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: Fri, 14 Dec 2018 09:58:52 +0200 [thread overview]
Message-ID: <20181214075852.GB1721@linux.intel.com> (raw)
In-Reply-To: <ae012b83-af66-6dfe-6131-e08507c3372e@huawei.com>
On Thu, Dec 13, 2018 at 08:57:17AM +0100, Roberto Sassu wrote:
> > 1. The function does not fail if alg_id is not found. This will go
> > silent.
>
> It is intentional. If alg_id is not found, the PCR is extended with the
> first digest passed by the caller of tpm_pcr_extend(). If no digest was
> provided, the PCR is extended with 0s. This is done to prevent that
> PCRs in unused banks are extended later with fake measurements.
>
>
> > 2. The function does not fail if there is a mismatch with the digest
> > sizes.
>
> The data passed by the caller of tpm_pcr_extend() is copied to
> dummy_hash, which has the maximum length. Then, tpm2_pcr_extend() takes
> from dummy_hash as many bytes as needed, depending on the current
> algorithm.
I would suggest to document these corner cases to the function long
description to make it easy and obvious to understand.
/Jarkko
next prev parent reply other threads:[~2018-12-14 7:59 UTC|newest]
Thread overview: 39+ 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
2018-12-04 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
2018-12-13 7:57 ` Roberto Sassu
2018-12-14 7:58 ` Jarkko Sakkinen [this message]
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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