cryb-to/lib/mpi/cryb_mpi_load.c
Dag-Erling Smørgrav 06c2f1280a Add a missing break.
This was harmless as it would either fall through to an empty default statement (if CRYB_COVERAGE was defined) or out of the switch, but it's still bad style.
2017-09-04 21:00:01 +02:00

78 lines
2.3 KiB
C

/*
* Copyright (c) 2014-2016 Dag-Erling Smørgrav
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include "cryb/impl.h"
#include <stddef.h>
#include <stdint.h>
#include <strings.h>
#include <cryb/bitwise.h>
#include <cryb/endian.h>
#include <cryb/mpi.h>
#include "cryb_mpi_impl.h"
/*
* Load value from an array of bytes
*/
int
mpi_load(cryb_mpi *X, const uint8_t *a, size_t len)
{
int i;
mpi_zero(X);
/* skip zeroes */
while (len > 0 && *a == 0)
--len, ++a;
if (len == 0)
return (0);
/* make room */
if (mpi_grow(X, len * 8) != 0)
return (-1);
/* load whole words */
for (i = 0; len >= 4; ++i, len -= 4)
X->words[i] = be32dec(&a[len - 4]);
/* load remaining bytes */
switch (len) {
case 3:
X->words[i] |= a[len - 3] << 16;
case 2:
X->words[i] |= a[len - 2] << 8;
case 1:
X->words[i] |= a[len - 1];
break;
case 0:
--i;
break;
CRYB_NO_DEFAULT_CASE;
}
X->msb = i * 32 + flsl(X->words[i]);
return (0);
}