linux-kernel - Re: [PATCH v6 07/13] crypto: ecc - Add special case for NIST P521 in ecc_point

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <CZX67UDST7WU.1LNVWGY9DM999@kernel.org>
Date: Mon, 18 Mar 2024 22:50:11 +0200
From: "Jarkko Sakkinen" <jarkko@...nel.org>
To: "Stefan Berger" <stefanb@...ux.vnet.ibm.com>,
 <keyrings@...r.kernel.org>, <linux-crypto@...r.kernel.org>,
 <herbert@...dor.apana.org.au>, <davem@...emloft.net>
Cc: <linux-kernel@...r.kernel.org>, <saulo.alessandre@....jus.br>,
 <lukas@...ner.de>, <bbhushan2@...vell.com>, "Stefan Berger"
 <stefanb@...ux.ibm.com>
Subject: Re: [PATCH v6 07/13] crypto: ecc - Add special case for NIST P521
 in ecc_point_mult

On Tue Mar 12, 2024 at 8:36 PM EET, Stefan Berger wrote:
> From: Stefan Berger <stefanb@...ux.ibm.com>
>
> In ecc_point_mult use the number of bits of the NIST P521 curve + 2. The
> change is required specifically for NIST P521 to pass mathematical tests
> on the public key.
>
> Signed-off-by: Stefan Berger <stefanb@...ux.ibm.com>
> Tested-by: Lukas Wunner <lukas@...ner.de>
> ---
>  crypto/ecc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/crypto/ecc.c b/crypto/ecc.c
> index 99d41887c005..ead40b5ebb46 100644
> --- a/crypto/ecc.c
> +++ b/crypto/ecc.c
> @@ -1320,7 +1320,10 @@ static void ecc_point_mult(struct ecc_point *result,
>  	carry = vli_add(sk[0], scalar, curve->n, ndigits);
>  	vli_add(sk[1], sk[0], curve->n, ndigits);
>  	scalar = sk[!carry];
> -	num_bits = sizeof(u64) * ndigits * 8 + 1;
> +	if (curve->nbits == 521)	/* NIST P521 */
> +		num_bits = curve->nbits + 2;
> +	else
> +		num_bits = sizeof(u64) * ndigits * 8 + 1;
>  
>  	vli_set(rx[1], point->x, ndigits);
>  	vli_set(ry[1], point->y, ndigits);


Reviewed-by: Jarkko Sakkinen <jarkko@...nel.org>

BR, Jarkko