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

Mon May 16 18:36:48 UTC 2022

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 at kernel.org>
> To: "Horia Geantă" <horia.geanta at nxp.com>
> To: Mimi Zohar <zohar at linux.ibm.com>
> To: Pankaj Gupta <pankaj.gupta at nxp.com>
> To: Herbert Xu <herbert at gondor.apana.org.au>
> To: "David S. Miller" <davem at davemloft.net>
> To: James Bottomley <jejb at linux.ibm.com>
> Cc: David Howells <dhowells at redhat.com>
> Cc: James Morris <jmorris at namei.org>
> Cc: "Serge E. Hallyn" <serge at hallyn.com>
> Cc: Steffen Trumtrar <s.trumtrar at pengutronix.de>
> Cc: Jan Luebbe <j.luebbe at pengutronix.de>
> Cc: David Gstir <david at sigma-star.at>
> Cc: Eric Biggers <ebiggers at kernel.org>
> Cc: Richard Weinberger <richard at nod.at>
> Cc: Franck LENORMAND <franck.lenormand at nxp.com>
> Cc: Sumit Garg <sumit.garg at linaro.org>
> Cc: Andreas Rammhold <andreas at rammhold.de>
> Cc: Tim Harvey <tharvey at gateworks.com>
> Cc: Matthias Schiffer <matthias.schiffer at ew.tq-group.com>
> Cc: Michael Walle <michael at walle.cc>
> Cc: John Ernberg <john.ernberg at actia.se>
> Cc: linux-integrity at vger.kernel.org
> Cc: keyrings at vger.kernel.org
> Cc: linux-crypto at vger.kernel.org
> Cc: linux-kernel at vger.kernel.org
> Cc: linux-security-module at 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