Increase GCM IV size from 96 to 128 bits

This pushes back the birthday bound for collisions to make it virtually
irrelevant.

3 files changed, 3 insertions, 2 deletions

diff --git a/pathfs_frontend/args.go b/pathfs_frontend/args.go
index fb0b81f..91f9ba7 100644
--- a/pathfs_frontend/args.go
+++ b/pathfs_frontend/args.go
@@ -8,4 +8,5 @@ type Args struct {
 	PlaintextNames bool
 	DirIV          bool
 	EMENames       bool
+	GCMIV128       bool
 }
diff --git a/pathfs_frontend/file.go b/pathfs_frontend/file.go
index 1f71bfb..d38a37b 100644
--- a/pathfs_frontend/file.go
+++ b/pathfs_frontend/file.go
@@ -266,7 +266,7 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) {
 		blockOffset, blockLen := b.CiphertextRange()
 		blockData = f.cfs.EncryptBlock(blockData, b.BlockNo, f.header.Id)
 		cryptfs.Debug.Printf("ino%d: Writing %d bytes to block #%d, md5=%s\n",
-			f.ino, len(blockData)-cryptfs.BLOCK_OVERHEAD, b.BlockNo, cryptfs.Debug.Md5sum(blockData))
+			f.ino, uint64(len(blockData))-f.cfs.BlockOverhead(), b.BlockNo, cryptfs.Debug.Md5sum(blockData))
 
 		// Prevent partially written (=corrupt) blocks by preallocating the space beforehand
 		f.fdLock.Lock()
diff --git a/pathfs_frontend/fs.go b/pathfs_frontend/fs.go
index e930228..324020d 100644
--- a/pathfs_frontend/fs.go
+++ b/pathfs_frontend/fs.go
@@ -29,7 +29,7 @@ type FS struct {
 // Encrypted FUSE overlay filesystem
 func NewFS(args Args) *FS {
 	return &FS{
-		CryptFS:    cryptfs.NewCryptFS(args.Masterkey, args.OpenSSL, args.PlaintextNames),
+		CryptFS:    cryptfs.NewCryptFS(args.Masterkey, args.OpenSSL, args.PlaintextNames, args.GCMIV128),
 		FileSystem: pathfs.NewLoopbackFileSystem(args.Cipherdir),
 		args:       args,
 	}