[RFC PATCH 0/2] Create CAAM HW key in linux keyring and use in dmcrypt

Jan Lübbe jlu at pengutronix.de
Wed Mar 6 16:47:46 UTC 2019

Hi Franck,

thanks for working on this!

On Fri, 2019-03-01 at 17:09 +0100, Franck LENORMAND wrote:
> The creation of such structures and its use was not exposed to userspace so
> it was complicated to use and required custom development. We would like to
> ease this using interface which are known and used:
>  - Linux key retention service : Allow to generate or load keys in a
>         keyring which can be used by applications.
>  - dm-crypt : device mapper allowing to encrypt data.
> The capacity to generate or load keys already available in the Linux key
> retention service does not allows to exploit CAAM capabilities hence we
> need to create a new key_type. The new key type "caam_tk" allows to:
>  - Create a black key from random
>  - Create a black key from a red key
>  - Load a black blob to retrieve the black key

On 2018-07-23, Udit Agarwal <udit.agarwal at nxp.com> sent a series which
seems related to this:
[PATCH v2 1/2] security/keys/secure_key: Adds the secure key support
based on CAAM.
[PATCH v2 2/2] encrypted_keys: Adds support for secure key-type as
master key.

Is this series intended to continue that work and cover the same uses-

If I remember correctly, the CAAM also supports marking blobs to allow
or disallow exporting the encapsulated key from the hardware. Or is
this unneeded and we could encrypt/decrypt other (less critical) key
material against the tk(cbc(aes)) CAAM key via the keyring mechanisms?

Best regards,
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