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   1 /* -*-c-*-
   2  *
   3  * $Id: gf.h,v 1.2 2004/03/21 22:52:06 mdw Exp $
   4  *
   5  * Arithmetic on binary polynomials
   6  *
   7  * (c) 2004 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: gf.h,v $
  33  * Revision 1.2  2004/03/21 22:52:06  mdw
  34  * Merge and close elliptic curve branch.
  35  *
  36  * Revision 1.1.2.1  2004/03/21 22:39:46  mdw
  37  * Elliptic curves on binary fields work.
  38  *
  39  */
  40
  41 #ifndef CATACOMB_GF_H
  42 #define CATACOMB_GF_H
  43
  44 #ifdef __cplusplus
  45   extern "C" {
  46 #endif
  47
  48 /*----- Header files ------------------------------------------------------*/
  49
  50 #ifndef CATACOMB_MP_H
  51 #  include "mp.h"
  52 #endif
  53
  54 #ifndef CATACOMB_GFX_H
  55 #  include "gfx.h"
  56 #endif
  57
  58 /*----- Functions provided ------------------------------------------------*/
  59
  60 /* --- @gf_add@ --- *
  61  *
  62  * Arguments:   @mp *d@ = destination
  63  *              @mp *a, *b@ = sources
  64  *
  65  * Returns:     Result, @a@ added to @b@.
  66  */
  67
  68 extern mp *gf_add(mp */*d*/, mp */*a*/, mp */*b*/);
  69 #define gf_sub gf_add
  70
  71 /* --- @gf_mul@ --- *
  72  *
  73  * Arguments:   @mp *d@ = destination
  74  *              @mp *a, *b@ = sources
  75  *
  76  * Returns:     Result, @a@ multiplied by @b@.
  77  */
  78
  79 extern mp *gf_mul(mp */*d*/, mp */*a*/, mp */*b*/);
  80
  81 /* --- @gf_sqr@ --- *
  82  *
  83  * Arguments:   @mp *d@ = destination
  84  *              @mp *a@ = source
  85  *
  86  * Returns:     Result, @a@ squared.
  87  */
  88
  89 extern mp *gf_sqr(mp */*d*/, mp */*a*/);
  90
  91 /* --- @gf_div@ --- *
  92  *
  93  * Arguments:   @mp **qq, **rr@ = destination, quotient and remainder
  94  *              @mp *a, *b@ = sources
  95  *
  96  * Use:         Calculates the quotient and remainder when @a@ is divided by
  97  *              @b@.  The destinations @*qq@ and @*rr@ must be distinct.
  98  *              Either of @qq@ or @rr@ may be null to indicate that the
  99  *              result is irrelevant.  (Discarding both results is silly.)
 100  *              There is a performance advantage if @a == *rr@.
 101  */
 102
 103 extern void gf_div(mp **/*qq*/, mp **/*rr*/, mp */*a*/, mp */*b*/);
 104
 105 /* --- @gf_gcd@ --- *
 106  *
 107  * Arguments:   @mp **gcd, **xx, **yy@ = where to write the results
 108  *              @mp *a, *b@ = sources (must be nonzero)
 109  *
 110  *
 111  * Returns:     ---
 112  *
 113  * Use:         Calculates @gcd(a, b)@, and two numbers @x@ and @y@ such that
 114  *              @ax + by = gcd(a, b)@.  This is useful for computing modular
 115  *              inverses.
 116  */
 117
 118 extern void gf_gcd(mp **/*gcd*/, mp **/*xx*/, mp **/*yy*/,
 119                    mp */*a*/, mp */*b*/);
 120
 121 /*----- That's all, folks -------------------------------------------------*/
 122
 123 #ifdef __cplusplus
 124   }
 125 #endif
 126
 127 #endif