From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Roberto Sassu <roberto.sassu@huawei.com>
Cc: zohar@linux.ibm.com, david.safford@ge.com, monty.wiseman@ge.com,
linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, silviu.vlasceanu@huawei.com
Subject: Re: [PATCH v6 7/7] tpm: pass an array of tpm_bank_list structures to tpm_pcr_extend()
Date: Wed, 12 Dec 2018 20:27:34 +0200 [thread overview]
Message-ID: <20181212182734.GH6333@linux.intel.com> (raw)
In-Reply-To: <9d6e47d9-3b88-86f6-1b60-6652dfe8dc00@huawei.com>
On Thu, Dec 06, 2018 at 07:38:30PM +0100, Roberto Sassu wrote:
> On 12/5/2018 1:14 AM, Jarkko Sakkinen wrote:
> > On Tue, Dec 04, 2018 at 09:21:38AM +0100, Roberto Sassu wrote:
> > > The new tpm_bank_list structure has been preferred to the tpm_digest
> > > structure, to let the caller specify the size of the digest (which may be
> > > unknown to the TPM driver).
> >
> > Why is that? Didn't previous commit query these?
>
> Since the TPM driver pads/truncates the first digest passed by the
> caller to extend PCRs for which no digest was provided, it must know
> which amount of data it can use. It is possible that the algorithm of
> the first digest is unknown for the TPM driver, if the caller of
> tpm_pcr_extend() didn't check chip->allocated_banks.
>
> By requiring that the caller passes also the digest size, this problem
> does not arise. It seems reasonable to me to pass this information, as
> the caller calculated the digest and it should know the digest size.
OK. I noticed something other things that look to alarming:
1. The function does not fail if alg_id is not found. This will go
silent.
2. The function does not fail if there is a mismatch with the digest
sizes.
/Jarkko
next prev parent reply other threads:[~2018-12-12 18:27 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-04 8:21 [PATCH v6 0/7] tpm: retrieve digest size of unknown algorithms from TPM Roberto Sassu
2018-12-04 8:21 ` [PATCH v6 1/7] tpm: dynamically allocate the allocated_banks array Roberto Sassu
2018-12-04 23:18 ` Jarkko Sakkinen
2018-12-06 17:56 ` Roberto Sassu
2018-12-12 18:32 ` Jarkko Sakkinen
2018-12-13 8:14 ` Roberto Sassu
2018-12-11 21:01 ` Ken Goldman
2018-12-04 8:21 ` [PATCH v6 2/7] tpm: add _head suffix to tcg_efi_specid_event and tcg_pcr_event2 Roberto Sassu
2018-12-04 23:26 ` Jarkko Sakkinen
2018-12-09 12:10 ` Nayna Jain
2018-12-04 8:21 ` [PATCH v6 3/7] tpm: rename and export tpm2_digest and tpm2_algorithms Roberto Sassu
2018-12-04 8:21 ` [PATCH v6 4/7] tpm: modify tpm_pcr_read() definition to pass a TPM hash algorithm Roberto Sassu
2018-12-04 23:40 ` Jarkko Sakkinen
2018-12-05 20:31 ` Mimi Zohar
2018-12-06 19:49 ` Mimi Zohar
2018-12-07 14:51 ` Roberto Sassu
2018-12-09 20:32 ` Mimi Zohar
2018-12-10 7:55 ` Roberto Sassu
2018-12-06 8:14 ` Nayna Jain
2018-12-12 18:29 ` Jarkko Sakkinen
2018-12-09 12:04 ` Nayna Jain
2018-12-04 8:21 ` [PATCH v6 5/7] tpm: retrieve digest size of unknown algorithms with PCR read Roberto Sassu
2018-12-04 23:53 ` Jarkko Sakkinen
2018-12-06 18:00 ` Roberto Sassu
2018-12-12 18:16 ` Jarkko Sakkinen
2018-12-04 8:21 ` [PATCH v6 6/7] tpm: ensure that the output of PCR read contains the correct digest size Roberto Sassu
2018-12-05 0:09 ` Jarkko Sakkinen
2018-12-05 0:46 ` Jarkko Sakkinen
2018-12-06 18:07 ` Roberto Sassu
2018-12-12 18:18 ` Jarkko Sakkinen
2018-12-04 8:21 ` [PATCH v6 7/7] tpm: pass an array of tpm_bank_list structures to tpm_pcr_extend() Roberto Sassu
2018-12-05 0:14 ` Jarkko Sakkinen
2018-12-06 18:09 ` Roberto Sassu
2018-12-12 18:25 ` Jarkko Sakkinen
2018-12-06 18:38 ` Roberto Sassu
2018-12-12 18:27 ` Jarkko Sakkinen [this message]
2018-12-13 7:57 ` Roberto Sassu
2018-12-14 7:58 ` Jarkko Sakkinen
2018-12-05 0:21 ` [PATCH v6 0/7] tpm: retrieve digest size of unknown algorithms from TPM Jarkko Sakkinen
2018-12-05 0:23 ` Jarkko Sakkinen
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