Line data Source code
1 : #include <tommath.h>
2 : #ifdef BN_MP_REDUCE_2K_SETUP_L_C
3 : /* LibTomMath, multiple-precision integer library -- Tom St Denis
4 : *
5 : * LibTomMath is a library that provides multiple-precision
6 : * integer arithmetic as well as number theoretic functionality.
7 : *
8 : * The library was designed directly after the MPI library by
9 : * Michael Fromberger but has been written from scratch with
10 : * additional optimizations in place.
11 : *
12 : * The library is free for all purposes without any express
13 : * guarantee it works.
14 : *
15 : * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
16 : */
17 :
18 : /* determines the setup value */
19 0 : int mp_reduce_2k_setup_l(mp_int *a, mp_int *d)
20 : {
21 : int res;
22 : mp_int tmp;
23 :
24 0 : if ((res = mp_init(&tmp)) != MP_OKAY) {
25 0 : return res;
26 : }
27 :
28 0 : if ((res = mp_2expt(&tmp, mp_count_bits(a))) != MP_OKAY) {
29 0 : goto ERR;
30 : }
31 :
32 0 : if ((res = s_mp_sub(&tmp, a, d)) != MP_OKAY) {
33 0 : goto ERR;
34 : }
35 :
36 0 : ERR:
37 0 : mp_clear(&tmp);
38 0 : return res;
39 : }
40 : #endif
41 :
42 : /* $Source: /cvs/libtom/libtommath/bn_mp_reduce_2k_setup_l.c,v $ */
43 : /* $Revision: 1.4 $ */
44 : /* $Date: 2006/12/28 01:25:13 $ */
|