[PATCH v1 0/3] KEYS: trusted: Introduce support for NXP CAAM-based trusted keys
richard.weinberger at gmail.com
Tue Mar 16 23:10:54 UTC 2021
On Tue, Mar 16, 2021 at 6:24 PM Ahmad Fatoum <a.fatoum at pengutronix.de> wrote:
> 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 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 added 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 a new "caam_tk" key type based on Udit's work. The key
> material stays within the kernel only, but can optionally be user-set
> instead of coming from RNG. 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 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 on an i.MX6DL.
Do have this series also in a git repo to pull from?
I'd like to give it a test on various systems.
> Looking forward to your feedback.
Thanks for working on this! David and I will have a closer look these days.
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