Re: [PATCH v10 0/7] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys

Jarkko Sakkinen
2022-05-16T18:38:33Z

On Fri, May 13, 2022 at 04:56:58PM +0200, Ahmad Fatoum wrote:
> Series applies on top of v5.18-rc6. Would be great if this could make it
> into v5.19.
>
> v9 was here:
> https://lore.kernel.org/linux-integrity/20220506062553.1068296-1-a.fatoum@pengutronix.de
>
> Changelog is beneath each individual patch. Compared to v9, only code
> change is checking whether CAAM can support blobbing at init-time for
> CAAM revisions < 10 (such as LS1046A) to avoid a cryptic error message
> at first use.
>
>
> The Cryptographic Acceleration and Assurance Module (CAAM) is an IP core
> built into many newer i.MX and QorIQ SoCs by NXP.
>
> Its blob mechanism can AES encrypt/decrypt user data using a unique
> never-disclosed device-specific key.
>
> There has been multiple discussions on how to represent this within the kernel:
>
> The Cryptographic Acceleration and Assurance Module (CAAM) is an IP core
> built into many newer i.MX and QorIQ SoCs by NXP.
>
> Its blob mechanism can AES encrypt/decrypt user data using a unique
> never-disclosed device-specific key. There has been multiple
> discussions on how to represent this within the kernel:
>
> - [RFC] crypto: caam - add red blobifier
> Steffen implemented[1] a PoC sysfs driver to start a discussion on how to
> best integrate the blob mechanism.
> Mimi suggested that it could be used to implement trusted keys.
> Trusted keys back then were a TPM-only feature.
>
> - security/keys/secure_key: Adds the secure key support based on CAAM.
> Udit Agarwal added[2] a new "secure" key type with the CAAM as backend.
> The key material stays within the kernel only.
> Mimi and James agreed that this needs a generic interface, not specific
> to CAAM. Mimi suggested trusted keys. Jan noted that this could serve as
> basis for TEE-backed keys.
>
> - [RFC] drivers: crypto: caam: key: Add caam_tk key type
> Franck added[3] a new "caam_tk" key type based on Udit's work. This time
> it uses CAAM "black blobs" instead of "red blobs", so key material stays
> within the CAAM and isn't exposed to kernel in plaintext.
> James voiced the opinion that there should be just one user-facing generic
> wrap/unwrap key type with multiple possible handlers.
> David suggested trusted keys.
>
> - Introduce TEE based Trusted Keys support
> Sumit reworked[4] trusted keys to support multiple possible backends with
> one chosen at boot time and added a new TEE backend along with TPM.
> This now sits in Jarkko's master branch to be sent out for v5.13
>
> This patch series builds on top of Sumit's rework to have the CAAM as yet another
> trusted key backend.
>
> The CAAM bits are based on Steffen's initial patch from 2015. His work had been
> used in the field for some years now, so I preferred not to deviate too much from it.
>
> This series has been tested with dmcrypt[5] on an i.MX6Q/DL, i.MX8M[6]
> and LS1028[7].
>
> Looking forward to your feedback.
>
> Cheers,
> Ahmad
>
> [1]: https://lore.kernel.org/linux-crypto/1447082306-19946-2-git-send-email-s.trumtrar@pengutronix.de/
> [2]: https://lore.kernel.org/linux-integrity/20180723111432.26830-1-udit.agarwal@nxp.com/
> [3]: https://lore.kernel.org/lkml/1551456599-10603-2-git-send-email-franck.lenormand@nxp.com/
> [4]: https://lore.kernel.org/lkml/1604419306-26105-1-git-send-email-sumit.garg@linaro.org/
> [5]: https://lore.kernel.org/linux-integrity/20210122084321.24012-2-a.fatoum@pengutronix.de/
> [6]: https://lore.kernel.org/linux-integrity/DU2PR04MB8630D83FE9BBC0D782C4FAF595089@DU2PR04MB8630.eurprd04.prod.outlook.com/
> [7]: https://lore.kernel.org/linux-integrity/49e1738c55c73819ee0e2cac0be74d81@walle.cc/
>
> ---
> To: Jarkko Sakkinen <jarkko@kernel.org>
> To: "Horia Geantă" <horia.geanta@nxp.com>
> To: Mimi Zohar <zohar@linux.ibm.com>
> To: Pankaj Gupta <pankaj.gupta@nxp.com>
> To: Herbert Xu <herbert@gondor.apana.org.au>
> To: "David S. Miller" <davem@davemloft.net>
> To: James Bottomley <jejb@linux.ibm.com>
> Cc: David Howells <dhowells@redhat.com>
> Cc: James Morris <jmorris@namei.org>
> Cc: "Serge E. Hallyn" <serge@hallyn.com>
> Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de>
> Cc: Jan Luebbe <j.luebbe@pengutronix.de>
> Cc: David Gstir <david@sigma-star.at>
> Cc: Eric Biggers <ebiggers@kernel.org>
> Cc: Richard Weinberger <richard@nod.at>
> Cc: Franck LENORMAND <franck.lenormand@nxp.com>
> Cc: Sumit Garg <sumit.garg@linaro.org>
> Cc: Andreas Rammhold <andreas@rammhold.de>
> Cc: Tim Harvey <tharvey@gateworks.com>
> Cc: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
> Cc: Michael Walle <michael@walle.cc>
> Cc: John Ernberg <john.ernberg@actia.se>
> Cc: linux-integrity@vger.kernel.org
> Cc: keyrings@vger.kernel.org
> Cc: linux-crypto@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-security-module@vger.kernel.org
>
>
>
> Ahmad Fatoum (7):
> KEYS: trusted: allow use of TEE as backend without TCG_TPM support
> KEYS: trusted: allow use of kernel RNG for key material
> crypto: caam - determine whether CAAM supports blob encap/decap
> crypto: caam - add in-kernel interface for blob generator
> KEYS: trusted: Introduce support for NXP CAAM-based trusted keys
> doc: trusted-encrypted: describe new CAAM trust source
> MAINTAINERS: add KEYS-TRUSTED-CAAM
>
> .../admin-guide/kernel-parameters.txt | 11 ++
> .../security/keys/trusted-encrypted.rst | 60 +++++-
> MAINTAINERS | 9 +
> drivers/crypto/caam/Kconfig | 3 +
> drivers/crypto/caam/Makefile | 1 +
> drivers/crypto/caam/blob_gen.c | 182 ++++++++++++++++++
> drivers/crypto/caam/ctrl.c | 17 +-
> drivers/crypto/caam/intern.h | 1 +
> drivers/crypto/caam/regs.h | 4 +-
> include/keys/trusted-type.h | 2 +-
> include/keys/trusted_caam.h | 11 ++
> include/soc/fsl/caam-blob.h | 103 ++++++++++
> security/keys/Kconfig | 18 +-
> security/keys/trusted-keys/Kconfig | 38 ++++
> security/keys/trusted-keys/Makefile | 10 +-
> security/keys/trusted-keys/trusted_caam.c | 80 ++++++++
> security/keys/trusted-keys/trusted_core.c | 45 ++++-
> 17 files changed, 563 insertions(+), 32 deletions(-)
> create mode 100644 drivers/crypto/caam/blob_gen.c
> create mode 100644 include/keys/trusted_caam.h
> create mode 100644 include/soc/fsl/caam-blob.h
> create mode 100644 security/keys/trusted-keys/Kconfig
> create mode 100644 security/keys/trusted-keys/trusted_caam.c
>
> --
> 2.30.2
>

I can probably pick these unless objections?

BR, Jarkko