diff options
| author | Denys Vlasenko <vda.linux@googlemail.com> | 2021-11-28 11:10:00 +0100 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2021-11-28 11:15:34 +0100 |
| commit | cfb615781df5c7439fe0060a85e6b6a56d10dc7f (patch) | |
| tree | ebe1994c221f733ac1d42b02b3f4e71ad37946ad | |
| parent | bfefa6ab6cf30507009cca7182c7302900fb5534 (diff) | |
| download | busybox-cfb615781df5c7439fe0060a85e6b6a56d10dc7f.tar.gz | |
tls: P256: simplify sp_256_mont_inv_8 (no need for a temporary)
function old new delta
sp_256_ecc_mulmod_8 543 517 -26
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | networking/tls_sp_c32.c | 10 |
1 files changed, 4 insertions, 6 deletions
diff --git a/networking/tls_sp_c32.c b/networking/tls_sp_c32.c index 37e1cfa1c..9bd5c6832 100644 --- a/networking/tls_sp_c32.c +++ b/networking/tls_sp_c32.c @@ -938,7 +938,7 @@ static void sp_256_mont_sqr_8(sp_digit* r, const sp_digit* a /* Invert the number, in Montgomery form, modulo the modulus (prime) of the * P256 curve. (r = 1 / a mod m) * - * r Inverse result. + * r Inverse result. Must not coincide with a. * a Number to invert. */ #if 0 @@ -952,17 +952,15 @@ static void sp_256_mont_sqr_8(sp_digit* r, const sp_digit* a #endif static void sp_256_mont_inv_8(sp_digit* r, sp_digit* a) { - sp_digit t[8]; int i; - memcpy(t, a, sizeof(sp_digit) * 8); + memcpy(r, a, sizeof(sp_digit) * 8); for (i = 254; i >= 0; i--) { - sp_256_mont_sqr_8(t, t /*, p256_mod, p256_mp_mod*/); + sp_256_mont_sqr_8(r, r /*, p256_mod, p256_mp_mod*/); /*if (p256_mod_2[i / 32] & ((sp_digit)1 << (i % 32)))*/ if (i >= 224 || i == 192 || (i <= 95 && i != 1)) - sp_256_mont_mul_8(t, t, a /*, p256_mod, p256_mp_mod*/); + sp_256_mont_mul_8(r, r, a /*, p256_mod, p256_mp_mod*/); } - memcpy(r, t, sizeof(sp_digit) * 8); } /* Multiply a number by Montogmery normalizer mod modulus (prime). |