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

   1 /* -*-c-*-
   2  *
   3  * $Id: limlee.h,v 1.5 2004/04/08 01:36:15 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 #ifndef CATACOMB_LIMLEE_H
  31 #define CATACOMB_LIMLEE_H
  32
  33 #ifdef __cplusplus
  34   extern "C" {
  35 #endif
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #ifndef CATACOMB_GRAND_H
  40 #  include "grand.h"
  41 #endif
  42
  43 #ifndef CATACOMB_MP_H
  44 #  include "mp.h"
  45 #endif
  46
  47 #ifndef CATACOMB_PGEN_H
  48 #  include "pgen.h"
  49 #endif
  50
  51 /*----- Data structures ---------------------------------------------------*/
  52
  53 typedef struct limlee_factor {
  54   mp *p;                                /* The actual prime */
  55   unsigned tag;                         /* A tag, usable by the generator */
  56   void *more;                           /* Pointer to more data */
  57 } limlee_factor;
  58
  59 typedef struct limlee_stepctx {
  60
  61   /* --- To be initialized by the caller --- */
  62
  63   unsigned f;                           /* Various useful flags */
  64   mp *newp;                             /* Initial valid for new primes */
  65   unsigned ql, pl;                      /* Size of factors and result */
  66   const struct limlee_primeops *pops;   /* Pointer to generator ops */
  67   void *pc;                             /* Context ptr for generator ops */
  68   pgen_proc *iev;                       /* Event handler for inner @pgen@ */
  69   void *iec;                            /* Context for inner @pgen@ */
  70   grand *r;                             /* Random number generator */
  71
  72   /* --- Output values --- */
  73
  74   size_t nf;                            /* Number of factors wanted */
  75   limlee_factor *v;                     /* Vector of factors */
  76
  77   /* --- Maintained internally --- */
  78
  79   octet *c;                             /* Combination byte-flag vector */
  80   unsigned long seq;                    /* Sequence number for primes */
  81   size_t poolsz;                        /* Size of the small-prime pool */
  82   dstr d;                               /* String for subprime name */
  83   limlee_factor qq;                     /* Big prime to pick up slack */
  84
  85 } limlee_stepctx;
  86
  87 typedef struct limlee_primeops {
  88   void (*pgen)(limlee_factor */*f*/, unsigned /*pl*/, limlee_stepctx */*l*/);
  89   void (*pfree)(limlee_factor */*f*/, limlee_stepctx */*l*/);
  90 } limlee_primeops;
  91
  92 /* --- Flags --- */
  93
  94 #define LIMLEE_KEEPFACTORS 1u
  95
  96 /*----- The Lim-Lee stepper function --------------------------------------*/
  97
  98 extern pgen_proc limlee_step;
  99
 100 /*----- Functions provided ------------------------------------------------*/
 101
 102 /* --- @limlee@ --- *
 103  *
 104  * Arguments:   @const char *name@ = pointer to name root
 105  *              @mp *d@ = pointer to destination integer
 106  *              @mp *newp@ = how to generate factor primes
 107  *              @unsigned ql@ = size of individual factors
 108  *              @unsigned pl@ = size of large prime
 109  *              @grand *r@ = a random number source
 110  *              @unsigned on@ = number of outer attempts to make
 111  *              @pgen_proc *oev@ = outer event handler function
 112  *              @void *oec@ = argument for the outer event handler
 113  *              @pgen_proc *iev@ = inner event handler function
 114  *              @void *iec@ = argument for the inner event handler
 115  *              @size_t *nf@, @mp ***f@ = output array for factors
 116  *
 117  * Returns:     A Lim-Lee prime, or null if generation failed.
 118  *
 119  * Use:         Generates Lim-Lee primes.  A Lim-Lee prime %$p$% is one which
 120  *              satisfies %$p = 2 \prod_i q_i + 1$%, where all of the %$q_i$%
 121  *              are large enough to resist square-root discrete log
 122  *              algorithms.
 123  *
 124  *              If we succeed, and @f@ is non-null, we write the array of
 125  *              factors chosen to @f@ for the benefit of the caller.
 126  */
 127
 128 extern mp *limlee(const char */*name*/, mp */*d*/, mp */*newp*/,
 129                   unsigned /*ql*/, unsigned /*pl*/, grand */*r*/,
 130                   unsigned /*on*/, pgen_proc */*oev*/, void */*oec*/,
 131                   pgen_proc */*iev*/, void */*iec*/,
 132                   size_t */*nf*/, mp ***/*f*/);
 133
 134 /*----- That's all, folks -------------------------------------------------*/
 135
 136 #ifdef __cplusplus
 137   }
 138 #endif
 139
 140 #endif