libtommath/bn_mp_to_unsigned_bin.c
2019-09-03 05:45:33 +02:00

36 lines
764 B
C

#include "tommath_private.h"
#ifdef BN_MP_TO_UNSIGNED_BIN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* store in unsigned [big endian] format */
mp_err mp_to_unsigned_bin(const mp_int *a, unsigned char *b)
{
int x;
mp_err err;
mp_int t;
if ((err = mp_init_copy(&t, a)) != MP_OKAY) {
return err;
}
x = 0;
while (!MP_IS_ZERO(&t)) {
#ifndef MP_8BIT
b[x++] = (unsigned char)(t.dp[0] & 255u);
#else
b[x++] = (unsigned char)(t.dp[0] | ((t.dp[1] & 1u) << 7));
#endif
if ((err = mp_div_2d(&t, 8, &t, NULL)) != MP_OKAY) {
goto LBL_ERR;
}
}
s_mp_reverse(b, x);
err = MP_OKAY;
LBL_ERR:
mp_clear(&t);
return err;
}
#endif