Encrypted overlay filesystem written in Go
An encrypted overlay filesystem written in Go. Official website: https://nuetzlich.net/gocryptfs (markdown source).
gocryptfs is built on top the excellent go-fuse FUSE library. This project was inspired by EncFS and strives to fix its security issues while providing good performance (benchmarks). For details on the security of gocryptfs see the Security design document.
All tags from v0.4 onward are signed by the gocryptfs signing key. Please check Signed Releases for details.
gocryptfs has reached version 1.0 on July 17, 2016. It has gone through hours and hours of stress (fsstress, extractloop.bash) and correctness testing (xfstests). It is now considered ready for general consumption.
The old principle still applies: Important data should have a backup. Also, keep a copy of your master key (printed on mount) in a safe place. This allows you to access the data even if the gocryptfs.conf config file is damaged or you lose the password.
The security of gocryptfs has been audited in March 3, 2017. The audit is available here (defuse.ca).
Linux is gocryptfs' native platform.
Beta-quality Mac OS X support is available, which means most things work fine but you may hit an occasional problem. Check out ticket #15 for the history of Mac OS X support but please create a new ticket if you hit a problem.
For Windows, an independent C++ reimplementation can be found here: cppcryptfs
A standalone Python tool that can decrypt files & file names is here: gocryptfs-inspect
Precompiled binaries that work on all x86_64 Linux systems are available for download from the github releases page.
On Debian, gocryptfs is available as a deb package:
bash apt install gocryptfs
On Mac OS X, gocryptfs is available as a Homebrew formula:
bash brew install gocryptfs
On Fedora, gocryptfs is available as an rpm package:
bash sudo dnf install gocryptfs
If you use the standalone binary, make sure you install the
fusepackage from your distributions package repository before running
See the Quickstart page for more info.
gocryptfs comes with is own test suite that is constantly expanded as features are added. Run it using
./test.bash. It takes about 1 minute and requires FUSE as it mounts several test filesystems.
stress_testsdirectory contains stress tests that run indefinitely.
In addition, I have ported
xfsteststo FUSE, the result is the fuse-xfstests project. gocryptfs passes the "generic" tests with one exception, results: XFSTESTS.md
A lot of work has gone into this. The testing has found bugs in gocryptfs as well as in the go-fuse library.
With go 1.11 or higher:
$ git clone https://github.com/rfjakob/gocryptfs.git $ cd gocryptfs $ ./build.bash
build.bash needs the OpenSSL headers installed (Debian:
apt install libssl-dev, Fedora:
dnf install openssl-devel). Alternatively, you can compile without OpenSSL using
$ mkdir cipher plain $ ./gocryptfs -init cipher $ ./gocryptfs cipher plain
See the Quickstart page for more info.
The MANPAGE.md describes all available command-line options.
$ mkdir cipher plain $ ./gocryptfs -reverse -init plain $ ./gocryptfs -reverse plain cipher
The SiriKali project supports gocryptfs and runs on Linux and OSX.
cppcryptfs on Windows provides its own GUI.
If you want to call gocryptfs from your app or script, see CLI_ABI.md for the official stable ABI. This ABI is regression-tested by the test suite.
file-format.md contains a more detailed description.
Since version 0.7.2, gocryptfs is as fast as EncFS in the default mode, and significantly faster than EncFS' "paranoia" mode that provides a security level comparable to gocryptfs.
On CPUs without AES-NI, gocryptfs uses OpenSSL through a thin wrapper called
stupidgcm. This provides a 4x speedup compared to Go's builtin AES-GCM implementation. See CPU-Benchmarks for details, or run
gocryptfs -speedto see the encryption performance of your CPU. Example for a CPU without AES-NI:
$ ./gocryptfs -speed AES-GCM-256-OpenSSL 165.67 MB/s (selected in auto mode) AES-GCM-256-Go 49.62 MB/s AES-SIV-512-Go 39.98 MB/s
You can run
./benchmark.bashto run gocryptfs' canonical set of benchmarks that include streaming write, extracting a linux kernel tarball, recursively listing and finally deleting it. The output will look like this:
$ ./benchmark.bash Testing gocryptfs at /tmp/benchmark.bash.DwL: gocryptfs v1.6; go-fuse v20170619-45-g95c6370; 2018-08-18 go1.10.3 WRITE: 262144000 bytes (262 MB, 250 MiB) copied, 1.1033 s, 238 MB/s READ: 262144000 bytes (262 MB, 250 MiB) copied, 0.945291 s, 277 MB/s UNTAR: 17.768 MD5: 8.459 LS: 1.460 RM: 3.379
vNEXT, in progress * MANPAGE: Split options into sections acc. to where they apply (#517) *
-idle: count cwd inside the mount as busy (#533) * Make
gocryptfs.xxx.namefiles world-readable to make encrypted backups easier when mounting via /etc/fstab (#539) * Make it work with MacFUSE v4.x (#524) * Disable ACL encryption, it causes a lot of problems (#543, #536) * Old encrypted ACLs are reported by
gocryptfs -fsckbut otherwise ignored * This fixes inheritance, but does not yet enforce them correctly
v2.0-beta1, 2020-10-15 * Switch to the improved go-fuse v2 API * This is a big change, a lot of code has been reorganized or rewritten to fit the v2 API model. * Please test & report bugs * No changes to the on-disk format * File descriptor caching is not yet implemented, causing a slowdown. Caching will be implemented for v2.0 final. * Add support for FIDO2 tokens (
-fido2, #505) * Add
gocryptfs-xray(#416) * Accept multiple
-passfiles (#288) * Make
-masterkey=stdinwork together with
-passwd(#461) * Fix
Unknown opcode 2016crash on Google Cloud (go-fuse #276, gocryptfs commit ec74d1d)
v1.8.0, 2020-05-09 * Enable ACL support (#453) * Warning 2021-02-07: This feature is incomplete! Do not use ACLs before gocryptfs v2.0 final! Reading and writing ACLs works, but they are not enforced or inherited (#542) * Ignore
.nfsXXXtemporary files (#367) * Handle inode number collisions from multiple devices (#435) * Drop
-nonemptyfor fusermount3 (#440) * Reverse mode: improve inode number mapping and max=1000000000000000000 limitation (#457) * Enable
--buildmode=pie(#460) * Migrate from dep to Go Modules (commit cad711993) * go mod: update dependencies (commit b23f77c) *
gocryptfs -speed: add XChaCha20-Poly1305-Go (#452) * Respect
GOMAXPROCSenvironment variable (commit ff210a06f * Completely remove Trezor-related code (commit 1364b44ae356da31e24e5605fe73a307e9d6fb03) * Has been disabled since v1.7 due to issues a third-party module. * Please use FIDO2 instead (gocryptfs v2.0)
v1.7.1, 2019-10-06 * Support wild cards in reverse mode via
--exclude-wildcard(#367). Thanks @ekalin! * Create
gocryptfs.dirivfiles with 0440 permissions to make it easier to share an encrypted folder via a network drive (#387). Note: as a security precaution, the owner must still manually
chmod gocryptfs.conf 0440to allow mounting. * Allow the
-passwdcan now change the
-scryptnparameter for existing filesystems (#400) * Fix
-idleunmounting the filesystem despite recent activity (#421) * Fix a race condition related to inode number reuse (#363). It could be triggered by concurrently creating and deleting files and can lead to data loss in the affected file. This bug was found by the automated tests on Travis and was very hard to trigger locally. * tests: use /var/tmp instead of /tmp by default (commit 8c4429)
v1.7, 2019-03-17 * Fix possible symlink race attacks in forward mode when using allowother + plaintextnames * If you use both `-allowother
, you should upgrade. Malicious users could trick gocryptfs into modifying files outside ofCIPHERDIR
, or reading files insideCIPHERDIR
that they should not have access to. * If you do not use-plaintextnames
(disabled per default), these attacks do not work as symlinks are encrypted. * Forward mode has been reworked to use the "\*at" family of system calls everywhere (Openat/Unlinkat/Symlinkat/...
). * As a result, gocryptfs may run slightly slower, as the caching logic has been replaced and is very simple at the moment. * The possibility for such attacks was found during an internal code review. * Reverse mode: fix excluded, unaccessible files showing up in directory listings ([#285](https://github.com/rfjakob/gocryptfs/issues/285), [#286](https://github.com/rfjakob/gocryptfs/issues/286)) * gocryptfs-xray: add-aessiv
flag for correctly parsing AES-SIV format files ([#299](https://github.com/rfjakob/gocryptfs/issues/299)) * Ensure that standard fds 0,1,2 are always initialized ([#320](https://github.com/rfjakob/gocryptfs/issues/320)). Prevents trouble in the unlikely case that gocryptfs is called with stdin,stdout and/or stderr closed. *-extpass
now can be specified multiple times to support arguments containing spaces ([#289](https://github.com/rfjakob/gocryptfs/issues/289)) * Drop Fstatat, Mkdirat, Syslinkat, Fchownat, Unlinkat, Renameat, Openat emulation of MacOS and instead use native functions (thanks @slackner !) * UseSetreuid` to robustly set the owner with allow_other (@slackner, (commit)) * Pack the rendered man page into the source code archive for user convenience (issue 355) * Disable Trezor support again (commit 16fac26c57ba303bf60266d24c17f5243e5ea376) * Trezor support has been broken since Sept 2018 due to issues in a third-party module (#261)
v1.6.1, 2018-12-12 * Fix "Operation not supported" chmod errors on Go 1.11 (#271)
v1.6, 2018-08-18 * Add
-excludeoption for reverse mode (#235, commit) * Add support for the Trezor One HSM PR#247, thanks @xaionaro! * Use
./build.bash -tags enable_trezorto compile with Trezor support * Then, use
gocryptfs -init -trezorto create a filesystem locked with a physical Trezor device. * Note 2021-01-31: Support was removed again in gocryptfs v1.7. Please use
-fido2in gocryptfs v2.0. * Only print master key once, on init (#76, commit) * Fall back to buffered IO even when passed
v1.5, 2018-06-12 * Support extended attributes (xattr) in forward mode (#217). Older gocryptfs versions will ignore the extended attributes. * Add
-fsckfunction (#191) * Fix clobbered timestamps on MacOS High Sierra (#229) * Add
-masterkey=stdinfunctionality (#218) * Accept
-rwflags to make mounting via
/etc/fstabpossible. Thanks @mahkoh! (#233, commit, commit) * Fix a
loggerpath issue on SuSE #225 * Stop printing the help text on a "flag provided but not defined" error (commit)
osxfuse: vnode changed generation/
Error code -36issue in go-fuse (#213, commit) * Fix various test issues on MacOS
v1.4.3, 2018-01-21 * Fix several symlink race attacks in connection with reverse mode and allowother. Thanks to @slackner for reporting and helping to fix the issues: * Fix symlink races in reverse mode (issue #165) * Fix symlink races in connection with `-allowother
([issue #177](https://github.com/rfjakob/gocryptfs/issues/177)) * Fix problems with special names when using-plaintextnames
([issue #174](https://github.com/rfjakob/gocryptfs/issues/174)) * Add-devrandom
command-line option ([commit](https://github.com/rfjakob/gocryptfs/commit/f3c777d5eaa682d878c638192311e52f9c204294)) * Add-sharedstorage` command-line option (commit, issue #156) * MacOS: let OSXFuse create the mountpoint if it does not exist (issue #194)
v1.4.2, 2017-11-01 * Add
depvendoring and reproducible builds (issue #142) * MacOS: deal with
.DS_Storefiles inside CIPHERDIR (issue #140) * Reverse mode: fix ENOENT error affecting names exactly 176 bytes long (issue #143) * Support kernels compiled with > 128 kiB FUSE request size (Synology NAS) (issue #145, commit) * Fix a startup hang when
$PATHcontains the mountpoint (issue #146)
v1.4.1, 2017-08-21 * Use memory pools for buffer handling ( 3c6fe98, b2a23e9, 12c0101) * On my machine, this doubles the streaming read speed (see performance.txt) * Implement and use the getdents(2) syscall for a more efficient OpenDir implementation (e50a6a5) * Purge masterkey from memory as soon as possible (issue #137) * Reverse mode: fix inode number collision between .name and .diriv files (d12aa57) * Prevent the logger from holding stdout open (issue #130) * MacOS: make testing without openssl work properly (ccf1a84) * MacOS: specify a volume name (9f8e19b) * Enable writing to write-only files (issue #125)
v1.4, 2017-06-20 * Switch to static binary releases * From gocryptfs v1.4, I will only release statically-built binaries. These support all Linux distributions but cannot use OpenSSL. * OpenSSL is still supported - just compile from source! * Add
-force_owneroption to allow files to be presented as owned by a different user or group from the user running gocryptfs. Please see caveats and guidance in the man page before using this functionality. * Increase open file limit to 4096 (#82). * Implement path decryption via ctlsock (#84). Previously, decryption was only implemented for reverse mode. Now both normal and reverse mode support both decryption and encryption of paths via ctlsock. * Add more specific exit codes for the most common failure modes, documented in CLI_ABI.md * Reverse mode: make sure hard-linked files always return the same ciphertext (commit 9ecf2d1a) * Display a shorter, friendlier help text by default. * Parallelize file content encryption by splitting data blocks into two threads (ticket#116) * Prefetch random nonces in the background (commit 80516ed) * Add
-infooption to pretty-print infos about a filesystem.
v1.3, 2017-04-29 * Use HKDF to derive separate keys for GCM and EME * New feature flag:
HKDF(enabled by default) * This is a forwards-compatible change. gocryptfs v1.3 can mount filesystems created by earlier versions but not the other way round. * Enable Raw64 filename encoding by default (gets rid of trailing
==characters) * This is a forwards-compatible change. gocryptfs v1.3 can mount filesystems created by earlier versions but not the other way round. * Drop Go 1.4 compatibility. You now need Go 1.5 (released 2015-08-19) or higher to build gocryptfs. * Add
-serialize_readscommand-line option * This can greatly improve performance on storage that is very slow for concurrent out-of-order reads. Example: Amazon Cloud Drive (#92) * Reject file-header-only files (#90 2.2, commit) * Increase max password size to 2048 bytes (#93) * Use stable 64-bit inode numbers in reverse mode * This may cause problems for very old 32-bit applications that were compiled without Large File Support. * Passing "--" now also blocks "-o" parsing
v1.2.1, 2017-02-26 * Add an integrated speed test,
gocryptfs -speed* Limit password size to 1000 bytes and reject trailing garbage after the newline * Make the test suite work on Mac OS X * Handle additional corner cases in
-ctlsockpath sanitization * Use dedicated exit code 12 on "password incorrect"
v1.2, 2016-12-04 * Add a control socket interface. Allows to encrypt and decrypt filenames. For details see backintime#644. * New command-line option:
-ctlsock* Under certain circumstances, concurrent truncate and read could return an I/O error. This is fixed by introducing a global open file table that stores the file IDs (commit). * Coalesce 4kB ciphertext block writes up to the size requested through the write FUSE call (commit with benchmarks) * Add
-noprealloccommand-line option * Greatly speeds up writes on Btrfs (#63) at the cost of reduced out-of-space robustness. * This is a workaround for Btrfs' slow fallocate(2) * Preserve owner for symlinks an device files (fixes bug #64) * Include rendered man page
gocryptfs.1in the release tarball
v1.1.1, 2016-10-30 * Fix a panic on setting file timestamps (go-fuse#131) * Work around an issue in tmpfs that caused a panic in xfstests generic/075 (gocryptfs#56) * Optimize NFS streaming writes (commit)
v1.1, 2016-10-19 * Add reverse mode (#19) * AES-SIV (RFC5297) encryption to implement deterministic encryption securely. Uses the excellent jacobsa/crypto library. The corresponding feature flag is called
AESSIV. * New command-line options:
-aessiv* Filesystems using reverse mode can only be mounted with gocryptfs v1.1 and later. * The default, forward mode, stays fully compatible with older versions. Forward mode will keep using GCM because it is much faster. * Accept
-o foo,bar,baz-style options that are passed at the end of the command-line, like mount(1) does. All other options must still precede the passed paths. * This allows mounting from /etc/fstab. See #45 for details. * Mounting on login using pam_mount works as well. It is described in the wiki. * To prevent confusion, the old
-ooption had to be renamed. It is now called
-ko. Arguments to
-koare passed directly to the kernel. * New
-passfilecommand-line option. Provides an easier way to read the password from a file. Internally, this is equivalent to
-extpass "/bin/cat FILE". * Enable changing the password when you only know the master key (#28)
v1.0, 2016-07-17 * Deprecate very old filesystems, stage 3/3 * Filesystems created by v0.6 can no longer be mounted * Drop command-line options
-diriv. These are now always enabled. * Add fallocate(2) support * New command-line option
-o* Allows to pass mount options directly to the kernel * Add support for device files and suid binaries * Only works when running as root * Must be explicitly enabled by passing "-o dev" or "-o suid" or "-o suid,dev" * Experimental Mac OS X support. See ticket #15 for details.
v0.12, 2016-06-19 * Deprecate very old filesystems, stage 2/3 * Filesystems created by v0.6 and older can only be mounted read-only * A message explaining the situation is printed as well * New command line option:
-ro* Mounts the filesystem read-only * Accept password from stdin as well (ticket #30)
v0.11, 2016-06-10 * Deprecate very old filesystems, stage 1/3 * Filesystems created by v0.6 and older can still be mounted but a warning is printed * See ticket #29 for details and join the discussion * Add rsync stress test "pingpong-rsync.bash" * Fix chown and utimens failures that caused rsync to complain * Build release binaries with Go 1.6.2 * Big speedup for CPUs with AES-NI, see ticket #23
v0.10, 2016-05-30 * Replace
stupidgcm* gocryptfs now has its own thin wrapper to OpenSSL's GCM implementation called
stupidgcm. * This should fix the compile issues people are seeing with
spacemonkeygo/openssl. It also gets us a 20% performance boost for streaming writes. * Automatically choose between OpenSSL and Go crypto issue #23 * Go 1.6 added an optimized GCM implementation in amd64 assembly that uses AES-NI. This is faster than OpenSSL and is used if available. In all other cases OpenSSL is much faster and is used instead. *
-openssl=autois the new default * Passing
-openssl=true/falseoverrides the autodetection. * Warn but continue anyway if fallocate(2) is not supported by the underlying filesystem, see issue #22 * Enables to use gocryptfs on ZFS and ext3, albeit with reduced out-of-space safety. * Fix statfs, by @lxp * Fix a fsstress failure in the go-fuse library.
v0.9, 2016-04-10 * Long file name support * gocryptfs now supports file names up to 255 characters. * This is a forwards-compatible change. gocryptfs v0.9 can mount filesystems created by earlier versions but not the other way round. * Refactor gocryptfs into multiple "internal" packages * New command-line options: *
-longnames: Enable long file name support (default true) *
-nosyslog: Print messages to stdout and stderr instead of syslog (default false) *
-wpanic: Make warning messages fatal (used for testing) *
-d: Alias for
-q: Alias for
v0.8, 2016-01-23 * Redirect output to syslog when running in the background * New command-line option: *
-memprofile: Write a memory allocation debugging profile the specified file
v0.7.2, 2016-01-19 * Fix performance issue in small file creation * This brings performance on-par with EncFS paranoia mode, with streaming writes significantly faster * The actual fix is in the go-fuse library. There are no code changes in gocryptfs.
v0.7.1, 2016-01-09 * Make the
build.bashscript compatible with Go 1.3 * Disable fallocate on OSX (system call not available) * Introduce pre-built binaries for Fedora 23 and Debian 8
v0.7, 2015-12-20 * Extend GCM IV size to 128 bit from Go's default of 96 bit * This pushes back the birthday bound to make IV collisions virtually impossible * This is a forwards-compatible change. gocryptfs v0.7 can mount filesystems created by earlier versions but not the other way round. * New command-line option: *
-gcmiv128: Use 128-bit GCM IVs (default true)
v0.6, 2015-12-08 * Wide-block filename encryption using EME + DirIV * EME (ECB-Mix-ECB) provides even better security than CBC as it fixes the prefix leak. The used Go EME implementation is https://github.com/rfjakob/eme which is, as far as I know, the first implementation of EME in Go. * This is a forwards-compatible change. gocryptfs v0.6 can mount filesystems created by earlier versions but not the other way round. * New command-line option: *
-emenames: Enable EME filename encryption (default true)
v0.5.1, 2015-12-06 * Fix a rename regression caused by DirIV and add test case * Use fallocate to guard against out-of-space errors
v0.5, 2015-12-04 * Stronger filename encryption: DirIV * Each directory gets a random 128 bit file name IV on creation, stored in
gocryptfs.diriv* This makes it impossible to identify identically-named files across directories * A single-entry IV cache brings the performance cost of DirIV close to zero for common operations (see performance.txt) * This is a forwards-compatible change. gocryptfs v0.5 can mount filesystems created by earlier versions but not the other way round. * New command-line option: *
-diriv: Use the new per-directory IV file name encryption (default true) *
-scryptn: allows to set the scrypt cost parameter N. This option can be used for faster mounting at the cost of lower brute-force resistance. It was mainly added to speed up the automated tests.
v0.4, 2015-11-15 * New command-line options: *
-plaintextnames: disables filename encryption, added on user request *
-extpass: calls an external program for prompting for the password *
-config: allows to specify a custom gocryptfs.conf path * Add
FeatureFlagsgocryptfs.conf parameter * This is a config format change, hence the on-disk format is incremented * Used for ext4-style filesystem feature flags. This should help avoid future format changes. The first user is
-plaintextnames. * On-disk format 2
v0.3, 2015-11-01 * Add a random 128 bit file header to authenticate file->block ownership * This is an on-disk-format change * On-disk format 1
v0.2, 2015-10-11 * Replace bash daemonization wrapper with native Go implementation * Better user feedback on mount failures
v0.1, 2015-10-07 * First release * On-disk format 0