libtommath/mp_reduce_2k_setup.c
Steffen Jaeckel 7a68f12873 Execute move.sh - Rename files from bn_* to match the function names.
* git blame <renamed-file> is not affected
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2019-10-19 16:24:39 +02:00

33 lines
653 B
C

#include "tommath_private.h"
#ifdef MP_REDUCE_2K_SETUP_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */
/* SPDX-License-Identifier: Unlicense */
/* determines the setup value */
mp_err mp_reduce_2k_setup(const mp_int *a, mp_digit *d)
{
mp_err err;
mp_int tmp;
int p;
if ((err = mp_init(&tmp)) != MP_OKAY) {
return err;
}
p = mp_count_bits(a);
if ((err = mp_2expt(&tmp, p)) != MP_OKAY) {
mp_clear(&tmp);
return err;
}
if ((err = s_mp_sub(&tmp, a, &tmp)) != MP_OKAY) {
mp_clear(&tmp);
return err;
}
*d = tmp.dp[0];
mp_clear(&tmp);
return MP_OKAY;
}
#endif