#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, count;

   mp_err  err;

   mp_int  t;

   count = mp_ubin_size(a);

   if (count > maxlen) {

      return MP_BUF;

   }

   if ((err = mp_init_copy(&t, a)) != MP_OKAY) {

      return err;

   }

   for (x = count; x --> 0u;) {

#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;

      }

   }

   if (written != NULL) {

      *written = count;

   }

LBL_ERR:

   mp_clear(&t);

   return err;

}

#endif