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| author | Denys Vlasenko | 2021-12-11 23:27:40 +0100 |
|---|---|---|
| committer | Denys Vlasenko | 2021-12-11 23:27:40 +0100 |
| commit | 27df6aeef2d0d4b726a8b3b1ce1b1cafbbce3431 (patch) | |
| tree | 441d462b77e035affaa327f2d5a2ab8da595c920 /networking | |
| parent | b240733ae7423cb8f542a624eef0cfa3037d05bc (diff) | |
| download | busybox-27df6aeef2d0d4b726a8b3b1ce1b1cafbbce3431.zip busybox-27df6aeef2d0d4b726a8b3b1ce1b1cafbbce3431.tar.gz | |
tls: P256: factor out "multiply then reduce" operation
function old new delta
sp_256_mont_mul_and_reduce_8 - 44 +44
sp_256_ecc_mulmod_8 517 442 -75
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/1 up/down: 44/-75) Total: -31 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'networking')
| -rw-r--r-- | networking/tls_sp_c32.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/networking/tls_sp_c32.c b/networking/tls_sp_c32.c index cb166e4..292dda2 100644 --- a/networking/tls_sp_c32.c +++ b/networking/tls_sp_c32.c @@ -1091,6 +1091,17 @@ static void sp_256_mont_sqr_8(sp_digit* r, const sp_digit* a sp_256_mont_mul_8(r, a, a /*, m, mp*/); } +static NOINLINE void sp_256_mont_mul_and_reduce_8(sp_digit* r, + const sp_digit* a, const sp_digit* b + /*, const sp_digit* m, sp_digit mp*/) +{ + sp_digit rr[2 * 8]; + + sp_256_mont_mul_8(rr, a, b /*, p256_mod, p256_mp_mod*/); + memset(rr + 8, 0, sizeof(rr) / 2); + sp_512to256_mont_reduce_8(r, rr /*, p256_mod, p256_mp_mod*/); +} + /* Invert the number, in Montgomery form, modulo the modulus (prime) of the * P256 curve. (r = 1 / a mod m) * @@ -1186,7 +1197,6 @@ static void sp_256_map_8(sp_point* r, sp_point* p) { sp_digit t1[8]; sp_digit t2[8]; - sp_digit rr[2 * 8]; sp_256_mont_inv_8(t1, p->z); @@ -1194,18 +1204,14 @@ static void sp_256_map_8(sp_point* r, sp_point* p) sp_256_mont_mul_8(t1, t2, t1 /*, p256_mod, p256_mp_mod*/); /* x /= z^2 */ - sp_256_mont_mul_8(rr, p->x, t2 /*, p256_mod, p256_mp_mod*/); - memset(rr + 8, 0, sizeof(rr) / 2); - sp_512to256_mont_reduce_8(r->x, rr /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_and_reduce_8(r->x, p->x, t2 /*, p256_mod, p256_mp_mod*/); /* Reduce x to less than modulus */ if (sp_256_cmp_8(r->x, p256_mod) >= 0) sp_256_sub_8_p256_mod(r->x); sp_256_norm_8(r->x); /* y /= z^3 */ - sp_256_mont_mul_8(rr, p->y, t1 /*, p256_mod, p256_mp_mod*/); - memset(rr + 8, 0, sizeof(rr) / 2); - sp_512to256_mont_reduce_8(r->y, rr /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_and_reduce_8(r->y, p->y, t1 /*, p256_mod, p256_mp_mod*/); /* Reduce y to less than modulus */ if (sp_256_cmp_8(r->y, p256_mod) >= 0) sp_256_sub_8_p256_mod(r->y); |