field: Static-assert that int args affecting magnitude are constant

See #1001.
This commit is contained in:
Tim Ruffing
2023-06-13 13:34:49 +02:00
parent 67214f5f7d
commit be8ff3a02a
6 changed files with 43 additions and 18 deletions

View File

@@ -314,7 +314,7 @@ static void secp256k1_fe_impl_get_b32(unsigned char *r, const secp256k1_fe *a) {
r[31] = a->n[0] & 0xFF;
}
SECP256K1_INLINE static void secp256k1_fe_impl_negate(secp256k1_fe *r, const secp256k1_fe *a, int m) {
SECP256K1_INLINE static void secp256k1_fe_impl_negate_unchecked(secp256k1_fe *r, const secp256k1_fe *a, int m) {
/* For all legal values of m (0..31), the following properties hold: */
VERIFY_CHECK(0xFFFFEFFFFFC2FULL * 2 * (m + 1) >= 0xFFFFFFFFFFFFFULL * 2 * m);
VERIFY_CHECK(0xFFFFFFFFFFFFFULL * 2 * (m + 1) >= 0xFFFFFFFFFFFFFULL * 2 * m);
@@ -329,7 +329,7 @@ SECP256K1_INLINE static void secp256k1_fe_impl_negate(secp256k1_fe *r, const sec
r->n[4] = 0x0FFFFFFFFFFFFULL * 2 * (m + 1) - a->n[4];
}
SECP256K1_INLINE static void secp256k1_fe_impl_mul_int(secp256k1_fe *r, int a) {
SECP256K1_INLINE static void secp256k1_fe_impl_mul_int_unchecked(secp256k1_fe *r, int a) {
r->n[0] *= a;
r->n[1] *= a;
r->n[2] *= a;