Abstract out verify logic for fe_from_storage

This commit is contained in:
Pieter Wuille 2022-01-28 19:02:03 -05:00
parent 76d31e5047
commit 3167646072
4 changed files with 17 additions and 13 deletions

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@ -94,6 +94,7 @@ static const secp256k1_fe secp256k1_const_beta = SECP256K1_FE_CONST(
# define secp256k1_fe_sqr secp256k1_fe_impl_sqr
# define secp256k1_fe_cmov secp256k1_fe_impl_cmov
# define secp256k1_fe_to_storage secp256k1_fe_impl_to_storage
# define secp256k1_fe_from_storage secp256k1_fe_impl_from_storage
#endif /* !defined(VERIFY) */
/** Normalize a field element.
@ -271,7 +272,12 @@ static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a);
*/
static void secp256k1_fe_to_storage(secp256k1_fe_storage *r, const secp256k1_fe *a);
/** Convert a field element back from the storage type. */
/** Convert a field element back from secp256k1_fe_storage.
*
* On input, r need not be initialized.
* Performs {r = a}.
* On output, r will be normalized and will have magnitude 1.
*/
static void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a);
/** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. Both *r and *a must be initialized.*/

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@ -1156,7 +1156,7 @@ static void secp256k1_fe_impl_to_storage(secp256k1_fe_storage *r, const secp256k
r->n[7] = a->n[8] >> 16 | a->n[9] << 10;
}
static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a) {
static SECP256K1_INLINE void secp256k1_fe_impl_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a) {
r->n[0] = a->n[0] & 0x3FFFFFFUL;
r->n[1] = a->n[0] >> 26 | ((a->n[1] << 6) & 0x3FFFFFFUL);
r->n[2] = a->n[1] >> 20 | ((a->n[2] << 12) & 0x3FFFFFFUL);
@ -1167,11 +1167,6 @@ static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe *r, const se
r->n[7] = a->n[5] >> 22 | ((a->n[6] << 10) & 0x3FFFFFFUL);
r->n[8] = a->n[6] >> 16 | ((a->n[7] << 16) & 0x3FFFFFFUL);
r->n[9] = a->n[7] >> 10;
#ifdef VERIFY
r->magnitude = 1;
r->normalized = 1;
secp256k1_fe_verify(r);
#endif
}
static void secp256k1_fe_from_signed30(secp256k1_fe *r, const secp256k1_modinv32_signed30 *a) {

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@ -466,17 +466,12 @@ static void secp256k1_fe_impl_to_storage(secp256k1_fe_storage *r, const secp256k
r->n[3] = a->n[3] >> 36 | a->n[4] << 16;
}
static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a) {
static SECP256K1_INLINE void secp256k1_fe_impl_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a) {
r->n[0] = a->n[0] & 0xFFFFFFFFFFFFFULL;
r->n[1] = a->n[0] >> 52 | ((a->n[1] << 12) & 0xFFFFFFFFFFFFFULL);
r->n[2] = a->n[1] >> 40 | ((a->n[2] << 24) & 0xFFFFFFFFFFFFFULL);
r->n[3] = a->n[2] >> 28 | ((a->n[3] << 36) & 0xFFFFFFFFFFFFFULL);
r->n[4] = a->n[3] >> 16;
#ifdef VERIFY
r->magnitude = 1;
r->normalized = 1;
secp256k1_fe_verify(r);
#endif
}
static void secp256k1_fe_from_signed62(secp256k1_fe *r, const secp256k1_modinv64_signed62 *a) {

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@ -343,6 +343,14 @@ SECP256K1_INLINE static void secp256k1_fe_to_storage(secp256k1_fe_storage *r, co
VERIFY_CHECK(a->normalized);
secp256k1_fe_impl_to_storage(r, a);
}
static void secp256k1_fe_impl_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a);
SECP256K1_INLINE static void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a) {
secp256k1_fe_impl_from_storage(r, a);
r->magnitude = 1;
r->normalized = 1;
secp256k1_fe_verify(r);
}
#endif /* defined(VERIFY) */
#endif /* SECP256K1_FIELD_IMPL_H */