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   1 /* -*-c-*-
   2  *
   3  * $Id: gf.h,v 1.3 2004/03/27 17:54:11 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 1.3  2004/03/27 17:54:11  mdw
  34  * Standard curves and curve checking.
  35  *
  36  * Revision 1.2  2004/03/21 22:52:06  mdw
  37  * Merge and close elliptic curve branch.
  38  *
  39  * Revision 1.1.2.1  2004/03/21 22:39:46  mdw
  40  * Elliptic curves on binary fields work.
  41  *
  42  */
  43
  44 #ifndef CATACOMB_GF_H
  45 #define CATACOMB_GF_H
  46
  47 #ifdef __cplusplus
  48   extern "C" {
  49 #endif
  50
  51 /*----- Header files ------------------------------------------------------*/
  52
  53 #ifndef CATACOMB_MP_H
  54 #  include "mp.h"
  55 #endif
  56
  57 #ifndef CATACOMB_GFX_H
  58 #  include "gfx.h"
  59 #endif
  60
  61 /*----- Functions provided ------------------------------------------------*/
  62
  63 /* --- @gf_add@ --- *
  64  *
  65  * Arguments:   @mp *d@ = destination
  66  *              @mp *a, *b@ = sources
  67  *
  68  * Returns:     Result, @a@ added to @b@.
  69  */
  70
  71 extern mp *gf_add(mp */*d*/, mp */*a*/, mp */*b*/);
  72 #define gf_sub gf_add
  73
  74 /* --- @gf_mul@ --- *
  75  *
  76  * Arguments:   @mp *d@ = destination
  77  *              @mp *a, *b@ = sources
  78  *
  79  * Returns:     Result, @a@ multiplied by @b@.
  80  */
  81
  82 extern mp *gf_mul(mp */*d*/, mp */*a*/, mp */*b*/);
  83
  84 /* --- @gf_sqr@ --- *
  85  *
  86  * Arguments:   @mp *d@ = destination
  87  *              @mp *a@ = source
  88  *
  89  * Returns:     Result, @a@ squared.
  90  */
  91
  92 extern mp *gf_sqr(mp */*d*/, mp */*a*/);
  93
  94 /* --- @gf_div@ --- *
  95  *
  96  * Arguments:   @mp **qq, **rr@ = destination, quotient and remainder
  97  *              @mp *a, *b@ = sources
  98  *
  99  * Use:         Calculates the quotient and remainder when @a@ is divided by
 100  *              @b@.  The destinations @*qq@ and @*rr@ must be distinct.
 101  *              Either of @qq@ or @rr@ may be null to indicate that the
 102  *              result is irrelevant.  (Discarding both results is silly.)
 103  *              There is a performance advantage if @a == *rr@.
 104  */
 105
 106 extern void gf_div(mp **/*qq*/, mp **/*rr*/, mp */*a*/, mp */*b*/);
 107
 108 /* --- @gf_irreduciblep@ --- *
 109  *
 110  * Arguments:   @mp *f@ = a polynomial
 111  *
 112  * Returns:     Nonzero if the polynomial is irreducible; otherwise zero.
 113  */
 114
 115 extern int gf_irreduciblep(mp */*f*/);
 116
 117 /* --- @gf_gcd@ --- *
 118  *
 119  * Arguments:   @mp **gcd, **xx, **yy@ = where to write the results
 120  *              @mp *a, *b@ = sources (must be nonzero)
 121  *
 122  *
 123  * Returns:     ---
 124  *
 125  * Use:         Calculates @gcd(a, b)@, and two numbers @x@ and @y@ such that
 126  *              @ax + by = gcd(a, b)@.  This is useful for computing modular
 127  *              inverses.
 128  */
 129
 130 extern void gf_gcd(mp **/*gcd*/, mp **/*xx*/, mp **/*yy*/,
 131                    mp */*a*/, mp */*b*/);
 132
 133 /*----- That's all, folks -------------------------------------------------*/
 134
 135 #ifdef __cplusplus
 136   }
 137 #endif
 138
 139 #endif