mp_copy.c

   1 #include "tommath_private.h"
   2 #ifdef MP_COPY_C
   3 /* LibTomMath, multiple-precision integer library -- Tom St Denis */
   4 /* SPDX-License-Identifier: Unlicense */
   5
   6 /* copy, b = a */
   7 mp_err mp_copy(const mp_int *a, mp_int *b)
   8 {
   9    mp_err err;
  10
  11    /* if dst == src do nothing */
  12    if (a == b) {
  13       return MP_OKAY;
  14    }
  15
  16    /* grow dest */
  17    if ((err = mp_grow(b, a->used)) != MP_OKAY) {
  18       return err;
  19    }
  20
  21    /* copy everything over and zero high digits */
  22    s_mp_copy_digs(b->dp, a->dp, a->used);
  23    s_mp_zero_digs(b->dp + a->used, b->used - a->used);
  24    b->used = a->used;
  25    b->sign = a->sign;
  26
  27    return MP_OKAY;
  28 }
  29 #endif