From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Roberto Sassu <roberto.sassu@huawei.com>
Cc: zohar@linux.ibm.com, linux-integrity@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, silviu.vlasceanu@huawei.com
Subject: Re: [PATCH v4 0/6] tpm: retrieve digest size of unknown algorithms from TPM
Date: Thu, 8 Nov 2018 15:51:40 +0200 [thread overview]
Message-ID: <20181108135140.GB8922@linux.intel.com> (raw)
In-Reply-To: <20181106150159.1136-1-roberto.sassu@huawei.com>
On Tue, Nov 06, 2018 at 04:01:53PM +0100, Roberto Sassu wrote:
> The TPM driver currently relies on the crypto subsystem to determine the
> digest size of supported TPM algorithms. In the future, TPM vendors might
> implement new algorithms in their chips, and those algorithms might not
> be supported by the crypto subsystem.
>
> Usually, vendors provide patches for the new hardware, and likely
> the crypto subsystem will be updated before the new algorithm is
> introduced. However, old kernels might be updated later, after patches
> are included in the mainline kernel. This would leave the opportunity
> for attackers to misuse PCRs, as PCR banks with an unknown algorithm
> are not extended.
>
> This patch set provides a long term solution for this issue. If a TPM
> algorithm is not known by the crypto subsystem, the TPM driver retrieves
> the digest size from the TPM with a PCR read. All the PCR banks are
> extended, even if the algorithm is not yet supported by the crypto
> subsystem.
>
> PCR bank information (TPM algorithm ID, digest size, crypto subsystem ID)
> is stored in the tpm_chip structure and available for users of the TPM
> driver.
>
> Changelog
>
> v3:
> - remove end marker change
> - replace active_banks static array with pointer to dynamic array
> - remove TPM2_ACTIVE_PCR_BANKS
>
> v2:
> - change the end marker of the active_banks array
> - check digest size from output of PCR read command
> - remove count parameter from tpm_pcr_read() and tpm2_pcr_read()
>
> v1:
> - modify definition of tpm_pcr_read()
> - move hash algorithms and definition of tpm2_digest to include/linux/tpm.h
>
> Roberto Sassu (6):
> tpm: dynamically allocate active_banks array
> tpm: remove definition of TPM2_ACTIVE_PCR_BANKS
> tpm: rename and export tpm2_digest and tpm2_algorithms
> tpm: modify tpm_pcr_read() definition to pass a TPM hash algorithm
> tpm: retrieve digest size of unknown algorithms with PCR read
> tpm: ensure that the output of PCR read contains the correct digest
> size
>
> drivers/char/tpm/tpm-chip.c | 1 +
> drivers/char/tpm/tpm-interface.c | 34 +++++---
> drivers/char/tpm/tpm.h | 19 ++---
> drivers/char/tpm/tpm2-cmd.c | 115 ++++++++++++++++++++--------
> include/linux/tpm.h | 30 +++++++-
> include/linux/tpm_eventlog.h | 12 +--
> security/integrity/ima/ima_crypto.c | 10 +--
> 7 files changed, 145 insertions(+), 76 deletions(-)
>
> --
> 2.17.1
>
You should rebase your series to the latest upstream.
/Jarkko
prev parent reply other threads:[~2018-11-08 13:51 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-06 15:01 [PATCH v4 0/6] tpm: retrieve digest size of unknown algorithms from TPM Roberto Sassu
2018-11-06 15:01 ` [PATCH v4 1/6] tpm: dynamically allocate active_banks array Roberto Sassu
2018-11-07 6:14 ` Nayna Jain
2018-11-07 9:41 ` Roberto Sassu
2018-11-08 13:50 ` Nayna Jain
2018-11-08 14:40 ` Roberto Sassu
2018-11-08 15:21 ` Jarkko Sakkinen
2018-11-08 15:29 ` Mimi Zohar
2018-11-08 18:57 ` Jarkko Sakkinen
2018-11-08 15:54 ` Ken Goldman
2018-12-13 20:21 ` Ken Goldman
2018-11-07 11:10 ` Mimi Zohar
2018-11-08 13:46 ` Jarkko Sakkinen
2018-11-08 14:24 ` Roberto Sassu
2018-11-08 15:22 ` Jarkko Sakkinen
2018-11-13 13:34 ` Roberto Sassu
2018-11-13 17:04 ` Jarkko Sakkinen
2018-11-13 13:53 ` Roberto Sassu
2018-11-06 15:01 ` [PATCH v4 2/6] tpm: remove definition of TPM2_ACTIVE_PCR_BANKS Roberto Sassu
2018-11-08 14:02 ` Jarkko Sakkinen
2018-11-08 14:03 ` Jarkko Sakkinen
2018-11-08 14:52 ` Roberto Sassu
2018-11-08 19:05 ` Jarkko Sakkinen
2018-11-06 15:01 ` [PATCH v4 3/6] tpm: rename and export tpm2_digest and tpm2_algorithms Roberto Sassu
2018-11-06 15:01 ` [PATCH v4 4/6] tpm: modify tpm_pcr_read() definition to pass a TPM hash algorithm Roberto Sassu
2018-11-08 14:04 ` Jarkko Sakkinen
2018-11-08 14:16 ` Roberto Sassu
2018-11-08 15:15 ` Jarkko Sakkinen
2018-11-08 15:19 ` Peter Huewe
2018-11-08 19:08 ` Jarkko Sakkinen
2018-11-13 12:34 ` Jarkko Sakkinen
2018-11-13 12:39 ` Roberto Sassu
2018-11-13 16:56 ` Jarkko Sakkinen
2018-11-06 15:01 ` [PATCH v4 5/6] tpm: retrieve digest size of unknown algorithms with PCR read Roberto Sassu
2018-11-06 15:01 ` [PATCH v4 6/6] tpm: ensure that the output of PCR read contains the correct digest size Roberto Sassu
2018-11-08 14:08 ` Jarkko Sakkinen
2018-11-08 14:47 ` Roberto Sassu
2018-11-08 18:52 ` Jarkko Sakkinen
2018-11-13 13:08 ` Roberto Sassu
2018-11-13 16:59 ` Jarkko Sakkinen
2018-11-08 13:51 ` Jarkko Sakkinen [this message]
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