Abstract out verify logic for fe_mul

This commit is contained in:
Pieter Wuille 2022-01-28 18:40:33 -05:00
parent e179e651cb
commit 4c25f6efbd
4 changed files with 25 additions and 30 deletions

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@ -90,6 +90,7 @@ static const secp256k1_fe secp256k1_const_beta = SECP256K1_FE_CONST(
# define secp256k1_fe_negate secp256k1_fe_impl_negate
# define secp256k1_fe_mul_int secp256k1_fe_impl_mul_int
# define secp256k1_fe_add secp256k1_fe_impl_add
# define secp256k1_fe_mul secp256k1_fe_impl_mul
#endif /* !defined(VERIFY) */
/** Normalize a field element.
@ -225,8 +226,14 @@ static void secp256k1_fe_mul_int(secp256k1_fe *r, int a);
*/
static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_fe *a);
/** Sets a field element to be the product of two others. Requires the inputs' magnitudes to be at most 8.
* The output magnitude is 1 (but not guaranteed to be normalized). */
/** Multiply two field elements.
*
* On input, a and b must be valid field elements; r does not need to be initialized.
* r and a may point to the same object, but neither can be equal to b. The magnitudes
* of a and b must not exceed 8.
* Performs {r = a * b}
* On output, r will have magnitude 1, but won't be normalized.
*/
static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b);
/** Sets a field element to be the square of another. Requires the input's magnitude to be at most 8.

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@ -1027,21 +1027,8 @@ SECP256K1_INLINE static void secp256k1_fe_sqr_inner(uint32_t *r, const uint32_t
}
#endif
static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
VERIFY_CHECK(b->magnitude <= 8);
secp256k1_fe_verify(a);
secp256k1_fe_verify(b);
VERIFY_CHECK(r != b);
VERIFY_CHECK(a != b);
#endif
SECP256K1_INLINE static void secp256k1_fe_impl_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b) {
secp256k1_fe_mul_inner(r->n, a->n, b->n);
#ifdef VERIFY
r->magnitude = 1;
r->normalized = 0;
secp256k1_fe_verify(r);
#endif
}
static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a) {

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@ -361,21 +361,8 @@ SECP256K1_INLINE static void secp256k1_fe_impl_add(secp256k1_fe *r, const secp25
r->n[4] += a->n[4];
}
static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
VERIFY_CHECK(b->magnitude <= 8);
secp256k1_fe_verify(a);
secp256k1_fe_verify(b);
VERIFY_CHECK(r != b);
VERIFY_CHECK(a != b);
#endif
SECP256K1_INLINE static void secp256k1_fe_impl_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b) {
secp256k1_fe_mul_inner(r->n, a->n, b->n);
#ifdef VERIFY
r->magnitude = 1;
r->normalized = 0;
secp256k1_fe_verify(r);
#endif
}
static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a) {

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@ -286,6 +286,20 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_f
r->normalized = 0;
secp256k1_fe_verify(r);
}
static void secp256k1_fe_impl_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b);
SECP256K1_INLINE static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b) {
secp256k1_fe_verify(a);
secp256k1_fe_verify(b);
VERIFY_CHECK(a->magnitude <= 8);
VERIFY_CHECK(b->magnitude <= 8);
VERIFY_CHECK(r != b);
VERIFY_CHECK(a != b);
secp256k1_fe_impl_mul(r, a, b);
r->magnitude = 1;
r->normalized = 0;
secp256k1_fe_verify(r);
}
#endif /* defined(VERIFY) */
#endif /* SECP256K1_FIELD_IMPL_H */