diff --git a/src/ecmult_const_impl.h b/src/ecmult_const_impl.h index 30b151ff9..b79787506 100644 --- a/src/ecmult_const_impl.h +++ b/src/ecmult_const_impl.h @@ -12,6 +12,22 @@ #include "ecmult_const.h" #include "ecmult_impl.h" +/** Fill a table 'pre' with precomputed odd multiples of a. + * + * The resulting point set is brought to a single constant Z denominator, stores the X and Y + * coordinates as ge_storage points in pre, and stores the global Z in globalz. + * It only operates on tables sized for WINDOW_A wnaf multiples. + */ +static void secp256k1_ecmult_odd_multiples_table_globalz_windowa(secp256k1_ge *pre, secp256k1_fe *globalz, const secp256k1_gej *a) { + secp256k1_gej prej[ECMULT_TABLE_SIZE(WINDOW_A)]; + secp256k1_fe zr[ECMULT_TABLE_SIZE(WINDOW_A)]; + + /* Compute the odd multiples in Jacobian form. */ + secp256k1_ecmult_odd_multiples_table(ECMULT_TABLE_SIZE(WINDOW_A), prej, zr, a); + /* Bring them to the same Z denominator. */ + secp256k1_ge_globalz_set_table_gej(ECMULT_TABLE_SIZE(WINDOW_A), pre, globalz, prej, zr); +} + /* This is like `ECMULT_TABLE_GET_GE` but is constant time */ #define ECMULT_CONST_TABLE_GET_GE(r,pre,n,w) do { \ int m = 0; \ diff --git a/src/ecmult_impl.h b/src/ecmult_impl.h index 0d9e55bb4..52af941fb 100644 --- a/src/ecmult_impl.h +++ b/src/ecmult_impl.h @@ -96,25 +96,6 @@ static void secp256k1_ecmult_odd_multiples_table(int n, secp256k1_gej *prej, sec secp256k1_fe_mul(&prej[n-1].z, &prej[n-1].z, &d.z); } -/** Fill a table 'pre' with precomputed odd multiples of a. - * - * The resulting point set is brought to a single constant Z denominator, stores the X and Y - * coordinates as ge_storage points in pre, and stores the global Z in rz. - * It only operates on tables sized for WINDOW_A wnaf multiples. - * - * To compute a*P + b*G, we compute a table for P using this function, - * and use the precomputed table in for G. - */ -static void secp256k1_ecmult_odd_multiples_table_globalz_windowa(secp256k1_ge *pre, secp256k1_fe *globalz, const secp256k1_gej *a) { - secp256k1_gej prej[ECMULT_TABLE_SIZE(WINDOW_A)]; - secp256k1_fe zr[ECMULT_TABLE_SIZE(WINDOW_A)]; - - /* Compute the odd multiples in Jacobian form. */ - secp256k1_ecmult_odd_multiples_table(ECMULT_TABLE_SIZE(WINDOW_A), prej, zr, a); - /* Bring them to the same Z denominator. */ - secp256k1_ge_globalz_set_table_gej(ECMULT_TABLE_SIZE(WINDOW_A), pre, globalz, prej, zr); -} - /** The following two macro retrieves a particular odd multiple from a table * of precomputed multiples. */ #define ECMULT_TABLE_GET_GE(r,pre,n,w) do { \