Commit Graph

63 Commits

Author SHA1 Message Date
Jakob Unterwurzacher
930c37e03d syscallcompat: use O_PATH in OpenDirNofollow
This fixes the "0100 directory" problem in reverse mode,
and should be slightly faster.
2018-09-08 18:06:33 +02:00
Jakob Unterwurzacher
9ec9d0c49c syscallcompat: untangle OpenNofollow and rename to OpenDirNofollow
The function used to do two things:

1) Walk the directory tree in a manner safe from symlink attacks
2) Open the final component in the mode requested by the caller

This change drops (2), which was only used once, and lets the caller
handle it. This simplifies the function and makes it fit for reuse in
forward mode in openBackingPath(), and for using O_PATH on Linux.
2018-09-08 17:41:17 +02:00
Jakob Unterwurzacher
7a02f71fc2 fusefrontend_reverse: reject excludes for the root directory ""
This is most likely a mistake by the user. Reject it.
2018-08-15 12:28:29 +02:00
Jakob Unterwurzacher
ec2fdc19cf reverse mode: add --exclude option
https://github.com/rfjakob/gocryptfs/issues/235
2018-08-11 23:26:49 +02:00
Jakob Unterwurzacher
bde7ba57b0 darwin does not have PATH_MAX
Define our own, with the value from Linux.
2018-06-08 00:47:48 +02:00
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
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
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
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
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
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
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
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
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
Jakob Unterwurzacher
0c520845f3 main: purge masterkey from memory as soon as possible
Remove the "Masterkey" field from fusefrontend.Args because it
should not be stored longer than neccessary. Instead pass the
masterkey as a separate argument to the filesystem initializers.

Then overwrite it with zeros immediately so we don't have
to wait for garbage collection.

Note that the crypto implementation still stores at least a
masterkey-derived value, so this change makes it harder, but not
impossible, to extract the encryption keys from memory.

Suggested at https://github.com/rfjakob/gocryptfs/issues/137
2017-08-11 19:02:26 +02:00
Jakob Unterwurzacher
d12aa57715 fusefronted_reverse: fix ino collision between .name and .diriv files
A directory with a long name has two associated virtual files:
the .name file and the .diriv files.

These used to get the same inode number:

  $ ls -di1  * */*
             33313535 gocryptfs.longname.2togDFouca9mrTwtfF1RNW5DZRAQY8alaR7wO_Xd5Zw
  1000000000033313535 gocryptfs.longname.2togDFouca9mrTwtfF1RNW5DZRAQY8alaR7wO_Xd5Zw/gocryptfs.diriv
  1000000000033313535 gocryptfs.longname.2togDFouca9mrTwtfF1RNW5DZRAQY8alaR7wO_Xd5Zw.name

With this change we use another prefix (2 instead of 1) for .name files.

  $ ls -di1 * */*
             33313535 gocryptfs.longname.2togDFouca9mrTwtfF1RNW5DZRAQY8alaR7wO_Xd5Zw
  1000000000033313535 gocryptfs.longname.2togDFouca9mrTwtfF1RNW5DZRAQY8alaR7wO_Xd5Zw/gocryptfs.diriv
  2000000000033313535 gocryptfs.longname.2togDFouca9mrTwtfF1RNW5DZRAQY8alaR7wO_Xd5Zw.name
2017-07-29 16:15:49 +02:00
Charles Duffy
cf1ded5236 Implement force_owner option to display ownership as a specific user. 2017-06-01 00:26:17 +02:00
Jakob Unterwurzacher
857507e8b1 fusefrontend_reverse: move pathiv to its own package
We will also need it in forward mode.
2017-05-30 17:04:46 +02:00
Jakob Unterwurzacher
edb3e19cb5 fix golint complaints 2017-04-29 14:50:58 +02:00
danim7
f1945c4daa Add -forcedecode
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 .
2017-04-23 23:11:56 +02:00
Jakob Unterwurzacher
778c955eea fusefrontend_reverse: switch to stable inode numbers
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
2017-04-01 17:19:15 +02:00
Jakob Unterwurzacher
e87aebb835 fusefrontend_reverse: drop unused dirIVAttr function
This has long been replaced by virtualFile.GetAttr().
2017-04-01 17:05:55 +02:00
Jakob Unterwurzacher
acb73ca436 fusefrontend_reverse: convert fmt.Printf calls to tlog
The fmt.Printfs output would end up in the paniclog.
2017-04-01 15:49:53 +02:00
danim7
fb1b8ced38 fusefrontend_reverse: consistent file owners for .diriv, .name files
This PR addresses the Issue #95, about "Confusing file owner for
longname files in reverse mode".

It affects only the reverse mode, and introduces two
modifications:

1) The "gocryptfs.longname.XXXX.name" files are assigned the owner and
group of the underlying plaintext file. Therefore it is consistent
with the file "gocryptfs.longname.XXXX" that has the encrypted
contents of the plaintext file.

2) The two virtual files mentioned above are given -r--r--r--
permissions. This is consistent with the behavior described in
function Access in internal/fusefrontend_reverse/rfs.go where all
virtual files are always readable. Behavior also observed in point
c) in #95 .

Issue #95 URL: https://github.com/rfjakob/gocryptfs/issues/95
Pull request URL: https://github.com/rfjakob/gocryptfs/pull/97
2017-03-28 22:58:03 +02:00
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
445b5019e3 nametransform: fix Raw64 not affecting symlink targets
The symlink functions incorrectly hardcoded the padded
base64 variant.
2017-03-05 22:59:25 +01:00
Jakob Unterwurzacher
5b54577d2e nametransform: fix Raw64 not affecting longnames
HashLongName() incorrectly hardcoded the call to base64.URLEncoding.
2017-03-05 22:25:41 +01:00
Jakob Unterwurzacher
d0bc7970f7 full stack: implement HKDF support
...but keep it disabled by default for new filesystems.

We are still missing an example filesystem and CLI arguments
to explicitely enable and disable it.
2017-03-05 21:59:55 +01:00
Jakob Unterwurzacher
e032539e2c cryptocore: use eme v1.1 interface
Version 1.1 of the EME package (github.com/rfjakob/eme) added
a more convenient interface. Use it.

Note that you have to upgrade your EME package (go get -u)!
2017-03-05 13:58:24 +01:00
Jakob Unterwurzacher
45c1ea499e fusefrontend_reverse: handle .name files in Access()
These were currently passed to decryptPath() were it caused
a warning.
2017-02-16 21:16:42 +01:00
Jakob Unterwurzacher
c9f4400e6d Replace all calls to naked panic() with log.Panic()
We want all panics to show up in the syslog.
2016-12-10 11:54:36 +01:00
Jakob Unterwurzacher
e04dc05012 fusefrontend: upgrade wlockMap to use device AND inode number
If there are multiple filesystems backing the gocryptfs filesystems
inode numbers are not guaranteed to be unique.
2016-11-17 20:32:19 +01:00
Jakob Unterwurzacher
e7f57695a6 Fix golint warnings
$ golint ./... | grep -v underscore | grep -v ALL_CAPS
internal/fusefrontend_reverse/rfs.go:52:36: exported func NewFS returns unexported type *fusefrontend_reverse.reverseFS, which can be annoying to use
internal/nametransform/raw64_go1.5.go:10:2: exported const HaveRaw64 should have comment (or a comment on this block) or be unexported
2016-11-10 00:38:01 +01:00
Jakob Unterwurzacher
75ebb28a62 ctlsock: add initial limited implementation
At the moment, in forward mode you can only encrypt paths
and in reverse mode you can only decrypt paths.
2016-11-10 00:27:08 +01:00
Jakob Unterwurzacher
2b991c9743 Add support for unpadded base64 filenames, "-raw64"
Through base64.RawURLEncoding.

New command-line parameter "-raw64".
2016-11-01 18:43:22 +01:00
Jakob Unterwurzacher
d3b78fea95 reverse: add panics against API abuse
These should help prevent later programming errors.
2016-10-09 17:05:12 +02:00
Jakob Unterwurzacher
d25fcc6a4b reverse: gocryptfs.conf was missing from the directory listings
Fix the test for that and add checks in example_filesystems_test.
2016-10-08 22:25:08 +02:00
Jakob Unterwurzacher
e47577834b reverse: merge config translation check into isTranslatedConfig
Also get rid of useless isFiltered function.
2016-10-08 21:14:16 +02:00
Jakob Unterwurzacher
f054353bd3 reverse: make gocryptfs.conf mapping plaintextnames-aware
Only in plaintextnames-mode AND with the config file at the
default location it will be mapped into the mountpoint.

Also adds a test for that.
2016-10-08 20:57:38 +02:00
Jakob Unterwurzacher
ff48dc1aab reverse: initialize the longname cache only when reverse mode is used
Gets rid of the idling longnameCacheCleaner thread in "normal" mode.
2016-10-05 22:22:28 +02:00
Valient Gough
b764917cd5 lint fixes 2016-10-04 23:18:33 +02:00
Romain
db72a4489d fusefrontend_reverse cast Stat_t.Dev to uint64 (#44)
The [Stat_t.Dev](https://golang.org/pkg/syscall/#Stat_t) docs say `Dev` is a `unit64`, but on [macOS amd64](https://golang.org/src/syscall/ztypes_darwin_amd64.go) it's an `int32`.
2016-10-04 15:03:47 +02:00
Jakob Unterwurzacher
a2510efe12 reverse: use per-purpose nonce generation
Also pull all the deterministic nonce code into fusefrontend_reverse
to greatly simplify the normal code path.
2016-09-29 21:56:49 +02:00
Jakob Unterwurzacher
166ba74a05 tests: enable all go vet checks
...and fix reported errors:

internal/fusefrontend_reverse/rfile.go:40: github.com/rfjakob/gocryptfs/internal/contentenc.FileHeader composite literal uses unkeyed fields
internal/fusefrontend_reverse/rfs.go:249: github.com/hanwen/go-fuse/fuse.DirEntry composite literal uses unkeyed fields
internal/fusefrontend_reverse/rfs.go:264: github.com/hanwen/go-fuse/fuse.DirEntry composite literal uses unkeyed fields
2016-09-25 19:02:12 +02:00
Jakob Unterwurzacher
abd61d968d contentenc: rename constant "IVBitLen" to "DefaultIVBits" and clarify comment
128-bit IVs are NOT used everywhere.
2016-09-25 18:40:29 +02:00
Jakob Unterwurzacher
b883dd10a6 reverse: add symlink encryption and Readlink support 2016-09-25 18:01:24 +02:00