From ec0916c59d0125ac785a50d3787fddbc451599bf Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Mon, 12 Dec 2016 15:20:40 +0000
Subject: [PATCH] crypt: return unexpected EOF instead of Failed to
authenticate decrypted block #873
Streams which truncated early with an EOF message would return a
"Failed to authenticate decrypted block" error. While technically
correct, this isn't a helpful error message as it masks the underlying
problem. This changes it to return "unexpected EOF" instead.
The rest of rclone knows it should retry such errors.
---
crypt/cipher.go | 5 +++++
crypt/cipher_test.go | 34 ++++++++++++++++++++++++++++------
2 files changed, 33 insertions(+), 6 deletions(-)
diff --git a/crypt/cipher.go b/crypt/cipher.go
index 58a81c71a..85ee101f1 100644
--- a/crypt/cipher.go
+++ b/crypt/cipher.go
@@ -579,6 +579,11 @@ func (fh *decrypter) fillBuffer() (err error) {
block := fh.buf
_, ok := secretbox.Open(block[:0], readBuf[:n], fh.nonce.pointer(), &fh.c.dataKey)
if !ok {
+ // if block wouldn't decode and got unexpected EOF
+ // then return that as it is probably a better error
+ if err != nil {
+ return err
+ }
return ErrorEncryptedBadBlock
}
fh.bufIndex = 0
diff --git a/crypt/cipher_test.go b/crypt/cipher_test.go
index 5bacdcdcd..0d4414bdd 100644
--- a/crypt/cipher_test.go
+++ b/crypt/cipher_test.go
@@ -917,14 +917,36 @@ func TestDecrypterRead(t *testing.T) {
c, err := newCipher(NameEncryptionStandard, "", "")
assert.NoError(t, err)
- // Test truncating the header
- for i := 1; i < blockHeaderSize; i++ {
- cd := newCloseDetector(bytes.NewBuffer(file1[:len(file1)-i]))
+ // Test truncating the file at each possible point
+ for i := 0; i < len(file16)-1; i++ {
+ what := fmt.Sprintf("truncating to %d/%d", i, len(file16))
+ cd := newCloseDetector(bytes.NewBuffer(file16[:i]))
fh, err := c.newDecrypter(cd)
- assert.NoError(t, err)
+ if i < fileHeaderSize {
+ assert.EqualError(t, err, ErrorEncryptedFileTooShort.Error(), what)
+ continue
+ }
+ if err != nil {
+ assert.NoError(t, err, what)
+ continue
+ }
_, err = ioutil.ReadAll(fh)
- assert.Error(t, err, ErrorEncryptedFileBadHeader.Error())
- assert.Equal(t, 0, cd.closed)
+ var expectedErr error
+ switch {
+ case i == fileHeaderSize:
+ // This would normally produce an error *except* on the first block
+ expectedErr = nil
+ case i <= fileHeaderSize+blockHeaderSize:
+ expectedErr = ErrorEncryptedFileBadHeader
+ default:
+ expectedErr = io.ErrUnexpectedEOF
+ }
+ if expectedErr != nil {
+ assert.EqualError(t, err, expectedErr.Error(), what)
+ } else {
+ assert.NoError(t, err, what)
+ }
+ assert.Equal(t, 0, cd.closed, what)
}
// Test producing an error on the file on Read the underlying file