libtommath/bn_mp_sub_d.c
2010-07-15 17:25:17 +02:00

34 lines
792 B
C

/* LibTomMath, multiple-precision integer library -- Tom St Denis
*
* LibTomMath is library that provides for multiple-precision
* integer arithmetic as well as number theoretic functionality.
*
* The library is 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
*/
#include <tommath.h>
/* single digit subtraction */
int
mp_sub_d (mp_int * a, mp_digit b, mp_int * c)
{
mp_int t;
int res;
if ((res = mp_init (&t)) != MP_OKAY) {
return res;
}
mp_set (&t, b);
res = mp_sub (a, &t, c);
mp_clear (&t);
return res;
}