Date:   Mon, 20 Feb 2023 12:44:29 +0800
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Ard Biesheuvel <ardb@kernel.org>
Cc:     linux-crypto@vger.kernel.org, ebiggers@kernel.org,
        James Bottomley <James.Bottomley@hansenpartnership.com>
Subject: Re: [PATCH v2] crypto: lib - implement library version of AES in CFB
 mode
Message-ID: <Y/L6rSGDidhhWq2v@gondor.apana.org.au>
References: <20230217144348.1537615-1-ardb@kernel.org>
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On Fri, Feb 17, 2023 at 03:43:48PM +0100, Ard Biesheuvel wrote:
> Implement AES in CFB mode using the existing, mostly constant-time
> generic AES library implementation. This will be used by the TPM code
> to encrypt communications with TPM hardware, which is often a discrete
> component connected using sniffable wires or traces.
> 
> While a CFB template does exist, using a skcipher is a major pain for
> non-performance critical synchronous crypto where the algorithm is known
> at compile time and the data is in contiguous buffers with valid kernel
> virtual addresses.
> 
> Tested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
> Link: https://lore.kernel.org/all/20230216201410.15010-1-James.Bottomley@HansenPartnership.com/
> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> ---
> v1 was sent out by James and is archived at the URL above
> 
> v2:
> - add test cases and kerneldoc comments
> - add memzero_explicit() calls to wipe the keystream buffers
> - add module exports
> - add James's Tb/Rb
> 
>  include/crypto/aes.h |   5 +
>  lib/crypto/Kconfig   |   5 +
>  lib/crypto/Makefile  |   3 +
>  lib/crypto/aescfb.c  | 257 ++++++++++++++++++++
>  4 files changed, 270 insertions(+)

Could we remove the crypto/cfb.c implementation after this work
is complete?

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