dropbear/libtommath/bn_mp_reduce_2k_setup_l.c
Matt Johnston 8608a8e64c propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 6c790cad5a7fa866ad062cb3a0c279f7ba788583)
to branch 'au.asn.ucc.matt.dropbear' (head fff0894a0399405a9410ea1c6d118f342cf2aa64)

--HG--
extra : convert_revision : fdf4a7a3b97ae5046139915de7e40399cceb2c01
2006-03-08 13:23:49 +00:00

41 lines
967 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, tomstdenis@iahu.ca, http://math.libtomcrypt.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