summaryrefslogtreecommitdiff
path: root/internal/fusefrontend/node_helpers.go
diff options
context:
space:
mode:
authorDerDonut2021-06-17 08:11:33 +0200
committerJakob Unterwurzacher2021-06-20 18:09:21 +0200
commita611810ff46ed0899d677f24c330a994ad125bfb (patch)
tree6f0abcf6c505374beef416c664b91e6e885e5263 /internal/fusefrontend/node_helpers.go
parentcdddd1d711c3398aa1093090296139aa3d331859 (diff)
Badname file content access
This proposal is the counterpart of the modifications from the `-badname` parameter. It modifies the plain -> cipher mapping for filenames when using `-badname` parameter. The new function `EncryptAndHashBadName` tries to find a cipher filename for the given plain name with the following steps: 1. If `badname` is disabled or direct mapping is successful: Map directly (default and current behaviour) 2. If a file with badname flag has a valid cipher file, this is returned (=File just ends with the badname flag) 3. If a file with a badname flag exists where only the badname flag was added, this is returned (=File cipher name could not be decrypted by function `DecryptName` and just the badname flag was added) 4. Search for all files which cipher file name extists when cropping more and more characters from the end. If only 1 file is found, return this 5. Return an error otherwise This allows file access in the file browsers but most important it allows that you rename files with undecryptable cipher names in the plain directories. Renaming those files will then generate a proper cipher filename One backdraft: When mounting the cipher dir with -badname parameter, you can never create (or rename to) files whose file name ends with the badname file flag (at the moment this is " GOCRYPTFS_BAD_NAME"). This will cause an error. I modified the CLI test function to cover additional test cases. Test [Case 7](https://github.com/DerDonut/gocryptfs/blob/badnamecontent/tests/cli/cli_test.go#L712) cannot be performed since the cli tests are executed in panic mode. The testing is stopped on error. Since the function`DecryptName` produces internal errors when hitting non-decryptable file names, this test was omitted. This implementation is a proposal where I tried to change the minimum amount of existing code. Another possibility would be instead of creating the new function `EncryptAndHashBadName` to modify the signature of the existing function `EncryptAndHashName(name string, iv []byte)` to `EncryptAndHashName(name string, iv []byte, dirfd int)` and integrate the functionality into this function directly. You may allow calling with dirfd=-1 or other invalid values an then performing the current functionality.
Diffstat (limited to 'internal/fusefrontend/node_helpers.go')
-rw-r--r--internal/fusefrontend/node_helpers.go10
1 files changed, 9 insertions, 1 deletions
diff --git a/internal/fusefrontend/node_helpers.go b/internal/fusefrontend/node_helpers.go
index b2f1d4a..f2d1e5e 100644
--- a/internal/fusefrontend/node_helpers.go
+++ b/internal/fusefrontend/node_helpers.go
@@ -121,7 +121,15 @@ func (n *Node) prepareAtSyscall(child string) (dirfd int, cName string, errno sy
var iv []byte
dirfd, iv = rn.dirCache.Lookup(n)
if dirfd > 0 {
- cName, err := rn.nameTransform.EncryptAndHashName(child, iv)
+ var cName string
+ var err error
+ if rn.nameTransform.HaveBadnamePatterns() {
+ //BadName allowed, try to determine filenames
+ cName, err = rn.nameTransform.EncryptAndHashBadName(child, iv, dirfd)
+ } else {
+ cName, err = rn.nameTransform.EncryptAndHashName(child, iv)
+ }
+
if err != nil {
return -1, "", fs.ToErrno(err)
}