diff options
Diffstat (limited to 'internal/nametransform')
| -rw-r--r-- | internal/nametransform/names.go | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/internal/nametransform/names.go b/internal/nametransform/names.go index 71c8cd3..c96f7ce 100644 --- a/internal/nametransform/names.go +++ b/internal/nametransform/names.go @@ -2,6 +2,7 @@ package nametransform import ( + "bytes" "crypto/aes" "encoding/base64" "syscall" @@ -34,10 +35,8 @@ func New(e *eme.EMECipher, longNames bool, raw64 bool) *NameTransform { } } -// DecryptName - decrypt base64-encoded encrypted filename "cipherName" -// -// This function is exported because it allows for a very efficient readdir -// implementation (read IV once, decrypt all names using this function). +// DecryptName decrypts a base64-encoded encrypted filename "cipherName" using the +// initialization vector "iv". func (n *NameTransform) DecryptName(cipherName string, iv []byte) (string, error) { bin, err := n.B64.DecodeString(cipherName) if err != nil { @@ -45,16 +44,21 @@ func (n *NameTransform) DecryptName(cipherName string, iv []byte) (string, error } if len(bin)%aes.BlockSize != 0 { tlog.Debug.Printf("DecryptName %q: decoded length %d is not a multiple of 16", cipherName, len(bin)) - return "", syscall.EINVAL + return "", syscall.EBADMSG } bin = n.emeCipher.Decrypt(iv, bin) bin, err = unPad16(bin) if err != nil { - tlog.Debug.Printf("pad16 error detail: %v", err) + tlog.Debug.Printf("DecryptName: unPad16 error: %v", err) // unPad16 returns detailed errors including the position of the // incorrect bytes. Kill the padding oracle by lumping everything into // a generic error. - return "", syscall.EINVAL + return "", syscall.EBADMSG + } + // A name can never contain a null byte or "/". Make sure we never return those + // to the user, even when we read a corrupted (or fuzzed) filesystem. + if bytes.Contains(bin, []byte{0}) || bytes.Contains(bin, []byte("/")) { + return "", syscall.EBADMSG } plain := string(bin) return plain, err |