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-rw-r--r--cryptfs/cryptfs_names.go48
-rw-r--r--cryptfs/names_diriv.go69
-rw-r--r--cryptfs/names_test.go4
-rw-r--r--integration_tests/main_test.go10
-rw-r--r--pathfs_frontend/fs.go156
-rw-r--r--pathfs_frontend/names.go11
6 files changed, 219 insertions, 79 deletions
diff --git a/cryptfs/cryptfs_names.go b/cryptfs/cryptfs_names.go
index 1282f53..37a769f 100644
--- a/cryptfs/cryptfs_names.go
+++ b/cryptfs/cryptfs_names.go
@@ -12,15 +12,15 @@ import (
)
const (
- ENCRYPT = true
- DECRYPT = false
+ OpEncrypt = iota
+ OpDecrypt
)
-// DecryptName - decrypt filename
-func (be *CryptFS) decryptName(cipherName string) (string, error) {
+// DecryptName - decrypt base64-encoded encrypted filename "cipherName"
+func (be *CryptFS) decryptName(cipherName string, iv []byte) (string, error) {
// Make sure relative symlinks still work after encryption
- // by passing these trough unchanged
+ // by passing these through unchanged
if cipherName == "." || cipherName == ".." {
return cipherName, nil
}
@@ -34,7 +34,6 @@ func (be *CryptFS) decryptName(cipherName string) (string, error) {
return "", fmt.Errorf("Decoded length %d is not a multiple of the AES block size", len(bin))
}
- iv := make([]byte, aes.BlockSize) // TODO ?
cbc := cipher.NewCBCDecrypter(be.blockCipher, iv)
cbc.CryptBlocks(bin, bin)
@@ -48,7 +47,7 @@ func (be *CryptFS) decryptName(cipherName string) (string, error) {
}
// EncryptName - encrypt filename
-func (be *CryptFS) encryptName(plainName string) string {
+func (be *CryptFS) encryptName(plainName string, iv []byte) string {
// Make sure relative symlinks still work after encryption
// by passing these trough unchanged
@@ -59,7 +58,6 @@ func (be *CryptFS) encryptName(plainName string) string {
bin := []byte(plainName)
bin = be.pad16(bin)
- iv := make([]byte, 16) // TODO ?
cbc := cipher.NewCBCEncrypter(be.blockCipher, iv)
cbc.CryptBlocks(bin, bin)
@@ -67,9 +65,10 @@ func (be *CryptFS) encryptName(plainName string) string {
return cipherName64
}
-// TranslatePath - encrypt or decrypt path. Just splits the string on "/"
-// and hands the parts to EncryptName() / DecryptName()
-func (be *CryptFS) translatePath(path string, op bool) (string, error) {
+
+// 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
@@ -77,6 +76,8 @@ func (be *CryptFS) translatePath(path string, op bool) (string, error) {
return path, err
}
+ zeroIV := make([]byte, DIRIV_LEN)
+
// Run operation on each path component
var translatedParts []string
parts := strings.Split(path, "/")
@@ -88,10 +89,10 @@ func (be *CryptFS) translatePath(path string, op bool) (string, error) {
continue
}
var newPart string
- if op == ENCRYPT {
- newPart = be.encryptName(part)
+ if op == OpEncrypt {
+ newPart = be.encryptName(part, zeroIV)
} else {
- newPart, err = be.decryptName(part)
+ newPart, err = be.decryptName(part, zeroIV)
if err != nil {
return "", err
}
@@ -102,23 +103,6 @@ func (be *CryptFS) translatePath(path string, op bool) (string, error) {
return strings.Join(translatedParts, "/"), err
}
-// EncryptPath - encrypt filename or path. Just hands it to translatePath().
-func (be *CryptFS) EncryptPath(path string) string {
- if be.plaintextNames {
- return path
- }
- newPath, _ := be.translatePath(path, ENCRYPT)
- return newPath
-}
-
-// DecryptPath - decrypt filename or path. Just hands it to translatePath().
-func (be *CryptFS) DecryptPath(path string) (string, error) {
- if be.plaintextNames {
- return path, nil
- }
- return be.translatePath(path, DECRYPT)
-}
-
// 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) {
@@ -171,3 +155,5 @@ func (be *CryptFS) unPad16(orig []byte) ([]byte, error) {
}
return orig[0:newLen], nil
}
+
+
diff --git a/cryptfs/names_diriv.go b/cryptfs/names_diriv.go
new file mode 100644
index 0000000..c9debab
--- /dev/null
+++ b/cryptfs/names_diriv.go
@@ -0,0 +1,69 @@
+package cryptfs
+
+import (
+ "path/filepath"
+ "io/ioutil"
+ "fmt"
+ "strings"
+)
+
+// readDirIV - read the "gocryptfs.diriv" file from "dir" (absolute path)
+func (be *CryptFS) readDirIV(dir string) (iv []byte, err error) {
+ ivfile := filepath.Join(dir, DIRIV_FILENAME)
+ iv, err = ioutil.ReadFile(ivfile)
+ if err != nil {
+ Warn.Printf("readDirIV: %v\n", err)
+ return nil, err
+ }
+ if len(iv) != DIRIV_LEN {
+ return nil, fmt.Errorf("readDirIV: Invalid length %d\n", len(iv))
+ }
+ return iv, nil
+}
+
+// EncryptPathDirIV - encrypt path using CBC with DirIV
+func (be *CryptFS) EncryptPathDirIV(plainPath string, rootDir string) (string, error) {
+ if be.plaintextNames {
+ return plainPath, nil
+ }
+ // Empty string means root directory
+ if plainPath == "" {
+ return plainPath, nil
+ }
+ var wd = rootDir
+ var encryptedNames []string
+ plainNames := strings.Split(plainPath, "/")
+ for _, plainName := range plainNames {
+ iv, err := be.readDirIV(wd)
+ if err != nil {
+ return "", err
+ }
+ encryptedName := be.encryptName(plainName, iv)
+ encryptedNames = append(encryptedNames, encryptedName)
+ wd = filepath.Join(wd, encryptedName)
+ }
+ return filepath.Join(encryptedNames...), nil
+}
+
+// DecryptPathDirIV - encrypt path using CBC with DirIV
+func (be *CryptFS) DecryptPathDirIV(encryptedPath string, rootDir string) (string, error) {
+ if be.plaintextNames {
+ return encryptedPath, nil
+ }
+ var wd = rootDir
+ var plainNames []string
+ encryptedNames := strings.Split(encryptedPath, "/")
+ for _, encryptedName := range encryptedNames {
+ iv, err := be.readDirIV(wd)
+ if err != nil {
+ return "", err
+ }
+ plainName, err := be.decryptName(encryptedName, iv)
+ if err != nil {
+ return "", err
+ }
+ plainNames = append(plainNames, plainName)
+ wd = filepath.Join(wd, encryptedName)
+ }
+ return filepath.Join(plainNames...), nil
+}
diff --git a/cryptfs/names_test.go b/cryptfs/names_test.go
index ccf08df..1ad3391 100644
--- a/cryptfs/names_test.go
+++ b/cryptfs/names_test.go
@@ -15,8 +15,8 @@ func TestTranslatePath(t *testing.T) {
fs := NewCryptFS(key, true, false)
for _, n := range s {
- c := fs.EncryptPath(n)
- d, err := fs.DecryptPath(c)
+ c, err := fs.TranslatePathZeroIV(n, OpEncrypt)
+ d, err := fs.TranslatePathZeroIV(c, OpDecrypt)
if err != nil {
t.Errorf("Got error from DecryptName: %s", err)
}
diff --git a/integration_tests/main_test.go b/integration_tests/main_test.go
index 4b2c11e..e46e2e4 100644
--- a/integration_tests/main_test.go
+++ b/integration_tests/main_test.go
@@ -60,16 +60,18 @@ func TestMain(m *testing.M) {
func testWriteN(t *testing.T, fn string, n int) string {
file, err := os.Create(defaultPlainDir + fn)
if err != nil {
- t.FailNow()
+ t.Fatal(err)
}
d := make([]byte, n)
written, err := file.Write(d)
if err != nil || written != len(d) {
- fmt.Printf("err=\"%s\", written=%d\n", err, written)
- t.Fail()
+ t.Errorf("err=\"%s\", written=%d\n", err, written)
+ }
+ err = file.Close()
+ if err != nil {
+ t.Error(err)
}
- file.Close()
verifySize(t, defaultPlainDir+fn, n)
diff --git a/pathfs_frontend/fs.go b/pathfs_frontend/fs.go
index 9c809df..48ea4a2 100644
--- a/pathfs_frontend/fs.go
+++ b/pathfs_frontend/fs.go
@@ -1,6 +1,7 @@
package pathfs_frontend
import (
+ "encoding/base64"
"fmt"
"sync"
"syscall"
@@ -17,9 +18,9 @@ import (
type FS struct {
*cryptfs.CryptFS
- pathfs.FileSystem // loopbackFileSystem, see go-fuse/fuse/pathfs/loopback.go
- backing string // Backing directory
- dirivLock sync.RWMutex // Global lock that is taken if any "gocryptfs.diriv" file is modified
+ pathfs.FileSystem // loopbackFileSystem, see go-fuse/fuse/pathfs/loopback.go
+ backingDir string // Backing directory, cipherdir
+ dirivLock sync.RWMutex // Global lock that is taken if any "gocryptfs.diriv" file is modified
}
// Encrypted FUSE overlay filesystem
@@ -27,14 +28,18 @@ func NewFS(key []byte, backing string, useOpenssl bool, plaintextNames bool) *FS
return &FS{
CryptFS: cryptfs.NewCryptFS(key, useOpenssl, plaintextNames),
FileSystem: pathfs.NewLoopbackFileSystem(backing),
- backing: backing,
+ backingDir: backing,
}
}
-// GetPath - get the absolute encrypted path of the backing file
+// GetBackingPath - get the absolute encrypted path of the backing file
// from the relative plaintext path "relPath"
-func (fs *FS) GetPath(relPath string) string {
- return filepath.Join(fs.backing, fs.EncryptPath(relPath))
+func (fs *FS) getBackingPath(relPath string) (string, error) {
+ encrypted, err := fs.encryptPath(relPath)
+ if err != nil {
+ return "", err
+ }
+ return filepath.Join(fs.backingDir, encrypted), nil
}
func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) {
@@ -42,7 +47,10 @@ func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Stat
if fs.CryptFS.IsFiltered(name) {
return nil, fuse.EPERM
}
- cName := fs.EncryptPath(name)
+ cName, err := fs.encryptPath(name)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
a, status := fs.FileSystem.GetAttr(cName, context)
if a == nil {
cryptfs.Debug.Printf("FS.GetAttr failed: %s\n", status.String())
@@ -59,7 +67,11 @@ func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Stat
func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) {
cryptfs.Debug.Printf("OpenDir(%s)\n", dirName)
- cipherEntries, status := fs.FileSystem.OpenDir(fs.EncryptPath(dirName), context)
+ cDirName, err := fs.encryptPath(dirName)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ cipherEntries, status := fs.FileSystem.OpenDir(cDirName, context)
var plain []fuse.DirEntry
if cipherEntries != nil {
for i := range cipherEntries {
@@ -72,7 +84,7 @@ func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, f
// silently ignore "gocryptfs.diriv" everywhere
continue
}
- name, err := fs.DecryptPath(cName)
+ name, err := fs.decryptPath(cName)
if err != nil {
cryptfs.Warn.Printf("Invalid name \"%s\" in dir \"%s\": %s\n", cName, dirName, err)
continue
@@ -103,7 +115,11 @@ func (fs *FS) Open(path string, flags uint32, context *fuse.Context) (fuseFile n
return nil, fuse.EPERM
}
iflags, writeOnly := fs.mangleOpenFlags(flags)
- f, err := os.OpenFile(fs.GetPath(path), iflags, 0666)
+ cPath, err := fs.getBackingPath(path)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ f, err := os.OpenFile(cPath, iflags, 0666)
if err != nil {
return nil, fuse.ToStatus(err)
}
@@ -116,7 +132,11 @@ func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Conte
return nil, fuse.EPERM
}
iflags, writeOnly := fs.mangleOpenFlags(flags)
- f, err := os.OpenFile(fs.GetPath(path), iflags|os.O_CREATE, os.FileMode(mode))
+ cPath, err := fs.getBackingPath(path)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ f, err := os.OpenFile(cPath, iflags|os.O_CREATE, os.FileMode(mode))
if err != nil {
return nil, fuse.ToStatus(err)
}
@@ -127,21 +147,33 @@ func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.
if fs.CryptFS.IsFiltered(path) {
return fuse.EPERM
}
- return fs.FileSystem.Chmod(fs.EncryptPath(path), mode, context)
+ cPath, err := fs.encryptPath(path)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fs.FileSystem.Chmod(cPath, mode, context)
}
func (fs *FS) Chown(path string, uid uint32, gid uint32, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(path) {
return fuse.EPERM
}
- return fs.FileSystem.Chown(fs.EncryptPath(path), uid, gid, context)
+ cPath, err := fs.encryptPath(path)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fs.FileSystem.Chown(cPath, uid, gid, context)
}
-func (fs *FS) Mknod(name string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) {
- if fs.CryptFS.IsFiltered(name) {
+func (fs *FS) Mknod(path string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) {
+ if fs.CryptFS.IsFiltered(path) {
return fuse.EPERM
}
- return fs.FileSystem.Mknod(fs.EncryptPath(name), mode, dev, context)
+ cPath, err := fs.encryptPath(path)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fs.FileSystem.Mknod(cPath, mode, dev, context)
}
func (fs *FS) Truncate(path string, offset uint64, context *fuse.Context) (code fuse.Status) {
@@ -153,15 +185,23 @@ func (fs *FS) Utimens(path string, Atime *time.Time, Mtime *time.Time, context *
if fs.CryptFS.IsFiltered(path) {
return fuse.EPERM
}
- return fs.FileSystem.Utimens(fs.EncryptPath(path), Atime, Mtime, context)
+ cPath, err := fs.encryptPath(path)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fs.FileSystem.Utimens(cPath, Atime, Mtime, context)
}
-func (fs *FS) Readlink(name string, context *fuse.Context) (out string, status fuse.Status) {
- dst, status := fs.FileSystem.Readlink(fs.EncryptPath(name), context)
+func (fs *FS) Readlink(path string, context *fuse.Context) (out string, status fuse.Status) {
+ cPath, err := fs.encryptPath(path)
+ if err != nil {
+ return "", fuse.ToStatus(err)
+ }
+ dst, status := fs.FileSystem.Readlink(cPath, context)
if status != fuse.OK {
return "", status
}
- dstPlain, err := fs.DecryptPath(dst)
+ dstPlain, err := fs.decryptPath(dst)
if err != nil {
cryptfs.Warn.Printf("Failed decrypting symlink: %s\n", err.Error())
return "", fuse.EIO
@@ -173,11 +213,14 @@ func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fu
if fs.CryptFS.IsFiltered(relPath) {
return fuse.EPERM
}
- encPath := fs.GetPath(relPath)
+ encPath, err := fs.getBackingPath(relPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
diriv := cryptfs.RandBytes(cryptfs.DIRIV_LEN)
dirivPath := filepath.Join(encPath, cryptfs.DIRIV_FILENAME)
// Create directory
- err := os.Mkdir(encPath, os.FileMode(mode))
+ err = os.Mkdir(encPath, os.FileMode(mode))
if err != nil {
return fuse.ToStatus(err)
}
@@ -196,20 +239,22 @@ func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fu
return fuse.OK
}
-func (fs *FS) Unlink(name string, context *fuse.Context) (code fuse.Status) {
- if fs.CryptFS.IsFiltered(name) {
+func (fs *FS) Unlink(path string, context *fuse.Context) (code fuse.Status) {
+ if fs.CryptFS.IsFiltered(path) {
return fuse.EPERM
}
- cName := fs.EncryptPath(name)
- code = fs.FileSystem.Unlink(cName, context)
- if code != fuse.OK {
- cryptfs.Debug.Printf("Unlink failed on %s [%s], code=%s\n", name, cName, code.String())
+ cPath, err := fs.getBackingPath(path)
+ if err != nil {
+ return fuse.ToStatus(err)
}
- return code
+ return fuse.ToStatus(syscall.Unlink(cPath))
}
func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
- encPath := fs.GetPath(name)
+ encPath, err := fs.getBackingPath(name)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
// If the directory is not empty besides gocryptfs.diriv, do not even
// attempt the dance around gocryptfs.diriv.
@@ -264,34 +309,61 @@ func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
return fuse.OK
}
-func (fs *FS) Symlink(pointedTo string, linkName 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) {
return fuse.EPERM
}
- // TODO symlink encryption
- cryptfs.Debug.Printf("Symlink(\"%s\", \"%s\")\n", pointedTo, linkName)
- return fs.FileSystem.Symlink(fs.EncryptPath(pointedTo), fs.EncryptPath(linkName), context)
+ cName, err := fs.encryptPath(linkName)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+
+ cBinTarget := fs.CryptFS.EncryptBlock([]byte(target), 0, nil)
+ cTarget := base64.URLEncoding.EncodeToString(cBinTarget)
+
+ return fuse.ToStatus(os.Symlink(cTarget, cName))
}
func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (code fuse.Status) {
if fs.CryptFS.IsFiltered(newPath) {
return fuse.EPERM
}
- return fs.FileSystem.Rename(fs.EncryptPath(oldPath), fs.EncryptPath(newPath), context)
+ cOldPath, err := fs.getBackingPath(oldPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ cNewPath, err := fs.getBackingPath(newPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fs.FileSystem.Rename(cOldPath, cNewPath, context)
}
-func (fs *FS) Link(orig string, newName string, context *fuse.Context) (code fuse.Status) {
- if fs.CryptFS.IsFiltered(newName) {
+func (fs *FS) Link(oldPath string, newPath string, context *fuse.Context) (code fuse.Status) {
+ if fs.CryptFS.IsFiltered(newPath) {
return fuse.EPERM
}
- return fs.FileSystem.Link(fs.EncryptPath(orig), fs.EncryptPath(newName), context)
+ cOldPath, err := fs.getBackingPath(oldPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ cNewPath, err := fs.getBackingPath(newPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fuse.ToStatus(os.Link(cOldPath, cNewPath))
}
-func (fs *FS) Access(name string, mode uint32, context *fuse.Context) (code fuse.Status) {
- if fs.CryptFS.IsFiltered(name) {
+func (fs *FS) Access(path string, mode uint32, context *fuse.Context) (code fuse.Status) {
+ if fs.CryptFS.IsFiltered(path) {
return fuse.EPERM
}
- return fs.FileSystem.Access(fs.EncryptPath(name), mode, context)
+ cPath, err := fs.getBackingPath(path)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fuse.ToStatus(syscall.Access(cPath, mode))
}
func (fs *FS) GetXAttr(name string, attr string, context *fuse.Context) ([]byte, fuse.Status) {
diff --git a/pathfs_frontend/names.go b/pathfs_frontend/names.go
new file mode 100644
index 0000000..5842d83
--- /dev/null
+++ b/pathfs_frontend/names.go
@@ -0,0 +1,11 @@
+package pathfs_frontend
+
+// This file handles filename encryption
+
+func (fs *FS) encryptPath(plainPath string) (string, error) {
+ return fs.CryptFS.EncryptPathDirIV(plainPath, fs.backingDir)
+}
+
+func (fs *FS) decryptPath(cipherPath string) (string, error) {
+ return fs.CryptFS.DecryptPathDirIV(cipherPath, fs.backingDir)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-01 10:22:06 +0000