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Diffstat (limited to 'cryptfs/cryptfs_names.go')
-rw-r--r--cryptfs/cryptfs_names.go156
1 files changed, 0 insertions, 156 deletions
diff --git a/cryptfs/cryptfs_names.go b/cryptfs/cryptfs_names.go
deleted file mode 100644
index 8f8486b..0000000
--- a/cryptfs/cryptfs_names.go
+++ /dev/null
@@ -1,156 +0,0 @@
-package cryptfs
-
-// Filename encryption / decryption function
-
-import (
- "crypto/aes"
- "crypto/cipher"
- "encoding/base64"
- "errors"
- "fmt"
- "strings"
-)
-
-const (
- OpEncrypt = iota
- OpDecrypt
-)
-
-// DecryptName - decrypt base64-encoded encrypted filename "cipherName"
-func (be *CryptFS) DecryptName(cipherName string, iv []byte) (string, error) {
-
- // Make sure relative symlinks still work after encryption
- // by passing these through unchanged
- if cipherName == "." || cipherName == ".." {
- return cipherName, nil
- }
-
- bin, err := base64.URLEncoding.DecodeString(cipherName)
- if err != nil {
- return "", err
- }
-
- if len(bin)%aes.BlockSize != 0 {
- return "", fmt.Errorf("Decoded length %d is not a multiple of the AES block size", len(bin))
- }
-
- 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, iv []byte) string {
-
- // Make sure relative symlinks still work after encryption
- // by passing these trough unchanged
- if plainName == "." || plainName == ".." {
- return plainName
- }
-
- bin := []byte(plainName)
- bin = be.pad16(bin)
-
- cbc := cipher.NewCBCEncrypter(be.blockCipher, iv)
- cbc.CryptBlocks(bin, bin)
-
- cipherName64 := base64.URLEncoding.EncodeToString(bin)
- return cipherName64
-}
-
-// TranslatePathZeroIV - encrypt or decrypt path using CBC with a constant all-zero IV.
-// Just splits the string on "/" and hands the parts to encryptName() / decryptName()
-func (be *CryptFS) TranslatePathZeroIV(path string, op int) (string, error) {
- var err error
-
- // Empty string means root directory
- if path == "" {
- return path, err
- }
-
- zeroIV := make([]byte, DIRIV_LEN)
-
- // Run operation on each path component
- var translatedParts []string
- parts := strings.Split(path, "/")
- for _, part := range parts {
- if part == "" {
- // This happens on "/foo/bar/" on the front and on the end.
- // Don't panic.
- translatedParts = append(translatedParts, "")
- continue
- }
- var newPart string
- if op == OpEncrypt {
- newPart = be.encryptName(part, zeroIV)
- } else {
- newPart, err = be.DecryptName(part, zeroIV)
- if err != nil {
- return "", err
- }
- }
- translatedParts = append(translatedParts, newPart)
- }
-
- return strings.Join(translatedParts, "/"), err
-}
-
-// 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
-}