diff options
| -rw-r--r-- | internal/contentenc/content.go | 18 | ||||
| -rw-r--r-- | internal/fusefrontend/file.go | 30 |
2 files changed, 27 insertions, 21 deletions
diff --git a/internal/contentenc/content.go b/internal/contentenc/content.go index 524296f..80bcf54 100644 --- a/internal/contentenc/content.go +++ b/internal/contentenc/content.go @@ -149,6 +149,24 @@ func (be *ContentEnc) DecryptBlock(ciphertext []byte, blockNo uint64, fileID []b return plaintext, nil } +// EncryptBlocks is like EncryptBlock but takes multiple plaintext blocks. +func (be *ContentEnc) EncryptBlocks(plaintextBlocks [][]byte, firstBlockNo uint64, fileID []byte) []byte { + // Encrypt piecewise. + ciphertextBlocks := make([][]byte, len(plaintextBlocks)) + for i, v := range plaintextBlocks { + ciphertextBlocks[i] = be.EncryptBlock(v, firstBlockNo+uint64(i), fileID) + } + // Concatenate ciphertext into a single byte array. + // Size the output buffer for the maximum possible size (all blocks complete) + // to allocations in out.Write() + tmp := make([]byte, len(plaintextBlocks)*int(be.CipherBS())) + out := bytes.NewBuffer(tmp[:0]) + for _, v := range ciphertextBlocks { + out.Write(v) + } + return out.Bytes() +} + // EncryptBlock - Encrypt plaintext using a random nonce. // blockNo and fileID are used as associated data. // The output is nonce + ciphertext + tag. diff --git a/internal/fusefrontend/file.go b/internal/fusefrontend/file.go index 57ec9ba..ca1798b 100644 --- a/internal/fusefrontend/file.go +++ b/internal/fusefrontend/file.go @@ -272,22 +272,17 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { // re-read it after the RLock(). f.fileTableEntry.HeaderLock.RLock() } - fileID := f.fileTableEntry.ID defer f.fileTableEntry.HeaderLock.RUnlock() // Handle payload data - status := fuse.OK dataBuf := bytes.NewBuffer(data) blocks := f.contentEnc.ExplodePlainRange(uint64(off), uint64(len(data))) - writeChain := make([][]byte, len(blocks)) - var numOutBytes int + toEncrypt := make([][]byte, len(blocks)) for i, b := range blocks { blockData := dataBuf.Next(int(b.Length)) // Incomplete block -> Read-Modify-Write if b.IsPartial() { // Read - o := b.BlockPlainOff() - var oldData []byte - oldData, status = f.doRead(o, f.contentEnc.PlainBS()) + oldData, status := f.doRead(b.BlockPlainOff(), f.contentEnc.PlainBS()) if status != fuse.OK { tlog.Warn.Printf("ino%d fh%d: RMW read failed: %s", f.qIno.Ino, f.intFd(), status.String()) return 0, status @@ -296,33 +291,26 @@ func (f *file) doWrite(data []byte, off int64) (uint32, fuse.Status) { blockData = f.contentEnc.MergeBlocks(oldData, blockData, int(b.Skip)) tlog.Debug.Printf("len(oldData)=%d len(blockData)=%d", len(oldData), len(blockData)) } - // Encrypt - 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 - writeChain[i] = blockData - numOutBytes += len(blockData) - } - // Concatenenate all elements in the writeChain into one contiguous buffer - tmp := make([]byte, numOutBytes) - writeBuf := bytes.NewBuffer(tmp[:0]) - for _, w := range writeChain { - writeBuf.Write(w) + // Write into the to-encrypt list + toEncrypt[i] = blockData } + // Encrypt all blocks + ciphertext := f.contentEnc.EncryptBlocks(toEncrypt, blocks[0].BlockNo, f.fileTableEntry.ID) // Preallocate so we cannot run out of space in the middle of the write. // This prevents partially written (=corrupt) blocks. var err error - cOff := blocks[0].BlockCipherOff() + cOff := int64(blocks[0].BlockCipherOff()) if !f.fs.args.NoPrealloc { - err = syscallcompat.EnospcPrealloc(int(f.fd.Fd()), int64(cOff), int64(writeBuf.Len())) + err = syscallcompat.EnospcPrealloc(int(f.fd.Fd()), cOff, int64(len(ciphertext))) if err != nil { tlog.Warn.Printf("ino%d fh%d: doWrite: prealloc failed: %s", f.qIno.Ino, f.intFd(), err.Error()) return 0, fuse.ToStatus(err) } } // Write - _, err = f.fd.WriteAt(writeBuf.Bytes(), int64(cOff)) + _, err = f.fd.WriteAt(ciphertext, cOff) if err != nil { tlog.Warn.Printf("doWrite: Write failed: %s", err.Error()) return 0, fuse.ToStatus(err) |