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2019-01-13macos: filter SUID and SGID bits in OpenatUser, MknodatUser, MkdiratUserJakob Unterwurzacher
When gocryptfs runs as root, we don't want to allow people to create SUID root files.
2019-01-12fusefrontend: Preserve SUID/SGID/sticky-bits in openWriteOnlyFile and Rmdir.Sebastian Lackner
Fixes https://github.com/rfjakob/gocryptfs/issues/336 and https://github.com/rfjakob/gocryptfs/issues/337.
2019-01-12fusefrontend: -allow_other: Use SymlinkatUser in Symlink FUSE call.Sebastian Lackner
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.
2019-01-12fusefrontend: -allow_other: Use MknodatUser in Mknod FUSE call.Sebastian Lackner
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.
2019-01-12fusefrontend: -allow_other: Use MkdiratUser in Mkdir FUSE call.Sebastian Lackner
Revert commit fcaca5fc94d981aa637beb752edc8cb3c2265e96. 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.
2019-01-12fusefrontend: -allow_other: Use OpenatUser in Create FUSE call.Sebastian Lackner
Revert commit b22cc03c7516b2003880db8375d26c76d6dff093. 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.
2019-01-12fusefrontend: Don't chown gocryptfs.diriv files.Sebastian Lackner
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.
2019-01-09fusefrontend: -allow_other: set file mode after chown in Mkdir().Sebastian Lackner
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.
2019-01-09nametransform: Create *.name files with 0400 permission.Sebastian Lackner
Similar to gocryptfs.iv files they are never modified.
2019-01-08fusefrontend: -allow_other: set file mode *after* chown in Create()Jakob Unterwurzacher
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.
2019-01-07syscallcompat: Implement workaround for Fchmodat with AT_SYMLINK_NOFOLLOW.Sebastian Lackner
Fixes https://github.com/rfjakob/gocryptfs/issues/259
2019-01-07tests: add Fchmodat testJakob Unterwurzacher
Test that we handle symlinks correctly.
2019-01-07fusefrontend: Clarify access mode check related to O_WRONLY handling.Sebastian Lackner
Use O_ACCMODE mask in openWriteOnlyFile for improved readability.
2019-01-07fusefrontend: Filter O_CREAT in mangleOpenFlags.Sebastian Lackner
2019-01-06fusefrontend: Check result of Fchmod syscall.Sebastian Lackner
Fixes https://github.com/rfjakob/gocryptfs/issues/328
2019-01-06fusefrontend: Fix computation of cipherSz in Allocate FUSE call.Sebastian Lackner
Do not use PlainSizeToCipherSize() since this adds the 18 bytes file header. Partially fixes https://github.com/rfjakob/gocryptfs/issues/311
2019-01-06tests: check that fallocate does not over-allocate spaceJakob Unterwurzacher
We currently allocate 18 bytes too much: https://github.com/rfjakob/gocryptfs/issues/311
2019-01-06tests: move fallocate tests to its own fileJakob Unterwurzacher
matrix_test.go is already too big.
2019-01-06tests: TestFallocate: comment what "d" and "h" meansJakob Unterwurzacher
Document what "d" and "h" means in the fancy ASCII diagrams. https://github.com/rfjakob/gocryptfs/pull/326
2019-01-06fusefrontend: Properly convert plaintext <-> ciphertext offsets in SeekData().Sebastian Lackner
Fixes https://github.com/rfjakob/gocryptfs/issues/304
2019-01-05Update changelogJakob Unterwurzacher
2019-01-05tests: add parallel_cp stress testJakob Unterwurzacher
Modeled after xfstests generic/273 https://github.com/rfjakob/gocryptfs/issues/322
2019-01-05main: Run 'ensure fds' code early during the program startup.Sebastian Lackner
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).
2019-01-05main: ensure fds 0,1,2 are always openJakob Unterwurzacher
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.
2019-01-05fusefrontend: Allow to set/remove xattr on directory without read permission.Sebastian Lackner
Setting/removing extended attributes on directories was partially fixed with commit eff35e60b63331e3e10f921792baa10b236a721d. 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 f320b76fd189a363a34bffe981aa67ab97df3362), 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.
2019-01-05A few more spelling fixes.Sebastian Lackner
2019-01-05Add MakefileJakob Unterwurzacher
We are going to use the Makefile to save useful commands without creating too many shell scripts in the top dir.
2019-01-05doc: update extractloop resultsJakob Unterwurzacher
Update output and add a nice plot.
2019-01-05doc: update XFSTESTS resultsJakob Unterwurzacher
2019-01-04tests: bump maxCacheFds to 3Jakob Unterwurzacher
As the dirCache now has 3 entries, the tests should accept up to 3 extra fds without declaring an fd leak.
2019-01-04fusefrontend: fix fd leak in dirCacheJakob Unterwurzacher
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.
2019-01-04nametransform: ReadDirIVAt: return raw syscall errorJakob Unterwurzacher
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.
2019-01-04fusefrontend: print warning when Create() runs out of file descriptorsJakob Unterwurzacher
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.
2019-01-04fusefrontend: fix setting xattrs on directoriesJakob Unterwurzacher
Directories cannot be opened read-write. Retry with RDONLY.
2019-01-04fusefrontend: disable dirCache stats printingJakob Unterwurzacher
This was inadvertedly kept enabled after benchmarking.
2019-01-04Documentation: Fix MANPAGE-render.bash script.Sebastian Lackner
2019-01-04Update performance.txtJakob Unterwurzacher
2019-01-04fusefrontend: upgrade to three-entry dirCachev1.7-rc1Jakob Unterwurzacher
3 entries should work well for up to three parallel users. It works well for extractloop.bash (two parallel tar extracts).
2019-01-04fsck: don't misdetect a file hole at EOFJakob Unterwurzacher
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.
2019-01-04Update gocryptfs-xray manpage, have MANPAGE-render.bash generate bothJakob Unterwurzacher
have MANPAGE-render.bash generate both gocryptfs.1 and gocryptfs-xray.1
2019-01-04Update changelog and gocryptfs-xray manpageJakob Unterwurzacher
2019-01-04fusefrontend_reverse: Fix redeclaration of 'entries' variable.Sebastian Lackner
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
2019-01-04xray: print "assuming AES-GCM mode" unless -aessiv is passedJakob Unterwurzacher
To alert the user that they can and should choose the right mode.
2019-01-04file-format.md: document AES-SIV block layoutJakob Unterwurzacher
Fixes https://github.com/rfjakob/gocryptfs/issues/299
2019-01-04xray: recreate test filesytems with -scrypt 10Jakob Unterwurzacher
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
2019-01-04xray: add dumpmasterkey testJakob Unterwurzacher
2019-01-04xray: add support for inspecting AES-SIV files (-aessiv flag)Jakob Unterwurzacher
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)) + } +}
2019-01-04xray: add tests and example aes-gcm fsJakob Unterwurzacher
The single test compares the gocryptfs-xray output with the expected output.
2019-01-04Update changelogJakob Unterwurzacher
2019-01-04reverse mode: -exclude: filter out excluded .name filesJakob Unterwurzacher
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 ```