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Date: Fri, 01 Mar 2024 22:50:30 +0200
Message-Id: <CZIPKTL42F1Z.2U4Q28IIQ159K@suppilovahvero>
Cc: <linux-kernel@vger.kernel.org>, <saulo.alessandre@tse.jus.br>,
 <lukas@wunner.de>
Subject: Re: [PATCH v4 09/12] crypto: ecdsa - Rename keylen to bufsize where
 necessary
From: "Jarkko Sakkinen" <jarkko@kernel.org>
To: "Stefan Berger" <stefanb@linux.ibm.com>, <keyrings@vger.kernel.org>,
 <linux-crypto@vger.kernel.org>, <herbert@gondor.apana.org.au>,
 <davem@davemloft.net>
References: <20240301022007.344948-1-stefanb@linux.ibm.com>
 <20240301022007.344948-10-stefanb@linux.ibm.com>
 <CZIPDP0W9TOP.3CCT8QUB0R4L3@suppilovahvero>
 <90606a3c-1384-407b-8270-dd76dccc700b@linux.ibm.com>
In-Reply-To: <90606a3c-1384-407b-8270-dd76dccc700b@linux.ibm.com>

On Fri Mar 1, 2024 at 10:47 PM EET, Stefan Berger wrote:
>
>
> On 3/1/24 15:41, Jarkko Sakkinen wrote:
> > On Fri Mar 1, 2024 at 4:20 AM EET, Stefan Berger wrote:
> >> In some cases the name keylen does not reflect the purpose of the vari=
able
> >> anymore once NIST P521 is used but it is the size of the buffer. There=
-
> >> for, rename keylen to bufsize where appropriate.
> >>
> >> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> >> ---
> >>   crypto/ecdsa.c | 12 ++++++------
> >>   1 file changed, 6 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c
> >> index 4daefb40c37a..4e847b59622a 100644
> >> --- a/crypto/ecdsa.c
> >> +++ b/crypto/ecdsa.c
> >> @@ -35,8 +35,8 @@ struct ecdsa_signature_ctx {
> >>   static int ecdsa_get_signature_rs(u64 *dest, size_t hdrlen, unsigned=
 char tag,
> >>   				  const void *value, size_t vlen, unsigned int ndigits)
> >>   {
> >> -	size_t keylen =3D ndigits * sizeof(u64);
> >> -	ssize_t diff =3D vlen - keylen;
> >> +	size_t bufsize =3D ndigits * sizeof(u64);
> >=20
> > why not just "* 8"? using sizeof here makes this function only unreadab=
le.
>
> 'unreadable' is a 'strong' word ...

so what is the gain when writing sizeof(u64)?

BR, Jarkko