go-ethereum/crypto/secp256k1/libsecp256k1/src/num.h

75 lines
2.7 KiB
C

/**********************************************************************
* Copyright (c) 2013, 2014 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_NUM_
#define _SECP256K1_NUM_
#ifndef USE_NUM_NONE
#if defined HAVE_CONFIG_H
#include "libsecp256k1-config.h"
#endif
#if defined(USE_NUM_GMP)
#include "num_gmp.h"
#else
#error "Please select num implementation"
#endif
/** Copy a number. */
static void secp256k1_num_copy(secp256k1_num *r, const secp256k1_num *a);
/** Convert a number's absolute value to a binary big-endian string.
* There must be enough place. */
static void secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num *a);
/** Set a number to the value of a binary big-endian string. */
static void secp256k1_num_set_bin(secp256k1_num *r, const unsigned char *a, unsigned int alen);
/** Compute a modular inverse. The input must be less than the modulus. */
static void secp256k1_num_mod_inverse(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *m);
/** Compute the jacobi symbol (a|b). b must be positive and odd. */
static int secp256k1_num_jacobi(const secp256k1_num *a, const secp256k1_num *b);
/** Compare the absolute value of two numbers. */
static int secp256k1_num_cmp(const secp256k1_num *a, const secp256k1_num *b);
/** Test whether two number are equal (including sign). */
static int secp256k1_num_eq(const secp256k1_num *a, const secp256k1_num *b);
/** Add two (signed) numbers. */
static void secp256k1_num_add(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b);
/** Subtract two (signed) numbers. */
static void secp256k1_num_sub(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b);
/** Multiply two (signed) numbers. */
static void secp256k1_num_mul(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b);
/** Replace a number by its remainder modulo m. M's sign is ignored. The result is a number between 0 and m-1,
even if r was negative. */
static void secp256k1_num_mod(secp256k1_num *r, const secp256k1_num *m);
/** Right-shift the passed number by bits bits. */
static void secp256k1_num_shift(secp256k1_num *r, int bits);
/** Check whether a number is zero. */
static int secp256k1_num_is_zero(const secp256k1_num *a);
/** Check whether a number is one. */
static int secp256k1_num_is_one(const secp256k1_num *a);
/** Check whether a number is strictly negative. */
static int secp256k1_num_is_neg(const secp256k1_num *a);
/** Change a number's sign. */
static void secp256k1_num_negate(secp256k1_num *r);
#endif
#endif