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#include "tommath_private.h"
#ifdef BN_MP_TO_UBIN_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* store in unsigned [big endian] format */
mp_err mp_to_ubin(const mp_int *a, unsigned char *buf, size_t maxlen, size_t *written)
{
size_t x;
mp_err err;
mp_int t;
if (buf == NULL) {
return MP_MEM;
}
if (maxlen == 0u) {
return MP_VAL;
}
if ((err = mp_init_copy(&t, a)) != MP_OKAY) {
return err;
}
x = 0u;
while (!MP_IS_ZERO(&t)) {
if (maxlen == 0u) {
err = MP_VAL;
goto LBL_ERR;
}
maxlen--;
#ifndef MP_8BIT
buf[x++] = (unsigned char)(t.dp[0] & 255u);
#else
buf[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(buf, x);
if (written != NULL) {
*written = x;
}
LBL_ERR:
mp_clear(&t);
return err;
}
#endif