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-rw-r--r--.gitignore7
-rw-r--r--cryptfs/cryptfs_content.go39
-rw-r--r--cryptfs/log.go2
-rw-r--r--main.go77
-rw-r--r--main_test.go2
-rw-r--r--pathfs_frontend/file.go235
-rw-r--r--pathfs_frontend/fs.go166
7 files changed, 509 insertions, 19 deletions
diff --git a/.gitignore b/.gitignore
index 8d65432..0929506 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,9 @@
# Binary
/gocryptfs
+
+# Manual test mounts
+/cipherdir
+/mountpoint
+
+# main_test.go temporary files
+/main_test_tmp
diff --git a/cryptfs/cryptfs_content.go b/cryptfs/cryptfs_content.go
index 4658529..e23d9b5 100644
--- a/cryptfs/cryptfs_content.go
+++ b/cryptfs/cryptfs_content.go
@@ -77,7 +77,7 @@ func (be *CryptFS) EncryptBlock(plaintext []byte) []byte {
return ciphertext
}
-// Split a plaintext byte range into (possible partial) blocks
+// Split a plaintext byte range into (possibly partial) blocks
func (be *CryptFS) SplitRange(offset uint64, length uint64) []intraBlock {
var b intraBlock
var parts []intraBlock
@@ -113,6 +113,22 @@ func (be *CryptFS) minu64(x uint64, y uint64) uint64 {
return y
}
+// CiphertextRange - Get byte range in backing ciphertext corresponding
+// to plaintext range. Returns a range aligned to ciphertext blocks.
+func (be *CryptFS) CiphertextRange(offset uint64, length uint64) (uint64, uint64, int) {
+ // Decrypting the ciphertext will yield too many plaintext bytes. Skip this number
+ // of bytes from the front.
+ skip := offset % be.plainBS
+
+ firstBlockNo := offset / be.plainBS
+ lastBlockNo := ( offset + length - 1 ) / be.plainBS
+
+ alignedOffset := firstBlockNo * be.cipherBS
+ alignedLength := (lastBlockNo - firstBlockNo + 1) * be.cipherBS
+
+ return alignedOffset, alignedLength, int(skip)
+}
+
// Get the byte range in the ciphertext corresponding to blocks
// (full blocks!)
func (be *CryptFS) JoinCiphertextRange(blocks []intraBlock) (uint64, uint64) {
@@ -138,3 +154,24 @@ func (be *CryptFS) CropPlaintext(plaintext []byte, blocks []intraBlock) []byte {
}
return cropped
}
+
+// MergeBlocks - Merge newData into oldData at offset
+// New block may be bigger than both newData and oldData
+func (be *CryptFS) MergeBlocks(oldData []byte, newData []byte, offset int) []byte {
+
+ // Make block of maximum size
+ out := make([]byte, be.plainBS)
+
+ // Copy old and new data into it
+ copy(out, oldData)
+ l := len(newData)
+ copy(out[offset:offset + l], newData)
+
+ // Crop to length
+ outLen := len(oldData)
+ newLen := offset + len(newData)
+ if outLen < newLen {
+ outLen = newLen
+ }
+ return out[0:outLen]
+}
diff --git a/cryptfs/log.go b/cryptfs/log.go
index f9c46c8..8233529 100644
--- a/cryptfs/log.go
+++ b/cryptfs/log.go
@@ -15,5 +15,5 @@ func (l logChannel) Printf(format string, args ...interface{}) {
}
-var Debug = logChannel{false}
+var Debug = logChannel{true}
var Warn = logChannel{true}
diff --git a/main.go b/main.go
index c279612..2a140ab 100644
--- a/main.go
+++ b/main.go
@@ -1,18 +1,29 @@
package main
import (
- "bazil.org/fuse"
- fusefs "bazil.org/fuse/fs"
"flag"
"fmt"
- frontend "github.com/rfjakob/gocryptfs/cluefs_frontend"
"os"
"path/filepath"
+ "time"
+
+ "github.com/rfjakob/gocryptfs/cluefs_frontend"
+ "github.com/rfjakob/gocryptfs/pathfs_frontend"
+
+ bazilfuse "bazil.org/fuse"
+ bazilfusefs "bazil.org/fuse/fs"
+
+ "github.com/hanwen/go-fuse/fuse"
+ "github.com/hanwen/go-fuse/fuse/nodefs"
+ "github.com/hanwen/go-fuse/fuse/pathfs"
)
const (
+ USE_CLUEFS = false
+ USE_OPENSSL = false
+ PATHFS_DEBUG = false
+
PROGRAM_NAME = "gocryptfs"
- USE_OPENSSL = true
ERREXIT_USAGE = 1
ERREXIT_NEWFS = 2
@@ -29,27 +40,34 @@ func main() {
fmt.Printf("usage: %s CIPHERDIR MOUNTPOINT\n", PROGRAM_NAME)
os.Exit(ERREXIT_USAGE)
}
-
cipherdir, _ := filepath.Abs(flag.Arg(0))
- mountpoint, err := filepath.Abs(flag.Arg(1))
+ mountpoint, _ := filepath.Abs(flag.Arg(1))
- // Create the file system object
var key [16]byte
- cfs, err := frontend.NewFS(key, cipherdir, USE_OPENSSL)
+
+ if USE_CLUEFS {
+ cluefsFrontend(key, cipherdir, mountpoint)
+ } else {
+ pathfsFrontend(key, cipherdir, mountpoint)
+ }
+}
+
+func cluefsFrontend(key [16]byte, cipherdir string, mountpoint string) {
+ cfs, err := cluefs_frontend.NewFS(key, cipherdir, USE_OPENSSL)
if err != nil {
fmt.Println(err)
os.Exit(ERREXIT_NEWFS)
}
// Mount the file system
- mountOpts := []fuse.MountOption{
- fuse.FSName(PROGRAM_NAME),
- fuse.Subtype(PROGRAM_NAME),
- fuse.VolumeName(PROGRAM_NAME),
- fuse.LocalVolume(),
- fuse.MaxReadahead(1024 * 1024),
+ mountOpts := []bazilfuse.MountOption{
+ bazilfuse.FSName(PROGRAM_NAME),
+ bazilfuse.Subtype(PROGRAM_NAME),
+ bazilfuse.VolumeName(PROGRAM_NAME),
+ bazilfuse.LocalVolume(),
+ bazilfuse.MaxReadahead(1024 * 1024),
}
- conn, err := fuse.Mount(mountpoint, mountOpts...)
+ conn, err := bazilfuse.Mount(mountpoint, mountOpts...)
if err != nil {
fmt.Println(err)
os.Exit(ERREXIT_MOUNT)
@@ -57,7 +75,7 @@ func main() {
defer conn.Close()
// Start serving requests
- if err = fusefs.Serve(conn, cfs); err != nil {
+ if err = bazilfusefs.Serve(conn, cfs); err != nil {
fmt.Println(err)
os.Exit(ERREXIT_SERVE)
}
@@ -72,3 +90,30 @@ func main() {
// We are done
os.Exit(0)
}
+
+func pathfsFrontend(key [16]byte, cipherdir string, mountpoint string){
+
+ finalFs := pathfs_frontend.NewFS(key, cipherdir, USE_OPENSSL)
+
+ opts := &nodefs.Options{
+ // These options are to be compatible with libfuse defaults,
+ // making benchmarking easier.
+ NegativeTimeout: time.Second,
+ AttrTimeout: time.Second,
+ EntryTimeout: time.Second,
+ }
+ pathFs := pathfs.NewPathNodeFs(finalFs, nil)
+ conn := nodefs.NewFileSystemConnector(pathFs.Root(), opts)
+ mOpts := &fuse.MountOptions{
+ AllowOther: false,
+ }
+ state, err := fuse.NewServer(conn.RawFS(), mountpoint, mOpts)
+ if err != nil {
+ fmt.Printf("Mount fail: %v\n", err)
+ os.Exit(1)
+ }
+ state.SetDebug(PATHFS_DEBUG)
+
+ fmt.Println("Mounted!")
+ state.Serve()
+}
diff --git a/main_test.go b/main_test.go
index 6b68b4a..70dbbe2 100644
--- a/main_test.go
+++ b/main_test.go
@@ -12,7 +12,7 @@ import (
"time"
)
-const tmpDir = "test_tmp_dir/"
+const tmpDir = "main_test_tmp/"
const plainDir = tmpDir + "plain/"
const cipherDir = tmpDir + "cipher/"
diff --git a/pathfs_frontend/file.go b/pathfs_frontend/file.go
new file mode 100644
index 0000000..8b6d61d
--- /dev/null
+++ b/pathfs_frontend/file.go
@@ -0,0 +1,235 @@
+package pathfs_frontend
+
+import (
+ "io"
+ "bytes"
+ "fmt"
+ "os"
+ "sync"
+ "syscall"
+ "time"
+
+ "github.com/hanwen/go-fuse/fuse"
+ "github.com/hanwen/go-fuse/fuse/nodefs"
+ "github.com/rfjakob/gocryptfs/cryptfs"
+)
+
+// File - based on loopbackFile in go-fuse/fuse/nodefs/files.go
+type file struct {
+ fd *os.File
+
+ // os.File is not threadsafe. Although fd themselves are
+ // constant during the lifetime of an open file, the OS may
+ // reuse the fd number after it is closed. When open races
+ // with another close, they may lead to confusion as which
+ // file gets written in the end.
+ lock sync.Mutex
+
+ // Was the file opened O_WRONLY?
+ writeOnly bool
+
+ // Parent CryptFS
+ cfs *cryptfs.CryptFS
+}
+
+func NewFile(fd *os.File, writeOnly bool, cfs *cryptfs.CryptFS) nodefs.File {
+ return &file{
+ fd: fd,
+ writeOnly: writeOnly,
+ cfs: cfs,
+ }
+}
+
+func (f *file) InnerFile() nodefs.File {
+ return nil
+}
+
+func (f *file) SetInode(n *nodefs.Inode) {
+}
+
+func (f *file) String() string {
+ return fmt.Sprintf("cryptFile(%s)", f.fd.Name())
+}
+
+// Read - FUSE call
+func (f *file) Read(buf []byte, off int64) (resultData fuse.ReadResult, code fuse.Status) {
+ cryptfs.Debug.Printf("\n\nGot read request: len=%d off=%d\n", len(buf), off)
+
+ if f.writeOnly {
+ return nil, fuse.EBADF
+ }
+
+ // Read the backing ciphertext in one go
+ alignedOffset, alignedLength, skip := f.cfs.CiphertextRange(uint64(off), uint64(len(buf)))
+ ciphertext := make([]byte, int(alignedLength))
+ _, err := f.fd.ReadAt(ciphertext, int64(alignedOffset))
+ if err != nil && err != io.EOF {
+ cryptfs.Warn.Printf("Read error: %s\n", err.Error())
+ return nil, fuse.ToStatus(err)
+ }
+
+ // Decrypt it
+ plaintext, err := f.cfs.DecryptBlocks(ciphertext)
+ if err != nil {
+ cryptfs.Warn.Printf("Decryption error: %s\n", err.Error())
+ return nil, fuse.EIO
+ }
+
+ // Crop down to the relevant part
+ var out []byte
+ lenHave := len(plaintext)
+ lenWant := skip + len(buf)
+ if lenHave > lenWant {
+ out = plaintext[skip:skip + len(buf)]
+ } else if lenHave > skip {
+ out = plaintext[skip:lenHave]
+ }
+ // else: out stays empty
+
+ fmt.Printf("Read: returning %d bytes\n", len(plaintext))
+
+ return fuse.ReadResultData(out), fuse.OK
+}
+
+// Write - FUSE call
+func (f *file) Write(data []byte, off int64) (uint32, fuse.Status) {
+ var written uint32
+ var status fuse.Status
+ dataBuf := bytes.NewBuffer(data)
+ blocks := f.cfs.SplitRange(uint64(off), uint64(len(data)))
+ for _, b := range(blocks) {
+
+ blockData := dataBuf.Next(int(b.Length))
+
+ // Incomplete block -> Read-Modify-Write
+ if b.IsPartial() {
+ // Read
+ oldData := make([]byte, f.cfs.PlainBS())
+ o, _ := b.PlaintextRange()
+ res, status := f.Read(oldData, int64(o))
+ oldData, _ = res.Bytes(oldData)
+ if status != fuse.OK {
+ return written, status
+ }
+ // Modify
+ blockData = f.cfs.MergeBlocks(oldData, blockData, int(b.Offset))
+ }
+ // Write
+ blockOffset, _ := b.CiphertextRange()
+ blockData = f.cfs.EncryptBlock(blockData)
+ _, err := f.fd.WriteAt(blockData, int64(blockOffset))
+
+ if err != nil {
+ cryptfs.Warn.Printf("Write failed: %s\n", err.Error())
+ status = fuse.ToStatus(err)
+ break
+ }
+ written += uint32(b.Length)
+ }
+
+ return written, status
+}
+
+// Release - FUSE call, forget file
+func (f *file) Release() {
+ f.lock.Lock()
+ f.fd.Close()
+ f.lock.Unlock()
+}
+
+// Flush - FUSE call
+func (f *file) Flush() fuse.Status {
+ f.lock.Lock()
+
+ // Since Flush() may be called for each dup'd fd, we don't
+ // want to really close the file, we just want to flush. This
+ // is achieved by closing a dup'd fd.
+ newFd, err := syscall.Dup(int(f.fd.Fd()))
+ f.lock.Unlock()
+
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ err = syscall.Close(newFd)
+ return fuse.ToStatus(err)
+}
+
+func (f *file) Fsync(flags int) (code fuse.Status) {
+ f.lock.Lock()
+ r := fuse.ToStatus(syscall.Fsync(int(f.fd.Fd())))
+ f.lock.Unlock()
+
+ return r
+}
+
+func (f *file) Truncate(size uint64) fuse.Status {
+ f.lock.Lock()
+ r := fuse.ToStatus(syscall.Ftruncate(int(f.fd.Fd()), int64(size)))
+ f.lock.Unlock()
+
+ return r
+}
+
+func (f *file) Chmod(mode uint32) fuse.Status {
+ f.lock.Lock()
+ r := fuse.ToStatus(f.fd.Chmod(os.FileMode(mode)))
+ f.lock.Unlock()
+
+ return r
+}
+
+func (f *file) Chown(uid uint32, gid uint32) fuse.Status {
+ f.lock.Lock()
+ r := fuse.ToStatus(f.fd.Chown(int(uid), int(gid)))
+ f.lock.Unlock()
+
+ return r
+}
+
+func (f *file) GetAttr(a *fuse.Attr) fuse.Status {
+ st := syscall.Stat_t{}
+ f.lock.Lock()
+ err := syscall.Fstat(int(f.fd.Fd()), &st)
+ f.lock.Unlock()
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ a.FromStat(&st)
+
+ return fuse.OK
+}
+
+func (f *file) Allocate(off uint64, sz uint64, mode uint32) fuse.Status {
+ f.lock.Lock()
+ err := syscall.Fallocate(int(f.fd.Fd()), mode, int64(off), int64(sz))
+ f.lock.Unlock()
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fuse.OK
+}
+
+const _UTIME_NOW = ((1 << 30) - 1)
+const _UTIME_OMIT = ((1 << 30) - 2)
+
+func (f *file) Utimens(a *time.Time, m *time.Time) fuse.Status {
+ tv := make([]syscall.Timeval, 2)
+ if a == nil {
+ tv[0].Usec = _UTIME_OMIT
+ } else {
+ n := a.UnixNano()
+ tv[0] = syscall.NsecToTimeval(n)
+ }
+
+ if m == nil {
+ tv[1].Usec = _UTIME_OMIT
+ } else {
+ n := a.UnixNano()
+ tv[1] = syscall.NsecToTimeval(n)
+ }
+
+ f.lock.Lock()
+ err := syscall.Futimes(int(f.fd.Fd()), tv)
+ f.lock.Unlock()
+ return fuse.ToStatus(err)
+}
diff --git a/pathfs_frontend/fs.go b/pathfs_frontend/fs.go
new file mode 100644
index 0000000..2f73462
--- /dev/null
+++ b/pathfs_frontend/fs.go
@@ -0,0 +1,166 @@
+package pathfs_frontend
+
+import (
+ "os"
+ "path/filepath"
+ "time"
+ "fmt"
+
+ "github.com/hanwen/go-fuse/fuse"
+ "github.com/hanwen/go-fuse/fuse/nodefs"
+ "github.com/hanwen/go-fuse/fuse/pathfs"
+ "github.com/rfjakob/gocryptfs/cryptfs"
+)
+
+type FS struct {
+ *cryptfs.CryptFS
+ pathfs.FileSystem // loopbackFileSystem
+ backing string // Backing directory
+}
+
+// Encrypted FUSE overlay filesystem
+func NewFS(key [16]byte, backing string, useOpenssl bool) *FS {
+ return &FS{
+ CryptFS: cryptfs.NewCryptFS(key, useOpenssl),
+ FileSystem: pathfs.NewLoopbackFileSystem(backing),
+ backing: backing,
+
+ }
+}
+
+// GetPath - get the absolute path of the backing file
+func (fs *FS) GetPath(relPath string) string {
+ return filepath.Join(fs.backing, fs.EncryptPath(relPath))
+}
+
+func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) {
+ a, status := fs.FileSystem.GetAttr(fs.EncryptPath(name), context)
+ if a == nil {
+ return a, status
+ }
+
+ a.Size = fs.PlainSize(a.Size)
+ return a, status
+}
+
+func (fs *FS) OpenDir(name string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) {
+ cipherEntries, status := fs.FileSystem.OpenDir(fs.EncryptPath(name), context);
+ var plain []fuse.DirEntry
+ var skipped int
+ if cipherEntries != nil {
+ for i := range cipherEntries {
+ n, err := fs.DecryptPath(cipherEntries[i].Name)
+ if err != nil {
+ fmt.Printf("Skipping invalid filename \"%s\": %s\n", cipherEntries[i].Name, err)
+ skipped++
+ continue
+ }
+ cipherEntries[i].Name = n
+ plain = append(plain, cipherEntries[i])
+ }
+ }
+ return plain, status
+}
+
+// We always need read access to do read-modify-write cycles
+func (fs *FS) mangleOpenFlags(flags uint32) (newFlags int, writeOnly bool) {
+ newFlags = int(flags)
+ if newFlags & os.O_WRONLY > 0 {
+ writeOnly = true
+ newFlags = newFlags ^ os.O_WRONLY | os.O_RDWR
+ }
+ // We also cannot open the file in append mode, we need to seek back for RMW
+ newFlags = newFlags &^ os.O_APPEND
+
+ return newFlags, writeOnly
+}
+
+func (fs *FS) Open(name string, flags uint32, context *fuse.Context) (fuseFile nodefs.File, status fuse.Status) {
+ cryptfs.Debug.Printf("Open(%s)\n", name)
+
+ iflags, writeOnly := fs.mangleOpenFlags(flags)
+ f, err := os.OpenFile(fs.GetPath(name), iflags, 0666)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+
+ return NewFile(f, writeOnly, fs.CryptFS), fuse.OK
+}
+
+func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Context) (fuseFile nodefs.File, code fuse.Status) {
+ iflags, writeOnly := fs.mangleOpenFlags(flags)
+ f, err := os.OpenFile(fs.GetPath(path), iflags|os.O_CREATE, os.FileMode(mode))
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ return NewFile(f, writeOnly, fs.CryptFS), fuse.OK
+}
+
+func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Chmod(fs.EncryptPath(path), mode, context)
+}
+
+func (fs *FS) Chown(path string, uid uint32, gid uint32, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Chmod(fs.EncryptPath(path), gid, context)
+}
+
+func (fs *FS) Truncate(path string, offset uint64, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Truncate(fs.EncryptPath(path), offset, context)
+}
+
+func (fs *FS) Utimens(path string, Atime *time.Time, Mtime *time.Time, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Utimens(fs.EncryptPath(path), Atime, Mtime, context)
+}
+
+func (fs *FS) Readlink(name string, context *fuse.Context) (out string, code fuse.Status) {
+ return fs.FileSystem.Readlink(fs.EncryptPath(name), context)
+}
+
+func (fs *FS) Mknod(name string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Mknod(fs.EncryptPath(name), mode, dev, context)
+}
+
+func (fs *FS) Mkdir(path string, mode uint32, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Mkdir(fs.EncryptPath(path), mode, context)
+}
+
+func (fs *FS) Unlink(name string, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Unlink(fs.EncryptPath(name), context)
+}
+
+func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Rmdir(fs.EncryptPath(name), context)
+}
+
+func (fs *FS) Symlink(pointedTo string, linkName string, context *fuse.Context) (code fuse.Status) {
+ // TODO symlink encryption
+ return fs.FileSystem.Symlink(fs.EncryptPath(pointedTo), fs.EncryptPath(linkName), context)
+}
+
+func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (codee fuse.Status) {
+ return fs.FileSystem.Rename(fs.EncryptPath(oldPath), fs.EncryptPath(newPath), context)
+}
+
+func (fs *FS) Link(orig string, newName string, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Link(fs.EncryptPath(orig), fs.EncryptPath(newName), context)
+}
+
+func (fs *FS) Access(name string, mode uint32, context *fuse.Context) (code fuse.Status) {
+ return fs.FileSystem.Access(fs.EncryptPath(name), mode, context)
+}
+
+func (fs *FS) GetXAttr(name string, attr string, context *fuse.Context) ([]byte, fuse.Status) {
+ return nil, fuse.ENOSYS
+}
+
+func (fs *FS) SetXAttr(name string, attr string, data []byte, flags int, context *fuse.Context) fuse.Status {
+ return fuse.ENOSYS
+}
+
+func (fs *FS) ListXAttr(name string, context *fuse.Context) ([]string, fuse.Status) {
+ return nil, fuse.ENOSYS
+}
+
+func (fs *FS) RemoveXAttr(name string, attr string, context *fuse.Context) fuse.Status {
+ return fuse.ENOSYS
+}