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-rw-r--r--cryptfs/nonce.go7
-rw-r--r--integration_tests/helpers.go32
-rw-r--r--main.go7
-rw-r--r--pathfs_frontend/fs.go99
-rw-r--r--pathfs_frontend/fs_dir.go151
5 files changed, 196 insertions, 100 deletions
diff --git a/cryptfs/nonce.go b/cryptfs/nonce.go
index 9bdbb09..a122ea5 100644
--- a/cryptfs/nonce.go
+++ b/cryptfs/nonce.go
@@ -1,6 +1,7 @@
package cryptfs
import (
+ "encoding/binary"
"bytes"
"crypto/rand"
"encoding/hex"
@@ -17,6 +18,12 @@ func RandBytes(n int) []byte {
return b
}
+// Return a secure random uint64
+func RandUint64() uint64 {
+ b := RandBytes(8)
+ return binary.BigEndian.Uint64(b)
+}
+
var gcmNonce nonce96
type nonce96 struct {
diff --git a/integration_tests/helpers.go b/integration_tests/helpers.go
index b269069..750283d 100644
--- a/integration_tests/helpers.go
+++ b/integration_tests/helpers.go
@@ -127,6 +127,38 @@ func testMkdirRmdir(t *testing.T, plainDir string) {
if err != nil {
t.Fatal(err)
}
+
+ // Removing a non-empty dir should fail with ENOTEMPTY
+ if os.Mkdir(dir, 0777) != nil {
+ t.Fatal(err)
+ }
+ f, err := os.Create(dir + "/file")
+ if err != nil {
+ t.Fatal(err)
+ }
+ f.Close()
+ err = syscall.Rmdir(dir)
+ errno := err.(syscall.Errno)
+ if errno != syscall.ENOTEMPTY {
+ t.Errorf("Should have gotten ENOTEMPTY, go %v", errno)
+ }
+ if syscall.Unlink(dir + "/file") != nil {
+ t.Fatal(err)
+ }
+ if syscall.Rmdir(dir) != nil {
+ t.Fatal(err)
+ }
+
+ // We should also be able to remove a directory we do not have permissions to
+ // read or write
+ err = os.Mkdir(dir, 0000)
+ if err != nil {
+ t.Fatal(err)
+ }
+ err = syscall.Rmdir(dir)
+ if err != nil {
+ t.Fatal(err)
+ }
}
// Create and rename a file
diff --git a/main.go b/main.go
index 21d8ed6..49b13d1 100644
--- a/main.go
+++ b/main.go
@@ -159,7 +159,7 @@ func main() {
"Setting this to a lower value speeds up mounting but makes the password susceptible to brute-force attacks")
flagSet.Parse(os.Args[1:])
- // Fork a child into the background if "-f" is not set and we are mounting a filesystem
+ // Fork a child into the background if "-f" is not set AND we are mounting a filesystem
if !args.foreground && flagSet.NArg() == 2 {
forkChild() // does not return
}
@@ -339,6 +339,11 @@ func pathfsFrontend(key []byte, args argContainer, confFile *cryptfs.ConfFile) *
}
srv.SetDebug(args.fusedebug)
+ // All FUSE file and directory create calls carry explicit permission
+ // information. We need an unrestricted umask to create the files and
+ // directories with the requested permissions.
+ syscall.Umask(0000)
+
return srv
}
diff --git a/pathfs_frontend/fs.go b/pathfs_frontend/fs.go
index 8d05c02..c7a9888 100644
--- a/pathfs_frontend/fs.go
+++ b/pathfs_frontend/fs.go
@@ -2,7 +2,6 @@ package pathfs_frontend
import (
"encoding/base64"
- "fmt"
"os"
"path/filepath"
"sync"
@@ -245,40 +244,7 @@ func (fs *FS) Readlink(path string, context *fuse.Context) (out string, status f
return string(target), fuse.OK
}
-func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fuse.Status) {
- if fs.isFiltered(relPath) {
- return fuse.EPERM
- }
- encPath, err := fs.getBackingPath(relPath)
- if err != nil {
- return fuse.ToStatus(err)
- }
- if !fs.args.DirIV {
- return fuse.ToStatus(os.Mkdir(encPath, os.FileMode(mode)))
- }
- // The new directory may take the place of an older one that is still in the cache
- fs.CryptFS.DirIVCacheEnc.Clear()
- // Create directory
- fs.dirIVLock.Lock()
- defer fs.dirIVLock.Unlock()
- err = os.Mkdir(encPath, os.FileMode(mode))
- if err != nil {
- return fuse.ToStatus(err)
- }
- // Create gocryptfs.diriv inside
- err = cryptfs.WriteDirIV(encPath)
- if err != nil {
- // This should not happen
- cryptfs.Warn.Printf("Creating %s in dir %s failed: %v\n", cryptfs.DIRIV_FILENAME, encPath, err)
- err2 := syscall.Rmdir(encPath)
- if err2 != nil {
- cryptfs.Warn.Printf("Mkdir: Rollback failed: %v\n", err2)
- }
- return fuse.ToStatus(err)
- }
- return fuse.OK
-}
func (fs *FS) Unlink(path string, context *fuse.Context) (code fuse.Status) {
if fs.isFiltered(path) {
@@ -291,71 +257,6 @@ func (fs *FS) Unlink(path string, context *fuse.Context) (code fuse.Status) {
return fuse.ToStatus(syscall.Unlink(cPath))
}
-func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
- encPath, err := fs.getBackingPath(name)
- if err != nil {
- return fuse.ToStatus(err)
- }
- if !fs.args.DirIV {
- return fuse.ToStatus(syscall.Rmdir(encPath))
- }
-
- // If the directory is not empty besides gocryptfs.diriv, do not even
- // attempt the dance around gocryptfs.diriv.
- fd, err := os.Open(encPath)
- if err != nil {
- return fuse.ToStatus(err)
- }
- defer fd.Close()
- list, err := fd.Readdirnames(10)
- if err != nil {
- return fuse.ToStatus(err)
- }
- if len(list) > 1 {
- return fuse.ToStatus(syscall.ENOTEMPTY)
- }
-
- // Move "gocryptfs.diriv" to the parent dir under name "gocryptfs.diriv.rmdir.INODENUMBER"
- var st syscall.Stat_t
- err = syscall.Fstat(int(fd.Fd()), &st)
- if err != nil {
- return fuse.ToStatus(err)
- }
- dirivPath := filepath.Join(encPath, cryptfs.DIRIV_FILENAME)
- parentDir := filepath.Dir(encPath)
- tmpName := fmt.Sprintf("gocryptfs.diriv.rmdir.%d", st.Ino)
- tmpDirivPath := filepath.Join(parentDir, tmpName)
- cryptfs.Debug.Printf("Rmdir: Renaming %s to %s\n", cryptfs.DIRIV_FILENAME, tmpDirivPath)
- // The directory is in an inconsistent state between rename and rmdir. Protect against
- // concurrent readers.
- fs.dirIVLock.Lock()
- defer fs.dirIVLock.Unlock()
- err = os.Rename(dirivPath, tmpDirivPath)
- if err != nil {
- cryptfs.Warn.Printf("Rmdir: Renaming %s to %s failed: %v\n", cryptfs.DIRIV_FILENAME, tmpDirivPath, err)
- return fuse.ToStatus(err)
- }
- // Actual Rmdir
- err = syscall.Rmdir(encPath)
- if err != nil {
- // This can happen if another file in the directory was created in the
- // meantime, undo the rename
- err2 := os.Rename(tmpDirivPath, dirivPath)
- if err2 != nil {
- cryptfs.Warn.Printf("Rmdir: Rollback failed: %v\n", err2)
- }
- return fuse.ToStatus(err)
- }
- // Delete "gocryptfs.diriv.rmdir.INODENUMBER"
- err = syscall.Unlink(tmpDirivPath)
- if err != nil {
- cryptfs.Warn.Printf("Rmdir: Could not clean up %s: %v\n", tmpName, err)
- }
- // The now-deleted directory may have been in the DirIV cache. Clear it.
- fs.CryptFS.DirIVCacheEnc.Clear()
- return fuse.OK
-}
-
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.isFiltered(linkName) {
diff --git a/pathfs_frontend/fs_dir.go b/pathfs_frontend/fs_dir.go
new file mode 100644
index 0000000..95257bb
--- /dev/null
+++ b/pathfs_frontend/fs_dir.go
@@ -0,0 +1,151 @@
+package pathfs_frontend
+
+import (
+ "os"
+ "path/filepath"
+ "syscall"
+ "fmt"
+
+ "github.com/hanwen/go-fuse/fuse"
+ "github.com/rfjakob/gocryptfs/cryptfs"
+)
+
+func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fuse.Status) {
+ if fs.isFiltered(relPath) {
+ return fuse.EPERM
+ }
+ encPath, err := fs.getBackingPath(relPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ if !fs.args.DirIV {
+ return fuse.ToStatus(os.Mkdir(encPath, os.FileMode(mode)))
+ }
+
+ // We need write and execute permissions to create gocryptfs.diriv
+ origMode := mode
+ mode = mode | 0300
+
+ // The new directory may take the place of an older one that is still in the cache
+ fs.CryptFS.DirIVCacheEnc.Clear()
+ // Create directory
+ fs.dirIVLock.Lock()
+ defer fs.dirIVLock.Unlock()
+ err = os.Mkdir(encPath, os.FileMode(mode))
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ // Create gocryptfs.diriv inside
+ err = cryptfs.WriteDirIV(encPath)
+ if err != nil {
+ // This should not happen
+ cryptfs.Warn.Printf("Mkdir: WriteDirIV failed: %v\n", err)
+ err2 := syscall.Rmdir(encPath)
+ if err2 != nil {
+ cryptfs.Warn.Printf("Mkdir: Rmdir rollback failed: %v\n", err2)
+ }
+ return fuse.ToStatus(err)
+ }
+
+ // Set permissions back to what the user wanted
+ if origMode != mode {
+ err = os.Chmod(encPath, os.FileMode(origMode))
+ if err != nil {
+ cryptfs.Warn.Printf("Mkdir: Chmod failed: %v\n", err)
+ }
+ }
+
+ return fuse.OK
+}
+
+func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
+ encPath, err := fs.getBackingPath(name)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ if !fs.args.DirIV {
+ return fuse.ToStatus(syscall.Rmdir(encPath))
+ }
+
+ // If the directory is not empty besides gocryptfs.diriv, do not even
+ // attempt the dance around gocryptfs.diriv.
+ fd, err := os.Open(encPath)
+ if perr, ok := err.(*os.PathError); ok && perr.Err == syscall.EACCES {
+ // We need permission to read and modify the directory
+ cryptfs.Debug.Printf("Rmdir: handling EACCESS\n")
+ fi, err2 := os.Stat(encPath)
+ if err2 != nil {
+ cryptfs.Debug.Printf("Rmdir: Stat: %v\n", err2)
+ return fuse.ToStatus(err2)
+ }
+ origMode := fi.Mode()
+ newMode := origMode | 0700
+ err2 = os.Chmod(encPath, newMode)
+ if err2 != nil {
+ cryptfs.Debug.Printf("Rmdir: Chmod failed: %v\n", err2)
+ return fuse.ToStatus(err)
+ }
+ defer func () {
+ if code != fuse.OK {
+ // Undo the chmod if removing the directory failed
+ err3 := os.Chmod(encPath, origMode)
+ if err3 != nil {
+ cryptfs.Warn.Printf("Rmdir: Chmod rollback failed: %v\n", err2)
+ }
+ }
+ }()
+ // Retry open
+ fd, err = os.Open(encPath)
+ }
+ if err != nil {
+ cryptfs.Debug.Printf("Rmdir: Open: %v\n", err)
+ return fuse.ToStatus(err)
+ }
+ list, err := fd.Readdirnames(10)
+ fd.Close()
+ if err != nil {
+ cryptfs.Debug.Printf("Rmdir: Readdirnames: %v\n", err)
+ return fuse.ToStatus(err)
+ }
+ if len(list) > 1 {
+ return fuse.ToStatus(syscall.ENOTEMPTY)
+ } else if len(list) == 0 {
+ cryptfs.Warn.Printf("Rmdir: gocryptfs.diriv missing, allowing deletion\n")
+ return fuse.ToStatus(syscall.Rmdir(encPath))
+ }
+
+ // Move "gocryptfs.diriv" to the parent dir as "gocryptfs.diriv.rmdir.XYZ"
+ dirivPath := filepath.Join(encPath, cryptfs.DIRIV_FILENAME)
+ parentDir := filepath.Dir(encPath)
+ tmpName := fmt.Sprintf("gocryptfs.diriv.rmdir.%d", cryptfs.RandUint64())
+ tmpDirivPath := filepath.Join(parentDir, tmpName)
+ cryptfs.Debug.Printf("Rmdir: Renaming %s to %s\n", cryptfs.DIRIV_FILENAME, tmpDirivPath)
+ // The directory is in an inconsistent state between rename and rmdir. Protect against
+ // concurrent readers.
+ fs.dirIVLock.Lock()
+ defer fs.dirIVLock.Unlock()
+ err = os.Rename(dirivPath, tmpDirivPath)
+ if err != nil {
+ cryptfs.Warn.Printf("Rmdir: Renaming %s to %s failed: %v\n", cryptfs.DIRIV_FILENAME, tmpDirivPath, err)
+ return fuse.ToStatus(err)
+ }
+ // Actual Rmdir
+ err = syscall.Rmdir(encPath)
+ if err != nil {
+ // This can happen if another file in the directory was created in the
+ // meantime, undo the rename
+ err2 := os.Rename(tmpDirivPath, dirivPath)
+ if err2 != nil {
+ cryptfs.Warn.Printf("Rmdir: Rename rollback failed: %v\n", err2)
+ }
+ return fuse.ToStatus(err)
+ }
+ // Delete "gocryptfs.diriv.rmdir.INODENUMBER"
+ err = syscall.Unlink(tmpDirivPath)
+ if err != nil {
+ cryptfs.Warn.Printf("Rmdir: Could not clean up %s: %v\n", tmpName, err)
+ }
+ // The now-deleted directory may have been in the DirIV cache. Clear it.
+ fs.CryptFS.DirIVCacheEnc.Clear()
+ return fuse.OK
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-03 05:23:00 +0000