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   1 /* -*-c-*-
   2  *
   3  * $Id: pgen.h,v 1.6 2000/06/17 11:52:12 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 1.6  2000/06/17 11:52:12  mdw
  34  * Add the GCD filter.
  35  *
  36  * Revision 1.5  2000/02/12 18:21:03  mdw
  37  * Overhaul of key management (again).
  38  *
  39  * Revision 1.4  1999/12/22 16:01:11  mdw
  40  * Same file, completely different code.  Main interface for new prime-
  41  * search system.
  42  *
  43  */
  44
  45 #ifndef CATACOMB_PGEN_H
  46 #define CATACOMB_PGEN_H
  47
  48 #ifdef __cplusplus
  49   extern "C" {
  50 #endif
  51
  52 /*----- Header files ------------------------------------------------------*/
  53
  54 #ifndef CATACOMB_GRAND_H
  55 #  include "grand.h"
  56 #endif
  57
  58 #ifndef CATACOMB_MP_H
  59 #  include "mp.h"
  60 #endif
  61
  62 #ifndef CATACOMB_PFILT_H
  63 #  include "pfilt.h"
  64 #endif
  65
  66 #ifndef CATACOMB_RABIN_H
  67 #  include "rabin.h"
  68 #endif
  69
  70 /*----- Event handling ----------------------------------------------------*
  71  *
  72  * Different programs and architectures will want to show progress of prime
  73  * searches and similar processes in different ways.  Of course, for simple
  74  * searches, it's possible to use the @pfilt@ and @rabin@ functions and
  75  * maintain control over the general control flow throughout the search.
  76  *
  77  * For more complex cases, this sort of control is undesirable.  It's
  78  * possible to specify an event handler which is informed in abstract about
  79  * the search.  The event handler can also request the search be aborted.
  80  */
  81
  82 /* --- Event code constants --- *
  83  *
  84  * You're allowed to rely on the values of @PGEN_DONE@ and @PGEN_ABORT@.
  85  */
  86
  87 enum {
  88   PGEN_BEGIN = 1,                       /* Search for value begins */
  89   PGEN_TRY,                             /* A new candidate has appeared */
  90   PGEN_FAIL,                            /* The candidate failed the test */
  91   PGEN_PASS,                            /* The candidate passed a test */
  92   PGEN_DONE = 0,                        /* A good value has been found */
  93   PGEN_ABORT = -1                       /* The search has been aborted */
  94 };
  95
  96 /* --- Event information --- *
  97  *
  98  * Note that the pseudorandom number generator supplied is not
  99  * cryptographically strong.
 100  */
 101
 102 typedef struct pgen_event {
 103   const char *name;                     /* Which quantity is being found */
 104   mp *m;                                /* Current value under test */
 105   unsigned steps;                       /* Number of candidates left */
 106   unsigned tests;                       /* Tests left before passing */
 107   grand *r;                             /* Source of random numbers */
 108 } pgen_event;
 109
 110 /*----- Prime search parameters -------------------------------------------*
 111  *
 112  * The prime search is parameterized in a large number of ways, although this
 113  * isn't so much of a surprise given the different sorts of properties
 114  * required from prime numbers in cryptographic applications.
 115  *
 116  * There are two main things which need to be configured: stepping, and
 117  * testing.  (Filtering is done as part of stepping.)
 118  *
 119  * The functions here provide a toolkit for constructing stepping and testing
 120  * routines.  In a lot of cases, the functions can be used directly; in
 121  * others, simple bits of glue need be written.
 122  *
 123  * Two types of functions are defined: steppers and testers, but their
 124  * interfaces are substantially similar.  Each is given a request code, a
 125  * context block and an event block.  It is meant to update its context and
 126  * the event block and return an event code.
 127  *
 128  * A call with a request of @PGEN_BEGIN@ asks the stepper or tester to
 129  * initialize itself using the information in its event block and context.  A
 130  * return of @PGEN_FAIL@ reports an immediate failure; @PGEN_ABORT@ reports a
 131  * fatal problem; @PGEN_DONE@ reports immediate success.  @PGEN_TRY@ reports
 132  * successful initialization and requests test iterations.
 133  *
 134  * A call to a stepper with a request of @PGEN_TRY@ asks it to step to the
 135  * next possible candidate, replacing the value @m@ in the event block with
 136  * the new candidate.  A call to a tester with a request of @PGEN_TRY@
 137  * runs one pass of the test.  It should return @PGEN_FAIL@ to report a
 138  * failure, @PGEN_PASS@ to report a success and request another iteration,
 139  * @PGEN_DONE@ to report final acceptance and @PGEN_ABORT@ to terminate the
 140  * search unsuccessfully.  Note that even if the search is aborted, a
 141  * shutdown request is still made.
 142  *
 143  * A call with a request of @PGEN_DONE@ closes down the stepper or tester.
 144  * After a successful initialization (i.e., a return of something other than
 145  * @PGEN_ABORT@), a shutdown call is guaranteed.  The return code is ignored.
 146  */
 147
 148 typedef int pgen_proc(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 149
 150 /*----- Simple handler functions ------------------------------------------*/
 151
 152 /* --- @pgen_filter@ --- *
 153  *
 154  * A prime generation context contains the information required for the
 155  * simple prime filter and tester presented here.
 156  */
 157
 158 typedef struct pgen_filterctx {
 159   unsigned step;                        /* Step size (set by client) */
 160   pfilt f;                              /* The rapid prime filter */
 161 } pgen_filterctx;
 162
 163 extern int pgen_filter(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 164
 165 /* --- @pgen_jump@ --- *
 166  *
 167  * Similar to the standard @pgen_filter@, but jumps in large steps rather
 168  * than small ones.
 169  */
 170
 171 typedef struct pgen_jumpctx {
 172   const pfilt *j;
 173   pfilt f;
 174 } pgen_jumpctx;
 175
 176 extern int pgen_jump(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 177
 178 /* --- @pgen_test@ --- *
 179  *
 180  * Runs the Rabin-Miller primality test.  The context block is simply a
 181  * @rabin@ context.
 182  */
 183
 184 extern int pgen_test(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 185
 186 /*----- Safe prime functions ----------------------------------------------*/
 187
 188 /* --- @pgen_safestep@ --- *
 189  *
 190  * Steps two numbers, %$q$% and %$p = 2q + 1$%, such that neither has any
 191  * small factors.  %$p$% is put in the event block.
 192  */
 193
 194 typedef struct pgen_safestepctx {
 195   pfilt q, p;
 196 } pgen_safestepctx;
 197
 198 extern int pgen_safestep(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 199
 200 /* --- @pgen_safejump@ --- *
 201  *
 202  * Jumps two numbers, %$q$% and %$p = 2q + 1$% such that neither has any
 203  * small factors.
 204  */
 205
 206 typedef struct pgen_safejumpctx {
 207   pfilt q, jq;
 208   pfilt p, jp;
 209 } pgen_safejumpctx;
 210
 211 extern int pgen_safejump(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 212
 213 /* --- @pgen_safetest@ --- *
 214  *
 215  * Applies Rabin-Miller tests to %$p$% and %$(p - 1)/2$%.
 216  */
 217
 218 typedef struct pgen_safetestctx {
 219   pgen_safestepctx c;
 220   rabin q, p;
 221 } pgen_safetestctx;
 222
 223 extern int pgen_safetest(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 224
 225 /*----- Miscellaneous steppers and testers --------------------------------*/
 226
 227 typedef struct pgen_gcdstepctx {
 228   pfilt p, jp;                          /* Prime filter and step filter */
 229   mp *q, *jq;                           /* %$p - 1$%, and a step value*/
 230   mp *r;                                /* Other argument for GCD */
 231   mp *g;                                /* GCD output (must be inited) */
 232   mp *max;                              /* Maximum permissible GCD */
 233 } pgen_gcdstepctx;
 234
 235 /* --- @pgen_gcdstep@ --- *
 236  *
 237  * Steps @p@ and @q@, until @p@ has no small factors, and
 238  * %$\gcd(p, r) \le max$%.
 239  */
 240
 241 extern int pgen_gcdstep(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 242
 243 /*----- Standard event handlers -------------------------------------------*/
 244
 245 /* --- @pgen_evspin@ --- *
 246  *
 247  * Displays a spinning baton to show progress.
 248  */
 249
 250 extern int pgen_evspin(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 251
 252 /* --- @pgen_ev@ --- *
 253  *
 254  * Traditional event handler, shows dots for each test.
 255  */
 256
 257 extern int pgen_ev(int /*rq*/, pgen_event */*ev*/, void */*p*/);
 258
 259 /*----- The main driver ---------------------------------------------------*/
 260
 261 /* --- @pgen@ --- *
 262  *
 263  * Arguments:   @const char *name@ = name of the value being searched for
 264  *              @mp *d@ = destination for resulting integer
 265  *              @mp *m@ = start value to pass to stepper
 266  *              @pgen_proc *event@ = event handler function
 267  *              @void *ectx@ = context argument for event andler
 268  *              @unsigned steps@ = number of steps to take in search
 269  *              @pgen_proc *step@ = stepper function to use
 270  *              @void *sctx@ = context argument for stepper
 271  *              @unsigned tests@ = number of tests to make
 272  *              @pgen_proc *test@ = tester function to use
 273  *              @void *tctx@ = context argument for tester
 274  *
 275  * Returns:     If successful, @PGEN_DONE@; otherwise @PGEN_ABORT@.
 276  *
 277  * Use:         A generalized prime-number search skeleton.  Yes, that's a
 278  *              scary number of arguments.
 279  */
 280
 281 extern mp *pgen(const char */*name*/, mp */*d*/, mp */*m*/,
 282                 pgen_proc */*event*/, void */*ectx*/,
 283                 unsigned /*steps*/, pgen_proc */*step*/, void */*sctx*/,
 284                 unsigned /*tests*/, pgen_proc */*test*/, void */*tctx*/);
 285
 286 /*----- That's all, folks -------------------------------------------------*/
 287
 288 #ifdef __cplusplus
 289   }
 290 #endif
 291
 292 #endif