Wilson,
Thanks for commenting. Pls see inline below..
On 09/14/2016 12:42 AM, Wilson Meier wrote:
Hi Anand,
these are great news! Thanks for yor work. I'm looking forward to use the
encryption.
I would like to ask a few question regarding the feature set.
1. is encryption of an existing, filled and unencrypted subvolume without
manually moving the data possible?
Encrypt contexts are set only on newly created files. However you can
create empty encrypted subvol and move files and dir into it. In short
you can't set encrypt property on non-empty subvolume as of now.
2. What about encrypting the root and boot subvolume? Will it work with grub2?
Keys are only in-memory, which does not persist or prompt
for it across boot. I had keyctl code written to prompt
for key but it isn't successful yet. Probably once we support
keyfile, then root/boot support is possible.
3. How does btrfs rescue handle the encrypted subvolume to recover data in case
of an emergency?
btrfs rescue / btrfsck works as usual. btrfs restore which
needs decrypt isn't supported.
4. Is it possible to unlock a subvolume using a keyfile?
keyfile support is on top of the list to be supported, it helps
testing as well.
Thanks, Anand
Thanks in advance,
Wilson
Am 13.09.2016 um 15:39 schrieb Anand Jain <anand.j...@oracle.com>:
This patchset adds btrfs encryption support.
The main objective of this series is to have bugs fixed and stability.
I have verified with fstests to confirm that there is no regression.
A design write-up is coming next, however here below is the quick example
on the cli usage. Please try out, let me know if I have missed something.
Also would like to mention that a review from the security experts is due,
which is important and I believe those review comments can be accommodated
without major changes from here.
Also yes, thanks for the emails, I hear, per file encryption and inline
with vfs layer is also important, which is wip among other things in the
list.
As of now these patch set supports encryption on per subvolume, as
managing properties on per subvolume is a kind of core to btrfs, which is
easier for data center solution-ing, seamlessly persistent and easy to
manage.
Steps:
-----
Make sure following kernel TFMs are compiled in.
# cat /proc/crypto | egrep 'cbc\(aes\)|ctr\(aes\)'
name : ctr(aes)
name : cbc(aes)
Create encrypted subvolume.
# btrfs su create -e 'ctr(aes)' /btrfs/e1
Create subvolume '/btrfs/e1'
Passphrase:
Again passphrase:
A key is created and its hash is updated into the subvolume item,
and then added to the system keyctl.
# btrfs su show /btrfs/e1 | egrep -i encrypt
Encryption: ctr(aes)@btrfs:75197c8e (594790215)
# keyctl show 594790215
Keyring
594790215 --alsw-v 0 0 logon: btrfs:75197c8e
Now any file data extents under the subvol /btrfs/e1 will be
encrypted.
You may revoke key using keyctl or btrfs(8) as below.
# btrfs su encrypt -k out /btrfs/e1
# btrfs su show /btrfs/e1 | egrep -i encrypt
Encryption: ctr(aes)@btrfs:75197c8e (Required key not available)
# keyctl show 594790215
Keyring
Unable to dump key: Key has been revoked
As the key hash is updated, If you provide wrong passphrase in the next
key in, it won't add key to the system. So we have key verification
from the day1.
# btrfs su encrypt -k in /btrfs/e1
Passphrase:
Again passphrase:
ERROR: failed to set attribute 'btrfs.encrypt' to 'ctr(aes)@btrfs:75197c8e' :
Key was rejected by service
ERROR: key set failed: Key was rejected by service
# btrfs su encrypt -k in /btrfs/e1
Passphrase:
Again passphrase:
key for '/btrfs/e1' has logged in with keytag 'btrfs:75197c8e'
Now if you revoke the key the read / write fails with key error.
# md5sum /btrfs/e1/2k-test-file
8c9fbc69125ebe84569a5c1ca088cb14 /btrfs/e1/2k-test-file
# btrfs su encrypt -k out /btrfs/e1
# md5sum /btrfs/e1/2k-test-file
md5sum: /btrfs/e1/2k-test-file: Key has been revoked
# cp /tfs/1k-test-file /btrfs/e1/
cp: cannot create regular file ‘/btrfs/e1/1k-test-file’: Key has been revoked
Plain text memory scratches for security reason is pending. As there are some
key revoke notification challenges to coincide with encryption context switch,
which I do believe should be fixed in the due course, but is not a roadblock
at this stage.
Thanks, Anand
Anand Jain (1):
btrfs: Encryption: Add btrfs encryption support
fs/btrfs/Makefile | 4 +-
fs/btrfs/btrfs_inode.h | 6 +
fs/btrfs/compression.c | 30 +-
fs/btrfs/compression.h | 10 +-
fs/btrfs/ctree.h | 4 +
fs/btrfs/disk-io.c | 3 +
fs/btrfs/encrypt.c | 807 ++++++++++++++++++++++++++++++++++++++++
fs/btrfs/encrypt.h | 94 +++++
fs/btrfs/inode.c | 255 ++++++++++++-
fs/btrfs/ioctl.c | 67 ++++
fs/btrfs/lzo.c | 2 +-
fs/btrfs/props.c | 331 +++++++++++++++-
fs/btrfs/super.c | 27 +-
fs/btrfs/tests/crypto-tests.c | 376 +++++++++++++++++++
fs/btrfs/tests/crypto-tests.h | 38 ++
fs/btrfs/zlib.c | 2 +-
include/uapi/linux/btrfs_tree.h | 6 +-
17 files changed, 2027 insertions(+), 35 deletions(-)
create mode 100644 fs/btrfs/encrypt.c
create mode 100644 fs/btrfs/encrypt.h
create mode 100755 fs/btrfs/tests/crypto-tests.c
create mode 100755 fs/btrfs/tests/crypto-tests.h
Anand Jain (2):
btrfs-progs: make wait_for_commit non static
btrfs-progs: add encryption support
Makefile.in | 5 +-
btrfs-list.c | 33 ++++
cmds-filesystem.c | 4 +-
cmds-restore.c | 16 ++
cmds-subvolume.c | 112 ++++++++++++--
commands.h | 1 +
ctree.h | 5 +-
encrypt.c | 455 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
encrypt.h | 46 ++++++
props.c | 4 +
utils.h | 2 +
11 files changed, 665 insertions(+), 18 deletions(-)
create mode 100644 encrypt.c
create mode 100644 encrypt.h
Anand Jain (1):
fstests: btrfs: support encryption
common/filter.btrfs | 2 +-
common/rc | 2 +-
tests/btrfs/041 | 2 +
tests/btrfs/041.out | 13 ++++
tests/btrfs/052 | 12 +++
tests/btrfs/052.out | 214 ++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/btrfs/079 | 2 +
tests/btrfs/125 | 2 +-
tests/generic/297 | 6 +-
tests/generic/298 | 2 +-
10 files changed, 251 insertions(+), 6 deletions(-)
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
