1 /* $NetBSD: bn_mp_reduce_2k_setup_l.c,v 1.1.1.2 2014/04/24 12:45:31 pettai Exp $ */
2
3 #include <tommath.h>
4 #ifdef BN_MP_REDUCE_2K_SETUP_L_C
5 /* LibTomMath, multiple-precision integer library -- Tom St Denis
6 *
7 * LibTomMath is a library that provides multiple-precision
8 * integer arithmetic as well as number theoretic functionality.
9 *
10 * The library was designed directly after the MPI library by
11 * Michael Fromberger but has been written from scratch with
12 * additional optimizations in place.
13 *
14 * The library is free for all purposes without any express
15 * guarantee it works.
16 *
17 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
18 */
19
20 /* determines the setup value */
mp_reduce_2k_setup_l(mp_int * a,mp_int * d)21 int mp_reduce_2k_setup_l(mp_int *a, mp_int *d)
22 {
23 int res;
24 mp_int tmp;
25
26 if ((res = mp_init(&tmp)) != MP_OKAY) {
27 return res;
28 }
29
30 if ((res = mp_2expt(&tmp, mp_count_bits(a))) != MP_OKAY) {
31 goto ERR;
32 }
33
34 if ((res = s_mp_sub(&tmp, a, d)) != MP_OKAY) {
35 goto ERR;
36 }
37
38 ERR:
39 mp_clear(&tmp);
40 return res;
41 }
42 #endif
43
44 /* Source: /cvs/libtom/libtommath/bn_mp_reduce_2k_setup_l.c,v */
45 /* Revision: 1.4 */
46 /* Date: 2006/12/28 01:25:13 */
47