diff options
| author | Stefan Berger <stefanb@linux.ibm.com> | 2024-04-04 10:18:50 -0400 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2024-04-12 15:07:52 +0800 |
| commit | 114e80437e0e48b967d0bd533a4c8ff1186ce12f (patch) | |
| tree | a60b37a701fca4729a0c5af6f0ec34bbce7a835a /crypto/ecc.c | |
| parent | e7fb062754ef9f656ee004f2be8f59ce8a79bffb (diff) | |
| download | lwn-114e80437e0e48b967d0bd533a4c8ff1186ce12f.tar.gz lwn-114e80437e0e48b967d0bd533a4c8ff1186ce12f.zip | |
crypto: ecc - Add special case for NIST P521 in ecc_point_mult
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.
Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/ecc.c')
| -rw-r--r-- | crypto/ecc.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/crypto/ecc.c b/crypto/ecc.c index 8914e437f94b..d15ef0747a76 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); |