Charon/blockchain
1
0
Fork 0
forked from lthn/blockchain
Code Pull requests Activity

crypto-ops: ge_p2_to_p3 implemented

Browse source
This commit is contained in:
sowle 2021-01-14 23:45:47 +03:00
parent 3c3f7ee7b6
commit 8063604b37
No known key found for this signature in database
GPG key ID: C07A24B2D89D49FC
1 changed files with 23 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
src/crypto/crypto-ops.c
View file

@ -3726,9 +3726,28 @@ void sc_invert(unsigned char* out, const unsigned char* z)
sc_mul(out, out, z);
}
// res = Hp(ge_bytes)
// where Hp = 8 * ge_fromfe_frombytes_vartime(cn_fast_hash(ge_bytes))
// In: ge_bytes -- points to 32 bytes data
/*
In: t (x, y, z)
Out: r (x, t, z, t)
Note: expensive conversion because of fe_invert
*/
void ge_p2_to_p3(ge_p3 *r, const ge_p2 *t)
{
fe_copy(r->X, t->X);
fe_copy(r->Y, t->Y);
fe_copy(r->Z, t->Z);
fe_invert(r->T, t->Z);
fe_mul(r->T, r->T, t->Y);
fe_mul(r->T, r->T, t->X);
}
/*
In: ge_bytes -- points to 32 bytes of data
Out: res = Hp(ge_bytes)
where Hp = 8 * ge_fromfe_frombytes_vartime(cn_fast_hash(ge_bytes))
*/
void ge_bytes_hash_to_ec(ge_p3 *res, const unsigned char *ge_bytes)
{
unsigned char h[HASH_SIZE];
@ -3737,6 +3756,7 @@ void ge_bytes_hash_to_ec(ge_p3 *res, const unsigned char *ge_bytes)
cn_fast_hash(ge_bytes, 32, h);
ge_fromfe_frombytes_vartime(&point, &h[0]);
/*ge_p2_to_p3(res, &point); /* -- can be used to avoid multiplication by 8 for debugging */
ge_mul8(&point2, &point);
ge_p1p1_to_p3(res, &point2);
}