mcci_tweetnacl_scalarmult.h

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/*
 
Module: mcci_tweetnacl_scalarmult.h
 
Function:
        MCCI TweetNacl equivalent of NaCl "crypto_scalarmult.h"
 
Copyright and License:
        This file copyright (C) 2021 by
 
                MCCI Corporation
                3520 Krums Corners Road
                Ithaca, NY  14850
 
        See accompanying LICENSE file for copyright and license information.
 
Author:
        fullname, MCCI Corporation      March 2021
 
*/
 
#ifndef _mcci_tweetnacl_scalarmult_h_
#define _mcci_tweetnacl_scalarmult_h_   /* prevent multiple includes */
 
#pragma once
 
#include "mcci_tweetnacl.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
/****************************************************************************\
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/// \addtogroup public-key-crypto       Public-key cryptography
/// @{
///     \defgroup crypto-scalarmult     Scalar multiplication
///     @{
 
/****************************************************************************\
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/// \brief curve25519 group element
/// \see https://nacl.cr.yp.to/scalarmult.html
typedef struct
        {
        /// bytes of the group element
        unsigned char bytes[32];
        } mcci_tweetnacl_curve25519_group_element_t;
 
/// \brief curve25519 scalar integer
/// \see https://nacl.cr.yp.to/scalarmult.html
typedef struct
        {
        /// bytes of the scalar
        unsigned char bytes[32];
        } mcci_tweetnacl_curve25519_scalar_t;
 
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///
/// \brief do a scalar multiplication of a curve255129 group element by an integer
///
/// \param[out] q is set to the result
/// \param[in] p is the input group element,
/// \param[in] n is the input integer scalalar.
///
/// \see https://nacl.cr.yp.to/scalarmult.html
///
static inline void
mcci_tweetnacl_scalarmult_curve25519(
        mcci_tweetnacl_curve25519_group_element_t *q,
        const mcci_tweetnacl_curve25519_group_element_t *p,
        const mcci_tweetnacl_curve25519_scalar_t *n
        )
        {
        extern int crypto_scalarmult_curve25519_tweet(unsigned char *,const unsigned char *,const unsigned char *);
        (void) crypto_scalarmult_curve25519_tweet(
                q->bytes,
                p->bytes,
                n->bytes
                );
        }
 
///
/// \brief do a scalar multiplication of the well known group element by an integer
///
/// \param[out] q is set to the result
/// \param[in] n is the input integer scalalar.
///
/// \see https://nacl.cr.yp.to/scalarmult.html
///
static inline void
mcci_tweetnacl_scalarmult_curve25519_base(
        mcci_tweetnacl_curve25519_group_element_t *q,
        const mcci_tweetnacl_curve25519_scalar_t *n
        )
        {
        extern int crypto_scalarmult_curve25519_tweet_base(unsigned char *,const unsigned char *);
        (void) crypto_scalarmult_curve25519_tweet_base(
                q->bytes,
                n->bytes
                );
        }
 
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//--- close groups ---
///     @}
///  @}
 
#ifdef __cplusplus
}
#endif
 
#endif /* _mcci_tweetnacl_scalarmult_h_ */