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   1 /* -*-c-*-
   2  *
   3  * $Id: grand.h,v 1.5 2004/04/08 01:36:15 mdw Exp $
   4  *
   5  * Generic interface to random number generators
   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 #ifndef CATACOMB_GRAND_H
  31 #define CATACOMB_GRAND_H
  32
  33 #ifdef __cplusplus
  34   extern "C" {
  35 #endif
  36
  37 /*----- Header files ------------------------------------------------------*/
  38
  39 #include <assert.h>
  40 #include <stddef.h>
  41
  42 #include <mLib/bits.h>
  43
  44 /*----- Generic random number generator interface -------------------------*/
  45
  46 typedef struct grand {
  47   const struct grand_ops *ops;
  48 } grand;
  49
  50 typedef struct grand_ops {
  51
  52   /* --- Various important properties --- */
  53
  54   const char *name;                     /* Generator's name */
  55   unsigned f;                           /* Various flags */
  56   uint32 max;                           /* Maximum raw output */
  57
  58   /* --- Maintenance methods --- */
  59
  60   int (*misc)(grand */*r*/, unsigned /*op*/, ...); /* Miscellaneous ops */
  61   void (*destroy)(grand */*r*/);        /* Destroy generator context */
  62
  63   /* --- Output methods --- *
  64    *
  65    * Only one of these operations need actually be implemented.  All the
  66    * other operations may be synthesized.  Of course, performance is improved
  67    * if more are provided.
  68    */
  69
  70   uint32 (*raw)(grand */*r*/);          /* Uniform over %$[0, max)$% */
  71   octet (*byte)(grand */*r*/);          /* Uniform over %$[0, 256)$% */
  72   uint32 (*word)(grand */*r*/);         /* Uniform over %$[0, 2^{32})$% */
  73   uint32 (*range)(grand */*r*/, uint32 /*l*/); /* Uniform over %$[0, l)$% */
  74   void (*fill)(grand */*r*/, void */*p*/, size_t /*sz*/); /* Fill buffer */
  75 } grand_ops;
  76
  77 #define GR_DESTROY(r)           (r)->ops->destroy((r))
  78 #define GR_RAW(r)               (r)->ops->raw((r))
  79 #define GR_WORD(r)              (r)->ops->word((r))
  80 #define GR_RANGE(r, l)          (r)->ops->range((r), (l))
  81 #define GR_FILL(r, p, sz)       (r)->ops->fill((r), (p), (sz))
  82
  83 /* --- Flag types --- */
  84
  85 #define GRAND_CRYPTO 1u                 /* Cryptographically strong */
  86
  87 /* --- Operation types --- */
  88
  89 enum {
  90
  91   /* --- Required operations --- */
  92
  93   GRAND_CHECK,                          /* @unsigned op2@ */
  94
  95   /* --- Standard seeding operations --- */
  96
  97   GRAND_SEEDINT,                        /* @int i@ */
  98   GRAND_SEEDUINT32,                     /* @uint32 i@ */
  99   GRAND_SEEDBLOCK,                      /* @const void *p, size_t sz@ */
 100   GRAND_SEEDMP,                         /* @mp *m@ */
 101   GRAND_SEEDRAND                        /* @grand *g@ */
 102
 103   /* --- Generator-specific operations --- */
 104
 105 #define GRAND_SPECIFIC(ch) ((unsigned)(ch) << 8)
 106 };
 107
 108 #define GRAND_BADOP assert(((void)"bad grand_misc op", 0))
 109
 110 /*----- Functions provided ------------------------------------------------*/
 111
 112 /* --- @grand_byte@ --- *
 113  *
 114  * Arguments:   @grand *r@ = pointet to generic generator
 115  *
 116  * Returns:     A uniformly-distributed pseudorandom integer in the interval
 117  *              %$[0, 256)$%.
 118  */
 119
 120 extern octet grand_byte(grand */*r*/);
 121
 122 /* --- @grand_word@ --- *
 123  *
 124  * Arguments:   @grand *r@ = pointet to generic generator
 125  *
 126  * Returns:     A uniformly-distributed pseudorandom integer in the interval
 127  *              %$[0, 2^{32})$%.
 128  */
 129
 130 extern uint32 grand_word(grand */*r*/);
 131
 132 /* --- @grand_range@ --- *
 133  *
 134  * Arguments:   @grand *r@ = pointet to generic generator
 135  *              @uint32 l@ = limit for acceptable results
 136  *
 137  * Returns:     A uniformly-distributed pseudorandom integer in the interval
 138  *              %$[0, l)$%.
 139  */
 140
 141 extern uint32 grand_range(grand */*r*/, uint32 /*l*/);
 142
 143 /* --- @grand_fill@ --- *
 144  *
 145  * Arguments:   @grand *r@ = pointet to generic generator
 146  *              @void *p@ = pointer to a buffer
 147  *              @size_t sz@ = size of the buffer
 148  *
 149  * Returns:     ---
 150  *
 151  * Use:         Fills a buffer with uniformly distributed pseudorandom bytes
 152  *              (see @grand_byte@).
 153  */
 154
 155 extern void grand_fill(grand */*r*/, void */*p*/, size_t /*sz*/);
 156
 157 /*----- That's all, folks -------------------------------------------------*/
 158
 159 #ifdef __cplusplus
 160   }
 161 #endif
 162
 163 #endif