/* -*-c-*-
*
- * $Id: mpmont-mexp.c,v 1.8 2004/04/01 12:50:09 mdw Exp $
+ * $Id: mpmont-mexp.c,v 1.9 2004/04/08 01:36:15 mdw Exp $
*
* Multiple simultaneous exponentiations
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: mpmont-mexp.c,v $
- * Revision 1.8 2004/04/01 12:50:09 mdw
- * Add cyclic group abstraction, with test code. Separate off exponentation
- * functions for better static linking. Fix a buttload of bugs on the way.
- * Generally ensure that negative exponents do inversion correctly. Add
- * table of standard prime-field subgroups. (Binary field subgroups are
- * currently unimplemented but easy to add if anyone ever finds a good one.)
- *
- * Revision 1.7 2002/01/13 13:49:14 mdw
- * Make @const@-correct.
- *
- * Revision 1.6 2001/06/16 13:00:20 mdw
- * Use the generic exponentiation functions.
- *
- * Revision 1.5 2000/10/08 12:11:22 mdw
- * Use @MP_EQ@ instead of @MP_CMP@.
- *
- * Revision 1.4 2000/06/17 11:45:09 mdw
- * Major memory management overhaul. Added arena support. Use the secure
- * arena for secret integers. Replace and improve the MP management macros
- * (e.g., replace MP_MODIFY by MP_DEST).
- *
- * Revision 1.3 1999/12/10 23:18:39 mdw
- * Change interface for suggested destinations.
- *
- * Revision 1.2 1999/11/21 11:35:10 mdw
- * Performance improvement: use @mp_sqr@ and @mpmont_reduce@ instead of
- * @mpmont_mul@ for squaring in exponentiation.
- *
- * Revision 1.1 1999/11/19 13:19:29 mdw
- * Simultaneous exponentiation support.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include "mp.h"
{
mp *a = MP_COPY(mm->r);
mp *spare = MP_NEW;
- mp *g = MP_NEW;
size_t i;
for (i = 0; i < n; i++) {
spare = MP_NEWSEC;
if (f[i].exp->f & MP_NEG) {
t = mpmont_reduce(mm, f[i].base, f[i].base);
- mp_gcd(&g, 0, &t, mm->m, t);
- assert(MP_EQ(g, MP_ONE));
+ t = mp_modinv(t, t, mm->m);
f[i].base = mpmont_mul(mm, t, t, mm->r2);
}
}
- mp_drop(g);
EXP_SIMUL(a, f, n);
mp_drop(d);
mp_drop(spare);