From decfc1ab798055234e16a2e9c0782f56ae50669b Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Fri, 27 Nov 2015 00:03:10 +0100 Subject: diriv: Convert filename encryption users to diriv --- pathfs_frontend/fs.go | 156 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 114 insertions(+), 42 deletions(-) (limited to 'pathfs_frontend/fs.go') 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) { -- cgit v1.2.3