Hello Horia,

On 21.03.21 21:01, Horia Geantă wrote:

quoted

 - [RFC] drivers: crypto: caam: key: Add caam_tk key type
   Franck added[3] 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.

The whole point was to use caam "black blobs", with the main advantage of
keys being kept encrypted in memory after "unsealing" the blobs.
(Keys in blobs are encrypted with a persistent BKEK - blob KEK, derived from
fuse-based OTPMK. OTOH black keys are keys encrypted with an ephemeral, random
KEK that is stored in an internal caam register. When a black blob is unsealed,
the key is practically rekeyed, the random key replacing the BKEK; key is never
exposed in plaintext, rekeying happens in caam).

Current implementation uses "red blobs", which means keys are left unprotected
in memory after blobs are unsealed.

Oh. I will reread the series when sending the v2 cover letter. Thanks for spotting.

(Sorry for the noise, missed this question first time)

quoted

 - 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.

Shouldn't the description under TRUSTED_KEYS (in security/keys/Kconfig)
be updated to reflect the availability of multiple backends?

Thanks,
Horia

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