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   1 /* -*-c-*-
   2  *
   3  * $Id: pgen.h,v 1.5 2000/02/12 18:21:03 mdw Exp $
   4  *
   5  * Prime generation glue
   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: pgen.h,v $
  33  * Revision 1.5  2000/02/12 18:21:03  mdw
  34  * Overhaul of key management (again).
  35  *
  36  * Revision 1.4  1999/12/22 16:01:11  mdw
  37  * Same file, completely different code.  Main interface for new prime-
  38  * search system.
  39  *
  40  */
  41
  42 #ifndef CATACOMB_PGEN_H
  43 #define CATACOMB_PGEN_H
  44
  45 #ifdef __cplusplus
  46   extern "C" {
  47 #endif
  48
  49 /*----- Header files ------------------------------------------------------*/
  50
  51 #ifndef CATACOMB_GRAND_H
  52 #  include "grand.h"
  53 #endif
  54
  55 #ifndef CATACOMB_MP_H
  56 #  include "mp.h"
  57 #endif
  58
  59 #ifndef CATACOMB_PFILT_H
  60 #  include "pfilt.h"
  61 #endif
  62
  63 #ifndef CATACOMB_RABIN_H
  64 #  include "rabin.h"
  65 #endif
  66
  67 /*----- Event handling ----------------------------------------------------*
  68  *
  69  * Different programs and architectures will want to show progress of prime
  70  * searches and similar processes in different ways.  Of course, for simple
  71  * searches, it's possible to use the @pfilt@ and @rabin@ functions and
  72  * maintain control over the general control flow throughout the search.
  73  *
  74  * For more complex cases, this sort of control is undesirable.  It's
  75  * possible to specify an event handler which is informed in abstract about
  76  * the search.  The event handler can also request the search be aborted.
  77  */
  78
  79 /* --- Event code constants --- *
  80  *
  81  * You're allowed to rely on the values of @PGEN_DONE@ and @PGEN_ABORT@.
  82  */
  83
  84 enum {
  85   PGEN_BEGIN = 1,                       /* Search for value begins */
  86   PGEN_TRY,                             /* A new candidate has appeared */
  87   PGEN_FAIL,                            /* The candidate failed the test */
  88   PGEN_PASS,                            /* The candidate passed a test */
  89   PGEN_DONE = 0,                        /* A good value has been found */
  90   PGEN_ABORT = -1                       /* The search has been aborted */
  91 };
  92
  93 /* --- Event information --- *
  94  *
  95  * Note that the pseudorandom number generator supplied is not
  96  * cryptographically strong.
  97  */
  98
  99 typedef struct pgen_event {
 100   const char *name;                     /* Which quantity is being found */
 101   mp *m;                                /* Current value under test */
 102   unsigned steps;                       /* Number of candidates left */
 103   unsigned tests;                       /* Tests left before passing */
 104   grand *r;                             /* Source of random numbers */
 105 } pgen_event;
 106
 107 /*----- Prime search parameters -------------------------------------------*
 108  *
 109  * The prime search is parameterized in a large number of ways, although this
 110  * isn't so much of a surprise given the different sorts of properties
 111  * required from prime numbers in cryptographic applications.
 112  *
 113  * There are two main things which need to be configured: stepping, and
 114  * testing.  (Filtering is done as part of stepping.)
 115  *
 116  * The functions here provide a toolkit for constructing stepping and testing
 117  * routines.  In a lot of cases, the functions can be used directly; in
 118  * others, simple bits of glue need be written.
 119  *
 120  * Two types of functions are defined: steppers and testers, but their
 121  * interfaces are substantially similar.  Each is given a request code, a
 122  * context block and an event block.  It is meant to update its context and
 123  * the event block and return an event code.
 124  *
 125  * A call with a request of @PGEN_BEGIN@ asks the stepper or tester to
 126  * initialize itself using the information in its event block and context.  A
 127  * return of @PGEN_FAIL@ reports an immediate failure; @PGEN_ABORT@ reports a
 128  * fatal problem; @PGEN_DONE@ reports immediate success.  @PGEN_TRY@ reports
 129  * successful initialization and requests test iterations.
 130  *
 131  * A call to a stepper with a request of @PGEN_TRY@ asks it to step to the
 132  * next possible candidate, replacing the value @m@ in the event block with
 133  * the new candidate.  A call to a tester with a request of @PGEN_TRY@
 134  * runs one pass of the test.  It should return @PGEN_FAIL@ to report a
 135  * failure, @PGEN_PASS@ to report a success and request another iteration,
 136  * @PGEN_DONE@ to report final acceptance and @PGEN_ABORT@ to terminate the
 137  * search unsuccessfully.  Note that even if the search is aborted, a
 138  * shutdown request is still made.
 139  *
 140  * A call with a request of @PGEN_DONE@ closes down the stepper or tester.
 141  * After a successful initialization (i.e., a return of something other than
 142  * @PGEN_ABORT@), a shutdown call is guaranteed.  The return code is ignored.
 143  */
 144
 145 typedef int pgen_proc(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 146
 147 /*----- Simple handler functions ------------------------------------------*/
 148
 149 /* --- @pgen_filter@ --- *
 150  *
 151  * A prime generation context contains the information required for the
 152  * simple prime filter and tester presented here.
 153  */
 154
 155 typedef struct pgen_filterctx {
 156   unsigned step;                        /* Step size (set by client) */
 157   pfilt f;                              /* The rapid prime filter */
 158 } pgen_filterctx;
 159
 160 extern int pgen_filter(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 161
 162 /* --- @pgen_jump@ --- *
 163  *
 164  * Similar to the standard @pgen_filter@, but jumps in large steps rather
 165  * than small ones.
 166  */
 167
 168 typedef struct pgen_jumpctx {
 169   const pfilt *j;
 170   pfilt f;
 171 } pgen_jumpctx;
 172
 173 extern int pgen_jump(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 174
 175 /* --- @pgen_test@ --- *
 176  *
 177  * Runs the Rabin-Miller primality test.  The context block is simply a
 178  * @rabin@ context.
 179  */
 180
 181 extern int pgen_test(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 182
 183 /*----- Safe prime functions ----------------------------------------------*/
 184
 185 /* --- @pgen_safestep@ --- *
 186  *
 187  * Steps two numbers, %$q$% and %$p = 2q + 1$%, such that neither has any
 188  * small factors.  %$p$% is put in the event block.
 189  */
 190
 191 typedef struct pgen_safestepctx {
 192   pfilt q, p;
 193 } pgen_safestepctx;
 194
 195 extern int pgen_safestep(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 196
 197 /* --- @pgen_safejump@ --- *
 198  *
 199  * Jumps two numbers, %$q$% and %$p = 2q + 1$% such that neither has any
 200  * small factors.
 201  */
 202
 203 typedef struct pgen_safejumpctx {
 204   pfilt q, jq;
 205   pfilt p, jp;
 206 } pgen_safejumpctx;
 207
 208 extern int pgen_safejump(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 209
 210 /* --- @pgen_safetest@ --- *
 211  *
 212  * Applies Rabin-Miller tests to %$p$% and %$(p - 1)/2$%.
 213  */
 214
 215 typedef struct pgen_safetestctx {
 216   pgen_safestepctx c;
 217   rabin q, p;
 218 } pgen_safetestctx;
 219
 220 extern int pgen_safetest(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 221
 222 /*----- Standard event handlers -------------------------------------------*/
 223
 224 /* --- @pgen_evspin@ --- *
 225  *
 226  * Displays a spinning baton to show progress.
 227  */
 228
 229 extern int pgen_evspin(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 230
 231 /* --- @pgen_ev@ --- *
 232  *
 233  * Traditional event handler, shows dots for each test.
 234  */
 235
 236 extern int pgen_ev(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 237
 238 /*----- The main driver ---------------------------------------------------*/
 239
 240 /* --- @pgen@ --- *
 241  *
 242  * Arguments:   @const char *name@ = name of the value being searched for
 243  *              @mp *d@ = destination for resulting integer
 244  *              @mp *m@ = start value to pass to stepper
 245  *              @pgen_proc *event@ = event handler function
 246  *              @void *ectx@ = context argument for event andler
 247  *              @unsigned steps@ = number of steps to take in search
 248  *              @pgen_proc *step@ = stepper function to use
 249  *              @void *sctx@ = context argument for stepper
 250  *              @unsigned tests@ = number of tests to make
 251  *              @pgen_proc *test@ = tester function to use
 252  *              @void *tctx@ = context argument for tester
 253  *
 254  * Returns:     If successful, @PGEN_DONE@; otherwise @PGEN_ABORT@.
 255  *
 256  * Use:         A generalized prime-number search skeleton.  Yes, that's a
 257  *              scary number of arguments.
 258  */
 259
 260 extern mp *pgen(const char */*name*/, mp */*d*/, mp */*m*/,
 261                 pgen_proc */*event*/, void */*ectx*/,
 262                 unsigned /*steps*/, pgen_proc */*step*/, void */*sctx*/,
 263                 unsigned /*tests*/, pgen_proc */*test*/, void */*tctx*/);
 264
 265 /*----- That's all, folks -------------------------------------------------*/
 266
 267 #ifdef __cplusplus
 268   }
 269 #endif
 270
 271 #endif