#include "tommath_private.h"
#ifdef BN_MP_RADIX_SIZE_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* returns size of ASCII reprensentation */
mp_err mp_radix_size(const mp_int *a, int radix, int *size)
{
mp_err err;
int digs;
mp_int t;
mp_digit d;
*size = 0;
/* make sure the radix is in range */
if ((radix < 2) || (radix > 64)) {
return MP_VAL;
}
if (MP_IS_ZERO(a)) {
*size = 2;
return MP_OKAY;
}
/* special case for binary */
if (radix == 2) {
*size = mp_count_bits(a) + ((a->sign == MP_NEG) ? 1 : 0) + 1;
return MP_OKAY;
}
/* digs is the digit count */
digs = 0;
/* if it's negative add one for the sign */
if (a->sign == MP_NEG) {
++digs;
}
/* init a copy of the input */
if ((err = mp_init_copy(&t, a)) != MP_OKAY) {
return err;
}
/* force temp to positive */
t.sign = MP_ZPOS;
/* fetch out all of the digits */
while (!MP_IS_ZERO(&t)) {
if ((err = mp_div_d(&t, (mp_digit)radix, &t, &d)) != MP_OKAY) {
goto LBL_ERR;
}
++digs;
}
/* return digs + 1, the 1 is for the NULL byte that would be required. */
*size = digs + 1;
err = MP_OKAY;
LBL_ERR:
mp_clear(&t);
return err;
}
#endif
