On Mon, May 20, 2019 at 08:16:36PM -0400, Theodore Ts'o wrote:
> On Mon, May 20, 2019 at 10:25:36AM -0700, Eric Biggers wrote:
> >
> > This patchset makes major improvements to how keys are added, removed,
> > and derived in fscrypt, aka ext4/f2fs/ubifs encryption. It does this by
> > adding new ioctls that add and remove encryption keys directly to/from
> > the filesystem, and by adding a new encryption policy version ("v2")
> > where the user-provided keys are only used as input to HKDF-SHA512 and
> > are identified by their cryptographic hash.
>
> Do you have userspace programs which use these new ioctl's? What's
> are testing strategy for these new ioctls?
>
> Thanks,
>
> - Ted
This was answered in the cover letter, quoted below:
I've written xfstests for the new APIs. They test the APIs themselves
as well as verify the correctness of the ciphertext stored on-disk for
v2 encryption policies. The tests can be found at:
Repository: https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/xfstests-dev.git
Branch: fscrypt-key-mgmt-improvements
The xfstests depend on new xfs_io commands which can be found at:
Repository: https://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/xfsprogs-dev.git
Branch: fscrypt-key-mgmt-improvements
I've also made proof-of-concept changes to the 'fscrypt' userspace
program (https://github.com/google/fscrypt) to make it support v2
encryption policies. You can find these changes in git at:
Repository: https://github.com/ebiggers/fscrypt.git
Branch: fscrypt-key-mgmt-improvements
To make the 'fscrypt' userspace program experimentally use v2 encryption
policies on new encrypted directories, add the following to
/etc/fscrypt.conf within the "options" section:
"policy_version": "2"
Finally, it's also planned for Android and Chromium OS to switch to the
new ioctls and eventually to v2 encryption policies. Work-in-progress,
proof-of-concept changes by Satya Tangirala for AOSP can be found at
https://android-review.googlesource.com/q/topic:fscrypt-key-mgmt-improvements
- Eric
