Date:   Fri, 17 Dec 2021 15:14:03 +1100
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Stephan Mueller <smueller@chronox.de>
Cc:     Yujie Liu <yujie.liu@intel.com>,
        Mat Martineau <mathew.j.martineau@linux.intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Memory Management List <linux-mm@kvack.org>,
        lkp@lists.01.org, lkp@intel.com,
        "Sang, Oliver" <oliver.sang@intel.com>
Subject: Re: [security] d3b04a4398:
 WARNING:at_crypto/kdf_sp800108.c:#crypto_kdf108_init
Message-ID: <20211217041403.GA19847@gondor.apana.org.au>
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On Fri, Dec 10, 2021 at 03:16:34PM +0100, Stephan Mueller wrote:
>
> Herbert, what is your preference in handling this:
> 
> - we could SELECT CRYPTO_SHA256 when the KDF is compiled. This would only be 
> necessary to satisfy the self test. Yet, there is no guarantee that SHA-256 
> would truly be needed because the DH code that calls the KDF obtains the 
> reference to the hash from user space. In the end we could hard compile a 
> crypto algorithm into the kernel that may never be used.

...

> I would prefer to consider the first option to also statically compile 
> SHA-256.

I think KDF800108_CTR should select SHA256 instead of HASH.

Thanks,
-- 
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