From: Richard Weinberger <richard@nod.at>
To: Johannes Thumshirn <Johannes.Thumshirn@wdc.com>
Cc: Eric Biggers <ebiggers@kernel.org>,
Johannes Thumshirn <jth@kernel.org>,
David Sterba <dsterba@suse.cz>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-btrfs <linux-btrfs@vger.kernel.org>,
david <david@sigma-star.at>,
Sascha Hauer <s.hauer@pengutronix.de>
Subject: Re: [PATCH v2 1/2] btrfs: add authentication support
Date: Mon, 4 May 2020 23:37:51 +0200 (CEST) [thread overview]
Message-ID: <769963893.184242.1588628271082.JavaMail.zimbra@nod.at> (raw)
In-Reply-To: <SN4PR0401MB3598198E5FB728B68B39A1589BA60@SN4PR0401MB3598.namprd04.prod.outlook.com>
----- Ursprüngliche Mail -----
>> The hash algorithm needs to be passed as a mount option. Otherwise the attacker
>> gets to choose it for you among all the supported keyed hash algorithms, as soon
>> as support for a second one is added. Maybe use 'auth_hash_name' like UBIFS
>> does?
>
> Can you elaborate a bit more on that? As far as I know, UBIFS doesn't
> save the 'auth_hash_name' on disk, whereas 'BTRFS_CSUM_TYPE_HMAC_SHA256'
> is part of the on-disk format. As soon as we add a 2nd keyed hash, say
> BTRFS_CSUM_TYPE_BLAKE2B_KEYED, this will be in the superblock as well,
> as struct btrfs_super_block::csum_type.
Well, UBIFS stores auth_hash_name on disk but does not trust it.
It is always required to provide auth_hash_name as mount parameter.
At mount time it is compared to the stored name (among with other parameters)
to detect misconfigurations.
Thanks,
//richard
next prev parent reply other threads:[~2020-05-04 21:43 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-28 10:58 [PATCH v2 0/2] Add file-system authentication to BTRFS Johannes Thumshirn
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
2020-05-06 22:57 ` Qu Wenruo
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 [this message]
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
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