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mirror of https://github.com/jedisct1/libsodium.git synced 2024-12-23 20:15:19 -07:00

Avoid useless pack/unpack operation

This commit is contained in:
Frank Denis 2019-05-02 15:04:31 +02:00
parent 4b7e497a92
commit f1309fd752

View File

@ -2526,7 +2526,7 @@ chi25519(fe25519 out, const fe25519 z)
}
static void
ge25519_elligator2(unsigned char s[32], const unsigned char x_sign)
ge25519_elligator2(unsigned char s[32], const fe25519 r, const unsigned char x_sign)
{
fe25519 e;
fe25519 negx;
@ -2537,9 +2537,7 @@ ge25519_elligator2(unsigned char s[32], const unsigned char x_sign)
ge25519_p2 p2;
unsigned int e_is_minus_1;
fe25519_frombytes(rr2, s);
fe25519_sq2(rr2, rr2);
fe25519_sq2(rr2, r);
rr2[0]++;
fe25519_invert(rr2, rr2);
fe25519_mul(x, curve25519_A, rr2);
@ -2597,12 +2595,14 @@ ge25519_elligator2(unsigned char s[32], const unsigned char x_sign)
void
ge25519_from_uniform(unsigned char s[32], const unsigned char r[32])
{
fe25519 r_fe;
unsigned char x_sign;
memcpy(s, r, 32);
x_sign = s[31] & 0x80;
s[31] &= 0x7f;
ge25519_elligator2(s, x_sign);
fe25519_frombytes(r_fe, s);
ge25519_elligator2(s, r_fe, x_sign);
}
void
@ -2627,8 +2627,8 @@ ge25519_from_hash(unsigned char s[32], const unsigned char h[64])
for (i = 0; i < sizeof (fe25519) / sizeof fe_f[0]; i++) {
fe_f[i] += 38 * fe_g[i];
}
fe25519_tobytes(s, fe_f);
ge25519_elligator2(s, x_sign);
fe25519_reduce(fe_f, fe_f);
ge25519_elligator2(s, fe_f, x_sign);
}
/* Ristretto group */