hardcoresushi/libgocryptfs
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383 Commits

Author SHA1 Message Date
Jakob Unterwurzacher
bd78b44389 cryptocore, main: add two comments 
While reading the code, I had to think about what it
does, so add a comment that explains it.
 2018-02-18 12:41:11 +01:00
Jakob Unterwurzacher
0efd220d1e configfile: overwrite and let keys run out of scope 
As soon as we don't need them anymore, overwrite
keys with zeros and make sure they run out of scope
so we don't create a risk of inadvertedly using all-zero
keys for encryption.

https://github.com/rfjakob/gocryptfs/issues/211
 2018-02-18 12:39:44 +01:00
Jakob Unterwurzacher
72ddbae1e6 stupidgcm: create private copy of the key 
Relieves the caller from worrying about whether they
can overwrite the key.
 2018-02-18 12:35:51 +01:00
Jakob Unterwurzacher
18f6c6106c main: try to wipe cryptocore's secret keys on unmount 
Raise the bar for recovering keys from memory.

https://github.com/rfjakob/gocryptfs/issues/211
 2018-02-18 11:39:10 +01:00
Jakob Unterwurzacher
719693ec5d fusefrontend[_reverse]: move crypto init up to caller 
Both fusefrontend and fusefrontend_reverse were doing
essentially the same thing, move it into main's
initFuseFrontend.

A side-effect is that we have a reference to cryptocore
in main, which will help with wiping the keys on exit
(https://github.com/rfjakob/gocryptfs/issues/211).
 2018-02-18 11:21:58 +01:00
Jakob Unterwurzacher
eeed4b4bef stupidgcm: implement key wipe 
Not bulletproof due to possible GC copies, but
still raises to bar for extracting the key.

https://github.com/rfjakob/gocryptfs/issues/211
 2018-02-17 15:14:55 +01:00
Jakob Unterwurzacher
7e0fefe970 stupidgcm: switch to pointer receivers 
What the key slice does not get copied around
will make it possible to check if the key has been wiped.
 2018-02-17 15:02:01 +01:00
Jakob Unterwurzacher
8151222ada gccgo: skip emulateGetdents on linux 
The test is known to fail on gccgo
(https://github.com/rfjakob/gocryptfs/issues/201), but
getdents emulation is not used on linux, so let's skip
the test and ignore the failure.
 2018-02-04 21:14:12 +01:00
Felix Lechner
bf2f9640c4 Fix spelling (#205) 2018-02-04 20:38:22 +01:00
Felix Lechner
5b986288cf Fix assignment error in Unix2syscall by converting Timespec into Nsec (#203) 
$ go.gcc build
# github.com/rfjakob/gocryptfs/internal/syscallcompat
internal/syscallcompat/unix2syscall_linux.go:32:13: error: incompatible types in assignment (cannot use type int64 as type syscall.Timespec_sec_t)
  s.Atim.Sec = u.Atim.Sec
             ^
 2018-02-03 13:42:49 +01:00
Jakob Unterwurzacher
9f8d0d8e57 gccgo: replace syscall.NAME_MAX with unix.NAME_MAX 
For some reason the syscall.NAME_MAX constant does not exist
on gccgo, and it does not hurt us to use unix.NAME_MAX instead.

https://github.com/rfjakob/gocryptfs/issues/201
 2018-02-01 23:50:11 +01:00
Jakob Unterwurzacher
26ba8103bf syscallcompat: switch from syscall.Getdents to unix.Getdents 
On mips64le, syscall.Getdents() and struct syscall.Dirent do
not fit together, causing our Getdents implementation to
return garbage ( https://github.com/rfjakob/gocryptfs/issues/200
and https://github.com/golang/go/issues/23624 ).

Switch to unix.Getdents which does not have this problem -
the next Go release with the syscall package fixes is too
far away, and will take time to trickle into distros.
 2018-01-31 18:59:10 +01:00
Jakob Unterwurzacher
f3838c09d8 syscallcompat: hardcode maxReclen = 280 for all architectures 
Due to padding between entries, it is 280 even on 32-bit architectures.
See https://github.com/rfjakob/gocryptfs/issues/197 for details.
 2018-01-25 22:22:13 +01:00
Jakob Unterwurzacher
b318572312 syscallcompat: fix reversed warning output 
We used to print somewhat strange messages:

	Getdents: corrupt entry #1: Reclen=276 > 280. Returning EBADR

Reported at https://github.com/rfjakob/gocryptfs/issues/197
 2018-01-25 21:42:15 +01:00
Jakob Unterwurzacher
ea51837361 fusefrontend: drop unused haveGetdents warning 
We don't actually print that warning anymore.
 2018-01-25 09:06:06 +01:00
Jakob Unterwurzacher
de878a3346 syscallcompat: explain why we don't use syscall.ParseDirent() 
syscall.ParseDirent only returns the NAMES, we want
everything.
 2018-01-25 08:43:30 +01:00
Jakob Unterwurzacher
a2677bce2a fusefrontend_reverse: use OpenNofollow in virtualFile.GetAttr 
Makes it robust against symlink races.

Final piece, closes https://github.com/rfjakob/gocryptfs/issues/165
 2018-01-17 21:36:38 +01:00
Jakob Unterwurzacher
959e1fc1e2 fusefrontend_reverse: use OpenNofollow in findLongnameParent 
Protects findLongnameParent against symlink races.

Also add comments to several functions along the way.

Reported at https://github.com/rfjakob/gocryptfs/issues/165
 2018-01-17 20:54:05 +01:00
Jakob Unterwurzacher
8951eb2472 fusefronted: add PlaintextNames special-cases for Create & Rename 
gocryptfs.longname.XXX files were considered magic in PlaintextNames
mode, which was wrong.

Fix that and add tests.

Fixes https://github.com/rfjakob/gocryptfs/issues/174
 2018-01-17 00:25:36 +01:00
Jakob Unterwurzacher
36ffd813cd Run go fmt 2018-01-16 23:18:53 +01:00
Sebastian Lackner
a85dbcab38 fusefrontend: Use Linkat syscall to implement Link 2017-12-25 15:07:37 +01:00
Sebastian Lackner
a24342f656 fusefrontend: Handle PlaintextNames mode in Link 
In PlaintextNames mode the "gocryptfs.longname." prefix does not have any
special meaning.

https://github.com/rfjakob/gocryptfs/issues/174
 2017-12-25 15:07:37 +01:00
Sebastian Lackner
631974f9e0 fusefrontend_reverse: Use O_DIRECTORY in OpenDir implementation 
Also get rid of the defer - it is not really necessary here.
 2017-12-11 21:18:20 +01:00
Sebastian Lackner
96dc2ca709 fusefrontend_reverse: Reject access to device nodes in newFile function 
Steps to reproduce:

* Create a regular reverse mount point
* Create a file "test" in the original directory
* Access the corresponding encrypted directory in the mount point (ls <encrypted dir>)
* Quickly delete the file in the original data - instead create a device node
* Access the file again, it will access the device node and attempt to read from it

Fixes https://github.com/rfjakob/gocryptfs/issues/187
 2017-12-11 09:55:16 +01:00
Sebastian Lackner
3af51736f3 fusefrontend_reverse: Use openBackingDir in GetAttr 
Also fixes 48bd59f388 - the directory FD should
also be closed in case of an error.
 2017-12-07 23:36:11 +01:00
Sebastian Lackner
ad0f110191 fusefrontend_reverse: Use openBackingDir in Readlink 2017-12-07 23:36:11 +01:00
Jakob Unterwurzacher
48bd59f388 fusefrontend_reverse: fix fd leak in GetAttr 
Fixes https://github.com/rfjakob/gocryptfs/issues/184
 2017-12-07 09:01:12 +01:00
Jakob Unterwurzacher
87736eb833 fusefrontend_reverse: secure Access against symlink races (somewhat) 
Unfortunately, faccessat in Linux ignores AT_SYMLINK_NOFOLLOW,
so this is not completely atomic.

Given that the information you get from access is not very
interesting, it seems good enough.

https://github.com/rfjakob/gocryptfs/issues/165
 2017-12-07 00:11:35 +01:00
Jakob Unterwurzacher
2ceef01afe syscallcompat: add Faccessat 
Add faccessat(2) with a hack for symlink, because the
kernel does not actually looks at the passed flags.

From man 2 faccessat:

   C library/kernel differences
       The  raw faccessat() system call takes only the first three argu‐
       ments.  The AT_EACCESS and AT_SYMLINK_NOFOLLOW flags are actually
       implemented  within  the  glibc wrapper function for faccessat().
 2017-12-07 00:05:28 +01:00
Jakob Unterwurzacher
e042eb38fa fusefrontend_reverse: secure Readlink against symlink races 
...by using Readlinkat.

Tracking ticket: https://github.com/rfjakob/gocryptfs/issues/165
 2017-12-06 21:13:08 +01:00
Jakob Unterwurzacher
f97494e89b syscallcompat: add Readlinkat 
We need readlinkat to implement Readlink
symlink-race-free.
 2017-12-06 21:07:24 +01:00
Jakob Unterwurzacher
6beb45e5b7 syscallcompat: add Darwin version of unix2syscall 
The "Atim" field is called "Atimespec" on Darwin,
same for Mtim and Ctim.
 2017-12-06 00:18:38 +01:00
Jakob Unterwurzacher
a3bdc2bf2b fusefrontend_reverse: secure GetAttr against symlink races 
...by using the OpenNofollow helper & Fstatat.

Also introduce a helper to convert from unix.Stat_t to
syscall.Stat_t.

Tracking ticket: https://github.com/rfjakob/gocryptfs/issues/165
 2017-12-06 00:06:31 +01:00
Jakob Unterwurzacher
03bf604fc0 syscallcompat: OpenNofollow: use O_DIRECTORY flag 
...when opening intermedia directories to give us an
extra layer of safety.

From the FreeBSD man page:

     This flag can be used to prevent applications with elevated
     privileges from opening files which are even unsafe to open with O_RDONLY,
     such as device nodes.
 2017-12-05 23:31:07 +01:00
Jakob Unterwurzacher
926cb93b50 fusefrontend_reverse: secure OpenDir against symlink races 
...by using the new OpenNofollow helper.

The benchmark shows a small but acceptable performance loss:

  $ ./benchmark-reverse.bash
  LS:  2.182
  CAT: 18.221

Tracking ticket: https://github.com/rfjakob/gocryptfs/issues/165
 2017-12-05 23:14:12 +01:00
Jakob Unterwurzacher
e604ce6dea syscallcompat: OpenNofollow: fix relPath="" case 
Sometimes want to open baseDir itself. This case
was broken, fix it.
 2017-12-05 23:08:55 +01:00
Jakob Unterwurzacher
70bcf58a9b syscallcompat: convert Getdents to fd input, add emulation 
Now that we have Fstatat we can use it in Getdents to
get rid of the path name.

Also, add an emulated version of getdents for MacOS. This allows
to drop the !HaveGetdents special cases from fusefrontend.

Modify the getdents test to test both native getdents and the emulated
version.
 2017-12-03 19:33:26 +01:00
Jakob Unterwurzacher
e33593d30d syscallcompat: add Fstatat + emulation + test 
Fstatat has recently been added to x/sys/unix. Make
it available for use in gocryptfs.
 2017-12-03 19:32:59 +01:00
Jakob Unterwurzacher
441e796e70 fusefrontend_reverse: secure StatFs agains symlink races 
...by ignoring the path that was passed in.

https://github.com/rfjakob/gocryptfs/issues/165
 2017-12-02 21:36:07 +01:00
Jakob Unterwurzacher
316b916358 fusefrontend_reverse: secure Open against symlink races 
...using the new syscallcompat.OpenNofollow helper.

This change secures Open() against symlink race attacks
as described in https://github.com/rfjakob/gocryptfs/issues/165
 2017-12-02 21:07:56 +01:00
Jakob Unterwurzacher
91e042e2ba syscallcompat: add OpenNofollow helper 
OpenNofollow = symlink-race-safe Open

Prepares fixing https://github.com/rfjakob/gocryptfs/issues/165
 2017-12-02 20:35:44 +01:00
Jakob Unterwurzacher
1d28973611 syscallcompat: move test setup into its own file 
The infrastructure will also be used by the upcoming
OpenNofollow tests.
 2017-12-02 19:57:23 +01:00
Jakob Unterwurzacher
77191c3485 syscallcompat: use Unlinkat and Symlinkat from x/sys/unix 
I'm unsure why I did not notice this earlier, but the
syscall wrappers provided by x/sys/unix seem to do just
fine.

Drop our own version.
 2017-12-02 18:36:18 +01:00
Sebastian Lackner
616a468180 syscallcompat: Improve the Openat and Mknodat syscall emulation 
This avoids the conversion to an absolute path.
 2017-12-01 09:41:52 +01:00
Sebastian Lackner
f30522a0c1 syscallcompat: Fix syscall emulation for absolute paths 
For absolute paths, the file descriptor should be ignored. In such a case
there is also no need to hold the lock or change the working directory.
 2017-12-01 09:41:52 +01:00
Sebastian Lackner
9bcde0c09e fusefrontend: Improve documentation of mkdirWithIv and WriteDirIV 
As requested in https://github.com/rfjakob/gocryptfs/pull/179
 2017-12-01 09:41:52 +01:00
Jakob Unterwurzacher
e97c23e083 syscallcompat: check that we get NOFOLLOW wherever possible 
...and fix the instances where the AT_SYMLINK_NOFOLLOW /
O_NOFOLLOW / O_EXCL flag was missing.
 2017-11-30 19:40:53 +01:00
Jakob Unterwurzacher
22282aefe6 syscallcompat: add tests for emulated syscalls 
Also fix the bug in emulateFchmodat that was found by the tests.
 2017-11-30 19:10:21 +01:00
Jakob Unterwurzacher
bd79a8cd0d syscallcompat: build emulated syscalls under linux, too 
This will allow to test them under linux as well.
 2017-11-30 17:07:55 +01:00
Sebastian Lackner
614745ee57 fusefrontend: allow_other: close race between mkdir and chown 
Fixes the same problem as described in 72b975867a,
except for directories instead of device nodes.
 2017-11-29 13:28:04 +01:00