primefld25519.h

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/*
 * primefld25519.h
 *
 * Prime Field Header for the field with p = 2^255 - 19 elements;
 *
 * Copyright 2019-2024 DigiCert, Inc. All Rights Reserved.
 * Proprietary and Confidential Material.
 *
 */

/*------------------------------------------------------------------*/

#ifndef __PRIMEFLD25519_HEADER__
#define __PRIMEFLD25519_HEADER__

#include "../common/moptions.h"
#include "../common/mtypes.h"
#include "../common/merrors.h"

#ifdef __cplusplus
extern "C" {
#endif

#define MOC_NUM_25519_BYTES 32
#define MOC_NUM_25519_UNITS 10
#define MOC_NUM_25519_ELEM_BYTES 40  /* 10 four byte units per element */

/*
 MACROS provided for addition and subtraction. These are for curve25519
 specific operations and not for general purpose. The words of pA and pB
 should be < 2^26 in absolute value. The resulting pResult will have words
 < 2^27 in absolute value. No carries are needed.
 */
#define PF_25519_add(pResult, pA, pB, i)  \
for (i = 0; i < MOC_NUM_25519_UNITS; ++i) \
{                                         \
    pResult[i] = pA[i] + pB[i];           \
}

#define PF_25519_subtract(pResult, pA, pB, i)  \
for (i = 0; i < MOC_NUM_25519_UNITS; ++i)      \
{                                              \
    pResult[i] = pA[i] - pB[i];                \
}

#ifdef __PF_25519_TWOS_COMPLIMENT_OK__
#define PF_25519_additiveInvert(pA, i) \
for (i = 0; i < MOC_NUM_25519_UNITS; ++i)      \
{                                              \
    pA[i] = (~(pA[i]))+1;                      \
}
#else
#define PF_25519_additiveInvert(pA, i) \
for (i = 0; i < MOC_NUM_25519_UNITS; ++i)      \
{                                              \
pA[i] = -1 * pA[i];                            \
}
#endif

MOC_EXTERN void PF_25519_multiply(sbyte4 *pResult, const sbyte4 *pA, const sbyte4 *pB);

MOC_EXTERN void PF_25519_square(sbyte4 *pResult, const sbyte4 *pA);

MOC_EXTERN MSTATUS PF_25519_specialExp(sbyte4 *pResult, const sbyte4 *pA, const byteBoolean isInverse);

MOC_EXTERN byteBoolean PF_25519_match(const sbyte4 *pA, const sbyte4 *pB);

MOC_EXTERN void PF_25519_to_bytes(ubyte *pResult, sbyte4 *pA);

MOC_EXTERN MSTATUS PF_25519_from_bytes(sbyte4 *pResult, const ubyte *pInput, byteBoolean compareToThePrime);

#ifdef __cplusplus
}
#endif

#endif /* __PRIMEFLD25519_HEADER__ */