libgocryptfs/README.md

375 lines
16 KiB
Markdown
Raw Normal View History

[![gocryptfs](Documentation/gocryptfs-logo.png)](https://nuetzlich.net/gocryptfs/)
2016-10-24 19:30:39 +02:00
[![Build Status](https://travis-ci.org/rfjakob/gocryptfs.svg?branch=master)](https://travis-ci.org/rfjakob/gocryptfs)
[![MIT License](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
[![Go Report Card](https://goreportcard.com/badge/github.com/rfjakob/gocryptfs)](https://goreportcard.com/report/github.com/rfjakob/gocryptfs)
2015-11-01 12:14:59 +01:00
An encrypted overlay filesystem written in Go.
Official website: https://nuetzlich.net/gocryptfs (Markdown [source](https://github.com/rfjakob/gocryptfs-website/tree/master/docs))
2015-09-06 12:12:14 +02:00
2015-10-06 00:31:53 +02:00
gocryptfs is built on top the excellent
[go-fuse](https://github.com/hanwen/go-fuse) FUSE library and its
LoopbackFileSystem API.
2015-09-06 12:12:14 +02:00
2015-12-08 16:41:45 +01:00
This project was inspired by EncFS and strives to fix its security
issues while providing good performance
([benchmarks](https://nuetzlich.net/gocryptfs/comparison/#performance)).
2015-11-01 12:14:59 +01:00
For details on the security of gocryptfs see the
[Security](https://nuetzlich.net/gocryptfs/security/) design document.
2015-12-20 21:15:49 +01:00
All tags from v0.4 onward are signed by the *gocryptfs signing key*.
2016-07-06 21:26:57 +02:00
Please check [Signed Releases](https://nuetzlich.net/gocryptfs/releases/)
for details.
2015-12-20 21:15:49 +01:00
2015-10-06 23:08:04 +02:00
Current Status
--------------
2017-04-01 13:57:18 +02:00
gocryptfs has reached version 1.0 on July 17, 2016. It has gone through
2016-07-17 12:19:50 +02:00
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.
2017-04-01 13:57:18 +02:00
The security of gocryptfs has been audited in March 3, 2017. The audit
is available [here (defuse.ca)](https://defuse.ca/audits/gocryptfs.htm).
2016-07-06 21:26:57 +02:00
Platforms
---------
Linux is gocryptfs' native platform.
Experimental Mac OS X support is available, check out
[ticket #15](https://github.com/rfjakob/gocryptfs/issues/15) for
2016-07-06 21:26:57 +02:00
details.
For Windows, an independent C++ reimplementation has been started:
[cppcryptfs](https://github.com/bailey27/cppcryptfs)
Testing
-------
gocryptfs comes with is own test suite that is constantly expanded as features are
2016-01-09 15:31:58 +01:00
added. Run it using `./test.bash`. It takes about 1 minute and requires FUSE
as it mounts several test filesystems.
The `stress_tests` directory contains stress tests that run indefinitely.
In addition, I have ported `xfstests` to FUSE, the result is the
[fuse-xfstests](https://github.com/rfjakob/fuse-xfstests) project. gocryptfs
2015-12-01 18:19:24 +01:00
passes the "generic" tests with one exception, results: [XFSTESTS.md](Documentation/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.
2015-10-06 23:08:04 +02:00
2016-01-09 15:31:58 +01:00
Compile
2015-10-06 23:08:04 +02:00
-------
2017-02-19 20:14:46 +01:00
$ go get -d github.com/rfjakob/gocryptfs
$ cd $(go env GOPATH)/src/github.com/rfjakob/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
2017-02-19 20:14:46 +01:00
$ ./build-without-openssl.bash
2015-10-07 23:30:45 +02:00
Use
---
$ mkdir cipher plain
$ ./gocryptfs -init cipher
$ ./gocryptfs cipher plain
2016-01-09 15:31:58 +01:00
See the [Quickstart](https://nuetzlich.net/gocryptfs/quickstart/) page for more info.
The [MANPAGE.md](Documentation/MANPAGE.md) describes all available command-line options.
2015-11-11 09:19:53 +01:00
2017-02-16 18:36:16 +01:00
Graphical Interface
-------------------
The [SiriKali](https://mhogomchungu.github.io/sirikali/) project supports
gocryptfs and runs on Linux and OSX.
2017-02-16 18:37:12 +01:00
[cppcryptfs](https://github.com/bailey27/cppcryptfs) on Windows provides
its own GUI.
2017-02-16 18:36:16 +01:00
Stable CLI ABI
--------------
If you want to call gocryptfs from your app or script, see
[CLI_ABI.md](Documentation/CLI_ABI.md) for the official stable
ABI. This ABI is regression-tested by the test suite.
2015-11-01 12:14:59 +01:00
Storage Overhead
----------------
* Empty files take 0 bytes on disk
* 18 byte file header for non-empty files (2 bytes version, 16 bytes random file id)
* 32 bytes of storage overhead per 4kB block (16 byte nonce, 16 bytes auth tag)
2015-11-01 12:14:59 +01:00
2016-01-09 15:31:58 +01:00
[file-format.md](Documentation/file-format.md) contains a more detailed description.
2015-10-06 23:08:04 +02:00
Performance
-----------
2016-05-04 19:55:20 +02:00
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.
2015-09-06 12:16:34 +02:00
2016-05-04 19:55:20 +02:00
gocryptfs uses OpenSSL through a thin wrapper called `stupidgcm`.
This provides a 4x speedup compared to Go's builtin AES-GCM
implementation - see [openssl-gcm.md](Documentation/openssl-gcm.md)
for details. The use of openssl can disabled on the command-line.
2015-09-06 12:12:14 +02:00
2016-05-04 19:55:20 +02:00
Run `./benchmark.bash` to 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:
2015-09-06 12:12:14 +02:00
```
$ ./benchmark.bash
2016-05-04 19:55:20 +02:00
linux-3.0.tar.gz 100%[==========================>] 92,20M 2,96MB/s in 35s
2016-05-04 19:29:20 URL:https://www.kernel.org/pub/linux/kernel/v3.0/linux-3.0.tar.gz
WRITE: 131072000 bytes (131 MB) copied, 1,43137 s, 91,6 MB/s
UNTAR: 23.25
LS: 1.75
RM: 4.42
```
2015-10-06 00:31:53 +02:00
Changelog
---------
2017-04-29 22:18:28 +02:00
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)
2017-03-05 17:45:59 +01:00
* Drop Go 1.4 compatibility. You now need Go 1.5 (released 2015-08-19)
or higher to build gocryptfs.
* Add `-serialize_reads` command-line option
* This can greatly improve performance on storage
that is very slow for concurrent out-of-order reads. Example:
2017-03-19 19:58:16 +01:00
Amazon Cloud Drive ([#92](https://github.com/rfjakob/gocryptfs/issues/92))
* Reject file-header-only files
([#90 2.2](https://github.com/rfjakob/gocryptfs/issues/90),
[commit](https://github.com/rfjakob/gocryptfs/commit/14038a1644f17f50b113a05d09a2a0a3b3e973b2))
* Increase max password size to 2048 bytes ([#93](https://github.com/rfjakob/gocryptfs/issues/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 block "-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](https://github.com/rfjakob/gocryptfs/issues/15)
* Handle additional corner cases in `-ctlsock` path sanitization
* Use dedicated exit code 12 on "password incorrect"
2016-12-04 19:32:23 +01:00
v1.2, 2016-12-04
2016-11-17 23:34:16 +01:00
* Add a control socket interface. Allows to encrypt and decrypt filenames.
2016-12-04 19:32:23 +01:00
For details see [backintime#644](https://github.com/bit-team/backintime/issues/644#issuecomment-259835183).
* New command-line option: `-ctlsock`
2016-11-17 23:34:16 +01:00
* Under certain circumstances, concurrent truncate and read could return
an I/O error. This is fixed by introducing a global open file table
2016-12-04 19:32:23 +01:00
that stores the file IDs
([commit](https://github.com/rfjakob/gocryptfs/commit/0489d08ae21107990d0efd0685443293aa26b35f)).
* Coalesce 4kB ciphertext block writes up to the size requested through
the write FUSE call
([commit with benchmarks](https://github.com/rfjakob/gocryptfs/commit/024511d9c71558be4b1169d6bb43bd18d65539e0))
* Add `-noprealloc` command-line option
* Greatly speeds up writes on Btrfs
([#63](https://github.com/rfjakob/gocryptfs/issues/63))
at the cost of reduced out-of-space robustness.
* This is a workaround for Btrfs' slow fallocate(2)
2016-12-04 19:32:23 +01:00
* Preserve owner for symlinks an device files (fixes bug [#64](https://github.com/rfjakob/gocryptfs/issues/64))
* Include rendered man page `gocryptfs.1` in the release tarball
2016-11-17 23:34:16 +01:00
2016-10-30 16:48:02 +01:00
v1.1.1, 2016-10-30
* Fix a panic on setting file timestamps ([go-fuse#131](https://github.com/hanwen/go-fuse/pull/131))
* Work around an issue in tmpfs that caused a panic in xfstests generic/075
([gocryptfs#56](https://github.com/rfjakob/gocryptfs/issues/56))
* Optimize NFS streaming writes
([commit](https://github.com/rfjakob/gocryptfs/commit/a08d55f42d5b11e265a8617bee16babceebfd026))
2016-10-19 22:49:57 +02:00
v1.1, 2016-10-19
* **Add reverse mode ([#19](https://github.com/rfjakob/gocryptfs/issues/19))**
* AES-SIV (RFC5297) encryption to implement deterministic encryption
securely. Uses the excellent
[jacobsa/crypto](https://github.com/jacobsa/crypto) library.
The corresponding feature flag is called `AESSIV`.
* New command-line options: `-reverse`, `-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.
2016-10-09 21:29:43 +02:00
* 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](https://github.com/rfjakob/gocryptfs/issues/45) for details.
* **Mounting on login using pam_mount** works as well. It is
[described in the wiki](https://github.com/rfjakob/gocryptfs/wiki/Mounting-on-login-using-pam_mount).
* To prevent confusion, the old `-o` option had to be renamed. It is now
called `-ko`. Arguments to `-ko` are passed directly to the kernel.
* New `-passfile` command-line option. Provides an easier way to read
the password from a file. Internally, this is equivalent to
`-extpass "/bin/cat FILE"`.
2016-10-19 22:49:57 +02:00
* Enable changing the password when you only know the master key
([#28](https://github.com/rfjakob/gocryptfs/issues/28))
2016-10-09 00:59:00 +02:00
2016-07-17 12:19:50 +02:00
v1.0, 2016-07-17
2016-07-06 21:26:57 +02:00
* Deprecate very old filesystems, stage 3/3
* Filesystems created by v0.6 can no longer be mounted
* Drop command-line options `-gcmiv128`, `-emenames`, `-diriv`. These
are now always enabled.
2016-07-06 21:26:57 +02:00
* Add fallocate(2) support
* New command-line option `-o`
* Allows to pass mount options directly to the kernel
2016-07-06 21:26:57 +02:00
* Add support for device files and suid binaries
* Only works when running as root
* Must be explicitely enabled by passing "-o dev" or "-o suid" or "-o suid,dev"
2016-07-06 21:26:57 +02:00
* Experimental Mac OS X support. See
2016-10-30 16:57:22 +01:00
[ticket #15](https://github.com/rfjakob/gocryptfs/issues/15) for details.
2016-06-19 19:03:17 +02:00
v0.12, 2016-06-19
2016-07-06 21:26:57 +02:00
* Deprecate very old filesystems, stage 2/3
* Filesystems created by v0.6 and older can only be mounted read-only
* A [message](https://github.com/rfjakob/gocryptfs/blob/v0.12/internal/configfile/config_file.go#L120)
explaining the situation is printed as well
* New command line option: `-ro`
* Mounts the filesystem read-only
2016-06-19 19:03:17 +02:00
* Accept password from stdin as well ([ticket #30](https://github.com/rfjakob/gocryptfs/issues/30))
2016-06-10 09:54:35 +02:00
v0.11, 2016-06-10
2016-07-06 21:26:57 +02:00
* Deprecate very old filesystems, stage 1/3
* Filesystems created by v0.6 and older can still be mounted but a
[warning](https://github.com/rfjakob/gocryptfs/blob/v0.11/internal/configfile/config_file.go#L120)
is printed
* See [ticket #29](https://github.com/rfjakob/gocryptfs/issues/29) for details and
join the discussion
2016-06-10 09:33:06 +02:00
* Add rsync stress test "pingpong-rsync.bash"
* Fix chown and utimens failures that caused rsync to complain
2016-06-10 09:52:49 +02:00
* Build release binaries with Go 1.6.2
* Big speedup for CPUs with AES-NI, see [ticket #23](https://github.com/rfjakob/gocryptfs/issues/23)
2016-06-10 09:33:06 +02:00
v0.10, 2016-05-30
* **Replace `spacemonkeygo/openssl` with `stupidgcm`**
* gocryptfs now has its own thin wrapper to OpenSSL's GCM implementation
called `stupidgcm`.
* This should fix the [compile issues](https://github.com/rfjakob/gocryptfs/issues/21)
people are seeing with `spacemonkeygo/openssl`. It also gets us
a 20% performance boost for streaming writes.
2016-05-13 22:18:17 +02:00
* **Automatically choose between OpenSSL and Go crypto** [issue #23](https://github.com/rfjakob/gocryptfs/issues/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=auto` is the new default
* Passing `-openssl=true/false` overrides the autodetection.
* Warn but continue anyway if fallocate(2) is not supported by the
underlying filesystem, see [issue #22](https://github.com/rfjakob/gocryptfs/issues/22)
* Enables to use gocryptfs on ZFS and ext3, albeit with reduced out-of-space safety.
2016-05-13 22:18:17 +02:00
* [Fix statfs](https://github.com/rfjakob/gocryptfs/pull/27), by @lxp
* Fix a fsstress [failure](https://github.com/hanwen/go-fuse/issues/106)
in the go-fuse library.
2016-05-04 19:55:20 +02:00
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
2016-04-03 23:11:46 +02:00
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 `-debug`
* `-q`: Alias for `-quiet`
2016-04-03 23:11:46 +02:00
v0.8, 2016-01-23
2016-01-23 19:35:51 +01:00
* Redirect output to syslog when running in the background
* New command-line option:
* `-memprofile`: Write a memory allocation debugging profile the specified
file
2016-01-23 19:35:51 +01:00
v0.7.2, 2016-01-19
2016-01-19 23:08:10 +01:00
* **Fix performance issue in small file creation**
* This brings performance on-par with EncFS paranoia mode, with streaming writes
significantly faster
* The actual [fix](https://github.com/hanwen/go-fuse/commit/c4b6b7949716d13eec856baffc7b7941ae21778c)
is in the go-fuse library. There are no code changes in gocryptfs.
2016-01-19 22:56:33 +01:00
v0.7.1, 2016-01-09
2016-01-09 15:31:58 +01:00
* Make the `build.bash` script compatible with Go 1.3
* Disable fallocate on OSX (system call not availabe)
* Introduce pre-built binaries for Fedora 23 and Debian 8
v0.7, 2015-12-20
2015-12-20 15:42:52 +01:00
* **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.
2015-12-20 15:42:52 +01:00
* New command-line option:
* `-gcmiv128`: Use 128-bit GCM IVs (default true)
2015-12-20 15:42:52 +01:00
v0.6, 2015-12-08
2015-12-08 16:41:45 +01:00
* **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.
2015-12-08 16:41:45 +01:00
* New command-line option:
* `-emenames`: Enable EME filename encryption (default true)
2015-12-08 16:41:45 +01:00
v0.5.1, 2015-12-06
2016-01-09 15:31:58 +01:00
* 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
2015-11-29 22:36:25 +01:00
* **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.
2015-11-29 22:36:25 +01:00
* 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.
2015-11-29 22:36:25 +01:00
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 `FeatureFlags` gocryptfs.conf paramter
* 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`.
2015-11-03 00:08:31 +01:00
* On-disk format 2
v0.3, 2015-11-01
2015-11-29 22:36:25 +01:00
* **Add a random 128 bit file header to authenticate file->block ownership**
* This is an on-disk-format change
2015-11-01 14:07:42 +01:00
* 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
2015-11-01 14:07:42 +01:00
* On-disk format 0