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

   1 /* -*-c-*-
   2  *
   3  * $Id: limlee.h,v 1.2 2000/08/18 19:16:51 mdw Exp $
   4  *
   5  * Generate Lim-Lee primes
   6  *
   7  * (c) 2000 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: limlee.h,v $
  33  * Revision 1.2  2000/08/18 19:16:51  mdw
  34  * New stepper interface for constructing Lim-Lee primes.
  35  *
  36  * Revision 1.1  2000/07/09 21:30:58  mdw
  37  * Lim-Lee prime generation.
  38  *
  39  */
  40
  41 #ifndef CATACOMB_LIMLEE_H
  42 #define CATACOMB_LIMLEE_H
  43
  44 #ifdef __cplusplus
  45   extern "C" {
  46 #endif
  47
  48 /*----- Header files ------------------------------------------------------*/
  49
  50 #ifndef CATACOMB_GRAND_H
  51 #  include "grand.h"
  52 #endif
  53
  54 #ifndef CATACOMB_MP_H
  55 #  include "mp.h"
  56 #endif
  57
  58 #ifndef CATACOMB_PGEN_H
  59 #  include "pgen.h"
  60 #endif
  61
  62 /*----- Data structures ---------------------------------------------------*/
  63
  64 typedef struct limlee_factor {
  65   mp *p;                                /* The actual prime */
  66   unsigned tag;                         /* A tag, usable by the generator */
  67   void *more;                           /* Pointer to more data */
  68 } limlee_factor;
  69
  70 typedef struct limlee_stepctx {
  71
  72   /* --- To be initialized by the caller --- */
  73
  74   unsigned f;                           /* Various useful flags */
  75   mp *newp;                             /* Initial valid for new primes */
  76   unsigned ql, pl;                      /* Size of factors and result */
  77   const struct limlee_primeops *pops;   /* Pointer to generator ops */
  78   void *pc;                             /* Context ptr for generator ops */
  79   pgen_proc *iev;                       /* Event handler for inner @pgen@ */
  80   void *iec;                            /* Context for inner @pgen@ */
  81
  82   /* --- Output values --- */
  83
  84   size_t nf;                            /* Number of factors wanted */
  85   limlee_factor *v;                     /* Vector of factors */
  86
  87   /* --- Maintained internally --- */
  88
  89   octet *c;                             /* Combination byte-flag vector */
  90   grand *r;                             /* Random number generator */
  91   unsigned long seq;                    /* Sequence number for primes */
  92   size_t poolsz;                        /* Size of the small-prime pool */
  93   dstr d;                               /* String for subprime name */
  94   limlee_factor qq;                     /* Big prime to pick up slack */
  95
  96 } limlee_stepctx;
  97
  98 typedef struct limlee_primeops {
  99   void (*pgen)(limlee_factor */*f*/, unsigned /*pl*/, limlee_stepctx */*l*/);
 100   void (*pfree)(limlee_factor */*f*/, limlee_stepctx */*l*/);
 101 } limlee_primeops;
 102
 103 /* --- Flags --- */
 104
 105 enum {
 106   LIMLEE_KEEPFACTORS = 1
 107 };
 108
 109 /*----- The Lim-Lee stepper function --------------------------------------*/
 110
 111 extern int limlee_step(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 112
 113 /*----- Functions provided ------------------------------------------------*/
 114
 115 /* --- @limlee@ --- *
 116  *
 117  * Arguments:   @const char *name@ = pointer to name root
 118  *              @mp *d@ = pointer to destination integer
 119  *              @mp *newp@ = how to generate factor primes
 120  *              @unsigned ql@ = size of individual factors
 121  *              @unsigned pl@ = size of large prime
 122  *              @grand *r@ = a random number source
 123  *              @unsigned on@ = number of outer attempts to make
 124  *              @pgen_proc *oev@ = outer event handler function
 125  *              @void *oec@ = argument for the outer event handler
 126  *              @pgen_proc *iev@ = inner event handler function
 127  *              @void *iec@ = argument for the inner event handler
 128  *              @size_t *nf@, @mp ***f@ = output array for factors
 129  *
 130  * Returns:     A Lim-Lee prime, or null if generation failed.
 131  *
 132  * Use:         Generates Lim-Lee primes.  A Lim-Lee prime %$p$% is one which
 133  *              satisfies %$p = 2 \prod_i q_i + 1$%, where all of the %$q_i$%
 134  *              are large enough to resist square-root discrete log
 135  *              algorithms.
 136  *
 137  *              If we succeed, and @f@ is non-null, we write the array of
 138  *              factors chosen to @f@ for the benefit of the caller.
 139  */
 140
 141 extern mp *limlee(const char */*name*/, mp */*d*/, mp */*newp*/,
 142                   unsigned /*ql*/, unsigned /*pl*/, grand */*r*/,
 143                   unsigned /*on*/, pgen_proc */*oev*/, void */*oec*/,
 144                   pgen_proc */*iev*/, void */*iec*/,
 145                   size_t */*nf*/, mp ***/*f*/);
 146
 147 /*----- That's all, folks -------------------------------------------------*/
 148
 149 #ifdef __cplusplus
 150   }
 151 #endif
 152
 153 #endif