longnames part II: Rename, Unlink, Rmdir, Mknod, Mkdir + testsv0.9-rc1

7 files changed, 104 insertions, 27 deletions

diff --git a/internal/contentenc/offsets.go b/internal/contentenc/offsets.go
index 1b5952f..cfb1c69 100644
--- a/internal/contentenc/offsets.go
+++ b/internal/contentenc/offsets.go
@@ -40,7 +40,7 @@ func (be *ContentEnc) CipherSizeToPlainSize(cipherSize uint64) uint64 {
 	}
 
 	if cipherSize < HEADER_LEN {
-		toggledlog.Warn.Printf("cipherSize %d < header size: corrupt file\n", cipherSize)
+		toggledlog.Warn.Printf("cipherSize %d < header size %d: corrupt file\n", cipherSize, HEADER_LEN)
 		return 0
 	}
 
diff --git a/internal/fusefrontend/fs.go b/internal/fusefrontend/fs.go
index f11c05e..fb82c6b 100644
--- a/internal/fusefrontend/fs.go
+++ b/internal/fusefrontend/fs.go
@@ -5,7 +5,6 @@ package fusefrontend
 import (
 	"encoding/base64"
 	"os"
-	"path/filepath"
 	"sync"
 	"syscall"
 	"time"
@@ -14,7 +13,6 @@ import (
 	"github.com/hanwen/go-fuse/fuse/nodefs"
 	"github.com/hanwen/go-fuse/fuse/pathfs"
 
-	"github.com/rfjakob/gocryptfs/internal/configfile"
 	"github.com/rfjakob/gocryptfs/internal/contentenc"
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
 	"github.com/rfjakob/gocryptfs/internal/nametransform"
@@ -113,10 +111,9 @@ func (fs *FS) Create(path string, flags uint32, mode uint32, context *fuse.Conte
 	if err != nil {
 		return nil, fuse.ToStatus(err)
 	}
-	cBaseName := filepath.Base(cPath)
-	if fs.args.LongNames && nametransform.IsLongName(cBaseName) == 1 {
-		// Create the ".name" file before creating the content
-		err = fs.nameTransform.WriteLongName(filepath.Dir(cPath), cBaseName, filepath.Base(path))
+	// Create .name file to store the long file name if needed
+	if !fs.args.PlaintextNames {
+		err = fs.nameTransform.WriteLongName(cPath, path)
 		if err != nil {
 			return nil, fuse.ToStatus(err)
 		}
@@ -158,6 +155,13 @@ func (fs *FS) Mknod(path string, mode uint32, dev uint32, context *fuse.Context)
 	if err != nil {
 		return fuse.ToStatus(err)
 	}
+	if !fs.args.PlaintextNames {
+		// Create .name file to store the long file name if needed
+		err = fs.nameTransform.WriteLongName(cPath, path)
+		if err != nil {
+			return fuse.ToStatus(err)
+		}
+	}
 	return fs.FileSystem.Mknod(cPath, mode, dev, context)
 }
 
@@ -223,7 +227,12 @@ func (fs *FS) Unlink(path string, context *fuse.Context) (code fuse.Status) {
 	if err != nil {
 		return fuse.ToStatus(err)
 	}
-	return fuse.ToStatus(syscall.Unlink(cPath))
+	err = syscall.Unlink(cPath)
+	// Delete .name file
+	if err == nil && !fs.args.PlaintextNames {
+		nametransform.DeleteLongName(cPath)
+	}
+	return fuse.ToStatus(err)
 }
 
 func (fs *FS) Symlink(target string, linkName string, context *fuse.Context) (code fuse.Status) {
@@ -236,6 +245,7 @@ func (fs *FS) Symlink(target string, linkName string, context *fuse.Context) (co
 		return fuse.ToStatus(err)
 	}
 	// Old filesystem: symlinks are encrypted like paths (CBC)
+	// TODO drop compatibility and simplify code
 	if !fs.args.DirIV {
 		cTarget, err := fs.encryptPath(target)
 		if err != nil {
@@ -248,7 +258,13 @@ func (fs *FS) Symlink(target string, linkName string, context *fuse.Context) (co
 	// Since gocryptfs v0.5 symlinks are encrypted like file contents (GCM)
 	cBinTarget := fs.contentEnc.EncryptBlock([]byte(target), 0, nil)
 	cTarget := base64.URLEncoding.EncodeToString(cBinTarget)
-
+	if !fs.args.PlaintextNames {
+		// Create .name file to store the long file name if needed
+		err = fs.nameTransform.WriteLongName(cPath, linkName)
+		if err != nil {
+			return fuse.ToStatus(err)
+		}
+	}
 	err = os.Symlink(cTarget, cPath)
 	toggledlog.Debug.Printf("Symlink: os.Symlink(%s, %s) = %v", cTarget, cPath, err)
 	return fuse.ToStatus(err)
@@ -270,6 +286,15 @@ func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (cod
 	// That directory may still be in the DirIV cache, clear it.
 	fs.nameTransform.DirIVCache.Clear()
 
+	if !fs.args.PlaintextNames {
+		// Create .name file to store the new long file name if needed
+		err = fs.nameTransform.WriteLongName(cNewPath, newPath)
+		if err != nil {
+			return fuse.ToStatus(err)
+		}
+	}
+
+	// Actual rename
 	err = os.Rename(cOldPath, cNewPath)
 
 	if lerr, ok := err.(*os.LinkError); ok && lerr.Err == syscall.ENOTEMPTY {
@@ -281,6 +306,13 @@ func (fs *FS) Rename(oldPath string, newPath string, context *fuse.Context) (cod
 			err = os.Rename(cOldPath, cNewPath)
 		}
 	}
+	if err == nil {
+		// Rename succeeded - delete old long name file
+		nametransform.DeleteLongName(cOldPath)
+	} else {
+		// Rename has failed - undo long name file creation
+		nametransform.DeleteLongName(cNewPath)
+	}
 
 	return fuse.ToStatus(err)
 }
@@ -297,6 +329,13 @@ func (fs *FS) Link(oldPath string, newPath string, context *fuse.Context) (code
 	if err != nil {
 		return fuse.ToStatus(err)
 	}
+	if !fs.args.PlaintextNames {
+		// Create .name file to store the long file name if needed
+		err = fs.nameTransform.WriteLongName(cNewPath, newPath)
+		if err != nil {
+			return fuse.ToStatus(err)
+		}
+	}
 	return fuse.ToStatus(os.Link(cOldPath, cNewPath))
 }
 
diff --git a/internal/fusefrontend/fs_dir.go b/internal/fusefrontend/fs_dir.go
index f1ade25..ebf7015 100644
--- a/internal/fusefrontend/fs_dir.go
+++ b/internal/fusefrontend/fs_dir.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/hanwen/go-fuse/fuse"
 
+	"github.com/rfjakob/gocryptfs/internal/configfile"
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
 	"github.com/rfjakob/gocryptfs/internal/nametransform"
 	"github.com/rfjakob/gocryptfs/internal/toggledlog"
@@ -30,7 +31,11 @@ func (fs *FS) Mkdir(relPath string, mode uint32, context *fuse.Context) (code fu
 	// We need write and execute permissions to create gocryptfs.diriv
 	origMode := mode
 	mode = mode | 0300
-
+	// Create .name file to store the long file name if needed
+	err = fs.nameTransform.WriteLongName(encPath, relPath)
+	if err != nil {
+		return fuse.ToStatus(err)
+	}
 	// The new directory may take the place of an older one that is still in the cache
 	fs.nameTransform.DirIVCache.Clear()
 	// Create directory
@@ -151,6 +156,10 @@ func (fs *FS) Rmdir(name string, context *fuse.Context) (code fuse.Status) {
 	if err != nil {
 		toggledlog.Warn.Printf("Rmdir: Could not clean up %s: %v", tmpName, err)
 	}
+	err = nametransform.DeleteLongName(encPath)
+	if err != nil {
+		toggledlog.Warn.Printf("Rmdir: Could not delete long name file: %v", err)
+	}
 	// The now-deleted directory may have been in the DirIV cache. Clear it.
 	fs.nameTransform.DirIVCache.Clear()
 	return fuse.OK
diff --git a/internal/nametransform/longnames.go b/internal/nametransform/longnames.go
index e442b64..dad269b 100644
--- a/internal/nametransform/longnames.go
+++ b/internal/nametransform/longnames.go
@@ -1,12 +1,12 @@
 package nametransform
 
 import (
-	"syscall"
-	"path/filepath"
-	"io/ioutil"
 	"crypto/sha256"
 	"encoding/base64"
+	"io/ioutil"
+	"path/filepath"
 	"strings"
+	"syscall"
 
 	"github.com/rfjakob/gocryptfs/internal/toggledlog"
 )
@@ -39,28 +39,47 @@ func IsLongName(cName string) int {
 	return 1
 }
 
-// ReadLongName - read "path".name
+// ReadLongName - read path.name
 func ReadLongName(path string) (string, error) {
-	content, err := ioutil.ReadFile(path+longNameSuffix)
+	content, err := ioutil.ReadFile(path + longNameSuffix)
 	if err != nil {
 		toggledlog.Warn.Printf("ReadLongName: %v", err)
 	}
 	return string(content), err
 }
 
-// WriteLongName -
-func (n *NameTransform) WriteLongName(cDir string, hashedName string, plainName string) (err error) {
-	if len(plainName) > syscall.NAME_MAX {
-		return syscall.ENAMETOOLONG
+// DeleteLongName - if cPath ends in "gocryptfs.longname.[sha256]",
+// delete the "gocryptfs.longname.[sha256].name" file
+func DeleteLongName(cPath string) error {
+	if IsLongName(filepath.Base(cPath)) == 1 {
+		err := syscall.Unlink(cPath + longNameSuffix)
+		if err != nil {
+			toggledlog.Warn.Printf("DeleteLongName: %v", err)
+		}
+		return err
 	}
+	return nil
+}
 
+// WriteLongName - if cPath ends in "gocryptfs.longname.[sha256]", write the
+// "gocryptfs.longname.[sha256].name" file
+func (n *NameTransform) WriteLongName(cPath string, plainPath string) (err error) {
+	cHashedName := filepath.Base(cPath)
+	if IsLongName(cHashedName) != 1 {
+		// This is not a hashed file name, nothing to do
+		return nil
+	}
+	// Encrypt (but do not hash) the plaintext name
+	cDir := filepath.Dir(cPath)
 	dirIV, err := ReadDirIV(cDir)
 	if err != nil {
 		toggledlog.Warn.Printf("WriteLongName: %v", err)
 		return err
 	}
+	plainName := filepath.Base(plainPath)
 	cName := n.EncryptName(plainName, dirIV)
-	err = ioutil.WriteFile(filepath.Join(cDir, hashedName + longNameSuffix), []byte(cName), 0600)
+	// Write the encrypted name into gocryptfs.longname.[sha256].name
+	err = ioutil.WriteFile(filepath.Join(cDir, cHashedName+longNameSuffix), []byte(cName), 0600)
 	if err != nil {
 		toggledlog.Warn.Printf("WriteLongName: %v", err)
 	}
diff --git a/internal/nametransform/name_api.go b/internal/nametransform/name_api.go
index 391a5ce..7ac7d26 100644
--- a/internal/nametransform/name_api.go
+++ b/internal/nametransform/name_api.go
@@ -12,7 +12,7 @@ type NameTransform struct {
 func New(c *cryptocore.CryptoCore, useEME bool, longNames bool) *NameTransform {
 	return &NameTransform{
 		cryptoCore: c,
-		longNames: longNames,
+		longNames:  longNames,
 		useEME:     useEME,
 	}
 }
diff --git a/internal/nametransform/names_diriv.go b/internal/nametransform/names_diriv.go
index d45f91b..9336f5d 100644
--- a/internal/nametransform/names_diriv.go
+++ b/internal/nametransform/names_diriv.go
@@ -1,12 +1,12 @@
 package nametransform
 
 import (
-	"syscall"
 	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
+	"syscall"
 
 	"github.com/rfjakob/gocryptfs/internal/cryptocore"
 	"github.com/rfjakob/gocryptfs/internal/toggledlog"
@@ -54,17 +54,23 @@ func WriteDirIV(dir string) error {
 	return ioutil.WriteFile(file, iv, 0444)
 }
 
-// EncryptPathDirIV - encrypt path using EME with DirIV
+// EncryptPathDirIV - encrypt relative plaintext path using EME with DirIV.
+// Components that are longer than 255 bytes are hashed.
 func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cipherPath string, err error) {
 	// Empty string means root directory
 	if plainPath == "" {
 		return plainPath, nil
 	}
+	// Reject names longer than 255 bytes already here. This relieves everybody
+	// who uses hashed long names from checking for that later.
+	baseName := filepath.Base(plainPath)
+	if len(baseName) > syscall.NAME_MAX {
+		return "", syscall.ENAMETOOLONG
+	}
 	// Check if the DirIV is cached
 	parentDir := filepath.Dir(plainPath)
 	found, iv, cParentDir := be.DirIVCache.lookup(parentDir)
 	if found {
-		baseName := filepath.Base(plainPath)
 		cBaseName := be.EncryptName(baseName, iv)
 		if be.longNames && len(cBaseName) > syscall.NAME_MAX {
 			cBaseName = HashLongName(cBaseName)
@@ -72,7 +78,7 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
 		cipherPath = cParentDir + "/" + cBaseName
 		return cipherPath, nil
 	}
-	// Walk the directory tree
+	// Not cached - walk the directory tree
 	var wd = rootDir
 	var encryptedNames []string
 	plainNames := strings.Split(plainPath, "/")
@@ -96,6 +102,9 @@ func (be *NameTransform) EncryptPathDirIV(plainPath string, rootDir string) (cip
 }
 
 // DecryptPathDirIV - decrypt path using EME with DirIV
+//
+// TODO This has only a single user, Readlink(), and only for compatability with
+// gocryptfs v0.5. Drop?
 func (be *NameTransform) DecryptPathDirIV(encryptedPath string, rootDir string) (string, error) {
 	var wd = rootDir
 	var plainNames []string
diff --git a/internal/toggledlog/log.go b/internal/toggledlog/log.go
index 5e5191a..31a9eb6 100644
--- a/internal/toggledlog/log.go
+++ b/internal/toggledlog/log.go
@@ -9,6 +9,7 @@ import (
 
 const (
 	ProgramName = "gocryptfs"
+	wpanicMsg   = "-wpanic turns this warning into a panic: "
 )
 
 func JSONDump(obj interface{}) string {
@@ -35,7 +36,7 @@ func (l *toggledLogger) Printf(format string, v ...interface{}) {
 	}
 	l.Logger.Printf(format, v...)
 	if l.Wpanic {
-		panic("-wpanic turns warning into panic: " + fmt.Sprintf(format, v...))
+		panic(wpanicMsg + fmt.Sprintf(format, v...))
 	}
 }
 func (l *toggledLogger) Println(v ...interface{}) {
@@ -44,7 +45,7 @@ func (l *toggledLogger) Println(v ...interface{}) {
 	}
 	l.Logger.Println(v...)
 	if l.Wpanic {
-		panic("-wpanic turns warning into panic: " + fmt.Sprintln(v...))
+		panic(wpanicMsg + fmt.Sprintln(v...))
 	}
 }