From 11fb037e7e7d84405b3bed9de2aa500e49d9502d Mon Sep 17 00:00:00 2001 From: Jakob Unterwurzacher Date: Sat, 5 Sep 2015 20:30:20 +0200 Subject: Cleanup and rename files --- cryptfs/cryptfile.go | 226 --------------------------------------------- cryptfs/cryptfs.go | 172 +--------------------------------- cryptfs/cryptfs_content.go | 94 +++++++++++++++++++ cryptfs/cryptfs_names.go | 150 ++++++++++++++++++++++++++++++ cryptfs/intrablock.go | 39 ++++++++ frontend/checks.go | 31 ------- frontend/dir.go | 122 ------------------------ frontend/fe_checks.go | 31 +++++++ frontend/fe_dir.go | 133 ++++++++++++++++++++++++++ frontend/fe_file.go | 144 +++++++++++++++++++++++++++++ frontend/fe_fs.go | 47 ++++++++++ frontend/file.go | 133 -------------------------- frontend/fs.go | 36 -------- 13 files changed, 640 insertions(+), 718 deletions(-) delete mode 100644 cryptfs/cryptfile.go create mode 100644 cryptfs/cryptfs_content.go create mode 100644 cryptfs/cryptfs_names.go create mode 100644 cryptfs/intrablock.go delete mode 100644 frontend/checks.go delete mode 100644 frontend/dir.go create mode 100644 frontend/fe_checks.go create mode 100644 frontend/fe_dir.go create mode 100644 frontend/fe_file.go create mode 100644 frontend/fe_fs.go delete mode 100644 frontend/file.go delete mode 100644 frontend/fs.go diff --git a/cryptfs/cryptfile.go b/cryptfs/cryptfile.go deleted file mode 100644 index e5e9462..0000000 --- a/cryptfs/cryptfile.go +++ /dev/null @@ -1,226 +0,0 @@ -package cryptfs - -import ( - //"fmt" - "os" - //"io" - "errors" - "crypto/cipher" -) - -type CryptFile struct { - file *os.File - gcm cipher.AEAD -} - -// decryptBlock - Verify and decrypt GCM block -func (be *CryptFS) DecryptBlock(ciphertext []byte) ([]byte, error) { - - // Empty block? - if len(ciphertext) == 0 { - return ciphertext, nil - } - - if len(ciphertext) < NONCE_LEN { - warn.Printf("decryptBlock: Block is too short: %d bytes\n", len(ciphertext)) - return nil, errors.New("Block is too short") - } - - // Extract nonce - nonce := ciphertext[:NONCE_LEN] - ciphertext = ciphertext[NONCE_LEN:] - - // Decrypt - var plaintext []byte - plaintext, err := be.gcm.Open(plaintext, nonce, ciphertext, nil) - if err != nil { - return nil, err - } - - return plaintext, nil -} - -// encryptBlock - Encrypt and add MAC using GCM -func (be *CryptFS) EncryptBlock(plaintext []byte) []byte { - - // Empty block? - if len(plaintext) == 0 { - return plaintext - } - - // Get fresh nonce - nonce := gcmNonce.Get() - - // Encrypt plaintext and append to nonce - ciphertext := be.gcm.Seal(nonce, nonce, plaintext, nil) - - return ciphertext -} - -/* -// readCipherBlock - Read ciphertext block number "blockNo", decrypt, -// return plaintext -func (be *CryptFile) readCipherBlock(blockNo int64) ([]byte, error) { - off := blockNo * int64(be.cipherBS) - buf := make([]byte, be.cipherBS) - - readN, err := be.file.ReadAt(buf, off) - - if err != nil && err != io.EOF { - return nil, err - } - - // Truncate buffer to actually read bytes - buf = buf[:readN] - - // Empty block? - if len(buf) == 0 { - return buf, nil - } - - if len(buf) < NONCE_LEN { - warn.Printf("readCipherBlock: Block is too short: %d bytes\n", len(buf)) - return nil, errors.New("Block is too short") - } - - // Extract nonce - nonce := buf[:NONCE_LEN] - buf = buf[NONCE_LEN:] - - // Decrypt - var plainBuf []byte - plainBuf, err = be.gcm.Open(plainBuf, nonce, buf, nil) - if err != nil { - fmt.Printf("gcm.Open() failed: %d\n", err) - return nil, err - } - - return plainBuf, nil -} -*/ - -// intraBlock identifies a part of a file block -type intraBlock struct { - BlockNo uint64 // Block number in file - Offset uint64 // Offset into block plaintext - Length uint64 // Length of data from this block - fs *CryptFS -} - -// isPartial - is the block partial? This means we have to do read-modify-write. -func (ib *intraBlock) IsPartial() bool { - if ib.Offset > 0 || ib.Length < ib.fs.plainBS { - return true - } - return false -} - -// CiphertextRange - get byte range in ciphertext file corresponding to BlockNo -// (complete block) -func (ib *intraBlock) CiphertextRange() (offset uint64, length uint64) { - return ib.BlockNo * ib.fs.cipherBS, ib.fs.cipherBS -} - -// PlaintextRange - get byte range in plaintext corresponding to BlockNo -// (complete block) -func (ib *intraBlock) PlaintextRange() (offset uint64, length uint64) { - return ib.BlockNo * ib.fs.plainBS, ib.fs.plainBS -} - -// CropBlock - crop a potentially larger plaintext block down to the relevant part -func (ib *intraBlock) CropBlock(d []byte) []byte{ - lenHave := len(d) - lenWant := int(ib.Offset+ib.Length) - if lenHave < lenWant { - return d[ib.Offset:lenHave] - } - return d[ib.Offset:lenWant] -} - -// Split a plaintext byte range into (possible partial) blocks -func (be *CryptFS) SplitRange(offset uint64, length uint64) []intraBlock { - var b intraBlock - var parts []intraBlock - - b.fs = be - - for length > 0 { - b.BlockNo = offset / be.plainBS - b.Offset = offset % be.plainBS - b.Length = be.minu64(length, be.plainBS - b.Offset) - parts = append(parts, b) - offset += b.Length - length -= b.Length - } - return parts -} - -func (be *CryptFS) minu64(x uint64, y uint64) uint64 { - if x < y { - return x - } - return y -} - -/* -// writeCipherBlock - Encrypt plaintext and write it to file block "blockNo" -func (be *CryptFile) writeCipherBlock(blockNo int64, plain []byte) error { - - if int64(len(plain)) > be.plainBS { - panic("writeCipherBlock: Cannot write block that is larger than plainBS") - } - - // Get fresh nonce - nonce := gcmNonce.Get() - // Encrypt data and append to nonce - cipherBuf := be.gcm.Seal(nonce, nonce, plain, nil) - - // WriteAt retries short writes autmatically - written, err := be.file.WriteAt(cipherBuf, blockNo * be.cipherBS) - - debug.Printf("writeCipherBlock: wrote %d ciphertext bytes to block %d\n", - written, blockNo) - - return err -} - -// Perform RMW cycle on block -// Write "data" into file location specified in "b" -func (be *CryptFile) rmwWrite(b intraBlock, data []byte, f *os.File) error { - if b.Length != uint64(len(data)) { - panic("Length mismatch") - } - - oldBlock, err := be.readCipherBlock(b.BlockNo) - if err != nil { - return err - } - newBlockLen := b.Offset + b.Length - debug.Printf("newBlockLen := %d + %d\n", b.Offset, b.Length) - var newBlock []byte - - // Write goes beyond the old block and grows the file? - // Must create a bigger newBlock - if newBlockLen > uint64(len(oldBlock)) { - newBlock = make([]byte, newBlockLen) - } else { - newBlock = make([]byte, len(oldBlock)) - } - - // Fill with old data - copy(newBlock, oldBlock) - // Then overwrite the relevant parts with new data - copy(newBlock[b.Offset:b.Offset + b.Length], data) - - // Actual write - err = be.writeCipherBlock(b.BlockNo, newBlock) - - if err != nil { - // An incomplete write to a ciphertext block means that the whole block - // is destroyed. - fmt.Printf("rmwWrite: Write error: %s\n", err) - } - - return err -} -*/ diff --git a/cryptfs/cryptfs.go b/cryptfs/cryptfs.go index d385a77..9ec511a 100644 --- a/cryptfs/cryptfs.go +++ b/cryptfs/cryptfs.go @@ -1,21 +1,16 @@ package cryptfs +// CryptFS is the crypto backend of GoCryptFS + import ( "crypto/cipher" "crypto/aes" - "fmt" - "strings" - "encoding/base64" - "errors" ) const ( NONCE_LEN = 12 AUTH_TAG_LEN = 16 DEFAULT_PLAINBS = 4096 - - ENCRYPT = true - DECRYPT = false ) type CryptFS struct { @@ -45,169 +40,6 @@ func NewCryptFS(key [16]byte) *CryptFS { } } -/* -func (fs *CryptFS) NewFile(f *os.File) *CryptFile { - return &CryptFile { - file: f, - gcm: fs.gcm, - plainBS: fs.plainBS, - cipherBS: fs.cipherBS, - } -} -*/ - func (be *CryptFS) PlainBS() uint64 { return be.plainBS } - -// DecryptName - decrypt filename -func (be *CryptFS) decryptName(cipherName string) (string, error) { - - bin, err := base64.URLEncoding.DecodeString(cipherName) - if err != nil { - return "", err - } - - if len(bin) % aes.BlockSize != 0 { - return "", errors.New(fmt.Sprintf("Name len=%d is not a multiple of 16", len(bin))) - } - - iv := make([]byte, aes.BlockSize) // TODO ? - cbc := cipher.NewCBCDecrypter(be.blockCipher, iv) - cbc.CryptBlocks(bin, bin) - - bin, err = be.unPad16(bin) - if err != nil { - return "", err - } - - plain := string(bin) - return plain, err -} - -// EncryptName - encrypt filename -func (be *CryptFS) encryptName(plainName string) string { - - bin := []byte(plainName) - bin = be.pad16(bin) - - iv := make([]byte, 16) // TODO ? - cbc := cipher.NewCBCEncrypter(be.blockCipher, iv) - cbc.CryptBlocks(bin, bin) - - cipherName64 := base64.URLEncoding.EncodeToString(bin) - - return cipherName64 -} - -// TranslatePath - encrypt or decrypt path. Just splits the string on "/" -// and hands the parts to EncryptName() / DecryptName() -func (be *CryptFS) translatePath(path string, op bool) (string, error) { - var err error - - // Empty string means root directory - if path == "" { - return path, err - } - - // Run operation on each path component - var translatedParts []string - parts := strings.Split(path, "/") - for _, part := range parts { - var newPart string - if op == ENCRYPT { - newPart = be.encryptName(part) - } else { - newPart, err = be.decryptName(part) - if err != nil { - return "", err - } - } - translatedParts = append(translatedParts, newPart) - } - - return strings.Join(translatedParts, "/"), err -} - -// EncryptPath - encrypt filename or path. Just hands it to TranslatePath(). -func (be *CryptFS) EncryptPath(path string) string { - newPath, _ := be.translatePath(path, ENCRYPT) - return newPath -} - -// DecryptPath - decrypt filename or path. Just hands it to TranslatePath(). -func (be *CryptFS) DecryptPath(path string) (string, error) { - return be.translatePath(path, DECRYPT) -} - -// PlainSize - calculate plaintext size from ciphertext size -func (be *CryptFS) PlainSize(size uint64) uint64 { - // Zero sized files stay zero-sized - if size > 0 { - overhead := be.cipherBS - be.plainBS - nBlocks := (size + be.cipherBS - 1) / be.cipherBS - size -= nBlocks * overhead - } - return size -} - - -// plainSizeFromCipherSize - calculate plaintext size from ciphertext size -func (be *CryptFS) plainSizeFromCipherSize(size int64) int64 { - if size > 0 { - - } - return size -} -// pad16 - pad filename to 16 byte blocks using standard PKCS#7 padding -// https://tools.ietf.org/html/rfc5652#section-6.3 -func (be *CryptFS) pad16(orig []byte) (padded []byte) { - oldLen := len(orig) - if oldLen == 0 { - panic("Padding zero-length string makes no sense") - } - padLen := aes.BlockSize - oldLen % aes.BlockSize - if padLen == 0 { - padLen = aes.BlockSize - } - newLen := oldLen + padLen - padded = make([]byte, newLen) - copy(padded, orig) - padByte := byte(padLen) - for i := oldLen; i < newLen; i++ { - padded[i] = padByte - } - return padded -} - -// unPad16 - remove padding -func (be *CryptFS) unPad16(orig []byte) ([]byte, error) { - oldLen := len(orig) - if oldLen % aes.BlockSize != 0 { - return nil, errors.New("Unaligned size") - } - // The last byte is always a padding byte - padByte := orig[oldLen -1] - // The padding byte's value is the padding length - padLen := int(padByte) - // Padding must be at least 1 byte - if padLen <= 0 { - return nil, errors.New("Padding cannot be zero-length") - } - // Larger paddings make no sense - if padLen > aes.BlockSize { - return nil, errors.New("Padding cannot be larger than 16") - } - // All padding bytes must be identical - for i := oldLen - padLen; i < oldLen; i++ { - if orig[i] != padByte { - return nil, errors.New(fmt.Sprintf("Padding byte at i=%d is invalid", i)) - } - } - newLen := oldLen - padLen - // Padding an empty string makes no sense - if newLen == 0 { - return nil, errors.New("Unpadded length is zero") - } - return orig[0:newLen], nil -} diff --git a/cryptfs/cryptfs_content.go b/cryptfs/cryptfs_content.go new file mode 100644 index 0000000..b3c7f95 --- /dev/null +++ b/cryptfs/cryptfs_content.go @@ -0,0 +1,94 @@ +package cryptfs + +// File content encryption / decryption + +import ( + "os" + "errors" + "crypto/cipher" +) + +type CryptFile struct { + file *os.File + gcm cipher.AEAD +} + +// decryptBlock - Verify and decrypt GCM block +func (be *CryptFS) DecryptBlock(ciphertext []byte) ([]byte, error) { + + // Empty block? + if len(ciphertext) == 0 { + return ciphertext, nil + } + + if len(ciphertext) < NONCE_LEN { + warn.Printf("decryptBlock: Block is too short: %d bytes\n", len(ciphertext)) + return nil, errors.New("Block is too short") + } + + // Extract nonce + nonce := ciphertext[:NONCE_LEN] + ciphertext = ciphertext[NONCE_LEN:] + + // Decrypt + var plaintext []byte + plaintext, err := be.gcm.Open(plaintext, nonce, ciphertext, nil) + if err != nil { + return nil, err + } + + return plaintext, nil +} + +// encryptBlock - Encrypt and add MAC using GCM +func (be *CryptFS) EncryptBlock(plaintext []byte) []byte { + + // Empty block? + if len(plaintext) == 0 { + return plaintext + } + + // Get fresh nonce + nonce := gcmNonce.Get() + + // Encrypt plaintext and append to nonce + ciphertext := be.gcm.Seal(nonce, nonce, plaintext, nil) + + return ciphertext +} + +// Split a plaintext byte range into (possible partial) blocks +func (be *CryptFS) SplitRange(offset uint64, length uint64) []intraBlock { + var b intraBlock + var parts []intraBlock + + b.fs = be + + for length > 0 { + b.BlockNo = offset / be.plainBS + b.Offset = offset % be.plainBS + b.Length = be.minu64(length, be.plainBS - b.Offset) + parts = append(parts, b) + offset += b.Length + length -= b.Length + } + return parts +} + +// PlainSize - calculate plaintext size from ciphertext size +func (be *CryptFS) PlainSize(size uint64) uint64 { + // Zero sized files stay zero-sized + if size > 0 { + overhead := be.cipherBS - be.plainBS + nBlocks := (size + be.cipherBS - 1) / be.cipherBS + size -= nBlocks * overhead + } + return size +} + +func (be *CryptFS) minu64(x uint64, y uint64) uint64 { + if x < y { + return x + } + return y +} diff --git a/cryptfs/cryptfs_names.go b/cryptfs/cryptfs_names.go new file mode 100644 index 0000000..3dfcae9 --- /dev/null +++ b/cryptfs/cryptfs_names.go @@ -0,0 +1,150 @@ +package cryptfs + +// Filename encryption / decryption function + +import ( + "crypto/cipher" + "crypto/aes" + "fmt" + "strings" + "encoding/base64" + "errors" +) + +const ( + ENCRYPT = true + DECRYPT = false +) + +// DecryptName - decrypt filename +func (be *CryptFS) decryptName(cipherName string) (string, error) { + + bin, err := base64.URLEncoding.DecodeString(cipherName) + if err != nil { + return "", err + } + + if len(bin) % aes.BlockSize != 0 { + return "", errors.New(fmt.Sprintf("Name len=%d is not a multiple of 16", len(bin))) + } + + iv := make([]byte, aes.BlockSize) // TODO ? + cbc := cipher.NewCBCDecrypter(be.blockCipher, iv) + cbc.CryptBlocks(bin, bin) + + bin, err = be.unPad16(bin) + if err != nil { + return "", err + } + + plain := string(bin) + return plain, err +} + +// EncryptName - encrypt filename +func (be *CryptFS) encryptName(plainName string) string { + + bin := []byte(plainName) + bin = be.pad16(bin) + + iv := make([]byte, 16) // TODO ? + cbc := cipher.NewCBCEncrypter(be.blockCipher, iv) + cbc.CryptBlocks(bin, bin) + + cipherName64 := base64.URLEncoding.EncodeToString(bin) + + return cipherName64 +} + +// TranslatePath - encrypt or decrypt path. Just splits the string on "/" +// and hands the parts to EncryptName() / DecryptName() +func (be *CryptFS) translatePath(path string, op bool) (string, error) { + var err error + + // Empty string means root directory + if path == "" { + return path, err + } + + // Run operation on each path component + var translatedParts []string + parts := strings.Split(path, "/") + for _, part := range parts { + var newPart string + if op == ENCRYPT { + newPart = be.encryptName(part) + } else { + newPart, err = be.decryptName(part) + if err != nil { + return "", err + } + } + translatedParts = append(translatedParts, newPart) + } + + return strings.Join(translatedParts, "/"), err +} + +// EncryptPath - encrypt filename or path. Just hands it to TranslatePath(). +func (be *CryptFS) EncryptPath(path string) string { + newPath, _ := be.translatePath(path, ENCRYPT) + return newPath +} + +// DecryptPath - decrypt filename or path. Just hands it to TranslatePath(). +func (be *CryptFS) DecryptPath(path string) (string, error) { + return be.translatePath(path, DECRYPT) +} + +// pad16 - pad filename to 16 byte blocks using standard PKCS#7 padding +// https://tools.ietf.org/html/rfc5652#section-6.3 +func (be *CryptFS) pad16(orig []byte) (padded []byte) { + oldLen := len(orig) + if oldLen == 0 { + panic("Padding zero-length string makes no sense") + } + padLen := aes.BlockSize - oldLen % aes.BlockSize + if padLen == 0 { + padLen = aes.BlockSize + } + newLen := oldLen + padLen + padded = make([]byte, newLen) + copy(padded, orig) + padByte := byte(padLen) + for i := oldLen; i < newLen; i++ { + padded[i] = padByte + } + return padded +} + +// unPad16 - remove padding +func (be *CryptFS) unPad16(orig []byte) ([]byte, error) { + oldLen := len(orig) + if oldLen % aes.BlockSize != 0 { + return nil, errors.New("Unaligned size") + } + // The last byte is always a padding byte + padByte := orig[oldLen -1] + // The padding byte's value is the padding length + padLen := int(padByte) + // Padding must be at least 1 byte + if padLen <= 0 { + return nil, errors.New("Padding cannot be zero-length") + } + // Larger paddings make no sense + if padLen > aes.BlockSize { + return nil, errors.New("Padding cannot be larger than 16") + } + // All padding bytes must be identical + for i := oldLen - padLen; i < oldLen; i++ { + if orig[i] != padByte { + return nil, errors.New(fmt.Sprintf("Padding byte at i=%d is invalid", i)) + } + } + newLen := oldLen - padLen + // Padding an empty string makes no sense + if newLen == 0 { + return nil, errors.New("Unpadded length is zero") + } + return orig[0:newLen], nil +} diff --git a/cryptfs/intrablock.go b/cryptfs/intrablock.go new file mode 100644 index 0000000..78fd140 --- /dev/null +++ b/cryptfs/intrablock.go @@ -0,0 +1,39 @@ +package cryptfs + +// intraBlock identifies a part of a file block +type intraBlock struct { + BlockNo uint64 // Block number in file + Offset uint64 // Offset into block plaintext + Length uint64 // Length of data from this block + fs *CryptFS +} + +// isPartial - is the block partial? This means we have to do read-modify-write. +func (ib *intraBlock) IsPartial() bool { + if ib.Offset > 0 || ib.Length < ib.fs.plainBS { + return true + } + return false +} + +// CiphertextRange - get byte range in ciphertext file corresponding to BlockNo +// (complete block) +func (ib *intraBlock) CiphertextRange() (offset uint64, length uint64) { + return ib.BlockNo * ib.fs.cipherBS, ib.fs.cipherBS +} + +// PlaintextRange - get byte range in plaintext corresponding to BlockNo +// (complete block) +func (ib *intraBlock) PlaintextRange() (offset uint64, length uint64) { + return ib.BlockNo * ib.fs.plainBS, ib.fs.plainBS +} + +// CropBlock - crop a potentially larger plaintext block down to the relevant part +func (ib *intraBlock) CropBlock(d []byte) []byte{ + lenHave := len(d) + lenWant := int(ib.Offset+ib.Length) + if lenHave < lenWant { + return d[ib.Offset:lenHave] + } + return d[ib.Offset:lenWant] +} diff --git a/frontend/checks.go b/frontend/checks.go deleted file mode 100644 index 30720f6..0000000 --- a/frontend/checks.go +++ /dev/null @@ -1,31 +0,0 @@ -package frontend - -import ( - "bazil.org/fuse/fs" -) - -// Compile-time interface checks. -var _ fs.FS = (*FS)(nil) -var _ fs.FSStatfser = (*FS)(nil) - -var _ fs.Node = (*Dir)(nil) -var _ fs.NodeCreater = (*Dir)(nil) -var _ fs.NodeMkdirer = (*Dir)(nil) -var _ fs.NodeRemover = (*Dir)(nil) -var _ fs.NodeRenamer = (*Dir)(nil) -var _ fs.HandleReadDirAller = (*Dir)(nil) - -var _ fs.HandleReader = (*File)(nil) -var _ fs.HandleWriter = (*File)(nil) -var _ fs.Node = (*File)(nil) -var _ fs.NodeOpener = (*File)(nil) -var _ fs.NodeSetattrer = (*File)(nil) - -func foo(h fs.HandleReadDirAller) { - -} - -func init() { - var d Dir - foo(&d) -} diff --git a/frontend/dir.go b/frontend/dir.go deleted file mode 100644 index ee5c474..0000000 --- a/frontend/dir.go +++ /dev/null @@ -1,122 +0,0 @@ -package frontend - -import ( - "fmt" - "github.com/rfjakob/gocryptfs/cryptfs" - "github.com/rfjakob/cluefs/lib/cluefs" - "bazil.org/fuse" - fusefs "bazil.org/fuse/fs" - "golang.org/x/net/context" -) - -type Dir struct { - *cluefs.Dir - - crfs *cryptfs.CryptFS -} - -func NewDir(parent string, name string, fs *FS) *Dir { - fmt.Printf("NewDir parent=%s name=%s\n", parent, name) - return &Dir { - Dir: cluefs.NewDir(parent, name, fs.ClueFS), - crfs: fs.CryptFS, - } -} - -func (d *Dir) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fusefs.Handle, error) { - fmt.Printf("Open\n") - h, err := d.Dir.Open(ctx, req, resp) - if err != nil { - return nil, err - } - clueDir := h.(*cluefs.Dir) - - return &Dir { - Dir: clueDir, - crfs: d.crfs, - }, nil -} - -func (d *Dir) Lookup(ctx context.Context, req *fuse.LookupRequest, resp *fuse.LookupResponse) (fusefs.Node, error) { - fmt.Printf("Lookup %s\n", req.Name) - req.Name = d.crfs.EncryptPath(req.Name) - node, err := d.Dir.Lookup(ctx, req, resp) - if err != nil { - return nil, err - } - clueDir, ok := node.(*cluefs.Dir) - if ok { - return &Dir { - Dir: clueDir, - crfs: d.crfs, - }, nil - } else { - resp.Attr.Size = d.crfs.PlainSize(resp.Attr.Size) - clueFile := node.(*cluefs.File) - return &File { - File: clueFile, - crfs: d.crfs, - }, nil - } -} - -func (d *Dir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) { - fmt.Printf("ReadDirAll\n") - entries, err := d.Dir.ReadDirAll(ctx) - if err != nil { - return nil, err - } - var decrypted []fuse.Dirent - for _, e := range entries { - if e.Name == "." || e.Name == ".." { - decrypted = append(decrypted, e) - continue - } - newName, err := d.crfs.DecryptPath(e.Name) - if err != nil { - fmt.Printf("ReadDirAll: Error decoding \"%s\": %s\n", e.Name, err.Error()) - continue - } - e.Name = newName - decrypted = append(decrypted, e) - } - return decrypted, nil -} - -func (d *Dir) Mkdir(ctx context.Context, req *fuse.MkdirRequest) (fusefs.Node, error) { - fmt.Printf("Mkdir %s\n", req.Name) - req.Name = d.crfs.EncryptPath(req.Name) - n, err := d.Dir.Mkdir(ctx, req) - if err != nil { - return nil, err - } - clueDir := n.(*cluefs.Dir) - return &Dir { - Dir: clueDir, - crfs: d.crfs, - }, nil -} - -func (d *Dir) Remove(ctx context.Context, req *fuse.RemoveRequest) error { - fmt.Printf("Remove\n") - req.Name = d.crfs.EncryptPath(req.Name) - return d.Dir.Remove(ctx, req) -} - -func (d *Dir) Create(ctx context.Context, req *fuse.CreateRequest, resp *fuse.CreateResponse) (fusefs.Node, fusefs.Handle, error) { - fmt.Printf("Create\n") - - req.Flags, _ = fixFlags(req.Flags) - - req.Name = d.crfs.EncryptPath(req.Name) - n, _, err := d.Dir.Create(ctx, req, resp) - if err != nil { - return nil, nil, err - } - clueFile := n.(*cluefs.File) - cryptFile := &File { - File: clueFile, - crfs: d.crfs, - } - return cryptFile, cryptFile, nil -} diff --git a/frontend/fe_checks.go b/frontend/fe_checks.go new file mode 100644 index 0000000..30720f6 --- /dev/null +++ b/frontend/fe_checks.go @@ -0,0 +1,31 @@ +package frontend + +import ( + "bazil.org/fuse/fs" +) + +// Compile-time interface checks. +var _ fs.FS = (*FS)(nil) +var _ fs.FSStatfser = (*FS)(nil) + +var _ fs.Node = (*Dir)(nil) +var _ fs.NodeCreater = (*Dir)(nil) +var _ fs.NodeMkdirer = (*Dir)(nil) +var _ fs.NodeRemover = (*Dir)(nil) +var _ fs.NodeRenamer = (*Dir)(nil) +var _ fs.HandleReadDirAller = (*Dir)(nil) + +var _ fs.HandleReader = (*File)(nil) +var _ fs.HandleWriter = (*File)(nil) +var _ fs.Node = (*File)(nil) +var _ fs.NodeOpener = (*File)(nil) +var _ fs.NodeSetattrer = (*File)(nil) + +func foo(h fs.HandleReadDirAller) { + +} + +func init() { + var d Dir + foo(&d) +} diff --git a/frontend/fe_dir.go b/frontend/fe_dir.go new file mode 100644 index 0000000..75b665b --- /dev/null +++ b/frontend/fe_dir.go @@ -0,0 +1,133 @@ +package frontend + +// frontend sits between FUSE and ClueFS +// and uses cryptfs for all crypto operations +// +// cryptfs +// ^ +// | +// v +// FUSE <-> frontend <-> ClueFS +// +// This file handles directories + +import ( + "fmt" + "github.com/rfjakob/gocryptfs/cryptfs" + "github.com/rfjakob/cluefs/lib/cluefs" + "bazil.org/fuse" + fusefs "bazil.org/fuse/fs" + "golang.org/x/net/context" +) + +type Dir struct { + *cluefs.Dir + + crfs *cryptfs.CryptFS +} + +func NewDir(parent string, name string, fs *FS) *Dir { + fmt.Printf("NewDir parent=%s name=%s\n", parent, name) + return &Dir { + Dir: cluefs.NewDir(parent, name, fs.ClueFS), + crfs: fs.CryptFS, + } +} + +func (d *Dir) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fusefs.Handle, error) { + fmt.Printf("Open\n") + h, err := d.Dir.Open(ctx, req, resp) + if err != nil { + return nil, err + } + clueDir := h.(*cluefs.Dir) + + return &Dir { + Dir: clueDir, + crfs: d.crfs, + }, nil +} + +func (d *Dir) Lookup(ctx context.Context, req *fuse.LookupRequest, resp *fuse.LookupResponse) (fusefs.Node, error) { + fmt.Printf("Lookup %s\n", req.Name) + req.Name = d.crfs.EncryptPath(req.Name) + node, err := d.Dir.Lookup(ctx, req, resp) + if err != nil { + return nil, err + } + clueDir, ok := node.(*cluefs.Dir) + if ok { + return &Dir { + Dir: clueDir, + crfs: d.crfs, + }, nil + } else { + resp.Attr.Size = d.crfs.PlainSize(resp.Attr.Size) + clueFile := node.(*cluefs.File) + return &File { + File: clueFile, + crfs: d.crfs, + }, nil + } +} + +func (d *Dir) ReadDirAll(ctx context.Context) ([]fuse.Dirent, error) { + fmt.Printf("ReadDirAll\n") + entries, err := d.Dir.ReadDirAll(ctx) + if err != nil { + return nil, err + } + var decrypted []fuse.Dirent + for _, e := range entries { + if e.Name == "." || e.Name == ".." { + decrypted = append(decrypted, e) + continue + } + newName, err := d.crfs.DecryptPath(e.Name) + if err != nil { + fmt.Printf("ReadDirAll: Error decoding \"%s\": %s\n", e.Name, err.Error()) + continue + } + e.Name = newName + decrypted = append(decrypted, e) + } + return decrypted, nil +} + +func (d *Dir) Mkdir(ctx context.Context, req *fuse.MkdirRequest) (fusefs.Node, error) { + fmt.Printf("Mkdir %s\n", req.Name) + req.Name = d.crfs.EncryptPath(req.Name) + n, err := d.Dir.Mkdir(ctx, req) + if err != nil { + return nil, err + } + clueDir := n.(*cluefs.Dir) + return &Dir { + Dir: clueDir, + crfs: d.crfs, + }, nil +} + +func (d *Dir) Remove(ctx context.Context, req *fuse.RemoveRequest) error { + fmt.Printf("Remove\n") + req.Name = d.crfs.EncryptPath(req.Name) + return d.Dir.Remove(ctx, req) +} + +func (d *Dir) Create(ctx context.Context, req *fuse.CreateRequest, resp *fuse.CreateResponse) (fusefs.Node, fusefs.Handle, error) { + fmt.Printf("Create\n") + + req.Flags, _ = fixFlags(req.Flags) + + req.Name = d.crfs.EncryptPath(req.Name) + n, _, err := d.Dir.Create(ctx, req, resp) + if err != nil { + return nil, nil, err + } + clueFile := n.(*cluefs.File) + cryptFile := &File { + File: clueFile, + crfs: d.crfs, + } + return cryptFile, cryptFile, nil +} diff --git a/frontend/fe_file.go b/frontend/fe_file.go new file mode 100644 index 0000000..4bd623f --- /dev/null +++ b/frontend/fe_file.go @@ -0,0 +1,144 @@ +package frontend + +// frontend sits between FUSE and ClueFS +// and uses cryptfs for all crypto operations +// +// cryptfs +// ^ +// | +// v +// FUSE <-> frontend <-> ClueFS +// +// This file handles files access + +import ( + "fmt" + "github.com/rfjakob/gocryptfs/cryptfs" + "github.com/rfjakob/cluefs/lib/cluefs" + + "bazil.org/fuse" + fusefs "bazil.org/fuse/fs" + "golang.org/x/net/context" +) + +func fixFlags(flags fuse.OpenFlags) (fuse.OpenFlags, bool) { + fmt.Printf("fixFlags: Before: %s\n", flags.String()) + var writeOnly bool + // We always need read access to do read-modify-write cycles + if flags & fuse.OpenWriteOnly > 0 { + flags = flags &^ fuse.OpenWriteOnly + flags = flags | fuse.OpenReadWrite + writeOnly = true + } + // We also cannot open the file in append mode, we need to seek back for RMW + flags = flags &^ fuse.OpenAppend + fmt.Printf("fixFlags: After: %s\n", flags.String()) + return flags, writeOnly +} + +func max(x int, y int) int { + if x > y { + return x + } + return y +} + +type File struct { + *cluefs.File + crfs *cryptfs.CryptFS + // Remember if the file is supposed to be write-only + writeOnly bool +} + +func (f *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fusefs.Handle, error) { + fmt.Printf("File.Open\n") + + req.Flags, f.writeOnly = fixFlags(req.Flags) + + h, err := f.File.Open(ctx, req, resp) + if err != nil { + return nil, err + } + clueFile := h.(*cluefs.File) + return &File { + File: clueFile, + crfs: f.crfs, + }, nil +} + +func (f *File) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error { + iblocks := f.crfs.SplitRange(uint64(req.Offset), uint64(req.Size)) + for _, ib := range iblocks { + var partReq fuse.ReadRequest + var partResp fuse.ReadResponse + o, l := ib.CiphertextRange() + partReq.Offset = int64(o) + partReq.Size = int(l) + partResp.Data = make([]byte, int(l)) + err := f.File.Read(ctx, &partReq, &partResp) + if err != nil { + return err + } + plaintext, err := f.crfs.DecryptBlock(partResp.Data) + if err != nil { + fmt.Printf("Read: Error reading block %d: %s\n", ib.BlockNo, err.Error()) + return err + } + plaintext = ib.CropBlock(plaintext) + resp.Data = append(resp.Data, plaintext...) + } + return nil +} + +func (f *File) Write(ctx context.Context, req *fuse.WriteRequest, resp *fuse.WriteResponse) error { + fmt.Printf("File.Write\n") + resp.Size = 0 + iblocks := f.crfs.SplitRange(uint64(req.Offset), uint64(len(req.Data))) + var blockData []byte + for _, ib := range iblocks { + if ib.IsPartial() { + // RMW + blockData = make([]byte, f.crfs.PlainBS()) + var readReq fuse.ReadRequest + var readResp fuse.ReadResponse + o, l := ib.PlaintextRange() + readReq.Offset = int64(o) + readReq.Size = int(l) + err := f.Read(ctx, &readReq, &readResp) + if err != nil { + return err + } + copy(blockData, readResp.Data) + copy(blockData[ib.Offset:ib.Offset+ib.Length], req.Data) + blockLen := max(len(readResp.Data), int(ib.Offset+ib.Length)) + blockData = blockData[0:blockLen] + } else { + blockData = req.Data[0:f.crfs.PlainBS()] + } + ciphertext := f.crfs.EncryptBlock(blockData) + var partReq fuse.WriteRequest + var partResp fuse.WriteResponse + o, _ := ib.CiphertextRange() + partReq.Data = ciphertext + partReq.Offset = int64(o) + err := f.File.Write(ctx, &partReq, &partResp) + if err != nil { + fmt.Printf("Write failure: %s\n", err.Error()) + return err + } + // Remove written data from the front of the request + req.Data = req.Data[len(blockData):len(req.Data)] + resp.Size += len(blockData) + } + return nil +} + +func (f *File) Attr(ctx context.Context, attr *fuse.Attr) error { + fmt.Printf("Attr\n") + err := f.File.Node.Attr(ctx, attr) + if err != nil { + return err + } + attr.Size = f.crfs.PlainSize(attr.Size) + return nil +} diff --git a/frontend/fe_fs.go b/frontend/fe_fs.go new file mode 100644 index 0000000..470095f --- /dev/null +++ b/frontend/fe_fs.go @@ -0,0 +1,47 @@ +package frontend + +// frontend sits between FUSE and ClueFS +// and uses cryptfs for all crypto operations +// +// cryptfs +// ^ +// | +// v +// FUSE <-> frontend <-> ClueFS +// +// This file handles just the root directory + +import ( + "fmt" + "github.com/rfjakob/gocryptfs/cryptfs" + "github.com/rfjakob/cluefs/lib/cluefs" + fusefs "bazil.org/fuse/fs" +) + +type FS struct { + *cryptfs.CryptFS + *cluefs.ClueFS + backing string +} + +type nullTracer struct {} + +func (nullTracer) Trace(op cluefs.FsOperTracer) {} + +func NewFS(key [16]byte, backing string) *FS { + var nt nullTracer + clfs, err := cluefs.NewClueFS(backing, nt) + if err != nil { + panic(err) + } + return &FS { + CryptFS: cryptfs.NewCryptFS(key), + ClueFS: clfs, + backing: backing, + } +} + +func (fs *FS) Root() (fusefs.Node, error) { + fmt.Printf("Root\n") + return NewDir("", fs.backing, fs), nil +} diff --git a/frontend/file.go b/frontend/file.go deleted file mode 100644 index ef74491..0000000 --- a/frontend/file.go +++ /dev/null @@ -1,133 +0,0 @@ -package frontend - -import ( - "fmt" - "github.com/rfjakob/gocryptfs/cryptfs" - "github.com/rfjakob/cluefs/lib/cluefs" - - "bazil.org/fuse" - fusefs "bazil.org/fuse/fs" - "golang.org/x/net/context" -) - -func fixFlags(flags fuse.OpenFlags) (fuse.OpenFlags, bool) { - fmt.Printf("fixFlags: Before: %s\n", flags.String()) - var writeOnly bool - // We always need read access to do read-modify-write cycles - if flags & fuse.OpenWriteOnly > 0 { - flags = flags &^ fuse.OpenWriteOnly - flags = flags | fuse.OpenReadWrite - writeOnly = true - } - // We also cannot open the file in append mode, we need to seek back for RMW - flags = flags &^ fuse.OpenAppend - fmt.Printf("fixFlags: After: %s\n", flags.String()) - return flags, writeOnly -} - -func max(x int, y int) int { - if x > y { - return x - } - return y -} - -type File struct { - *cluefs.File - crfs *cryptfs.CryptFS - // Remember if the file is supposed to be write-only - writeOnly bool -} - -func (f *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fusefs.Handle, error) { - fmt.Printf("File.Open\n") - - req.Flags, f.writeOnly = fixFlags(req.Flags) - - h, err := f.File.Open(ctx, req, resp) - if err != nil { - return nil, err - } - clueFile := h.(*cluefs.File) - return &File { - File: clueFile, - crfs: f.crfs, - }, nil -} - -func (f *File) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error { - iblocks := f.crfs.SplitRange(uint64(req.Offset), uint64(req.Size)) - for _, ib := range iblocks { - var partReq fuse.ReadRequest - var partResp fuse.ReadResponse - o, l := ib.CiphertextRange() - partReq.Offset = int64(o) - partReq.Size = int(l) - partResp.Data = make([]byte, int(l)) - err := f.File.Read(ctx, &partReq, &partResp) - if err != nil { - return err - } - plaintext, err := f.crfs.DecryptBlock(partResp.Data) - if err != nil { - fmt.Printf("Read: Error reading block %d: %s\n", ib.BlockNo, err.Error()) - return err - } - plaintext = ib.CropBlock(plaintext) - resp.Data = append(resp.Data, plaintext...) - } - return nil -} - -func (f *File) Write(ctx context.Context, req *fuse.WriteRequest, resp *fuse.WriteResponse) error { - fmt.Printf("File.Write\n") - resp.Size = 0 - iblocks := f.crfs.SplitRange(uint64(req.Offset), uint64(len(req.Data))) - var blockData []byte - for _, ib := range iblocks { - if ib.IsPartial() { - // RMW - blockData = make([]byte, f.crfs.PlainBS()) - var readReq fuse.ReadRequest - var readResp fuse.ReadResponse - o, l := ib.PlaintextRange() - readReq.Offset = int64(o) - readReq.Size = int(l) - err := f.Read(ctx, &readReq, &readResp) - if err != nil { - return err - } - copy(blockData, readResp.Data) - copy(blockData[ib.Offset:ib.Offset+ib.Length], req.Data) - blockLen := max(len(readResp.Data), int(ib.Offset+ib.Length)) - blockData = blockData[0:blockLen] - } else { - blockData = req.Data[0:f.crfs.PlainBS()] - } - ciphertext := f.crfs.EncryptBlock(blockData) - var partReq fuse.WriteRequest - var partResp fuse.WriteResponse - o, _ := ib.CiphertextRange() - partReq.Data = ciphertext - partReq.Offset = int64(o) - err := f.File.Write(ctx, &partReq, &partResp) - if err != nil { - fmt.Printf("Write failure: %s\n", err.Error()) - return err - } - // Remove written data from the front of the request - req.Data = req.Data[len(blockData):len(req.Data)] - resp.Size += len(blockData) - } - return nil -} - -func (f *File) Attr(ctx context.Context, attr *fuse.Attr) error { - fmt.Printf("Attr\n") - err := f.File.Node.Attr(ctx, attr) - if err != nil { - return err - } - attr.Size = f.crfs.PlainSize(attr.Size) - return nil -} diff --git a/frontend/fs.go b/frontend/fs.go deleted file mode 100644 index 83d1953..0000000 --- a/frontend/fs.go +++ /dev/null @@ -1,36 +0,0 @@ -package frontend - -import ( - "fmt" - "github.com/rfjakob/gocryptfs/cryptfs" - "github.com/rfjakob/cluefs/lib/cluefs" - fusefs "bazil.org/fuse/fs" -) - -type FS struct { - *cryptfs.CryptFS - *cluefs.ClueFS - backing string -} - -type nullTracer struct {} - -func (nullTracer) Trace(op cluefs.FsOperTracer) {} - -func NewFS(key [16]byte, backing string) *FS { - var nt nullTracer - clfs, err := cluefs.NewClueFS(backing, nt) - if err != nil { - panic(err) - } - return &FS { - CryptFS: cryptfs.NewCryptFS(key), - ClueFS: clfs, - backing: backing, - } -} - -func (fs *FS) Root() (fusefs.Node, error) { - fmt.Printf("Root\n") - return NewDir("", fs.backing, fs), nil -} -- cgit v1.2.3