hardcoresushi/libgocryptfs
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Add EME filename encryption & enable it by default

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This commit is contained in:
Jakob Unterwurzacher 2015-12-08 16:13:29 +01:00
parent ff8c81f95b
commit c6dacd6f91
15 changed files with 209 additions and 129 deletions
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3
Documentation/MANPAGE.md
View File

@ -42,6 +42,9 @@ Options:
**-diriv**
: Use per-directory file name IV (default true)
**-emenames**
: Use EME filename encryption (default true). This option implies diriv.
**-extpass string**
: Use an external program (like ssh-askpass) for the password prompt.
The program should return the password on stdout, a trailing newline is

20
cryptfs/config_file.go
View File

@ -12,10 +12,6 @@ const (
// The dot "." is not used in base64url (RFC4648), hence
// we can never clash with an encrypted file.
ConfDefaultName = "gocryptfs.conf"
// Understood Feature Flags
// Also teach isFeatureFlagKnown() about any additions
FlagPlaintextNames = "PlaintextNames"
FlagDirIV = "DirIV"
)
type ConfFile struct {
@ -37,7 +33,7 @@ type ConfFile struct {
// CreateConfFile - create a new config with a random key encrypted with
// "password" and write it to "filename".
// Uses scrypt with cost parameter logN.
func CreateConfFile(filename string, password string, plaintextNames bool, logN int) error {
func CreateConfFile(filename string, password string, plaintextNames bool, logN int, EMENames bool) error {
var cf ConfFile
cf.filename = filename
@ -50,11 +46,13 @@ func CreateConfFile(filename string, password string, plaintextNames bool, logN
// Set defaults
cf.Version = HEADER_CURRENT_VERSION
cf.FeatureFlags = []string{FlagDirIV}
// Set values chosen by the user
if plaintextNames {
cf.FeatureFlags = append(cf.FeatureFlags, FlagPlaintextNames)
} else {
cf.FeatureFlags = append(cf.FeatureFlags, FlagDirIV)
cf.FeatureFlags = append(cf.FeatureFlags, FlagEMENames)
}
// Write file to disk
@ -157,10 +155,18 @@ func (cf *ConfFile) WriteFile() error {
return nil
}
const (
// Understood Feature Flags.
// Also teach isFeatureFlagKnown() about any additions
FlagPlaintextNames = "PlaintextNames"
FlagDirIV = "DirIV"
FlagEMENames = "EMENames"
)
// Verify that we understand a feature flag
func (cf *ConfFile) isFeatureFlagKnown(flag string) bool {
switch flag {
case FlagPlaintextNames, FlagDirIV:
case FlagPlaintextNames, FlagDirIV, FlagEMENames:
return true
default:
return false

2
cryptfs/config_test.go
View File

@ -59,7 +59,7 @@ func TestLoadV2StrangeFeature(t *testing.T) {
}
func TestCreateConfFile(t *testing.T) {
err := CreateConfFile("config_test/tmp.conf", "test", false, 0)
err := CreateConfFile("config_test/tmp.conf", "test", false, 10, true)
if err != nil {
t.Fatal(err)
}

2
cryptfs/cryptfs.go
View File

@ -25,7 +25,6 @@ type CryptFS struct {
cipherBS uint64
// Stores an all-zero block of size cipherBS
allZeroBlock []byte
plaintextNames bool
// DirIV cache for filename encryption
DirIVCacheEnc DirIVCache
}
@ -59,7 +58,6 @@ func NewCryptFS(key []byte, useOpenssl bool, plaintextNames bool) *CryptFS {
plainBS: DEFAULT_PLAINBS,
cipherBS: uint64(cipherBS),
allZeroBlock: make([]byte, cipherBS),
plaintextNames: plaintextNames,
}
}

15
cryptfs/filter.go
View File

@ -1,15 +0,0 @@
package cryptfs
// IsFiltered - check if "path" should be forbidden
//
// Used to prevent name clashes with gocryptfs.conf
// when file names are not encrypted
func (be *CryptFS) IsFiltered(path string) bool {
// gocryptfs.conf in the root directory is forbidden
if be.plaintextNames == true && path == ConfDefaultName {
Warn.Printf("The name /%s is reserved when -plaintextnames is used\n",
ConfDefaultName)
return true
}
return false
}

13
cryptfs/log.go
View File

@ -3,6 +3,7 @@ package cryptfs
import (
"fmt"
"strings"
"encoding/json"
)
type logChannel struct {
@ -26,6 +27,18 @@ func (l *logChannel) Dump(d []byte) {
fmt.Println(strings.Replace(s, "\000", "\\0", -1))
}
func (l *logChannel) JSONDump(obj interface{}) {
if !l.enabled {
return
}
b, err := json.MarshalIndent(obj, "", "\t")
if err != nil {
fmt.Println(err)
} else {
fmt.Println(string(b))
}
}
func (l *logChannel) Enable() {
l.enabled = true
}

80
cryptfs/cryptfs_names.go → cryptfs/names_core.go
View File

@ -1,6 +1,6 @@
package cryptfs
// Filename encryption / decryption function
// Filename encryption / decryption functions
import (
"crypto/aes"
@ -8,16 +8,22 @@ import (
"encoding/base64"
"errors"
"fmt"
"strings"
)
const (
OpEncrypt = iota
OpDecrypt
"github.com/rfjakob/eme"
)
// DecryptName - decrypt base64-encoded encrypted filename "cipherName"
func (be *CryptFS) DecryptName(cipherName string, iv []byte) (string, error) {
// The used encryption is either CBC or EME, depending on the "EMENames" argument.
//
// This function is exported because it allows for a very efficient readdir
// implementation (read IV once, decrypt all names using this function).
func (be *CryptFS) DecryptName(cipherName string, iv []byte, EMENames bool) (string, error) {
return be.decryptName(cipherName, iv, EMENames)
}
// decryptName - decrypt base64-encoded encrypted filename "cipherName".
// The used encryption is either CBC or EME, depending on the "EMENames" argument.
func (be *CryptFS) decryptName(cipherName string, iv []byte, EMENames bool) (string, error) {
// Make sure relative symlinks still work after encryption
// by passing these through unchanged
@ -34,8 +40,12 @@ func (be *CryptFS) DecryptName(cipherName string, iv []byte) (string, error) {
return "", fmt.Errorf("Decoded length %d is not a multiple of the AES block size", len(bin))
}
cbc := cipher.NewCBCDecrypter(be.blockCipher, iv)
cbc.CryptBlocks(bin, bin)
if EMENames {
bin = eme.Transform(be.blockCipher, iv, bin, eme.DirectionDecrypt)
} else {
cbc := cipher.NewCBCDecrypter(be.blockCipher, iv)
cbc.CryptBlocks(bin, bin)
}
bin, err = be.unPad16(bin)
if err != nil {
@ -46,8 +56,9 @@ func (be *CryptFS) DecryptName(cipherName string, iv []byte) (string, error) {
return plain, err
}
// EncryptName - encrypt filename
func (be *CryptFS) encryptName(plainName string, iv []byte) string {
// encryptName - encrypt "plainName", return base64-encoded "cipherName64"
// The used encryption is either CBC or EME, depending on the "EMENames" argument.
func (be *CryptFS) encryptName(plainName string, iv []byte, EMENames bool) (cipherName64 string) {
// Make sure relative symlinks still work after encryption
// by passing these trough unchanged
@ -58,50 +69,17 @@ func (be *CryptFS) encryptName(plainName string, iv []byte) string {
bin := []byte(plainName)
bin = be.pad16(bin)
cbc := cipher.NewCBCEncrypter(be.blockCipher, iv)
cbc.CryptBlocks(bin, bin)
if EMENames {
bin = eme.Transform(be.blockCipher, iv, bin, eme.DirectionEncrypt)
} else {
cbc := cipher.NewCBCEncrypter(be.blockCipher, iv)
cbc.CryptBlocks(bin, bin)
}
cipherName64 := base64.URLEncoding.EncodeToString(bin)
cipherName64 = base64.URLEncoding.EncodeToString(bin)
return cipherName64
}
// TranslatePathZeroIV - encrypt or decrypt path using CBC with a constant all-zero IV.
// Just splits the string on "/" and hands the parts to encryptName() / decryptName()
func (be *CryptFS) TranslatePathZeroIV(path string, op int) (string, error) {
var err error
// Empty string means root directory
if path == "" {
return path, err
}
zeroIV := make([]byte, DIRIV_LEN)
// Run operation on each path component
var translatedParts []string
parts := strings.Split(path, "/")
for _, part := range parts {
if part == "" {
// This happens on "/foo/bar/" on the front and on the end.
// Don't panic.
translatedParts = append(translatedParts, "")
continue
}
var newPart string
if op == OpEncrypt {
newPart = be.encryptName(part, zeroIV)
} else {
newPart, err = be.DecryptName(part, zeroIV)
if err != nil {
return "", err
}
}
translatedParts = append(translatedParts, newPart)
}
return strings.Join(translatedParts, "/"), err
}
// pad16 - pad filename to 16 byte blocks using standard PKCS#7 padding
// https://tools.ietf.org/html/rfc5652#section-6.3
func (be *CryptFS) pad16(orig []byte) (padded []byte) {

31
cryptfs/names_diriv.go
View File

@ -73,11 +73,8 @@ func WriteDirIV(dir string) error {
return ioutil.WriteFile(file, iv, 0444)
}
// EncryptPathDirIV - encrypt path using CBC with DirIV
func (be *CryptFS) EncryptPathDirIV(plainPath string, rootDir string) (string, error) {
if be.plaintextNames {
return plainPath, nil
}
// EncryptPathDirIV - encrypt path using CBC or EME with DirIV
func (be *CryptFS) EncryptPathDirIV(plainPath string, rootDir string, eme bool) (cipherPath string, err error) {
// Empty string means root directory
if plainPath == "" {
return plainPath, nil
@ -88,36 +85,32 @@ func (be *CryptFS) EncryptPathDirIV(plainPath string, rootDir string) (string, e
if found {
//fmt.Print("h")
baseName := filepath.Base(plainPath)
cBaseName := be.encryptName(baseName, iv)
cPath := cParentDir + "/" + cBaseName
return cPath, nil
cBaseName := be.encryptName(baseName, iv, eme)
cipherPath = cParentDir + "/" + cBaseName
return cipherPath, nil
}
// Walk the directory tree
var wd = rootDir
var encryptedNames []string
var err error
plainNames := strings.Split(plainPath, "/")
for _, plainName := range plainNames {
iv, err = be.ReadDirIV(wd)
if err != nil {
return "", err
}
encryptedName := be.encryptName(plainName, iv)
encryptedName := be.encryptName(plainName, iv, eme)
encryptedNames = append(encryptedNames, encryptedName)
wd = filepath.Join(wd, encryptedName)
}
// Cache the final DirIV
cPath := strings.Join(encryptedNames, "/")
cParentDir = filepath.Dir(cPath)
cipherPath = strings.Join(encryptedNames, "/")
cParentDir = filepath.Dir(cipherPath)
be.DirIVCacheEnc.store(parentDir, iv, cParentDir)
return cPath, nil
return cipherPath, nil
}
// DecryptPathDirIV - encrypt path using CBC with DirIV
func (be *CryptFS) DecryptPathDirIV(encryptedPath string, rootDir string) (string, error) {
if be.plaintextNames {
return encryptedPath, nil
}
// DecryptPathDirIV - encrypt path using CBC or EME with DirIV
func (be *CryptFS) DecryptPathDirIV(encryptedPath string, rootDir string, eme bool) (string, error) {
var wd = rootDir
var plainNames []string
encryptedNames := strings.Split(encryptedPath, "/")
@ -127,7 +120,7 @@ func (be *CryptFS) DecryptPathDirIV(encryptedPath string, rootDir string) (strin
if err != nil {
return "", err
}
plainName, err := be.DecryptName(encryptedName, iv)
plainName, err := be.decryptName(encryptedName, iv, eme)
if err != nil {
return "", err
}

63
cryptfs/names_noiv.go Normal file
View File

@ -0,0 +1,63 @@
package cryptfs
import (
"strings"
)
const (
OpEncrypt = iota
OpDecrypt
)
// DecryptPathNoIV - decrypt path using CBC without any IV.
// This function is deprecated by the the more secure DirIV variant and only retained
// for compatability with old filesystems.
func (be *CryptFS) DecryptPathNoIV(cipherPath string) (plainPath string, err error) {
plainPath, err = be.translatePathNoIV(cipherPath, OpDecrypt)
return plainPath, err
}
// EncryptPathNoIV - decrypt path using CBC without any IV.
// This function is deprecated by the the more secure DirIV variant and only retained
// for compatability with old filesystems.
func (be *CryptFS) EncryptPathNoIV(plainPath string) (cipherPath string) {
cipherPath, _ = be.translatePathNoIV(plainPath, OpEncrypt)
return cipherPath
}
// translatePathZeroIV - encrypt or decrypt path using CBC with an all-zero IV.
// Just splits the string on "/" and hands the parts to encryptName() / decryptName()
func (be *CryptFS) translatePathNoIV(path string, op int) (string, error) {
var err error
// Empty string means root directory
if path == "" {
return path, err
}
zeroIV := make([]byte, DIRIV_LEN)
// Run operation on each path component
var translatedParts []string
parts := strings.Split(path, "/")
for _, part := range parts {
if part == "" {
// This happens on "/foo/bar/" on the front and on the end.
// Don't panic.
translatedParts = append(translatedParts, "")
continue
}
var newPart string
if op == OpEncrypt {
newPart = be.encryptName(part, zeroIV, false)
} else {
newPart, err = be.decryptName(part, zeroIV, false)
if err != nil {
return "", err
}
}
translatedParts = append(translatedParts, newPart)
}
return strings.Join(translatedParts, "/"), err
}

11
cryptfs/names_test.go
View File

@ -5,7 +5,7 @@ import (
"testing"
)
func TestTranslatePath(t *testing.T) {
func TestEncryptPathNoIV(t *testing.T) {
var s []string
s = append(s, "foo")
s = append(s, "foo12312312312312312313123123123")
@ -15,15 +15,14 @@ func TestTranslatePath(t *testing.T) {
fs := NewCryptFS(key, true, false)
for _, n := range s {
c, err := fs.TranslatePathZeroIV(n, OpEncrypt)
d, err := fs.TranslatePathZeroIV(c, OpDecrypt)
c := fs.EncryptPathNoIV(n)
d, err := fs.DecryptPathNoIV(c)
if err != nil {
t.Errorf("Got error from DecryptName: %s", err)
t.Errorf("Got error from DecryptPathNoIV: %s", err)
}
if d != n {
t.Errorf("Content mismatch, n=\"%s\" d=\"%s\"", n, d)
t.Errorf("Content mismatch, n != d: n=%s c=%s d=%s", n, c, d)
}
//fmt.Printf("n=%s c=%s d=%s\n", n, c, d)
}
}

4
integration_tests/example_filesystems_test.go
View File

@ -57,7 +57,7 @@ func TestExampleFsV04(t *testing.T) {
checkExampleContent(t, pDir)
unmount(pDir)
mount(cDir, pDir, "-masterkey", "74676e34-0b47c145-00dac61a-17a92316-"+
"bb57044c-e205b71f-65f4fdca-7cabd4b3", "-diriv=false")
"bb57044c-e205b71f-65f4fdca-7cabd4b3", "-diriv=false", "-emenames=false")
checkExampleContent(t, pDir)
unmount(pDir)
err = os.Remove(pDir)
@ -79,7 +79,7 @@ func TestExampleFsV05(t *testing.T) {
checkExampleContent(t, pDir)
unmount(pDir)
mount(cDir, pDir, "-masterkey", "199eae55-36bff4af-83b9a3a2-4fa16f65-"+
"1549ccdb-2d08d1f0-b1b26965-1b61f896")
"1549ccdb-2d08d1f0-b1b26965-1b61f896", "-emenames=false")
checkExampleContent(t, pDir)
unmount(pDir)
err = os.Remove(pDir)

20
main.go
View File

@ -35,7 +35,7 @@ const (
type argContainer struct {
debug, init, zerokey, fusedebug, openssl, passwd, foreground, version,
plaintextnames, quiet, diriv bool
plaintextnames, quiet, diriv, emenames bool
masterkey, mountpoint, cipherdir, cpuprofile, config, extpass string
notifypid, scryptn int
}
@ -55,7 +55,7 @@ func initDir(args *argContainer) {
// Create gocryptfs.conf
cryptfs.Info.Printf("Choose a password for protecting your files.\n")
password := readPasswordTwice(args.extpass)
err = cryptfs.CreateConfFile(args.config, password, args.plaintextnames, args.scryptn)
err = cryptfs.CreateConfFile(args.config, password, args.plaintextnames, args.scryptn, args.emenames)
if err != nil {
fmt.Println(err)
os.Exit(ERREXIT_INIT)
@ -146,6 +146,7 @@ func main() {
"file names")
flagSet.BoolVar(&args.quiet, "q", false, "Quiet - silence informational messages")
flagSet.BoolVar(&args.diriv, "diriv", true, "Use per-directory file name IV")
flagSet.BoolVar(&args.emenames, "emenames", true, "Use EME filename encryption. This option implies diriv.")
flagSet.StringVar(&args.masterkey, "masterkey", "", "Mount with explicit master key")
flagSet.StringVar(&args.cpuprofile, "cpuprofile", "", "Write cpu profile to specified file")
flagSet.StringVar(&args.config, "config", "", "Use specified config file instead of CIPHERDIR/gocryptfs.conf")
@ -262,7 +263,7 @@ func main() {
printMasterKey(masterkey)
}
// Initialize FUSE server
cryptfs.Debug.Printf("args: %v\n", args)
cryptfs.Debug.Printf("cli args: %v\n", args)
srv := pathfsFrontend(masterkey, args, confFile)
cryptfs.Info.Println("Filesystem ready.")
// We are ready - send USR1 signal to our parent
@ -289,13 +290,26 @@ func pathfsFrontend(key []byte, args argContainer, confFile *cryptfs.ConfFile) *
OpenSSL: args.openssl,
PlaintextNames: args.plaintextnames,
DirIV: args.diriv,
EMENames: args.emenames,
}
// confFile is nil when "-zerokey" or "-masterkey" was used
if confFile != nil {
// Settings from the config file override command line args
frontendArgs.PlaintextNames = confFile.IsFeatureFlagSet(cryptfs.FlagPlaintextNames)
frontendArgs.DirIV = confFile.IsFeatureFlagSet(cryptfs.FlagDirIV)
frontendArgs.EMENames = confFile.IsFeatureFlagSet(cryptfs.FlagEMENames)
}
// EMENames implies DirIV, both on the command line and in the config file.
if frontendArgs.EMENames {
frontendArgs.DirIV = true
}
// PlainTexnames disables both EMENames and DirIV
if frontendArgs.PlaintextNames {
frontendArgs.DirIV = false
frontendArgs.EMENames = false
}
cryptfs.Debug.Printf("frontendArgs: ")
cryptfs.Debug.JSONDump(frontendArgs)
finalFs := pathfs_frontend.NewFS(frontendArgs)
pathFsOpts := &pathfs.PathNodeFsOptions{ClientInodes: true}

1
pathfs_frontend/args.go
View File

@ -7,4 +7,5 @@ type Args struct {
OpenSSL bool
PlaintextNames bool
DirIV bool
EMENames bool
}

28
pathfs_frontend/fs.go
View File

@ -48,7 +48,7 @@ func (fs *FS) getBackingPath(relPath string) (string, error) {
func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) {
cryptfs.Debug.Printf("FS.GetAttr('%s')\n", name)
if fs.CryptFS.IsFiltered(name) {
if fs.isFiltered(name) {
return nil, fuse.EPERM
}
cName, err := fs.encryptPath(name)
@ -103,7 +103,7 @@ func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, f
continue
}
var name string
name, err = fs.CryptFS.DecryptName(cName, cachedIV)
name, err = fs.CryptFS.DecryptName(cName, cachedIV, fs.args.EMENames)
if err != nil {
cryptfs.Warn.Printf("Invalid name \"%s\" in dir \"%s\": %s\n", cName, dirName, err)
continue
@ -128,7 +128,7 @@ func (fs *FS) mangleOpenFlags(flags uint32) (newFlags int, writeOnly bool) {
}
func (fs *FS) Open(path string, flags uint32, context *fuse.Context) (fuseFile nodefs.File, status fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return nil, fuse.EPERM
}
iflags, writeOnly := fs.mangleOpenFlags(flags)
@ -147,7 +147,7 @@ func (fs *FS) Open(path string, flags uint32, context *fuse.Context) (fuseFile n
}
func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Context) (fuseFile nodefs.File, code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return nil, fuse.EPERM
}
iflags, writeOnly := fs.mangleOpenFlags(flags)
@ -163,7 +163,7 @@ func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Conte
}
func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return fuse.EPERM
}
cPath, err := fs.encryptPath(path)
@ -174,7 +174,7 @@ func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.
}
func (fs *FS) Chown(path string, uid uint32, gid uint32, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return fuse.EPERM
}
cPath, err := fs.encryptPath(path)
@ -185,7 +185,7 @@ func (fs *FS) Chown(path string, uid uint32, gid uint32, context *fuse.Context)
}
func (fs *FS) Mknod(path string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return fuse.EPERM
}
cPath, err := fs.encryptPath(path)
@ -201,7 +201,7 @@ func (fs *FS) Truncate(path string, offset uint64, context *fuse.Context) (code
}
func (fs *FS) Utimens(path string, Atime *time.Time, Mtime *time.Time, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return fuse.EPERM
}
cPath, err := fs.encryptPath(path)
@ -244,7 +244,7 @@ func (fs *FS) Readlink(path string, context *fuse.Context) (out string, status f
}
func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(relPath) {
if fs.isFiltered(relPath) {
return fuse.EPERM
}
encPath, err := fs.getBackingPath(relPath)
@ -275,7 +275,7 @@ func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fu
}
func (fs *FS) Unlink(path string, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return fuse.EPERM
}
cPath, err := fs.getBackingPath(path)
@ -349,7 +349,7 @@ func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
func (fs *FS) Symlink(target string, linkName string, context *fuse.Context) (code fuse.Status) {
cryptfs.Debug.Printf("Symlink(\"%s\", \"%s\")\n", target, linkName)
if fs.CryptFS.IsFiltered(linkName) {
if fs.isFiltered(linkName) {
return fuse.EPERM
}
cPath, err := fs.getBackingPath(linkName)
@ -376,7 +376,7 @@ func (fs *FS) Symlink(target string, linkName string, context *fuse.Context) (co
}
func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(newPath) {
if fs.isFiltered(newPath) {
return fuse.EPERM
}
cOldPath, err := fs.getBackingPath(oldPath)
@ -396,7 +396,7 @@ func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (cod
}
func (fs *FS) Link(oldPath string, newPath string, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(newPath) {
if fs.isFiltered(newPath) {
return fuse.EPERM
}
cOldPath, err := fs.getBackingPath(oldPath)
@ -411,7 +411,7 @@ func (fs *FS) Link(oldPath string, newPath string, context *fuse.Context) (code
}
func (fs *FS) Access(path string, mode uint32, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
if fs.isFiltered(path) {
return fuse.EPERM
}
cPath, err := fs.getBackingPath(path)

45
pathfs_frontend/names.go
View File

@ -6,20 +6,47 @@ import (
"github.com/rfjakob/gocryptfs/cryptfs"
)
func (fs *FS) encryptPath(plainPath string) (string, error) {
if !fs.args.DirIV {
return fs.CryptFS.TranslatePathZeroIV(plainPath, cryptfs.OpEncrypt)
// isFiltered - check if plaintext "path" should be forbidden
//
// Prevents name clashes with internal files when file names are not encrypted
func (fs *FS) isFiltered(path string) bool {
if !fs.args.PlaintextNames {
return false
}
fs.dirIVLock.RLock()
defer fs.dirIVLock.RUnlock()
return fs.CryptFS.EncryptPathDirIV(plainPath, fs.args.Cipherdir)
// gocryptfs.conf in the root directory is forbidden
if path == cryptfs.ConfDefaultName {
cryptfs.Warn.Printf("The name /%s is reserved when -plaintextnames is used\n",
cryptfs.ConfDefaultName)
return true
}
// Note: gocryptfs.diriv is NOT forbidden because diriv and plaintextnames
// are exclusive
return false
}
func (fs *FS) decryptPath(cipherPath string) (string, error) {
// encryptPath - encrypt relative plaintext path
func (fs *FS) encryptPath(plainPath string) (string, error) {
if fs.args.PlaintextNames {
return plainPath, nil
}
if !fs.args.DirIV {
return fs.CryptFS.TranslatePathZeroIV(cipherPath, cryptfs.OpDecrypt)
return fs.CryptFS.EncryptPathNoIV(plainPath), nil
}
fs.dirIVLock.RLock()
defer fs.dirIVLock.RUnlock()
return fs.CryptFS.DecryptPathDirIV(cipherPath, fs.args.Cipherdir)
return fs.CryptFS.EncryptPathDirIV(plainPath, fs.args.Cipherdir, fs.args.EMENames)
}
// decryptPath - decrypt relative ciphertext path
func (fs *FS) decryptPath(cipherPath string) (string, error) {
if fs.args.PlaintextNames {
return cipherPath, nil
}
if !fs.args.DirIV {
return fs.CryptFS.DecryptPathNoIV(cipherPath)
}
fs.dirIVLock.RLock()
defer fs.dirIVLock.RUnlock()
return fs.CryptFS.DecryptPathDirIV(cipherPath, fs.args.Cipherdir, fs.args.EMENames)
}