/gocryptfs/issues/574
xfstests generic/523 discovered that we allowed to set
xattrs with "/" in the name, but did not allow to read
them later.
With this change we do not allow to set them in the first
place.
In response to the discussion of the xfstests mailing list [1],
I looked at the Lseek implementation, which was naive and
did not handle all cases correctly.
The new implementation aligns the returned values to 4096 bytes
as most callers expect.
A lot of tests are added to verify that we handle all
cases correctly now.
[1]: https://www.spinics.net/lists/fstests/msg16554.html
Error was:
internal/fusefrontend/node.go:371:2: duplicate case syscallcompat.RENAME_NOREPLACE (value 0) in switch
previous case at internal/fusefrontend/node.go:368:7
Rewrite using "if"s instead.
Discovered by xfstests generic/013: or implementation for
RENAME_EXCHANGE and RENAME_WHITEOUT is incomplete. Reject the
flags so that the caller retries with regular rename.
This test only worked accidentially, and would
break once dirfd caching is added.
fs.Mkdir(..., "dir1/dir2", ...) is illegal
(child name cannot contain slashes).
Make `gocryptfs.diriv` and `gocryptfs.xxx.name` files world-readable to make encrypted backups easier
when mounting via fstab.
Having the files follow chmod/chown of their parent does not seem
to be worth the hassle. The content of the diriv files is not
secret, and both diriv and name files are protected by the
perms of the parent dir.
Fixes https://github.com/rfjakob/gocryptfs/issues/539
Retry operations that have been shown to throw EINTR
errors on CIFS.
Todo: Solution for this pain in the back:
warning: unix.Getdents returned errno 2 in the middle of data
rm: cannot remove 'linux-3.0.old3/Documentation/ABI/removed': Input/output error
Progress towards fixing https://github.com/rfjakob/gocryptfs/issues/483 .
Jakob Unterwurzacher