Mirror of gocryptfs source code on Github http://nuetzlich.net/cgit/gocryptfs/atom?h=xattr_user_buffer 2025-07-07T17:59:35+00:00 2025-07-07T17:59:35+00:00 Jakob Unterwurzacher 2025-07-07T17:54:48+00:00 urn:sha1:8f5df19b353e02ffba842fd1b15ccf93da7ee3b4 Tool-assisted. 2021-09-28T16:09:31+00:00 Jakob Unterwurzacher 2021-09-28T15:45:26+00:00 urn:sha1:db1824a23ac8e47cda714796e55cf6927b0cbecc Used in gocryptfs-xray, and will also be used in -info. 2021-08-23T20:19:30+00:00 Jakob Unterwurzacher 2021-08-23T20:19:30+00:00 urn:sha1:abaa12992ce9d59c94a8530237dfaa4ebe6063f0 Also use the new cryptocore algo names. 2021-08-23T13:05:15+00:00 Jakob Unterwurzacher 2021-08-23T13:05:15+00:00 urn:sha1:69d88505fd7f4cb0d9e4f1918de296342fe05858 Our git version is v2+ for some time now, but go.mod still declared v1. Hopefully making both match makes https://pkg.go.dev/github.com/rfjakob/gocryptfs/v2 work. All the import paths have been fixed like this: find . -name \*.go | xargs sed -i s%github.com/rfjakob/gocryptfs/%github.com/rfjakob/gocryptfs/v2/% 2021-08-19T06:34:44+00:00 Jakob Unterwurzacher 2021-08-19T05:51:47+00:00 urn:sha1:c86981342b46875525f2b214687553e23e58eb1a Everything except the if err2.Err == syscall.EOPNOTSUPP case. Gets too confusing when collapsed into a single line. Issues were: $ golangci-lint run --disable-all --enable gosimple mount.go:473:2: S1008: should use 'return strings.HasPrefix(v, "fusermount version")' instead of 'if strings.HasPrefix(v, "fusermount version") { return true }; return false' (gosimple) if strings.HasPrefix(v, "fusermount version") { ^ cli_args.go:258:5: S1002: should omit comparison to bool constant, can be simplified to `args.forcedecode` (gosimple) if args.forcedecode == true { ^ cli_args.go:263:6: S1002: should omit comparison to bool constant, can be simplified to `args.aessiv` (gosimple) if args.aessiv == true { ^ cli_args.go:267:6: S1002: should omit comparison to bool constant, can be simplified to `args.reverse` (gosimple) if args.reverse == true { ^ internal/stupidgcm/stupidgcm.go:227:6: S1002: should omit comparison to bool constant, can be simplified to `g.forceDecode` (gosimple) if g.forceDecode == true { ^ gocryptfs-xray/xray_tests/xray_test.go:23:5: S1004: should use !bytes.Equal(out, expected) instead (gosimple) if bytes.Compare(out, expected) != 0 { ^ gocryptfs-xray/xray_tests/xray_test.go:40:5: S1004: should use !bytes.Equal(out, expected) instead (gosimple) if bytes.Compare(out, expected) != 0 { ^ gocryptfs-xray/paths_ctlsock.go:34:20: S1002: should omit comparison to bool constant, can be simplified to `!eof` (gosimple) for eof := false; eof == false; line++ { ^ tests/reverse/xattr_test.go:19:2: S1008: should use 'return err2.Err != syscall.EOPNOTSUPP' instead of 'if err2.Err == syscall.EOPNOTSUPP { return false }; return true' (gosimple) if err2.Err == syscall.EOPNOTSUPP { ^ internal/fusefrontend/node.go:459:45: S1002: should omit comparison to bool constant, can be simplified to `!nameFileAlreadyThere` (gosimple) if nametransform.IsLongContent(cName2) && nameFileAlreadyThere == false { ^ tests/xattr/xattr_integration_test.go:221:2: S1008: should use 'return err2.Err != syscall.EOPNOTSUPP' instead of 'if err2.Err == syscall.EOPNOTSUPP { return false }; return true' (gosimple) if err2.Err == syscall.EOPNOTSUPP { ^ tests/test_helpers/helpers.go:338:19: S1002: should omit comparison to bool constant, can be simplified to `open` (gosimple) if err != nil && open == true { ^ tests/matrix/concurrency_test.go:121:7: S1004: should use !bytes.Equal(buf, content) instead (gosimple) if bytes.Compare(buf, content) != 0 { ^ 2020-05-09T22:04:14+00:00 Jakob Unterwurzacher 2020-05-09T22:04:14+00:00 urn:sha1:a9895b34872d2299cfe424444fab15516e7f96c9 The -0 flags works like xargs -0. 2019-01-04T18:34:15+00:00 Jakob Unterwurzacher 2019-01-04T18:34:15+00:00 urn:sha1:2024616722ee18c3a8886490166d090f81f2ecaf To alert the user that they can and should choose the right mode. 2019-01-04T18:31:08+00:00 Jakob Unterwurzacher 2019-01-04T18:30:05+00:00 urn:sha1:28584d0d2c829fa1824bebc13e446968ebdee6b6 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 2019-01-04T18:21:09+00:00 Jakob Unterwurzacher 2019-01-04T18:21:09+00:00 urn:sha1:8d71f8fe523a1c117ec8f4b47dd6067203a92551 2019-01-04T18:10:36+00:00 Jakob Unterwurzacher 2019-01-04T18:10:36+00:00 urn:sha1:44e860d1055c0ee946919b0a49baa85272123f5f 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)) + } +}