From: jarkko.sakkinen@linux.intel.com (Jarkko Sakkinen)
To: linux-security-module@vger.kernel.org
Subject: [PATCH 0/3] tpm: retrieve digest size of unknown algorithms from TPM
Date: Wed, 4 Oct 2017 10:32:58 +0300 [thread overview]
Message-ID: <20171004073258.be2j7mdeud2pjbyk@linux.intel.com> (raw)
In-Reply-To: <20170925111950.21511-1-roberto.sassu@huawei.com>
Hi
And apologies for late review.
On Mon, Sep 25, 2017 at 01:19:47PM +0200, Roberto Sassu wrote:
> This patch set derives from a larger patch set which modifies the TPM
> driver API in order to extend a PCR with multiple digests. It can be
> retrieved at the URL:
>
> https://sourceforge.net/p/tpmdd/mailman/message/35905412/
A patch set should be able to live on its own. Please remove this link.
I don't care about that patch set at this point and I'm not going to
give any distant promises.
> 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.
This part makes sense to me.
/Jarkko
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
prev parent reply other threads:[~2017-10-04 7:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-25 11:19 [PATCH 0/3] tpm: retrieve digest size of unknown algorithms from TPM Roberto Sassu
2017-09-25 11:19 ` [PATCH 1/3] tpm: move PCR read code to static function tpm2_pcr_read_common() Roberto Sassu
2017-10-04 10:45 ` Jarkko Sakkinen
2017-09-25 11:19 ` [PATCH 2/3] tpm: retrieve digest size of unknown algorithms with PCR read Roberto Sassu
2017-10-04 11:12 ` Jarkko Sakkinen
2017-09-25 11:19 ` [PATCH 3/3] tpm: add the crypto algorithm identifier to active_bank_info Roberto Sassu
2017-10-04 11:22 ` Jarkko Sakkinen
2017-10-04 7:32 ` Jarkko Sakkinen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171004073258.be2j7mdeud2pjbyk@linux.intel.com \
--to=jarkko.sakkinen@linux.intel.com \
--cc=linux-security-module@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).