libtommath/mp_copy.c
2019-10-29 19:30:23 +01:00

40 lines
795 B
C

#include "tommath_private.h"
#ifdef MP_COPY_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* copy, b = a */
mp_err mp_copy(const mp_int *a, mp_int *b)
{
int n;
/* if dst == src do nothing */
if (a == b) {
return MP_OKAY;
}
/* grow dest */
if (b->alloc < a->used) {
mp_err err;
if ((err = mp_grow(b, a->used)) != MP_OKAY) {
return err;
}
}
/* zero b and copy the parameters over */
/* copy all the digits */
for (n = 0; n < a->used; n++) {
b->dp[n] = a->dp[n];
}
/* clear high digits */
MP_ZERO_DIGITS(b->dp + a->used, b->used - a->used);
/* copy used count and sign */
b->used = a->used;
b->sign = a->sign;
return MP_OKAY;
}
#endif