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   1 /* -*-c-*-
   2  *
   3  * $Id: ghash.h,v 1.6 2004/04/04 19:42:30 mdw Exp $
   4  *
   5  * Generic hash function interface
   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: ghash.h,v $
  33  * Revision 1.6  2004/04/04 19:42:30  mdw
  34  * Make tables of standard encryption schemes etc.
  35  *
  36  * Revision 1.5  2000/07/15 10:00:58  mdw
  37  * New generic hash operation for copying hash contexts.
  38  *
  39  * Revision 1.4  2000/07/03 18:08:24  mdw
  40  * Include `bits.h'.
  41  *
  42  * Revision 1.3  2000/07/02 18:27:42  mdw
  43  * (ghash->ops->done): Interface change.  Passing in a null buffer pointer
  44  * uses a buffer internal to the ghash object.  The operation returns the
  45  * address of the buffer it used.  Clients of generic hashes no longer need
  46  * to use dynamically allocated memory for hash results.
  47  *
  48  * Revision 1.2  2000/06/17 11:22:17  mdw
  49  * Minor changes in the generic hash interface.
  50  *
  51  * Revision 1.1  1999/12/10 23:16:01  mdw
  52  * Generic interface.
  53  *
  54  */
  55
  56 #ifndef CATACOMB_GHASH_H
  57 #define CATACOMB_GHASH_H
  58
  59 #ifdef __cplusplus
  60   extern "C" {
  61 #endif
  62
  63 /*----- Header files ------------------------------------------------------*/
  64
  65 #include <stddef.h>
  66
  67 #include <mLib/bits.h>
  68
  69 /*----- Generic hash function interface -----------------------------------*/
  70
  71 typedef struct ghash {
  72   const struct ghash_ops *ops;          /* Pointer to hash operations */
  73 } ghash;
  74
  75 typedef struct ghash_ops {
  76   const struct gchash *c;               /* Pointer to hash class */
  77   void (*hash)(ghash */*h*/, const void */*p*/, size_t /*sz*/); /* Hash */
  78   octet *(*done)(ghash */*h*/, void */*buf*/); /* Write result */
  79   void (*destroy)(ghash */*h*/);        /* Destroy hash block */
  80   ghash *(*copy)(ghash */*h*/);         /* Make a copy of the hash context */
  81 } ghash_ops;
  82
  83 #define GH_INIT(ch)             (ch)->init()
  84 #define GH_CLASS(H)             (h)->ops->c
  85 #define GH_HASH(h, p, sz)       (h)->ops->hash((h), (p), (sz))
  86 #define GH_DONE(h, buf)         (h)->ops->done((h), (buf))
  87 #define GH_DESTROY(h)           (h)->ops->destroy((h))
  88 #define GH_COPY(h)              (h)->ops->copy((h))
  89
  90 typedef struct gchash {
  91   const char *name;                     /* Name of the hash function */
  92   size_t hashsz;                        /* Size of output hash */
  93   ghash *(*init)(void);                 /* Create a new hash instance */
  94   size_t bufsz;                         /* Buffer size, or zero */
  95 } gchash;
  96
  97 /*----- Tables ------------------------------------------------------------*/
  98
  99 extern const gchash *const ghashtab[];
 100
 101 /* --- @ghash_byname@ --- *
 102  *
 103  * Arguments:   @const char *p@ = pointer to name string
 104  *
 105  * Returns:     The named cipher class, or null.
 106  */
 107
 108 extern const gchash *ghash_byname(const char */*p*/);
 109
 110 /*----- That's all, folks -------------------------------------------------*/
 111
 112 #ifdef __cplusplus
 113   }
 114 #endif
 115
 116 #endif