[PATCH v5 08/12] crypto: ecdsa - Replace ndigits with nbits where precision is needed

From: Stefan Berger
Date: Wed Mar 06 2024 - 17:25:20 EST


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

Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
Tested-by: Lukas Wunner <lukas@xxxxxxxxx>
---
crypto/ecdsa.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c
index 1814f009f971..4daefb40c37a 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