dropbear/libtommath/bn_mp_mod.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

45 lines
972 B
C

#include <tommath.h>
#ifdef BN_MP_MOD_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
*/
/* c = a mod b, 0 <= c < b */
int
mp_mod (mp_int * a, mp_int * b, mp_int * c)
{
mp_int t;
int res;
if ((res = mp_init (&t)) != MP_OKAY) {
return res;
}
if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) {
mp_clear (&t);
return res;
}
if (t.sign != b->sign) {
res = mp_add (b, &t, c);
} else {
res = MP_OKAY;
mp_exch (&t, c);
}
mp_clear (&t);
return res;
}
#endif