/*
|
* Copyright (C) 2015 Southern Storm Software, Pty Ltd.
|
*
|
* Permission is hereby granted, free of charge, to any person obtaining a
|
* copy of this software and associated documentation files (the "Software"),
|
* to deal in the Software without restriction, including without limitation
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
* and/or sell copies of the Software, and to permit persons to whom the
|
* Software is furnished to do so, subject to the following conditions:
|
*
|
* The above copyright notice and this permission notice shall be included
|
* in all copies or substantial portions of the Software.
|
*
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
|
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
* DEALINGS IN THE SOFTWARE.
|
*/
|
|
#ifndef CRYPTO_LIMBUTIL_H
|
#define CRYPTO_LIMBUTIL_H
|
|
#include "ProgMemUtil.h"
|
|
// Number of limbs in a big number value of various sizes.
|
#define NUM_LIMBS_BITS(n) \
|
(((n) + sizeof(limb_t) * 8 - 1) / (8 * sizeof(limb_t)))
|
#define NUM_LIMBS_128BIT NUM_LIMBS_BITS(128)
|
#define NUM_LIMBS_256BIT NUM_LIMBS_BITS(256)
|
#define NUM_LIMBS_512BIT NUM_LIMBS_BITS(512)
|
|
// The number of bits in a limb.
|
#define LIMB_BITS (8 * sizeof(limb_t))
|
|
// Read a limb-sized quantity from program memory.
|
#if BIGNUMBER_LIMB_8BIT
|
#define pgm_read_limb(x) (pgm_read_byte((x)))
|
#elif BIGNUMBER_LIMB_16BIT
|
#define pgm_read_limb(x) (pgm_read_word((x)))
|
#elif BIGNUMBER_LIMB_32BIT
|
#define pgm_read_limb(x) (pgm_read_dword((x)))
|
#elif BIGNUMBER_LIMB_64BIT
|
#define pgm_read_limb(x) (pgm_read_qword((x)))
|
#endif
|
|
// Expand a 32-bit value into a set of limbs depending upon the limb size.
|
// This is used when initializing constant big number values in the code.
|
// For 64-bit system compatibility it is necessary to use LIMB_PAIR(x, y).
|
#if BIGNUMBER_LIMB_8BIT
|
#define LIMB(value) ((uint8_t)(value)), \
|
((uint8_t)((value) >> 8)), \
|
((uint8_t)((value) >> 16)), \
|
((uint8_t)((value) >> 24))
|
#define LIMB_PAIR(x,y) LIMB((x)), LIMB((y))
|
#elif BIGNUMBER_LIMB_16BIT
|
#define LIMB(value) ((uint16_t)(value)), \
|
((uint16_t)(((uint32_t)(value)) >> 16))
|
#define LIMB_PAIR(x,y) LIMB((x)), LIMB((y))
|
#elif BIGNUMBER_LIMB_32BIT
|
#define LIMB(value) (value)
|
#define LIMB_PAIR(x,y) LIMB((x)), LIMB((y))
|
#elif BIGNUMBER_LIMB_64BIT
|
#define LIMB(value) (value)
|
#define LIMB_PAIR(x,y) ((((uint64_t)(y)) << 32) | ((uint64_t)(x)))
|
#endif
|
|
#endif
|
