From de56fe9e3503d98e359551072633c804794b94e1 Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Tue, 3 Nov 2015 00:00:13 +0100 Subject: Implement PlainTextNames mode Also, forbid access to "gocryptfs.conf" in the root dir. --- pathfs_frontend/fs.go | 68 ++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 59 insertions(+), 9 deletions(-) (limited to 'pathfs_frontend') diff --git a/pathfs_frontend/fs.go b/pathfs_frontend/fs.go index 3ec503f..1ef19d2 100644 --- a/pathfs_frontend/fs.go +++ b/pathfs_frontend/fs.go @@ -19,9 +19,9 @@ type FS struct { } // Encrypted FUSE overlay filesystem -func NewFS(key []byte, backing string, useOpenssl bool) *FS { +func NewFS(key []byte, backing string, useOpenssl bool, plaintextNames bool) *FS { return &FS{ - CryptFS: cryptfs.NewCryptFS(key, useOpenssl), + CryptFS: cryptfs.NewCryptFS(key, useOpenssl, plaintextNames), FileSystem: pathfs.NewLoopbackFileSystem(backing), backing: backing, } @@ -34,6 +34,9 @@ func (fs *FS) GetPath(relPath string) string { func (fs *FS) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) { cryptfs.Debug.Printf("FS.GetAttr('%s')\n", name) + if name == cryptfs.ConfDefaultName { + return nil, fuse.EPERM // See comment in Open() + } cName := fs.EncryptPath(name) a, status := fs.FileSystem.GetAttr(cName, context) if a == nil { @@ -56,12 +59,12 @@ func (fs *FS) OpenDir(dirName string, context *fuse.Context) ([]fuse.DirEntry, f if cipherEntries != nil { for i := range cipherEntries { cName := cipherEntries[i].Name + if dirName == "" && cName == cryptfs.ConfDefaultName { + // ignore "gocryptfs.conf" in the top level dir + continue + } name, err := fs.DecryptPath(cName) if err != nil { - if dirName == "" && cName == cryptfs.ConfDefaultName { - // Silently ignore "gocryptfs.conf" in the top level dir - continue - } fmt.Printf("Invalid name \"%s\" in dir \"%s\": %s\n", cName, name, err) continue } @@ -85,11 +88,18 @@ func (fs *FS) mangleOpenFlags(flags uint32) (newFlags int, writeOnly bool) { 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) +func (fs *FS) Open(path string, flags uint32, context *fuse.Context) (fuseFile nodefs.File, status fuse.Status) { + cryptfs.Debug.Printf("Open(%s)\n", path) + + if path == cryptfs.ConfDefaultName { + // "gocryptfs.conf" in the top level dir is forbidden + // to protect the config file of this filesystem if + // "--plaintextnames" is enabled + return nil, fuse.EPERM + } iflags, writeOnly := fs.mangleOpenFlags(flags) - f, err := os.OpenFile(fs.GetPath(name), iflags, 0666) + f, err := os.OpenFile(fs.GetPath(path), iflags, 0666) if err != nil { return nil, fuse.ToStatus(err) } @@ -98,6 +108,10 @@ func (fs *FS) Open(name 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 path == cryptfs.ConfDefaultName { + return nil, fuse.EPERM // See comment in Open() + } + iflags, writeOnly := fs.mangleOpenFlags(flags) f, err := os.OpenFile(fs.GetPath(path), iflags|os.O_CREATE, os.FileMode(mode)) if err != nil { @@ -107,14 +121,26 @@ 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 path == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + 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) { + if path == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + return fs.FileSystem.Chown(fs.EncryptPath(path), uid, gid, context) } func (fs *FS) Mknod(name string, mode uint32, dev uint32, context *fuse.Context) (code fuse.Status) { + if name == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + return fs.FileSystem.Mknod(fs.EncryptPath(name), mode, dev, context) } @@ -124,6 +150,10 @@ 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 path == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + return fs.FileSystem.Utimens(fs.EncryptPath(path), Atime, Mtime, context) } @@ -141,10 +171,18 @@ func (fs *FS) Readlink(name string, context *fuse.Context) (out string, status f } func (fs *FS) Mkdir(path string, mode uint32, context *fuse.Context) (code fuse.Status) { + if path == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + return fs.FileSystem.Mkdir(fs.EncryptPath(path), mode, context) } func (fs *FS) Unlink(name string, context *fuse.Context) (code fuse.Status) { + if name == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + cName := fs.EncryptPath(name) code = fs.FileSystem.Unlink(cName, context) if code != fuse.OK { @@ -158,16 +196,28 @@ func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) { } func (fs *FS) Symlink(pointedTo string, linkName string, context *fuse.Context) (code fuse.Status) { + if linkName == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + // TODO symlink encryption cryptfs.Debug.Printf("Symlink(\"%s\", \"%s\")\n", pointedTo, linkName) 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) { + if newPath == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + 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) { + if newName == cryptfs.ConfDefaultName { + return fuse.EPERM // See comment in Open() + } + return fs.FileSystem.Link(fs.EncryptPath(orig), fs.EncryptPath(newName), context) } -- cgit v1.2.3