Stefan,
On Thu, Mar 04, 2021 at 07:51:57PM -0500, Stefan Berger wrote:
> From: Saulo Alessandre <saulo.alessan...@tse.jus.br>
>
> * crypto/ecc.c
> - add vli_mmod_fast_384
> - change some routines to pass ecc_curve forward until vli_mmod_fast
>
> * crypto/ecc.h
> - add ECC_CURVE_NIST_P384_DIGITS
> - change ECC_MAX_DIGITS to P384 size
>
> Signed-off-by: Saulo Alessandre <saulo.alessan...@tse.jus.br>
> Tested-by: Stefan Berger <stef...@linux.ibm.com>
> ---
> crypto/ecc.c | 266 +++++++++++++++++++++++++++++++++++++--------------
> crypto/ecc.h | 3 +-
> 2 files changed, 194 insertions(+), 75 deletions(-)
>
> diff --git a/crypto/ecc.c b/crypto/ecc.c
> index f6cef5a7942d..c125576cda6b 100644
> --- a/crypto/ecc.c
> +++ b/crypto/ecc.c
> @@ -778,18 +778,133 @@ static void vli_mmod_fast_256(u64 *result, const u64
> *product,
> ...
> /* Computes result = product % curve_prime for different curve_primes.
> *
> * Note that curve_primes are distinguished just by heuristic check and
> * not by complete conformance check.
> */
> static bool vli_mmod_fast(u64 *result, u64 *product,
> - const u64 *curve_prime, unsigned int ndigits)
> + const struct ecc_curve *curve)
> {
> u64 tmp[2 * ECC_MAX_DIGITS];
> + const u64 *curve_prime = curve->p;
> + const unsigned int ndigits = curve->g.ndigits;
>
> - /* Currently, both NIST primes have -1 in lowest qword. */
> - if (curve_prime[0] != -1ull) {
> + /* Currently, all NIST have name nist_.* */
> + if (strncmp(curve->name, "nist_", 5) != 0) {
I am not sure, but maybe this strncmp should not be optimized somehow,
since vli_mmod_fast could be called quite frequently. Perhaps by integer
algo id or even callback?
Thanks,
> /* Try to handle Pseudo-Marsenne primes. */
> if (curve_prime[ndigits - 1] == -1ull) {
> vli_mmod_special(result, product, curve_prime,
> @@ -812,6 +927,9 @@ static bool vli_mmod_fast(u64 *result, u64 *product,
> case 4:
> vli_mmod_fast_256(result, product, curve_prime, tmp);
> break;
> + case 6:
> + vli_mmod_fast_384(result, product, curve_prime, tmp);
> + break;
> default:
> pr_err_ratelimited("ecc: unsupported digits size!\n");
> return false;
> @@ -835,22 +953,22 @@ EXPORT_SYMBOL(vli_mod_mult_slow);
>
> /* Computes result = (left * right) % curve_prime. */
> static void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right,
> - const u64 *curve_prime, unsigned int ndigits)
> + const struct ecc_curve *curve)
> {
> u64 product[2 * ECC_MAX_DIGITS];
>
> - vli_mult(product, left, right, ndigits);
> - vli_mmod_fast(result, product, curve_prime, ndigits);
> + vli_mult(product, left, right, curve->g.ndigits);
> + vli_mmod_fast(result, product, curve);
> }
>
> /* Computes result = left^2 % curve_prime. */
> static void vli_mod_square_fast(u64 *result, const u64 *left,
> - const u64 *curve_prime, unsigned int ndigits)
> + const struct ecc_curve *curve)
> {
> u64 product[2 * ECC_MAX_DIGITS];
>
> - vli_square(product, left, ndigits);
> - vli_mmod_fast(result, product, curve_prime, ndigits);
> + vli_square(product, left, curve->g.ndigits);
> + vli_mmod_fast(result, product, curve);
> }
>
> #define EVEN(vli) (!(vli[0] & 1))
