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Date:   Thu, 30 May 2019 10:33:57 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Richard Weinberger <richard@nod.at>
Cc:     linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-imx@nxp.com,
        festevam@gmail.com, kernel@pengutronix.de, s.hauer@pengutronix.de,
        shawnguo@kernel.org, davem@davemloft.net, david@sigma-star.at
Subject: Re: [RFC PATCH 1/2] crypto: Allow working with key references
Message-ID: <20190530023357.2mrjtslnka4i6dbl@gondor.apana.org.au>
References: <20190529224844.25203-1-richard@nod.at>
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On Thu, May 30, 2019 at 12:48:43AM +0200, Richard Weinberger wrote:
> Some crypto accelerators allow working with secure or hidden keys.
> This keys are not exposed to Linux nor main memory. To use them
> for a crypto operation they are referenced with a device specific id.
> 
> This patch adds a new flag, CRYPTO_TFM_REQ_REF_KEY.
> If this flag is set, crypto drivers should tread the key as
> specified via setkey as reference and not as regular key.
> Since we reuse the key data structure such a reference is limited
> by the key size of the chiper and is chip specific.
> 
> TODO: If the cipher implementation or the driver does not
> support reference keys, we need a way to detect this an fail
> upon setkey.
> How should the driver indicate that it supports this feature?
> 
> Signed-off-by: Richard Weinberger <richard@nod.at>

We already have existing drivers doing this.  Please have a look
at how they're doing it and use the same paradigm.  You can grep
for paes under drivers/crypto.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt