//------------------------------------------------------------------------------
//
// fpga_ecdsa_multiword.cpp
// -----------------------------------------
// Models of multi-precision FPGA primitives
//
// Authors: Pavel Shatov
//
// Copyright (c) 2015-2016, 2018 NORDUnet A/S
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// - Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// - Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// - Neither the name of the NORDUnet nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include "ecdsa_fpga_model.h"
//------------------------------------------------------------------------------
// Globals
//------------------------------------------------------------------------------
FPGA_BUFFER ECDSA_ZERO;
FPGA_BUFFER ECDSA_ONE;
//------------------------------------------------------------------------------
void fpga_multiword_init()
//------------------------------------------------------------------------------
{
int w; // word counter
/* fill buffers for large multi-word integers */
for ( w = FPGA_OPERAND_NUM_WORDS - 1;
w >= 0;
w -= 1)
{
ECDSA_ZERO.words[w] = 0; // all words are zero
ECDSA_ONE.words[w] = w ? 0 : 1; // only the lowest word is 1
}
}
//------------------------------------------------------------------------------
void fpga_multiword_copy(const FPGA_BUFFER *src, FPGA_BUFFER *dst)
//------------------------------------------------------------------------------
//
// Copies large multi-word integer from src into dst.
//
//------------------------------------------------------------------------------
{
int w; // word counter
// copy all the words from src into dst
for (w=0; w<FPGA_OPERAND_NUM_WORDS; w++)
dst->words[w] = src->words[w];
}
//------------------------------------------------------------------------------
bool fpga_multiword_is_zero(const FPGA_BUFFER *x)
//------------------------------------------------------------------------------
//
// Returns true when large multi-word integer x is zero.
//
//------------------------------------------------------------------------------
{
int w; // word counter
// try to find non-zero words
for (w=0; w<FPGA_OPERAND_NUM_WORDS; w++)
if (x->words[w]) return false;
// no non-zero words found
return true;
}
//------------------------------------------------------------------------------
// End-of-File
//------------------------------------------------------------------------------
