diff options
Diffstat (limited to 'pathfs_frontend/fs.go')
| -rw-r--r-- | pathfs_frontend/fs.go | 381 |
1 files changed, 0 insertions, 381 deletions
diff --git a/pathfs_frontend/fs.go b/pathfs_frontend/fs.go deleted file mode 100644 index 212f0a7..0000000 --- a/pathfs_frontend/fs.go +++ /dev/null @@ -1,381 +0,0 @@ -package pathfs_frontend - -// FUSE operations on paths - -import ( - "encoding/base64" - "os" - "path/filepath" - "sync" - "syscall" - "time" - - "github.com/hanwen/go-fuse/fuse" - "github.com/hanwen/go-fuse/fuse/nodefs" - "github.com/hanwen/go-fuse/fuse/pathfs" - - "github.com/rfjakob/gocryptfs/internal/toggledlog" - "github.com/rfjakob/gocryptfs/internal/cryptocore" - "github.com/rfjakob/gocryptfs/internal/nametransform" - "github.com/rfjakob/gocryptfs/internal/contentenc" - "github.com/rfjakob/gocryptfs/internal/configfile" -) - -const plainBS = 4096 - -type FS struct { - pathfs.FileSystem // loopbackFileSystem, see go-fuse/fuse/pathfs/loopback.go - args Args // Stores configuration arguments - // dirIVLock: Lock()ed if any "gocryptfs.diriv" file is modified - // Readers must RLock() it to prevent them from seeing intermediate - // states - dirIVLock sync.RWMutex - // Filename encryption helper - nameTransform *nametransform.NameTransform - // Content encryption helper - contentEnc *contentenc.ContentEnc -} - -// Encrypted FUSE overlay filesystem -func NewFS(args Args) *FS { - - cryptoCore := cryptocore.New(args.Masterkey, args.OpenSSL, args.GCMIV128) - contentEnc := contentenc.New(cryptoCore, plainBS) - nameTransform := nametransform.New(cryptoCore, args.EMENames) - - return &FS{ - FileSystem: pathfs.NewLoopbackFileSystem(args.Cipherdir), - args: args, - nameTransform: nameTransform, - contentEnc: contentEnc, - } -} - -// GetBackingPath - get the absolute encrypted path of the backing file -// from the relative plaintext path "relPath" -func (fs *FS) getBackingPath(relPath string) (string, error) { - cPath, err := fs.encryptPath(relPath) - if err != nil { - return "", err - } - cAbsPath := filepath.Join(fs.args.Cipherdir, cPath) - toggledlog.Debug.Printf("getBackingPath: %s + %s -> %s", fs.args.Cipherdir, relPath, cAbsPath) - return cAbsPath, nil -} - -func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) { - toggledlog.Debug.Printf("FS.GetAttr('%s')", name) - if fs.isFiltered(name) { - return nil, fuse.EPERM - } - cName, err := fs.encryptPath(name) - if err != nil { - return nil, fuse.ToStatus(err) - } - a, status := fs.FileSystem.GetAttr(cName, context) - if a == nil { - toggledlog.Debug.Printf("FS.GetAttr failed: %s", status.String()) - return a, status - } - if a.IsRegular() { - a.Size = fs.contentEnc.CipherSizeToPlainSize(a.Size) - } else if a.IsSymlink() { - target, _ := fs.Readlink(name, context) - a.Size = uint64(len(target)) - } - return a, status -} - -func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) { - toggledlog.Debug.Printf("OpenDir(%s)", dirName) - cDirName, err := fs.encryptPath(dirName) - if err != nil { - return nil, fuse.ToStatus(err) - } - // Read ciphertext directory - cipherEntries, status := fs.FileSystem.OpenDir(cDirName, context) - if cipherEntries == nil { - return nil, status - } - // Get DirIV (stays nil if DirIV if off) - var cachedIV []byte - if fs.args.DirIV { - // Read the DirIV once and use it for all later name decryptions - cDirAbsPath := filepath.Join(fs.args.Cipherdir, cDirName) - cachedIV, err = fs.nameTransform.ReadDirIV(cDirAbsPath) - if err != nil { - return nil, fuse.ToStatus(err) - } - } - // Filter and decrypt filenames - var plain []fuse.DirEntry - for i := range cipherEntries { - cName := cipherEntries[i].Name - if dirName == "" && cName == configfile.ConfDefaultName { - // silently ignore "gocryptfs.conf" in the top level dir - continue - } - if fs.args.DirIV && cName == nametransform.DirIVFilename { - // silently ignore "gocryptfs.diriv" everywhere if dirIV is enabled - continue - } - var name string = cName - if !fs.args.PlaintextNames { - name, err = fs.nameTransform.DecryptName(cName, cachedIV) - if err != nil { - toggledlog.Warn.Printf("Invalid name \"%s\" in dir \"%s\": %s", cName, cDirName, err) - continue - } - } - cipherEntries[i].Name = name - 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(path string, flags uint32, context *fuse.Context) (fuseFile nodefs.File, status fuse.Status) { - if fs.isFiltered(path) { - return nil, fuse.EPERM - } - iflags, writeOnly := fs.mangleOpenFlags(flags) - cPath, err := fs.getBackingPath(path) - if err != nil { - toggledlog.Debug.Printf("Open: getBackingPath: %v", err) - return nil, fuse.ToStatus(err) - } - toggledlog.Debug.Printf("Open: %s", cPath) - f, err := os.OpenFile(cPath, iflags, 0666) - if err != nil { - return nil, fuse.ToStatus(err) - } - - return NewFile(f, writeOnly, fs.contentEnc), fuse.OK -} - -func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Context) (fuseFile nodefs.File, code fuse.Status) { - if fs.isFiltered(path) { - return nil, fuse.EPERM - } - iflags, writeOnly := fs.mangleOpenFlags(flags) - 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) - } - return NewFile(f, writeOnly, fs.contentEnc), fuse.OK -} - -func (fs *FS) Chmod(path string, mode uint32, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(path) { - return fuse.EPERM - } - 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.isFiltered(path) { - return fuse.EPERM - } - cPath, err := fs.encryptPath(path) - if err != nil { - return fuse.ToStatus(err) - } - return fs.FileSystem.Chown(cPath, uid, gid, context) -} - -func (fs *FS) Mknod(path string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(path) { - return fuse.EPERM - } - cPath, err := fs.encryptPath(path) - if err != nil { - return fuse.ToStatus(err) - } - return fs.FileSystem.Mknod(cPath, mode, dev, context) -} - -var truncateWarned bool - -func (fs *FS) Truncate(path string, offset uint64, context *fuse.Context) (code fuse.Status) { - // Only warn once - if !truncateWarned { - toggledlog.Warn.Printf("truncate(2) is not supported, returning ENOSYS - use ftruncate(2)") - truncateWarned = true - } - return fuse.ENOSYS -} - -func (fs *FS) Utimens(path string, Atime *time.Time, Mtime *time.Time, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(path) { - return fuse.EPERM - } - cPath, err := fs.encryptPath(path) - if err != nil { - return fuse.ToStatus(err) - } - return fs.FileSystem.Utimens(cPath, Atime, Mtime, 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) - } - cTarget, status := fs.FileSystem.Readlink(cPath, context) - if status != fuse.OK { - return "", status - } - // Old filesystem: symlinks are encrypted like paths (CBC) - if !fs.args.DirIV { - target, err := fs.decryptPath(cTarget) - if err != nil { - toggledlog.Warn.Printf("Readlink: CBC decryption failed: %v", err) - return "", fuse.EIO - } - return target, fuse.OK - } - // Since gocryptfs v0.5 symlinks are encrypted like file contents (GCM) - cBinTarget, err := base64.URLEncoding.DecodeString(cTarget) - if err != nil { - toggledlog.Warn.Printf("Readlink: %v", err) - return "", fuse.EIO - } - target, err := fs.contentEnc.DecryptBlock([]byte(cBinTarget), 0, nil) - if err != nil { - toggledlog.Warn.Printf("Readlink: %v", err) - return "", fuse.EIO - } - return string(target), fuse.OK -} - -func (fs *FS) Unlink(path string, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(path) { - return fuse.EPERM - } - cPath, err := fs.getBackingPath(path) - if err != nil { - return fuse.ToStatus(err) - } - return fuse.ToStatus(syscall.Unlink(cPath)) -} - -func (fs *FS) Symlink(target string, linkName string, context *fuse.Context) (code fuse.Status) { - toggledlog.Debug.Printf("Symlink(\"%s\", \"%s\")", target, linkName) - if fs.isFiltered(linkName) { - return fuse.EPERM - } - cPath, err := fs.getBackingPath(linkName) - if err != nil { - return fuse.ToStatus(err) - } - // Old filesystem: symlinks are encrypted like paths (CBC) - if !fs.args.DirIV { - cTarget, err := fs.encryptPath(target) - if err != nil { - toggledlog.Warn.Printf("Symlink: BUG: we should not get an error here: %v", err) - return fuse.ToStatus(err) - } - err = os.Symlink(cTarget, cPath) - return fuse.ToStatus(err) - } - // Since gocryptfs v0.5 symlinks are encrypted like file contents (GCM) - cBinTarget := fs.contentEnc.EncryptBlock([]byte(target), 0, nil) - cTarget := base64.URLEncoding.EncodeToString(cBinTarget) - - err = os.Symlink(cTarget, cPath) - toggledlog.Debug.Printf("Symlink: os.Symlink(%s, %s) = %v", cTarget, cPath, err) - return fuse.ToStatus(err) -} - -func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(newPath) { - return fuse.EPERM - } - cOldPath, err := fs.getBackingPath(oldPath) - if err != nil { - return fuse.ToStatus(err) - } - cNewPath, err := fs.getBackingPath(newPath) - if err != nil { - return fuse.ToStatus(err) - } - // The Rename may cause a directory to take the place of another directory. - // That directory may still be in the DirIV cache, clear it. - fs.nameTransform.DirIVCache.Clear() - - err = os.Rename(cOldPath, cNewPath) - - if lerr, ok := err.(*os.LinkError); ok && lerr.Err == syscall.ENOTEMPTY { - // If an empty directory is overwritten we will always get - // ENOTEMPTY as the "empty" directory will still contain gocryptfs.diriv. - // Handle that case by removing the target directory and trying again. - toggledlog.Debug.Printf("Rename: Handling ENOTEMPTY") - if fs.Rmdir(newPath, context) == fuse.OK { - err = os.Rename(cOldPath, cNewPath) - } - } - - return fuse.ToStatus(err) -} - -func (fs *FS) Link(oldPath string, newPath string, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(newPath) { - return fuse.EPERM - } - 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(path string, mode uint32, context *fuse.Context) (code fuse.Status) { - if fs.isFiltered(path) { - return fuse.EPERM - } - 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) { - 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 -} |