Commit Graph

1363 Commits

Author SHA1 Message Date
Jakob Unterwurzacher
711ef81bfb macos: filter SUID and SGID bits in OpenatUser, MknodatUser, MkdiratUser
When gocryptfs runs as root, we don't want to allow people to create
SUID root files.
2019-01-13 14:05:03 +01:00
Sebastian Lackner
99e8b6d288 fusefrontend: Preserve SUID/SGID/sticky-bits in openWriteOnlyFile and Rmdir.
Fixes https://github.com/rfjakob/gocryptfs/issues/336 and
https://github.com/rfjakob/gocryptfs/issues/337.
2019-01-12 21:24:50 +01:00
Sebastian Lackner
efc280330c fusefrontend: -allow_other: Use SymlinkatUser in Symlink FUSE call.
Instead of manually adjusting the user after creating the symlink,
adjust effective permissions and let the kernel deal with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 21:22:58 +01:00
Sebastian Lackner
1fbe7798cf fusefrontend: -allow_other: Use MknodatUser in Mknod FUSE call.
Instead of manually adjusting the user and mode after creating the
device file, adjust effective permissions and let the kernel deal
with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 21:20:16 +01:00
Sebastian Lackner
a525e33eaa fusefrontend: -allow_other: Use MkdiratUser in Mkdir FUSE call.
Revert commit fcaca5fc94.

Instead of manually adjusting the user and mode after creating the
directory, adjust effective permissions and let the kernel deal with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 21:20:07 +01:00
Sebastian Lackner
03b9d65cce fusefrontend: -allow_other: Use OpenatUser in Create FUSE call.
Revert commit b22cc03c75.

Instead of manually adjusting the user and mode after creating the
file, adjust effective permissions and let the kernel deal with it.

Related to https://github.com/rfjakob/gocryptfs/issues/338.
2019-01-12 20:54:39 +01:00
Sebastian Lackner
669322482a fusefrontend: Don't chown gocryptfs.diriv files.
The current code has a risk of race-conditions, since we pass a path
containing "/" to Fchownat. We could fix this by opening a file descriptor,
however, this does not seem worth the effort. We also don't chown *.name files.
2019-01-12 20:35:50 +01:00
Sebastian Lackner
fcaca5fc94 fusefrontend: -allow_other: set file mode after chown in Mkdir().
Make sure that the directory belongs to the correct owner before users
can access it. For directories with SUID/SGID mode, there is a risk of
race-conditions when files are created before the correct owner is set.
They will then inherit the wrong user and/or group.

See https://github.com/rfjakob/gocryptfs/issues/327 for more details.
2019-01-09 20:48:00 +01:00
Sebastian Lackner
aae45b4d77 nametransform: Create *.name files with 0400 permission.
Similar to gocryptfs.iv files they are never modified.
2019-01-09 20:42:18 +01:00
Jakob Unterwurzacher
b22cc03c75 fusefrontend: -allow_other: set file mode *after* chown in Create()
Reported by @slackner at https://github.com/rfjakob/gocryptfs/issues/327 :

Possible race-conditions between file creation and Fchownat

* Assume a system contains a gocryptfs mount as root user
  with -allow_other
* As a regular user create a new file with mode containing
  the SUID flag and write access for other users
* Before gocryptfs executes the Fchownat call, try to open
  the file again, write some exploit code to it, and try to run it.

For a short time, the file is owned by root and has the SUID flag, so
this is pretty dangerous.
2019-01-08 21:50:10 +01:00
Sebastian Lackner
4170ef00f3 syscallcompat: Implement workaround for Fchmodat with AT_SYMLINK_NOFOLLOW.
Fixes https://github.com/rfjakob/gocryptfs/issues/259
2019-01-07 23:07:53 +01:00
Jakob Unterwurzacher
8253c55386 tests: add Fchmodat test
Test that we handle symlinks correctly.
2019-01-07 23:07:53 +01:00
Sebastian Lackner
57a52d6aef fusefrontend: Clarify access mode check related to O_WRONLY handling.
Use O_ACCMODE mask in openWriteOnlyFile for improved readability.
2019-01-07 21:25:23 +01:00
Sebastian Lackner
2332462e78 fusefrontend: Filter O_CREAT in mangleOpenFlags. 2019-01-07 21:19:13 +01:00
Sebastian Lackner
aa2fa24c42 fusefrontend: Check result of Fchmod syscall.
Fixes https://github.com/rfjakob/gocryptfs/issues/328
2019-01-06 21:00:17 +01:00
Sebastian Lackner
40d2427fd7 fusefrontend: Fix computation of cipherSz in Allocate FUSE call.
Do not use PlainSizeToCipherSize() since this adds the 18 bytes file header.

Partially fixes https://github.com/rfjakob/gocryptfs/issues/311
2019-01-06 20:56:59 +01:00
Jakob Unterwurzacher
5c8e7feabd tests: check that fallocate does not over-allocate space
We currently allocate 18 bytes too much:
https://github.com/rfjakob/gocryptfs/issues/311
2019-01-06 20:56:53 +01:00
Jakob Unterwurzacher
c83aa417e4 tests: move fallocate tests to its own file
matrix_test.go is already too big.
2019-01-06 20:31:41 +01:00
Jakob Unterwurzacher
db425cab9e tests: TestFallocate: comment what "d" and "h" means
Document what "d" and "h" means in the fancy ASCII diagrams.
https://github.com/rfjakob/gocryptfs/pull/326
2019-01-06 12:49:27 +01:00
Sebastian Lackner
8310dd95be fusefrontend: Properly convert plaintext <-> ciphertext offsets in SeekData().
Fixes https://github.com/rfjakob/gocryptfs/issues/304
2019-01-06 12:21:54 +01:00
Jakob Unterwurzacher
bd055ed7de Update changelog 2019-01-05 18:34:22 +01:00
Jakob Unterwurzacher
fb705f9978 tests: add parallel_cp stress test
Modeled after xfstests generic/273
https://github.com/rfjakob/gocryptfs/issues/322
2019-01-05 18:20:04 +01:00
Sebastian Lackner
7e05e809b7 main: Run 'ensure fds' code early during the program startup.
The files are apparently processed in alphabetic order, so cli_args.go is
processed before main.go. In order to run before the go-fuse imports, put
the 'ensure fds' code in a separate package. Debug messages are omitted
to avoid additional imports (that might contain other code messing up our
file descriptors).
2019-01-05 16:12:16 +01:00
Jakob Unterwurzacher
ad15ad9985 main: ensure fds 0,1,2 are always open
The Go stdlib, as well as the gocryptfs code, relies on the fact
that fds 0,1,2 are always open.

See https://github.com/rfjakob/gocryptfs/issues/320 for details.
2019-01-05 14:17:51 +01:00
Sebastian Lackner
5055f39bd5 fusefrontend: Allow to set/remove xattr on directory without read permission.
Setting/removing extended attributes on directories was partially fixed with
commit eff35e60b6. However, on most file systems
it is also possible to do these operations without read access (see tests).

Since we cannot open a write-access fd to a directory, we have to use the
/proc/self/fd trick (already used for ListXAttr) for the other operations aswell.
For simplicity, let's separate the Linux and Darwin code again (basically revert
commit f320b76fd1), and always use the
/proc/self/fd trick on Linux. On Darwin we use the best-effort approach with
openBackingFile() as a fallback.

More discussion about the available options is available in
https://github.com/rfjakob/gocryptfs/issues/308.
2019-01-05 12:34:40 +01:00
Sebastian Lackner
f17721c364 A few more spelling fixes. 2019-01-05 12:27:55 +01:00
Jakob Unterwurzacher
8c35235c34 Add Makefile
We are going to use the Makefile to save useful commands
without creating too many shell scripts in the top dir.
2019-01-05 12:25:38 +01:00
Jakob Unterwurzacher
61a6b24d4e doc: update extractloop results
Update output and add a nice plot.
2019-01-05 12:17:17 +01:00
Jakob Unterwurzacher
28139ca91d doc: update XFSTESTS results 2019-01-05 12:06:00 +01:00
Jakob Unterwurzacher
65eded4a22 tests: bump maxCacheFds to 3
As the dirCache now has 3 entries, the tests should accept
up to 3 extra fds without declaring an fd leak.
2019-01-04 23:50:01 +01:00
Jakob Unterwurzacher
c32066c5b0 fusefrontend: fix fd leak in dirCache
The missing break meant that we may find a second
hit in the cache, Dup() a second fd, and leak the first
one.

Thanks @slackner for finding this.
2019-01-04 23:35:48 +01:00
Jakob Unterwurzacher
8074f12beb nametransform: ReadDirIVAt: return raw syscall error
Otherwise this can happen, as triggered by xfstests generic/011:

  go-fuse: can't convert error type: openat failed: too many open files

The app then gets a misleading "Function not implemented" error.
2019-01-04 23:21:27 +01:00
Jakob Unterwurzacher
3473a84963 fusefrontend: print warning when Create() runs out of file descriptors
We alread have this warning in Open(), but xfstests generic/488
causes "too many open files" via Create. Add the same message so
the user sees what is going on.
2019-01-04 23:15:04 +01:00
Jakob Unterwurzacher
eff35e60b6 fusefrontend: fix setting xattrs on directories
Directories cannot be opened read-write. Retry with RDONLY.
2019-01-04 22:22:24 +01:00
Jakob Unterwurzacher
3365cfc02b fusefrontend: disable dirCache stats printing
This was inadvertedly kept enabled after benchmarking.
2019-01-04 22:07:02 +01:00
Sebastian Lackner
fab695fa60 Documentation: Fix MANPAGE-render.bash script. 2019-01-04 22:04:44 +01:00
Jakob Unterwurzacher
23b5c80a04 Update performance.txt 2019-01-04 22:04:14 +01:00
Jakob Unterwurzacher
c0a7a14cde fusefrontend: upgrade to three-entry dirCache
3 entries should work well for up to three parallel users.
It works well for extractloop.bash (two parallel tar extracts).
2019-01-04 21:45:03 +01:00
Jakob Unterwurzacher
c1a2a36a79 fsck: don't misdetect a file hole at EOF
https://github.com/rfjakob/gocryptfs/issues/304 :

A second minor issue is that `if bytes.Equal(buf, allZero) {` compares the whole
buffer, although the last read could have been shorter. This could trigger the
"skip file hole" code at the end of a file although there isn't any hole to
skip.
2019-01-04 20:26:16 +01:00
Jakob Unterwurzacher
4b1d080673 Update gocryptfs-xray manpage, have MANPAGE-render.bash generate both
have MANPAGE-render.bash generate both gocryptfs.1 and gocryptfs-xray.1
2019-01-04 20:12:07 +01:00
Jakob Unterwurzacher
7f0de69fe2 Update changelog and gocryptfs-xray manpage 2019-01-04 20:12:07 +01:00
Sebastian Lackner
117dc3f2cc fusefrontend_reverse: Fix redeclaration of 'entries' variable.
Go version go1.10.7 linux/amd64 complains with:

 internal/fusefrontend_reverse/rfs.go:333: declaration of "entries" shadows
 declaration at internal/fusefrontend_reverse/rfs.go:327
2019-01-04 20:11:45 +01:00
Jakob Unterwurzacher
2024616722 xray: print "assuming AES-GCM mode" unless -aessiv is passed
To alert the user that they can and should choose the
right mode.
2019-01-04 19:34:15 +01:00
Jakob Unterwurzacher
8c18fb5db9 file-format.md: document AES-SIV block layout
Fixes https://github.com/rfjakob/gocryptfs/issues/299
2019-01-04 19:31:41 +01:00
Jakob Unterwurzacher
28584d0d2c xray: recreate test filesytems with -scrypt 10
Speeds up the dumpmasterkey test *a lot*:

Before:
  ok  	github.com/rfjakob/gocryptfs/gocryptfs-xray/xray_tests	0.398s

After:
  ok  	github.com/rfjakob/gocryptfs/gocryptfs-xray/xray_tests	0.023s
2019-01-04 19:31:08 +01:00
Jakob Unterwurzacher
8d71f8fe52 xray: add dumpmasterkey test 2019-01-04 19:21:09 +01:00
Jakob Unterwurzacher
44e860d105 xray: add support for inspecting AES-SIV files (-aessiv flag)
https://github.com/rfjakob/gocryptfs/issues/299 :

In GCM mode the auth tags are at the end of each block, but in
SIV mode the auth tags follow immediately after the nonce. As a
result, in AES-SIV mode the output of gocryptfs-xray is misleading
and does not actually print the auth tag, but just the last
16-byte of the ciphertext.

diff --git a/gocryptfs-xray/xray_main.go b/gocryptfs-xray/xray_main.go index 74c9fb3..5a81caf 100644 ---
a/gocryptfs-xray/xray_main.go +++ b/gocryptfs-xray/xray_main.go @@ -16,9 +16,10 @@ import (
 )

 const ( - ivLen = contentenc.DefaultIVBits / 8 - blockSize = contentenc.DefaultBS + ivLen + cryptocore.AuthTagLen - myName =
"gocryptfs-xray" + ivLen = contentenc.DefaultIVBits / 8 + authTagLen = cryptocore.AuthTagLen + blockSize = contentenc.DefaultBS +
ivLen + cryptocore.AuthTagLen + myName = "gocryptfs-xray"
 )

 func errExit(err error) { @@ -26,13 +27,18 @@ func errExit(err error) { os.Exit(1)
 }

-func prettyPrintHeader(h *contentenc.FileHeader) { +func prettyPrintHeader(h *contentenc.FileHeader, aessiv bool) { id :=
 	hex.EncodeToString(h.ID)
- fmt.Printf("Header: Version: %d, Id: %s\n", h.Version, id) + msg := "Header: Version: %d, Id: %s" + if aessiv { + msg += ",
assuming AES-SIV mode" + } + fmt.Printf(msg+"\n", h.Version, id)
 }

 func main() { dumpmasterkey := flag.Bool("dumpmasterkey", false, "Decrypt and dump the master key") +	aessiv :=
flag.Bool("aessiv", false, "Assume AES-SIV mode instead of AES-GCM")
 	flag.Parse() if flag.NArg() != 1 { fmt.Fprintf(os.Stderr, "Usage: %s [OPTIONS] FILE\n"+ @@ -54,7 +60,7 @@ func main() { if
 	*dumpmasterkey {
 		dumpMasterKey(fn)
 	} else {
- inspectCiphertext(fd) + inspectCiphertext(fd, *aessiv)
 	}
 }

@@ -72,7 +78,7 @@ func dumpMasterKey(fn string) {
 	}
 }

-func inspectCiphertext(fd *os.File) { +func inspectCiphertext(fd *os.File, aessiv bool) { headerBytes := make([]byte,
 	contentenc.HeaderLen) n, err := fd.ReadAt(headerBytes, 0) if err == io.EOF && n == 0 {
@@ -88,34 +94,30 @@ func inspectCiphertext(fd *os.File) { if err != nil { errExit(err)
 	}
-	prettyPrintHeader(header) +	prettyPrintHeader(header, aessiv) var i int64 +	buf := make([]byte, blockSize) for i = 0; ;
 	i++ {
- blockLen := int64(blockSize) off := contentenc.HeaderLen + i*blockSize - iv := make([]byte, ivLen) - _, err := fd.ReadAt(iv, off)
- if err == io.EOF { - break - } else if err != nil { + n, err := fd.ReadAt(buf, off) + if err != nil && err != io.EOF {
 			errExit(err)
 		}
- tag := make([]byte, cryptocore.AuthTagLen) - _, err = fd.ReadAt(tag, off+blockSize-cryptocore.AuthTagLen) - if err == io.EOF { -
fi, err2 := fd.Stat() - if err2 != nil { - errExit(err2) - } - _, err2 = fd.ReadAt(tag, fi.Size()-cryptocore.AuthTagLen) - if err2
!= nil { - errExit(err2) - } - blockLen = (fi.Size() - contentenc.HeaderLen) % blockSize - } else if err != nil { - errExit(err) +
if n == 0 && err == io.EOF { + break + } + // A block contains at least the IV, the Auth Tag and 1 data byte + if n <
ivLen+authTagLen+1 { + errExit(fmt.Errorf("corrupt block: truncated data, len=%d", n)) + } + data := buf[:n] + // Parse block data +
iv := data[:ivLen] + tag := data[len(data)-authTagLen:] + if aessiv { + tag = data[ivLen : ivLen+authTagLen]
 		}
 		fmt.Printf("Block %2d: IV: %s, Tag: %s, Offset: %5d Len: %d\n", - i, hex.EncodeToString(iv),
hex.EncodeToString(tag), off, blockLen) + i, hex.EncodeToString(iv), hex.EncodeToString(tag), off, len(data))
 	}
 }
diff --git a/gocryptfs-xray/xray_tests/aessiv_fs.masterkey.txt b/gocryptfs-xray/xray_tests/aessiv_fs.masterkey.txt new file mode
100644 index 0000000..70835ac --- /dev/null +++ b/gocryptfs-xray/xray_tests/aessiv_fs.masterkey.txt @@ -0,0 +1,5 @@ +Your master key
is: + + 29dd219d-e227ff20-8474469d-9fc9fdc6- + b434ab35-404e808c-489d441e-2c1003f2 + diff --git
a/gocryptfs-xray/xray_tests/aessiv_fs.xray.txt b/gocryptfs-xray/xray_tests/aessiv_fs.xray.txt new file mode 100644 index
0000000..6a48079 --- /dev/null +++ b/gocryptfs-xray/xray_tests/aessiv_fs.xray.txt @@ -0,0 +1,3 @@ +Header: Version: 2, Id:
c2f21142e108952a47edfe16053d2bb9, assuming AES-SIV mode +Block 0: IV: 7621fdc35be7671ac6f369214436e8ff, Tag:
e8108c158b22cad6bb3296645357eb75, Offset: 18 Len: 4128 +Block 1: IV: f096d86a4dc3461ef17655cfcf865b13, Tag:
925f23d647e4ab7add2c8d36362cc5a9, Offset: 4146 Len: 936 diff --git a/gocryptfs-xray/xray_tests/aessiv_fs/Ldq-c4ADpM5iGSSrPjUAqQ
b/gocryptfs-xray/xray_tests/aessiv_fs/Ldq-c4ADpM5iGSSrPjUAqQ new file mode 100644 index 0000000..bfd4dfe Binary files /dev/null and
b/gocryptfs-xray/xray_tests/aessiv_fs/Ldq-c4ADpM5iGSSrPjUAqQ differ diff --git a/gocryptfs-xray/xray_tests/aessiv_fs/gocryptfs.conf
b/gocryptfs-xray/xray_tests/aessiv_fs/gocryptfs.conf new file mode 100644 index 0000000..9b8b95f --- /dev/null +++
b/gocryptfs-xray/xray_tests/aessiv_fs/gocryptfs.conf @@ -0,0 +1,21 @@ +{ + "Creator": "gocryptfs v1.7-beta1-7-g6b94f5e", +
"EncryptedKey": "D0kHfg/pryMO9Ydo15EwpYjNHf3iWKq2GJyNocbjwJt9blEeMoLD5DnoARuDzQs54hblw+9MHwFjCSHYmJrFbA==", + "ScryptObject": { +
"Salt": "ehn0LM/Hy/4QkXAMCZq3c3p0O9G7gu5e3OQSR8MiJ6c=", + "N": 65536, + "R": 8, + "P": 1, + "KeyLen": 32 + }, + "Version": 2, +
"FeatureFlags": [ + "GCMIV128", + "HKDF", + "DirIV", + "EMENames", + "LongNames", + "Raw64", + "AESSIV" + ] +} diff --git
a/gocryptfs-xray/xray_tests/aessiv_fs/gocryptfs.diriv b/gocryptfs-xray/xray_tests/aessiv_fs/gocryptfs.diriv new file mode 100644
index 0000000..dd57ce1 --- /dev/null +++ b/gocryptfs-xray/xray_tests/aessiv_fs/gocryptfs.diriv @@ -0,0 +1 @@ +.¨Í1Aiõ&Á4—öÉ \
No newline at end of file diff --git a/gocryptfs-xray/xray_tests/xray_test.go b/gocryptfs-xray/xray_tests/xray_test.go index
a3374b0..8e5fc0c 100644 --- a/gocryptfs-xray/xray_tests/xray_test.go +++ b/gocryptfs-xray/xray_tests/xray_test.go @@ -24,3 +24,20 @@
func TestAesgcmXray(t *testing.T) {
 		fmt.Printf("have:\n%s", string(out))
 	}
 }
+ +func TestAessivXray(t *testing.T) { + expected, err := ioutil.ReadFile("aessiv_fs.xray.txt") + if err != nil { + t.Fatal(err) + }
+ cmd := exec.Command("../gocryptfs-xray", "-aessiv", "aessiv_fs/Ldq-c4ADpM5iGSSrPjUAqQ") + out, err := cmd.CombinedOutput() + if
err != nil { + t.Fatal(err) + } + if bytes.Compare(out, expected) != 0 { + t.Errorf("Unexpected output") +
fmt.Printf("expected:\n%s", string(expected)) + fmt.Printf("have:\n%s", string(out)) + } +}
2019-01-04 19:10:36 +01:00
Jakob Unterwurzacher
30a8fda0a1 xray: add tests and example aes-gcm fs
The single test compares the gocryptfs-xray output with the expected output.
2019-01-04 19:02:36 +01:00
Jakob Unterwurzacher
cb524b60b4 Update changelog 2019-01-04 18:05:37 +01:00
Jakob Unterwurzacher
6b94f5ef51 reverse mode: -exclude: filter out excluded .name files
Fixes https://github.com/rfjakob/gocryptfs/issues/286 :

While the actual file is properly excluded, the * .name file is still leaked in the directory listing:

```
drwxr-xr-x 2 sebastian sebastian 4,0K Dez 17 14:58 .
drwxr-xr-x 7 sebastian sebastian 4,0K Dez 17 14:45 ..
-r-------- 1 sebastian sebastian  408 Dez 17 14:56 gocryptfs.conf
-r--r--r-- 1 sebastian sebastian   16 Dez 17 14:58 gocryptfs.diriv
-r--r--r-- 1 sebastian sebastian  320 Dez 17 14:58 gocryptfs.longname.3vZ_r3eDPb1_fL3j5VA4rd_bcKWLKT9eaxOVIGK5HFA.name
```
2019-01-04 17:59:00 +01:00