From: Chuck Lever <chucklever@gmail.com>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>,
James Morris <jmorris@namei.org>,
Deven Bowers <deven.desai@linux.microsoft.com>,
Pavel Machek <pavel@ucw.cz>, Sasha Levin <sashal@kernel.org>,
snitzer@redhat.com, dm-devel@redhat.com,
tyhicks@linux.microsoft.com, agk@redhat.com,
Paul Moore <paul@paul-moore.com>,
Jonathan Corbet <corbet@lwn.net>,
nramas@linux.microsoft.com, serge@hallyn.com,
pasha.tatashin@soleen.com, Jann Horn <jannh@google.com>,
linux-block@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
Jens Axboe <axboe@kernel.dk>,
mdsakib@microsoft.com, open list <linux-kernel@vger.kernel.org>,
eparis@redhat.com, linux-security-module@vger.kernel.org,
linux-audit@redhat.com,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-integrity@vger.kernel.org,
jaskarankhurana@linux.microsoft.com
Subject: Re: [dm-devel] [RFC PATCH v5 00/11] Integrity Policy Enforcement LSM (IPE)
Date: Thu, 13 Aug 2020 10:56:17 -0400 [thread overview]
Message-ID: <49A45475-20D8-456E-92AD-F63DBC71F900@gmail.com> (raw)
In-Reply-To: <1597329763.3708.13.camel@HansenPartnership.com>
> On Aug 13, 2020, at 10:42 AM, James Bottomley <James.Bottomley@HansenPartnership.com> wrote:
>
> On Thu, 2020-08-13 at 10:21 -0400, Chuck Lever wrote:
>>> On Aug 12, 2020, at 11:42 AM, James Bottomley <James.Bottomley@Hans
>>> enPartnership.com> wrote:
> [...]
>>> For most people the security mechanism of local xattrs is
>>> sufficient. If you're paranoid, you don't believe it is and you
>>> use EVM.
>>
>> When IMA metadata happens to be stored in local filesystems in
>> a trusted xattr, it's going to enjoy the protection you describe
>> without needing the addition of a cryptographic signature.
>>
>> However, that metadata doesn't live its whole life there. It
>> can reside in a tar file, it can cross a network, it can live
>> on a back-up tape. I think we agree that any time that metadata
>> is in transit or at rest outside of a Linux local filesystem, it
>> is exposed.
>>
>> Thus I'm interested in a metadata protection mechanism that does
>> not rely on the security characteristics of a particular storage
>> container. For me, a cryptographic signature fits that bill
>> nicely.
>
> Sure, but one of the points about IMA is a separation of mechanism from
> policy. Signed hashes (called appraisal in IMA terms) is just one
> policy you can decide to require or not or even make it conditional on
> other things.
AFAICT, the current EVM_IMA_DIGSIG and EVM_PORTABLE_DIGSIG formats are
always signed. The policy choice is whether or not to verify the
signature, not whether or not the metadata format is signed.
--
Chuck Lever
chucklever@gmail.com
next prev parent reply other threads:[~2020-08-13 14:56 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-28 21:36 [RFC PATCH v5 00/11] Integrity Policy Enforcement LSM (IPE) Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 01/11] scripts: add ipe tooling to generate boot policy Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 02/11] security: add ipe lsm evaluation loop and audit system Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 03/11] security: add ipe lsm policy parser and policy loading Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 04/11] ipe: add property for trust of boot volume Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 05/11] fs: add security blob and hooks for block_device Deven Bowers
2020-07-28 22:22 ` Casey Schaufler
2020-07-28 22:40 ` Al Viro
2020-07-28 23:55 ` Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 06/11] dm-verity: move signature check after tree validation Deven Bowers
2020-07-28 21:50 ` Eric Biggers
2020-07-28 23:55 ` Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 07/11] dm-verity: add bdev_setsecurity hook for dm-verity signature Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 08/11] ipe: add property for signed dmverity volumes Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 09/11] dm-verity: add bdev_setsecurity hook for root-hash Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 10/11] documentation: add ipe documentation Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 10/12] ipe: add property for dmverity roothash Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 11/11] cleanup: uapi/linux/audit.h Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 11/12] documentation: add ipe documentation Deven Bowers
2020-07-28 21:36 ` [RFC PATCH v5 12/12] cleanup: uapi/linux/audit.h Deven Bowers
2020-08-02 11:55 ` [RFC PATCH v5 00/11] Integrity Policy Enforcement LSM (IPE) Pavel Machek
2020-08-02 14:03 ` Sasha Levin
2020-08-02 14:31 ` Pavel Machek
2020-08-02 16:43 ` [dm-devel] " James Bottomley
2020-08-04 16:07 ` Deven Bowers
2020-08-05 15:01 ` James Bottomley
2020-08-05 16:59 ` James Morris
2020-08-05 18:15 ` Mimi Zohar
2020-08-05 23:51 ` James Morris
2020-08-06 14:33 ` Mimi Zohar
2020-08-07 16:41 ` James Morris
2020-08-07 17:31 ` Mimi Zohar
2020-08-07 18:40 ` Mimi Zohar
2020-08-10 20:29 ` James Morris
2020-08-08 17:47 ` Chuck Lever
2020-08-09 17:16 ` Mimi Zohar
2020-08-10 15:35 ` James Bottomley
2020-08-10 16:35 ` Mimi Zohar
2020-08-10 17:13 ` James Bottomley
2020-08-10 17:57 ` Mimi Zohar
2020-08-10 23:36 ` Chuck Lever
2020-08-11 5:43 ` James Bottomley
2020-08-11 14:48 ` Chuck Lever
2020-08-11 15:32 ` James Bottomley
2020-08-11 19:30 ` Pavel Machek
2020-08-12 14:45 ` Chuck Lever
2020-08-11 15:53 ` James Bottomley
2020-08-12 14:15 ` Chuck Lever
2020-08-12 15:51 ` James Bottomley
2020-08-13 14:42 ` Chuck Lever
2020-08-13 15:10 ` James Bottomley
2020-08-14 14:21 ` Chuck Lever
2020-08-11 18:28 ` James Bottomley
2020-08-12 13:56 ` Chuck Lever
2020-08-12 15:42 ` James Bottomley
2020-08-13 14:21 ` Chuck Lever
2020-08-13 14:42 ` James Bottomley
2020-08-13 14:56 ` Chuck Lever [this message]
2020-08-11 21:03 ` James Morris
2020-08-12 14:18 ` Chuck Lever
2020-08-12 17:07 ` Deven Bowers
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