linux-kernel - [PATCH v8 09/13] crypto: ecdsa - Replace ndigits with nbits where precision is needed

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Date: Thu,  4 Apr 2024 10:18:52 -0400
From: Stefan Berger <stefanb@...ux.ibm.com>
To: 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, jarkko@...nel.org,
        Stefan Berger <stefanb@...ux.ibm.com>
Subject: [PATCH v8 09/13] crypto: ecdsa - Replace ndigits with nbits where precision is needed

Replace the usage of ndigits with nbits where precise space calculations
are needed, such as in ecdsa_max_size where the length of a coordinate is
determined.

Tested-by: Lukas Wunner <lukas@...ner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@...nel.org>
Signed-off-by: Stefan Berger <stefanb@...ux.ibm.com>
---
 crypto/ecdsa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c
index 9b84ab503276..75d3eea885db 100644
--- a/crypto/ecdsa.c
+++ b/crypto/ecdsa.c
@@ -266,7 +266,7 @@ static unsigned int ecdsa_max_size(struct crypto_akcipher *tfm)
 {
 	struct ecc_ctx *ctx = akcipher_tfm_ctx(tfm);
 
-	return ctx->pub_key.ndigits << ECC_DIGITS_TO_BYTES_SHIFT;
+	return DIV_ROUND_UP(ctx->curve->nbits, 8);
 }
 
 static int ecdsa_nist_p384_init_tfm(struct crypto_akcipher *tfm)
-- 
2.43.0