Commit Graph

138 Commits

Author SHA1 Message Date
Jakob Unterwurzacher
72b975867a fusefronted: allow_other: close race between mknod and chown
If the user manages to replace the directory with
a symlink at just the right time, we could be tricked
into chown'ing the wrong file.

This change fixes the race by using fchownat, which
unfortunately is not available on darwin, hence a compat
wrapper is added.

Scenario, as described by @slackner at
https://github.com/rfjakob/gocryptfs/issues/177 :

1. Create a forward mount point with `plaintextnames` enabled
2. Mount as root user with `allow_other`
3. For testing purposes create a file `/tmp/file_owned_by_root`
   which is owned by the root user
4. As a regular user run inside of the GoCryptFS mount:

```
mkdir tempdir
mknod tempdir/file_owned_by_root p &
mv tempdir tempdir2
ln -s /tmp tempdir
```

When the steps are done fast enough and in the right order
(run in a loop!), the device file will be created in
`tempdir`, but the `lchown` will be executed by following
the symlink. As a result, the ownership of the file located
at `/tmp/file_owned_by_root` will be changed.
2017-11-27 21:04:45 +01:00
Jakob Unterwurzacher
1bb47b6796 reverse: reject too-long symlink target reads with ENAMETOOLONG
If the symlink target gets too long due to base64 encoding, we should
return ENAMETOOLONG instead of having the kernel reject the data and
returning an I/O error to the user.

Fixes https://github.com/rfjakob/gocryptfs/issues/167
2017-11-26 21:37:12 +01:00
Sebastian Lackner
90687215a4 fusefrontend_reverse: Do not mix up cache information for different directories
Fixes https://github.com/rfjakob/gocryptfs/issues/168

Steps to reproduce the problem:

* Create a regular reverse mount point
* Create files with the same very long name in multiple directories - so far
  everything works as expected, and it will appear with a different name each
  time, for example, gocryptfs.longname.A in directory A and
  gocryptfs.longname.B in directory B
* Try to access a path with A/gocryptfs.longname.B or B/gocryptfs.longname.A -
  this should fail, but it actually works.

The problem is that the longname cache only uses the path as key and not the
dir or divIV. Assume an attacker can directly interact with a reverse mount and
knows the relation longname path -> unencoded path in one directory, it allows
to test if the same unencoded filename appears in any other directory.
2017-11-25 16:20:48 +01:00
Sebastian Lackner
9f56b33e0c fusefrontend: Fix longname handling for renames with existing target
Fixes https://github.com/rfjakob/gocryptfs/issues/170

Steps to reproduce the problem:

* Create a regular forward mount point
* Create a file with a shortname and one with a long filename
* Try to run 'mv <shortname> <longname>'

This should actually work and replace the existing file, but instead it
fails with:

    mv: cannot move '<shortname>' to '<longname>': File exists

The problem is the creation of the .name file. If the target already exists
we can safely ignore the EEXIST error and just keep the existing .name file.
2017-11-25 16:19:09 +01:00
Sebastian Lackner
d257bb34c1 tests: Add test for access to encrypted version of '.' and '..'
To show that https://github.com/rfjakob/gocryptfs/issues/163 has been fixed.
2017-11-23 08:48:00 +01:00
Sebastian Lackner
f3c777d5ea main: Add '-devrandom' commandline option
Allows to use /dev/random for generating the master key instead of the
default Go implementation. When the kernel random generator has been
properly initialized both are considered equally secure, however:

* Versions of Go prior to 1.9 just fall back to /dev/urandom if the
  getrandom() syscall would be blocking (Go Bug #19274)

* Kernel versions prior to 3.17 do not support getrandom(), and there
  is no check if the random generator has been properly initialized
  before reading from /dev/urandom

This is especially useful for embedded hardware with low-entroy. Please
note that generation of the master key might block indefinitely if the
kernel cannot harvest enough entropy.
2017-11-21 23:37:06 +01:00
Jakob Unterwurzacher
64e5906ffa fusefrontend_reverse: workaround ext4 test failure
The extended TestLongnameStat() exposes a pathological case
when run on ext4, as ext4 reuses inode numbers immediately.

This change modifies the test to not delete the files immediately,
so the inode numbers cannot be reused immediately.

Fix for the underlying issue is a TODO.
2017-10-03 21:15:17 +02:00
Jakob Unterwurzacher
4da245c69d fusefrontend_reverse: fix 176-byte names
A file with a name of exactly 176 bytes length caused this error:

  ls: cannot access ./tmp/dsg/sXSGJLTuZuW1FarwIkJs0w/b6mGjdxIRpaeanTo0rbh0A/QjMRrQZC_4WLhmHI1UOBcA/gocryptfs.longname.QV-UipdDXeUVdl05WruoEzBNPrQCfpu6OzJL0_QnDKY: No such file or directory
  ls: cannot access ./tmp/dsg/sXSGJLTuZuW1FarwIkJs0w/b6mGjdxIRpaeanTo0rbh0A/QjMRrQZC_4WLhmHI1UOBcA/gocryptfs.longname.QV-UipdDXeUVdl05WruoEzBNPrQCfpu6OzJL0_QnDKY.name: No such file or directory
  -????????? ? ?     ?             ?            ? gocryptfs.longname.QV-UipdDXeUVdl05WruoEzBNPrQCfpu6OzJL0_QnDKY
  -????????? ? ?     ?             ?            ? gocryptfs.longname.QV-UipdDXeUVdl05WruoEzBNPrQCfpu6OzJL0_QnDKY.name

Root cause was a wrong shortNameMax constant that failed to
account for the obligatory padding byte.

Fix the constant and also expand the TestLongnameStat test case
to test ALL file name lengths from 1-255 bytes.

Fixes https://github.com/rfjakob/gocryptfs/issues/143 .
2017-10-01 13:50:25 +02:00
Jakob Unterwurzacher
f59479736b tests: add diriv cache race test
Passes.
2017-08-10 21:01:19 +02:00
Jakob Unterwurzacher
d5133ca5ac fusefrontend_reverse: return ENOENT for undecryptable names
This was working until DecryptName switched to returning
EBADMSG instead of EINVAL.

Add a test to catch the regression next time.
2017-07-27 20:31:22 +02:00
Jakob Unterwurzacher
318c41827c tests: check if we close stderr and stdout correctly on mount
Currently fails, as reported at
https://github.com/rfjakob/gocryptfs/issues/130 .
2017-07-24 00:05:29 +02:00
Jakob Unterwurzacher
74e58ae8e6 tests: fsstress-gocryptfs.bash: sync up with EncFS
I have added a subset of fsstress-gocryptfs.bash to EncFS as
fsstress-encfs.sh, improving the code a bit.

This change forward-ports these improvements to
fsstress-gocryptfs.bash.
2017-07-21 23:34:44 +02:00
Jakob Unterwurzacher
3062de6187 fusefronted: enable writing to write-only files
Due to RMW, we always need read permissions on the backing file. This is a
problem if the file permissions do not allow reading (i.e. 0200 permissions).
This patch works around that problem by chmod'ing the file, obtaining a fd,
and chmod'ing it back.

Test included.

Issue reported at: https://github.com/rfjakob/gocryptfs/issues/125
2017-07-11 23:19:58 +02:00
Jakob Unterwurzacher
c12a50d4c8 benchmarks: add streaming read benchmark 2017-06-27 00:04:58 +02:00
Jakob Unterwurzacher
f44902aaae Fix two comments
One out-of-date and the other with a typo.
2017-06-01 18:53:57 +02:00
Jakob Unterwurzacher
e43eb36da3 tests: add v1.3-reverse example filesystem
We check the md5 sum of the encrypted version of a file to make sure we don't
accidentially change the ciphertext generation.
2017-05-30 17:04:46 +02:00
Jakob Unterwurzacher
18f354d84b main: password change: exit with code 12 on wrong password
We used to return code 8, now we return code 12 as documented in
the man page.

Also adds a test.
2017-05-14 13:14:00 +02:00
Jakob Unterwurzacher
d5adde1eeb exitcodes: pull all exit code definitions into the package
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 .
2017-05-07 22:16:22 +02:00
Jakob Unterwurzacher
ad7942f434 fusefrontend: implement path decryption via ctlsock
Closes https://github.com/rfjakob/gocryptfs/issues/84 .
2017-05-07 21:01:39 +02:00
Jakob Unterwurzacher
68387b470c Fix typos found by Misspell
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)
2017-05-07 12:22:15 +02:00
Jakob Unterwurzacher
daada9d7c6 tests: support encfs in the fsstress script
May be helpful for https://github.com/vgough/encfs/issues/214 .
2017-05-01 23:50:49 +02:00
Jakob Unterwurzacher
9768376bd1 tests: add TestXfs124
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?
2017-05-01 18:44:03 +02:00
Jakob Unterwurzacher
9ab11aa4d7 fusefrontend: drop writeOnly flag
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.
2017-05-01 17:49:37 +02:00
Jakob Unterwurzacher
f1dbd19fe9 tests: add hkdf_sanity tests with broken example filesystem
These are deliberately corrupt.
2017-03-18 16:48:58 +01:00
Jakob Unterwurzacher
61502f9b94 benchmark: add md5sum read performance benchmark 2017-03-18 16:23:33 +01:00
Jakob Unterwurzacher
efc88346be cli: enable "-raw64" by default
This brings the CLI options back in sync with the default
feature flags.
2017-03-07 20:56:50 +01:00
Jakob Unterwurzacher
f1244b6d06 tests: recreate v1.3 example filesystem
The filesystem was created with a gocryptfs version that ignored
the HKDF flag (hence everything was actually encrypted WITHOUT hkdf).

Fix it by recreating it.
2017-03-07 20:56:50 +01:00
Jakob Unterwurzacher
2362e67a9e cli: add "-hkdf" option
This commit also enables actually passing the HKDF setting to
fusefrontend, this was missing till now.
2017-03-07 20:56:50 +01:00
Jakob Unterwurzacher
a80d798c2d tests: reverse: don't run tests that ignore "-plaintextnames" twice
TestMain() runs all tests twice, once with plaintextnames=true and once
with false. Several tests mount their own filesystem and ignore the
plaintextnames variable. It makes no sense to run them twice, so
skip execution when plaintextnames is set.
2017-03-07 20:53:58 +01:00
M. Vefa Bicakci
d48ccb3dda Report correct symbolic link dentry sizes
Prior to this commit, gocryptfs's reverse mode did not report correct
directory entry sizes for symbolic links, where the dentry size needs to
be the same as the length of a string containing the target path.

This commit corrects this issue and adds a test case to verify the
correctness of the implementation.

This issue was discovered during the use of a strict file copying program
on a reverse-mounted gocryptfs file system.
2017-03-07 20:46:58 +01:00
Jakob Unterwurzacher
b7538fc026 tests: add v1.3 example filesystem
This filesystem has both HKDF and Raw64 enabled.
2017-03-05 23:07:52 +01:00
Jakob Unterwurzacher
966308eeb7 Drop Go 1.4 compatability code everywhere
Yields a nice reduction in code size.
2017-03-05 17:44:14 +01:00
Jakob Unterwurzacher
b2f154a9a9 tests: stop calling t.Fatal from example_test_helpers
Calling t.Fatal immeadiately aborts the test, which means the
filesystem will not get unmounted, which means test.bash will
hang.
2017-03-05 13:39:25 +01:00
Jakob Unterwurzacher
d2c0fae4f6 tests: somewhat support testing without openssl
You will still get lots of test error, but at least the tests
will run.
2017-02-26 19:53:29 +01:00
Jakob Unterwurzacher
b056776a01 tests: adapt dir overwrite test for Go 1.8
In Go 1.8, os.Rename refuses to overwrite an empty directory.
Switch to syscall.Rename, which still does the right thing.
2017-02-20 21:27:37 +01:00
Jakob Unterwurzacher
e406eb22ba Get rid of remaining $GOPATH dependencies 2017-02-20 21:26:42 +01:00
Jakob Unterwurzacher
62e7eb7d04 tests: reverse: check Access() call 2017-02-16 21:20:29 +01:00
Jakob Unterwurzacher
0b19e637c9 tests: OSX compat: wrap Stat_t atime extract
Linux has st.Atim, st.Mtim,
OSX hat st.Atimespec, st.Mtimespec.

Reported at https://github.com/rfjakob/gocryptfs/issues/15#issuecomment-279130217
2017-02-16 19:39:56 +01:00
Jakob Unterwurzacher
e5bee6a6aa tests: OSX compat: use OSX-style "stat -f"
Reported at https://github.com/rfjakob/gocryptfs/issues/15#issuecomment-279130217
2017-02-16 19:10:36 +01:00
Jakob Unterwurzacher
9f6841373d benchmarks: OSX compat: replace /usr/bin/time with bash builtin
On OSX, /usr/bin/time does not support "-f".

Reported in https://github.com/rfjakob/gocryptfs/issues/15#issuecomment-279130217 .
2017-02-16 19:01:24 +01:00
Jakob Unterwurzacher
ca5c06ef4e tests: get rid of syscall.PathMax
Does not exist on OSX

Reported in https://github.com/rfjakob/gocryptfs/issues/15
2017-02-16 18:47:04 +01:00
Jakob Unterwurzacher
6ac9dcaae0 tests: use fuse-unmount.bash
...instead of having separate compatability logic.
2017-02-15 23:13:33 +01:00
Jakob Unterwurzacher
ce2e610428 OSX compat: replace fusermount calls with fuse-unmount.bash
Mac OS X does not have fusermount and uses umount instead.
The fuse-unmount.bash calls the appropriate command.
2017-02-15 23:02:01 +01:00
Jakob Unterwurzacher
8adfbf2dc3 Check for trailing garbage after the password
From the comment:

// CheckTrailingGarbage tries to read one byte from stdin and exits with a
// fatal error if the read returns any data.
// This is meant to be called after reading the password, when there is no more
// data expected. This helps to catch problems with third-party tools that
// interface with gocryptfs.
2017-02-12 17:59:09 +01:00
Jakob Unterwurzacher
357307cbcf tests: ctlsock: check warning for non-canonical paths 2017-02-12 12:22:25 +01:00
Jakob Unterwurzacher
d2224aec58 tests: add TestLongLink (currently broken) 2017-01-26 20:49:35 +01:00
Jakob Unterwurzacher
94b66ee1b2 tests: only check the size in dl-linux-tarball.bash
Getting rid of the MD5 calculation makes calling the script
virtually free, where it took 0.2 seconds before.
2017-01-03 14:33:55 +01:00
Jakob Unterwurzacher
53555fec1c tests: factor out dl-linux-tarball.bash
This will be also used by the reverse benchmarks.
2017-01-03 14:17:42 +01:00
Jakob Unterwurzacher
2bacbdf99d benchmark.bash: OSX dd does not support "K" postfix 2016-12-13 22:13:12 +01:00
Jakob Unterwurzacher
2758c75cae ctlsock: sanitize paths before passing them to the backend
You used to be able to crash gocryptfs by passing "/foo"
of "foo/" to the ctlsock.

Fixes https://github.com/rfjakob/gocryptfs/issues/66
2016-12-10 12:59:54 +01:00