X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/34e4f738bcba58e6d8c4cabbb0b3232a65b42a9d..908ebb29ff621f582b34d48fd4278b60b78379b6:/mpbarrett.h diff --git a/mpbarrett.h b/mpbarrett.h index 3168205..71d9ba7 100644 --- a/mpbarrett.h +++ b/mpbarrett.h @@ -1,13 +1,13 @@ /* -*-c-*- * - * $Id: mpbarrett.h,v 1.4 2004/04/01 12:50:09 mdw Exp $ + * $Id$ * * Barrett modular reduction * * (c) 1999 Straylight/Edgeware */ -/*----- Licensing notice --------------------------------------------------* +/*----- Licensing notice --------------------------------------------------* * * This file is part of Catacomb. * @@ -15,39 +15,18 @@ * 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 1.4 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 1.3 2001/06/16 12:58:47 mdw - * Added simultaneous exponentiation with Barrett reduction. - * - * Revision 1.2 2000/10/08 12:03:44 mdw - * (mpbarrett_reduce): Cope with negative numbers. - * - * 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 @@ -93,13 +72,12 @@ typedef struct mpbarrett { * 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@ --- * * @@ -130,11 +108,11 @@ 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*/);