frost/secp256k1-zkp
3
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Split fe_set_b32 into reducing and normalizing variants

Browse Source
This commit is contained in:
Pieter Wuille
2023-02-05 17:19:00 -05:00
parent 006ddc1f42
commit 5b32602295
16 changed files with 69 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
src/field_10x26_impl.h
View File

@@ -290,7 +290,7 @@ static int secp256k1_fe_impl_cmp_var(const secp256k1_fe *a, const secp256k1_fe *
return 0;
}
static int secp256k1_fe_impl_set_b32(secp256k1_fe *r, const unsigned char *a) {
static void secp256k1_fe_impl_set_b32_mod(secp256k1_fe *r, const unsigned char *a) {
r->n[0] = (uint32_t)a[31] | ((uint32_t)a[30] << 8) | ((uint32_t)a[29] << 16) | ((uint32_t)(a[28] & 0x3) << 24);
r->n[1] = (uint32_t)((a[28] >> 2) & 0x3f) | ((uint32_t)a[27] << 6) | ((uint32_t)a[26] << 14) | ((uint32_t)(a[25] & 0xf) << 22);
r->n[2] = (uint32_t)((a[25] >> 4) & 0xf) | ((uint32_t)a[24] << 4) | ((uint32_t)a[23] << 12) | ((uint32_t)(a[22] & 0x3f) << 20);
@@ -301,7 +301,10 @@ static int secp256k1_fe_impl_set_b32(secp256k1_fe *r, const unsigned char *a) {
r->n[7] = (uint32_t)((a[9] >> 6) & 0x3) | ((uint32_t)a[8] << 2) | ((uint32_t)a[7] << 10) | ((uint32_t)a[6] << 18);
r->n[8] = (uint32_t)a[5] | ((uint32_t)a[4] << 8) | ((uint32_t)a[3] << 16) | ((uint32_t)(a[2] & 0x3) << 24);
r->n[9] = (uint32_t)((a[2] >> 2) & 0x3f) | ((uint32_t)a[1] << 6) | ((uint32_t)a[0] << 14);
}
static int secp256k1_fe_impl_set_b32_limit(secp256k1_fe *r, const unsigned char *a) {
secp256k1_fe_impl_set_b32_mod(r, a);
return !((r->n[9] == 0x3FFFFFUL) & ((r->n[8] & r->n[7] & r->n[6] & r->n[5] & r->n[4] & r->n[3] & r->n[2]) == 0x3FFFFFFUL) & ((r->n[1] + 0x40UL + ((r->n[0] + 0x3D1UL) >> 26)) > 0x3FFFFFFUL));
}