9455aab4fe
Most of these were in point_448.h. While I was at it I spotted some unused declarations, so I deleted those too. Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de> (Merged from https://github.com/openssl/openssl/pull/5105)
363 lines
10 KiB
C
363 lines
10 KiB
C
/**
|
|
* @file decaf/point_448.h
|
|
* @author Mike Hamburg
|
|
*
|
|
* @copyright
|
|
* Copyright (c) 2015-2016 Cryptography Research, Inc. \n
|
|
* Released under the MIT License. See LICENSE.txt for license information.
|
|
*
|
|
* @brief A group of prime order p, based on Ed448-Goldilocks.
|
|
*
|
|
* @warning This file was automatically generated in Python.
|
|
* Please do not edit it.
|
|
*/
|
|
|
|
#ifndef __DECAF_POINT_448_H__
|
|
#define __DECAF_POINT_448_H__ 1
|
|
|
|
#include "curve448utils.h"
|
|
#include "field.h"
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
|
|
/** @cond internal */
|
|
#define DECAF_448_SCALAR_LIMBS ((446-1)/DECAF_WORD_BITS+1)
|
|
/** @endcond */
|
|
|
|
/** The number of bits in a scalar */
|
|
#define DECAF_448_SCALAR_BITS 446
|
|
|
|
/** Number of bytes in a serialized point. */
|
|
#define DECAF_448_SER_BYTES 56
|
|
|
|
/** Number of bytes in an elligated point. For now set the same as SER_BYTES
|
|
* but could be different for other curves.
|
|
*/
|
|
#define DECAF_448_HASH_BYTES 56
|
|
|
|
/** Number of bytes in a serialized scalar. */
|
|
#define DECAF_448_SCALAR_BYTES 56
|
|
|
|
/** Number of bits in the "which" field of an elligator inverse */
|
|
#define DECAF_448_INVERT_ELLIGATOR_WHICH_BITS 3
|
|
|
|
/** The cofactor the curve would have, if we hadn't removed it */
|
|
#define DECAF_448_REMOVED_COFACTOR 4
|
|
|
|
/** X448 encoding ratio. */
|
|
#define DECAF_X448_ENCODE_RATIO 2
|
|
|
|
/** Number of bytes in an x448 public key */
|
|
#define DECAF_X448_PUBLIC_BYTES 56
|
|
|
|
/** Number of bytes in an x448 private key */
|
|
#define DECAF_X448_PRIVATE_BYTES 56
|
|
|
|
/** Twisted Edwards extended homogeneous coordinates */
|
|
typedef struct curve448_point_s {
|
|
/** @cond internal */
|
|
gf_448_t x,y,z,t;
|
|
/** @endcond */
|
|
} curve448_point_t[1];
|
|
|
|
/** Precomputed table based on a point. Can be trivial implementation. */
|
|
struct curve448_precomputed_s;
|
|
|
|
/** Precomputed table based on a point. Can be trivial implementation. */
|
|
typedef struct curve448_precomputed_s curve448_precomputed_s;
|
|
|
|
/** Scalar is stored packed, because we don't need the speed. */
|
|
typedef struct curve448_scalar_s {
|
|
/** @cond internal */
|
|
decaf_word_t limb[DECAF_448_SCALAR_LIMBS];
|
|
/** @endcond */
|
|
} curve448_scalar_t[1];
|
|
|
|
/** A scalar equal to 1. */
|
|
extern const curve448_scalar_t curve448_scalar_one DECAF_API_VIS;
|
|
|
|
/** A scalar equal to 0. */
|
|
extern const curve448_scalar_t curve448_scalar_zero DECAF_API_VIS;
|
|
|
|
/** The identity point on the curve. */
|
|
extern const curve448_point_t curve448_point_identity DECAF_API_VIS;
|
|
|
|
/** An arbitrarily chosen base point on the curve. */
|
|
extern const curve448_point_t curve448_point_base DECAF_API_VIS;
|
|
|
|
/** Precomputed table for the base point on the curve. */
|
|
extern const struct curve448_precomputed_s *curve448_precomputed_base DECAF_API_VIS;
|
|
|
|
/**
|
|
* @brief Read a scalar from wire format or from bytes.
|
|
*
|
|
* @param [in] ser Serialized form of a scalar.
|
|
* @param [out] out Deserialized form.
|
|
*
|
|
* @retval DECAF_SUCCESS The scalar was correctly encoded.
|
|
* @retval DECAF_FAILURE The scalar was greater than the modulus,
|
|
* and has been reduced modulo that modulus.
|
|
*/
|
|
__owur decaf_error_t curve448_scalar_decode (
|
|
curve448_scalar_t out,
|
|
const unsigned char ser[DECAF_448_SCALAR_BYTES]
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Read a scalar from wire format or from bytes. Reduces mod
|
|
* scalar prime.
|
|
*
|
|
* @param [in] ser Serialized form of a scalar.
|
|
* @param [in] ser_len Length of serialized form.
|
|
* @param [out] out Deserialized form.
|
|
*/
|
|
void curve448_scalar_decode_long (
|
|
curve448_scalar_t out,
|
|
const unsigned char *ser,
|
|
size_t ser_len
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Serialize a scalar to wire format.
|
|
*
|
|
* @param [out] ser Serialized form of a scalar.
|
|
* @param [in] s Deserialized scalar.
|
|
*/
|
|
void curve448_scalar_encode (
|
|
unsigned char ser[DECAF_448_SCALAR_BYTES],
|
|
const curve448_scalar_t s
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Add two scalars. The scalars may use the same memory.
|
|
* @param [in] a One scalar.
|
|
* @param [in] b Another scalar.
|
|
* @param [out] out a+b.
|
|
*/
|
|
void curve448_scalar_add (
|
|
curve448_scalar_t out,
|
|
const curve448_scalar_t a,
|
|
const curve448_scalar_t b
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Subtract two scalars. The scalars may use the same memory.
|
|
* @param [in] a One scalar.
|
|
* @param [in] b Another scalar.
|
|
* @param [out] out a-b.
|
|
*/
|
|
void curve448_scalar_sub (
|
|
curve448_scalar_t out,
|
|
const curve448_scalar_t a,
|
|
const curve448_scalar_t b
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Multiply two scalars. The scalars may use the same memory.
|
|
* @param [in] a One scalar.
|
|
* @param [in] b Another scalar.
|
|
* @param [out] out a*b.
|
|
*/
|
|
void curve448_scalar_mul (
|
|
curve448_scalar_t out,
|
|
const curve448_scalar_t a,
|
|
const curve448_scalar_t b
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Halve a scalar. The scalars may use the same memory.
|
|
* @param [in] a A scalar.
|
|
* @param [out] out a/2.
|
|
*/
|
|
void curve448_scalar_halve (
|
|
curve448_scalar_t out,
|
|
const curve448_scalar_t a
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Copy a scalar. The scalars may use the same memory, in which
|
|
* case this function does nothing.
|
|
* @param [in] a A scalar.
|
|
* @param [out] out Will become a copy of a.
|
|
*/
|
|
static inline void DECAF_NONNULL curve448_scalar_copy (
|
|
curve448_scalar_t out,
|
|
const curve448_scalar_t a
|
|
) {
|
|
*out = *a;
|
|
}
|
|
|
|
/**
|
|
* @brief Copy a point. The input and output may alias,
|
|
* in which case this function does nothing.
|
|
*
|
|
* @param [out] a A copy of the point.
|
|
* @param [in] b Any point.
|
|
*/
|
|
static inline void DECAF_NONNULL curve448_point_copy (
|
|
curve448_point_t a,
|
|
const curve448_point_t b
|
|
) {
|
|
*a=*b;
|
|
}
|
|
|
|
/**
|
|
* @brief Test whether two points are equal. If yes, return
|
|
* DECAF_TRUE, else return DECAF_FALSE.
|
|
*
|
|
* @param [in] a A point.
|
|
* @param [in] b Another point.
|
|
* @retval DECAF_TRUE The points are equal.
|
|
* @retval DECAF_FALSE The points are not equal.
|
|
*/
|
|
__owur decaf_bool_t curve448_point_eq (
|
|
const curve448_point_t a,
|
|
const curve448_point_t b
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Double a point. Equivalent to
|
|
* curve448_point_add(two_a,a,a), but potentially faster.
|
|
*
|
|
* @param [out] two_a The sum a+a.
|
|
* @param [in] a A point.
|
|
*/
|
|
void curve448_point_double (
|
|
curve448_point_t two_a,
|
|
const curve448_point_t a
|
|
) DECAF_API_VIS DECAF_NONNULL;
|
|
|
|
/**
|
|
* @brief RFC 7748 Diffie-Hellman scalarmul. This function uses a different
|
|
* (non-Decaf) encoding.
|
|
*
|
|
* @param [out] scaled The scaled point base*scalar
|
|
* @param [in] base The point to be scaled.
|
|
* @param [in] scalar The scalar to multiply by.
|
|
*
|
|
* @retval DECAF_SUCCESS The scalarmul succeeded.
|
|
* @retval DECAF_FAILURE The scalarmul didn't succeed, because the base
|
|
* point is in a small subgroup.
|
|
*/
|
|
__owur decaf_error_t decaf_x448 (
|
|
uint8_t out[DECAF_X448_PUBLIC_BYTES],
|
|
const uint8_t base[DECAF_X448_PUBLIC_BYTES],
|
|
const uint8_t scalar[DECAF_X448_PRIVATE_BYTES]
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Multiply a point by DECAF_X448_ENCODE_RATIO,
|
|
* then encode it like RFC 7748.
|
|
*
|
|
* This function is mainly used internally, but is exported in case
|
|
* it will be useful.
|
|
*
|
|
* The ratio is necessary because the internal representation doesn't
|
|
* track the cofactor information, so on output we must clear the cofactor.
|
|
* This would multiply by the cofactor, but in fact internally libdecaf's
|
|
* points are always even, so it multiplies by half the cofactor instead.
|
|
*
|
|
* As it happens, this aligns with the base point definitions; that is,
|
|
* if you pass the Decaf/Ristretto base point to this function, the result
|
|
* will be DECAF_X448_ENCODE_RATIO times the X448
|
|
* base point.
|
|
*
|
|
* @param [out] out The scaled and encoded point.
|
|
* @param [in] p The point to be scaled and encoded.
|
|
*/
|
|
void curve448_point_mul_by_ratio_and_encode_like_x448 (
|
|
uint8_t out[DECAF_X448_PUBLIC_BYTES],
|
|
const curve448_point_t p
|
|
) DECAF_API_VIS DECAF_NONNULL;
|
|
|
|
/** The base point for X448 Diffie-Hellman */
|
|
extern const uint8_t decaf_x448_base_point[DECAF_X448_PUBLIC_BYTES] DECAF_API_VIS;
|
|
|
|
/**
|
|
* @brief RFC 7748 Diffie-Hellman base point scalarmul. This function uses
|
|
* a different (non-Decaf) encoding.
|
|
*
|
|
* Does exactly the same thing as decaf_x448_generate_key,
|
|
* but has a better name.
|
|
*
|
|
* @param [out] scaled The scaled point base*scalar
|
|
* @param [in] scalar The scalar to multiply by.
|
|
*/
|
|
void decaf_x448_derive_public_key (
|
|
uint8_t out[DECAF_X448_PUBLIC_BYTES],
|
|
const uint8_t scalar[DECAF_X448_PRIVATE_BYTES]
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
|
|
/**
|
|
* @brief Multiply a precomputed base point by a scalar:
|
|
* scaled = scalar*base.
|
|
* Some implementations do not include precomputed points; for
|
|
* those implementations, this function is the same as
|
|
* curve448_point_scalarmul
|
|
*
|
|
* @param [out] scaled The scaled point base*scalar
|
|
* @param [in] base The point to be scaled.
|
|
* @param [in] scalar The scalar to multiply by.
|
|
*/
|
|
void curve448_precomputed_scalarmul (
|
|
curve448_point_t scaled,
|
|
const curve448_precomputed_s *base,
|
|
const curve448_scalar_t scalar
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
|
|
/**
|
|
* @brief Multiply two base points by two scalars:
|
|
* scaled = scalar1*curve448_point_base + scalar2*base2.
|
|
*
|
|
* Otherwise equivalent to curve448_point_double_scalarmul, but may be
|
|
* faster at the expense of being variable time.
|
|
*
|
|
* @param [out] combo The linear combination scalar1*base + scalar2*base2.
|
|
* @param [in] scalar1 A first scalar to multiply by.
|
|
* @param [in] base2 A second point to be scaled.
|
|
* @param [in] scalar2 A second scalar to multiply by.
|
|
*
|
|
* @warning: This function takes variable time, and may leak the scalars
|
|
* used. It is designed for signature verification.
|
|
*/
|
|
void curve448_base_double_scalarmul_non_secret (
|
|
curve448_point_t combo,
|
|
const curve448_scalar_t scalar1,
|
|
const curve448_point_t base2,
|
|
const curve448_scalar_t scalar2
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Test that a point is valid, for debugging purposes.
|
|
*
|
|
* @param [in] to_test The point to test.
|
|
* @retval DECAF_TRUE The point is valid.
|
|
* @retval DECAF_FALSE The point is invalid.
|
|
*/
|
|
__owur decaf_bool_t curve448_point_valid (
|
|
const curve448_point_t to_test
|
|
) DECAF_API_VIS DECAF_NONNULL DECAF_NOINLINE;
|
|
|
|
/**
|
|
* @brief Overwrite scalar with zeros.
|
|
*/
|
|
void curve448_scalar_destroy (
|
|
curve448_scalar_t scalar
|
|
) DECAF_NONNULL DECAF_API_VIS;
|
|
|
|
/**
|
|
* @brief Overwrite point with zeros.
|
|
*/
|
|
void curve448_point_destroy (
|
|
curve448_point_t point
|
|
) DECAF_NONNULL DECAF_API_VIS;
|
|
|
|
#ifdef __cplusplus
|
|
} /* extern "C" */
|
|
#endif
|
|
|
|
#endif /* __DECAF_POINT_448_H__ */
|