scalar_low.h (1149B)
1 /*********************************************************************** 2 * Copyright (c) 2015, 2022 Andrew Poelstra, Pieter Wuille * 3 * Distributed under the MIT software license, see the accompanying * 4 * file COPYING or https://www.opensource.org/licenses/mit-license.php.* 5 ***********************************************************************/ 6 7 #ifndef SECP256K1_SCALAR_REPR_H 8 #define SECP256K1_SCALAR_REPR_H 9 10 #include <stdint.h> 11 12 /** A scalar modulo the group order of the secp256k1 curve. */ 13 typedef uint32_t haskellsecp256k1_v0_1_0_scalar; 14 15 /* A compile-time constant equal to 2^32 (modulo order). */ 16 #define SCALAR_2P32 ((0xffffffffUL % EXHAUSTIVE_TEST_ORDER) + 1U) 17 18 /* Compute a*2^32 + b (modulo order). */ 19 #define SCALAR_HORNER(a, b) (((uint64_t)(a) * SCALAR_2P32 + (b)) % EXHAUSTIVE_TEST_ORDER) 20 21 /* Evaluates to the provided 256-bit constant reduced modulo order. */ 22 #define SECP256K1_SCALAR_CONST(d7, d6, d5, d4, d3, d2, d1, d0) SCALAR_HORNER(SCALAR_HORNER(SCALAR_HORNER(SCALAR_HORNER(SCALAR_HORNER(SCALAR_HORNER(SCALAR_HORNER((d7), (d6)), (d5)), (d4)), (d3)), (d2)), (d1)), (d0)) 23 24 #endif /* SECP256K1_SCALAR_REPR_H */