From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: linux-integrity@vger.kernel.org, Mimi Zohar <zohar@linux.ibm.com>,
David Woodhouse <dwmw2@infradead.org>,
keyrings@vger.kernel.org, David Howells <dhowells@redhat.com>
Subject: Re: [PATCH v13 5/5] security: keys: trusted: Make sealed key properly interoperable
Date: Wed, 30 Sep 2020 11:24:44 +0000 [thread overview]
Message-ID: <20200930112444.GC5145@linux.intel.com> (raw)
In-Reply-To: <20200922022809.7105-6-James.Bottomley@HansenPartnership.com>
On Mon, Sep 21, 2020 at 07:28:09PM -0700, James Bottomley wrote:
> The current implementation appends a migratable flag to the end of a
> key, meaning the format isn't exactly interoperable because the using
> party needs to know to strip this extra byte. However, all other
> consumers of TPM sealed blobs expect the unseal to return exactly the
> key. Since TPM2 keys have a key property flag that corresponds to
> migratable, use that flag instead and make the actual key the only
> sealed quantity. This is secure because the key properties are bound
> to a hash in the private part, so if they're altered the key won't
> load.
>
> Backwards compatibility is implemented by detecting whether we're
> loading a new format key or not and correctly setting migratable from
> the last byte of old format keys.
>
> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
➜ tpm2-scripts (master) ✗ sudo keyctl add trusted kmk2 "new 32 blobauth=world keyhandle�000000 migratable=1" @u
add_key: Invalid argument
➜ tpm2-scripts (master) ✗ sudo keyctl add trusted kmk2 "new 32 blobauth=world keyhandle�000000 migratable=0" @u
608433517
Showed the -EINVAL example just to point out this:
case Opt_migratable:
if (*args[0].from = '0')
pay->migratable = 0;
else
return -EINVAL;
break;
I think it should just set migratable in both cases even if no-op,
given that it takes the value and also the documentation says that
"migratable=1" is legit:
"migratable= 0|1 indicating permission to reseal to new PCR values,
default 1 (resealing allowed)"
Obviously not a concern of this patch but this is still IMHO a bug.
Would be nce if you could drop a prepending patch to fix this, when you
rebase the series, with this fixes tag:
Fixes: d00a1c72f7f4 ("keys: add new trusted key-type")
BTW, please check my fixes so that I can push them ASAP and you get to
rebase this and we can land it. Now everything is properly tested.
/Jarkko
next prev parent reply other threads:[~2020-09-30 11:24 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 2:28 [PATCH v13 0/5] TPM 2.0 trusted key rework James Bottomley
2020-09-22 2:28 ` [PATCH v13 1/5] lib: add ASN.1 encoder James Bottomley
2020-09-22 2:28 ` [PATCH v13 2/5] oid_registry: Add TCG defined OIDS for TPM keys James Bottomley
2020-09-22 2:28 ` [PATCH v13 3/5] security: keys: trusted: fix TPM2 authorizations James Bottomley
2020-09-25 7:28 ` Jarkko Sakkinen
2020-09-25 17:39 ` James Bottomley
2020-09-27 23:48 ` Jarkko Sakkinen
2020-09-30 11:02 ` Jarkko Sakkinen
2020-09-22 2:28 ` [PATCH v13 4/5] security: keys: trusted: use ASN.1 TPM2 key format for the blobs James Bottomley
2020-09-26 11:33 ` kernel test robot
2020-09-30 11:11 ` Jarkko Sakkinen
2020-09-30 14:49 ` James Bottomley
2020-09-30 15:35 ` Jarkko Sakkinen
2020-09-22 2:28 ` [PATCH v13 5/5] security: keys: trusted: Make sealed key properly interoperable James Bottomley
2020-09-30 11:24 ` Jarkko Sakkinen [this message]
2020-09-30 3:43 ` [PATCH v13 0/5] TPM 2.0 trusted key rework Jarkko Sakkinen
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