From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: "Safford, David (GE Global Research, US)" <david.safford@ge.com>
Cc: Ken Goldman <kgold@linux.ibm.com>,
Mimi Zohar <zohar@linux.ibm.com>,
"linux-integrity@vger.kernel.org"
<linux-integrity@vger.kernel.org>,
"stable@vger.kernel.org" <stable@vger.kernel.org>,
"open list:ASYMMETRIC KEYS" <keyrings@vger.kernel.org>,
"open list:CRYPTO API" <linux-crypto@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] KEYS: asym_tpm: Switch to get_random_bytes()
Date: Mon, 14 Oct 2019 22:29:13 +0300 [thread overview]
Message-ID: <20191014192913.GD15552@linux.intel.com> (raw)
In-Reply-To: <20191014190033.GA15552@linux.intel.com>
On Mon, Oct 14, 2019 at 10:00:33PM +0300, Jarkko Sakkinen wrote:
> On Wed, Oct 09, 2019 at 12:11:06PM +0000, Safford, David (GE Global Research, US) wrote:
> >
> > > From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > > Sent: Tuesday, October 8, 2019 7:54 PM
> > > To: Ken Goldman <kgold@linux.ibm.com>
> > > Cc: Safford, David (GE Global Research, US) <david.safford@ge.com>; Mimi
> > > Zohar <zohar@linux.ibm.com>; linux-integrity@vger.kernel.org;
> > > stable@vger.kernel.org; open list:ASYMMETRIC KEYS
> > > <keyrings@vger.kernel.org>; open list:CRYPTO API <linux-
> > > crypto@vger.kernel.org>; open list <linux-kernel@vger.kernel.org>
> > > Subject: EXT: Re: [PATCH] KEYS: asym_tpm: Switch to get_random_bytes()
> > >
> > > On Wed, Oct 09, 2019 at 02:49:35AM +0300, Jarkko Sakkinen wrote:
> > > > On Mon, Oct 07, 2019 at 06:13:01PM -0400, Ken Goldman wrote:
> > > > > The TPM library specification states that the TPM must comply with
> > > > > NIST
> > > > > SP800-90 A.
> > > > >
> > > > > https://trustedcomputinggroup.org/membership/certification/tpm-certi
> > > > > fied-products/
> > > > >
> > > > > shows that the TPMs get third party certification, Common Criteria EAL 4+.
> > > > >
> > > > > While it's theoretically possible that an attacker could compromise
> > > > > both the TPM vendors and the evaluation agencies, we do have EAL 4+
> > > > > assurance against both 1 and 2.
> > > >
> > > > Certifications do not equal to trust.
> > >
> > > And for trusted keys the least trust solution is to do generation with the kernel
> > > assets and sealing with TPM. With TEE the least trust solution is equivalent.
> > >
> > > Are you proposing that the kernel random number generation should be
> > > removed? That would be my conclusion of this discussion if I would agree any
> > > of this (I don't).
> > >
> > > /Jarkko
> >
> > No one is suggesting that.
> >
> > You are suggesting changing the documented behavior of trusted keys, and
> > that would cause problems for some of our use cases. While certification
> > may not in your mind be equal to trust, it is equal to compliance with
> > mandatory regulations.
> >
> > Perhaps rather than arguing past each other, we should look into
> > providing users the ability to choose, as an argument to keyctl?
> >
> > dave
>
> I'm taking my words back in the regression part as regression would need
> really a failing system. Definitely the fixes tag should be removed from
> my patch.
>
> What is anyway the role of the kernel rng? Why does it exist and when
> exactly it should be used? This exactly where the whole review process
> throughout the "chain of command" failed misserably with tpm_asym.c.
>
> The commit message for tpm_asym.c does not document the design choice in
> any possible way and still was merged to the mainline.
>
> Before knowning the answer to the "existential" question we are
> somewhat paralyzed on moving forward with trusted keys (e.g. paralyzed
> to merge TEE backend).
>
> Your proposal might make sense but I don't really want to say anything
> since I'm completely cluesless of the role of the kernel rng. Looks like
> everyone who participated to the review process of tpm_asym.c, is too.
As a ABI backwards compatibility workaround I'd agree most likely agree
with you. As a guideline for new features there should be a framework on
how to decide what to do.
/Jarkko
next prev parent reply other threads:[~2019-10-14 19:29 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-26 17:16 [PATCH] KEYS: asym_tpm: Switch to get_random_bytes() Jarkko Sakkinen
2019-09-28 18:05 ` Jerry Snitselaar
2019-10-01 20:54 ` Jarkko Sakkinen
2019-10-02 14:00 ` Mimi Zohar
2019-10-03 11:41 ` Jarkko Sakkinen
2019-10-03 11:43 ` Jarkko Sakkinen
2019-10-03 13:02 ` Mimi Zohar
2019-10-03 17:58 ` Jarkko Sakkinen
2019-10-03 18:53 ` Mimi Zohar
2019-10-03 21:51 ` Jarkko Sakkinen
2019-10-03 21:57 ` Jarkko Sakkinen
2019-10-03 22:08 ` Mimi Zohar
2019-10-03 23:59 ` James Bottomley
2019-10-04 18:22 ` Jarkko Sakkinen
2019-10-04 18:24 ` James Bottomley
2019-10-04 18:33 ` Jerry Snitselaar
2019-10-04 18:42 ` James Bottomley
2019-10-04 20:07 ` Jerry Snitselaar
2019-10-04 20:11 ` Jerry Snitselaar
2019-10-04 22:11 ` James Bottomley
2019-10-06 0:38 ` Mimi Zohar
2019-10-06 23:52 ` Jarkko Sakkinen
2019-10-07 18:08 ` Mimi Zohar
2019-10-04 18:20 ` Jarkko Sakkinen
2019-10-03 22:10 ` Jarkko Sakkinen
2019-10-04 13:26 ` Safford, David (GE Global Research, US)
2019-10-04 18:27 ` Jarkko Sakkinen
2019-10-04 18:30 ` Jarkko Sakkinen
2019-10-04 19:56 ` Safford, David (GE Global Research, US)
2019-10-07 0:05 ` Jarkko Sakkinen
2019-10-07 22:13 ` Ken Goldman
2019-10-08 23:49 ` Jarkko Sakkinen
2019-10-08 23:53 ` Jarkko Sakkinen
2019-10-09 7:10 ` Pascal Van Leeuwen
2019-10-09 7:33 ` Jarkko Sakkinen
2019-10-09 7:41 ` Jarkko Sakkinen
2019-10-09 8:09 ` Pascal Van Leeuwen
2019-10-14 19:11 ` Jarkko Sakkinen
2019-10-09 8:02 ` Pascal Van Leeuwen
2019-10-09 12:11 ` Safford, David (GE Global Research, US)
2019-10-14 19:00 ` Jarkko Sakkinen
2019-10-14 19:29 ` Jarkko Sakkinen [this message]
2019-10-14 19:29 ` James Bottomley
2019-10-16 11:00 ` Jarkko Sakkinen
2019-10-16 12:34 ` James Bottomley
2019-10-16 16:25 ` Jarkko Sakkinen
2019-10-16 19:10 ` James Bottomley
2019-10-17 12:52 ` Sumit Garg
2019-10-17 12:58 ` James Bottomley
2019-10-17 18:04 ` Jarkko Sakkinen
2019-10-21 11:39 ` Jarkko Sakkinen
2019-10-29 8:42 ` Jarkko Sakkinen
2019-10-29 14:58 ` James Bottomley
2019-10-31 21:03 ` Jarkko Sakkinen
2019-10-18 7:32 ` Janne Karhunen
2019-10-03 18:02 ` Jarkko Sakkinen
2019-10-03 18:15 ` Jarkko Sakkinen
2019-10-07 10:33 ` Janne Karhunen
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