With hard links, the path to a file is not unique. This means
that the ciphertext data depends on the path that is used to access
the files.
Fix that by storing the derived values when we encounter a hard-linked
file. This means that the first path wins.
Instead of redirecting stdout and stderr to /tmp/gocryptfs_paniclog,
where it is hard to find, redirect them to a newly spawned logger(1)
instance that forwards the messages to syslog.
See https://github.com/rfjakob/gocryptfs/issues/109 for an example
where the paniclog was lost due to a reboot.
Also, instead of closing stdin, redirect it to /dev/null, like most
daemons seem to do.
This fixes a few issues I have found reviewing the code:
1) Limit the amount of data ReadLongName() will read. Previously,
you could send gocryptfs into out-of-memory by symlinking
gocryptfs.diriv to /dev/zero.
2) Handle the empty input case in unPad16() by returning an
error. Previously, it would panic with an out-of-bounds array
read. It is unclear to me if this could actually be triggered.
3) Reject empty names after base64-decoding in DecryptName().
An empty name crashes emeCipher.Decrypt().
It is unclear to me if B64.DecodeString() can actually return
a non-error empty result, but let's guard against it anyway.
When a user calls into a deep directory hierarchy, we often
get a sequence like this from the kernel:
LOOKUP a
LOOKUP a/b
LOOKUP a/b/c
LOOKUP a/b/c/d
The diriv cache was not effective for this pattern, because it
was designed for this:
LOOKUP a/a
LOOKUP a/b
LOOKUP a/c
LOOKUP a/d
By also using the cached entry of the grandparent we can avoid lots
of diriv reads.
This benchmark is against a large encrypted directory hosted on NFS:
Before:
$ time ls -R nfs-backed-mount > /dev/null
real 1m35.976s
user 0m0.248s
sys 0m0.281s
After:
$ time ls -R nfs-backed-mount > /dev/null
real 1m3.670s
user 0m0.217s
sys 0m0.403s
This commit defines all exit codes in one place in the exitcodes
package.
Also, it adds a test to verify the exit code on incorrect
password, which is what SiriKali cares about the most.
Fixes https://github.com/rfjakob/gocryptfs/issues/77 .
Misspell Finds commonly misspelled English words
gocryptfs/internal/configfile/scrypt.go
Line 41: warning: "paramter" is a misspelling of "parameter" (misspell)
gocryptfs/internal/ctlsock/ctlsock_serve.go
Line 1: warning: "implementes" is a misspelling of "implements" (misspell)
gocryptfs/tests/test_helpers/helpers.go
Line 27: warning: "compatability" is a misspelling of "compatibility" (misspell)
Now looks like this:
$ ./gocryptfs -version
gocryptfs [GitVersion not set - please compile using ./build.bash]; go-fuse [GitVersionFuse not set - please compile using ./build.bash]; 0000-00-00 go1.8
Hopefully easier to grep for.
Linux by default has a soft limit of 1024 and a hard limit of
4096 on open files. We can increase it so 4096 without root
permissions.
This should help reduce the risk of gocryptfs running out of
file descriptors, as reported at
https://github.com/rfjakob/gocryptfs/issues/82 .
This can happen during normal operation, and is harmless since
14038a1644
"fusefrontend: readFileID: reject files that consist only of a header"
causes dormant header-only files to be rewritten on the next write.
This test reproduces the problem xfstests generic/124 uncovered.
The warning itself is harmless, but we should either (1) add locking
so that this cannot happen anymore or (2) drop the warning.
Currently fails:
$ go test -v
=== RUN Test1980Tar
--- PASS: Test1980Tar (0.00s)
=== RUN TestCtlSock
--- PASS: TestCtlSock (0.10s)
=== RUN TestOpenTruncateRead
--- PASS: TestOpenTruncateRead (0.00s)
=== RUN TestWORead
--- PASS: TestWORead (0.00s)
=== RUN TestXfs124
cipherSize 18 == header size: interrupted write?
-wpanic turns this warning into a panic: cipherSize 18 == header size: interrupted write?
We do not have to track the writeOnly status because the kernel
will not forward read requests on a write-only FD to us anyway.
I have verified this behavoir manually on a 4.10.8 kernel and also
added a testcase.
As reported at https://github.com/rfjakob/gocryptfs/issues/105 ,
the "ioutil.WriteFile(file, iv, 0400)" call causes "permissions denied"
errors on an NFSv4 setup.
"strace"ing diriv creation and gocryptfs.conf creation shows this:
conf (works on the user's NFSv4 mount):
openat(AT_FDCWD, "/tmp/a/gocryptfs.conf.tmp", O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0400) = 3
diriv (fails):
openat(AT_FDCWD, "/tmp/a/gocryptfs.diriv", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0400) = 3
This patch creates the diriv file with the same flags that are used for
creating the conf:
openat(AT_FDCWD, "/tmp/a/gocryptfs.diriv", O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0400) = 3
Closes https://github.com/rfjakob/gocryptfs/issues/105
Force decode of encrypted files even if the integrity check fails, instead of
failing with an IO error. Warning messages are still printed to syslog if corrupted
files are encountered.
It can be useful to recover files from disks with bad sectors or other corrupted
media.
Closes https://github.com/rfjakob/gocryptfs/pull/102 .
go-fuse has added a new method to the nodefs.File interface that
caused this build error:
internal/fusefrontend/file.go:75: cannot use file literal (type *file) as type nodefs.File in return argument:
*file does not implement nodefs.File (missing Flock method)
Fixes https://github.com/rfjakob/gocryptfs/issues/104 and
prevents the problem from happening again.
The volatile inode numbers that we used before cause "find" to complain and error out.
Virtual inode numbers are derived from their parent file inode number by adding 10^19,
which is hopefully large enough no never cause problems in practice.
If the backing directory contains inode numbers higher than that, stat() on these files
will return EOVERFLOW.
Example directory lising after this change:
$ ls -i
926473 gocryptfs.conf
1000000000000926466 gocryptfs.diriv
944878 gocryptfs.longname.hmZojMqC6ns47eyVxLlH2ailKjN9bxfosi3C-FR8mjA
1000000000000944878 gocryptfs.longname.hmZojMqC6ns47eyVxLlH2ailKjN9bxfosi3C-FR8mjA.name
934408 Tdfbf02CKsTaGVYnAsSypA
Note: find currently complains like this:
find: failed to read file names from file system at or below
‘/tmp/linux-3.0.reverse.mnt.vNI’: No such file or directory
I have analyzed this and it is caused by the non-stable inode numbers
that gocryptfs -reverse uses. Will be fixed in a later commit.
