diff options
Diffstat (limited to 'internal/fusefrontend/file.go')
| -rw-r--r-- | internal/fusefrontend/file.go | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index 57ec9ba..27c8f70 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -16,6 +16,7 @@ import ( "github.com/rfjakob/gocryptfs/internal/contentenc" "github.com/rfjakob/gocryptfs/internal/openfiletable" + "github.com/rfjakob/gocryptfs/internal/pathiv" "github.com/rfjakob/gocryptfs/internal/serialize_reads" "github.com/rfjakob/gocryptfs/internal/stupidgcm" "github.com/rfjakob/gocryptfs/internal/syscallcompat" @@ -56,10 +57,13 @@ type file struct { // have not implemented. This prevents build breakage when the go-fuse library // adds new methods to the nodefs.File interface. nodefs.File + // In AES-SIV mode, file ID and block IVs are deterministically derived from + // the path that was used to open the file. + pathIVs pathiv.FileIVs } // NewFile returns a new go-fuse File instance. -func NewFile(fd *os.File, fs *FS) (nodefs.File, fuse.Status) { +func NewFile(fd *os.File, fs *FS, relPath string) (nodefs.File, fuse.Status) { var st syscall.Stat_t err := syscall.Fstat(int(fd.Fd()), &st) if err != nil { @@ -68,8 +72,7 @@ func NewFile(fd *os.File, fs *FS) (nodefs.File, fuse.Status) { } qi := openfiletable.QInoFromStat(&st) e := openfiletable.Register(qi) - - return &file{ + f := &file{ fd: fd, contentEnc: fs.contentEnc, qIno: qi, @@ -77,7 +80,11 @@ func NewFile(fd *os.File, fs *FS) (nodefs.File, fuse.Status) { loopbackFile: nodefs.NewLoopbackFile(fd), fs: fs, File: nodefs.NewDefaultFile(), - }, fuse.OK + } + if fs.contentEnc.UsingSIV() { + f.pathIVs = pathiv.DeriveFile(relPath) + } + return f, fuse.OK } // intFd - return the backing file descriptor as an integer. Used for debug @@ -115,6 +122,10 @@ func (f *file) readFileID() ([]byte, error) { // The caller must hold fileIDLock.Lock(). func (f *file) createHeader() (fileID []byte, err error) { h := contentenc.RandomHeader() + if f.contentEnc.UsingSIV() { + // We use a deterministic file ID in SIV mode. + h.ID = f.pathIVs.ID + } buf := h.Pack() // Prevent partially written (=corrupt) header by preallocating the space beforehand if !f.fs.args.NoPrealloc { @@ -297,7 +308,13 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { tlog.Debug.Printf("len(oldData)=%d len(blockData)=%d", len(oldData), len(blockData)) } // Encrypt - blockData = f.contentEnc.EncryptBlock(blockData, b.BlockNo, fileID) + if f.fs.contentEnc.UsingSIV() { + // We use a deterministic block IV in SIV mode. + iv := pathiv.BlockIV(f.pathIVs.Block0IV, b.BlockNo) + blockData = f.contentEnc.EncryptBlockNonce(blockData, b.BlockNo, fileID, iv) + } else { + blockData = f.contentEnc.EncryptBlock(blockData, b.BlockNo, fileID) + } tlog.Debug.Printf("ino%d: Writing %d bytes to block #%d", f.qIno.Ino, uint64(len(blockData))-f.contentEnc.BlockOverhead(), b.BlockNo) // Store output data in the writeChain |