7#ifndef SECP256K1_SCALAR_H
8#define SECP256K1_SCALAR_H
12#if defined HAVE_CONFIG_H
13#include "libsecp256k1-config.h"
16#if defined(EXHAUSTIVE_TEST_ORDER)
18#elif defined(SECP256K1_WIDEMUL_INT128)
20#elif defined(SECP256K1_WIDEMUL_INT64)
23#error "Please select wide multiplication implementation"
T GetRand(T nMax=std::numeric_limits< T >::max()) noexcept
Generate a uniform random integer of type T in the range [0..nMax) nMax defaults to std::numeric_limi...
static void secp256k1_scalar_cmov(secp256k1_scalar *r, const secp256k1_scalar *a, int flag)
If flag is true, set *r equal to *a; otherwise leave it.
static void secp256k1_scalar_split_128(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *k)
Find r1 and r2 such that r1+r2*2^128 = k.
static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *bin, int *overflow)
Set a scalar from a big endian byte array.
static int secp256k1_scalar_set_b32_seckey(secp256k1_scalar *r, const unsigned char *bin)
Set a scalar from a big endian byte array and returns 1 if it is a valid seckey and 0 otherwise.
static int secp256k1_scalar_is_even(const secp256k1_scalar *a)
Check whether a scalar, considered as an nonnegative integer, is even.
static int secp256k1_scalar_is_zero(const secp256k1_scalar *a)
Check whether a scalar equals zero.
static void secp256k1_scalar_set_int(secp256k1_scalar *r, unsigned int v)
Set a scalar to an unsigned integer.
static int secp256k1_scalar_eq(const secp256k1_scalar *a, const secp256k1_scalar *b)
Compare two scalars.
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar *a)
Convert a scalar to a byte array.
static int secp256k1_scalar_cond_negate(secp256k1_scalar *a, int flag)
Conditionally negate a number, in constant time.
static void secp256k1_scalar_inverse_var(secp256k1_scalar *r, const secp256k1_scalar *a)
Compute the inverse of a scalar (modulo the group order), without constant-time guarantee.
static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar *a, unsigned int offset, unsigned int count)
Access bits from a scalar.
static int secp256k1_scalar_add(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b)
Add two scalars together (modulo the group order).
static void secp256k1_scalar_mul(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b)
Multiply two scalars (modulo the group order).
static void secp256k1_scalar_mul_shift_var(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b, unsigned int shift)
Multiply a and b (without taking the modulus!), divide by 2**shift, and round to the nearest integer.
static int secp256k1_scalar_is_one(const secp256k1_scalar *a)
Check whether a scalar equals one.
static void secp256k1_scalar_negate(secp256k1_scalar *r, const secp256k1_scalar *a)
Compute the complement of a scalar (modulo the group order).
static int secp256k1_scalar_is_high(const secp256k1_scalar *a)
Check whether a scalar is higher than the group order divided by 2.
static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, unsigned int offset, unsigned int count)
Access bits from a scalar.
static void secp256k1_scalar_inverse(secp256k1_scalar *r, const secp256k1_scalar *a)
Compute the inverse of a scalar (modulo the group order).
static void secp256k1_scalar_cadd_bit(secp256k1_scalar *r, unsigned int bit, int flag)
Conditionally add a power of two to a scalar.
static void secp256k1_scalar_clear(secp256k1_scalar *r)
Clear a scalar to prevent the leak of sensitive data.
static void secp256k1_scalar_split_lambda(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *k)
Find r1 and r2 such that r1+r2*lambda = k, where r1 and r2 or their negations are maximum 128 bits lo...
static int secp256k1_scalar_shr_int(secp256k1_scalar *r, int n)
Shift a scalar right by some amount strictly between 0 and 16, returning the low bits that were shift...
A scalar modulo the group order of the secp256k1 curve.
1.9.8