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Move secp256k1_scalar_{inverse{_var},is_even} to per-impl files

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This temporarily duplicates the inversion code across the 4x64 and 8x32
implementations. Those implementations will be replaced in a later commit.
This commit is contained in:
Pieter Wuille
2020-10-11 15:30:37 -07:00
parent 08d54964e5
commit aa404d53be
4 changed files with 373 additions and 191 deletions
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15
src/scalar_low_impl.h
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@@ -125,4 +125,19 @@ static SECP256K1_INLINE void secp256k1_scalar_cmov(secp256k1_scalar *r, const se
*r = (*r & mask0) | (*a & mask1);
}
static void secp256k1_scalar_inverse(secp256k1_scalar *r, const secp256k1_scalar *x) {
int i;
*r = 0;
for (i = 0; i < EXHAUSTIVE_TEST_ORDER; i++)
if ((i * *x) % EXHAUSTIVE_TEST_ORDER == 1)
*r = i;
/* If this VERIFY_CHECK triggers we were given a noninvertible scalar (and thus
* have a composite group order; fix it in exhaustive_tests.c). */
VERIFY_CHECK(*r != 0);
}
static void secp256k1_scalar_inverse_var(secp256k1_scalar *r, const secp256k1_scalar *x) {
secp256k1_scalar_inverse(r, x);
}
#endif /* SECP256K1_SCALAR_REPR_IMPL_H */