Linux-Fsdevel Archive on lore.kernel.org
 help / color / Atom feed
From: Johannes Thumshirn <jth@kernel.org>
To: David Sterba <dsterba@suse.cz>
Cc: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org,
	Eric Biggers <ebiggers@google.com>,
	Richard Weinberger <richard@nod.at>,
	Johannes Thumshirn <johannes.thumshirn@wdc.com>
Subject: [PATCH v2 0/2] Add file-system authentication to BTRFS
Date: Tue, 28 Apr 2020 12:58:57 +0200
Message-ID: <20200428105859.4719-1-jth@kernel.org> (raw)

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

This series adds file-system authentication to BTRFS. 

Unlike other verified file-system techniques like fs-verity the
authenticated version of BTRFS does not need extra meta-data on disk.

This works because in BTRFS every on-disk block has a checksum, for meta-data
the checksum is in the header of each meta-data item. For data blocks, a
separate checksum tree exists, which holds the checksums for each block.

Currently BRTFS supports CRC32C, XXHASH64, SHA256 and Blake2b for checksumming
these blocks. This series adds a new checksum algorithm, HMAC(SHA-256), which
does need an authentication key. When no, or an incoreect authentication key
is supplied no valid checksum can be generated and a read, fsck or scrub
operation would detect invalid or tampered blocks once the file-system is
mounted again with the correct key. 

Getting the key inside the kernel is out of scope of this implementation, the
file-system driver assumes the key is already in the kernel's keyring at mount
time.

There was interest in also using a HMAC version of Blake2b from the community,
but as none of the crypto libraries used by user-space BTRFS tools as a
backend does currently implement a HMAC version with Blake2b, it is not (yet)
included.

I have CCed Eric Biggers and Richard Weinberger in the submission, as they
previously have worked on filesystem authentication and I hope we can get
input from them as well.

Example usage:
Create a file-system with authentication key 0123456
mkfs.btrfs --csum hmac-sha256 --auth-key 0123456 /dev/disk

Add the key to the kernel's keyring as keyid 'btrfs:foo'
keyctl add logon btrfs:foo 0123456 @u

Mount the fs using the 'btrfs:foo' key
mount -t btrfs -o auth_key=btrfs:foo /dev/disk /mnt/point

Note, this is a re-base of the work I did when I was still at SUSE, hence the
S-o-b being my SUSE address, while the Author being with my WDC address (to
not generate bouncing mails).

Changes since v1:
- None, only rebased the series

Johannes Thumshirn (2):
  btrfs: add authentication support
  btrfs: rename btrfs_parse_device_options back to
    btrfs_parse_early_options

 fs/btrfs/ctree.c                |  3 ++-
 fs/btrfs/ctree.h                |  2 ++
 fs/btrfs/disk-io.c              | 53 ++++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/super.c                | 31 +++++++++++++++++++-----
 include/uapi/linux/btrfs_tree.h |  1 +
 5 files changed, 82 insertions(+), 8 deletions(-)

-- 
2.16.4


             reply index

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-28 10:58 Johannes Thumshirn [this message]
2020-04-28 10:58 ` [PATCH v2 1/2] btrfs: add authentication support Johannes Thumshirn
2020-04-29  7:23   ` kbuild test robot
2020-04-29 11:46   ` Johannes Thumshirn
2020-05-01  5:39   ` Eric Biggers
2020-05-01  6:30     ` Eric Biggers
2020-05-04  8:38       ` Johannes Thumshirn
2020-05-05 22:33         ` David Sterba
2020-05-06  8:10           ` Johannes Thumshirn
2020-05-04 10:09     ` Johannes Thumshirn
2020-05-04 20:59       ` Eric Biggers
2020-05-05  8:11         ` Johannes Thumshirn
2020-05-05  9:26           ` Qu Wenruo
2020-05-05  9:59             ` Qu Wenruo
2020-05-05 22:32               ` David Sterba
2020-05-05 23:55                 ` Qu Wenruo
2020-05-06 20:40             ` btree [was Re: [PATCH v2 1/2] btrfs: add authentication support] Goffredo Baroncelli
2020-05-05 22:19           ` [PATCH v2 1/2] btrfs: add authentication support David Sterba
2020-05-05 22:37           ` Eric Biggers
2020-05-06  8:30             ` Johannes Thumshirn
2020-05-05 22:14         ` David Sterba
2020-05-05 22:31           ` Eric Biggers
2020-05-05 22:46             ` David Sterba
2020-05-05 23:31               ` Eric Biggers
2020-05-06  0:29                 ` David Sterba
2020-05-06  0:44                   ` Eric Biggers
2020-05-04 21:37       ` Richard Weinberger
2020-05-05  7:46         ` Johannes Thumshirn
2020-05-05 11:56           ` Richard Weinberger
2020-05-04 21:59   ` Richard Weinberger
2020-05-05  7:55     ` Johannes Thumshirn
2020-05-05 12:36       ` Jeff Mahoney
2020-05-05 12:39         ` Qu Wenruo
2020-05-05 12:41           ` Jeff Mahoney
2020-05-05 12:48             ` Qu Wenruo
2020-05-05 23:02           ` David Sterba
2020-05-06 21:24         ` Goffredo Baroncelli
2020-05-05 23:00     ` David Sterba
2020-05-05  9:43   ` Qu Wenruo
2020-05-06 20:59     ` Goffredo Baroncelli
2020-04-28 10:58 ` [PATCH v2 2/2] btrfs: rename btrfs_parse_device_options back to btrfs_parse_early_options Johannes Thumshirn
2020-05-01  6:03 ` [PATCH v2 0/2] Add file-system authentication to BTRFS Eric Biggers
2020-05-04  8:39   ` Johannes Thumshirn
2020-05-05 23:16   ` David Sterba
2020-05-01 21:26 ` Jason A. Donenfeld
2020-05-05 23:38   ` David Sterba

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200428105859.4719-1-jth@kernel.org \
    --to=jth@kernel.org \
    --cc=dsterba@suse.cz \
    --cc=ebiggers@google.com \
    --cc=johannes.thumshirn@wdc.com \
    --cc=linux-btrfs@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=richard@nod.at \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Fsdevel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-fsdevel/0 linux-fsdevel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-fsdevel linux-fsdevel/ https://lore.kernel.org/linux-fsdevel \
		linux-fsdevel@vger.kernel.org
	public-inbox-index linux-fsdevel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-fsdevel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git