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From: Stephan Mueller <smueller@chronox.de>
To: Andrei Botila <andrei.botila@oss.nxp.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC] crypto: xts - add check for input length equal to zero
Date: Thu, 05 Mar 2020 11:33:40 +0100	[thread overview]
Message-ID: <4145904.A5P2xsN9yQ@tauon.chronox.de> (raw)
In-Reply-To: <20200305102255.12548-1-andrei.botila@oss.nxp.com>

Am Donnerstag, 5. März 2020, 11:22:55 CET schrieb Andrei Botila:

Hi Andrei,

> From: Andrei Botila <andrei.botila@nxp.com>
> 
> Through this RFC we try to standardize the way input lengths equal to 0
> are handled in all skcipher algorithms. Currently, in xts when an input
> has a length smaller than XTS_BLOCK_SIZE it returns -EINVAL while the
> other algorithms return 0 for input lengths equal to zero.
> The algorithms that implement this check are CBC, ARC4, CFB, OFB, SALSA20,
> CTR, ECB and PCBC, XTS being the outlier here. All of them call
> skcipher_walk_virt() which returns 0 if skcipher_walk_skcipher() finds
> that input length is equal to 0.
> This case was discovered when fuzz testing was enabled since it generates
> this input length.
> This RFC wants to find out if the approach is ok before updating the
> other xts implementations.

It may be a good idea to consolidate that. However, changing only one 
implementation is not good.

All XTS implementations would need to be converted then.

Ciao
Stephan



      reply	other threads:[~2020-03-05 10:33 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-05 10:22 [RFC] crypto: xts - add check for input length equal to zero Andrei Botila
2020-03-05 10:33 ` Stephan Mueller [this message]

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