/* -*-c-*-
*
- * $Id: mpbarrett.h,v 1.1 1999/12/10 23:22:00 mdw Exp $
+ * $Id$
*
* Barrett modular reduction
*
* (c) 1999 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of Catacomb.
*
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
- *
+ *
* Catacomb is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
- *
+ *
* You should have received a copy of the GNU Library General Public
* License along with Catacomb; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: mpbarrett.h,v $
- * Revision 1.1 1999/12/10 23:22:00 mdw
- * Barrett reduction support: works with even moduli.
- *
- */
-
/*----- Notes on Barrett reduction ----------------------------------------*
*
* Barrett reduction is a technique for computing modular residues. Unlike
* Arguments: @mpbarrett *mb@ = pointer to Barrett reduction context
* @mp *m@ = modulus to work to
*
- *
- * Returns: ---
+ * Returns: Zero on success, nonzero on error.
*
* Use: Initializes a Barrett reduction context ready for use.
*/
-extern void mpbarrett_create(mpbarrett */*mb*/, mp */*m*/);
+extern int mpbarrett_create(mpbarrett */*mb*/, mp */*m*/);
/* --- @mpbarrett_destroy@ --- *
*
* Returns: The residue of @m@ modulo the number in the reduction
* context.
*
- * Use: Performs an efficient modular reduction. The argument is
- * assumed to be positive.
+ * Use: Performs an efficient modular reduction.
*/
extern mp *mpbarrett_reduce(mpbarrett */*mb*/, mp */*d*/, mp */*m*/);
/* --- @mpbarrett_exp@ --- *
*
* Arguments: @mpbarrett *mb@ = pointer to Barrett reduction context
- * @mp *d@ = fake destination
- * @mp *a@ = base
- * @mp *e@ = exponent
+ * @mp *d@ = fake destination
+ * @mp *a@ = base
+ * @mp *e@ = exponent
*
- * Returns: Result, %$a^e \bmod m$%.
+ * Returns: Result, %$a^e \bmod m$%.
*/
extern mp *mpbarrett_exp(mpbarrett */*mb*/, mp */*d*/, mp */*a*/, mp */*e*/);
+/* --- @mpbarrett_mexp@ --- *
+ *
+ * Arguments: @mpbarrett *mb@ = pointer to Barrett reduction context
+ * @mp *d@ = fake destination
+ * @const mp_expfactor *f@ = pointer to array of factors
+ * @size_t n@ = number of factors supplied
+ *
+ * Returns: If the bases are %$g_0, g_1, \ldots, g_{n-1}$% and the
+ * exponents are %$e_0, e_1, \ldots, e_{n-1}$% then the result
+ * is:
+ *
+ * %$g_0^{e_0} g_1^{e_1} \ldots g_{n-1}^{e_{n-1}} \bmod m$%
+ */
+
+extern mp *mpbarrett_mexp(mpbarrett */*mb*/, mp */*d*/,
+ const mp_expfactor */*f*/, size_t /*n*/);
+
/*----- That's all, folks -------------------------------------------------*/
#ifdef __cplusplus