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author | Stefan Berger <stefanb@linux.ibm.com> | 2024-04-04 10:18:50 -0400 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2024-04-12 15:07:52 +0800 |
commit | 0de2c02d3cf9af5f08ae135b0c5f1ffd6464ff19 (patch) | |
tree | 22f42efecb6062661c9b5ad28b0192e0f2df4918 /crypto | |
parent | d2a3837737aa1fe32cd3a6719f921cb74512cfa2 (diff) | |
download | linux-crypto-0de2c02d3cf9af5f08ae135b0c5f1ffd6464ff19.tar.gz linux-crypto-0de2c02d3cf9af5f08ae135b0c5f1ffd6464ff19.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')
-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 8914e437..d15ef074 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); |