diff options
Diffstat (limited to 'vendor/github.com/ethereum/go-ethereum/crypto/secp256k1/libsecp256k1/src/scalar.h')
-rw-r--r-- | vendor/github.com/ethereum/go-ethereum/crypto/secp256k1/libsecp256k1/src/scalar.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/vendor/github.com/ethereum/go-ethereum/crypto/secp256k1/libsecp256k1/src/scalar.h b/vendor/github.com/ethereum/go-ethereum/crypto/secp256k1/libsecp256k1/src/scalar.h new file mode 100644 index 000000000..27e9d8375 --- /dev/null +++ b/vendor/github.com/ethereum/go-ethereum/crypto/secp256k1/libsecp256k1/src/scalar.h @@ -0,0 +1,106 @@ +/********************************************************************** + * Copyright (c) 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_SCALAR_ +#define _SECP256K1_SCALAR_ + +#include "num.h" + +#if defined HAVE_CONFIG_H +#include "libsecp256k1-config.h" +#endif + +#if defined(EXHAUSTIVE_TEST_ORDER) +#include "scalar_low.h" +#elif defined(USE_SCALAR_4X64) +#include "scalar_4x64.h" +#elif defined(USE_SCALAR_8X32) +#include "scalar_8x32.h" +#else +#error "Please select scalar implementation" +#endif + +/** Clear a scalar to prevent the leak of sensitive data. */ +static void secp256k1_scalar_clear(secp256k1_scalar *r); + +/** Access bits from a scalar. All requested bits must belong to the same 32-bit limb. */ +static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar *a, unsigned int offset, unsigned int count); + +/** Access bits from a scalar. Not constant time. */ +static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, unsigned int offset, unsigned int count); + +/** Set a scalar from a big endian byte array. */ +static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *bin, int *overflow); + +/** Set a scalar to an unsigned integer. */ +static void secp256k1_scalar_set_int(secp256k1_scalar *r, unsigned int v); + +/** Convert a scalar to a byte array. */ +static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar* a); + +/** Add two scalars together (modulo the group order). Returns whether it overflowed. */ +static int secp256k1_scalar_add(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b); + +/** Conditionally add a power of two to a scalar. The result is not allowed to overflow. */ +static void secp256k1_scalar_cadd_bit(secp256k1_scalar *r, unsigned int bit, int flag); + +/** Multiply two scalars (modulo the group order). */ +static void secp256k1_scalar_mul(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b); + +/** Shift a scalar right by some amount strictly between 0 and 16, returning + * the low bits that were shifted off */ +static int secp256k1_scalar_shr_int(secp256k1_scalar *r, int n); + +/** Compute the square of a scalar (modulo the group order). */ +static void secp256k1_scalar_sqr(secp256k1_scalar *r, const secp256k1_scalar *a); + +/** Compute the inverse of a scalar (modulo the group order). */ +static void secp256k1_scalar_inverse(secp256k1_scalar *r, const secp256k1_scalar *a); + +/** Compute the inverse of a scalar (modulo the group order), without constant-time guarantee. */ +static void secp256k1_scalar_inverse_var(secp256k1_scalar *r, const secp256k1_scalar *a); + +/** Compute the complement of a scalar (modulo the group order). */ +static void secp256k1_scalar_negate(secp256k1_scalar *r, const secp256k1_scalar *a); + +/** Check whether a scalar equals zero. */ +static int secp256k1_scalar_is_zero(const secp256k1_scalar *a); + +/** Check whether a scalar equals one. */ +static int secp256k1_scalar_is_one(const secp256k1_scalar *a); + +/** Check whether a scalar, considered as an nonnegative integer, is even. */ +static int secp256k1_scalar_is_even(const secp256k1_scalar *a); + +/** Check whether a scalar is higher than the group order divided by 2. */ +static int secp256k1_scalar_is_high(const secp256k1_scalar *a); + +/** Conditionally negate a number, in constant time. + * Returns -1 if the number was negated, 1 otherwise */ +static int secp256k1_scalar_cond_negate(secp256k1_scalar *a, int flag); + +#ifndef USE_NUM_NONE +/** Convert a scalar to a number. */ +static void secp256k1_scalar_get_num(secp256k1_num *r, const secp256k1_scalar *a); + +/** Get the order of the group as a number. */ +static void secp256k1_scalar_order_get_num(secp256k1_num *r); +#endif + +/** Compare two scalars. */ +static int secp256k1_scalar_eq(const secp256k1_scalar *a, const secp256k1_scalar *b); + +#ifdef USE_ENDOMORPHISM +/** Find r1 and r2 such that r1+r2*2^128 = a. */ +static void secp256k1_scalar_split_128(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *a); +/** Find r1 and r2 such that r1+r2*lambda = a, and r1 and r2 are maximum 128 bits long (see secp256k1_gej_mul_lambda). */ +static void secp256k1_scalar_split_lambda(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *a); +#endif + +/** Multiply a and b (without taking the modulus!), divide by 2**shift, and round to the nearest integer. Shift must be at least 256. */ +static void secp256k1_scalar_mul_shift_var(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b, unsigned int shift); + +#endif |