#include "tommath_private.h"

#ifdef BN_MP_FROM_UBIN_C

/* LibTomMath, multiple-precision integer library -- Tom St Denis */

/* SPDX-License-Identifier: Unlicense */

/* reads a unsigned char array, assumes the msb is stored first [big endian] */

mp_err mp_from_ubin(mp_int *a, const unsigned char *buf, size_t size)

{

   mp_err err;

   /* make sure there are at least two digits */

   if (a->alloc < 2) {

      if ((err = mp_grow(a, 2)) != MP_OKAY) {

         return err;

      }

   }

   /* zero the int */

   mp_zero(a);

   /* read the bytes in */

   while (size-- > 0u) {

      if ((err = mp_mul_2d(a, 8, a)) != MP_OKAY) {

         return err;

      }

#ifndef MP_8BIT

      a->dp[0] |= *buf++;

      a->used += 1;

#else

      a->dp[0] = (*buf & MP_MASK);

      a->dp[1] |= ((*buf++ >> 7) & 1u);

      a->used += 2;

#endif

   }

   mp_clamp(a);

   return MP_OKAY;

}

#endif