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authorJakob Unterwurzacher2017-05-28 18:09:02 +0200
committerJakob Unterwurzacher2017-05-28 18:09:02 +0200
commitab10cf63ed21d09e239986ac125b990fe06b5572 (patch)
tree575db69995d180bcdc5463713855847947b70ada
parentd59e7da6a6ee9883d61958ccd3ed3acb7c6ba8dc (diff)
fusefrontend_reverse: move pathiv to its own package
We will also need it in forward mode.
-rw-r--r--internal/fusefrontend_reverse/ctlsock_interface.go3
-rw-r--r--internal/fusefrontend_reverse/reverse_longnames.go3
-rw-r--r--internal/fusefrontend_reverse/rfile.go5
-rw-r--r--internal/fusefrontend_reverse/rfs.go5
-rw-r--r--internal/fusefrontend_reverse/rpath.go21
-rw-r--r--internal/fusefrontend_reverse/virtualfile.go3
-rw-r--r--internal/pathiv/pathiv.go24
7 files changed, 38 insertions, 26 deletions
diff --git a/internal/fusefrontend_reverse/ctlsock_interface.go b/internal/fusefrontend_reverse/ctlsock_interface.go
index 4d9a446..5f61f37 100644
--- a/internal/fusefrontend_reverse/ctlsock_interface.go
+++ b/internal/fusefrontend_reverse/ctlsock_interface.go
@@ -6,6 +6,7 @@ import (
"syscall"
"github.com/rfjakob/gocryptfs/internal/ctlsock"
+ "github.com/rfjakob/gocryptfs/internal/pathiv"
)
var _ ctlsock.Interface = &ReverseFS{} // Verify that interface is implemented.
@@ -20,7 +21,7 @@ func (rfs *ReverseFS) EncryptPath(plainPath string) (string, error) {
cipherPath := ""
parts := strings.Split(plainPath, "/")
for _, part := range parts {
- dirIV := derivePathIV(cipherPath, ivPurposeDirIV)
+ dirIV := pathiv.Derive(cipherPath, pathiv.PurposeDirIV)
encryptedPart := rfs.nameTransform.EncryptName(part, dirIV)
if rfs.args.LongNames && len(encryptedPart) > syscall.NAME_MAX {
encryptedPart = rfs.nameTransform.HashLongName(encryptedPart)
diff --git a/internal/fusefrontend_reverse/reverse_longnames.go b/internal/fusefrontend_reverse/reverse_longnames.go
index 0830298..7e26c90 100644
--- a/internal/fusefrontend_reverse/reverse_longnames.go
+++ b/internal/fusefrontend_reverse/reverse_longnames.go
@@ -12,6 +12,7 @@ import (
"github.com/hanwen/go-fuse/fuse/nodefs"
"github.com/rfjakob/gocryptfs/internal/nametransform"
+ "github.com/rfjakob/gocryptfs/internal/pathiv"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -91,7 +92,7 @@ func (rfs *ReverseFS) newNameFile(relPath string) (nodefs.File, fuse.Status) {
if err != nil {
return nil, fuse.ToStatus(err)
}
- dirIV := derivePathIV(cDir, ivPurposeDirIV)
+ dirIV := pathiv.Derive(cDir, pathiv.PurposeDirIV)
// plain name
pName, err := rfs.findLongnameParent(pDir, dirIV, longname)
if err != nil {
diff --git a/internal/fusefrontend_reverse/rfile.go b/internal/fusefrontend_reverse/rfile.go
index 9a680bb..b19ad5e 100644
--- a/internal/fusefrontend_reverse/rfile.go
+++ b/internal/fusefrontend_reverse/rfile.go
@@ -14,6 +14,7 @@ import (
"github.com/hanwen/go-fuse/fuse/nodefs"
"github.com/rfjakob/gocryptfs/internal/contentenc"
+ "github.com/rfjakob/gocryptfs/internal/pathiv"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -60,8 +61,8 @@ func (rfs *ReverseFS) newFile(relPath string, flags uint32) (nodefs.File, fuse.S
tlog.Debug.Printf("ino%d: newFile: found in the inode table", st.Ino)
derivedIVs = v.(derivedIVContainer)
} else {
- derivedIVs.id = derivePathIV(relPath, ivPurposeFileID)
- derivedIVs.block0IV = derivePathIV(relPath, ivPurposeBlock0IV)
+ derivedIVs.id = pathiv.Derive(relPath, pathiv.PurposeFileID)
+ derivedIVs.block0IV = pathiv.Derive(relPath, pathiv.PurposeBlock0IV)
// Nlink > 1 means there is more than one path to this file.
// Store the derived values so we always return the same data,
// regardless of the path that is used to access the file.
diff --git a/internal/fusefrontend_reverse/rfs.go b/internal/fusefrontend_reverse/rfs.go
index 06bbfe9..63384ac 100644
--- a/internal/fusefrontend_reverse/rfs.go
+++ b/internal/fusefrontend_reverse/rfs.go
@@ -16,6 +16,7 @@ import (
"github.com/rfjakob/gocryptfs/internal/cryptocore"
"github.com/rfjakob/gocryptfs/internal/fusefrontend"
"github.com/rfjakob/gocryptfs/internal/nametransform"
+ "github.com/rfjakob/gocryptfs/internal/pathiv"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -263,7 +264,7 @@ func (rfs *ReverseFS) OpenDir(cipherPath string, context *fuse.Context) ([]fuse.
nVirtual := 1
// Encrypt names
- dirIV := derivePathIV(cipherPath, ivPurposeDirIV)
+ dirIV := pathiv.Derive(cipherPath, pathiv.PurposeDirIV)
for i := range entries {
var cName string
// ".gocryptfs.reverse.conf" in the root directory is mapped to "gocryptfs.conf"
@@ -305,7 +306,7 @@ func (rfs *ReverseFS) Readlink(cipherPath string, context *fuse.Context) (string
if rfs.args.PlaintextNames {
return plainTarget, fuse.OK
}
- nonce := derivePathIV(cipherPath, ivPurposeSymlinkIV)
+ nonce := pathiv.Derive(cipherPath, pathiv.PurposeSymlinkIV)
// Symlinks are encrypted like file contents and base64-encoded
cBinTarget := rfs.contentEnc.EncryptBlockNonce([]byte(plainTarget), 0, nil, nonce)
cTarget := rfs.nameTransform.B64.EncodeToString(cBinTarget)
diff --git a/internal/fusefrontend_reverse/rpath.go b/internal/fusefrontend_reverse/rpath.go
index 5082d11..58e8c91 100644
--- a/internal/fusefrontend_reverse/rpath.go
+++ b/internal/fusefrontend_reverse/rpath.go
@@ -1,13 +1,13 @@
package fusefrontend_reverse
import (
- "crypto/sha256"
"encoding/base64"
"path/filepath"
"strings"
"syscall"
"github.com/rfjakob/gocryptfs/internal/nametransform"
+ "github.com/rfjakob/gocryptfs/internal/pathiv"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -20,23 +20,6 @@ func saneDir(path string) string {
return d
}
-type ivPurposeType string
-
-const (
- ivPurposeDirIV ivPurposeType = "DIRIV"
- ivPurposeFileID ivPurposeType = "FILEID"
- ivPurposeSymlinkIV ivPurposeType = "SYMLINKIV"
- ivPurposeBlock0IV ivPurposeType = "BLOCK0IV"
-)
-
-// derivePathIV derives an IV from an encrypted path by hashing it with sha256
-func derivePathIV(path string, purpose ivPurposeType) []byte {
- // Use null byte as separator as it cannot occur in the path
- extended := []byte(path + "\000" + string(purpose))
- hash := sha256.Sum256(extended)
- return hash[:nametransform.DirIVLen]
-}
-
// abs basically returns storage dir + "/" + relPath.
// It takes an error parameter so it can directly wrap decryptPath like this:
// a, err := rfs.abs(rfs.decryptPath(relPath))
@@ -104,7 +87,7 @@ func (rfs *ReverseFS) decryptPath(relPath string) (string, error) {
// Start at the top and recurse
currentCipherDir := filepath.Join(parts[:i]...)
currentPlainDir := filepath.Join(transformedParts[:i]...)
- dirIV = derivePathIV(currentCipherDir, ivPurposeDirIV)
+ dirIV = pathiv.Derive(currentCipherDir, pathiv.PurposeDirIV)
transformedPart, err := rfs.rDecryptName(parts[i], dirIV, currentPlainDir)
if err != nil {
return "", err
diff --git a/internal/fusefrontend_reverse/virtualfile.go b/internal/fusefrontend_reverse/virtualfile.go
index 00fa726..5d5d80d 100644
--- a/internal/fusefrontend_reverse/virtualfile.go
+++ b/internal/fusefrontend_reverse/virtualfile.go
@@ -6,6 +6,7 @@ import (
"github.com/hanwen/go-fuse/fuse"
"github.com/hanwen/go-fuse/fuse/nodefs"
+ "github.com/rfjakob/gocryptfs/internal/pathiv"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -27,7 +28,7 @@ func (rfs *ReverseFS) newDirIVFile(cRelPath string) (nodefs.File, fuse.Status) {
if err != nil {
return nil, fuse.ToStatus(err)
}
- return rfs.newVirtualFile(derivePathIV(cDir, ivPurposeDirIV), absDir)
+ return rfs.newVirtualFile(pathiv.Derive(cDir, pathiv.PurposeDirIV), absDir)
}
type virtualFile struct {
diff --git a/internal/pathiv/pathiv.go b/internal/pathiv/pathiv.go
new file mode 100644
index 0000000..d2d90a2
--- /dev/null
+++ b/internal/pathiv/pathiv.go
@@ -0,0 +1,24 @@
+package pathiv
+
+import (
+ "crypto/sha256"
+
+ "github.com/rfjakob/gocryptfs/internal/nametransform"
+)
+
+type Purpose string
+
+const (
+ PurposeDirIV Purpose = "DIRIV"
+ PurposeFileID Purpose = "FILEID"
+ PurposeSymlinkIV Purpose = "SYMLINKIV"
+ PurposeBlock0IV Purpose = "BLOCK0IV"
+)
+
+// Derive derives an IV from an encrypted path by hashing it with sha256
+func Derive(path string, purpose Purpose) []byte {
+ // Use null byte as separator as it cannot occur in the path
+ extended := []byte(path + "\000" + string(purpose))
+ hash := sha256.Sum256(extended)
+ return hash[:nametransform.DirIVLen]
+}