### view libtommath/bn_mp_reduce_2k_l.c @ 1856:8f28519e34b0defaulttipmainmaster

Don't include sk keys at all in KEX list
author Matt Johnston Sun, 23 Jan 2022 17:29:39 +0800 1051e4eea25a
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line source
```#include "tommath_private.h"
#ifdef BN_MP_REDUCE_2K_L_C
/* LibTomMath, multiple-precision integer library -- Tom St Denis */

/* reduces a modulo n where n is of the form 2**p - d
This differs from reduce_2k since "d" can be larger
than a single digit.
*/
mp_err mp_reduce_2k_l(mp_int *a, const mp_int *n, const mp_int *d)
{
mp_int q;
mp_err err;
int    p;

if ((err = mp_init(&q)) != MP_OKAY) {
return err;
}

p = mp_count_bits(n);
top:
/* q = a/2**p, a = a mod 2**p */
if ((err = mp_div_2d(a, p, &q, a)) != MP_OKAY) {
goto LBL_ERR;
}

/* q = q * d */
if ((err = mp_mul(&q, d, &q)) != MP_OKAY) {
goto LBL_ERR;
}

/* a = a + q */
if ((err = s_mp_add(a, &q, a)) != MP_OKAY) {
goto LBL_ERR;
}

if (mp_cmp_mag(a, n) != MP_LT) {
if ((err = s_mp_sub(a, n, a)) != MP_OKAY) {
goto LBL_ERR;
}
goto top;
}

LBL_ERR:
mp_clear(&q);
return err;
}

#endif
```