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   1 /* -*-c-*-
   2  *
   3  * $Id: gfn.h,v 1.2 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * Normal-basis translation for binary fields
   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 #ifndef CATACOMB_GFN_H
  31 #define CATACOMB_GFN_H
  32
  33 #ifdef __cplusplus
  34   extern "C" {
  35 #endif
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include "gf.h"
  40
  41 /*----- Data structures ---------------------------------------------------*/
  42
  43 typedef struct gfn {
  44   size_t n;                             /* Number of rows */
  45   mp **r;                               /* Array of the rows */
  46 } gfn;
  47
  48 /*----- Functions provided ------------------------------------------------*/
  49
  50 /* --- @gfn_copy@ --- *
  51  *
  52  * Arguments:   @gfn *d@ = where to put the copy
  53  *              @const gfn *s@ = where the source is
  54  *
  55  * Returns:     ---
  56  *
  57  * Use:         Makes a copy of a translation matrix.
  58  */
  59
  60 extern void gfn_copy(gfn */*d*/, const gfn */*s*/);
  61
  62 /* --- @gfn_destroy@ --- *
  63  *
  64  * Arguments:   @gfn *m@ = a transformation matrix to free
  65  *
  66  * Returns:     ---
  67  *
  68  * Use:         Frees up a transformation matrix when it's no longer wanted.
  69  */
  70
  71 extern void gfn_destroy(gfn */*m*/);
  72
  73 /* --- @gfn_identity@ --- *
  74  *
  75  * Arguments:   @gfn *m@ = where to put the matrix
  76  *              @size_t n@ = size of the matrix
  77  *
  78  * Returns:     ---
  79  *
  80  * Use:         Fills @m@ with an identity matrix.
  81  */
  82
  83 extern void gfn_identity(gfn */*m*/, size_t /*n*/);
  84
  85 /* --- @gfn_invert@ --- *
  86  *
  87  * Arguments:   @gfn *m@ = a transformation matrix
  88  *
  89  * Returns:     Zero if successful, nonzero if the matrix was singular.
  90  *
  91  * Use:         Inverts a transformation matrix.
  92  */
  93
  94 extern int gfn_invert(gfn */*m*/);
  95
  96 /* --- @gfn_transform@ --- *
  97  *
  98  * Arguments:   @gfn *m@ = conversion matrix to apply
  99  *              @mp *d@ = destination pointer
 100  *              @mp *x@ = input value
 101  *
 102  * Returns:     The transformed element.
 103  *
 104  * Use:         Transforms a field element according to the given matrix.
 105  */
 106
 107 extern mp *gfn_transform(gfn */*m*/, mp */*d*/, mp */*x*/);
 108
 109 /* --- @gfn_create@ --- *
 110  *
 111  * Arguments:   @mp *p@ = modulus for polynomial basis
 112  *              @mp *beta@ = the generator of the normal basis, expressed
 113  *                      relative to the polynomial basis
 114  *              @gfn *ntop@ = output normal-to-polynomail conversion matrix
 115  *              @gfn *pton@ = output polynomial-to-normal conversion matrix
 116  *
 117  * Returns:     Zero if it worked, nonzero otherwise (e.g., if %$\beta$%
 118  *              doesn't generate a proper basis).
 119  *
 120  * Use:         Constructs conversion matrices between polynomial and normal
 121  *              basis representations of binary field elements.
 122  */
 123
 124 extern int gfn_create(mp */*p*/, mp */*beta*/, gfn */*ntop*/, gfn */*pton*/);
 125
 126 /*----- That's all, folks -------------------------------------------------*/
 127
 128 #ifdef __cplusplus
 129   }
 130 #endif
 131
 132 #endif