Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 6 Sep 2022 11:58:17 +0300
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Pankaj Gupta <pankaj.gupta@nxp.com>
Cc:     a.fatoum@pengutronix.de, Jason@zx2c4.com, jejb@linux.ibm.com,
        zohar@linux.ibm.com, dhowells@redhat.com, sumit.garg@linaro.org,
        david@sigma-star.at, michael@walle.cc, john.ernberg@actia.se,
        jmorris@namei.org, serge@hallyn.com, herbert@gondor.apana.org.au,
        davem@davemloft.net, j.luebbe@pengutronix.de, ebiggers@kernel.org,
        richard@nod.at, keyrings@vger.kernel.org,
        linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        linux-security-module@vger.kernel.org, sahil.malhotra@nxp.com,
        kshitiz.varshney@nxp.com, horia.geanta@nxp.com, V.Sethi@nxp.com
Subject: Re: [RFC PATCH HBK: 0/8] HW BOUND KEY as TRUSTED KEY
Message-ID: <YxcLqepquOuOOjvq@kernel.org>
References: <20220906065157.10662-1-pankaj.gupta@nxp.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220906065157.10662-1-pankaj.gupta@nxp.com>
Precedence: bulk

On Tue, Sep 06, 2022 at 12:21:49PM +0530, Pankaj Gupta wrote:
> Hardware Bound key(HBK), is never acessible as plain key outside of the
                                    ~~~~~~~~~
                                    accesible.

> hardware boundary. Thus, it is un-usable, even if somehow fetched
> from kernel memory. It ensures run-time security.

Why is it called "HBK" here and "hw" in the context of keyctl?

> This patchset adds generic support for classing the Hardware Bound Key,
> based on:
> 
> - Newly added flag-'is_hbk', added to the tfm.
> 
>   Consumer of the kernel crypto api, after allocating
>   the transformation, sets this flag based on the basis
>   of the type of key consumer has.
> 
> - This helps to influence the core processing logic
>   for the encapsulated algorithm.
> 
> - This flag is set by the consumer after allocating
>   the tfm and before calling the function crypto_xxx_setkey().
> 
> First implementation is based on CAAM.

CAAM is implementation of what exactly?

I'm sorry but I don't know your definition of unusable.

BR, Jarkko