diff options
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | ecc-internal.h | 7 | ||||
| -rw-r--r-- | ecc-mod-arith.c | 10 | ||||
| -rw-r--r-- | testsuite/ecc-modinv-test.c | 14 |
4 files changed, 24 insertions, 13 deletions
@@ -39,6 +39,12 @@ (struct ecc_modulo): Renamed corresponding function pointer to sqrt_ratio. Updated all uses. +2021-10-28 Niels Möller <nisse@lysator.liu.se> + + * ecc-mod-arith.c (ecc_mod_equal_p): New function, moved from + ecc-modinv-test.c. Based on patch by Wim Lewis. + * testsuite/ecc-modinv-test.c (mod_eq_p): Deleted, replaced with ecc_mod_equal_p. + 2021-10-26 Niels Möller <nisse@lysator.liu.se> * ecc-mod-arith.c (ecc_mod_zero_p): New function. diff --git a/ecc-internal.h b/ecc-internal.h index 277f5a02..2ea553b5 100644 --- a/ecc-internal.h +++ b/ecc-internal.h @@ -43,6 +43,7 @@ #define ecc_pp1_redc _nettle_ecc_pp1_redc #define ecc_pm1_redc _nettle_ecc_pm1_redc #define ecc_mod_zero_p _nettle_ecc_mod_zero_p +#define ecc_mod_equal_p _nettle_ecc_mod_equal_p #define ecc_mod_add _nettle_ecc_mod_add #define ecc_mod_sub _nettle_ecc_mod_sub #define ecc_mod_mul_1 _nettle_ecc_mod_mul_1 @@ -248,6 +249,12 @@ ecc_mod_inv_func ecc_mod_inv; int ecc_mod_zero_p (const struct ecc_modulo *m, const mp_limb_t *xp); +/* Requires that a < 2m, and ref < m, needs m->size limbs of scratch + space. Overlap, a == scratch or ref == scratch, is allowed. */ +int +ecc_mod_equal_p (const struct ecc_modulo *m, const mp_limb_t *a, + const mp_limb_t *ref, mp_limb_t *scratch); + void ecc_mod_add (const struct ecc_modulo *m, mp_limb_t *rp, const mp_limb_t *ap, const mp_limb_t *bp); diff --git a/ecc-mod-arith.c b/ecc-mod-arith.c index 0b0631af..310cbb1d 100644 --- a/ecc-mod-arith.c +++ b/ecc-mod-arith.c @@ -58,6 +58,16 @@ ecc_mod_zero_p (const struct ecc_modulo *m, const mp_limb_t *xp_in) return (is_non_zero == 0) | (is_not_p == 0); } +int +ecc_mod_equal_p (const struct ecc_modulo *m, const mp_limb_t *a, + const mp_limb_t *ref, mp_limb_t *scratch) +{ + mp_limb_t cy; + cy = mpn_sub_n (scratch, a, ref, m->size); + /* If cy > 0, i.e., a < ref, then they can't be equal mod m. */ + return (cy == 0) & ecc_mod_zero_p (m, scratch); +} + void ecc_mod_add (const struct ecc_modulo *m, mp_limb_t *rp, const mp_limb_t *ap, const mp_limb_t *bp) diff --git a/testsuite/ecc-modinv-test.c b/testsuite/ecc-modinv-test.c index b9993e02..a30f182e 100644 --- a/testsuite/ecc-modinv-test.c +++ b/testsuite/ecc-modinv-test.c @@ -38,18 +38,6 @@ ref_modinv (mp_limb_t *rp, const mp_limb_t *ap, return res; } -/* Requires that a < 2m, and ref < m. */ -static int -mod_eq_p (const struct ecc_modulo *m, const mp_limb_t *a, const mp_limb_t *ref, - mp_limb_t *scratch) { - mp_limb_t cy; - assert (mpn_cmp (ref, m->m, m->size) < 0); - cy = mpn_sub_n (scratch, a, ref, m->size); - /* If cy > 0, i.e., a < ref, then they can't be equal mod m. */ - return (cy == 0) & ecc_mod_zero_p (m, scratch); - -} - #define MAX_ECC_SIZE (1 + 521 / GMP_NUMB_BITS) #define COUNT 500 @@ -120,7 +108,7 @@ test_modulo (gmp_randstate_t rands, const char *name, continue; } m->invert (m, ai, a, scratch); - if (!mod_eq_p (m, ai, ref, scratch)) + if (!ecc_mod_equal_p (m, ai, ref, scratch)) { fprintf (stderr, "%s->invert failed (test %u, bit size %u):\n", name, j, m->bit_size); |