All of lore.kernel.org
 help / color / mirror / Atom feed
From: Ken Goldman <kgold@linux.ibm.com>
To: Paul Moore <paul@paul-moore.com>, Mimi Zohar <zohar@linux.ibm.com>
Cc: Tushar Sugandhi <tusharsu@linux.microsoft.com>,
	linux-integrity@vger.kernel.org, peterhuewe@gmx.de,
	Jarkko Sakkinen <jarkko@kernel.org>,
	jgg@ziepe.ca, bhe@redhat.com, vgoyal@redhat.com,
	Dave Young <dyoung@redhat.com>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	jmorris@namei.org, serge@hallyn.com,
	James Bottomley <James.Bottomley@hansenpartnership.com>,
	linux-security-module@vger.kernel.org,
	Tyler Hicks <tyhicks@linux.microsoft.com>,
	Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
	Sush Shringarputale <sushring@linux.microsoft.com>
Subject: Re: [RFC V2] IMA Log Snapshotting Design Proposal
Date: Wed, 20 Dec 2023 17:13:47 -0500	[thread overview]
Message-ID: <1c370ecf-272a-4052-8f06-4fcfd9bf08b5@linux.ibm.com> (raw)
In-Reply-To: <CAHC9VhSnDQ-d9dh_icqNyhpT+cTGQOqGh8+cbN3QzF_qPehvaA@mail.gmail.com>

I'm still struggling with the "new root of trust" concept.

Something - a user space agent, a third party, etc. - has to
retain the entire log from event 0, because a new verifier
needs all measurements.

Therefore, the snapshot aggregate seems redundant.  It has to
be verified to match the snapshotted events.

A redundancy is an attack surface.  A badly written verifier
might not do that verification, and this permits snapshotted
events to be forged. No aggregate means the verifier can't
make a mistake.

On 11/22/2023 9:22 AM, Paul Moore wrote:
> I believe the intent is to only pause the measurements while the
> snapshot_aggregate is generated, not for the duration of the entire
> snapshot process.  The purpose of the snapshot_aggregate is to
> establish a new root of trust, similar to the boot_aggregate, to help
> improve attestation performance.

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Ken Goldman <kgold@linux.ibm.com>
To: Paul Moore <paul@paul-moore.com>, Mimi Zohar <zohar@linux.ibm.com>
Cc: Tushar Sugandhi <tusharsu@linux.microsoft.com>,
	linux-integrity@vger.kernel.org, peterhuewe@gmx.de,
	Jarkko Sakkinen <jarkko@kernel.org>,
	jgg@ziepe.ca, bhe@redhat.com, vgoyal@redhat.com,
	Dave Young <dyoung@redhat.com>,
	"kexec@lists.infradead.org" <kexec@lists.infradead.org>,
	jmorris@namei.org, serge@hallyn.com,
	James Bottomley <James.Bottomley@hansenpartnership.com>,
	linux-security-module@vger.kernel.org,
	Tyler Hicks <tyhicks@linux.microsoft.com>,
	Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
	Sush Shringarputale <sushring@linux.microsoft.com>
Subject: Re: [RFC V2] IMA Log Snapshotting Design Proposal
Date: Wed, 20 Dec 2023 17:13:47 -0500	[thread overview]
Message-ID: <1c370ecf-272a-4052-8f06-4fcfd9bf08b5@linux.ibm.com> (raw)
In-Reply-To: <CAHC9VhSnDQ-d9dh_icqNyhpT+cTGQOqGh8+cbN3QzF_qPehvaA@mail.gmail.com>

I'm still struggling with the "new root of trust" concept.

Something - a user space agent, a third party, etc. - has to
retain the entire log from event 0, because a new verifier
needs all measurements.

Therefore, the snapshot aggregate seems redundant.  It has to
be verified to match the snapshotted events.

A redundancy is an attack surface.  A badly written verifier
might not do that verification, and this permits snapshotted
events to be forged. No aggregate means the verifier can't
make a mistake.

On 11/22/2023 9:22 AM, Paul Moore wrote:
> I believe the intent is to only pause the measurements while the
> snapshot_aggregate is generated, not for the duration of the entire
> snapshot process.  The purpose of the snapshot_aggregate is to
> establish a new root of trust, similar to the boot_aggregate, to help
> improve attestation performance.

  parent reply	other threads:[~2023-12-20 22:14 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-19 18:49 [RFC V2] IMA Log Snapshotting Design Proposal Tushar Sugandhi
2023-10-19 18:49 ` Tushar Sugandhi
2023-10-31 18:37 ` Ken Goldman
2023-10-31 18:37   ` Ken Goldman
2023-11-13 18:14   ` Sush Shringarputale
2023-11-13 18:14     ` Sush Shringarputale
2023-10-31 19:15 ` Mimi Zohar
2023-10-31 19:15   ` Mimi Zohar
2023-11-16 22:28   ` Paul Moore
2023-11-16 22:28     ` Paul Moore
2023-11-22  1:01     ` Tushar Sugandhi
2023-11-22  1:01       ` Tushar Sugandhi
2023-11-22  1:18       ` Mimi Zohar
2023-11-22  1:18         ` Mimi Zohar
2023-11-22  4:27     ` Paul Moore
2023-11-22  4:27       ` Paul Moore
2023-11-22 13:18       ` Mimi Zohar
2023-11-22 13:18         ` Mimi Zohar
2023-11-22 14:22         ` Paul Moore
2023-11-22 14:22           ` Paul Moore
2023-11-27 17:07           ` Mimi Zohar
2023-11-27 17:07             ` Mimi Zohar
2023-11-27 22:16             ` Paul Moore
2023-11-27 22:16               ` Paul Moore
2023-11-28 12:09               ` Mimi Zohar
2023-11-28 12:09                 ` Mimi Zohar
2023-11-29  1:06                 ` Paul Moore
2023-11-29  1:06                   ` Paul Moore
2023-11-29  2:07                   ` Mimi Zohar
2023-11-29  2:07                     ` Mimi Zohar
2024-01-06 23:27                     ` Paul Moore
2024-01-06 23:27                       ` Paul Moore
2024-01-07 12:58                       ` Mimi Zohar
2024-01-07 12:58                         ` Mimi Zohar
2024-01-08  2:58                         ` Paul Moore
2024-01-08  2:58                           ` Paul Moore
2024-01-08 11:48                           ` Mimi Zohar
2024-01-08 11:48                             ` Mimi Zohar
2024-01-08 17:15                             ` Paul Moore
2024-01-08 17:15                               ` Paul Moore
2023-12-20 22:13           ` Ken Goldman [this message]
2023-12-20 22:13             ` Ken Goldman
2024-01-06 23:44             ` Paul Moore
2024-01-06 23:44               ` Paul Moore
2023-11-13 18:59 ` Stefan Berger
2023-11-13 18:59   ` Stefan Berger
2023-11-14 18:36   ` Sush Shringarputale
2023-11-14 18:36     ` Sush Shringarputale
2023-11-14 18:58     ` Stefan Berger
2023-11-14 18:58       ` Stefan Berger
2023-11-16 22:07       ` Paul Moore
2023-11-16 22:07         ` Paul Moore
2023-11-16 22:41         ` Stefan Berger
2023-11-16 22:41           ` Stefan Berger
2023-11-16 22:56           ` Paul Moore
2023-11-16 22:56             ` Paul Moore
2023-11-17 22:41             ` Sush Shringarputale
2023-11-17 22:41               ` Sush Shringarputale
2023-11-20 20:03         ` Tushar Sugandhi
2023-11-20 20:03           ` Tushar Sugandhi

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=1c370ecf-272a-4052-8f06-4fcfd9bf08b5@linux.ibm.com \
    --to=kgold@linux.ibm.com \
    --cc=James.Bottomley@hansenpartnership.com \
    --cc=bhe@redhat.com \
    --cc=dyoung@redhat.com \
    --cc=jarkko@kernel.org \
    --cc=jgg@ziepe.ca \
    --cc=jmorris@namei.org \
    --cc=kexec@lists.infradead.org \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=nramas@linux.microsoft.com \
    --cc=paul@paul-moore.com \
    --cc=peterhuewe@gmx.de \
    --cc=serge@hallyn.com \
    --cc=sushring@linux.microsoft.com \
    --cc=tusharsu@linux.microsoft.com \
    --cc=tyhicks@linux.microsoft.com \
    --cc=vgoyal@redhat.com \
    --cc=zohar@linux.ibm.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.