kevin/libsodium
1
Fork 0
mirror of https://github.com/jedisct1/libsodium.git synced 2024-12-23 20:15:19 -07:00
Code Releases Wiki Activity

Move 2^511 -> 2^255-19 reduction to its own function

Browse Source
This commit is contained in:
Frank Denis 2020-08-23 18:28:17 +02:00
parent 3b8891540b
commit ee962b33ae
1 changed files with 13 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c
View File

@ -2702,18 +2702,13 @@ ge25519_from_uniform(unsigned char s[32], const unsigned char r[32])
ge25519_p3_tobytes(s, &p3);
}
void
ge25519_from_hash(unsigned char s[32], const unsigned char h[64])
static void
fe25519_reduce64(fe25519 fe_f, const unsigned char h[64])
{
unsigned char fl[32];
unsigned char gl[32];
ge25519_p3 p3;
fe25519 x, y, negy;
fe25519 fe_f;
fe25519 fe_g;
size_t i;
int notsquare;
unsigned char y_sign;
for (i = 0; i < 32; i++) {
fl[i] = h[63 - i];
@ -2728,7 +2723,18 @@ ge25519_from_hash(unsigned char s[32], const unsigned char h[64])
fe_f[i] += 38 * fe_g[i];
}
fe25519_reduce(fe_f, fe_f);
}
void
ge25519_from_hash(unsigned char s[32], const unsigned char h[64])
{
ge25519_p3 p3;
fe25519 fe_f;
fe25519 x, y, negy;
int notsquare;
unsigned char y_sign;
fe25519_reduce64(fe_f, h);
ge25519_elligator2(x, y, fe_f, &notsquare);
y_sign = notsquare;