From 05a5c0a0fffb4cb27c6e2dccda42d18ee067631c Mon Sep 17 00:00:00 2001
From: Jakob Unterwurzacher
Date: Sat, 5 Sep 2015 11:49:05 +0200
Subject: Wrap cluefs part I

---
 cryptfs/fs.go | 201 ----------------------------------------------------------
 1 file changed, 201 deletions(-)
 delete mode 100644 cryptfs/fs.go

(limited to 'cryptfs/fs.go')

diff --git a/cryptfs/fs.go b/cryptfs/fs.go
deleted file mode 100644
index f5781e2..0000000
--- a/cryptfs/fs.go
+++ /dev/null
@@ -1,201 +0,0 @@
-package cryptfs
-
-import (
-	"crypto/cipher"
-	"crypto/aes"
-	"fmt"
-	"strings"
-	"encoding/base64"
-	"errors"
-	"os"
-)
-
-const (
-	NONCE_LEN = 12
-	AUTH_TAG_LEN = 16
-	DEFAULT_PLAINBS = 4096
-
-	ENCRYPT = true
-	DECRYPT = false
-)
-
-type CryptFS struct {
-	blockCipher cipher.Block
-	gcm cipher.AEAD
-	plainBS	int64
-	cipherBS int64
-}
-
-func NewCryptFS(key [16]byte) *CryptFS {
-
-	b, err := aes.NewCipher(key[:])
-	if err != nil {
-		panic(err)
-	}
-
-	g, err := cipher.NewGCM(b)
-	if err != nil {
-		panic(err)
-	}
-
-	return &CryptFS{
-		blockCipher: b,
-		gcm: g,
-		plainBS: DEFAULT_PLAINBS,
-		cipherBS: DEFAULT_PLAINBS + NONCE_LEN + AUTH_TAG_LEN,
-	}
-}
-
-func (fs *CryptFS) NewFile(f *os.File) *CryptFile {
-	return &CryptFile {
-		file: f,
-		gcm: fs.gcm,
-		plainBS: fs.plainBS,
-		cipherBS: fs.cipherBS,
-	}
-}
-
-// 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(s int64) int64 {
-	// Zero sized files stay zero-sized
-	if s > 0 {
-		// Number of blocks
-		n := s / be.cipherBS + 1
-		overhead := be.cipherBS - be.plainBS
-		s -= n * overhead
-	}
-	return s
-}
-
-// 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
-}
-- 
cgit v1.2.3