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Date:   Thu, 6 Oct 2022 08:42:32 -0400
From:   Ben Boeckel <me@benboeckel.net>
To:     Pankaj Gupta <pankaj.gupta@nxp.com>
Cc:     jarkko@kernel.org, a.fatoum@pengutronix.de, gilad@benyossef.com,
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Subject: Re: [PATCH v0 6/8] KEYS: trusted: caam based black key
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References: <20221006130837.17587-1-pankaj.gupta@nxp.com>
 <20221006130837.17587-7-pankaj.gupta@nxp.com>
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On Thu, Oct 06, 2022 at 18:38:35 +0530, Pankaj Gupta wrote:
> - CAAM supports two types of black keys:
>   -- Plain key encrypted with ECB
>   -- Plain key encrypted with CCM

What is a "black key"? Is this described in the documentation or local
comments at all? (I know I'm unfamiliar with CAAM, but maybe this should
be mentioned somewhere?).

>   Note: Due to robustness, default encytption used for black key is CCM.
                                     ^^^^^^^^^^ encryption

What "robustness"? Surely there's some more technical details involved
here?

> - A black key blob is generated, and added to trusted key payload.
>   This is done as part of sealing operation, that was triggered as a result of:
>   -- new key generation
>   -- load key,

It seems that "black keys" are what the uapi calls "hw". I think this
should be mentioned in the commit message (and CAAM docs).

What do other keytypes do if `hw` is requested and it's not possible
(say, `big_key`)?

Thanks,

--Ben