45 lines
1005 B
C
45 lines
1005 B
C
#include <tommath.h>
|
|
#ifdef BN_MP_REDUCE_2K_SETUP_L_C
|
|
/* LibTomMath, multiple-precision integer library -- Tom St Denis
|
|
*
|
|
* LibTomMath is a library that provides multiple-precision
|
|
* integer arithmetic as well as number theoretic functionality.
|
|
*
|
|
* The library was designed directly after the MPI library by
|
|
* Michael Fromberger but has been written from scratch with
|
|
* additional optimizations in place.
|
|
*
|
|
* The library is free for all purposes without any express
|
|
* guarantee it works.
|
|
*
|
|
* Tom St Denis, tstdenis82@gmail.com, http://libtom.org
|
|
*/
|
|
|
|
/* determines the setup value */
|
|
int mp_reduce_2k_setup_l(mp_int *a, mp_int *d)
|
|
{
|
|
int res;
|
|
mp_int tmp;
|
|
|
|
if ((res = mp_init(&tmp)) != MP_OKAY) {
|
|
return res;
|
|
}
|
|
|
|
if ((res = mp_2expt(&tmp, mp_count_bits(a))) != MP_OKAY) {
|
|
goto ERR;
|
|
}
|
|
|
|
if ((res = s_mp_sub(&tmp, a, d)) != MP_OKAY) {
|
|
goto ERR;
|
|
}
|
|
|
|
ERR:
|
|
mp_clear(&tmp);
|
|
return res;
|
|
}
|
|
#endif
|
|
|
|
/* $Source$ */
|
|
/* $Revision$ */
|
|
/* $Date$ */
|