git.distorted.org.uk Git - u/mdw/catacomb/blob - prim.h

   1 /* -*-c-*-
   2  *
   3  * $Id: prim.h,v 1.2 2000/07/29 09:57:42 mdw Exp $
   4  *
   5  * Finding primitive elements
   6  *
   7  * (c) 1999 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: prim.h,v $
  33  * Revision 1.2  2000/07/29 09:57:42  mdw
  34  * Improve primitive-element testing a lot.  Now much more sensible and
  35  * orthogonal: you can find a generator for any given subgroup order by
  36  * putting in the appropriate parameters.
  37  *
  38  * Revision 1.1  1999/12/22 15:58:59  mdw
  39  * Search for primitive elements using prime-search equipment.
  40  *
  41  */
  42
  43 #ifndef CATACOMB_PRIM_H
  44 #define CATACOMB_PRIM_H
  45
  46 #ifdef __cplusplus
  47   extern "C" {
  48 #endif
  49
  50 /*----- Header files ------------------------------------------------------*/
  51
  52 #include <stddef.h>
  53
  54 #ifndef CATACOMB_MP_H
  55 #  include "mp.h"
  56 #endif
  57
  58 #ifndef CATACOMB_MPMONT_H
  59 #  include "mpmont.h"
  60 #endif
  61
  62 #ifndef CATACOMB_PGEN_H
  63 #  include "pgen.h"
  64 #endif
  65
  66 /*----- Data structures ---------------------------------------------------*/
  67
  68 /* --- @prim_ctx@ --- *
  69  *
  70  * All fields must be configured by the client.  Set @n@ to zero to discover
  71  * generators of the subgroup of order %$m / f$%.
  72  *
  73  * Let %$p = \prod q_i + 1$% be a prime number.  In order to find an element
  74  * %$g$% with order %$o$%, we choose elements %$h_j$% from %$\gf{p}^*$%,
  75  * compute $%g_j = h_j^{p/o}$%, rejecting %$h_j$% where %$g_j = 1$%, and then
  76  * for each proper prime factor %$q_i$% of %$p/o$% we check that
  77  * %$g^{f_i} \ne 1$%, where the %$f_i$% are cofactors of the %$q_i$%
  78  * (%$f_i q_i = p/o$%).
  79  */
  80
  81 typedef struct prim_ctx {
  82   mpmont mm;                            /* Montgomery context for modulus */
  83   mp *exp;                              /* Exponent (%$p/o$%; may be zero) */
  84   size_t n;                             /* Number of cofactors */
  85   mp **f;                               /* Array of cofactors */
  86 } prim_ctx;
  87
  88 /*----- Functions provided ------------------------------------------------*/
  89
  90 /* --- @prim_test@ --- */
  91
  92 extern int prim_test(int /*rq*/, pgen_event */*ev*/, void */*p*/);
  93
  94 /* --- @prim_step@ --- */
  95
  96 extern int prim_step(int /*rq*/, pgen_event */*ev*/, void */*p*/);
  97
  98 /*----- That's all, folks -------------------------------------------------*/
  99
 100 #ifdef __cplusplus
 101   }
 102 #endif
 103
 104 #endif