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   1 /* -*-c-*-
   2  *
   3  * $Id: grand.h,v 1.2 2000/06/17 11:23:11 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 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: grand.h,v $
  33  * Revision 1.2  2000/06/17 11:23:11  mdw
  34  * Typesetting fix.  Add a flags word to the generic generator.
  35  *
  36  * Revision 1.1  1999/12/10 23:16:01  mdw
  37  * Generic interface.
  38  *
  39  */
  40
  41 #ifndef CATACOMB_GRAND_H
  42 #define CATACOMB_GRAND_H
  43
  44 #ifdef __cplusplus
  45   extern "C" {
  46 #endif
  47
  48 /*----- Header files ------------------------------------------------------*/
  49
  50 #include <assert.h>
  51 #include <stddef.h>
  52
  53 #include <mLib/bits.h>
  54
  55 /*----- Generic random number generator interface -------------------------*/
  56
  57 typedef struct grand {
  58   const struct grand_ops *ops;
  59 } grand;
  60
  61 typedef struct grand_ops {
  62
  63   /* --- Various important properties --- */
  64
  65   const char *name;                     /* Generator's name */
  66   unsigned f;                           /* Various flags */
  67   uint32 max;                           /* Maximum raw output */
  68
  69   /* --- Maintenance methods --- */
  70
  71   int (*misc)(grand */*r*/, unsigned /*op*/, ...); /* Miscellaneous ops */
  72   void (*destroy)(grand */*r*/);        /* Destroy generator context */
  73
  74   /* --- Output methods --- *
  75    *
  76    * Only one of these operations need actually be implemented.  All the
  77    * other operations may be synthesized.  Of course, performance is improved
  78    * if more are provided.
  79    */
  80
  81   uint32 (*raw)(grand */*r*/);          /* Uniform over %$[0, max)$% */
  82   octet (*byte)(grand */*r*/);          /* Uniform over %$[0, 256)$% */
  83   uint32 (*word)(grand */*r*/);         /* Uniform over %$[0, 2^{32})$% */
  84   uint32 (*range)(grand */*r*/, uint32 /*l*/); /* Uniform over %$[0, l)$% */
  85   void (*fill)(grand */*r*/, void */*p*/, size_t /*sz*/); /* Fill buffer */
  86 } grand_ops;
  87
  88 /* --- Flag types --- */
  89
  90 enum {
  91   GRAND_CRYPTO = 1u                     /* Cryptographically strong */
  92 };
  93
  94 /* --- Operation types --- */
  95
  96 enum {
  97
  98   /* --- Required operations --- */
  99
 100   GRAND_CHECK,                          /* @unsigned op2@ */
 101
 102   /* --- Standard seeding operations --- */
 103
 104   GRAND_SEEDINT,                        /* @int i@ */
 105   GRAND_SEEDUINT32,                     /* @uint32 i@ */
 106   GRAND_SEEDBLOCK,                      /* @const void *p, size_t sz@ */
 107   GRAND_SEEDMP,                         /* @mp *m@ */
 108   GRAND_SEEDRAND,                       /* @grand *g@ */
 109
 110   /* --- Generator-specific operations --- */
 111
 112   GRAND_SPECIFIC = 256u
 113 };
 114
 115 #define GRAND_BADOP assert(((void)"bad grand_misc op", 0))
 116
 117 /*----- Functions provided ------------------------------------------------*/
 118
 119 /* --- @grand_byte@ --- *
 120  *
 121  * Arguments:   @grand *r@ = pointet to generic generator
 122  *
 123  * Returns:     A uniformly-distributed pseudorandom integer in the interval
 124  *              %$[0, 256)$%.
 125  */
 126
 127 extern octet grand_byte(grand */*r*/);
 128
 129 /* --- @grand_word@ --- *
 130  *
 131  * Arguments:   @grand *r@ = pointet to generic generator
 132  *
 133  * Returns:     A uniformly-distributed pseudorandom integer in the interval
 134  *              %$[0, 2^{32})$%.
 135  */
 136
 137 extern uint32 grand_word(grand */*r*/);
 138
 139 /* --- @grand_range@ --- *
 140  *
 141  * Arguments:   @grand *r@ = pointet to generic generator
 142  *              @uint32 l@ = limit for acceptable results
 143  *
 144  * Returns:     A uniformly-distributed pseudorandom integer in the interval
 145  *              %$[0, l)$%.
 146  */
 147
 148 extern uint32 grand_range(grand */*r*/, uint32 /*l*/);
 149
 150 /* --- @grand_fill@ --- *
 151  *
 152  * Arguments:   @grand *r@ = pointet to generic generator
 153  *              @void *p@ = pointer to a buffer
 154  *              @size_t sz@ = size of the buffer
 155  *
 156  * Returns:     ---
 157  *
 158  * Use:         Fills a buffer with uniformly distributed pseudorandom bytes
 159  *              (see @grand_byte@).
 160  */
 161
 162 extern void grand_fill(grand */*r*/, void */*p*/, size_t /*sz*/);
 163
 164 /*----- That's all, folks -------------------------------------------------*/
 165
 166 #ifdef __cplusplus
 167   }
 168 #endif
 169
 170 #endif